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  1. 08 9月, 2015 2 次提交
  3. 06 5月, 2015 1 次提交
  5. 11 4月, 2015 1 次提交
    • J
      sd, mmc, virtio_blk, string_helpers: fix block size units · b9f28d86
      由 James Bottomley 提交于 
      The current string_get_size() overflows when the device size goes over
2^64 bytes because the string helper routine computes the suffix from
the size in bytes.  However, the entirety of Linux thinks in terms of
blocks, not bytes, so this will artificially induce an overflow on very
large devices.  Fix this by making the function string_get_size() take
blocks and the block size instead of bytes.  This should allow us to
keep working until the current SCSI standard overflows.

Also fix virtio_blk and mmc (both of which were also artificially
multiplying by the block size to pass a byte side to string_get_size()).

The mathematics of this is pretty simple:  we're taking a product of
size in blocks (S) and block size (B) and trying to re-express this in
exponential form: S*B = R*N^E (where N, the exponent is either 1000 or
1024) and R < N.  Mathematically, S = RS*N^ES and B=RB*N^EB, so if RS*RB
< N it's easy to see that S*B = RS*RB*N^(ES+EB).  However, if RS*BS > N,
we can see that this can be re-expressed as RS*BS = R*N (where R =
RS*BS/N < N) so the whole exponent becomes R*N^(ES+EB+1)

[jejb: fix incorrect 32 bit do_div spotted by kbuild test robot <fengguang.wu@intel.com>]
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>
      b9f28d86
  7. 21 1月, 2015 2 次提交
  9. 03 1月, 2015 1 次提交
  11. 09 12月, 2014 4 次提交
  13. 11 11月, 2014 1 次提交
  15. 30 10月, 2014 1 次提交
    • J
      blk-mq: add a 'list' parameter to ->queue_rq() · 74c45052
      由 Jens Axboe 提交于 
      Since we have the notion of a 'last' request in a chain, we can use
this to have the hardware optimize the issuing of requests. Add
a list_head parameter to queue_rq that the driver can use to
temporarily store hw commands for issue when 'last' is true. If we
are doing a chain of requests, pass in a NULL list for the first
request to force issue of that immediately, then batch the remainder
for deferred issue until the last request has been sent.

Instead of adding yet another argument to the hot ->queue_rq path,
encapsulate the passed arguments in a blk_mq_queue_data structure.
This is passed as a constant, and has been tested as faster than
passing 4 (or even 3) args through ->queue_rq. Update drivers for
the new ->queue_rq() prototype. There are no functional changes
in this patch for drivers - if they don't use the passed in list,
then they will just queue requests individually like before.
Signed-off-by: NJens Axboe <axboe@fb.com>
      74c45052
  17. 15 10月, 2014 4 次提交
  19. 23 9月, 2014 3 次提交
  21. 02 7月, 2014 1 次提交
  23. 30 5月, 2014 1 次提交
    • M
      block: virtio_blk: don't hold spin lock during world switch · e8edca6f
      由 Ming Lei 提交于 
      Firstly, it isn't necessary to hold lock of vblk->vq_lock
when notifying hypervisor about queued I/O.

Secondly, virtqueue_notify() will cause world switch and
it may take long time on some hypervisors(such as, qemu-arm),
so it isn't good to hold the lock and block other vCPUs.

On arm64 quad core VM(qemu-kvm), the patch can increase I/O
performance a lot with VIRTIO_RING_F_EVENT_IDX enabled:
	- without the patch: 14K IOPS
	- with the patch: 34K IOPS

fio script:
	[global]
	direct=1
	bsrange=4k-4k
	timeout=10
	numjobs=4
	ioengine=libaio
	iodepth=64

	filename=/dev/vdc
	group_reporting=1

	[f1]
	rw=randread

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: NMing Lei <ming.lei@canonical.com>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org # 3.13+
Signed-off-by: NJens Axboe <axboe@fb.com>
      e8edca6f
  25. 29 5月, 2014 1 次提交
  27. 27 5月, 2014 1 次提交
    • M
      virtio_blk: fix race between start and stop queue · aa0818c6
      由 Ming Lei 提交于 
      When there isn't enough vring descriptor for adding to vq,
blk-mq will be put as stopped state until some of pending
descriptors are completed & freed.

Unfortunately, the vq's interrupt may come just before
blk-mq's BLK_MQ_S_STOPPED flag is set, so the blk-mq will
still be kept as stopped even though lots of descriptors
are completed and freed in the interrupt handler. The worst
case is that all pending descriptors are freed in the
interrupt handler, and the queue is kept as stopped forever.

This patch fixes the problem by starting/stopping blk-mq
with holding vq_lock.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NMing Lei <tom.leiming@gmail.com>
Cc: stable@kernel.org
Signed-off-by: NJens Axboe <axboe@fb.com>

Conflicts:
	drivers/block/virtio_blk.c
      aa0818c6
  29. 16 5月, 2014 1 次提交
    • M
      virtio_blk: fix race between start and stop queue · 0c29e93e
      由 Ming Lei 提交于 
      When there isn't enough vring descriptor for adding to vq,
blk-mq will be put as stopped state until some of pending
descriptors are completed & freed.

