Re: 4.3 group scheduling regression

From: Mike Galbraith
Date: Mon Oct 12 2015 - 06:23:40 EST


On Mon, 2015-10-12 at 10:12 +0800, Yuyang Du wrote:

> I am guessing it is in calc_tg_weight(), and naughty boys do make them more
> favored, what a reality...
>
> Mike, beg you test the following?

Wow, that was quick. Dinky patch made it all better.

-----------------------------------------------------------------------------------------------------------------
Task | Runtime ms | Switches | Average delay ms | Maximum delay ms | Maximum delay at |
-----------------------------------------------------------------------------------------------------------------
oink:(8) | 739056.970 ms | 27270 | avg: 2.043 ms | max: 29.105 ms | max at: 339.988310 s
mplayer:(25) | 36448.997 ms | 44670 | avg: 1.886 ms | max: 72.808 ms | max at: 302.153121 s
Xorg:988 | 13334.908 ms | 22210 | avg: 0.081 ms | max: 25.005 ms | max at: 269.068666 s
testo:(9) | 2558.540 ms | 13703 | avg: 0.124 ms | max: 6.412 ms | max at: 279.235272 s
konsole:1781 | 1084.316 ms | 1457 | avg: 0.006 ms | max: 1.039 ms | max at: 268.863379 s
kwin:1734 | 879.645 ms | 17855 | avg: 0.458 ms | max: 15.788 ms | max at: 268.854992 s
pulseaudio:1808 | 356.334 ms | 15023 | avg: 0.028 ms | max: 6.134 ms | max at: 324.479766 s
threaded-ml:3483 | 292.782 ms | 25769 | avg: 0.364 ms | max: 40.387 ms | max at: 294.550515 s
plasma-desktop:1745 | 265.055 ms | 1470 | avg: 0.102 ms | max: 21.886 ms | max at: 267.724902 s
perf:3439 | 61.677 ms | 2 | avg: 0.117 ms | max: 0.232 ms | max at: 367.043889 s


> --
>
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 4df37a4..b184da0 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -2370,7 +2370,7 @@ static inline long calc_tg_weight(struct task_group *tg, struct cfs_rq *cfs_rq)
> */
> tg_weight = atomic_long_read(&tg->load_avg);
> tg_weight -= cfs_rq->tg_load_avg_contrib;
> - tg_weight += cfs_rq_load_avg(cfs_rq);
> + tg_weight += cfs_rq->load.weight;
>
> return tg_weight;
> }
> @@ -2380,7 +2380,7 @@ static long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg)
> long tg_weight, load, shares;
>
> tg_weight = calc_tg_weight(tg, cfs_rq);
> - load = cfs_rq_load_avg(cfs_rq);
> + load = cfs_rq->load.weight;
>
> shares = (tg->shares * load);
> if (tg_weight)


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/