Hi Will, On Tue, May 29, 2018 at 5:08 PM, Will Deacon <will.deacon@xxxxxxx> 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@xxxxxxx> 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@xxxxxxxxxxxxxx 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