[CFT] Improved ZFS metaslab code (faster write speed)

[Alexander Leidinger]

On Fri, 27 Aug 2010 20:34:18 -0700 Artem Belevich <fbsdlist at src.cx>
wrote:

> Perhaps reduced UMA fragmentation helps those subsystem that do use
> UMA (including ZFS which always uses uma for various housekeeping
> data).

PJD told me once that ZFS is always using UMA, it is just not using it
for everything (except when the sysctl is switched to use it for
everything).

FYI: I have a 9-current system which panics (without a backtrace/dump)
after 1-2 days of uptime when the zfs-uma-sysctl is activated. When it
is not activated it survives several weeks (let's say about a month).
So any work on the UMA fragmentation issue is well spend time.

No, I haven't tested any of the patches on this machine.

Bye,
Alexander.