From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1753182AbcB2RiA (ORCPT <rfc822;w@1wt.eu>);
	Mon, 29 Feb 2016 12:38:00 -0500
Received: from mx2.suse.de ([195.135.220.15]:44563 "EHLO mx2.suse.de"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1751447AbcB2Rh7 convert rfc822-to-8bit (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Mon, 29 Feb 2016 12:37:59 -0500
Date: Mon, 29 Feb 2016 09:37:47 -0800
From: Davidlohr Bueso <dave@stgolabs.net>
To: Ingo Molnar <mingo@kernel.org>
Cc: kernel test robot <ying.huang@linux.intel.com>,
        Mel Gorman <mgorman@suse.de>, lkp@01.org,
        LKML <linux-kernel@vger.kernel.org>,
        Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
        Peter Zijlstra <peterz@infradead.org>,
        Mel Gorman <mgorman@techsingularity.net>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Hugh Dickins <hughd@google.com>, Darren Hart <dvhart@linux.intel.com>,
        Chris Mason <clm@fb.com>, Thomas Gleixner <tglx@linutronix.de>,
        Davidlohr Bueso <dbueso@suse.de>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: Re: [lkp] [futex] 65d8fc777f: +25.6% will-it-scale.per_process_ops
Message-ID: <20160229173747.GA17288@linux-uzut.site>
References: <871t7vzze1.fsf@yhuang-dev.intel.com>
 <20160229093708.GA21037@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1; format=flowed
Content-Disposition: inline
Content-Transfer-Encoding: 8BIT
In-Reply-To: <20160229093708.GA21037@gmail.com>
User-Agent: Mutt/1.5.21 (2010-09-15)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Mon, 29 Feb 2016, Ingo Molnar wrote:

>
>* kernel test robot <ying.huang@linux.intel.com> wrote:
>
>> FYI, we noticed the below changes on
>>
>> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
>> commit 65d8fc777f6dcfee12785c057a6b57f679641c90 ("futex: Remove requirement for
>> lock_page() in get_futex_key()")
>
>I have asked for this before, but let me try again: could you _PLEASE_ make these
>emails more readable?
>
>For example what are the 'below changes'? Changes in the profile output? Profiles
>always change from run to run, so that alone is not informative.
>
>Also, there are a lot of changes - which ones prompted the email to be generated?
>
>All in one, this email is hard to parse, because it just dumps a lot of
>information with very little explanatory structure for someone not versed in their
>format. Please try to create an easy to parse 'story' that leads the reader
>towards what you want these emails to tell - not just a raw dump of seemingly
>unconnected pieces of data ...
>↓
>Thanks,
>
>	Ingo
>
>>
>>
>> =========================================================================================
>> compiler/cpufreq_governor/kconfig/rootfs/tbox_group/test/testcase:
>>   gcc-4.9/performance/x86_64-rhel/debian-x86_64-2015-02-07.cgz/lkp-sbx04/futex1/will-it-scale

If I'm reading this correctly, it is similar to what I measured wrt ~lockleless get_futex_key()
stuff using the perf runs, with similar performance improvement numbers (per process/thread ops).
The futex1 test will just pound on FUTEX_WAKE without anyone actually blocked on a futex, so it
mainly measures the key/hashing part of the operation.

Thanks,
Davidlohr