We found that the blk_mq_hw_sysfs_store interface has no place to use.
The object default_hw_ctx_attrs using blk_mq_hw_sysfs_ops only uses
the show method and does not use the store method.
Since this patch:
4a46f05ebf ("blk-mq: move hctx and ctx counters from sysfs to debugfs")
moved the store method to debugfs, the store method is not used anymore.
So let me do some tiny work to clean up unused code.
Signed-off-by: Zhong Jinghua <zhongjinghua@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230128030419.2780298-1-zhongjinghua@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
s390 iterates over the bio using bio_for_each_segment and doesn't need
any bio splitting.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/r/20230123075356.60847-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
ps3vram iterates over the bio one segment, that is page aligned and max
page sized chunk, a time. Because of that there is no point in
calling bio_split_to_limits, or explicitly setting the default limits
that are only used by bio_split_to_limits.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Geoff Levand <geoff@infradead.org>
Link: https://lore.kernel.org/r/20230123074718.57951-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We ran into an issue where a production workload would randomly grind to
a halt and not continue until the pending IO had timed out. This turned
out to be a complicated interaction between queue freezing and polled
IO:
1) You have an application that does polled IO. At any point in time,
there may be polled IO pending.
2) You have a monitoring application that issues a passthrough command,
which is marked with side effects such that it needs to freeze the
queue.
3) Passthrough command is started, which calls blk_freeze_queue_start()
on the device. At this point the queue is marked frozen, and any
attempt to enter the queue will fail (for non-blocking) or block.
4) Now the driver calls blk_mq_freeze_queue_wait(), which will return
when the queue is quiesced and pending IO has completed.
5) The pending IO is polled IO, but any attempt to poll IO through the
normal iocb_bio_iopoll() -> bio_poll() will fail when it gets to
bio_queue_enter() as the queue is frozen. Rather than poll and
complete IO, the polling threads will sit in a tight loop attempting
to poll, but failing to enter the queue to do so.
The end result is that progress for either application will be stalled
until all pending polled IO has timed out. This causes obvious huge
latency issues for the application doing polled IO, but also long delays
for passthrough command.
Fix this by treating queue enter for polled IO just like we do for
timeouts. This allows quick quiesce of the queue as we still poll and
complete this IO, while still disallowing queueing up new IO.
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
vrate_min is calculated by DIV64_U64_ROUND_UP, but vrate_max is calculated
by div64_u64. Vrate_min may be 1 greater than vrate_max if the input
values min and max of cost.qos are equal.
Signed-off-by: Li Nan <linan122@huawei.com>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230117070806.3857142-6-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
echo max of u64 to cost.model can cause divide by 0 error.
# echo 8:0 rbps=18446744073709551615 > /sys/fs/cgroup/io.cost.model
divide error: 0000 [#1] PREEMPT SMP
RIP: 0010:calc_lcoefs+0x4c/0xc0
Call Trace:
<TASK>
ioc_refresh_params+0x2b3/0x4f0
ioc_cost_model_write+0x3cb/0x4c0
? _copy_from_iter+0x6d/0x6c0
? kernfs_fop_write_iter+0xfc/0x270
cgroup_file_write+0xa0/0x200
kernfs_fop_write_iter+0x17d/0x270
vfs_write+0x414/0x620
ksys_write+0x73/0x160
__x64_sys_write+0x1e/0x30
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
calc_lcoefs() uses the input value of cost.model in DIV_ROUND_UP_ULL,
overflow would happen if bps plus IOC_PAGE_SIZE is greater than
ULLONG_MAX, it can cause divide by 0 error.
Fix the problem by setting basecost
Signed-off-by: Li Nan <linan122@huawei.com>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230117070806.3857142-5-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
iocost is based on rq_qos, which can only work for request based device,
thus it doesn't make sense to configure iocost for bio based device.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230117070806.3857142-3-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The behavior of 'enum' types has changed in gcc-13, so now the
UNBUSY_THR_PCT constant is interpreted as a 64-bit number because
it is defined as part of the same enum definition as some other
constants that do not fit within a 32-bit integer. This in turn
leads to some inefficient code on 32-bit architectures as well
as a link error:
arm-linux-gnueabi/bin/arm-linux-gnueabi-ld: block/blk-iocost.o: in function `ioc_timer_fn':
blk-iocost.c:(.text+0x68e8): undefined reference to `__aeabi_uldivmod'
arm-linux-gnueabi-ld: blk-iocost.c:(.text+0x6908): undefined reference to `__aeabi_uldivmod'
Split the enum definition to keep the 64-bit timing constants in
a separate enum type from those constants that can clearly fit
within a smaller type.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230118080706.3303186-1-arnd@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Fix the following warning:
Documentation/block/ublk.rst:157: WARNING: Enumerated list ends without a blank line; unexpected unindent.
