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Since the inclusion of blk-mq, elevator argument was not being
considered anymore, and it's utility died long with the legacy IO path,
now removed too.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Marcos Paulo de Souza <marcos.souza.org@gmail.com>
Fold with doc removal patch.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Commit 7211aef86f79 ("block: mq-deadline: Fix write completion
handling") added a call to blk_mq_sched_mark_restart_hctx() in
dd_dispatch_request() to make sure that write request dispatching does
not stall when all target zones are locked. This fix left a subtle race
when a write completion happens during a dispatch execution on another
CPU:
CPU 0: Dispatch CPU1: write completion
dd_dispatch_request()
lock(&dd->lock);
...
lock(&dd->zone_lock); dd_finish_request()
rq = find request lock(&dd->zone_lock);
unlock(&dd->zone_lock);
zone write unlock
unlock(&dd->zone_lock);
...
__blk_mq_free_request
check restart flag (not set)
-> queue not run
...
if (!rq && have writes)
blk_mq_sched_mark_restart_hctx()
unlock(&dd->lock)
Since the dispatch context finishes after the write request completion
handling, marking the queue as needing a restart is not seen from
__blk_mq_free_request() and blk_mq_sched_restart() not executed leading
to the dispatch stall under 100% write workloads.
Fix this by moving the call to blk_mq_sched_mark_restart_hctx() from
dd_dispatch_request() into dd_finish_request() under the zone lock to
ensure full mutual exclusion between write request dispatch selection
and zone unlock on write request completion.
Fixes: 7211aef86f79 ("block: mq-deadline: Fix write completion handling")
Cc: stable@vger.kernel.org
Reported-by: Hans Holmberg <Hans.Holmberg@wdc.com>
Reviewed-by: Hans Holmberg <hans.holmberg@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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This patch adds a helper function whether a queue can merge
the segments by the DMA MAP layer (e.g. via IOMMU).
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au
Signed-off-by: Christoph Hellwig <hch@lst.de>
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ioc_cpd_alloc() forgot to check NULL return from kzalloc(). Add it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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blk_iocost_init() forgot to free its percpu stat on the error path.
Fix it.
Fixes: 7caa47151ab2 ("blkcg: implement blk-iocost")
Reported-by: Hillf Danton <hdanton@sina.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Add a script which can be used to generate device-specific iocost
linear model coefficients.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Instead of mucking with debugfs and ->pd_stat(), add drgn based
monitoring script.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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This patchset implements IO cost model based work-conserving
proportional controller.
While io.latency provides the capability to comprehensively prioritize
and protect IOs depending on the cgroups, its protection is binary -
the lowest latency target cgroup which is suffering is protected at
the cost of all others. In many use cases including stacking multiple
workload containers in a single system, it's necessary to distribute
IO capacity with better granularity.
One challenge of controlling IO resources is the lack of trivially
observable cost metric. The most common metrics - bandwidth and iops
- can be off by orders of magnitude depending on the device type and
IO pattern. However, the cost isn't a complete mystery. Given
several key attributes, we can make fairly reliable predictions on how
expensive a given stream of IOs would be, at least compared to other
IO patterns.
The function which determines the cost of a given IO is the IO cost
model for the device. This controller distributes IO capacity based
on the costs estimated by such model. The more accurate the cost
model the better but the controller adapts based on IO completion
latency and as long as the relative costs across differents IO
patterns are consistent and sensible, it'll adapt to the actual
performance of the device.
Currently, the only implemented cost model is a simple linear one with
a few sets of default parameters for different classes of device.
This covers most common devices reasonably well. All the
infrastructure to tune and add different cost models is already in
place and a later patch will also allow using bpf progs for cost
models.
