Re-adds a recalculation step for the ARC stats after the MRU
eviction so that we don't pathologically attempt to evict the MFU.
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Authored-by: Mark Johnston <markj@freebsd.org>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes#7855
Assertion failed in arc_buf_destroy() when concurrently reading
block with checksum error.
Porting notes:
* The ability to zinject decompression errors has been added, but
this only works at the zio_decompress() level, where we have all
of the info we need to match against the user's zinject options.
* The decompress_fault test has been added to test the new zinject
functionality
* We attempted to set zio_decompress_fail_fraction to (1 << 18) in
ztest for further test coverage. Although this did uncover a few
low priority issues, this unfortuantely also causes ztest to
ASSERT in many locations where the code is working correctly since
it is designed to fail on IO errors. Developers can manually set
this variable with the '-o' option to find and debug issues.
Authored by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Matt Ahrens <mahrens@delphix.com>
Ported-by: Tom Caputi <tcaputi@datto.com>
OpenZFS-issue: https://illumos.org/issues/9403
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/fa98e487a9Closes#7822
This patch fixes 2 issues with raw, deduplicated send streams. The
first is that datasets who had been completely received earlier in
the stream were not still marked as raw receives. This caused
problems when newly received datasets attempted to fetch raw data
from these datasets without this flag set.
The second problem was that the arc freeze checksum code was not
consistent about which locks needed to be held while performing
its asserts. The proper locking needed to run these asserts is
actually fairly nuanced, since the asserts touch the linked list
of buffers (requiring the header lock), the arc_state (requiring
the b_evict_lock), and the b_freeze_cksum (requiring the
b_freeze_lock). This seems like a large performance sacrifice and
a lot of unneeded complexity to verify that this relatively small
debug feature is working as intended, so this patch simply removes
these asserts instead.
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#7701
In the case of one pool being built on another pool, we want
to make sure we don't end up throttling the lower (backing)
pool when the upper pool is the majority contributor to dirty
data. To insure we make forward progress during throttling, we
also check the current pool's net dirty data and only throttle
if it exceeds zfs_arc_pool_dirty_percent of the anonymous dirty
data in the cache.
Authored by: Don Brady <don.brady@delphix.com>
Reviewed by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: Prashanth Sreenivasa <pks@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Porting Notes:
* The new global variables zfs_arc_dirty_limit_percent,
zfs_arc_anon_limit_percent, and zfs_arc_pool_dirty_percent
were intentially not added as tunable module parameters.
OpenZFS-issue: https://illumos.org/issues/9465
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/d6a4c3efCloses#7749
The arc_hdr_realloc_crypt() function is responsible for converting
a "full" arc header to an extended "crypt" header and visa versa.
This code was originally written with a bcopy() so that any new
members added to arc headers would automatically be included
without requiring a code change. However, in practice this (along
with small differences in kmem_cache implementations between
various platforms) has caused a number of hard-to-find problems in
ports to other operating systems. This patch solves this problem
by making all member copies explicit and adding ASSERTs for fields
that cannot be set during the transfer. It also manually resets the
old header after the reallocation is finished so it can be properly
reallocated and reused.
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#7711
This patch fixes two problems with the encryption code. First, the
current code does not correctly prohibit the DMU from updating
dn_maxblkid during object truncation within a raw receive. This
usually only causes issues when the truncating DRR_FREE record is
aggregated with DRR_FREE records later in the receive, so it is
relatively hard to hit.
Second, this patch fixes a security issue where reading blocks
within an encrypted object did not guarantee that the dnode block
itself had ever been verified against its MAC. Usually the
verification happened anyway when the bonus buffer was read, but
some use cases (notably zvols) might never perform the check.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#7632
This patch fixes an issue where l2arc_read_done() would always
write data to b_pabd, even if raw encrypted data was requested.
This only occured in cases where the L2ARC device had a different
ashift than the main pool.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#7586Closes#7593
This patch fixes a small bug found where receive_spill() sometimes
attempted to decrypt spill blocks when doing a raw receive. In
addition, this patch fixes another small issue in arc_buf_fill()'s
error handling where a decryption failure (which could be caused by
the first bug) would attempt to set the arc header's IO_ERROR flag
without holding the header's lock.
Reviewed-by: Matthew Thode <prometheanfire@gentoo.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#7564Closes#7584Closes#7592
In pursuit of improving performance on multi-core systems, we should
implements fanned out counters and use them to improve the performance of
some of the arc statistics. These stats are updated extremely frequently,
and can consume a significant amount of CPU time.
Authored by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported-by: Paul Dagnelie <pcd@delphix.com>
OpenZFS-issue: https://www.illumos.org/issues/8484
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/7028a8b92b7
Issue #3752Closes#7462
Minimal changes required to integrate the SPL sources in to the
ZFS repository build infrastructure and packaging.
Build system and packaging:
* Renamed SPL_* autoconf m4 macros to ZFS_*.
* Removed redundant SPL_* autoconf m4 macros.
* Updated the RPM spec files to remove SPL package dependency.
* The zfs package obsoletes the spl package, and the zfs-kmod
package obsoletes the spl-kmod package.
* The zfs-kmod-devel* packages were updated to add compatibility
symlinks under /usr/src/spl-x.y.z until all dependent packages
can be updated. They will be removed in a future release.
* Updated copy-builtin script for in-kernel builds.
* Updated DKMS package to include the spl.ko.
* Updated stale AUTHORS file to include all contributors.
* Updated stale COPYRIGHT and included the SPL as an exception.
* Renamed README.markdown to README.md
* Renamed OPENSOLARIS.LICENSE to LICENSE.
* Renamed DISCLAIMER to NOTICE.
Required code changes:
* Removed redundant HAVE_SPL macro.
* Removed _BOOT from nvpairs since it doesn't apply for Linux.
* Initial header cleanup (removal of empty headers, refactoring).
* Remove SPL repository clone/build from zimport.sh.
* Use of DEFINE_RATELIMIT_STATE and DEFINE_SPINLOCK removed due
to build issues when forcing C99 compilation.
* Replaced legacy ACCESS_ONCE with READ_ONCE.
* Include needed headers for `current` and `EXPORT_SYMBOL`.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Olaf Faaland <faaland1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
TEST_ZIMPORT_SKIP="yes"
Closes#7556
This patch adds the ability for zinject to trigger decryption
and authentication faults in the ZIO and ARC layers. This
functionality is exposed via the new "decrypt" error type, which
may be provided for "data" object types.
This patch also refactors some of the core encryption / decryption
functions so that they have consistent prototypes, handle errors
consistently, and do not have unused arguments.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#7474
Two deadlocks / ASSERT failures were introduced in a2c2ed1b which
would occur whenever arc_buf_fill() failed to decrypt a block of
data. This occurred because the call to arc_buf_destroy() which
was responsible for cleaning up the newly created buffer would
attempt to take out the hdr lock that it was already holding. This
was resolved by calling the underlying functions directly without
retaking the lock.
In addition, the dmu_diff() code did not properly ensure that keys
were loaded and mapped before begining dataset traversal. It turns
out that this code does not need to look at any encrypted values,
so the code was altered to perform raw IO only.
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#7354Closes#7456
OpenZFS 7614 - zfs device evacuation/removal
OpenZFS 9064 - remove_mirror should wait for device removal to complete
This project allows top-level vdevs to be removed from the storage pool
with "zpool remove", reducing the total amount of storage in the pool.
This operation copies all allocated regions of the device to be removed
onto other devices, recording the mapping from old to new location.
After the removal is complete, read and free operations to the removed
(now "indirect") vdev must be remapped and performed at the new location
on disk. The indirect mapping table is kept in memory whenever the pool
is loaded, so there is minimal performance overhead when doing operations
on the indirect vdev.
The size of the in-memory mapping table will be reduced when its entries
become "obsolete" because they are no longer used by any block pointers
in the pool. An entry becomes obsolete when all the blocks that use
it are freed. An entry can also become obsolete when all the snapshots
that reference it are deleted, and the block pointers that reference it
have been "remapped" in all filesystems/zvols (and clones). Whenever an
indirect block is written, all the block pointers in it will be "remapped"
to their new (concrete) locations if possible. This process can be
accelerated by using the "zfs remap" command to proactively rewrite all
indirect blocks that reference indirect (removed) vdevs.
Note that when a device is removed, we do not verify the checksum of
the data that is copied. This makes the process much faster, but if it
were used on redundant vdevs (i.e. mirror or raidz vdevs), it would be
possible to copy the wrong data, when we have the correct data on e.g.
the other side of the mirror.
At the moment, only mirrors and simple top-level vdevs can be removed
and no removal is allowed if any of the top-level vdevs are raidz.
Porting Notes:
* Avoid zero-sized kmem_alloc() in vdev_compact_children().
The device evacuation code adds a dependency that
vdev_compact_children() be able to properly empty the vdev_child
array by setting it to NULL and zeroing vdev_children. Under Linux,
kmem_alloc() and related functions return a sentinel pointer rather
than NULL for zero-sized allocations.
* Remove comment regarding "mpt" driver where zfs_remove_max_segment
is initialized to SPA_MAXBLOCKSIZE.
Change zfs_condense_indirect_commit_entry_delay_ticks to
zfs_condense_indirect_commit_entry_delay_ms for consistency with
most other tunables in which delays are specified in ms.
* ZTS changes:
Use set_tunable rather than mdb
Use zpool sync as appropriate
Use sync_pool instead of sync
Kill jobs during test_removal_with_operation to allow unmount/export
Don't add non-disk names such as "mirror" or "raidz" to $DISKS
Use $TEST_BASE_DIR instead of /tmp
Increase HZ from 100 to 1000 which is more common on Linux
removal_multiple_indirection.ksh
Reduce iterations in order to not time out on the code
coverage builders.
removal_resume_export:
Functionally, the test case is correct but there exists a race
where the kernel thread hasn't been fully started yet and is
not visible. Wait for up to 1 second for the removal thread
to be started before giving up on it. Also, increase the
amount of data copied in order that the removal not finish
before the export has a chance to fail.
* MMP compatibility, the concept of concrete versus non-concrete devices
has slightly changed the semantics of vdev_writeable(). Update
mmp_random_leaf_impl() accordingly.
* Updated dbuf_remap() to handle the org.zfsonlinux:large_dnode pool
feature which is not supported by OpenZFS.
* Added support for new vdev removal tracepoints.
* Test cases removal_with_zdb and removal_condense_export have been
intentionally disabled. When run manually they pass as intended,
but when running in the automated test environment they produce
unreliable results on the latest Fedora release.
They may work better once the upstream pool import refectoring is
merged into ZoL at which point they will be re-enabled.
Authored by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Alex Reece <alex@delphix.com>
Reviewed-by: George Wilson <george.wilson@delphix.com>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Richard Laager <rlaager@wiktel.com>
Reviewed by: Tim Chase <tim@chase2k.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Garrett D'Amore <garrett@damore.org>
Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Tim Chase <tim@chase2k.com>
OpenZFS-issue: https://www.illumos.org/issues/7614
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/f539f1ebCloses#6900
When setting `zfs_arc_max` its minimum value is allowed
to be 64 MiB. There was an off-by-1 error which can matter
on tiny systems.
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chris Zubrzycki <github@mid-earth.net>
Closes#7417
The ASSERT was erroneously copied from the next section of code.
The buffer's size should be expanded from "psize" to "asize"
if necessary.
Reviewed-by: Tom Caputi <tcaputi@datto.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Closes#7375
Currently, the decryption and block authentication code in
the ZIO / ARC layers is a bit inconsistent with regards to
the ereports that are produces and the error codes that are
passed to calling functions. This patch ensures that all of
these errors (which begin as ECKSUM) are converted to EIO
before they leave the ZIO or ARC layer and that ereports
are correctly generated on each decryption / authentication
failure.
In addition, this patch fixes a bug in zio_decrypt() where
ECKSUM never gets written to zio->io_error.
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#7372
Authored by: Allan Jude <allanjude@freebsd.org>
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Garrett D'Amore <garrett@damore.org>
Ported-by: Giuseppe Di Natale <dinatale2@llnl.gov>
OpenZFS-issue: https://www.illumos.org/issues/9321
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/92b05f3a18Closes#7333
Currently, ZFS tracks statistics about calls to arc_read()
via the /proc/spl/kstat/zfs/<pool>/reads file for debugging.
Unfortunately, this file currently counts embedded bps as
disk reads since they are technically processed by the ZIO
layer. This pollutes the log since the ARC will never cache
embedded bps. This patch corrects this issue by preventing
the logging of embedded bp reads.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#7334
zfs_dbgmsg() should record a message by default. As a general
principal, these messages shouldn't be too verbose. Furthermore, the
amount of memory used is limited to 4MB (by default).
dprintf() should only record a message if this is a debug build, and
ZFS_DEBUG_DPRINTF is set in zfs_flags. This flag is not set by default
(even on debug builds). These messages are extremely verbose, and
sometimes nontrivial to compute.
SET_ERROR() should only record a message if ZFS_DEBUG_SET_ERROR is set
in zfs_flags. This flag is not set by default (even on debug builds).
This brings our behavior in line with illumos. Note that the message
format is unchanged (including file, line, and function, even though
these are not recorded on illumos).
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Prakash Surya <prakash.surya@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#7314
Provide infrastructure to auto-configure to enum and API changes in the
global page stats used for our free memory calculations.
arc_free_memory has been broken since an API change in Linux v3.14:
2016-07-28 v4.8 599d0c95 mm, vmscan: move LRU lists to node
2016-07-28 v4.8 75ef7184 mm, vmstat: add infrastructure for per-node
vmstats
These commits moved some of global_page_state() into
global_node_page_state(). The API change was particularly egregious as,
instead of breaking the old code, it silently did the wrong thing and we
continued using global_page_state() where we should have been using
global_node_page_state(), thus indexing into the wrong array via
NR_SLAB_RECLAIMABLE et al.
There have been further API changes along the way:
2017-07-06 v4.13 385386cf mm: vmstat: move slab statistics from zone to
node counters
2017-09-06 v4.14 c41f012a mm: rename global_page_state to
global_zone_page_state
...and various (incomplete, as it turns out) attempts to accomodate
these changes in ZoL:
2017-08-24 2209e409 Linux 4.8+ compatibility fix for vm stats
2017-09-16 787acae0 Linux 3.14 compat: IO acct, global_page_state, etc
2017-09-19 661907e6 Linux 4.14 compat: IO acct, global_page_state, etc
The config infrastructure provided here resolves these issues going back
to the original API change in v3.14 and is robust against further Linux
changes in this area.
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Chris Dunlop <chris@onthe.net.au>
Closes#7170
Currently, the DMU relies on ZIO layer compression to free LO
dnode blocks that no longer have objects in them. However,
raw receives disable all compression, meaning that these blocks
can never be freed. In addition to the obvious space concerns,
this could also cause incremental raw receives to fail to mount
since the MAC of a hole is different from that of a completely
zeroed block.
This patch corrects this issue by adding a special case in
zio_write_compress() which will attempt to compress these blocks
to a hole even if ZIO_FLAG_RAW_ENCRYPT is set. This patch also
removes the zfs_mdcomp_disable tunable, since tuning it could
cause these same issues.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#7198
zfs_arc_p_aggressive_disable is no more. This PR removes docs
and module parameters for zfs_arc_p_aggressive_disable.
