diff options
| author | Ingo Molnar <mingo@elte.hu> | 2005-01-07 21:49:52 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@evo.osdl.org> | 2005-01-07 21:49:52 -0800 |
| commit | a298f2eefe18888907e9feffb477b66843912d10 (patch) | |
| tree | 9bc83a440552e8a9c91cd1590b2db0c14355eb30 | |
| parent | f6aaca35e0aa4c7e3de79ace85f7380f4d451648 (diff) | |
[PATCH] sched: add cond_resched_softirq()
It adds cond_resched_softirq() which can be used by _process context_
softirqs-disabled codepaths to preempt if necessary. The function will
enable softirqs before scheduling. (Later patches will use this
primitive.)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | include/linux/sched.h | 3 | ||||
| -rw-r--r-- | kernel/sched.c | 16 |
2 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index c69d26d50fb0..fa3cb372c554 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1069,9 +1069,12 @@ static inline int need_resched(void) * cond_resched() and cond_resched_lock(): latency reduction via * explicit rescheduling in places that are safe. The return * value indicates whether a reschedule was done in fact. + * cond_resched_lock() will drop the spinlock before scheduling, + * cond_resched_softirq() will enable bhs before scheduling. */ extern int cond_resched(void); extern int cond_resched_lock(spinlock_t * lock); +extern int cond_resched_softirq(void); /* * Does a critical section need to be broken due to another diff --git a/kernel/sched.c b/kernel/sched.c index a55af06f9976..c0d7126b2c7b 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -3483,6 +3483,22 @@ int cond_resched_lock(spinlock_t * lock) EXPORT_SYMBOL(cond_resched_lock); +int __sched cond_resched_softirq(void) +{ + BUG_ON(!in_softirq()); + + if (need_resched()) { + __local_bh_enable(); + __cond_resched(); + local_bh_disable(); + return 1; + } + return 0; +} + +EXPORT_SYMBOL(cond_resched_softirq); + + /** * yield - yield the current processor to other threads. * |