For short transactions overhead of context switch can be too large.
Skipping it gives significant latency reduction. For large ones,
including multiple ZIOs, latency is less critical, while throughput
there may become limited by checksumming speed of single CPU core.
To get best of both cases, execute last ZIO directly from calling
thread context to save latency, while all others (if there are any)
enqueue to taskqueues in traditional way.
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
7570 tunable to allow zvol SCSI unmap to return on commit of txn to ZIL
illumos/illumos-gate@1c9272b8611c9272b861https://www.illumos.org/issues/7570
Based on the discovery that every unmap waits for the commit of the txn to the ZIL,
introducing a very high latency to unmap commands, this behavior was made into a
tunable zvol_unmap_sync_enabled and set to false. The net impact of this change is
that by default SCSI unmap commands will result in space being freed within the zvol
(today they are ignored and returned with good status). However, unlike the code
today, instead of 18+ms per unmap, they take about 30us.
With the testing done on NTFS against a Win2k12 target, the new behavior should work
seamlessly. Files on the zvol that have already been set with the zfree application
will continue to write 0's when deleted, and any new files created since zvol
creation will send unmap commands when deleted. This behavior exists today, but with
this change the unmap commands will be processed and result in reclaim of space.
Author: Stephen Blinick <stephen.blinick@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Steve Gonczi <steve.gonczi@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: Saso Kiselkov <saso.kiselkov@nexenta.com>
Reviewed by: Yuri Pankov <yuri.pankov@nexenta.com>
Approved by: Robert Mustacchi <rm@joyent.com>
While there, make a change to not evict a first buffer outside the
requested eviciton range.
To do:
- give more consistent names to the size variables
- upstream to OpenZFS
PR: 216178
Reported by: lev
Tested by: lev
MFC after: 2 weeks
callout(9) prohibits callout functions from sleeping.
illumos mutexes are emulated using sx(9).
spa_deadman() calls vdev_deadman() and the latter acquires vq_lock.
As a result we can get a more confusing panic instead of a specific
panic or no panic:
sleepq_add: td 0xfffff80019669960 to sleep on wchan 0xfffff8001cff4d88 with sleeping prohibited
This change adds another level of indirection where the deadman
callout schedules spa_deadman() to be executed on taskqueue_thread.
While there, use callout_schedule(0 instead of callout_reset()
in spa_sync().
Discussed with: mav
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D9762
6676 Race between unique_insert() and unique_remove() causes ZFS fsid change
illumos/illumos-gate@40510e8eba40510e8ebahttps://www.illumos.org/issues/6676
The fsid of zfs filesystems might change after reboot or remount. The problem seems to
be caused by a race between unique_insert() and unique_remove(). The unique_remove()
is called from dsl_dataset_evict() which is now an asynchronous thread. In a case the
dsl_dataset_evict() thread is very slow and calls unique_remove() too late we will end
up with changed fsid on zfs mount.
This problem is very likely caused by #5056.
Steps to Reproduce
Note: I'm able to reproduce this always on a single core (virtual) machine. On multicore
machines it is not so easy to reproduce.
# uname -a
SunOS openindiana 5.11 illumos-633aa80 i86pc i386 i86pc Solaris
# zfs create rpool/TEST
# FS=$(echo ::fsinfo | mdb -k | grep TEST | awk '{print $1}')
# echo $FS::print vfs_t vfs_fsid | mdb -k
vfs_fsid = {
vfs_fsid.val = [ 0x54d7028a, 0x70311508 ]
}
# zfs umount rpool/TEST
# zfs mount rpool/TEST
# FS=$(echo ::fsinfo | mdb -k | grep TEST | awk '{print $1}')
# echo $FS::print vfs_t vfs_fsid | mdb -k
vfs_fsid = {
vfs_fsid.val = [ 0xd9454e49, 0x6b36d08 ]
}
#
Impact
The persistent fsid (filesystem id) is essential for proper NFS functionality.