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Richard Elling <Richard.Elling@RichardElling.com>
Closes#7135
Currently, the ARC exposes 2 tunables (zfs_arc_min_prefetch_ms
and zfs_arc_min_prescient_prefetch_ms) which are documented
to be specified in milliseconds. However, the code actually
uses the values as though they were in seconds. This patch
adjusts the code to match the names and documentation of the
tunables.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#7126
The on-disk format for encrypted datasets protects not only
the encrypted and authenticated blocks themselves, but also
the order and interpretation of these blocks. In order to
make this work while maintaining the ability to do raw
sends, the indirect bps maintain a secure checksum of all
the MACs in the block below it along with a few other
fields that determine how the data is interpreted.
Unfortunately, the current on-disk format erroneously
includes some fields which are not portable and thus cannot
support raw sends. It is not possible to easily work around
this issue due to a separate and much smaller bug which
causes indirect blocks for encrypted dnodes to not be
compressed, which conflicts with the previous bug. In
addition, the current code generates incompatible on-disk
formats on big endian and little endian systems due to an
issue with how block pointers are authenticated. Finally,
raw send streams do not currently include dn_maxblkid when
sending both the metadnode and normal dnodes which are
needed in order to ensure that we are correctly maintaining
the portable objset MAC.
This patch zero's out the offending fields when computing
the bp MAC and ensures that these MACs are always
calculated in little endian order (regardless of the host
system's byte order). This patch also registers an errata
for the old on-disk format, which we detect by adding a
"version" field to newly created DSL Crypto Keys. We allow
datasets without a version (version 0) to only be mounted
for read so that they can easily be migrated. We also now
include dn_maxblkid in raw send streams to ensure the MAC
can be maintained correctly.
This patch also contains minor bug fixes and cleanups.
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#6845Closes#6864Closes#7052
When the compressed ARC feature was added in commit d3c2ae1
the method of reference counting in the ARC was modified. As
part of this accounting change the arc_buf_add_ref() function
was removed entirely.
This would have be fine but the arc_buf_add_ref() function
served a second undocumented purpose of updating the ARC access
information when taking a hold on a dbuf. Without this logic
in place a cached dbuf would not migrate its associated
arc_buf_hdr_t to the MFU list. This would negatively impact
the ARC hit rate, particularly on systems with a small ARC.
This change reinstates the missing call to arc_access() from
dbuf_hold() by implementing a new arc_buf_access() function.
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#6171Closes#6852Closes#6989
When sequential scrubs were merged, all calls to arc_read()
(including prefetch IOs) were given ZIO_PRIORITY_ASYNC_READ.
Unfortunately, this behaves badly with an existing issue where
prefetch IOs cannot be re-prioritized after the issue. The
result is that synchronous reads end up in the same vdev_queue
as the scrub IOs and can have (in some workloads) multiple
seconds of latency.
This patch incorporates 2 changes. The first ensures that all
scrub IOs are given ZIO_PRIORITY_SCRUB to allow the vdev_queue
code to differentiate between these I/Os and user prefetches.
Second, this patch introduces zio_change_priority() to provide
the missing capability to upgrade a zio's priority.
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#6921Closes#6926
Only access the `b_crypt_hdr` field of an ARC header if the content
is encrypted.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tom Caputi <tcaputi@datto.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: DHE <git@dehacked.net>
Closes#6877
Currently, scrubs and resilvers can take an extremely
long time to complete. This is largely due to the fact
that zfs scans process pools in logical order, as
determined by each block's bookmark. This makes sense
from a simplicity perspective, but blocks in zfs are
often scattered randomly across disks, particularly
due to zfs's copy-on-write mechanisms.
This patch improves performance by splitting scrubs
and resilvers into a metadata scanning phase and an IO
issuing phase. The metadata scan reads through the
structure of the pool and gathers an in-memory queue
of I/Os, sorted by size and offset on disk. The issuing
phase will then issue the scrub I/Os as sequentially as
possible, greatly improving performance.
This patch also updates and cleans up some of the scan
code which has not been updated in several years.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Authored-by: Saso Kiselkov <saso.kiselkov@nexenta.com>
Authored-by: Alek Pinchuk <apinchuk@datto.com>
Authored-by: Tom Caputi <tcaputi@datto.com>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#3625Closes#6256
In __dbuf_hold_impl(), if a buffer is currently syncing and is still
referenced from db_data, a copy is made in case it is dirtied again in
the txg. Previously, the buffer for the copy was simply allocated with
arc_alloc_buf() which doesn't handle compressed or encrypted buffers
(which are a special case of a compressed buffer). The result was
typically an invalid memory access because the newly-allocated buffer
was of the uncompressed size.
This commit fixes the problem by handling the 2 compressed cases,
encrypted and unencrypted, respectively, with arc_alloc_raw_buf() and
arc_alloc_compressed_buf().
Although using the proper allocation functions fixes the invalid memory
access by allocating a buffer of the compressed size, another unrelated
issue made it impossible to properly detect compressed buffers in the
first place. The header's compression flag was set to ZIO_COMPRESS_OFF
in arc_write() when it was possible that an attached buffer was actually
compressed. This commit adds logic to only set ZIO_COMPRESS_OFF in
the non-ZIO_RAW case which wil handle both cases of compressed buffers
(encrypted or unencrypted).
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Closes#5742Closes#6797
Fixed build regression in non-debug builds from recent cleanups of
c89 workarounds.
Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Don Brady <don.brady@delphix.com>
Closes#6832
With PR 5756 the zfs module now supports c99 and the
remaining past c89 workarounds can be undone.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Don Brady <don.brady@delphix.com>
Closes#6816
Fix compiler warnings in zdb. With these changes, FreeBSD can compile
zdb with all compiler warnings enabled save -Wunused-parameter.
usr/src/cmd/zdb/zdb.c
usr/src/cmd/zdb/zdb_il.c
usr/src/uts/common/fs/zfs/sys/sa.h
usr/src/uts/common/fs/zfs/sys/spa.h
Fix numerous warnings, including:
* const-correctness
* shadowing global definitions
* signed vs unsigned comparisons
* missing prototypes, or missing static declarations
* unused variables and functions
* Unreadable array initializations
* Missing struct initializers
usr/src/cmd/zdb/zdb.h
Add a header file to declare common symbols
usr/src/lib/libzpool/common/sys/zfs_context.h
usr/src/uts/common/fs/zfs/arc.c
usr/src/uts/common/fs/zfs/dbuf.c
usr/src/uts/common/fs/zfs/spa.c
usr/src/uts/common/fs/zfs/txg.c
Add a function prototype for zk_thread_create, and ensure that every
callback supplied to this function actually matches the prototype.
usr/src/cmd/ztest/ztest.c
usr/src/uts/common/fs/zfs/sys/zil.h
usr/src/uts/common/fs/zfs/zfs_replay.c
usr/src/uts/common/fs/zfs/zvol.c
Add a function prototype for zil_replay_func_t, and ensure that
every function of this type actually matches the prototype.
usr/src/uts/common/fs/zfs/sys/refcount.h
Change FTAG so it discards any constness of __func__, necessary
since existing APIs expect it passed as void *.
Porting Notes:
- Many of these fixes have already been applied to Linux. For
consistency the OpenZFS version of a change was applied if the
warning was addressed in an equivalent but different fashion.
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Authored by: Alan Somers <asomers@gmail.com>
Approved by: Richard Lowe <richlowe@richlowe.net>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
OpenZFS-issue: https://www.illumos.org/issues/8081
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/843abe1b8aCloses#6787
Several issues were uncovered by running stress tests with zfs
encryption and raw sends in particular. The issues and their
associated fixes are as follows:
* arc_read_done() has the ability to chain several requests for
the same block of data via the arc_callback_t struct. In these
cases, the ARC would only use the first request's dsobj from
the bookmark to decrypt the data. This is problematic because
the first request might be a prefetch zio which is able to
handle the key not being loaded, while the second might use a
different key that it is sure will work. The fix here is to
pass the dsobj with each individual arc_callback_t so that each
request can attempt to decrypt the data separately.
* DRR_FREE and DRR_FREEOBJECT records in a send file were not
having their transactions properly tagged as raw during raw
sends, which caused a panic when the dbuf code attempted to
decrypt these blocks.
* traverse_prefetch_metadata() did not properly set
ZIO_FLAG_SPECULATIVE when issuing prefetch IOs.
* Added a few asserts and code cleanups to ensure these issues
are more detectable in the future.
Signed-off-by: Tom Caputi <tcaputi@datto.com>
* PBKDF2 implementation changed to OpenSSL implementation.
* HKDF implementation moved to its own file and tests
added to ensure correctness.
* Removed libzfs's now unnecessary dependency on libzpool
and libicp.
* Ztest can now create and test encrypted datasets. This is
currently disabled until issue #6526 is resolved, but
otherwise functions as advertised.
* Several small bug fixes discovered after enabling ztest
to run on encrypted datasets.
* Fixed coverity defects added by the encryption patch.
* Updated man pages for encrypted send / receive behavior.
* Fixed a bug where encrypted datasets could receive
DRR_WRITE_EMBEDDED records.
* Minor code cleanups / consolidation.
Signed-off-by: Tom Caputi <tcaputi@datto.com>
With the addition of the ABD changes consumption of the virtual
address space has been greatly reduced. This exposed an issue on
CONFIG_HIGHMEM systems where free memory was being calculated
incorrectly. Functionally this didn't cause any major problems
prior to ABD because a lack of available virtual address space
was used as an indicator of low memory.
This patch makes the following changes to address the issue and
in the process realigns the code further with OpenZFS. There
are no substantive changes in behavior for 64-bit systems.
* Added CONFIG_HIGHMEM case to the arc_all_memory() and
arc_free_memory() functions to only consider low memory pages
on CONFIG_HIGHMEM systems.
* The arc_free_memory() function was updated to return bytes
instead of pages to be consistent with the other helper
functions. In user space we make up some reasonable values
since currently only testing is performed in this context.
* Adds three new values to the arcstats kstat to provide visibility
in to the ARC's assessment of the memory situation:
memory_all_bytes, memory_free_bytes, and memory_available_bytes.
* Added kmem_reap() call to arc_available_memory() for 32-bit
builds to realign code with OpenZFS.
* Reduced size of test file in /async_destroy_001_pos.ksh to
speed up test case. Multiple txgs are still required.
* Move vdevs used by zpool_clear_001_pos and zpool_upgrade_002_pos
to TEST_BASE_DIR location to speed up test cases.
Reviewed-by: David Quigley <david.quigley@intel.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#5352Closes#6734
Commit d3c2ae1 introduced a dbuf cache with a default size of the
minimum of 100M or 1/32 maximum ARC size. (These figures may be adjusted
using dbuf_cache_max_bytes and dbuf_cache_max_shift.) The dbuf cache
is counted as metadata for the purposes of ARC size calculations.
On a 1GB box the ARC maximum size defaults to c_max 493M which gives a
dbuf cache default minimum size of 15.4M, and the ARC metadata defaults
to minimum 16M. I.e. the dbuf cache is an significant proportion of the
minimum metadata size. With other overheads involved this actually means
the ARC metadata doesn't get down to the minimum.
This patch dynamically scales the dbuf cache to the target ARC size
instead of statically scaling it to the maximum ARC size. (The scale is
still set by dbuf_cache_max_shift and the maximum size is still fixed by
dbuf_cache_max_bytes.) Using the target ARC size rather than the current
ARC size is done to help the ARC reach the target rather than simply
focusing on the current size.
Reviewed-by: Chunwei Chen <tuxoko@gmail.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Chris Dunlop <chris@onthe.net.au>
Issue #6506Closes#6561
Increase the default arc_c_min value to which whichever is larger,
either 32M or 1/32 of total system memory. This is advantageous for
systems with more than 1G of memory where performance issues may
occur when the ARC is allowed to collapse below a minimum size.
At the same time we want to use the bare minimum value which is
still functional so the filesystem can be used in very low memory
environments.
Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#6659
generic_start_io_acct/generic_end_io_acct in the master
branch of the linux kernel requires that the request_queue
be provided.
Move the logic from freemem in the spl to arc_free_memory
in arc.c. Do this so we can take advantage of global_page_state
interface checks in zfs.
Upstream kernel replaced struct block_device with
struct gendisk in struct bio. Determine if the
function bio_set_dev exists during configure
and have zfs use that if it exists.
bio_set_dev https://github.com/torvalds/linux/commit/74d4699
global_node_page_state https://github.com/torvalds/linux/commit/75ef718
io acct https://github.com/torvalds/linux/commit/d62e26b
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Closes#6635
vm_node_stat must be used instead of vm_zone_stat. Unfortunately the
old code still compiles potentially leading to silent failure of
arc_evictable_memory()
AKAMAI: CR 3816601: Regression in zfs dropcache test
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Chunwei Chen <tuxoko@gmail.com>
Signed-off-by: Debabrata Banerjee <dbanerje@akamai.com>
Closes#6528
This change incorporates three major pieces:
The first change is a keystore that manages wrapping
and encryption keys for encrypted datasets. These
commands mostly involve manipulating the new
DSL Crypto Key ZAP Objects that live in the MOS. Each
encrypted dataset has its own DSL Crypto Key that is
protected with a user's key. This level of indirection
allows users to change their keys without re-encrypting
their entire datasets. The change implements the new
subcommands "zfs load-key", "zfs unload-key" and
"zfs change-key" which allow the user to manage their
encryption keys and settings. In addition, several new
flags and properties have been added to allow dataset
creation and to make mounting and unmounting more
convenient.
The second piece of this patch provides the ability to
encrypt, decyrpt, and authenticate protected datasets.
Each object set maintains a Merkel tree of Message
Authentication Codes that protect the lower layers,
similarly to how checksums are maintained. This part
impacts the zio layer, which handles the actual
encryption and generation of MACs, as well as the ARC
and DMU, which need to be able to handle encrypted
buffers and protected data.
The last addition is the ability to do raw, encrypted
sends and receives. The idea here is to send raw
encrypted and compressed data and receive it exactly
as is on a backup system. This means that the dataset
on the receiving system is protected using the same
user key that is in use on the sending side. By doing
so, datasets can be efficiently backed up to an
untrusted system without fear of data being
compromised.
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#494Closes#5769
* Simplify threads, mutexs, cvs and rwlocks
* Update the zk_thread_create() function to use the same trick
as Illumos. Specifically, cast the new pthread_t to a void
pointer and return that as the kthread_t *. This avoids the
issues associated with managing a wrapper structure and is
safe as long as the callers never attempt to dereference it.
* Update all function prototypes passed to pthread_create() to
match the expected prototype. We were getting away this with
before since the function were explicitly cast.
* Replaced direct zk_thread_create() calls with thread_create()
for code consistency. All consumers of libzpool now use the
proper wrappers.
* The mutex_held() calls were converted to MUTEX_HELD().
* Removed all mutex_owner() calls and retired the interface.
Instead use MUTEX_HELD() which provides the same information
and allows the implementation details to be hidden. In this
case the use of the pthread_equals() function.
* The kthread_t, kmutex_t, krwlock_t, and krwlock_t types had
any non essential fields removed. In the case of kthread_t
and kcondvar_t they could be directly typedef'd to pthread_t
and pthread_cond_t respectively.
* Removed all extra ASSERTS from the thread, mutex, rwlock, and
cv wrapper functions. In practice, pthreads already provides
the vast majority of checks as long as we check the return
code. Removing this code from our wrappers help readability.
* Added TS_JOINABLE state flag to pass to request a joinable rather
than detached thread. This isn't a standard thread_create() state
but it's the least invasive way to pass this information and is
only used by ztest.
