Re: [GIT pull] irq updates for 4.13

[Max Gurtovoy]

On 7/4/2017 11:48 PM, Max Gurtovoy wrote:
> On 7/4/2017 10:10 PM, Thomas Gleixner wrote:
> > On Tue, 4 Jul 2017, Linus Torvalds wrote:
> > > On Tue, Jul 4, 2017 at 8:17 AM, Jens Axboe <axboe@xxxxxxxxx> wrote:
> > > > On 07/03/2017 06:00 PM, Linus Torvalds wrote:
> > > > > If they ever do come online, does that get fixed? I don't know.
> > > > > Somebody should check.
> > > >
> > > > Yes, the blk-mq cpu hotplug code updates mappings when CPUs come and
> > > > go, so that part is fine. That's exercised everytime the laptop is
> > > > suspended and resumed.
> > >
> > > I don't think that's true any more. Commit fe631457ff3e changed it to
> > > map the initial CPU's sequentially whether they are online or not.
> > > Only after you run out of hardware queues will we start playing games.
> > >
> > > That's what worries me about the conflict - the two changes did very
> > > different things to the same code. I'd really like somebody to take a
> > > look at my resolution, and just in general how those two different
> > > changes work together.
> >
> > Hmm, I leave that to Christoph. He wrote the irq stuff and reviewed
> > fe631457ff3e.
> >
> > Thanks,
> >
> >     tglx
>
> Hi Linus,
> From code reviewing the changes you made during the merge, I'm good with
> my commit purpose (fix the mapping between CPUs and HWQs). You actually
> replaced the "struct cpumask *online_mask" with cpu_online(cpu) function
> and it's fine. I'll run some tests to see that I'm not missing something.
> Regarding the second patch from Christoph, let's wait for his review (I
> can also test other scenarios like offline/online CPU's after initial
> mapping of CPUs to HWQs).
>
> Cheers,
> Max.

FYI,
My tests for the mapping between (72) CPUs and (64) HWQs passed 
successfully with 4.12.0+.