diff options
| author | Waiman Long <longman@redhat.com> | 2017-01-21 21:33:35 -0500 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-01-22 09:54:00 +0100 |
| commit | bcc9a76d5ac426bc45c9e863b1830347827ca77a (patch) | |
| tree | 9071148e7e216738ff5b9b0896019415425d42ee /kernel/locking | |
| parent | 06321dd2d1ae5b5bdc847958ab9e71d22a29a33e (diff) | |
| download | lwn-bcc9a76d5ac426bc45c9e863b1830347827ca77a.tar.gz lwn-bcc9a76d5ac426bc45c9e863b1830347827ca77a.zip | |
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.c | 7 |
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 |