If the fsid of a filesystem changes on remount (or after reboot) the NFS
clients might not be able to automatically recover from such event and the
manual remount of the NFS filesystems on every NFS client might be needed.
Author: Josef 'Jeff' Sipek <josef.sipek@nexenta.com>
Reviewed by: Saso Kiselkov <saso.kiselkov@nexenta.com>
Reviewed by: Sanjay Nadkarni <sanjay.nadkarni@nexenta.com>
Reviewed by: Dan Vatca <dan.vatca@gmail.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Sebastien Roy <sebastien.roy@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
As the current zfs file system is providing symlink via system attributes, need
to update the code accordingly.
Note, as the zfsboot code does not free the memory at this time, the
object list will put some stress on the boot2 heap, eventually we should
address the issue.
Reviewed by: allanjude, smh
Approved by: allanjude (mentor)
Differential Revision: https://reviews.freebsd.org/D9706
The difference of one was insignificant because zio_write_issue threads
ended up on the same run queues as other zio threads.
See sys/priority.h and sys/runq.h for more details.
Add a comment describing FreeBSD priority considerations and restore
the illumos variant of the code for comparison.
Obtained from: Panzura
MFC after: 2 weeks
Sponsored by: Panzura
The current code is written on top of GFS, a library with the generic
support for writing filesystems, which was ported from illumos.
Because of significant differences between illumos VFS and FreeBSD
VFS models, both the GFS and zfsctl code were heavily modified to
work on FreeBSD. Nonetheless, they still contain quite a few ugly
hacks and bugs.
This is a reimplementation of the zfsctl code where the VFS-specific
bits are written from scratch and only the code that interacts with
the rest of ZFS is reused.
Some highlights.
We use two types of nodes, static and on-demand. The static nodes
are used for permanent directories like .zfs, .zfs/snapshot, etc. The
on-demand nodes are used for ephemeral directories that act as snapshot
mount points.
Initially only static nodes are created. Their vnodes are instantiated
when they are looked up. The on-demand nodes and vnodes are instantiated
as needed and the nodes are destroyed as soon as the corresponding
vnodes are reclaimed.
We also try very hard to ensure that uncovered snapshot vnodes do not
linger. They are supposed to become inactive as soon as they are
uncovered and we try to recycle them immediately.
When a filesystem is unmounted all snapshots under .zfs are unmounted
first, then all vnodes are flushed and finally the static .zfs nodes
are destroyed.
There are some changes outside of zfsctl code too.
z_ctldir is never used directly (as it is an opaque pointer),
zfsctl_root() has to be used instead. The function returns a locked
vnode now, so it accepts a lock flags parameter. The function can
also fail now, e.g. during force unmounting, whereas previously it
was infallible.
zfsctl_root_lookup() is retired, instead of it VOP_LOOKUP() on the .zfs
vnode (obtained with zfsctl_root) is used.
Some ideas are picked from an independent work by will.
Reviewed by: asomers, smh
MFC after: 1 month
Relnotes: maybe
Differential Revision: https://reviews.freebsd.org/D7421
7504 kmem_reap hangs spa_sync and administrative tasks
illumos/illumos-gate@405a5a0f5chttps://github.com/illumos/illumos-gate/commit/405a5a0f5c3ab36cb76559467d1a62ba648bd80https://www.illumos.org/issues/7504
We see long spa_sync(). We are waiting to hold dp_config_rwlock for writer. Some
other thread holds dp_config_rwlock for reader, then calls arc_get_data_buf(),
which finds that arc_is_overflowing()==B_TRUE. So it waits (while holding
dp_config_rwlock for reader) for arc_reclaim_thread to signal arc_reclaim_waiters_cv.
Before signaling, arc_reclaim_thread does arc_kmem_reap_now(), which takes ~seconds.
