From mboxrd@z Thu Jan 1 00:00:00 1970 From: Waiman Long Subject: Re: [PATCH v6 0/5] sched/deadline: fix cpusets bandwidth accounting Date: Mon, 4 Feb 2019 13:45:03 -0500 Message-ID: <90ece065-8634-7a6c-7852-e04f6d727a13@redhat.com> References: <20190117084739.17078-1-juri.lelli@redhat.com> <20190118161739.GE50184@devbig004.ftw2.facebook.com> <20190118164642.GC26615@localhost.localdomain> <20190204090211.GA10449@localhost.localdomain> <20190204121825.GE17550@hirez.programming.kicks-ass.net> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190204121825.GE17550@hirez.programming.kicks-ass.net> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Peter Zijlstra , Juri Lelli Cc: mingo@redhat.com, rostedt@goodmis.org, linux-kernel@vger.kernel.org, luca.abeni@santannapisa.it, claudio@evidence.eu.com, tommaso.cucinotta@santannapisa.it, bristot@redhat.com, mathieu.poirier@linaro.org, lizefan@huawei.com, cgroups@vger.kernel.org, tj@kernel.org On 02/04/2019 07:18 AM, Peter Zijlstra wrote: > On Mon, Feb 04, 2019 at 10:02:11AM +0100, Juri Lelli wrote: >> On 18/01/19 17:46, Juri Lelli wrote: >>> On 18/01/19 08:17, Tejun Heo wrote: >>>> On Thu, Jan 17, 2019 at 09:47:34AM +0100, Juri Lelli wrote: >>>>> Hi, >>>>> >>>>> v6 of a series of patches, originally authored by Mathieu, with the intent >>>>> of fixing a long standing issue of SCHED_DEADLINE bandwidth accounting. >>>>> As originally reported by Steve [1], when hotplug and/or (certain) >>>>> cpuset reconfiguration operations take place, DEADLINE bandwidth >>>>> accounting information is lost since root domains are destroyed and >>>>> recreated. >>>>> >>>>> Mathieu's approach is based on restoring bandwidth accounting info on >>>>> the newly created root domains by iterating through the (DEADLINE) tasks >>>>> belonging to the configured cpuset(s). >>>>> >>>>> Apart from some minor refactoring needed to rebase the set on top of >>>>> Waiman Long's cpuset for cgroup series (now mainline), two changes worth >>>>> of notice: >>>> Generally looks good to me but can you please ask Waiman to take a >>>> look? >>> Argh! I should have cc-ed him in the first instance. >>> >>> Thanks for reviewing. >>> >>> Waiman, do you see anything wrong with this series? Thanks! >>> >>> https://lore.kernel.org/lkml/20190117084739.17078-1-juri.lelli@redhat.com/ >> Ping? > Basically looks OK to me; wlthough I think I prefer the callback_lock / > rq->lock ordering to be the other way around. > > Waiman, you OK with this one? Sorry for the late reply. I reviewed the patchset and don't see anything wrong with it. However, my knowledge of the internal operation of the deadline scheduler is limited. Cheers, Longman