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Date: Wed, 29 Jun 2016 10:46:37 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Jirka Hladky <jhladky@redhat.com>
Cc: linux-kernel <linux-kernel@vger.kernel.org>,
        Kamil Kolakowski <kkolakow@redhat.com>, Ingo Molnar <mingo@redhat.com>,
        jplozi@unice.fr, Alexandra Fedorova <sasha@ece.ubc.ca>,
        Baptiste Lepers <baptiste.lepers@gmail.com>
Subject: Re: Kernel v4.7-rc5 - performance degradation upto 40% after
 disabling and re-enabling a core
Message-ID: <20160629084637.GV30921@twins.programming.kicks-ass.net>
References: <CAE4VaGCPbQki+JbG=rs5Pj9x0hocZ16L4uXif_-iag8cT_RkQg@mail.gmail.com>
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On Wed, Jun 29, 2016 at 01:15:17AM +0200, Jirka Hladky wrote:
> Hello,
> 
> on NUMA enabled server equipped with 4 Intel E5-4610 v2 CPUs we
> observe following performance degradation:

Do you have cluster on die enabled on that machine? If you disable it,
does it still reproduce?