Re: [PATCH v3 3/5] x86: fix list corruption on CPU hotplug

From: Igor Mammedov
Date: Mon Apr 14 2014 - 06:49:27 EST


On Mon, 14 Apr 2014 12:34:13 +0200
Ingo Molnar <mingo@xxxxxxxxxx> wrote:

>
> * Igor Mammedov <imammedo@xxxxxxxxxx> wrote:
>
> > On Mon, 14 Apr 2014 12:04:57 +0200
> > Ingo Molnar <mingo@xxxxxxxxxx> wrote:
> >
> > >
> > > * Igor Mammedov <imammedo@xxxxxxxxxx> wrote:
> > >
> > > > On Mon, 14 Apr 2014 11:19:54 +0200
> > > > Ingo Molnar <mingo@xxxxxxxxxx> wrote:
> > > >
> > > > >
> > > > > * Igor Mammedov <imammedo@xxxxxxxxxx> wrote:
> > > > >
> > > > > > currently if AP wake up is failed, master CPU marks AP as not present
> > > > > > in do_boot_cpu() by calling set_cpu_present(cpu, false).
> > > > > > That leads to following list corruption on the next physical CPU
> > > > > > hotplug:
> > > > >
> > > > > Shouldn't this fix precede the main change to the smp bootup logic?
> > > > >
> > > > > Can this bug trigger with current upstream kernels?
> > > > That's not impossible, tests showed that with current kernel there will
> > > > be other problems due wild AP running around.
> > > >
> > > > I'll reorder patch anyway.
> > >
> > > So, could you please first make sure that with only the fixes applied
> > > there's no problems left?
> >
> > Sure, I'll retest reordered series.
>
> Please don't jus test a reodered series, but a 'fixes only' series,
> which does not include patch #1.
>
Yep, that's ^^^ what I've meant to do, I'm sorry for not being clear enough.
I'll check that bugs, that patches fix, are fixed and they don't break
something else except of issues #1 fixes of cause.

> We will apply that patch too, to improve the bootup of virtualized
> environments, but we first want to know whether the 'baseline' is OK
> and fixed 100%.
>
> Thanks,
>
> Ingo


--
Regards,
Igor
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