Documentation/block/ublk.rst:171: WARNING: Enumerated list ends without a blank line; unexpected unindent.
Fixes: 56f5160bc1b8 ("ublk_drv: add mechanism for supporting unprivileged ublk device")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230118042318.127900-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add a generic bdev_zone_no() helper to calculate zone number for a
given sector in a block device. This helper internally uses disk_zone_no()
to find the zone number.
Use the helper bdev_zone_no() to calculate nr of zones. This lets us
make modifications to the math if needed in one place.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Link: https://lore.kernel.org/r/20230110143635.77300-4-p.raghav@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Instead of open coding to check for zone start, add a helper to improve
readability and store the logic in one place.
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230110143635.77300-3-p.raghav@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Remove the superfluous request queue check in bdev_is_zoned() as
bdev_get_queue() can never return NULL.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Link: https://lore.kernel.org/r/20230110143635.77300-2-p.raghav@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This patch modifies the present check, so that bio-cache is not limited
to iopoll.
Signed-off-by: Anuj Gupta <anuj20.g@samsung.com>
Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
Link: https://lore.kernel.org/r/20230117120638.72254-3-anuj20.g@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This patch sets REQ_ALLOC_CACHE flag for uring-passthru requests.
This is a prep-patch so that normal / IRQ-driven uring-passthru
I/Os can also leverage bio-cache.
Signed-off-by: Anuj Gupta <anuj20.g@samsung.com>
Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
Link: https://lore.kernel.org/r/20230117120638.72254-2-anuj20.g@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
unprivileged ublk device is helpful for container use case, such
as: ublk device created in one unprivileged container can be controlled
and accessed by this container only.
Implement this feature by adding flag of UBLK_F_UNPRIVILEGED_DEV, and if
this flag isn't set, any control command has been run from privileged
user. Otherwise, any control command can be sent from any unprivileged
user, but the user has to be permitted to access the ublk char device
to be controlled.
In case of UBLK_F_UNPRIVILEGED_DEV:
1) for command UBLK_CMD_ADD_DEV, it is always allowed, and user needs
to provide owner's uid/gid in this command, so that udev can set correct
ownership for the created ublk device, since the device owner uid/gid
can be queried via command of UBLK_CMD_GET_DEV_INFO.
2) for other control commands, they can only be run successfully if the
current user is allowed to access the specified ublk char device, for
running the permission check, path of the ublk char device has to be
provided by these commands.
Also add one control of command UBLK_CMD_GET_DEV_INFO2 which always
include the char dev path in payload since userspace may not have
knowledge if this device is created in unprivileged mode.
For applying this mechanism, system administrator needs to take
the following policies:
1) chmod 0666 /dev/ublk-control
2) change ownership of ublkcN & ublkbN
- chown owner_uid:owner_gid /dev/ublkcN
- chown owner_uid:owner_gid /dev/ublkbN
Both can be done via one simple udev rule.
Userspace:
https://github.com/ming1/ubdsrv/tree/unprivileged-ublk
'ublk add -t $TYPE --un_privileged=1' is for creating one un-privileged
ublk device if the user is un-privileged.
Link: https://lore.kernel.org/linux-block/YoOr6jBfgVm8GvWg@stefanha-x1.localdomain/
Suggested-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230106041711.914434-7-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Prepare for supporting unprivileged ublk device by limiting max number
ublk devices added. Otherwise too many ublk devices could be added by
un-trusted user, which can be thought as one DoS.
Reviewed-by: ZiyangZhang <ZiyangZhang@linux.alibaba.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230106041711.914434-6-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Userspace side only knows device ID, but the associated path of ublkc* and
ublkb* could be changed by udev, and that depends on userspace's policy, so
add parameter of UBLK_PARAM_TYPE_DEVT for retrieving major/minor of the
ublkc* and ublkb*, then user may figure out major/minor of the ublk disks
he/she owns. With major/minor, it is easy to find the device node path.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230106041711.914434-5-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
It is annoying for each control command handler to get/put ublk
device and deal with failure.
Control command handler is simplified a lot by moving
ublk_get_device_from_id into ublk_ctrl_uring_cmd().
Reviewed-by: ZiyangZhang <ZiyangZhang@linux.alibaba.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230106041711.914434-4-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If any ubq daemon is unprivileged, the ublk char device is allowed
for unprivileged user actually, and we can't trust the current user,
so not probe partitions.
Fixes: 71f28f3136 ("ublk_drv: add io_uring based userspace block driver")
Reviewed-by: ZiyangZhang <ZiyangZhang@linux.alibaba.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230106041711.914434-3-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
No one uses 'nr_aborted_queues' any more, so remove it.
Reviewed-by: ZiyangZhang <ZiyangZhang@linux.alibaba.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230106041711.914434-2-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If we're doing a large IO request which needs to be split into multiple
bios for issue, then we can run into the same situation as the below
marked commit fixes - parts will complete just fine, one or more parts
will fail to allocate a request. This will result in a partially
completed read or write request, where the caller gets EAGAIN even though
parts of the IO completed just fine.
Do the same for large bios as we do for splits - fail a NOWAIT request
with EAGAIN. This isn't technically fixing an issue in the below marked
patch, but for stable purposes, we should have either none of them or
both.
This depends on: 613b14884b ("block: handle bio_split_to_limits() NULL return")
Cc: stable@vger.kernel.org # 5.15+
Fixes: 9cea62b2cb ("block: don't allow splitting of a REQ_NOWAIT bio")
Link: https://github.com/axboe/liburing/issues/766
Reported-and-tested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Trying to remove an "empty" (just initialized, or "cleared") interval
from the tree, this results in an endless loop.
As we typically protect the tree with a spinlock_irq,
the result is a hung system.
Be nice to error cleanup code paths, ignore removal of empty intervals.
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Link: https://lore.kernel.org/r/20230113123538.144276-8-christoph.boehmwalder@linbit.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This require_context attribute originated in a proposed sparse patch by
Philipp Reisner back in 2008. Johannes Berg had a different solution to
a similar problem, and that patch "won" in the end; so the require_context
thing never got merged. The whole history can be read at [0].
DRBD kept using these annotations anyway for a while. Nowadays, on a
modern unmodified sparse, they obviously do nothing, and they are hardly
used anymore anyway.
So, just remove the definitions of these macros.
[0] https://www.spinics.net/lists/linux-sparse/msg01150.html
Signed-off-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Reviewed-by: Joel Colledge <joel.colledge@linbit.com>
Link: https://lore.kernel.org/r/20230113123538.144276-6-christoph.boehmwalder@linbit.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
These are almost always used as unsigned integers, so mark them as such.
Signed-off-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Reviewed-by: Joel Colledge <joel.colledge@linbit.com>
Link: https://lore.kernel.org/r/20230113123538.144276-4-christoph.boehmwalder@linbit.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The protocol uses -1 as a reserved value for
'no specific volume', and since the protocol field
is a 16 bit unsigned value, -1 is converted to
65535. Therefore, limit the range of valid volume
numbers to [0, 65534].
Signed-off-by: Robert Altnoeder <robert.altnoeder@linbit.com>
Signed-off-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Reviewed-by: Joel Colledge <joel.colledge@linbit.com>
Link: https://lore.kernel.org/r/20230113123538.144276-3-christoph.boehmwalder@linbit.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
See also commit 93c68cc46a ("drbd: use consistent license"). We only
want to license drbd under GPL-2.0, so use the corresponding SPDX header
consistently.
Signed-off-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Reviewed-by: Joel Colledge <joel.colledge@linbit.com>
Link: https://lore.kernel.org/r/20230113123538.144276-2-christoph.boehmwalder@linbit.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
To be more similar to what we do in the out-of-tree module and ease the
upstreaming process.
Signed-off-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Reviewed-by: Joel Colledge <joel.colledge@linbit.com>
Link: https://lore.kernel.org/r/20230113123506.144082-4-christoph.boehmwalder@linbit.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
To be more similar to what we do in the out-of-tree module and ease the
upstreaming process.
Signed-off-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Reviewed-by: Joel Colledge <joel.colledge@linbit.com>
Link: https://lore.kernel.org/r/20230113123506.144082-2-christoph.boehmwalder@linbit.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We have BIO_FLAG_LAST in the enum for bio specific flags, but it's
not used to check that we're not exceeding the size of them. Add
such a check.
