SCTP. They are based on what is specified in the Solaris DTrace manual
for Solaris 11.4.
Reviewed by: 0mp, dteske, markj
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D16839
Some background: in the GSoC project, libbe/Makefile lived in lib/libbe. I
created projects/bectl branch, maintained the above for all of five
minutes before I misread Makefile.inc1 and decided that it couldn't possibly
build outside of cddl/, so I kicked the Makefile out into the cddl/ build
and all was good. The misreading was of the bit where .WAIT is added to
SUBDIR after lib, libexec but prior to building bin and cddl *only during
the install targets*, which is the critical part.
Fast forward- buildworld was still broken in my branch unbeknownst to me
because I didn't nuke my OBJDIR. Combing through Makefile.inc1 eventually
revealed the necessary magic to make sure that libbe's dependencies are
specified well enough, and it becomes clear what needs done to make a
non-cddl/ build work. This is an interesting prospect, because the build
split is kind of annoying to work with.
IGNORE_PRAGMA is added to avoid dropping WARNS by one more. This was
previously pulled in via cddl/Makefile.inc.
Some options are still missing descriptions, but they can be filled in
over time.
Submitted by: raichoo <raichoo@googlemail.com>
Reviewed by: 0mp (previous version)
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D16671
This program is currently failing, and has been for >6 months on HEAD.
Ideally, this should be run 24x7 in CI, to discover hard-to-find bugs that
only manifest with concurrent i/o.
Requested by: lwhsu, mmacy
These were previously necessary because the libnvpair and libzfs_core
includes were not installed into the SYSROOT, being a part of the copies
target in include/Makefile rather than being installed with the library.
This was fixed in r337696 and the headers are now installed properly, so we
may let go of the cruft.
While nothing was wrong with libnvpair.h, libzfs_core.h was only guarded by
MK_CDDL rather than MK_CDDL && MK_ZFS. Rather than ugl'if'ying
include/Makefile to impose the extra restriction, just move the non-sys/
includes into INCS with the respect lib builds.
This has the added bonus of allowing third party packagers to try and split
these libs out of the FreeBSD-runtime package, if they are so inclined.
The sys/ include was left alone- generally userland libraries shouldn't
install kernel headers.
MFC after: 1 week
commit 50c957f702
Author: Ned Bass <bass6@llnl.gov>
Date: Wed Mar 16 18:25:34 2016 -0700
Implement large_dnode pool feature
Justification
-------------
This feature adds support for variable length dnodes. Our motivation is
to eliminate the overhead associated with using spill blocks. Spill
blocks are used to store system attribute data (i.e. file metadata) that
does not fit in the dnode's bonus buffer. By allowing a larger bonus
buffer area the use of a spill block can be avoided. Spill blocks
potentially incur an additional read I/O for every dnode in a dnode
block. As a worst case example, reading 32 dnodes from a 16k dnode block
and all of the spill blocks could issue 33 separate reads. Now suppose
those dnodes have size 1024 and therefore don't need spill blocks. Then
the worst case number of blocks read is reduced to from 33 to two--one
per dnode block. In practice spill blocks may tend to be co-located on
disk with the dnode blocks so the reduction in I/O would not be this
drastic. In a badly fragmented pool, however, the improvement could be
significant.
ZFS-on-Linux systems that make heavy use of extended attributes would
benefit from this feature. In particular, ZFS-on-Linux supports the
xattr=sa dataset property which allows file extended attribute data
to be stored in the dnode bonus buffer as an alternative to the
traditional directory-based format. Workloads such as SELinux and the
Lustre distributed filesystem often store enough xattr data to force
spill bocks when xattr=sa is in effect. Large dnodes may therefore
provide a performance benefit to such systems.
Other use cases that may benefit from this feature include files with
large ACLs and symbolic links with long target names. Furthermore,
this feature may be desirable on other platforms in case future
applications or features are developed that could make use of a
larger bonus buffer area.
