Re: [PATCH 0/8] Suspend block api (version 8)

Matthew Garrett
2010-05-27T22:08:19Z

On Thu, May 27, 2010 at 10:56:37PM +0100, Alan Cox wrote:
> On Thu, 27 May 2010 22:36:35 +0100
> Matthew Garrett <mjg59@srcf.ucam.org> wrote:
> > No it doesn't. The kernel continues executing anything that was on the
>
> Would you like to come and watch my laptop resume ? With printk's if you
> want. You appear at this point to be arguing that bumble bees can't
> fly, while watching one.

The kernel performs no explicit notification to userspace. With legacy
graphics setups you'll get a VT switch, but X is entirely unaware that
that's due to suspend and that's going away in any case. On a typical
setup it's not even the kernel that does the VT switch to and from X -
that's handled by a script that happens to be on the runqueue. So yeah,
things kind of work as you suggest right now - but only by accident, not
design. What you're describing requires a new interface to inform
interested bits of userspace whenever you transition from your deep idle
state into a less deep one.

--
Matthew Garrett | mjg59@srcf.ucam.org