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Date: Wed, 5 Aug 2015 10:38:58 +0200
From: Ingo Molnar <mingo@kernel.org>
To: kernel test robot <ying.huang@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>, lkp@01.org,
        LKML <linux-kernel@vger.kernel.org>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>,
        Thomas Gleixner <tglx@linutronix.de>,
        Denys Vlasenko <dvlasenk@redhat.com>
Subject: Re: [lkp] [x86/build] b2c51106c75: -18.1%
 will-it-scale.per_process_ops
Message-ID: <20150805083858.GA21506@gmail.com>
References: <87pp37y4cy.fsf@yhuang-dev.intel.com>
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* kernel test robot <ying.huang@intel.com> wrote:

> FYI, we noticed the below changes on
> 
> git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/asm
> commit b2c51106c7581866c37ffc77c5d739f3d4b7cbc9 ("x86/build: Fix detection of GCC -mpreferred-stack-boundary support")

Does the performance regression go away reproducibly if you do:

   git revert b2c51106c7581866c37ffc77c5d739f3d4b7cbc9

?

Thanks,

	Ingo