Re: [PATCH v9 00/12] Support PPTT for ARM64

Geert Uytterhoeven
2018-05-29T15:51:37Z

Hi Will,

On Tue, May 29, 2018 at 5:08 PM, Will Deacon <will.deacon@arm.com> wrote:
> On Tue, May 29, 2018 at 02:18:40PM +0100, Sudeep Holla wrote:
>> On 29/05/18 12:56, Geert Uytterhoeven wrote:
>> > On Tue, May 29, 2018 at 1:14 PM, Sudeep Holla <sudeep.holla@arm.com> wrote:
>> >> On 29/05/18 11:48, Geert Uytterhoeven wrote:
>> >>> System supend still works fine on systems with big cores only:
>> >>>
>> >>> R-Car H3 ES1.0 (4xCA57 (4xCA53 disabled in firmware))
>> >>> R-Car M3-N (2xCA57)
>> >>>
>> >>> Reverting this commit fixes the issue for me.
>> >>
>> >> I can't find anything that relates to system suspend in these patches
>> >> unless they are messing with something during CPU hot plug-in back
>> >> during resume.
>> >
>> > It's only the last patch that introduces the breakage.
>> >
>>
>> As specified in the commit log, it won't change any behavior for DT
>> systems if it's non-NUMA or single node system. So I am still wondering
>> what could trigger this regression.
>
> I wonder if we're somehow giving an uninitialised/invalid NUMA configuration
> to the scheduler, although I can't see how this would happen.
>
> Geert -- if you enable CONFIG_DEBUG_PER_CPU_MAPS=y and apply the diff below
> do you see anything shouting in dmesg?

Thanks, but unfortunately it doesn't help.
I added some debug code to print cpumask, but so far I don't see anything
suspicious.

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds