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zvol: Support blk-mq for better performance (updated) #13148

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merged 1 commit into from
Jun 9, 2022

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tonyhutter
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@tonyhutter tonyhutter commented Feb 24, 2022

Motivation and Context

Better zvol performance

Description

Add support for the kernel's block multiqueue (blk-mq) interface in the zvol block driver. blk-mq creates multiple request queues on different CPUs rather than having a single request queue. This can improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer kernels. Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the zvol_use_blk_mq module param to enable the blk-mq API. It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole struct request IOs at a time, rather than breaking them down
into their individual BIOs. This reduces dbuf lock contention and overhead versus the legacy zvol submit_bio() codepath.

	Sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new zvol_blk_mq_chunks_per_thread module parameter. This parameter represents how many volblocksize'd chunks to process per each zvol thread. It can be used to tune your zvols for better read vs write performance (higher values favor write, lower favor read).

Note: this is an updated version of #12664 that adds in the request-at-a-time processing. I'm closing that PR in favor of this one.

Issue #12483

How Has This Been Tested?

Types of changes

  • Bug fix (non-breaking change which fixes an issue)
  • New feature (non-breaking change which adds functionality)
  • Performance enhancement (non-breaking change which improves efficiency)
  • Code cleanup (non-breaking change which makes code smaller or more readable)
  • Breaking change (fix or feature that would cause existing functionality to change)
  • Library ABI change (libzfs, libzfs_core, libnvpair, libuutil and libzfsbootenv)
  • Documentation (a change to man pages or other documentation)

Checklist:

@rincebrain
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Why have zvol_use_blk_mq off by default? IMO, it's just going to become the default advice for anyone when setting up a zvol once merged, and then you get all the downsides of slower defaults and people mindlessly telling everyone who asks to set one more non-default parameter.

@sempervictus
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@rincebrain: in the last pr, we saw somewhat workload-dependent results with regression in sequential IO. IIUC, the idea is to prevent performance regressions on-upgrade to the next release which will have this for folks expecting those workloads to continue to work at their current rate and having no idea about the ZVOL changes (the apt-get dist-upgrade -y crowd)

man/man4/zfs.4 Outdated Show resolved Hide resolved
module/os/linux/zfs/zvol_os.c Outdated Show resolved Hide resolved
module/os/linux/zfs/zvol_os.c Outdated Show resolved Hide resolved
module/os/linux/zfs/zvol_os.c Outdated Show resolved Hide resolved
@tonyhutter
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@rincebrain yea I would also like it enabled by default, assuming the random RW performance regressions we were seeing with the earlier PR go away.

@tonynguien would you mind re-running your benchmarks against this PR when you get a chance?

@tonynguien
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@rincebrain yea I would also like it enabled by default, assuming the random RW performance regressions we were seeing with the earlier PR go away.

@tonynguien would you mind re-running your benchmarks against this PR when you get a chance?

Yes, I'd be happy to and should have time in a couple weeks.

@tonyhutter
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@nabijaczleweli thanks, I'll work on those fixes. I'm also working on a test case that will test TRIM and FUA (Force Unit Access) on zvols.

@adamdmoss
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adamdmoss commented Mar 1, 2022

FWIW I've been using this branch for some days and >1TB of file-juggling featuring a device with TRIM (autotrim is off but I've done an explicit trim). Nothing has conspicuously exploded yet.

edit: It's not a zvol though, it's just a zfs filesystem/dataset.

@tonyhutter
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@adamdmoss nice! Probably a dumb question but, did you enable zvol_use_blk_mq? How is the performance looking for you?

@tonyhutter
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@adamdmoss whoops spoke too soon - if you're using a zfs filesystem/dataset then it wouldn't touch this codepath.

@adamdmoss
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zvol_use_blk_mq=1 but you're right it'd have been infinitely smarter to test with actual zvols 😬

@adamdmoss
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Okay, ext4-on-zvol seemed happy enough after creating a lot of data, deleting some of it, and trimming (the trim correctly discarded the corresponding amount of logical data according to the zfs accounting). It re-fsck'd fine, at least.

@adamdmoss
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Hmm, I guess that only tested a logical trim from ext4's point of view, and I should test a physical trim on the backing device also.

