zfs/include/sys
Brian Behlendorf 34dbc618f5
Reduce dbuf_find() lock contention
Holding a dbuf is a common operation which can become highly contended
in dbuf_find() when acquiring the dbuf hash mutex.  This is particularly
true on Linux when reading/writing volumes since by default up to 32
threads from the zvol_taskq may be taking a hold of the same dbuf.
This should also be observable on FreeBSD as long as there are enough
processes accessing the volume concurrently.

This is further aggregrated by the fact that only the block id will
be unique when calculating the dbuf hash for a single volume.  The
objset id, object id, and level will be the same for data blocks.
This has been observed to result in a somehwat less than uniform hash
distribution and a longer than expected max hash chain depth (~20)
on a large memory system (256 GB) using volumes.

This commit improves the siutation by switching the hash mutex to
an rwlock to allow concurrent lookups, and increasing DBUF_RWLOCKS
from 2048 to 8192 to further reduce the odds of a hash collision.

Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #13405
2022-05-04 11:17:29 -07:00
..
crypto module: icp: remove vestigia of crypto sessions 2022-02-15 16:25:56 -08:00
fm Upstream: Add snapshot and zvol events 2021-09-09 10:44:21 -07:00
fs Add physical device size to SIZE column in 'zpool list -v' 2022-03-08 16:20:41 -08:00
lua Clean up CSTYLEDs 2022-01-26 11:38:52 -08:00
sysevent Avoid installing kernel headers on FreeBSD 2020-06-27 17:40:14 -07:00
zstd Update `checkstyle` workflow env to ubuntu-20.04 2021-11-02 14:02:57 -06:00
Makefile.am Remove NOTE(CONSTCOND) and note.h 2021-07-26 12:07:53 -07:00
abd.h Avoid small buffer copying on write 2021-07-27 16:05:47 -07:00
abd_impl.h Avoid small buffer copying on write 2021-07-27 16:05:47 -07:00
aggsum.h More aggsum optimizations 2021-06-07 09:02:47 -07:00
arc.h include: sys/arc.h: shim out arc_referenced() 2021-12-23 09:36:26 -08:00
arc_impl.h Replace *CTASSERT() with _Static_assert() 2022-01-26 11:38:52 -08:00
avl.h lib{efi,avl,share,tpool,zfs_core,zfsbootenv,zutil}: -fvisibility=hidden 2021-06-09 17:04:32 -07:00
avl_impl.h Remove avl_size field from struct avl_tree 2021-07-01 09:32:31 -06:00
bitops.h Remove NOTE(CONSTCOND) and note.h 2021-07-26 12:07:53 -07:00
blkptr.h OpenZFS 8067 - zdb should be able to dump literal embedded block pointer 2017-07-07 11:28:01 -07:00
bplist.h Fast Clone Deletion 2019-07-26 10:54:14 -07:00
bpobj.h Fast Clone Deletion 2019-07-26 10:54:14 -07:00
bptree.h Illumos 4914 - zfs on-disk bookmark structure should be named *_phys_t 2014-08-06 14:48:41 -07:00
bqueue.h Implement Redacted Send/Receive 2019-06-19 09:48:12 -07:00
btree.h Fix typos 2020-06-09 21:24:09 -07:00
dataset_kstats.h Introduce write-mostly sums 2021-05-27 14:27:29 -06:00
dbuf.h Reduce dbuf_find() lock contention 2022-05-04 11:17:29 -07:00
ddt.h Appease GCC sprintf warnings found on Fedora 32/GCC 10.0.1 2020-08-24 10:32:59 -07:00
dmu.h Improve log spacemap load time 2022-04-26 10:44:21 -07:00
dmu_impl.h Remove UIO_ZEROCOPY functions structures 2020-10-30 10:00:33 -07:00
