Re: [PATCH v5 6/7] sched: consider runnable load average in move_tasks

[Paul Turner]

On Mon, May 6, 2013 at 8:04 AM, Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> wrote:
> On Mon, May 06, 2013 at 01:53:44AM -0700, Paul Turner wrote:
>> On Sun, May 5, 2013 at 6:45 PM, Alex Shi <alex.shi@xxxxxxxxx> wrote:
>> > Except using runnable load average in background, move_tasks is also
>> > the key functions in load balance. We need consider the runnable load
>> > average in it in order to the apple to apple load comparison.
>> >
>> > Signed-off-by: Alex Shi <alex.shi@xxxxxxxxx>
>> > ---
>> >  kernel/sched/fair.c | 8 +++++++-
>> >  1 file changed, 7 insertions(+), 1 deletion(-)
>> >
>> > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
>> > index 0bf88e8..790e23d 100644
>> > --- a/kernel/sched/fair.c
>> > +++ b/kernel/sched/fair.c
>> > @@ -3966,6 +3966,12 @@ static unsigned long task_h_load(struct task_struct *p);
>> >
>> >  static const unsigned int sched_nr_migrate_break = 32;
>> >
>> > +static unsigned long task_h_load_avg(struct task_struct *p)
>> > +{
>> > +       return div_u64(task_h_load(p) * (u64)p->se.avg.runnable_avg_sum,
>> > +                       p->se.avg.runnable_avg_period + 1);
>>
>> Similarly, I think you also want to at least include blocked_load_avg here.
>
> I'm puzzled, this is an entity weight. Entity's don't have blocked_load_avg.
>
> The purpose here is to compute the amount of weight that's being moved by this
> task; to subtract from the imbalance.

Sorry, what I meant to say here is:
If we're going to be using a runnable average based load here the
fraction we take (currently instantaneous) in tg_load_down should be
consistent.
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