diff options
113 files changed, 3503 insertions, 1570 deletions
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index 9d4c1d1..4273b2d 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -355,6 +355,82 @@ utilize. ============================================================== +numa_balancing + +Enables/disables automatic page fault based NUMA memory +balancing. Memory is moved automatically to nodes +that access it often. + +Enables/disables automatic NUMA memory balancing. On NUMA machines, there +is a performance penalty if remote memory is accessed by a CPU. When this +feature is enabled the kernel samples what task thread is accessing memory +by periodically unmapping pages and later trapping a page fault. At the +time of the page fault, it is determined if the data being accessed should +be migrated to a local memory node. + +The unmapping of pages and trapping faults incur additional overhead that +ideally is offset by improved memory locality but there is no universal +guarantee. If the target workload is already bound to NUMA nodes then this +feature should be disabled. Otherwise, if the system overhead from the +feature is too high then the rate the kernel samples for NUMA hinting +faults may be controlled by the numa_balancing_scan_period_min_ms, +numa_balancing_scan_delay_ms, numa_balancing_scan_period_max_ms, +numa_balancing_scan_size_mb, numa_balancing_settle_count sysctls and +numa_balancing_migrate_deferred. + +============================================================== + +numa_balancing_scan_period_min_ms, numa_balancing_scan_delay_ms, +numa_balancing_scan_period_max_ms, numa_balancing_scan_size_mb + +Automatic NUMA balancing scans tasks address space and unmaps pages to +detect if pages are properly placed or if the data should be migrated to a +memory node local to where the task is running. Every "scan delay" the task +scans the next "scan size" number of pages in its address space. When the +end of the address space is reached the scanner restarts from the beginning. + +In combination, the "scan delay" and "scan size" determine the scan rate. +When "scan delay" decreases, the scan rate increases. The scan delay and +hence the scan rate of every task is adaptive and depends on historical +behaviour. If pages are properly placed then the scan delay increases, +otherwise the scan delay decreases. The "scan size" is not adaptive but +the higher the "scan size", the higher the scan rate. + +Higher scan rates incur higher system overhead as page faults must be +trapped and potentially data must be migrated. However, the higher the scan +rate, the more quickly a tasks memory is migrated to a local node if the +workload pattern changes and minimises performance impact due to remote +memory accesses. These sysctls control the thresholds for scan delays and +the number of pages scanned. + +numa_balancing_scan_period_min_ms is the minimum time in milliseconds to +scan a tasks virtual memory. It effectively controls the maximum scanning +rate for each task. + +numa_balancing_scan_delay_ms is the starting "scan delay" used for a task +when it initially forks. + +numa_balancing_scan_period_max_ms is the maximum time in milliseconds to +scan a tasks virtual memory. It effectively controls the minimum scanning +rate for each task. + +numa_balancing_scan_size_mb is how many megabytes worth of pages are +scanned for a given scan. + +numa_balancing_settle_count is how many scan periods must complete before +the schedule balancer stops pushing the task towards a preferred node. This +gives the scheduler a chance to place the task on an alternative node if the +preferred node is overloaded. + +numa_balancing_migrate_deferred is how many page migrations get skipped +unconditionally, after a page migration is skipped because a page is shared +with other tasks. This reduces page migration overhead, and determines +how much stronger the "move task near its memory" policy scheduler becomes, +versus the "move memory near its task" memory management policy, for workloads +with shared memory. + +============================================================== + osrelease, ostype & version: # cat osrelease diff --git a/MAINTAINERS b/MAINTAINERS index 4d07f09..ddabf70 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -7304,6 +7304,8 @@ S: Maintained F: kernel/sched/ F: include/linux/sched.h F: include/uapi/linux/sched.h +F: kernel/wait.c +F: include/linux/wait.h SCORE ARCHITECTURE M: Chen Liqin <liqin.linux@gmail.com> diff --git a/arch/alpha/include/asm/Kbuild b/arch/alpha/include/asm/Kbuild index a6e85f44..f01fb50 100644 --- a/arch/alpha/include/asm/Kbuild +++ b/arch/alpha/include/asm/Kbuild @@ -3,3 +3,4 @@ generic-y += clkdev.h generic-y += exec.h generic-y += trace_clock.h +generic-y += preempt.h diff --git a/arch/arc/include/asm/Kbuild b/arch/arc/include/asm/Kbuild index d8dd660..5943f7f 100644 --- a/arch/arc/include/asm/Kbuild +++ b/arch/arc/include/asm/Kbuild @@ -46,3 +46,4 @@ generic-y += ucontext.h generic-y += user.h generic-y += vga.h generic-y += xor.h +generic-y += preempt.h diff --git a/arch/arm/include/asm/Kbuild b/arch/arm/include/asm/Kbuild index 59ceae8..1a7024b 100644 --- a/arch/arm/include/asm/Kbuild +++ b/arch/arm/include/asm/Kbuild @@ -32,3 +32,4 @@ generic-y += termios.h generic-y += timex.h generic-y += trace_clock.h generic-y += unaligned.h +generic-y += preempt.h diff --git a/arch/arm64/include/asm/Kbuild b/arch/arm64/include/asm/Kbuild index 79a642d..519f89f 100644 --- a/arch/arm64/include/asm/Kbuild +++ b/arch/arm64/include/asm/Kbuild @@ -50,3 +50,4 @@ generic-y += unaligned.h generic-y += user.h generic-y += vga.h generic-y += xor.h +generic-y += preempt.h diff --git a/arch/avr32/include/asm/Kbuild b/arch/avr32/include/asm/Kbuild index fd79807..658001b 100644 --- a/arch/avr32/include/asm/Kbuild +++ b/arch/avr32/include/asm/Kbuild @@ -7,6 +7,7 @@ generic-y += div64.h generic-y += emergency-restart.h generic-y += exec.h generic-y += futex.h +generic-y += preempt.h generic-y += irq_regs.h generic-y += param.h generic-y += local.h diff --git a/arch/blackfin/include/asm/Kbuild b/arch/blackfin/include/asm/Kbuild index 127826f..f2b4347 100644 --- a/arch/blackfin/include/asm/Kbuild +++ b/arch/blackfin/include/asm/Kbuild @@ -44,3 +44,4 @@ generic-y += ucontext.h generic-y += unaligned.h generic-y += user.h generic-y += xor.h +generic-y += preempt.h diff --git a/arch/c6x/include/asm/Kbuild b/arch/c6x/include/asm/Kbuild index e49f918..fc0b3c3 100644 --- a/arch/c6x/include/asm/Kbuild +++ b/arch/c6x/include/asm/Kbuild @@ -56,3 +56,4 @@ generic-y += ucontext.h generic-y += user.h generic-y += vga.h generic-y += xor.h +generic-y += preempt.h diff --git a/arch/cris/include/asm/Kbuild b/arch/cris/include/asm/Kbuild index c832545..b06caf6 100644 --- a/arch/cris/include/asm/Kbuild +++ b/arch/cris/include/asm/Kbuild @@ -11,3 +11,4 @@ generic-y += module.h generic-y += trace_clock.h generic-y += vga.h generic-y += xor.h +generic-y += preempt.h diff --git a/arch/frv/include/asm/Kbuild b/arch/frv/include/asm/Kbuild index c5d7670..74742dc 100644 --- a/arch/frv/include/asm/Kbuild +++ b/arch/frv/include/asm/Kbuild @@ -2,3 +2,4 @@ generic-y += clkdev.h generic-y += exec.h generic-y += trace_clock.h +generic-y += preempt.h diff --git a/arch/h8300/include/asm/Kbuild b/arch/h8300/include/asm/Kbuild index 8ada3cf..7e0e721 100644 --- a/arch/h8300/include/asm/Kbuild +++ b/arch/h8300/include/asm/Kbuild @@ -6,3 +6,4 @@ generic-y += mmu.h generic-y += module.h generic-y += trace_clock.h generic-y += xor.h +generic-y += preempt.h diff --git a/arch/hexagon/include/asm/Kbuild b/arch/hexagon/include/asm/Kbuild index 1da17ca..67c3450 100644 --- a/arch/hexagon/include/asm/Kbuild +++ b/arch/hexagon/include/asm/Kbuild @@ -53,3 +53,4 @@ generic-y += types.h generic-y += ucontext.h generic-y += unaligned.h generic-y += xor.h +generic-y += preempt.h diff --git a/arch/ia64/include/asm/Kbuild b/arch/ia64/include/asm/Kbuild index a3456f3..f93ee08 100644 --- a/arch/ia64/include/asm/Kbuild +++ b/arch/ia64/include/asm/Kbuild @@ -3,4 +3,5 @@ generic-y += clkdev.h generic-y += exec.h generic-y += kvm_para.h generic-y += trace_clock.h +generic-y += preempt.h generic-y += vtime.h
\ No newline at end of file diff --git a/arch/m32r/include/asm/Kbuild b/arch/m32r/include/asm/Kbuild index bebdc36..2b58c5f 100644 --- a/arch/m32r/include/asm/Kbuild +++ b/arch/m32r/include/asm/Kbuild @@ -3,3 +3,4 @@ generic-y += clkdev.h generic-y += exec.h generic-y += module.h generic-y += trace_clock.h +generic-y += preempt.h diff --git a/arch/m68k/include/asm/Kbuild b/arch/m68k/include/asm/Kbuild index 09d77a8..a5d27f2 100644 --- a/arch/m68k/include/asm/Kbuild +++ b/arch/m68k/include/asm/Kbuild @@ -31,3 +31,4 @@ generic-y += trace_clock.h generic-y += types.h generic-y += word-at-a-time.h generic-y += xor.h +generic-y += preempt.h diff --git a/arch/metag/include/asm/Kbuild b/arch/metag/include/asm/Kbuild index 6ae0ccb..84d0c1d 100644 --- a/arch/metag/include/asm/Kbuild +++ b/arch/metag/include/asm/Kbuild @@ -52,3 +52,4 @@ generic-y += unaligned.h generic-y += user.h generic-y += vga.h generic-y += xor.h +generic-y += preempt.h diff --git a/arch/metag/include/asm/topology.h b/arch/metag/include/asm/topology.h index 23f5118..8e9c0b3 100644 --- a/arch/metag/include/asm/topology.h +++ b/arch/metag/include/asm/topology.h @@ -26,6 +26,8 @@ .last_balance = jiffies, \ .balance_interval = 1, \ .nr_balance_failed = 0, \ + .max_newidle_lb_cost = 0, \ + .next_decay_max_lb_cost = jiffies, \ } #define cpu_to_node(cpu) ((void)(cpu), 0) diff --git a/arch/microblaze/include/asm/Kbuild b/arch/microblaze/include/asm/Kbuild index d3c51a6..ce0bbf8 100644 --- a/arch/microblaze/include/asm/Kbuild +++ b/arch/microblaze/include/asm/Kbuild @@ -3,3 +3,4 @@ generic-y += clkdev.h generic-y += exec.h generic-y += trace_clock.h generic-y += syscalls.h +generic-y += preempt.h diff --git a/arch/mips/include/asm/Kbuild b/arch/mips/include/asm/Kbuild index 454ddf9..1acbb8b 100644 --- a/arch/mips/include/asm/Kbuild +++ b/arch/mips/include/asm/Kbuild @@ -11,5 +11,6 @@ generic-y += sections.h generic-y += segment.h generic-y += serial.h generic-y += trace_clock.h +generic-y += preempt.h generic-y += ucontext.h generic-y += xor.h diff --git a/arch/mips/kernel/rtlx.c b/arch/mips/kernel/rtlx.c index d763f11..2c12ea1 100644 --- a/arch/mips/kernel/rtlx.c +++ b/arch/mips/kernel/rtlx.c @@ -172,8 +172,9 @@ int rtlx_open(int index, int can_sleep) if (rtlx == NULL) { if( (p = vpe_get_shared(tclimit)) == NULL) { if (can_sleep) { - __wait_event_interruptible(channel_wqs[index].lx_queue, - (p = vpe_get_shared(tclimit)), ret); + ret = __wait_event_interruptible( + channel_wqs[index].lx_queue, + (p = vpe_get_shared(tclimit))); if (ret) goto out_fail; } else { @@ -263,11 +264,10 @@ unsigned int rtlx_read_poll(int index, int can_sleep) /* data available to read? */ if (chan->lx_read == chan->lx_write) { if (can_sleep) { - int ret = 0; - - __wait_event_interruptible(channel_wqs[index].lx_queue, + int ret = __wait_event_interruptible( + channel_wqs[index].lx_queue, (chan->lx_read != chan->lx_write) || - sp_stopping, ret); + sp_stopping); if (ret) return ret; @@ -440,14 +440,13 @@ static ssize_t file_write(struct file *file, const char __user * buffer, /* any space left... */ if (!rtlx_write_poll(minor)) { - int ret = 0; + int ret; if (file->f_flags & O_NONBLOCK) return -EAGAIN; - __wait_event_interruptible(channel_wqs[minor].rt_queue, - rtlx_write_poll(minor), - ret); + ret = __wait_event_interruptible(channel_wqs[minor].rt_queue, + rtlx_write_poll(minor)); if (ret) return ret; } diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c index e205ef5..1215617 100644 --- a/arch/mips/mm/init.c +++ b/arch/mips/mm/init.c @@ -124,7 +124,7 @@ void *kmap_coherent(struct page *page, unsigned long addr) BUG_ON(Page_dcache_dirty(page)); - inc_preempt_count(); + pagefault_disable(); idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1); #ifdef CONFIG_MIPS_MT_SMTC idx += FIX_N_COLOURS * smp_processor_id() + @@ -193,8 +193,7 @@ void kunmap_coherent(void) write_c0_entryhi(old_ctx); EXIT_CRITICAL(flags); #endif - dec_preempt_count(); - preempt_check_resched(); + pagefault_enable(); } void copy_user_highpage(struct page *to, struct page *from, diff --git a/arch/mn10300/include/asm/Kbuild b/arch/mn10300/include/asm/Kbuild index c5d7670..74742dc 100644 --- a/arch/mn10300/include/asm/Kbuild +++ b/arch/mn10300/include/asm/Kbuild @@ -2,3 +2,4 @@ generic-y += clkdev.h generic-y += exec.h generic-y += trace_clock.h +generic-y += preempt.h diff --git a/arch/openrisc/include/asm/Kbuild b/arch/openrisc/include/asm/Kbuild index 195653e..7840562 100644 --- a/arch/openrisc/include/asm/Kbuild +++ b/arch/openrisc/include/asm/Kbuild @@ -67,3 +67,4 @@ generic-y += ucontext.h generic-y += user.h generic-y += word-at-a-time.h generic-y += xor.h +generic-y += preempt.h diff --git a/arch/parisc/include/asm/Kbuild b/arch/parisc/include/asm/Kbuild index ff4c9fa..a603b9e 100644 --- a/arch/parisc/include/asm/Kbuild +++ b/arch/parisc/include/asm/Kbuild @@ -4,3 +4,4 @@ generic-y += word-at-a-time.h auxvec.h user.h cputime.h emergency-restart.h \ div64.h irq_regs.h kdebug.h kvm_para.h local64.h local.h param.h \ poll.h xor.h clkdev.h exec.h generic-y += trace_clock.h +generic-y += preempt.h diff --git a/arch/powerpc/include/asm/Kbuild b/arch/powerpc/include/asm/Kbuild index 704e6f1..d8f9d2f 100644 --- a/arch/powerpc/include/asm/Kbuild +++ b/arch/powerpc/include/asm/Kbuild @@ -2,4 +2,5 @@ generic-y += clkdev.h generic-y += rwsem.h generic-y += trace_clock.h +generic-y += preempt.h generic-y += vtime.h
\ No newline at end of file diff --git a/arch/s390/include/asm/Kbuild b/arch/s390/include/asm/Kbuild index f313f9c..7a5288f 100644 --- a/arch/s390/include/asm/Kbuild +++ b/arch/s390/include/asm/Kbuild @@ -2,3 +2,4 @@ generic-y += clkdev.h generic-y += trace_clock.h +generic-y += preempt.h diff --git a/arch/score/include/asm/Kbuild b/arch/score/include/asm/Kbuild index e1c7bb9..f3414ad 100644 --- a/arch/score/include/asm/Kbuild +++ b/arch/score/include/asm/Kbuild @@ -4,3 +4,4 @@ header-y += generic-y += clkdev.h generic-y += trace_clock.h generic-y += xor.h +generic-y += preempt.h diff --git a/arch/sh/include/asm/Kbuild b/arch/sh/include/asm/Kbuild index 280bea9..231efbb 100644 --- a/arch/sh/include/asm/Kbuild +++ b/arch/sh/include/asm/Kbuild @@ -34,3 +34,4 @@ generic-y += termios.h generic-y += trace_clock.h generic-y += ucontext.h generic-y += xor.h +generic-y += preempt.h diff --git a/arch/sparc/include/asm/Kbuild b/arch/sparc/include/asm/Kbuild index 7e4a97f..bf39066 100644 --- a/arch/sparc/include/asm/Kbuild +++ b/arch/sparc/include/asm/Kbuild @@ -16,3 +16,4 @@ generic-y += serial.h generic-y += trace_clock.h generic-y += types.h generic-y += word-at-a-time.h +generic-y += preempt.h diff --git a/arch/tile/include/asm/Kbuild b/arch/tile/include/asm/Kbuild index 664d6ad..22f3bd1 100644 --- a/arch/tile/include/asm/Kbuild +++ b/arch/tile/include/asm/Kbuild @@ -38,3 +38,4 @@ generic-y += termios.h generic-y += trace_clock.h generic-y += types.h generic-y += xor.h +generic-y += preempt.h diff --git a/arch/um/include/asm/Kbuild b/arch/um/include/asm/Kbuild index b30f34a..fdde187 100644 --- a/arch/um/include/asm/Kbuild +++ b/arch/um/include/asm/Kbuild @@ -3,3 +3,4 @@ generic-y += hw_irq.h irq_regs.h kdebug.h percpu.h sections.h topology.h xor.h generic-y += ftrace.h pci.h io.h param.h delay.h mutex.h current.h exec.h generic-y += switch_to.h clkdev.h generic-y += trace_clock.h +generic-y += preempt.h diff --git a/arch/unicore32/include/asm/Kbuild b/arch/unicore32/include/asm/Kbuild index 89d8b6c..00045cb 100644 --- a/arch/unicore32/include/asm/Kbuild +++ b/arch/unicore32/include/asm/Kbuild @@ -60,3 +60,4 @@ generic-y += unaligned.h generic-y += user.h generic-y += vga.h generic-y += xor.h +generic-y += preempt.h diff --git a/arch/x86/include/asm/atomic.h b/arch/x86/include/asm/atomic.h index 722aa3b..da31c8b 100644 --- a/arch/x86/include/asm/atomic.h +++ b/arch/x86/include/asm/atomic.h @@ -6,6 +6,7 @@ #include <asm/processor.h> #include <asm/alternative.h> #include <asm/cmpxchg.h> +#include <asm/rmwcc.h> /* * Atomic operations that C can't guarantee us. Useful for @@ -76,12 +77,7 @@ static inline void atomic_sub(int i, atomic_t *v) */ static inline int atomic_sub_and_test(int i, atomic_t *v) { - unsigned char c; - - asm volatile(LOCK_PREFIX "subl %2,%0; sete %1" - : "+m" (v->counter), "=qm" (c) - : "ir" (i) : "memory"); - return c; + GEN_BINARY_RMWcc(LOCK_PREFIX "subl", v->counter, i, "%0", "e"); } /** @@ -118,12 +114,7 @@ static inline void atomic_dec(atomic_t *v) */ static inline int atomic_dec_and_test(atomic_t *v) { - unsigned char c; - - asm volatile(LOCK_PREFIX "decl %0; sete %1" - : "+m" (v->counter), "=qm" (c) - : : "memory"); - return c != 0; + GEN_UNARY_RMWcc(LOCK_PREFIX "decl", v->counter, "%0", "e"); } /** @@ -136,12 +127,7 @@ static inline int atomic_dec_and_test(atomic_t *v) */ static inline int atomic_inc_and_test(atomic_t *v) { - unsigned char c; - - asm volatile(LOCK_PREFIX "incl %0; sete %1" - : "+m" (v->counter), "=qm" (c) - : : "memory"); - return c != 0; + GEN_UNARY_RMWcc(LOCK_PREFIX "incl", v->counter, "%0", "e"); } /** @@ -155,12 +141,7 @@ static inline int atomic_inc_and_test(atomic_t *v) */ static inline int atomic_add_negative(int i, atomic_t *v) { - unsigned char c; - - asm volatile(LOCK_PREFIX "addl %2,%0; sets %1" - : "+m" (v->counter), "=qm" (c) - : "ir" (i) : "memory"); - return c; + GEN_BINARY_RMWcc(LOCK_PREFIX "addl", v->counter, i, "%0", "s"); } /** diff --git a/arch/x86/include/asm/atomic64_64.h b/arch/x86/include/asm/atomic64_64.h index 0e1cbfc..3f065c9 100644 --- a/arch/x86/include/asm/atomic64_64.h +++ b/arch/x86/include/asm/atomic64_64.h @@ -72,12 +72,7 @@ static inline void atomic64_sub(long i, atomic64_t *v) */ static inline int atomic64_sub_and_test(long i, atomic64_t *v) { - unsigned char c; - - asm volatile(LOCK_PREFIX "subq %2,%0; sete %1" - : "=m" (v->counter), "=qm" (c) - : "er" (i), "m" (v->counter) : "memory"); - return c; + GEN_BINARY_RMWcc(LOCK_PREFIX "subq", v->counter, i, "%0", "e"); } /** @@ -116,12 +111,7 @@ static inline void atomic64_dec(atomic64_t *v) */ static inline int atomic64_dec_and_test(atomic64_t *v) { - unsigned char c; - - asm volatile(LOCK_PREFIX "decq %0; sete %1" - : "=m" (v->counter), "=qm" (c) - : "m" (v->counter) : "memory"); - return c != 0; + GEN_UNARY_RMWcc(LOCK_PREFIX "decq", v->counter, "%0", "e"); } /** @@ -134,12 +124,7 @@ static inline int atomic64_dec_and_test(atomic64_t *v) */ static inline int atomic64_inc_and_test(atomic64_t *v) { - unsigned char c; - - asm volatile(LOCK_PREFIX "incq %0; sete %1" - : "=m" (v->counter), "=qm" (c) - : "m" (v->counter) : "memory"); - return c != 0; + GEN_UNARY_RMWcc(LOCK_PREFIX "incq", v->counter, "%0", "e"); } /** @@ -153,12 +138,7 @@ static inline int atomic64_inc_and_test(atomic64_t *v) */ static inline int atomic64_add_negative(long i, atomic64_t *v) { - unsigned char c; - - asm volatile(LOCK_PREFIX "addq %2,%0; sets %1" - : "=m" (v->counter), "=qm" (c) - : "er" (i), "m" (v->counter) : "memory"); - return c; + GEN_BINARY_RMWcc(LOCK_PREFIX "addq", v->counter, i, "%0", "s"); } /** diff --git a/arch/x86/include/asm/bitops.h b/arch/x86/include/asm/bitops.h index 41639ce..6d76d09 100644 --- a/arch/x86/include/asm/bitops.h +++ b/arch/x86/include/asm/bitops.h @@ -14,6 +14,7 @@ #include <linux/compiler.h> #include <asm/alternative.h> +#include <asm/rmwcc.h> #if BITS_PER_LONG == 32 # define _BITOPS_LONG_SHIFT 5 @@ -204,12 +205,7 @@ static inline void change_bit(long nr, volatile unsigned long *addr) */ static inline int test_and_set_bit(long nr, volatile unsigned long *addr) { - int oldbit; - - asm volatile(LOCK_PREFIX "bts %2,%1\n\t" - "sbb %0,%0" : "=r" (oldbit), ADDR : "Ir" (nr) : "memory"); - - return oldbit; + GEN_BINARY_RMWcc(LOCK_PREFIX "bts", *addr, nr, "%0", "c"); } /** @@ -255,13 +251,7 @@ static inline int __test_and_set_bit(long nr, volatile unsigned long *addr) */ static inline int test_and_clear_bit(long nr, volatile unsigned long *addr) { - int oldbit; - - asm volatile(LOCK_PREFIX "btr %2,%1\n\t" - "sbb %0,%0" - : "=r" (oldbit), ADDR : "Ir" (nr) : "memory"); - - return oldbit; + GEN_BINARY_RMWcc(LOCK_PREFIX "btr", *addr, nr, "%0", "c"); } /** @@ -314,13 +304,7 @@ static inline int __test_and_change_bit(long nr, volatile unsigned long *addr) */ static inline int test_and_change_bit(long nr, volatile unsigned long *addr) { - int oldbit; - - asm volatile(LOCK_PREFIX "btc %2,%1\n\t" - "sbb %0,%0" - : "=r" (oldbit), ADDR : "Ir" (nr) : "memory"); - - return oldbit; + GEN_BINARY_RMWcc(LOCK_PREFIX "btc", *addr, nr, "%0", "c"); } static __always_inline int constant_test_bit(long nr, const volatile unsigned long *addr) diff --git a/arch/x86/include/asm/calling.h b/arch/x86/include/asm/calling.h index 0fa6750..cb4c73b 100644 --- a/arch/x86/include/asm/calling.h +++ b/arch/x86/include/asm/calling.h @@ -48,6 +48,8 @@ For 32-bit we have the following conventions - kernel is built with #include <asm/dwarf2.h> +#ifdef CONFIG_X86_64 + /* * 64-bit system call stack frame layout defines and helpers, * for assembly code: @@ -192,3 +194,51 @@ For 32-bit we have the following conventions - kernel is built with .macro icebp .byte 0xf1 .endm + +#else /* CONFIG_X86_64 */ + +/* + * For 32bit only simplified versions of SAVE_ALL/RESTORE_ALL. These + * are different from the entry_32.S versions in not changing the segment + * registers. So only suitable for in kernel use, not when transitioning + * from or to user space. The resulting stack frame is not a standard + * pt_regs frame. The main use case is calling C code from assembler + * when all the registers need to be preserved. + */ + + .macro SAVE_ALL + pushl_cfi %eax + CFI_REL_OFFSET eax, 0 + pushl_cfi %ebp + CFI_REL_OFFSET ebp, 0 + pushl_cfi %edi + CFI_REL_OFFSET edi, 0 + pushl_cfi %esi + CFI_REL_OFFSET esi, 0 + pushl_cfi %edx + CFI_REL_OFFSET edx, 0 + pushl_cfi %ecx + CFI_REL_OFFSET ecx, 0 + pushl_cfi %ebx + CFI_REL_OFFSET ebx, 0 + .endm + + .macro RESTORE_ALL + popl_cfi %ebx + CFI_RESTORE ebx + popl_cfi %ecx + CFI_RESTORE ecx + popl_cfi %edx + CFI_RESTORE edx + popl_cfi %esi + CFI_RESTORE esi + popl_cfi %edi + CFI_RESTORE edi + popl_cfi %ebp + CFI_RESTORE ebp + popl_cfi %eax + CFI_RESTORE eax + .endm + +#endif /* CONFIG_X86_64 */ + diff --git a/arch/x86/include/asm/local.h b/arch/x86/include/asm/local.h index 2d89e39..5b23e60 100644 --- a/arch/x86/include/asm/local.h +++ b/arch/x86/include/asm/local.h @@ -52,12 +52,7 @@ static inline void local_sub(long i, local_t *l) */ static inline int local_sub_and_test(long i, local_t *l) { - unsigned char c; - - asm volatile(_ASM_SUB "%2,%0; sete %1" - : "+m" (l->a.counter), "=qm" (c) - : "ir" (i) : "memory"); - return c; + GEN_BINARY_RMWcc(_ASM_SUB, l->a.counter, i, "%0", "e"); } /** @@ -70,12 +65,7 @@ static inline int local_sub_and_test(long i, local_t *l) */ static inline int local_dec_and_test(local_t *l) { - unsigned char c; - - asm volatile(_ASM_DEC "%0; sete %1" - : "+m" (l->a.counter), "=qm" (c) - : : "memory"); - return c != 0; + GEN_UNARY_RMWcc(_ASM_DEC, l->a.counter, "%0", "e"); } /** @@ -88,12 +78,7 @@ static inline int local_dec_and_test(local_t *l) */ static inline int local_inc_and_test(local_t *l) { - unsigned char c; - - asm volatile(_ASM_INC "%0; sete %1" - : "+m" (l->a.counter), "=qm" (c) - : : "memory"); - return c != 0; + GEN_UNARY_RMWcc(_ASM_INC, l->a.counter, "%0", "e"); } /** @@ -107,12 +92,7 @@ static inline int local_inc_and_test(local_t *l) */ static inline int local_add_negative(long i, local_t *l) { - unsigned char c; - - asm volatile(_ASM_ADD "%2,%0; sets %1" - : "+m" (l->a.counter), "=qm" (c) - : "ir" (i) : "memory"); - return c; + GEN_BINARY_RMWcc(_ASM_ADD, l->a.counter, i, "%0", "s"); } /** diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h new file mode 100644 index 0000000..8729723 --- /dev/null +++ b/arch/x86/include/asm/preempt.h @@ -0,0 +1,100 @@ +#ifndef __ASM_PREEMPT_H +#define __ASM_PREEMPT_H + +#include <asm/rmwcc.h> +#include <asm/percpu.h> +#include <linux/thread_info.h> + +DECLARE_PER_CPU(int, __preempt_count); + +/* + * We mask the PREEMPT_NEED_RESCHED bit so as not to confuse all current users + * that think a non-zero value indicates we cannot preempt. + */ +static __always_inline int preempt_count(void) +{ + return __this_cpu_read_4(__preempt_count) & ~PREEMPT_NEED_RESCHED; +} + +static __always_inline void preempt_count_set(int pc) +{ + __this_cpu_write_4(__preempt_count, pc); +} + +/* + * must be macros to avoid header recursion hell + */ +#define task_preempt_count(p) \ + (task_thread_info(p)->saved_preempt_count & ~PREEMPT_NEED_RESCHED) + +#define init_task_preempt_count(p) do { \ + task_thread_info(p)->saved_preempt_count = PREEMPT_DISABLED; \ +} while (0) + +#define init_idle_preempt_count(p, cpu) do { \ + task_thread_info(p)->saved_preempt_count = PREEMPT_ENABLED; \ + per_cpu(__preempt_count, (cpu)) = PREEMPT_ENABLED; \ +} while (0) + +/* + * We fold the NEED_RESCHED bit into the preempt count such that + * preempt_enable() can decrement and test for needing to reschedule with a + * single instruction. + * + * We invert the actual bit, so that when the decrement hits 0 we know we both + * need to resched (the bit is cleared) and can resched (no preempt count). + */ + +static __always_inline void set_preempt_need_resched(void) +{ + __this_cpu_and_4(__preempt_count, ~PREEMPT_NEED_RESCHED); +} + +static __always_inline void clear_preempt_need_resched(void) +{ + __this_cpu_or_4(__preempt_count, PREEMPT_NEED_RESCHED); +} + +static __always_inline bool test_preempt_need_resched(void) +{ + return !(__this_cpu_read_4(__preempt_count) & PREEMPT_NEED_RESCHED); +} + +/* + * The various preempt_count add/sub methods + */ + +static __always_inline void __preempt_count_add(int val) +{ + __this_cpu_add_4(__preempt_count, val); +} + +static __always_inline void __preempt_count_sub(int val) +{ + __this_cpu_add_4(__preempt_count, -val); +} + +static __always_inline bool __preempt_count_dec_and_test(void) +{ + GEN_UNARY_RMWcc("decl", __preempt_count, __percpu_arg(0), "e"); +} + +/* + * Returns true when we need to resched and can (barring IRQ state). + */ +static __always_inline bool should_resched(void) +{ + return unlikely(!