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

Matthew Garrett
2010-05-27T17:07:59Z

On Thu, May 27, 2010 at 07:04:38PM +0200, Thomas Gleixner wrote:
> On Thu, 27 May 2010, Matthew Garrett wrote:
> > Sure, if you're not using opportunistic suspend then I don't think
> > there's any real need for the userspace side of this. The question is
> > how to implement something with the useful properties of opportunistic
> > suspend without without implementing something pretty much equivalent to
> > the userspace suspend blockers. I've sent another mail expressing why I
> > don't think your proposed QoS style behaviour provides that.
>
> Opportunistic suspend is just a deep idle state, nothing else.

No. The useful property of opportunistic suspend is that nothing gets
scheduled. That's fundamentally different to a deep idle state.

> Stop thinking about suspend as a special mechanism. It's not - except
> for s2disk, which is an entirely different beast.

On PCs, suspend has more in common with s2disk than it does C states.

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