path: root/ipc/sem.c
diff options
authorPaul E. McKenney <>2017-06-29 12:59:32 -0700
committerPaul E. McKenney <>2017-08-17 08:08:57 -0700
commite0892e086aae8d86e33dc8fb87f3d36c901df574 (patch)
tree6a480513ccaa1bb3e2427bddf8f452994bc3d901 /ipc/sem.c
parent8083f29349372d5b949dc022ae9a981edc89ac41 (diff)
ipc: Replace spin_unlock_wait() with lock/unlock pair
There is no agreed-upon definition of spin_unlock_wait()'s semantics, and it appears that all callers could do just as well with a lock/unlock pair. This commit therefore replaces the spin_unlock_wait() call in exit_sem() with spin_lock() followed immediately by spin_unlock(). This should be safe from a performance perspective because exit_sem() is rarely invoked in production. Signed-off-by: Paul E. McKenney <> Cc: Andrew Morton <> Cc: Davidlohr Bueso <> Cc: Will Deacon <> Cc: Peter Zijlstra <> Cc: Alan Stern <> Cc: Andrea Parri <> Cc: Linus Torvalds <> Acked-by: Manfred Spraul <>
Diffstat (limited to 'ipc/sem.c')
1 files changed, 2 insertions, 1 deletions
diff --git a/ipc/sem.c b/ipc/sem.c
index 9e70cd7a17da..2570830e29fc 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -2091,7 +2091,8 @@ void exit_sem(struct task_struct *tsk)
* possibility where we exit while freeary() didn't
* finish unlocking sem_undo_list.
- spin_unlock_wait(&ulp->lock);
+ spin_lock(&ulp->lock);
+ spin_unlock(&ulp->lock);