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=-8.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 CFBA0C63777 for ; Thu, 3 Dec 2020 10:26:05 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2EE0722203 for ; Thu, 3 Dec 2020 10:26:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2EE0722203 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 0F3B66B005C; Thu, 3 Dec 2020 05:26:04 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 0A43C6B005D; Thu, 3 Dec 2020 05:26:04 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id ED6AA6B0068; Thu, 3 Dec 2020 05:26:03 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0113.hostedemail.com [216.40.44.113]) by kanga.kvack.org (Postfix) with ESMTP id D6FA36B005C for ; Thu, 3 Dec 2020 05:26:03 -0500 (EST) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 94C50180AD80F for ; Thu, 3 Dec 2020 10:26:03 +0000 (UTC) X-FDA: 77551590606.08.home08_1e068b6273bb Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin08.hostedemail.com (Postfix) with ESMTP id 747B91819E621 for ; Thu, 3 Dec 2020 10:26:03 +0000 (UTC) X-HE-Tag: home08_1e068b6273bb X-Filterd-Recvd-Size: 3560 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf38.hostedemail.com (Postfix) with ESMTP for ; Thu, 3 Dec 2020 10:26:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=XCWg7Tb5mZvG/2h9CQXFxMTAJ32rXCudkFDrtro7Gcc=; b=X4Zcth9JiusNnNnWu7clwftyDq K8OL3GQ2KYXRgp+9HQySN/sgRAPUMbF0WtNs/OOtYPr9Qty0LJ2jg5YVe4MkzOQECLOilt529ucBq yEX1qDpFCsYEAbsGf6LnwTPTAK1B1jxTvvpZjxjEyh+V0isms7IbTIpycgadu4TGpssSLt8UeLXQh AQEsJGDUy/Y4qM64Z+fVepduWehHYj6pGfPVDnwh4DmIVDfiGgRx8zjiaGNoIkMoz+fb+/hr+4X1T uAPx4fchwaaWS/WiU4zCCcs7EYFI+g3658KtLnOuKBL82Pw8yvEHn6/Gk373iNYiJQelAdEjj7cuy T+Zd7McA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kklo8-0007qk-6I; Thu, 03 Dec 2020 10:25:52 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id B1B67302753; Thu, 3 Dec 2020 11:25:50 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 9308A201BAA75; Thu, 3 Dec 2020 11:25:50 +0100 (CET) Date: Thu, 3 Dec 2020 11:25:50 +0100 From: Peter Zijlstra To: Mel Gorman Cc: Huang Ying , 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: <20201203102550.GK2414@hirez.programming.kicks-ass.net> References: <20201202084234.15797-1-ying.huang@intel.com> <20201202084234.15797-2-ying.huang@intel.com> <20201202114054.GV3306@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201202114054.GV3306@suse.de> 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 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 ?