lkml.org 
[lkml]   [2010]   [Sep]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH 1/2] sched: normalize sleeper's vruntime during group change
    From
    Date
    On Tue, 2010-09-28 at 23:46 -0700, Dima Zavin wrote:
    > This adds a new callback, prep_move_task, to struct sched_class
    > to give sched_fair the opportunity to adjust the task's vruntime
    > just before setting its new group.
    >
    > This allows us to properly normalize a sleeping task's vruntime
    > when moving it between different cgroups.


    > diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
    > index db3f674..008fe57 100644
    > --- a/kernel/sched_fair.c
    > +++ b/kernel/sched_fair.c
    > @@ -3827,10 +3827,23 @@ static void set_curr_task_fair(struct rq *rq)
    > static void moved_group_fair(struct task_struct *p, int on_rq)
    > {
    > struct cfs_rq *cfs_rq = task_cfs_rq(p);
    > + struct sched_entity *se = &p->se;
    >
    > update_curr(cfs_rq);
    > - if (!on_rq)
    > + if (!on_rq) {
    > + se->vruntime += cfs_rq->min_vruntime;
    > place_entity(cfs_rq, &p->se, 1);
    > + }
    > +}

    I'm still missing the place_entity() rationale. Why is a sleeping task
    eligible for pain therapy that a runnable task is spared? That state
    can change a usec from now.

    Nit: place_entity(cfs_rq, se, 1);

    -Mike



    \
     
     \ /
      Last update: 2010-09-29 10:15    [W:3.910 / U:0.420 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site