Messages in this thread | | | Subject | Re: [PATCH -tip/master 3/7] locking/mcs: Remove obsolete comment | From | Jason Low <> | Date | Mon, 28 Jul 2014 10:19:53 -0700 |
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On Mon, 2014-07-28 at 18:57 +0200, Peter Zijlstra wrote: > On Mon, Jul 28, 2014 at 09:53:58AM -0700, Davidlohr Bueso wrote: > > Well, it's not hard to see where the contention is when working on > > locking issues with perf. With mutexes there are only two sources, > > either the task is just spinning trying to get the lock, or its gone to > > the slowpath, and you can see a lot of contention on the wait_lock. > > > > So unless I'm missing something, I don't think we'd need to make this > > noinline again -- although I forget why it was changed in the first > > place. > > Not to mention that there's no actual caller of this function in the > entire kernel ;-) Currently its just 'documentation' describing what an > actual MCS lock looks like.
Yeah, we only use the cancellable version of the lock anyway and there's currently no benefit of changing the regular mcs lock to noinline.
I was mainly thinking it could be helpful in potential later uses of the regular mcs lock (if anyone comes up with a need to use it) where it might not be as obvious where the contention is occurring.
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