zfs/man/man5
Matthew Ahrens 516a08ebb4 fat zap should prefetch when iterating
When iterating over a ZAP object, we're almost always certain to iterate
over the entire object. If there are multiple leaf blocks, we can
realize a performance win by issuing reads for all the leaf blocks in
parallel when the iteration begins.

For example, if we have 10,000 snapshots, "zfs destroy -nv
pool/fs@1%9999" can take 30 minutes when the cache is cold. This change
provides a >3x performance improvement, by issuing the reads for all ~64
blocks of each ZAP object in parallel.

Reviewed-by: Andreas Dilger <andreas.dilger@whamcloud.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
External-issue: DLPX-58347
Closes #8862
2019-09-25 11:27:47 -07:00
..
Makefile.am Update build system and packaging 2018-05-29 16:00:33 -07:00
spl-module-parameters.5 Update spl module parameters man5 with missing parameter details 2017-10-27 15:46:34 -07:00
vdev_id.conf.5 Add enclosure_symlinks option to vdev_id 2018-12-14 17:27:49 -08:00
zfs-events.5 Add zpool status -s (slow I/Os) and -p (parseable) 2018-11-08 16:47:24 -08:00
zfs-module-parameters.5 fat zap should prefetch when iterating 2019-09-25 11:27:47 -07:00
zpool-features.5 Eliminate useless double-bolding in man pages 2019-04-24 17:04:35 -07:00