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=-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 128A2C47080 for ; Tue, 1 Jun 2021 15:15:04 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 9BB546138C for ; Tue, 1 Jun 2021 15:15:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9BB546138C 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 E68E66B0070; Tue, 1 Jun 2021 11:15:02 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E19166B0072; Tue, 1 Jun 2021 11:15:02 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CC6EF6B0073; Tue, 1 Jun 2021 11:15:02 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0183.hostedemail.com [216.40.44.183]) by kanga.kvack.org (Postfix) with ESMTP id 9B96E6B0070 for ; Tue, 1 Jun 2021 11:15:02 -0400 (EDT) Received: from smtpin34.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 20718A8C8 for ; Tue, 1 Jun 2021 15:15:02 +0000 (UTC) X-FDA: 78205502844.34.CB3B260 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by imf02.hostedemail.com (Postfix) with ESMTP id 97C914202A32 for ; Tue, 1 Jun 2021 15:14:54 +0000 (UTC) IronPort-SDR: ys2IsLYKj3UaaNaFIaCSy21zqsknus7k2SosADlhOluuM5IeuOTF5g3eRGk0MLxF+X6GZ+1QC+ TC2qg4SB7I7Q== X-IronPort-AV: E=McAfee;i="6200,9189,10002"; a="183926904" X-IronPort-AV: E=Sophos;i="5.83,240,1616482800"; d="scan'208";a="183926904" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Jun 2021 08:15:00 -0700 IronPort-SDR: Obq35QqSmQQp3aaLkf3lAIxP7EArbyjT5WVgxwRFZDL5Od3K5lwsSihK2dzD0bAWmFuTvh+UdY iwznmudzGHZw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.83,240,1616482800"; d="scan'208";a="482522142" Received: from shbuild999.sh.intel.com ([10.239.147.94]) by fmsmga002.fm.intel.com with ESMTP; 01 Jun 2021 08:14:56 -0700 From: Feng Tang To: linux-mm@kvack.org, Andrew Morton , Michal Hocko , David Rientjes , Dave Hansen , Ben Widawsky Cc: Andrea Arcangeli , Mel Gorman , Mike Kravetz , Randy Dunlap , Vlastimil Babka , Andi Kleen , Dan Williams , ying.huang@intel.com, Feng Tang Subject: [v4 PATCH 1/3] mm/mempolicy: cleanup nodemask intersection check for oom Date: Tue, 1 Jun 2021 23:14:50 +0800 Message-Id: <1622560492-1294-2-git-send-email-feng.tang@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1622560492-1294-1-git-send-email-feng.tang@intel.com> References: <1622560492-1294-1-git-send-email-feng.tang@intel.com> Authentication-Results: imf02.hostedemail.com; dkim=none; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=intel.com (policy=none); spf=none (imf02.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-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 97C914202A32 X-Stat-Signature: ft16cendq4hxqmeinehpe6kechhbb1ut X-HE-Tag: 1622560494-270430 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 seems to be a general purpose mempolicy function. In fact it is partially tailored for the OOM purpose instead. The oom proper is the only existing user so rename the function to make that purpose explicit. While at it drop the MPOL_INTERLEAVE as those allocations never has a nodemask defined (see alloc_page_interleave) so this is a dead code and a confusing one because MPOL_INTERLEAVE is a hint rather than a hard requirement so it shouldn't be considered during the OOM. The final code can be reduced to a check for MPOL_BIND which is the only memory policy that is a hard requirement and thus relevant to a constrained OOM logic. Suggested-by: Michal Hocko Signed-off-by: Feng Tang Acked-by: Michal Hocko --- include/linux/mempolicy.h | 2 +- mm/mempolicy.c | 34 +++++++++------------------------- mm/oom_kill.c | 2 +- 3 files changed, 11 insertions(+), 27 deletions(-) diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h index 5f1c74d..8773c55 100644 --- a/include/linux/mempolicy.h +++ b/include/linux/mempolicy.h @@ -150,7 +150,7 @@ extern int huge_node(struct vm_area_struct *vma, unsigned long addr, gfp_t gfp_flags, struct mempolicy **mpol, nodemask_t **nodemask); extern bool init_nodemask_of_mempolicy(nodemask_t *mask); -extern bool mempolicy_nodemask_intersects(struct task_struct *tsk, +extern bool mempolicy_in_oom_domain(struct task_struct *tsk, const nodemask_t *mask); extern nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy); diff --git a/mm/mempolicy.c b/mm/mempolicy.c index d79fa29..6795a6a 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -2094,16 +2094,16 @@ bool init_nodemask_of_mempolicy(nodemask_t *mask) #endif /* - * mempolicy_nodemask_intersects + * mempolicy_in_oom_domain * - * 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' - * policy, always return true since it may allocate elsewhere on fallback. + * If tsk's mempolicy is "bind", check for intersection between mask and + * the policy nodemask. Otherwise, return true for all other policies + * including "interleave", as a tsk with "interleave" policy may have + * memory allocated from all nodes in system. * * Takes task_lock(tsk) to prevent freeing of its mempolicy. */ -bool mempolicy_nodemask_intersects(struct task_struct *tsk, +bool mempolicy_in_oom_domain(struct task_struct *tsk, const nodemask_t *mask) { struct mempolicy *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; } diff --git a/mm/oom_kill.c b/mm/oom_kill.c index eefd3f5..fcc29e9 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -104,7 +104,7 @@ static bool oom_cpuset_eligible(struct task_struct *start, * mempolicy intersects current, otherwise it may be * needlessly killed. */ - ret = mempolicy_nodemask_intersects(tsk, mask); + ret = mempolicy_in_oom_domain(tsk, mask); } else { /* * This is not a mempolicy constrained oom, so only -- 2.7.4