diff options
| -rw-r--r-- | arch/alpha/Kconfig | 1 | ||||
| -rw-r--r-- | arch/arm/Kconfig | 1 | ||||
| -rw-r--r-- | arch/arm64/Kconfig | 1 | ||||
| -rw-r--r-- | arch/blackfin/Kconfig | 2 | ||||
| -rw-r--r-- | arch/frv/Kconfig | 1 | ||||
| -rw-r--r-- | arch/hexagon/Kconfig | 2 | ||||
| -rw-r--r-- | arch/ia64/Kconfig | 1 | ||||
| -rw-r--r-- | arch/mips/Kconfig | 2 | ||||
| -rw-r--r-- | arch/parisc/Kconfig | 2 | ||||
| -rw-r--r-- | arch/powerpc/Kconfig | 2 | ||||
| -rw-r--r-- | arch/s390/Kconfig | 1 | ||||
| -rw-r--r-- | arch/sh/Kconfig | 4 | ||||
| -rw-r--r-- | arch/sparc/Kconfig | 1 | ||||
| -rw-r--r-- | arch/x86/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/staging/iio/trigger/Kconfig | 1 | ||||
| -rw-r--r-- | include/linux/irq_work.h | 22 | ||||
| -rw-r--r-- | include/linux/printk.h | 3 | ||||
| -rw-r--r-- | include/linux/tick.h | 17 | ||||
| -rw-r--r-- | init/Kconfig | 5 | ||||
| -rw-r--r-- | kernel/irq/manage.c | 2 | ||||
| -rw-r--r-- | kernel/irq/spurious.c | 7 | ||||
| -rw-r--r-- | kernel/irq_work.c | 150 | ||||
| -rw-r--r-- | kernel/printk.c | 36 | ||||
| -rw-r--r-- | kernel/time/tick-sched.c | 7 | ||||
| -rw-r--r-- | kernel/timer.c | 1 |
25 files changed, 171 insertions, 102 deletions
diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig index 9d5904c..9b504af 100644 --- a/arch/alpha/Kconfig +++ b/arch/alpha/Kconfig @@ -5,7 +5,6 @@ config ALPHA select HAVE_IDE select HAVE_OPROFILE select HAVE_SYSCALL_WRAPPERS - select HAVE_IRQ_WORK select HAVE_PCSPKR_PLATFORM select HAVE_PERF_EVENTS select HAVE_DMA_ATTRS diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 67874b8..9bbe760 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -36,7 +36,6 @@ config ARM select HAVE_GENERIC_HARDIRQS select HAVE_HW_BREAKPOINT if (PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7)) select HAVE_IDE if PCI || ISA || PCMCIA - select HAVE_IRQ_WORK select HAVE_KERNEL_GZIP select HAVE_KERNEL_LZMA select HAVE_KERNEL_LZO diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index f8f362a..75e915b 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -21,7 +21,6 @@ config ARM64 select HAVE_GENERIC_DMA_COHERENT select HAVE_GENERIC_HARDIRQS select HAVE_HW_BREAKPOINT if PERF_EVENTS - select HAVE_IRQ_WORK select HAVE_MEMBLOCK select HAVE_PERF_EVENTS select IRQ_DOMAIN diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig index b6f3ad5..67e4aaa 100644 --- a/arch/blackfin/Kconfig +++ b/arch/blackfin/Kconfig @@ -24,7 +24,6 @@ config BLACKFIN select HAVE_FUNCTION_TRACER select HAVE_FUNCTION_TRACE_MCOUNT_TEST select HAVE_IDE - select HAVE_IRQ_WORK select HAVE_KERNEL_GZIP if RAMKERNEL select HAVE_KERNEL_BZIP2 if RAMKERNEL select HAVE_KERNEL_LZMA if RAMKERNEL @@ -38,7 +37,6 @@ config BLACKFIN select HAVE_GENERIC_HARDIRQS select GENERIC_ATOMIC64 select GENERIC_IRQ_PROBE - select IRQ_PER_CPU if SMP select USE_GENERIC_SMP_HELPERS if SMP select HAVE_NMI_WATCHDOG if NMI_WATCHDOG select GENERIC_SMP_IDLE_THREAD diff --git a/arch/frv/Kconfig b/arch/frv/Kconfig index 9d26264..17df48f 100644 --- a/arch/frv/Kconfig +++ b/arch/frv/Kconfig @@ -3,7 +3,6 @@ config FRV default y select HAVE_IDE select HAVE_ARCH_TRACEHOOK - select HAVE_IRQ_WORK select HAVE_PERF_EVENTS select HAVE_UID16 select HAVE_GENERIC_HARDIRQS diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig index 0744f7d..e4decc6 100644 --- a/arch/hexagon/Kconfig +++ b/arch/hexagon/Kconfig @@ -12,9 +12,7 @@ config HEXAGON # select ARCH_WANT_OPTIONAL_GPIOLIB # select ARCH_REQUIRE_GPIOLIB # select HAVE_CLK - # select IRQ_PER_CPU # select GENERIC_PENDING_IRQ if SMP - select HAVE_IRQ_WORK select GENERIC_ATOMIC64 select HAVE_PERF_EVENTS select HAVE_GENERIC_HARDIRQS diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig index 3279646..00c2e88 100644 --- a/arch/ia64/Kconfig +++ b/arch/ia64/Kconfig @@ -29,7 +29,6 @@ config IA64 select ARCH_DISCARD_MEMBLOCK select GENERIC_IRQ_PROBE select GENERIC_PENDING_IRQ if SMP - select IRQ_PER_CPU select GENERIC_IRQ_SHOW select ARCH_WANT_OPTIONAL_GPIOLIB select ARCH_HAVE_NMI_SAFE_CMPXCHG diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index 2ac626a..9becc44 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -4,7 +4,6 @@ config MIPS select HAVE_GENERIC_DMA_COHERENT select HAVE_IDE select HAVE_OPROFILE - select HAVE_IRQ_WORK select HAVE_PERF_EVENTS select PERF_USE_VMALLOC select HAVE_ARCH_KGDB @@ -2161,7 +2160,6 @@ source "mm/Kconfig" config SMP bool "Multi-Processing support" depends on SYS_SUPPORTS_SMP - select IRQ_PER_CPU select USE_GENERIC_SMP_HELPERS help This enables support for systems with more than one CPU. If you have diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig index b77feff..a32e34e 100644 --- a/arch/parisc/Kconfig +++ b/arch/parisc/Kconfig @@ -9,14 +9,12 @@ config PARISC select RTC_DRV_GENERIC select INIT_ALL_POSSIBLE select BUG - select HAVE_IRQ_WORK select HAVE_PERF_EVENTS select GENERIC_ATOMIC64 if !64BIT select HAVE_GENERIC_HARDIRQS select BROKEN_RODATA select GENERIC_IRQ_PROBE select GENERIC_PCI_IOMAP - select IRQ_PER_CPU select ARCH_HAVE_NMI_SAFE_CMPXCHG select GENERIC_SMP_IDLE_THREAD select GENERIC_STRNCPY_FROM_USER diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 17903f1..561ccca 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -118,14 +118,12 @@ config PPC select HAVE_SYSCALL_WRAPPERS if PPC64 select GENERIC_ATOMIC64 if PPC32 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE - select HAVE_IRQ_WORK select HAVE_PERF_EVENTS select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_HW_BREAKPOINT if PERF_EVENTS && PPC_BOOK3S_64 select HAVE_GENERIC_HARDIRQS select ARCH_WANT_IPC_PARSE_VERSION select SPARSE_IRQ - select IRQ_PER_CPU select IRQ_DOMAIN select GENERIC_IRQ_SHOW select GENERIC_IRQ_SHOW_LEVEL diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index b5ea38c..c15ba7d 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -78,7 +78,6 @@ config S390 select HAVE_KVM if 64BIT select HAVE_ARCH_TRACEHOOK select INIT_ALL_POSSIBLE - select HAVE_IRQ_WORK select HAVE_PERF_EVENTS select ARCH_HAVE_NMI_SAFE_CMPXCHG select HAVE_DEBUG_KMEMLEAK diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig index babc2b8..9c833c5 100644 --- a/arch/sh/Kconfig +++ b/arch/sh/Kconfig @@ -11,7 +11,6 @@ config SUPERH select HAVE_ARCH_TRACEHOOK select HAVE_DMA_API_DEBUG select HAVE_DMA_ATTRS - select HAVE_IRQ_WORK select HAVE_PERF_EVENTS select HAVE_DEBUG_BUGVERBOSE select ARCH_HAVE_CUSTOM_GPIO_H @@ -91,9 +90,6 @@ config GENERIC_CSUM config GENERIC_HWEIGHT def_bool y -config IRQ_PER_CPU - def_bool y - config GENERIC_GPIO def_bool n diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig index cb9c333..9bff3db 100644 --- a/arch/sparc/Kconfig +++ b/arch/sparc/Kconfig @@ -23,7 +23,6 @@ config SPARC select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE select RTC_CLASS select RTC_DRV_M48T59 - select HAVE_IRQ_WORK select HAVE_DMA_ATTRS select HAVE_DMA_API_DEBUG select HAVE_ARCH_JUMP_LABEL diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 225543b..36b05ed 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -28,7 +28,6 @@ config X86 select HAVE_OPROFILE select HAVE_PCSPKR_PLATFORM select HAVE_PERF_EVENTS - select HAVE_IRQ_WORK select HAVE_IOREMAP_PROT select HAVE_KPROBES select HAVE_MEMBLOCK diff --git a/drivers/staging/iio/trigger/Kconfig b/drivers/staging/iio/trigger/Kconfig index 7d32075..d44d3ad 100644 --- a/drivers/staging/iio/trigger/Kconfig +++ b/drivers/staging/iio/trigger/Kconfig @@ -21,7 +21,6 @@ config IIO_GPIO_TRIGGER config IIO_SYSFS_TRIGGER tristate "SYSFS trigger" depends on SYSFS - depends on HAVE_IRQ_WORK select IRQ_WORK help Provides support for using SYSFS entry as IIO triggers. diff --git a/include/linux/irq_work.h b/include/linux/irq_work.h index 6a9e8f5..f5dbce5 100644 --- a/include/linux/irq_work.h +++ b/include/linux/irq_work.h @@ -3,6 +3,20 @@ #include <linux/llist.h> +/* + * An entry can be in one of four states: + * + * free NULL, 0 -> {claimed} : free to be used + * claimed NULL, 3 -> {pending} : claimed to be enqueued + * pending next, 3 -> {busy} : queued, pending callback + * busy NULL, 2 -> {free, claimed} : callback in progress, can be claimed + */ + +#define IRQ_WORK_PENDING 1UL +#define IRQ_WORK_BUSY 2UL +#define IRQ_WORK_FLAGS 3UL +#define IRQ_WORK_LAZY 4UL /* Doesn't want IPI, wait for tick */ + struct irq_work { unsigned long flags; struct llist_node llnode; @@ -16,8 +30,14 @@ void init_irq_work(struct irq_work *work, void (*func)(struct irq_work *)) work->func = func; } -bool irq_work_queue(struct irq_work *work); +void irq_work_queue(struct irq_work *work); void irq_work_run(void); void irq_work_sync(struct irq_work *work); +#ifdef CONFIG_IRQ_WORK +bool irq_work_needs_cpu(void); +#else +static bool irq_work_needs_cpu(void) { return false; } +#endif + #endif /* _LINUX_IRQ_WORK_H */ diff --git a/include/linux/printk.h b/include/linux/printk.h index 9afc01e..86c4b62 100644 --- a/include/linux/printk.h +++ b/include/linux/printk.h @@ -98,9 +98,6 @@ int no_printk(const char *fmt, ...) extern asmlinkage __printf(1, 2) void early_printk(const char *fmt, ...); -extern int printk_needs_cpu(int cpu); -extern void printk_tick(void); - #ifdef CONFIG_PRINTK asmlinkage __printf(5, 0) int vprintk_emit(int facility, int level, diff --git a/include/linux/tick.h b/include/linux/tick.h index 1a6567b..553272e 100644 --- a/include/linux/tick.h +++ b/include/linux/tick.h @@ -8,6 +8,8 @@ #include <linux/clockchips.h> #include <linux/irqflags.h> +#include <linux/percpu.h> +#include <linux/hrtimer.h> #ifdef CONFIG_GENERIC_CLOCKEVENTS @@ -122,13 +124,26 @@ static inline int tick_oneshot_mode_active(void) { return 0; } #endif /* !CONFIG_GENERIC_CLOCKEVENTS */ # ifdef CONFIG_NO_HZ +DECLARE_PER_CPU(struct tick_sched, tick_cpu_sched); + +static inline int tick_nohz_tick_stopped(void) +{ + return __this_cpu_read(tick_cpu_sched.tick_stopped); +} + extern void tick_nohz_idle_enter(void); extern void tick_nohz_idle_exit(void); extern void tick_nohz_irq_exit(void); extern ktime_t tick_nohz_get_sleep_length(void); extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time); extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time); -# else + +# else /* !CONFIG_NO_HZ */ +static inline int tick_nohz_tick_stopped(void) +{ + return 0; +} + static inline void tick_nohz_idle_enter(void) { } static inline void tick_nohz_idle_exit(void) { } diff --git a/init/Kconfig b/init/Kconfig index b023334..dcb68ac 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -20,12 +20,8 @@ config CONSTRUCTORS bool depends on !UML -config HAVE_IRQ_WORK - bool - config IRQ_WORK bool - depends on HAVE_IRQ_WORK config BUILDTIME_EXTABLE_SORT bool @@ -1273,6 +1269,7 @@ config HOTPLUG config PRINTK default y bool "Enable support for printk" if EXPERT + select IRQ_WORK help This option enables normal printk support. Removing it eliminates most of the message strings from the kernel image diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index e49a288..88e7bed 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -1524,6 +1524,7 @@ void enable_percpu_irq(unsigned int irq, unsigned int type) out: irq_put_desc_unlock(desc, flags); } +EXPORT_SYMBOL_GPL(enable_percpu_irq); void disable_percpu_irq(unsigned int irq) { @@ -1537,6 +1538,7 @@ void disable_percpu_irq(unsigned int irq) irq_percpu_disable(desc, cpu); irq_put_desc_unlock(desc, flags); } +EXPORT_SYMBOL_GPL(disable_percpu_irq); /* * Internal function to unregister a percpu irqaction. diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c index 611cd60..7b5f012 100644 --- a/kernel/irq/spurious.c +++ b/kernel/irq/spurious.c @@ -80,13 +80,11 @@ static int try_one_irq(int irq, struct irq_desc *desc, bool force) /* * All handlers must agree on IRQF_SHARED, so we test just the - * first. Check for action->next as well. + * first. */ action = desc->action; if (!action || !(action->flags & IRQF_SHARED) || - (action->flags & __IRQF_TIMER) || - (action->handler(irq, action->dev_id) == IRQ_HANDLED) || - !action->next) + (action->flags & __IRQF_TIMER)) goto out; /* Already running on another processor */ @@ -104,6 +102,7 @@ static int try_one_irq(int irq, struct irq_desc *desc, bool force) do { if (handle_irq_event(desc) == IRQ_HANDLED) ret = IRQ_HANDLED; + /* Make sure that there is still a valid action */ action = desc->action; } while ((desc->istate & IRQS_PENDING) && action); desc->istate &= ~IRQS_POLL_INPROGRESS; diff --git a/kernel/irq_work.c b/kernel/irq_work.c index 1588e3b..55fcce6 100644 --- a/kernel/irq_work.c +++ b/kernel/irq_work.c @@ -12,37 +12,36 @@ #include <linux/percpu.h> #include <linux/hardirq.h> #include <linux/irqflags.h> +#include <linux/sched.h> +#include <linux/tick.h> +#include <linux/cpu.h> +#include <linux/notifier.h> #include <asm/processor.h> -/* - * An entry can be in one of four states: - * - * free NULL, 0 -> {claimed} : free to be used - * claimed NULL, 3 -> {pending} : claimed to be enqueued - * pending next, 3 -> {busy} : queued, pending callback - * busy NULL, 2 -> {free, claimed} : callback in progress, can be claimed - */ - -#define IRQ_WORK_PENDING 1UL -#define IRQ_WORK_BUSY 2UL -#define IRQ_WORK_FLAGS 3UL static DEFINE_PER_CPU(struct llist_head, irq_work_list); +static DEFINE_PER_CPU(int, irq_work_raised); /* * Claim the entry so that no one else will poke at it. */ static bool irq_work_claim(struct irq_work *work) { - unsigned long flags, nflags; + unsigned long flags, oflags, nflags; + /* + * Start with our best wish as a premise but only trust any + * flag value after cmpxchg() result. + */ + flags = work->flags & ~IRQ_WORK_PENDING; for (;;) { - flags = work->flags; - if (flags & IRQ_WORK_PENDING) - return false; nflags = flags | IRQ_WORK_FLAGS; - if (cmpxchg(&work->flags, flags, nflags) == flags) + oflags = cmpxchg(&work->flags, flags, nflags); + if (oflags == flags) break; + if (oflags & IRQ_WORK_PENDING) + return false; + flags = oflags; cpu_relax(); } @@ -57,57 +56,69 @@ void __weak arch_irq_work_raise(void) } /* - * Queue the entry and raise the IPI if needed. + * Enqueue the irq_work @entry unless it's already pending + * somewhere. + * + * Can be