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authorIngo Molnar <mingo@kernel.org>2016-01-06 11:02:29 +0100
committerIngo Molnar <mingo@kernel.org>2016-01-06 11:02:29 +0100
commit567bee2803cb46caeb6011de5b738fde33dc3896 (patch)
tree05bab01377bffa356bfbe06c4b6193b23b7c24ca /kernel/locking/osq_lock.c
parentaa0b7ae06387d40a988ce16a189082dee6e570bc (diff)
parent093e5840ae76f1082633503964d035f40ed0216d (diff)
downloadlinux-next-567bee2803cb46caeb6011de5b738fde33dc3896.tar.gz
linux-next-567bee2803cb46caeb6011de5b738fde33dc3896.zip
Merge branch 'sched/urgent' into sched/core, to pick up fixes before merging new patches
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/locking/osq_lock.c')
-rw-r--r--kernel/locking/osq_lock.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/kernel/locking/osq_lock.c b/kernel/locking/osq_lock.c
index d092a0c9c2d4..05a37857ab55 100644
--- a/kernel/locking/osq_lock.c
+++ b/kernel/locking/osq_lock.c
@@ -93,10 +93,12 @@ bool osq_lock(struct optimistic_spin_queue *lock)
node->cpu = curr;
/*
- * ACQUIRE semantics, pairs with corresponding RELEASE
- * in unlock() uncontended, or fastpath.
+ * We need both ACQUIRE (pairs with corresponding RELEASE in
+ * unlock() uncontended, or fastpath) and RELEASE (to publish
+ * the node fields we just initialised) semantics when updating
+ * the lock tail.
*/
- old = atomic_xchg_acquire(&lock->tail, curr);
+ old = atomic_xchg(&lock->tail, curr);
if (old == OSQ_UNLOCKED_VAL)
return true;