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The user can set the max_sectors limit to any valid value via sysfs
/sys/block/<dev>/queue/max_sectors_kb attribute. If the device limits
are ever rescanned, though, the limit reverts back to the potentially
artificially low BLK_DEF_MAX_SECTORS value.
Preserve the user's setting as the max_sectors limit as long as it's
valid. The user can reset back to defaults by writing 0 to the sysfs
file.
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20230105205146.3610282-3-kbusch@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This is used as an unsigned value, so define it that way to avoid
having to cast it.
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20230105205146.3610282-2-kbusch@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Upon the invocation of its dispatch function, BFQ returns the next I/O
request of the in-service bfq_queue, unless some exception holds. One
such exception is that there is some underutilized actuator, different
from the actuator for which the in-service queue contains I/O, and
that some other bfq_queue happens to contain I/O for such an
actuator. In this case, the next I/O request of the latter bfq_queue,
and not of the in-service bfq_queue, is returned (I/O is injected from
that bfq_queue). To find such an actuator, a linear scan, in
increasing index order, is performed among actuators.
Performing a linear scan entails a prioritization among actuators: an
underutilized actuator may be considered for injection only if all
actuators with a lower index are currently fully utilized, or if there
is no pending I/O for any lower-index actuator that happens to be
underutilized.
This commits breaks this prioritization and tends to distribute
injection uniformly across actuators. This is obtained by adding the
following condition to the linear scan: even if an actuator A is
underutilized, A is however skipped if its load is higher than that of
the next actuator.
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Davide Zini <davidezini2@gmail.com>
Link: https://lore.kernel.org/r/20230103145503.71712-9-paolo.valente@linaro.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The main service scheme of BFQ for sync I/O is serving one sync
bfq_queue at a time, for a while. In particular, BFQ enforces this
scheme when it deems the latter necessary to boost throughput or
to preserve service guarantees. Unfortunately, when BFQ enforces
this policy, only one actuator at a time gets served for a while,
because each bfq_queue contains I/O only for one actuator. The
other actuators may remain underutilized.
Actually, BFQ may serve (inject) extra I/O, taken from other
bfq_queues, in parallel with that of the in-service queue. This
injection mechanism may provide the ground for dealing also with
the above actuator-underutilization problem. Yet BFQ does not take
the actuator load into account when choosing which queue to pick
extra I/O from. In addition, BFQ may happen to inject extra I/O
only when the in-service queue is temporarily empty.
In view of these facts, this commit extends the
injection mechanism in such a way that the latter:
(1) takes into account also the actuator load;
(2) checks such a load on each dispatch, and injects I/O for an
underutilized actuator, if there is one and there is I/O for it.
To perform the check in (2), this commit introduces a load
threshold, currently set to 4. A linear scan of each actuator is
performed, until an actuator is found for which the following two
conditions hold: the load of the actuator is below the threshold,
and there is at least one non-in-service queue that contains I/O
for that actuator. If such a pair (actuator, queue) is found, then
the head request of that queue is returned for dispatch, instead
of the head request of the in-service queue.
We have set the threshold, empirically, to the minimum possible
value for which an actuator is fully utilized, or close to be
fully utilized. By doing so, injected I/O 'steals' as few
drive-queue slots as possibile to the in-service queue. This
reduces as much as possible the probability that the service of
I/O from the in-service bfq_queue gets delayed because of slot
exhaustion, i.e., because all the slots of the drive queue are
filled with I/O injected from other queues (NCQ provides for 32
slots).
This new mechanism also counters actuator underutilization in the
case of asymmetric configurations of bfq_queues. Namely if there
are few bfq_queues containing I/O for some actuators and many
bfq_queues containing I/O for other actuators. Or if the
bfq_queues containing I/O for some actuators have lower weights
than the other bfq_queues.
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Davide Zini <davidezini2@gmail.com>
Link: https://lore.kernel.org/r/20230103145503.71712-8-paolo.valente@linaro.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This patch implements the code to gather the content of the
independent_access_ranges structure from the request_queue and copy
it into the queue's bfq_data. This copy is done at queue initialization.
We copy the access ranges into the bfq_data to avoid taking the queue
lock each time we access the ranges.
This implementation, however, puts a limit to the maximum independent
ranges supported by the scheduler. Such a limit is equal to the constant
BFQ_MAX_ACTUATORS. This limit was placed to avoid the allocation of
dynamic memory.
