[linux-pm] [RFC 07/10] powermac: support G5 CPU hotplug

[Johannes Berg]

Hi,

> > +	/* it seems to be possible that we died from within
> > +	 * an interrupt ... reset the in-irq counts */
> > +	task_thread_info(paca[cpu].__current)->preempt_count &=
> > +		~(SOFTIRQ_MASK|HARDIRQ_MASK);
> > +
> >  	cpu_idle();
> >  	return 0;
> 
> This is quite a nasty hack. Are you sure?
> 
> I've seen similar weirdness on pc, and it was caused by
> swsusp-copying-code using FPU and incrementing preempt_count...

I know. I'm not really happy with it. But I can't figure out where the
hardirq count can be incremented. The preempt count is fine (well, in my
latest patchset, this one forgot one spot), but the hard irq count is
not. Which is really strange because we only use that for actual in-irq
stuff...

johannes
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 190 bytes
Desc: This is a digitally signed message part
URL: <http://lists.ozlabs.org/pipermail/linuxppc-dev/attachments/20070207/430b8348/attachment.pgp>