Re: invalidate caches before going into suspend

[Mark Langsdorf <mark.langsdorf@amd.com>]

On Wednesday 13 August 2008, Linus Torvalds wrote:
> 
> On Wed, 13 Aug 2008, Mark Langsdorf wrote:
> > 
> > I don't think it's necessary.  I can submit a delta patch later if you
> > think it's really necessary.
> 
> Why not at least move it to after the local_irq_disable()?
> 
> That local_irq_disable() will do tons of writes if you have 
> lockdep enabled, it calls trace_hardirqs_off() etc. Maybe they don't end 
> up ever mattering, but wouldn't it make much more sense to just move the 
> wbinvd down to just before the
> 
> 	while (1)
> 		halt();
> 
> which is also likely to make sure that the compiler won't do anything at 
> all because everything is dead at that point with no function calls etc 
> happening.

I don't think we realized that local_irq_disable() did all that and
so we only tested the submitted patch.  I've resubmitted the unified
patch after applying your suggestion.  Thanks.

-Mark Langsdorf
Operating System Research Center
AMD