redonkable/remarkable-linux
redonkable/remarkable-linux
1
0
Fork 0
Code Releases Activity

locking/mutex: Move MCS related comments to proper location

Browse source 
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>
This commit is contained in:
Davidlohr Bueso 2015-01-06 11:45:05 -08:00 committed by Ingo Molnar
parent 63dc47e956
commit e42f678a02
1 changed files with 5 additions and 11 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

16
kernel/locking/mutex.c
View file

@ -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;