Re: [RFC PATCH 2/2] sched/eevdf: Introduce a cgroup interface for slice

[Tianchen Ding <dtcccc@linux.alibaba.com>]

On 2024/10/29 01:37, Tejun Heo wrote:
> Hello,
> 
> On Mon, Oct 28, 2024 at 02:33:13PM +0800, Tianchen Ding wrote:
>> Introduce "cpu.fair_slice" for cgroup v2 and "cpu.fair_slice_us" for v1
>> according to their name styles. The unit is always microseconds.
>>
>> A cgroup with shorter slice can preempt others more easily. This could be
>> useful in container scenarios.
>>
>> By default, cpu.fair_slice is 0, which means the slice of se is
>> calculated by min_slice from its cfs_rq. If cpu.fair_slice is set, it
>> will overwrite se->slice with the customized value.
> 
> Provided that this tunable is necessary, wouldn't it be more useful to
> figure out what per-task interface would look like first? Maybe there are
> cases where per-cgroup slice config makes sense but that sounds
> significantly less useful than being able to configure it per-task.
> 
> Thanks.
> 

For eevdf, per-task interface has been introduced in commit 857b158dc5e8 
("sched/eevdf: Use sched_attr::sched_runtime to set request/slice suggestion")

So This patch is trying to introduce a cgroup level interface.

Thanks.