Implementation
--------------
The size of a dnode may be a multiple of 512 bytes up to the size of
a dnode block (currently 16384 bytes). A dn_extra_slots field was
added to the current on-disk dnode_phys_t structure to describe the
size of the physical dnode on disk. The 8 bits for this field were
taken from the zero filled dn_pad2 field. The field represents how
many "extra" dnode_phys_t slots a dnode consumes in its dnode block.
This convention results in a value of 0 for 512 byte dnodes which
preserves on-disk format compatibility with older software.
Similarly, the in-memory dnode_t structure has a new dn_num_slots field
to represent the total number of dnode_phys_t slots consumed on disk.
Thus dn->dn_num_slots is 1 greater than the corresponding
dnp->dn_extra_slots. This difference in convention was adopted
because, unlike on-disk structures, backward compatibility is not a
concern for in-memory objects, so we used a more natural way to
represent size for a dnode_t.
The default size for newly created dnodes is determined by the value of
a new "dnodesize" dataset property. By default the property is set to
"legacy" which is compatible with older software. Setting the property
to "auto" will allow the filesystem to choose the most suitable dnode
size. Currently this just sets the default dnode size to 1k, but future
code improvements could dynamically choose a size based on observed
workload patterns. Dnodes of varying sizes can coexist within the same
dataset and even within the same dnode block. For example, to enable
automatically-sized dnodes, run
# zfs set dnodesize=auto tank/fish
The user can also specify literal values for the dnodesize property.
These are currently limited to powers of two from 1k to 16k. The
power-of-2 limitation is only for simplicity of the user interface.
Internally the implementation can handle any multiple of 512 up to 16k,
and consumers of the DMU API can specify any legal dnode value.
The size of a new dnode is determined at object allocation time and
stored as a new field in the znode in-memory structure. New DMU
interfaces are added to allow the consumer to specify the dnode size
that a newly allocated object should use. Existing interfaces are
unchanged to avoid having to update every call site and to preserve
compatibility with external consumers such as Lustre. The new
interfaces names are given below. The versions of these functions that
don't take a dnodesize parameter now just call the _dnsize() versions
with a dnodesize of 0, which means use the legacy dnode size.
New DMU interfaces:
dmu_object_alloc_dnsize()
dmu_object_claim_dnsize()
dmu_object_reclaim_dnsize()
New ZAP interfaces:
zap_create_dnsize()
zap_create_norm_dnsize()
zap_create_flags_dnsize()
zap_create_claim_norm_dnsize()
zap_create_link_dnsize()
The constant DN_MAX_BONUSLEN is renamed to DN_OLD_MAX_BONUSLEN. The
spa_maxdnodesize() function should be used to determine the maximum
bonus length for a pool.
These are a few noteworthy changes to key functions:
* The prototype for dnode_hold_impl() now takes a "slots" parameter.
When the DNODE_MUST_BE_FREE flag is set, this parameter is used to
ensure the hole at the specified object offset is large enough to
hold the dnode being created. The slots parameter is also used
to ensure a dnode does not span multiple dnode blocks. In both of
these cases, if a failure occurs, ENOSPC is returned. Keep in mind,
these failure cases are only possible when using DNODE_MUST_BE_FREE.
If the DNODE_MUST_BE_ALLOCATED flag is set, "slots" must be 0.
dnode_hold_impl() will check if the requested dnode is already
consumed as an extra dnode slot by an large dnode, in which case
it returns ENOENT.
* The function dmu_object_alloc() advances to the next dnode block
if dnode_hold_impl() returns an error for a requested object.
This is because the beginning of the next dnode block is the only
location it can safely assume to either be a hole or a valid
starting point for a dnode.
* dnode_next_offset_level() and other functions that iterate
through dnode blocks may no longer use a simple array indexing
scheme. These now use the current dnode's dn_num_slots field to
advance to the next dnode in the block. This is to ensure we
properly skip the current dnode's bonus area and don't interpret it
as a valid dnode.
zdb
---
The zdb command was updated to display a dnode's size under the
"dnsize" column when the object is dumped.
