Re: [PATCH v4] x86/power: Fix 'nosmt' vs. hibernation triple fault during resume

From: Josh Poimboeuf
Date: Fri May 31 2019 - 12:23:42 EST


On Fri, May 31, 2019 at 05:41:18PM +0200, Jiri Kosina wrote:
> On Fri, 31 May 2019, Josh Poimboeuf wrote:
>
> > The only question I'd have is if we have data on the power savings
> > difference between hlt and mwait. mwait seems to wake up on a lot of
> > different conditions which might negate its deeper sleep state.
>
> hlt wakes up on basically the same set of events, but has the
> auto-restarting semantics on some of them (especially SMM). So the wakeup
> frequency itself shouldn't really contribute to power consumption
> difference; it's the C-state that mwait allows CPU to enter.

Ok. I reluctantly surrender :-) For your v4:

Reviewed-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>

It works as a short term fix, but it's fragile, and it does feel like
we're just adding more duct tape, as Andy said.

--
Josh