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 5A344C4332F for ; Wed, 14 Dec 2022 09:49:38 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A7A518E0003; Wed, 14 Dec 2022 04:49:37 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A2A408E0002; Wed, 14 Dec 2022 04:49:37 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9192A8E0003; Wed, 14 Dec 2022 04:49:37 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 8366E8E0002 for ; Wed, 14 Dec 2022 04:49:37 -0500 (EST) Received: from smtpin10.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 3AF79120E72 for ; Wed, 14 Dec 2022 09:49:37 +0000 (UTC) X-FDA: 80240439594.10.E3EE679 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by imf29.hostedemail.com (Postfix) with ESMTP id 93EC1120002 for ; Wed, 14 Dec 2022 09:49:35 +0000 (UTC) Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=suse.com header.s=susede1 header.b=WINsMeIS; spf=pass (imf29.hostedemail.com: domain of mhocko@suse.com designates 195.135.220.28 as permitted sender) smtp.mailfrom=mhocko@suse.com; dmarc=pass (policy=quarantine) header.from=suse.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1671011375; a=rsa-sha256; cv=none; b=Dk9AaUHrslATm0jth2cZajx1iqEsyfQollYWb0jgFLHvaElOHq4GMyEnVILrywoQWBVygd v9PHS2/Rm2QUaNEHlW90EgBBhPe7rcP72V4+mjtDKK0xjEaV1PZE39dGsdbMcdV5/4uSD3 8VrBkyyUA90p62REZ3EVuJ3TjP2ApKc= ARC-Authentication-Results: i=1; imf29.hostedemail.com; dkim=pass header.d=suse.com header.s=susede1 header.b=WINsMeIS; spf=pass (imf29.hostedemail.com: domain of mhocko@suse.com designates 195.135.220.28 as permitted sender) smtp.mailfrom=mhocko@suse.com; dmarc=pass (policy=quarantine) header.from=suse.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1671011375; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=pHdWVKfeYZq6y/WmzLIRqkeKhdSpQQ7ZcE8kCD7Cabo=; b=zKcZkKojSs86mGxbJD2CvJwrM2ITLKMdhRSoajSdvnDSThCaqdJUvZ/lUITX5cnzWhMRFw eWUb53UtUQ2FsbtBXojA5dqNb89MrxIVfwvR+0zD/9VI+lKGEpAFS6ONMuPTs7f1T4gYjS u6cIE7sqxIsKCqbM9gJejyAV4L//AB4= 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-out1.suse.de (Postfix) with ESMTPS id 401F3220CD; Wed, 14 Dec 2022 09:49:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1671011374; 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=pHdWVKfeYZq6y/WmzLIRqkeKhdSpQQ7ZcE8kCD7Cabo=; b=WINsMeISNalOR9upZ+0zhqD+eZzA+K5UzPcgXbfrec5WJLpmu6F33xROuLt1RRVcU17Dm3 XTLFJYVUZUPLWiGEFqHd6gf9kKA1i7QH2ouzh1B322Vn3xwNwLEcq8IjWKSbP1inLxoEX0 wOklHx1ozM3ahD0HytipguTpTcVjw0M= 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 2082E138F6; Wed, 14 Dec 2022 09:49:34 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id vlxCBS6cmWPOCwAAMHmgww (envelope-from ); Wed, 14 Dec 2022 09:49:34 +0000 Date: Wed, 14 Dec 2022 10:49:33 +0100 From: Michal Hocko To: "Huang, Ying" Cc: Dave Hansen , Yang Shi , Wei Xu , Johannes Weiner , Andrew Morton , linux-mm@kvack.org, LKML , Feng Tang Subject: Re: memcg reclaim demotion wrt. isolation Message-ID: References: <87o7s6g09b.fsf@yhuang6-desk2.ccr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87o7s6g09b.fsf@yhuang6-desk2.ccr.corp.intel.com> X-Rspam-User: X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 93EC1120002 X-Stat-Signature: xaaibyxh59pag38ynaffsn7o19i6tr5a X-HE-Tag: 1671011375-399718 X-HE-Meta: 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 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 Wed 14-12-22 10:57:52, Huang, Ying wrote: > Michal Hocko writes: [...] > > This makes sense but I suspect that this wasn't intended also for > > memcg triggered reclaim. This would mean that a memory pressure in one > > hierarchy could trigger paging out pages of a different hierarchy if the > > demotion target is close to full. > > It seems that it's unnecessary to wake up kswapd of demotion target node > in most cases. Because we will try to reclaim on the demotion target > nodes in the loop of do_try_to_free_pages(). It may be better to loop > the zonelist in the reverse order. Because the demotion targets are > usually located at the latter of the zonelist. Reclaiming from demotion targets first would deal with that as well. Thanks! Let's establish whether this is something we really need/want fix first. -- Michal Hocko SUSE Labs