Re: [PATCH tip/locking/core v9 4/6] locking/pvqspinlock: Collect slowpath lock statistics

From	Peter Zijlstra <peterz@infradead.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH tip/locking/core v9 4/6] locking/pvqspinlock: Collect slowpath lock statistics
Date	2015-11-05 18:10 +0100
Message-ID	<qrwcV-15C-1@gated-at.bofh.it> (permalink)
References	(1 earlier) <qprhn-3F0-19@gated-at.bofh.it> <qqqsW-7Ek-15@gated-at.bofh.it> <qrvAg-C9-37@gated-at.bofh.it> <qrvTA-IK-17@gated-at.bofh.it> <qrw3i-Mt-37@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Thu, Nov 05, 2015 at 11:59:21AM -0500, Waiman Long wrote:
> >Mostly I just wanted to point out that it was possible; you need not
> >change to sysfs because debugfs lacks the capability.
> >
> >But now that you ask, I think debugfs might be the better place, such
> >statistics (and the proposed CONFIG symbol) are purely for debug
> >purposes, right?
> 
> Davidlohr had asked me to use per-cpu counters to reduce performance
> overhead so that they can be usable in production system. That is another
> reason why I move to sysfs.

Yes, the per-cpu thing certainly makes sense. But as said, that does not
require you to move to sysfs.

> BTW, do you have comments on the other patches in the series? I would like
> to collect all the comments before I renew the series.

I still have to look at the last two patches, I've sadly not had time
for that yet.
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Thread

Re: [PATCH tip/locking/core v9 4/6] locking/pvqspinlock: Collect  slowpath lock statistics Peter Zijlstra <peterz@infradead.org> - 2015-11-02 17:50 +0100
  Re: [PATCH tip/locking/core v9 4/6] locking/pvqspinlock: Collect  slowpath lock statistics Waiman Long <waiman.long@hpe.com> - 2015-11-05 17:30 +0100
    Re: [PATCH tip/locking/core v9 4/6] locking/pvqspinlock: Collect  slowpath lock statistics Peter Zijlstra <peterz@infradead.org> - 2015-11-05 17:50 +0100
      Re: [PATCH tip/locking/core v9 4/6] locking/pvqspinlock: Collect  slowpath lock statistics Waiman Long <waiman.long@hpe.com> - 2015-11-05 18:00 +0100
        Re: [PATCH tip/locking/core v9 4/6] locking/pvqspinlock: Collect  slowpath lock statistics Peter Zijlstra <peterz@infradead.org> - 2015-11-05 18:10 +0100
          Re: [PATCH tip/locking/core v9 4/6] locking/pvqspinlock: Collect  slowpath lock statistics Waiman Long <waiman.long@hpe.com> - 2015-11-05 18:40 +0100

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