From: Vikram Mulukutla <markivx@codeaurora.org>
To: qiaozhou <qiaozhou@asrmicro.com>
Cc: Will Deacon <will.deacon@arm.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: Thu, 03 Aug 2017 16:32:25 -0700 [thread overview]
Message-ID: <a1530fab213076be576adce4d5fbbb44@codeaurora.org> (raw)
In-Reply-To: <c2450453-0a42-0c68-db9b-3d097dc62c34@asrmicro.com>
Hi Qiao,
On 2017-08-01 00:37, qiaozhou wrote:
> On 2017年07月31日 19:20, qiaozhou wrote:
>>
>>
<snip>
>>> =====================================================
>>> Also apply Vikram's patch and have a test.
>
> cpu2: a53, 832MHz, cpu7: a73, 1.75Hz
> Without cpu_relax bodging patch
> =====================================================
> cpu2 time | cpu2 counter | cpu7 time | cpu7 counter |
> ==========|==============|===========|==============|
> 16505| 5243| 2| 12487322|
> 16494| 5619| 1| 12013291|
> 16498| 5276| 2| 11706824|
> 16494| 7123| 1| 12532355|
> 16470| 7208| 2| 11784617|
> =====================================================
>
> cpu2: a53, 832MHz, cpu7: a73, 1.75Hz
> With cpu_relax bodging patch:
> =====================================================
> cpu2 time | cpu2 counter | cpu7 time | cpu7 counter |
> ==========|==============|===========|==============|
> 3991| 140714| 1| 11430528|
> 4018| 144371| 1| 11430528|
> 4034| 143250| 1| 11427011|
> 4330| 147345| 1| 11423583|
> 4752| 138273| 1| 11433241|
> =====================================================
>
> It has some improvements, but not so good as Vikram's data. The big
> core still has much more chance to acquire lock.
>>>
>>> Thanks,
>>> Vikram
>>>
Thanks for your data! I'll check on one of our other platforms to see
if I see similar behavior. This may have something to do with the
event-stream on your platform or the A53 revision as Sudeep pointed
out here [1] - something to check I suppose...
Thanks,
Vikram
[1] - https://lkml.org/lkml/2016/11/21/458
--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
next prev parent reply other threads:[~2017-08-03 23:32 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 [this message]
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
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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