Currently when non-mq aware IO scheduler (BFQ, mq-deadline) is used for
a queue with multiple HW queues, the performance it rather bad. The
problem is that these IO schedulers use queue-wide locking and their
dispatch function does not respect the hctx it is passed in and returns
any request it finds appropriate. Thus locality of request access is
broken and dispatch from multiple CPUs just contends on IO scheduler
locks. For these IO schedulers there's little point in dispatching from
multiple CPUs. Instead dispatch always only from a single CPU to limit
contention.
Below is a comparison of dbench runs on XFS filesystem where the storage
is a raid card with 64 HW queues and to it attached a single rotating
disk. BFQ is used as IO scheduler:
clients MQ SQ MQ-Patched
Amean 1 39.12 (0.00%) 43.29 * -10.67%* 36.09 * 7.74%*
Amean 2 128.58 (0.00%) 101.30 * 21.22%* 96.14 * 25.23%*
Amean 4 577.42 (0.00%) 494.47 * 14.37%* 508.49 * 11.94%*
Amean 8 610.95 (0.00%) 363.86 * 40.44%* 362.12 * 40.73%*
Amean 16 391.78 (0.00%) 261.49 * 33.25%* 282.94 * 27.78%*
Amean 32 324.64 (0.00%) 267.71 * 17.54%* 233.00 * 28.23%*
Amean 64 295.04 (0.00%) 253.02 * 14.24%* 242.37 * 17.85%*
Amean 512 10281.61 (0.00%) 10211.16 * 0.69%* 10447.53 * -1.61%*
Numbers are times so lower is better. MQ is stock 5.10-rc6 kernel. SQ is
the same kernel with megaraid_sas.host_tagset_enable=0 so that the card
advertises just a single HW queue. MQ-Patched is a kernel with this
patch applied.
You can see multiple hardware queues heavily hurt performance in
combination with BFQ. The patch restores the performance.
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This reverts commit b445547ec1.
Since both mq-deadline and BFQ completely ignore hctx they are passed to
their dispatch function and dispatch whatever request they deem fit
checking whether any request for a particular hctx is queued is just
pointless since we'll very likely get a request from a different hctx
anyway. In the following commit we'll deal with lock contention in these
IO schedulers in presence of multiple HW queues in a different way.
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Replace the gendisk pointer in struct bio with a pointer to the newly
improved struct block device. From that the gendisk can be trivially
accessed with an extra indirection, but it also allows to directly
look up all information related to partition remapping.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This is a load of driver fixes (12 ufs, 1 mpt3sas, 1 cxgbi). The big
core two fixes are for power management ("block: Do not accept any
requests while suspended" and "block: Fix a race in the runtime power
management code") which finally sorts out the resume problems we've
occasionally been having. To make the resume fix, there are seven
necessary precursors which effectively renames REQ_PREEMPT to REQ_PM,
so every "special" request in block is automatically a power
management exempt one. All of the non-PM preempt cases are removed
except for the one in the SCSI Parallel Interface (spi) domain
validation which is a genuine case where we have to run requests at
high priority to validate the bus so this becomes an autopm get/put
protected request.
Signed-off-by: James E.J. Bottomley <jejb@linux.ibm.com>
-----BEGIN PGP SIGNATURE-----
iJwEABMIAEQWIQTnYEDbdso9F2cI+arnQslM7pishQUCX+98LyYcamFtZXMuYm90
dG9tbGV5QGhhbnNlbnBhcnRuZXJzaGlwLmNvbQAKCRDnQslM7pishYvLAP9K+HBT
Lrkt3VWc9gq6F36+QH/SeW8IyXGaj77ysFHXxwD/UambRjRK8IA24mvf9sWeLLj6
p8CqCHUkCXqP48IiymE=
=NHrx
-----END PGP SIGNATURE-----
Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI fixes from James Bottomley:
"This is a load of driver fixes (12 ufs, 1 mpt3sas, 1 cxgbi).
The big core two fixes are for power management ("block: Do not accept
any requests while suspended" and "block: Fix a race in the runtime
power management code") which finally sorts out the resume problems
we've occasionally been having.
To make the resume fix, there are seven necessary precursors which
effectively renames REQ_PREEMPT to REQ_PM, so every "special" request
in block is automatically a power management exempt one.
All of the non-PM preempt cases are removed except for the one in the
SCSI Parallel Interface (spi) domain validation which is a genuine
case where we have to run requests at high priority to validate the
bus so this becomes an autopm get/put protected request"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (22 commits)
scsi: cxgb4i: Fix TLS dependency
scsi: ufs: Un-inline ufshcd_vops_device_reset function
scsi: ufs: Re-enable WriteBooster after device reset
scsi: ufs-mediatek: Use correct path to fix compile error
scsi: mpt3sas: Signedness bug in _base_get_diag_triggers()
scsi: block: Do not accept any requests while suspended
scsi: block: Remove RQF_PREEMPT and BLK_MQ_REQ_PREEMPT
scsi: core: Only process PM requests if rpm_status != RPM_ACTIVE
scsi: scsi_transport_spi: Set RQF_PM for domain validation commands
scsi: ide: Mark power management requests with RQF_PM instead of RQF_PREEMPT
scsi: ide: Do not set the RQF_PREEMPT flag for sense requests
scsi: block: Introduce BLK_MQ_REQ_PM
scsi: block: Fix a race in the runtime power management code
scsi: ufs-pci: Enable UFSHCD_CAP_RPM_AUTOSUSPEND for Intel controllers
scsi: ufs-pci: Fix recovery from hibernate exit errors for Intel controllers
scsi: ufs-pci: Ensure UFS device is in PowerDown mode for suspend-to-disk ->poweroff()
scsi: ufs-pci: Fix restore from S4 for Intel controllers
scsi: ufs-mediatek: Keep VCC always-on for specific devices
scsi: ufs: Allow regulators being always-on
scsi: ufs: Clear UAC for RPMB after ufshcd resets
...
