mirror_zfs/module/zfs
Tony Nguyen 64b6c47d90 dbuf_hold_impl() cleanup to improve cached read performance
Currently every dbuf_hold_impl() incurs kmem_alloc() and kmem_free()
which can be costly for cached read performance.

This change reverts the dbuf_hold_impl() fix stack commit, i.e.
fc5bb51f08 to eliminate the extra
kmem_alloc() and kmem_free() operations and improve cached read
performance. With the change, each dbuf_hold_impl() frame uses 40 bytes
more, total of 800 for 20 recursive levels. Linux kernel stack sizes are
8K and 16K for 32bit and 64bit, respectively, so stack overrun risk is
limited.

Sample stack output comparisons with 50 PB file and recordsize=512
Current code
 11)     2240      64   arc_alloc_buf+0x4a/0xd0 [zfs]
 12)     2176     264   dbuf_read_impl.constprop.16+0x2e3/0x7f0 [zfs]
 13)     1912     120   dbuf_read+0xe5/0x520 [zfs]
 14)     1792      56   dbuf_hold_impl_arg+0x572/0x630 [zfs]
 15)     1736      64   dbuf_hold_impl_arg+0x508/0x630 [zfs]
 16)     1672      64   dbuf_hold_impl_arg+0x508/0x630 [zfs]
 17)     1608      40   dbuf_hold_impl+0x23/0x40 [zfs]
 18)     1568      40   dbuf_hold_level+0x32/0x60 [zfs]
 19)     1528      16   dbuf_hold+0x16/0x20 [zfs]

dbuf_hold_impl() cleanup
 11)     2320      64   arc_alloc_buf+0x4a/0xd0 [zfs]
 12)     2256     264   dbuf_read_impl.constprop.17+0x2e3/0x7f0 [zfs]
 13)     1992     120   dbuf_read+0xe5/0x520 [zfs]
 14)     1872      96   dbuf_hold_impl+0x50f/0x5e0 [zfs]
 15)     1776     104   dbuf_hold_impl+0x4df/0x5e0 [zfs]
 16)     1672     104   dbuf_hold_impl+0x4df/0x5e0 [zfs]
 17)     1568      40   dbuf_hold_level+0x32/0x60 [zfs]
 18)     1528      16   dbuf_hold+0x16/0x20 [zfs]

Performance observations on 8K recordsize filesystem:
- 8/128/1024K at 1-128 sequential cached read, ~3% improvement

Testing done on Ubuntu 18.04 with 4.15 kernel, 8vCPUs and SSD storage on
VMware ESX.

Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Nguyen <tony.nguyen@delphix.com>
Closes #9351
2019-10-03 15:33:38 -07:00
..
aggsum.c OpenZFS 9688 - aggsum_fini leaks memory 2018-10-19 12:08:03 -07:00
arc.c OpenZFS restructuring - arc_stats 2019-10-01 16:35:05 -07:00
blkptr.c Undo c89 workarounds to match with upstream 2017-11-04 13:25:13 -07:00
bplist.c Fast Clone Deletion 2019-07-26 10:54:14 -07:00
bpobj.c Add subcommand to wait for background zfs activity to complete 2019-09-13 18:09:06 -07:00
bptree.c Implement Redacted Send/Receive 2019-06-19 09:48:12 -07:00
bqueue.c Implement Redacted Send/Receive 2019-06-19 09:48:12 -07:00
cityhash.c OpenZFS 8484 - Implement aggregate sum and use for arc counters 2018-06-06 09:35:59 -07:00
dataset_kstats.c Fix panic on DilOS with kstat per dataset statistics 2019-09-03 12:12:31 -07:00
dbuf_stats.c Make module tunables cross platform 2019-09-05 14:49:49 -07:00
dbuf.c dbuf_hold_impl() cleanup to improve cached read performance 2019-10-03 15:33:38 -07:00
ddt_zap.c fat zap should prefetch when iterating 2019-06-12 13:13:09 -07:00
ddt.c Make module tunables cross platform 2019-09-05 14:49:49 -07:00
dmu_diff.c diff_cb() does not handle large dnodes 2019-09-24 12:01:37 -07:00
dmu_object.c Make module tunables cross platform 2019-09-05 14:49:49 -07:00
dmu_objset.c OpenZFS restructuring - zvol 2019-09-25 09:20:30 -07:00
dmu_recv.c Enable compiler to typecheck logging 2019-09-12 13:28:26 -07:00
dmu_redact.c Move objnode handling to common code 2019-09-12 13:31:09 -07:00
dmu_send.c Make module tunables cross platform 2019-09-05 14:49:49 -07:00
dmu_traverse.c Make module tunables cross platform 2019-09-05 14:49:49 -07:00
dmu_tx.c OpenZFS restructuring - move linux tracing code to platform directories 2019-09-11 14:25:53 -07:00
dmu_zfetch.c Make module tunables cross platform 2019-09-05 14:49:49 -07:00
dmu.c OpenZFS restructuring - move linux tracing code to platform directories 2019-09-11 14:25:53 -07:00
dnode_sync.c Decrease contention on dn_struct_rwlock 2019-07-08 13:18:50 -07:00
dnode.c OpenZFS restructuring - move linux tracing code to platform directories 2019-09-11 14:25:53 -07:00
dsl_bookmark.c Fix typos in module/zfs/ 2019-09-02 17:56:41 -07:00
dsl_crypt.c Fix clone handling with encryption roots 2019-09-16 10:07:33 -07:00
dsl_dataset.c Enable compiler to typecheck logging 2019-09-12 13:28:26 -07:00
dsl_deadlist.c Make module tunables cross platform 2019-09-05 14:49:49 -07:00
dsl_deleg.c Update build system and packaging 2018-05-29 16:00:33 -07:00
dsl_destroy.c Enable compiler to typecheck logging 2019-09-12 13:28:26 -07:00
dsl_dir.c Fix typos in module/zfs/ 2019-09-02 17:56:41 -07:00
dsl_pool.c OpenZFS restructuring - move linux tracing code to platform directories 2019-09-11 14:25:53 -07:00
dsl_prop.c Update build system and packaging 2018-05-29 16:00:33 -07:00
dsl_scan.c Disabled resilver_defer feature leads to looping resilvers 2019-09-22 15:25:39 -07:00
dsl_synctask.c Fix typos in module/zfs/ 2019-09-02 17:56:41 -07:00
dsl_userhold.c Enable compiler to typecheck logging 2019-09-12 13:28:26 -07:00
edonr_zfs.c DLPX-44812 integrate EP-220 large memory scalability 2016-11-29 14:34:27 -08:00
fm.c Fix typos in module/zfs/ 2019-09-02 17:56:41 -07:00
gzip.c OpenZFS restructuring - move platform specific sources 2019-09-06 11:26:26 -07:00
hkdf.c Encryption patch follow-up 2017-10-11 16:54:48 -04:00
lz4.c Enable clang to use intrinsics for lz4 2019-10-01 13:17:32 -07:00
lzjb.c Change KM_PUSHPAGE -> KM_SLEEP 2015-01-16 14:41:26 -08:00
Makefile.in OpenZFS restructuring - move linux tracing code to platform directories 2019-09-11 14:25:53 -07:00
metaslab.c Make module tunables cross platform 2019-09-05 14:49:49 -07:00
mmp.c Make module tunables cross platform 2019-09-05 14:49:49 -07:00
multilist.c OpenZFS restructuring - move linux tracing code to platform directories 2019-09-11 14:25:53 -07:00
objlist.c Implement Redacted Send/Receive 2019-06-19 09:48:12 -07:00
pathname.c Disable unused pathname::pn_path* (unneeded in Linux) 2019-07-15 13:57:56 -07:00
range_tree.c Metaslab max_size should be persisted while unloaded 2019-08-05 14:34:27 -07:00
refcount.c Prevent race in blkptr_verify against device removal 2019-08-13 21:24:43 -06:00
rrwlock.c OpenZFS restructuring - move linux tracing code to platform directories 2019-09-11 14:25:53 -07:00
sa.c Add inode accessors to common code 2019-10-02 09:15:12 -07:00
sha256.c OpenZFS restructuring - move platform specific sources 2019-09-06 11:26:26 -07:00
skein_zfs.c DLPX-44812 integrate EP-220 large memory scalability 2016-11-29 14:34:27 -08:00
spa_boot.c Add linux kernel module support 2010-08-31 13:41:58 -07:00
spa_checkpoint.c Add subcommand to wait for background zfs activity to complete 2019-09-13 18:09:06 -07:00
spa_config.c Fix /etc/hostid on root pool deadlock 2019-09-10 13:42:30 -07:00
spa_errlog.c Fix typos in module/zfs/ 2019-09-02 17:56:41 -07:00
spa_history.c Fix typos in module/zfs/ 2019-09-02 17:56:41 -07:00
