lkml.org 
[lkml]   [2007]   [Jun]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: Interesting interaction between lguest and CFS

    * Rusty Russell <rusty@rustcorp.com.au> wrote:

    > This sounds like the waker process (nice 19) not getting a chance to
    > run. You can hack around it for the moment by changing "nice(19)" in
    > Documentation/lguest/lguest.c to something less aggressive.

    even if the waker runs at nice+19, under CFS (which schedules
    deterministically) it should not be delayed by a single nice-0 task by
    more than ~70 msecs. That is a far cry from the 'seconds' that Matt saw
    - and the sched stats he sent look anomalous too. Also, i'm not able to
    reproduce it at all - while any nice+19 related problem should be
    readily reproducable on my box too. So my current take is that this is
    some sort of host-side CFS related problem and that the lguest host
    threads somehow were the first ones that managed to trigger it in some
    really bad way.

    OTOH i do agree with your patch, that nice+19 thing is quite hacky :-)

    Ingo
    -
    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: 2007-06-05 09:13    [W:3.825 / U:0.044 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site