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=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 44BA8C4361B for ; Fri, 4 Dec 2020 09:20:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E8111227C3 for ; Fri, 4 Dec 2020 09:20:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729502AbgLDJUa (ORCPT ); Fri, 4 Dec 2020 04:20:30 -0500 Received: from mga14.intel.com ([192.55.52.115]:31264 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727518AbgLDJU3 (ORCPT ); Fri, 4 Dec 2020 04:20:29 -0500 IronPort-SDR: sH59V9v+e6q5cPCnG1ZTpGmQ7p3AyooHWRrIqqyJMSLwgJFSqIMe9kuQay7NISKVFIb9NmuqUM +HB0lkUgFC1A== X-IronPort-AV: E=McAfee;i="6000,8403,9824"; a="172569553" X-IronPort-AV: E=Sophos;i="5.78,392,1599548400"; d="scan'208";a="172569553" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Dec 2020 01:19:47 -0800 IronPort-SDR: aFiaaPkZWWqyxh5clPDGED9VSPqi4LCqSepHW4MVnQMjcnc6V82VYRsUGsblGD/XX2/aHufqht 3U1Oi9S9CG0A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.78,392,1599548400"; d="scan'208";a="366213115" Received: from yhuang-dev.sh.intel.com (HELO yhuang-dev) ([10.239.159.50]) by fmsmga004.fm.intel.com with ESMTP; 04 Dec 2020 01:19:44 -0800 From: "Huang\, Ying" To: Peter Zijlstra , Andrew Morton Cc: Mel Gorman , linux-mm@kvack.org, linux-kernel@vger.kernel.org, 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 References: <20201202084234.15797-1-ying.huang@intel.com> <20201202084234.15797-2-ying.huang@intel.com> <20201202114054.GV3306@suse.de> <20201203102550.GK2414@hirez.programming.kicks-ass.net> Date: Fri, 04 Dec 2020 17:19:43 +0800 In-Reply-To: <20201203102550.GK2414@hirez.programming.kicks-ass.net> (Peter Zijlstra's message of "Thu, 3 Dec 2020 11:25:50 +0100") Message-ID: <87zh2ulyhc.fsf@yhuang-dev.intel.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=ascii Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org Peter Zijlstra writes: > On Wed, Dec 02, 2020 at 11:40:54AM +0000, Mel Gorman wrote: >> 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 > > Who do we expect to merge this, me through tip/sched/core or akpm ? Hi, Peter, Per my understanding, this is NUMA balancing related, so could go through your tree. BTW: I have just sent -V7 with some small changes per Mel's latest comments. Hi, Andrew, Do you agree? Best Regards, Huang, Ying