Re: SCHED_4BSD in RELENG_7 disturbs workflow

On Tue, 16 Oct 2007, [LoN]Kamikaze wrote:

> 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.
>

Can you give us a full dmesg?

Thanks,
jeff