TEST_ZTEST_TIMEOUT=3600
Chunwei Chen <tuxoko@gmail.com>
Reviewed-by: Tom Caputi <tcaputi@datto.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4547Closes#5503Closes#5523Closes#6377Closes#6495
Update many return and assignment statements to follow the convention
of using the SET_ERROR macro when returning a hard-coded non-zero
value from a function. This aids debugging by recording the error
codes in the debug log.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Closes#6441
Authored by: Andriy Gapon <avg@FreeBSD.org>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported-by: Giuseppe Di Natale <dinatale2@llnl.gov>
OpenZFS-issue: https://www.illumos.org/issues/7910
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/cb6af4bCloses#6291
Make zfs_arc_meta_limit_percent and zfs_arc_dnode_limit_percent behave
as you would expect from zfs-module-parameters.5.
- recalculate arc_meta_limit if zfs_arc_meta_limit_percent changes
- recalculate arc_dnode_limit if zfs_arc_dnode_limit_percent changes
- correctly set arc_meta_limit and arc_dnode_limit if zfs_arc_max or
zfs_arc_meta_min changes
Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chris Dunlop <chris@onthe.net.au>
Closes#6269
Authored by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported-by: Giuseppe Di Natale <dinatale2@llnl.gov>
When writing pre-compressed buffers, arc_write() requires that
the compression algorithm used to compress the buffer matches
the compression algorithm requested by the zio_prop_t, which is
set by dmu_write_policy(). This makes dmu_write_policy() and its
callers a bit more complicated.
We simplify this by making arc_write() trust the caller to supply
the type of pre-compressed buffer that it wants to write,
and override the compression setting in the zio_prop_t.
OpenZFS-issue: https://www.illumos.org/issues/8155
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/b55ff58Closes#6200
The arc layer tracks checksums of its data in the arc header
so that it can ensure that buffers haven't changed when they're
not supposed to. This checksum is only maintained while there
is an uncompressed buffer still attached to the header.
Unfortunately there is a missing call to arc_free_cksum() in
arc_release() that can trigger ASSERTs. This has not been a
common issue because the checksums are only maintained for
debug builds and triggering the bug requires writing a block
(and therefore calling arc_release()) while a compressed buffer
is still being used on a debug build. This simply corrects the
issue.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#6105
When multiple filesystems are in use, memory pressure causes arc_cache
to collapse to a minimum. Allow arc_cache to maintain proportional size
even when hit rates are disproportionate. We do this only via evictable
size from the kernel shrinker, thus it's only in effect under memory
pressure.
AKAMAI: zfs: CR 3695072
Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed-by: Richard Yao <ryao@gentoo.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Debabrata Banerjee <dbanerje@akamai.com>
Closes#6035
Could return the wrong pages value
AKAMAI: zfs: CR 3695072
Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed-by: Richard Yao <ryao@gentoo.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Debabrata Banerjee <dbanerje@akamai.com>
Issue #6035
Calling it when nothing is evictable will cause extra kswapd cpu. Also
if we didn't shrink it's unlikely to have memory to reap because we
likely just called it microseconds ago. The exception is if we are in
direct reclaim.
You can see how hard this is being hit in kswapd with a light test
workload:
34.95% [zfs] [k] arc_kmem_reap_now
5.40% [spl] [k] spl_kmem_cache_reap_now
3.79% [kernel] [k] _raw_spin_lock
2.86% [spl] [k] __spl_kmem_cache_generic_shrinker.isra.7
2.70% [kernel] [k] shrink_slab.part.37
1.93% [kernel] [k] isolate_lru_pages.isra.43
1.55% [kernel] [k] __wake_up_bit
1.20% [kernel] [k] super_cache_count
1.20% [kernel] [k] __radix_tree_lookup
With ZFS just mounted but only ext4/pagecache memory pressure
arc_kmem_reap_now still consumes excessive CPU:
12.69% [kernel] [k] isolate_lru_pages.isra.43
10.76% [kernel] [k] free_pcppages_bulk
7.98% [kernel] [k] drop_buffers
7.31% [kernel] [k] shrink_page_list
6.44% [zfs] [k] arc_kmem_reap_now
4.19% [kernel] [k] free_hot_cold_page
4.00% [kernel] [k] __slab_free
3.95% [kernel] [k] __isolate_lru_page
3.09% [kernel] [k] __radix_tree_lookup
Same pagecache only workload as above with this patch series:
11.58% [kernel] [k] isolate_lru_pages.isra.43
11.20% [kernel] [k] drop_buffers
9.67% [kernel] [k] free_pcppages_bulk
8.44% [kernel] [k] shrink_page_list
4.86% [kernel] [k] __isolate_lru_page
4.43% [kernel] [k] free_hot_cold_page
4.00% [kernel] [k] __slab_free
3.44% [kernel] [k] __radix_tree_lookup
(arc_kmem_reap_now has 0 samples in perf)
AKAMAI: zfs: CR 3695042
Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed-by: Richard Yao <ryao@gentoo.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Debabrata Banerjee <dbanerje@akamai.com>
Issue #6035
Lock contention, by itself, shouldn't indicate a stop condition to the
kernel's slab shrinker. Doing so can cause stalls when the kernel is
trying to free large parts of the cache such as is done by drop_caches
Also, perhaps arc_reclaim_lock should be a spinlock, and this code
eliminated.
AKAMAI: zfs: CR 3593801
Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed-by: Richard Yao <ryao@gentoo.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Debabrata Banerjee <dbanerje@akamai.com>
Issue #6035
Move arcstat_need_free increment from all direct calls to when
arc_reclaim_lock is busy and we exit wihout doing anything. Data will
be reclaimed in reclaim thread. The previous location meant that we
both reclaim the memory in this thread, and also schedule the same
amount of memory for reclaim in arc_reclaim, effectively doubling the
requested reclaim.
AKAMAI: zfs: CR 3695072
Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed-by: Richard Yao <ryao@gentoo.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Debabrata Banerjee <dbanerje@akamai.com>
Issue #6035
Ensures proper accounting of bytes we requested to free
AKAMAI: zfs: CR 3695072
Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed-by: Richard Yao <ryao@gentoo.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Debabrata Banerjee <dbanerje@akamai.com>
Issue #6035
Ghost meta/data buffers are not actually allocated
AKAMAI: zfs: CR 3695072
Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed-by: Richard Yao <ryao@gentoo.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Debabrata Banerjee <dbanerje@akamai.com>
Issue #6035
OpenZFS 7252 - compressed zfs send / receive
OpenZFS 7628 - create long versions of ZFS send / receive options
Authored by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: John Kennedy <john.kennedy@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed by: David Quigley <dpquigl@davequigley.com>
Reviewed by: Thomas Caputi <tcaputi@datto.com>
Approved by: Dan McDonald <danmcd@omniti.com>
Reviewed by: David Quigley <dpquigl@davequigley.com>
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Ported-by: bunder2015 <omfgbunder@gmail.com>
Ported-by: Don Brady <don.brady@intel.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Porting Notes:
- Most of 7252 was already picked up during ABD work. This
commit represents the gap from the final commit to openzfs.
- Fixed split_large_blocks check in do_dump()
- An alternate version of the write_compressible() function was
implemented for Linux which does not depend on fio. The behavior
of fio differs significantly based on the exact version.
- mkholes was replaced with truncate for Linux.
OpenZFS-issue: https://www.illumos.org/issues/7252
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/5602294Closes#6067
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: Brad Lewis <brad.lewis@delphix.com>
Reviewed by: Saso Kiselkov <saso.kiselkov@nexenta.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported-by: Matthew Ahrens <mahrens@delphix.com>
spa_sync() iterates over all the dirty dnodes and processes each of them
by calling dnode_sync(). If there are many dirty dnodes (e.g. because we
created or removed a lot of files), the single thread of spa_sync()
calling dnode_sync() can become a bottleneck. Additionally, if many
dnodes are dirtied concurrently in open context (e.g. due to concurrent
file creation), the os_lock will experience lock contention via
dnode_setdirty().
The solution is to track dirty dnodes on a multilist_t, and for
spa_sync() to use separate threads to process each of the sublists in
the multilist.
OpenZFS-issue: https://www.illumos.org/issues/7968
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/4a2a54cCloses#5752
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Tim Chase <tim@chase2k.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
OpenZFS-issue: https://www.illumos.org/issues/7867
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/aa1f740dCloses#5874
The global tunable zfs_arc_num_sublists_per_state is used by the ARC and
the dbuf cache, and other users are planned. We should change this
tunable to be common to all multilists. This tuning may be overridden
on a per-multilist basis.
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#5764
A likely cut/paste error caused the description to be applied to
zfs_arc_average_blocksize.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Closes#5788
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Haakan T Johansson <f96hajo@chalmers.se>
Closes#5547Closes#5543
Enable picky cstyle checks and resolve the new warnings. The vast
majority of the changes needed were to handle minor issues with
whitespace formatting. This patch contains no functional changes.
Non-whitespace changes are as follows:
* 8 times ; to { } in for/while loop
* fix missing ; in cmd/zed/agents/zfs_diagnosis.c
* comment (confim -> confirm)
* change endline , to ; in cmd/zpool/zpool_main.c
* a number of /* BEGIN CSTYLED */ /* END CSTYLED */ blocks
* /* CSTYLED */ markers
* change == 0 to !
* ulong to unsigned long in module/zfs/dsl_scan.c
* rearrangement of module_param lines in module/zfs/metaslab.c
* add { } block around statement after for_each_online_node
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Håkan Johansson <f96hajo@chalmers.se>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#5465
On 32-bit Linux systems use vmem_size() to correctly size the ARC
and better determine when IO should be throttle due to low memory.
On 64-bit systems this change has no effect since the virtual
address space available far exceeds the physical memory available.
Reviewed-by: Tom Caputi <tcaputi@datto.com>
Reviewed-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #5347
Add the TASKQID_INVALID macros and update callers to use the macro
instead of testing against 0. There is no functional change
even though the functions in zfs_ctldir.c incorrectly used -1
instead of 0.
Reviewed-by: Tom Caputi <tcaputi@datto.com>
Reviewed-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #5347
CID 147509: Explicit null dereferenced
- l2arc_sublist_lock is fragile as relied on caller too much.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: GeLiXin <ge.lixin@zte.com.cn>
Closes#5319
CID 150924: Unchecked return value (CHECKED_RETURN)
- On taskq_dispatch failure the reference must be dropped and
this entry can be safely skipped. This case should be impossible
in the existing implementation but should be handled regardless.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: luozhengzheng <luo.zhengzheng@zte.com.cn>
Closes#5278
The following new test cases need to have execute permissions set:
userquota/groupspace_003_pos.ksh
userquota/userquota_013_pos.ksh
userquota/userspace_003_pos.ksh
upgrade/upgrade_userobj_001_pos.ksh
upgrade/setup.ksh
upgrade/cleanup.ksh
The following source files accidentally were marked executable:
lib/libzpool/kernel.c
lib/libshare/nfs.c
lib/libzfs/libzfs_dataset.c
lib/libzfs/libzfs_util.c
tests/zfs-tests/cmd/rm_lnkcnt_zero_file/rm_lnkcnt_zero_file.c
tests/zfs-tests/cmd/dir_rd_update/dir_rd_update.c
cmd/zed/zed_exec.c
module/icp/core/kcf_sched.c
module/zfs/dsl_pool.c
module/zfs/arc.c
module/nvpair/nvpair.c
man/man5/zfs-module-parameters.5
Reviewed-by: GeLiXin <ge.lixin@zte.com.cn>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#5241
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Saso Kiselkov <saso.kiselkov@nexenta.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Approved by: Garrett D'Amore <garrett@damore.org>
Ported by: Tony Hutter <hutter2@llnl.gov>
OpenZFS-issue: https://www.illumos.org/issues/4185
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/45818ee
Porting Notes:
This code is ported on top of the Illumos Crypto Framework code:
b5e030c8db
The list of porting changes includes:
- Copied module/icp/include/sha2/sha2.h directly from illumos
- Removed from module/icp/algs/sha2/sha2.c:
#pragma inline(SHA256Init, SHA384Init, SHA512Init)
- Added 'ctx' to lib/libzfs/libzfs_sendrecv.c:zio_checksum_SHA256() since
it now takes in an extra parameter.
- Added CTASSERT() to assert.h from for module/zfs/edonr_zfs.c
- Added skein & edonr to libicp/Makefile.am
- Added sha512.S. It was generated from sha512-x86_64.pl in Illumos.
- Updated ztest.c with new fletcher_4_*() args; used NULL for new CTX argument.
- In icp/algs/edonr/edonr_byteorder.h, Removed the #if defined(__linux) section
to not #include the non-existant endian.h.
- In skein_test.c, renane NULL to 0 in "no test vector" array entries to get
around a compiler warning.
- Fixup test files:
- Rename <sys/varargs.h> -> <varargs.h>, <strings.h> -> <string.h>,
- Remove <note.h> and define NOTE() as NOP.
- Define u_longlong_t
- Rename "#!/usr/bin/ksh" -> "#!/bin/ksh -p"
- Rename NULL to 0 in "no test vector" array entries to get around a
compiler warning.
- Remove "for isa in $($ISAINFO); do" stuff
- Add/update Makefiles
- Add some userspace headers like stdio.h/stdlib.h in places of
sys/types.h.
- EXPORT_SYMBOL *_Init/*_Update/*_Final... routines in ICP modules.
- Update scripts/zfs2zol-patch.sed
- include <sys/sha2.h> in sha2_impl.h
- Add sha2.h to include/sys/Makefile.am
- Add skein and edonr dirs to icp Makefile
- Add new checksums to zpool_get.cfg
- Move checksum switch block from zfs_secpolicy_setprop() to
zfs_check_settable()
- Fix -Wuninitialized error in edonr_byteorder.h on PPC
- Fix stack frame size errors on ARM32
- Don't unroll loops in Skein on 32-bit to save stack space
- Add memory barriers in sha2.c on 32-bit to save stack space
- Add filetest_001_pos.ksh checksum sanity test
- Add option to write psudorandom data in file_write utility
Cppcheck 1.63 erroneously complains about an uninitialized value
in buf_init(). Newer versions of cppcheck (1.72) handle this
correctly but we'll initialize the value anyway to silence the
warning.
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#5203
In arc_state_fini() the `arc_l2c_only->arcs_list[*]` multilists
must be destroyed. This accidentally regressed in d3c2ae1c.
Reviewed by: Tom Caputi <tcaputi@datto.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #5151Closes#5152
The type of "adjustmnt" was erroneously changed to unsigned when the compressed
ARC code was ported in d3c2ae1c08.
As a result of it being unsigned, the balanced metadata eviction logic
would evict all of the non-metadata.
Reviewed-by: Chris Severance <github.severach@spamgourmet.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: David Quigley <david.quigley@intel.com>
Signed-off-by: Tim Chase <tim@onlight.com>
Closes#5128Closes#5129
Authored by: George Wilson <george.wilson@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Tom Caputi <tcaputi@datto.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported by: David Quigley <david.quigley@intel.com>
This review covers the reading and writing of compressed arc headers, sharing
data between the arc_hdr_t and the arc_buf_t, and the implementation of a new
dbuf cache to keep frequently access data uncompressed.
