Skip site navigation (1)Skip section navigation (2)
Date:      Wed, 7 Jul 2021 22:56:55 +0200
From:      Miroslav Lachman <000.fbsd@quip.cz>
To:        gljennjohn@gmail.com, George Mitchell <george+freebsd@m5p.com>
Cc:        FreeBSD Hackers <freebsd-hackers@FreeBSD.org>
Subject:   Re: Periodic rant about SCHED_ULE
Message-ID:  <054b4735-7740-617d-6c61-c5b48ef1d85a@quip.cz>
In-Reply-To: <20210707181835.75601d54@ernst.home>
References:  <13445948-7804-20b4-4ae6-aaac14d11e87@m5p.com> <20210707181835.75601d54@ernst.home>

next in thread | previous in thread | raw e-mail | index | archive | help
On 07/07/2021 20:18, Gary Jennejohn wrote:
> On Wed, 7 Jul 2021 13:47:47 -0400
> George Mitchell <george+freebsd@m5p.com> wrote:

[..]

>> I've been ranting about this for years now, and I've had my say -- but
>> no one has ever answered my question about what workload SCHED_ULE is
>> best for, though numerous people have claimed that it's better than
>> SCHED_4BSD for -- some rumored workload or other.          -- George
>>
> 
> IIRC there was talk about making the scheduler loadable in the early
> days.  But that was years ago and I may be misrembering.
> 
> I have a Ryzen 5 1600 with 6 cores, so older tech and "only" 3200MHz.
> 
> I can do a clean buildworld on FreeBSD-14 using only 10 of the 12 SMTs
> in about 40 minutes using SCHED_4BSD.  While still browsing the
> interwebs or watching a film etc.  with no noticeable lags in
> performance.
> 
> So, for my normal desktop usage SCHED_4BSD is the only way to go.

I had some performance problems with VirtualBox as hypervisor on 
somewhat older Intel Xeon with 4 cores 8 threads. So I tested 4BSD and 
ULE -  SCHED_4BSD had slightly better results than SCHED_ULE.
I am also curious why ULE is the default. Where are some real world 
performance results for comparing the two FreeBSD schedulers.

Kind regards
Miroslav Lachman



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?054b4735-7740-617d-6c61-c5b48ef1d85a>