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  1. 01 6月, 2018 5 次提交
  3. 19 1月, 2018 2 次提交
  5. 07 1月, 2018 1 次提交
  7. 26 10月, 2017 2 次提交
  9. 06 10月, 2017 1 次提交
  11. 29 8月, 2017 1 次提交
    • D
      block: fix warning when I/O elevator is changed as request_queue is being removed · e9a823fb
      由 David Jeffery 提交于 
      There is a race between changing I/O elevator and request_queue removal
which can trigger the warning in kobject_add_internal.  A program can
use sysfs to request a change of elevator at the same time another task
is unregistering the request_queue the elevator would be attached to.
The elevator's kobject will then attempt to be connected to the
request_queue in the object tree when the request_queue has just been
removed from sysfs.  This triggers the warning in kobject_add_internal
as the request_queue no longer has a sysfs directory:

kobject_add_internal failed for iosched (error: -2 parent: queue)
------------[ cut here ]------------
WARNING: CPU: 3 PID: 14075 at lib/kobject.c:244 kobject_add_internal+0x103/0x2d0

To fix this warning, we can check the QUEUE_FLAG_REGISTERED flag when
changing the elevator and use the request_queue's sysfs_lock to
serialize between clearing the flag and the elevator testing the flag.
Signed-off-by: NDavid Jeffery <djeffery@redhat.com>
Tested-by: NMing Lei <ming.lei@redhat.com>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      e9a823fb
  13. 22 6月, 2017 1 次提交
  15. 10 5月, 2017 1 次提交
    • J
      elevator: remove redundant warnings on IO scheduler switch · 340ff321
      由 Jens Axboe 提交于 
      We warn twice for switching to a scheduler, if that switch fails.
As we also report the failure in the return value to the
sysfs write, remove the dmesg induced failures.

Keep the failure print for warning to switch to the kconfig
selected IO scheduler, as we can't report errors for that in
any other way.
Signed-off-by: NJens Axboe <axboe@fb.com>
      340ff321
  17. 03 5月, 2017 1 次提交
  19. 02 5月, 2017 1 次提交
  21. 20 4月, 2017 1 次提交
  23. 19 4月, 2017 1 次提交
  25. 07 4月, 2017 2 次提交
  27. 03 3月, 2017 1 次提交
  29. 23 2月, 2017 1 次提交
  31. 14 2月, 2017 1 次提交
  33. 09 2月, 2017 1 次提交
  35. 02 2月, 2017 1 次提交
  37. 01 2月, 2017 1 次提交
  39. 19 1月, 2017 1 次提交
  41. 18 1月, 2017 3 次提交
  43. 10 12月, 2016 1 次提交
  45. 28 10月, 2016 2 次提交
    • C
      block: better op and flags encoding · ef295ecf
      由 Christoph Hellwig 提交于 
      Now that we don't need the common flags to overflow outside the range
of a 32-bit type we can encode them the same way for both the bio and
request fields.  This in addition allows us to place the operation
first (and make some room for more ops while we're at it) and to
stop having to shift around the operation values.

In addition this allows passing around only one value in the block layer
instead of two (and eventuall also in the file systems, but we can do
that later) and thus clean up a lot of code.

Last but not least this allows decreasing the size of the cmd_flags
field in struct request to 32-bits.  Various functions passing this
value could also be updated, but I'd like to avoid the churn for now.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>
      ef295ecf
    • C
      block: split out request-only flags into a new namespace · e8064021
      由 Christoph Hellwig 提交于 
      A lot of the REQ_* flags are only used on struct requests, and only of
use to the block layer and a few drivers that dig into struct request
internals.

This patch adds a new req_flags_t rq_flags field to struct request for
them, and thus dramatically shrinks the number of common requests.  It
also removes the unfortunate situation where we have to fit the fields
from the same enum into 32 bits for struct bio and 64 bits for
struct request.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NShaun Tancheff <shaun.tancheff@seagate.com>
Signed-off-by: NJens Axboe <axboe@fb.com>
      e8064021
  47. 16 8月, 2016 1 次提交
  49. 21 7月, 2016 1 次提交
    • T
      block: do not merge requests without consulting with io scheduler · 72ef799b
      由 Tahsin Erdogan 提交于 
      Before merging a bio into an existing request, io scheduler is called to
get its approval first. However, the requests that come from a plug
flush may get merged by block layer without consulting with io
scheduler.

In case of CFQ, this can cause fairness problems. For instance, if a
request gets merged into a low weight cgroup's request, high weight cgroup
now will depend on low weight cgroup to get scheduled. If high weigt cgroup
needs that io request to complete before submitting more requests, then it
will also lose its timeslice.

Following script demonstrates the problem. Group g1 has a low weight, g2
and g3 have equal high weights but g2's requests are adjacent to g1's
requests so they are subject to merging. Due to these merges, g2 gets
poor disk time allocation.

cat > cfq-merge-repro.sh << "EOF"
#!/bin/bash
set -e

IO_ROOT=/mnt-cgroup/io

mkdir -p $IO_ROOT

if ! mount | grep -qw $IO_ROOT; then
  mount -t cgroup none -oblkio $IO_ROOT
fi

cd $IO_ROOT

for i in g1 g2 g3; do
  if [ -d $i ]; then
    rmdir $i
  fi
done

mkdir g1 && echo 10 > g1/blkio.weight
mkdir g2 && echo 495 > g2/blkio.weight
mkdir g3 && echo 495 > g3/blkio.weight

RUNTIME=10

(echo $BASHPID > g1/cgroup.procs &&
 fio --readonly --name name1 --filename /dev/sdb \
     --rw read --size 64k --bs 64k --time_based \
     --runtime=$RUNTIME --offset=0k &> /dev/null)&

(echo $BASHPID > g2/cgroup.procs &&
 fio --readonly --name name1 --filename /dev/sdb \
     --rw read --size 64k --bs 64k --time_based \
     --runtime=$RUNTIME --offset=64k &> /dev/null)&

(echo $BASHPID > g3/cgroup.procs &&
 fio --readonly --name name1 --filename /dev/sdb \
     --rw read --size 64k --bs 64k --time_based \
     --runtime=$RUNTIME --offset=256k &> /dev/null)&

sleep $((RUNTIME+1))

for i in g1 g2 g3; do
  echo ---- $i ----
  cat $i/blkio.time
done

EOF
# ./cfq-merge-repro.sh
---- g1 ----
8:16 162
---- g2 ----
8:16 165
---- g3 ----
8:16 686

After applying the patch:

# ./cfq-merge-repro.sh
---- g1 ----
8:16 90
---- g2 ----
8:16 445
---- g3 ----
8:16 471
Signed-off-by: NTahsin Erdogan <tahsin@google.com>
Signed-off-by: NJens Axboe <axboe@fb.com>
      72ef799b
  51. 08 6月, 2016 1 次提交
  53. 22 10月, 2015 1 次提交
  55. 10 6月, 2015 1 次提交
    • J
      cfq-iosched: fix the setting of IOPS mode on SSDs · 0bb97947
      由 Jens Axboe 提交于 
      A previous commit wanted to make CFQ default to IOPS mode on
non-rotational storage, however it did so when the queue was
initialized and the non-rotational flag is only set later on
in the probe.

Add an elevator hook that gets called off the add_disk() path,
at that point we know that feature probing has finished, and
we can reliably check for the various flags that drivers can
set.

Fixes: 41c0126b ("block: Make CFQ default to IOPS mode on SSDs")
Tested-by: NRomain Francoise <romain@orebokech.com>
Signed-off-by: NJens Axboe <axboe@fb.com>
      0bb97947
  57. 02 6月, 2015 1 次提交
  59. 24 4月, 2015 1 次提交