mirror_zfs/module/zfs
Brian Behlendorf bb29f1eb38 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
2022-05-06 12:02:45 -07:00
..
abd.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
aggsum.c More aggsum optimizations 2021-06-09 13:05:34 -07:00
arc.c module/zfs: arc: arc_hdr_realloc_crypt: remove unused variables 2022-05-02 15:42:58 -07:00
blkptr.c Add zstd support to zfs 2020-08-20 10:30:06 -07:00
bplist.c Fast Clone Deletion 2019-07-26 10:54:14 -07:00
bpobj.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
bptree.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
bqueue.c Implement Redacted Send/Receive 2019-06-19 09:48:12 -07:00
btree.c Fix typo in btree.c 2020-08-17 15:25:37 -07:00
dataset_kstats.c Introduce write-mostly sums 2021-06-09 13:05:34 -07:00
dbuf_stats.c Reduce dbuf_find() lock contention 2022-05-06 12:02:45 -07:00
dbuf.c Reduce dbuf_find() lock contention 2022-05-06 12:02:45 -07:00
ddt_zap.c Refactor dnode dirty context from dbuf_dirty 2020-02-26 16:09:17 -08:00
ddt.c Tinker with slop space accounting with dedup 2021-09-14 12:38:05 -07:00
dmu_diff.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
dmu_object.c Introduce CPU_SEQID_UNSTABLE 2020-11-02 11:51:12 -08:00
dmu_objset.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
dmu_recv.c Receive checks should allow unencrypted child datasets 2022-02-16 17:58:55 -08:00
dmu_redact.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
dmu_send.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
dmu_traverse.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
dmu_tx.c Annotated dprintf as printf-like 2021-06-24 13:12:36 -07:00
dmu_zfetch.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
dmu.c Default to zfs_dmu_offset_next_sync=1 2022-04-01 09:59:47 -07:00
dnode_sync.c Report dnodes with faulty bonuslen 2022-02-16 17:58:55 -08:00
dnode.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
dsl_bookmark.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
dsl_crypt.c Introduce a flag to skip comparing the local mac when raw sending 2022-02-04 16:14:56 -08:00
dsl_dataset.c Remove unneeded "extern inline" function declarations 2022-02-16 17:58:56 -08:00
dsl_deadlist.c Livelist logic should handle dedup blkptrs 2021-06-09 13:05:34 -07:00
dsl_deleg.c Reduce loaded range tree memory usage 2019-10-09 10:36:03 -07:00
dsl_destroy.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
dsl_dir.c Fix ENOSPC when unlinking multiple files from full pool 2022-03-08 11:46:03 -08:00
dsl_pool.c Fix ENOSPC when unlinking multiple files from full pool 2022-03-08 11:46:03 -08:00
dsl_prop.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
dsl_scan.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
dsl_synctask.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
dsl_userhold.c Replace sprintf()->snprintf() and strcpy()->strlcpy() 2020-06-07 11:42:12 -07:00
edonr_zfs.c Add include files for prototypes 2020-06-18 12:21:25 -07:00
fm.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
gzip.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
hkdf.c Encryption patch follow-up 2017-10-11 16:54:48 -04:00
lz4.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
lzjb.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
Makefile.in Distributed Spare (dRAID) Feature 2020-11-13 13:51:51 -08:00
metaslab.c Skip spacemaps reading in case of pool readonly import 2022-04-28 16:47:12 -07:00
mmp.c Optimize small random numbers generation 2021-09-14 12:10:17 -07:00
multilist.c Optimize small random numbers generation 2021-09-14 12:10:17 -07:00
objlist.c Implement Redacted Send/Receive 2019-06-19 09:48:12 -07:00
pathname.c Replace ZFS on Linux references with OpenZFS 2020-10-08 20:10:13 -07:00
range_tree.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
refcount.c Export minimal zfs_refcount interfaces 2022-04-06 10:29:00 -07:00
rrwlock.c Rename refcount.h to zfs_refcount.h 2020-07-29 16:35:33 -07:00
sa.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
sha256.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
skein_zfs.c Add include files for prototypes 2020-06-18 12:21:25 -07:00
spa_boot.c Add include files for prototypes 2020-06-18 12:21:25 -07:00
spa_checkpoint.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
spa_config.c Cleaning up uio headers 2021-02-20 20:16:50 -08:00
spa_errlog.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
spa_history.c Annotated dprintf as printf-like 2021-06-24 13:12:36 -07:00
spa_log_spacemap.c Balance parentheses in parameter descriptions 2021-04-14 13:23:07 -07:00
spa_misc.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
spa_stats.c Remove pool io kstats 2021-06-10 10:50:16 -07:00
spa.c Skip spacemaps reading in case of pool readonly import 2022-04-28 16:47:12 -07:00
space_map.c Optimize small random numbers generation 2021-09-14 12:10:17 -07:00
space_reftree.c Reduce loaded range tree memory usage 2019-10-09 10:36:03 -07:00
THIRDPARTYLICENSE.cityhash OpenZFS 8484 - Implement aggregate sum and use for arc counters 2018-06-06 09:35:59 -07:00
THIRDPARTYLICENSE.cityhash.descrip OpenZFS 8484 - Implement aggregate sum and use for arc counters 2018-06-06 09:35:59 -07:00
