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 32F86C77B7E for ; Thu, 25 May 2023 14:14:18 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8CF58900006; Thu, 25 May 2023 10:14:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 87FD6900002; Thu, 25 May 2023 10:14:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7471A900006; Thu, 25 May 2023 10:14:17 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 669A0900002 for ; Thu, 25 May 2023 10:14:17 -0400 (EDT) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 3602D120C20 for ; Thu, 25 May 2023 14:14:17 +0000 (UTC) X-FDA: 80828972154.08.6A32EDD Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by imf20.hostedemail.com (Postfix) with ESMTP id DBAF01C02E0 for ; Thu, 25 May 2023 14:11:53 +0000 (UTC) Authentication-Results: imf20.hostedemail.com; dkim=pass header.d=suse.com header.s=susede1 header.b=RGyV9NO3; dmarc=pass (policy=quarantine) header.from=suse.com; spf=pass (imf20.hostedemail.com: domain of mkoutny@suse.com designates 195.135.220.29 as permitted sender) smtp.mailfrom=mkoutny@suse.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1685023914; a=rsa-sha256; cv=none; b=4CMbbwJ6hUqd35SRHT3eKw+rIJBJRBae+bB3MN6QCe0jN1hEF2Gj7I4X3hjsTPunWUiVko QiWFioF6bn4zz3JgO/HN7QYn7XPbOY7Bh2xFTmmCk6UrUdT+gySRmdILvY0a0vWKF5uIbv 1Vq15u7KQh/a9VSLDVMPcmqp84Of7+k= ARC-Authentication-Results: i=1; imf20.hostedemail.com; dkim=pass header.d=suse.com header.s=susede1 header.b=RGyV9NO3; dmarc=pass (policy=quarantine) header.from=suse.com; spf=pass (imf20.hostedemail.com: domain of mkoutny@suse.com designates 195.135.220.29 as permitted sender) smtp.mailfrom=mkoutny@suse.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1685023914; 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=s2JH6pTYcJePjQtM79Iqz39SbWKAXK4Qz2x1GSVTfLY=; b=jq1UUmf5rAVIEPCZps05GDk3DukAI1fMvsVzd2JaxvNfq2v/AwZsOeTv7SVGU7kZGNSlke hCYdx+2W+n+C/plMBHU/FrxDBybKEC08zQuWLj5OJsBPqEhla0qHGm053zRhBJcAIreRJj jL1jngsPAgL5yUdr7m3ztAmghkloJl0= 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 5A32F1FE6A; Thu, 25 May 2023 14:11:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1685023912; 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=s2JH6pTYcJePjQtM79Iqz39SbWKAXK4Qz2x1GSVTfLY=; b=RGyV9NO3PzYGEcee4AtXtXB1xO4jeCtqPc89Ldtc0+jxV2LTOn8SQ2TVpUKhPg82a72hSf YbPYy5G/nF0nG2sLTc/iU8w/kbOdF8XcQEeWGzx+nvYujx9CrkrQOgXNaZVwM/7RqJZIQQ djbtpQ6hb7F/xxxVsfTH6VBOufQttEQ= 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 23246134B2; Thu, 25 May 2023 14:11:52 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id yJTQB6hsb2RpZQAAMHmgww (envelope-from ); Thu, 25 May 2023 14:11:52 +0000 Date: Thu, 25 May 2023 16:11:50 +0200 From: Michal =?utf-8?Q?Koutn=C3=BD?= To: Ming Lei Cc: Yosry Ahmed , Linux-MM , Michal Hocko , Shakeel Butt , Johannes Weiner , Roman Gushchin , Muchun Song , Jens Axboe , linux-block@vger.kernel.org, Waiman Long , cgroups@vger.kernel.org, Tejun Heo Subject: Re: [PATCH] blk-cgroup: Flush stats before releasing blkcg_gq Message-ID: <3ej42djuuzwx36yf2yeo5ggyrvogeaguos5jtve2bvuaejnwff@fak3yjwe2fbi> References: <20230524011935.719659-1-ming.lei@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="yw4zsdelcidbb6wx" Content-Disposition: inline In-Reply-To: X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: DBAF01C02E0 X-Stat-Signature: sw49y6oqkf3ac554gcf8tgyzdnua47ci X-HE-Tag: 1685023913-359276 X-HE-Meta: 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 K/lk05Wb n7s9mFF/RrG2wdfF65WZHcSXIdHvJ9bgU/i4anXIRm31T/vCSTuTGh/0i+yNqmqIwba+xZVmaPrft3JkvSN48rtF7ae9736ZqhDOoTzTJQOz+8twAkIUvxL/zZPR010NMY5YgkpF/Tu09cMvp6xT2eKKO+8brL9bFacogza2VFwEq1NOegtmiKxyAEtyKPgPK0V66qvUOymp/UGQiqEw26ZDm++EnP47FpRaeVehFlUTfIvPcSHmoB0hc/N0IENu+tgSo8ssNOryq0MXVyoimBpYlT0OEd44SGCvBWrcUG5munmzoi0Sd3h2LKnb0DFKtCwYSuffyU0RUJceSQAiURxJY33DCkYw0rY3d8oUa4HE9LKyXwA5TGymmFdqCw6T9PyF1k6s4He2Nx4EPRL+63XI7Ug== 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: --yw4zsdelcidbb6wx Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, May 24, 2023 at 10:37:10AM +0800, Ming Lei wr= ote: > > I am not at all familiar with blkcg, but does calling > > cgroup_rstat_flush() in offline_css() fix the problem? >=20 > Except for offline, this list needs to be flushed after the associated di= sk > is deleted. Why the second flush trigger? a) To break another ref-dependency cycle (like on the blkcg side)? b) To avoid stale data upon device removal? (Because b) should be unnecessary, a future reader would flush when needed.) Thanks, Michal --yw4zsdelcidbb6wx Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTrXXag4J0QvXXBmkMkDQmsBEOquQUCZG9spAAKCRAkDQmsBEOq ufTLAP9NX8DIiij6/hpnoy9/M+nnSBemEZ9lY1LODUguhjSJrAEA5g8mQPrBr8KR A7VHGk9AX3B3eIPAFYavVz4cMoIrYwE= =56eg -----END PGP SIGNATURE----- --yw4zsdelcidbb6wx--