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 E5A29C433FE for ; Fri, 14 Jan 2022 08:51:36 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C87856B0072; Fri, 14 Jan 2022 03:51:35 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id C36196B0073; Fri, 14 Jan 2022 03:51:35 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B253A6B0074; Fri, 14 Jan 2022 03:51:35 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0006.hostedemail.com [216.40.44.6]) by kanga.kvack.org (Postfix) with ESMTP id A246F6B0072 for ; Fri, 14 Jan 2022 03:51:35 -0500 (EST) Received: from smtpin19.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 5C628951B1 for ; Fri, 14 Jan 2022 08:51:35 +0000 (UTC) X-FDA: 79028274150.19.AEC15AF Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by imf16.hostedemail.com (Postfix) with ESMTP id E6A30180007 for ; Fri, 14 Jan 2022 08:51:34 +0000 (UTC) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id 6E26D21900; Fri, 14 Jan 2022 08:51:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1642150293; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=/nWKNw9opZBY8w53yyW2tw6i8XJ7sKPnF1rYIP33e7U=; b=BbgHB4lMU5Bw7t4w8SdHquX2ho+IFQvfmdx6G1qwqkwTk9juAzikwnAZaSjZS2by/n3y2R wC9rGTGeNDE6hWqWRGgWO6EryXFsCAQXxNIsWCQVPzlPnrJM1bgxJLpHBAkpuMk4FnWJLB uzGtDWkxQ9dNowTd6ZytR1hEJc5Xz/o= Received: from suse.cz (unknown [10.100.201.86]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 0428DA3B85; Fri, 14 Jan 2022 08:51:33 +0000 (UTC) Date: Fri, 14 Jan 2022 09:51:31 +0100 From: Michal Hocko To: Wei Yang Cc: hannes@cmpxchg.org, vdavydov.dev@gmail.com, akpm@linux-foundation.org, shakeelb@google.com, guro@fb.com, vbabka@suse.cz, willy@infradead.org, songmuchun@bytedance.com, shy828301@gmail.com, surenb@google.com, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 1/4] mm/memcg: use NUMA_NO_NODE to indicate allocation from unspecified node Message-ID: References: <20220111010302.8864-1-richard.weiyang@gmail.com> <20220112004634.dc5suwei4ymyxaxg@master> <20220114002937.fnyq3yyk36j4nb3d@master> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220114002937.fnyq3yyk36j4nb3d@master> X-Rspamd-Queue-Id: E6A30180007 X-Stat-Signature: 8ck7f631oywcunt74qsapom38n7s6np5 Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=suse.com header.s=susede1 header.b=BbgHB4lM; dmarc=pass (policy=quarantine) header.from=suse.com; spf=pass (imf16.hostedemail.com: domain of mhocko@suse.com designates 195.135.220.28 as permitted sender) smtp.mailfrom=mhocko@suse.com X-Rspamd-Server: rspam08 X-HE-Tag: 1642150294-44881 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 Fri 14-01-22 00:29:37, Wei Yang wrote: > On Wed, Jan 12, 2022 at 09:56:15AM +0100, Michal Hocko wrote: > >On Wed 12-01-22 00:46:34, Wei Yang wrote: > >> On Tue, Jan 11, 2022 at 09:40:20AM +0100, Michal Hocko wrote: > >> >On Tue 11-01-22 01:02:59, Wei Yang wrote: > >> >> Instead of use "-1", let's use NUMA_NO_NODE for consistency. > >> >> > >> >> Signed-off-by: Wei Yang > >> > > >> >I am not really sure this is worth it. After the merge window I plan to > >> >post http://lkml.kernel.org/r/20211214100732.26335-1-mhocko@kernel.org. > >> > >> Give me some time to understand it :-) > > > >Just for the record, here is what I have put on top of that series: > > Ok, I got what you try to resolve. I am ok with the following change except > one point. > > >--- > >>From b7195eba02fe6308a6927450f4630057c05e808e Mon Sep 17 00:00:00 2001 > >From: Wei Yang > >Date: Tue, 11 Jan 2022 09:45:25 +0100 > >Subject: [PATCH] memcg: do not tweak node in alloc_mem_cgroup_per_node_info > > > >alloc_mem_cgroup_per_node_info is allocated for each possible node and > >this used to be a problem because not !node_online nodes didn't have > >appropriate data structure allocated. This has changed by "mm: handle > >uninitialized numa nodes gracefully" so we can drop the special casing > >here. > > > >Signed-off-by: Wei Yang > >Signed-off-by: Michal Hocko > >--- > > mm/memcontrol.c | 14 ++------------ > > 1 file changed, 2 insertions(+), 12 deletions(-) > > > >diff --git a/mm/memcontrol.c b/mm/memcontrol.c > >index 781605e92015..ed19a21ee14e 100644 > >--- a/mm/memcontrol.c > >+++ b/mm/memcontrol.c > >@@ -5044,18 +5044,8 @@ struct mem_cgroup *mem_cgroup_from_id(unsigned short id) > > static int alloc_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node) > > { > > struct mem_cgroup_per_node *pn; > >- int tmp = node; > >- /* > >- * This routine is called against possible nodes. > >- * But it's BUG to call kmalloc() against offline node. > >- * > >- * TODO: this routine can waste much memory for nodes which will > >- * never be onlined. It's better to use memory hotplug callback > >- * function. > >- */ > > Do you think this TODO is not related to this change? It is not really related but I am not sure how useful it is. Essentially any allocation that is per-possible node is in the same situation and if we really need to deal with large and sparse possible nodes masks. If you want me to keep the TODO I will do it though. -- Michal Hocko SUSE Labs