Re: Periodic rant about SCHED_ULE

On Thu, 8 Jul 2021 10:19:07 +0300
Rozhuk Ivan wrote:


> and sysctl tunings on desktop only:
>
> # SCHEDULER
> kern.sched.steal_thresh=1
> kern.sched.balance=0			 
> kern.sched.balance_interval=1000
> kern.sched.affinity=10000	


You missed out

kern.sched.preempt_thresh=224

(perhaps because it's so well known).

In my experience this makes a big difference for desktop use. If I set
that and build on tmpfs, to minimise the effect of I/O contention, I
don't see any discernible effect on Xfce when building world with -j4.

This is on a bottom of the range i5 from 9 years ago. It's not
particularly fast. 

I think the default only allows preemption by real-time and kernel
threads.