Please see the top comment in blk-iocost.c and documentation for
more details.
v2: Rebased on top of RQ_ALLOC_TIME changes and folded in Rik's fix
for a divide-by-zero bug in current_hweight() triggered by zero
inuse_sum.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Andy Newell <newella@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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There are currently two start time timestamps - start_time_ns and
io_start_time_ns. The former marks the request allocation and and the
second issue-to-device time. The planned io.weight controller needs
to measure the total time bios take to execute after it leaves rq_qos
including the time spent waiting for request to become available,
which can easily dominate on saturated devices.
This patch adds request->alloc_time_ns which records when the request
allocation attempt started. As it isn't used for the usual stats,
make it optional behind CONFIG_BLK_RQ_ALLOC_TIME and
QUEUE_FLAG_RQ_ALLOC_TIME so that it can be compiled out when there are
no users and it's active only on queues which need it even when
compiled in.
v2: s/pre_start_time/alloc_time/ and add CONFIG_BLK_RQ_ALLOC_TIME
gating as suggested by Jens.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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io.weight is gonna be another rq_qos cgroup mechanism. Let's rename
RQ_QOS_CGROUP which is being used by io.latency to RQ_QOS_LATENCY in
preparation.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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wbt already gets queue depth changed notification through
wbt_set_queue_depth(). Generalize it into
rq_qos_ops->queue_depth_changed() so that other rq_qos policies can
easily hook into the events too.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Add a merge hook for rq_qos. This will be used by io.weight.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Separate out blkcg_conf_get_disk() so that it can be used by blkcg
policy interface file input parsers before the policy is actually
enabled. This doesn't introduce any functional changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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For policies which can do enough initialization from ->cpd_alloc_fn(),
make ->cpd_init_fn() optional.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Instead of @node, pass in @q and @blkcg so that the alloc function has
more context. This doesn't cause any behavior change and will be used
by io.weight implementation.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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The kernfs built-in lock of 'kn->count' is held in sysfs .show/.store
path. Meantime, inside block's .show/.store callback, q->sysfs_lock is
required.
However, when mq & iosched kobjects are removed via
blk_mq_unregister_dev() & elv_unregister_queue(), q->sysfs_lock is held
too. This way causes AB-BA lock because the kernfs built-in lock of
'kn-count' is required inside kobject_del() too, see the lockdep warning[1].
On the other hand, it isn't necessary to acquire q->sysfs_lock for
both blk_mq_unregister_dev() & elv_unregister_queue() because
clearing REGISTERED flag prevents storing to 'queue/scheduler'
from being happened. Also sysfs write(store) is exclusive, so no
necessary to hold the lock for elv_unregister_queue() when it is
called in switching elevator path.
So split .sysfs_lock into two: one is still named as .sysfs_lock for
covering sync .store, the other one is named as .sysfs_dir_lock
for covering kobjects and related status change.
sysfs itself can handle the race between add/remove kobjects and
showing/storing attributes under kobjects. For switching scheduler
via storing to 'queue/scheduler', we use the queue flag of
QUEUE_FLAG_REGISTERED with .sysfs_lock for avoiding the race, then
we can avoid to hold .sysfs_lock during removing/adding kobjects.
