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

From: Peter Zijlstra
Date: Mon Feb 04 2019 - 07:18:43 EST


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?