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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6A23CC761A6 for ; Tue, 4 Apr 2023 09:08:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234277AbjDDJIL (ORCPT ); Tue, 4 Apr 2023 05:08:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44778 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234275AbjDDJH6 (ORCPT ); Tue, 4 Apr 2023 05:07:58 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 34001211B; Tue, 4 Apr 2023 02:07:40 -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 DD1F0204A6; Tue, 4 Apr 2023 09:07:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1680599258; 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=rp1byrR7s3fkY4PjvvNsxVQi+oUszqEO+iMKVPDKdIk=; b=vN5Ed2ujeDnWAjclyPn/8Eom7F+TJM78c7KtgnToFgnIAyfD/Aqnrk2NbDUMKyifUwUr3n 1Z0YS0qvLrdWg5nhZro2NuiBBACFME+zaWDHYJj5dEu53In+Z1Nw3swHJXTXv6oHw5ffoW rhiePGvP9y7/aefjEMuTGxZqtjWmjIc= 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 A5BCA1391A; Tue, 4 Apr 2023 09:07:38 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id 62d7J9roK2TfLAAAMHmgww (envelope-from ); Tue, 04 Apr 2023 09:07:38 +0000 Date: Tue, 4 Apr 2023 11:07:37 +0200 From: Michal =?utf-8?Q?Koutn=C3=BD?= To: Waiman Long Cc: Tejun Heo , Zefan Li , Johannes Weiner , Christian Brauner , cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Juri Lelli , Dietmar Eggemann , gscrivan@redhat.com Subject: Re: [PATCH 3/3] cgroup/cpuset: Allow only one active attach operation per cpuset Message-ID: <20230404090737.3g3uxga52bojgdu5@blackpad> References: <20230331145045.2251683-1-longman@redhat.com> <20230331145045.2251683-4-longman@redhat.com> <20230403164736.lpjdpzxxnjlpxrqv@blackpad> <24b67530-62ce-4f9c-7b74-d41d2ccc710e@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="ilogas4aec7si4wz" Content-Disposition: inline In-Reply-To: <24b67530-62ce-4f9c-7b74-d41d2ccc710e@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --ilogas4aec7si4wz Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Hi. On Mon, Apr 03, 2023 at 01:41:33PM -0400, Waiman Long wrote: > This patch is actually not related to the CLONE_INTO_GROUP problem in patch > 1. It is a generic problem when multiple users are moving threads into > cgroup.threads of the same or different cpusets simultaneously. I meant this: __cgroup_procs_write cgroup_kn_lock_live mutex_lock(&cgroup_mutex) and (more succintly) cgroup_update_dfl_csses lockdep_assert_held(&cgroup_mutex) Even the threaded migrations should be synchronized here. Can you please explain in more detail what's the problematic case? > I don't believe this patch has a dependency on patch 1. (I meant the opposite, patch 1 would depend in this 3/3. But maybe this one isn't need.) Michal --ilogas4aec7si4wz Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTrXXag4J0QvXXBmkMkDQmsBEOquQUCZCvoyAAKCRAkDQmsBEOq uWSoAP41lQ11CXnVKE2G4jMF7tULituGE65Jni9yu8QGOPvQEAD/cthzkgC2745v rrgDBOyUhh+6zjNzCq6nigOTN7j16w8= =z1SR -----END PGP SIGNATURE----- --ilogas4aec7si4wz--