mirror_zfs/module/zfs
Matthew Ahrens ba67d82142
Improve zfs receive performance with lightweight write
The performance of `zfs receive` can be bottlenecked on the CPU consumed
by the `receive_writer` thread, especially when receiving streams with
small compressed block sizes.  Much of the CPU is spent creating and
destroying dbuf's and arc buf's, one for each `WRITE` record in the send
stream.

This commit introduces the concept of "lightweight writes", which allows
`zfs receive` to write to the DMU by providing an ABD, and instantiating
only a new type of `dbuf_dirty_record_t`.  The dbuf and arc buf for this
"dirty leaf block" are not instantiated.

Because there is no dbuf with the dirty data, this mechanism doesn't
support reading from "lightweight-dirty" blocks (they would see the
on-disk state rather than the dirty data).  Since the dedup-receive code
has been removed, `zfs receive` is write-only, so this works fine.

Because there are no arc bufs for the received data, the received data
is no longer cached in the ARC.

Testing a receive of a stream with average compressed block size of 4KB,
this commit improves performance by 50%, while also reducing CPU usage
by 50% of a CPU.  On a per-block basis, CPU consumed by receive_writer()
and dbuf_evict() is now 1/7th (14%) of what it was.

Baseline: 450MB/s, CPU in receive_writer() 40% + dbuf_evict() 35%
New: 670MB/s, CPU in receive_writer() 17% + dbuf_evict() 0%

The code is also restructured in a few ways:

Added a `dr_dnode` field to the dbuf_dirty_record_t.  This simplifies
some existing code that no longer needs `DB_DNODE_ENTER()` and related
routines.  The new field is needed by the lightweight-type dirty record.

To ensure that the `dr_dnode` field remains valid until the dirty record
is freed, we have to ensure that the `dnode_move()` doesn't relocate the
dnode_t.  To do this we keep a hold on the dnode until it's zio's have
completed.  This is already done by the user-accounting code
(`userquota_updates_task()`), this commit extends that so that it always
keeps the dnode hold until zio completion (see `dnode_rele_task()`).

`dn_dirty_txg` was previously zeroed when the dnode was synced.  This
was not necessary, since its meaning can be "when was this dnode last
dirtied".  This change simplifies the new `dnode_rele_task()` code.

