Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757270AbdLUBlF (ORCPT ); Wed, 20 Dec 2017 20:41:05 -0500 Received: from mga04.intel.com ([192.55.52.120]:51512 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755864AbdLUBlE (ORCPT ); Wed, 20 Dec 2017 20:41:04 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.45,434,1508828400"; d="scan'208";a="14391760" Subject: Re: [PATCH v2 4/5] mm: use node_page_state_snapshot to avoid deviation To: Christopher Lameter Cc: Michal Hocko , Greg Kroah-Hartman , Andrew Morton , Vlastimil Babka , Mel Gorman , Johannes Weiner , YASUAKI ISHIMATSU , Andrey Ryabinin , Nikolay Borisov , Pavel Tatashin , David Rientjes , Sebastian Andrzej Siewior , Dave , Andi Kleen , Tim Chen , Jesper Dangaard Brouer , Ying Huang , Aaron Lu , Aubrey Li , Linux MM , Linux Kernel References: <1513665566-4465-1-git-send-email-kemi.wang@intel.com> <1513665566-4465-5-git-send-email-kemi.wang@intel.com> <20171219124317.GP2787@dhcp22.suse.cz> <94187fd5-ad70-eba7-2724-0fe5bed750d6@intel.com> <20171220100650.GI4831@dhcp22.suse.cz> <1f3a6d05-2756-93fd-a380-df808c94ece8@intel.com> From: kemi Message-ID: <1f0d8933-60a3-e2e0-f7a3-36e98ade48bb@intel.com> Date: Thu, 21 Dec 2017 09:39:01 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 900 Lines: 25 On 2017年12月20日 23:58, Christopher Lameter wrote: > On Wed, 20 Dec 2017, kemi wrote: > >>> You are making numastats special and I yet haven't heard any sounds >>> arguments for that. But that should be discussed in the respective >>> patch. >>> >> >> That is because we have much larger threshold size for NUMA counters, that means larger >> deviation. So, the number in local cpus may not be simply ignored. > > Some numbers showing the effect of these changes would be helpful. You can > probably create some in kernel synthetic tests to start with which would > allow you to see any significant effects of those changes. > > Then run the larger testsuites (f.e. those that Mel has published) and > benchmarks to figure out how behavior of real apps *may* change? > OK. I will do that when available. Let's just drop this patch in this series and consider this issue in another patch.