lkml.org 
[lkml]   [2016]   [Jun]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    Date
    SubjectRe: [PATCH 4/4] sched,fair: Fix PELT integrity for new tasks
    On 17 June 2016 at 18:02, Peter Zijlstra <peterz@infradead.org> wrote:
    > On Fri, Jun 17, 2016 at 04:28:14PM +0200, Peter Zijlstra wrote:
    >> On Fri, Jun 17, 2016 at 04:09:01PM +0200, Vincent Guittot wrote:
    >> > >
    >> > > Scenario 1: switch to fair class
    >> > >
    >> > > p->sched_class = fair_class;
    >> > > if (queued)
    >> > > enqueue_task(p);
    >> > > ...
    >> > > enqueue_entity()
    >> > > enqueue_entity_load_avg()
    >> > > migrated = !sa->last_update_time (true)
    >> > > if (migrated)
    >> > > attach_entity_load_avg()
    >> > > check_class_changed()
    >> > > switched_from() (!fair)
    >> > > switched_to() (fair)
    >> > > switched_to_fair()
    >> > > attach_entity_load_avg()
    >>
    >> > > @@ -733,18 +737,21 @@ void post_init_entity_util_avg(struct sc
    >> > > }
    >> > > sa->util_sum = sa->util_avg * LOAD_AVG_MAX;
    >> > > }
    >> > > +
    >> > > + update_cfs_rq_load_avg(cfs_rq_clock_task(cfs_rq), cfs_rq, false);
    >> > > + attach_entity_load_avg(cfs_rq, se);
    >> >
    >> > A new RT task will be attached and will contribute to the load until
    >> > it decays to 0
    >
    >> > Should we detach it for non cfs task ?
    >
    > Right, an attach + detach, which basically ends up being:
    >
    >> > We just want to update
    >> > last_update_time of RT task to something different from 0
    >
    > this. That's the same as starting as fair and then doing
    > switched_from_fair().

    Yes that's also a possibility to add a way to call switched_from_fair
    for non fair task

    >
    > So yes, ho-humm, how to go about doing that bestest. Lemme have a play.
    >

    \
     
     \ /
      Last update: 2016-06-17 18:41    [W:5.618 / U:0.132 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site