Removed some dead code related to `DRR_WRITE_BYREF` (dedup receive).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: George Wilson <gwilson@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #11105
2020-12-11 10:26:02 -08:00
..
abd.c Distributed Spare (dRAID) Feature 2020-11-13 13:51:51 -08:00
aggsum.c Implement memory and CPU hotplug 2020-12-10 14:09:23 -08:00
arc.c Implement memory and CPU hotplug 2020-12-10 14:09:23 -08:00
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 Rename refcount.h to zfs_refcount.h 2020-07-29 16:35:33 -07:00
bptree.c Rename refcount.h to zfs_refcount.h 2020-07-29 16:35:33 -07:00
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 Fix panic on DilOS with kstat per dataset statistics 2019-09-03 12:12:31 -07:00
dbuf_stats.c Eliminate gratuitous bzeroing in dbuf_stats_hash_table_data 2020-09-30 13:24:38 -07:00
dbuf.c Improve zfs receive performance with lightweight write 2020-12-11 10:26:02 -08:00
ddt_zap.c Refactor dnode dirty context from dbuf_dirty 2020-02-26 16:09:17 -08:00
ddt.c Remove dead code 2020-06-18 12:21:18 -07:00
dmu_diff.c Mark write_record static 2019-12-03 09:51:44 -08:00
dmu_object.c Introduce CPU_SEQID_UNSTABLE 2020-11-02 11:51:12 -08:00
dmu_objset.c Improve zfs receive performance with lightweight write 2020-12-11 10:26:02 -08:00
dmu_recv.c Improve zfs receive performance with lightweight write 2020-12-11 10:26:02 -08:00
dmu_redact.c Fix dnode refcount tracking 2020-11-10 10:37:10 -08:00
dmu_send.c Drop references when skipping dmu_send due to EXDEV 2020-09-30 13:19:49 -07:00
dmu_traverse.c zil_parse: make callback parameters const 2020-10-09 09:34:54 -07:00
dmu_tx.c Refactor dnode dirty context from dbuf_dirty 2020-02-26 16:09:17 -08:00
dmu_zfetch.c dmu_zfetch: don't leak unreferenced stream when zfetch is freed 2020-10-13 21:03:36 -07:00
dmu.c Improve zfs receive performance with lightweight write 2020-12-11 10:26:02 -08:00
dnode_sync.c Improve zfs receive performance with lightweight write 2020-12-11 10:26:02 -08:00
dnode.c Improve zfs receive performance with lightweight write 2020-12-11 10:26:02 -08:00
dsl_bookmark.c Fix kernel panic induced by redacted send 2020-12-11 10:22:29 -08:00
dsl_crypt.c Fix raw sends on encrypted datasets when copying back snapshots 2020-12-04 14:34:29 -08:00
dsl_dataset.c Improve zfs receive performance with lightweight write 2020-12-11 10:26:02 -08:00
dsl_deadlist.c Fix i/o error handling of livelists and zap iteration 2020-08-05 10:22:09 -07:00
dsl_deleg.c Reduce loaded range tree memory usage 2019-10-09 10:36:03 -07:00
dsl_destroy.c Fix i/o error handling of livelists and zap iteration 2020-08-05 10:22:09 -07:00
dsl_dir.c Add 'zfs rename -u' to rename without remounting 2020-09-01 16:14:16 -07:00
dsl_pool.c Improve zfs receive performance with lightweight write 2020-12-11 10:26:02 -08:00
dsl_prop.c Replace sprintf()->snprintf() and strcpy()->strlcpy() 2020-06-07 11:42:12 -07:00
dsl_scan.c Distributed Spare (dRAID) Feature 2020-11-13 13:51:51 -08:00
dsl_synctask.c nowait synctask must succeed 2020-09-04 10:29:39 -07:00
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 Avoid posting duplicate zpool events 2020-09-04 10:34:28 -07:00
gzip.c Add include files for prototypes 2020-06-18 12:21:25 -07:00
hkdf.c Encryption patch follow-up 2017-10-11 16:54:48 -04:00
lz4.c Prefix zfs internal endian checks with _ZFS 2020-07-28 13:02:49 -07:00
lzjb.c Add include files for prototypes 2020-06-18 12:21:25 -07:00
Makefile.in Distributed Spare (dRAID) Feature 2020-11-13 13:51:51 -08:00
metaslab.c Distributed Spare (dRAID) Feature 2020-11-13 13:51:51 -08:00
mmp.c Distributed Spare (dRAID) Feature 2020-11-13 13:51:51 -08:00
multilist.c Implement memory and CPU hotplug 2020-12-10 14:09:23 -08:00
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 Fix incorrect deletion order in range_tree_add_impl gap case 2020-10-14 08:59:54 -07:00
refcount.c Rename refcount.h to zfs_refcount.h 2020-07-29 16:35:33 -07:00
rrwlock.c Rename refcount.h to zfs_refcount.h 2020-07-29 16:35:33 -07:00
