Re: [patch v7 7/8] sched: consider runnable load average inmove_tasks

From: Morten Rasmussen
Date: Fri May 31 2013 - 06:19:49 EST


On Thu, May 30, 2013 at 08:02:03AM +0100, Alex Shi 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 | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index eadd2e7..bb2470a 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -4178,11 +4178,11 @@ static int tg_load_down(struct task_group *tg, void *data)
> long cpu = (long)data;
>
> if (!tg->parent) {
> - load = cpu_rq(cpu)->load.weight;
> + load = cpu_rq(cpu)->avg.load_avg_contrib;
> } else {
> load = tg->parent->cfs_rq[cpu]->h_load;
> - load *= tg->se[cpu]->load.weight;
> - load /= tg->parent->cfs_rq[cpu]->load.weight + 1;
> + load *= tg->se[cpu]->avg.load_avg_contrib;
> + load /= tg->parent->cfs_rq[cpu]->runnable_load_avg + 1;

runnable_load_avg is u64, so you need to use div_u64() similar to how it
is already done in task_h_load() further down in this patch. It doesn't
build on ARM as is.

Fix:
- load /= tg->parent->cfs_rq[cpu]->runnable_load_avg + 1;
+ load = div_u64(load,
tg->parent->cfs_rq[cpu]->runnable_load_avg + 1);

Morten

> }
>
> tg->cfs_rq[cpu]->h_load = load;
> @@ -4210,8 +4210,8 @@ static unsigned long task_h_load(struct task_struct *p)
> struct cfs_rq *cfs_rq = task_cfs_rq(p);
> unsigned long load;
>
> - load = p->se.load.weight;
> - load = div_u64(load * cfs_rq->h_load, cfs_rq->load.weight + 1);
> + load = p->se.avg.load_avg_contrib;
> + load = div_u64(load * cfs_rq->h_load, cfs_rq->runnable_load_avg + 1);
>
> return load;
> }
> --
> 1.7.12
>
>

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