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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 6C178C433E0 for ; Mon, 1 Mar 2021 07:39:28 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B137864E3F for ; Mon, 1 Mar 2021 07:39:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B137864E3F Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 1DDFA8D0038; Mon, 1 Mar 2021 02:39:27 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 18DF98D0019; Mon, 1 Mar 2021 02:39:27 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 07D618D0038; Mon, 1 Mar 2021 02:39:27 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0029.hostedemail.com [216.40.44.29]) by kanga.kvack.org (Postfix) with ESMTP id E32D78D0019 for ; Mon, 1 Mar 2021 02:39:26 -0500 (EST) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id A5155181AF5F4 for ; Mon, 1 Mar 2021 07:39:26 +0000 (UTC) X-FDA: 77870505132.22.89CCCB6 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf29.hostedemail.com (Postfix) with ESMTP id 15014DE for ; Mon, 1 Mar 2021 07:39:25 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1614584364; 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=34KjJW6+smFTvdlwXxTHDLwnzuvbuoymQf/sE3k7JDk=; b=vU+v0gpxQZomsgNvE8gpmxUfse2pH+A/rl+TVwbFGvyrWd8cPG1s4z3QEmjtqqVzhvUOGz CNOgbtrM+9vHwXEKis5Iw6Dx2e/rVoIweBr7mXZ+roPJJXen8HgAP06WQiIoWY0oB3d4Cv uQmB3+xzn6iXB4207y2xgFbDmKCiDR4= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 9E026AF11; Mon, 1 Mar 2021 07:39:24 +0000 (UTC) Date: Mon, 1 Mar 2021 08:39:23 +0100 From: Michal Hocko To: Tim Chen Cc: Andrew Morton , Johannes Weiner , Vladimir Davydov , Dave Hansen , Ying Huang , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 2/3] mm: Force update of mem cgroup soft limit tree on usage excess Message-ID: References: <884d7559-e118-3773-351d-84c02642ca96@linux.intel.com> <781634ee-ffb9-598d-fdb6-0ae6067448b7@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <781634ee-ffb9-598d-fdb6-0ae6067448b7@linux.intel.com> X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 15014DE X-Stat-Signature: 8hqs1a3p6cedtptnc3ijx171cy775j7s Received-SPF: none (suse.com>: No applicable sender policy available) receiver=imf29; identity=mailfrom; envelope-from=""; helo=mx2.suse.de; client-ip=195.135.220.15 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1614584365-149141 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 26-02-21 16:56:28, Tim Chen wrote: > > > On 2/26/21 12:52 AM, Michal Hocko wrote: > > >> > >> Michal, > >> > >> Let's take an extreme case where memcg 1 always generate the > >> first event and memcg 2 generates the rest of 128*8-1 events > >> and the pattern repeat. > > > > I do not follow. Events are per-memcg, aren't they? > > __this_cpu_read(memcg->vmstats_percpu->targets[target]); > > [...] > > __this_cpu_write(memcg->vmstats_percpu->targets[target], next); > > > > You are right. My previous reasoning is incorrect as the sampling is done per memcg. > I'll do some additional debugging on why memcg is not on the tree. OK, thanks for the confirmation. I think we want to do 2 things. Remove the soft limit specific threshold and stay with a single one and recognize THPs. -- Michal Hocko SUSE Labs