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Re: [PATCH -v11][RFC] mutex: implement adaptive spinning
On Wed, Jan 14, 2009 at 06:00:36PM +0100, Peter Zijlstra wrote: > Full series, including changelogs available at: > > http://programming.kicks-ass.net/kernel-patches/mutex-ada... > > and should shortly appear in a git tree near Ingo :-) Linus is going to take a wholesale conversion of mutexes to adaptive mutexes? He's gone soft. I put on my asbestos underwear for no reason, then. > @@ -173,21 +237,21 @@ __mutex_lock_common(struct mutex *lock, > spin_unlock_mutex(&lock->wait_lock, flags); > > debug_mutex_free_waiter(&waiter); > + preempt_enable(); > return -EINTR; > } > __set_task_state(task, state); > > /* didnt get the lock, go to sleep: */ > spin_unlock_mutex(&lock->wait_lock, flags); > - schedule(); > + __schedule(); Why does this need to do a preempt-disabled schedule? After we schedule away, the next task can do arbitrary things or reschedule itself, so if we have not anticipated such a condition here, then I can't see what __schedule protects. At least a comment is in order? Pity to add the call overhead to schedule just for this case. BTW. __schedule shouldn't need to be asmlinkage? > spin_lock_mutex(&lock->wait_lock, flags); > } > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html (Log in to post comments)
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