For ZIL create log records, zdb will now display the slot count for
the object.
ztest
-----
Ztest chooses a random dnodesize for every newly created object. The
random distribution is more heavily weighted toward small dnodes to
better simulate real-world datasets.
Unused bonus buffer space is filled with non-zero values computed from
the object number, dataset id, offset, and generation number. This
helps ensure that the dnode traversal code properly skips the interior
regions of large dnodes, and that these interior regions are not
overwritten by data belonging to other dnodes. A new test visits each
object in a dataset. It verifies that the actual dnode size matches what
was stored in the ztest block tag when it was created. It also verifies
that the unused bonus buffer space is filled with the expected data
patterns.
ZFS Test Suite
--------------
Added six new large dnode-specific tests, and integrated the dnodesize
property into existing tests for zfs allow and send/recv.
Send/Receive
------------
ZFS send streams for datasets containing large dnodes cannot be received
on pools that don't support the large_dnode feature. A send stream with
large dnodes sets a DMU_BACKUP_FEATURE_LARGE_DNODE flag which will be
unrecognized by an incompatible receiving pool so that the zfs receive
will fail gracefully.
While not implemented here, it may be possible to generate a
backward-compatible send stream from a dataset containing large
dnodes. The implementation may be tricky, however, because the send
object record for a large dnode would need to be resized to a 512
byte dnode, possibly kicking in a spill block in the process. This
means we would need to construct a new SA layout and possibly
register it in the SA layout object. The SA layout is normally just
sent as an ordinary object record. But if we are constructing new
layouts while generating the send stream we'd have to build the SA
layout object dynamically and send it at the end of the stream.
For sending and receiving between pools that do support large dnodes,
the drr_object send record type is extended with a new field to store
the dnode slot count. This field was repurposed from unused padding
in the structure.
ZIL Replay
----------
The dnode slot count is stored in the uppermost 8 bits of the lr_foid
field. The bits were unused as the object id is currently capped at
48 bits.
Resizing Dnodes
---------------
It should be possible to resize a dnode when it is dirtied if the
current dnodesize dataset property differs from the dnode's size, but
this functionality is not currently implemented. Clearly a dnode can
only grow if there are sufficient contiguous unused slots in the
dnode block, but it should always be possible to shrink a dnode.
Growing dnodes may be useful to reduce fragmentation in a pool with
many spill blocks in use. Shrinking dnodes may be useful to allow
sending a dataset to a pool that doesn't support the large_dnode
feature.
Feature Reference Counting
--------------------------
The reference count for the large_dnode pool feature tracks the
number of datasets that have ever contained a dnode of size larger
than 512 bytes. The first time a large dnode is created in a dataset
the dataset is converted to an extensible dataset. This is a one-way
operation and the only way to decrement the feature count is to
destroy the dataset, even if the dataset no longer contains any large
dnodes. The complexity of reference counting on a per-dnode basis was
too high, so we chose to track it on a per-dataset basis similarly to
the large_block feature.
Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3542
bectl(8) is an administrative interface for working with ZFS boot
environments, intended to provide a superset of the functionality provided
by sysutils/beadm.
libbe(3) is the back-end library that the required functionality has been
pulled out into for later reuse.
These were originally written for GSoC 2017 under the mentorship of
allanjude@.
bectl(8) has proven pretty stable in my testing, with the known bug
documented in the man page.
Relnotes: yes
- Missing include path
- Fully specify libzfs's dependencies (except for deps pulled in by other
deps) in Makefile.inc1
- Drop WARNS back down to 2 for libbe(3). I do this with much hesitation,
but the libzfs headers are apparently a hot warning-filled mess as far as
GCC 4.2 is concerned.