@adamdmoss
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Okay, trimmed the underlying pool/vdev too, and then re-scrubbed, and for good measure re-fsck'd the ext4 on the volume. All appears happy.
(Not that this is a proof of correctness, but it indicates non-total-brokenness. 😁 )

man/man4/zfs.4 Outdated Show resolved Hide resolved
@tonyhutter tonyhutter force-pushed the blkmq-biomerge branch 2 times, most recently from e9f7fcb to a81b15f Compare March 2, 2022 22:48
@liyimeng
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liyimeng commented Mar 4, 2022

nice work!

@tonyhutter tonyhutter force-pushed the blkmq-biomerge branch 3 times, most recently from 9987df7 to f86003a Compare March 4, 2022 21:46
@tonyhutter
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This PR is currently panicking on Fedora 35 with zvol_misc_002_pos:

[21975.259788] VERIFY3(dmu_objset_is_snapshot(zilog->zl_os) == B_FALSE) failed (1 == 0)
[21975.259812] PANIC at zil.c:2958:zil_commit()
[21975.259814] Showing stack for process 660990
[21975.259822] CPU: 0 PID: 660990 Comm: zvol Tainted: P           OE     5.16.11-200.fc35.x86_64 #1
[21975.259824] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
[21975.259830] Call Trace:
[21975.259877]  <TASK>
[21975.259887]  dump_stack_lvl+0x48/0x5e
[21975.259923]  spl_panic+0xd1/0xe9 [spl]
[21975.259944]  ? dbuf_rele_and_unlock+0x5b9/0x5f0 [zfs]
[21975.260117]  ? zio_wait+0x280/0x470 [zfs]
[21975.260276]  ? preempt_count_add+0x68/0xa0
[21975.260295]  ? _raw_spin_unlock+0x16/0x30
[21975.260308]  ? update_load_avg+0x7e/0x610
[21975.260318]  ? update_load_avg+0x7e/0x610
[21975.260321]  zil_commit+0xc8/0x150 [zfs]
[21975.260479]  zvol_write+0x334/0x4e0 [zfs]
[21975.260630]  ? _raw_spin_unlock+0x16/0x30
[21975.260633]  ? __switch_to+0x114/0x440
[21975.260655]  ? __schedule+0x2df/0xfa0
[21975.260657]  ? _raw_spin_unlock_irqrestore+0x25/0x40
[21975.260660]  ? __wake_up_common_lock+0x7a/0x90
[21975.260665]  zvol_write_task+0xe/0x20 [zfs]
[21975.260815]  taskq_thread+0x1e8/0x430 [spl]
[21975.260829]  ? wake_up_q+0x90/0x90
[21975.260834]  ? zvol_write+0x4e0/0x4e0 [zfs]
[21975.260983]  ? taskq_thread_spawn+0x50/0x50 [spl]
[21975.260995]  kthread+0x16b/0x190
[21975.261020]  ? set_kthread_struct+0x40/0x40
[21975.261023]  ret_from_fork+0x22/0x30
[21975.261042]  </TASK>

That test only used the the submit_bio() codepath so I must have broken something there with my changes. I'm looking into it.

@tonyhutter tonyhutter force-pushed the blkmq-biomerge branch 3 times, most recently from a7e5a62 to 4b8202d Compare March 9, 2022 14:52
beren12 pushed a commit to beren12/zfs that referenced this pull request Sep 19, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
andrewc12 pushed a commit to andrewc12/openzfs that referenced this pull request Sep 23, 2022
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver.  blk-mq creates multiple request queues on
different CPUs rather than having a single request queue.  This can
improve zvol performance with multithreaded reads/writes.

This implementation uses the blk-mq interfaces on 4.13 or newer
kernels.  Building against older kernels will fall back to the
older BIO interfaces.

Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API.  It is disabled by default.

In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs.  This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.

	sequential dd to one zvol, 8k volblocksize, no O_DIRECT:

	legacy submit_bio()     292MB/s write  453MB/s read
	this commit             453MB/s write  885MB/s read

It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread.  It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes openzfs#13148
Issue openzfs#12483
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[Performance] Extreme performance penalty, holdups and write amplification when writing to ZVOLs
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