Eric Lee / linux-smarc-t335x-v3.2

29 Dec, 2008

1 commit

09 Oct, 2008

2 commits

  • c7c22e4d5   block: add support for IO CPU affinity ... Browse Code »

    This patch adds support for controlling the IO completion CPU of
    either all requests on a queue, or on a per-request basis. We export
    a sysfs variable (rq_affinity) which, if set, migrates completions
    of requests to the CPU that originally submitted it. A bio helper
    (bio_set_completion_cpu()) is also added, so that queuers can ask
    for completion on that specific CPU.

    In testing, this has been show to cut the system time by as much
    as 20-40% on synthetic workloads where CPU affinity is desired.

    This requires a little help from the architecture, so it'll only
    work as designed for archs that are using the new generic smp
    helper infrastructure.

    Signed-off-by: Jens Axboe

    Jens Axboe
     
  • ed9e19823   block: implement and use {disk|part}_to_dev() ... Browse Code »

    Implement {disk|part}_to_dev() and use them to access generic device
    instead of directly dereferencing {disk|part}->dev. To make sure no
    user is left behind, rename generic devices fields to __dev.

    This is in preparation of unifying partition 0 handling with other
    partitions.

    Signed-off-by: Tejun Heo
    Signed-off-by: Jens Axboe

    Tejun Heo
     

07 May, 2008

1 commit

29 Apr, 2008

1 commit

  • ac9fafa12   block: Skip I/O merges when disabled ... Browse Code »

    The block I/O + elevator + I/O scheduler code spend a lot of time trying
    to merge I/Os -- rightfully so under "normal" circumstances. However,
    if one were to know that the incoming I/O stream was /very/ random in
    nature, the cycles are wasted.

    This patch adds a per-request_queue tunable that (when set) disables
    merge attempts (beyond the simple one-hit cache check), thus freeing up
    a non-trivial amount of CPU cycles.

    Signed-off-by: Alan D. Brunelle
    Signed-off-by: Jens Axboe

    Alan D. Brunelle
     

21 Apr, 2008

1 commit

  • fb1997463   block: fix blk_register_queue() return value ... Browse Code »

    blk_register_queue() returns -ENXIO when queue->request_fn is NULL. But there
    are some block drivers that call blk_register_queue() via add_disk() with
    queue->request_fn == NULL. (For example, brd, loop)

    Although no one checks return value of blk_register_queue(), this patch makes
    it return 0 instead of -ENXIO when queue->request_fn is NULL,

    Also this patch adds warning when blk_register_queue() and
    blk_unregister_queue() are called with queue == NULL rather than ignore
    invalid usage silently.

    Signed-off-by: Akinobu Mita
    Cc: Jens Axboe
    Signed-off-by: Andrew Morton
    Signed-off-by: Jens Axboe

    Akinobu Mita
     

01 Feb, 2008

1 commit

30 Jan, 2008

2 commits