SCHED_4BSD in RELENG_7 disturbs workflow

[[LoN]Kamikaze]

Bengt Ahlgren wrote:
> "[LoN]Kamikaze" <LoN_Kamikaze at gmx.de> writes:
> 
>> 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.
> 
> Do you have ATA write-caching on or off?  My experience is that if you
> turn caching off (on RELENG_6_x at least, have not tried 7) the
> machine often freezes for seconds when you are writing a lot to the
> disk.
> 
> Bengt
> 

Write-caching is on on my machines.