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

Florian Mickler
2010-06-03T13:56:07Z

On Thu, 3 Jun 2010 00:10:03 -0700
Arve Hjønnevåg <arve@android.com> wrote:

> On Wed, Jun 2, 2010 at 10:40 PM, mark gross <640e9920@gmail.com> wrote:

> > well I think for a pm_qos class that has boolean dynamic range we can
> > get away with not walking the list on every request update.  we can use
> > a counter, and the list will be for mostly for stats.
> >
>
> Did you give any thought to my suggestion to only use one entry per
> unique value on the first level list and then use secondary lists of
> identical values. That way if you only have two constraints values the
> list you have to walk when updating a request will never have more
> than two entries regardless of how many total request you have.
>
> A request update then becomes something like this:
> if on primary list {
> unlink from primary list
> if secondary list is not empty
> get next secondary entry and add in same spot on primary list
> }
> unlink from secondary list
> find new spot on primary list
> if already there
> add to secondary list
> else
> add to primary list
>

Yes. I think that would be good. If we keep the primary list sorted,
then this becomes a nice priority queue implementation which does
GetMax in constant time and Insert and Delete in logarithmic
complexity to the number of different values.

Cheers,
Flo