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Date: Wed, 5 Jul 2017 18:48:50 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Ben Guthro <ben@guthro.net>
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
Message-ID: <20170705164850.lnziwloc6mko3mxo@hirez.programming.kicks-ass.net>
References: <CAOvdn6UhFUG-NDBf5P9EqS+6UA6LCeDTw1aBbW-dbzPU3Z4T1A@mail.gmail.com>
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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()")