Messages in this thread Patch in this message |  | | Date | Sun, 2 Aug 2009 13:11:32 GMT | From | tip-bot for Frederic Weisbecker <> | Subject | [tip:sched/core] sched: Fix cond_resched_lock() in !CONFIG_PREEMPT |
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Commit-ID: 716a42348cdaf04534b15fbdc9c83e25baebfed5 Gitweb: http://git.kernel.org/tip/716a42348cdaf04534b15fbdc9c83e25baebfed5 Author: Frederic Weisbecker <fweisbec@gmail.com> AuthorDate: Fri, 24 Jul 2009 20:05:23 +0200 Committer: Ingo Molnar <mingo@elte.hu> CommitDate: Sun, 2 Aug 2009 14:03:57 +0200
sched: Fix cond_resched_lock() in !CONFIG_PREEMPT
The might_sleep() test inside cond_resched_lock() assumes the spinlock is held and then preemption is disabled. This is true with CONFIG_PREEMPT but the preempt_count() doesn't change otherwise.
Check by starting from the appropriate preempt offset depending on the config.
Reported-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1248458723-12146-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
--- include/linux/sched.h | 8 +++++++- 1 files changed, 7 insertions(+), 1 deletions(-)
diff --git a/include/linux/sched.h b/include/linux/sched.h index cbbfca6..c472414 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2293,8 +2293,14 @@ extern int _cond_resched(void); extern int __cond_resched_lock(spinlock_t *lock); +#ifdef CONFIG_PREEMPT +#define PREEMPT_LOCK_OFFSET PREEMPT_OFFSET +#else +#define PREEMPT_LOCK_OFFSET 0 +#endif + #define cond_resched_lock(lock) ({ \ - __might_sleep(__FILE__, __LINE__, PREEMPT_OFFSET); \ + __might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET); \ __cond_resched_lock(lock); \ })
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