[1] lockdep warning
======================================================
WARNING: possible circular locking dependency detected
5.3.0-rc3-00044-g73277fc75ea0 #1380 Not tainted
------------------------------------------------------
rmmod/777 is trying to acquire lock:
00000000ac50e981 (kn->count#202){++++}, at: kernfs_remove_by_name_ns+0x59/0x72
but task is already holding lock:
00000000fb16ae21 (&q->sysfs_lock){+.+.}, at: blk_unregister_queue+0x78/0x10b
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&q->sysfs_lock){+.+.}:
__lock_acquire+0x95f/0xa2f
lock_acquire+0x1b4/0x1e8
__mutex_lock+0x14a/0xa9b
blk_mq_hw_sysfs_show+0x63/0xb6
sysfs_kf_seq_show+0x11f/0x196
seq_read+0x2cd/0x5f2
vfs_read+0xc7/0x18c
ksys_read+0xc4/0x13e
do_syscall_64+0xa7/0x295
entry_SYSCALL_64_after_hwframe+0x49/0xbe
-> #0 (kn->count#202){++++}:
check_prev_add+0x5d2/0xc45
validate_chain+0xed3/0xf94
__lock_acquire+0x95f/0xa2f
lock_acquire+0x1b4/0x1e8
__kernfs_remove+0x237/0x40b
kernfs_remove_by_name_ns+0x59/0x72
remove_files+0x61/0x96
sysfs_remove_group+0x81/0xa4
sysfs_remove_groups+0x3b/0x44
kobject_del+0x44/0x94
blk_mq_unregister_dev+0x83/0xdd
blk_unregister_queue+0xa0/0x10b
del_gendisk+0x259/0x3fa
null_del_dev+0x8b/0x1c3 [null_blk]
null_exit+0x5c/0x95 [null_blk]
__se_sys_delete_module+0x204/0x337
do_syscall_64+0xa7/0x295
entry_SYSCALL_64_after_hwframe+0x49/0xbe
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&q->sysfs_lock);
lock(kn->count#202);
lock(&q->sysfs_lock);
lock(kn->count#202);
*** DEADLOCK ***
2 locks held by rmmod/777:
#0: 00000000e69bd9de (&lock){+.+.}, at: null_exit+0x2e/0x95 [null_blk]
#1: 00000000fb16ae21 (&q->sysfs_lock){+.+.}, at: blk_unregister_queue+0x78/0x10b
stack backtrace:
CPU: 0 PID: 777 Comm: rmmod Not tainted 5.3.0-rc3-00044-g73277fc75ea0 #1380
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS ?-20180724_192412-buildhw-07.phx4
Call Trace:
dump_stack+0x9a/0xe6
check_noncircular+0x207/0x251
? print_circular_bug+0x32a/0x32a
? find_usage_backwards+0x84/0xb0
check_prev_add+0x5d2/0xc45
validate_chain+0xed3/0xf94
? check_prev_add+0xc45/0xc45
? mark_lock+0x11b/0x804
? check_usage_forwards+0x1ca/0x1ca
__lock_acquire+0x95f/0xa2f
lock_acquire+0x1b4/0x1e8
? kernfs_remove_by_name_ns+0x59/0x72
__kernfs_remove+0x237/0x40b
? kernfs_remove_by_name_ns+0x59/0x72
? kernfs_next_descendant_post+0x7d/0x7d
? strlen+0x10/0x23
? strcmp+0x22/0x44
kernfs_remove_by_name_ns+0x59/0x72
remove_files+0x61/0x96
sysfs_remove_group+0x81/0xa4
sysfs_remove_groups+0x3b/0x44
kobject_del+0x44/0x94
blk_mq_unregister_dev+0x83/0xdd
blk_unregister_queue+0xa0/0x10b
del_gendisk+0x259/0x3fa
? disk_events_poll_msecs_store+0x12b/0x12b
? check_flags+0x1ea/0x204
? mark_held_locks+0x1f/0x7a
null_del_dev+0x8b/0x1c3 [null_blk]
null_exit+0x5c/0x95 [null_blk]
__se_sys_delete_module+0x204/0x337
? free_module+0x39f/0x39f
? blkcg_maybe_throttle_current+0x8a/0x718
? rwlock_bug+0x62/0x62
? __blkcg_punt_bio_submit+0xd0/0xd0
? trace_hardirqs_on_thunk+0x1a/0x20
? mark_held_locks+0x1f/0x7a
? do_syscall_64+0x4c/0x295
do_syscall_64+0xa7/0x295
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fb696cdbe6b
Code: 73 01 c3 48 8b 0d 1d 20 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 008
RSP: 002b:00007ffec9588788 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
RAX: ffffffffffffffda RBX: 0000559e589137c0 RCX: 00007fb696cdbe6b
RDX: 000000000000000a RSI: 0000000000000800 RDI: 0000559e58913828
RBP: 0000000000000000 R08: 00007ffec9587701 R09: 0000000000000000
R10: 00007fb696d4eae0 R11: 0000000000000206 R12: 00007ffec95889b0
R13: 00007ffec95896b3 R14: 0000559e58913260 R15: 0000559e589137c0
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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There are 4 users which check if queue is registered, so add one helper
to check it.
