From mboxrd@z Thu Jan 1 00:00:00 1970 From: Juri Lelli Subject: Re: [PATCH] sched/core: Fix cpu controller for !RT_GROUP_SCHED Date: Wed, 19 Jun 2019 14:34:05 +0200 Message-ID: <20190619123405.GN26005@localhost.localdomain> References: <20190605114935.7683-1-juri.lelli@redhat.com> <20190605142003.GD4255@blackbody.suse.cz> <20190619092904.GB28937@blackbody.suse.cz> Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Return-path: Content-Disposition: inline In-Reply-To: <20190619092904.GB28937@blackbody.suse.cz> Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="iso-8859-1" To: Michal =?iso-8859-1?Q?Koutn=FD?= Cc: peterz@infradead.org, mingo@redhat.com, rostedt@goodmis.org, lizefan@huawei.com, tj@kernel.org, bristot@redhat.com, luca.abeni@santannapisa.it, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Hi, On 19/06/19 11:29, Michal Koutn=FD wrote: > On Wed, Jun 05, 2019 at 04:20:03PM +0200, Michal Koutn=FD wrote: > > I considered relaxing the check to non-root cgroups only, however, as > > your example shows, it doesn't prevent reaching the avoided state by > > other paths. I'm not that familiar with RT sched to tell whether > > RT-priority tasks in different task_groups break any assumptions. > So I had another look and the check is bogus. >=20 > The RT sched with !CONFIG_RT_GROUP_SCHED works only with the struct > rt_rq embedded in the generic struct rq -- regardless of the task's > membership in the cpu controller hierarchy. Yep. > Perhaps, the commit message may mention this also prevents enabling cpu > controller on unified hierarchy (if there are any (kernel) RT tasks to > migrate). Sure. Can add such a comment. > Reviewed-by: Michal Koutn=FD Thanks! Peter? Best, Juri