mirror_zfs/man
Alexander Motin 04bae5ec95
Disable high priority ZIO threads on FreeBSD and Linux
High priority threads are handling ZIL writes.  While there is no
ZIL compression, there is encryption, checksuming and RAIDZ math.
We've found that on large systems 1 taskq with 5 threads can be
a bottleneck for throughput, IOPS or both. Instead of just bumping
number of threads with a risk of overloading CPUs and increasing
latency, switch to using TQ_FRONT mechanism to increase sync write
requests priority within standard write threads.  Do not do it on
Illumos, since its TQ_FRONT implementation is inherently unfair.
FreeBSD and Linux don't have this problem, so we can do it there.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Rob Norris <robn@despairlabs.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes #16146
2024-05-03 09:53:34 -07:00
..
man1 RAID-Z expansion feature 2023-11-08 10:19:41 -08:00
man4 Disable high priority ZIO threads on FreeBSD and Linux 2024-05-03 09:53:34 -07:00
man5 Consistentify miscellaneous style on remaining manpages 2021-06-09 14:35:53 -07:00
man7 vdev props comment and manpage should include zfsd and FreeBSD mentions 2024-04-03 17:56:34 -07:00
man8 vdev probe to slow disk can stall mmp write checker 2024-04-29 14:35:53 -07:00
Makefile.am man: move zfs_prepare_disk.8 to nodist_man_MANS 2024-04-03 18:04:15 -07:00