re-enqueued while the callback is still in progress. */ -static void __irq_work_queue(struct irq_work *work) +void irq_work_queue(struct irq_work *work) { - bool empty; + /* Only queue if not already pending */ + if (!irq_work_claim(work)) + return; + /* Queue the entry and raise the IPI if needed. */ preempt_disable(); - empty = llist_add(&work->llnode, &__get_cpu_var(irq_work_list)); - /* The list was empty, raise self-interrupt to start processing. */ - if (empty) - arch_irq_work_raise(); + llist_add(&work->llnode, &__get_cpu_var(irq_work_list)); + + /* + * If the work is not "lazy" or the tick is stopped, raise the irq + * work interrupt (if supported by the arch), otherwise, just wait + * for the next tick. + */ + if (!(work->flags & IRQ_WORK_LAZY) || tick_nohz_tick_stopped()) { + if (!this_cpu_cmpxchg(irq_work_raised, 0, 1)) + arch_irq_work_raise(); + } preempt_enable(); } +EXPORT_SYMBOL_GPL(irq_work_queue); -/* - * Enqueue the irq_work @entry, returns true on success, failure when the - * @entry was already enqueued by someone else. - * - * Can be re-enqueued while the callback is still in progress. - */ -bool irq_work_queue(struct irq_work *work) +bool irq_work_needs_cpu(void) { - if (!irq_work_claim(work)) { - /* - * Already enqueued, can't do! - */ + struct llist_head *this_list; + + this_list = &__get_cpu_var(irq_work_list); + if (llist_empty(this_list)) return false; - } - __irq_work_queue(work); + /* All work should have been flushed before going offline */ + WARN_ON_ONCE(cpu_is_offline(smp_processor_id())); + return true; } -EXPORT_SYMBOL_GPL(irq_work_queue); -/* - * Run the irq_work entries on this cpu. Requires to be ran from hardirq - * context with local IRQs disabled. - */ -void irq_work_run(void) +static void __irq_work_run(void) { + unsigned long flags; struct irq_work *work; struct llist_head *this_list; struct llist_node *llnode; + + /* + * Reset the "raised" state right before we check the list because + * an NMI may enqueue after we find the list empty from the runner. + */ + __this_cpu_write(irq_work_raised, 0); + barrier(); + this_list = &__get_cpu_var(irq_work_list); if (llist_empty(this_list)) return; - BUG_ON(!in_irq()); BUG_ON(!irqs_disabled()); llnode = llist_del_all(this_list); @@ -119,16 +130,31 @@ void irq_work_run(void) /* * Clear the PENDING bit, after this point the @work * can be re-used. + * Make it immediately visible so that other CPUs trying + * to claim that work don't rely on us to handle their data + * while we are in the middle of the func. */ - work->flags = IRQ_WORK_BUSY; + flags = work->flags & ~IRQ_WORK_PENDING; + xchg(&work->flags, flags); + work->func(work); /* * Clear the BUSY bit and return to the free state if * no-one else claimed it meanwhile. */ - (void)cmpxchg(&work->flags, IRQ_WORK_BUSY, 0); + (void)cmpxchg(&work->flags, flags, flags & ~IRQ_WORK_BUSY); } } + +/* + * Run the irq_work entries on this cpu. Requires to be ran from hardirq + * context with local IRQs disabled. + */ +void irq_work_run(void) +{ + BUG_ON(!in_irq()); + __irq_work_run(); +} EXPORT_SYMBOL_GPL(irq_work_run); /* @@ -143,3 +169,35 @@ void irq_work_sync(struct irq_work *work) cpu_relax(); } EXPORT_SYMBOL_GPL(irq_work_sync); + +#ifdef CONFIG_HOTPLUG_CPU +static int irq_work_cpu_notify(struct notifier_block *self, + unsigned long action, void *hcpu) +{ + long cpu = (long)hcpu; + + switch (action) { + case CPU_DYING: + /* Called from stop_machine */ + if (WARN_ON_ONCE(cpu != smp_processor_id())) + break; + __irq_work_run(); + break; + default: + break; + } + return NOTIFY_OK; +} + +static struct notifier_block cpu_notify; + +static __init int irq_work_init_cpu_notifier(void) +{ + cpu_notify.notifier_call = irq_work_cpu_notify; + cpu_notify.priority = 0; + register_cpu_notifier(&cpu_notify); + return 0; +} +device_initcall(irq_work_init_cpu_notifier); + +#endif /* CONFIG_HOTPLUG_CPU */ diff --git a/kernel/printk.c b/kernel/printk.c index 267ce78..f24633a 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -42,6 +42,7 @@ #include <linux/notifier.h> #include <linux/rculist.h> #include <linux/poll.h> +#include <linux/irq_work.h> #include <asm/uaccess.h> @@ -1959,30 +1960,32 @@ int is_console_locked(void) static DEFINE_PER_CPU(int, printk_pending); static DEFINE_PER_CPU(char [PRINTK_BUF_SIZE], printk_sched_buf); -void printk_tick(void) +static void wake_up_klogd_work_func(struct irq_work *irq_work) { - if (__this_cpu_read(printk_pending)) { - int pending = __this_cpu_xchg(printk_pending, 0); - if (pending & PRINTK_PENDING_SCHED) { - char *buf = __get_cpu_var(printk_sched_buf); - printk(KERN_WARNING "[sched_delayed] %s", buf); - } - if (pending & PRINTK_PENDING_WAKEUP) - wake_up_interruptible(&log_wait); + int pending = __this_cpu_xchg(printk_pending, 0); + + if (pending & PRINTK_PENDING_SCHED) { + char *buf = __get_cpu_var(printk_sched_buf); + printk(KERN_WARNING "[sched_delayed] %s", buf); } -} -int printk_needs_cpu(int cpu) -{ - if (cpu_is_offline(cpu)) - printk_tick(); - return __this_cpu_read(printk_pending); + if (pending & PRINTK_PENDING_WAKEUP) + wake_up_interruptible(&log_wait); } +static DEFINE_PER_CPU(struct irq_work, wake_up_klogd_work) = { + .func = wake_up_klogd_work_func, + .flags = IRQ_WORK_LAZY, +}; + void wake_up_klogd(void) { - if (waitqueue_active(&log_wait)) + preempt_disable(); + if (waitqueue_active(&log_wait)) { this_cpu_or(printk_pending, PRINTK_PENDING_WAKEUP); + irq_work_queue(&__get_cpu_var(wake_up_klogd_work)); + } + preempt_enable(); } static void console_cont_flush(char *text, size_t size) @@ -2462,6 +2465,7 @@ int printk_sched(const char *fmt, ...) va_end(args); __this_cpu_or(printk_pending, PRINTK_PENDING_SCHED); + irq_work_queue(&__get_cpu_var(wake_up_klogd_work)); local_irq_restore(flags); return r; diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index d58e552..fb8e5e4 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -20,6 +20,7 @@ #include <linux/profile.h> #include <linux/sched.h> #include <linux/module.h> +#include <linux/irq_work.h> #include <asm/irq_regs.h> @@ -28,7 +29,7 @@ /* * Per cpu nohz control structure */ -static DEFINE_PER_CPU(struct tick_sched, tick_cpu_sched); +DEFINE_PER_CPU(struct tick_sched, tick_cpu_sched); /* * The time, when the last jiffy update happened. Protected by jiffies_lock. @@ -331,8 +332,8 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, time_delta = timekeeping_max_deferment(); } while (read_seqretry(&jiffies_lock, seq)); - if (rcu_needs_cpu(cpu, &rcu_delta_jiffies) || printk_needs_cpu(cpu) || - arch_needs_cpu(cpu)) { + if (rcu_needs_cpu(cpu, &rcu_delta_jiffies) || + arch_needs_cpu(cpu) || irq_work_needs_cpu()) { next_jiffies = last_jiffies + 1; delta_jiffies = 1; } else { diff --git a/kernel/timer.c b/kernel/timer.c index 367d008..ff3b516 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -1351,7 +1351,6 @@ void update_process_times(int user_tick) account_process_tick(p, user_tick); run_local_timers(); rcu_check_callbacks(cpu, user_tick); - printk_tick(); #ifdef CONFIG_IRQ_WORK if (in_irq()) irq_work_run(); |
