Christoph Hellwig [Mon, 11 Oct 2021 14:55:32 +0000 (16:55 +0200)]
ntfs: use sb_bdev_nr_blocks
Use the sb_bdev_nr_blocks helper instead of open coding it and clean up
ntfs_fill_super a bit by moving an assignment a little earlier that has
no negative side effects.
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Anton Altaparmakov <anton@tuxera.com>
Jens Axboe [Thu, 14 Oct 2021 13:24:07 +0000 (07:24 -0600)]
block: only check previous entry for plug merge attempt
Currently we scan the entire plug list, which is potentially very
expensive. In an IOPS bound workload, we can drive about 5.6M IOPS with
merging enabled, and profiling shows that the plug merge check is the
(by far) most expensive thing we're doing:
Instead of browsing the whole list, just check the previously inserted
entry. That is enough for a naive merge check and will catch most cases,
and for devices that need full merging, the IO scheduler attached to
such devices will do that anyway. The plug merge is meant to be an
inexpensive check to avoid getting a request, but if we repeatedly
scan the list for every single insert, it is very much not a cheap
check.
With this patch, the workload instead runs at ~7.0M IOPS, providing
a 25% improvement. Disabling merging entirely yields another 5%
improvement.
Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Sat, 9 Oct 2021 19:10:39 +0000 (13:10 -0600)]
block: improve batched tag allocation
Add a blk_mq_get_tags() helper, which uses the new sbitmap API for
allocating a batch of tags all at once. This both simplifies the block
code for batched allocation, and it is also more efficient than just
doing repeated calls into __sbitmap_queue_get().
This reduces the sbitmap overhead in peak runs from ~3% to ~1% and
yields a performanc increase from 6.6M IOPS to 6.8M IOPS for a single
CPU core.
Jens Axboe [Sat, 9 Oct 2021 19:02:23 +0000 (13:02 -0600)]
sbitmap: add __sbitmap_queue_get_batch()
The block layer tag allocation batching still calls into sbitmap to get
each tag, but we can improve on that. Add __sbitmap_queue_get_batch(),
which returns a mask of tags all at once, along with an offset for
those tags.
An example return would be 0xff, where bits 0..7 are set, with
tag_offset == 128. The valid tags in this case would be 128..135.
A batch is specific to an individual sbitmap_map, hence it cannot be
larger than that. The requested number of tags is automatically reduced
to the max that can be satisfied with a single map.
On failure, 0 is returned. Caller should fall back to single tag
allocation at that point/
Pavel Begunkov [Wed, 13 Oct 2021 08:57:13 +0000 (09:57 +0100)]
blk-mq: optimise *end_request non-stat path
We already have a blk_mq_need_time_stamp() check in
__blk_mq_end_request() to get a timestamp, hide all the statistics
accounting under it. It cuts some cycles for requests that don't need
stats, and is free otherwise.
Christoph Hellwig [Tue, 12 Oct 2021 10:40:45 +0000 (12:40 +0200)]
blk-mq: cleanup blk_mq_submit_bio
Move the blk_mq_alloc_data stack allocation only into the branch
that actually needs it, and use rq->mq_hctx instead of data.hctx
to refer to the hctx.
Christoph Hellwig [Tue, 12 Oct 2021 10:40:44 +0000 (12:40 +0200)]
blk-mq: cleanup and rename __blk_mq_alloc_request
The newly added loop for the cached requests in __blk_mq_alloc_request
is a little too convoluted for my taste, so unwind it a bit. Also
rename the function to __blk_mq_alloc_requests now that it can allocate
more than a single request.
Jens Axboe [Wed, 6 Oct 2021 12:34:11 +0000 (06:34 -0600)]
block: pre-allocate requests if plug is started and is a batch
The caller typically has a good (or even exact) idea of how many requests
it needs to submit. We can make the request/tag allocation a lot more
efficient if we just allocate N requests/tags upfront when we queue the
first bio from the batch.
Provide a new plug start helper that allows the caller to specify how many
IOs are expected. This sets plug->nr_ios, and we can use that for smarter
request allocation. The plug provides a holding spot for requests, and
request allocation will check it before calling into the normal request
allocation path.
The blk_finish_plug() is called, check if there are unused requests and
free them. This should not happen in normal operations. The exception is
if we get merging, then we may be left with requests that need freeing
when done.
This raises the per-core performance on my setup from ~5.8M to ~6.1M
IOPS.