MFV:
commit ee36c709c3
Author: Gvozden Neskovic <neskovic@gmail.com>
Date: Sat Aug 27 20:12:53 2016 +0200
perf: 2.75x faster ddt_entry_compare()
First 256bits of ddt_key_t is a block checksum, which are expected
to be close to random data. Hence, on average, comparison only needs to
look at first few bytes of the keys. To reduce number of conditional
jump instructions, the result is computed as: sign(memcmp(k1, k2)).
Sign of an integer 'a' can be obtained as: `(0 < a) - (a < 0)` := {-1, 0, 1} ,
which is computed efficiently. Synthetic performance evaluation of
original and new algorithm over 1G random keys on 2.6GHz Intel(R) Xeon(R)
CPU E5-2660 v3:
old 6.85789 s
new 2.49089 s
perf: 2.8x faster vdev_queue_offset_compare() and vdev_queue_timestamp_compare()
Compute the result directly instead of using conditionals
perf: zfs_range_compare()
Speedup between 1.1x - 2.5x, depending on compiler version and
optimization level.
perf: spa_error_entry_compare()
`bcmp()` is not suitable for comparator use. Use `memcmp()` instead.
perf: 2.8x faster metaslab_compare() and metaslab_rangesize_compare()
perf: 2.8x faster zil_bp_compare()
perf: 2.8x faster mze_compare()
perf: faster dbuf_compare()
perf: faster compares in spa_misc
perf: 2.8x faster layout_hash_compare()
perf: 2.8x faster space_reftree_compare()
perf: libzfs: faster avl tree comparators
perf: guid_compare()
perf: dsl_deadlist_compare()
perf: perm_set_compare()
perf: 2x faster range_tree_seg_compare()
perf: faster unique_compare()
perf: faster vdev_cache _compare()
perf: faster vdev_uberblock_compare()
perf: faster fuid _compare()
perf: faster zfs_znode_hold_compare()
Signed-off-by: Gvozden Neskovic <neskovic@gmail.com>
Signed-off-by: Richard Elling <richard.elling@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#5033
9580 Add a hash-table on top of nvlist to speed-up operations
illumos/illumos-gate@2ec7644aab
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: Sebastien Roy <sebastien.roy@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Author: Serapheim Dimitropoulos <serapheim@delphix.com>
A memory leak occurs on lines 209 and 213 because the config is not freed
in the error case. The interface to add_config() seems less than ideal -
it would be better if it copied any data necessary from the config and the
caller freed it.
illumos/illumos-gate@ddfe901b12
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Author: sara hartse <sara.hartse@delphix.com>
Datasets that are deeply nested (~100 levels) are impractical. We just put
a limit of 50 levels to newly created datasets. Existing datasets should
work without a problem.
illumos/illumos-gate@5ac95da7d6
Reviewed by: John Kennedy <john.kennedy@delphix.com>
Reviewed by: Matt Ahrens <matt@delphix.com>
Approved by: Garrett D'Amore <garrett@damore.org>
Author: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
16MB alloc in zdb_embedded_block() can cause cores in certain situations
(clang, gcc55).
OsX commit: ced236a5da
FreeBSD commit: https://svnweb.freebsd.org/base?view=revision&revision=326150illumos/illumos-gate@03a4c2f4bf
Reviewed by: Igor Kozhukhov <igor@dilos.org>
Reviewed by: Andriy Gapon <avg@FreeBSD.org>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Author: Jorgen Lundman <lundman@lundman.net>
This is an update for r326150 (by avg), where this change comes from.
Only filesystems and volumes are valid "zfs remap" parameters: when passed
a snapshot name zfs_remap_indirects() does not handle the EINVAL returned
from libzfs_core, which results in failing an assertion and consequently
crashing.
illumos/illumos-gate@0b2e825398
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: John Wren Kennedy <john.kennedy@delphix.com>
Reviewed by: Sara Hartse <sara.hartse@delphix.com>
Approved by: Matt Ahrens <mahrens@delphix.com>
Author: loli10K <ezomori.nozomu@gmail.com>
7955 libshare needs to initialize only those datasets being modified by the consumer
illumos/illumos-gate@8a981c33568a981c3356https://www.illumos.org/issues/7955
Libshare currently initializes all available filesystems when doing any
libshare operation. This requires iterating through all the filesystem
multiple times, which is a huge performance problem for sharing and
unsharing operations.
