On Wed, Aug 19, 2009 at 06:01:34PM +0200, Jerome Marchand wrote:
> Hi Vivek,
>
> Vivek Goyal wrote:
> > o This is core of the io scheduler implemented at elevator layer. This is a mix
> > of cpu CFS scheduler and CFQ IO scheduler. Some of the bits from CFS have
> > to be derived so that we can support hierarchical scheduling. Without
> > cgroups or with-in group, we should essentially get same behavior as CFQ.
> >
> > o This patch only shows non-hierarchical bits. Hierarhical code comes in later
> > patches.
> >
> > o This code is the building base of introducing fair queuing logic in common
> > elevator layer so that it can be used by all the four IO schedulers.
>
> > +static void enqueue_io_entity(struct io_entity *entity)
> > +{
> > + struct io_service_tree *st = entity->st;
> > + struct io_sched_data *sd = io_entity_sched_data(entity);
> > +
> > + /* In case task ioprio class changed while entity was off tree */
> > + io_entity_update_prio(entity);
> > + st->nr_active++;
> > + sd->nr_active++;
> > + entity->on_st = 1;
> > + place_entity(st, entity, 0);
> > + __enqueue_io_entity(st, entity);
> > +}
>
> > +static void put_prev_io_entity(struct io_entity *entity)
> > +{
> > + struct io_service_tree *st = entity->st;
> > + struct io_sched_data *sd = io_entity_sched_data(entity);
> > +
> > + st->active_entity = NULL;
> > + sd->active_entity = NULL;
> > +
> > + if (unlikely(entity->ioprio_changed)) {
> > + dequeue_io_entity(entity);
> > + io_entity_update_prio(entity);
>
> That call to io_entity_update_prio() looks redundant with the one in
> enqueue_io_entity().
>
thanks Jerome. Yes it does look like a redundant call. Will get rid of it
in next posting.
Vivek
> > + enqueue_io_entity(entity);
> > + } else
> > + __enqueue_io_entity(st, entity);
> > +}
>
> Jerome
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