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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blk_mq_map_swqueue() is called from blk_mq_init_allocated_queue()
and blk_mq_update_nr_hw_queues(). For the former caller, the kobject
isn't exposed to userspace yet. For the latter caller, hctx sysfs entries
and debugfs are un-registered before updating nr_hw_queues.
On the other hand, commit 2f8f1336a48b ("blk-mq: always free hctx after
request queue is freed") moves freeing hctx into queue's release
handler, so there won't be race with queue release path too.
So don't hold q->sysfs_lock in blk_mq_map_swqueue().
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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The original comment says:
q->sysfs_lock must be held to provide mutual exclusion between
elevator_switch() and here.
Which is simply wrong. elevator_init_mq() is only called from
blk_mq_init_allocated_queue, which is always called before the request
queue is registered via blk_register_queue(), for dm-rq or normal rq
based driver. However, queue's kobject is only exposed and added to sysfs
in blk_register_queue(). So there isn't such race between elevator_switch()
and elevator_init_mq().
So avoid to hold q->sysfs_lock in elevator_init_mq().
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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This function has no callers. Hence remove it.
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Hiding page refcount manipulation inside a low-level bio helper is
somewhat awkward. Instead return the same page information to the
callers, where it fits in much better.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Passsthrough bio handling should be the same as normal bio handling,
except that we need to take hardware limitations into account. Thus
use the common try_merge implementation after checking the hardware
limits. This changes behavior in that we now also check segment
and dma boundary settings for same page merges, which is a little
more work but has no effect as those need to be larger than the
page size.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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If we can add more data into an existing segment we do not create a gap
per definition, so move the check for a gap after the attempt to merge
into the segment.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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The original commit adding the sed-opal library by mistake added two
definitions of OPAL_METHOD_LENGTH, remove one of them.
Signed-off-by: Revanth Rajashekar <revanth.rajashekar@intel.com>
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Reviewed-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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In the function 'response_parse', num_entries will never be 0 as
slen is checked for 0. Hence, the condition 'if (num_entries == 0)'
can never be true.
Signed-off-by: Revanth Rajashekar <revanth.rajashekar@intel.com>
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Reviewed-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Signed-off-by: Revanth Rajashekar <revanth.rajashekar@intel.com>
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Reviewed-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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The dispatch list is not used any more, as the legacy block IO stack
has been removed.
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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We had a few issues with this code, and there's still a problem around
how we deal with error handling for chained/split bios. For now, just
revert the code and we'll try again with a thoroug solution. This
reverts commits:
e15c2ffa1091 ("block: fix O_DIRECT error handling for bio fragments")
0eb6ddfb865c ("block: Fix __blkdev_direct_IO() for bio fragments")
6a43074e2f46 ("block: properly handle IOCB_NOWAIT for async O_DIRECT IO")
893a1c97205a ("blk-mq: allow REQ_NOWAIT to return an error inline")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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psi tracks the time tasks wait for refaulting pages to become
uptodate, but it does not track the time spent submitting the IO. The
submission part can be significant if backing storage is contended or
when cgroup throttling (io.latency) is in effect - a lot of time is
spent in submit_bio(). In that case, we underreport memory pressure.
Annotate submit_bio() to account submission time as memory stall when
the bio is reading userspace workingset pages.
Tested-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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If blk_mq_init_allocated_queue->elevator_init_mq fails, need to release
the previously requested resources.
