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| author | Peter Zijlstra <peterz@infradead.org> | 2013-11-20 15:22:37 +0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2014-01-13 20:38:55 +0400 |
| commit | 8cb75e0c4ec9786b81439761eac1d18d4a931af3 (patch) | |
| tree | 9d13e6c3580a36cd76d1b3a96827795949519409 /include/linux/preempt.h | |
| parent | c9c8986847d2f4fc474c10ee08afa57e7474096d (diff) | |
| download | linux-8cb75e0c4ec9786b81439761eac1d18d4a931af3.tar.xz | |
sched/preempt: Fix up missed PREEMPT_NEED_RESCHED folding
With various drivers wanting to inject idle time; we get people
calling idle routines outside of the idle loop proper.
Therefore we need to be extra careful about not missing
TIF_NEED_RESCHED -> PREEMPT_NEED_RESCHED propagations.
While looking at this, I also realized there's a small window in the
existing idle loop where we can miss TIF_NEED_RESCHED; when it hits
right after the tif_need_resched() test at the end of the loop but
right before the need_resched() test at the start of the loop.
So move preempt_fold_need_resched() out of the loop where we're
guaranteed to have TIF_NEED_RESCHED set.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-x9jgh45oeayzajz2mjt0y7d6@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/preempt.h')
| -rw-r--r-- | include/linux/preempt.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/include/linux/preempt.h b/include/linux/preempt.h index dd9ddf8af205..59749fc48328 100644 --- a/include/linux/preempt.h +++ b/include/linux/preempt.h @@ -134,6 +134,21 @@ do { \ #undef preempt_check_resched #endif +#ifdef CONFIG_PREEMPT +#define preempt_set_need_resched() \ +do { \ + set_preempt_need_resched(); \ +} while (0) +#define preempt_fold_need_resched() \ +do { \ + if (tif_need_resched()) \ + set_preempt_need_resched(); \ +} while (0) +#else +#define preempt_set_need_resched() do { } while (0) +#define preempt_fold_need_resched() do { } while (0) +#endif + #ifdef CONFIG_PREEMPT_NOTIFIERS struct preempt_notifier; |