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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 AB27FC4320A for ; Wed, 28 Jul 2021 12:31:07 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4817C60F9C for ; Wed, 28 Jul 2021 12:31:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 4817C60F9C 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 C0BE06B0036; Wed, 28 Jul 2021 08:31:06 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B952F6B005D; Wed, 28 Jul 2021 08:31:06 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A353C8D0001; Wed, 28 Jul 2021 08:31:06 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0071.hostedemail.com [216.40.44.71]) by kanga.kvack.org (Postfix) with ESMTP id 84F486B0036 for ; Wed, 28 Jul 2021 08:31:06 -0400 (EDT) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 377E08249980 for ; Wed, 28 Jul 2021 12:31:06 +0000 (UTC) X-FDA: 78411931332.04.A777EBF Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by imf23.hostedemail.com (Postfix) with ESMTP id B45B9900ED55 for ; Wed, 28 Jul 2021 12:31:05 +0000 (UTC) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id 6277922314; Wed, 28 Jul 2021 12:31:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1627475464; 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=npMFGiRKpe9E2NAzxS4y+5J6eprtxsqTY9vAsITRMUg=; b=grWfSWG5enS6L02jqEBUn/cVF8gY3gQ3BR/4ugX8P8YwDZw4VnyA+reyvLfcyqIgY4MIpT 0MJ3wYrCYgUP+x91sRjSi6f5dMTVuwsiNqWRFiTLidGMb7HGnVyjgfrQgLS49ehsYtzyir CmoaE91Mp8qa0YNxL6qXl30SHvYJJHE= 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 1EE79A3B81; Wed, 28 Jul 2021 12:31:04 +0000 (UTC) Date: Wed, 28 Jul 2021 14:31:03 +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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1626077374-81682-2-git-send-email-feng.tang@intel.com> X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: B45B9900ED55 Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=suse.com header.s=susede1 header.b=grWfSWG5; dmarc=pass (policy=quarantine) header.from=suse.com; spf=pass (imf23.hostedemail.com: domain of mhocko@suse.com designates 195.135.220.28 as permitted sender) smtp.mailfrom=mhocko@suse.com X-Stat-Signature: z8gxes5tatjz3913hnac1odtrw4hz1p1 X-HE-Tag: 1627475465-852880 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: [Sorry for a late review] On Mon 12-07-21 16:09:29, Feng Tang wrote: [...] > @@ -1887,7 +1909,8 @@ nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy) > /* Return the node id preferred by the given mempolicy, or the given id */ > static int policy_node(gfp_t gfp, struct mempolicy *policy, int nd) > { > - if (policy->mode == MPOL_PREFERRED) { > + if (policy->mode == MPOL_PREFERRED || > + policy->mode == MPOL_PREFERRED_MANY) { > nd = first_node(policy->nodes); > } else { > /* Do we really want to have the preferred node to be always the first node in the node mask? Shouldn't that strive for a locality as well? Existing callers already prefer numa_node_id() - aka local node - and I belive we shouldn't just throw that away here. > @@ -1931,6 +1954,7 @@ unsigned int mempolicy_slab_node(void) > > switch (policy->mode) { > case MPOL_PREFERRED: > + case MPOL_PREFERRED_MANY: > return first_node(policy->nodes); Similarly here but I am not really familiar with the slab numa code enough to have strong opinions here. > @@ -2173,10 +2198,12 @@ struct page *alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma, > * node and don't fall back to other nodes, as the cost of > * remote accesses would likely offset THP benefits. > * > - * If the policy is interleave, or does not allow the current > - * node in its nodemask, we allocate the standard way. > + * If the policy is interleave or multiple preferred nodes, or > + * does not allow the current node in its nodemask, we allocate > + * the standard way. > */ > - if (pol->mode == MPOL_PREFERRED) > + if ((pol->mode == MPOL_PREFERRED || > + pol->mode == MPOL_PREFERRED_MANY)) > hpage_node = first_node(pol->nodes); Same here. > @@ -2451,6 +2479,9 @@ int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long > break; > > case MPOL_PREFERRED: > + case MPOL_PREFERRED_MANY: > + if (node_isset(curnid, pol->nodes)) > + goto out; > polnid = first_node(pol->nodes); > break; I do not follow what is the point of using first_node here. Either the node is in the mask or it is misplaced. What are you trying to achieve here? -- Michal Hocko SUSE Labs