dmu_objset.h Introduce a tunable to exclude special class buffers from L2ARC 2021-11-11 12:52:16 -08:00
dmu_recv.h module/*.ko: prune .data, global .rodata 2022-01-14 15:37:55 -08:00
dmu_redact.h Suppress cppcheck invalidSyntax warninigs 2021-03-05 17:56:35 -08:00
dmu_send.h Removed duplicated includes 2021-03-22 12:34:58 -07:00
dmu_traverse.h Implement Redacted Send/Receive 2019-06-19 09:48:12 -07:00
dmu_tx.h Add Module Parameter Regarding Log Size Limit 2021-07-20 09:40:24 -06:00
dmu_zfetch.h Split dmu_zfetch() speculation and execution parts 2021-03-19 22:56:11 -07:00
dnode.h Fix lseek(SEEK_DATA/SEEK_HOLE) mmap consistency 2021-11-07 14:27:44 -07:00
dsl_bookmark.h Rename refcount.h to zfs_refcount.h 2020-07-29 16:35:33 -07:00
dsl_crypt.h dmu_objset_from_ds must be called with dp_config_rwlock held 2020-03-12 10:55:02 -07:00
dsl_dataset.h Improve zpool status output, list all affected datasets 2022-04-25 17:25:42 -07:00
dsl_deadlist.h Add fast path for zfs_ioc_space_snaps() handling of empty_bpobj 2019-08-20 11:34:52 -07:00
dsl_deleg.h Remove code for zfs remap 2019-06-24 16:44:01 -07:00
dsl_destroy.h Fast Clone Deletion 2019-07-26 10:54:14 -07:00
dsl_dir.h Remove NOTE(CONSTCOND) and note.h 2021-07-26 12:07:53 -07:00
dsl_pool.h Fix ENOSPC when unlinking multiple files from full pool 2022-03-08 09:16:35 -08:00
dsl_prop.h Support inheriting properties in channel programs 2020-01-22 17:03:17 -08:00
dsl_scan.h Use dsl_scan_setup_check() to setup a scrub 2021-04-08 14:33:15 -07:00
dsl_synctask.h Add upper bound for slop space calculation 2021-02-24 09:52:43 -08:00
dsl_userhold.h Illumos #3740 2013-11-04 11:17:48 -08:00
edonr.h OpenZFS 4185 - add new cryptographic checksums to ZFS: SHA-512, Skein, Edon-R 2016-10-03 14:51:15 -07:00
efi_partition.h Integrate carcass of libspl/i/s/vtoc.h into i/s/efi_partition.h 2022-03-15 15:13:54 -07:00
frame.h Linux 5.10 compat: frame.h renamed objtool.h 2020-11-02 22:01:10 +00:00
hkdf.h Encryption patch follow-up 2017-10-11 16:54:48 -04:00
metaslab.h Improve log spacemap load time 2022-04-26 10:44:21 -07:00
metaslab_impl.h Improve log spacemap load time 2022-04-26 10:44:21 -07:00
mmp.h Add zfs_multihost_interval tunable handler for FreeBSD 2020-06-23 13:32:42 -07:00
mntent.h Add FreeBSD required defines to mntent.h 2019-11-30 15:49:09 -08:00
mod.h linux: module: weld all but spl.ko into zfs.ko 2022-04-20 13:28:24 -07:00
multilist.h Re-embed multilist_t storage 2021-06-10 10:42:31 -06:00
nvpair.h module/*.ko: prune .data, global .rodata 2022-01-14 15:37:55 -08:00
nvpair_impl.h Add `const` to nvlist functions to properly expose their real behavior 2021-12-06 18:19:13 -07:00
objlist.h Implement Redacted Send/Receive 2019-06-19 09:48:12 -07:00
pathname.h Replace ZFS on Linux references with OpenZFS 2020-10-08 20:10:13 -07:00
qat.h include: qat.h: mark unused macro arguments as used 2021-12-23 09:36:21 -08:00
range_tree.h module/*.ko: prune .data, global .rodata 2022-01-14 15:37:55 -08:00
rrwlock.h Rename refcount.h to zfs_refcount.h 2020-07-29 16:35:33 -07:00