sa.c Remove duplicate dnode.h include 2020-08-26 21:41:09 -07:00
sha256.c Add include files for prototypes 2020-06-18 12:21:25 -07:00
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 Refactor dnode dirty context from dbuf_dirty 2020-02-26 16:09:17 -08:00
spa_config.c vdev_ashift should only be set once 2020-09-18 12:13:47 -07:00
spa_errlog.c Fix typos in module/zfs/ 2019-09-02 17:56:41 -07:00
spa_history.c Update references to nonexistent man pages in code 2020-10-30 08:55:59 -07:00
spa_log_spacemap.c Make module tunables cross platform 2019-09-05 14:49:49 -07:00
spa_misc.c Distributed Spare (dRAID) Feature 2020-11-13 13:51:51 -08:00
spa_stats.c FreeBSD: Add support for procfs_list 2020-09-23 16:43:51 -07:00
spa.c Implement memory and CPU hotplug 2020-12-10 14:09:23 -08:00
space_map.c Rename refcount.h to zfs_refcount.h 2020-07-29 16:35:33 -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 Implement memory and CPU hotplug 2020-12-10 14:09:23 -08:00
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 Distributed Spare (dRAID) Feature 2020-11-13 13:51:51 -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 Distributed Spare (dRAID) Feature 2020-11-13 13:51:51 -08:00
vdev_initialize.c Distributed Spare (dRAID) Feature 2020-11-13 13:51:51 -08:00
vdev_label.c Distributed Spare (dRAID) Feature 2020-11-13 13:51:51 -08:00
vdev_mirror.c Distributed Spare (dRAID) Feature 2020-11-13 13:51:51 -08:00
vdev_missing.c Distributed Spare (dRAID) Feature 2020-11-13 13:51:51 -08:00
vdev_queue.c Avoid some spa_has_pending_synctask() calls. 2020-12-06 09:55:02 -08:00
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 Linux 5.3: Fix switch() fall though compiler errors 2019-08-21 09:29:23 -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 Reduce fletcher4 and raidz benchmark times 2020-12-06 09:57:20 -08:00
vdev_raidz.c Distributed Spare (dRAID) Feature 2020-11-13 13:51:51 -08:00
vdev_rebuild.c Distributed Spare (dRAID) Feature 2020-11-13 13:51:51 -08:00
vdev_removal.c Distributed Spare (dRAID) Feature 2020-11-13 13:51:51 -08:00
vdev_root.c Distributed Spare (dRAID) Feature 2020-11-13 13:51:51 -08:00
vdev_trim.c Distributed Spare (dRAID) Feature 2020-11-13 13:51:51 -08:00
vdev.c Correct missing zil_claim() DTL updates 2020-11-20 13:14:45 -08:00
zap_leaf.c Refactor dnode dirty context from dbuf_dirty 2020-02-26 16:09:17 -08:00
zap_micro.c Rename refcount.h to zfs_refcount.h 2020-07-29 16:35:33 -07:00
zap.c Rename refcount.h to zfs_refcount.h 2020-07-29 16:35:33 -07:00
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 filesystem_limit/snapshot_limit is incorrectly enforced against root 2020-07-11 17:18:02 -07:00
zcp.c Channel program may spuriously fail with "memory limit exhausted" 2020-11-11 17:16:15 -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 Distributed Spare (dRAID) Feature 2020-11-13 13:51:51 -08:00
zfs_fuid.c FreeBSD: Fix UNIX permissions checking 2020-08-18 09:57:07 -07:00
zfs_ioctl.c Fix optional "force" arg handing in zfs_ioc_pool_sync() 2020-12-09 14:52:45 -08:00
zfs_log.c Throw const on some strings 2020-10-02 17:44:10 -07:00
zfs_onexit.c Remove deduplicated send/receive code 2020-04-23 10:06:57 -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 Simplify FreeBSD's locking requirements in zfs_replay.c 2020-01-22 17:55:56 -08:00
zfs_rlock.c Add a "try" operation for range locks 2020-07-06 11:53:31 -07:00
zfs_sa.c Add convenience wrappers for common uio usage 2020-06-14 10:09:55 -07:00
zfs_vnops.c Remove incorrect assertion 2020-11-24 09:28:42 -08:00
zil.c zil_parse: make callback parameters const 2020-10-09 09:34:54 -07:00
zio_checksum.c Mark functions as static 2020-06-18 12:20:38 -07:00
zio_compress.c Avoid symbol collision with in-kernel zstdlib 2020-08-24 12:20:41 -07:00
zio_inject.c Distributed Spare (dRAID) Feature 2020-11-13 13:51:51 -08:00
zio.c Distributed Spare (dRAID) Feature 2020-11-13 13:51:51 -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 Retain thread name when resuming a zthr 2020-09-03 20:09:52 -07:00
zvol.c Fix problems in zvol_set_volmode_impl 2020-11-17 09:50:52 -08:00