mirror_zfs/module
Alexander Motin 55cbd1f9bd Reduce dirty records memory usage
Small block workloads may use a very large number of dirty records.
During simple block cloning test due to BRT still using 4KB blocks
I can easily see up to 2.5M of those used.  Before this change
dbuf_dirty_record_t structures representing them were allocated via
kmem_zalloc(), that rounded their size up to 512 bytes.

Introduction of specialized kmem cache allows to reduce the size
from 512 to 408 bytes.  Additionally, since override and raw params
in dirty records are mutually exclusive, puting them into a union
allows to reduce structure size down to 368 bytes, increasing the
saving to 28%, that can be a 0.5GB or more of RAM.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by:	Alexander Motin <mav@FreeBSD.org>
Sponsored by:	iXsystems, Inc.
Closes #16694
2024-11-04 16:46:39 -08:00
..
avl Suppress Clang Static Analyzer false positive in the AVL tree code. 2023-03-08 13:51:21 -08:00
icp icp: remove redundant FreeBSD check 2024-05-31 15:13:59 -07:00
lua lua: add flex array field to TString type 2024-09-30 10:30:03 -07:00
nvpair xdr: header cleanup 2024-04-03 15:13:27 -07:00
os vdev_disk: move abd return and free off the interrupt handler 2024-11-01 09:49:23 -07:00
unicode Illumos #15286: do_composition() needs sign awareness 2023-01-05 11:16:21 -08:00
zcommon Always validate checksums for Direct I/O reads 2024-10-09 13:45:06 -07:00
zfs Reduce dirty records memory usage 2024-11-04 16:46:39 -08:00
zstd compress: change zio_compress API to use ABDs 2024-08-22 16:22:24 -07:00
.gitignore FreeBSD: Ignore symlink to i386 includes 2022-08-02 16:34:23 -07:00
Kbuild.in Add SIMD metadata in /proc on Linux 2024-09-20 08:16:44 -07:00
Makefile.bsd zfs_znode: lift common code to a single shared file 2024-09-19 15:49:45 -07:00
Makefile.in check-zstd-symbols: also ignore __pfx_ symbols 2023-09-18 09:08:41 -07:00