Re: [PATCH] locking/ww_mutex: Replace cpu_relax with cond_resched for tests

From	Chris Wilson <chris@chris-wilson.co.uk>
Newsgroups	linux.kernel
Subject	Re: [PATCH] locking/ww_mutex: Replace cpu_relax with cond_resched for tests
Date	2017-02-28 11:00 +0100
Message-ID	<tfMJz-2En-11@gated-at.bofh.it> (permalink)
References	<tfHqx-7zd-9@gated-at.bofh.it> <tfMzT-2zF-7@gated-at.bofh.it> <tfMzU-2zF-13@gated-at.bofh.it>
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On Tue, Feb 28, 2017 at 10:48:53AM +0100, Peter Zijlstra wrote:
> On Tue, Feb 28, 2017 at 09:40:11AM +0000, Chris Wilson wrote:
> > When busy-spinning on a ww_mutex_trylock(), we depend upon the other
> > thread advancing and releasing the lock. This can not happen on a single
> > CPU unless we relinquish it.
> 
> Thanks, do you have any clue about those other ww-mutex test fails? So
> far I've not had much luck poking at them.

Not yet, they didn't seem quite so self-explanatory as this trace :(
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre

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Re: [PATCH] locking/ww_mutex: Replace cpu_relax with cond_resched  for tests Peter Zijlstra <peterz@infradead.org> - 2017-02-28 10:50 +0100
  Re: [PATCH] locking/ww_mutex: Replace cpu_relax with cond_resched  for tests Chris Wilson <chris@chris-wilson.co.uk> - 2017-02-28 11:00 +0100

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