Re: Performance regression from switching lock to rw-sem for anon-vma tree

From: Michel Lespinasse
Date: Fri Jun 14 2013 - 18:47:20 EST

On Fri, Jun 14, 2013 at 3:31 PM, Davidlohr Bueso <davidlohr.bueso@xxxxxx> wrote:
> A few ideas that come to mind are avoiding taking the ->wait_lock and
> avoid dealing with waiters when doing the optimistic spinning (just like
> mutexes do).
> I agree that we should first deal with the optimistic spinning before
> adding the MCS complexity.

Maybe it would be worth disabling the MCS patch in mutex and comparing
that to the rwsem patches ? Just to make sure the rwsem performance
delta isn't related to that.

Michel "Walken" Lespinasse
A program is never fully debugged until the last user dies.
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