Re: [RFC PATCH V3 5/6] sched/fair: Add trivial fair server

[Peter Zijlstra]

On Fri, Jun 16, 2023 at 03:00:57PM +0200, Daniel Bristot de Oliveira wrote:
> On 6/16/23 14:59, Peter Zijlstra wrote:
> > On Thu, Jun 08, 2023 at 05:58:17PM +0200, Daniel Bristot de Oliveira wrote:
> >> +void fair_server_init(struct rq *rq)
> >> +{
> >> +	struct sched_dl_entity *dl_se = &rq->fair_server;
> >> +
> >> +	init_dl_entity(dl_se);
> >> +
> >> +	dl_se->dl_runtime = TICK_NSEC;
> >> +	dl_se->dl_deadline = 20 * TICK_NSEC;
> >> +	dl_se->dl_period = 20 * TICK_NSEC;
> >> +
> >> +	dl_server_init(dl_se, rq, fair_server_has_tasks, fair_server_pick);
> >> +}
> > 
> > These here numbers should obviously become a tunable somewhere... :-)
> 
> From sched_rt_runtime and sched_rt_period, no?

Well, probably new names. IIRC those are also limits on the whole
rt-cgroup mess, so e can't trivially change it without also ripping all
that out, and that's a little bit more work.

Ripping out the basic throttle is much simpler than replacing all that
and should be done earlier.