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From: Jiri Slaby <jslaby@suse.cz>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Andrei Vagin <avagin@gmail.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-kernel@vger.kernel.org,
	"Eric W. Biederman" <ebiederm@xmission.com>
Subject: Re: [PATCH v2] kernel: release ptraced tasks before zap_pid_ns_processes
Date: Wed, 27 Feb 2019 09:03:35 +0100	[thread overview]
Message-ID: <945c0ec2-8e5f-a273-c2cd-3f2fd43a1766@suse.cz> (raw)
In-Reply-To: <20190226153039.GA21443@redhat.com>

On 26. 02. 19, 16:30, Oleg Nesterov wrote:
>> from our (SUSE) QA we received a report that this patch causes a
>> performance decline in libmicro pthread_* benchmark as reported in:
>> https://bugzilla.suse.com/show_bug.cgi?id=1126762
> 
> Access Denied
> 
>> I tried myself from the repo:
>> https://github.com/redhat-performance/libMicro
>>
>> I ran
>> pthread_create -B 8 -C 200 -S
>>
>> and with the patch applied:
>> # STATISTICS       usecs/call (raw)          usecs/call (outliers removed)
>> #                   mean     23.38611                17.29311
>>
>> Without:
>> #                   mean     41.36539                39.21347
> 
> can't reproduce, I see the same numbers with or without this patch.
> However, I did "./bin/pthread_create -B 8 -C 200 -S" under KVM.

Correct. I did the tests also under KVM. The above difference happens
when you compare (by stupid mistake) a LOCKDEP and non-LOCKDEP kernel --
sorry. So the proper results are comparably the same -- the difference
is on the noise level. So it must be their setup broken too.

Thanks for the input anyway.

-- 
js
suse labs

      reply	other threads:[~2019-02-27  8:03 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-10 17:52 [PATCH v2] kernel: release ptraced tasks before zap_pid_ns_processes Andrei Vagin
2019-01-10 23:37 ` Andrew Morton
2019-01-11 15:39   ` Oleg Nesterov
2019-02-26  9:19 ` Jiri Slaby
2019-02-26 15:30   ` Oleg Nesterov
2019-02-27  8:03     ` Jiri Slaby [this message]

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