I've added a new member to l1 arc hdr called b_pdata. The b_pdata always hangs
off the arc_buf_hdr_t (if an L1 hdr is in use) and points to the physical block
for that DVA. The physical block may or may not be compressed. If compressed
arc is enabled and the block on-disk is compressed, then the b_pdata will match
the block on-disk and remain compressed in memory. If the block on disk is not
compressed, then neither will the b_pdata. Lastly, if compressed arc is
disabled, then b_pdata will always be an uncompressed version of the on-disk
block.
Typically the arc will cache only the arc_buf_hdr_t and will aggressively evict
any arc_buf_t's that are no longer referenced. This means that the arc will
primarily have compressed blocks as the arc_buf_t's are considered overhead and
are always uncompressed. When a consumer reads a block we first look to see if
the arc_buf_hdr_t is cached. If the hdr is cached then we allocate a new
arc_buf_t and decompress the b_pdata contents into the arc_buf_t's b_data. If
the hdr already has a arc_buf_t, then we will allocate an additional arc_buf_t
and bcopy the uncompressed contents from the first arc_buf_t to the new one.
Writing to the compressed arc requires that we first discard the b_pdata since
the physical block is about to be rewritten. The new data contents will be
passed in via an arc_buf_t (uncompressed) and during the I/O pipeline stages we
will copy the physical block contents to a newly allocated b_pdata.
When an l2arc is inuse it will also take advantage of the b_pdata. Now the
l2arc will always write the contents of b_pdata to the l2arc. This means that
when compressed arc is enabled that the l2arc blocks are identical to those
stored in the main data pool. This provides a significant advantage since we
can leverage the bp's checksum when reading from the l2arc to determine if the
contents are valid. If the compressed arc is disabled, then we must first
transform the read block to look like the physical block in the main data pool
before comparing the checksum and determining it's valid.
OpenZFS-issue: https://www.illumos.org/issues/6950
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/7fc10f0
Issue #5078
Several assignments to arc_c had no effect because it is ultimately
initialized to arc_c_max.
This aligns ZoL better with the upstream code which removed these
assignments some time ago.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@onlight.com>
Closes#5081
ARC will evict meta buffers that exceed the arc_meta_limit. Before a further
investigating on whether we should take special protection on meta buffers,
this tunable make arc_meta_limit adjustable for different workloads.
People can set zfs_arc_meta_limit_percent to any value while insmod zfs.ko,
so some range check is added to guarantee a suitable arc_meta_limit.
Suggested by Tim Chase, zfs_arc_dnode_limit is changed to a percent-style
tunable as well.
Signed-off-by: GeLiXin <ge.lixin@zte.com.cn>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4957
When arc_max is increased, arc_meta_limit will not be updated to 3/4
of the new arc_c_max value. This was done originally to preserve any
existing maximum value. This turned out to be counter intuitive to
users and this fix changes that behavior. If zfs_arc_meta_limit is
non-default, it will be picked up later in the ARC tuning function.
Signed-off-by: Gaurav Kumar <gaurav.kumar@nutanix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4893
Metadata-intensive workloads can cause the ARC to become permanently
filled with dnode_t objects as they're pinned by the VFS layer.
Subsequent data-intensive workloads may only benefit from about
25% of the potential ARC (arc_c_max - arc_meta_limit).
In order to help track metadata usage more precisely, the other_size
metadata arcstat has replaced with dbuf_size, dnode_size and bonus_size.
The new zfs_arc_dnode_limit tunable, which defaults to 10% of
zfs_arc_meta_limit, defines the minimum number of bytes which is desirable
to be consumed by dnodes. Attempts to evict non-metadata will trigger
async prune tasks if the space used by dnodes exceeds this limit.
The new zfs_arc_dnode_reduce_percent tunable specifies the amount by
which the excess dnode space is attempted to be pruned as a percentage of
the amount by which zfs_arc_dnode_limit is being exceeded. By default,
it tries to unpin 10% of the dnodes.
The problem of dnode metadata pinning was observed with the following
testing procedure (in this example, zfs_arc_max is set to 4GiB):
- Create a large number of small files until arc_meta_used exceeds
arc_meta_limit (3GiB with default tuning) and arc_prune
starts increasing.
- Create a 3GiB file with dd. Observe arc_mata_used. It will still
be around 3GiB.
- Repeatedly read the 3GiB file and observe arc_meta_limit as before.
It will continue to stay around 3GiB.
With this modification, space for the 3GiB file is gradually made
available as subsequent demands on the ARC are made. The previous behavior
can be restored by setting zfs_arc_dnode_limit to the same value as the
zfs_arc_meta_limit.
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #4345
Issue #4512
Issue #4773Closes#4858
In arc_buf_info(), the arc_buf_t may have no header. If not, don't try
to fetch the arc buffer stats and instead just zero them.
The null dereferences were observed while accessing the dbuf kstat with
awk on a system in which millions of small files were being created in
order to overflow the system's metadata limit.
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Closes#4837
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Boris Protopopov <bprotopopov@hotmail.com>
Approved by: Richard Lowe <richlowe@richlowe.net>a
Ported by: Boris Protopopov <bprotopopov@actifio.com>
Signed-off-by: Boris Protopopov <bprotopopov@actifio.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
OpenZFS-issue: https://www.illumos.org/issues/6513
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/8df0bcf0
If a ZFS object contains a hole at level one, and then a data block is
created at level 0 underneath that l1 block, l0 holes will be created.
However, these l0 holes do not have the birth time property set; as a
result, incremental sends will not send those holes.
Fix is to modify the dbuf_read code to fill in birth time data.
arc_prune_task uses a refcount to protect arc_prune_t, but it doesn't prevent
the underlying zsb from disappearing if there's a concurrent umount. We fix
this by force the caller of arc_remove_prune_callback to wait for
arc_prune_taskq to finish.
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4687Closes#4690
The was originally using interruptible cv_timedwait_sig, but was changed
to uninterruptible cv_timedwait_hires in ae6d0c6. Use _sig_hires instead
to allow interruptible sleep.
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4633Closes#4634
Set a limit for the largest compressed block which can be written
to an L2ARC device. By default this limit is set to 16M so there
is no change in behavior.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Elling <Richard.Elling@RichardElling.com>
Signed-off-by: Tim Chase <tim@chase2k.com>
Closes#4323
Since it's set to arc_c_max / 2, it must be set after arc_c_max is set.
Also added protection against it falling below 2 * maxblocksize in
userland builds.
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4268
Adjusting arc_c directly is racy because it can happen in the context
of multiple threads. It should always be >= 2 * maxblocksize. Set it
to a known valid value rather than adjusting it directly.
In addition refactor arc_shrink() to a simpler structure, protect against
underflow in the calculation of the new arc_c value.
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reverts: 935434efCloses: #3904Closes: #4161
Commit 5f6d0b6 was originally added to gracefully handle block
pointers with a damaged logical size. However, it incorrectly
assumed that all passed arc_done_func_t could handle a NULL
arc_buf_t.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4069Closes#4080
On 32 bit, the calculation of zfs_dirty_data_max from phymem will overflow,
causing it to be smaller than zfs_dirty_data_sync, and will cause txg being
delayed while no one write to disk. The end result is horrendous write speed.
On 4G ram 32-bit VM, before this patch, simple dd results in ~7MB/s. Now it
can reach speed on par with 64-bit VM.
Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3973
On 32 bit system, zio_buf_cache is limit to 1M. Larger than that is all NULL.
So we need to avoid reaping them.
Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #3973
When decreasing the maximum ARC size preserve the 3/4 default
ratio for the arc_meta_limit. Otherwise, the arc_meta_limit
may be set the same as arc_max.
Signed-off-by: AndCycle <andcycle@andcycle.idv.tw>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4001
Strictly enforce keeping 'arc_c >= arc_c_min'. The ASSERTs are
left in place to catch this in a debug build but logic has been
added to gracefully handle in a production build.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #3904
As described in the comment above arc_reclaim_thread() it's critical
that the reclaim thread be careful about blocking. Just like it must
never wait on a hash lock, it must never wait on a task which can in
turn wait on the CV in arc_get_data_buf(). This will deadlock, see
issue #3822 for full backtraces showing the problem.
To resolve this issue arc_kmem_reap_now() has been updated to use the
asynchronous arc prune function. This means that arc_prune_async()
may now be called while there are still outstanding arc_prune_tasks.
However, this isn't a problem because arc_prune_async() already
keeps a reference count preventing multiple outstanding tasks per
registered consumer. Functionally, this behavior is the same as
the counterpart illumos function dnlc_reduce_cache().
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Issue #3808
Issue #3834
Issue #3822
6214 zpools going south
Reviewed by: Igor Kozhukhov <ikozhukhov@gmail.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Reviewed by: Saso Kiselkov <skiselkov.ml@gmail.com>
References:
https://www.illumos.org/issues/6214http://cr.illumos.org/~webrev/sensille/6214_zpools_going_south/
Porting Notes:
Reintroduce b_compress to the l2arc_buf_hdr_t. In commit b9541d6
the compression flags were moved to the generic b_flags in the
arc_buf_hdr_t. This is a problem because l2arc_compress_buf()
may manipulate the compression flags and this can only be done
safely under the hash lock which is not held. See Illumos 6214
for a detailed analysis of the race.
HDR_GET_COMPRESS() macro was removed from arc_buf_info().
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3757
This brings the behavior of arc_memory_throttle() back in sync with
illumos. The updated memory throttling policy roughly goes like this:
* Never throttle if more than 10% of memory is free. This threshold
is configurable with the zfs_arc_lotsfree_percent module option.
* Minimize any throttling of kswapd even when free memory is below
the set threshold. Allow it to write out pages as quickly as
possible to help alleviate the memory pressure.
* Delay all other threads when free memory is below the set threshold
in order to avoid compounding the memory pressure. Buffers will be
evicted from the ARC to reduce the issue.
The Linux specific zfs_arc_memory_throttle_disable module option has
been removed in favor of the existing zfs_arc_lotsfree_percent tuning.
Setting zfs_arc_lotsfree_percent=0 will have the same effect as
zfs_arc_memory_throttle_disable and it was therefore redundant.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3637
While Linux doesn't provide detailed information about the state of
the VM it does provide us total free pages. This information should
be incorporated in to the arc_available_memory() calculation rather
than solely relying on a signal from direct reclaim. Conceptually
this brings arc_available_memory() back in sync with illumos.
It is also desirable that the target amount of free memory be tunable
on a system. While the default values are expected to work well
for most workloads there may be cases where custom values are needed.
The zfs_arc_sys_free module option was added for this purpose.
zfs_arc_sys_free - The target number of bytes the ARC should leave
as free memory on the system. This value can
checked in /proc/spl/kstat/zfs/arcstats and
setting this module option will override the
default value.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3637
Under Linux filesystem threads responsible for handling I/O are
normally created with the maximum priority. Non-I/O filesystem
processes run with the default priority. ZFS should adopt the
same priority scheme under Linux to maintain good performance
and so that it will complete fairly when other Linux filesystems
are active. The priorities have been updated to the following:
$ ps -eLo rtprio,cls,pid,pri,nice,cmd | egrep 'z_|spl_|zvol|arc|dbu|meta'
- TS 10743 19 -20 [spl_kmem_cache]
- TS 10744 19 -20 [spl_system_task]
- TS 10745 19 -20 [spl_dynamic_tas]
- TS 10764 19 0 [dbu_evict]
- TS 10765 19 0 [arc_prune]
- TS 10766 19 0 [arc_reclaim]
- TS 10767 19 0 [arc_user_evicts]
- TS 10768 19 0 [l2arc_feed]
- TS 10769 39 0 [z_unmount]
- TS 10770 39 -20 [zvol]
- TS 11011 39 -20 [z_null_iss]
- TS 11012 39 -20 [z_null_int]
- TS 11013 39 -20 [z_rd_iss]
- TS 11014 39 -20 [z_rd_int_0]
- TS 11022 38 -19 [z_wr_iss]
- TS 11023 39 -20 [z_wr_iss_h]
- TS 11024 39 -20 [z_wr_int_0]
- TS 11032 39 -20 [z_wr_int_h]
- TS 11033 39 -20 [z_fr_iss_0]
- TS 11041 39 -20 [z_fr_int]
- TS 11042 39 -20 [z_cl_iss]
- TS 11043 39 -20 [z_cl_int]
- TS 11044 39 -20 [z_ioctl_iss]
- TS 11045 39 -20 [z_ioctl_int]
- TS 11046 39 -20 [metaslab_group_]
- TS 11050 19 0 [z_iput]
- TS 11121 38 -19 [z_wr_iss]
Note that under Linux the meaning of a processes priority is inverted
with respect to illumos. High values on Linux indicate a _low_ priority
while high value on illumos indicate a _high_ priority.
In order to preserve the logical meaning of the minclsyspri and
maxclsyspri macros when they are used by the illumos wrapper functions
their values have been inverted. This way when changes are merged
from upstream illumos we won't need to remember to invert the macro.
It could also lead to confusion.
This patch depends on https://github.com/zfsonlinux/spl/pull/466.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Closes#3607
Address minor differences in style between upstream and ZoL. This
patch contains no functional differences and is solely designed to
minimize the delta from upstream.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #3533
Commit d962d5d didn't quite properly resolve the HDR_L2ONLY_SIZE
accounting. Accounting is now performed only in the constructor
and destructor which is a nice simplification. It should have
been removed the from create and destroy functions. This brings
up back in sync with upstream.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #3533
Originally removed because it wasn't required under Linux. However,
there may still be some utility in signaling the arc reclaim thread
under Linux via reclaim. This should already have happened by other
means but it's not harmless and reduces another point of divergence
with upstream.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #3533
Commit f521ce1 removed the minimum value for "arc_p" allowing it to
drop to zero or grow to "arc_c". This was done to improve specific
workload which constantly dirties new "metadata" but also frequently
touches a "small" amount of mfu data (e.g. mkdir's).
This change may still be desirable but it needs to be re-investigated.
in the context of the recent ARC changes from upstream. Therefore
this code is being restored to facilitate benchmarking. By setting
"zfs_arc_p_min_shift=64" we easily compare the performance.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #3533
5817 change type of arcs_size from uint64_t to refcount_t
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Paul Dagnelie <paul.dagnelie@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Alex Reece <alex@delphix.com>
Reviewed by: Richard Elling <richard.elling@richardelling.com>
Approved by: Garrett D'Amore <garrett@damore.org>
References:
https://www.illumos.org/issues/5817https://github.com/illumos/illumos-gate/commit/2fd872a
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #3533
5445 Add more visibility via arcstats; specifically arc_state_t
stats and differentiate between "data" and "metadata"
Reviewed by: Basil Crow <basil.crow@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Bayard Bell <bayard.bell@nexenta.com>
Approved by: Robert Mustacchi <rm@joyent.com>
References:
https://www.illumos.org/issues/5445https://github.com/illumos/illumos-gate/commit/4076b1b
Porting Notes:
This patch is an improved version of cc7f677 which was previously
merged in ZoL. This patch incorporates the additional improvements
which were made upstream.
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #3533
5376 arc_kmem_reap_now() should not result in clearing arc_no_grow
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Steven Hartland <killing@multiplay.co.uk>
Reviewed by: Richard Elling <richard.elling@richardelling.com>
Approved by: Dan McDonald <danmcd@omniti.com>
References:
https://www.illumos.org/issues/5376https://github.com/illumos/illumos-gate/commit/2ec99e3
Porting Notes:
The good news is that many of the recent changes made upstream to the
ARC tackled issues previously observed by ZoL with similar solutions.