sa.h module/*.ko: prune .data, global .rodata 2022-01-14 15:37:55 -08:00
sa_impl.h Rename refcount.h to zfs_refcount.h 2020-07-29 16:35:33 -07:00
skein.h OpenZFS 4185 - add new cryptographic checksums to ZFS: SHA-512, Skein, Edon-R 2016-10-03 14:51:15 -07:00
spa.h Improve zpool status output, list all affected datasets 2022-04-25 17:25:42 -07:00
spa_boot.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
spa_checkpoint.h Serialize ZTHR operations to eliminate races 2019-01-13 10:09:46 -08:00
spa_checksum.h Implementation of AVX2 optimized Fletcher-4 2016-06-02 14:30:51 -07:00
spa_impl.h module/*.ko: prune .data, global .rodata 2022-01-14 15:37:55 -08:00
spa_log_spacemap.h Improve log spacemap load time 2022-04-26 10:44:21 -07:00
space_map.h Extend zdb to print inconsistencies in livelists and metaslabs 2020-07-14 17:51:05 -07:00
space_reftree.h Reduce loaded range tree memory usage 2019-10-09 10:36:03 -07:00
sysevent.h OpenZFS 6939 - add sysevents to zfs core for commands 2017-07-12 21:28:13 -07:00
txg.h Optimize txg_kick() process (#12274) 2021-07-01 09:20:27 -06:00
txg_impl.h Fix typos in include/ 2019-08-30 09:53:15 -07:00
u8_textprep.h Throw const on some strings 2020-10-02 17:44:10 -07:00
u8_textprep_data.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
uberblock.h Multi-modifier protection (MMP) 2017-07-13 13:54:00 -04:00
uberblock_impl.h MMP interval and fail_intervals in uberblock 2019-03-21 12:47:57 -07:00
uio_impl.h Cleaning up uio headers 2021-02-20 20:16:50 -08:00
unique.h Illumos #3742 2013-11-04 10:55:25 -08:00
uuid.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
vdev.h Vdev Properties Feature 2021-11-30 07:46:25 -07:00
vdev_disk.h Make struct vdev_disk_t be platform private 2020-06-16 11:43:33 -07:00
vdev_draid.h Verify dRAID empty sectors 2022-01-04 16:46:32 -08:00
vdev_file.h Add zfs_file_* interface, remove vnodes 2019-11-21 09:32:57 -08:00
vdev_impl.h Replace *CTASSERT() with _Static_assert() 2022-01-26 11:38:52 -08:00
vdev_indirect_births.h OpenZFS 7614, 9064 - zfs device evacuation/removal 2018-04-14 12:16:17 -07:00
vdev_indirect_mapping.h OpenZFS 7614, 9064 - zfs device evacuation/removal 2018-04-14 12:16:17 -07:00
vdev_initialize.h Add TRIM support 2019-03-29 09:13:20 -07:00
vdev_raidz.h Verify dRAID empty sectors 2022-01-04 16:46:32 -08:00
vdev_raidz_impl.h module/*.ko: prune .data, global .rodata 2022-01-14 15:37:55 -08:00
vdev_rebuild.h Fix various typos 2021-04-02 18:52:15 -07:00
vdev_removal.h panic in removal_remap test on 4K devices 2019-06-13 13:12:39 -07:00
vdev_trim.h Trim L2ARC 2020-06-09 10:15:08 -07:00
xvattr.h Forbid b{copy,zero,cmp}(). Don't include <strings.h> for <string.h> 2022-03-15 15:13:48 -07:00
zap.h fat zap should prefetch when iterating 2019-06-12 13:13:09 -07:00
zap_impl.h OpenZFS 7793 - ztest fails assertion in dmu_tx_willuse_space 2017-03-07 09:51:59 -08:00
zap_leaf.h Fix ENOSPC in "Handle zap_add() failures in ..." 2018-04-18 14:19:50 -07:00
zcp.h filesystem_limit/snapshot_limit is incorrectly enforced against root 2020-07-11 17:18:02 -07:00
zcp_global.h OpenZFS 7431 - ZFS Channel Programs 2018-02-08 15:28:18 -08:00
