On 04/03/2013 01:38 PM, Michael Wang wrote:
> On 04/03/2013 12:28 PM, Alex Shi wrote:
> [snip]
>>
>> but the patch may cause some unfairness if this/prev cpu are not burst at
>> same time. So could like try the following patch?
>
> I will try it later, some doubt below :)
>
> [snip]
>> +
>> + if (cpu_rq(this_cpu)->avg_idle < sysctl_sched_migration_cost ||
>> + cpu_rq(prev_cpu)->avg_idle < sysctl_sched_migration_cost)
>> + burst= 1;
>> +
>> + /* use instant load for bursty waking up */
>> + if (!burst) {
>> + load = source_load(prev_cpu, idx);
>> + this_load = target_load(this_cpu, idx);
>> + } else {
>> + load = cpu_rq(prev_cpu)->load.weight;
>> + this_load = cpu_rq(this_cpu)->load.weight;
>
> Ok, my understanding is, we want pull if 'prev_cpu' is burst, and don't
> want pull if 'this_cpu' is burst, correct?
>
> And we do this by guess the load higher or lower, is that right?
>
> And I think target_load() is capable enough to choose the higher load,
> if 'cpu_rq(cpu)->load.weight' is really higher, the results will be the
> same.
>
> So what about this:
>
> /* prefer higher load if burst */
> load = burst_prev ?
And this check could also be:
load = burst_prev && !burst_this ?
if we don't prefer the pull when this_cpu also bursted.
Regards,
Michael Wang
> target_load(prev_cpu, idx) : source_load(prev_cpu, idx);
>
> this_load = target_load(this_cpu, idx);
>
> Regards,
> Michael Wang
>
>> + }
>>
>> /*
>> * If sync wakeup then subtract the (maximum possible)
>>
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