The bad news is those solution weren't identical to the ones we applied.
This patch is designed to split the difference and apply as much of the
upstream work as possible.
* The arc_available_memory() function was removed previous in ZoL but
due to the upstream changes it makes sense to add it back. This function
has been customized for Linux so that it can be used to determine a low
memory. This provides the same basic functionality as the illumos version
allowing us to minimize changes through the rest of the code base. The
exact mechanism used to detect a low memory state remains unchanged so
this change isn't a significant as it might first appear.
* This patch includes the long standing fix for arc_shrink() which was
originally proposed in #2167. Since there were related changes to this
function it made sense to include that work.
* The arc_init() function has been re-factored. As before it sets sane
default values for the ARC but then calls arc_tuning_update() to apply
user specific tuning made via module options. The arc_tuning_update()
function is then called periodically by the arc_reclaim_thread() to
apply changes to the tunings made during normal operation.
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3616Closes#2167
5368 ARC should cache more metadata
Reviewed by: Alex Reece <alex.reece@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Richard Elling <richard.elling@richardelling.com>
Approved by: Dan McDonald <danmcd@omniti.com>
References:
https://www.illumos.org/issues/5368https://github.com/illumos/illumos-gate/commit/3a5286a
Porting Notes:
The vast majority of this patch was already merged in the context
of the 06358ea changes. This is just a small hunk which was missed.
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
5163 arc should reap range_seg_cache
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Richard Elling <richard.elling@gmail.com>
Reviewed by: Saso Kiselkov <skiselkov.ml@gmail.com>
Approved by: Dan McDonald <danmcd@omniti.com>
References:
https://www.illumos.org/issues/5163https://github.com/illumos/illumos-gate/commit/83803b5
Porting Notes:
Added umem_cache_reap_now() wrapped to suppress unused variable
warning for user space build in arc_kmem_reap_now().
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Over the years the default values for the taskqs used on Linux have
differed slightly from illumos. In the vast majority of cases this
was done to avoid creating an obnoxious number of idle threads which
would pollute the process listing.
With the addition of support for dynamic taskqs all multi-threaded
queues should be created as dynamic taskqs. This allows us to get
the best of both worlds.
* The illumos default values for the I/O pipeline can be restored.
These values are known to work well for most workloads. The only
exception is the zio write interrupt taskq which is changed to
ZTI_P(12, 8). At least under Linux more threads has been shown
to improve performance, see commit 7e55f4e.
* Reduces the number of idle threads on the system when it's not
under heavy load. The maximum number of threads will only be
created when they are required.
* Remove the vdev_file_taskq and rely on the system_taskq instead
which is now dynamic and may have up to 64-threads. Again this
brings us back inline with upstream.
* Tasks dispatched with taskq_dispatch_ent() are allowed to use
dynamic taskqs. The Linux taskq implementation supports this.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Closes#3507
If we don't account for that, then we might end up overwriting disk
area of buffers that have not been evicted yet, because l2arc_evict
operates in terms of disk addresses.
The discrepancy between the write size calculation and the actual
increment to l2ad_hand was introduced in commit 3a17a7a9.
The change that introduced l2ad_hand alignment was almost correct
as the write size was accumulated as a sum of rounded buffer sizes.
See commit illumos/illumos-gate@e14bb32.
Also, we now consistently use asize / a_sz for the allocated size and
psize / p_sz for the physical size. The latter accounts for a
possible size reduction because of the compression, whereas the
former accounts for a possible subsequent size expansion because of
the alignment requirements.
The code still assumes that either underlying storage subsystems or
hardware is able to do read-modify-write when an L2ARC buffer size is
not a multiple of a disk's block size. This is true for 4KB sector disks
that provide 512B sector emulation, but may not be true in general.
In other words, we currently do not have any code to make sure that
an L2ARC buffer, whether compressed or not, which is used for physical
I/O has a suitable size.
Note that currently the cache device utilization is calculated based
on the physical size, not the allocated size. The same applies to
l2_asize kstat. That is wrong, but this commit does not fix that.
The accounting problem was introduced partially in commit 3a17a7a9
and partially in 3038a2b (accounting became consistent but in favour
of the wrong size).
Porting Notes:
Reworked to be C90 compatible and the 'write_psize' variable was
removed because it is now unused.
References:
https://reviews.csiden.org/r/229/https://reviews.freebsd.org/D2764
Ported-by: kernelOfTruth <kerneloftruth@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3400Closes#3433Closes#3451
This is the counterpart to zfsonlinux/spl@2345368 which replaces the
cv_wait_interruptible() function with cv_wait_sig(). There is no
functional change to patch merely brings the function names in to
sync to maximize portability.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #3450
Issue #3402
ZoL had lowered the minimum ARC size to 4MiB to better accommodate tiny
systems such as the raspberry pi, however, as of addition of large block
support, the arc_adapt() function depends on arc_c being >= 32MiB (2 *
SPA_MAXBLOCKSIZE).
This patch raises the minimum ARC size to 32MiB and adds a VERIFY test
to arc_adapt() for future-proofing.
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
As described in the comment above arc_adapt_thread() it is critical
that the arc_adapt_thread() function never sleep while holding a hash
lock. This behavior was possible in the Linux implementation because
the arc_prune() logic was implemented to be synchronous. Under
illumos the analogous dnlc_reduce_cache() function is asynchronous.
To address this the arc_do_user_prune() function is has been reworked
in to two new functions as follows:
* arc_prune_async() is an asynchronous implementation which dispatches
the prune callback to be run by the system taskq. This makes it
suitable to use in the context of the arc_adapt_thread().
* arc_prune() is a synchronous implementation which depends on the
arc_prune_async() implementation but blocks until the outstanding
callbacks complete. This is used in arc_kmem_reap_now() where it
is safe, and expected, that memory will be freed.
This patch additionally adds the zfs_arc_meta_strategy module option
while allows the meta reclaim strategy to be configured. It defaults
to a balanced strategy which has been proved to work well under Linux
but the illumos meta-only strategy can be enabled.
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Richard Elling <richard.elling@richardelling.com>
Approved by: Dan McDonald <danmcd@omniti.com>
Porting notes and other significant code changes:
The illumos 5368 patch (ARC should cache more metadata), which
was never picked up by ZoL, is mostly reverted by this patch.
Since ZoL relies on the kernel asynchronously calling the shrinker to
actually reap memory, the shrinker wakes up arc_reclaim_waiters_cv every
time it runs.
The arc_adapt_thread() function no longer calls arc_do_user_evicts()
since the newly-added arc_user_evicts_thread() calls it periodically.
Notable conflicting ZoL commits which conflicted with this patch or
whose effects are either duplicated or un-done by this patch:
302f753 - Integrate ARC more tightly with Linux
39e055c - Adjust arc_p based on "bytes" in arc_shrink
f521ce1 - Allow "arc_p" to drop to zero or grow to "arc_c"
77765b5 - Remove "arc_meta_used" from arc_adjust calculation
94520ca - Prune metadata from ghost lists in arc_adjust_meta
Trace support for multilist_insert() and multilist_remove() has been
added and produces the following output:
fio-12498 [077] .... 112936.448324: zfs_multilist__insert: ml { offset 240 numsublists 80 sublistidx 63 }
fio-12498 [077] .... 112936.448347: zfs_multilist__remove: ml { offset 240 numsublists 80 sublistidx 29 }
The following arcstats have been removed:
recycle_miss - Used by arcstat.py and arc_summary.py, both of which
have been updated appropriately.
l2_writes_hdr_miss
The following arcstats have been added:
evict_not_enough - Number of times arc_evict_state() was unable to
evict enough buffers to reach its target amount.
evict_l2_skip - Number of times arc_evict_hdr() skipped eviction
because it was being written to the l2arc.
l2_writes_lock_retry - Replaces l2_writes_hdr_miss. Number of times
l2arc_write_done() failed to acquire hash_lock (and re-tries).
arc_meta_min - Shows the value of the zfs_arc_meta_min module
parameter (see below).
The "index" column of the "dbuf" kstat has been removed since it doesn't
have a direct analog in the new multilist scheme. Additional multilist-
related stats could be added in the future but would likely require
extensions to the mulilist API.
The following module parameters have been added:
zfs_arc_evict_batch_limit - Number of ARC headers to free per sub-list
before moving on to the next sub-list.
zfs_arc_meta_min - Enforce a floor on the amount of metadata in
the ARC.
zfs_arc_num_sublists_per_state - Number of multilist sub-lists per
ARC state.
zfs_arc_overflow_shift - Controls amount by which the ARC must exceed
the target size to be considered "overflowing".
Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov
5408 managing ZFS cache devices requires lots of RAM
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Don Brady <dev.fs.zfs@gmail.com>
Reviewed by: Josef 'Jeff' Sipek <josef.sipek@nexenta.com>
Approved by: Garrett D'Amore <garrett@damore.org>
Porting notes:
Due to the restructuring of the ARC-related structures, this
patch conflicts with at least the following existing ZoL commits:
6e1d7276c9
Fix inaccurate arcstat_l2_hdr_size calculations
The ARC_SPACE_HDRS constant no longer exists and has been
somewhat equivalently replaced by HDR_L2ONLY_SIZE.
e0b0ca983d
Add visibility in to cached dbufs
The new layering of l{1,2}arc_buf_hdr_t within the arc_buf_hdr
struct requires additional structure member names to be used
when referencing the inner items. Also, the presence of L1 or L2
inner member is indicated by flags using the new HDR_HAS_L{1,2}HDR
macros.
Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
5369 arc flags should be an enum
5370 consistent arc_buf_hdr_t naming scheme
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Alex Reece <alex.reece@delphix.com>
Reviewed by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed by: Richard Elling <richard.elling@richardelling.com>
Approved by: Richard Lowe <richlowe@richlowe.net>
Porting notes:
ZoL has moved some ARC definitions into arc_impl.h.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported by: Tim Chase <tim@chase2k.com>
This reverts only the l2arc_hdr part of commit
ecf3d9b8e6 in preparation for the illumos
5497 "lock contention on arcs_mtx" patch which does the same thing
but uses the newer two-level ARC structure following the Illumos 5408
"managing ZFS cache devices requires lots of RAM" patch.
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Illumos 5497 "lock contention on arcs_mtx" reworks eviction and obviates
the need for this.
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
This reverts commit 037763e44e in
preparation for the illumos 5497 "lock contention on arcs_mtx" patch
which includes a fix for this very problem.
ZoL had picked up a subset of the illumos 5497 patch to deal with the
l2arc compression buffer leak.
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
This reverts commit 16fcdea363 in preparation
for the illumos 5497 "lock contention on arcs_mtx" patch which eliminates
"marker" within the ARC code.
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
5027 zfs large block support
Reviewed by: Alek Pinchuk <pinchuk.alek@gmail.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Josef 'Jeff' Sipek <josef.sipek@nexenta.com>
Reviewed by: Richard Elling <richard.elling@richardelling.com>
Reviewed by: Saso Kiselkov <skiselkov.ml@gmail.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Dan McDonald <danmcd@omniti.com>
References:
https://www.illumos.org/issues/5027https://github.com/illumos/illumos-gate/commit/b515258
Porting Notes:
* Included in this patch is a tiny ISP2() cleanup in zio_init() from
Illumos 5255.
* Unlike the upstream Illumos commit this patch does not impose an
arbitrary 128K block size limit on volumes. Volumes, like filesystems,
are limited by the zfs_max_recordsize=1M module option.
* By default the maximum record size is limited to 1M by the module
option zfs_max_recordsize. This value may be safely increased up to
16M which is the largest block size supported by the on-disk format.
At the moment, 1M blocks clearly offer a significant performance
improvement but the benefits of going beyond this for the majority
of workloads are less clear.
* The illumos version of this patch increased DMU_MAX_ACCESS to 32M.
This was determined not to be large enough when using 16M blocks
because the zfs_make_xattrdir() function will fail (EFBIG) when
assigning a TX. This was immediately observed under Linux because
all newly created files must have a security xattr created and
that was failing. Therefore, we've set DMU_MAX_ACCESS to 64M.
* On 32-bit platforms a hard limit of 1M is set for blocks due
to the limited virtual address space. We should be able to relax
this one the ABD patches are merged.
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#354
With debugging enabled and depending on your kernel config, the size of
arc_buf_hdr_t can blow out the stack of arc_evict() and arc_evict_ghost()
to greater than 1024 bytes. Let's avoid this.
Signed-off-by: Chris Dunlop <chris@onthe.net.au>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3377
Prevent deadlocks by disabling direct reclaim during all ZPL and ioctl
calls as well as the l2arc and adapt ARC threads.
This obviates the need for MUTEX_FSTRANS so its previous uses and
definition have been eliminated.
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3225
The goal of this function is to evict enough meta data buffers from the
ARC in order to enforce the arc_meta_limit. Achieving this is slightly
more complicated than it appears because it is common for data buffers
to have holds on meta data buffers. In addition, dnode meta data buffers
will be held by the dnodes in the block preventing them from being freed.
This means we can't simply traverse the ARC and expect to always find
enough unheld meta data buffer to release.
Therefore, this function has been updated to make alternating passes
over the ARC releasing data buffers and then newly unheld meta data
buffers. This ensures forward progress is maintained and arc_meta_used
will decrease. Normally this is sufficient, but if required the ARC
will call the registered prune callbacks causing dentry and inodes to
be dropped from the VFS cache. This will make dnode meta data buffers
available for reclaim. The number of total restarts in limited by
zfs_arc_meta_adjust_restarts to prevent spinning in the rare case
where all meta data is pinned.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Pavel Snajdr <snajpa@snajpa.net>
Issue #3160
Originally when the ARC prune callback was introduced the idea was
to register a single callback for the ZPL. The ARC could invoke this
call back if it needed the ZPL to drop dentries, inodes, or other
cache objects which might be pinning buffers in the ARC. The ZPL
would iterate over all ZFS super blocks and perform the reclaim.
For the most part this design has worked well but due to limitations
in 2.6.35 and earlier kernels there were some problems. This patch
is designed to address those issues.
1) iterate_supers_type() is not provided by all kernels which makes
it impossible to safely iterate over all zpl_fs_type filesystems in
a single callback. The most straight forward and portable way to
resolve this is to register a callback per-filesystem during mount.
The arc_*_prune_callback() functions have always supported multiple
callbacks so this is functionally a very small change.
2) Commit 050d22b removed the non-portable shrink_dcache_memory()
and shrink_icache_memory() functions and didn't replace them with
equivalent functionality. This meant that for Linux 3.1 and older
kernels the ARC had no mechanism to drop dentries and inodes from
the caches if needed. This patch adds that missing functionality
by calling shrink_dcache_parent() to release dentries which may be
pinning inodes. This will result in all unused cache entries being
dropped which is a bit heavy handed but it's the only interface
available for old kernels.
3) A zpl_drop_inode() callback is registered for kernels older than
2.6.35 which do not support the .evict_inode callback. This ensures
that when the last reference on an inode is dropped it is immediately
removed from the cache. If this isn't done than inode can end up on
the global unused LRU with no mechanism available to ZFS to drop them.