__this_cpu_read_4(__preempt_count)); +} + +#ifdef CONFIG_PREEMPT + extern asmlinkage void ___preempt_schedule(void); +# define __preempt_schedule() asm ("call ___preempt_schedule") + extern asmlinkage void preempt_schedule(void); +# ifdef CONFIG_CONTEXT_TRACKING + extern asmlinkage void ___preempt_schedule_context(void); +# define __preempt_schedule_context() asm ("call ___preempt_schedule_context") +# endif +#endif + +#endif /* __ASM_PREEMPT_H */ diff --git a/arch/x86/include/asm/rmwcc.h b/arch/x86/include/asm/rmwcc.h new file mode 100644 index 0000000..1ff990f --- /dev/null +++ b/arch/x86/include/asm/rmwcc.h @@ -0,0 +1,41 @@ +#ifndef _ASM_X86_RMWcc +#define _ASM_X86_RMWcc + +#ifdef CC_HAVE_ASM_GOTO + +#define __GEN_RMWcc(fullop, var, cc, ...) \ +do { \ + asm_volatile_goto (fullop "; j" cc " %l[cc_label]" \ + : : "m" (var), ## __VA_ARGS__ \ + : "memory" : cc_label); \ + return 0; \ +cc_label: \ + return 1; \ +} while (0) + +#define GEN_UNARY_RMWcc(op, var, arg0, cc) \ + __GEN_RMWcc(op " " arg0, var, cc) + +#define GEN_BINARY_RMWcc(op, var, val, arg0, cc) \ + __GEN_RMWcc(op " %1, " arg0, var, cc, "er" (val)) + +#else /* !CC_HAVE_ASM_GOTO */ + +#define __GEN_RMWcc(fullop, var, cc, ...) \ +do { \ + char c; \ + asm volatile (fullop "; set" cc " %1" \ + : "+m" (var), "=qm" (c) \ + : __VA_ARGS__ : "memory"); \ + return c != 0; \ +} while (0) + +#define GEN_UNARY_RMWcc(op, var, arg0, cc) \ + __GEN_RMWcc(op " " arg0, var, cc) + +#define GEN_BINARY_RMWcc(op, var, val, arg0, cc) \ + __GEN_RMWcc(op " %2, " arg0, var, cc, "er" (val)) + +#endif /* CC_HAVE_ASM_GOTO */ + +#endif /* _ASM_X86_RMWcc */ diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h index 2781119..c46a46b 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -28,8 +28,7 @@ struct thread_info { __u32 flags; /* low level flags */ __u32 status; /* thread synchronous flags */ __u32 cpu; /* current CPU */ - int preempt_count; /* 0 => preemptable, - <0 => BUG */ + int saved_preempt_count; mm_segment_t addr_limit; struct restart_block restart_block; void __user *sysenter_return; @@ -49,7 +48,7 @@ struct thread_info { .exec_domain = &default_exec_domain, \ .flags = 0, \ .cpu = 0, \ - .preempt_count = INIT_PREEMPT_COUNT, \ + .saved_preempt_count = INIT_PREEMPT_COUNT, \ .addr_limit = KERNEL_DS, \ .restart_block = { \ .fn = do_no_restart_syscall, \ diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index a5408b9..9b0a34e 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -36,6 +36,8 @@ obj-y += tsc.o io_delay.o rtc.o obj-y += pci-iommu_table.o obj-y += resource.o +obj-$(CONFIG_PREEMPT) += preempt.o + obj-y += process.o obj-y += i387.o xsave.o obj-y += ptrace.o diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c index 2861082..9f6b934 100644 --- a/arch/x86/kernel/asm-offsets.c +++ b/arch/x86/kernel/asm-offsets.c @@ -32,7 +32,6 @@ void common(void) { OFFSET(TI_flags, thread_info, flags); OFFSET(TI_status, thread_info, status); OFFSET(TI_addr_limit, thread_info, addr_limit); - OFFSET(TI_preempt_count, thread_info, preempt_count); BLANK(); OFFSET(crypto_tfm_ctx_offset, crypto_tfm, __crt_ctx); diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 2793d1f..5223fe6 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1095,6 +1095,9 @@ DEFINE_PER_CPU(char *, irq_stack_ptr) = DEFINE_PER_CPU(unsigned int, irq_count) __visible = -1; +DEFINE_PER_CPU(int, __preempt_count) = INIT_PREEMPT_COUNT; +EXPORT_PER_CPU_SYMBOL(__preempt_count); + DEFINE_PER_CPU(struct task_struct *, fpu_owner_task); /* @@ -1169,6 +1172,8 @@ void debug_stack_reset(void) DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task; EXPORT_PER_CPU_SYMBOL(current_task); +DEFINE_PER_CPU(int, __preempt_count) = INIT_PREEMPT_COUNT; +EXPORT_PER_CPU_SYMBOL(__preempt_count); DEFINE_PER_CPU(struct task_struct *, fpu_owner_task); #ifdef CONFIG_CC_STACKPROTECTOR diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index f0dcb0c..fd1bc1b 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S @@ -362,12 +362,9 @@ END(ret_from_exception) #ifdef CONFIG_PREEMPT ENTRY(resume_kernel) DISABLE_INTERRUPTS(CLBR_ANY) - cmpl $0,TI_preempt_count(%ebp) # non-zero preempt_count ? - jnz restore_all need_resched: - movl TI_flags(%ebp), %ecx # need_resched set ? - testb $_TIF_NEED_RESCHED, %cl - jz restore_all + cmpl $0,PER_CPU_VAR(__preempt_count) + jnz restore_all testl $X86_EFLAGS_IF,PT_EFLAGS(%esp) # interrupts off (exception path) ? jz restore_all call preempt_schedule_irq diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index b077f4c..1a2cc64 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -1103,10 +1103,8 @@ retint_signal: /* Returning to kernel space. Check if we need preemption */ /* rcx: threadinfo. interrupts off. */ ENTRY(retint_kernel) - cmpl $0,TI_preempt_count(%rcx) + cmpl $0,PER_CPU_VAR(__preempt_count) jnz retint_restore_args - bt $TIF_NEED_RESCHED,TI_flags(%rcx) - jnc retint_restore_args bt $9,EFLAGS-ARGOFFSET(%rsp) /* interrupts off? */ jnc retint_restore_args call preempt_schedule_irq diff --git a/arch/x86/kernel/i386_ksyms_32.c b/arch/x86/kernel/i386_ksyms_32.c index 0fa6912..05fd74f 100644 --- a/arch/x86/kernel/i386_ksyms_32.c +++ b/arch/x86/kernel/i386_ksyms_32.c @@ -37,3 +37,10 @@ EXPORT_SYMBOL(strstr); EXPORT_SYMBOL(csum_partial); EXPORT_SYMBOL(empty_zero_page); + +#ifdef CONFIG_PREEMPT +EXPORT_SYMBOL(___preempt_schedule); +#ifdef CONFIG_CONTEXT_TRACKING +EXPORT_SYMBOL(___preempt_schedule_context); +#endif +#endif diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c index 4186755..3fe0663 100644 --- a/arch/x86/kernel/irq_32.c +++ b/arch/x86/kernel/irq_32.c @@ -100,9 +100,6 @@ execute_on_irq_stack(int overflow, struct irq_desc *desc, int irq) irqctx->tinfo.task = curctx->tinfo.task; irqctx->tinfo.previous_esp = current_stack_pointer; - /* Copy the preempt_count so that the [soft]irq checks work. */ - irqctx->tinfo.preempt_count = curctx->tinfo.preempt_count; - if (unlikely(overflow)) call_on_stack(print_stack_overflow, isp); @@ -131,7 +128,6 @@ void irq_ctx_init(int cpu) THREAD_SIZE_ORDER)); memset(&irqctx->tinfo, 0, sizeof(struct thread_info)); irqctx->tinfo.cpu = cpu; - irqctx->tinfo.preempt_count = HARDIRQ_OFFSET; irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); per_cpu(hardirq_ctx, cpu) = irqctx; diff --git a/arch/x86/kernel/preempt.S b/arch/x86/kernel/preempt.S new file mode 100644 index 0000000..ca7f0d5 --- /dev/null +++ b/arch/x86/kernel/preempt.S @@ -0,0 +1,25 @@ + +#include <linux/linkage.h> +#include <asm/dwarf2.h> +#include <asm/asm.h> +#include <asm/calling.h> + +ENTRY(___preempt_schedule) + CFI_STARTPROC + SAVE_ALL + call preempt_schedule + RESTORE_ALL + ret + CFI_ENDPROC + +#ifdef CONFIG_CONTEXT_TRACKING + +ENTRY(___preempt_schedule_context) + CFI_STARTPROC + SAVE_ALL + call preempt_schedule_context + RESTORE_ALL + ret + CFI_ENDPROC + +#endif diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index c83516b..3fb8d95 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -391,9 +391,9 @@ static void amd_e400_idle(void) * The switch back from broadcast mode needs to be * called with interrupts disabled. */ - local_irq_disable(); - clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu); - local_irq_enable(); + local_irq_disable(); + clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu); + local_irq_enable(); } else default_idle(); } diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index 884f98f..c2ec1aa 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -292,6 +292,14 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) set_iopl_mask(next->iopl); /* + * If it were not for PREEMPT_ACTIVE we could guarantee that the + * preempt_count of all tasks was equal here and this would not be + * needed. + */ + task_thread_info(prev_p)->saved_preempt_count = this_cpu_read(__preempt_count); + this_cpu_write(__preempt_count, task_thread_info(next_p)->saved_preempt_count); + + /* * Now maybe handle debug registers and/or IO bitmaps */ if (unlikely(task_thread_info(prev_p)->flags & _TIF_WORK_CTXSW_PREV || diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index bb1dc51..45ab4d6 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -363,6 +363,14 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) this_cpu_write(old_rsp, next->usersp); this_cpu_write(current_task, next_p); + /* + * If it were not for PREEMPT_ACTIVE we could guarantee that the + * preempt_count of all tasks was equal here and this would not be + * needed. + */ + task_thread_info(prev_p)->saved_preempt_count = this_cpu_read(__preempt_count); + this_cpu_write(__preempt_count, task_thread_info(next_p)->saved_preempt_count); + this_cpu_write(kernel_stack, (unsigned long)task_stack_page(next_p) + THREAD_SIZE - KERNEL_STACK_OFFSET); diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 8c8093b..729aa77 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -88,7 +88,7 @@ static inline void conditional_sti(struct pt_regs *regs) static inline void preempt_conditional_sti(struct pt_regs *regs) { - inc_preempt_count(); + preempt_count_inc(); if (regs->flags & X86_EFLAGS_IF) local_irq_enable(); } @@ -103,7 +103,7 @@ static inline void preempt_conditional_cli(struct pt_regs *regs) { if (regs->flags & X86_EFLAGS_IF) local_irq_disable(); - dec_preempt_count(); + preempt_count_dec(); } static int __kprobes diff --git a/arch/x86/kernel/x8664_ksyms_64.c b/arch/x86/kernel/x8664_ksyms_64.c index b014d94..0406819 100644 --- a/arch/x86/kernel/x8664_ksyms_64.c +++ b/arch/x86/kernel/x8664_ksyms_64.c @@ -66,3 +66,10 @@ EXPORT_SYMBOL(empty_zero_page); #ifndef CONFIG_PARAVIRT EXPORT_SYMBOL(native_load_gs_index); #endif + +#ifdef CONFIG_PREEMPT +EXPORT_SYMBOL(___preempt_schedule); +#ifdef CONFIG_CONTEXT_TRACKING +EXPORT_SYMBOL(___preempt_schedule_context); +#endif +#endif diff --git a/arch/xtensa/include/asm/Kbuild b/arch/xtensa/include/asm/Kbuild index 1b98264..228d6ae 100644 --- a/arch/xtensa/include/asm/Kbuild +++ b/arch/xtensa/include/asm/Kbuild @@ -28,3 +28,4 @@ generic-y += termios.h generic-y += topology.h generic-y += trace_clock.h generic-y += xor.h +generic-y += preempt.h diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index f98dd00..c7414a5 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -119,17 +119,10 @@ static struct dmi_system_id processor_power_dmi_table[] = { */ static void acpi_safe_halt(void) { - current_thread_info()->status &= ~TS_POLLING; - /* - * TS_POLLING-cleared state must be visible before we - * test NEED_RESCHED: - */ - smp_mb(); - if (!need_resched()) { + if (!tif_need_resched()) { safe_halt(); local_irq_disable(); } - current_thread_info()->status |= TS_POLLING; } #ifdef ARCH_APICTIMER_STOPS_ON_C3 @@ -737,6 +730,11 @@ static int acpi_idle_enter_c1(struct cpuidle_device *dev, if (unlikely(!pr)) return -EINVAL; + if (cx->entry_method == ACPI_CSTATE_FFH) { + if (current_set_polling_and_test()) + return -EINVAL; + } + lapic_timer_state_broadcast(pr, cx, 1); acpi_idle_do_entry(cx); @@ -790,18 +788,9 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev, if (unlikely(!pr)) return -EINVAL; - if (cx->entry_method != ACPI_CSTATE_FFH) { - current_thread_info()->status &= ~TS_POLLING; - /* - * TS_POLLING-cleared state must be visible before we test - * NEED_RESCHED: - */ - smp_mb(); - - if (unlikely(need_resched())) { - current_thread_info()->status |= TS_POLLING; + if (cx->entry_method == ACPI_CSTATE_FFH) { + if (current_set_polling_and_test()) return -EINVAL; - } } /* @@ -819,9 +808,6 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev, sched_clock_idle_wakeup_event(0); - if (cx->entry_method != ACPI_CSTATE_FFH) - current_thread_info()->status |= TS_POLLING; - lapic_timer_state_broadcast(pr, cx, 0); return index; } @@ -858,18 +844,9 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev, } } - if (cx->entry_method != ACPI_CSTATE_FFH) { - current_thread_info()->status &= ~TS_POLLING; - /* - * TS_POLLING-cleared state must be visible before we test - * NEED_RESCHED: - */ - smp_mb(); - - if (unlikely(need_resched())) { - current_thread_info()->status |= TS_POLLING; + if (cx->entry_method == ACPI_CSTATE_FFH) { + if (current_set_polling_and_test()) return -EINVAL; - } } acpi_unlazy_tlb(smp_processor_id()); @@ -915,9 +892,6 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev, sched_clock_idle_wakeup_event(0); - if (cx->entry_method != ACPI_CSTATE_FFH) - current_thread_info()->status |= TS_POLLING; - lapic_timer_state_broadcast(pr, cx, 0); return index; } diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index fa6964d..f116d66 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -359,7 +359,7 @@ static int intel_idle(struct cpuidle_device *dev, if (!(lapic_timer_reliable_states & (1 << (cstate)))) clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu); - if (!need_resched()) { + if (!current_set_polling_and_test()) { __monitor((void *)¤t_thread_info()->flags, 0, 0); smp_mb(); @@ -1547,6 +1547,7 @@ static int do_execve_common(const char *filename, current->fs->in_exec = 0; current->in_execve = 0; acct_update_integrals(current); + task_numa_free(current); free_bprm(bprm); if (displaced) put_files_struct(displaced); diff --git a/fs/proc/array.c b/fs/proc/array.c index cbd0f1b..1bd2077 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -183,6 +183,7 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns, seq_printf(m, "State:\t%s\n" "Tgid:\t%d\n" + "Ngid:\t%d\n" "Pid:\t%d\n" "PPid:\t%d\n" "TracerPid:\t%d\n" @@ -190,6 +191,7 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns, "Gid:\t%d\t%d\t%d\t%d\n", get_task_state(p), task_tgid_nr_ns(p, ns), + task_numa_group_id(p), pid_nr_ns(pid, ns), ppid, tpid, from_kuid_munged(user_ns, cred->uid), diff --git a/include/asm-generic/preempt.h b/include/asm-generic/preempt.h new file mode 100644 index 0000000..ddf2b42 --- /dev/null +++ b/include/asm-generic/preempt.h @@ -0,0 +1,105 @@ +#ifndef __ASM_PREEMPT_H +#define __ASM_PREEMPT_H + +#include <linux/thread_info.h> + +/* + * We mask the PREEMPT_NEED_RESCHED bit so as not to confuse all current users + * that think a non-zero value indicates we cannot preempt. + */ +static __always_inline int preempt_count(void) +{ + return current_thread_info()->preempt_count & ~PREEMPT_NEED_RESCHED; +} + +static __always_inline int *preempt_count_ptr(void) +{ + return ¤t_thread_info()->preempt_count; +} + +/* + * We now loose PREEMPT_NEED_RESCHED and cause an extra reschedule; however the + * alternative is loosing a reschedule. Better schedule too often -- also this + * should be a very rare operation. + */ +static __always_inline void preempt_count_set(int pc) +{ + *preempt_count_ptr() = pc; +} + +/* + * must be macros to avoid header recursion hell + */ +#define task_preempt_count(p) \ + (task_thread_info(p)->preempt_count & ~PREEMPT_NEED_RESCHED) + +#define init_task_preempt_count(p) do { \ + task_thread_info(p)->preempt_count = PREEMPT_DISABLED; \ +} while (0) + +#define init_idle_preempt_count(p, cpu) do { \ + task_thread_info(p)->preempt_count = PREEMPT_ENABLED; \ +} while (0) + +/* + * We fold the NEED_RESCHED bit into the preempt count such that + * preempt_enable() can decrement and test for needing to reschedule with a + * single instruction. + * + * We invert the actual bit, so that when the decrement hits 0 we know we both + * need to resched (the bit is cleared) and can resched (no preempt count). + */ + +static __always_inline void set_preempt_need_resched(void) +{ + *preempt_count_ptr() &= ~PREEMPT_NEED_RESCHED; +} + +static __always_inline void clear_preempt_need_resched(void) +{ + *preempt_count_ptr() |= PREEMPT_NEED_RESCHED; +} + +static __always_inline bool test_preempt_need_resched(void) +{ + return !(*preempt_count_ptr() & PREEMPT_NEED_RESCHED); +} + +/* + * The various preempt_count add/sub methods + */ + +static __always_inline void __preempt_count_add(int val) +{ + *preempt_count_ptr() += val; +} + +static __always_inline void __preempt_count_sub(int val) +{ + *preempt_count_ptr() -= val; +} + +static __always_inline bool __preempt_count_dec_and_test(void) +{ + return !--*preempt_count_ptr(); +} + +/* + * Returns true when we need to resched and can (barring IRQ state). + */ +static __always_inline bool should_resched(void) +{ + return unlikely(!*preempt_count_ptr()); +} + +#ifdef CONFIG_PREEMPT +extern asmlinkage void preempt_schedule(void); +#define __preempt_schedule() preempt_schedule() + +#ifdef CONFIG_CONTEXT_TRACKING +extern asmlinkage void preempt_schedule_context(void); +#define __preempt_schedule_context() preempt_schedule_context() +#endif +#endif /* CONFIG_PREEMPT */ + +#endif /* __ASM_PREEMPT_H */ diff --git a/include/linux/completion.h b/include/linux/completion.h index 3cd574d..22c33e3 100644 --- a/include/linux/completion.h +++ b/include/linux/completion.h @@ -5,7 +5,7 @@ * (C) Copyright 2001 Linus Torvalds * * Atomic wait-for-completion handler data structures. - * See kernel/sched/core.c for details. + * See kernel/sched/completion.c for details. */ #include <linux/wait.h> diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h index 1e04106..d9cf963 100644 --- a/include/linux/hardirq.h +++ b/include/linux/hardirq.h @@ -33,7 +33,7 @@ extern void rcu_nmi_exit(void); #define __irq_enter() \ do { \ account_irq_enter_time(current); \ - add_preempt_count(HARDIRQ_OFFSET); \ + preempt_count_add(HARDIRQ_OFFSET); \ trace_hardirq_enter(); \ } while (0) @@ -49,7 +49,7 @@ extern void irq_enter(void); do { \ trace_hardirq_exit(); \ account_irq_exit_time(current); \ - sub_preempt_count(HARDIRQ_OFFSET); \ + preempt_count_sub(HARDIRQ_OFFSET); \ } while (0) /* @@ -62,7 +62,7 @@ extern void irq_exit(void); lockdep_off(); \ ftrace_nmi_enter(); \ BUG_ON(in_nmi()); \ - add_preempt_count(NMI_OFFSET + HARDIRQ_OFFSET); \ + preempt_count_add(NMI_OFFSET + HARDIRQ_OFFSET); \ rcu_nmi_enter(); \ trace_hardirq_enter(); \ } while (0) @@ -72,7 +72,7 @@ extern void irq_exit(void); trace_hardirq_exit(); \ rcu_nmi_exit(); \ BUG_ON(!in_nmi()); \ - sub_preempt_count(NMI_OFFSET + HARDIRQ_OFFSET); \ + preempt_count_sub(NMI_OFFSET + HARDIRQ_OFFSET); \ ftrace_nmi_exit(); \ lockdep_on(); \ } while (0) diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h index da6716b..ea4d249 100644 --- a/include/linux/mempolicy.h +++ b/include/linux/mempolicy.h @@ -136,6 +136,7 @@ struct mempolicy *mpol_shared_policy_lookup(struct shared_policy *sp, struct mempolicy *get_vma_policy(struct task_struct *tsk, struct vm_area_struct *vma, unsigned long addr); +bool vma_policy_mof(struct task_struct *task, struct vm_area_struct *vma); extern void numa_default_policy(void); extern void numa_policy_init(void); diff --git a/include/linux/migrate.h b/include/linux/migrate.h index 8d3c57f..f5096b5 100644 --- a/include/linux/migrate.h +++ b/include/linux/migrate.h @@ -90,11 +90,12 @@ static inline int migrate_huge_page_move_mapping(struct address_space *mapping, #endif /* CONFIG_MIGRATION */ #ifdef CONFIG_NUMA_BALANCING -extern int migrate_misplaced_page(struct page *page, int node); -extern int migrate_misplaced_page(struct page *page, int node); +extern int migrate_misplaced_page(struct page *page, + struct vm_area_struct *vma, int node); extern bool migrate_ratelimited(int node); #else -static inline int migrate_misplaced_page(struct page *page, int node) +static inline int migrate_misplaced_page(struct page *page, + struct vm_area_struct *vma, int node) { return -EAGAIN; /* can't migrate now */ } diff --git a/include/linux/mm.h b/include/linux/mm.h index 8b6e55e..81443d5 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -581,11 +581,11 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) * sets it, so none of the operations on it need to be atomic. */ -/* Page flags: | [SECTION] | [NODE] | ZONE | [LAST_NID] | ... | FLAGS | */ +/* Page flags: | [SECTION] | [NODE] | ZONE | [LAST_CPUPID] | ... | FLAGS | */ #define SECTIONS_PGOFF ((sizeof(unsigned long)*8) - SECTIONS_WIDTH) #define NODES_PGOFF (SECTIONS_PGOFF - NODES_WIDTH) #define ZONES_PGOFF (NODES_PGOFF - ZONES_WIDTH) -#define LAST_NID_PGOFF (ZONES_PGOFF - LAST_NID_WIDTH) +#define LAST_CPUPID_PGOFF (ZONES_PGOFF - LAST_CPUPID_WIDTH) /* * Define the bit shifts to access each section. For non-existent @@ -595,7 +595,7 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) #define SECTIONS_PGSHIFT (SECTIONS_PGOFF * (SECTIONS_WIDTH != 0)) #define NODES_PGSHIFT (NODES_PGOFF * (NODES_WIDTH != 0)) #define ZONES_PGSHIFT (ZONES_PGOFF * (ZONES_WIDTH != 0)) -#define LAST_NID_PGSHIFT (LAST_NID_PGOFF * (LAST_NID_WIDTH != 0)) +#define LAST_CPUPID_PGSHIFT (LAST_CPUPID_PGOFF * (LAST_CPUPID_WIDTH != 0)) /* NODE:ZONE or SECTION:ZONE is used to ID a zone for the buddy allocator */ #ifdef NODE_NOT_IN_PAGE_FLAGS @@ -617,7 +617,7 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) #define ZONES_MASK ((1UL << ZONES_WIDTH) - 1) #define NODES_MASK ((1UL << NODES_WIDTH) - 1) #define SECTIONS_MASK ((1UL << SECTIONS_WIDTH) - 1) -#define LAST_NID_MASK ((1UL << LAST_NID_WIDTH) - 1) +#define LAST_CPUPID_MASK ((1UL << LAST_CPUPID_WIDTH) - 1) #define ZONEID_MASK ((1UL << ZONEID_SHIFT) - 1) static inline enum zone_type page_zonenum(const struct page *page) @@ -661,51 +661,117 @@ static inline int page_to_nid(const struct page *page) #endif #ifdef CONFIG_NUMA_BALANCING -#ifdef LAST_NID_NOT_IN_PAGE_FLAGS -static inline int page_nid_xchg_last(struct page *page, int nid) +static inline int cpu_pid_to_cpupid(int cpu, int pid) { - return xchg(&page->_last_nid, nid); + return ((cpu & LAST__CPU_MASK) << LAST__PID_SHIFT) | (pid & LAST__PID_MASK); } -static inline int page_nid_last(struct page *page) +static inline int cpupid_to_pid(int cpupid) { - return page->_last_nid; + return cpupid & LAST__PID_MASK; } -static inline void page_nid_reset_last(struct page *page) + +static inline int cpupid_to_cpu(int cpupid) { - page->_last_nid = -1; + return (cpupid >> LAST__PID_SHIFT) & LAST__CPU_MASK; } -#else -static inline int page_nid_last(struct page *page) + +static inline int cpupid_to_nid(int cpupid) { - return (page->flags >> LAST_NID_PGSHIFT) & LAST_NID_MASK; + return cpu_to_node(cpupid_to_cpu(cpupid)); } -extern int page_nid_xchg_last(struct page *page, int nid); +static inline bool cpupid_pid_unset(int cpupid) +{ + return cpupid_to_pid(cpupid) == (-1 & LAST__PID_MASK); +} -static inline void page_nid_reset_last(struct page *page) +static inline bool cpupid_cpu_unset(int cpupid) { - int nid = (1 << LAST_NID_SHIFT) - 1; + return cpupid_to_cpu(cpupid) == (-1 & LAST__CPU_MASK); +} - page->flags &= ~(LAST_NID_MASK << LAST_NID_PGSHIFT); - page->flags |= (nid & LAST_NID_MASK) << LAST_NID_PGSHIFT; +static inline bool __cpupid_match_pid(pid_t task_pid, int cpupid) +{ + return (task_pid & LAST__PID_MASK) == cpupid_to_pid(cpupid); +} + +#define cpupid_match_pid(task, cpupid) __cpupid_match_pid(task->pid, cpupid) +#ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS +static inline int page_cpupid_xchg_last(struct page *page, int cpupid) +{ + return xchg(&page->_last_cpupid, cpupid); +} + +static inline int page_cpupid_last(struct page *page) +{ + return page->_last_cpupid; +} +static inline void page_cpupid_reset_last(struct page *page) +{ + page->_last_cpupid = -1; } -#endif /* LAST_NID_NOT_IN_PAGE_FLAGS */ #else -static inline int page_nid_xchg_last(struct page *page, int nid) +static inline int page_cpupid_last(struct page *page) { - return page_to_nid(page); + return (page->flags >> LAST_CPUPID_PGSHIFT) & LAST_CPUPID_MASK; } -static inline int page_nid_last(struct page *page) +extern int page_cpupid_xchg_last(struct page *page, int cpupid); + +static inline void page_cpupid_reset_last(struct page *page) { - return page_to_nid(page); + int cpupid = (1 << LAST_CPUPID_SHIFT) - 1; + + page->flags &= ~(LAST_CPUPID_MASK << LAST_CPUPID_PGSHIFT); + page->flags |= (cpupid & LAST_CPUPID_MASK) << LAST_CPUPID_PGSHIFT; +} +#endif /* LAST_CPUPID_NOT_IN_PAGE_FLAGS */ +#else /* !CONFIG_NUMA_BALANCING */ +static inline int page_cpupid_xchg_last(struct page *page, int cpupid) +{ + return page_to_nid(page); /* XXX */ } -static inline void page_nid_reset_last(struct page *page) +static inline int page_cpupid_last(struct page *page) { + return page_to_nid(page); /* XXX */ } -#endif + +static inline int cpupid_to_nid(int cpupid) +{ + return -1; +} + +static inline int cpupid_to_pid(int cpupid) +{ + return -1; +} + +static inline int cpupid_to_cpu(int cpupid) +{ + return -1; +} + +static inline int cpu_pid_to_cpupid(int nid, int pid) +{ + return -1; +} + +static inline bool cpupid_pid_unset(int cpupid) +{ + return 1; +} + +static inline void page_cpupid_reset_last(struct page *page) +{ +} + +static inline bool cpupid_match_pid(struct task_struct *task, int cpupid) +{ + return false; +} +#endif /* CONFIG_NUMA_BALANCING */ static inline struct zone *page_zone(const struct page *page) { diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index d9851ee..a3198e5 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -174,8 +174,8 @@ struct page { void *shadow; #endif -#ifdef LAST_NID_NOT_IN_PAGE_FLAGS - int _last_nid; +#ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS + int _last_cpupid; #endif } /* @@ -420,28 +420,15 @@ struct mm_struct { */ unsigned long numa_next_scan; - /* numa_next_reset is when the PTE scanner period will be reset */ - unsigned long numa_next_reset; - /* Restart point for scanning and setting pte_numa */ unsigned long numa_scan_offset; /* numa_scan_seq prevents two threads setting pte_numa */ int numa_scan_seq; - - /* - * The first node a task was scheduled on. If a task runs on - * a different node than Make PTE Scan Go Now. - */ - int first_nid; #endif struct uprobes_state uprobes_state; }; -/* first nid will either be a valid NID or one of these values */ -#define NUMA_PTE_SCAN_INIT -1 -#define NUMA_PTE_SCAN_ACTIVE -2 - static inline void mm_init_cpumask(struct mm_struct *mm) { #ifdef CONFIG_CPUMASK_OFFSTACK diff --git a/include/linux/page-flags-layout.h b/include/linux/page-flags-layout.h index 93506a1..da52366 100644 --- a/include/linux/page-flags-layout.h +++ b/include/linux/page-flags-layout.h @@ -38,10 +38,10 @@ * The last is when there is insufficient space in page->flags and a separate * lookup is necessary. * - * No sparsemem or sparsemem vmemmap: | NODE | ZONE | ... | FLAGS | - * " plus space for last_nid: | NODE | ZONE | LAST_NID ... | FLAGS | - * classic sparse with space for node:| SECTION | NODE | ZONE | ... | FLAGS | - * " plus space for last_nid: | SECTION | NODE | ZONE | LAST_NID ... | FLAGS | + * No sparsemem or sparsemem vmemmap: | NODE | ZONE | ... | FLAGS | + * " plus space for last_cpupid: | NODE | ZONE | LAST_CPUPID ... | FLAGS | + * classic sparse with space for node:| SECTION | NODE | ZONE | ... | FLAGS | + * " plus space for last_cpupid: | SECTION | NODE | ZONE | LAST_CPUPID ... | FLAGS | * classic sparse no space for node: | SECTION | ZONE | ... | FLAGS | */ #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP) @@ -62,15 +62,21 @@ #endif #ifdef CONFIG_NUMA_BALANCING -#define LAST_NID_SHIFT NODES_SHIFT +#define LAST__PID_SHIFT 8 +#define LAST__PID_MASK ((1 << LAST__PID_SHIFT)-1) + +#define LAST__CPU_SHIFT NR_CPUS_BITS +#define LAST__CPU_MASK ((1 << LAST__CPU_SHIFT)-1) + +#define LAST_CPUPID_SHIFT (LAST__PID_SHIFT+LAST__CPU_SHIFT) #else -#define LAST_NID_SHIFT 0 +#define LAST_CPUPID_SHIFT 0 #endif -#if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT+LAST_NID_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS -#define LAST_NID_WIDTH LAST_NID_SHIFT +#if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT+LAST_CPUPID_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS +#define LAST_CPUPID_WIDTH LAST_CPUPID_SHIFT #else -#define LAST_NID_WIDTH 0 +#define LAST_CPUPID_WIDTH 0 #endif /* @@ -81,8 +87,8 @@ #define NODE_NOT_IN_PAGE_FLAGS #endif -#if defined(CONFIG_NUMA_BALANCING) && LAST_NID_WIDTH == 0 -#define LAST_NID_NOT_IN_PAGE_FLAGS +#if defined(CONFIG_NUMA_BALANCING) && LAST_CPUPID_WIDTH == 0 +#define LAST_CPUPID_NOT_IN_PAGE_FLAGS #endif #endif /* _LINUX_PAGE_FLAGS_LAYOUT */ diff --git a/include/linux/preempt.h b/include/linux/preempt.h index f5d4723..a3d9dc8 100644 --- a/include/linux/preempt.h +++ b/include/linux/preempt.h @@ -6,106 +6,95 @@ * preempt_count (used for kernel preemption, interrupt count, etc.) */ -#include <linux/thread_info.h> #include <linux/linkage.h> #include <linux/list.h> -#if defined(CONFIG_DEBUG_PREEMPT) || defined(CONFIG_PREEMPT_TRACER) - extern void add_preempt_count(int val); - extern void sub_preempt_count(int val); -#else -# define add_preempt_count(val) do { preempt_count() += (val); } while (0) -# define sub_preempt_count(val) do { preempt_count() -= (val); } while (0) -#endif - -#define inc_preempt_count() add_preempt_count(1) -#define dec_preempt_count() sub_preempt_count(1) - -#define preempt_count() (current_thread_info()->preempt_count) - -#ifdef CONFIG_PREEMPT - -asmlinkage void preempt_schedule(void); - -#define preempt_check_resched() \ -do { \ - if (unlikely(test_thread_flag(TIF_NEED_RESCHED))) \ - preempt_schedule(); \ -} while (0) - -#ifdef CONFIG_CONTEXT_TRACKING +/* + * We use the MSB mostly because its available; see <linux/preempt_mask.h> for + * the other bits -- can't include that header due to inclusion hell. + */ +#define PREEMPT_NEED_RESCHED 0x80000000 -void preempt_schedule_context(void); +#include <asm/preempt.h> -#define preempt_check_resched_context() \ -do { \ - if (unlikely(test_thread_flag(TIF_NEED_RESCHED))) \ - preempt_schedule_context(); \ -} while (0) +#if defined(CONFIG_DEBUG_PREEMPT) || defined(CONFIG_PREEMPT_TRACER) +extern void preempt_count_add(int val); +extern void preempt_count_sub(int val); +#define preempt_count_dec_and_test() ({ preempt_count_sub(1); should_resched(); }) #else +#define preempt_count_add(val) __preempt_count_add(val) +#define preempt_count_sub(val) __preempt_count_sub(val) +#define preempt_count_dec_and_test() __preempt_count_dec_and_test() +#endif -#define preempt_check_resched_context() preempt_check_resched() - -#endif /* CONFIG_CONTEXT_TRACKING */ - -#else /* !CONFIG_PREEMPT */ - -#define preempt_check_resched() do { } while (0) -#define preempt_check_resched_context() do { } while (0) - -#endif /* CONFIG_PREEMPT */ +#define __preempt_count_inc() __preempt_count_add(1) +#define __preempt_count_dec() __preempt_count_sub(1) +#define preempt_count_inc() preempt_count_add(1) +#define preempt_count_dec() preempt_count_sub(1) #ifdef CONFIG_PREEMPT_COUNT #define preempt_disable() \ do { \ - inc_preempt_count(); \ + preempt_count_inc(); \ barrier(); \ } while (0) #define sched_preempt_enable_no_resched() \ do { \ barrier(); \ - dec_preempt_count(); \ + preempt_count_dec(); \ } while (0) -#define preempt_enable_no_resched() sched_preempt_enable_no_resched() +#define preempt_enable_no_resched() sched_preempt_enable_no_resched() +#ifdef CONFIG_PREEMPT #define preempt_enable() \ do { \ - preempt_enable_no_resched(); \ barrier(); \ - preempt_check_resched(); \ + if (unlikely(preempt_count_dec_and_test())) \ + __preempt_schedule(); \ +} while (0) + +#define preempt_check_resched() \ +do { \ + if (should_resched()) \ + __preempt_schedule(); \ } while (0) -/* For debugging and tracer internals only! */ -#define add_preempt_count_notrace(val) \ - do { preempt_count() += (val); } while (0) -#define sub_preempt_count_notrace(val) \ - do { preempt_count() -= (val); } while (0) -#define inc_preempt_count_notrace() add_preempt_count_notrace(1) -#define dec_preempt_count_notrace() sub_preempt_count_notrace(1) +#else +#define preempt_enable() preempt_enable_no_resched() +#define preempt_check_resched() do { } while (0) +#endif #define preempt_disable_notrace() \ do { \ - inc_preempt_count_notrace(); \ + __preempt_count_inc(); \ barrier(); \ } while (0) #define preempt_enable_no_resched_notrace() \ do { \ barrier(); \ - dec_preempt_count_notrace(); \ + __preempt_count_dec(); \ } while (0) -/* preempt_check_resched is OK to trace */ +#ifdef CONFIG_PREEMPT + +#ifndef CONFIG_CONTEXT_TRACKING +#define __preempt_schedule_context() __preempt_schedule() +#endif + #define preempt_enable_notrace() \ do { \ - preempt_enable_no_resched_notrace(); \ barrier(); \ - preempt_check_resched_context(); \ + if (unlikely(__preempt_count_dec_and_test())) \ + __preempt_schedule_context(); \ } while (0) +#else +#define preempt_enable_notrace() preempt_enable_no_resched_notrace() +#endif #else /* !CONFIG_PREEMPT_COUNT */ @@ -115,10 +104,11 @@ do { \ * that can cause faults and scheduling migrate into our preempt-protected * region. */ -#define preempt_disable() barrier() +#define preempt_disable() barrier() #define sched_preempt_enable_no_resched() barrier() -#define preempt_enable_no_resched() barrier() -#define preempt_enable() barrier() +#define preempt_enable_no_resched() barrier() +#define preempt_enable() barrier() +#define preempt_check_resched() do { } while (0) #define preempt_disable_notrace() barrier() #define preempt_enable_no_resched_notrace() barrier() diff --git a/include/linux/sched.h b/include/linux/sched.h index e27baee..045b0d2 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -22,6 +22,7 @@ struct sched_param { #include <linux/errno.h> #include <linux/nodemask.h> #include <linux/mm_types.h> +#include <linux/preempt.h> #include <asm/page.h> #include <asm/ptrace.h> @@ -427,6 +428,14 @@ struct task_cputime { .sum_exec_runtime = 0, \ } +#define PREEMPT_ENABLED (PREEMPT_NEED_RESCHED) + +#ifdef CONFIG_PREEMPT_COUNT +#define PREEMPT_DISABLED (1 + PREEMPT_ENABLED) +#else +#define PREEMPT_DISABLED PREEMPT_ENABLED +#endif + /* * Disable preemption until the scheduler is running. * Reset by start_kernel()->sched_init()->init_idle(). @@ -434,7 +443,7 @@ struct task_cputime { * We include PREEMPT_ACTIVE to avoid cond_resched() from working * before the scheduler is active -- see should_resched(). */ -#define INIT_PREEMPT_COUNT (1 + PREEMPT_ACTIVE) +#define INIT_PREEMPT_COUNT (PREEMPT_DISABLED + PREEMPT_ACTIVE) /** * struct thread_group_cputimer - thread group interval timer counts @@ -768,6 +777,7 @@ enum cpu_idle_type { #define SD_ASYM_PACKING 0x0800 /* Place busy groups earlier in the domain */ #define SD_PREFER_SIBLING 0x1000 /* Prefer to place tasks in a sibling domain */ #define SD_OVERLAP 0x2000 /* sched_domains of this level overlap */ +#define SD_NUMA 0x4000 /* cross-node balancing */ extern int __weak arch_sd_sibiling_asym_packing(void); @@ -811,6 +821,10 @@ struct sched_domain { u64 last_update; + /* idle_balance() stats */ + u64 max_newidle_lb_cost; + unsigned long next_decay_max_lb_cost; + #ifdef CONFIG_SCHEDSTATS /* load_balance() stats */ unsigned int lb_count[CPU_MAX_IDLE_TYPES]; @@ -1029,6 +1043,8 @@ struct task_struct { struct task_struct *last_wakee; unsigned long wakee_flips; unsigned long wakee_flip_decay_ts; + + int wake_cpu; #endif int on_rq; @@ -1324,10 +1340,41 @@ struct task_struct { #endif #ifdef CONFIG_NUMA_BALANCING int numa_scan_seq; - int numa_migrate_seq; unsigned int numa_scan_period; + unsigned int numa_scan_period_max; + int