Jens Axboe [Wed, 6 Oct 2021 18:01:07 +0000 (12:01 -0600)]
block: bump max plugged deferred size from 16 to 32
Particularly for NVMe with efficient deferred submission for many
requests, there are nice benefits to be seen by bumping the default max
plug count from 16 to 32. This is especially true for virtualized setups,
where the submit part is more expensive. But can be noticed even on
native hardware.
Reduce the multiple queue factor from 4 to 2, since we're changing the
default size.
While changing it, move the defines into the block layer private header.
These aren't values that anyone outside of the block layer uses, or
should use.
Jens Axboe [Tue, 5 Oct 2021 15:23:59 +0000 (09:23 -0600)]
block: inherit request start time from bio for BLK_CGROUP
Doing high IOPS testing with blk-cgroups enabled spends ~15-20% of the
time just doing ktime_get_ns() -> readtsc. We essentially read and
set the start time twice, one for the bio and then again when that bio
is mapped to a request.
Given that the time between the two is very short, inherit the bio
start time instead of reading it again. This cuts 1/3rd of the overhead
of the time keeping.
John Garry [Tue, 5 Oct 2021 10:23:37 +0000 (18:23 +0800)]
blk-mq: Use shared tags for shared sbitmap support
Currently we use separate sbitmap pairs and active_queues atomic_t for
shared sbitmap support.
However a full sets of static requests are used per HW queue, which is
quite wasteful, considering that the total number of requests usable at
any given time across all HW queues is limited by the shared sbitmap depth.
As such, it is considerably more memory efficient in the case of shared
sbitmap to allocate a set of static rqs per tag set or request queue, and
not per HW queue.
So replace the sbitmap pairs and active_queues atomic_t with a shared
tags per tagset and request queue, which will hold a set of shared static
rqs.
Since there is now no valid HW queue index to be passed to the blk_mq_ops
.init and .exit_request callbacks, pass an invalid index token. This
changes the semantics of the APIs, such that the callback would need to
validate the HW queue index before using it. Currently no user of shared
sbitmap actually uses the HW queue index (as would be expected).
John Garry [Tue, 5 Oct 2021 10:23:35 +0000 (18:23 +0800)]
blk-mq: Add blk_mq_alloc_map_and_rqs()
Add a function to combine allocating tags and the associated requests,
and factor out common patterns to use this new function.
Some function only call blk_mq_alloc_map_and_rqs() now, but more
functionality will be added later.
Also make blk_mq_alloc_rq_map() and blk_mq_alloc_rqs() static since they
are only used in blk-mq.c, and finally rename some functions for
conciseness and consistency with other function names:
- __blk_mq_alloc_map_and_{request -> rqs}()
- blk_mq_alloc_{map_and_requests -> set_map_and_rqs}()
John Garry [Tue, 5 Oct 2021 10:23:32 +0000 (18:23 +0800)]
blk-mq: Pass driver tags to blk_mq_clear_rq_mapping()
Function blk_mq_clear_rq_mapping() will be used for shared sbitmap tags
in future, so pass a driver tags pointer instead of the tagset container
and HW queue index.
John Garry [Tue, 5 Oct 2021 10:23:28 +0000 (18:23 +0800)]
blk-mq: Relocate shared sbitmap resize in blk_mq_update_nr_requests()
For shared sbitmap, if the call to blk_mq_tag_update_depth() was
successful for any hctx when hctx->sched_tags is not set, then it would be
successful for all (due to nature in which blk_mq_tag_update_depth()
fails).
As such, there is no need to call blk_mq_tag_resize_shared_sbitmap() for
each hctx. So relocate the call until after the hctx iteration under the
!q->elevator check, which is equivalent (to !hctx->sched_tags).
John Garry [Tue, 5 Oct 2021 10:23:26 +0000 (18:23 +0800)]
blk-mq: Change rqs check in blk_mq_free_rqs()
The original code in commit 24d2f90309b23 ("blk-mq: split out tag
initialization, support shared tags") would check tags->rqs is non-NULL and
then dereference tags->rqs[].
Then in commit 2af8cbe30531 ("blk-mq: split tag ->rqs[] into two"), we
started to dereference tags->static_rqs[], but continued to check non-NULL
tags->rqs.
Check tags->static_rqs as non-NULL instead, which is more logical.
In addition to reverting commit 7b05bf771084 ("Revert "block/mq-deadline:
Prioritize high-priority requests""), this patch uses 'jiffies' instead
of ktime_get() in the code for aging lower priority requests.