Reviewed by: Steve Gonczi <steve.gonczi@delphix.com>
Reviewed by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: Yuri Pankov <yuri.pankov@gmail.com>
Approved by: Gordon Ross <gordon.w.ross@gmail.com>
Author: Daniel Hoffman <dj.hoffman@delphix.com>
For FreeBSD this is practically a NOP, just a diff reduction.
The dtrace provider for UDP-Lite is modeled after the UDP provider.
This fixes the bug that UDP-Lite packets were triggering the UDP
provider.
Thanks to dteske@ for providing the dwatch module.
Reviewed by: dteske@, markj@, rrs@
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D16377
9421 zdb should detect and print out the number of "leaked" objects
9422 zfs diff and zdb should explicitly mark objects that are on the deleted queue
illumos/illumos-gate@20b5dafb42
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Approved by: Matt Ahrens <mahrens@delphix.com>
Author: Paul Dagnelie <pcd@delphix.com>
9102 zfs should be able to initialize storage devices
The first access to a disk block can incur a performance penalty on some
platforms (e.g. AWS's EBS, VMware VMDKs). Therefore it is recommended that
volumes be "thick provisioned", where supported by the platform (VMware).
Thick provisioning is time consuming and often is ignored. If the thick
provision step is omitted, customers will see suboptimal performance until
we have written to all parts of the LUN. ZFS should be able to initialize
any unused storage to remove any first-write penalty that exists.
illumos/illumos-gate@094e47e980
Reviewed by: John Wren Kennedy <john.kennedy@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Approved by: Richard Lowe <richlowe@richlowe.net>
Author: George Wilson <george.wilson@delphix.com>
We should use zfs_dbgmsg instead of spa_dbgmsg. Or at least,
metaslab_condense() should call zfs_dbgmsg because it's important and rare
enough to always log. It's possible that the message in zio_dva_allocate()
would be too high-frequency for zfs_dbgmsg.
illumos/illumos-gate@21f7c81cc1
Reviewed by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Richard Elling <Richard.Elling@RichardElling.com>
Approved by: Richard Lowe <richlowe@richlowe.net>
Author: Matthew Ahrens <mahrens@delphix.com>
Mirrors are supposed to provide redundancy in the face of whole-disk failure
and silent damage (e.g. some data on disk is not right, but ZFS hasn't
detected the whole device as being broken). However, the current device
removal implementation bypasses some of the mirror's redundancy.
illumos/illumos-gate@3a4b1be953
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Prashanth Sreenivasa <pks@delphix.com>
Reviewed by: Sara Hartse <sara.hartse@delphix.com>
Reviewed by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Tim Chase <tim@chase2k.com>
Approved by: Richard Lowe <richlowe@richlowe.net>
Author: Matthew Ahrens <mahrens@delphix.com>
The current space map encoding has the following disadvantages:
[1] Assuming 512 sector size each entry can represent at most 16MB for a segment.
This makes the encoding very inefficient for large regions of space.
[2] As vdev-wide space maps have started to be used by new features (i.e.
device removal, zpool checkpoint) we've started imposing limits in the
vdevs that can be used with them based on the maximum addressable offset
(currently 64PB for a top-level vdev).
The new remains backwards compatible with the old one. The introduced
two-word entry format, besides extending the limits imposed by the single-entry
layout, also includes a vdev field and some extra padding after its prefix.
The extra padding after the prefix should is reserved for future usage (e.g.
new prefixes for future encodings or new fields for flags). The new vdev field
not only makes the space maps more self-descriptive, but also opens the doors
for pool-wide space maps.
