> On Tue, Mar 23, 2010 at 11:18 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> > On Tuesday 23 March 2010, Clemens Ladisch wrote:
> >> Stephane Eranian wrote:
> >> > On Tue, Mar 23, 2010 at 1:02 PM, Clemens Ladisch <clemens@ladisch.de> wrote:
> >> > > The only pointer access in this function is cpuhw->amd_nb, but
> >> > > I don't see any obvious bugs.
> >> >
> >> > I reported a problem with the AMD initialization just last week.
> >> > There is an issue with amd_pmu_cpu_online() which gets called
> >> > too early, and thus fails. That leaves some bogus state and causes
> >> > a crash in amd_pmu_cpu_offline().
> >> >
> >> > I proposed a fix which was rejected. The alternative involves moving
> >> > some the of CPU initialization code (on AMD) to an earlier position,i.e.,
> >> > which would be executed before the CPU_STARTED notifier. Nobody
> >> > has proposed anything else so far.
> >>
> >> I don't know about the early bootmem stuff, but regardless of this issue,
> >> if amd_pmu_cpu_online() can fail, then amd_pmu_cpu_offline() must be able
> >> to handle this without blowing up. Something like this (untested):
> >
> > I guess we handle that already:
> >
> >
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=a90110c610...
> >
> Ok, the fix avoids the crash but perf_events support for AMD is still broken.
>
> The root of the problem is elsewhere as I pointed out last week. Peter proposed
> a patch today and I think this would be enough to avoid the crash and have
> perf_events working again on AMD.
