Matthew Ahrens be5c6d9653 Only examine best metaslabs on each vdev ... On a system with very high fragmentation, we may need to do lots of gang allocations (e.g. most indirect block allocations (~50KB) may need to gang). Before failing a "normal" allocation and resorting to ganging, we try every metaslab. This has the impact of loading every metaslab (not a huge deal since we now typically keep all metaslabs loaded), and also iterating over every metaslab for every failing allocation. If there are many metaslabs (more than the typical ~200, e.g. due to vdev expansion or very large vdevs), the CPU cost of this iteration can be very impactful. This iteration is done with the mg_lock held, creating long hold times and high lock contention for concurrent allocations, ultimately causing long txg sync times and poor application performance. To address this, this commit changes the behavior of "normal" (not try_hard, not ZIL) allocations. These will now only examine the 100 best metaslabs (as determined by their ms_weight). If none of these have a large enough free segment, then the allocation will fail and we'll fall back on ganging. To accomplish this, we will now (normally) gang before doing a `try_hard` allocation. Non-try_hard allocations will only examine the 100 best metaslabs of each vdev. In summary, we will first try normal allocation. If that fails then we will do a gang allocation. If that fails then we will do a "try hard" gang allocation. If that fails then we will have a multi-layer gang block. Reviewed-by: Paul Dagnelie <pcd@delphix.com> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Matthew Ahrens <mahrens@delphix.com> Closes #11327		2020-12-16 14:40:05 -08:00
..
crypto	Avoid installing kernel headers on FreeBSD	2020-06-27 17:40:14 -07:00
fm	Avoid posting duplicate zpool events	2020-09-04 10:34:28 -07:00
fs	Assertion failure when logging large output of channel program	2020-11-14 10:17:16 -08:00
lua	FreeBSD: Reduce stack usage of Lua	2020-09-22 16:03:11 -07:00
sysevent	Avoid installing kernel headers on FreeBSD	2020-06-27 17:40:14 -07:00
zstd	zstd: track allocator statistics	2020-10-30 15:26:10 -07:00
abd_impl.h	Removing ZERO_PAGE abd_alloc_zero_scatter	2020-06-10 17:54:11 -07:00
abd.h	Rename refcount.h to zfs_refcount.h	2020-07-29 16:35:33 -07:00
aggsum.h	Reduce number of atomic_add() calls in aggsum	2020-02-06 13:21:06 -08:00
arc_impl.h	dmu_zfetch: fix memory leak	2020-12-12 16:00:00 -08:00
arc.h	Implement memory and CPU hotplug	2020-12-10 14:09:23 -08:00
avl_impl.h
avl.h	Restore avl_update() calls and related functions	2020-06-03 09:49:32 -07:00
bitops.h
blkptr.h
bplist.h
bpobj.h
bptree.h
bqueue.h
btree.h	Fix typos	2020-06-09 21:24:09 -07:00
dataset_kstats.h
dbuf.h	Improve zfs receive performance with lightweight write	2020-12-11 10:26:02 -08:00
ddt.h	Appease GCC sprintf warnings found on Fedora 32/GCC 10.0.1	2020-08-24 10:32:59 -07:00
dmu_impl.h	Remove UIO_ZEROCOPY functions structures	2020-10-30 10:00:33 -07:00
dmu_objset.h	Improve zfs receive performance with lightweight write	2020-12-11 10:26:02 -08:00
dmu_recv.h	filesystem_limit/snapshot_limit is incorrectly enforced against root	2020-07-11 17:18:02 -07:00
dmu_redact.h
dmu_send.h	Add 'zfs send --saved' flag	2020-01-10 10:16:58 -08:00
dmu_traverse.h
dmu_tx.h	Rename refcount.h to zfs_refcount.h	2020-07-29 16:35:33 -07:00
dmu_zfetch.h	zfetch: Don't issue new streams when old have not completed	2020-09-27 17:08:38 -07:00
dmu.h	Remove UIO_ZEROCOPY functions structures	2020-10-30 10:00:33 -07:00
dnode.h	Rename refcount.h to zfs_refcount.h	2020-07-29 16:35:33 -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	Add zstd support to zfs	2020-08-20 10:30:06 -07:00
dsl_deadlist.h
dsl_deleg.h
dsl_destroy.h
dsl_dir.h	Rename refcount.h to zfs_refcount.h	2020-07-29 16:35:33 -07:00
dsl_pool.h	Eliminate Linux specific inode usage from common code	2019-12-11 11:53:57 -08:00
dsl_prop.h	Support inheriting properties in channel programs	2020-01-22 17:03:17 -08:00
dsl_scan.h	Distributed Spare (dRAID) Feature	2020-11-13 13:51:51 -08:00
dsl_synctask.h	nowait synctask must succeed	2020-09-04 10:29:39 -07:00
dsl_userhold.h
edonr.h
efi_partition.h
