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

Rafael J. Wysocki
2010-05-27T21:15:28Z

On Thursday 27 May 2010, Thomas Gleixner wrote:
> On Thu, 27 May 2010, Alan Stern wrote:
>
> > On Thu, 27 May 2010, Felipe Balbi wrote:
> >
> > > On Thu, May 27, 2010 at 05:06:23PM +0200, ext Alan Stern wrote:
> > > >If people don't mind, here is a greatly simplified summary of the
> > > >comments and objections I have seen so far on this thread:
> > > >
> > > > The in-kernel suspend blocker implementation is okay, even
> > > > beneficial.
> > >
> > > I disagree here. I believe expressing that as QoS is much better. Let
> > > the kernel decide which power state is better as long as I can say I
> > > need 100us IRQ latency or 100ms wakeup latency.
> >
> > Does this mean you believe "echo mem >/sys/power/state" is bad and
> > should be removed? Or "echo disk >/sys/power/state"? They pay no
>
> mem should be replaced by an idle suspend to ram mechanism

Well, what about when I want the machine to suspend _regardless_ of whether
or not it's idle at the moment? That actually happens quite often to me. :-)

> > attention to latencies or other requirements.
>
> s2disk is a totally different beast as it shuts down the box into the
> complete power off state.

I don't see much difference between that and ACPI S3 other than the memory
contents are preserved in S3. It also is complete power off state - except for
memory refresh and wakeup sources (which also may be active in S4).

Rafael