Re: [PATCH] PM: acquire device locks prior to suspending

Rafael J. Wysocki
2007-12-15T00:17:21Z

On Friday, 14 of December 2007, Alan Stern wrote:
> On Thu, 13 Dec 2007, Andrew Morton wrote:
>
> > hm, that was all fairly helpful. <looks at the document> <erk, long>
> >
> > This:
>
> > gives me this:
> >
> > http://userweb.kernel.org/~akpm/pc131699.jpg
> >
> > which identifies your culprit: msr.
> >
> > I'd suggest that the above debug patch be turned into some
> > boot-option-enabled thing and that it be rolled out with this locking
> > change for a while at least.
>
> Rafael, that looks like exactly the same sort of problem as we saw
> before. Global searching for CPU_DEAD_FROZEN shows several other
> places that perhaps also could be simplified; the actions they take may
> or may not be needed for hibernation.
>
> The following three seem definitely dangerous:
>
> arch/x86/kernel/cpu/mcheck/mce_64.c
> arch/x86/kernel/cpuid.c
> arch/x86/kernel/msr.c
>
> And of course the third is the one that Andrew spotted. Would you like
> to address them?

Yes, I think I can take care of them, but not earlier than on Sunday.

> I can package up Andrew's debugging changes into a real patch.

Yes, that certainly is worth doing. :-)

Thanks,
Rafael