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authorWaiman Long <longman@redhat.com>2017-01-21 21:33:35 -0500
committerIngo Molnar <mingo@kernel.org>2017-01-22 09:54:00 +0100
commitbcc9a76d5ac426bc45c9e863b1830347827ca77a (patch)
tree9071148e7e216738ff5b9b0896019415425d42ee /kernel/locking
parent06321dd2d1ae5b5bdc847958ab9e71d22a29a33e (diff)
downloadlinux-bcc9a76d5ac426bc45c9e863b1830347827ca77a.tar.gz
linux-bcc9a76d5ac426bc45c9e863b1830347827ca77a.tar.xz
locking/rwsem: Reinit wake_q after use
In __rwsem_down_write_failed_common(), the same wake_q variable name is defined twice, with the inner wake_q hiding the one in outer scope. We can either use different names for the two wake_q's. Even better, we can use the same wake_q twice, if necessary. To enable the latter change, we need to define a new helper function wake_q_init() to enable reinitalization of wake_q after use. Signed-off-by: Waiman Long <longman@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1485052415-9611-1-git-send-email-longman@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/locking')
-rw-r--r--kernel/locking/rwsem-xadd.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c
index a3a381aee24b..2ad8d8dc3bb1 100644
--- a/kernel/locking/rwsem-xadd.c
+++ b/kernel/locking/rwsem-xadd.c
@@ -502,8 +502,6 @@ __rwsem_down_write_failed_common(struct rw_semaphore *sem, int state)
* wake any read locks that were queued ahead of us.
*/
if (count > RWSEM_WAITING_BIAS) {
- DEFINE_WAKE_Q(wake_q);
-
__rwsem_mark_wake(sem, RWSEM_WAKE_READERS, &wake_q);
/*
* The wakeup is normally called _after_ the wait_lock
@@ -513,6 +511,11 @@ __rwsem_down_write_failed_common(struct rw_semaphore *sem, int state)
* for attempting rwsem_try_write_lock().
*/
wake_up_q(&wake_q);
+
+ /*
+ * Reinitialize wake_q after use.
+ */
+ wake_q_init(&wake_q);
}
} else