Re: Periodic rant about SCHED_ULE

From: RW via freebsd-hackers <freebsd-hackers_at_freebsd.org>
Date: Wed, 14 Jul 2021 16:47:45 +0100
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. 
Received on Wed Jul 14 2021 - 15:47:45 UTC

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