lkml.org 
[lkml]   [2004]   [Dec]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    Subjectdynamic-hz
    The below patch allows to set the HZ dynamically at boot time with
    command line parameter. HZ=1000 HZ=100 HZ=333 any other value just works
    (though certain value may cause more or less drift to the system time
    advance/decrease).

    Is there any interest from the mainline developers to merge this into
    2.6? I'm getting requests for this feature being forward ported to
    2.6 (both for batch jobs and for the powersaved that can trim the hz
    down to 80mhz). It should be up to the user to choose the HZ like it was
    in 2.4-aa.

    This patch is quite intrusive since many HZ visible to userspace have to
    be converted to USER_HZ, and most important because HZ isn't available
    at compile time anymore and every variable in function of HZ must be
    either changed to be in function of USER_HZ or it must be initialized at
    runtime. The code has debugging code (optional at compile time) so that
    I can guarantee that there cannot be any regression.

    Technically this makes a lot of sense to me (well, you can guess why I
    implemented it in the first place), at least in archs where one cannot
    reprogram the timer chip in a performant way (to stop timer ticks
    completely until the next posted timer). This is in production for years
    in SLES8 btw.

    http://www.kernel.org/pub/linux/kernel/people/andrea/kernels/v2.4/2.4.23aa3/9999_zzz-dynamic-hz-5.gz

    Comments welcome thanks.
    -
    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 14:08    [W:3.206 / U:0.400 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site