Since the ARC buffers are not dropped the hottest inodes can still
be recreated without performing disk IO.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Pavel Snajdr <snajpa@snajpa.net>
Issue #3160
The arc_meta_max value should be increased when space it consumed not when
it is returned. This ensure's that arc_meta_max is always up to date.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Pavel Snajdr <snajpa@snajpa.net>
Issue #3160
There are a handful of ASSERT(!"...")'s throughout the code base for
cases which should be impossible. This patch converts them to use
cmn_err(CE_PANIC, ...) to ensure they are always enabled and so that
additional debugging is logged if they were to occur.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1445
There are regions in the ZFS code where it is desirable to be able
to be set PF_FSTRANS while a specific mutex is held. The ZFS code
could be updated to set/clear this flag in all the correct places,
but this is undesirable for a few reasons.
1) It would require changes to a significant amount of the ZFS
code. This would complicate applying patches from upstream.
2) It would be easy to accidentally miss a critical region in
the initial patch or to have an future change introduce a
new one.
Both of these concerns can be addressed by using a new mutex type
which is responsible for managing PF_FSTRANS, support for which was
added to the SPL in commit zfsonlinux/spl@9099312 - Merge branch
'kmem-rework'.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Closes#3050Closes#3055Closes#3062Closes#3132Closes#3142Closes#2983
Commit log from FreeBSD:
We have observed that arc_release() can be called concurrently with a
l2arc in-flight write. Also, we have observed that arc_hdr_destroy()
can be called from arc_write_done() for a zio with ZIO_FLAG_IO_REWRITE
flag in similar circumstances.
Previously the l2arc headers would be freed while leaking their
associated compression buffers. Now the buffers are placed on
l2arc_free_on_write list for delayed freeing. This is similar to
what was already done to arc buffers that were supposed to be freed
concurrently with in-flight writes of those buffers.
In addition to fixing the discovered leaks this change also adds
some protective code to assert that a compression buffer associated
with a l2arc header is never leaked.
A new kstat l2_cdata_free_on_write is added. It keeps a count
of delayed compression buffer frees which previously would have
been leaks.
Tested by: Vitalij Satanivskij <satan@ukr.net> et al
Requested by: many
MFC after: 2 weeks
Sponsored by: HybridCluster / ClusterHQ
References:
https://illumos.org/issues/5222https://github.com/freebsd/freebsd/commit/b98f85dhttp://thread.gmane.org/gmane.os.freebsd.current/155757/focus=155781http://lists.open-zfs.org/pipermail/developer/2014-January/000455.htmlhttp://lists.open-zfs.org/pipermail/developer/2014-February/000523.html
Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3029
By marking DMU transaction processing contexts with PF_FSTRANS
we can revert the KM_PUSHPAGE -> KM_SLEEP changes. This brings
us back in line with upstream. In some cases this means simply
swapping the flags back. For others fnvlist_alloc() was replaced
by nvlist_alloc(..., KM_PUSHPAGE) and must be reverted back to
fnvlist_alloc() which assumes KM_SLEEP.
The one place KM_PUSHPAGE is kept is when allocating ARC buffers
which allows us to dip in to reserved memory. This is again the
same as upstream.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Older versions of GCC (e.g. GCC 4.4.7 on RHEL6) do not allow duplicate
typedef declarations with the same type. The trace.h header contains
some typedefs to avoid 'unknown type' errors for C files that haven't
declared the type in question. But this causes build failures for C
files that have already declared the type. Newer versions of GCC (e.g.
v4.6) allow duplicate typedefs with the same type unless pedantic error
checking is in force. To support the older versions we need to remove
the duplicate typedefs.
Removal of the typedefs means we can't built tracepoints code using
those types unless the required headers have been included. To
facilitate this, all tracepoint event declarations have been moved out
of trace.h into separate headers. Each new header is explicitly included
from the C file that uses the events defined therein. The trace.h header
is still indirectly included form zfs_context.h and provides the
implementation of the dprintf(), dbgmsg(), and SET_ERROR() interfaces.
This makes those interfaces readily available throughout the code base.
The macros that redefine DTRACE_PROBE* to use Linux tracepoints are also
still provided by trace.h, so it is a prerequisite for the other
trace_*.h headers.
These new Linux implementation-specific headers do introduce a small
divergence from upstream ZFS in several core C files, but this should
not present a significant maintenance burden.
Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2953
Inclusion of SPL compatibility headers was moved out of the public
header sys/types.h to avoid conflicts with external packages. Include a
few compatiblity headers explicitly to cope with that change. Also,
sort some linux-specific inclusions alphabetically.
Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2898
Fix a few dprintf format specifiers that disagreed with their argument
types. These came to light as compiler errors when converting dprintf
to use the Linux trace buffer. Previously this wasn't a problem,
presumably because the SPL debug logging uses vsnprintf which must
perform automatic type conversion.
Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Add a new file named arc_impl.h and move a few internal
ARC structure definitions into this file. This is
needed in order to allow the Linux tracepoint functions to grub
around in the internals of these structures.
Signed-off-by: Prakash Surya <prakash.surya@delphix.com>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Due to evidence of contention both the buf_hash_table and the
dbuf_hash_table sizes have been increased from 256 to 8192.
This increase in hash table size adds approximating 0.5M to
our fixed memory footprint. This relatively small increase
is not expected to cause problems even on low memory machines.
This footprint will also become dynamic when the persistent
L2ARC support is finalized. In the meanwhile, this small
change significantly reduces contention for certain workloads.
Signed-off-by: Chris Wedgwood <cw@f00f.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Pavel Snajdr <snajpa@snajpa.net>
Closes#1291
These symbols are needed by consumers (i.e. Lustre) who wish to
integrate with the ZIL. In addition the zil_rollback_destroy()
prototype was removed because the implementation of this function
was removed long ago.
Signed-off-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2892
The new shrinker API as of Linux 3.12 modifies "struct shrinker" by
replacing the @shrink callback with the pair of @count_objects and
@scan_objects. It also requires the return value of @count_objects to
return the number of objects actually freed whereas the previous @shrink
callback returned the number of remaining freeable objects.
This patch adds support for the new @scan_objects return value semantics.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Closes#2837
The general strategy used by ZFS to verify that blocks are valid is
to checksum everything. This has the advantage of being extremely
robust and generically applicable regardless of the contents of
the block. If a blocks checksum is valid then its contents are
trusted by the higher layers.
This system works exceptionally well as long as bad data is never
written with a valid checksum. If this does somehow occur due to
a software bug or a memory bit-flip on a non-ECC system it may
result in kernel panic.
One such place where this could occur is if somehow the logical
size stored in a block pointer exceeds the maximum block size.
This will result in an attempt to allocate a buffer greater than
the maximum block size causing a system panic.
To prevent this from happening the arc_read() function has been
updated to detect this specific case. If a block pointer with an
invalid logical size is passed it will treat the block as if it
contained a checksum error.
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2678
5034 ARC's buf_hash_table is too small
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Saso Kiselkov <skiselkov.ml@gmail.com>
Reviewed by: Richard Elling <richard.elling@gmail.com>
Approved by: Gordon Ross <gwr@nexenta.com>
References:
https://www.illumos.org/issues/5034https://github.com/illumos/illumos-gate/commit/63e911b
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2615
4631 zvol_get_stats triggering too many reads
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Approved by: Dan McDonald <danmcd@omniti.com>
References:
https://www.illumos.org/issues/4631https://github.com/illumos/illumos-gate/commit/bbfa8ea
Ported-by: Boris Protopopov <bprotopopov@hotmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2612Closes#2480
4914 zfs on-disk bookmark structure should be named *_phys_t
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Reviewed by: Saso Kiselkov <skiselkov.ml@gmail.com>
Approved by: Robert Mustacchi <rm@joyent.com>
References:
https://www.illumos.org/issues/4914https://github.com/illumos/illumos-gate/commit/7802d7b
Porting notes:
There were a number of zfsonlinux-specific uses of zbookmark_t which
needed to be updated. This should reduce the likelihood of further
problems like issue #2094 from occurring.
Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2558
4897 Space accounting mismatch in L2ARC/zpool
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Boris Protopopov <bprotopopov@hotmail.com>
Approved by: Dan McDonald <danmcd@omniti.com>
From the illumos issue tracker:
L2ARC vdev space usage statistics are calculated as the delta
between the maximum and minimum vdev offset ever written to
by the L2ARC fill thread, but do not inform the user of how
much space in between these two offsets is actually taken up by
cached buffers. This fix changes that so that vdev space usage
stats on L2ARC devices accurately track the volume of buffers
stored on them, allowing users to see the exact L2ARC usage in
"zpool iostat -v".
References:
https://www.illumos.org/issues/4897https://github.com/illumos/illumos-gate/commit/3038a2b
Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2555
4757 ZFS embedded-data block pointers ("zero block compression")
4913 zfs release should not be subject to space checks
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Max Grossman <max.grossman@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Approved by: Dan McDonald <danmcd@omniti.com>
References:
https://www.illumos.org/issues/4757https://www.illumos.org/issues/4913https://github.com/illumos/illumos-gate/commit/5d7b4d4
Porting notes:
For compatibility with the fastpath code the zio_done() function
needed to be updated. Because embedded-data block pointers do
not require DVAs to be allocated the associated vdevs will not
be marked and therefore should not be unmarked.
Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2544
4370 avoid transmitting holes during zfs send
4371 DMU code clean up
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
Approved by: Garrett D'Amore <garrett@damore.org>a
References:
https://www.illumos.org/issues/4370https://www.illumos.org/issues/4371https://github.com/illumos/illumos-gate/commit/43466aa
Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2529
As described in the comment above dmu_tx_assign() this function must
only fail if the pool is out of space. If for some other reason the
TX cannot be assigned (such as memory pressure) ERESTART must be
returned. Alternately, EAGAIN could be returned to inject a delay
but that isn't required because the caller will block on the condition
variable waiting for the next TXG.
/*
* Assign tx to a transaction group. txg_how can be one of:
*
* (1) TXG_WAIT. If the current open txg is full, waits until there's
* a new one. This should be used when you're not holding locks.
* It will only fail if we're truly out of space (or over quota).
* ...
*/
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Closes#2287
Also, make sure we use clock_t for ddi_get_lbolt to prevent type conversion
from screwing things.
Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2142
4088 use after free in arc_release()
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Garrett D'Amore <garrett@damore.org>
Reviewed by: Saso Kiselkov <skiselkov.ml@gmail.com>
Approved by: Dan McDonald <danmcd@nexenta.com>
References:
https://www.illumos.org/issues/4088illumos/illumos-gate@ccc22e1304
From the illumos issue:
A race-induced use after free occurs in arc_release() where the
ARC header is used outside the critical section protected by the
hash_lock.
Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <ryao@gentoo.org>
Closes#2162
Unfortunately, this change is an cheap attempt to work around a
pathological workload for the ARC. A "real" solution still needs to be
fleshed out, so this patch is intended to alleviate the situation in the
meantime. Let me try and describe the problem..
Data buffers residing in the dbuf hash table (dbuf cache) will keep a
hold on their respective dnode, this dnode will in turn keep a hold on
its backing dbuf (the physical block of the dnode object backing it).
Since the dnode has a hold on its backing dbuf, the arc buffer for this
dbuf is unevictable. What this essentially boils down to, "data" buffers
have the potential to pin "metadata" in the arc (as a result of these
dnode object buffers being unevictable).
This scenario becomes a real problem when the workload consists of many
small files (e.g. creating millions of 4K files). With this workload,
the arc's "arc_meta_used" space get filled up with buffers for any
resident directories as well as buffers for the objset's dnode object.
Once the "arc_meta_limit" is reached, the directory buffers will be
evicted and only the unevictable dnode object buffers will reside. If
the workload is simply creating new small files, these dnode object
buffers will never even be needed again, whereas the directory buffers
will be used constantly until the creates move to a new directory.
If "arc_c" and "arc_meta_limit" are sized appropriately, this
situation wont occur. This is because as the data buffers accumulate,
"arc_size" will eventually approach "arc_c" (before "arc_meta_used"
reaches "arc_meta_limit"); at that point the data buffers will be
evicted, which releases the hold on the dnode, which releases the hold
on the dnode object's dbuf, which allows that buffer to be evicted from
the arc in preference to more "useful" metadata.
So, to side step the issue, we simply need to ensure "arc_size" reaches
"arc_c" before "arc_meta_used" reaches "arc_meta_limit". In order to
pick a proper limit, we have to do some math.
To make things a little easier to follow, it is assumed that there will
only be a single data buffer per file (which is probably always the case
for "small" files anyways).
Based on the current internals of the arc, if N files residing in the
dbuf cache all pin a single dnode buffer (i.e. their dnodes all share
the same physical dnode object block), then the following amount of
"arc_meta_used" space will be consumed:
- 16K for the dnode object's block - [ 16384 bytes]
- N * sizeof(dnode_t) -------------- [ N * 928 bytes]
- (N + 1) * sizeof(arc_buf_t) ------ [(N + 1) * 72 bytes]
- (N + 1) * sizeof(arc_buf_hdr_t) -- [(N + 1) * 264 bytes]
- (N + 1) * sizeof(dmu_buf_impl_t) - [(N + 1) * 280 bytes]
To simplify, these N files will pin the following amount of
"arc_meta_used" space as unevictable:
Pinned "arc_meta_used" bytes = 16384 + N * 928 + (N + 1) * (72 + 264 + 280)
Pinned "arc_meta_used" bytes = 17000 + N * 1544
This pinned space is regardless of the size of the files, and is only
dependent on the number of pinned dnodes sharing a physical block
(i.e. N). For example, 32 512b files sharing a single dnode object
block would consume the same "arc_meta_used" space as 32 4K files
sharing a single dnode object block.
Now, given a files size of S, we can determine the total amount of
space that will be consumed in the arc:
Total = 17000 + N * 1544 + S * N
^^^^^^^^^^^^^^^^ ^^^^^
metadata data
So, given these formulas, we can generate a table which states the ratio
of pinned metadata to total arc (meta + data) using different values of
N (number of pinned dnodes per pinned physical dnode block) and S (size
of the file).
File Sizes (S)
| 512 | 1024 | 2048 | 4096 | 8192 | 16384 |
---+----------+----------+----------+----------+----------+----------+
1 | 0.973132 | 0.947670 | 0.900544 | 0.819081 | 0.693597 | 0.530921 |
2 | 0.951497 | 0.907481 | 0.830632 | 0.710325 | 0.550779 | 0.380051 |
N 4 | 0.918807 | 0.849809 | 0.738842 | 0.585844 | 0.414271 | 0.261250 |
8 | 0.877541 | 0.781803 | 0.641770 | 0.472505 | 0.309333 | 0.182965 |
16 | 0.835819 | 0.717945 | 0.559996 | 0.388885 | 0.241376 | 0.137253 |
32 | 0.802106 | 0.669597 | 0.503304 | 0.336277 | 0.202123 | 0.112423 |
As you can see, if we wanted to support the absolute worst case of 1
dnode per physical dnode block and 512b files, we would have to set the
"arc_meta_limit" to something greater than 97.3132% of "arc_c_max". At
that point, it essentially defeats the purpose of having an
"arc_meta_limit" at all.
This patch changes the default value of "arc_meta_limit" to be 75% of
"arc_c_max", which should be good enough for "most" workloads (I think).
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2110
Previously, the "data_size" field in the arcstats kstat contained the
amount of cached "metadata" and "data" in the ARC. The problem is this
then made it difficult to extract out just the "metadata" size, or just
the "data" size.
To make it easier to distinguish the two values, "data_size" has been
modified to count only buffers of type ARC_BUFC_DATA, and "meta_size"
was added to count only buffers of type ARC_BUFC_METADATA. If one wants
the old "data_size" value, simply sum the new "data_size" and
"meta_size" values.