numa_preferred_nid; + int numa_migrate_deferred; + unsigned long numa_migrate_retry; u64 node_stamp; /* migration stamp */ struct callback_head numa_work; + + struct list_head numa_entry; + struct numa_group *numa_group; + + /* + * Exponential decaying average of faults on a per-node basis. + * Scheduling placement decisions are made based on the these counts. + * The values remain static for the duration of a PTE scan + */ + unsigned long *numa_faults; + unsigned long total_numa_faults; + + /* + * numa_faults_buffer records faults per node during the current + * scan window. When the scan completes, the counts in numa_faults + * decay and these values are copied. + */ + unsigned long *numa_faults_buffer; + + /* + * numa_faults_locality tracks if faults recorded during the last + * scan window were remote/local. The task scan period is adapted + * based on the locality of the faults with different weights + * depending on whether they were shared or private faults + */ + unsigned long numa_faults_locality[2]; + + unsigned long numa_pages_migrated; #endif /* CONFIG_NUMA_BALANCING */ struct rcu_head rcu; @@ -1412,16 +1459,33 @@ struct task_struct { /* Future-safe accessor for struct task_struct's cpus_allowed. */ #define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed) +#define TNF_MIGRATED 0x01 +#define TNF_NO_GROUP 0x02 +#define TNF_SHARED 0x04 +#define TNF_FAULT_LOCAL 0x08 + #ifdef CONFIG_NUMA_BALANCING -extern void task_numa_fault(int node, int pages, bool migrated); +extern void task_numa_fault(int last_node, int node, int pages, int flags); +extern pid_t task_numa_group_id(struct task_struct *p); extern void set_numabalancing_state(bool enabled); +extern void task_numa_free(struct task_struct *p); + +extern unsigned int sysctl_numa_balancing_migrate_deferred; #else -static inline void task_numa_fault(int node, int pages, bool migrated) +static inline void task_numa_fault(int last_node, int node, int pages, + int flags) { } +static inline pid_t task_numa_group_id(struct task_struct *p) +{ + return 0; +} static inline void set_numabalancing_state(bool enabled) { } +static inline void task_numa_free(struct task_struct *p) +{ +} #endif static inline struct pid *task_pid(struct task_struct *task) @@ -1974,7 +2038,7 @@ extern void wake_up_new_task(struct task_struct *tsk); #else static inline void kick_process(struct task_struct *tsk) { } #endif -extern void sched_fork(struct task_struct *p); +extern void sched_fork(unsigned long clone_flags, struct task_struct *p); extern void sched_dead(struct task_struct *p); extern void proc_caches_init(void); @@ -2401,11 +2465,6 @@ static inline int signal_pending_state(long state, struct task_struct *p) return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p); } -static inline int need_resched(void) -{ - return unlikely(test_thread_flag(TIF_NEED_RESCHED)); -} - /* * cond_resched() and cond_resched_lock(): latency reduction via * explicit rescheduling in places that are safe. The return @@ -2474,36 +2533,105 @@ static inline int tsk_is_polling(struct task_struct *p) { return task_thread_info(p)->status & TS_POLLING; } -static inline void current_set_polling(void) +static inline void __current_set_polling(void) { current_thread_info()->status |= TS_POLLING; } -static inline void current_clr_polling(void) +static inline bool __must_check current_set_polling_and_test(void) +{ + __current_set_polling(); + + /* + * Polling state must be visible before we test NEED_RESCHED, + * paired by resched_task() + */ + smp_mb(); + + return unlikely(tif_need_resched()); +} + +static inline void __current_clr_polling(void) { current_thread_info()->status &= ~TS_POLLING; - smp_mb__after_clear_bit(); +} + +static inline bool __must_check current_clr_polling_and_test(void) +{ + __current_clr_polling(); + + /* + * Polling state must be visible before we test NEED_RESCHED, + * paired by resched_task() + */ + smp_mb(); + + return unlikely(tif_need_resched()); } #elif defined(TIF_POLLING_NRFLAG) static inline int tsk_is_polling(struct task_struct *p) { return test_tsk_thread_flag(p, TIF_POLLING_NRFLAG); } -static inline void current_set_polling(void) + +static inline void __current_set_polling(void) { set_thread_flag(TIF_POLLING_NRFLAG); } -static inline void current_clr_polling(void) +static inline bool __must_check current_set_polling_and_test(void) +{ + __current_set_polling(); + + /* + * Polling state must be visible before we test NEED_RESCHED, + * paired by resched_task() + * + * XXX: assumes set/clear bit are identical barrier wise. + */ + smp_mb__after_clear_bit(); + + return unlikely(tif_need_resched()); +} + +static inline void __current_clr_polling(void) { clear_thread_flag(TIF_POLLING_NRFLAG); } + +static inline bool __must_check current_clr_polling_and_test(void) +{ + __current_clr_polling(); + + /* + * Polling state must be visible before we test NEED_RESCHED, + * paired by resched_task() + */ + smp_mb__after_clear_bit(); + + return unlikely(tif_need_resched()); +} + #else static inline int tsk_is_polling(struct task_struct *p) { return 0; } -static inline void current_set_polling(void) { } -static inline void current_clr_polling(void) { } +static inline void __current_set_polling(void) { } +static inline void __current_clr_polling(void) { } + +static inline bool __must_check current_set_polling_and_test(void) +{ + return unlikely(tif_need_resched()); +} +static inline bool __must_check current_clr_polling_and_test(void) +{ + return unlikely(tif_need_resched()); +} #endif +static __always_inline bool need_resched(void) +{ + return unlikely(tif_need_resched()); +} + /* * Thread group CPU time accounting. */ @@ -2545,6 +2673,11 @@ static inline unsigned int task_cpu(const struct task_struct *p) return task_thread_info(p)->cpu; } +static inline int task_node(const struct task_struct *p) +{ + return cpu_to_node(task_cpu(p)); +} + extern void set_task_cpu(struct task_struct *p, unsigned int cpu); #else diff --git a/include/linux/sched/sysctl.h b/include/linux/sched/sysctl.h index 9552afa..41467f8 100644 --- a/include/linux/sched/sysctl.h +++ b/include/linux/sched/sysctl.h @@ -47,7 +47,6 @@ extern enum sched_tunable_scaling sysctl_sched_tunable_scaling; extern unsigned int sysctl_numa_balancing_scan_delay; extern unsigned int sysctl_numa_balancing_scan_period_min; extern unsigned int sysctl_numa_balancing_scan_period_max; -extern unsigned int sysctl_numa_balancing_scan_period_reset; extern unsigned int sysctl_numa_balancing_scan_size; extern unsigned int sysctl_numa_balancing_settle_count; diff --git a/include/linux/stop_machine.h b/include/linux/stop_machine.h index 3b5e910..d2abbdb 100644 --- a/include/linux/stop_machine.h +++ b/include/linux/stop_machine.h @@ -28,6 +28,7 @@ struct cpu_stop_work { }; int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg); +int stop_two_cpus(unsigned int cpu1, unsigned int cpu2, cpu_stop_fn_t fn, void *arg); void stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg, struct cpu_stop_work *work_buf); int stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg); diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h index e7e0473..fddbe20 100644 --- a/include/linux/thread_info.h +++ b/include/linux/thread_info.h @@ -104,8 +104,21 @@ static inline int test_ti_thread_flag(struct thread_info *ti, int flag) #define test_thread_flag(flag) \ test_ti_thread_flag(current_thread_info(), flag) -#define set_need_resched() set_thread_flag(TIF_NEED_RESCHED) -#define clear_need_resched() clear_thread_flag(TIF_NEED_RESCHED) +static inline __deprecated void set_need_resched(void) +{ + /* + * Use of this function in deprecated. + * + * As of this writing there are only a few users in the DRM tree left + * all of which are wrong and can be removed without causing too much + * grief. + * + * The DRM people are aware and are working on removing the last few + * instances. + */ +} + +#define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED) #if defined TIF_RESTORE_SIGMASK && !defined HAVE_SET_RESTORE_SIGMASK /* diff --git a/include/linux/topology.h b/include/linux/topology.h index d3cf0d6..12ae6ce 100644 --- a/include/linux/topology.h +++ b/include/linux/topology.h @@ -106,6 +106,8 @@ int arch_update_cpu_topology(void); .last_balance = jiffies, \ .balance_interval = 1, \ .smt_gain = 1178, /* 15% */ \ + .max_newidle_lb_cost = 0, \ + .next_decay_max_lb_cost = jiffies, \ } #endif #endif /* CONFIG_SCHED_SMT */ @@ -135,6 +137,8 @@ int arch_update_cpu_topology(void); , \ .last_balance = jiffies, \ .balance_interval = 1, \ + .max_newidle_lb_cost = 0, \ + .next_decay_max_lb_cost = jiffies, \ } #endif #endif /* CONFIG_SCHED_MC */ @@ -166,6 +170,8 @@ int arch_update_cpu_topology(void); , \ .last_balance = jiffies, \ .balance_interval = 1, \ + .max_newidle_lb_cost = 0, \ + .next_decay_max_lb_cost = jiffies, \ } #endif diff --git a/include/linux/tty.h b/include/linux/tty.h index 64f8646..633cac7 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -672,31 +672,17 @@ static inline void tty_wait_until_sent_from_close(struct tty_struct *tty, #define wait_event_interruptible_tty(tty, wq, condition) \ ({ \ int __ret = 0; \ - if (!(condition)) { \ - __wait_event_interruptible_tty(tty, wq, condition, __ret); \ - } \ + if (!(condition)) \ + __ret = __wait_event_interruptible_tty(tty, wq, \ + condition); \ __ret; \ }) -#define __wait_event_interruptible_tty(tty, wq, condition, ret) \ -do { \ - DEFINE_WAIT(__wait); \ - \ - for (;;) { \ - prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \ - if (condition) \ - break; \ - if (!signal_pending(current)) { \ - tty_unlock(tty); \ +#define __wait_event_interruptible_tty(tty, wq, condition) \ + ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \ + tty_unlock(tty); \ schedule(); \ - tty_lock(tty); \ - continue; \ - } \ - ret = -ERESTARTSYS; \ - break; \ - } \ - finish_wait(&wq, &__wait); \ -} while (0) + tty_lock(tty)) #ifdef CONFIG_PROC_FS extern void proc_tty_register_driver(struct tty_driver *); diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h index 5ca0951..9d8cf05 100644 --- a/include/linux/uaccess.h +++ b/include/linux/uaccess.h @@ -15,7 +15,7 @@ */ static inline void pagefault_disable(void) { - inc_preempt_count(); + preempt_count_inc(); /* * make sure to have issued the store before a pagefault * can hit. @@ -30,11 +30,7 @@ static inline void pagefault_enable(void) * the pagefault handler again. */ barrier(); - dec_preempt_count(); - /* - * make sure we do.. - */ - barrier(); + preempt_count_dec(); preempt_check_resched(); } diff --git a/include/linux/wait.h b/include/linux/wait.h index a67fc16..61939ba 100644 --- a/include/linux/wait.h +++ b/include/linux/wait.h @@ -1,7 +1,8 @@ #ifndef _LINUX_WAIT_H #define _LINUX_WAIT_H - - +/* + * Linux wait queue related types and methods + */ #include <linux/list.h> #include <linux/stddef.h> #include <linux/spinlock.h> @@ -13,27 +14,27 @@ typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int flags, v int default_wake_function(wait_queue_t *wait, unsigned mode, int flags, void *key); struct __wait_queue { - unsigned int flags; + unsigned int flags; #define WQ_FLAG_EXCLUSIVE 0x01 - void *private; - wait_queue_func_t func; - struct list_head task_list; + void *private; + wait_queue_func_t func; + struct list_head task_list; }; struct wait_bit_key { - void *flags; - int bit_nr; -#define WAIT_ATOMIC_T_BIT_NR -1 + void *flags; + int bit_nr; +#define WAIT_ATOMIC_T_BIT_NR -1 }; struct wait_bit_queue { - struct wait_bit_key key; - wait_queue_t wait; + struct wait_bit_key key; + wait_queue_t wait; }; struct __wait_queue_head { - spinlock_t lock; - struct list_head task_list; + spinlock_t lock; + struct list_head task_list; }; typedef struct __wait_queue_head wait_queue_head_t; @@ -84,17 +85,17 @@ extern void __init_waitqueue_head(wait_queue_head_t *q, const char *name, struct static inline void init_waitqueue_entry(wait_queue_t *q, struct task_struct *p) { - q->flags = 0; - q->private = p; - q->func = default_wake_function; + q->flags = 0; + q->private = p; + q->func = default_wake_function; } -static inline void init_waitqueue_func_entry(wait_queue_t *q, - wait_queue_func_t func) +static inline void +init_waitqueue_func_entry(wait_queue_t *q, wait_queue_func_t func) { - q->flags = 0; - q->private = NULL; - q->func = func; + q->flags = 0; + q->private = NULL; + q->func = func; } static inline int waitqueue_active(wait_queue_head_t *q) @@ -114,8 +115,8 @@ static inline void __add_wait_queue(wait_queue_head_t *head, wait_queue_t *new) /* * Used for wake-one threads: */ -static inline void __add_wait_queue_exclusive(wait_queue_head_t *q, - wait_queue_t *wait) +static inline void +__add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t *wait) { wait->flags |= WQ_FLAG_EXCLUSIVE; __add_wait_queue(q, wait); @@ -127,23 +128,22 @@ static inline void __add_wait_queue_tail(wait_queue_head_t *head, list_add_tail(&new->task_list, &head->task_list); } -static inline void __add_wait_queue_tail_exclusive(wait_queue_head_t *q, - wait_queue_t *wait) +static inline void +__add_wait_queue_tail_exclusive(wait_queue_head_t *q, wait_queue_t *wait) { wait->flags |= WQ_FLAG_EXCLUSIVE; __add_wait_queue_tail(q, wait); } -static inline void __remove_wait_queue(wait_queue_head_t *head, - wait_queue_t *old) +static inline void +__remove_wait_queue(wait_queue_head_t *head, wait_queue_t *old) { list_del(&old->task_list); } void __wake_up(wait_queue_head_t *q, unsigned int mode, int nr, void *key); void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key); -void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, int nr, - void *key); +void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, int nr, void *key); void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr); void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr); void __wake_up_bit(wait_queue_head_t *, void *, int); @@ -170,27 +170,64 @@ wait_queue_head_t *bit_waitqueue(void *, int); /* * Wakeup macros to be used to report events to the targets. */ -#define wake_up_poll(x, m) \ +#define wake_up_poll(x, m) \ __wake_up(x, TASK_NORMAL, 1, (void *) (m)) -#define wake_up_locked_poll(x, m) \ +#define wake_up_locked_poll(x, m) \ __wake_up_locked_key((x), TASK_NORMAL, (void *) (m)) -#define wake_up_interruptible_poll(x, m) \ +#define wake_up_interruptible_poll(x, m) \ __wake_up(x, TASK_INTERRUPTIBLE, 1, (void *) (m)) #define wake_up_interruptible_sync_poll(x, m) \ __wake_up_sync_key((x), TASK_INTERRUPTIBLE, 1, (void *) (m)) -#define __wait_event(wq, condition) \ -do { \ - DEFINE_WAIT(__wait); \ +#define ___wait_cond_timeout(condition) \ +({ \ + bool __cond = (condition); \ + if (__cond && !__ret) \ + __ret = 1; \ + __cond || !__ret; \ +}) + +#define ___wait_is_interruptible(state) \ + (!__builtin_constant_p(state) || \ + state == TASK_INTERRUPTIBLE || state == TASK_KILLABLE) \ + +#define ___wait_event(wq, condition, state, exclusive, ret, cmd) \ +({ \ + __label__ __out; \ + wait_queue_t __wait; \ + long __ret = ret; \ + \ + INIT_LIST_HEAD(&__wait.task_list); \ + if (exclusive) \ + __wait.flags = WQ_FLAG_EXCLUSIVE; \ + else \ + __wait.flags = 0; \ \ for (;;) { \ - prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \ + long __int = prepare_to_wait_event(&wq, &__wait, state);\ + \ if (condition) \ break; \ - schedule(); \ + \ + if (___wait_is_interruptible(state) && __int) { \ + __ret = __int; \ + if (exclusive) { \ + abort_exclusive_wait(&wq, &__wait, \ + state, NULL); \ + goto __out; \ + } \ + break; \ + } \ + \ + cmd; \ } \ finish_wait(&wq, &__wait); \ -} while (0) +__out: __ret; \ +}) + +#define __wait_event(wq, condition) \ + (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ + schedule()) /** * wait_event - sleep until a condition gets true @@ -204,29 +241,17 @@ do { \ * wake_up() has to be called after changing any variable that could * change the result of the wait condition. */ -#define wait_event(wq, condition) \ +#define wait_event(wq, condition) \ do { \ - if (condition) \ + if (condition) \ break; \ __wait_event(wq, condition); \ } while (0) -#define __wait_event_timeout(wq, condition, ret) \ -do { \ - DEFINE_WAIT(__wait); \ - \ - for (;;) { \ - prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \ - if (condition) \ - break; \ - ret = schedule_timeout(ret); \ - if (!ret) \ - break; \ - } \ - if (!ret && (condition)) \ - ret = 1; \ - finish_wait(&wq, &__wait); \ -} while (0) +#define __wait_event_timeout(wq, condition, timeout) \ + ___wait_event(wq, ___wait_cond_timeout(condition), \ + TASK_UNINTERRUPTIBLE, 0, timeout, \ + __ret = schedule_timeout(__ret)) /** * wait_event_timeout - sleep until a condition gets true or a timeout elapses @@ -248,28 +273,14 @@ do { \ #define wait_event_timeout(wq, condition, timeout) \ ({ \ long __ret = timeout; \ - if (!(condition)) \ - __wait_event_timeout(wq, condition, __ret); \ + if (!___wait_cond_timeout(condition)) \ + __ret = __wait_event_timeout(wq, condition, timeout); \ __ret; \ }) -#define __wait_event_interruptible(wq, condition, ret) \ -do { \ - DEFINE_WAIT(__wait); \ - \ - for (;;) { \ - prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \ - if (condition) \ - break; \ - if (!signal_pending(current)) { \ - schedule(); \ - continue; \ - } \ - ret = -ERESTARTSYS; \ - break; \ - } \ - finish_wait(&wq, &__wait); \ -} while (0) +#define __wait_event_interruptible(wq, condition) \ + ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \ + schedule()) /** * wait_event_interruptible - sleep until a condition gets true @@ -290,31 +301,14 @@ do { \ ({ \ int __ret = 0; \ if (!(condition)) \ - __wait_event_interruptible(wq, condition, __ret); \ + __ret = __wait_event_interruptible(wq, condition); \ __ret; \ }) -#define __wait_event_interruptible_timeout(wq, condition, ret) \ -do { \ - DEFINE_WAIT(__wait); \ - \ - for (;;) { \ - prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \ - if (condition) \ - break; \ - if (!signal_pending(current)) { \ - ret = schedule_timeout(ret); \ - if (!ret) \ - break; \ - continue; \ - } \ - ret = -ERESTARTSYS; \ - break; \ - } \ - if (!ret && (condition)) \ - ret = 1; \ - finish_wait(&wq, &__wait); \ -} while (0) +#define __wait_event_interruptible_timeout(wq, condition, timeout) \ + ___wait_event(wq, ___wait_cond_timeout(condition), \ + TASK_INTERRUPTIBLE, 0, timeout, \ + __ret = schedule_timeout(__ret)) /** * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses @@ -337,15 +331,15 @@ do { \ #define wait_event_interruptible_timeout(wq, condition, timeout) \ ({ \ long __ret = timeout; \ - if (!(condition)) \ - __wait_event_interruptible_timeout(wq, condition, __ret); \ + if (!___wait_cond_timeout(condition)) \ + __ret = __wait_event_interruptible_timeout(wq, \ + condition, timeout); \ __ret; \ }) #define __wait_event_hrtimeout(wq, condition, timeout, state) \ ({ \ int __ret = 0; \ - DEFINE_WAIT(__wait); \ struct hrtimer_sleeper __t; \ \ hrtimer_init_on_stack(&__t.timer, CLOCK_MONOTONIC, \ @@ -356,25 +350,15 @@ do { \ current->timer_slack_ns, \ HRTIMER_MODE_REL); \ \ - for (;;) { \ - prepare_to_wait(&wq, &__wait, state); \ - if (condition) \ - break; \ - if (state == TASK_INTERRUPTIBLE && \ - signal_pending(current)) { \ - __ret = -ERESTARTSYS; \ - break; \ - } \ + __ret = ___wait_event(wq, condition, state, 0, 0, \ if (!__t.task) { \ __ret = -ETIME; \ break; \ } \ - schedule(); \ - } \ + schedule()); \ \ hrtimer_cancel(&__t.timer); \ destroy_hrtimer_on_stack(&__t.timer); \ - finish_wait(&wq, &__wait); \ __ret; \ }) @@ -428,33 +412,15 @@ do { \ __ret; \ }) -#define __wait_event_interruptible_exclusive(wq, condition, ret) \ -do { \ - DEFINE_WAIT(__wait); \ - \ - for (;;) { \ - prepare_to_wait_exclusive(&wq, &__wait, \ - TASK_INTERRUPTIBLE); \ - if (condition) { \ - finish_wait(&wq, &__wait); \ - break; \ - } \ - if (!signal_pending(current)) { \ - schedule(); \ - continue; \ - } \ - ret = -ERESTARTSYS; \ - abort_exclusive_wait(&wq, &__wait, \ - TASK_INTERRUPTIBLE, NULL); \ - break; \ - } \ -} while (0) +#define __wait_event_interruptible_exclusive(wq, condition) \ + ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0, \ + schedule()) #define wait_event_interruptible_exclusive(wq, condition) \ ({ \ int __ret = 0; \ if (!(condition)) \ - __wait_event_interruptible_exclusive(wq, condition, __ret);\ + __ret = __wait_event_interruptible_exclusive(wq, condition);\ __ret; \ }) @@ -606,24 +572,8 @@ do { \ ? 0 : __wait_event_interruptible_locked(wq, condition, 1, 1)) - -#define __wait_event_killable(wq, condition, ret) \ -do { \ - DEFINE_WAIT(__wait); \ - \ - for (;;) { \ - prepare_to_wait(&wq, &__wait, TASK_KILLABLE); \ - if (condition) \ - break; \ - if (!fatal_signal_pending(current)) { \ - schedule(); \ - continue; \ - } \ - ret = -ERESTARTSYS; \ - break; \ - } \ - finish_wait(&wq, &__wait); \ -} while (0) +#define __wait_event_killable(wq, condition) \ + ___wait_event(wq, condition, TASK_KILLABLE, 0, 0, schedule()) /** * wait_event_killable - sleep until a condition gets true @@ -644,26 +594,17 @@ do { \ ({ \ int __ret = 0; \ if (!(condition)) \ - __wait_event_killable(wq, condition, __ret); \ + __ret = __wait_event_killable(wq, condition); \ __ret; \ }) #define __wait_event_lock_irq(wq, condition, lock, cmd) \ -do { \ - DEFINE_WAIT(__wait); \ - \ - for (;;) { \ - prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \ - if (condition) \ - break; \ - spin_unlock_irq(&lock); \ - cmd; \ - schedule(); \ - spin_lock_irq(&lock); \ - } \ - finish_wait(&wq, &__wait); \ -} while (0) + (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ + spin_unlock_irq(&lock); \ + cmd; \ + schedule(); \ + spin_lock_irq(&lock)) /** * wait_event_lock_irq_cmd - sleep until a condition gets true. The @@ -723,26 +664,12 @@ do { \ } while (0) -#define __wait_event_interruptible_lock_irq(wq, condition, \ - lock, ret, cmd) \ -do { \ - DEFINE_WAIT(__wait); \ - \ - for (;;) { \ - prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \ - if (condition) \ - break; \ - if (signal_pending(current)) { \ - ret = -ERESTARTSYS; \ - break; \ - } \ - spin_unlock_irq(&lock); \ - cmd; \ - schedule(); \ - spin_lock_irq(&lock); \ - } \ - finish_wait(&wq, &__wait); \ -} while (0) +#define __wait_event_interruptible_lock_irq(wq, condition, lock, cmd) \ + ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \ + spin_unlock_irq(&lock); \ + cmd; \ + schedule(); \ + spin_lock_irq(&lock)) /** * wait_event_interruptible_lock_irq_cmd - sleep until a condition gets true. @@ -772,10 +699,9 @@ do { \ #define wait_event_interruptible_lock_irq_cmd(wq, condition, lock, cmd) \ ({ \ int __ret = 0; \ - \ if (!(condition)) \ - __wait_event_interruptible_lock_irq(wq, condition, \ - lock, __ret, cmd); \ + __ret = __wait_event_interruptible_lock_irq(wq, \ + condition, lock, cmd); \ __ret; \ }) @@ -804,39 +730,24 @@ do { \ #define wait_event_interruptible_lock_irq(wq, condition, lock) \ ({ \ int __ret = 0; \ - \ if (!(condition)) \ - __wait_event_interruptible_lock_irq(wq, condition, \ - lock, __ret, ); \ + __ret = __wait_event_interruptible_lock_irq(wq, \ + condition, lock,); \ __ret; \ }) #define __wait_event_interruptible_lock_irq_timeout(wq, condition, \ - lock, ret) \ -do { \ - DEFINE_WAIT(__wait); \ - \ - for (;;) { \ - prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \ - if (condition) \ - break; \ - if (signal_pending(current)) { \ - ret = -ERESTARTSYS; \ - break; \ - } \ - spin_unlock_irq(&lock); \ - ret = schedule_timeout(ret); \ - spin_lock_irq(&lock); \ - if (!ret) \ - break; \ - } \ - finish_wait(&wq, &__wait); \ -} while (0) + lock, timeout) \ + ___wait_event(wq, ___wait_cond_timeout(condition), \ + TASK_INTERRUPTIBLE, 0, timeout, \ + spin_unlock_irq(&lock); \ + __ret = schedule_timeout(__ret); \ + spin_lock_irq(&lock)); /** - * wait_event_interruptible_lock_irq_timeout - sleep until a condition gets true or a timeout elapses. - * The condition is checked under the lock. This is expected - * to be called with the lock taken. + * wait_event_interruptible_lock_irq_timeout - sleep until a condition gets + * true or a timeout elapses. The condition is checked under + * the lock. This is expected to be called with the lock taken. * @wq: the waitqueue to wait on * @condition: a C expression for the event to wait for * @lock: a locked spinlock_t, which will be released before schedule() @@ -860,11 +771,10 @@ do { \ #define wait_event_interruptible_lock_irq_timeout(wq, condition, lock, \ timeout) \ ({ \ - int __ret = timeout; \ - \ - if (!(condition)) \ - __wait_event_interruptible_lock_irq_timeout( \ - wq, condition, lock, __ret); \ + long __ret = timeout; \ + if (!___wait_cond_timeout(condition)) \ + __ret = __wait_event_interruptible_lock_irq_timeout( \ + wq, condition, lock, timeout); \ __ret; \ }) @@ -875,20 +785,18 @@ do { \ * We plan to remove these interfaces. */ extern void sleep_on(wait_queue_head_t *q); -extern long sleep_on_timeout(wait_queue_head_t *q, - signed long timeout); +extern long sleep_on_timeout(wait_queue_head_t *q, signed long timeout); extern void interruptible_sleep_on(wait_queue_head_t *q); -extern long interruptible_sleep_on_timeout(wait_queue_head_t *q, - signed long timeout); +extern long interruptible_sleep_on_timeout(wait_queue_head_t *q, signed long timeout); /* * Waitqueues which are removed from the waitqueue_head at wakeup time */ void prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state); void prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state); +long prepare_to_wait_event(wait_queue_head_t *q, wait_queue_t *wait, int state); void finish_wait(wait_queue_head_t *q, wait_queue_t *wait); -void abort_exclusive_wait(wait_queue_head_t *q, wait_queue_t *wait, - unsigned int mode, void *key); +void abort_exclusive_wait(wait_queue_head_t *q, wait_queue_t *wait, unsigned int mode, void *key); int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key); int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key); @@ -934,8 +842,8 @@ int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key); * One uses wait_on_bit() where one is waiting for the bit to clear, * but has no intention of setting it. */ -static inline int wait_on_bit(void *word, int bit, - int (*action)(void *), unsigned mode) +static inline int +wait_on_bit(void *word, int bit, int (*action)(void *), unsigned mode) { if (!test_bit(bit, word)) return 0; @@ -958,8 +866,8 @@ static inline int wait_on_bit(void *word, int bit, * One uses wait_on_bit_lock() where one is waiting for the bit to * clear with the intention of setting it, and when done, clearing it. */ -static inline int wait_on_bit_lock(void *word, int bit, - int (*action)(void *), unsigned mode) +static inline int +wait_on_bit_lock(void *word, int bit, int (*action)(void *), unsigned mode) { if (!test_and_set_bit(bit, word)) return 0; @@ -983,5 +891,5 @@ int wait_on_atomic_t(atomic_t *val, int (*action)(atomic_t *), unsigned mode) return 0; return out_of_line_wait_on_atomic_t(val, action, mode); } - -#endif + +#endif /* _LINUX_WAIT_H */ diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h index 2a652d1..04c3084 100644 --- a/include/trace/events/sched.h +++ b/include/trace/events/sched.h @@ -100,7 +100,7 @@ static inline long __trace_sched_switch_state(struct task_struct *p) /* * For all intents and purposes a preempted task is a running task. */ - if (task_thread_info(p)->preempt_count & PREEMPT_ACTIVE) + if (task_preempt_count(p) & PREEMPT_ACTIVE) state = TASK_RUNNING | TASK_STATE_MAX; #endif diff --git a/init/main.c b/init/main.c index 63d3e8f..379090f 100644 --- a/init/main.c +++ b/init/main.c @@ -693,7 +693,7 @@ int __init_or_module do_one_initcall(initcall_t fn) if (preempt_count() != count) { sprintf(msgbuf, "preemption imbalance "); - preempt_count() = count; + preempt_count_set(count); } if (irqs_disabled()) { strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf)); diff --git a/kernel/Makefile b/kernel/Makefile index f99d908..a4d1aa8 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -7,7 +7,7 @@ obj-y = fork.o exec_domain.o panic.o \ sysctl.o sysctl_binary.o capability.o ptrace.o timer.o user.o \ signal.o sys.o kmod.o workqueue.o pid.o task_work.o \ extable.o params.o posix-timers.o \ - kthread.o wait.o sys_ni.o posix-cpu-timers.o mutex.o \ + kthread.o sys_ni.o posix-cpu-timers.o mutex.o \ hrtimer.o rwsem.o nsproxy.o semaphore.o \ notifier.o ksysfs.o cred.o reboot.o \ async.o range.o groups.o lglock.o smpboot.o diff --git a/kernel/bounds.c b/kernel/bounds.c index 0c9b862..e8ca97b 100644 --- a/kernel/bounds.c +++ b/kernel/bounds.c @@ -10,6 +10,7 @@ #include <linux/mmzone.h> #include <linux/kbuild.h> #include <linux/page_cgroup.h> +#include <linux/log2.h> void foo(void) { @@ -17,5 +18,8 @@ void foo(void) DEFINE(NR_PAGEFLAGS, __NR_PAGEFLAGS); DEFINE(MAX_NR_ZONES, __MAX_NR_ZONES); DEFINE(NR_PCG_FLAGS, __NR_PCG_FLAGS); +#ifdef CONFIG_SMP + DEFINE(NR_CPUS_BITS, ilog2(CONFIG_NR_CPUS)); +#endif /* End of constants */ } diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c index 859c8df..e5f3917 100644 --- a/kernel/context_tracking.c +++ b/kernel/context_tracking.c @@ -120,7 +120,7 @@ void context_tracking_user_enter(void) * instead of preempt_schedule() to exit user context if needed before * calling the scheduler. */ -void __sched notrace preempt_schedule_context(void) +asmlinkage void __sched notrace preempt_schedule_context(void) { enum ctx_state prev_ctx; diff --git a/kernel/cpu.c b/kernel/cpu.c index d7f07a2..63aa50d 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -308,6 +308,23 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) } smpboot_park_threads(cpu); + /* + * By now we've cleared cpu_active_mask, wait for all preempt-disabled + * and RCU users of this state to go away such that all new such users + * will observe it. + * + * For CONFIG_PREEMPT we have preemptible RCU and its sync_rcu() might + * not imply sync_sched(), so explicitly call both. + */ +#ifdef CONFIG_PREEMPT + synchronize_sched(); +#endif + synchronize_rcu(); + + /* + * So now all preempt/rcu users must observe !cpu_active(). + */ + err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu)); if (err) { /* CPU didn't die: tell everyone. Can't complain. */ diff --git a/kernel/cpu/idle.c b/kernel/cpu/idle.c index e695c0a..988573a 100644 --- a/kernel/cpu/idle.c +++ b/kernel/cpu/idle.c @@ -44,7 +44,7 @@ static inline int cpu_idle_poll(void) rcu_idle_enter(); trace_cpu_idle_rcuidle(0, smp_processor_id()); local_irq_enable(); - while (!need_resched()) + while (!tif_need_resched()) cpu_relax(); trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id()); rcu_idle_exit(); @@ -92,8 +92,7 @@ static void cpu_idle_loop(void) if (cpu_idle_force_poll || tick_check_broadcast_expired()) { cpu_idle_poll(); } else { - current_clr_polling(); - if (!need_resched()) { + if (!current_clr_polling_and_test()) { stop_critical_timings(); rcu_idle_enter(); arch_cpu_idle(); @@ -103,9 +102,16 @@ static void cpu_idle_loop(void) } else { local_irq_enable(); } - current_set_polling(); + __current_set_polling(); } arch_cpu_idle_exit(); + /* + * We need to test and propagate the TIF_NEED_RESCHED + * bit here because we might not have send the + * reschedule IPI to idle tasks. + */ + if (tif_need_resched()) + set_preempt_need_resched(); } tick_nohz_idle_exit(); schedule_preempt_disabled(); @@ -129,7 +135,7 @@ void cpu_startup_entry(enum cpuhp_state state) */ boot_init_stack_canary(); #endif - current_set_polling(); + __current_set_polling(); arch_cpu_idle_prepare(); cpu_idle_loop(); } diff --git a/kernel/fork.c b/kernel/fork.c index 086fe73..c93be06 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -817,9 +817,6 @@ struct mm_struct *dup_mm(struct task_struct *tsk) #ifdef CONFIG_TRANSPARENT_HUGEPAGE mm->pmd_huge_pte = NULL; #endif -#ifdef CONFIG_NUMA_BALANCING - mm->first_nid = NUMA_PTE_SCAN_INIT; -#endif if (!mm_init(mm, tsk)) goto fail_nomem; @@ -1313,7 +1310,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, #endif /* Perform scheduler related setup. Assign this task to a CPU. */ - sched_fork(p); + sched_fork(clone_flags, p); retval = perf_event_init_task(p); if (retval) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 8a2c81e8..4c06ddf 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -916,6 +916,12 @@ static void print_other_cpu_stall(struct rcu_state *rsp) force_quiescent_state(rsp); /* Kick them all. */ } +/* + * This function really isn't for public consumption, but RCU is special in + * that context switches can allow the state machine to make progress. + */ +extern void resched_cpu(int cpu); + static void print_cpu_stall(struct rcu_state *rsp) { int cpu; @@ -945,7 +951,14 @@ static void print_cpu_stall(struct rcu_state *rsp) 3 * rcu_jiffies_till_stall_check() + 3; raw_spin_unlock_irqrestore(&rnp->lock, flags); - set_need_resched(); /* kick ourselves to get things going. */ + /* + * Attempt to revive the RCU machinery by forcing a context switch. + * + * A context switch would normally allow the RCU state machine to make + * progress and it could be we're stuck in kernel space without context + * switches for an entirely unreasonable amount of time. + */ + resched_cpu(smp_processor_id()); } static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp) diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile index 54adcf3..7b62140 100644 --- a/kernel/sched/Makefile +++ b/kernel/sched/Makefile @@ -12,6 +12,7 @@ CFLAGS_core.o := $(PROFILING) -fno-omit-frame-pointer endif obj-y += core.o proc.o clock.o cputime.o idle_task.o fair.o rt.o stop_task.o +obj-y += wait.o completion.o obj-$(CONFIG_SMP) += cpupri.o obj-$(CONFIG_SCHED_AUTOGROUP) += auto_group.o obj-$(CONFIG_SCHEDSTATS) += stats.o diff --git a/kernel/sched/completion.c b/kernel/sched/completion.c new file mode 100644 index 0000000..a63f4dc --- /dev/null +++ b/kernel/sched/completion.c @@ -0,0 +1,299 @@ +/* + * Generic wait-for-completion handler; + * + * It differs from semaphores in that their default case is the opposite, + * wait_for_completion default blocks whereas semaphore default non-block. The + * interface also makes it easy to 'complete' multiple waiting threads, + * something which isn't entirely natural for semaphores. + * + * But more importantly, the primitive documents the usage. Semaphores would + * typically be used for exclusion which gives rise to priority inversion. + * Waiting for completion is a typically sync point, but not an exclusion point. + */ + +#include <linux/sched.h> +#include <linux/completion.h> + +/** + * complete: - signals a single thread waiting on this completion + * @x: holds the state of this particular completion + * + * This will wake up a single thread waiting on this completion. Threads will be + * awakened in the same order in which they were queued. + * + * See also complete_all(), wait_for_completion() and related routines. + * + * It may be assumed that this function implies a write memory barrier before + * changing the task state if and only if any tasks are woken up. + */ +void complete(struct completion *x) +{ + unsigned long flags; + + spin_lock_irqsave(&x->wait.lock, flags); + x->done++; + __wake_up_locked(&x->wait, TASK_NORMAL, 1); + spin_unlock_irqrestore(&x->wait.lock, flags); +} +EXPORT_SYMBOL(complete); + +/** + * complete_all: - signals all threads waiting on this completion + * @x: holds the state of this particular completion + * + * This will wake up all threads waiting on this particular completion event. + * + * It may be assumed that this function implies a write memory barrier before + * changing the task state if and only if any tasks are woken up. + */ +void complete_all(struct completion *x) +{ + unsigned long flags; + + spin_lock_irqsave(&x->wait.lock, flags); + x->done += UINT_MAX/2; + __wake_up_locked(&x->wait, TASK_NORMAL, 0); + spin_unlock_irqrestore(&x->wait.lock, flags); +} +EXPORT_SYMBOL(complete_all); + +static inline long __sched +do_wait_for_common(struct completion *x, + long (*action)(long), long timeout, int state) +{ + if (!x->done) { + DECLARE_WAITQUEUE(wait, current); + + __add_wait_queue_tail_exclusive(&x->wait, &wait); + do { + if (signal_pending_state(state, current)) { + timeout = -ERESTARTSYS; + break; + } + __set_current_state(state); + spin_unlock_irq(&x->wait.lock); + timeout = action(timeout); + spin_lock_irq(&x->wait.lock); + } while (!x->done && timeout); + __remove_wait_queue(&x->wait, &wait); + if (!x->done) + return timeout; + } + x->done--; + return timeout ?: 1; +} + +static inline long __sched +__wait_for_common(struct completion *x, + long (*action)(long), long timeout, int state) +{ + might_sleep(); + + spin_lock_irq(&x->wait.lock); + timeout = do_wait_for_common(x, action, timeout, state); + spin_unlock_irq(&x->wait.lock); + return timeout; +} + +static long __sched +wait_for_common(struct completion *x, long timeout, int state) +{ + return __wait_for_common(x, schedule_timeout, timeout, state); +} + +static long __sched +wait_for_common_io(struct completion *x, long timeout, int state) +{ + return __wait_for_common(x, io_schedule_timeout, timeout, state); +} + +/** + * wait_for_completion: - waits for completion of a task + * @x: holds the state of this particular completion + * + * This waits to be signaled for completion of a specific task. It is NOT + * interruptible and there is no timeout. + * + * See also similar routines (i.e. wait_for_completion_timeout()) with timeout + * and interrupt capability. Also see complete(). + */ +void __sched wait_for_completion(struct completion *x) +{ + wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE); +} +EXPORT_SYMBOL(wait_for_completion); + +/** + * wait_for_completion_timeout: - waits for completion of a task (w/timeout) + * @x: holds the state of this particular completion + * @timeout: timeout value in jiffies + * + * This waits for either a completion of a specific task to be signaled or for a + * specified timeout to expire. The timeout is in jiffies. It is not + * interruptible. + * + * Return: 0 if timed out, and positive (at least 1, or number of jiffies left + * till timeout) if completed. + */ +unsigned long __sched +wait_for_completion_timeout(struct completion *x, unsigned long timeout) +{ + return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE); +} +EXPORT_SYMBOL(wait_for_completion_timeout); + +/** + * wait_for_completion_io: - waits for completion of a task + * @x: holds the state of this particular completion + * + * This waits to be signaled for completion of a specific task. It is NOT + * interruptible and there is no timeout. The caller is accounted as waiting + * for IO. + */ +void __sched wait_for_completion_io(struct completion *x) +{ + wait_for_common_io(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE); +} +EXPORT_SYMBOL(wait_for_completion_io); + +/** + * wait_for_completion_io_timeout: - waits for completion of a task (w/timeout) + * @x: holds the state of this particular completion + * @timeout: timeout value in jiffies + * + * This waits for either a completion of a specific task to be signaled or for a + * specified timeout to expire. The timeout is in jiffies. It is not + * interruptible. The caller is accounted as waiting for IO. + * + * Return: 0 if timed out, and positive (at least 1, or number of jiffies left + * till timeout) if completed. + */ +unsigned long __sched +wait_for_completion_io_timeout(struct completion *x, unsigned long timeout) +{ + return wait_for_common_io(x, timeout, TASK_UNINTERRUPTIBLE); +} +EXPORT_SYMBOL(wait_for_completion_io_timeout); + +/** + * wait_for_completion_interruptible: - waits for completion of a task (w/intr) + * @x: holds the state of this particular completion + * + * This waits for completion of a specific task to be signaled. It is + * interruptible. + * + * Return: -ERESTARTSYS if interrupted, 0 if completed. + */ +int __sched wait_for_completion_interruptible(struct completion *x) +{ + long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE); + if (t == -ERESTARTSYS) + return t; + return 0; +} +EXPORT_SYMBOL(wait_for_completion_interruptible); + +/** + * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr)) + * @x: holds the state of this particular completion + * @timeout: timeout value in jiffies + * + * This waits for either a completion of a specific task to be signaled or for a + * specified timeout to expire. It is interruptible. The timeout is in jiffies. + * + * Return: -ERESTARTSYS if interrupted, 0 if timed out, positive (at least 1, + * or number of jiffies left till timeout) if completed. + */ +long __sched +wait_for_completion_interruptible_timeout(struct completion *x, + unsigned long timeout) +{ + return wait_for_common(x, timeout, TASK_INTERRUPTIBLE); +} +EXPORT_SYMBOL(wait_for_completion_interruptible_timeout); + +/** + * wait_for_completion_killable: - waits for completion of a task (killable) + * @x: holds the state of this particular completion + * + * This waits to be signaled for completion of a specific task. It can be + * interrupted by a kill signal. + * + * Return: -ERESTARTSYS if interrupted, 0 if completed. + */ +int __sched wait_for_completion_killable(struct completion *x) +{ + long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE); + if (t == -ERESTARTSYS) + return t; + return 0; +} +EXPORT_SYMBOL(wait_for_completion_killable); + +/** + * wait_for_completion_killable_timeout: - waits for completion of a task (w/(to,killable)) + * @x: holds the state of this particular completion + * @timeout: timeout value in jiffies + * + * This waits for either a completion of a specific task to be + * signaled or for a specified timeout to expire. It can be + * interrupted by a kill signal. The timeout is in jiffies. + * + * Return: -ERESTARTSYS if interrupted, 0 if timed out, positive (at least 1, + * or number of jiffies left till timeout) if completed. + */ +long __sched +wait_for_completion_killable_timeout(struct completion *x, + unsigned long timeout) +{ + return wait_for_common(x, timeout, TASK_KILLABLE); +} +EXPORT_SYMBOL(wait_for_completion_killable_timeout); + +/** + * try_wait_for_completion - try to decrement a completion without blocking + * @x: completion structure + * + * Return: 0 if a decrement cannot be done without blocking + * 1 if a decrement succeeded. + * + * If a completion is being used as a counting completion, + * attempt to decrement the counter without blocking. This + * enables us to avoid waiting if the resource the completion + * is protecting is not available. + */ +bool try_wait_for_completion(struct completion *x) +{ + unsigned long flags; + int ret = 1; + + spin_lock_irqsave(&x->wait.lock, flags); + if (!x->done) + ret = 0; + else + x->done--; + spin_unlock_irqrestore(&x->wait.lock, flags); + return ret; +} +EXPORT_SYMBOL(try_wait_for_completion); + +/** + * completion_done - Test to see if a completion has any waiters + * @x: completion structure + * + * Return: 0 if there are waiters (wait_for_completion() in progress) + * 1 if there are no waiters. + * + */ +bool completion_done(struct completion *x) +{ + unsigned long flags; + int ret = 1; + + spin_lock_irqsave(&x->wait.lock, flags); + if (!x->done) + ret = 0; + spin_unlock_irqrestore(&x->wait.lock, flags); + return ret; +} +EXPORT_SYMBOL(completion_done); diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 5ac63c9..aa066f3 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -513,12 +513,11 @@ static inline void init_hrtick(void) * might also involve a cross-CPU call to trigger the scheduler on * the target CPU. */ -#ifdef CONFIG_SMP void resched_task(struct task_struct *p) { int cpu; - assert_raw_spin_locked(&task_rq(p)->lock); + lockdep_assert_held(&task_rq(p)->lock); if (test_tsk_need_resched(p)) return; @@ -526,8 +525,10 @@ void resched_task(struct task_struct *p) set_tsk_need_resched(p); cpu = task_cpu(p); - if (cpu == smp_processor_id()) + if (cpu == smp_processor_id()) { + set_preempt_need_resched(); return; + } /* NEED_RESCHED must be visible before we test polling */ smp_mb(); @@ -546,6 +547,7 @@ void resched_cpu(int cpu) raw_spin_unlock_irqrestore(&rq->lock, flags); } +#ifdef CONFIG_SMP #ifdef CONFIG_NO_HZ_COMMON /* * In the semi idle case, use the nearest busy cpu for migrating timers @@ -693,12 +695,6 @@ void sched_avg_update(struct rq *rq) } } -#else /* !CONFIG_SMP */ -void resched_task(struct task_struct *p) -{ - assert_raw_spin_locked(&task_rq(p)->lock); - set_tsk_need_resched(p); -} #endif /* CONFIG_SMP */ #if defined(CONFIG_RT_GROUP_SCHED) || (defined(CONFIG_FAIR_GROUP_SCHED) && \ @@ -767,14 +763,14 @@ static void set_load_weight(struct task_struct *p) static void enqueue_task(struct rq *rq, struct task_struct *p, int flags) { update_rq_clock(rq); - sched_info_queued(p); + sched_info_queued(rq, p); p->sched_class->enqueue_task(rq, p, flags); } static void dequeue_task(struct rq *rq, struct task_struct *p, int flags) { update_rq_clock(rq); - sched_info_dequeued(p); + sched_info_dequeued(rq, p); p->sched_class->dequeue_task(rq, p, flags); } @@ -987,7 +983,7 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu) * ttwu() will sort out the placement. */ WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING && - !(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE)); + !(task_preempt_count(p) & PREEMPT_ACTIVE)); #ifdef CONFIG_LOCKDEP /* @@ -1017,6 +1013,107 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu) __set_task_cpu(p, new_cpu); } +static void __migrate_swap_task(struct task_struct *p, int cpu) +{ + if (p->on_rq) { + struct rq *src_rq, *dst_rq; + + src_rq = task_rq(p); + dst_rq = cpu_rq(cpu); + + deactivate_task(src_rq, p, 0); + set_task_cpu(p, cpu); + activate_task(dst_rq, p, 0); + check_preempt_curr(dst_rq, p, 0); + } else { + /* + * Task isn't running anymore; make it appear like we migrated + * it before it went to sleep. This means on wakeup we make the + * previous cpu our targer instead of where it really is. + */ + p->wake_cpu = cpu; + } +} + +struct migration_swap_arg { + struct task_struct *src_task, *dst_task; + int src_cpu, dst_cpu; +}; + +static int migrate_swap_stop(void *data) +{ + struct migration_swap_arg *arg = data; + struct rq *src_rq, *dst_rq; + int ret = -EAGAIN; + + src_rq = cpu_rq(arg->src_cpu); + dst_rq = cpu_rq(arg->dst_cpu); + + double_raw_lock(&arg->src_task->pi_lock, + &arg->dst_task->pi_lock); + double_rq_lock(src_rq, dst_rq); + if (task_cpu(arg->dst_task) != arg->dst_cpu) + goto unlock; + + if (task_cpu(arg->src_task) != arg->src_cpu) + goto unlock; + + if (!cpumask_test_cpu(arg->dst_cpu, tsk_cpus_allowed(arg->src_task))) + goto unlock; + + if (!cpumask_test_cpu(arg->src_cpu, tsk_cpus_allowed(arg->dst_task))) + goto unlock; + + __migrate_swap_task(arg->src_task, arg->dst_cpu); + __migrate_swap_task(arg->dst_task, arg->src_cpu); + + ret = 0; + +unlock: + double_rq_unlock(src_rq, dst_rq); + raw_spin_unlock(&arg->dst_task->pi_lock); + raw_spin_unlock(&arg->src_task->pi_lock); + + return ret; +} + +/* + * Cross migrate two tasks + */ +int migrate_swap(struct task_struct *cur, struct task_struct *p) +{ + struct migration_swap_arg arg; + int ret = -EINVAL; + + arg = (struct migration_swap_arg){ + .src_task = cur, + .src_cpu = task_cpu(cur), + .dst_task = p, + .dst_cpu = task_cpu(p), + }; + + if (arg.src_cpu == arg.dst_cpu) + goto out; + + /* + * These three tests are all lockless; this is OK since all of them + * will be re-checked with proper locks held further down the line. + */ + if (!cpu_active(arg.src_cpu) || !cpu_active(arg.dst_cpu)) + goto out; + + if (!cpumask_test_cpu(arg.dst_cpu, tsk_cpus_allowed(arg.src_task))) + goto out; + + if (!cpumask_test_cpu(arg.src_cpu, tsk_cpus_allowed(arg.dst_task))) + goto out; + + ret = stop_two_cpus(arg.dst_cpu, arg.src_cpu, migrate_swap_stop, &arg); + +out: + return ret; +} + struct migration_arg { struct task_struct *task; int dest_cpu; @@ -1236,9 +1333,9 @@ out: * The caller (fork, wakeup) owns p->pi_lock, ->cpus_allowed is stable. */ static inline -int select_task_rq(struct task_struct *p, int sd_flags, int wake_flags) +int select_task_rq(struct task_struct *p, int cpu, int sd_flags, int wake_flags) { - int cpu = p->sched_class->select_task_rq(p, sd_flags, wake_flags); + cpu = p->sched_class->select_task_rq(p, cpu, sd_flags, wake_flags); /* * In order not to call set_task_cpu() on a blocking task we need @@ -1330,12 +1427,13 @@ ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags) if (rq->idle_stamp) { u64 delta = rq_clock(rq) - rq->idle_stamp; - u64 max = 2*sysctl_sched_migration_cost; + u64 max = 2*rq->max_idle_balance_cost; - if (delta > max) + update_avg(&rq->avg_idle, delta); + + if (rq->avg_idle > max) rq->avg_idle = max; - else - update_avg(&rq->avg_idle, delta); + rq->idle_stamp = 0; } #endif @@ -1396,6 +1494,14 @@ static void sched_ttwu_pending(void) void scheduler_ipi(void) { + /* + * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting + * TIF_NEED_RESCHED remotely (for the first time) will also send + * this IPI. + */ + if (tif_need_resched()) + set_preempt_need_resched(); + if (llist_empty(&this_rq()->wake_list) && !tick_nohz_full_cpu(smp_processor_id()) && !got_nohz_idle_kick()) @@ -1513,7 +1619,7 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) if (p->sched_class->task_waking) p->sched_class->task_waking(p); - cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags); + cpu = select_task_rq(p, p->wake_cpu, SD_BALANCE_WAKE, wake_flags); if (task_cpu(p) != cpu) { wake_flags |= WF_MIGRATED; set_task_cpu(p, cpu); @@ -1595,7 +1701,7 @@ int wake_up_state(struct task_struct *p, unsigned int state) * * __sched_fork() is basic setup used by init_idle() too: */ -static void __sched_fork(struct task_struct *p) +static void __sched_fork(unsigned long clone_flags, struct task_struct *p) { p->on_rq = 0; @@ -1619,16 +1725,24 @@ static void __sched_fork(struct task_struct *p) #ifdef CONFIG_NUMA_BALANCING if (p->mm && atomic_read(&p->mm->mm_users) == 1) { - p->mm->numa_next_scan = jiffies; - p->mm->numa_next_reset = jiffies; + p->mm->numa_next_scan = jiffies + msecs_to_jiffies(sysctl_numa_balancing_scan_delay); p->mm->numa_scan_seq = 0; } + if (clone_flags & CLONE_VM) + p->numa_preferred_nid = current->numa_preferred_nid; + else + p->numa_preferred_nid = -1; + p->node_stamp = 0ULL; p->numa_scan_seq = p->mm ? p->mm->numa_scan_seq : 0; - p->numa_migrate_seq = p->mm ? p->mm->numa_scan_seq - 1 : 0; p->numa_scan_period = sysctl_numa_balancing_scan_delay; p->numa_work.next = &p->numa_work; + p->numa_faults = NULL; + p->numa_faults_buffer = NULL; + + INIT_LIST_HEAD(&p->numa_entry); + p->numa_group = NULL; #endif /* CONFIG_NUMA_BALANCING */ } @@ -1654,12 +1768,12 @@ void set_numabalancing_state(bool enabled) /* * fork()/clone()-time setup: */ -void sched_fork(struct task_struct *p) +void sched_fork(unsigned long clone_flags, struct task_struct *p) { unsigned long flags; int cpu = get_cpu(); - __sched_fork(p); + __sched_fork(clone_flags, p); /* * We mark the process as running here. This guarantees that * nobody will actually run it, and a signal or other external @@ -1717,10 +1831,7 @@ void sched_fork(struct task_struct *p) #if defined(CONFIG_SMP) p->on_cpu = 0; #endif -#ifdef CONFIG_PREEMPT_COUNT - /* Want to start with kernel preemption disabled. */ - task_thread_info(p)->preempt_count = 1; -#endif + init_task_preempt_count(p); #ifdef CONFIG_SMP plist_node_init(&p->pushable_tasks, MAX_PRIO); #endif @@ -1747,7 +1858,7 @@ void wake_up_new_task(struct task_struct *p) * - cpus_allowed can change in the fork path * - any previously selected cpu might disappear through hotplug */ - set_task_cpu(p, select_task_rq(p, SD_BALANCE_FORK, 0)); + set_task_cpu(p, select_task_rq(p, task_cpu(p), SD_BALANCE_FORK, 0)); #endif /* Initialize new task's runnable average */ @@ -1838,7 +1949,7 @@ prepare_task_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next) { trace_sched_switch(prev, next); - sched_info_switch(prev, next); + sched_info_switch(rq, prev, next); perf_event_task_sched_out(prev, next); fire_sched_out_preempt_notifiers(prev, next); prepare_lock_switch(rq, next); @@ -1890,6 +2001,8 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev) if (mm) mmdrop(mm); if (unlikely(prev_state == TASK_DEAD)) { + task_numa_free(prev); + /* * Remove function-return probe instances associated with this * task and put them back on the free list. @@ -2073,7 +2186,7 @@ void sched_exec(void) int dest_cpu; raw_spin_lock_irqsave(&p->pi_lock, flags); - dest_cpu = p->sched_class->select_task_rq(p, SD_BALANCE_EXEC, 0); + dest_cpu = p->sched_class->select_task_rq(p, task_cpu(p), SD_BALANCE_EXEC, 0); if (dest_cpu == smp_processor_id()) goto unlock; @@ -2215,7 +2328,7 @@ notrace unsigned long get_parent_ip(unsigned long addr) #if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \ defined(CONFIG_PREEMPT_TRACER)) -void __kprobes add_preempt_count(int val) +void __kprobes preempt_count_add(int val) { #ifdef CONFIG_DEBUG_PREEMPT /* @@ -2224,7 +2337,7 @@ void __kprobes add_preempt_count(int val) if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) return; #endif - preempt_count() += val; + __preempt_count_add(val); #ifdef CONFIG_DEBUG_PREEMPT /* * Spinlock count overflowing soon? @@ -2235,9 +2348,9 @@ void __kprobes add_preempt_count(int val) if (preempt_count() == val) trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); } -EXPORT_SYMBOL(add_preempt_count); +EXPORT_SYMBOL(preempt_count_add); -void __kprobes sub_preempt_count(int val) +void __kprobes preempt_count_sub(int val) { #ifdef CONFIG_DEBUG_PREEMPT /* @@ -2255,9 +2368,9 @@ void __kprobes sub_preempt_count(int val) if (preempt_count() == val) trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); - preempt_count() -= val; + __preempt_count_sub(val); } -EXPORT_SYMBOL(sub_preempt_count); +EXPORT_SYMBOL(preempt_count_sub); #endif @@ -2430,6 +2543,7 @@ need_resched: put_prev_task(rq, prev); next = pick_next_task(rq); clear_tsk_need_resched(prev); + clear_preempt_need_resched(); rq->skip_clock_update = 0; if (likely(prev != next)) { @@ -2520,9 +2634,9 @@ asmlinkage void __sched notrace preempt_schedule(void) return; do { - add_preempt_count_notrace(PREEMPT_ACTIVE); + __preempt_count_add(PREEMPT_ACTIVE); __schedule(); - sub_preempt_count_notrace(PREEMPT_ACTIVE); + __preempt_count_sub(PREEMPT_ACTIVE); /* * Check again in case we missed a preemption opportunity @@ -2541,20 +2655,19 @@ EXPORT_SYMBOL(preempt_schedule); */ asmlinkage void __sched preempt_schedule_irq(void) { - struct thread_info *ti = current_thread_info(); enum ctx_state prev_state; /* Catch callers which need to be fixed */ - BUG_ON(ti->preempt_count || !irqs_disabled()); + BUG_ON(preempt_count() || !irqs_disabled()); prev_state = exception_enter(); do { - add_preempt_count(PREEMPT_ACTIVE); + __preempt_count_add(PREEMPT_ACTIVE); local_irq_enable(); __schedule(); local_irq_disable(); - sub_preempt_count(PREEMPT_ACTIVE); + __preempt_count_sub(PREEMPT_ACTIVE); /* * Check again in case we missed a preemption opportunity @@ -2575,393 +2688,6 @@ int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags, } EXPORT_SYMBOL(default_wake_function); -/* - * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just - * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve - * number) then we wake all the non-exclusive tasks and one exclusive task. - * - * There are circumstances in which we can try to wake a task which has already - * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns - * zero in this (rare) case, and we handle it by continuing to scan the queue. - */ -static void __wake_up_common(wait_queue_head_t *q, unsigned int mode, - int nr_exclusive, int wake_flags, void *key) -{ - wait_queue_t *curr, *next; - - list_for_each_entry_safe(curr, next, &q->task_list, task_list) { - unsigned flags = curr->flags; - - if (curr->func(curr, mode, wake_flags, key) && - (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive) - break; - } -} - -/** - * __wake_up - wake up threads blocked on a waitqueue. - * @q: the waitqueue - * @mode: which threads - * @nr_exclusive: how many wake-one or wake-many threads to wake up - * @key: is directly passed to the wakeup function - * - * It may be assumed that this function implies a write memory barrier before - * changing the task state if and only if any tasks are woken up. - */ -void __wake_up(wait_queue_head_t *q, unsigned int mode, - int nr_exclusive, void *key) -{ - unsigned long flags; - - spin_lock_irqsave(&q->lock, flags); - __wake_up_common(q, mode, nr_exclusive, 0, key); - spin_unlock_irqrestore(&q->lock, flags); -} -EXPORT_SYMBOL(__wake_up); - -/* - * Same as __wake_up but called with the spinlock in wait_queue_head_t held. - */ -void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr) -{ - __wake_up_common(q, mode, nr, 0, NULL); -} -EXPORT_SYMBOL_GPL(__wake_up_locked); - -void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key) -{ - __wake_up_common(q, mode, 1, 0, key); -} -EXPORT_SYMBOL_GPL(__wake_up_locked_key); - -/** - * __wake_up_sync_key - wake up threads blocked on a waitqueue. - * @q: the waitqueue - * @mode: which threads - * @nr_exclusive: how many wake-one or wake-many threads to wake up - * @key: opaque value to be passed to wakeup targets - * - * The sync wakeup differs that the waker knows that it will schedule - * away soon, so while the target thread will be woken up, it will not - * be migrated to another CPU - ie. the two threads are 'synchronized' - * with each other. This can prevent needless bouncing between CPUs. - * - * On UP it can prevent extra preemption. - * - * It may be assumed that this function implies a write memory barrier before - * changing the task state if and only if any tasks are woken up. - */ -void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, - int nr_exclusive, void *key) -{ - unsigned long flags; - int wake_flags = WF_SYNC; - - if (unlikely(!q)) - return; - - if (unlikely(nr_exclusive != 1)) - wake_flags = 0; - - spin_lock_irqsave(&q->lock, flags); - __wake_up_common(q, mode, nr_exclusive, wake_flags, key); - spin_unlock_irqrestore(&q->lock, flags); -} -EXPORT_SYMBOL_GPL(__wake_up_sync_key); - -/* - * __wake_up_sync - see __wake_up_sync_key() - */ -void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive) -{ - __wake_up_sync_key(q, mode, nr_exclusive, NULL); -} -EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */ - -/** - * complete: - signals a single thread waiting on this completion - * @x: holds the state of this particular completion - * - * This will wake up a single thread waiting on this completion. Threads will be - * awakened in the same order in which they were queued. - * - * See also complete_all(), wait_for_completion() and related routines. - * - * It may be assumed that this function implies a write memory barrier before - * changing the task state if and only if any tasks are woken up. - */ -void complete(struct completion *x) -{ - unsigned long flags; - - spin_lock_irqsave(&x->wait.lock, flags); - x->done++; - __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL); - spin_unlock_irqrestore(&x->wait.lock, flags); -} -EXPORT_SYMBOL(complete); - -/** - * complete_all: - signals all threads waiting on this completion - * @x: holds the state of this particular completion - * - * This will wake up all threads waiting on this particular completion event. - * - * It may be assumed that this function implies a write memory barrier before - * changing the task state if and only if any tasks are woken up. - */ -void complete_all(struct completion *x) -{ - unsigned long flags; - - spin_lock_irqsave(&x->wait.lock, flags); - x->done += UINT_MAX/2; - __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL); - spin_unlock_irqrestore(&x->wait.lock, flags); -} -EXPORT_SYMBOL(complete_all); - -static inline long __sched -do_wait_for_common(struct completion *x, - long (*action)(long), long timeout, int state) -{ - if (!x->done) { - DECLARE_WAITQUEUE(wait, current); - - __add_wait_queue_tail_exclusive(&x->wait, &wait); - do { - if (signal_pending_state(state, current)) { - timeout = -ERESTARTSYS; - break; - } - __set_current_state(state); - spin_unlock_irq(&x->wait.lock); - timeout = action(timeout); - spin_lock_irq(&x->wait.lock); - } while (!x->done && timeout); - __remove_wait_queue(&x->wait, &wait); - if (!x->done) - return timeout; - } - x->done--; - return timeout ?: 1; -} - -static inline long __sched -__wait_for_common(struct completion *x, - long (*action)(long), long timeout, int state) -{ - might_sleep(); - - spin_lock_irq(&x->wait.lock); - timeout = do_wait_for_common(x, action, timeout, state); - spin_unlock_irq(&x->wait.lock); - return timeout; -} - -static long __sched -wait_for_common(struct completion *x, long timeout, int state) -{ - return __wait_for_common(x, schedule_timeout, timeout, state); -} - -static long __sched -wait_for_common_io(struct completion *x, long timeout, int state) -{ - return __wait_for_common(x, io_schedule_timeout, timeout, state); -} - -/** - * wait_for_completion: - waits for completion of a task - * @x: holds the state of this particular completion - * - * This waits to be signaled for completion of a specific task. It is NOT - * interruptible and there is no timeout. - * - * See also similar routines (i.e. wait_for_completion_timeout()) with timeout - * and interrupt capability. Also see complete(). - */ -void __sched wait_for_completion(struct