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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 A2D57C432BE for ; Fri, 30 Jul 2021 06:36:54 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4533B6101C for ; Fri, 30 Jul 2021 06:36:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 4533B6101C Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 97F286B0036; Fri, 30 Jul 2021 02:36:53 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 92D886B005D; Fri, 30 Jul 2021 02:36:53 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 81C328D0001; Fri, 30 Jul 2021 02:36:53 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0170.hostedemail.com [216.40.44.170]) by kanga.kvack.org (Postfix) with ESMTP id 673196B0036 for ; Fri, 30 Jul 2021 02:36:53 -0400 (EDT) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 0B4B98249980 for ; Fri, 30 Jul 2021 06:36:53 +0000 (UTC) X-FDA: 78418296306.12.259455A Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by imf17.hostedemail.com (Postfix) with ESMTP id 77A63F003490 for ; Fri, 30 Jul 2021 06:36:52 +0000 (UTC) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id 1311422254; Fri, 30 Jul 2021 06:36:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1627627011; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=CQoiuOtQizQ1P3NzC2UpgAVz64H8oYKXgC33uSSYg5k=; b=RqY0P6/UWT3A05JkuBUlU6MX5gX2+tBxO+oMt+xBtWSGC9B0O2+ZxXvVcM9J2gcUYzPmWo WBufMu0pwcbO9Doj9HG1t8jpQVV33vHQyMWccrpxKUuccTdFJQvG+VD2ze43GqTPyu2v40 5mvvNVtAPXKyCSGPxWsaMDEXkXs818A= Received: from suse.cz (unknown [10.100.201.86]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id A4633A3B8A; Fri, 30 Jul 2021 06:36:50 +0000 (UTC) Date: Fri, 30 Jul 2021 08:36:50 +0200 From: Michal Hocko To: Feng Tang Cc: linux-mm@kvack.org, Andrew Morton , David Rientjes , Dave Hansen , Ben Widawsky , linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, Andrea Arcangeli , Mel Gorman , Mike Kravetz , Randy Dunlap , Vlastimil Babka , Andi Kleen , Dan Williams , ying.huang@intel.com, Dave Hansen Subject: Re: [PATCH v6 1/6] mm/mempolicy: Add MPOL_PREFERRED_MANY for multiple preferred nodes Message-ID: References: <1626077374-81682-1-git-send-email-feng.tang@intel.com> <1626077374-81682-2-git-send-email-feng.tang@intel.com> <20210728141156.GC43486@shbuild999.sh.intel.com> <20210729070918.GA96680@shbuild999.sh.intel.com> <20210729151242.GA42865@shbuild999.sh.intel.com> <20210730030502.GA87066@shbuild999.sh.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210730030502.GA87066@shbuild999.sh.intel.com> Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=suse.com header.s=susede1 header.b="RqY0P6/U"; spf=pass (imf17.hostedemail.com: domain of mhocko@suse.com designates 195.135.220.28 as permitted sender) smtp.mailfrom=mhocko@suse.com; dmarc=pass (policy=quarantine) header.from=suse.com X-Rspamd-Server: rspam02 X-Stat-Signature: 1nqr1pmfzhtas93fp96kpsa7cdobkqa6 X-Rspamd-Queue-Id: 77A63F003490 X-HE-Tag: 1627627012-884875 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 Fri 30-07-21 11:05:02, Feng Tang wrote: > On Thu, Jul 29, 2021 at 06:21:19PM +0200, Michal Hocko wrote: > > On Thu 29-07-21 23:12:42, Feng Tang wrote: > > > On Thu, Jul 29, 2021 at 03:38:44PM +0200, Michal Hocko wrote: > > [...] > > > > Also the > > > > semantic to give nodes some ordering based on their numbers sounds > > > > rather weird to me. > > > > > > I agree, and as I admitted in the first reply, this need to be fixed. > > > > OK. I was not really clear that we are on the same page here. > > > > > > The semantic I am proposing is to allocate from prefered nodes in > > > > distance order starting from the local node. > > > > > > So the plan is: > > > * if the local node is set in 'prefer-many's nodemask, then chose > > > * otherwise chose the node with the shortest distance to local node > > > ? > > > > Yes and what I am trying to say is that you will achieve that simply by > > doing the following in policy_node: > > if (policy->mode == MPOL_PREFERRED_MANY) > > return nd; > > One thing is, it's possible that 'nd' is not set in the preferred > nodemask. Yes, and there shouldn't be any problem with that. The given node is only used to get the respective zonelist (order distance ordered list of zones to try). get_page_from_freelist will then use the preferred node mask to filter this zone list. Is that more clear now? -- Michal Hocko SUSE Labs