Re: [RFC] pm_qos: reimplement using plists

James Bottomley
2010-06-05T18:19:29Z

On Sat, 2010-06-05 at 20:17 +0200, Rafael J. Wysocki wrote:
> On Saturday 05 June 2010, James Bottomley wrote:
> > A lot of the pm_qos extremal value handling is really duplicating what a
> > priority ordered list does, just in a less efficient fashion. Simply
> > redoing the implementation in terms of a plist gets rid of a lot of this
> > junk (although there are several other strange things that could do with
> > tidying up, like pm_qos_request_list has to carry the pm_qos_class with
> > every node, simply because it doesn't get passed in to
> > pm_qos_update_request even though every caller knows full well what
> > parameter it's updating).
> >
> > I think this redo is a win independent of android, so we should do
> > something like this now.
>
> I like it.
>
> > There is one nasty that should probably be fixed in plists not open
> > coded here: plist_first gives the highest priority value, but there's no
> > corresponding API to give the lowest (even though you can get it from
> > the head.nodes_list.prev) ... if the sched people are OK, I'll correct
> > this with the final patch set.
>
> I assume you'll send a signed-off version at one point.

Yes ... probably as a two parter with the plist changes.

James