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| author | Jim Houston <jim.houston@ccur.com> | 2006-07-30 03:03:39 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-07-31 13:28:40 -0700 |
| commit | 2d7d253548cffdce80f4e03664686e9ccb1b0ed7 (patch) | |
| tree | 08771f36c2506e39f9adfc0bb09e4a574ce196dd /kernel/sched.c | |
| parent | 6ea24f9ad18c65cc179593b5cc2a88cdadf8cc0c (diff) | |
| download | op-kernel-dev-2d7d253548cffdce80f4e03664686e9ccb1b0ed7.zip op-kernel-dev-2d7d253548cffdce80f4e03664686e9ccb1b0ed7.tar.gz | |
[PATCH] fix cond_resched() fix
In cond_resched_lock() it calls __resched_legal() before dropping the spin
lock. __resched_legal() will always finds the preempt_count non-zero and
will prevent the call to __cond_resched().
The attached patch adds a parameter to __resched_legal() with the expected
preempt_count value.
Cc: Ingo Molnar <mingo@elte.hu>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/sched.c')
| -rw-r--r-- | kernel/sched.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 41a5718..de440b2 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -4456,9 +4456,9 @@ asmlinkage long sys_sched_yield(void) return 0; } -static inline int __resched_legal(void) +static inline int __resched_legal(int expected_preempt_count) { - if (unlikely(preempt_count())) + if (unlikely(preempt_count() != expected_preempt_count)) return 0; if (unlikely(system_state != SYSTEM_RUNNING)) return 0; @@ -4484,7 +4484,7 @@ static void __cond_resched(void) int __sched cond_resched(void) { - if (need_resched() && __resched_legal()) { + if (need_resched() && __resched_legal(0)) { __cond_resched(); return 1; } @@ -4510,7 +4510,7 @@ int cond_resched_lock(spinlock_t *lock) ret = 1; spin_lock(lock); } - if (need_resched() && __resched_legal()) { + if (need_resched() && __resched_legal(1)) { spin_release(&lock->dep_map, 1, _THIS_IP_); _raw_spin_unlock(lock); preempt_enable_no_resched(); @@ -4526,7 +4526,7 @@ int __sched cond_resched_softirq(void) { BUG_ON(!in_softirq()); - if (need_resched() && __resched_legal()) { + if (need_resched() && __resched_legal(0)) { raw_local_irq_disable(); _local_bh_enable(); raw_local_irq_enable(); |
