Re: [PATCH 4/6 v8] sched/fair: Add push task mechanism for fair

[K Prateek Nayak]

On 12/5/2025 7:06 PM, Vincent Guittot wrote:
>> So I was experimenting with:
>>
>>     deactivate_task(rq, p, 0);
>>     set_task_cpu(p, target_cpu);
>>     __ttwu_queue_wakelist(p, target_cpu, 0);
>>
>> and nothing has screamed at me yet during the benchmark runs.
>> Would this be any good instead of the whole lock juggling?
>>
>> Since this CPU is found to be going overloaded, pushing via an
> 
> Just to make sure that we speak about the same thing. With EAS
> overloaded and overutilized are 2 different things. EAS don't care and
> some time want to overload a CPU( having more than1 task on the CPU)
> but EAS is diable once teh CPU becomes overutilized

I meant to say overutilized in this context. Sorry about that.

> 
>> IPI vs taking the overhead ourselves seems to make more sense
>> to me from EAS standpoint.
> 
> I suppose that it's worth trying the IPI on EAS and embedded device

If they are cheap enough, we can simply use TTWU_QUEUE check for the
!PREEMPT_RT and use move queued task otherwise.

-- 
Thanks and Regards,
Prateek