One final important note is that the number of bits used for vdevs is reduced
to 24 bits for blkptrs. That was decided as we don't know of any setups that
use more than 16M vdevs for the time being and
we wanted to fit the vdev field in the space map. In addition that gives us
some extra bits in dva_t.
illumos/illumos-gate@17f11284b4
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <gwilson@zfsmail.com>
Approved by: Gordon Ross <gwr@nexenta.com>
Author: Serapheim Dimitropoulos <serapheim@delphix.com>
When a ZFS volume is created with zfs create -V (but without -s), the
refreservation property is set to a value that is volsize plus the maximum
size of metadata. If refreservation is ever set to another value, it is
impossible to set it back to the automatically determined value. There are
other cases where refreservation may be wrong. These include receiving a
volume that was sent without properties and zfs clone.
We need:
zfs set refreservation=auto <volume>
zfs clone -o refreservation=auto <volume>
Each one would use the same function used by zfs create -V to determine the
proper value for refreservation.
illumos/illumos-gate@1c10ae76c0
Reviewed by: Allan Jude <allanjude@freebsd.org>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: John Kennedy <john.kennedy@delphix.com>
Reviewed by: Andy Stormont <astormont@racktopsystems.com>
Approved by: Richard Lowe <richlowe@richlowe.net>
Author: Mike Gerdts <mike.gerdts@joyent.com>
Based on the idea that we shouldn't have all-new library and utility going
into base that need WARNS=1...
- Decent amount of constification
- Lots of parentheses
- Minor other nits
Ensure that the TCP connections are terminated gracefully as expected
by the test. Use appropriate numbers for sent/received packets.
In addition, enable tst.localtcpstate.ksh, which should pass, but
doesn't until https://reviews.freebsd.org/D16369 is committed.
Reviewed by: markj@
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D16288
This change is similar to the one done in r286171 for
tst.ipv4localtcp.ksh. This not only reduces the requirements on the
system used for testing but results also in a graceful teardown of
the TCP connection.
Reviewed by: gnn@
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D16276
The code imported from opensolaris was depending on ping supporting
UDP for sending probes. Since this is not supported by ping on FreeBSD
use a perl script instead.
The remote test requires the usage of ksh93, so state that in the
sheband.
Enable the local test, but keep the remote test disabled, since it
requires a remote machine on the LAN.
Reviewed by: markj@, gnn@
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D16268
Since we don't have /usr/bin/ksh, use a generic way of specifying
ksh. Some of the tests only run with ksh93, so use this shell
for these tests. Two of the tests don't have the execute bit set,
so fix this, too.
Reviewed by: markj@
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D16270
In some cases, the required information is not available and the
UDP provider reported an empty string in this case and the IP
and TCP provider reported a NULL pointer.
This patch changes the value provided in this case to the string
"<unknown>". This make the behaviour consistent and in-line with
the behaviour of Solaris.
Reviewed by: markj@, dteske@, gnn@
Differential Revision: https://reviews.freebsd.org/D15855
At the moment ctfconvert(1) does not do much with such CUs, but
that may not be true in the future, and we run ctfconvert on several
assembly files during the build.
X-MFC with: r334883
ctfconvert(1) is not designed to handle DWARF generated from such code,
and will generally fail in non-obvious ways. Use an explicit check to
help catch such potential failures.
Reported by: Johannes Lundberg <johalun0@gmail.com>
MFC after: 2 weeks
d4a72f2386
During scans (scrubs or resilvers), it sorts the blocks in each transaction
group by block offset; the result can be a significant improvement. (On my
test system just now, which I put some effort to introduce fragmentation into
the pool since I set it up yesterday, a scrub went from 1h2m to 33.5m with the
changes.) I've seen similar rations on production systems.
Approved by: Alexander Motin
Obtained from: ZFS On Linux
Relnotes: Yes (improved scrub performance, with tunables)
Differential Revision: https://reviews.freebsd.org/D15562