With force threaded interrupts enabled, raising softirq from an SMP
function call will always result in waking the ksoftirqd thread. This is
not optimal given that the thread runs at SCHED_OTHER priority.
Completing the request in hard IRQ-context on PREEMPT_RT (which enforces
the force threaded mode) is bad because the completion handler may
acquire sleeping locks which violate the locking context.
Disable request completing on a remote CPU in force threaded mode.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
It's guaranteed that no request is in flight when a hctx is going
offline. This warning is only triggered when the wq's CPU is hot
plugged and the blk-mq is not synced up yet.
As this state is temporary and the request is still processed
correctly, better remove the warning as this is the fast path.
Suggested-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This series consists of the usual driver updates (ufs, qla2xxx,
smartpqi, target, zfcp, fnic, mpt3sas, ibmvfc) plus a load of
cleanups, a major power management rework and a load of assorted minor
updates. There are a few core updates (formatting fixes being the big
one) but nothing major this cycle.
Signed-off-by: James E.J. Bottomley <jejb@linux.ibm.com>
-----BEGIN PGP SIGNATURE-----
iJwEABMIAEQWIQTnYEDbdso9F2cI+arnQslM7pishQUCX9o0KSYcamFtZXMuYm90
dG9tbGV5QGhhbnNlbnBhcnRuZXJzaGlwLmNvbQAKCRDnQslM7pishbOZAP9D5NTN
J7dJUo2MIMy84YBu+d9ag7yLlNiRWVY2yw5vHwD/Z7JjAVLwz/tzmyjU9//o2J6w
hwhOv6Uto89gLCWSEz8=
=KUPT
-----END PGP SIGNATURE-----
Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI updates from James Bottomley:
"This consists of the usual driver updates (ufs, qla2xxx, smartpqi,
target, zfcp, fnic, mpt3sas, ibmvfc) plus a load of cleanups, a major
power management rework and a load of assorted minor updates.
There are a few core updates (formatting fixes being the big one) but
nothing major this cycle"
* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (279 commits)
scsi: mpt3sas: Update driver version to 36.100.00.00
scsi: mpt3sas: Handle trigger page after firmware update
scsi: mpt3sas: Add persistent MPI trigger page
scsi: mpt3sas: Add persistent SCSI sense trigger page
scsi: mpt3sas: Add persistent Event trigger page
scsi: mpt3sas: Add persistent Master trigger page
scsi: mpt3sas: Add persistent trigger pages support
scsi: mpt3sas: Sync time periodically between driver and firmware
scsi: qla2xxx: Update version to 10.02.00.104-k
scsi: qla2xxx: Fix device loss on 4G and older HBAs
scsi: qla2xxx: If fcport is undergoing deletion complete I/O with retry
scsi: qla2xxx: Fix the call trace for flush workqueue
scsi: qla2xxx: Fix flash update in 28XX adapters on big endian machines
scsi: qla2xxx: Handle aborts correctly for port undergoing deletion
scsi: qla2xxx: Fix N2N and NVMe connect retry failure
scsi: qla2xxx: Fix FW initialization error on big endian machines
scsi: qla2xxx: Fix crash during driver load on big endian machines
scsi: qla2xxx: Fix compilation issue in PPC systems
scsi: qla2xxx: Don't check for fw_started while posting NVMe command
scsi: qla2xxx: Tear down session if FW say it is down
...
-----BEGIN PGP SIGNATURE-----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=zo4w
-----END PGP SIGNATURE-----
Merge tag 'for-5.11/block-2020-12-14' of git://git.kernel.dk/linux-block
Pull block updates from Jens Axboe:
"Another series of killing more code than what is being added, again
thanks to Christoph's relentless cleanups and tech debt tackling.
This contains:
- blk-iocost improvements (Baolin Wang)
- part0 iostat fix (Jeffle Xu)
- Disable iopoll for split bios (Jeffle Xu)
- block tracepoint cleanups (Christoph Hellwig)
- Merging of struct block_device and hd_struct (Christoph Hellwig)
- Rework/cleanup of how block device sizes are updated (Christoph
Hellwig)
- Simplification of gendisk lookup and removal of block device
aliasing (Christoph Hellwig)
- Block device ioctl cleanups (Christoph Hellwig)
- Removal of bdget()/blkdev_get() as exported API (Christoph Hellwig)
- Disk change rework, avoid ->revalidate_disk() (Christoph Hellwig)
- sbitmap improvements (Pavel Begunkov)
- Hybrid polling fix (Pavel Begunkov)
- bvec iteration improvements (Pavel Begunkov)
- Zone revalidation fixes (Damien Le Moal)
- blk-throttle limit fix (Yu Kuai)
- Various little fixes"
* tag 'for-5.11/block-2020-12-14' of git://git.kernel.dk/linux-block: (126 commits)
blk-mq: fix msec comment from micro to milli seconds
blk-mq: update arg in comment of blk_mq_map_queue
blk-mq: add helper allocating tagset->tags
Revert "block: Fix a lockdep complaint triggered by request queue flushing"
nvme-loop: use blk_mq_hctx_set_fq_lock_class to set loop's lock class
blk-mq: add new API of blk_mq_hctx_set_fq_lock_class
block: disable iopoll for split bio
block: Improve blk_revalidate_disk_zones() checks
sbitmap: simplify wrap check
sbitmap: replace CAS with atomic and
sbitmap: remove swap_lock
sbitmap: optimise sbitmap_deferred_clear()
blk-mq: skip hybrid polling if iopoll doesn't spin
blk-iocost: Factor out the base vrate change into a separate function
blk-iocost: Factor out the active iocgs' state check into a separate function
blk-iocost: Move the usage ratio calculation to the correct place
blk-iocost: Remove unnecessary advance declaration
blk-iocost: Fix some typos in comments
blktrace: fix up a kerneldoc comment
block: remove the request_queue to argument request based tracepoints
...
