diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/asm-arm/system.h | 30 | ||||
| -rw-r--r-- | include/asm-ia64/system.h | 10 | ||||
| -rw-r--r-- | include/asm-mips/system.h | 10 | ||||
| -rw-r--r-- | include/asm-s390/system.h | 17 | ||||
| -rw-r--r-- | include/asm-sparc/system.h | 4 | ||||
| -rw-r--r-- | include/asm-sparc64/system.h | 14 | ||||
| -rw-r--r-- | include/linux/init_task.h | 1 | ||||
| -rw-r--r-- | include/linux/sched.h | 10 |
8 files changed, 23 insertions, 73 deletions
diff --git a/include/asm-arm/system.h b/include/asm-arm/system.h index 39dd700..3d0d286 100644 --- a/include/asm-arm/system.h +++ b/include/asm-arm/system.h @@ -145,34 +145,12 @@ extern unsigned int user_debug; #define set_wmb(var, value) do { var = value; wmb(); } while (0) #define nop() __asm__ __volatile__("mov\tr0,r0\t@ nop\n\t"); -#ifdef CONFIG_SMP /* - * Define our own context switch locking. This allows us to enable - * interrupts over the context switch, otherwise we end up with high - * interrupt latency. The real problem area is switch_mm() which may - * do a full cache flush. + * switch_mm() may do a full cache flush over the context switch, + * so enable interrupts over the context switch to avoid high + * latency. */ -#define prepare_arch_switch(rq,next) \ -do { \ - spin_lock(&(next)->switch_lock); \ - spin_unlock_irq(&(rq)->lock); \ -} while (0) - -#define finish_arch_switch(rq,prev) \ - spin_unlock(&(prev)->switch_lock) - -#define task_running(rq,p) \ - ((rq)->curr == (p) || spin_is_locked(&(p)->switch_lock)) -#else -/* - * Our UP-case is more simple, but we assume knowledge of how - * spin_unlock_irq() and friends are implemented. This avoids - * us needlessly decrementing and incrementing the preempt count. - */ -#define prepare_arch_switch(rq,next) local_irq_enable() -#define finish_arch_switch(rq,prev) spin_unlock(&(rq)->lock) -#define task_running(rq,p) ((rq)->curr == (p)) -#endif +#define __ARCH_WANT_INTERRUPTS_ON_CTXSW /* * switch_to(prev, next) should switch from task `prev' to `next' diff --git a/include/asm-ia64/system.h b/include/asm-ia64/system.h index 6f516e7..cd2cf76 100644 --- a/include/asm-ia64/system.h +++ b/include/asm-ia64/system.h @@ -183,8 +183,6 @@ do { \ #ifdef __KERNEL__ -#define prepare_to_switch() do { } while(0) - #ifdef CONFIG_IA32_SUPPORT # define IS_IA32_PROCESS(regs) (ia64_psr(regs)->is != 0) #else @@ -274,13 +272,7 @@ extern void ia64_load_extra (struct task_struct *task); * of that CPU which will not be released, because there we wait for the * tasklist_lock to become available. */ -#define prepare_arch_switch(rq, next) \ -do { \ - spin_lock(&(next)->switch_lock); \ - spin_unlock(&(rq)->lock); \ -} while (0) -#define finish_arch_switch(rq, prev) spin_unlock_irq(&(prev)->switch_lock) -#define task_running(rq, p) ((rq)->curr == (p) || spin_is_locked(&(p)->switch_lock)) +#define __ARCH_WANT_UNLOCKED_CTXSW #define ia64_platform_is(x) (strcmp(x, platform_name) == 0) diff --git a/include/asm-mips/system.h b/include/asm-mips/system.h index 888fd89..169f3d4 100644 --- a/include/asm-mips/system.h +++ b/include/asm-mips/system.h @@ -422,16 +422,10 @@ extern void __die_if_kernel(const char *, struct pt_regs *, const char *file, extern int stop_a_enabled; /* - * Taken from include/asm-ia64/system.h; prevents deadlock on SMP + * See include/asm-ia64/system.h; prevents deadlock on SMP * systems. */ -#define prepare_arch_switch(rq, next) \ -do { \ - spin_lock(&(next)->switch_lock); \ - spin_unlock(&(rq)->lock); \ -} while (0) -#define finish_arch_switch(rq, prev) spin_unlock_irq(&(prev)->switch_lock) -#define task_running(rq, p) ((rq)->curr == (p) || spin_is_locked(&(p)->switch_lock)) +#define __ARCH_WANT_UNLOCKED_CTXSW #define arch_align_stack(x) (x) diff --git a/include/asm-s390/system.h b/include/asm-s390/system.h index e3cb3ce..b4a9f05 100644 --- a/include/asm-s390/system.h +++ b/include/asm-s390/system.h @@ -104,29 +104,18 @@ static inline void restore_access_regs(unsigned int *acrs) prev = __switch_to(prev,next); \ } while (0) -#define prepare_arch_switch(rq, next) do { } while(0) -#define task_running(rq, p) ((rq)->curr == (p)) - #ifdef CONFIG_VIRT_CPU_ACCOUNTING extern void account_user_vtime(struct task_struct *); extern void account_system_vtime(struct task_struct *); - -#define finish_arch_switch(rq, prev) do { \ - set_fs(current->thread.mm_segment); \ - spin_unlock(&(rq)->lock); \ - account_system_vtime(prev); \ - local_irq_enable(); \ -} while (0) - #else +#define account_system_vtime(prev) do { } while (0) +#endif #define finish_arch_switch(rq, prev) do { \ set_fs(current->thread.mm_segment); \ - spin_unlock_irq(&(rq)->lock); \ + account_system_vtime(prev); \ } while (0) -#endif - #define nop() __asm__ __volatile__ ("nop") #define xchg(ptr,x) \ diff --git a/include/asm-sparc/system.h b/include/asm-sparc/system.h index 80cf20c..898562e 100644 --- a/include/asm-sparc/system.h +++ b/include/asm-sparc/system.h @@ -101,7 +101,7 @@ extern void fpsave(unsigned long *fpregs, unsigned long *fsr, * SWITCH_ENTER and SWITH_DO_LAZY_FPU do not work yet (e.g. SMP does not work) * XXX WTF is the above comment? Found in late teen 2.4.x. */ -#define prepare_arch_switch(rq, next) do { \ +#define prepare_arch_switch(next) do { \ __asm__ __volatile__( \ ".globl\tflush_patch_switch\nflush_patch_switch:\n\t" \ "save %sp, -0x40, %sp; save %sp, -0x40, %sp; save %sp, -0x40, %sp\n\t" \ @@ -109,8 +109,6 @@ extern void fpsave(unsigned long *fpregs, unsigned long *fsr, "save %sp, -0x40, %sp\n\t" \ "restore; restore; restore; restore; restore; restore; restore"); \ } while(0) -#define finish_arch_switch(rq, next) spin_unlock_irq(&(rq)->lock) -#define task_running(rq, p) ((rq)->curr == (p)) /* Much care has gone into this code, do not touch it. * diff --git a/include/asm-sparc64/system.h b/include/asm-sparc64/system.h index fd12ca3..f9be2c5 100644 --- a/include/asm-sparc64/system.h +++ b/include/asm-sparc64/system.h @@ -139,19 +139,13 @@ extern void __flushw_user(void); #define flush_user_windows flushw_user #define flush_register_windows flushw_all -#define prepare_arch_switch(rq, next) \ -do { spin_lock(&(next)->switch_lock); \ - spin_unlock(&(rq)->lock); \ +/* Don't hold the runqueue lock over context switch */ +#define __ARCH_WANT_UNLOCKED_CTXSW +#define prepare_arch_switch(next) \ +do { \ flushw_all(); \ } while (0) -#define finish_arch_switch(rq, prev) \ -do { spin_unlock_irq(&(prev)->switch_lock); \ -} while (0) - -#define task_running(rq, p) \ - ((rq)->curr == (p) || spin_is_locked(&(p)->switch_lock)) - /* See what happens when you design the chip correctly? * * We tell gcc we clobber all non-fixed-usage registers except diff --git a/include/linux/init_task.h b/include/linux/init_task.h index a6a8c1a..03206a4 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -108,7 +108,6 @@ extern struct group_info init_groups; .blocked = {{0}}, \ .alloc_lock = SPIN_LOCK_UNLOCKED, \ .proc_lock = SPIN_LOCK_UNLOCKED, \ - .switch_lock = SPIN_LOCK_UNLOCKED, \ .journal_info = NULL, \ .cpu_timers = INIT_CPU_TIMERS(tsk.cpu_timers), \ } diff --git a/include/linux/sched.h b/include/linux/sched.h index 36a1078..d27be93 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -368,6 +368,11 @@ struct signal_struct { #endif }; +/* Context switch must be unlocked if interrupts are to be enabled */ +#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW +# define __ARCH_WANT_UNLOCKED_CTXSW +#endif + /* * Bits in flags field of signal_struct. */ @@ -594,6 +599,9 @@ struct task_struct { int lock_depth; /* BKL lock depth */ +#if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) + int oncpu; +#endif int prio, static_prio; struct list_head run_list; prio_array_t *array; @@ -716,8 +724,6 @@ struct task_struct { spinlock_t alloc_lock; /* Protection of proc_dentry: nesting proc_lock, dcache_lock, write_lock_irq(&tasklist_lock); */ spinlock_t proc_lock; -/* context-switch lock */ - spinlock_t switch_lock; /* journalling filesystem info */ void *journal_info; |
