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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id D5D82C433EF for ; Mon, 7 Mar 2022 02:30:38 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4D8718D0002; Sun, 6 Mar 2022 21:30:38 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 46C7A8D0001; Sun, 6 Mar 2022 21:30:38 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3288F8D0002; Sun, 6 Mar 2022 21:30:38 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.27]) by kanga.kvack.org (Postfix) with ESMTP id 20C618D0001 for ; Sun, 6 Mar 2022 21:30:38 -0500 (EST) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay13.hostedemail.com (Postfix) with ESMTP id BDC51609D5 for ; Mon, 7 Mar 2022 02:30:37 +0000 (UTC) X-FDA: 79216011714.03.3628EBF Received: from out199-6.us.a.mail.aliyun.com (out199-6.us.a.mail.aliyun.com [47.90.199.6]) by imf20.hostedemail.com (Postfix) with ESMTP id 54DBA1C0003 for ; Mon, 7 Mar 2022 02:30:35 +0000 (UTC) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R161e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04394;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=20;SR=0;TI=SMTPD_---0V6O9B5W_1646620230; Received: from 30.97.48.83(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0V6O9B5W_1646620230) by smtp.aliyun-inc.com(127.0.0.1); Mon, 07 Mar 2022 10:30:31 +0800 Message-ID: Date: Mon, 7 Mar 2022 10:31:33 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.6.1 Subject: Re: [PATCH 08/16] mm/migration: avoid unneeded nodemask_t initialization To: Miaohe Lin , akpm@linux-foundation.org Cc: mike.kravetz@oracle.com, shy828301@gmail.com, willy@infradead.org, ying.huang@intel.com, ziy@nvidia.com, minchan@kernel.org, apopple@nvidia.com, dave.hansen@linux.intel.com, o451686892@gmail.com, almasrymina@google.com, jhubbard@nvidia.com, rcampbell@nvidia.com, peterx@redhat.com, naoya.horiguchi@nec.com, mhocko@suse.com, riel@redhat.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20220304093409.25829-1-linmiaohe@huawei.com> <20220304093409.25829-9-linmiaohe@huawei.com> From: Baolin Wang In-Reply-To: <20220304093409.25829-9-linmiaohe@huawei.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 54DBA1C0003 X-Stat-Signature: qydckjepg6x9ia78d5suedx7598c5j4y Authentication-Results: imf20.hostedemail.com; dkim=none; spf=pass (imf20.hostedemail.com: domain of baolin.wang@linux.alibaba.com designates 47.90.199.6 as permitted sender) smtp.mailfrom=baolin.wang@linux.alibaba.com; dmarc=pass (policy=none) header.from=alibaba.com X-Rspam-User: X-HE-Tag: 1646620235-23991 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 3/4/2022 5:34 PM, Miaohe Lin wrote: > Avoid unneeded next_pass and this_pass initialization as they're always > set before using to save possible cpu cycles when there are plenty of > nodes in the system. > > Signed-off-by: Miaohe Lin > --- > mm/migrate.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/mm/migrate.c b/mm/migrate.c > index c84eec19072a..abb0c6715e1f 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -2378,8 +2378,8 @@ static int establish_migrate_target(int node, nodemask_t *used, > */ > static void __set_migration_target_nodes(void) > { > - nodemask_t next_pass = NODE_MASK_NONE; > - nodemask_t this_pass = NODE_MASK_NONE; > + nodemask_t next_pass; > + nodemask_t this_pass; > nodemask_t used_targets = NODE_MASK_NONE; > int node, best_distance; LGTM. Reviewed-by: Baolin Wang