From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michal =?utf-8?Q?Koutn=C3=BD?= Subject: Re: [PATCH 3/3] cgroup/cpuset: Allow only one active attach operation per cpuset Date: Tue, 4 Apr 2023 11:07:37 +0200 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" Return-path: 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= Content-Disposition: inline In-Reply-To: <24b67530-62ce-4f9c-7b74-d41d2ccc710e-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> List-ID: To: Waiman Long Cc: Tejun Heo , Zefan Li , Johannes Weiner , Christian Brauner , cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Juri Lelli , Dietmar Eggemann , gscrivan-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.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--