This patch has been tested as follows:
Measured QD=1/jobs=1 IOPS for nullb with the mq-deadline scheduler.
Result without and with this patch: 555 K IOPS.
Measured QD=1/jobs=8 IOPS for nullb with the mq-deadline scheduler.
Result without and with this patch: about 380 K IOPS.
Ran the following script:
set -e
scriptdir=$(dirname "$0")
if [ -e /sys/module/scsi_debug ]; then modprobe -r scsi_debug; fi
modprobe scsi_debug ndelay=1000000 max_queue=16
sd=''
while [ -z "$sd" ]; do
sd=$(basename /sys/bus/pseudo/drivers/scsi_debug/adapter*/host*/target*/*/block/*)
done
echo $((100*1000)) > "/sys/block/$sd/queue/iosched/prio_aging_expire"
if [ -e /sys/fs/cgroup/io.prio.class ]; then
cd /sys/fs/cgroup
echo restrict-to-be >io.prio.class
echo +io > cgroup.subtree_control
else
cd /sys/fs/cgroup/blkio/
echo restrict-to-be >blkio.prio.class
fi
echo $$ >cgroup.procs
mkdir -p hipri
cd hipri
if [ -e io.prio.class ]; then
echo none-to-rt >io.prio.class
else
echo none-to-rt >blkio.prio.class
fi
{ "${scriptdir}/max-iops" -a1 -d32 -j1 -e mq-deadline "/dev/$sd" >& ~/low-pri.txt & }
echo $$ >cgroup.procs
"${scriptdir}/max-iops" -a1 -d32 -j1 -e mq-deadline "/dev/$sd" >& ~/hi-pri.txt
Result:
* 11000 IOPS for the high-priority job
* 40 IOPS for the low-priority job
If the prio aging expiry time is changed from 100s into 0, the IOPS results
change into 6712 and 6796 IOPS.
The max-iops script is a script that runs fio with the following arguments:
--bs=4K --gtod_reduce=1 --ioengine=libaio --ioscheduler=${arg_e} --runtime=60
--norandommap --rw=read --thread --buffered=0 --numjobs=${arg_j}
--iodepth=${arg_d} --iodepth_batch_submit=${arg_a}
--iodepth_batch_complete=$((arg_d / 2)) --name=${positional_argument_1}
--filename=${positional_argument_1}
Cc: Damien Le Moal <damien.lemoal@wdc.com> Cc: Niklas Cassel <Niklas.Cassel@wdc.com> Cc: Hannes Reinecke <hare@suse.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Link: https://lore.kernel.org/r/20210927220328.1410161-5-bvanassche@acm.org
[axboe: @latest -> @latest_start] Signed-off-by: Jens Axboe <axboe@kernel.dk>
Calculating the sum over all CPUs of per-CPU counters frequently is
inefficient. Hence switch from per-CPU to individual counters. Three
counters are protected by the mq-deadline spinlock since these are
only accessed from contexts that already hold that spinlock. The fourth
counter is atomic because protecting it with the mq-deadline spinlock
would trigger lock contention.
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Niklas Cassel <Niklas.Cassel@wdc.com> Cc: Hannes Reinecke <hare@suse.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20210927220328.1410161-4-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
Check a statistics invariant at module unload time. When running
blktests, the invariant is verified every time a request queue is
removed and hence is verified at least once per test.
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Niklas Cassel <Niklas.Cassel@wdc.com> Cc: Hannes Reinecke <hare@suse.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20210927220328.1410161-3-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
block/mq-deadline: Improve request accounting further
The scheduler .insert_requests() callback is called when a request is
queued for the first time and also when it is requeued. Only count a
request the first time it is queued. Additionally, since the mq-deadline
scheduler only performs zone locking for requests that have been
inserted, skip the zone unlock code for requests that have not been
inserted into the mq-deadline scheduler.
Fixes: 38ba64d12d4c ("block/mq-deadline: Track I/O statistics") Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Niklas Cassel <Niklas.Cassel@wdc.com> Cc: Hannes Reinecke <hare@suse.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20210927220328.1410161-2-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
Christoph Hellwig [Mon, 20 Sep 2021 12:33:23 +0000 (14:33 +0200)]
block: move elevator.h to block/
Except for the features passed to blk_queue_required_elevator_features,
elevator.h is only needed internally to the block layer. Move the
ELEVATOR_F_* definitions to blkdev.h, and the move elevator.h to
block/, dropping all the spurious includes outside of that.
