Re: [PATCH v7 6/9] sched/fair: Add sched group latency support

Qais Yousef
2022-11-05T14:29:02Z

On 11/04/22 09:13, Joel Fernandes wrote:

> > If I have a task that has p->latency_nice = 20 but it belongs to a cgroup
> > that has tg->cpu.latency.nice = -19
>
> Just for the task placement signal, One way is to go through the se hierarchy
> till the root and get the minimum. Then make that the effective value. So In
> your example that would make it -19 so prefer idle = 1. We should need
> a Boolean signal. Not pretty but not the end of the world imho.

It is not hard to hack something. My worry is about consistency; and
maintainers in the future saying that doesn't fit the current design.

I'd love for this to be usable everywhere as-is. That requires the expectations
for both users and consumers are being made clear from the beginning.

What I was asking for is for the documentation to reflect this, and the
implementation of this effective function being made available from the start.

Cheers

--
Qais Yousef