Delay to wait for queue running is milli second unit which is passed to
delayed work via msecs_to_jiffies() which is to convert milliseconds to
jiffies.
Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
tagset->set is allocated from blk_mq_alloc_tag_set() rather than being
reallocated. This patch added a helper to make its meaning explicitly
which is to allocate rather than to reallocate.
Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Remove flag RQF_PREEMPT and BLK_MQ_REQ_PREEMPT since these are no longer
used by any kernel code.
Link: https://lore.kernel.org/r/20201209052951.16136-8-bvanassche@acm.org
Cc: Can Guo <cang@codeaurora.org>
Cc: Stanley Chu <stanley.chu@mediatek.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Martin Kepplinger <martin.kepplinger@puri.sm>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Introduce the BLK_MQ_REQ_PM flag. This flag makes the request allocation
functions set RQF_PM. This is the first step towards removing
BLK_MQ_REQ_PREEMPT.
Link: https://lore.kernel.org/r/20201209052951.16136-3-bvanassche@acm.org
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Stanley Chu <stanley.chu@mediatek.com>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Can Guo <cang@codeaurora.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
iopoll is initially for small size, latency sensitive IO. It doesn't
work well for big IO, especially when it needs to be split to multiple
bios. In this case, the returned cookie of __submit_bio_noacct_mq() is
indeed the cookie of the last split bio. The completion of *this* last
split bio done by iopoll doesn't mean the whole original bio has
completed. Callers of iopoll still need to wait for completion of other
split bios.
Besides bio splitting may cause more trouble for iopoll which isn't
supposed to be used in case of big IO.
iopoll for split bio may cause potential race if CPU migration happens
during bio submission. Since the returned cookie is that of the last
split bio, polling on the corresponding hardware queue doesn't help
complete other split bios, if these split bios are enqueued into
different hardware queues. Since interrupts are disabled for polling
queues, the completion of these other split bios depends on timeout
mechanism, thus causing a potential hang.
iopoll for split bio may also cause hang for sync polling. Currently
both the blkdev and iomap-based fs (ext4/xfs, etc) support sync polling
in direct IO routine. These routines will submit bio without REQ_NOWAIT
flag set, and then start sync polling in current process context. The
process may hang in blk_mq_get_tag() if the submitted bio has to be
split into multiple bios and can rapidly exhaust the queue depth. The
process are waiting for the completion of the previously allocated
requests, which should be reaped by the following polling, and thus
causing a deadlock.
To avoid these subtle trouble described above, just disable iopoll for
split bio and return BLK_QC_T_NONE in this case. The side effect is that
non-HIPRI IO also returns BLK_QC_T_NONE now. It should be acceptable
since the returned cookie is never used for non-HIPRI IO.
Suggested-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If blk_poll() is not going to spin (i.e. @spin=false), it also must not
sleep in hybrid polling, otherwise it might be pretty suprising for
users trying to do a quick check and expecting no-wait behaviour.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The request_queue can trivially be derived from the request.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The block_bio_merge tracepoint class can be reused for most bio-based
tracepoints. For that it just needs to lose the superfluous q and rq
parameters.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The inflight of partition 0 doesn't include inflight IOs to all
sub-partitions, since currently mq calculates inflight of specific
partition by simply camparing the value of the partition pointer.
Thus the following case is possible:
$ cat /sys/block/vda/inflight
0 0
$ cat /sys/block/vda/vda1/inflight
0 128
While single queue device (on a previous version, e.g. v3.10) has no
this issue:
$cat /sys/block/sda/sda3/inflight
0 33
$cat /sys/block/sda/inflight
0 33
Partition 0 should be specially handled since it represents the whole
disk. This issue is introduced since commit bf0ddaba65 ("blk-mq: fix
sysfs inflight counter").
Besides, this patch can also fix the inflight statistics of part 0 in
/proc/diskstats. Before this patch, the inflight statistics of part 0
doesn't include that of sub partitions. (I have marked the 'inflight'
field with asterisk.)
$cat /proc/diskstats
259 0 nvme0n1 45974469 0 367814768 6445794 1 0 1 0 *0* 111062 6445794 0 0 0 0 0 0
259 2 nvme0n1p1 45974058 0 367797952 6445727 0 0 0 0 *33* 111001 6445727 0 0 0 0 0 0
This is introduced since commit f299b7c7a9 ("blk-mq: provide internal
in-flight variant").
Fixes: bf0ddaba65 ("blk-mq: fix sysfs inflight counter")
Fixes: f299b7c7a9 ("blk-mq: provide internal in-flight variant")
Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
[axboe: adapt for 5.11 partition change]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Use struct block_device to lookup partitions on a disk. This removes
all usage of struct hd_struct from the I/O path.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Coly Li <colyli@suse.de> [bcache]
Acked-by: Chao Yu <yuchao0@huawei.com> [f2fs]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Get rid of the __call_single_node union and cleanup the API a little
to avoid external code relying on the structure layout as much.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
blk_mq_end_request() will use the block status returned from queue_rq() as
argument, except in one instance in blk_mq_dispatch_rq_list(), where the
generic BLK_STS_IOERR is used.
