Re: [RFC PATCH v2 6/6] sched/fair: Implement starvation monitor

From: Juri Lelli
Date: Fri Aug 07 2020 - 09:44:12 EST


On 07/08/20 15:28, luca abeni wrote:
> Hi Juri,
>
> On Fri, 7 Aug 2020 11:56:04 +0200
> Juri Lelli <juri.lelli@xxxxxxxxxx> wrote:
>
> > Starting deadline server for lower priority classes right away when
> > first task is enqueued might break guarantees
>
> Which guarantees are you thinking about, here? Response times of fixed
> priority tasks?

Response time, but also wakeup latency (which, for better or worse, is
another important metric).

> If fixed priority tasks are also scheduled through deadline servers,
> then you can provide response-time guarantees to them even when
> lower-priority/non-real-time tasks are scheduled through deadline
> servers.

Right, but I fear we won't be able to keep current behavior for wakeups:
RT with highest prio always gets scheduled right away?