completion *x) -{ - wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE); -} -EXPORT_SYMBOL(wait_for_completion); - -/** - * wait_for_completion_timeout: - waits for completion of a task (w/timeout) - * @x: holds the state of this particular completion - * @timeout: timeout value in jiffies - * - * This waits for either a completion of a specific task to be signaled or for a - * specified timeout to expire. The timeout is in jiffies. It is not - * interruptible. - * - * Return: 0 if timed out, and positive (at least 1, or number of jiffies left - * till timeout) if completed. - */ -unsigned long __sched -wait_for_completion_timeout(struct completion *x, unsigned long timeout) -{ - return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE); -} -EXPORT_SYMBOL(wait_for_completion_timeout); - -/** - * wait_for_completion_io: - waits for completion of a task - * @x: holds the state of this particular completion - * - * This waits to be signaled for completion of a specific task. It is NOT - * interruptible and there is no timeout. The caller is accounted as waiting - * for IO. - */ -void __sched wait_for_completion_io(struct completion *x) -{ - wait_for_common_io(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE); -} -EXPORT_SYMBOL(wait_for_completion_io); - -/** - * wait_for_completion_io_timeout: - waits for completion of a task (w/timeout) - * @x: holds the state of this particular completion - * @timeout: timeout value in jiffies - * - * This waits for either a completion of a specific task to be signaled or for a - * specified timeout to expire. The timeout is in jiffies. It is not - * interruptible. The caller is accounted as waiting for IO. - * - * Return: 0 if timed out, and positive (at least 1, or number of jiffies left - * till timeout) if completed. - */ -unsigned long __sched -wait_for_completion_io_timeout(struct completion *x, unsigned long timeout) -{ - return wait_for_common_io(x, timeout, TASK_UNINTERRUPTIBLE); -} -EXPORT_SYMBOL(wait_for_completion_io_timeout); - -/** - * wait_for_completion_interruptible: - waits for completion of a task (w/intr) - * @x: holds the state of this particular completion - * - * This waits for completion of a specific task to be signaled. It is - * interruptible. - * - * Return: -ERESTARTSYS if interrupted, 0 if completed. - */ -int __sched wait_for_completion_interruptible(struct completion *x) -{ - long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE); - if (t == -ERESTARTSYS) - return t; - return 0; -} -EXPORT_SYMBOL(wait_for_completion_interruptible); - -/** - * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr)) - * @x: holds the state of this particular completion - * @timeout: timeout value in jiffies - * - * This waits for either a completion of a specific task to be signaled or for a - * specified timeout to expire. It is interruptible. The timeout is in jiffies. - * - * Return: -ERESTARTSYS if interrupted, 0 if timed out, positive (at least 1, - * or number of jiffies left till timeout) if completed. - */ -long __sched -wait_for_completion_interruptible_timeout(struct completion *x, - unsigned long timeout) -{ - return wait_for_common(x, timeout, TASK_INTERRUPTIBLE); -} -EXPORT_SYMBOL(wait_for_completion_interruptible_timeout); - -/** - * wait_for_completion_killable: - waits for completion of a task (killable) - * @x: holds the state of this particular completion - * - * This waits to be signaled for completion of a specific task. It can be - * interrupted by a kill signal. - * - * Return: -ERESTARTSYS if interrupted, 0 if completed. - */ -int __sched wait_for_completion_killable(struct completion *x) -{ - long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE); - if (t == -ERESTARTSYS) - return t; - return 0; -} -EXPORT_SYMBOL(wait_for_completion_killable); - -/** - * wait_for_completion_killable_timeout: - waits for completion of a task (w/(to,killable)) - * @x: holds the state of this particular completion - * @timeout: timeout value in jiffies - * - * This waits for either a completion of a specific task to be - * signaled or for a specified timeout to expire. It can be - * interrupted by a kill signal. The timeout is in jiffies. - * - * Return: -ERESTARTSYS if interrupted, 0 if timed out, positive (at least 1, - * or number of jiffies left till timeout) if completed. - */ -long __sched -wait_for_completion_killable_timeout(struct completion *x, - unsigned long timeout) -{ - return wait_for_common(x, timeout, TASK_KILLABLE); -} -EXPORT_SYMBOL(wait_for_completion_killable_timeout); - -/** - * try_wait_for_completion - try to decrement a completion without blocking - * @x: completion structure - * - * Return: 0 if a decrement cannot be done without blocking - * 1 if a decrement succeeded. - * - * If a completion is being used as a counting completion, - * attempt to decrement the counter without blocking. This - * enables us to avoid waiting if the resource the completion - * is protecting is not available. - */ -bool try_wait_for_completion(struct completion *x) -{ - unsigned long flags; - int ret = 1; - - spin_lock_irqsave(&x->wait.lock, flags); - if (!x->done) - ret = 0; - else - x->done--; - spin_unlock_irqrestore(&x->wait.lock, flags); - return ret; -} -EXPORT_SYMBOL(try_wait_for_completion); - -/** - * completion_done - Test to see if a completion has any waiters - * @x: completion structure - * - * Return: 0 if there are waiters (wait_for_completion() in progress) - * 1 if there are no waiters. - * - */ -bool completion_done(struct completion *x) -{ - unsigned long flags; - int ret = 1; - - spin_lock_irqsave(&x->wait.lock, flags); - if (!x->done) - ret = 0; - spin_unlock_irqrestore(&x->wait.lock, flags); - return ret; -} -EXPORT_SYMBOL(completion_done); - static long __sched sleep_on_common(wait_queue_head_t *q, int state, long timeout) { @@ -3598,13 +3324,11 @@ long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) struct task_struct *p; int retval; - get_online_cpus(); rcu_read_lock(); p = find_process_by_pid(pid); if (!p) { rcu_read_unlock(); - put_online_cpus(); return -ESRCH; } @@ -3661,7 +3385,6 @@ out_free_cpus_allowed: free_cpumask_var(cpus_allowed); out_put_task: put_task_struct(p); - put_online_cpus(); return retval; } @@ -3706,7 +3429,6 @@ long sched_getaffinity(pid_t pid, struct cpumask *mask) unsigned long flags; int retval; - get_online_cpus(); rcu_read_lock(); retval = -ESRCH; @@ -3719,12 +3441,11 @@ long sched_getaffinity(pid_t pid, struct cpumask *mask) goto out_unlock; raw_spin_lock_irqsave(&p->pi_lock, flags); - cpumask_and(mask, &p->cpus_allowed, cpu_online_mask); + cpumask_and(mask, &p->cpus_allowed, cpu_active_mask); raw_spin_unlock_irqrestore(&p->pi_lock, flags); out_unlock: rcu_read_unlock(); - put_online_cpus(); return retval; } @@ -3794,16 +3515,11 @@ SYSCALL_DEFINE0(sched_yield) return 0; } -static inline int should_resched(void) -{ - return need_resched() && !(preempt_count() & PREEMPT_ACTIVE); -} - static void __cond_resched(void) { - add_preempt_count(PREEMPT_ACTIVE); + __preempt_count_add(PREEMPT_ACTIVE); __schedule(); - sub_preempt_count(PREEMPT_ACTIVE); + __preempt_count_sub(PREEMPT_ACTIVE); } int __sched _cond_resched(void) @@ -4186,7 +3902,7 @@ void init_idle(struct task_struct *idle, int cpu) raw_spin_lock_irqsave(&rq->lock, flags); - __sched_fork(idle); + __sched_fork(0, idle); idle->state = TASK_RUNNING; idle->se.exec_start = sched_clock(); @@ -4212,7 +3928,7 @@ void init_idle(struct task_struct *idle, int cpu) raw_spin_unlock_irqrestore(&rq->lock, flags); /* Set the preempt count _outside_ the spinlocks! */ - task_thread_info(idle)->preempt_count = 0; + init_idle_preempt_count(idle, cpu); /* * The idle tasks have their own, simple scheduling class: @@ -4346,6 +4062,53 @@ fail: return ret; } +#ifdef CONFIG_NUMA_BALANCING +/* Migrate current task p to target_cpu */ +int migrate_task_to(struct task_struct *p, int target_cpu) +{ + struct migration_arg arg = { p, target_cpu }; + int curr_cpu = task_cpu(p); + + if (curr_cpu == target_cpu) + return 0; + + if (!cpumask_test_cpu(target_cpu, tsk_cpus_allowed(p))) + return -EINVAL; + + /* TODO: This is not properly updating schedstats */ + + return stop_one_cpu(curr_cpu, migration_cpu_stop, &arg); +} + +/* + * Requeue a task on a given node and accurately track the number of NUMA + * tasks on the runqueues + */ +void sched_setnuma(struct task_struct *p, int nid) +{ + struct rq *rq; + unsigned long flags; + bool on_rq, running; + + rq = task_rq_lock(p, &flags); + on_rq = p->on_rq; + running = task_current(rq, p); + + if (on_rq) + dequeue_task(rq, p, 0); + if (running) + p->sched_class->put_prev_task(rq, p); + + p->numa_preferred_nid = nid; + + if (running) + p->sched_class->set_curr_task(rq); + if (on_rq) + enqueue_task(rq, p, 0); + task_rq_unlock(rq, p, &flags); +} +#endif + /* * migration_cpu_stop - this will be executed by a highprio stopper thread * and performs thread migration by bumping thread off CPU then @@ -5119,6 +4882,7 @@ static void destroy_sched_domains(struct sched_domain *sd, int cpu) DEFINE_PER_CPU(struct sched_domain *, sd_llc); DEFINE_PER_CPU(int, sd_llc_size); DEFINE_PER_CPU(int, sd_llc_id); +DEFINE_PER_CPU(struct sched_domain *, sd_numa); static void update_top_cache_domain(int cpu) { @@ -5135,6 +4899,9 @@ static void update_top_cache_domain(int cpu) rcu_assign_pointer(per_cpu(sd_llc, cpu), sd); per_cpu(sd_llc_size, cpu) = size; per_cpu(sd_llc_id, cpu) = id; + + sd = lowest_flag_domain(cpu, SD_NUMA); + rcu_assign_pointer(per_cpu(sd_numa, cpu), sd); } /* @@ -5654,6 +5421,7 @@ sd_numa_init(struct sched_domain_topology_level *tl, int cpu) | 0*SD_SHARE_PKG_RESOURCES | 1*SD_SERIALIZE | 0*SD_PREFER_SIBLING + | 1*SD_NUMA | sd_local_flags(level) , .last_balance = jiffies, @@ -6335,14 +6103,17 @@ void __init sched_init_smp(void) sched_init_numa(); - get_online_cpus(); + /* + * There's no userspace yet to cause hotplug operations; hence all the + * cpu masks are stable and all blatant races in the below code cannot + * happen. + */ mutex_lock(&sched_domains_mutex); init_sched_domains(cpu_active_mask); cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map); if (cpumask_empty(non_isolated_cpus)) cpumask_set_cpu(smp_processor_id(), non_isolated_cpus); mutex_unlock(&sched_domains_mutex); - put_online_cpus(); hotcpu_notifier(sched_domains_numa_masks_update, CPU_PRI_SCHED_ACTIVE); hotcpu_notifier(cpuset_cpu_active, CPU_PRI_CPUSET_ACTIVE); @@ -6505,6 +6276,7 @@ void __init sched_init(void) rq->online = 0; rq->idle_stamp = 0; rq->avg_idle = 2*sysctl_sched_migration_cost; + rq->max_idle_balance_cost = sysctl_sched_migration_cost; INIT_LIST_HEAD(&rq->cfs_tasks); @@ -7277,7 +7049,12 @@ static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota) runtime_enabled = quota != RUNTIME_INF; runtime_was_enabled = cfs_b->quota != RUNTIME_INF; - account_cfs_bandwidth_used(runtime_enabled, runtime_was_enabled); + /* + * If we need to toggle cfs_bandwidth_used, off->on must occur + * before making related changes, and on->off must occur afterwards + */ + if (runtime_enabled && !runtime_was_enabled) + cfs_bandwidth_usage_inc(); raw_spin_lock_irq(&cfs_b->lock); cfs_b->period = ns_to_ktime(period); cfs_b->quota = quota; @@ -7303,6 +7080,8 @@ static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota) unthrottle_cfs_rq(cfs_rq); raw_spin_unlock_irq(&rq->lock); } + if (runtime_was_enabled && !runtime_enabled) + cfs_bandwidth_usage_dec(); out_unlock: mutex_unlock(&cfs_constraints_mutex); diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index 1965599..5c34d18 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -15,6 +15,7 @@ #include <linux/seq_file.h> #include <linux/kallsyms.h> #include <linux/utsname.h> +#include <linux/mempolicy.h> #include "sched.h" @@ -137,6 +138,9 @@ print_task(struct seq_file *m, struct rq *rq, struct task_struct *p) SEQ_printf(m, "%15Ld %15Ld %15Ld.%06ld %15Ld.%06ld %15Ld.%06ld", 0LL, 0LL, 0LL, 0L, 0LL, 0L, 0LL, 0L); #endif +#ifdef CONFIG_NUMA_BALANCING + SEQ_printf(m, " %d", cpu_to_node(task_cpu(p))); +#endif #ifdef CONFIG_CGROUP_SCHED SEQ_printf(m, " %s", task_group_path(task_group(p))); #endif @@ -159,7 +163,7 @@ static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu) read_lock_irqsave(&tasklist_lock, flags); do_each_thread(g, p) { - if (!p->on_rq || task_cpu(p) != rq_cpu) + if (task_cpu(p) != rq_cpu) continue; print_task(m, rq, p); @@ -225,6 +229,14 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) atomic_read(&cfs_rq->tg->runnable_avg)); #endif #endif +#ifdef CONFIG_CFS_BANDWIDTH + SEQ_printf(m, " .%-30s: %d\n", "tg->cfs_bandwidth.timer_active", + cfs_rq->tg->cfs_bandwidth.timer_active); + SEQ_printf(m, " .%-30s: %d\n", "throttled", + cfs_rq->throttled); + SEQ_printf(m, " .%-30s: %d\n", "throttle_count", + cfs_rq->throttle_count); +#endif #ifdef CONFIG_FAIR_GROUP_SCHED print_cfs_group_stats(m, cpu, cfs_rq->tg); @@ -345,7 +357,7 @@ static void sched_debug_header(struct seq_file *m) cpu_clk = local_clock(); local_irq_restore(flags); - SEQ_printf(m, "Sched Debug Version: v0.10, %s %.*s\n", + SEQ_printf(m, "Sched Debug Version: v0.11, %s %.*s\n", init_utsname()->release, (int)strcspn(init_utsname()->version, " "), init_utsname()->version); @@ -488,6 +500,56 @@ static int __init init_sched_debug_procfs(void) __initcall(init_sched_debug_procfs); +#define __P(F) \ + SEQ_printf(m, "%-45s:%21Ld\n", #F, (long long)F) +#define P(F) \ + SEQ_printf(m, "%-45s:%21Ld\n", #F, (long long)p->F) +#define __PN(F) \ + SEQ_printf(m, "%-45s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)F)) +#define PN(F) \ + SEQ_printf(m, "%-45s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)p->F)) + + +static void sched_show_numa(struct task_struct *p, struct seq_file *m) +{ +#ifdef CONFIG_NUMA_BALANCING + struct mempolicy *pol; + int node, i; + + if (p->mm) + P(mm->numa_scan_seq); + + task_lock(p); + pol = p->mempolicy; + if (pol && !(pol->flags & MPOL_F_MORON)) + pol = NULL; + mpol_get(pol); + task_unlock(p); + + SEQ_printf(m, "numa_migrations, %ld\n", xchg(&p->numa_pages_migrated, 0)); + + for_each_online_node(node) { + for (i = 0; i < 2; i++) { + unsigned long nr_faults = -1; + int cpu_current, home_node; + + if (p->numa_faults) + nr_faults = p->numa_faults[2*node + i]; + + cpu_current = !i ? (task_node(p) == node) : + (pol && node_isset(node, pol->v.nodes)); + + home_node = (p->numa_preferred_nid == node); + + SEQ_printf(m, "numa_faults, %d, %d, %d, %d, %ld\n", + i, node, cpu_current, home_node, nr_faults); + } + } + + mpol_put(pol); +#endif +} + void proc_sched_show_task(struct task_struct *p, struct seq_file *m) { unsigned long nr_switches; @@ -591,6 +653,8 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m) SEQ_printf(m, "%-45s:%21Ld\n", "clock-delta", (long long)(t1-t0)); } + + sched_show_numa(p, m); } void proc_sched_set_task(struct task_struct *p) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 7c70201..41c02b6 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -681,6 +681,8 @@ static u64 sched_vslice(struct cfs_rq *cfs_rq, struct sched_entity *se) } #ifdef CONFIG_SMP +static unsigned long task_h_load(struct task_struct *p); + static inline void __update_task_entity_contrib(struct sched_entity *se); /* Give new task start runnable values to heavy its load in infant time */ @@ -818,11 +820,12 @@ update_stats_curr_start(struct cfs_rq *cfs_rq, struct sched_entity *se) #ifdef CONFIG_NUMA_BALANCING /* - * numa task sample period in ms + * Approximate time to scan a full NUMA task in ms. The task scan period is + * calculated based on the tasks virtual memory size and + * numa_balancing_scan_size. */ -unsigned int sysctl_numa_balancing_scan_period_min = 100; -unsigned int sysctl_numa_balancing_scan_period_max = 100*50; -unsigned int sysctl_numa_balancing_scan_period_reset = 100*600; +unsigned int sysctl_numa_balancing_scan_period_min = 1000; +unsigned int sysctl_numa_balancing_scan_period_max = 60000; /* Portion of address space to scan in MB */ unsigned int sysctl_numa_balancing_scan_size = 256; @@ -830,41 +833,810 @@ unsigned int sysctl_numa_balancing_scan_size = 256; /* Scan @scan_size MB every @scan_period after an initial @scan_delay in ms */ unsigned int sysctl_numa_balancing_scan_delay = 1000; -static void task_numa_placement(struct task_struct *p) +/* + * After skipping a page migration on a shared page, skip N more numa page + * migrations unconditionally. This reduces the number of NUMA migrations + * in shared memory workloads, and has the effect of pulling tasks towards + * where their memory lives, over pulling the memory towards the task. + */ +unsigned int sysctl_numa_balancing_migrate_deferred = 16; + +static unsigned int task_nr_scan_windows(struct task_struct *p) +{ + unsigned long rss = 0; + unsigned long nr_scan_pages; + + /* + * Calculations based on RSS as non-present and empty pages are skipped + * by the PTE scanner and NUMA hinting faults should be trapped based + * on resident pages + */ + nr_scan_pages = sysctl_numa_balancing_scan_size << (20 - PAGE_SHIFT); + rss = get_mm_rss(p->mm); + if (!rss) + rss = nr_scan_pages; + + rss = round_up(rss, nr_scan_pages); + return rss / nr_scan_pages; +} + +/* For sanitys sake, never scan more PTEs than MAX_SCAN_WINDOW MB/sec. */ +#define MAX_SCAN_WINDOW 2560 + +static unsigned int task_scan_min(struct task_struct *p) +{ + unsigned int scan, floor; + unsigned int windows = 1; + + if (sysctl_numa_balancing_scan_size < MAX_SCAN_WINDOW) + windows = MAX_SCAN_WINDOW / sysctl_numa_balancing_scan_size; + floor = 1000 / windows; + + scan = sysctl_numa_balancing_scan_period_min / task_nr_scan_windows(p); + return max_t(unsigned int, floor, scan); +} + +static unsigned int task_scan_max(struct task_struct *p) +{ + unsigned int smin = task_scan_min(p); + unsigned int smax; + + /* Watch for min being lower than max due to floor calculations */ + smax = sysctl_numa_balancing_scan_period_max / task_nr_scan_windows(p); + return max(smin, smax); +} + +/* + * Once a preferred node is selected the scheduler balancer will prefer moving + * a task to that node for sysctl_numa_balancing_settle_count number of PTE + * scans. This will give the process the chance to accumulate more faults on + * the preferred node but still allow the scheduler to move the task again if + * the nodes CPUs are overloaded. + */ +unsigned int sysctl_numa_balancing_settle_count __read_mostly = 4; + +static void account_numa_enqueue(struct rq *rq, struct task_struct *p) +{ + rq->nr_numa_running += (p->numa_preferred_nid != -1); + rq->nr_preferred_running += (p->numa_preferred_nid == task_node(p)); +} + +static void account_numa_dequeue(struct rq *rq, struct task_struct *p) +{ + rq->nr_numa_running -= (p->numa_preferred_nid != -1); + rq->nr_preferred_running -= (p->numa_preferred_nid == task_node(p)); +} + +struct numa_group { + atomic_t refcount; + + spinlock_t lock; /* nr_tasks, tasks */ + int nr_tasks; + pid_t gid; + struct list_head task_list; + + struct rcu_head rcu; + unsigned long total_faults; + unsigned long faults[0]; +}; + +pid_t task_numa_group_id(struct task_struct *p) +{ + return p->numa_group ? p->numa_group->gid : 0; +} + +static inline int task_faults_idx(int nid, int priv) +{ + return 2 * nid + priv; +} + +static inline unsigned long task_faults(struct task_struct *p, int nid) +{ + if (!p->numa_faults) + return 0; + + return p->numa_faults[task_faults_idx(nid, 0)] + + p->numa_faults[task_faults_idx(nid, 1)]; +} + +static inline unsigned long group_faults(struct task_struct *p, int nid) +{ + if (!p->numa_group) + return 0; + + return p->numa_group->faults[2*nid] + p->numa_group->faults[2*nid+1]; +} + +/* + * These return the fraction of accesses done by a particular task, or + * task group, on a particular numa node. The group weight is given a + * larger multiplier, in order to group tasks together that are almost + * evenly spread out between numa nodes. + */ +static inline unsigned long task_weight(struct task_struct *p, int nid) +{ + unsigned long total_faults; + + if (!p->numa_faults) + return 0; + + total_faults = p->total_numa_faults; + + if (!total_faults) + return 0; + + return 1000 * task_faults(p, nid) / total_faults; +} + +static inline unsigned long group_weight(struct task_struct *p, int nid) { - int seq; + if (!p->numa_group || !p->numa_group->total_faults) + return 0; + + return 1000 * group_faults(p, nid) / p->numa_group->total_faults; +} + +static unsigned long weighted_cpuload(const int cpu); +static unsigned long source_load(int cpu, int type); +static unsigned long target_load(int cpu, int type); +static unsigned long power_of(int cpu); +static long effective_load(struct task_group *tg, int cpu, long wl, long wg); + +/* Cached statistics for all CPUs within a node */ +struct numa_stats { + unsigned long nr_running; + unsigned long load; + + /* Total compute capacity of CPUs on a node */ + unsigned long power; + + /* Approximate capacity in terms of runnable tasks on a node */ + unsigned long capacity; + int has_capacity; +}; + +/* + * XXX borrowed from update_sg_lb_stats + */ +static void update_numa_stats(struct numa_stats *ns, int nid) +{ + int cpu; + + memset(ns, 0, sizeof(*ns)); + for_each_cpu(cpu, cpumask_of_node(nid)) { + struct rq *rq = cpu_rq(cpu); + + ns->nr_running += rq->nr_running; + ns->load += weighted_cpuload(cpu); + ns->power += power_of(cpu); + } + + ns->load = (ns->load * SCHED_POWER_SCALE) / ns->power; + ns->capacity = DIV_ROUND_CLOSEST(ns->power, SCHED_POWER_SCALE); + ns->has_capacity = (ns->nr_running < ns->capacity); +} + +struct task_numa_env { + struct task_struct *p; + + int src_cpu, src_nid; + int dst_cpu, dst_nid; + + struct numa_stats src_stats, dst_stats; + + int imbalance_pct, idx; + + struct task_struct *best_task; + long best_imp; + int best_cpu; +}; + +static void task_numa_assign(struct task_numa_env *env, + struct task_struct *p, long imp) +{ + if (env->best_task) + put_task_struct(env->best_task); + if (p) + get_task_struct(p); + + env->best_task = p; + env->best_imp = imp; + env->best_cpu = env->dst_cpu; +} + +/* + * This checks if the overall compute and NUMA accesses of the system would + * be improved if the source tasks was migrated to the target dst_cpu taking + * into account that it might be best if task running on the dst_cpu should + * be exchanged with the source task + */ +static void task_numa_compare(struct task_numa_env *env, + long taskimp, long groupimp) +{ + struct rq *src_rq = cpu_rq(env->src_cpu); + struct rq *dst_rq = cpu_rq(env->dst_cpu); + struct task_struct *cur; + long dst_load, src_load; + long load; + long imp = (groupimp > 0) ? groupimp : taskimp; + + rcu_read_lock(); + cur = ACCESS_ONCE(dst_rq->curr); + if (cur->pid == 0) /* idle */ + cur = NULL; + + /* + * "imp" is the fault differential for the source task between the + * source and destination node. Calculate the total differential for + * the source task and potential destination task. The more negative + * the value is, the more rmeote accesses that would be expected to + * be incurred if the tasks were swapped. + */ + if (cur) { + /* Skip this swap candidate if cannot move to the source cpu */ + if (!cpumask_test_cpu(env->src_cpu, tsk_cpus_allowed(cur))) + goto unlock; + + /* + * If dst and source tasks are in the same NUMA group, or not + * in any group then look only at task weights. + */ + if (cur->numa_group == env->p->numa_group) { + imp = taskimp + task_weight(cur, env->src_nid) - + task_weight(cur, env->dst_nid); + /* + * Add some hysteresis to prevent swapping the + * tasks within a group over tiny differences. + */ + if (cur->numa_group) + imp -= imp/16; + } else { + /* + * Compare the group weights. If a task is all by + * itself (not part of a group), use the task weight + * instead. + */ + if (env->p->numa_group) + imp = groupimp; + else + imp = taskimp; + + if (cur->numa_group) + imp += group_weight(cur, env->src_nid) - + group_weight(cur, env->dst_nid); + else + imp += task_weight(cur, env->src_nid) - + task_weight(cur, env->dst_nid); + } + } + + if (imp < env->best_imp) + goto unlock; + + if (!cur) { + /* Is there capacity at our destination? */ + if (env->src_stats.has_capacity && + !env->dst_stats.has_capacity) + goto unlock; + + goto balance; + } + + /* Balance doesn't matter much if we're running a task per cpu */ + if (src_rq->nr_running == 1 && dst_rq->nr_running == 1) + goto assign; + + /* + * In the overloaded case, try and keep the load balanced. + */ +balance: + dst_load = env->dst_stats.load; + src_load = env->src_stats.load; + + /* XXX missing power terms */ + load = task_h_load(env->p); + dst_load += load; + src_load -= load; + + if (cur) { + load = task_h_load(cur); + dst_load -= load; + src_load += load; + } + + /* make src_load the smaller */ + if (dst_load < src_load) + swap(dst_load, src_load); + + if (src_load * env->imbalance_pct < dst_load * 100) + goto unlock; + +assign: + task_numa_assign(env, cur, imp); +unlock: + rcu_read_unlock(); +} + +static void task_numa_find_cpu(struct task_numa_env *env, + long taskimp, long groupimp) +{ + int cpu; + + for_each_cpu(cpu, cpumask_of_node(env->dst_nid)) { + /* Skip this CPU if the source task cannot migrate */ + if (!cpumask_test_cpu(cpu, tsk_cpus_allowed(env->p))) + continue; + + env->dst_cpu = cpu; + task_numa_compare(env, taskimp, groupimp); + } +} + +static int task_numa_migrate(struct task_struct *p) +{ + struct task_numa_env env = { + .p = p, + + .src_cpu = task_cpu(p), + .src_nid = task_node(p), + + .imbalance_pct = 112, + + .best_task = NULL, + .best_imp = 0, + .best_cpu = -1 + }; + struct sched_domain *sd; + unsigned long taskweight, groupweight; + int nid, ret; + long taskimp, groupimp; + + /* + * Pick the lowest SD_NUMA domain, as that would have the smallest + * imbalance and would be the first to start moving tasks about. + * + * And we want to avoid any moving of tasks about, as that would create + * random movement of tasks -- counter the numa conditions we're trying + * to satisfy here. + */ + rcu_read_lock(); + sd = rcu_dereference(per_cpu(sd_numa, env.src_cpu)); + env.imbalance_pct = 100 + (sd->imbalance_pct - 100) / 2; + rcu_read_unlock(); + + taskweight = task_weight(p, env.src_nid); + groupweight = group_weight(p, env.src_nid); + update_numa_stats(&env.src_stats, env.src_nid); + env.dst_nid = p->numa_preferred_nid; + taskimp = task_weight(p, env.dst_nid) - taskweight; + groupimp = group_weight(p, env.dst_nid) - groupweight; + update_numa_stats(&env.dst_stats, env.dst_nid); + + /* If the preferred nid has capacity, try to use it. */ + if (env.dst_stats.has_capacity) + task_numa_find_cpu(&env, taskimp, groupimp); + + /* No space available on the preferred nid. Look elsewhere. */ + if (env.best_cpu == -1) { + for_each_online_node(nid) { + if (nid == env.src_nid || nid == p->numa_preferred_nid) + continue; + + /* Only consider nodes where both task and groups benefit */ + taskimp = task_weight(p, nid) - taskweight; + groupimp = group_weight(p, nid) - groupweight; + if (taskimp < 0 && groupimp < 0) + continue; + + env.dst_nid = nid; + update_numa_stats(&env.dst_stats, env.dst_nid); + task_numa_find_cpu(&env, taskimp, groupimp); + } + } + + /* No better CPU than the current one was found. */ + if (env.best_cpu == -1) + return -EAGAIN; + + sched_setnuma(p, env.dst_nid); + + /* + * Reset the scan period if the task is being rescheduled on an + * alternative node to recheck if the tasks is now properly placed. + */ + p->numa_scan_period = task_scan_min(p); + + if (env.best_task == NULL) { + int ret = migrate_task_to(p, env.best_cpu); + return ret; + } + + ret = migrate_swap(p, env.best_task); + put_task_struct(env.best_task); + return ret; +} + +/* Attempt to migrate a task to a CPU on the preferred node. */ +static void numa_migrate_preferred(struct task_struct *p) +{ + /* This task has no NUMA fault statistics yet */ + if (unlikely(p->numa_preferred_nid == -1 || !p->numa_faults)) + return; + + /* Periodically retry migrating the task to the preferred node */ + p->numa_migrate_retry = jiffies + HZ; + + /* Success if task is already running on preferred CPU */ + if (cpu_to_node(task_cpu(p)) == p->numa_preferred_nid) + return; + + /* Otherwise, try migrate to a CPU on the preferred node */ + task_numa_migrate(p); +} + +/* + * When adapting the scan rate, the period is divided into NUMA_PERIOD_SLOTS + * increments. The more local the fault statistics are, the higher the scan + * period will be for the next scan window. If local/remote ratio is below + * NUMA_PERIOD_THRESHOLD (where range of ratio is 1..NUMA_PERIOD_SLOTS) the + * scan period will decrease + */ +#define NUMA_PERIOD_SLOTS 10 +#define NUMA_PERIOD_THRESHOLD 3 + +/* + * Increase the scan period (slow down scanning) if the majority of + * our memory is already on our local node, or if the majority of + * the page accesses are shared with other processes. + * Otherwise, decrease the scan period. + */ +static void update_task_scan_period(struct task_struct *p, + unsigned long shared, unsigned long private) +{ + unsigned int period_slot; + int ratio; + int diff; + + unsigned long remote = p->numa_faults_locality[0]; + unsigned long local = p->numa_faults_locality[1]; + + /* + * If there were no record hinting faults then either the task is + * completely idle or all activity is areas that are not of interest + * to automatic numa balancing. Scan slower + */ + if (local + shared == 0) { + p->numa_scan_period = min(p->numa_scan_period_max, + p->numa_scan_period << 1); + + p->mm->numa_next_scan = jiffies + + msecs_to_jiffies(p->numa_scan_period); - if (!p->mm) /* for example, ksmd faulting in a user's mm */ return; + } + + /* + * Prepare to scale scan period relative to the current period. + * == NUMA_PERIOD_THRESHOLD scan period stays the same + * < NUMA_PERIOD_THRESHOLD scan period decreases (scan faster) + * >= NUMA_PERIOD_THRESHOLD scan period increases (scan slower) + */ + period_slot = DIV_ROUND_UP(p->numa_scan_period, NUMA_PERIOD_SLOTS); + ratio = (local * NUMA_PERIOD_SLOTS) / (local + remote); + if (ratio >= NUMA_PERIOD_THRESHOLD) { + int slot = ratio - NUMA_PERIOD_THRESHOLD; + if (!slot) + slot = 1; + diff = slot * period_slot; + } else { + diff = -(NUMA_PERIOD_THRESHOLD - ratio) * period_slot; + + /* + * Scale scan rate increases based on sharing. There is an + * inverse relationship between the degree of sharing and + * the adjustment made to the scanning period. Broadly + * speaking the intent is that there is little point + * scanning faster if shared accesses dominate as it may + * simply bounce migrations uselessly + */ + period_slot = DIV_ROUND_UP(diff, NUMA_PERIOD_SLOTS); + ratio = DIV_ROUND_UP(private * NUMA_PERIOD_SLOTS, (private + shared)); + diff = (diff * ratio) / NUMA_PERIOD_SLOTS; + } + + p->numa_scan_period = clamp(p->numa_scan_period + diff, + task_scan_min(p), task_scan_max(p)); + memset(p->numa_faults_locality, 0, sizeof(p->numa_faults_locality)); +} + +static void task_numa_placement(struct task_struct *p) +{ + int seq, nid, max_nid = -1, max_group_nid = -1; + unsigned long max_faults = 0, max_group_faults = 0; + unsigned long fault_types[2] = { 0, 0 }; + spinlock_t *group_lock = NULL; + seq = ACCESS_ONCE(p->mm->numa_scan_seq); if (p->numa_scan_seq == seq) return; p->numa_scan_seq = seq; + p->numa_scan_period_max = task_scan_max(p); + + /* If the task is part of a group prevent parallel updates to group stats */ + if (p->numa_group) { + group_lock = &p->numa_group->lock; + spin_lock(group_lock); + } + + /* Find the node with the highest number of faults */ + for_each_online_node(nid) { + unsigned long faults = 0, group_faults = 0; + int priv, i; + + for (priv = 0; priv < 2; priv++) { + long diff; + + i = task_faults_idx(nid, priv); + diff = -p->numa_faults[i]; + + /* Decay existing window, copy faults since last scan */ + p->numa_faults[i] >>= 1; + p->numa_faults[i] += p->numa_faults_buffer[i]; + fault_types[priv] += p->numa_faults_buffer[i]; + p->numa_faults_buffer[i] = 0; + + faults += p->numa_faults[i]; + diff += p->numa_faults[i]; + p->total_numa_faults += diff; + if (p->numa_group) { + /* safe because we can only change our own group */ + p->numa_group->faults[i] += diff; + p->numa_group->total_faults += diff; + group_faults += p->numa_group->faults[i]; + } + } + + if (faults > max_faults) { + max_faults = faults; + max_nid = nid; + } + + if (group_faults > max_group_faults) { + max_group_faults = group_faults; + max_group_nid = nid; + } + } + + update_task_scan_period(p, fault_types[0], fault_types[1]); + + if (p->numa_group) { + /* + * If the preferred task and group nids are different, + * iterate over the nodes again to find the best place. + */ + if (max_nid != max_group_nid) { + unsigned long weight, max_weight = 0; + + for_each_online_node(nid) { + weight = task_weight(p, nid) + group_weight(p, nid); + if (weight > max_weight) { + max_weight = weight; + max_nid = nid; + } + } + } + + spin_unlock(group_lock); + } - /* FIXME: Scheduling placement policy hints go here */ + /* Preferred node as the node with the most faults */ + if (max_faults && max_nid != p->numa_preferred_nid) { + /* Update the preferred nid and migrate task if possible */ + sched_setnuma(p, max_nid); + numa_migrate_preferred(p); + } +} + +static inline int get_numa_group(struct numa_group *grp) +{ + return atomic_inc_not_zero(&grp->refcount); +} + +static inline void put_numa_group(struct numa_group *grp) +{ + if (atomic_dec_and_test(&grp->refcount)) + kfree_rcu(grp, rcu); +} + +static void task_numa_group(struct task_struct *p, int cpupid, int flags, + int *priv) +{ + struct numa_group *grp, *my_grp; + struct task_struct *tsk; + bool join = false; + int cpu = cpupid_to_cpu(cpupid); + int i; + + if (unlikely(!p->numa_group)) { + unsigned int size = sizeof(struct numa_group) + + 2*nr_node_ids*sizeof(unsigned long); + + grp = kzalloc(size, GFP_KERNEL | __GFP_NOWARN); + if (!grp) + return; + + atomic_set(&grp->refcount, 1); + spin_lock_init(&grp->lock); + INIT_LIST_HEAD(&grp->task_list); + grp->gid = p->pid; + + for (i = 0; i < 2*nr_node_ids; i++) + grp->faults[i] = p->numa_faults[i]; + + grp->total_faults = p->total_numa_faults; + + list_add(&p->numa_entry, &grp->task_list); + grp->nr_tasks++; + rcu_assign_pointer(p->numa_group, grp); + } + + rcu_read_lock(); + tsk = ACCESS_ONCE(cpu_rq(cpu)->curr); + + if (!cpupid_match_pid(tsk, cpupid)) + goto no_join; + + grp = rcu_dereference(tsk->numa_group); + if (!grp) + goto no_join; + + my_grp = p->numa_group; + if (grp == my_grp) + goto no_join; + + /* + * Only join the other group if its bigger; if we're the bigger group, + * the other task will join us. + */ + if (my_grp->nr_tasks > grp->nr_tasks) + goto no_join; + + /* + * Tie-break on the grp address. + */ + if (my_grp->nr_tasks == grp->nr_tasks && my_grp > grp) + goto no_join; + + /* Always join threads in the same process. */ + if (tsk->mm == current->mm) + join = true; + + /* Simple filter to avoid false positives due to PID collisions */ + if (flags & TNF_SHARED) + join = true; + + /* Update priv based on whether false sharing was detected */ + *priv = !join; + + if (join && !get_numa_group(grp)) + goto no_join; + + rcu_read_unlock(); + + if (!join) + return; + + double_lock(&my_grp->lock, &grp->lock); + + for (i = 0; i < 2*nr_node_ids; i++) { + my_grp->faults[i] -= p->numa_faults[i]; + grp->faults[i] += p->numa_faults[i]; + } + my_grp->total_faults -= p->total_numa_faults; + grp->total_faults += p->total_numa_faults; + + list_move(&p->numa_entry, &grp->task_list); + my_grp->nr_tasks--; + grp->nr_tasks++; + + spin_unlock(&my_grp->lock); + spin_unlock(&grp->lock); + + rcu_assign_pointer(p->numa_group, grp); + + put_numa_group(my_grp); + return; + +no_join: + rcu_read_unlock(); + return; +} + +void task_numa_free(struct task_struct *p) +{ + struct numa_group *grp = p->numa_group; + int i; + void *numa_faults = p->numa_faults; + + if (grp) { + spin_lock(&grp->lock); + for (i = 0; i < 2*nr_node_ids; i++) + grp->faults[i] -= p->numa_faults[i]; + grp->total_faults -= p->total_numa_faults; + + list_del(&p->numa_entry); + grp->nr_tasks--; + spin_unlock(&grp->lock); + rcu_assign_pointer(p->numa_group, NULL); + put_numa_group(grp); + } + + p->numa_faults = NULL; + p->numa_faults_buffer = NULL; + kfree(numa_faults); } /* * Got a PROT_NONE fault for a page on @node. */ -void task_numa_fault(int node, int pages, bool migrated) +void task_numa_fault(int last_cpupid, int node, int pages, int flags) { struct task_struct *p = current; + bool migrated = flags & TNF_MIGRATED; + int priv; if (!numabalancing_enabled) return; - /* FIXME: Allocate task-specific structure for placement policy here */ + /* for example, ksmd faulting in a user's mm */ + if (!p->mm) + return; + + /* Do not worry about placement if exiting */ + if (p->state == TASK_DEAD) + return; + + /* Allocate buffer to track faults on a per-node basis */ + if (unlikely(!p->numa_faults)) { + int size = sizeof(*p->numa_faults) * 2 * nr_node_ids; + + /* numa_faults and numa_faults_buffer share the allocation */ + p->numa_faults = kzalloc(size * 2, GFP_KERNEL|__GFP_NOWARN); + if (!p->numa_faults) + return; + + BUG_ON(p->numa_faults_buffer); + p->numa_faults_buffer = p->numa_faults + (2 * nr_node_ids); + p->total_numa_faults = 0; + memset(p->numa_faults_locality, 0, sizeof(p->numa_faults_locality)); + } /* - * If pages are properly placed (did not migrate) then scan slower. - * This is reset periodically in case of phase changes + * First accesses are treated as private, otherwise consider accesses + * to be private if the accessing pid has not changed */ - if (!migrated) - p->numa_scan_period = min(sysctl_numa_balancing_scan_period_max, - p->numa_scan_period + jiffies_to_msecs(10)); + if (unlikely(last_cpupid == (-1 & LAST_CPUPID_MASK))) { + priv = 1; + } else { + priv = cpupid_match_pid(p, last_cpupid); + if (!priv && !(flags & TNF_NO_GROUP)) + task_numa_group(p, last_cpupid, flags, &priv); + } task_numa_placement(p); + + /* + * Retry task to preferred node migration periodically, in case it + * case it previously failed, or the scheduler moved us. + */ + if (time_after(jiffies, p->numa_migrate_retry)) + numa_migrate_preferred(p); + + if (migrated) + p->numa_pages_migrated += pages; + + p->numa_faults_buffer[task_faults_idx(node, priv)] += pages; + p->numa_faults_locality[!!(flags & TNF_FAULT_LOCAL)] += pages; } static void reset_ptenuma_scan(struct task_struct *p) @@ -884,6 +1656,7 @@ void task_numa_work(struct callback_head *work) struct mm_struct *mm = p->mm; struct vm_area_struct *vma; unsigned long start, end; + unsigned long nr_pte_updates = 0; long pages; WARN_ON_ONCE(p != container_of(work, struct task_struct, numa_work)); @@ -900,35 +1673,9 @@ void task_numa_work(struct callback_head *work) if (p->flags & PF_EXITING) return; - /* - * We do not care about task placement until a task runs on a node - * other than the first one used by the address space. This is - * largely because migrations are driven by what CPU the task - * is running on. If it's never scheduled on another node, it'll - * not migrate so why bother trapping the fault. - */ - if (mm->first_nid == NUMA_PTE_SCAN_INIT) - mm->first_nid = numa_node_id(); - if (mm->first_nid != NUMA_PTE_SCAN_ACTIVE) { - /* Are we running on a new node yet? */ - if (numa_node_id() == mm->first_nid && - !sched_feat_numa(NUMA_FORCE)) - return; - - mm->first_nid = NUMA_PTE_SCAN_ACTIVE; - } - - /* - * Reset the scan period if enough time has gone by. Objective is that - * scanning will be reduced if pages are properly placed. As tasks - * can enter different phases this needs to be re-examined. Lacking - * proper tracking of reference behaviour, this blunt hammer is used. - */ - migrate = mm->numa_next_reset; - if (time_after(now, migrate)) { - p->numa_scan_period = sysctl_numa_balancing_scan_period_min; - next_scan = now + msecs_to_jiffies(sysctl_numa_balancing_scan_period_reset); - xchg(&mm->numa_next_reset, next_scan); + if (!mm->numa_next_scan) { + mm->numa_next_scan = now + + msecs_to_jiffies(sysctl_numa_balancing_scan_delay); } /* @@ -938,20 +1685,20 @@ void task_numa_work(struct callback_head *work) if (time_before(now, migrate)) return; - if (p->numa_scan_period == 0) - p->numa_scan_period = sysctl_numa_balancing_scan_period_min; + if (p->numa_scan_period == 0) { + p->numa_scan_period_max = task_scan_max(p); + p->numa_scan_period = task_scan_min(p); + } next_scan = now + msecs_to_jiffies(p->numa_scan_period); if (cmpxchg(&mm->numa_next_scan, migrate, next_scan) != migrate) return; /* - * Do not set pte_numa if the current running node is rate-limited. - * This loses statistics on the fault but if we are unwilling to - * migrate to this node, it is less likely we can do useful work + * Delay this task enough that another task of this mm will likely win + * the next time around. */ - if (migrate_ratelimited(numa_node_id())) - return; + p->node_stamp += 2 * TICK_NSEC; start = mm->numa_scan_offset; pages = sysctl_numa_balancing_scan_size; @@ -967,18 +1714,32 @@ void task_numa_work(struct callback_head *work) vma = mm->mmap; } for (; vma; vma = vma->vm_next) { - if (!vma_migratable(vma)) + if (!vma_migratable(vma) || !vma_policy_mof(p, vma)) continue; - /* Skip small VMAs. They are not likely to be of relevance */ - if (vma->vm_end - vma->vm_start < HPAGE_SIZE) + /* + * Shared library pages mapped by multiple processes are not + * migrated as it is expected they are cache replicated. Avoid + * hinting faults in read-only file-backed mappings or the vdso + * as migrating the pages will be of marginal benefit. + */ + if (!vma->vm_mm || + (vma->vm_file && (vma->vm_flags & (VM_READ|VM_WRITE)) == (VM_READ))) continue; do { start = max(start, vma->vm_start); end = ALIGN(start + (pages << PAGE_SHIFT), HPAGE_SIZE); end = min(end, vma->vm_end); - pages -= change_prot_numa(vma, start, end); + nr_pte_updates += change_prot_numa(vma, start, end); + + /* + * Scan sysctl_numa_balancing_scan_size but ensure that + * at least one PTE is updated so that unused virtual + * address space is quickly skipped. + */ + if (nr_pte_updates) + pages -= (end - start) >> PAGE_SHIFT; start = end; if (pages <= 0) @@ -988,10 +1749,10 @@ void task_numa_work(struct callback_head *work) out: /* - * It is possible to reach the end of the VMA list but the last few VMAs are - * not guaranteed to the vma_migratable. If they are not, we would find the - * !migratable VMA on the next scan but not reset the scanner to the start - * so check it now. + * It is possible to reach the end of the VMA list but the last few + * VMAs are not guaranteed to the vma_migratable. If they are not, we + * would find the !migratable VMA on the next scan but not reset the + * scanner to the start so check it now. */ if (vma) mm->numa_scan_offset = start; @@ -1025,8 +1786,8 @@ void task_tick_numa(struct rq *rq, struct task_struct *curr) if (now - curr->node_stamp > period) { if (!curr->node_stamp) - curr->numa_scan_period = sysctl_numa_balancing_scan_period_min; - curr->node_stamp = now; + curr->numa_scan_period = task_scan_min(curr); + curr->node_stamp += period; if (!time_before(jiffies, curr->mm->numa_next_scan)) { init_task_work(work, task_numa_work); /* TODO: move this into sched_fork() */ @@ -1038,6 +1799,14 @@ void task_tick_numa(struct rq *rq, struct task_struct *curr) static void task_tick_numa(struct rq *rq, struct task_struct *curr) { } + +static inline void account_numa_enqueue(struct rq *rq, struct task_struct *p) +{ +} + +static inline void account_numa_dequeue(struct rq *rq, struct task_struct *p) +{ +} #endif /* CONFIG_NUMA_BALANCING */ static void @@ -1047,8 +1816,12 @@ account_entity_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se) if (!parent_entity(se)) update_load_add(&rq_of(cfs_rq)->load, se->load.weight); #ifdef CONFIG_SMP - if (entity_is_task(se)) - list_add(&se->group_node, &rq_of(cfs_rq)->cfs_tasks); + if (entity_is_task(se)) { + struct rq *rq = rq_of(cfs_rq); + + account_numa_enqueue(rq, task_of(se)); + list_add(&se->group_node, &rq->cfs_tasks); + } #endif cfs_rq->nr_running++; } @@ -1059,8 +1832,10 @@ account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se) update_load_sub(&cfs_rq->load, se->load.weight); if (!parent_entity(se)) update_load_sub(&rq_of(cfs_rq)->load, se->load.weight); - if (entity_is_task(se)) + if (entity_is_task(se)) { + account_numa_dequeue(rq_of(cfs_rq), task_of(se)); list_del_init(&se->group_node); + } cfs_rq->nr_running--; } @@ -2070,13 +2845,14 @@ static inline bool cfs_bandwidth_used(void) return static_key_false(&__cfs_bandwidth_used); } -void account_cfs_bandwidth_used(int enabled, int was_enabled) +void cfs_bandwidth_usage_inc(void) { - /* only need to count groups transitioning between enabled/!enabled */ - if (enabled && !was_enabled) - static_key_slow_inc(&__cfs_bandwidth_used); - else if (!enabled && was_enabled) - static_key_slow_dec(&__cfs_bandwidth_used); + static_key_slow_inc(&__cfs_bandwidth_used); +} + +void cfs_bandwidth_usage_dec(void) +{ + static_key_slow_dec(&__cfs_bandwidth_used); } #else /* HAVE_JUMP_LABEL */ static bool cfs_bandwidth_used(void) @@ -2084,7 +2860,8 @@ static bool cfs_bandwidth_used(void) return true; } -void account_cfs_bandwidth_used(int enabled, int was_enabled) {} +void cfs_bandwidth_usage_inc(void) {} +void cfs_bandwidth_usage_dec(void) {} #endif /* HAVE_JUMP_LABEL */ /* @@ -2335,6 +3112,8 @@ static void throttle_cfs_rq(struct cfs_rq *cfs_rq) cfs_rq->throttled_clock = rq_clock(rq); raw_spin_lock(&cfs_b->lock); list_add_tail_rcu(&cfs_rq->throttled_list, &cfs_b->throttled_cfs_rq); + if (!cfs_b->timer_active) + __start_cfs_bandwidth(cfs_b); raw_spin_unlock(&cfs_b->lock); } @@ -2448,6 +3227,13 @@ static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun) if (idle) goto out_unlock; + /* + * if we have relooped after returning idle once, we need to update our + * status as actually running, so that other cpus doing + * __start_cfs_bandwidth will stop trying to cancel us. + */ + cfs_b->timer_active = 1; + __refill_cfs_bandwidth_runtime(cfs_b); if (!throttled) { @@ -2508,7 +3294,13 @@ static const u64 min_bandwidth_expiration = 2 * NSEC_PER_MSEC; /* how long we wait to gather additional slack before distributing */ static const u64 cfs_bandwidth_slack_period = 5 * NSEC_PER_MSEC; -/* are we near the end of the current quota period? */ +/* + * Are we near the end of the current quota period? + * + * Requires cfs_b->lock for hrtimer_expires_remaining to be safe against the + * hrtimer base being cleared by __hrtimer_start_range_ns. In the case of + * migrate_hrtimers, base is never cleared, so we are fine. + */ static int runtime_refresh_within(struct cfs_bandwidth *cfs_b, u64 min_expire) { struct hrtimer *refresh_timer = &cfs_b->period_timer; @@ -2584,10 +3376,12 @@ static void do_sched_cfs_slack_timer(struct cfs_bandwidth *cfs_b) u64 expires; /* confirm we're still not at a refresh boundary */ - if (runtime_refresh_within(cfs_b, min_bandwidth_expiration)) + raw_spin_lock(&cfs_b->lock); + if (runtime_refresh_within(cfs_b, min_bandwidth_expiration)) { + raw_spin_unlock(&cfs_b->lock); return; + } - raw_spin_lock(&cfs_b->lock); if (cfs_b->quota != RUNTIME_INF && cfs_b->runtime > slice) { runtime = cfs_b->runtime; cfs_b->runtime = 0; @@ -2708,11 +3502,11 @@ void __start_cfs_bandwidth(struct cfs_bandwidth *cfs_b) * (timer_active==0 becomes visible before the hrtimer call-back * terminates). In either case we ensure that it's re-programmed */ - while (unlikely(hrtimer_active(&cfs_b->period_timer))) { + while (unlikely(hrtimer_active(&cfs_b->period_timer)) && + hrtimer_try_to_cancel(&cfs_b->period_timer) < 0) { + /* bounce the lock to allow do_sched_cfs_period_timer to run */ raw_spin_unlock(&cfs_b->lock); - /* ensure cfs_b->lock is available while we wait */ - hrtimer_cancel(&cfs_b->period_timer); - + cpu_relax(); raw_spin_lock(&cfs_b->lock); /* if someone else restarted the timer then we're done */ if (cfs_b->timer_active) @@ -3113,7 +3907,7 @@ static long effective_load(struct task_group *tg, int cpu, long wl, long wg) { struct sched_entity *se = tg->se[cpu]; - if (!tg->parent) /* the trivial, non-cgroup case */ + if (!tg->parent || !wl) /* the trivial, non-cgroup case */ return wl; for_each_sched_entity(se) { @@ -3166,8 +3960,7 @@ static long effective_load(struct task_group *tg, int cpu, long wl, long wg) } #else -static inline unsigned long effective_load(struct task_group *tg, int cpu, - unsigned long wl, unsigned long wg) +static long effective_load(struct task_group *tg, int cpu, long wl, long wg) { return wl; } @@ -3420,11 +4213,10 @@ done: * preempt must be disabled. */ static int -select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flags) +select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_flags) { struct sched_domain *tmp, *affine_sd = NULL, *sd = NULL; int cpu = smp_processor_id(); - int prev_cpu = task_cpu(p); int new_cpu = cpu; int want_affine = 0; int sync = wake_flags & WF_SYNC; @@ -3904,9 +4696,12 @@ static bool yield_to_task_fair(struct rq *rq, struct task_struct *p, bool preemp static unsigned long __read_mostly max_load_balance_interval = HZ/10; +enum fbq_type { regular, remote, all }; + #define LBF_ALL_PINNED 0x01 #define LBF_NEED_BREAK 0x02 -#define LBF_SOME_PINNED 0x04 +#define LBF_DST_PINNED 0x04 +#define LBF_SOME_PINNED 0x08 struct lb_env { struct sched_domain *sd; @@ -3929,6 +4724,8 @@ struct lb_env { unsigned int loop; unsigned int loop_break; unsigned int loop_max; + + enum fbq_type fbq_type; }; /* @@ -3975,6 +4772,78 @@ task_hot(struct task_struct *p, u64 now, struct sched_domain *sd) return delta < (s64)sysctl_sched_migration_cost; } +#ifdef CONFIG_NUMA_BALANCING +/* Returns true if the destination node has incurred more faults */ +static bool migrate_improves_locality(struct task_struct *p, struct lb_env *env) +{ + int src_nid, dst_nid; + + if (!sched_feat(NUMA_FAVOUR_HIGHER) || !p->numa_faults || + !(env->sd->flags & SD_NUMA)) { + return false; + } + + src_nid = cpu_to_node(env->src_cpu); + dst_nid = cpu_to_node(env->dst_cpu); + + if (src_nid == dst_nid) + return false; + + /* Always encourage migration to the preferred node. */ + if (dst_nid == p->numa_preferred_nid) + return true; + + /* If both task and group weight improve, this move is a winner. */ + if (task_weight(p, dst_nid) > task_weight(p, src_nid) && + group_weight(p, dst_nid) > group_weight(p, src_nid)) + return true; + + return false; +} + + +static bool migrate_degrades_locality(struct task_struct *p, struct lb_env *env) +{ + int src_nid, dst_nid; + + if (!sched_feat(NUMA) || !sched_feat(NUMA_RESIST_LOWER)) + return false; + + if (!p->numa_faults || !(env->sd->flags & SD_NUMA)) + return false; + + src_nid = cpu_to_node(env->src_cpu); + dst_nid = cpu_to_node(env->dst_cpu); + + if (src_nid == dst_nid) + return false; + + /* Migrating away from the preferred node is always bad. */ + if (src_nid == p->numa_preferred_nid) + return true; + + /* If either task or group weight get worse, don't do it. */ + if (task_weight(p, dst_nid) < task_weight(p, src_nid) || + group_weight(p, dst_nid) < group_weight(p, src_nid)) + return true; + + return false; +} + +#else +static inline bool migrate_improves_locality(struct task_struct *p, + struct lb_env *env) +{ + return false; +} + +static inline bool migrate_degrades_locality(struct task_struct *p, + struct lb_env *env) +{ + return false; +} +#endif + /* * can_migrate_task - may task p from runqueue rq be migrated to this_cpu? */ @@ -3997,6 +4866,8 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env) schedstat_inc(p, se.statistics.nr_failed_migrations_affine); + env->flags |= LBF_SOME_PINNED; + /* * Remember if this task can be migrated to any other cpu in * our sched_group. We may want to revisit it if we couldn't @@ -4005,13 +4876,13 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env) * Also avoid computing new_dst_cpu if we have already computed * one in current iteration. */ - if (!env->dst_grpmask || (env->flags & LBF_SOME_PINNED)) + if (!env->dst_grpmask || (env->flags & LBF_DST_PINNED)) return 0; /* Prevent to re-select dst_cpu via env's cpus */ for_each_cpu_and(cpu, env->dst_grpmask, env->cpus) { if (cpumask_test_cpu(cpu, tsk_cpus_allowed(p))) { - env->flags |= LBF_SOME_PINNED; + env->flags |= LBF_DST_PINNED; env->new_dst_cpu = cpu; break; } @@ -4030,11 +4901,24 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env) /* * Aggressive migration if: - * 1) task is cache cold, or - * 2) too many balance attempts have failed. + * 1) destination numa is preferred + * 2) task is cache cold, or + * 3) too many balance attempts have failed. */ - tsk_cache_hot = task_hot(p, rq_clock_task(env->src_rq), env->sd); + if (!tsk_cache_hot) + tsk_cache_hot = migrate_degrades_locality(p, env); + + if (migrate_improves_locality(p, env)) { +#ifdef CONFIG_SCHEDSTATS + if (tsk_cache_hot) { + schedstat_inc(env->sd, lb_hot_gained[env->idle]); + schedstat_inc(p, se.statistics.nr_forced_migrations); + } +#endif + return 1; + } + if (!tsk_cache_hot || env->sd->nr_balance_failed > env->sd->cache_nice_tries) { @@ -4077,8 +4961,6 @@ static int move_one_task(struct lb_env *env) return 0; } -static unsigned long task_h_load(struct task_struct *p); - static const unsigned int sched_nr_migrate_break = 32; /* @@ -4291,6 +5173,10 @@ struct sg_lb_stats { unsigned int group_weight; int group_imb; /* Is there an imbalance in the group ? */ int group_has_capacity; /* Is there extra capacity in the group? */ +#ifdef CONFIG_NUMA_BALANCING + unsigned int nr_numa_running; + unsigned int nr_preferred_running; +#endif }; /* @@ -4330,7 +5216,7 @@ static inline void init_sd_lb_stats(struct sd_lb_stats *sds) /** * get_sd_load_idx - Obtain the load index for a given sched domain. * @sd: The sched_domain whose load_idx is to be obtained. - * @idle: The Idle status of the CPU for whose sd load_icx is obtained. + * @idle: The idle status of the CPU for whose sd load_idx is obtained. * * Return: The load index. */ @@ -4447,7 +5333,7 @@ void update_group_power(struct sched_domain *sd, int cpu) { struct sched_domain *child = sd->child; struct sched_group *group, *sdg = sd->groups; - unsigned long power; + unsigned long power, power_orig; unsigned long interval; interval = msecs_to_jiffies(sd->balance_interval); @@ -4459,7 +5345,7 @@ void update_group_power(struct sched_domain *sd, int cpu) return; } - power = 0; + power_orig = power = 0; if (child->flags & SD_OVERLAP) { /* @@ -4467,8 +5353,12 @@ void update_group_power(struct sched_domain *sd, int cpu) * span the current group. */ - for_each_cpu(cpu, sched_group_cpus(sdg)) - power += power_of(cpu); + for_each_cpu(cpu, sched_group_cpus(sdg)) { + struct sched_group *sg = cpu_rq(cpu)->sd->groups; + + power_orig += sg->sgp->power_orig; + power += sg->sgp->power; + } } else { /* * !SD_OVERLAP domains can assume that child groups @@ -4477,12 +5367,14 @@ void update_group_power(struct sched_domain *sd, int cpu) group = child->groups; do { + power_orig += group->sgp->power_orig; power += group->sgp->power; group = group->next; } while (group != child->groups); } - sdg->sgp->power_orig = sdg->sgp->power = power; + sdg->sgp->power_orig = power_orig; + sdg->sgp->power = power; } /* @@ -4526,13 +5418,12 @@ fix_small_capacity(struct sched_domain *sd, struct sched_group *group) * cpu 3 and leave one of the cpus in the second group unused. * * The current solution to this issue is detecting the skew in the first group - * by noticing it has a cpu that is overloaded while the remaining cpus are - * idle -- or rather, there's a distinct imbalance in the cpus; see - * sg_imbalanced(). + * by noticing the lower domain failed to reach balance and had difficulty + * moving tasks due to affinity constraints. * * When this is so detected; this group becomes a candidate for busiest; see - * update_sd_pick_busiest(). And calculcate_imbalance() and - * find_busiest_group() avoid some of the usual balance conditional to allow it + * update_sd_pick_busiest(). And calculate_imbalance() and + * find_busiest_group() avoid some of the usual balance conditions to allow it * to create an effective group imbalance. * * This is a somewhat tricky proposition since the next run might not find the @@ -4540,49 +5431,36 @@ fix_small_capacity(struct sched_domain *sd, struct sched_group *group) * subtle and fragile situation. */ -struct sg_imb_stats { - unsigned long max_nr_running, min_nr_running; - unsigned long max_cpu_load, min_cpu_load; -}; - -static inline void init_sg_imb_stats(struct sg_imb_stats *sgi) +static inline int sg_imbalanced(struct sched_group *group) { - sgi->max_cpu_load = sgi->max_nr_running = 0UL; - sgi->min_cpu_load = sgi->min_nr_running = ~0UL; + return group->sgp->imbalance; } -static inline void -update_sg_imb_stats(struct sg_imb_stats *sgi, - unsigned long load, unsigned long nr_running) +/* + * Compute the group capacity. + * + * Avoid the issue where N*frac(smt_power) >= 1 creates 'phantom' cores by + * first dividing out the smt factor and computing the actual number of cores + * and limit power unit capacity with that. + */ +static inline int sg_capacity(struct lb_env *env, struct sched_group *group) { - if (load > sgi->max_cpu_load) - sgi->max_cpu_load = load; - if (sgi->min_cpu_load > load) - sgi->min_cpu_load = load; + unsigned int capacity, smt, cpus; + unsigned int power, power_orig; - if (nr_running > sgi->max_nr_running) - sgi->max_nr_running = nr_running; - if (sgi->min_nr_running > nr_running) - sgi->min_nr_running = nr_running; -} + power = group->sgp->power; + power_orig = group->sgp->power_orig; + cpus = group->group_weight; -static inline int -sg_imbalanced(struct sg_lb_stats *sgs, struct sg_imb_stats *sgi) -{ - /* - * Consider the group unbalanced when the imbalance is larger - * than the average weight of a task. - * - * APZ: with cgroup the avg task weight can vary wildly and - * might not be a suitable number - should we keep a - * normalized nr_running number somewhere that negates - * the hierarchy? - */ - if ((sgi->max_cpu_load - sgi->min_cpu_load) >= sgs->load_per_task && - (sgi->max_nr_running - sgi->min_nr_running) > 1) - return 1; + /* smt := ceil(cpus / power), assumes: 1 < smt_power < 2 */ + smt = DIV_ROUND_UP(SCHED_POWER_SCALE * cpus, power_orig); + capacity = cpus / smt; /* cores */ - return 0; + capacity = min_t(unsigned, capacity, DIV_ROUND_CLOSEST(power, SCHED_POWER_SCALE)); + if (!capacity) + capacity = fix_small_capacity(env->sd, group); + + return capacity; } /** @@ -4597,12 +5475,11 @@ static inline void update_sg_lb_stats(struct lb_env *env, struct sched_group *group, int load_idx, int local_group, struct sg_lb_stats *sgs) { - struct sg_imb_stats sgi; unsigned long nr_running; unsigned long load; int i; - init_sg_imb_stats(&sgi); + memset(sgs, 0, sizeof(*sgs)); for_each_cpu_and(i, sched_group_cpus(group), env->cpus) { struct rq *rq = cpu_rq(i); @@ -4610,24 +5487,22 @@ static inline void update_sg_lb_stats(struct lb_env *env, nr_running = rq->nr_running; /* Bias balancing toward cpus of our domain */ - if (local_group) { + if (local_group) load = target_load(i, load_idx); - } else { + else load = source_load(i, load_idx); - update_sg_imb_stats(&sgi, load, nr_running); - } sgs->group_load += load; sgs->sum_nr_running += nr_running; +#ifdef CONFIG_NUMA_BALANCING + sgs->nr_numa_running += rq->nr_numa_running; + sgs->nr_preferred_running += rq->nr_preferred_running; +#endif sgs->sum_weighted_load += weighted_cpuload(i); if (idle_cpu(i)) sgs->idle_cpus++; } - if (local_group && (env->idle != CPU_NEWLY_IDLE || - time_after_eq(jiffies, group->sgp->next_update))) - update_group_power(env->sd, env->dst_cpu); - /* Adjust by relative CPU power of the group */ sgs->group_power = group->sgp->power; sgs->avg_load = (sgs->group_load*SCHED_POWER_SCALE) / sgs->group_power; @@ -4635,16 +5510,11 @@ static inline void update_sg_lb_stats(struct lb_env *env, if (sgs->sum_nr_running) sgs->load_per_task = sgs->sum_weighted_load / sgs->sum_nr_running; - sgs->group_imb = sg_imbalanced(sgs, &sgi); - - sgs->group_capacity = - DIV_ROUND_CLOSEST(sgs->group_power, SCHED_POWER_SCALE); - - if (!sgs->group_capacity) - sgs->group_capacity = fix_small_capacity(env->sd, group); - sgs->group_weight = group->group_weight; + sgs->group_imb = sg_imbalanced(group); + sgs->group_capacity = sg_capacity(env, group); + if (sgs->group_capacity > sgs->sum_nr_running) sgs->group_has_capacity = 1; } @@ -4693,14 +5563,42 @@ static bool update_sd_pick_busiest(struct lb_env *env, return false; } +#ifdef CONFIG_NUMA_BALANCING +static inline enum fbq_type fbq_classify_group(struct sg_lb_stats *sgs) +{ + if (sgs->sum_nr_running > sgs->nr_numa_running) + return regular; + if (sgs->sum_nr_running > sgs->nr_preferred_running) + return remote; + return all; +} + +static inline enum fbq_type fbq_classify_rq(struct rq *rq) +{ + if (rq->nr_running > rq->nr_numa_running) + return regular; + if (rq->nr_running > rq->nr_preferred_running) + return remote; + return all; +} +#else +static inline enum fbq_type fbq_classify_group(struct sg_lb_stats *sgs) +{ + return all; +} + +static inline enum fbq_type fbq_classify_rq(struct rq *rq) +{ + return regular; +} +#endif /* CONFIG_NUMA_BALANCING */ + /** * update_sd_lb_stats - Update sched_domain's statistics for load balancing. * @env: The load balancing