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2110
When the arc is at it's size limit and a new buffer is added, data will
be evicted (or recycled) from the arc to make room for this new buffer.
As far as I can tell, this is to try and keep the arc from over stepping
it's bounds (i.e. keep it below the size limitation placed on it).
This makes sense conceptually, but there appears to be a subtle flaw in
its current implementation, resulting in metadata buffers being
throttled. When it evicts from the arc's lists, it also passes in a
"type" so as to remove a buffer of the same type that it is adding. The
problem with this is that once the size limit is hit, the ratio of
"metadata" to "data" contained in the arc essentially becomes fixed.
For example, consider the following scenario:
* the size of the arc is capped at 10G
* the meta_limit is capped at 4G
* 9G of the arc contains "data"
* 1G of the arc contains "metadata"
Now, every time a new "metadata" buffer is created and added to the arc,
an older "metadata" buffer(s) will be removed from the arc; preserving
the 9G "data" to 1G "metadata" ratio that was in-place when the size
limit was reached. This occurs even though the amount of "metadata" is
far below the "metadata" limit. This can result in the arc behaving
pathologically for certain workloads.
To fix this, the arc_get_data_buf function was modified to evict "data"
from the arc even when adding a "metadata" buffer; unless it's at the
"metadata" limit. In addition, arc_evict now more closely resembles
arc_evict_ghost; such that when evicting "data" from the arc, it may
make a second pass over the arc lists and evict "metadata" if it cannot
meet the eviction size the first time around.
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2110
Using "arc_meta_used" to determine if the arc's mru list is over it's
target value of "arc_p" doesn't seem correct. The size of the mru list
and the value of "arc_meta_used", although related, are completely
independent. Buffers contained in "arc_meta_used" may not even be
contained in the arc's mru list. As such, this patch removes
"arc_meta_used" from the calculation in arc_adjust.
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2110
To maintain a strict limit on the metadata contained in the arc, while
preventing the arc buffer headers from completely consuming the
"arc_meta_used" space, we need to evict metadata buffers from the arc's
ghost lists along with the regular lists.
This change modifies arc_adjust_meta such that it more closely models
the adjustments made in arc_adjust. "arc_meta_used" is used similarly to
"arc_size", and "arc_meta_limit" is used similarly to "arc_c".
Testing metadata intensive workloads (e.g. creating, copying, and
removing millions of small files and/or directories) has shown this
change to make a dramatic improvement to the hit rate maintained in the
arc. While I think there is still room for improvement, this is a big
step in the right direction.
In addition, zpl_free_cached_objects was made into a no-op as I'm not
yet sure how to properly implement that function.
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2110
This reverts commit c11a12bc3b.
Out of memory events were fixed by reverting this patch.
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2110
It's unclear why adjustments to arc_p need to be dampened as they are in
arc_adjust. With that said, it's removal significantly improves the arc's
ability to "warm up" to a given workload. Thus, I'm disabling by default
until its usefulness is better understood.
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2110
Setting a limit on the minimum value of "arc_p" has been shown to have
detrimental effects on the arc hit rate for certain "metadata" intensive
workloads. Specifically, this has been exhibited with a workload that
constantly dirties new "metadata" but also frequently touches a "small"
amount of mfu data (e.g. mkdir's).
What is seen is that the new anon data throttles the mfu list to a
negligible size (because arc_p > anon + mru in arc_get_data_buf), even
though the mfu ghost list receives a constant stream of hits. To remedy
this, arc_p is now allowed to drop to zero if the algorithm deems it
necessary.
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2110
For specific workloads consisting mainly of mfu data and new anon data
buffers, the aggressive growth of arc_p found in the arc_get_data_buf()
function can have detrimental effects on the mfu list size and ghost
list hit rate.
Running a workload consisting of two processes:
* Process 1 is creating many small files
* Process 2 is tar'ing a directory consisting of many small files
I've seen arc_p and the mru grow to their maximum size, while the mru
ghost list receives 100K times fewer hits than the mfu ghost list.
Ideally, as the mfu ghost list receives hits, arc_p should be driven
down and the size of the mfu should increase. Given the specific
workload I was testing with, the mfu list size should grow to a point
where almost no mfu ghost list hits would occur. Unfortunately, this
does not happen because the newly dirtied anon buffers constancy drive
arc_p to its maximum value and keep it there (effectively prioritizing
the mru list and starving the mfu list down to a negligible size).
The logic to increment arc_p from within the arc_get_data_buf() function
was introduced many years ago in this upstream commit:
commit 641fbdae3a027d12b3c3dcd18927ccafae6d58bc
Author: maybee <none@none>
Date: Wed Dec 20 15:46:12 2006 -0800
6505658 target MRU size (arc.p) needs to be adjusted more aggressively
and since I don't fully understand the motivation for the change, I am
reluctant to completely remove it.
As a way to test out how it's removal might affect performance, I've
disabled that code by default, but left it tunable via a module option.
Thus, if its removal is found to be grossly detrimental for certain
workloads, it can be re-enabled on the fly, without a code change.
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2110
In an attempt to prevent arc_c from collapsing "too fast", the
arc_shrink() function was updated to take a "bytes" parameter by this
change:
commit 302f753f16
Author: Brian Behlendorf <behlendorf1@llnl.gov>
Date: Tue Mar 13 14:29:16 2012 -0700
Integrate ARC more tightly with Linux
Unfortunately, that change failed to make a similar change to the way
that arc_p was updated. So, there still exists the possibility for arc_p
to collapse to near 0 when the kernel start calling the arc's shrinkers.
This change attempts to fix this, by decrementing arc_p by the "bytes"
parameter in the same way that arc_c is updated.
In addition, a minimum value of arc_p is attempted to be maintained,
similar to the way a minimum arc_p value is maintained in arc_adapt().
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2110
Decrease the mimimum ARC size from 1/32 of total system memory
(or 64MB) to a much smaller 4MB.
1) Large systems with over a 1TB of memory are being deployed
and reserving 1/32 of this memory (32GB) as the mimimum
requirement is overkill.
2) Tiny systems like the raspberry pi may only have 256MB of
memory in which case 64MB is far too large.
The ARC should be reclaimable if the VFS determines it needs
the memory for some other purpose. If you want to ensure the
ARC is never completely reclaimed due to memory pressure you
may still set a larger value with zfs_arc_min.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Issue #2110
Commit e0b0ca9 accidentally corrupted the l2_asize displayed in
arcstats. This was caused by changing the l2arc_buf_hdr.b_asize
member from an int to uint32_t type. There are places in the
code where this field is cast to a uint64_t resulting in the
b_hits member being treated as part of b_asize.
To resolve the issue the type has been changed to a uint64_t,
and the b_hits member is placed after the enum to prevent the
size of the structure from increasing.
This is a good example of exactly why it's a bad idea to use
ambiguous types (int) in these structures.
Signed-off-by: DHE <git@dehacked.net>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#1990
Back the allocations for ddt tables+entries and l2arc headers with
kmem caches. This will reduce the cost of allocating these commonly
used structures and allow for greater visibility of them through the
/proc/spl/kmem/slab interface.
Signed-off-by: John Layman <jlayman@sagecloud.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#1893
The vast majority of these changes are in Linux specific code.
They are the result of not having an automated style checker to
validate the code when it was originally written. Others were
caused when the common code was slightly adjusted for Linux.
This patch contains no functional changes. It only refreshes
the code to conform to style guide.
Everyone submitting patches for inclusion upstream should now
run 'make checkstyle' and resolve any warning prior to opening
a pull request. The automated builders have been updated to
fail a build if when 'make checkstyle' detects an issue.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#1821
The MAX when initializing arc_c_max doesn't make any sense because
it hasn't been set anywhere before. Though, arc_c_max should be
implicitly set to zero when initializing arc_stats, so the MAX
doesn't make any difference.
The MAX was mistakenly left if place when the Illumos default
values were changed for Linux.
Signed-off-by: david.chen <tuxoko@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#1941
4045 zfs write throttle & i/o scheduler performance work
1. The ZFS i/o scheduler (vdev_queue.c) now divides i/os into 5 classes: sync
read, sync write, async read, async write, and scrub/resilver. The scheduler
issues a number of concurrent i/os from each class to the device. Once a class
has been selected, an i/o is selected from this class using either an elevator
algorithem (async, scrub classes) or FIFO (sync classes). The number of
concurrent async write i/os is tuned dynamically based on i/o load, to achieve
good sync i/o latency when there is not a high load of writes, and good write
throughput when there is. See the block comment in vdev_queue.c (reproduced
below) for more details.
2. The write throttle (dsl_pool_tempreserve_space() and
txg_constrain_throughput()) is rewritten to produce much more consistent delays
when under constant load. The new write throttle is based on the amount of
dirty data, rather than guesses about future performance of the system. When
there is a lot of dirty data, each transaction (e.g. write() syscall) will be
delayed by the same small amount. This eliminates the "brick wall of wait"
that the old write throttle could hit, causing all transactions to wait several
seconds until the next txg opens. One of the keys to the new write throttle is
decrementing the amount of dirty data as i/o completes, rather than at the end
of spa_sync(). Note that the write throttle is only applied once the i/o
scheduler is issuing the maximum number of outstanding async writes. See the
block comments in dsl_pool.c and above dmu_tx_delay() (reproduced below) for
more details.
This diff has several other effects, including:
* the commonly-tuned global variable zfs_vdev_max_pending has been removed;
use per-class zfs_vdev_*_max_active values or zfs_vdev_max_active instead.
* the size of each txg (meaning the amount of dirty data written, and thus the
time it takes to write out) is now controlled differently. There is no longer
an explicit time goal; the primary determinant is amount of dirty data.
Systems that are under light or medium load will now often see that a txg is
always syncing, but the impact to performance (e.g. read latency) is minimal.
Tune zfs_dirty_data_max and zfs_dirty_data_sync to control this.
* zio_taskq_batch_pct = 75 -- Only use 75% of all CPUs for compression,
checksum, etc. This improves latency by not allowing these CPU-intensive tasks
to consume all CPU (on machines with at least 4 CPU's; the percentage is
rounded up).
--matt
APPENDIX: problems with the current i/o scheduler
The current ZFS i/o scheduler (vdev_queue.c) is deadline based. The problem
with this is that if there are always i/os pending, then certain classes of
i/os can see very long delays.
For example, if there are always synchronous reads outstanding, then no async
writes will be serviced until they become "past due". One symptom of this
situation is that each pass of the txg sync takes at least several seconds
(typically 3 seconds).
If many i/os become "past due" (their deadline is in the past), then we must
service all of these overdue i/os before any new i/os. This happens when we
enqueue a batch of async writes for the txg sync, with deadlines 2.5 seconds in
the future. If we can't complete all the i/os in 2.5 seconds (e.g. because
there were always reads pending), then these i/os will become past due. Now we
must service all the "async" writes (which could be hundreds of megabytes)
before we service any reads, introducing considerable latency to synchronous
i/os (reads or ZIL writes).
Notes on porting to ZFS on Linux:
- zio_t gained new members io_physdone and io_phys_children. Because
object caches in the Linux port call the constructor only once at
allocation time, objects may contain residual data when retrieved
from the cache. Therefore zio_create() was updated to zero out the two
new fields.
- vdev_mirror_pending() relied on the depth of the per-vdev pending queue
(vq->vq_pending_tree) to select the least-busy leaf vdev to read from.
This tree has been replaced by vq->vq_active_tree which is now used
for the same purpose.
- vdev_queue_init() used the value of zfs_vdev_max_pending to determine
the number of vdev I/O buffers to pre-allocate. That global no longer
exists, so we instead use the sum of the *_max_active values for each of
the five I/O classes described above.
- The Illumos implementation of dmu_tx_delay() delays a transaction by
sleeping in condition variable embedded in the thread
(curthread->t_delay_cv). We do not have an equivalent CV to use in
Linux, so this change replaced the delay logic with a wrapper called
zfs_sleep_until(). This wrapper could be adopted upstream and in other
downstream ports to abstract away operating system-specific delay logic.
- These tunables are added as module parameters, and descriptions added
to the zfs-module-parameters.5 man page.
spa_asize_inflation
zfs_deadman_synctime_ms
zfs_vdev_max_active
zfs_vdev_async_write_active_min_dirty_percent
zfs_vdev_async_write_active_max_dirty_percent
zfs_vdev_async_read_max_active
zfs_vdev_async_read_min_active
zfs_vdev_async_write_max_active
zfs_vdev_async_write_min_active
zfs_vdev_scrub_max_active
zfs_vdev_scrub_min_active
zfs_vdev_sync_read_max_active
zfs_vdev_sync_read_min_active
zfs_vdev_sync_write_max_active
zfs_vdev_sync_write_min_active
zfs_dirty_data_max_percent
zfs_delay_min_dirty_percent
zfs_dirty_data_max_max_percent
zfs_dirty_data_max
zfs_dirty_data_max_max
zfs_dirty_data_sync
zfs_delay_scale
The latter four have type unsigned long, whereas they are uint64_t in
Illumos. This accommodates Linux's module_param() supported types, but
means they may overflow on 32-bit architectures.
The values zfs_dirty_data_max and zfs_dirty_data_max_max are the most
likely to overflow on 32-bit systems, since they express physical RAM
sizes in bytes. In fact, Illumos initializes zfs_dirty_data_max_max to
2^32 which does overflow. To resolve that, this port instead initializes
it in arc_init() to 25% of physical RAM, and adds the tunable
zfs_dirty_data_max_max_percent to override that percentage. While this
solution doesn't completely avoid the overflow issue, it should be a
reasonable default for most systems, and the minority of affected
systems can work around the issue by overriding the defaults.
- Fixed reversed logic in comment above zfs_delay_scale declaration.
- Clarified comments in vdev_queue.c regarding when per-queue minimums take
effect.
- Replaced dmu_tx_write_limit in the dmu_tx kstat file
with dmu_tx_dirty_delay and dmu_tx_dirty_over_max. The first counts
how many times a transaction has been delayed because the pool dirty
data has exceeded zfs_delay_min_dirty_percent. The latter counts how
many times the pool dirty data has exceeded zfs_dirty_data_max (which
we expect to never happen).
- The original patch would have regressed the bug fixed in
zfsonlinux/zfs@c418410, which prevented users from setting the
zfs_vdev_aggregation_limit tuning larger than SPA_MAXBLOCKSIZE.
A similar fix is added to vdev_queue_aggregate().
- In vdev_queue_io_to_issue(), dynamically allocate 'zio_t search' on the
heap instead of the stack. In Linux we can't afford such large
structures on the stack.
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Ned Bass <bass6@llnl.gov>
Reviewed by: Brendan Gregg <brendan.gregg@joyent.com>
Approved by: Robert Mustacchi <rm@joyent.com>
References:
http://www.illumos.org/issues/4045illumos/illumos-gate@69962b5647
Ported-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#1913
3995 Memory leak of compressed buffers in l2arc_write_done
References:
https://illumos.org/issues/3995
Ported-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#1688
Issue #1775
3112 ztest does not honor ZFS_DEBUG
3113 ztest should use watchpoints to protect frozen arc bufs
3114 some leaked nvlists in zfsdev_ioctl
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Matt Amdur <Matt.Amdur@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <chris.siden@delphix.com>
Approved by: Eric Schrock <eric.schrock@delphix.com>
References:
https://www.illumos.org/issues/3112https://www.illumos.org/issues/3113https://www.illumos.org/issues/3114illumos/illumos-gate@cd1c8b85eb
The /proc/self/cmd watchpoint interface is specific to Solaris.
