[lkml]   [2002]   [Sep]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: DAC960 in 2.5.38, with new changes

    I'm looking over the main body of the interrupt handler
    for the DAC960 ( the DAC960_V[12]_ProcessCompletedCommand()).

    The V1 version of this function is over 800 lines long.
    The V2 version is 600 lines long.

    First off I have an intense dislike for ANY function that
    is this long.

    Secondly, most of the stuff in these functions doesn't
    seem appropriate for an interrupt handler. 90% of
    the code in these functions is executed rarely, and
    isn't performance critical. Most of
    these functions involve health monitoring. In some cases,
    where logical drives appear or disappear, the set of
    disks visible through the controller must change.

    It seems to me that most of this functionality
    should be moved into a kernel daemon associated with the
    driver. The interrupt handler could be shrunk to as few
    instructions and "if then else" branches as possible, to
    shorten the time the spent in the handler and the time the
    controller's lock is held.

    This is a bigger change than I'm ready to deal with
    right now. First thing is to get the old code structure
    to work with the DMA interfaces. But I think daemon-izing
    this code would clean it up and make it more easily
    understood as well.

    Perhaps we could do this as part of a "stage-two"
    set of changes.

    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2005-03-22 13:29    [W:0.022 / U:26.272 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site