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

Peter Zijlstra
2010-05-28T05:15:42Z

On Thu, 2010-05-27 at 15:19 -0400, Alan Stern wrote:
> On Thu, 27 May 2010, Peter Zijlstra wrote:
>
> > I still don't see how blocking applications will cause missed wakeups in
> > anything but a buggy application at worst, and even those will
> > eventually get the event when they unblock.
> >
> > What seems to be the confusion?
>
> During forced suspend, applications are block because they are frozen.
>
> When an event occurs, the application is notified somehow. But it
> can't respond because it is frozen. Hence the event remains sitting in
> a kernel queue and the system goes ahead and suspends anyway. The
> application doesn't get thawed until the system wakes up at some
> indefinite time in the future.

If the kernel is awake to put things in queues, we're clearly not
suspended and userspace is running ?!