Re: invalidate caches before going into suspend

From: Mark Langsdorf
Date: Wed Aug 13 2008 - 13:25:10 EST


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

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