Author: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Approved by: Dan McDonald <danmcd@omniti.com>
dtrace_trap() consumes page and protection faults triggered by code running
in DTrace probe context. Such faults occur with interrupts disabled and are
detected using a per-CPU flag. Regular faults cause dtrace_trap() to be
called with interrupts enabled, and nothing was ensuring that the flag was
read from the correct CPU. This may result in dtrace_trap() consuming
unrelated page and protection faults when DTrace is enabled, causing the
fault handler to return without actually having handled the fault.
Diagnosed by: Ryan Libby <rlibby@gmail.com>
MFC after: 3 days
Sponsored by: Dell EMC Isilon
7500 Simplify dbuf_free_range by removing dn_unlisted_l0_blkid
illumos/illumos-gate@653af1b809653af1b809https://www.illumos.org/issues/7500
With the integration of:
commit 0f6d88aded0d165f5954688a9b13bac76c38da84
Author: Alex Reece <alex@delphix.com>
Date: Sat Jul 26 13:40:04 2014 -0800
4873 zvol unmap calls can take a very long time for larger datasets
the dnode's dn_bufs field was changed from a list to a tree. As a result,
the dn_unlisted_l0_blkid field is no longer necessary.
Author: Stephen Blinick <stephen.blinick@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Approved by: Gordon Ross <gordon.w.ross@gmail.com>
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c
* In zfs_freebsd_setattr, if the caller wants to set the birthtime,
set the bits that zfs_settattr expects
* In zfs_setattr, if XAT_CREATETIME is set, set xoa_createtime,
expected by zfs_xvattr_set. The two levels of indirection seem
excessive, but it minimizes diffs vs OpenZFS.
* In zfs_setattr, check for overflow of va_birthtime (from delphij)
* Remove red herring in zfs_getattr
sys/cddl/contrib/opensolaris/uts/common/sys/vnode.h
* Un-booby-trap some macros
New tests are under review at https://github.com/pjd/pjdfstest/pull/6
Reviewed by: avg
MFC after: 3 weeks
Sponsored by: Spectra Logic Corp
Differential Revision: https://reviews.freebsd.org/D9353
It is an ASCII encoding of a hexadecimal representation of the DOF file
used to enable anonymous tracing, so its length should always be even.
MFC after: 1 week
When recording probe site addresses in the output DOF file, dtrace -G
needs to emit relocations for the .SUNW_dof section in order to obtain
the addresses of functions containing probe sites. DTrace expects the
addresses to be relative to the base address of the final ELF file,
and the amd64 USDT implementation was relying on some unspecified and
incorrect behaviour in the base system GNU ld to achieve this.
This change reimplements the probe site relocation handling to allow
USDT to be used with lld and newer GNU binutils. Specifically, it
makes use of R_X86_64_PC64/R_386_PC32 relocations to obtain the
probe site address relative to the DOF file address, and adds and uses a
new DOF relocation type which computes the final probe site address using
these relative offsets.
Reported by and discussed with: Rafael Espíndola
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D9374
low-quality random numbers with a modern implementation (xoroshiro128+)
that is capable of generating better quality randomness without compromising performance.
Submitted by: Graeme Jenkinson
Reviewed by: markj
MFC after: 2 weeks
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D9051
This corresponds to the following illumos issues:
5755 want support for Intel FMA instrs
5756 want support for Intel BMI1 instrs
5757 want support for Intel BMI2 instrs
5758 want support for Intel AVX2 instrs
7204 Want broadwell rdseed and adx support
7208 Want stac/clac disasm support
7733 Need SHA Instruction dis support
7756 dis can't handle x86 SSE 3 instructions
7757 want avx2 disasm tests
7758 want SSE 4.1 disasm tests
MFC after: 2 weeks
FASTTRAP_MAX_INSTR_SIZE is the largest valid value of a tracepoint, so
correct the assertion accordingly. This limit was hit with a 15-byte NOP.