Link: https://lore.kernel.org/r/20200930080256.90964-2-hare@suse.de
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
-----BEGIN PGP SIGNATURE-----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=dFJi
-----END PGP SIGNATURE-----
Merge tag 'block-5.10-2020-10-24' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
- NVMe pull request from Christoph
- rdma error handling fixes (Chao Leng)
- fc error handling and reconnect fixes (James Smart)
- fix the qid displace when tracing ioctl command (Keith Busch)
- don't use BLK_MQ_REQ_NOWAIT for passthru (Chaitanya Kulkarni)
- fix MTDT for passthru (Logan Gunthorpe)
- blacklist Write Same on more devices (Kai-Heng Feng)
- fix an uninitialized work struct (zhenwei pi)"
- lightnvm out-of-bounds fix (Colin)
- SG allocation leak fix (Doug)
- rnbd fixes (Gioh, Guoqing, Jack)
- zone error translation fixes (Keith)
- kerneldoc markup fix (Mauro)
- zram lockdep fix (Peter)
- Kill unused io_context members (Yufen)
- NUMA memory allocation cleanup (Xianting)
- NBD config wakeup fix (Xiubo)
* tag 'block-5.10-2020-10-24' of git://git.kernel.dk/linux-block: (27 commits)
block: blk-mq: fix a kernel-doc markup
nvme-fc: shorten reconnect delay if possible for FC
nvme-fc: wait for queues to freeze before calling update_hr_hw_queues
nvme-fc: fix error loop in create_hw_io_queues
nvme-fc: fix io timeout to abort I/O
null_blk: use zone status for max active/open
nvmet: don't use BLK_MQ_REQ_NOWAIT for passthru
nvmet: cleanup nvmet_passthru_map_sg()
nvmet: limit passthru MTDS by BIO_MAX_PAGES
nvmet: fix uninitialized work for zero kato
nvme-pci: disable Write Zeroes on Sandisk Skyhawk
nvme: use queuedata for nvme_req_qid
nvme-rdma: fix crash due to incorrect cqe
nvme-rdma: fix crash when connect rejected
block: remove unused members for io_context
blk-mq: remove the calling of local_memory_node()
zram: Fix __zram_bvec_{read,write}() locking order
skd_main: remove unused including <linux/version.h>
sgl_alloc_order: fix memory leak
lightnvm: fix out-of-bounds write to array devices->info[]
...
We don't need to check whether the node is memoryless numa node before
calling allocator interface. SLUB(and SLAB,SLOB) relies on the page
allocator to pick a node. Page allocator should deal with memoryless
nodes just fine. It has zonelists constructed for each possible nodes.
And it will automatically fall back into a node which is closest to the
requested node. As long as __GFP_THISNODE is not enforced of course.
The code comments of kmem_cache_alloc_node() of SLAB also showed this:
* Fallback to other node is possible if __GFP_THISNODE is not set.
blk-mq code doesn't set __GFP_THISNODE, so we can remove the calling
of local_memory_node().
Signed-off-by: Xianting Tian <tian.xianting@h3c.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
fix bio splitting for bios that were deferred to the worker thread
due to a DM device being suspended.
- Remove DM core's special handling of NVMe devices now that block
core has internalized efficiencies drivers previously needed to
be concerned about (via now removed direct_make_request).
- Fix request-based DM to not bounce through indirect dm_submit_bio;
instead have block core make direct call to blk_mq_submit_bio().
- Various DM core cleanups to simplify and improve code.
- Update DM cryot to not use drivers that set
CRYPTO_ALG_ALLOCATES_MEMORY.
- Fix DM raid's raid1 and raid10 discard limits for the purposes of
linux-stable. But then remove DM raid's discard limits settings now
that MD raid can efficiently handle large discards.
- A couple small cleanups across various targets.
-----BEGIN PGP SIGNATURE-----
iQFHBAABCAAxFiEEJfWUX4UqZ4x1O2wixSPxCi2dA1oFAl+Fx1gTHHNuaXR6ZXJA
cmVkaGF0LmNvbQAKCRDFI/EKLZ0DWk5iB/9pONYmtfQ5oBx4jg/PU8cVYYIfOtwS
ZtItFbw7T9bkHVZ8d4hDr5LTq898cADuRD5edlR82gDOcXkiJlb5PqU39RoOTVvF
Xz87sWzHdGAK7rdnCMAc2hiX3oQOje9o7NxGeGQ/uPaNU+U/vJS0AZtEAwltocBd
j9MGESddBC636Gzbg5C0c0frikXd0am6qp6SCYJNpP5I0G2beHk2YX5Jqt9c7zMk
8kyQend5b5RvkPNWTAjkVfWUsIjwYHh6MF48ZoGvD0X3lWjIBiwyxC0UX5hSXq63
kB+nqxbXcvQLEBtJuDZ2bjyvrwzCVLpmfgLgzxOOU8fI5Q2U0zpsPaa0
=6YDu
-----END PGP SIGNATURE-----
Merge tag 'for-5.10/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper updates from Mike Snitzer:
- Improve DM core's bio splitting to use blk_max_size_offset(). Also
fix bio splitting for bios that were deferred to the worker thread
due to a DM device being suspended.
- Remove DM core's special handling of NVMe devices now that block core
has internalized efficiencies drivers previously needed to be
concerned about (via now removed direct_make_request).
- Fix request-based DM to not bounce through indirect dm_submit_bio;
instead have block core make direct call to blk_mq_submit_bio().
- Various DM core cleanups to simplify and improve code.
- Update DM cryot to not use drivers that set
CRYPTO_ALG_ALLOCATES_MEMORY.
- Fix DM raid's raid1 and raid10 discard limits for the purposes of
linux-stable. But then remove DM raid's discard limits settings now
that MD raid can efficiently handle large discards.
- A couple small cleanups across various targets.
