From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 76C6EC64E8A for ; Wed, 2 Dec 2020 11:41:01 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B997420709 for ; Wed, 2 Dec 2020 11:41:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B997420709 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id E20476B005C; Wed, 2 Dec 2020 06:40:59 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id DA9EB6B005D; Wed, 2 Dec 2020 06:40:59 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CBFCA8D0001; Wed, 2 Dec 2020 06:40:59 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0226.hostedemail.com [216.40.44.226]) by kanga.kvack.org (Postfix) with ESMTP id B180C6B005C for ; Wed, 2 Dec 2020 06:40:59 -0500 (EST) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 73468824999B for ; Wed, 2 Dec 2020 11:40:59 +0000 (UTC) X-FDA: 77548150638.08.foot61_470b872273b2 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin08.hostedemail.com (Postfix) with ESMTP id 551DE1819E624 for ; Wed, 2 Dec 2020 11:40:59 +0000 (UTC) X-HE-Tag: foot61_470b872273b2 X-Filterd-Recvd-Size: 2243 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf25.hostedemail.com (Postfix) with ESMTP for ; Wed, 2 Dec 2020 11:40:58 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 75D70AB7F; Wed, 2 Dec 2020 11:40:57 +0000 (UTC) Date: Wed, 2 Dec 2020 11:40:54 +0000 From: Mel Gorman To: Huang Ying Cc: Peter Zijlstra , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Ingo Molnar , Rik van Riel , Johannes Weiner , "Matthew Wilcox (Oracle)" , Dave Hansen , Andi Kleen , Michal Hocko , David Rientjes , linux-api@vger.kernel.org Subject: Re: [PATCH -V6 RESEND 1/3] numa balancing: Migrate on fault among multiple bound nodes Message-ID: <20201202114054.GV3306@suse.de> References: <20201202084234.15797-1-ying.huang@intel.com> <20201202084234.15797-2-ying.huang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20201202084234.15797-2-ying.huang@intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Dec 02, 2020 at 04:42:32PM +0800, Huang Ying wrote: > Now, NUMA balancing can only optimize the page placement among the > NUMA nodes if the default memory policy is used. Because the memory > policy specified explicitly should take precedence. But this seems > too strict in some situations. For example, on a system with 4 NUMA > nodes, if the memory of an application is bound to the node 0 and 1, > NUMA balancing can potentially migrate the pages between the node 0 > and 1 to reduce cross-node accessing without breaking the explicit > memory binding policy. > Ok, I think this part is ok and while the test case is somewhat superficial, it at least demonstrated that the NUMA balancing overhead did not offset any potential benefit Acked-by: Mel Gorman -- Mel Gorman SUSE Labs