Some comments on ZFS

[Gary Jennejohn]

I wrote:
> With the old setup I saw:
> a) ``make -j2 buildworld'' usually pegged the CPU at 97%.
>
[snip]
> With the new setup:
> a) ``make -j2 buildworld'' only reaches about 70% CPU load. Is ZFS stealing
>    so much CPU?
>

This turned out to be a problem with SCHED_ULE. I was seeing cpu0 80% idle
almost all the time. After switching to SCHED_4BSD I see both CPUs used
to within about 5% of each other. SCHED_4BSD tends to use cpu1 more than
cpu0. SCED_ULE exhibited the same behavior, but more dramatically.

-- 
Gary Jennejohn / garyjATjennejohnDOTorg gjATfreebsdDOTorg garyjATdenxDOTde