* tag 'for-5.10/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm: fix request-based DM to not bounce through indirect dm_submit_bio
dm: remove special-casing of bio-based immutable singleton target on NVMe
dm: export dm_copy_name_and_uuid
dm: fix comment in __dm_suspend()
dm: fold dm_process_bio() into dm_submit_bio()
dm: fix missing imposition of queue_limits from dm_wq_work() thread
dm snap persistent: simplify area_io()
dm thin metadata: Remove unused local variable when create thin and snap
dm raid: remove unnecessary discard limits for raid10
dm raid: fix discard limits for raid1 and raid10
dm crypt: don't use drivers that have CRYPTO_ALG_ALLOCATES_MEMORY
dm: use dm_table_get_device_name() where appropriate in targets
dm table: make 'struct dm_table' definition accessible to all of DM core
dm: eliminate need for start_io_acct() forward declaration
dm: simplify __process_abnormal_io()
dm: push use of on-stack flush_bio down to __send_empty_flush()
dm: optimize max_io_len() by inlining max_io_len_target_boundary()
dm: push md->immutable_target optimization down to __process_bio()
dm: change max_io_len() to use blk_max_size_offset()
dm table: stack 'chunk_sectors' limit to account for target-specific splitting
-----BEGIN PGP SIGNATURE-----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=LzyE
-----END PGP SIGNATURE-----
Merge tag 'block-5.10-2020-10-12' of git://git.kernel.dk/linux-block
Pull block updates from Jens Axboe:
- Series of merge handling cleanups (Baolin, Christoph)
- Series of blk-throttle fixes and cleanups (Baolin)
- Series cleaning up BDI, seperating the block device from the
backing_dev_info (Christoph)
- Removal of bdget() as a generic API (Christoph)
- Removal of blkdev_get() as a generic API (Christoph)
- Cleanup of is-partition checks (Christoph)
- Series reworking disk revalidation (Christoph)
- Series cleaning up bio flags (Christoph)
- bio crypt fixes (Eric)
- IO stats inflight tweak (Gabriel)
- blk-mq tags fixes (Hannes)
- Buffer invalidation fixes (Jan)
- Allow soft limits for zone append (Johannes)
- Shared tag set improvements (John, Kashyap)
- Allow IOPRIO_CLASS_RT for CAP_SYS_NICE (Khazhismel)
- DM no-wait support (Mike, Konstantin)
- Request allocation improvements (Ming)
- Allow md/dm/bcache to use IO stat helpers (Song)
- Series improving blk-iocost (Tejun)
- Various cleanups (Geert, Damien, Danny, Julia, Tetsuo, Tian, Wang,
Xianting, Yang, Yufen, yangerkun)
* tag 'block-5.10-2020-10-12' of git://git.kernel.dk/linux-block: (191 commits)
block: fix uapi blkzoned.h comments
blk-mq: move cancel of hctx->run_work to the front of blk_exit_queue
blk-mq: get rid of the dead flush handle code path
block: get rid of unnecessary local variable
block: fix comment and add lockdep assert
blk-mq: use helper function to test hw stopped
block: use helper function to test queue register
block: remove redundant mq check
block: invoke blk_mq_exit_sched no matter whether have .exit_sched
percpu_ref: don't refer to ref->data if it isn't allocated
block: ratelimit handle_bad_sector() message
blk-throttle: Re-use the throtl_set_slice_end()
blk-throttle: Open code __throtl_de/enqueue_tg()
blk-throttle: Move service tree validation out of the throtl_rb_first()
blk-throttle: Move the list operation after list validation
blk-throttle: Fix IO hang for a corner case
blk-throttle: Avoid tracking latency if low limit is invalid
blk-throttle: Avoid getting the current time if tg->last_finish_time is 0
blk-throttle: Remove a meaningless parameter for throtl_downgrade_state()
block: Remove redundant 'return' statement
...
We have introduced helper function blk_mq_hctx_stopped() to test
BLK_MQ_S_STOPPED.
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
It is unnecessary to force request-based DM to call into bio-based
dm_submit_bio (via indirect disk->fops->submit_bio) only to have it then
call blk_mq_submit_bio().
Fix this by establishing a request-based DM block_device_operations
(dm_rq_blk_dops, which doesn't have .submit_bio) and update
dm_setup_md_queue() to set md->disk->fops to it for
DM_TYPE_REQUEST_BASED.
Remove DM_TYPE_REQUEST_BASED conditional in dm_submit_bio and unexport
blk_mq_submit_bio.
Fixes: c62b37d96b ("block: move ->make_request_fn to struct block_device_operations")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
According to Documentation/block/stat.rst, inflight should not include
I/O requests that are in the queue but not yet dispatched to the device,
but blk-mq identifies as inflight any request that has a tag allocated,
which, for queues without elevator, happens at request allocation time
and before it is queued in the ctx (default case in blk_mq_submit_bio).
In addition, current behavior is different for queues with elevator from
queues without it, since for the former the driver tag is allocated at
dispatch time. A more precise approach would be to only consider
requests with state MQ_RQ_IN_FLIGHT.
This effectively reverts commit 6131837b1d ("blk-mq: count allocated
but not started requests in iostats inflight") to consolidate blk-mq
behavior with itself (elevator case) and with original documentation,
but it differs from the behavior used by the legacy path.
This version differs from v1 by using blk_mq_rq_state to access the
state attribute. Avoid using blk_mq_request_started, which was
suggested, since we don't want to include MQ_RQ_COMPLETE.
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Cc: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blk_crypto_rq_bio_prep() assumes its gfp_mask argument always includes
__GFP_DIRECT_RECLAIM, so that the mempool_alloc() will always succeed.
However, blk_crypto_rq_bio_prep() might be called with GFP_ATOMIC via
setup_clone() in drivers/md/dm-rq.c.
This case isn't currently reachable with a bio that actually has an
encryption context. However, it's fragile to rely on this. Just make
blk_crypto_rq_bio_prep() able to fail.
Suggested-by: Satya Tangirala <satyat@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Satya Tangirala <satyat@google.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Blk-mq should call commit_rqs once 'bd.last != true' and no more
request will come(so virtscsi can kick the virtqueue, e.g.). We already
do that in 'blk_mq_dispatch_rq_list/blk_mq_try_issue_list_directly' while
list not empty and 'queued > 0'. However, we can seen the same scene
once the last request in list call queue_rq and return error like
BLK_STS_IOERR which will not requeue the request, and lead that list
empty but need call commit_rqs too(Or the request for virtscsi will stay
timeout until other request kick virtqueue).