environment. - * @balance: Should we balance. * @sds: variable to hold the statistics for this sched_domain. */ -static inline void update_sd_lb_stats(struct lb_env *env, - struct sd_lb_stats *sds) +static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sds) { struct sched_domain *child = env->sd->child; struct sched_group *sg = env->sd->groups; @@ -4720,11 +5618,17 @@ static inline void update_sd_lb_stats(struct lb_env *env, if (local_group) { sds->local = sg; sgs = &sds->local_stat; + + if (env->idle != CPU_NEWLY_IDLE || + time_after_eq(jiffies, sg->sgp->next_update)) + update_group_power(env->sd, env->dst_cpu); } - memset(sgs, 0, sizeof(*sgs)); update_sg_lb_stats(env, sg, load_idx, local_group, sgs); + if (local_group) + goto next_group; + /* * In case the child domain prefers tasks go to siblings * first, lower the sg capacity to one so that we'll try @@ -4735,21 +5639,25 @@ static inline void update_sd_lb_stats(struct lb_env *env, * heaviest group when it is already under-utilized (possible * with a large weight task outweighs the tasks on the system). */ - if (prefer_sibling && !local_group && - sds->local && sds->local_stat.group_has_capacity) + if (prefer_sibling && sds->local && + sds->local_stat.group_has_capacity) sgs->group_capacity = min(sgs->group_capacity, 1U); - /* Now, start updating sd_lb_stats */ - sds->total_load += sgs->group_load; - sds->total_pwr += sgs->group_power; - - if (!local_group && update_sd_pick_busiest(env, sds, sg, sgs)) { + if (update_sd_pick_busiest(env, sds, sg, sgs)) { sds->busiest = sg; sds->busiest_stat = *sgs; } +next_group: + /* Now, start updating sd_lb_stats */ + sds->total_load += sgs->group_load; + sds->total_pwr += sgs->group_power; + sg = sg->next; } while (sg != env->sd->groups); + + if (env->sd->flags & SD_NUMA) + env->fbq_type = fbq_classify_group(&sds->busiest_stat); } /** @@ -5053,15 +5961,39 @@ static struct rq *find_busiest_queue(struct lb_env *env, int i; for_each_cpu_and(i, sched_group_cpus(group), env->cpus) { - unsigned long power = power_of(i); - unsigned long capacity = DIV_ROUND_CLOSEST(power, - SCHED_POWER_SCALE); - unsigned long wl; + unsigned long power, capacity, wl; + enum fbq_type rt; + rq = cpu_rq(i); + rt = fbq_classify_rq(rq); + + /* + * We classify groups/runqueues into three groups: + * - regular: there are !numa tasks + * - remote: there are numa tasks that run on the 'wrong' node + * - all: there is no distinction + * + * In order to avoid migrating ideally placed numa tasks, + * ignore those when there's better options. + * + * If we ignore the actual busiest queue to migrate another + * task, the next balance pass can still reduce the busiest + * queue by moving tasks around inside the node. + * + * If we cannot move enough load due to this classification + * the next pass will adjust the group classification and + * allow migration of more tasks. + * + * Both cases only affect the total convergence complexity. + */ + if (rt > env->fbq_type) + continue; + + power = power_of(i); + capacity = DIV_ROUND_CLOSEST(power, SCHED_POWER_SCALE); if (!capacity) capacity = fix_small_capacity(env->sd, group); - rq = cpu_rq(i); wl = weighted_cpuload(i); /* @@ -5164,6 +6096,7 @@ static int load_balance(int this_cpu, struct rq *this_rq, int *continue_balancing) { int ld_moved, cur_ld_moved, active_balance = 0; + struct sched_domain *sd_parent = sd->parent; struct sched_group *group; struct rq *busiest; unsigned long flags; @@ -5177,6 +6110,7 @@ static int load_balance(int this_cpu, struct rq *this_rq, .idle = idle, .loop_break = sched_nr_migrate_break, .cpus = cpus, + .fbq_type = all, }; /* @@ -5268,17 +6202,17 @@ more_balance: * moreover subsequent load balance cycles should correct the * excess load moved. */ - if ((env.flags & LBF_SOME_PINNED) && env.imbalance > 0) { + if ((env.flags & LBF_DST_PINNED) && env.imbalance > 0) { + + /* Prevent to re-select dst_cpu via env's cpus */ + cpumask_clear_cpu(env.dst_cpu, env.cpus); env.dst_rq = cpu_rq(env.new_dst_cpu); env.dst_cpu = env.new_dst_cpu; - env.flags &= ~LBF_SOME_PINNED; + env.flags &= ~LBF_DST_PINNED; env.loop = 0; env.loop_break = sched_nr_migrate_break; - /* Prevent to re-select dst_cpu via env's cpus */ - cpumask_clear_cpu(env.dst_cpu, env.cpus); - /* * Go back to "more_balance" rather than "redo" since we * need to continue with same src_cpu. @@ -5286,6 +6220,18 @@ more_balance: goto more_balance; } + /* + * We failed to reach balance because of affinity. + */ + if (sd_parent) { + int *group_imbalance = &sd_parent->groups->sgp->imbalance; + + if ((env.flags & LBF_SOME_PINNED) && env.imbalance > 0) { + *group_imbalance = 1; + } else if (*group_imbalance) + *group_imbalance = 0; + } + /* All tasks on this runqueue were pinned by CPU affinity */ if (unlikely(env.flags & LBF_ALL_PINNED)) { cpumask_clear_cpu(cpu_of(busiest), cpus); @@ -5393,6 +6339,7 @@ void idle_balance(int this_cpu, struct rq *this_rq) struct sched_domain *sd; int pulled_task = 0; unsigned long next_balance = jiffies + HZ; + u64 curr_cost = 0; this_rq->idle_stamp = rq_clock(this_rq); @@ -5409,15 +6356,27 @@ void idle_balance(int this_cpu, struct rq *this_rq) for_each_domain(this_cpu, sd) { unsigned long interval; int continue_balancing = 1; + u64 t0, domain_cost; if (!(sd->flags & SD_LOAD_BALANCE)) continue; + if (this_rq->avg_idle < curr_cost + sd->max_newidle_lb_cost) + break; + if (sd->flags & SD_BALANCE_NEWIDLE) { + t0 = sched_clock_cpu(this_cpu); + /* If we've pulled tasks over stop searching: */ pulled_task = load_balance(this_cpu, this_rq, sd, CPU_NEWLY_IDLE, &continue_balancing); + + domain_cost = sched_clock_cpu(this_cpu) - t0; + if (domain_cost > sd->max_newidle_lb_cost) + sd->max_newidle_lb_cost = domain_cost; + + curr_cost += domain_cost; } interval = msecs_to_jiffies(sd->balance_interval); @@ -5439,6 +6398,9 @@ void idle_balance(int this_cpu, struct rq *this_rq) */ this_rq->next_balance = next_balance; } + + if (curr_cost > this_rq->max_idle_balance_cost) + this_rq->max_idle_balance_cost = curr_cost; } /* @@ -5662,15 +6624,39 @@ static void rebalance_domains(int cpu, enum cpu_idle_type idle) /* Earliest time when we have to do rebalance again */ unsigned long next_balance = jiffies + 60*HZ; int update_next_balance = 0; - int need_serialize; + int need_serialize, need_decay = 0; + u64 max_cost = 0; update_blocked_averages(cpu); rcu_read_lock(); for_each_domain(cpu, sd) { + /* + * Decay the newidle max times here because this is a regular + * visit to all the domains. Decay ~1% per second. + */ + if (time_after(jiffies, sd->next_decay_max_lb_cost)) { + sd->max_newidle_lb_cost = + (sd->max_newidle_lb_cost * 253) / 256; + sd->next_decay_max_lb_cost = jiffies + HZ; + need_decay = 1; + } + max_cost += sd->max_newidle_lb_cost; + if (!(sd->flags & SD_LOAD_BALANCE)) continue; + /* + * Stop the load balance at this level. There is another + * CPU in our sched group which is doing load balancing more + * actively. + */ + if (!continue_balancing) { + if (need_decay) + continue; + break; + } + interval = sd->balance_interval; if (idle != CPU_IDLE) interval *= sd->busy_factor; @@ -5689,7 +6675,7 @@ static void rebalance_domains(int cpu, enum cpu_idle_type idle) if (time_after_eq(jiffies, sd->last_balance + interval)) { if (load_balance(cpu, rq, sd, idle, &continue_balancing)) { /* - * The LBF_SOME_PINNED logic could have changed + * The LBF_DST_PINNED logic could have changed * env->dst_cpu, so we can't know our idle * state even if we migrated tasks. Update it. */ @@ -5704,14 +6690,14 @@ out: next_balance = sd->last_balance + interval; update_next_balance = 1; } - + } + if (need_decay) { /* - * Stop the load balance at this level. There is another - * CPU in our sched group which is doing load balancing more - * actively. + * Ensure the rq-wide value also decays but keep it at a + * reasonable floor to avoid funnies with rq->avg_idle. */ - if (!continue_balancing) - break; + rq->max_idle_balance_cost = + max((u64)sysctl_sched_migration_cost, max_cost); } rcu_read_unlock(); @@ -6214,7 +7200,8 @@ void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, se->cfs_rq = parent->my_q; se->my_q = cfs_rq; - update_load_set(&se->load, 0); + /* guarantee group entities always have weight */ + update_load_set(&se->load, NICE_0_LOAD); se->parent = parent; } diff --git a/kernel/sched/features.h b/kernel/sched/features.h index 99399f8..5716929 100644 --- a/kernel/sched/features.h +++ b/kernel/sched/features.h @@ -63,10 +63,23 @@ SCHED_FEAT(LB_MIN, false) /* * Apply the automatic NUMA scheduling policy. Enabled automatically * at runtime if running on a NUMA machine. Can be controlled via - * numa_balancing=. Allow PTE scanning to be forced on UMA machines - * for debugging the core machinery. + * numa_balancing= */ #ifdef CONFIG_NUMA_BALANCING SCHED_FEAT(NUMA, false) -SCHED_FEAT(NUMA_FORCE, false) + +/* + * NUMA_FAVOUR_HIGHER will favor moving tasks towards nodes where a + * higher number of hinting faults are recorded during active load + * balancing. + */ +SCHED_FEAT(NUMA_FAVOUR_HIGHER, true) + +/* + * NUMA_RESIST_LOWER will resist moving tasks towards nodes where a + * lower number of hinting faults have been recorded. As this has + * the potential to prevent a task ever migrating to a new node + * due to CPU overload it is disabled by default. + */ +SCHED_FEAT(NUMA_RESIST_LOWER, false) #endif diff --git a/kernel/sched/idle_task.c b/kernel/sched/idle_task.c index d8da010..516c3d9 100644 --- a/kernel/sched/idle_task.c +++ b/kernel/sched/idle_task.c @@ -9,7 +9,7 @@ #ifdef CONFIG_SMP static int -select_task_rq_idle(struct task_struct *p, int sd_flag, int flags) +select_task_rq_idle(struct task_struct *p, int cpu, int sd_flag, int flags) { return task_cpu(p); /* IDLE tasks as never migrated */ } diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 01970c8..7d57275 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -246,8 +246,10 @@ static inline void rt_set_overload(struct rq *rq) * if we should look at the mask. It would be a shame * if we looked at the mask, but the mask was not * updated yet. + * + * Matched by the barrier in pull_rt_task(). */ - wmb(); + smp_wmb(); atomic_inc(&rq->rd->rto_count); } @@ -1169,13 +1171,10 @@ static void yield_task_rt(struct rq *rq) static int find_lowest_rq(struct task_struct *task); static int -select_task_rq_rt(struct task_struct *p, int sd_flag, int flags) +select_task_rq_rt(struct task_struct *p, int cpu, int sd_flag, int flags) { struct task_struct *curr; struct rq *rq; - int cpu; - - cpu = task_cpu(p); if (p->nr_cpus_allowed == 1) goto out; @@ -1213,8 +1212,7 @@ select_task_rq_rt(struct task_struct *p, int sd_flag, int flags) */ if (curr && unlikely(rt_task(curr)) && (curr->nr_cpus_allowed < 2 || - curr->prio <= p->prio) && - (p->nr_cpus_allowed > 1)) { + curr->prio <= p->prio)) { int target = find_lowest_rq(p); if (target != -1) @@ -1630,6 +1628,12 @@ static int pull_rt_task(struct rq *this_rq) if (likely(!rt_overloaded(this_rq))) return 0; + /* + * Match the barrier from rt_set_overloaded; this guarantees that if we + * see overloaded we must also see the rto_mask bit. + */ + smp_rmb(); + for_each_cpu(cpu, this_rq->rd->rto_mask) { if (this_cpu == cpu) continue; @@ -1931,8 +1935,8 @@ static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued) p->rt.time_slice = sched_rr_timeslice; /* - * Requeue to the end of queue if we (and all of our ancestors) are the - * only element on the queue + * Requeue to the end of queue if we (and all of our ancestors) are not + * the only element on the queue */ for_each_sched_rt_entity(rt_se) { if (rt_se->run_list.prev != rt_se->run_list.next) { diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index b3c5653..4e650ac 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -6,6 +6,7 @@ #include <linux/spinlock.h> #include <linux/stop_machine.h> #include <linux/tick.h> +#include <linux/slab.h> #include "cpupri.h" #include "cpuacct.h" @@ -408,6 +409,10 @@ struct rq { * remote CPUs use both these fields when doing load calculation. */ unsigned int nr_running; +#ifdef CONFIG_NUMA_BALANCING + unsigned int nr_numa_running; + unsigned int nr_preferred_running; +#endif #define CPU_LOAD_IDX_MAX 5 unsigned long cpu_load[CPU_LOAD_IDX_MAX]; unsigned long last_load_update_tick; @@ -476,6 +481,9 @@ struct rq { u64 age_stamp; u64 idle_stamp; u64 avg_idle; + + /* This is used to determine avg_idle's max value */ + u64 max_idle_balance_cost; #endif #ifdef CONFIG_IRQ_TIME_ACCOUNTING @@ -552,6 +560,12 @@ static inline u64 rq_clock_task(struct rq *rq) return rq->clock_task; } +#ifdef CONFIG_NUMA_BALANCING +extern void sched_setnuma(struct task_struct *p, int node); +extern int migrate_task_to(struct task_struct *p, int cpu); +extern int migrate_swap(struct task_struct *, struct task_struct *); +#endif /* CONFIG_NUMA_BALANCING */ + #ifdef CONFIG_SMP #define rcu_dereference_check_sched_domain(p) \ @@ -593,9 +607,22 @@ static inline struct sched_domain *highest_flag_domain(int cpu, int flag) return hsd; } +static inline struct sched_domain *lowest_flag_domain(int cpu, int flag) +{ + struct sched_domain *sd; + + for_each_domain(cpu, sd) { + if (sd->flags & flag) + break; + } + + return sd; +} + DECLARE_PER_CPU(struct sched_domain *, sd_llc); DECLARE_PER_CPU(int, sd_llc_size); DECLARE_PER_CPU(int, sd_llc_id); +DECLARE_PER_CPU(struct sched_domain *, sd_numa); struct sched_group_power { atomic_t ref; @@ -605,6 +632,7 @@ struct sched_group_power { */ unsigned int power, power_orig; unsigned long next_update; + int imbalance; /* XXX unrelated to power but shared group state */ /* * Number of busy cpus in this group. */ @@ -719,6 +747,7 @@ static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) */ smp_wmb(); task_thread_info(p)->cpu = cpu; + p->wake_cpu = cpu; #endif } @@ -974,7 +1003,7 @@ struct sched_class { void (*put_prev_task) (struct rq *rq, struct task_struct *p); #ifdef CONFIG_SMP - int (*select_task_rq)(struct task_struct *p, int sd_flag, int flags); + int (*select_task_rq)(struct task_struct *p, int task_cpu, int sd_flag, int flags); void (*migrate_task_rq)(struct task_struct *p, int next_cpu); void (*pre_schedule) (struct rq *this_rq, struct task_struct *task); @@ -1220,6 +1249,24 @@ static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_); } +static inline void double_lock(spinlock_t *l1, spinlock_t *l2) +{ + if (l1 > l2) + swap(l1, l2); + + spin_lock(l1); + spin_lock_nested(l2, SINGLE_DEPTH_NESTING); +} + +static inline void double_raw_lock(raw_spinlock_t *l1, raw_spinlock_t *l2) +{ + if (l1 > l2) + swap(l1, l2); + + raw_spin_lock(l1); + raw_spin_lock_nested(l2, SINGLE_DEPTH_NESTING); +} + /* * double_rq_lock - safely lock two runqueues * @@ -1305,7 +1352,8 @@ extern void print_rt_stats(struct seq_file *m, int cpu); extern void init_cfs_rq(struct cfs_rq *cfs_rq); extern void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq); -extern void account_cfs_bandwidth_used(int enabled, int was_enabled); +extern void cfs_bandwidth_usage_inc(void); +extern void cfs_bandwidth_usage_dec(void); #ifdef CONFIG_NO_HZ_COMMON enum rq_nohz_flag_bits { diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h index c7edee7..4ab7043 100644 --- a/kernel/sched/stats.h +++ b/kernel/sched/stats.h @@ -59,9 +59,9 @@ static inline void sched_info_reset_dequeued(struct task_struct *t) * from dequeue_task() to account for possible rq->clock skew across cpus. The * delta taken on each cpu would annul the skew. */ -static inline void sched_info_dequeued(struct task_struct *t) +static inline void sched_info_dequeued(struct rq *rq, struct task_struct *t) { - unsigned long long now = rq_clock(task_rq(t)), delta = 0; + unsigned long long now = rq_clock(rq), delta = 0; if (unlikely(sched_info_on())) if (t->sched_info.last_queued) @@ -69,7 +69,7 @@ static inline void sched_info_dequeued(struct task_struct *t) sched_info_reset_dequeued(t); t->sched_info.run_delay += delta; - rq_sched_info_dequeued(task_rq(t), delta); + rq_sched_info_dequeued(rq, delta); } /* @@ -77,9 +77,9 @@ static inline void sched_info_dequeued(struct task_struct *t) * long it was waiting to run. We also note when it began so that we * can keep stats on how long its timeslice is. */ -static void sched_info_arrive(struct task_struct *t) +static void sched_info_arrive(struct rq *rq, struct task_struct *t) { - unsigned long long now = rq_clock(task_rq(t)), delta = 0; + unsigned long long now = rq_clock(rq), delta = 0; if (t->sched_info.last_queued) delta = now - t->sched_info.last_queued; @@ -88,7 +88,7 @@ static void sched_info_arrive(struct task_struct *t) t->sched_info.last_arrival = now; t->sched_info.pcount++; - rq_sched_info_arrive(task_rq(t), delta); + rq_sched_info_arrive(rq, delta); } /* @@ -96,11 +96,11 @@ static void sched_info_arrive(struct task_struct *t) * the timestamp if it is already not set. It's assumed that * sched_info_dequeued() will clear that stamp when appropriate. */ -static inline void sched_info_queued(struct task_struct *t) +static inline void sched_info_queued(struct rq *rq, struct task_struct *t) { if (unlikely(sched_info_on())) if (!t->sched_info.last_queued) - t->sched_info.last_queued = rq_clock(task_rq(t)); + t->sched_info.last_queued = rq_clock(rq); } /* @@ -111,15 +111,15 @@ static inline void sched_info_queued(struct task_struct *t) * sched_info_queued() to mark that it has now again started waiting on * the runqueue. */ -static inline void sched_info_depart(struct task_struct *t) +static inline void sched_info_depart(struct rq *rq, struct task_struct *t) { - unsigned long long delta = rq_clock(task_rq(t)) - + unsigned long long delta = rq_clock(rq) - t->sched_info.last_arrival; - rq_sched_info_depart(task_rq(t), delta); + rq_sched_info_depart(rq, delta); if (t->state == TASK_RUNNING) - sched_info_queued(t); + sched_info_queued(rq, t); } /* @@ -128,32 +128,34 @@ static inline void sched_info_depart(struct task_struct *t) * the idle task.) We are only called when prev != next. */ static inline void -__sched_info_switch(struct task_struct *prev, struct task_struct *next) +__sched_info_switch(struct rq *rq, + struct task_struct *prev, struct task_struct *next) { - struct rq *rq = task_rq(prev); - /* * prev now departs the cpu. It's not interesting to record * stats about how efficient we were at scheduling the idle * process, however. */ if (prev != rq->idle) - sched_info_depart(prev); + sched_info_depart(rq, prev); if (next != rq->idle) - sched_info_arrive(next); + sched_info_arrive(rq, next); } static inline void -sched_info_switch(struct task_struct *prev, struct task_struct *next) +sched_info_switch(struct rq *rq, + struct task_struct *prev, struct task_struct *next) { if (unlikely(sched_info_on())) - __sched_info_switch(prev, next); + __sched_info_switch(rq, prev, next); } #else -#define sched_info_queued(t) do { } while (0) +#define sched_info_queued(rq, t) do { } while (0) #define sched_info_reset_dequeued(t) do { } while (0) -#define sched_info_dequeued(t) do { } while (0) -#define sched_info_switch(t, next) do { } while (0) +#define sched_info_dequeued(rq, t) do { } while (0) +#define sched_info_depart(rq, t) do { } while (0) +#define sched_info_arrive(rq, next) do { } while (0) +#define sched_info_switch(rq, t, next) do { } while (0) #endif /* CONFIG_SCHEDSTATS || CONFIG_TASK_DELAY_ACCT */ /* diff --git a/kernel/sched/stop_task.c b/kernel/sched/stop_task.c index e08fbee..47197de 100644 --- a/kernel/sched/stop_task.c +++ b/kernel/sched/stop_task.c @@ -11,7 +11,7 @@ #ifdef CONFIG_SMP static int -select_task_rq_stop(struct task_struct *p, int sd_flag, int flags) +select_task_rq_stop(struct task_struct *p, int cpu, int sd_flag, int flags) { return task_cpu(p); /* stop tasks as never migrate */ } diff --git a/kernel/wait.c b/kernel/sched/wait.c index d550920..7d50f79 100644 --- a/kernel/wait.c +++ b/kernel/sched/wait.c @@ -53,6 +53,109 @@ EXPORT_SYMBOL(remove_wait_queue); /* + * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just + * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve + * number) then we wake all the non-exclusive tasks and one exclusive task. + * + * There are circumstances in which we can try to wake a task which has already + * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns + * zero in this (rare) case, and we handle it by continuing to scan the queue. + */ +static void __wake_up_common(wait_queue_head_t *q, unsigned int mode, + int nr_exclusive, int wake_flags, void *key) +{ + wait_queue_t *curr, *next; + + list_for_each_entry_safe(curr, next, &q->task_list, task_list) { + unsigned flags = curr->flags; + + if (curr->func(curr, mode, wake_flags, key) && + (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive) + break; + } +} + +/** + * __wake_up - wake up threads blocked on a waitqueue. + * @q: the waitqueue + * @mode: which threads + * @nr_exclusive: how many wake-one or wake-many threads to wake up + * @key: is directly passed to the wakeup function + * + * It may be assumed that this function implies a write memory barrier before + * changing the task state if and only if any tasks are woken up. + */ +void __wake_up(wait_queue_head_t *q, unsigned int mode, + int nr_exclusive, void *key) +{ + unsigned long flags; + + spin_lock_irqsave(&q->lock, flags); + __wake_up_common(q, mode, nr_exclusive, 0, key); + spin_unlock_irqrestore(&q->lock, flags); +} +EXPORT_SYMBOL(__wake_up); + +/* + * Same as __wake_up but called with the spinlock in wait_queue_head_t held. + */ +void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr) +{ + __wake_up_common(q, mode, nr, 0, NULL); +} +EXPORT_SYMBOL_GPL(__wake_up_locked); + +void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key) +{ + __wake_up_common(q, mode, 1, 0, key); +} +EXPORT_SYMBOL_GPL(__wake_up_locked_key); + +/** + * __wake_up_sync_key - wake up threads blocked on a waitqueue. + * @q: the waitqueue + * @mode: which threads + * @nr_exclusive: how many wake-one or wake-many threads to wake up + * @key: opaque value to be passed to wakeup targets + * + * The sync wakeup differs that the waker knows that it will schedule + * away soon, so while the target thread will be woken up, it will not + * be migrated to another CPU - ie. the two threads are 'synchronized' + * with each other. This can prevent needless bouncing between CPUs. + * + * On UP it can prevent extra preemption. + * + * It may be assumed that this function implies a write memory barrier before + * changing the task state if and only if any tasks are woken up. + */ +void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, + int nr_exclusive, void *key) +{ + unsigned long flags; + int wake_flags = 1; /* XXX WF_SYNC */ + + if (unlikely(!q)) + return; + + if (unlikely(nr_exclusive != 1)) + wake_flags = 0; + + spin_lock_irqsave(&q->lock, flags); + __wake_up_common(q, mode, nr_exclusive, wake_flags, key); + spin_unlock_irqrestore(&q->lock, flags); +} +EXPORT_SYMBOL_GPL(__wake_up_sync_key); + +/* + * __wake_up_sync - see __wake_up_sync_key() + */ +void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive) +{ + __wake_up_sync_key(q, mode, nr_exclusive, NULL); +} +EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */ + +/* * Note: we use "set_current_state()" _after_ the wait-queue add, * because we need a memory barrier there on SMP, so that any * wake-function that tests for the wait-queue being active @@ -92,6 +195,30 @@ prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state) } EXPORT_SYMBOL(prepare_to_wait_exclusive); +long prepare_to_wait_event(wait_queue_head_t *q, wait_queue_t *wait, int state) +{ + unsigned long flags; + + if (signal_pending_state(state, current)) + return -ERESTARTSYS; + + wait->private = current; + wait->func = autoremove_wake_function; + + spin_lock_irqsave(&q->lock, flags); + if (list_empty(&wait->task_list)) { + if (wait->flags & WQ_FLAG_EXCLUSIVE) + __add_wait_queue_tail(q, wait); + else + __add_wait_queue(q, wait); + } + set_current_state(state); + spin_unlock_irqrestore(&q->lock, flags); + + return 0; +} +EXPORT_SYMBOL(prepare_to_wait_event); + /** * finish_wait - clean up after waiting in a queue * @q: waitqueue waited on diff --git a/kernel/softirq.c b/kernel/softirq.c index d7d498d..dcab1d3 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -100,13 +100,13 @@ static void __local_bh_disable(unsigned long ip, unsigned int cnt) raw_local_irq_save(flags); /* - * The preempt tracer hooks into add_preempt_count and will break + * The preempt tracer hooks into preempt_count_add and will break * lockdep because it calls back into lockdep after SOFTIRQ_OFFSET * is set and before current->softirq_enabled is cleared. * We must manually increment preempt_count here and manually * call the trace_preempt_off later. */ - preempt_count() += cnt; + __preempt_count_add(cnt); /* * Were softirqs turned off above: */ @@ -120,7 +120,7 @@ static void __local_bh_disable(unsigned long ip, unsigned int cnt) #else /* !CONFIG_TRACE_IRQFLAGS */ static inline void __local_bh_disable(unsigned long ip, unsigned int cnt) { - add_preempt_count(cnt); + preempt_count_add(cnt); barrier(); } #endif /* CONFIG_TRACE_IRQFLAGS */ @@ -139,7 +139,7 @@ static void __local_bh_enable(unsigned int cnt) if (softirq_count() == cnt) trace_softirqs_on(_RET_IP_); - sub_preempt_count(cnt); + preempt_count_sub(cnt); } /* @@ -169,12 +169,12 @@ static inline void _local_bh_enable_ip(unsigned long ip) * Keep preemption disabled until we are done with * softirq processing: */ - sub_preempt_count(SOFTIRQ_DISABLE_OFFSET - 1); + preempt_count_sub(SOFTIRQ_DISABLE_OFFSET - 1); if (unlikely(!in_interrupt() && local_softirq_pending())) do_softirq(); - dec_preempt_count(); + preempt_count_dec(); #ifdef CONFIG_TRACE_IRQFLAGS local_irq_enable(); #endif @@ -256,7 +256,7 @@ restart: " exited with %08x?\n", vec_nr, softirq_to_name[vec_nr], h->action, prev_count, preempt_count()); - preempt_count() = prev_count; + preempt_count_set(prev_count); } rcu_bh_qs(cpu); @@ -369,7 +369,7 @@ void irq_exit(void) account_irq_exit_time(current); trace_hardirq_exit(); - sub_preempt_count(HARDIRQ_OFFSET); + preempt_count_sub(HARDIRQ_OFFSET); if (!in_interrupt() && local_softirq_pending()) invoke_softirq(); diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index c09f295..c530bc5 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -115,6 +115,182 @@ int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg) return done.executed ? done.ret : -ENOENT; } +/* This controls the threads on each CPU. */ +enum multi_stop_state { + /* Dummy starting state for thread. */ + MULTI_STOP_NONE, + /* Awaiting everyone to be scheduled. */ + MULTI_STOP_PREPARE, + /* Disable interrupts. */ + MULTI_STOP_DISABLE_IRQ, + /* Run the function */ + MULTI_STOP_RUN, + /* Exit */ + MULTI_STOP_EXIT, +}; + +struct multi_stop_data { + int (*fn)(void *); + void *data; + /* Like num_online_cpus(), but hotplug cpu uses us, so we need this. */ + unsigned int num_threads; + const struct cpumask *active_cpus; + + enum multi_stop_state state; + atomic_t thread_ack; +}; + +static void set_state(struct multi_stop_data *msdata, + enum multi_stop_state newstate) +{ + /* Reset ack counter. */ + atomic_set(&msdata->thread_ack, msdata->num_threads); + smp_wmb(); + msdata->state = newstate; +} + +/* Last one to ack a state moves to the next state. */ +static void ack_state(struct multi_stop_data *msdata) +{ + if (atomic_dec_and_test(&msdata->thread_ack)) + set_state(msdata, msdata->state + 1); +} + +/* This is the cpu_stop function which stops the CPU. */ +static int multi_cpu_stop(void *data) +{ + struct multi_stop_data *msdata = data; + enum multi_stop_state curstate = MULTI_STOP_NONE; + int cpu = smp_processor_id(), err = 0; + unsigned long flags; + bool is_active; + + /* + * When called from stop_machine_from_inactive_cpu(), irq might + * already be disabled. Save the state and restore it on exit. + */ + local_save_flags(flags); + + if (!msdata->active_cpus) + is_active = cpu == cpumask_first(cpu_online_mask); + else + is_active = cpumask_test_cpu(cpu, msdata->active_cpus); + + /* Simple state machine */ + do { + /* Chill out and ensure we re-read multi_stop_state. */ + cpu_relax(); + if (msdata->state != curstate) { + curstate = msdata->state; + switch (curstate) { + case MULTI_STOP_DISABLE_IRQ: + local_irq_disable(); + hard_irq_disable(); + break; + case MULTI_STOP_RUN: + if (is_active) + err = msdata->fn(msdata->data); + break; + default: + break; + } + ack_state(msdata); + } + } while (curstate != MULTI_STOP_EXIT); + + local_irq_restore(flags); + return err; +} + +struct irq_cpu_stop_queue_work_info { + int cpu1; + int cpu2; + struct cpu_stop_work *work1; + struct cpu_stop_work *work2; +}; + +/* + * This function is always run with irqs and preemption disabled. + * This guarantees that both work1 and work2 get queued, before + * our local migrate thread gets the chance to preempt us. + */ +static void irq_cpu_stop_queue_work(void *arg) +{ + struct irq_cpu_stop_queue_work_info *info = arg; + cpu_stop_queue_work(info->cpu1, info->work1); + cpu_stop_queue_work(info->cpu2, info->work2); +} + +/** + * stop_two_cpus - stops two cpus + * @cpu1: the cpu to stop + * @cpu2: the other cpu to stop + * @fn: function to execute + * @arg: argument to @fn + * + * Stops both the current and specified CPU and runs @fn on one of them. + * + * returns when both are completed. + */ +int stop_two_cpus(unsigned int cpu1, unsigned int cpu2, cpu_stop_fn_t fn, void *arg) +{ + struct cpu_stop_done done; + struct cpu_stop_work work1, work2; + struct irq_cpu_stop_queue_work_info call_args; + struct multi_stop_data msdata; + + preempt_disable(); + msdata = (struct multi_stop_data){ + .fn = fn, + .data = arg, + .num_threads = 2, + .active_cpus = cpumask_of(cpu1), + }; + + work1 = work2 = (struct cpu_stop_work){ + .fn = multi_cpu_stop, + .arg = &msdata, + .done = &done + }; + + call_args = (struct irq_cpu_stop_queue_work_info){ + .cpu1 = cpu1, + .cpu2 = cpu2, + .work1 = &work1, + .work2 = &work2, + }; + + cpu_stop_init_done(&done, 2); + set_state(&msdata, MULTI_STOP_PREPARE); + + /* + * If we observe both CPUs active we know _cpu_down() cannot yet have + * queued its stop_machine works and therefore ours will get executed + * first. Or its not either one of our CPUs that's getting unplugged, + * in which case we don't care. + * + * This relies on the stopper workqueues to be FIFO. + */ + if (!cpu_active(cpu1) || !cpu_active(cpu2)) { + preempt_enable(); + return -ENOENT; + } + + /* + * Queuing needs to be done by the lowest numbered CPU, to ensure + * that works are always queued in the same order on every CPU. + * This prevents deadlocks. + */ + smp_call_function_single(min(cpu1, cpu2), + &irq_cpu_stop_queue_work, + &call_args, 