SCHED_4BSD in RELENG_7 disturbs workflow

[[LoN]Kamikaze]

Josh Carroll wrote:
>> 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).
> 
> For my particular work load, 4BSD is actually faster than ULE in
> RELENG_7. Specifically, on a Q6600 running ffmpeg -threads 8 to
> transcode some H.264 video, 4BSD is about 5% faster. I took a sample
> video and transcoded the first 120 seconds of it, and here are the
> results (including a control from 6.2-RELEASE-p7/4BSD scheduler):
> 
> releng_6_2 (4BSD)   1:32.39
> releng_7 (4BSD)       1:32.44
> releng_7 (ULE)         1:37.15
> 
> This is obviously a different scenario from MySQL. So perhaps ULE
> isn't as well tuned for cases like ffmpeg?
> 
> Josh
> 

I suspect that the increased performance is stolen from the process with
focus. I don't care much about my calculation being 5% faster if that renders
the machine unusable.