diff options
| author |   Davidlohr Bueso <dave@stgolabs.net> | 2015-01-06 11:45:05 -0800 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2015-01-14 15:07:22 +0100 |
| commit | e42f678a0237f84f0004fbaf0fad0b844751eadd (patch) | |
| tree | d9de2910392e8644711b014262c3a8e8ef968e17 /kernel/locking | |
| parent | locking/mutex: Checking the stamp is WW only (diff) | |
| download | linux-dev-e42f678a0237f84f0004fbaf0fad0b844751eadd.tar.xz linux-dev-e42f678a0237f84f0004fbaf0fad0b844751eadd.zip | |
locking/mutex: Move MCS related comments to proper location
It serves much better if the comments are right before the osq_lock() call.
Also delete a useless comment.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1420573509-24774-3-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/locking')
| -rw-r--r-- | kernel/locking/mutex.c | 16 |
1 files changed, 5 insertions, 11 deletions
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c index b042ea57bbea..6db3d0dea6da 100644 --- a/kernel/locking/mutex.c +++ b/kernel/locking/mutex.c @@ -193,17 +193,6 @@ ww_mutex_set_context_fastpath(struct ww_mutex *lock, #ifdef CONFIG_MUTEX_SPIN_ON_OWNER -/* - * In order to avoid a stampede of mutex spinners from acquiring the mutex - * more or less simultaneously, the spinners need to acquire a MCS lock - * first before spinning on the owner field. - * - */ - -/* - * Mutex spinning code migrated from kernel/sched/core.c - */ - static inline bool owner_running(struct mutex *lock, struct task_struct *owner) { if (lock->owner != owner) @@ -307,6 +296,11 @@ static bool mutex_optimistic_spin(struct mutex *lock, if (!mutex_can_spin_on_owner(lock)) goto done; + /* + * In order to avoid a stampede of mutex spinners trying to + * acquire the mutex all at once, the spinners need to take a + * MCS (queued) lock first before spinning on the owner field. + */ if (!osq_lock(&lock->osq)) goto done; |