Re: [PATCH V6 3/6] sched/fair: Fair server interface

From: Peter Zijlstra
Date: Thu Apr 11 2024 - 10:45:10 EST


On Fri, Apr 05, 2024 at 07:28:02PM +0200, Daniel Bristot de Oliveira wrote:
> Add an interface for fair server setup on debugfs.
>
> Each CPU has three files under /debug/sched/fair_server/cpu{ID}:
>
> - runtime: set runtime in ns
> - period: set period in ns
> - defer: on/off for the defer mechanism
>
> This then leaves /proc/sys/kernel/sched_rt_{period,runtime}_us to set
> bounds on admission control.
>
> The interface also add the server to the dl bandwidth accounting.

I suppose most people will want to use it like:

for i in /debug/sched/fair_server/cpu*
do
echo $PERIOD > ${i}/period
ecoh $RUNTIME > ${i}/runtime
done

And I think we agreed to keep this loop in userspace, but memory is
vague.

The 'defer' thing is dubious though, I don't suppose anybody would ever
want to actually change that, other than you while poking around at this
code, right?