lkml.org 
[lkml]   [2009]   [Jan]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
SubjectRe: [PATCH -v7][RFC]: mutex: implement adaptive spinning
From
Date
On Fri, 2009-01-09 at 11:44 -0500, Steven Rostedt wrote:

> When we get to the schedule() it then needs to be a:
>
> preempt_enable_no_resched();
> schedule();

On that note:

Index: linux-2.6/kernel/mutex.c
===================================================================
--- linux-2.6.orig/kernel/mutex.c
+++ linux-2.6/kernel/mutex.c
@@ -220,7 +220,9 @@ __mutex_lock_common(struct mutex *lock,
__set_task_state(task, state);

/* didnt get the lock, go to sleep: */
+ preempt_disable();
spin_unlock_mutex(&lock->wait_lock, flags);
+ preempt_enable_no_resched();
schedule();
spin_lock_mutex(&lock->wait_lock, flags);
}

actually improves mutex performance on PREEMPT=y


\
 
 \ /
  Last update: 2009-01-09 19:19    [W:0.734 / U:0.892 seconds]
©2003-2014 Jasper Spaans. Advertise on this site