Unfortunately, the vq's interrupt may come just before
blk-mq's BLK_MQ_S_STOPPED flag is set, so the blk-mq will
still be kept as stopped even though lots of descriptors
are completed and freed in the interrupt handler. The worst
case is that all pending descriptors are freed in the
interrupt handler, and the queue is kept as stopped forever.

This patch fixes the problem by starting/stopping blk-mq
with holding vq_lock.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NMing Lei <tom.leiming@gmail.com>
Signed-off-by: NJens Axboe <axboe@fb.com>
      0c29e93e
  31. 17 4月, 2014 1 次提交
  33. 16 4月, 2014 3 次提交
    • C
      blk-mq: split out tag initialization, support shared tags · 24d2f903
      由 Christoph Hellwig 提交于 
      Add a new blk_mq_tag_set structure that gets set up before we initialize
the queue.  A single blk_mq_tag_set structure can be shared by multiple
queues.
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Modular export of blk_mq_{alloc,free}_tagset added by me.
Signed-off-by: NJens Axboe <axboe@fb.com>
      24d2f903
    • C
      blk-mq: add ->init_request and ->exit_request methods · e9b267d9
      由 Christoph Hellwig 提交于 
      The current blk_mq_init_commands/blk_mq_free_commands interface has a
two problems:

 1) Because only the constructor is passed to blk_mq_init_commands there
    is no easy way to clean up when a comman initialization failed.  The
    current code simply leaks the allocations done in the constructor.

 2) There is no good place to call blk_mq_free_commands: before
    blk_cleanup_queue there is no guarantee that all outstanding
    commands have completed, so we can't free them yet.  After
    blk_cleanup_queue the queue has usually been freed.  This can be
    worked around by grabbing an unconditional reference before calling
    blk_cleanup_queue and dropping it after blk_mq_free_commands is
    done, although that's not exatly pretty and driver writers are
    guaranteed to get it wrong sooner or later.

Both issues are easily fixed by making the request constructor and
destructor normal blk_mq_ops methods.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>
      e9b267d9
    • C
      blk-mq: do not initialize req->special · 9d74e257
      由 Christoph Hellwig 提交于 
      Drivers can reach their private data easily using the blk_mq_rq_to_pdu
helper and don't need req->special.  By not initializing it code can
be simplified nicely, and we also shave off a few more instructions from
the I/O path.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>
      9d74e257
  35. 24 3月, 2014 1 次提交
    • R
      virtio-blk: base queue-depth on virtqueue ringsize or module param · fc4324b4
      由 Rusty Russell 提交于 
      Venkatash spake thus:

  virtio-blk set the default queue depth to 64 requests, which was
  insufficient for high-IOPS devices. Instead set the blk-queue depth to
  the device's virtqueue depth divided by two (each I/O requires at least
  two VQ entries).

But behold, Ted added a module parameter:

  Also allow the queue depth to be something which can be set at module
  load time or via a kernel boot-time parameter, for
  testing/benchmarking purposes.

And I rewrote it substantially, mainly to take
VIRTIO_RING_F_INDIRECT_DESC into account.

As QEMU sets the vq size for PCI to 128, Venkatash's patch wouldn't
have made a change.  This version does (since QEMU also offers
VIRTIO_RING_F_INDIRECT_DESC.
Inspired-by: N"Theodore Ts'o" <tytso@mit.edu>
Based-on-the-true-story-of: Venkatesh Srinivas <venkateshs@google.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: virtio-dev@lists.oasis-open.org
Cc: virtualization@lists.linux-foundation.org
Cc: Frank Swiderski <fes@google.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      fc4324b4
  37. 15 3月, 2014 1 次提交
    • J
      blk-mq: allow blk_mq_init_commands() to return failure · 95363efd
      由 Jens Axboe 提交于 
      If drivers do dynamic allocation in the hardware command init
path, then we need to be able to handle and return failures.

And if they do allocations or mappings in the init command path,
then we need a cleanup function to free up that space at exit
time. So add blk_mq_free_commands() as the cleanup function.

This is required for the mtip32xx driver conversion to blk-mq.
Signed-off-by: NJens Axboe <axboe@fb.com>
      95363efd
  39. 13 3月, 2014 1 次提交
  41. 11 2月, 2014 1 次提交
  43. 20 11月, 2013 1 次提交
  45. 14 11月, 2013 1 次提交
  47. 29 10月, 2013 1 次提交
  49. 17 10月, 2013 1 次提交
  51. 23 9月, 2013 1 次提交
  53. 20 5月, 2013 1 次提交
  55. 20 3月, 2013 1 次提交