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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-01-27 11:52:50 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-01-27 11:52:50 -0800 |
| commit | 9881051828375a872964f91bf985b8a35e4fbaef (patch) | |
| tree | a7e8a0503ecdb19bdcd5cf2bf5696143f2c4900b /include | |
| parent | 0d484375d73ad2ec39a395365449a70c200645b1 (diff) | |
| parent | e158488be27b157802753a59b336142dc0eb0380 (diff) | |
| download | linux-9881051828375a872964f91bf985b8a35e4fbaef.tar.bz2 | |
Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Thomas Gleixner:
"A small series of fixes which all address possible missed wakeups:
- Document and fix the wakeup ordering of wake_q
- Add the missing barrier in rcuwait_wake_up(), which was documented
in the comment but missing in the code
- Fix the possible missed wakeups in the rwsem and futex code"
* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/rwsem: Fix (possible) missed wakeup
futex: Fix (possible) missed wakeup
sched/wake_q: Fix wakeup ordering for wake_q
sched/wake_q: Document wake_q_add()
sched/wait: Fix rcuwait_wake_up() ordering
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/sched/wake_q.h | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/include/linux/sched/wake_q.h b/include/linux/sched/wake_q.h index 10b19a192b2d..545f37138057 100644 --- a/include/linux/sched/wake_q.h +++ b/include/linux/sched/wake_q.h @@ -24,9 +24,13 @@ * called near the end of a function. Otherwise, the list can be * re-initialized for later re-use by wake_q_init(). * - * Note that this can cause spurious wakeups. schedule() callers + * NOTE that this can cause spurious wakeups. schedule() callers * must ensure the call is done inside a loop, confirming that the * wakeup condition has in fact occurred. + * + * NOTE that there is no guarantee the wakeup will happen any later than the + * wake_q_add() location. Therefore task must be ready to be woken at the + * location of the wake_q_add(). */ #include <linux/sched.h> |