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Co-developed-by: Rory Chen <rory.c.chen@seagate.com>
Signed-off-by: Rory Chen <rory.c.chen@seagate.com>
Signed-off-by: Federico Gavioli <f.gavioli97@gmail.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Link: https://lore.kernel.org/r/20230103145503.71712-7-paolo.valente@linaro.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Similarly to sync bfq_queues, also async bfq_queues need to be split
on a per-actuator basis.
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Davide Zini <davidezini2@gmail.com>
Link: https://lore.kernel.org/r/20230103145503.71712-6-paolo.valente@linaro.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When a bfq_queue Q is merged with another queue, several pieces of
information are saved about Q. These pieces are stored in the
bfqq_data field in the bfq_io_cq data structure of the process
associated with Q.
Yet, with a multi-actuator drive, a process may get associated with
multiple bfq_queues: one queue for each of the N actuators. Each of
these queues may undergo a merge. So, the bfq_io_cq data structure
must be able to accommodate the above information for N queues.
This commit solves this problem by turning the bfqq_data scalar field
into an array of N elements (and by changing code so as to handle
this array).
This solution is written under the assumption that bfq_queues
associated with different actuators cannot be cross-merged. This
assumption holds naturally with basic queue merging: the latter is
triggered by spatial locality, and sectors for different actuators are
not close to each other (apart from the corner case of the last
sectors served by a given actuator and the first sectors served by the
next actuator). As for stable cross-merging, the assumption here is
that it is disabled.
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Gabriele Felici <felicigb@gmail.com>
Signed-off-by: Gianmarco Lusvardi <glusvardi@posteo.net>
Signed-off-by: Giulio Barabino <giuliobarabino99@gmail.com>
Signed-off-by: Emiliano Maccaferri <inbox@emilianomaccaferri.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Link: https://lore.kernel.org/r/20230103145503.71712-5-paolo.valente@linaro.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
With a multi-actuator drive, a process may get associated with multiple
bfq_queues: one queue for each of the N actuators. So, the bfq_io_cq
data structure must be able to accommodate its per-queue persistent
information for N queues. Currently it stores this information for
just one queue, in several scalar fields.
This is a preparatory commit for moving to accommodating persistent
information for N queues. In particular, this commit packs all the
above scalar fields into a single data structure. Then there is now
only one field, in bfq_io_cq, that stores all the above information. This
scalar field will then be turned into an array by a following commit.
Suggested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Gianmarco Lusvardi <glusvardi@posteo.net>
Signed-off-by: Giulio Barabino <giuliobarabino99@gmail.com>
Signed-off-by: Emiliano Maccaferri <inbox@emilianomaccaferri.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Link: https://lore.kernel.org/r/20230103145503.71712-4-paolo.valente@linaro.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If queues associated with different actuators are merged, then control
is lost on each actuator. Therefore some actuator may be
underutilized, and throughput may decrease. This problem cannot occur
with basic queue merging, because the latter is triggered by spatial
locality, and sectors for different actuators are not close to each
other. Yet it may happen with stable merging. To address this issue,
this commit prevents stable merging from occurring among queues
associated with different actuators.
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Link: https://lore.kernel.org/r/20230103145503.71712-3-paolo.valente@linaro.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Single-LUN multi-actuator SCSI drives, as well as all multi-actuator
SATA drives appear as a single device to the I/O subsystem [1]. Yet
they address commands to different actuators internally, as a function
of Logical Block Addressing (LBAs). A given sector is reachable by
only one of the actuators. For example, Seagate’s Serial Advanced
Technology Attachment (SATA) version contains two actuators and maps
the lower half of the SATA LBA space to the lower actuator and the
upper half to the upper actuator.
Evidently, to fully utilize actuators, no actuator must be left idle
or underutilized while there is pending I/O for it. The block layer
must somehow control the load of each actuator individually. This
commit lays the ground for allowing BFQ to provide such a per-actuator
control.
BFQ associates an I/O-request sync bfq_queue with each process doing
synchronous I/O, or with a group of processes, in case of queue
merging. Then BFQ serves one bfq_queue at a time. While in service, a
bfq_queue is emptied in request-position order. Yet the same process,
or group of processes, may generate I/O for different actuators. In
this case, different streams of I/O (each for a different actuator)
get all inserted into the same sync bfq_queue. So there is basically
no individual control on when each stream is served, i.e., on when the
I/O requests of the stream are picked from the bfq_queue and
dispatched to the drive.