frame.h	Linux 5.10 compat: frame.h renamed objtool.h	2020-11-02 22:01:10 +00:00
hkdf.h
Makefile.am	Distributed Spare (dRAID) Feature	2020-11-13 13:51:51 -08:00
metaslab_impl.h	Make metaslab class rotor and aliquot per-allocator.	2020-12-15 10:55:44 -08:00
metaslab.h	Only examine best metaslabs on each vdev	2020-12-16 14:40:05 -08:00
mmp.h	Add zfs_multihost_interval tunable handler for FreeBSD	2020-06-23 13:32:42 -07:00
mntent.h
mod.h	Replace ZFS on Linux references with OpenZFS	2020-10-08 20:10:13 -07:00
multilist.h
note.h
nvpair_impl.h
nvpair.h	FreeBSD: make adjustments for the standalone environment	2020-10-13 21:05:49 -07:00
objlist.h
pathname.h	Replace ZFS on Linux references with OpenZFS	2020-10-08 20:10:13 -07:00
qat.h
range_tree.h	Improve compatibility with C++ consumers	2020-06-06 12:54:04 -07:00
rrwlock.h	Rename refcount.h to zfs_refcount.h	2020-07-29 16:35:33 -07:00
sa_impl.h	Rename refcount.h to zfs_refcount.h	2020-07-29 16:35:33 -07:00
sa.h
skein.h
spa_boot.h
spa_checkpoint.h
spa_checksum.h
spa_impl.h	spa: avoid type narrowing warning	2020-12-15 09:20:06 -08:00
spa_log_spacemap.h
spa.h	Throw const on some strings	2020-10-02 17:44:10 -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
sysevent.h
txg_impl.h
txg.h	Distributed Spare (dRAID) Feature	2020-11-13 13:51:51 -08:00
u8_textprep_data.h
u8_textprep.h	Throw const on some strings	2020-10-02 17:44:10 -07:00
uberblock_impl.h
uberblock.h
uio_impl.h
unique.h
uuid.h
vdev_disk.h	Make struct vdev_disk_t be platform private	2020-06-16 11:43:33 -07:00
vdev_draid.h	Distributed Spare (dRAID) Feature	2020-11-13 13:51:51 -08:00
vdev_file.h
vdev_impl.h	Reduce latency effects of non-interactive I/O	2020-11-24 09:26:42 -08:00
vdev_indirect_births.h
vdev_indirect_mapping.h
vdev_initialize.h
vdev_raidz_impl.h	Distributed Spare (dRAID) Feature	2020-11-13 13:51:51 -08:00
vdev_raidz.h	Distributed Spare (dRAID) Feature	2020-11-13 13:51:51 -08:00
vdev_rebuild.h	Distributed Spare (dRAID) Feature	2020-11-13 13:51:51 -08:00
vdev_removal.h
vdev_trim.h	Trim L2ARC	2020-06-09 10:15:08 -07:00
vdev.h	Distributed Spare (dRAID) Feature	2020-11-13 13:51:51 -08:00
xvattr.h
zap_impl.h
zap_leaf.h
zap.h
zcp_global.h
zcp_iter.h
zcp_prop.h
zcp_set.h	Support setting user properties in a channel program	2020-02-14 13:41:42 -08:00
zcp.h	filesystem_limit/snapshot_limit is incorrectly enforced against root	2020-07-11 17:18:02 -07:00
zfeature.h
zfs_acl.h
zfs_bootenv.h	zfs label bootenv should store data as nvlist	2020-09-15 15:42:27 -07:00
zfs_context.h	Introduce CPU_SEQID_UNSTABLE	2020-11-02 11:51:12 -08:00
zfs_debug.h
zfs_delay.h
zfs_file.h	Re-share zfsdev_getminor and zfs_onexit_fd_hold	2020-02-28 14:50:32 -08:00
zfs_fuid.h	Replace sprintf()->snprintf() and strcpy()->strlcpy()	2020-06-07 11:42:12 -07:00
zfs_ioctl_impl.h	Make zc_nvlist_src_size limit tunable	2020-08-18 09:33:55 -07:00
zfs_ioctl.h	Cross-platform acltype	2020-10-13 21:25:48 -07:00
zfs_onexit.h	Remove deduplicated send/receive code	2020-04-23 10:06:57 -07:00
zfs_project.h
zfs_quota.h	File incorrectly zeroed when receiving incremental stream that toggles -L	2020-06-09 10:41:01 -07:00
zfs_ratelimit.h
zfs_refcount.h	Rename refcount.h to zfs_refcount.h	2020-07-29 16:35:33 -07:00
zfs_rlock.h	Add a "try" operation for range locks	2020-07-06 11:53:31 -07:00
zfs_sa.h
zfs_stat.h
zfs_sysfs.h
zfs_vfsops.h	Add 'zfs rename -u' to rename without remounting	2020-09-01 16:14:16 -07:00
zfs_vnops.h	Remove redundant oid parameter to update_pages	2020-11-10 10:54:30 -08:00
zfs_znode.h	G/C struct znode -> z_moved	2020-11-10 12:42:47 -08:00
zil_impl.h
zil.h	zil_parse: make callback parameters const	2020-10-09 09:34:54 -07:00
zio_checksum.h
zio_compress.h	Add zstd support to zfs	2020-08-20 10:30:06 -07:00
zio_crypt.h	Rename refcount.h to zfs_refcount.h	2020-07-29 16:35:33 -07:00
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
zio.h	Distributed Spare (dRAID) Feature	2020-11-13 13:51:51 -08:00
zrlock.h
zthr.h	Introduce names for ZTHRs	2020-07-29 09:43:33 -07:00
zvol_impl.h	Fix problems in zvol_set_volmode_impl	2020-11-17 09:50:52 -08:00
zvol.h	async zvol minor node creation interferes with receive	2020-02-03 09:33:14 -08:00