spa_log_spacemap.c Make module tunables cross platform 2019-09-05 14:49:49 -07:00
spa_misc.c Add subcommand to wait for background zfs activity to complete 2019-09-13 18:09:06 -07:00
spa.c Prevent gcc -Werror=maybe-uninitialized warnings in spa_wait_common() 2019-09-16 10:46:02 -07:00
space_map.c Log Spacemap Project 2019-07-16 10:11:49 -07:00
space_reftree.c OpenZFS 7614, 9064 - zfs device evacuation/removal 2018-04-14 12:16:17 -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 OpenZFS restructuring - move linux tracing code to platform directories 2019-09-11 14:25:53 -07:00
uberblock.c MMP interval and fail_intervals in uberblock 2019-03-21 12:47:57 -07:00
unique.c Performance optimization of AVL tree comparator functions 2016-08-31 14:35:34 -07:00
vdev_cache.c Make module tunables cross platform 2019-09-05 14:49:49 -07:00
vdev_indirect_births.c Fixes: #8934 Large kmem_alloc 2019-07-10 15:54:49 -07:00
vdev_indirect_mapping.c Get rid of space_map_update() for ms_synced_length 2019-02-12 10:38:11 -08:00
vdev_indirect.c Make module tunables cross platform 2019-09-05 14:49:49 -07:00
vdev_initialize.c Add subcommand to wait for background zfs activity to complete 2019-09-13 18:09:06 -07:00
vdev_label.c panic in removal_remap test on 4K devices 2019-06-13 13:12:39 -07:00
vdev_mirror.c Make module tunables cross platform 2019-09-05 14:49:49 -07:00
vdev_missing.c Update vdev_ops_t from illumos 2019-06-20 18:29:02 -07:00
vdev_queue.c Make module tunables cross platform 2019-09-05 14:49:49 -07:00
vdev_raidz_math_aarch64_neon_common.h OpenZFS restructuring - move platform specific headers 2019-09-05 09:34:54 -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 OpenZFS restructuring - move platform specific headers 2019-09-05 09:34:54 -07:00
vdev_raidz_math_avx512bw.c OpenZFS restructuring - move platform specific headers 2019-09-05 09:34:54 -07:00
vdev_raidz_math_avx512f.c OpenZFS restructuring - move platform specific headers 2019-09-05 09:34:54 -07:00
vdev_raidz_math_impl.h codebase style improvements for OpenZFS 6459 port 2017-01-22 13:25:40 -08:00
vdev_raidz_math_scalar.c Linux 5.3: Fix switch() fall though compiler errors 2019-08-21 09:29:23 -07:00
vdev_raidz_math_sse2.c OpenZFS restructuring - move platform specific headers 2019-09-05 09:34:54 -07:00
vdev_raidz_math_ssse3.c OpenZFS restructuring - move platform specific headers 2019-09-05 09:34:54 -07:00
vdev_raidz_math.c Make module tunables cross platform 2019-09-05 14:49:49 -07:00
vdev_raidz.c Fix typos in module/zfs/ 2019-09-02 17:56:41 -07:00
vdev_removal.c Device removal of indirect vdev panics the kernel 2019-09-16 10:46:59 -07:00
vdev_root.c Update vdev_ops_t from illumos 2019-06-20 18:29:02 -07:00
vdev_trim.c Make module tunables cross platform 2019-09-05 14:49:49 -07:00
vdev.c Add subcommand to wait for background zfs activity to complete 2019-09-13 18:09:06 -07:00
zap_leaf.c Off-by-one in zap_leaf_array_create() 2019-01-18 09:58:46 -08:00
zap_micro.c fat zap should prefetch when iterating 2019-06-12 13:13:09 -07:00
zap.c Make module tunables cross platform 2019-09-05 14:49:49 -07:00
zcp_get.c Fix typos in module/zfs/ 2019-09-02 17:56:41 -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_synctask.c OpenZFS 9166 - zfs storage pool checkpoint 2018-06-26 10:07:42 -07:00
zcp.c Make module tunables cross platform 2019-09-05 14:49:49 -07:00
zfeature.c Consistently captialize GUID for features 2019-04-16 10:01:51 -07:00
zfs_byteswap.c Fix typos in module/zfs/ 2019-09-02 17:56:41 -07:00
zfs_fm.c Add zpool status -s (slow I/Os) and -p (parseable) 2018-11-08 16:47:24 -08:00
zfs_fuid.c Add inode accessors to common code 2019-10-02 09:15:12 -07:00
zfs_ioctl.c OpenZFS restructuring - zfs_ioctl 2019-09-27 10:46:28 -07:00
zfs_log.c Add inode accessors to common code 2019-10-02 09:15:12 -07:00
zfs_onexit.c Update build system and packaging 2018-05-29 16:00:33 -07:00
zfs_ratelimit.c Change checksum & IO delay ratelimit values 2018-03-04 17:34:51 -08:00
zfs_replay.c Fix zil replay panic when TX_REMOVE followed by TX_CREATE 2019-08-28 10:42:02 -07:00
zfs_rlock.c OpenZFS 9689 - zfs range lock code should not be zpl-specific 2018-10-11 10:19:33 -07:00
zfs_sa.c Add inode accessors to common code 2019-10-02 09:15:12 -07:00
zil.c OpenZFS restructuring - move linux tracing code to platform directories 2019-09-11 14:25:53 -07:00
zio_checksum.c Fix typos in module/zfs/ 2019-09-02 17:56:41 -07:00
zio_compress.c Fix typos in module/zfs/ 2019-09-02 17:56:41 -07:00
zio_inject.c Fix typos in module/zfs/ 2019-09-02 17:56:41 -07:00
zio.c OpenZFS restructuring - move linux tracing code to platform directories 2019-09-11 14:25:53 -07:00
zle.c Fix zle_decompress out of bound access 2018-02-09 10:08:05 -08:00
zrlock.c OpenZFS restructuring - move linux tracing code to platform directories 2019-09-11 14:25:53 -07:00
zthr.c Fast Clone Deletion 2019-07-26 10:54:14 -07:00
zvol.c Timeout waiting for ZVOL device to be created 2019-10-01 12:33:12 -07:00