Fixes: d34849913819 ("blk-mq-sched: allow setting of default IO scheduler")
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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blk_exit_queue will free elevator_data, while blk_mq_requeue_work
will access it. Move cancel of requeue_work to the front of
blk_exit_queue to avoid use-after-free.
blk_exit_queue blk_mq_requeue_work
__elevator_exit blk_mq_run_hw_queues
blk_mq_exit_sched blk_mq_run_hw_queue
dd_exit_queue blk_mq_hctx_has_pending
kfree(elevator_data) blk_mq_sched_has_work
dd_has_work
Fixes: fbc2a15e3433 ("blk-mq: move cancel of requeue_work into blk_mq_release")
Cc: stable@vger.kernel.org
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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As reported in [1], the call bfq_init_rq(rq) may return NULL in case
of OOM (in particular, if rq->elv.icq is NULL because memory
allocation failed in failed in ioc_create_icq()).
This commit handles this circumstance.
[1] https://lkml.org/lkml/2019/7/22/824
Cc: Hsin-Yi Wang <hsinyi@google.com>
Cc: Nicolas Boichat <drinkcat@chromium.org>
Cc: Doug Anderson <dianders@chromium.org>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Reported-by: Hsin-Yi Wang <hsinyi@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Since commit 13a857a4c4e8 ("block, bfq: detect wakers and
unconditionally inject their I/O"), every bfq_queue has a pointer to a
waker bfq_queue and a list of the bfq_queues it may wake. In this
respect, when a bfq_queue, say Q, remains with no I/O source attached
to it, Q cannot be woken by any other bfq_queue, and cannot wake any
other bfq_queue. Then Q must be removed from the woken list of its
possible waker bfq_queue, and all bfq_queues in the woken list of Q
must stop having a waker bfq_queue.
Q remains with no I/O source in two cases: when the last process
associated with Q exits or when such a process gets associated with a
different bfq_queue. Unfortunately, commit 13a857a4c4e8 ("block, bfq:
detect wakers and unconditionally inject their I/O") performed the
above updates only in the first case.
This commit fixes this bug by moving these updates to when Q gets
freed. This is a simple and safe way to handle all cases, as both the
above events, process exit and re-association, lead to Q being freed
soon, and because dangling references would come out only after Q gets
freed (if no update were performed).
Fixes: 13a857a4c4e8 ("block, bfq: detect wakers and unconditionally inject their I/O")
Reported-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Since commit 13a857a4c4e8 ("block, bfq: detect wakers and
unconditionally inject their I/O"), BFQ stores, in a per-device
pointer last_completed_rq_bfqq, the last bfq_queue that had an I/O
request completed. If some bfq_queue receives new I/O right after the
last request of last_completed_rq_bfqq has been completed, then
last_completed_rq_bfqq may be a waker bfq_queue.
But if the bfq_queue last_completed_rq_bfqq points to is freed, then
last_completed_rq_bfqq becomes a dangling reference. This commit
resets last_completed_rq_bfqq if the pointed bfq_queue is freed.
Fixes: 13a857a4c4e8 ("block, bfq: detect wakers and unconditionally inject their I/O")
Reported-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Now that there no module users left of bio_map_kern, stop exporting the
symbol.
Reviewed-by: Javier González <javier@javigon.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Hans Holmberg <hans@owltronix.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Spread queues among present CPUs first, then building mapping on other
non-present CPUs.
So we can minimize count of dead queues which are mapped by un-present
CPUs only. Then bad IO performance can be avoided by unbalanced mapping
between present CPUs and queues.
The similar policy has been applied on Managed IRQ affinity.
Cc: Yi Zhang <yi.zhang@redhat.com>
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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This implements REQ_OP_ZONE_RESET_ALL as a special case of the block
device zone reset operations where we just simply issue bio with the
newly introduced req op.
We issue this req op when the number of sectors is equal to the device's
partition's number of sectors and device has no partitions.
We also add support so that blk_op_str() can print the new reset-all
zone operation.
