raid3 is slow

[Dag-Erling Smørgrav]

Szabó Péter <matyee at mail.alba.hu> writes:
> It seems fine, but the load 1.0, i think is a litle bit high. gbde
> gets only ~30% of WCPU and g_down gets ~3%. I don't know what is the
> task of g_down.

You don't seem to understand what the load averages mean.  They are
the average number of runnable threads in the scheduler queue over the
last one, five and fifteen seconds.  Certain workloads will drive up
the load averages without consuming all available CPU time.  This is
particularly the case for workloads where small chunks of data (e.g.
RAID3 stripes) are passed around between multiple threads.

FYI, g_up and g_down are the threads responsible for passing data up
and down the GEOM stack, respectively.  For further details, see for
instance <URL:http://www.freebsd.org/doc/en/articles/geom-class/>.

DES
-- 
Dag-Erling Smørgrav - des at des.no