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=-3.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 A211EC433E7 for ; Tue, 20 Oct 2020 12:02:40 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2E26820770 for ; Tue, 20 Oct 2020 12:02:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2E26820770 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 882056B005C; Tue, 20 Oct 2020 08:02:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 830B86B0062; Tue, 20 Oct 2020 08:02:39 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 746B16B0068; Tue, 20 Oct 2020 08:02:39 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0058.hostedemail.com [216.40.44.58]) by kanga.kvack.org (Postfix) with ESMTP id 47F026B005C for ; Tue, 20 Oct 2020 08:02:39 -0400 (EDT) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id B4AA6181AEF1A for ; Tue, 20 Oct 2020 12:02:38 +0000 (UTC) X-FDA: 77392166796.12.show76_0b1025b2723f Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin12.hostedemail.com (Postfix) with ESMTP id 8E1CC180101EF for ; Tue, 20 Oct 2020 12:02:38 +0000 (UTC) X-HE-Tag: show76_0b1025b2723f X-Filterd-Recvd-Size: 2749 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf44.hostedemail.com (Postfix) with ESMTP for ; Tue, 20 Oct 2020 12:02:37 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 01499ABD1; Tue, 20 Oct 2020 12:02:37 +0000 (UTC) References: <20201014190749.24607-1-rpalethorpe@suse.com> <20201016094702.GA95052@blackbook> <20201016145308.GA312010@cmpxchg.org> <20201016171502.GA102311@blackbook> <20201019222845.GA64774@carbon.dhcp.thefacebook.com> <87k0vlwhzt.fsf@suse.de> User-agent: mu4e 1.4.13; emacs 27.1 From: Richard Palethorpe To: Roman Gushchin Cc: Michal =?utf-8?Q?Koutn=C3=BD?= , Johannes Weiner , ltp@lists.linux.it, Andrew Morton , "Shakeel Butt" , "Christoph Lameter" , Michal Hocko , Tejun Heo , Vlastimil Babka , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Michal Hocko Subject: Re: [RFC PATCH] mm: memcg/slab: Stop reparented obj_cgroups from charging root Reply-To: rpalethorpe@suse.de In-reply-to: <87k0vlwhzt.fsf@suse.de> Date: Tue, 20 Oct 2020 13:02:35 +0100 Message-ID: <87h7qpw1es.fsf@suse.de> MIME-Version: 1.0 Content-Type: text/plain 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: Hello, Richard Palethorpe writes: > Hello Roman, > > Roman Gushchin writes: > >> - page_counter_init(&memcg->memory, NULL); >> - page_counter_init(&memcg->swap, NULL); >> - page_counter_init(&memcg->kmem, NULL); >> - page_counter_init(&memcg->tcpmem, NULL); >> + /* >> + * If use_hierarchy == false, consider all page counters direct >> + * descendants of the corresponding root level counters. >> + */ >> + page_counter_init(&memcg->memory, &root_mem_cgroup->memory); >> + page_counter_init(&memcg->swap, &root_mem_cgroup->swap); >> + page_counter_init(&memcg->kmem, &root_mem_cgroup->kmem); >> + page_counter_init(&memcg->tcpmem, &root_mem_cgroup->tcpmem); >> + >> /* >> * Deeper hierachy with use_hierarchy == false doesn't make >> * much sense so let cgroup subsystem know about this > > Perhaps in this case, where the hierarchy is broken, objcgs should also > be reparented directly to root? Otherwise it will still be possible to > underflow the counter in a descendant of root which has use_hierarchy=0, > but also has children. Sorry ignore me, parent_mem_cgroup already selects root. So in the case of a broken hierarchy objcgs are reparented directly to root. -- Thank you, Richard.