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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 178DCC4338F for ; Mon, 23 Aug 2021 16:09:35 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 7E1F1613D5 for ; Mon, 23 Aug 2021 16:09:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 7E1F1613D5 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id C93918D0001; Mon, 23 Aug 2021 12:09:33 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C426C6B0072; Mon, 23 Aug 2021 12:09:33 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B32F18D0001; Mon, 23 Aug 2021 12:09:33 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0041.hostedemail.com [216.40.44.41]) by kanga.kvack.org (Postfix) with ESMTP id 9655D6B006C for ; Mon, 23 Aug 2021 12:09:33 -0400 (EDT) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 2EEAD252CE for ; Mon, 23 Aug 2021 16:09:33 +0000 (UTC) X-FDA: 78506830626.28.9A5F826 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by imf13.hostedemail.com (Postfix) with ESMTP id B14F010134C4 for ; Mon, 23 Aug 2021 16:09:32 +0000 (UTC) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id DF3AF1FFCA; Mon, 23 Aug 2021 16:09:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1629734970; 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=4eFiPUzslOJAtwIAy5T1boXHUjZS+B3BFncyco1H9t0=; b=NquIf+8HHYFommojg9qouyGn7kgUzV1xmNACFJshhh9se3FdrIE5O4RaqMolDjBC5qJXP+ RdQ/9+JCgPxmJgZPlLeOLSnW5XB1Au8FPrJdcsY8lpb+3zyuNQQ2LIHB36CbjdSeGkwG8F 6qgCzo2IBMVEZ4s1MHEi8GO28hWMb9k= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 9577E13BE6; Mon, 23 Aug 2021 16:09:30 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id G048IzrII2HvUgAAMHmgww (envelope-from ); Mon, 23 Aug 2021 16:09:30 +0000 Date: Mon, 23 Aug 2021 18:09:29 +0200 From: Michal =?iso-8859-1?Q?Koutn=FD?= To: Johannes Weiner Cc: Andrew Morton , Leon Yang , Chris Down , Roman Gushchin , Michal Hocko , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com Subject: Re: [PATCH] mm: memcontrol: fix occasional OOMs due to proportional memory.low reclaim Message-ID: References: <20210817180506.220056-1-hannes@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210817180506.220056-1-hannes@cmpxchg.org> Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=suse.com header.s=susede1 header.b=NquIf+8H; dmarc=pass (policy=quarantine) header.from=suse.com; spf=pass (imf13.hostedemail.com: domain of mkoutny@suse.com designates 195.135.220.29 as permitted sender) smtp.mailfrom=mkoutny@suse.com X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: B14F010134C4 X-Stat-Signature: jnqif79zbkw31tjip9yiyhoohogd9qoj X-HE-Tag: 1629734972-350961 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 (and sorry for a belated reply). On Tue, Aug 17, 2021 at 02:05:06PM -0400, Johannes Weiner wrote: > @@ -2576,6 +2578,15 @@ static void get_scan_count(struct lruvec *lruvec, struct scan_control *sc, > [...] > + /* memory.low scaling, make sure we retry before OOM */ > + if (!sc->memcg_low_reclaim && low > min) { > + protection = low; > + sc->memcg_low_skipped = 1; IIUC, this won't result in memory.events:low increment although the effect is similar (breaching (partial) memory.low protection) and signal to the user is comparable (overcommited memory.low). Admittedly, this patch's behavior adheres to the current documentation (Documentation/admin-guide/cgroup-v2.rst): > The number of times the cgroup is reclaimed due to high memory > pressure even though its usage is under the low boundary, however, that definition might not be what the useful indicator would be now. Is it worth including these partial breaches into memory.events:low? Regards, Michal