Therefore, the #3113 implementation was reworked to use the more
portable mprotect(2) system call. When the pages are watched they
are marked read-only for protection. Any write to the protected
address range immediately trigger a SIGSEGV. The pages are marked
writable again when they are unwatched.
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1489
3236 zio nop-write
Reviewed by: Matt Ahrens <matthew.ahrens@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Christopher Siden <chris.siden@delphix.com>
Approved by: Garrett D'Amore <garrett@damore.org>
References:
illumos/illumos-gate@80901aea8ehttps://www.illumos.org/issues/3236
Porting Notes
1. This patch is being merged dispite an increased instance of
https://www.illumos.org/issues/3113 being triggered by ztest.
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1489
3742 zfs comments need cleaner, more consistent style
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Approved by: Christopher Siden <christopher.siden@delphix.com>
References:
https://www.illumos.org/issues/3742illumos/illumos-gate@f717074149
Ported-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1775
Porting notes:
1. The change to zfs_vfsops.c was dropped because it involves
zfs_mount_label_policy, which does not exist in the Linux port.
3741 zfs needs better comments
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Approved by: Christopher Siden <christopher.siden@delphix.com>
References:
https://www.illumos.org/issues/3741illumos/illumos-gate@3e30c24aee
Ported-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1775
3598 want to dtrace when errors are generated in zfs
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Approved by: Garrett D'Amore <garrett@damore.org>
References:
https://www.illumos.org/issues/3598illumos/illumos-gate@be6fd75a69
Ported-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1775
Porting notes:
1. include/sys/zfs_context.h has been modified to render some new
macros inert until dtrace is available on Linux.
2. Linux-specific changes have been adapted to use SET_ERROR().
3. I'm NOT happy about this change. It does nothing but ugly
up the code under Linux. Unfortunately we need to take it to
avoid more merge conflicts in the future. -Brian
3561 arc_meta_limit should be exposed via kstats
3116 zpool reguid may log negative guids to internal SPA history
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Gordon Ross <gordon.ross@nexenta.com>
Approved by: Garrett D'Amore <garrett@damore.org>
References:
https://www.illumos.org/issues/3561https://www.illumos.org/issues/3116illumos/illumos-gate@20128a0826
Ported-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Porting Notes:
1. The spa change was accidentally included in the libzfs_core merge.
2. "Add missing arcstats" (1834f2d8b7)
already implemented these kstats a few years ago.
3522 zfs module should not allow uninitialized variables
Reviewed by: Sebastien Roy <seb@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Garrett D'Amore <garrett@damore.org>
References:
https://www.illumos.org/issues/3522illumos/illumos-gate@d5285cae91
Ported-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Porting notes:
1. ZFSOnLinux had already addressed many of these issues because of
its use of -Wall. However, the manner in which they were addressed
differed. The illumos fixes replace the ones previously made in
ZFSOnLinux to reduce code differences.
2. Part of the upstream patch made a small change to arc.c that might
address zfsonlinux/zfs#1334.
3. The initialization of aclsize in zfs_log_create() differs because
vsecp is a NULL pointer on ZFSOnLinux.
4. The changes to zfs_register_callbacks() were dropped because it
has diverged and needs to be resynced.
Currently there is no mechanism to inspect which dbufs are being
cached by the system. There are some coarse counters in arcstats
by they only give a rough idea of what's being cached. This patch
aims to improve the current situation by adding a new dbufs kstat.
When read this new kstat will walk all cached dbufs linked in to
the dbuf_hash. For each dbuf it will dump detailed information
about the buffer. It will also dump additional information about
the referenced arc buffer and its related dnode. This provides a
more complete view in to exactly what is being cached.
With this generic infrastructure in place utilities can be written
to post-process the data to understand exactly how the caching is
working. For example, the data could be processed to show a list
of all cached dnodes and how much space they're consuming. Or a
similar list could be generated based on dnode type. Many other
ways to interpret the data exist based on what kinds of questions
you're trying to answer.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Prakash Surya <surya1@llnl.gov>
This change is an attempt to add visibility into the arc_read calls
occurring on a system, in real time. To do this, a list was added to the
in memory SPA data structure for a pool, with each element on the list
corresponding to a call to arc_read. These entries are then exported
through the kstat interface, which can then be interpreted in userspace.
For each arc_read call, the following information is exported:
* A unique identifier (uint64_t)
* The time the entry was added to the list (hrtime_t)
(*not* wall clock time; relative to the other entries on the list)
* The objset ID (uint64_t)
* The object number (uint64_t)
* The indirection level (uint64_t)
* The block ID (uint64_t)
* The name of the function originating the arc_read call (char[24])
* The arc_flags from the arc_read call (uint32_t)
* The PID of the reading thread (pid_t)
* The command or name of thread originating read (char[16])
From this exported information one can see, in real time, exactly what
is being read, what function is generating the read, and whether or not
the read was found to be already cached.
There is still some work to be done, but this should serve as a good
starting point.
Specifically, dbuf_read's are not accounted for in the currently
exported information. Thus, a follow up patch should probably be added
to export these calls that never call into arc_read (they only hit the
dbuf hash table). In addition, it might be nice to create a utility
similar to "arcstat.py" to digest the exported information and display
it in a more readable format. Or perhaps, log the information and allow
for it to be "replayed" at a later time.
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
This reverts commit fadd0c4da1 which
introduced a regression in honoring the meta limit.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Close#1660
When the meta limit is exceeded the ARC evicts some meta data
buffers from the mfu+mru lists. Unfortunately, for meta data
heavy workloads it's possible for these buffers to accumulate
on the ghost lists if arc_c doesn't exceed arc_size.
To handle this case arc_adjust_meta() has been entended to
explicitly evict meta data buffers from the ghost lists in
proportion to what was evicted from the mfu+mru lists.
If this is insufficient we request that the VFS release
some inodes and dentries. This will result in the release
of some dnodes which are counted as 'other' metadata.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
The default behavior of arc_evict_ghost() is to start by evicting
data buffers. Then only if the requested number of bytes to evict
cannot be satisfied by data buffers move on to meta data buffers.
This is ideal for honoring arc_c since it's preferable to keep the
meta data cached. However, if we're trying to free memory from the
arc to honor the meta limit it's a problem because we will need to
discard all the data to get to the meta data.
To avoid this issue the arc_evict_ghost() is now passed a fourth
argumented describing which buffer type to start with. The
arc_evict() function already behaves exactly like this for a
same reason so this is consistent with the existing code.
All existing callers have been updated to pass ARC_BUFC_DATA so
this patch introduces no functional change. New callers may
pass ARC_BUFC_METADATA to skip immediately to evicting meta
data leaving the normal data untouched.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
3137 L2ARC compression
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Dan McDonald <danmcd@nexenta.com>
References:
illumos/illumos-gate@aad02571bchttps://www.illumos.org/issues/3137http://wiki.illumos.org/display/illumos/L2ARC+Compression
Notes for Linux port:
A l2arc_nocompress module option was added to prevent the
compression of l2arc buffers regardless of how a dataset's
compression property is set. This allows the legacy behavior
to be preserved.
Ported by: James H <james@kagisoft.co.uk>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#1379
This is analogous to SPL commit zfsonlinux/spl@b9b3715. While
we don't have clear evidence of systems getting caught here
indefinately like in the SPL this ensures that it will never
happen.
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#1579
The code involving b_thawed appears to be dead, so lets discard it.
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1614
These functions are used in neither Illumos nor ZFSOnLinux. They appear
to have been replaced by arc_buf_alloc()/arc_buf_free(), so lets remove
them.
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1614
The l2arc module options can be made safely writable. This allows
the options to be changed without unloading/loading the modules.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
These days modern SSDs can efficiently service concurrent reads
and writes. When this flag was added that wasn't really the
case for a variety of SSD controllers. But now we can set the
default value to take advantage of this parallelism and only
disable this as needed for specific troublesome hardware.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Based on the comments in arc.c we know that buffers can exist both
in arc and l2arc, under this circumstance both arc_buf_hdr_t and
l2arc_buf_hdr_t will be allocated. However the current logic only
cares for memory that l2arc_buf_hdr takes up when the buffer's
state transfers from or to arc_l2c_only. This will cause obvious
deviations for illumos's zfs version since the sizeof(l2arc_buf_hdr)
is larger than ZOL's. We can implement the calcuation in the
following simple way:
1. When allocate a l2arc_buf_hdr_t we add its memory consumption
instantly and subtract it when we free or evict the l2arc buf.
2. According to l2arc_hdr_stat_add and l2arc_hdr_stat_remove, if
the buffer only stays in l2arc we should also add the memory
its arc_buf_hdr_t consumes, so we only need to add HDR_SIZE to
arcstat_l2_hdr_size since we already concerned with L2HDR_SIZE
in step 1 and the same for transfering arc bufs from l2arc only
state.
The testbox has 2 4-core Intel Xeon CPUs(2.13GHz), with 16GB memory
and tests were set upped in the following way:
1. Fdisked a SATA disk into two partitions, one partition for zpool
storage and the other one was used as the cache device.
2. Generated some files occupying 14GB altogether in the zpool
prepared in step 1 using iozone.
3. Read them all using md5sum and watched the l2arc related statistics
in /proc/spl/kstat/zfs/arcstats. After the reading ended the
l2_hdr_size and l2_size were shown like this:
l2_size 4 4403780608
l2_hdr_size 4 0
which was weird.
4. After applying this patch and reran step 1-3, the results were
as following:
l2_size 4 4306443264
l2_hdr_size 4 535600
these numbers made sense, on 64-bit systems the
sizeof(l2arc_buf_hdr_t) is 16 bytes. Assue all blocks cached by
l2arc are 128KB, so 535600/16*128*1024=4387635200, since not all
blocks are equal-sized, the theoretical result will be a little
bigger, as we can see.
Since I'm familiar with systemtap instrumentation tool I used it to
examine what had happened. The script looked like this:
probe module("zfs").function("arc_chage_state")
{
if ($new_state == $arc_l2_only)
printf("change arc buf to arc_l2_only\n")
}
It will print out some information each time we call funciton
arc_chage_state if the argument new_state is arc_l2_only. I
gathered the trace logs and found that none of the arc bufs ran
into arc state arc_l2_only when the tests was running, this was
the reason why l2_hdr_size in step 3 was 0. The arc bufs fell into
arc_l2_only when the pool or the filesystem was offlined.
Signed-off-by: Ying Zhu <casualfisher@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
When we remove references of arc bufs in the arc_anon state we
needn't take its header's hash_lock, so postpone it to where we
really need it to avoid unnecessary invocations of function buf_hash.
Signed-off-by: Ying Zhu <casualfisher@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#1557
3805 arc shouldn't cache freed blocks
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Richard Elling <richard.elling@dey-sys.com>
Reviewed by: Will Andrews <will@firepipe.net>
Approved by: Dan McDonald <danmcd@nexenta.com>
References:
illumos/illumos-gate@6e6d5868f5https://www.illumos.org/issues/3805
ZFS should proactively evict freed blocks from the cache.
On dcenter, we saw that we were caching ~256GB of metadata, while the
pool only had <4GB of metadata on disk. We were wasting about half the
system's RAM (252GB) on blocks that have been freed.
Even though these freed blocks will never be used again, and thus will
eventually be evicted, this causes us to use memory inefficiently for 2
reasons:
1. A block that is freed has no chance of being accessed again, but will
be kept in memory preferentially to a block that was accessed before it
(and is thus older) but has not been freed and thus has at least some
chance of being accessed again.
2. We partition the ARC into several buckets:
user data that has been accessed only once (MRU)
metadata that has been accessed only once (MRU)
user data that has been accessed more than once (MFU)
metadata that has been accessed more than once (MFU)
The user data vs metadata split is somewhat arbitrary, and the primary
control on how much memory is used to cache data vs metadata is to
simply try to keep the proportion the same as it has been in the past
(each bucket "evicts against" itself). The secondary control is to
evict data before evicting metadata.
Because of this bucketing, we may end up with one bucket mostly
containing freed blocks that are very old, while another bucket has more
recently accessed, still-allocated blocks. Data in the useful bucket
(with still-allocated blocks) may be evicted in preference to data in
the useless bucket (with old, freed blocks).
On dcenter, we saw that the MFU metadata bucket was 230MB, while the MFU
data bucket was 27GB and the MRU metadata bucket was 256GB. However,
the vast majority of data in the MRU metadata bucket (256GB) was freed
blocks, and thus useless. Meanwhile, the MFU metadata bucket (230MB)
was constantly evicting useful blocks that will be soon needed.
The problem of cache segmentation is a larger problem that needs more
investigation. However, if we stop caching freed blocks, it should
reduce the impact of this more fundamental issue.
Ported-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#1503
3006 VERIFY[S,U,P] and ASSERT[S,U,P] frequently check if first
argument is zero
Reviewed by Matt Ahrens <matthew.ahrens@delphix.com>
Reviewed by George Wilson <george.wilson@delphix.com>
Approved by Eric Schrock <eric.schrock@delphix.com>
References:
illumos/illumos-gate@fb09f5aad4https://illumos.org/issues/3006
Requires:
zfsonlinux/spl@1c6d149feb
Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#1509
The PaX team modified the kernel's modpost to report writeable function
pointers as section mismatches because they are potential exploit
targets. We could ignore the warnings, but their presence can obscure
actual issues. Proper const correctness can also catch programming
mistakes.
Building the kernel modules against a PaX/GrSecurity patched Linux 3.4.2
kernel reports 133 section mismatches prior to this patch. This patch
eliminates 130 of them. The quantity of writeable function pointers
eliminated by constifying each structure is as follows:
vdev_opts_t 52
zil_replay_func_t 24
zio_compress_info_t 24
zio_checksum_info_t 9
space_map_ops_t 7
arc_byteswap_func_t 5
The remaining 3 writeable function pointers cannot be addressed by this
patch. 2 of them are in zpl_fs_type. The kernel's sget function requires
that this be non-const. The final writeable function pointer is created
by SPL_SHRINKER_DECLARE. The kernel's set_shrinker() and
remove_shrinker() functions also require that this be non-const.
Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#1300
The zfs_arc_memory_throttle_disable module option was introduced
by commit 0c5493d470 to resolve a
memory miscalculation which could result in the txg_sync thread
spinning.
When this was first introduced the default behavior was left
unchanged until enough real world usage confirmed there were no
unexpected issues. We've now reached that point. Linux's
direct reclaim is working as expected so we're enabling this
behavior by default.
This helps pave the way to retire the spl_kmem_availrmem()
functionality in the SPL layer. This was the only caller.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #938
The way in which virtual box ab(uses) memory can throw off the
free memory calculation in arc_memory_throttle(). The result is
the txg_sync thread will effectively spin waiting for memory to
be released even though there's lots of memory on the system.
To handle this case I'm adding a zfs_arc_memory_throttle_disable
module option largely for virtual box users. Setting this option
disables free memory checks which allows the txg_sync thread to
make progress.
By default this option is disabled to preserve the current
behavior. However, because Linux supports direct memory reclaim
it's doubtful throttling due to perceived memory pressure is ever
a good idea. We should enable this option by default once we've
done enough real world testing to convince ourselve there aren't
any unexpected side effects.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#938
Commit 1eb5bfa introduced a new zfs_disable_dup_eviction tunable.
It should have been made available as a module option in the
original patch but was overlooked.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