We found this problem by do fsstress test with offline/online virtscsi
device repeat quickly.
Fixes: d666ba98f8 ("blk-mq: add mq_ops->commit_rqs()")
Reported-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: yangerkun <yangerkun@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We found blk_mq_alloc_rq_maps() takes more time in kernel space when
testing nvme device hot-plugging. The test and anlysis as below.
Debug code,
1, blk_mq_alloc_rq_maps():
u64 start, end;
depth = set->queue_depth;
start = ktime_get_ns();
pr_err("[%d:%s switch:%ld,%ld] queue depth %d, nr_hw_queues %d\n",
current->pid, current->comm, current->nvcsw, current->nivcsw,
set->queue_depth, set->nr_hw_queues);
do {
err = __blk_mq_alloc_rq_maps(set);
if (!err)
break;
set->queue_depth >>= 1;
if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) {
err = -ENOMEM;
break;
}
} while (set->queue_depth);
end = ktime_get_ns();
pr_err("[%d:%s switch:%ld,%ld] all hw queues init cost time %lld ns\n",
current->pid, current->comm,
current->nvcsw, current->nivcsw, end - start);
2, __blk_mq_alloc_rq_maps():
u64 start, end;
for (i = 0; i < set->nr_hw_queues; i++) {
start = ktime_get_ns();
if (!__blk_mq_alloc_rq_map(set, i))
goto out_unwind;
end = ktime_get_ns();
pr_err("hw queue %d init cost time %lld ns\n", i, end - start);
}
Test nvme hot-plugging with above debug code, we found it totally cost more
than 3ms in kernel space without being scheduled out when alloc rqs for all
16 hw queues with depth 1023, each hw queue cost about 140-250us. The cost
time will be increased with hw queue number and queue depth increasing. And
in an extreme case, if __blk_mq_alloc_rq_maps() returns -ENOMEM, it will try
"queue_depth >>= 1", more time will be consumed.
[ 428.428771] nvme nvme0: pci function 10000:01:00.0
[ 428.428798] nvme 10000:01:00.0: enabling device (0000 -> 0002)
[ 428.428806] pcieport 10000:00:00.0: can't derive routing for PCI INT A
[ 428.428809] nvme 10000:01:00.0: PCI INT A: no GSI
[ 432.593374] [4688:kworker/u33:8 switch:663,2] queue depth 30, nr_hw_queues 1
[ 432.593404] hw queue 0 init cost time 22883 ns
[ 432.593408] [4688:kworker/u33:8 switch:663,2] all hw queues init cost time 35960 ns
[ 432.595953] nvme nvme0: 16/0/0 default/read/poll queues
[ 432.595958] [4688:kworker/u33:8 switch:700,2] queue depth 1023, nr_hw_queues 16
[ 432.596203] hw queue 0 init cost time 242630 ns
[ 432.596441] hw queue 1 init cost time 235913 ns
[ 432.596659] hw queue 2 init cost time 216461 ns
[ 432.596877] hw queue 3 init cost time 215851 ns
[ 432.597107] hw queue 4 init cost time 228406 ns
[ 432.597336] hw queue 5 init cost time 227298 ns
[ 432.597564] hw queue 6 init cost time 224633 ns
[ 432.597785] hw queue 7 init cost time 219954 ns
[ 432.597937] hw queue 8 init cost time 150930 ns
[ 432.598082] hw queue 9 init cost time 143496 ns
[ 432.598231] hw queue 10 init cost time 147261 ns
[ 432.598397] hw queue 11 init cost time 164522 ns
[ 432.598542] hw queue 12 init cost time 143401 ns
[ 432.598692] hw queue 13 init cost time 148934 ns
[ 432.598841] hw queue 14 init cost time 147194 ns
[ 432.598991] hw queue 15 init cost time 148942 ns
[ 432.598993] [4688:kworker/u33:8 switch:700,2] all hw queues init cost time 3035099 ns
[ 432.602611] nvme0n1: p1
So use this patch to trigger schedule between each hw queue init, to avoid
other threads getting stuck. It is not in atomic context when executing
__blk_mq_alloc_rq_maps(), so it is safe to call cond_resched().
Signed-off-by: Xianting Tian <tian.xianting@h3c.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
NVMe shares tagset between fabric queue and admin queue or between
connect_q and NS queue, so hctx_may_queue() can be called to allocate
request for these queues.
Tags can be reserved in these tagset. Before error recovery, there is
often lots of in-flight requests which can't be completed, and new
reserved request may be needed in error recovery path. However,
hctx_may_queue() can always return false because there is too many
in-flight requests which can't be completed during error handling.
Finally, nothing can proceed.
Fix this issue by always allowing reserved tag allocation in
hctx_may_queue(). This is reasonable because reserved tags are supposed
to always be available.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: David Milburn <dmilburn@redhat.com>
Cc: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
High CPU utilization on "native_queued_spin_lock_slowpath" due to lock
contention is possible for mq-deadline and bfq IO schedulers
when nr_hw_queues is more than one.
It is because kblockd work queue can submit IO from all online CPUs
(through blk_mq_run_hw_queues()) even though only one hctx has pending
commands.
The elevator callback .has_work for mq-deadline and bfq scheduler considers
pending work if there are any IOs on request queue but it does not account
hctx context.
Add a per-hctx 'elevator_queued' count to the hctx to avoid triggering
the elevator even though there are no requests queued.
[jpg: Relocated atomic_dec() in dd_dispatch_request(), update commit message per Kashyap]
Signed-off-by: Kashyap Desai <kashyap.desai@broadcom.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: John Garry <john.garry@huawei.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
For when using a shared sbitmap, no longer should the number of active
request queues per hctx be relied on for when judging how to share the tag
bitmap.
