lkml.org 
[lkml]   [2006]   [Sep]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] sched.c: Be a bit more conservative in SMP
    Antonio Vargas wrote:
    > A variant on this theme would be (not tested or somewhat, just a
    > random idea for considering):
    >
    > 1. find if the process is a cpu-hog, if not then ignore
    >
    > 2. find somehow how much time has this process on it's current cpu
    >
    > 3. then, instead of always substracting 1 from th current load on the
    > current cpu, substract for example 1...0 when running from 0 to 60
    > seconds... this way cpu hogs would only rotate slowly?
    >
    > in code:
    >
    > number_to_sub_from_queue_load = (256 - min(256,
    > time_from_last_change_of_cpu)) >> 8;
    >
    > somehow managing to get fixedpoint loadlevels on the runqueues would
    > make this work better....
    >

    Yes ! That might be a better idea !
    In fact, I tested the 1st patch on our cluster (Finite elements computing on 8
    CPUs):
    - Under Windows: 875 seconds
    - Linux 2.6.16 : 1019 s
    - Linux 2.6.16 + manual taskset : 842 s
    - Linux 2.6.16 + Vincent's patch : 1373 s :-(

    If you find time to write a patch, Antonio, I would be pleased to try it !

    Cheers,

    --
    Ludovic DROLEZ
    http://lrs.linbox.org - Free asset management software
    -
    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: 2006-09-20 09:45    [W:6.599 / U:0.028 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site