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

mark gross
2010-06-02T02:51:23Z

On Tue, Jun 01, 2010 at 09:07:37AM +0200, Florian Mickler wrote:
> On Mon, 31 May 2010 16:26:17 -0700
> mark gross <640e9920@gmail.com> wrote:
>
> > On Mon, May 31, 2010 at 11:38:55PM +0200, Rafael J. Wysocki wrote:
> > > On Monday 31 May 2010, Arve Hjønnevåg wrote:
> > > > 2010/5/29 Alan Stern <stern@rowland.harvard.edu>:
> > > > > On Sat, 29 May 2010, Arve Hjønnevåg wrote:
> > > > >
> > > > >> > In place of in-kernel suspend blockers, there will be a new type of QoS
> > > > >> > constraint -- call it QOS_EVENTUALLY. It's a very weak constraint,
> > > > >> > compatible with all cpuidle modes in which runnable threads are allowed
> > > > >> > to run (which is all of them), but not compatible with suspend.
> > > > >> >
> > > > >> This sound just like another API rename. It will work, but given that
> > > > >> suspend blockers was the name least objectionable last time around,
> > > > >> I'm not sure what this would solve.
> > > > >
> > > > > It's not just a rename. By changing this into a QoS constraint, we
> > > > > make it more generally useful. Instead of standing on its own, it
> > > > > becomes part of the PM-QOS framework.
> > > > >
> > > >
> > > > We cannot use the existing pm-qos framework. It is not safe to call
> > > > from atomic context.
> > >
> > > We've just merged a patch that fixed that if I'm not mistaken. Mark, did your
> > > PM QoS update fix that?
> > >
> >
> > I'm pretty sure it can be called in atomic context, and if its not I'm
> > sure we can fix that. It can be called in atomic context. I don't
> > think it was ever a problem to call it in atomic context. The problem it
> > had was that crappy list of string compares. Thats been fixed.
> >
> > --mgross
> >
>
> Well, the register call uses kzalloc. Apart from that I
> think we're good.

registering shouldn't need to be called in atomic context. Its the
update_request that needs to be callible form atomic context.

--mgross