Re: [BUG] cpu controller can't provide fair CPU time for each group

From: Yasunori Goto
Date: Wed Nov 11 2009 - 20:13:17 EST


> On Wed, 2009-11-11 at 15:21 +0900, Yasunori Goto wrote:
> > > Someone needs to fix that if they really care.
> >
> > To be honest, I don't have any good idea because I'm not familiar with
> > schduler's code.
>
> You could possible try something like the below, its rather gross but
> might maybe work,.. has other issues though.

Thank you very much for your patch. I'm very glad.

Unfortunately, my test staff and I don't have test box today,
I'll report the result later.

Thanks again for your time.

>
>
> ---
> kernel/sched.c | 9 +++++++--
> 1 files changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/sched.c b/kernel/sched.c
> index 91642c1..65629a3 100644
> --- a/kernel/sched.c
> +++ b/kernel/sched.c
> @@ -1614,7 +1614,7 @@ static void update_group_shares_cpu(struct task_group *tg, int cpu,
> */
> static int tg_shares_up(struct task_group *tg, void *data)
> {
> - unsigned long weight, rq_weight = 0, shares = 0;
> + unsigned long weight, rq_weight = 0, sum_weight = 0, shares = 0;
> unsigned long *usd_rq_weight;
> struct sched_domain *sd = data;
> unsigned long flags;
> @@ -1630,6 +1630,7 @@ static int tg_shares_up(struct task_group *tg, void *data)
> weight = tg->cfs_rq[i]->load.weight;
> usd_rq_weight[i] = weight;
>
> + rq_weight += weight;
> /*
> * If there are currently no tasks on the cpu pretend there
> * is one of average load so that when a new task gets to
> @@ -1638,10 +1639,14 @@ static int tg_shares_up(struct task_group *tg, void *data)
> if (!weight)
> weight = NICE_0_LOAD;
>
> - rq_weight += weight;
> + sum_weight += weight;
> +
> shares += tg->cfs_rq[i]->shares;
> }
>
> + if (!rq_weight)
> + rq_weight = sum_weight;
> +
> if ((!shares && rq_weight) || shares > tg->shares)
> shares = tg->shares;
>
>

--
Yasunori Goto


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