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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-05-11 16:04:48 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-05-11 16:04:48 -0700 |
| commit | c3921ab71507b108d51a0f1ee960f80cd668a93d (patch) | |
| tree | b1408b898a8b50f15ad4a0cf1f29e17cc0138485 | |
| parent | 9662369786b9d07fd46d65b0f9e3938a3e01a5d9 (diff) | |
| download | op-kernel-dev-c3921ab71507b108d51a0f1ee960f80cd668a93d.zip op-kernel-dev-c3921ab71507b108d51a0f1ee960f80cd668a93d.tar.gz | |
Add new 'cond_resched_bkl()' helper function
It acts exactly like a regular 'cond_resched()', but will not get
optimized away when CONFIG_PREEMPT is set.
Normal kernel code is already preemptable in the presense of
CONFIG_PREEMPT, so cond_resched() is optimized away (see commit
02b67cc3ba36bdba351d6c3a00593f4ec550d9d3 "sched: do not do
cond_resched() when CONFIG_PREEMPT").
But when wanting to conditionally reschedule while holding a lock, you
need to use "cond_sched_lock(lock)", and the new function is the BKL
equivalent of that.
Also make fs/locks.c use it.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/locks.c | 2 | ||||
| -rw-r--r-- | include/linux/sched.h | 6 | ||||
| -rw-r--r-- | kernel/sched.c | 2 |
3 files changed, 6 insertions, 4 deletions
@@ -773,7 +773,7 @@ static int flock_lock_file(struct file *filp, struct file_lock *request) * give it the opportunity to lock the file. */ if (found) - cond_resched(); + cond_resched_bkl(); find_conflict: for_each_lock(inode, before) { diff --git a/include/linux/sched.h b/include/linux/sched.h index 0c35b03..4ab9f32 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2037,13 +2037,13 @@ static inline int need_resched(void) * cond_resched_lock() will drop the spinlock before scheduling, * cond_resched_softirq() will enable bhs before scheduling. */ +extern int _cond_resched(void); #ifdef CONFIG_PREEMPT static inline int cond_resched(void) { return 0; } #else -extern int _cond_resched(void); static inline int cond_resched(void) { return _cond_resched(); @@ -2051,6 +2051,10 @@ static inline int cond_resched(void) #endif extern int cond_resched_lock(spinlock_t * lock); extern int cond_resched_softirq(void); +static inline int cond_resched_bkl(void) +{ + return _cond_resched(); +} /* * Does a critical section need to be broken due to another diff --git a/kernel/sched.c b/kernel/sched.c index c51b656..8841a91 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -5525,7 +5525,6 @@ static void __cond_resched(void) } while (need_resched()); } -#if !defined(CONFIG_PREEMPT) || defined(CONFIG_PREEMPT_VOLUNTARY) int __sched _cond_resched(void) { if (need_resched() && !(preempt_count() & PREEMPT_ACTIVE) && @@ -5536,7 +5535,6 @@ int __sched _cond_resched(void) return 0; } EXPORT_SYMBOL(_cond_resched); -#endif /* * cond_resched_lock() - if a reschedule is pending, drop the given lock, |
