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From: Ben Guthro <ben@guthro.net>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Mike Galbraith <efault@gmx.de>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@kernel.org>
Subject: Re: Potential scheduler regression
Date: Fri, 7 Jul 2017 16:55:27 -0400	[thread overview]
Message-ID: <CAOvdn6WHAqnyr4WFz3ogA8FAueVcASJGYZOBjit=diMud7N4mw@mail.gmail.com> (raw)
In-Reply-To: <20170705164850.lnziwloc6mko3mxo@hirez.programming.kicks-ass.net>

On Wed, Jul 5, 2017 at 12:48 PM, Peter Zijlstra <peterz@infradead.org> wrote:
> On Wed, Jul 05, 2017 at 11:42:46AM -0400, Ben Guthro wrote:
>> Hello,
>>
>> I've been in the process of updating our kernel in our appliance VM
>> from an old LTS kernel (4.1.y) to something a bit more modern (4.9.y)
>> - and ran into a performance regression, when our QA team was running
>> some regression suites.
>>
>>
>> I bisect this behavior to the following commit, introduced in the 4.9
>> merge window:
>>
>
> Could you test a later kernel that includes commit:
>
>   1ad3aaf3fcd2 ("sched/core: Implement new approach to scale select_idle_cpu()")
>

(resend without html)

Apologies on the delay - it took a bit to get the machines, to run the test.

I am happy to report that the kernel at 1ad3aaf3fcd2, seems to regain
performance loss from 1b568f0aab, in our test environment.

Since 4.9 is an LTS kernel - is this appropriate to suggest to be
included in the linux-stable list?

  reply	other threads:[~2017-07-07 20:55 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-07-05 15:42 Potential scheduler regression Ben Guthro
2017-07-05 16:48 ` Peter Zijlstra
2017-07-07 20:55   ` Ben Guthro [this message]
2017-07-10  9:25     ` Peter Zijlstra
2017-07-10 15:26       ` Greg KH
2017-07-10 15:43         ` Ben Guthro
2017-07-11  8:30           ` Ingo Molnar
2017-07-11  9:55             ` Greg KH
2017-07-13 19:24               ` Ben Guthro
2017-07-14  6:54                 ` Greg KH
2017-07-19  8:02                   ` Greg KH

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