Re: [linux-pm] [PATCH 0/8] Suspend block api (version 6)

[Rafael J. Wysocki]

On Thursday 13 May 2010, Matthew Garrett wrote:
> On Thu, May 13, 2010 at 01:23:20PM -0700, Tony Lindgren wrote:
> > * Matthew Garrett <mjg@xxxxxxxxxx> [100513 13:03]:
> > > On Thu, May 13, 2010 at 01:00:04PM -0700, Tony Lindgren wrote:
> > > 
> > > > The system stays running because there's something to do. The system
> > > > won't suspend until all the processors hit the kernel idle loop and
> > > > the next_timer_interrupt_critical() returns nothing.
> > > 
> > > At which point an application in a busy loop cripples you.
> > 
> > Maybe you could deal with the misbehaving untrusted apps in the userspace
> > by sending kill -STOP to them when the screen blanks? Then continue
> > when some event wakes up the system again.
> 
> And if that's the application that's listening to the network socket 
> that you want to get a wakeup event from? This problem is hard. I'd love 
> there to be an elegant solution based on using the scheduler, but I 
> really don't know what it is.

I agree and I don't understand the problem that people have with the
opportunistic suspend feature.

It solves a practical issue that _at_ _the_ _moment_ cannot be solved
differently, while there's a growing number of out-of-tree drivers depending
on this framework.  We need those drivers in and because we don't have any
viable alternative at hand, we have no good reason to reject it.

Rafael
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/