lkml.org 
[lkml]   [2001]   [Mar]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectJiffy question and sound.
    With the 2.4.0 kernel the loops_per_sec field was replaced (for i386)
    with current_cpu_data.loops_per_jiffy.

    So... since I am using the ALSA drivers that Mandrake supplied, for the
    2.4.x series of kernels I replaced the equated #define with


    #define LOOPS_PER_SEC current_cpu_data.loops_per_jiffy * 100

    This seems to build modules that work for 2.4.0. However, if you play
    many songs then do some heavy disk I/0 after awhile the songs start
    sounding like a hellicoptor is hovering right next to the speakers.
    This wasn't too bad as it usually took about 30 to 40 mins to go
    south.

    Now compiling the same ALSA modules with 2.4.2 this problem happens
    much quicker and you don't need any other activity. In fact it is hard
    to play more than half a song. (MP3)
    It doesn't matter if what set of music players or tools I use the
    problem is quite visible.

    When I boot back to the original 2.2.x kernel everything is perfect.

    So I guess I have a few questions here.
    1) Is a jiffy 100th of a second or is it smaller (so my loop count
    is starving things.) (10ms) ?
    2) Why is it so much worse in 2.4.2 than 2.4.0?
    3) Any other "gotch's" that are important to watch for when moving
    2.2.x drivers to 2.4.x?

    Thanks....

    Watermodem
    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2005-03-22 13:29    [W:0.026 / U:31.076 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site