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Subject: Re: [LKP] Re: [sched] bdfcae1140: will-it-scale.per_thread_ops -37.0%
 regression
To:     Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Anton Blanchard <anton@au.ibm.com>, anton@ozlabs.org
Cc:     Rong Chen <rong.a.chen@intel.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Boqun Feng <boqun.feng@gmail.com>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Will Deacon <will@kernel.org>, paulmck <paulmck@kernel.org>,
        Nicholas Piggin <npiggin@gmail.com>,
        Andy Lutomirski <luto@amacapital.net>,
        Andrew Morton <akpm@linux-foundation.org>,
        0day robot <lkp@intel.com>, lkp <lkp@lists.01.org>,
        zhengjun xing <zhengjun.xing@intel.com>,
        aubrey li <aubrey.li@linux.intel.com>,
        yu c chen <yu.c.chen@intel.com>
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From:   Xing Zhengjun <zhengjun.xing@linux.intel.com>
Message-ID: <61ff00c3-4f55-e186-3ba7-93f96340ebd0@linux.intel.com>
Date:   Fri, 23 Oct 2020 13:37:50 +0800
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On 10/22/2020 9:19 PM, Mathieu Desnoyers wrote:
> ----- On Oct 21, 2020, at 9:54 PM, Xing Zhengjun zhengjun.xing@linux.intel.com wrote:
> [...]
>> In fact, 0-day just copy the will-it-scale benchmark from the GitHub, if
>> you think the will-it-scale benchmark has some issues, you can
>> contribute your idea and help to improve it, later we will update the
>> will-it-scale benchmark to the new version.
> 
> This is why I CC'd the maintainer of the will-it-scale github project, Anton Blanchard.
> My main intent is to report this issue to him, but I have not heard back from him yet.
> Is this project maintained ? Let me try to add his ozlabs.org address in CC.
> 
>> For this test case, if we bind the workload to a specific CPU, then it
>> will hide the scheduler balance issue. In the real world, we seldom bind
>> the CPU...
> 
> When you say that you bind the workload to a specific CPU, is that done
> outside of the will-it-scale testsuite, thus limiting the entire testsuite
> to a single CPU, or you expect that internally the will-it-scale context-switch1
> test gets affined to a single specific CPU/core/hardware thread through use of
> hwloc ?
> 
The later one.

> Thanks,
> 
> Mathieu
> 

-- 
Zhengjun Xing