Re: [PATCH v6 0/5] sched/deadline: fix cpusets bandwidth accounting

From: Juri Lelli
Date: Tue Feb 05 2019 - 04:18:50 EST


On 04/02/19 13:45, Waiman Long wrote:
> 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@xxxxxxxxxx/
> >> 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.

Thanks for reviewing!