Christoph Hellwig [Mon, 20 Sep 2021 12:33:12 +0000 (14:33 +0200)]
mm: don't include <linux/blk-cgroup.h> in <linux/writeback.h>
blk-cgroup.h pulls in blkdev.h and thus pretty much all the block
headers. Break this dependency chain by turning wbc_blkcg_css into a
macro and dropping the blk-cgroup.h include.
Merge tag '5.15-rc2-ksmbd-fixes' of git://git.samba.org/ksmbd
Pull ksmbd fixes from Steve French:
"Five fixes for the ksmbd kernel server, including three security
fixes:
- remove follow symlinks support
- use LOOKUP_BENEATH to prevent out of share access
- SMB3 compounding security fix
- fix for returning the default streams correctly, fixing a bug when
writing ppt or doc files from some clients
- logging more clearly that ksmbd is experimental (at module load
time)"
* tag '5.15-rc2-ksmbd-fixes' of git://git.samba.org/ksmbd:
ksmbd: use LOOKUP_BENEATH to prevent the out of share access
ksmbd: remove follow symlinks support
ksmbd: check protocol id in ksmbd_verify_smb_message()
ksmbd: add default data stream name in FILE_STREAM_INFORMATION
ksmbd: log that server is experimental at module load
Merge tag 'edac_urgent_for_v5.15_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras
Pull EDAC fixes from Borislav Petkov:
"Fix two EDAC drivers using the wrong value type for the DIMM mode"
* tag 'edac_urgent_for_v5.15_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras:
EDAC/dmc520: Assign the proper type to dimm->edac_mode
EDAC/synopsys: Fix wrong value type assignment for edac_mode
Merge tag 'thermal-v5.15-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/thermal/linux
Pull thermal fixes from Daniel Lezcano:
- Fix thermal shutdown after a suspend/resume due to a wrong TCC value
restored on Intel platform (Antoine Tenart)
- Fix potential buffer overflow when building the list of policies. The
buffer size is not updated after writing to it (Dan Carpenter)
- Fix wrong check against IS_ERR instead of NULL (Ansuel Smith)
* tag 'thermal-v5.15-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/thermal/linux:
thermal/drivers/tsens: Fix wrong check for tzd in irq handlers
thermal/core: Potential buffer overflow in thermal_build_list_of_policies()
thermal/drivers/int340x: Do not set a wrong tcc offset on resume
Merge tag 'x86-urgent-2021-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
"A set of fixes for X86:
- Prevent sending the wrong signal when protection keys are enabled
and the kernel handles a fault in the vsyscall emulation.
- Invoke early_reserve_memory() before invoking e820_memory_setup()
which is required to make the Xen dom0 e820 hooks work correctly.
- Use the correct data type for the SETZ operand in the EMQCMDS
instruction wrapper.
- Prevent undefined behaviour to the potential unaligned accesss in
the instruction decoder library"
* tag 'x86-urgent-2021-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/insn, tools/x86: Fix undefined behavior due to potential unaligned accesses
x86/asm: Fix SETZ size enqcmds() build failure
x86/setup: Call early_reserve_memory() earlier
x86/fault: Fix wrong signal when vsyscall fails with pkey
Merge tag 'timers-urgent-2021-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Thomas Gleixner:
"A single fix for the recently introduced regression in posix CPU
timers which failed to stop the timer when requested. That caused
unexpected signals to be sent to the process/thread causing
malfunction"
* tag 'timers-urgent-2021-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
posix-cpu-timers: Prevent spuriously armed 0-value itimer
Merge tag 'irq-urgent-2021-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Thomas Gleixner:
"A set of fixes for interrupt chip drivers:
- Work around a bad GIC integration on a Renesas platform which can't
handle byte-sized MMIO access
- Plug a potential memory leak in the GICv4 driver
- Fix a regression in the Armada 370-XP IPI code which was caused by
issuing EOI instack of ACK.
- A couple of small fixes here and there"
* tag 'irq-urgent-2021-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/gic: Work around broken Renesas integration
irqchip/renesas-rza1: Use semicolons instead of commas
irqchip/gic-v3-its: Fix potential VPE leak on error
irqchip/goldfish-pic: Select GENERIC_IRQ_CHIP to fix build
irqchip/mbigen: Repair non-kernel-doc notation
irqdomain: Change the type of 'size' in __irq_domain_add() to be consistent
irqchip/armada-370-xp: Fix ack/eoi breakage
Documentation: Fix irq-domain.rst build warning