This commit enables BFQ to control the service of each actuator
individually for synchronous I/O, by simply splitting each sync
bfq_queue into N queues, one for each actuator. In other words, a sync
bfq_queue is now associated to a pair (process, actuator). As a
consequence of this split, the per-queue proportional-share policy
implemented by BFQ will guarantee that the sync I/O generated for each
actuator, by each process, receives its fair share of service.
This is just a preparatory patch. If the I/O of the same process
happens to be sent to different queues, then each of these queues may
undergo queue merging. To handle this event, the bfq_io_cq data
structure must be properly extended. In addition, stable merging must
be disabled to avoid loss of control on individual actuators. Finally,
also async queues must be split. These issues are described in detail
and addressed in next commits. As for this commit, although multiple
per-process bfq_queues are provided, the I/O of each process or group
of processes is still sent to only one queue, regardless of the
actuator the I/O is for. The forwarding to distinct bfq_queues will be
enabled after addressing the above issues.
[1] https://www.linaro.org/blog/budget-fair-queueing-bfq-linux-io-scheduler-optimizations-for-multi-actuator-sata-hard-drives/
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Gabriele Felici <felicigb@gmail.com>
Signed-off-by: Carmine Zaccagnino <carmine@carminezacc.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Link: https://lore.kernel.org/r/20230103145503.71712-2-paolo.valente@linaro.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
avoid leaking memory
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Merge tag 'irq_urgent_for_v6.2_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fix from Borislav Petkov:
- Cleanup the firmware node for the new IRQ MSI domain properly, to
avoid leaking memory
* tag 'irq_urgent_for_v6.2_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq/msi: Free the fwnode created by msi_create_device_irq_domain()
16 will support it
- Fix a NULL ptr deref when suspending with Xen PV
- Have a SEV-SNP guest check explicitly for features enabled by the hypervisor
and fail gracefully if some are unsupported by the guest instead of failing in
a non-obvious and hard-to-debug way
- Fix a MSI descriptor leakage under Xen
- Mark Xen's MSI domain as supporting MSI-X
- Prevent legacy PIC interrupts from being resent in software by marking them
level triggered, as they should be, which lead to a NULL ptr deref
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Merge tag 'x86_urgent_for_v6.2_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov:
- Start checking for -mindirect-branch-cs-prefix clang support too now
that LLVM 16 will support it
- Fix a NULL ptr deref when suspending with Xen PV
- Have a SEV-SNP guest check explicitly for features enabled by the
hypervisor and fail gracefully if some are unsupported by the guest
instead of failing in a non-obvious and hard-to-debug way
- Fix a MSI descriptor leakage under Xen
- Mark Xen's MSI domain as supporting MSI-X
- Prevent legacy PIC interrupts from being resent in software by
marking them level triggered, as they should be, which lead to a NULL
ptr deref
* tag 'x86_urgent_for_v6.2_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/build: Move '-mindirect-branch-cs-prefix' out of GCC-only block
acpi: Fix suspend with Xen PV
x86/sev: Add SEV-SNP guest feature negotiation support
x86/pci/xen: Fixup fallout from the PCI/MSI overhaul
x86/pci/xen: Set MSI_FLAG_PCI_MSIX support in Xen MSI domain
x86/i8259: Mark legacy PIC interrupts with IRQ_LEVEL
- touchpads on HP 15-* laptops switched back to PS/2 emulation mode
- a quirk for Clevo PCX0DX/TUXEDO XP1511 to make sure keyboard is
responding after resume
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Merge tag 'input-for-v6.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
Pull input fixes from Dmitry Torokhov:
- touchpads on HP 15-* laptops switched back to PS/2 emulation mode
- a quirk for Clevo PCX0DX/TUXEDO XP1511 to make sure keyboard is
responding after resume
* tag 'input-for-v6.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: i8042 - add Clevo PCX0DX to i8042 quirk table
Revert "Input: synaptics - switch touchpad on HP Laptop 15-da3001TU to RMI mode"
- Fix a crash regression due to module load order of cxl_pmem.ko
- Fix wrong register offset read in CXL AER handling path
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Merge tag 'cxl-fixes-for-6.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl
Pull cxl fixes from Dan Williams:
"A couple of fixes for bugs introduced during the merge window. One is
a regression, the other was a bug in the CXL AER handler:
- Fix a crash regression due to module load order of cxl_pmem.ko
- Fix wrong register offset read in CXL AER handling path"
* tag 'cxl-fixes-for-6.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl:
cxl/pmem: Fix nvdimm unregistration when cxl_pmem driver is absent
cxl: fix cxl_report_and_clear() RAS UE addr mis-assignment
