From: Will Deacon <will.deacon@arm.com>
To: Vikram Mulukutla <markivx@codeaurora.org>
Cc: qiaozhou <qiaozhou@asrmicro.com>,
Thomas Gleixner <tglx@linutronix.de>,
John Stultz <john.stultz@linaro.org>,
sboyd@codeaurora.org, LKML <linux-kernel@vger.kernel.org>,
Wang Wilbur <wilburwang@asrmicro.com>,
Marc Zyngier <marc.zyngier@arm.com>,
Peter Zijlstra <peterz@infradead.org>,
linux-kernel-owner@vger.kernel.org, sudeep.holla@arm.com
Subject: Re: [Question]: try to fix contention between expire_timers and try_to_del_timer_sync
Date: Tue, 15 Aug 2017 19:40:40 +0100 [thread overview]
Message-ID: <20170815184039.GE10801@arm.com> (raw)
In-Reply-To: <a858eaf3973979d0759ee016d39887e3@codeaurora.org>
Hi Vikram,
On Thu, Aug 03, 2017 at 04:25:12PM -0700, Vikram Mulukutla wrote:
> On 2017-07-31 06:13, Will Deacon wrote:
> >On Fri, Jul 28, 2017 at 12:09:38PM -0700, Vikram Mulukutla wrote:
> >>On 2017-07-28 02:28, Will Deacon wrote:
> >>>On Thu, Jul 27, 2017 at 06:10:34PM -0700, Vikram Mulukutla wrote:
>
> >>>
> >>This does seem to help. Here's some data after 5 runs with and without
> >>the
> >>patch.
> >
> >Blimey, that does seem to make a difference. Shame it's so ugly! Would you
> >be able to experiment with other values for CPU_RELAX_WFE_THRESHOLD? I had
> >it set to 10000 in the diff I posted, but that might be higher than
> >optimal.
> >It would be interested to see if it correlates with num_possible_cpus()
> >for the highly contended case.
> >
> >Will
>
> Sorry for the late response - I should hopefully have some more data with
> different thresholds before the week is finished or on Monday.
Did you get anywhere with the threshold heuristic?
Will
next prev parent reply other threads:[~2017-08-15 18:40 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <3d2459c7-defd-a47e-6cea-007c10cecaac@asrmicro.com>
2017-07-26 14:16 ` [Question]: try to fix contention between expire_timers and try_to_del_timer_sync Thomas Gleixner
2017-07-27 1:29 ` qiaozhou
2017-07-27 15:14 ` Will Deacon
2017-07-27 15:19 ` Thomas Gleixner
2017-07-28 1:10 ` Vikram Mulukutla
2017-07-28 9:28 ` Peter Zijlstra
2017-07-28 19:11 ` Vikram Mulukutla
2017-07-28 9:28 ` Will Deacon
2017-07-28 19:09 ` Vikram Mulukutla
2017-07-31 11:20 ` qiaozhou
2017-08-01 7:37 ` qiaozhou
2017-08-03 23:32 ` Vikram Mulukutla
2017-08-04 3:15 ` qiaozhou
2017-07-31 13:13 ` Will Deacon
2017-08-03 23:25 ` Vikram Mulukutla
2017-08-15 18:40 ` Will Deacon [this message]
2017-08-25 19:48 ` Vikram Mulukutla
2017-08-25 20:25 ` Vikram Mulukutla
2017-08-28 23:12 ` Vikram Mulukutla
2017-09-06 11:19 ` qiaozhou
2017-09-25 11:02 ` qiaozhou
2017-10-02 14:14 ` Will Deacon
2017-10-11 8:33 ` qiaozhou
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