Reported by: bdrewery
MFC after: 1 week
Sponsored by: Dell EMC Isilon
This ioctl has been considered legacy by upstream since the DTrace code
was first imported, and is unused. The removal also allows some
simplification of dtrace_helper_slurp().
Also remove a bogus copyout in the DTRACEHIOC_ADDDOF handler. Due to a
bug, it would overwrite an in-memory copy of the DOF header rather than
the passed-in DOF helper. Moreover, DTRACEHIOC_ADDDOF already copies the
helper back out automatically since its argument has the IOC_OUT attribute.
6569 large file delete can starve out write ops
illumos/illumos-gate@ff5177ee8bff5177ee8bhttps://www.illumos.org/issues/6569
The core issue I've found is that there is no throttle for how many
deletes get assigned to one TXG. As a results when deleting large files
we end up filling consecutive TXGs with deletes/frees, then write
throttling other (more important) ops.
There is an easy test case for this problem. Try deleting several
large files (at least 1/2 TB) while you do write ops on the same
pool. What we've seen is performance of these write ops (let's
call it sideload I/O) would drop to zero.
More specifically the problem is that dmu_free_long_range_impl()
can/will fill up all of the dirty data in the pool "instantly",
before many of the sideload ops can get in. So sideload
performance will be impacted until all the files are freed.
The solution we have tested at Nexenta (with positive results)
creates a relatively simple throttle for how many "free" ops we let
into one TXG.
However this solution exposes other problems that should also be
addressed. If we are to slow down freeing of data that means one
has to wait even longer (assuming vnode ref count of 1) to get shell
back after an rm or for NFS thread to finish the free-ing op.
To avoid this the proposed solution is to call zfs_inactive() async
for "large" files. Async freeing then begs for the reclaimed space
to be accounted for in the zpool's "freeing" prop.
The other issue with having a longer delete is the inability to
export/unmount for a longer period of time. The proposed solution
is to interrupt freeing of blocks when a fs is unmounted.
Author: Alek Pinchuk <alek@nexenta.com>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Sanjay Nadkarni <sanjay.nadkarni@nexenta.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Approved by: Dan McDonald <danmcd@omniti.com>
Reviewed by: avg
Differential Revision: D9008
the fifth argument to functions being traced, however there was an error
where the userspace stack was being used. This may be invalid leading to
a kernel panic if this address is unmapped.
Submitted by: Graeme Jenkinson <graeme.jenkinson@cl.cam.ac.uk>
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D9229
It was a temporary change to ease an import of native atomic_cas primitives.
Instead, atomic_fcmpset was devised with different semantics. See r311168.
At least on FreeBSD there are no legal way to access media or get its
size without opening device/provider first. Postponing this caching
allows to skip several disk seeks per ZVOL/snapshot during import.
For HDD pool with 1 ZVOL in dev mode with 1000 snapshots this reduces
pool import time from 40 to 10 seconds.
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
These functions may be called in DTrace probe context, so they cannot be
safely traced. Moreover, they are currently only used by DTrace, so their
corresponding FBT probes are not particularly useful.
MFC after: 2 weeks
Original commit "7090 zfs should improve allocation order" declares alloc
queue sorted by time and offset. But in practice io_offset is always zero,
so sorting happened only by time, while order of writes with equal time was
completely random. On Illumos this did not affected much thanks to using
high resolution timestamps. On FreeBSD due to using much faster but low
resolution timestamps it caused bad data placement on disks, affecting
further read performance.
This change switches zio_timestamp_compare() from comparing uninitialized
io_offset to really populated io_bookmark values. I haven't decided yet
what to do with timestampts, but on simple tests this change gives the
same peformance results by just making code to work as declared.
MFC after: 1 week
On FreeBSD the sense of rw_write_held() and rw_iswriter() were reversed,
probably due to a cut and paste error. Using rw_iswriter() would cause
the kernel to panic.
Reviewed by: markj
MFC after: 2 weeks
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D8718
