SCHED_4BSD in RELENG_7 disturbs workflow

[[LoN]Kamikaze]

Jeff Roberson wrote:
> On Tue, 16 Oct 2007, Kris Kennaway wrote:
> 
>> [LoN]Kamikaze wrote:
>>> I know that RELENG_7 is not considered very near-release, but I
>>> thought I'd
>>> give my 2¢ in the hope that I might have a little influence on the
>>> scheduler
>>> development to my benefit.
>>>
>>> The switch from RELENG_6 to RELENG_7 went relatively smooth and apart
>>> from ipw
>>> causing panics. However there is one thing that's disturbing and this
>>> is the
>>> scheduler. I only have single core machines, so whatever I say only
>>> applies to
>>> those. If you think single-core machines are no longer important,
>>> feel free to
>>> ignore this. In deed, just ignore me however much you like.
>>>
>>>> From my perspective scheduling on RELENG_6 was way better. Even on a
>>>> full
>>> workload like a portupgrade the focused application (both in X and on
>>> the
>>> console) always received enough cycles to run smoothly and
>>> applications that
>>> ran in background like audio players also kept on running fine.
>>>
>>> Quite the contrary on RELENG_7. During a portupgrade or even worse
>>> 'pkgdb -L'
>>> (recovering lost dependencies) audio players (both graphical and
>>> mplayer)
>>> scatter, either because they don't get the hard-disk or CPU-cycles
>>> (which one,
>>> I don't know) and the focused application also often hangs. It just
>>> looks like
>>> occasionally (under load) everything freezes for a second and then
>>> goes on
>>> relatively normal.
>>>
>>> I've got the impression that things compile a little faster (that
>>> might be my
>>> imagination, though), but I'd rather have a smooth working experience.
>>>
>>> This is just my view of the situation and I suppose it is only one of
>>> many. I
>>> bid you be merciful with us single-core people, who cannot afford a
>>> slick
>>> multi-core machine, because we worry how to pay for our food at the
>>> end of the
>>> month.
>>
>> Not to say that any problems that might have developed with SCHED_4BSD
>> should not be fixed, but you should give SCHED_ULE a try since it
>> brings benefits even for single CPU systems (e.g. better interactive
>> response).
> 
> It would indeed be good to know if ULE improves things for you. 
> However, there have been a number of other reports about non-scheduler
> related regressions with x windows on 7.0.  I run 7.0 on a UP laptop
> without difficulty.  I wonder if it has something to do with a
> particular device or driver.
> 
> Jeff

Well, I'll certainly see soon. However I have switched from Xorg 7.2 to 7.3
first and that worked fine. Only after the update RELENG_6 to RELENG_7 did
those issues appear. I have now recompiled all my 700+ ports to rule out
compatibility problems (I had lots of panics before I did that, now everything
is stable, unless I try to use my wireless device) and the performance issue
remains.