3537 want pool io kstats
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Reviewed by: Sa?o Kiselkov <skiselkov.ml@gmail.com>
Reviewed by: Garrett D'Amore <garrett@damore.org>
Reviewed by: Brendan Gregg <brendan.gregg@joyent.com>
Approved by: Gordon Ross <gwr@nexenta.com>
References:
http://www.illumos.org/issues/3537illumos/illumos-gate@c3a6601
Ported by: Cyril Plisko <cyril.plisko@mountall.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Porting Notes:
1. The patch was restructured to take advantage of the existing
spa statistics infrastructure. To accomplish this the kstat
was moved in to spa->io_stats and the init/destroy code moved
to spa_stats.c.
2. The I/O kstat was simply named <pool> which conflicted with the
pool directory we had already created. Therefore it was renamed
to <pool>/io
3. An update handler was added to allow the kstat to be zeroed.