From patchwork Tue Aug 3 05:59:21 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Feng Tang X-Patchwork-Id: 12415415 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=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 BD899C4338F for ; Tue, 3 Aug 2021 05:59:45 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2E21360F94 for ; Tue, 3 Aug 2021 05:59:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 2E21360F94 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id C46806B0070; Tue, 3 Aug 2021 01:59:44 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C1C5D6B0072; Tue, 3 Aug 2021 01:59:44 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AE5096B0073; Tue, 3 Aug 2021 01:59:44 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0222.hostedemail.com [216.40.44.222]) by kanga.kvack.org (Postfix) with ESMTP id 860D66B0070 for ; Tue, 3 Aug 2021 01:59:44 -0400 (EDT) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 305A28249980 for ; Tue, 3 Aug 2021 05:59:44 +0000 (UTC) X-FDA: 78432717888.17.79ADF60 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by imf18.hostedemail.com (Postfix) with ESMTP id 7E6D94005FDE for ; Tue, 3 Aug 2021 05:59:43 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10064"; a="213579903" X-IronPort-AV: E=Sophos;i="5.84,291,1620716400"; d="scan'208";a="213579903" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Aug 2021 22:59:43 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.84,291,1620716400"; d="scan'208";a="479233384" Received: from shbuild999.sh.intel.com ([10.239.146.151]) by fmsmga008.fm.intel.com with ESMTP; 02 Aug 2021 22:59:39 -0700 From: Feng Tang To: linux-mm@kvack.org, Andrew Morton , Michal Hocko , David Rientjes , Dave Hansen , Ben Widawsky Cc: 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, Feng Tang Subject: [PATCH v7 4/5] mm/mempolicy: Advertise new MPOL_PREFERRED_MANY Date: Tue, 3 Aug 2021 13:59:21 +0800 Message-Id: <1627970362-61305-5-git-send-email-feng.tang@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1627970362-61305-1-git-send-email-feng.tang@intel.com> References: <1627970362-61305-1-git-send-email-feng.tang@intel.com> Authentication-Results: imf18.hostedemail.com; dkim=none; spf=none (imf18.hostedemail.com: domain of feng.tang@intel.com has no SPF policy when checking 134.134.136.24) smtp.mailfrom=feng.tang@intel.com; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=intel.com (policy=none) X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 7E6D94005FDE X-Stat-Signature: x6ewj5hr7du8swsx7im5qzqt51fb1gbf X-HE-Tag: 1627970383-466259 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: From: Ben Widawsky Adds a new mode to the existing mempolicy modes, MPOL_PREFERRED_MANY. MPOL_PREFERRED_MANY will be adequately documented in the internal admin-guide with this patch. Eventually, the man pages for mbind(2), get_mempolicy(2), set_mempolicy(2) and numactl(8) will also have text about this mode. Those shall contain the canonical reference. NUMA systems continue to become more prevalent. New technologies like PMEM make finer grain control over memory access patterns increasingly desirable. MPOL_PREFERRED_MANY allows userspace to specify a set of nodes that will be tried first when performing allocations. If those allocations fail, all remaining nodes will be tried. It's a straight forward API which solves many of the presumptive needs of system administrators wanting to optimize workloads on such machines. The mode will work either per VMA, or per thread. [Michal Hocko: refine kernel doc for MPOL_PREFERRED_MANY] Link: https://lore.kernel.org/r/20200630212517.308045-13-ben.widawsky@intel.com Signed-off-by: Ben Widawsky Signed-off-by: Feng Tang Acked-by: Michal Hocko --- Documentation/admin-guide/mm/numa_memory_policy.rst | 15 +++++++++++---- mm/mempolicy.c | 7 +------ 2 files changed, 12 insertions(+), 10 deletions(-) diff --git a/Documentation/admin-guide/mm/numa_memory_policy.rst b/Documentation/admin-guide/mm/numa_memory_policy.rst index 067a90a1499c..64fd0ba0d057 100644 --- a/Documentation/admin-guide/mm/numa_memory_policy.rst +++ b/Documentation/admin-guide/mm/numa_memory_policy.rst @@ -245,6 +245,13 @@ MPOL_INTERLEAVED address range or file. During system boot up, the temporary interleaved system default policy works in this mode. +MPOL_PREFERRED_MANY + This mode specifices that the allocation should be preferrably + satisfied from the nodemask specified in the policy. If there is + a memory pressure on all nodes in the nodemask, the allocation + can fall back to all existing numa nodes. This is effectively + MPOL_PREFERRED allowed for a mask rather than a single node. + NUMA memory policy supports the following optional mode flags: MPOL_F_STATIC_NODES @@ -253,10 +260,10 @@ MPOL_F_STATIC_NODES nodes changes after the memory policy has been defined. Without this flag, any time a mempolicy is rebound because of a - change in the set of allowed nodes, the node (Preferred) or - nodemask (Bind, Interleave) is remapped to the new set of - allowed nodes. This may result in nodes being used that were - previously undesired. + change in the set of allowed nodes, the preferred nodemask (Preferred + Many), preferred node (Preferred) or nodemask (Bind, Interleave) is + remapped to the new set of allowed nodes. This may result in nodes + being used that were previously undesired. With this flag, if the user-specified nodes overlap with the nodes allowed by the task's cpuset, then the memory policy is diff --git a/mm/mempolicy.c b/mm/mempolicy.c index a00bb1c48a15..e437fe96acd0 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1463,12 +1463,7 @@ static inline int sanitize_mpol_flags(int *mode, unsigned short *flags) *flags = *mode & MPOL_MODE_FLAGS; *mode &= ~MPOL_MODE_FLAGS; - /* - * The check should be 'mode >= MPOL_MAX', but as 'prefer_many' - * is not fully implemented, don't permit it to be used for now, - * and the logic will be restored in following patch - */ - if ((unsigned int)(*mode) >= MPOL_PREFERRED_MANY) + if ((unsigned int)(*mode) >= MPOL_MAX) return -EINVAL; if ((*flags & MPOL_F_STATIC_NODES) && (*flags & MPOL_F_RELATIVE_NODES)) return -EINVAL;