Bring per_txg_dirty_frees_percent back to 30

The current value causes significant artificial slowdown during mass
parallel file removal, which can be observed both on FreeBSD and Linux
when running real workloads.

Sample results from Linux doing make -j 96 clean after an allyesconfig
modules build:

before: 4.14s user 6.79s system 48% cpu 22.631 total
after:	4.17s user 6.44s system 153% cpu 6.927 total

FreeBSD results in the ticket.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by:	Mateusz Guzik <mjguzik@gmail.com>
Closes #13932
Closes #13938
This commit is contained in:
Mateusz Guzik 2022-09-28 02:38:03 +02:00 committed by Brian Behlendorf
parent 7ac732b8d6
commit c8d6a91a99
2 changed files with 2 additions and 2 deletions

View File

@ -1651,7 +1651,7 @@ prefetched during a pool traversal, like
.Nm zfs Cm send
or other data crawling operations.
.
.It Sy zfs_per_txg_dirty_frees_percent Ns = Ns Sy 5 Ns % Pq ulong
.It Sy zfs_per_txg_dirty_frees_percent Ns = Ns Sy 30 Ns % Pq ulong
Control percentage of dirtied indirect blocks from frees allowed into one TXG.
After this threshold is crossed, additional frees will wait until the next TXG.
.Sy 0 No disables this throttle.

View File

@ -71,7 +71,7 @@ int zfs_nopwrite_enabled = 1;
* will wait until the next TXG.
* A value of zero will disable this throttle.
*/
unsigned long zfs_per_txg_dirty_frees_percent = 5;
unsigned long zfs_per_txg_dirty_frees_percent = 30;
/*
* Enable/disable forcing txg sync when dirty checking for holes with lseek().