Hi, Alex
On 05/06/2013 09:45 AM, Alex Shi wrote:
> effective_load calculates the load change as seen from the
> root_task_group. It needs to engage the runnable average
> of changed task.
[snip]
> */
> @@ -3045,7 +3045,7 @@ static long effective_load(struct task_group *tg, int
> cpu, long wl, long wg)
> /*
> * w = rw_i + @wl
> */
> - w = se->my_q->load.weight + wl;
> + w = se->my_q->tg_load_contrib + wl;
I've tested the patch set, seems like the last patch caused big
regression on pgbench:
base patch 1~6 patch 1~7
| db_size | clients | tps | | tps | | tps |
+---------+---------+-------+ +-------+ +-------+
| 22 MB | 32 | 43420 | | 53387 | | 41625 |
I guess some magic thing happened in effective_load() while calculating
group decay combined with load decay, what's your opinion?
Regards,
Michael Wang
>
> /*
> * wl = S * s'_i; see (2)
> @@ -3066,7 +3066,7 @@ static long effective_load(struct task_group *tg, int
> cpu, long wl, long wg)
> /*
> * wl = dw_i = S * (s'_i - s_i); see (3)
> */
> - wl -= se->load.weight;
> + wl -= se->avg.load_avg_contrib;
>
> /*
> * Recursively apply this logic to all parent groups to compute
> @@ -3112,14 +3112,14 @@ static int wake_affine(struct sched_domain *sd,
> struct task_struct *p, int sync)
> */
> if (sync) {
> tg = task_group(current);
> - weight = current->se.load.weight;
> + weight = current->se.avg.load_avg_contrib;
>
> this_load += effective_load(tg, this_cpu, -weight, -weight);
> load += effective_load(tg, prev_cpu, 0, -weight);
> }
>
> tg = task_group(p);
> - weight = p->se.load.weight;
> + weight = p->se.avg.load_avg_contrib;
>
> /*
> * In low-load situations, where prev_cpu is idle and this_cpu is idle
>
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