txg.c Annotated dprintf as printf-like 2021-06-24 13:12:36 -07:00
uberblock.c MMP interval and fail_intervals in uberblock 2019-03-21 12:47:57 -07:00
unique.c Reduce loaded range tree memory usage 2019-10-09 10:36:03 -07:00
vdev_cache.c Replace ASSERTV macro with compiler annotation 2019-12-05 12:37:00 -08:00
vdev_draid_rand.c Distributed Spare (dRAID) Feature 2020-11-13 13:51:51 -08:00
vdev_draid.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
vdev_indirect_births.c Fixes: #8934 Large kmem_alloc 2019-07-10 15:54:49 -07:00
vdev_indirect_mapping.c Replace ASSERTV macro with compiler annotation 2019-12-05 12:37:00 -08:00
vdev_indirect.c module/zfs: vdev_indirect: vdev_indirect_repair: remove unused variable 2022-05-02 15:42:58 -07:00
vdev_initialize.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
vdev_label.c Use fallthrough macro 2021-11-02 09:50:30 -07:00
vdev_mirror.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
vdev_missing.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
vdev_queue.c Avoid vq_lock drop in vdev_queue_aggregate() 2021-09-14 14:31:22 -07:00
vdev_raidz_math_aarch64_neon_common.h FreeBSD: fix the build with Clang 11 2020-08-17 15:40:17 -07:00
vdev_raidz_math_aarch64_neon.c Linux 5.0 compat: SIMD compatibility 2019-07-12 09:31:20 -07:00
vdev_raidz_math_aarch64_neonx2.c Linux 5.0 compat: SIMD compatibility 2019-07-12 09:31:20 -07:00
vdev_raidz_math_avx2.c FreeBSD: fix the build with Clang 11 2020-08-17 15:40:17 -07:00
vdev_raidz_math_avx512bw.c Refactor ccompile.h to not include system headers 2020-07-25 20:09:50 -07:00
vdev_raidz_math_avx512f.c FreeBSD: fix the build with Clang 11 2020-08-17 15:40:17 -07:00
vdev_raidz_math_impl.h Distributed Spare (dRAID) Feature 2020-11-13 13:51:51 -08:00
vdev_raidz_math_powerpc_altivec_common.h FreeBSD: fix the build with Clang 11 2020-08-17 15:40:17 -07:00
vdev_raidz_math_powerpc_altivec.c Prefix zfs internal endian checks with _ZFS 2020-07-28 13:02:49 -07:00
vdev_raidz_math_scalar.c Use fallthrough macro 2021-11-02 09:50:30 -07:00
vdev_raidz_math_sse2.c FreeBSD: fix the build with Clang 11 2020-08-17 15:40:17 -07:00
vdev_raidz_math_ssse3.c Refactor ccompile.h to not include system headers 2020-07-25 20:09:50 -07:00
vdev_raidz_math.c Initialize parity blocks before RAID-Z reconstruction benchmarking 2021-09-14 14:32:16 -07:00
vdev_raidz.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
vdev_rebuild.c Use dsl_scan_setup_check() to setup a scrub 2021-04-14 13:19:49 -07:00
vdev_removal.c module/zfs: vdev_removal: spa_vdev_remove_thread: remove unused variable 2022-05-02 15:42:58 -07:00
vdev_root.c Distributed Spare (dRAID) Feature 2020-11-13 13:51:51 -08:00
vdev_trim.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
vdev.c Skip spacemaps reading in case of pool readonly import 2022-04-28 16:47:12 -07:00
zap_leaf.c Remove unneeded "extern inline" function declarations 2022-02-16 17:58:56 -08:00
zap_micro.c Remove unneeded "extern inline" function declarations 2022-02-16 17:58:56 -08:00
zap.c Remove unneeded "extern inline" function declarations 2022-02-16 17:58:56 -08:00
zcp_get.c Add include files for prototypes 2020-06-18 12:21:25 -07:00
zcp_global.c OpenZFS 8600 - ZFS channel programs - snapshot 2018-02-08 15:29:24 -08:00
zcp_iter.c Fix typos in module/zfs/ 2019-09-02 17:56:41 -07:00
zcp_set.c Support setting user properties in a channel program 2020-02-14 13:41:42 -08:00
zcp_synctask.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
zcp.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
zfeature.c Throw const on some strings 2020-10-02 17:44:10 -07:00
zfs_byteswap.c Mark functions as static 2020-06-18 12:20:38 -07:00
zfs_fm.c fm: remove unused variables 2022-05-02 15:42:58 -07:00
zfs_fuid.c Fix regression in POSIX mode behavior 2021-03-19 22:50:46 -07:00
zfs_ioctl.c file reference counts can get corrupted 2021-09-14 12:37:38 -07:00
zfs_log.c Initialize all fields in zfs_log_xvattr() 2021-09-14 12:42:21 -07:00
zfs_onexit.c file reference counts can get corrupted 2021-09-14 12:37:38 -07:00
zfs_quota.c File incorrectly zeroed when receiving incremental stream that toggles -L 2020-06-09 10:41:01 -07:00
zfs_ratelimit.c Change checksum & IO delay ratelimit values 2018-03-04 17:34:51 -08:00
zfs_replay.c Use fallthrough macro 2021-11-02 09:50:30 -07:00
zfs_rlock.c Add a "try" operation for range locks 2020-07-06 11:53:31 -07:00
zfs_sa.c Extending FreeBSD UIO Struct 2021-01-20 21:27:30 -08:00
zfs_vnops.c Fix clearing set-uid and set-gid bits on a file when replying a write 2022-02-16 17:58:55 -08:00
zil.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
zio_checksum.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
zio_compress.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
zio_inject.c Optimize small random numbers generation 2021-09-14 12:10:17 -07:00
zio.c Enable encrypted raw sending to pools with greater ashift 2022-02-23 16:47:37 -08:00
zle.c Add include files for prototypes 2020-06-18 12:21:25 -07:00
zrlock.c Remove dead code 2020-06-18 12:21:18 -07:00
zthr.c Avoid memory allocations in the ARC eviction thread 2022-02-03 15:30:52 -08:00
zvol.c zvol: remove unused variable 2022-05-02 15:42:58 -07:00