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 1E1FFC433EF for ; Thu, 10 Mar 2022 06:23:42 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 765138D0002; Thu, 10 Mar 2022 01:23:41 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 713CC8D0001; Thu, 10 Mar 2022 01:23:41 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 629CB8D0002; Thu, 10 Mar 2022 01:23:41 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.a.hostedemail.com [64.99.140.24]) by kanga.kvack.org (Postfix) with ESMTP id 550F68D0001 for ; Thu, 10 Mar 2022 01:23:41 -0500 (EST) Received: from smtpin04.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 1A0BE60FE3 for ; Thu, 10 Mar 2022 06:23:41 +0000 (UTC) X-FDA: 79227485442.04.DA86746 Received: from out30-45.freemail.mail.aliyun.com (out30-45.freemail.mail.aliyun.com [115.124.30.45]) by imf03.hostedemail.com (Postfix) with ESMTP id 0A4F32000A for ; Thu, 10 Mar 2022 06:23:39 +0000 (UTC) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R191e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04357;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0V6nNtMc_1646893414; Received: from 30.97.48.73(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0V6nNtMc_1646893414) by smtp.aliyun-inc.com(127.0.0.1); Thu, 10 Mar 2022 14:23:35 +0800 Message-ID: Date: Thu, 10 Mar 2022 14:24:38 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.6.2 Subject: Re: [PATCH] mm: Only re-generate demotion targets when a numa node changes its N_CPU state To: Oscar Salvador , "Huang, Ying" Cc: Andrew Morton , Dave Hansen , Abhishek Goel , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20220309144644.4278-1-osalvador@suse.de> <87bkyefxnq.fsf@yhuang6-desk2.ccr.corp.intel.com> From: Baolin Wang In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 0A4F32000A X-Stat-Signature: 4ticcem93wio1xxhyeb8i7dyjmqayd79 Authentication-Results: imf03.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=alibaba.com; spf=pass (imf03.hostedemail.com: domain of baolin.wang@linux.alibaba.com designates 115.124.30.45 as permitted sender) smtp.mailfrom=baolin.wang@linux.alibaba.com X-HE-Tag: 1646893419-288968 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: Hi Oscar, On 3/10/2022 1:48 PM, Oscar Salvador wrote: > On Thu, Mar 10, 2022 at 08:39:53AM +0800, Huang, Ying wrote: >> We need to call set_migration_target_nodes() during system boot >> somewhere, either here or in init_mm_internals(). > > Hi Huang Ying, > > vmstat_cpu_online() already gets called during boot: > > static struct cpuhp_step cpuhp_hp_states[] = { > ... > #ifdef CONFIG_SMP > [CPUHP_CREATE_THREADS]= { > .name = "threads:prepare", > .startup.single = smpboot_create_threads, > .teardown.single = NULL, > .cant_stop = true, > }, > ... > > smpboot_create_threads > __smpboot_create_thread > smpboot_thread_fn > ht->thread_fn() > cpuhp_thread_fun > cpuhp_invoke_callback > vmstat_cpu_online > > That for every CPU that is brought up during boot. > > So unless I am missing something, I would say we are already covered > there, right? I've tested your patch, unfortunately it can not work. It already set the node with N_CPU state in init_cpu_node_state() earlier, so in vmstat_cpu_online() ,the sentence 'if(!node_state(cpu_to_node(cpu), N_CPU))' is always false, which means it will not call set_migration_target_nodes(). Like Huang Ying said, we should call set_migration_target_nodes() in migrate_on_reclaim_init() or init_mm_internals().