Re: [PATCH] sched/fair: Do not decay new task load on first enqueue

[Wanpeng Li]

2016-09-29 3:37 GMT+08:00 Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx>:
> On Wed, 28 Sep, at 12:14:22PM, Peter Zijlstra wrote:
>>
>> Which suggests we do something like the below (not compile tested or
>> anything, also I ran out of tea again).
>
> I'm away on FTO right now. I can test this when I return on Friday.
>
> Funnily enough, I now remember that I already sent a fix for the
> missing update_rq_clock() in post_init_entity_util_avg(), but didn't
> apply it when chasing this hackbench regression (oops),
>
>   https://lkml.kernel.org/r/20160921133813.31976-3-matt@xxxxxxxxxxxxxxxxxxx

The difference between this patch and Peterz's is your patch have a
delta since activate_task()->enqueue_task() does do update_rq_clock(),
so why don't have the delta will cause low cpu machines (4 or 8) to
regress against your another reply in this thread?

Regards,
Wanpeng Li