From patchwork Thu May 20 08:30:01 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Feng Tang X-Patchwork-Id: 12269449 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 8ECDBC433ED for ; Thu, 20 May 2021 08:30:18 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 29C7160FEE for ; Thu, 20 May 2021 08:30:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 29C7160FEE Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id BF8C36B0075; Thu, 20 May 2021 04:30:16 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B811D6B0078; Thu, 20 May 2021 04:30:16 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A48676B007D; Thu, 20 May 2021 04:30:16 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0004.hostedemail.com [216.40.44.4]) by kanga.kvack.org (Postfix) with ESMTP id 6D6156B0075 for ; Thu, 20 May 2021 04:30:16 -0400 (EDT) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 071F482C879D for ; Thu, 20 May 2021 08:30:16 +0000 (UTC) X-FDA: 78160937232.02.1FD587F Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by imf05.hostedemail.com (Postfix) with ESMTP id 73A58E00013F for ; Thu, 20 May 2021 08:30:13 +0000 (UTC) IronPort-SDR: Gni1T62nK5ViM5p6q0eRZrH6VGhkdWUdWdqE7+q1T18oIdgd9yCmARMQV0crJkpKxZJXmbuyHm DN4DVJ23ZsQA== X-IronPort-AV: E=McAfee;i="6200,9189,9989"; a="181454376" X-IronPort-AV: E=Sophos;i="5.82,313,1613462400"; d="scan'208";a="181454376" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 May 2021 01:30:15 -0700 IronPort-SDR: v1wQCbBUT3aWfY0Cm3DhdLDmQJeIfEP4e3JYnUQnAfONRhH6N0bAgFZR9Rf8qDZqRAEcFnXKim bL2UVqCIHMow== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.82,313,1613462400"; d="scan'208";a="473899320" Received: from shbuild999.sh.intel.com ([10.239.147.94]) by orsmga001.jf.intel.com with ESMTP; 20 May 2021 01:30:09 -0700 From: Feng Tang To: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Michal Hocko Cc: Andrea Arcangeli , David Rientjes , Mel Gorman , Mike Kravetz , Randy Dunlap , Vlastimil Babka , Dave Hansen , Ben Widawsky , Andi Kleen , Dan Williams , ying.huang@intel.com, Feng Tang Subject: [RFC Patch v2 1/4] mm/mempolicy: skip nodemask intersect check for 'interleave' when oom Date: Thu, 20 May 2021 16:30:01 +0800 Message-Id: <1621499404-67756-2-git-send-email-feng.tang@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1621499404-67756-1-git-send-email-feng.tang@intel.com> References: <1621499404-67756-1-git-send-email-feng.tang@intel.com> Authentication-Results: imf05.hostedemail.com; dkim=none; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=intel.com (policy=none); spf=none (imf05.hostedemail.com: domain of feng.tang@intel.com has no SPF policy when checking 192.55.52.151) smtp.mailfrom=feng.tang@intel.com X-Stat-Signature: 1z6aq7mnwd1d7cn8tsai6xgp5uwgaq7q X-Rspamd-Queue-Id: 73A58E00013F X-Rspamd-Server: rspam02 X-HE-Tag: 1621499413-442720 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: mempolicy_nodemask_intersects() is used in oom case to check if a task may have memory allocated on some memory nodes. MPOL_INTERLEAVE has set a nodemask, which is not a forced requirement, but just a hint for chosing a node to allocate memory from, and the task may have memory allocated on other nodes than this nodemask. So skip the check. Suggested-by: Michal Hocko Signed-off-by: Feng Tang --- mm/mempolicy.c | 24 ++++-------------------- 1 file changed, 4 insertions(+), 20 deletions(-) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index d79fa29..1964cca 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -2098,7 +2098,7 @@ bool init_nodemask_of_mempolicy(nodemask_t *mask) * * If tsk's mempolicy is "default" [NULL], return 'true' to indicate default * policy. Otherwise, check for intersection between mask and the policy - * nodemask for 'bind' or 'interleave' policy. For 'preferred' or 'local' + * nodemask for 'bind' policy. For 'interleave', 'preferred' or 'local' * policy, always return true since it may allocate elsewhere on fallback. * * Takes task_lock(tsk) to prevent freeing of its mempolicy. @@ -2111,29 +2111,13 @@ bool mempolicy_nodemask_intersects(struct task_struct *tsk, if (!mask) return ret; + task_lock(tsk); mempolicy = tsk->mempolicy; - if (!mempolicy) - goto out; - - switch (mempolicy->mode) { - case MPOL_PREFERRED: - /* - * MPOL_PREFERRED and MPOL_F_LOCAL are only preferred nodes to - * allocate from, they may fallback to other nodes when oom. - * Thus, it's possible for tsk to have allocated memory from - * nodes in mask. - */ - break; - case MPOL_BIND: - case MPOL_INTERLEAVE: + if (mempolicy && mempolicy->mode == MPOL_BIND) ret = nodes_intersects(mempolicy->v.nodes, *mask); - break; - default: - BUG(); - } -out: task_unlock(tsk); + return ret; }