Re: [RFC 1/3] Introduce latency-tolerance as an per-task attribute

From: Parth Shah
Date: Thu Dec 05 2019 - 06:42:30 EST




On 12/5/19 2:54 PM, Dietmar Eggemann wrote:
> On 03/12/2019 16:47, Parth Shah wrote:
>>
>> On 12/3/19 2:06 PM, Qais Yousef wrote:
>>> On 11/25/19 15:16, Parth Shah wrote:
>>>> Latency-tolerance indicates the latency requirements of a task with respect
>>>> to the other tasks in the system. The value of the attribute can be within
>>>> the range of [-20, 19] both inclusive to be in-line with the values just
>>>> like task nice values.
>>>>
>>>> latency_tolerance = -20 indicates the task to have the least latency as
>>>> compared to the tasks having latency_tolerance = +19.
>>>>
>>>> The latency_tolerance may affect only the CFS SCHED_CLASS by getting
>>>> latency requirements from the userspace.
>
> [...]
>
>>>> diff --git a/include/linux/sched/latency_tolerance.h b/include/linux/sched/latency_tolerance.h
>
> Do we really need an extra header file for this? I know there is
> linux/sched/prio.h but couldn't this go into kernel/sched/sched.h?

We can include this in kernel/sched/sched.h itself unless we have any plans
to use it outside the scheduler subsystem. I will then add it as specified
in next revision.

>
> [...]
>