> -----Original Message-----
> From: linux-arm-kernel-bounces at lists.infradead.org [mailto:linux-arm-kernel-
> bounces at lists.infradead.org] On Behalf Of Shilimkar, Santosh
> Sent: Friday, April 16, 2010 7:31 PM
> To: Sundar R IYER; linux-arm-kernel at lists.infradead.org
> Subject: RE: Re : [PATCH] ARM: Fix "BUG: scheduling while atomic: swapper/0/0x00000002"
>
> > -----Original Message-----
> > From: linux-arm-kernel-bounces at lists.infradead.org [mailto:linux-arm-kernel-
> > bounces at lists.infradead.org] On Behalf Of Sundar R IYER
> > Sent: Friday, April 16, 2010 7:14 PM
> > To: linux-arm-kernel at lists.infradead.org
> > Subject: Re : [PATCH] ARM: Fix "BUG: scheduling while atomic: swapper/0/0x00000002"
> >
> > Hi Santosh/Russell,
> >
> > >Hmm, I don't think this is how we should be solving this problem.
> > >x86 calls init_idle() on the idle task when it's re-used, and this
> > >resets the preempt count amongst other things. So maybe we want to
> > >do this instead in the __cpu_up path:
> >
> > The following patch fixes the dump messages at my end during re-onlining the offline CPU.
> >
> > diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
> > index 577543f..ee1d608 100644
> > --- a/arch/arm/kernel/smp.c
> > +++ b/arch/arm/kernel/smp.c
> > @@ -86,6 +86,9 @@ int __cpuinit __cpu_up(unsigned int cpu)
> > return PTR_ERR(idle);
> > }
> > ci->idle = idle;
> > + } else {
> > + /* fix any preempt leaks whilst going down */
> > + init_idle(idle, cpu);
> > }
> >
> Actually I found there is while the CPU is going down. If you fix that, both paths
> - going down and coming up - gets fixed.
>
Will check this again and confirm.
Regards,
Santosh