Instead maintain the number of active request queues per tag_set, and make
the judgement based on that.
Originally-from: Kashyap Desai <kashyap.desai@broadcom.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Tested-by: Don Brace<don.brace@microsemi.com> #SCSI resv cmds patches used
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The per-hctx nr_active value can no longer be used to fairly assign a share
of tag depth per request queue for when using a shared sbitmap, as it does
not consider that the tags are shared tags over all hctx's.
For this case, record the nr_active_requests per request_queue, and make
the judgement based on that value.
Co-developed-with: Kashyap Desai <kashyap.desai@broadcom.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Tested-by: Don Brace<don.brace@microsemi.com> #SCSI resv cmds patches used
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Some SCSI HBAs (such as HPSA, megaraid, mpt3sas, hisi_sas_v3 ..) support
multiple reply queues with single hostwide tags.
In addition, these drivers want to use interrupt assignment in
pci_alloc_irq_vectors(PCI_IRQ_AFFINITY). However, as discussed in [0],
CPU hotplug may cause in-flight IO completion to not be serviced when an
interrupt is shutdown. That problem is solved in commit bf0beec060
("blk-mq: drain I/O when all CPUs in a hctx are offline").
However, to take advantage of that blk-mq feature, the HBA HW queuess are
required to be mapped to that of the blk-mq hctx's; to do that, the HBA HW
queues need to be exposed to the upper layer.
In making that transition, the per-SCSI command request tags are no
longer unique per Scsi host - they are just unique per hctx. As such, the
HBA LLDD would have to generate this tag internally, which has a certain
performance overhead.
However another problem is that blk-mq assumes the host may accept
(Scsi_host.can_queue * #hw queue) commands. In commit 6eb045e092 ("scsi:
core: avoid host-wide host_busy counter for scsi_mq"), the Scsi host busy
counter was removed, which would stop the LLDD being sent more than
.can_queue commands; however, it should still be ensured that the block
layer does not issue more than .can_queue commands to the Scsi host.
To solve this problem, introduce a shared sbitmap per blk_mq_tag_set,
which may be requested at init time.
New flag BLK_MQ_F_TAG_HCTX_SHARED should be set when requesting the
tagset to indicate whether the shared sbitmap should be used.
Even when BLK_MQ_F_TAG_HCTX_SHARED is set, a full set of tags and requests
are still allocated per hctx; the reason for this is that if tags and
requests were only allocated for a single hctx - like hctx0 - it may break
block drivers which expect a request be associated with a specific hctx,
i.e. not always hctx0. This will introduce extra memory usage.
This change is based on work originally from Ming Lei in [1] and from
Bart's suggestion in [2].
[0] https://lore.kernel.org/linux-block/alpine.DEB.2.21.1904051331270.1802@nanos.tec.linutronix.de/
[1] https://lore.kernel.org/linux-block/20190531022801.10003-1-ming.lei@redhat.com/
[2] https://lore.kernel.org/linux-block/ff77beff-5fd9-9f05-12b6-826922bace1f@huawei.com/T/#m3db0a602f095cbcbff27e9c884d6b4ae826144be
Signed-off-by: John Garry <john.garry@huawei.com>
Tested-by: Don Brace<don.brace@microsemi.com> #SCSI resv cmds patches used
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Introduce pointers for the blk_mq_tags regular and reserved bitmap tags,
with the goal of later being able to use a common shared tag bitmap across
all HW contexts in a set.
Signed-off-by: John Garry <john.garry@huawei.com>
Tested-by: Don Brace<don.brace@microsemi.com> #SCSI resv cmds patches used
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pass hctx/tagset flags argument down to blk_mq_init_tags() and
blk_mq_free_tags() for selective init/free.
For now, make it include the alloc policy flag, which can be evaluated
when needed (in blk_mq_init_tags()).
Signed-off-by: John Garry <john.garry@huawei.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The function does not set the depth, but rather transitions from
shared to non-shared queues and vice versa.
So rename it to blk_mq_update_tag_set_shared() to better reflect
its purpose.
[jpg: take out some unrelated changes in blk_mq_init_bitmap_tags()]
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: John Garry <john.garry@huawei.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
BLK_MQ_F_TAG_SHARED actually means that tags is shared among request
queues, all of which should belong to LUNs attached to same HBA.
So rename it to make the point explicitly.
[jpg: rebase a few times, add rnbd-clt.c change]
Suggested-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
c616cbee97 ("blk-mq: punt failed direct issue to dispatch list") supposed
to add request which has been through ->queue_rq() to the hw queue dispatch
list, however it adds request running out of budget or driver tag to hw queue
too. This way basically bypasses request merge, and causes too many request
dispatched to LLD, and system% is unnecessary increased.
Fixes this issue by adding request not through ->queue_rq into sw/scheduler
queue, and this way is safe because no ->queue_rq is called on this request
yet.
High %system can be observed on Azure storvsc device, and even soft lock
is observed. This patch reduces %system during heavy sequential IO,
meantime decreases soft lockup risk.
Fixes: c616cbee97 ("blk-mq: punt failed direct issue to dispatch list")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
SCHED_RESTART code path is relied to re-run queue for dispatch requests
in hctx->dispatch. Meantime the SCHED_RSTART flag is checked when adding
requests to hctx->dispatch.
memory barriers have to be used for ordering the following two pair of OPs:
1) adding requests to hctx->dispatch and checking SCHED_RESTART in
blk_mq_dispatch_rq_list()
2) clearing SCHED_RESTART and checking if there is request in hctx->dispatch
in blk_mq_sched_restart().
Without the added memory barrier, either:
1) blk_mq_sched_restart() may miss requests added to hctx->dispatch meantime
blk_mq_dispatch_rq_list() observes SCHED_RESTART, and not run queue in
dispatch side
or
2) blk_mq_dispatch_rq_list still sees SCHED_RESTART, and not run queue
in dispatch side, meantime checking if there is request in
hctx->dispatch from blk_mq_sched_restart() is missed.
