Is kern.sched.preempt_thresh=0 a sensible default?

[Gary Jennejohn]

On Thu, 7 Jun 2018 20:14:10 +0300
Andriy Gapon <avg at FreeBSD.org> wrote:

> On 03/05/2018 12:41, Andriy Gapon wrote:
> > I think that we need preemption policies that might not be expressible as one or
> > two numbers.  A policy could be something like this:
> > - interrupt threads can preempt only threads from "lower" classes: real-time,
> > kernel, timeshare, idle;
> > - interrupt threads cannot preempt other interrupt threads
> > - real-time threads can preempt other real-time threads and threads from "lower"
> > classes: kernel, timeshare, idle
> > - kernel threads can preempt only threads from lower classes: timeshare, idle
> > - interactive timeshare threads can only preempt batch and idle threads
> > - batch threads can only preempt idle threads  
> 
> 
> Here is a sketch of the idea: https://reviews.freebsd.org/D15693
> 

What about SCHED_4BSD?  Or is this just an example and you chose
SCHED_ULE for it?

-- 
Gary Jennejohn