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

[Jiri Kosina]

On Fri, 31 May 2019, Jiri Kosina wrote:

> On Fri, 31 May 2019, Andy Lutomirski wrote:
> 
> > 2. Put the CPU all the way to sleep by sending it an INIT IPI.
> > 
> > Version 2 seems very simple and robust.  Is there a reason we can't do
> > it?  We obviously don't want to do it for normal offline because it
> > might be a high-power state, but a cpu in the wait-for-SIPI state is
> > not going to exit that state all by itself.
> > 
> > The patch to implement #2 should be short and sweet as long as we are
> > careful to only put genuine APs to sleep like this.  The only downside
> > I can see is that an new kernel resuming and old kernel that was
> > booted with nosmt is going to waste power, but I don't think that's a
> > showstopper.
> 
> Well, if *that* is not an issue, than the original 3-liner that just 
> forces them to 'hlt' [1] would be good enough as well.

Actually no, scratch that, I misunderstood your proposal, sorry.

-- 
Jiri Kosina
SUSE Labs