Re: S3 resume regression [1cf4f629d9d2 ("cpu/hotplug: Move online calls to hotplugged cpu")]

From: Ville Syrjälä
Date: Fri Oct 28 2016 - 11:56:29 EST


On Thu, Oct 27, 2016 at 10:41:18PM +0200, Thomas Gleixner wrote:
> On Thu, 27 Oct 2016, Ville Syrjälä wrote:
> > On Thu, Oct 27, 2016 at 09:25:05PM +0200, Thomas Gleixner wrote:
> > > So it would be interesting whether that hunk in resume_broadcast() is
> > > sufficient.
> >
> > So far it looks like the answer is yes.
> >
> > Looks to be about 5 seconds slower than acpi-idle in resuming, but
> > I suppose that's not all that surprising ;)
>
> Well, set it to 1msec then. If that works reliably then we really can do
> that unconditionally. There is no harm in firing a useless timer during
> resume once.

I narrowed down the required timeout, and looks like 25ms is the
minimum that works. With 24ms I already started to have failures. So
maybe just bump it up by an order of magnitude to 250ms for some
safety margin?

In any case I think I'll leave the machine running S3 cycles over the
weekend with the 25ms timeout just to see if it will eventually fail.

--
Ville Syrjälä
Intel OTC