Re: [BENCHMARK] scheduler tunables with contest - prio_bonus_ratio

Con Kolivas (conman@kolivas.net)
Wed, 25 Dec 2002 18:29:23 +1100


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On Wed, 25 Dec 2002 09:26 am, scott thomason wrote:
> On Thursday 19 December 2002 05:41 pm, Robert Love wrote:
> > On Thu, 2002-12-19 at 18:18, Andrew Morton wrote:
> > > That is too often not the case.
> >
> > I knew you would say that!
> >
> > > I can get the desktop machine working about as comfortably
> > > as 2.4.19 with:
> > >
> > > # echo 10 > max_timeslice
> > > # echo 0 > prio_bonus_ratio
> > >
> > > ie: disabling all the fancy new scheduler features :(
> > >
> > > Dropping max_timeslice fixes the enormous stalls which happen
> > > when an interactive process gets incorrectly identified as a
> > > cpu hog. (OK, that's expected)
>
> My experiences to add to the pot...I started by booting 2.5.52-mm2 and
> launching KDE3. I have a dual AMD MP2000+, 1GB RAM, with most of the
> data used below on striped/RAID0 ATA/133 drives. Taking Andrew's
> advice, I created a continuous load with:
>
> while [ 1 ]; do ( make -j4 clean; make -j4 bzImage ); done
>
> ...in a kernel tree, then sat down for a leisurely email and web
> cruising session. After about fifteen minutes, it became apparent I
> wasn't suffering any interactive slowdown. So I increased the load:
>
> while [ 1 ]; do ( make -j8 clean; make -j8 bzImage ); done
> while [ 1 ]; do ( cp dump1 dump2; rm dump2; sync ); done
>
> ...where file "dump1" is 100MB. Now we're seeing some impact :)
>
> To combat this I tried:
>
> echo 3000 > starvation_limit
> echo 4 > interactive_delta
> echo 200 max_timeslice
> echo 20 min_timeslice
>
> This works pretty well. The "spinning envelope" on the email monitor
> of gkrellm actually corresponds quite nicely with the actual feel of
> my system, so after awhile, I just sat back and observed it. Both the
> tactile response and the gkrellm obervations show this: it's common
> to experience maybe a .1--.3 second lag every 2 or 3 seconds with
> this load, with maybe the odd .5 second lag occurring once or twice a
> minute. Watching the compile job in the background scroll by, I
> noticed that there are times when it comes to a dead stop. The next
> step, I guess, needs to be a ConTest with the final settings...
>
> child_penalty: 95
>
> exit_weight: 3
>
> interactive_delta: 4
>
> max_sleep_avg: 2000
>
> max_timeslice: 300
>
> min_timeslice: 10
>
> parent_penalty: 100
>
> prio_bonus_ratio: 25
>
> starvation_limit: 3000

Scott

These don't correspond to your values listed above. Typo?

Con
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