This patch also adds a generic make request check for newly
introduced REQ_OP_ZONE_RESET_ALL req_opf. We simply return error
when queue is zoned and reset-all flag is not set for
REQ_OP_ZONE_RESET_ALL.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Change a reference to the legacy block layer into a reference to blk-mq.
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hannes Reinecke <hare@suse.com>
Cc: James Smart <james.smart@broadcom.com>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Jianchao Wang <jianchao.w.wang@oracle.com>
Cc: Dongli Zhang <dongli.zhang@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Consider the following example:
* The logical block size is 4 KB.
* The physical block size is 8 KB.
* max_sectors equals (16 KB >> 9) sectors.
* A non-aligned 4 KB and an aligned 64 KB bio are merged into a single
non-aligned 68 KB bio.
The current behavior is to split such a bio into (16 KB + 16 KB + 16 KB
+ 16 KB + 4 KB). The start of none of these five bio's is aligned to a
physical block boundary.
This patch ensures that such a bio is split into four aligned and
one non-aligned bio instead of being split into five non-aligned bios.
This improves performance because most block devices can handle aligned
requests faster than non-aligned requests.
Since the physical block size is larger than or equal to the logical
block size, this patch preserves the guarantee that the returned
value is a multiple of the logical block size.
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Move the max_sectors check into bvec_split_segs() such that a single
call to that function can do all the necessary checks. This patch
optimizes the fast path further, namely if a bvec fits in a page.
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Simplify this function by by removing two if-tests. Other than requiring
that the @sectors pointer is not NULL, this patch does not change the
behavior of bvec_split_segs().
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Since what the bio splitting functions do is nontrivial, document these
functions.
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Make it clear to the compiler and also to humans that the functions
that query request queue properties do not modify any member of the
request_queue data structure.
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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blk_mq_tagset_wait_completed_request() has been applied for waiting
for completed request's fn, so not necessary to use
blk_mq_complete_request_sync() any more.
Cc: Max Gurtovoy <maxg@mellanox.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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blk-mq may schedule to call queue's complete function on remote CPU via
IPI, but doesn't provide any way to synchronize the request's complete
fn. The current queue freeze interface can't provide the synchonization
because aborted requests stay at blk-mq queues during EH.
In some driver's EH(such as NVMe), hardware queue's resource may be freed &
re-allocated. If the completed request's complete fn is run finally after the
hardware queue's resource is released, kernel crash will be triggered.
Prepare for fixing this kind of issue by introducing
blk_mq_tagset_wait_completed_request().
Cc: Max Gurtovoy <maxg@mellanox.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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NVMe needs this function to decide if one request to be aborted has
been completed in normal IO path already.
So introduce it.
Cc: Max Gurtovoy <maxg@mellanox.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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hrtimer_sleepers will gain a scheduling class dependent treatment on
PREEMPT_RT. Use the new hrtimer_sleeper_start_expires() function to make
that possible.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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hrtimer_init_sleeper() calls require prior initialisation of the hrtimer
object which is embedded into the hrtimer_sleeper.
Combine the initialization and spare a function call. Fixup all call sites.
This is also a preparatory change for PREEMPT_RT to do hrtimer sleeper
specific initializations of the embedded hrtimer without modifying any of
the call sites.
No functional change.
[ anna-maria: Minor cleanups ]
[ tglx: Adopted to the removal of the task argument of
hrtimer_init_sleeper() and trivial polishing.
Folded a fix from Stephen Rothwell for the vsoc code ]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190726185752.887468908@linutronix.de
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All callers hand in 'current' and that's the only task pointer which
actually makes sense. Remove the task argument and set current in the
function.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190726185752.791885290@linutronix.de
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Pull block DMA segment fix from Jens Axboe:
"Here's the virtual boundary segment size fix"
* tag 'for-linus-20190726-2' of git://git.kernel.dk/linux-block:
block: fix max segment size handling in blk_queue_virt_boundary
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