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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E08CEC7618D for ; Tue, 14 Mar 2023 16:50:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230469AbjCNQui (ORCPT ); Tue, 14 Mar 2023 12:50:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32980 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229885AbjCNQue (ORCPT ); Tue, 14 Mar 2023 12:50:34 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [IPv6:2001:67c:2178:6::1d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DA0D49E301; Tue, 14 Mar 2023 09:50:32 -0700 (PDT) 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 9057E1F8A6; Tue, 14 Mar 2023 16:50:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1678812631; 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=6k/rQNu/3JyQ0BkZUFMKmdlCm0FllNjLs/p7eJHqbcg=; b=qAycucas010i4uea/GBqMOUweebj+BqtWiQY5kdCyAyeeC5Nq4Jd4YxHpuyx/9ulQeHhxQ 5ZXX+V+S7NJjDJiPZ52HRgXL4afacwBG2RW/BtBSsdsIaf8n47HyAhXn4eYhv2C4Bvg4y7 S1ZnBDCq6m40G47JaT0JjlCoN0PL8FY= 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 615C113A26; Tue, 14 Mar 2023 16:50:31 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id otCyFtelEGRscQAAMHmgww (envelope-from ); Tue, 14 Mar 2023 16:50:31 +0000 Date: Tue, 14 Mar 2023 17:50:30 +0100 From: Michal =?utf-8?Q?Koutn=C3=BD?= To: Waiman Long Cc: Tejun Heo , Zefan Li , Johannes Weiner , Shuah Khan , cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, Will Deacon , Peter Zijlstra Subject: Re: [PATCH 1/5] cgroup/cpuset: Skip task update if hotplug doesn't affect current cpuset Message-ID: <20230314165030.beu2ywtvqa3p45ta@blackpad> References: <20230306200849.376804-1-longman@redhat.com> <20230306200849.376804-2-longman@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="unrarqlmrlmuhj23" Content-Disposition: inline In-Reply-To: <20230306200849.376804-2-longman@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --unrarqlmrlmuhj23 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Mar 06, 2023 at 03:08:45PM -0500, Waiman Long = wrote: > If a hotplug event doesn't affect the current cpuset, there is no point > to call hotplug_update_tasks() or hotplug_update_tasks_legacy(). So > just skip it. This skips "insane" modification of cs->cpus_allowed in hotplug_update_tasks_legacy() but assuming cs->cpus_allowed is kept in sync with cs->effective_cpus on v1, it is OK to skip the update based only on effective_cpus check. Hence, > kernel/cgroup/cpuset.c | 3 +++ > 1 file changed, 3 insertions(+) Reviewed-by: Michal Koutn=FD --unrarqlmrlmuhj23 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTrXXag4J0QvXXBmkMkDQmsBEOquQUCZBCl1AAKCRAkDQmsBEOq ub7vAQDuvydF9uT/t92mbXmbdJFDwYtaoBzZSBR7muvk51dYZAD/VflSkqUiEoJf DK7RTVV/JCWxbff4B8Ud16JHw7PsfQU= =Phpc -----END PGP SIGNATURE----- --unrarqlmrlmuhj23--