IO hang in ltp/fs_fill test is reported by kernel test robot:
https://lkml.org/lkml/2020/7/26/77
Turns out it is caused by the above out-of-order OPs. And the IO hang
can't be observed any more after applying this patch.
Fixes: bd166ef183 ("blk-mq-sched: add framework for MQ capable IO schedulers")
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Jeffery <djeffery@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Fix a kernel-doc warning in block/blk-mq.c:
../block/blk-mq.c:1844: warning: Function parameter or member 'at_head' not described in 'blk_mq_request_bypass_insert'
Fixes: 01e99aeca3 ("blk-mq: insert passthrough request into hctx->dispatch directly")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: André Almeida <andrealmeid@collabora.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: linux-block@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
-----BEGIN PGP SIGNATURE-----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=abJG
-----END PGP SIGNATURE-----
Merge tag 'for-5.9/block-20200802' of git://git.kernel.dk/linux-block
Pull core block updates from Jens Axboe:
"Good amount of cleanups and tech debt removals in here, and as a
result, the diffstat shows a nice net reduction in code.
- Softirq completion cleanups (Christoph)
- Stop using ->queuedata (Christoph)
- Cleanup bd claiming (Christoph)
- Use check_events, moving away from the legacy media change
(Christoph)
- Use inode i_blkbits consistently (Christoph)
- Remove old unused writeback congestion bits (Christoph)
- Cleanup/unify submission path (Christoph)
- Use bio_uninit consistently, instead of bio_disassociate_blkg
(Christoph)
- sbitmap cleared bits handling (John)
- Request merging blktrace event addition (Jan)
- sysfs add/remove race fixes (Luis)
- blk-mq tag fixes/optimizations (Ming)
- Duplicate words in comments (Randy)
- Flush deferral cleanup (Yufen)
- IO context locking/retry fixes (John)
- struct_size() usage (Gustavo)
- blk-iocost fixes (Chengming)
- blk-cgroup IO stats fixes (Boris)
- Various little fixes"
* tag 'for-5.9/block-20200802' of git://git.kernel.dk/linux-block: (135 commits)
block: blk-timeout: delete duplicated word
block: blk-mq-sched: delete duplicated word
block: blk-mq: delete duplicated word
block: genhd: delete duplicated words
block: elevator: delete duplicated word and fix typos
block: bio: delete duplicated words
block: bfq-iosched: fix duplicated word
iocost_monitor: start from the oldest usage index
iocost: Fix check condition of iocg abs_vdebt
block: Remove callback typedefs for blk_mq_ops
block: Use non _rcu version of list functions for tag_set_list
blk-cgroup: show global disk stats in root cgroup io.stat
blk-cgroup: make iostat functions visible to stat printing
block: improve discard bio alignment in __blkdev_issue_discard()
block: change REQ_OP_ZONE_RESET and REQ_OP_ZONE_RESET_ALL to be odd numbers
block: defer flush request no matter whether we have elevator
block: make blk_timeout_init() static
block: remove retry loop in ioc_release_fn()
block: remove unnecessary ioc nested locking
block: integrate bd_start_claiming into __blkdev_get
...
Drop the repeated word "the".
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
tag_set_list is only accessed under the tag_set_lock lock. There is
no need for using the _rcu list functions.
The _rcu list function were introduced to allow read access to the
tag_set_list protected under RCU, see 705cda97ee ("blk-mq: Make it
safe to use RCU to iterate over blk_mq_tag_set.tag_list") and
05b7941394 ("Revert "blk-mq: don't handle TAG_SHARED in restart"").
Those changes got reverted later but the cleanup commit missed a
couple of places to undo the changes.
Fixes: 97889f9ac2 ("blk-mq: remove synchronize_rcu() from blk_mq_del_queue_tag_set()"
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We've already validated the 'q->elevator' before calling
->ops.completed_request() in blk_mq_sched_completed_request(), thus no
need to validate rq->internal_tag again. Rmove it.
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move .nr_active update and request assignment into blk_mq_get_driver_tag(),
all are good to do during getting driver tag.
Meantime blk-flush related code is simplified and flush request needn't
to update the request table manually any more.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Current handling of q->mq_ops->queue_rq result is a bit ugly:
- two branches which needs to 'continue' have to check if the
dispatch local list is empty, otherwise one bad request may
be retrieved via 'rq = list_first_entry(list, struct request, queuelist);'
- the branch of 'if (unlikely(ret != BLK_STS_OK))' isn't easy
to follow, since it is actually one error branch.
Streamline this handling, so the code becomes more readable, meantime
potential kernel oops can be avoided in case that the last request in
local dispatch list is failed.
Fixes: fc17b6534e ("blk-mq: switch ->queue_rq return value to blk_status_t")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
dm-multipath is the only user of blk_mq_queue_inflight(). When
dm-multipath calls blk_mq_queue_inflight() to check if it has
outstanding IO it can get a false negative. The reason for this is
blk_mq_rq_inflight() doesn't consider requests that are no longer
MQ_RQ_IN_FLIGHT but that are now MQ_RQ_COMPLETE (->complete isn't
called or finished yet) as "inflight".
This causes request-based dm-multipath's dm_wait_for_completion() to
return before all outstanding dm-multipath requests have actually
completed. This breaks DM multipath's suspend functionality because
blk-mq requests complete after DM's suspend has finished -- which
shouldn't happen.
Fix this by considering any request not in the MQ_RQ_IDLE state
(so either MQ_RQ_COMPLETE or MQ_RQ_IN_FLIGHT) as "inflight" in
blk_mq_rq_inflight().
Fixes: 3c94d83cb3 ("blk-mq: change blk_mq_queue_busy() to blk_mq_queue_inflight()")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jan Kara