Re: SCHED_4BSD in RELENG_7 disturbs workflow

Kris Kennaway 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.
> 
> Or xorg 7.3 vs 7.2, if this was an older 6.x install.
> 
> Kris
> 


I was on Xorg 7.3 before I switched to RELENG_7.

Now, my problems have been solved, thanks to all your suggestions. It turned
out that I actually had 2 problems, which only appeared to be one.

The first one was the scheduler. ULE feels much better to me, the system
responds fine now.

The other problem was the strange occurance that X froze when the mouse was
not in movement on one of my machines. The solution was to rebuild
x11-drivers/xf86-input-mouse . Now everything seems to run fine.

Thanks everyone for all the feedback and suggestions. My next project will be
to build my kernel with debugging and produce decent traces for my ipw panics.