25 Feb, 2009

1 commit

  • Oleg noticed that we don't strictly need CSD_FLAG_WAIT, rework
    the code so that we can use CSD_FLAG_LOCK for both purposes.

    Signed-off-by: Peter Zijlstra
    Cc: Oleg Nesterov
    Cc: Linus Torvalds
    Cc: Nick Piggin
    Cc: Jens Axboe
    Cc: "Paul E. McKenney"
    Cc: Rusty Russell
    Signed-off-by: Ingo Molnar

    Peter Zijlstra
     

29 Dec, 2008

1 commit


09 Oct, 2008

4 commits

  • Only works for the generic request timer handling. Allows one to
    sporadically ignore request completions, thus exercising the timeout
    handling.

    Signed-off-by: Jens Axboe

    Jens Axboe
     
  • Right now SCSI and others do their own command timeout handling.
    Move those bits to the block layer.

    Instead of having a timer per command, we try to be a bit more clever
    and simply have one per-queue. This avoids the overhead of having to
    tear down and setup a timer for each command, so it will result in a lot
    less timer fiddling.

    Signed-off-by: Mike Anderson
    Signed-off-by: Jens Axboe

    Jens Axboe
     
  • 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
     
  • Signed-off-by: Jens Axboe

    Jens Axboe