Re: Current ULE state and plans (was Re: HMP scheduling on FreeBSD)

> On 1/19/26 15:51, Olivier Certner wrote:
> >> Why remove functioning code that people actually use?
> > 
> > How can you be sure it is functioning correctly?  Have you reviewed it?  Has it been tested on a variety of workloads?  What does guarantee it will not break, more or less badly, when some code surrounding it is changed, even when these changes are done carefully?
> > 
> > And who is using it, exactly? You count for 1. Given the past threads on the topic, I expect a few more, but can we even reach 10 or 20, I wouldn't bet on it.
> > [...]
> 
> Speaking as the guy who periodically bitched about what ULE was doing
> to misc/dnetc until someone pointed out idprio to me (a setting that
> 4BSD couldn't care less about but that ULE goes nuts over if you set it
> wrong), count me as a continuing user of 4BSD.  Because it just works.

Since we seem to need a "count" on useful use of old code, add me.  Also
IIRC, bde had several issues with ULE.
> 
> Anecdotally, I don't personally observe the purported interactivity
> improvement ascribed to ULE, either, but I can't give you numbers on it.

I actually find ULE to be BAD on interactive systems, often blocking my
login shell for long enough that I think the system might be crashed
when a heavy compute (make world for example) is running.

> 
> And why shouldn't people try to create other new schedulers?  And should
> we not at least keep testing that the scheduler interface is simple and
> promotes scheduler modularity?                               -- George

-- 
Rod Grimes                                                 rgrimes@freebsd.org