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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

  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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