diff options
| author | Peter Zijlstra <[email protected]> | 2016-09-19 12:57:53 +0200 |
|---|---|---|
| committer | Ingo Molnar <[email protected]> | 2016-09-22 14:53:46 +0200 |
| commit | 35a773a07926a22bf19d77ee00024522279c4e68 (patch) | |
| tree | 23f24c6a2932df3cb5078e438abbfb1966e4733b | |
| parent | 9af6528ee9b682df7f29dbee86fbba0b67eab944 (diff) | |
sched/core: Avoid _cond_resched() for PREEMPT=y
On fully preemptible kernels _cond_resched() is pointless, so avoid
emitting any code for it.
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mikulas Patocka <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Signed-off-by: Ingo Molnar <[email protected]>
| -rw-r--r-- | include/linux/sched.h | 4 | ||||
| -rw-r--r-- | kernel/sched/core.c | 2 |
2 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index f00ee8e90a29..b99fcd1b341e 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -3209,7 +3209,11 @@ static inline int signal_pending_state(long state, struct task_struct *p) * cond_resched_lock() will drop the spinlock before scheduling, * cond_resched_softirq() will enable bhs before scheduling. */ +#ifndef CONFIG_PREEMPT extern int _cond_resched(void); +#else +static inline int _cond_resched(void) { return 0; } +#endif #define cond_resched() ({ \ ___might_sleep(__FILE__, __LINE__, 0); \ diff --git a/kernel/sched/core.c b/kernel/sched/core.c index b2ec53c1a974..d7babcc7cb76 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4883,6 +4883,7 @@ SYSCALL_DEFINE0(sched_yield) return 0; } +#ifndef CONFIG_PREEMPT int __sched _cond_resched(void) { if (should_resched(0)) { @@ -4892,6 +4893,7 @@ int __sched _cond_resched(void) return 0; } EXPORT_SYMBOL(_cond_resched); +#endif /* * __cond_resched_lock() - if a reschedule is pending, drop the given lock, |