Adjust prefetch parameters.
commit81be809a25b8d3ef859f203664d1981163d87983
authorAlexander Motin <mav@FreeBSD.org>
Fri, 21 Jul 2023 18:51:47 +0000 (21 14:51 -0400)
committerBrian Behlendorf <behlendorf1@llnl.gov>
Fri, 21 Jul 2023 23:35:12 +0000 (21 16:35 -0700)
tree7bc2eccf9d5450fb2d361df59aaa854037b4c1a7
parent8a6fde8213797df1acd24d4afb9ada0d005f6b1d
Adjust prefetch parameters.

- Reduce maximum prefetch distance for 32bit platforms to 8MB as it
was previously.  Those systems didn't grow much probably, so better
stay conservative there.
 - Retire array_rd_sz tunable, blocking prefetch for large requests.
We should not penalize applications trying to be more efficient. The
speculative prefetcher by itself has reasonable distance limits, and
1MB is not much at all these days.

Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes #15072
include/sys/dmu_zfetch.h
man/man4/zfs.4
module/zfs/dmu.c
module/zfs/dmu_zfetch.c