0); + preempt_enable(); + + wait_for_completion(&done.completion); + + return done.executed ? done.ret : -ENOENT; +} + /** * stop_one_cpu_nowait - stop a cpu but don't wait for completion * @cpu: cpu to stop @@ -359,98 +535,14 @@ early_initcall(cpu_stop_init); #ifdef CONFIG_STOP_MACHINE -/* This controls the threads on each CPU. */ -enum stopmachine_state { - /* Dummy starting state for thread. */ - STOPMACHINE_NONE, - /* Awaiting everyone to be scheduled. */ - STOPMACHINE_PREPARE, - /* Disable interrupts. */ - STOPMACHINE_DISABLE_IRQ, - /* Run the function */ - STOPMACHINE_RUN, - /* Exit */ - STOPMACHINE_EXIT, -}; - -struct stop_machine_data { - int (*fn)(void *); - void *data; - /* Like num_online_cpus(), but hotplug cpu uses us, so we need this. */ - unsigned int num_threads; - const struct cpumask *active_cpus; - - enum stopmachine_state state; - atomic_t thread_ack; -}; - -static void set_state(struct stop_machine_data *smdata, - enum stopmachine_state newstate) -{ - /* Reset ack counter. */ - atomic_set(&smdata->thread_ack, smdata->num_threads); - smp_wmb(); - smdata->state = newstate; -} - -/* Last one to ack a state moves to the next state. */ -static void ack_state(struct stop_machine_data *smdata) -{ - if (atomic_dec_and_test(&smdata->thread_ack)) - set_state(smdata, smdata->state + 1); -} - -/* This is the cpu_stop function which stops the CPU. */ -static int stop_machine_cpu_stop(void *data) -{ - struct stop_machine_data *smdata = data; - enum stopmachine_state curstate = STOPMACHINE_NONE; - int cpu = smp_processor_id(), err = 0; - unsigned long flags; - bool is_active; - - /* - * When called from stop_machine_from_inactive_cpu(), irq might - * already be disabled. Save the state and restore it on exit. - */ - local_save_flags(flags); - - if (!smdata->active_cpus) - is_active = cpu == cpumask_first(cpu_online_mask); - else - is_active = cpumask_test_cpu(cpu, smdata->active_cpus); - - /* Simple state machine */ - do { - /* Chill out and ensure we re-read stopmachine_state. */ - cpu_relax(); - if (smdata->state != curstate) { - curstate = smdata->state; - switch (curstate) { - case STOPMACHINE_DISABLE_IRQ: - local_irq_disable(); - hard_irq_disable(); - break; - case STOPMACHINE_RUN: - if (is_active) - err = smdata->fn(smdata->data); - break; - default: - break; - } - ack_state(smdata); - } - } while (curstate != STOPMACHINE_EXIT); - - local_irq_restore(flags); - return err; -} - int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus) { - struct stop_machine_data smdata = { .fn = fn, .data = data, - .num_threads = num_online_cpus(), - .active_cpus = cpus }; + struct multi_stop_data msdata = { + .fn = fn, + .data = data, + .num_threads = num_online_cpus(), + .active_cpus = cpus, + }; if (!stop_machine_initialized) { /* @@ -461,7 +553,7 @@ int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus) unsigned long flags; int ret; - WARN_ON_ONCE(smdata.num_threads != 1); + WARN_ON_ONCE(msdata.num_threads != 1); local_irq_save(flags); hard_irq_disable(); @@ -472,8 +564,8 @@ int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus) } /* Set the initial state and stop all online cpus. */ - set_state(&smdata, STOPMACHINE_PREPARE); - return stop_cpus(cpu_online_mask, stop_machine_cpu_stop, &smdata); + set_state(&msdata, MULTI_STOP_PREPARE); + return stop_cpus(cpu_online_mask, multi_cpu_stop, &msdata); } int stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus) @@ -513,25 +605,25 @@ EXPORT_SYMBOL_GPL(stop_machine); int stop_machine_from_inactive_cpu(int (*fn)(void *), void *data, const struct cpumask *cpus) { - struct stop_machine_data smdata = { .fn = fn, .data = data, + struct multi_stop_data msdata = { .fn = fn, .data = data, .active_cpus = cpus }; struct cpu_stop_done done; int ret; /* Local CPU must be inactive and CPU hotplug in progress. */ BUG_ON(cpu_active(raw_smp_processor_id())); - smdata.num_threads = num_active_cpus() + 1; /* +1 for local */ + msdata.num_threads = num_active_cpus() + 1; /* +1 for local */ /* No proper task established and can't sleep - busy wait for lock. */ while (!mutex_trylock(&stop_cpus_mutex)) cpu_relax(); /* Schedule work on other CPUs and execute directly for local CPU */ - set_state(&smdata, STOPMACHINE_PREPARE); + set_state(&msdata, MULTI_STOP_PREPARE); cpu_stop_init_done(&done, num_active_cpus()); - queue_stop_cpus_work(cpu_active_mask, stop_machine_cpu_stop, &smdata, + queue_stop_cpus_work(cpu_active_mask, multi_cpu_stop, &msdata, &done); - ret = stop_machine_cpu_stop(&smdata); + ret = multi_cpu_stop(&msdata); /* Busy wait for completion. */ while (!completion_done(&done.completion)) diff --git a/kernel/sysctl.c b/kernel/sysctl.c index b24ed7f..339c003 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -371,13 +371,6 @@ static struct ctl_table kern_table[] = { .proc_handler = proc_dointvec, }, { - .procname = "numa_balancing_scan_period_reset", - .data = &sysctl_numa_balancing_scan_period_reset, - .maxlen = sizeof(unsigned int), - .mode = 0644, - .proc_handler = proc_dointvec, - }, - { .procname = "numa_balancing_scan_period_max_ms", .data = &sysctl_numa_balancing_scan_period_max, .maxlen = sizeof(unsigned int), @@ -391,6 +384,20 @@ static struct ctl_table kern_table[] = { .mode = 0644, .proc_handler = proc_dointvec, }, + { + .procname = "numa_balancing_settle_count", + .data = &sysctl_numa_balancing_settle_count, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "numa_balancing_migrate_deferred", + .data = &sysctl_numa_balancing_migrate_deferred, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, #endif /* CONFIG_NUMA_BALANCING */ #endif /* CONFIG_SCHED_DEBUG */ { diff --git a/kernel/timer.c b/kernel/timer.c index 4296d13..6582b82 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -1092,7 +1092,7 @@ static int cascade(struct tvec_base *base, struct tvec *tv, int index) static void call_timer_fn(struct timer_list *timer, void (*fn)(unsigned long), unsigned long data) { - int preempt_count = preempt_count(); + int count = preempt_count(); #ifdef CONFIG_LOCKDEP /* @@ -1119,16 +1119,16 @@ static void call_timer_fn(struct timer_list *timer, void (*fn)(unsigned long), lock_map_release(&lockdep_map); - if (preempt_count != preempt_count()) { + if (count != preempt_count()) { WARN_ONCE(1, "timer: %pF preempt leak: %08x -> %08x\n", - fn, preempt_count, preempt_count()); + fn, count, preempt_count()); /* * Restore the preempt count. That gives us a decent * chance to survive and extract information. If the * callback kept a lock held, bad luck, but not worse * than the BUG() we had. */ - preempt_count() = preempt_count; + preempt_count_set(count); } } diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c index 6dc09d8..872a15a 100644 --- a/lib/locking-selftest.c +++ b/lib/locking-selftest.c @@ -1002,7 +1002,7 @@ static void dotest(void (*testcase_fn)(void), int expected, int lockclass_mask) * Some tests (e.g. double-unlock) might corrupt the preemption * count, so restore it: */ - preempt_count() = saved_preempt_count; + preempt_count_set(saved_preempt_count); #ifdef CONFIG_TRACE_IRQFLAGS if (softirq_count()) current->softirqs_enabled = 0; diff --git a/lib/smp_processor_id.c b/lib/smp_processor_id.c index 4c0d0e5..04abe53 100644 --- a/lib/smp_processor_id.c +++ b/lib/smp_processor_id.c @@ -9,10 +9,9 @@ notrace unsigned int debug_smp_processor_id(void) { - unsigned long preempt_count = preempt_count(); int this_cpu = raw_smp_processor_id(); - if (likely(preempt_count)) + if (likely(preempt_count())) goto out; if (irqs_disabled()) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index cca80d9..2612f60 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1282,19 +1282,32 @@ int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, struct page *page; unsigned long haddr = addr & HPAGE_PMD_MASK; int page_nid = -1, this_nid = numa_node_id(); - int target_nid; + int target_nid, last_cpupid = -1; bool page_locked; bool migrated = false; + int flags = 0; spin_lock(&mm->page_table_lock); if (unlikely(!pmd_same(pmd, *pmdp))) goto out_unlock; page = pmd_page(pmd); + BUG_ON(is_huge_zero_page(page)); page_nid = page_to_nid(page); + last_cpupid = page_cpupid_last(page); count_vm_numa_event(NUMA_HINT_FAULTS); - if (page_nid == this_nid) + if (page_nid == this_nid) { count_vm_numa_event(NUMA_HINT_FAULTS_LOCAL); + flags |= TNF_FAULT_LOCAL; + } + + /* + * Avoid grouping on DSO/COW pages in specific and RO pages + * in general, RO pages shouldn't hurt as much anyway since + * they can be in shared cache state. + */ + if (!pmd_write(pmd)) + flags |= TNF_NO_GROUP; /* * Acquire the page lock to serialise THP migrations but avoid dropping @@ -1325,7 +1338,7 @@ int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, lock_page(page); anon_vma = page_lock_anon_vma_read(page); - /* Confirm the PTE did not while locked */ + /* Confirm the PMD did not change while page_table_lock was released */ spin_lock(&mm->page_table_lock); if (unlikely(!pmd_same(pmd, *pmdp))) { unlock_page(page); @@ -1341,8 +1354,10 @@ int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, spin_unlock(&mm->page_table_lock); migrated = migrate_misplaced_transhuge_page(mm, vma, pmdp, pmd, addr, page, target_nid); - if (migrated) + if (migrated) { + flags |= TNF_MIGRATED; page_nid = target_nid; + } goto out; clear_pmdnuma: @@ -1360,7 +1375,7 @@ out: page_unlock_anon_vma_read(anon_vma); if (page_nid != -1) - task_numa_fault(page_nid, HPAGE_PMD_NR, migrated); + task_numa_fault(last_cpupid, page_nid, HPAGE_PMD_NR, flags); return 0; } @@ -1458,6 +1473,12 @@ out: return ret; } +/* + * Returns + * - 0 if PMD could not be locked + * - 1 if PMD was locked but protections unchange and TLB flush unnecessary + * - HPAGE_PMD_NR is protections changed and TLB flush necessary + */ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr, pgprot_t newprot, int prot_numa) { @@ -1466,22 +1487,34 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, if (__pmd_trans_huge_lock(pmd, vma) == 1) { pmd_t entry; - entry = pmdp_get_and_clear(mm, addr, pmd); + ret = 1; if (!prot_numa) { + entry = pmdp_get_and_clear(mm, addr, pmd); entry = pmd_modify(entry, newprot); + ret = HPAGE_PMD_NR; BUG_ON(pmd_write(entry)); } else { struct page *page = pmd_page(*pmd); - /* only check non-shared pages */ - if (page_mapcount(page) == 1 && + /* + * Do not trap faults against the zero page. The + * read-only data is likely to be read-cached on the + * local CPU cache and it is less useful to know about + * local vs remote hits on the zero page. + */ + if (!is_huge_zero_page(page) && !pmd_numa(*pmd)) { + entry = pmdp_get_and_clear(mm, addr, pmd); entry = pmd_mknuma(entry); + ret = HPAGE_PMD_NR; } } - set_pmd_at(mm, addr, pmd, entry); + + /* Set PMD if cleared earlier */ + if (ret == HPAGE_PMD_NR) + set_pmd_at(mm, addr, pmd, entry); + spin_unlock(&vma->vm_mm->page_table_lock); - ret = 1; } return ret; @@ -1662,7 +1695,7 @@ static void __split_huge_page_refcount(struct page *page, page_tail->mapping = page->mapping; page_tail->index = page->index + i; - page_nid_xchg_last(page_tail, page_nid_last(page)); + page_cpupid_xchg_last(page_tail, page_cpupid_last(page)); BUG_ON(!PageAnon(page_tail)); BUG_ON(!PageUptodate(page_tail)); diff --git a/mm/memory.c b/mm/memory.c index d176154..1f2287e 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -69,8 +69,8 @@ #include "internal.h" -#ifdef LAST_NID_NOT_IN_PAGE_FLAGS -#warning Unfortunate NUMA and NUMA Balancing config, growing page-frame for last_nid. +#ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS +#warning Unfortunate NUMA and NUMA Balancing config, growing page-frame for last_cpupid. #endif #ifndef CONFIG_NEED_MULTIPLE_NODES @@ -2721,6 +2721,14 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, get_page(dirty_page); reuse: + /* + * Clear the pages cpupid information as the existing + * information potentially belongs to a now completely + * unrelated process. + */ + if (old_page) + page_cpupid_xchg_last(old_page, (1 << LAST_CPUPID_SHIFT) - 1); + flush_cache_page(vma, address, pte_pfn(orig_pte)); entry = pte_mkyoung(orig_pte); entry = maybe_mkwrite(pte_mkdirty(entry), vma); @@ -3521,13 +3529,16 @@ static int do_nonlinear_fault(struct mm_struct *mm, struct vm_area_struct *vma, } int numa_migrate_prep(struct page *page, struct vm_area_struct *vma, - unsigned long addr, int page_nid) + unsigned long addr, int page_nid, + int *flags) { get_page(page); count_vm_numa_event(NUMA_HINT_FAULTS); - if (page_nid == numa_node_id()) + if (page_nid == numa_node_id()) { count_vm_numa_event(NUMA_HINT_FAULTS_LOCAL); + *flags |= TNF_FAULT_LOCAL; + } return mpol_misplaced(page, vma, addr); } @@ -3538,8 +3549,10 @@ int do_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, struct page *page = NULL; spinlock_t *ptl; int page_nid = -1; + int last_cpupid; int target_nid; bool migrated = false; + int flags = 0; /* * The "pte" at this point cannot be used safely without @@ -3566,9 +3579,26 @@ int do_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, pte_unmap_unlock(ptep, ptl); return 0; } + BUG_ON(is_zero_pfn(page_to_pfn(page))); + /* + * Avoid grouping on DSO/COW pages in specific and RO pages + * in general, RO pages shouldn't hurt as much anyway since + * they can be in shared cache state. + */ + if (!pte_write(pte)) + flags |= TNF_NO_GROUP; + + /* + * Flag if the page is shared between multiple address spaces. This + * is later used when determining whether to group tasks together + */ + if (page_mapcount(page) > 1 && (vma->vm_flags & VM_SHARED)) + flags |= TNF_SHARED; + + last_cpupid = page_cpupid_last(page); page_nid = page_to_nid(page); - target_nid = numa_migrate_prep(page, vma, addr, page_nid); + target_nid = numa_migrate_prep(page, vma, addr, page_nid, &flags); pte_unmap_unlock(ptep, ptl); if (target_nid == -1) { put_page(page); @@ -3576,102 +3606,17 @@ int do_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, } /* Migrate to the requested node */ - migrated = migrate_misplaced_page(page, target_nid); - if (migrated) + migrated = migrate_misplaced_page(page, vma, target_nid); + if (migrated) { page_nid = target_nid; + flags |= TNF_MIGRATED; + } out: if (page_nid != -1) - task_numa_fault(page_nid, 1, migrated); - return 0; -} - -/* NUMA hinting page fault entry point for regular pmds */ -#ifdef CONFIG_NUMA_BALANCING -static int do_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, - unsigned long addr, pmd_t *pmdp) -{ - pmd_t pmd; - pte_t *pte, *orig_pte; - unsigned long _addr = addr & PMD_MASK; - unsigned long offset; - spinlock_t *ptl; - bool numa = false; - - spin_lock(&mm->page_table_lock); - pmd = *pmdp; - if (pmd_numa(pmd)) { - set_pmd_at(mm, _addr, pmdp, pmd_mknonnuma(pmd)); - numa = true; - } - spin_unlock(&mm->page_table_lock); - - if (!numa) - return 0; - - /* we're in a page fault so some vma must be in the range */ - BUG_ON(!vma); - BUG_ON(vma->vm_start >= _addr + PMD_SIZE); - offset = max(_addr, vma->vm_start) & ~PMD_MASK; - VM_BUG_ON(offset >= PMD_SIZE); - orig_pte = pte = pte_offset_map_lock(mm, pmdp, _addr, &ptl); - pte += offset >> PAGE_SHIFT; - for (addr = _addr + offset; addr < _addr + PMD_SIZE; pte++, addr += PAGE_SIZE) { - pte_t pteval = *pte; - struct page *page; - int page_nid = -1; - int target_nid; - bool migrated = false; - - if (!pte_present(pteval)) - continue; - if (!pte_numa(pteval)) - continue; - if (addr >= vma->vm_end) { - vma = find_vma(mm, addr); - /* there's a pte present so there must be a vma */ - BUG_ON(!vma); - BUG_ON(addr < vma->vm_start); - } - if (pte_numa(pteval)) { - pteval = pte_mknonnuma(pteval); - set_pte_at(mm, addr, pte, pteval); - } - page = vm_normal_page(vma, addr, pteval); - if (unlikely(!page)) - continue; - /* only check non-shared pages */ - if (unlikely(page_mapcount(page) != 1)) - continue; - - page_nid = page_to_nid(page); - target_nid = numa_migrate_prep(page, vma, addr, page_nid); - pte_unmap_unlock(pte, ptl); - if (target_nid != -1) { - migrated = migrate_misplaced_page(page, target_nid); - if (migrated) - page_nid = target_nid; - } else { - put_page(page); - } - - if (page_nid != -1) - task_numa_fault(page_nid, 1, migrated); - - pte = pte_offset_map_lock(mm, pmdp, addr, &ptl); - } - pte_unmap_unlock(orig_pte, ptl); - - return 0; -} -#else -static int do_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, - unsigned long addr, pmd_t *pmdp) -{ - BUG(); + task_numa_fault(last_cpupid, page_nid, 1, flags); return 0; } -#endif /* CONFIG_NUMA_BALANCING */ /* * These routines also need to handle stuff like marking pages dirty @@ -3811,8 +3756,8 @@ retry: } } - if (pmd_numa(*pmd)) - return do_pmd_numa_page(mm, vma, address, pmd); + /* THP should already have been handled */ + BUG_ON(pmd_numa(*pmd)); /* * Use __pte_alloc instead of pte_alloc_map, because we can't diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 0472964..71cb253 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1679,6 +1679,30 @@ struct mempolicy *get_vma_policy(struct task_struct *task, return pol; } +bool vma_policy_mof(struct task_struct *task, struct vm_area_struct *vma) +{ + struct mempolicy *pol = get_task_policy(task); + if (vma) { + if (vma->vm_ops && vma->vm_ops->get_policy) { + bool ret = false; + + pol = vma->vm_ops->get_policy(vma, vma->vm_start); + if (pol && (pol->flags & MPOL_F_MOF)) + ret = true; + mpol_cond_put(pol); + + return ret; + } else if (vma->vm_policy) { + pol = vma->vm_policy; + } + } + + if (!pol) + return default_policy.flags & MPOL_F_MOF; + + return pol->flags & MPOL_F_MOF; +} + static int apply_policy_zone(struct mempolicy *policy, enum zone_type zone) { enum zone_type dynamic_policy_zone = policy_zone; @@ -2277,6 +2301,35 @@ static void sp_free(struct sp_node *n) kmem_cache_free(sn_cache, n); } +#ifdef CONFIG_NUMA_BALANCING +static bool numa_migrate_deferred(struct task_struct *p, int last_cpupid) +{ + /* Never defer a private fault */ + if (cpupid_match_pid(p, last_cpupid)) + return false; + + if (p->numa_migrate_deferred) { + p->numa_migrate_deferred--; + return true; + } + return false; +} + +static inline void defer_numa_migrate(struct task_struct *p) +{ + p->numa_migrate_deferred = sysctl_numa_balancing_migrate_deferred; +} +#else +static inline bool numa_migrate_deferred(struct task_struct *p, int last_cpupid) +{ + return false; +} + +static inline void defer_numa_migrate(struct task_struct *p) +{ +} +#endif /* CONFIG_NUMA_BALANCING */ + /** * mpol_misplaced - check whether current page node is valid in policy * @@ -2300,6 +2353,8 @@ int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long struct zone *zone; int curnid = page_to_nid(page); unsigned long pgoff; + int thiscpu = raw_smp_processor_id(); + int thisnid = cpu_to_node(thiscpu); int polnid = -1; int ret = -1; @@ -2348,9 +2403,11 @@ int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long /* Migrate the page towards the node whose CPU is referencing it */ if (pol->flags & MPOL_F_MORON) { - int last_nid; + int last_cpupid; + int this_cpupid; - polnid = numa_node_id(); + polnid = thisnid; + this_cpupid = cpu_pid_to_cpupid(thiscpu, current->pid); /* * Multi-stage node selection is used in conjunction @@ -2373,8 +2430,25 @@ int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long * it less likely we act on an unlikely task<->page * relation. */ - last_nid = page_nid_xchg_last(page, polnid); - if (last_nid != polnid) + last_cpupid = page_cpupid_xchg_last(page, this_cpupid); + if (!cpupid_pid_unset(last_cpupid) && cpupid_to_nid(last_cpupid) != thisnid) { + + /* See sysctl_numa_balancing_migrate_deferred comment */ + if (!cpupid_match_pid(current, last_cpupid)) + defer_numa_migrate(current); + + goto out; + } + + /* + * The quadratic filter above reduces extraneous migration + * of shared pages somewhat. This code reduces it even more, + * reducing the overhead of page migrations of shared pages. + * This makes workloads with shared pages rely more on + * "move task near its memory", and less on "move memory + * towards its task", which is exactly what we want. + */ + if (numa_migrate_deferred(current, last_cpupid)) goto out; } diff --git a/mm/migrate.c b/mm/migrate.c index c046927..dfc8300 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -445,6 +445,8 @@ int migrate_huge_page_move_mapping(struct address_space *mapping, */ void migrate_page_copy(struct page *newpage, struct page *page) { + int cpupid; + if (PageHuge(page) || PageTransHuge(page)) copy_huge_page(newpage, page); else @@ -481,6 +483,13 @@ void migrate_page_copy(struct page *newpage, struct page *page) __set_page_dirty_nobuffers(newpage); } + /* + * Copy NUMA information to the new page, to prevent over-eager + * future migrations of this same page. + */ + cpupid = page_cpupid_xchg_last(page, -1); + page_cpupid_xchg_last(newpage, cpupid); + mlock_migrate_page(newpage, page); ksm_migrate_page(newpage, page); /* @@ -1500,7 +1509,7 @@ static struct page *alloc_misplaced_dst_page(struct page *page, __GFP_NOWARN) & ~GFP_IOFS, 0); if (newpage) - page_nid_xchg_last(newpage, page_nid_last(page)); + page_cpupid_xchg_last(newpage, page_cpupid_last(page)); return newpage; } @@ -1601,7 +1610,8 @@ int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page) * node. Caller is expected to have an elevated reference count on * the page that will be dropped by this function before returning. */ -int migrate_misplaced_page(struct page *page, int node) +int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma, + int node) { pg_data_t *pgdat = NODE_DATA(node); int isolated; @@ -1609,10 +1619,11 @@ int migrate_misplaced_page(struct page *page, int node) LIST_HEAD(migratepages); /* - * Don't migrate pages that are mapped in multiple processes. - * TODO: Handle false sharing detection instead of this hammer + * Don't migrate file pages that are mapped in multiple processes + * with execute permissions as they are probably shared libraries. */ - if (page_mapcount(page) != 1) + if (page_mapcount(page) != 1 && page_is_file_cache(page) && + (vma->vm_flags & VM_EXEC)) goto out; /* @@ -1663,13 +1674,6 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm, int page_lru = page_is_file_cache(page); /* - * Don't migrate pages that are mapped in multiple processes. - * TODO: Handle false sharing detection instead of this hammer - */ - if (page_mapcount(page) != 1) - goto out_dropref; - - /* * Rate-limit the amount of data that is being migrated to a node. * Optimal placement is no good if the memory bus is saturated and * all the time is being spent migrating! @@ -1682,7 +1686,7 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm, if (!new_page) goto out_fail; - page_nid_xchg_last(new_page, page_nid_last(page)); + page_cpupid_xchg_last(new_page, page_cpupid_last(page)); isolated = numamigrate_isolate_page(pgdat, page); if (!isolated) { diff --git a/mm/mm_init.c b/mm/mm_init.c index 633c088..68562e9 100644 --- a/mm/mm_init.c +++ b/mm/mm_init.c @@ -71,26 +71,26 @@ void __init mminit_verify_pageflags_layout(void) unsigned long or_mask, add_mask; shift = 8 * sizeof(unsigned long); - width = shift - SECTIONS_WIDTH - NODES_WIDTH - ZONES_WIDTH - LAST_NID_SHIFT; + width = shift - SECTIONS_WIDTH - NODES_WIDTH - ZONES_WIDTH - LAST_CPUPID_SHIFT; mminit_dprintk(MMINIT_TRACE, "pageflags_layout_widths", - "Section %d Node %d Zone %d Lastnid %d Flags %d\n", + "Section %d Node %d Zone %d Lastcpupid %d Flags %d\n", SECTIONS_WIDTH, NODES_WIDTH, ZONES_WIDTH, - LAST_NID_WIDTH, + LAST_CPUPID_WIDTH, NR_PAGEFLAGS); mminit_dprintk(MMINIT_TRACE, "pageflags_layout_shifts", - "Section %d Node %d Zone %d Lastnid %d\n", + "Section %d Node %d Zone %d Lastcpupid %d\n", SECTIONS_SHIFT, NODES_SHIFT, ZONES_SHIFT, - LAST_NID_SHIFT); + LAST_CPUPID_SHIFT); mminit_dprintk(MMINIT_TRACE, "pageflags_layout_pgshifts", - "Section %lu Node %lu Zone %lu Lastnid %lu\n", + "Section %lu Node %lu Zone %lu Lastcpupid %lu\n", (unsigned long)SECTIONS_PGSHIFT, (unsigned long)NODES_PGSHIFT, (unsigned long)ZONES_PGSHIFT, - (unsigned long)LAST_NID_PGSHIFT); + (unsigned long)LAST_CPUPID_PGSHIFT); mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodezoneid", "Node/Zone ID: %lu -> %lu\n", (unsigned long)(ZONEID_PGOFF + ZONEID_SHIFT), @@ -102,9 +102,9 @@ void __init mminit_verify_pageflags_layout(void) mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodeflags", "Node not in page flags"); #endif -#ifdef LAST_NID_NOT_IN_PAGE_FLAGS +#ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodeflags", - "Last nid not in page flags"); + "Last cpupid not in page flags"); #endif if (SECTIONS_WIDTH) { diff --git a/mm/mmzone.c b/mm/mmzone.c index 2ac0afb..bf34fb8 100644 --- a/mm/mmzone.c +++ b/mm/mmzone.c @@ -97,20 +97,20 @@ void lruvec_init(struct lruvec *lruvec) INIT_LIST_HEAD(&lruvec->lists[lru]); } -#if defined(CONFIG_NUMA_BALANCING) && !defined(LAST_NID_NOT_IN_PAGE_FLAGS) -int page_nid_xchg_last(struct page *page, int nid) +#if defined(CONFIG_NUMA_BALANCING) && !defined(LAST_CPUPID_NOT_IN_PAGE_FLAGS) +int page_cpupid_xchg_last(struct page *page, int cpupid) { unsigned long old_flags, flags; - int last_nid; + int last_cpupid; do { old_flags = flags = page->flags; - last_nid = page_nid_last(page); + last_cpupid = page_cpupid_last(page); - flags &= ~(LAST_NID_MASK << LAST_NID_PGSHIFT); - flags |= (nid & LAST_NID_MASK) << LAST_NID_PGSHIFT; + flags &= ~(LAST_CPUPID_MASK << LAST_CPUPID_PGSHIFT); + flags |= (cpupid & LAST_CPUPID_MASK) << LAST_CPUPID_PGSHIFT; } while (unlikely(cmpxchg(&page->flags, old_flags, flags) != old_flags)); - return last_nid; + return last_cpupid; } #endif diff --git a/mm/mprotect.c b/mm/mprotect.c index 412ba2b..a597f2f 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -37,14 +37,12 @@ static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot) static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr, unsigned long end, pgprot_t newprot, - int dirty_accountable, int prot_numa, bool *ret_all_same_node) + int dirty_accountable, int prot_numa) { struct mm_struct *mm = vma->vm_mm; pte_t *pte, oldpte; spinlock_t *ptl; unsigned long pages = 0; - bool all_same_node = true; - int last_nid = -1; pte = pte_offset_map_lock(mm, pmd, addr, &ptl); arch_enter_lazy_mmu_mode(); @@ -63,15 +61,7 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, page = vm_normal_page(vma, addr, oldpte); if (page) { - int this_nid = page_to_nid(page); - if (last_nid == -1) - last_nid = this_nid; - if (last_nid != this_nid) - all_same_node = false; - - /* only check non-shared pages */ - if (!pte_numa(oldpte) && - page_mapcount(page) == 1) { + if (!pte_numa(oldpte)) { ptent = pte_mknuma(ptent); updated = true; } @@ -104,33 +94,17 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, if (pte_swp_soft_dirty(oldpte)) newpte = pte_swp_mksoft_dirty(newpte); set_pte_at(mm, addr, pte, newpte); + + pages++; } - pages++; } } while (pte++, addr += PAGE_SIZE, addr != end); arch_leave_lazy_mmu_mode(); pte_unmap_unlock(pte - 1, ptl); - *ret_all_same_node = all_same_node; return pages; } -#ifdef CONFIG_NUMA_BALANCING -static inline void change_pmd_protnuma(struct mm_struct *mm, unsigned long addr, - pmd_t *pmd) -{ - spin_lock(&mm->page_table_lock); - set_pmd_at(mm, addr & PMD_MASK, pmd, pmd_mknuma(*pmd)); - spin_unlock(&mm->page_table_lock); -} -#else -static inline void change_pmd_protnuma(struct mm_struct *mm, unsigned long addr, - pmd_t *pmd) -{ - BUG(); -} -#endif /* CONFIG_NUMA_BALANCING */ - static inline unsigned long change_pmd_range(struct vm_area_struct *vma, pud_t *pud, unsigned long addr, unsigned long end, pgprot_t newprot, int dirty_accountable, int prot_numa) @@ -138,34 +112,33 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma, pmd_t *pmd; unsigned long next; unsigned long pages = 0; - bool all_same_node; pmd = pmd_offset(pud, addr); do { + unsigned long this_pages; + next = pmd_addr_end(addr, end); if (pmd_trans_huge(*pmd)) { if (next - addr != HPAGE_PMD_SIZE) split_huge_page_pmd(vma, addr, pmd); - else if (change_huge_pmd(vma, pmd, addr, newprot, - prot_numa)) { - pages++; - continue; + else { + int nr_ptes = change_huge_pmd(vma, pmd, addr, + newprot, prot_numa); + + if (nr_ptes) { + if (nr_ptes == HPAGE_PMD_NR) + pages++; + + continue; + } } /* fall through */ } if (pmd_none_or_clear_bad(pmd)) continue; - pages += change_pte_range(vma, pmd, addr, next, newprot, - dirty_accountable, prot_numa, &all_same_node); - - /* - * If we are changing protections for NUMA hinting faults then - * set pmd_numa if the examined pages were all on the same - * node. This allows a regular PMD to be handled as one fault - * and effectively batches the taking of the PTL - */ - if (prot_numa && all_same_node) - change_pmd_protnuma(vma->vm_mm, addr, pmd); + this_pages = change_pte_range(vma, pmd, addr, next, newprot, + dirty_accountable, prot_numa); + pages += this_pages; } while (pmd++, addr = next, addr != end); return pages; diff --git a/mm/page_alloc.c b/mm/page_alloc.c index dd886fa..73d812f 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -626,7 +626,7 @@ static inline int free_pages_check(struct page *page) bad_page(page); return 1; } - page_nid_reset_last(page); + page_cpupid_reset_last(page); if (page->flags & PAGE_FLAGS_CHECK_AT_PREP) page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; return 0; @@ -4015,7 +4015,7 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, mminit_verify_page_links(page, zone, nid, pfn); init_page_count(page); page_mapcount_reset(page); - page_nid_reset_last(page); + page_cpupid_reset_last(page); SetPageReserved(page); /* * Mark the block movable so that blocks are reserved for diff --git a/net/irda/af_irda.c b/net/irda/af_irda.c index 0578d4f..0f67690 100644 --- a/net/irda/af_irda.c +++ b/net/irda/af_irda.c @@ -2563,9 +2563,8 @@ bed: jiffies + msecs_to_jiffies(val)); /* Wait for IR-LMP to call us back */ - __wait_event_interruptible(self->query_wait, - (self->cachedaddr != 0 || self->errno == -ETIME), - err); + err = __wait_event_interruptible(self->query_wait, + (self->cachedaddr != 0 || self->errno == -ETIME)); /* If watchdog is still activated, kill it! */ del_timer(&(self->watchdog)); diff --git a/net/netfilter/ipvs/ip_vs_sync.c b/net/netfilter/ipvs/ip_vs_sync.c index f448471..f63c238 100644 --- a/net/netfilter/ipvs/ip_vs_sync.c +++ b/net/netfilter/ipvs/ip_vs_sync.c @@ -1637,12 +1637,9 @@ static int sync_thread_master(void *data) continue; } while (ip_vs_send_sync_msg(tinfo->sock, sb->mesg) < 0) { - int ret = 0; - - __wait_event_interruptible(*sk_sleep(sk), + int ret = __wait_event_interruptible(*sk_sleep(sk), sock_writeable(sk) || - kthread_should_stop(), - ret); + kthread_should_stop()); if (unlikely(kthread_should_stop())) goto done; } |
