4.2.8-ckt9 -stable review patch. If anyone has any objections, please let me know.
---8<------------------------------------------------------------ From: Davidlohr Bueso <[email protected]> commit fe1bce9e2107ba3a8faffe572483b6974201a0e6 upstream. Otherwise an incoming waker on the dest hash bucket can miss the waiter adding itself to the plist during the lockless check optimization (small window but still the correct way of doing this); similarly to the decrement counterpart. Suggested-by: Peter Zijlstra <[email protected]> Signed-off-by: Davidlohr Bueso <[email protected]> Cc: Davidlohr Bueso <[email protected]> Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Thomas Gleixner <[email protected]> Signed-off-by: Kamal Mostafa <[email protected]> --- kernel/futex.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/futex.c b/kernel/futex.c index df4203b2..02113e5 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -1395,8 +1395,8 @@ void requeue_futex(struct futex_q *q, struct futex_hash_bucket *hb1, if (likely(&hb1->chain != &hb2->chain)) { plist_del(&q->list, &hb1->chain); hb_waiters_dec(hb1); - plist_add(&q->list, &hb2->chain); hb_waiters_inc(hb2); + plist_add(&q->list, &hb2->chain); q->lock_ptr = &hb2->lock; } get_futex_key_refs(key2); -- 2.7.4