zcp_iter.h OpenZFS 7431 - ZFS Channel Programs 2018-02-08 15:28:18 -08:00
zcp_prop.h OpenZFS 7431 - ZFS Channel Programs 2018-02-08 15:28:18 -08:00
zcp_set.h Support setting user properties in a channel program 2020-02-14 13:41:42 -08:00
zfeature.h Revert "zhack: Add 'feature disable' command" 2016-05-17 11:52:07 -07:00
zfs_acl.h module/*.ko: prune .data, global .rodata 2022-01-14 15:37:55 -08:00
zfs_bootenv.h zfs label bootenv should store data as nvlist 2020-09-15 15:42:27 -07:00
zfs_context.h Switch from _Noreturn to __attribute__((noreturn)) 2022-03-23 08:51:00 -07:00
zfs_debug.h Annotated dprintf as printf-like 2021-06-22 21:53:45 -07:00
zfs_delay.h Update build system and packaging 2018-05-29 16:00:33 -07:00
zfs_file.h file reference counts can get corrupted 2021-07-10 19:00:37 -06:00
zfs_fuid.h Replace sprintf()->snprintf() and strcpy()->strlcpy() 2020-06-07 11:42:12 -07:00
zfs_ioctl.h file reference counts can get corrupted 2021-07-10 19:00:37 -06:00
zfs_ioctl_impl.h module/*.ko: prune .data, global .rodata 2022-01-14 15:37:55 -08:00
zfs_onexit.h file reference counts can get corrupted 2021-07-10 19:00:37 -06:00
zfs_project.h Minor diff reduction with ZoF in include/sys 2019-11-27 11:11:03 -08:00
zfs_quota.h File incorrectly zeroed when receiving incremental stream that toggles -L 2020-06-09 10:41:01 -07:00
zfs_racct.h Restore FreeBSD resource usage accounting 2021-02-19 22:34:33 -08:00
zfs_ratelimit.h Change checksum & IO delay ratelimit values 2018-03-04 17:34:51 -08:00
zfs_refcount.h Correct refcount_add in dmu_zfetch 2021-10-08 11:10:34 -07:00
zfs_rlock.h Add a "try" operation for range locks 2020-07-06 11:53:31 -07:00
zfs_sa.h log xattr=sa create/remove/update to ZIL 2022-02-22 13:06:43 -08:00
zfs_stat.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
zfs_sysfs.h zcommon: pre-iterate over sysfs instead of statting every feature 2021-12-16 16:43:10 -08:00
zfs_vfsops.h Add 'zfs rename -u' to rename without remounting 2020-09-01 16:14:16 -07:00
zfs_vnops.h Extending FreeBSD UIO Struct 2021-01-20 21:27:30 -08:00
zfs_znode.h Speed up WB_SYNC_NONE when a WB_SYNC_ALL occurs simultaneously 2022-05-03 13:23:26 -07:00
zil.h log xattr=sa create/remove/update to ZIL 2022-02-22 13:06:43 -08:00
zil_impl.h make zil max block size tunable 2019-06-10 11:48:42 -07:00
zio.h Improve zpool status output, list all affected datasets 2022-04-25 17:25:42 -07:00
zio_checksum.h libzfs: convert to -fvisibility=hidden 2021-06-03 13:17:55 -07:00
zio_compress.h Add zstd support to zfs 2020-08-20 10:30:06 -07:00
zio_crypt.h module/*.ko: prune .data, global .rodata 2022-01-14 15:37:55 -08:00
zio_impl.h Add zstd support to zfs 2020-08-20 10:30:06 -07:00
zio_priority.h Add device rebuild feature 2020-07-03 11:05:50 -07:00
zrlock.h OpenZFS 6328 - Fix cstyle errors in zfs codebase 2017-01-12 09:42:11 -08:00
zthr.h Avoid memory allocations in the ARC eviction thread 2022-01-21 10:28:13 -08:00
zvol.h Remove unused function zvol_set_volblocksize() 2021-10-26 17:07:53 -07:00
zvol_impl.h zvol: make calls to platform ops static 2022-02-07 10:24:38 -08:00