lkml.org 
[lkml]   [2005]   [Nov]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: 2.6.14-rt1
    On 11/1/05, Steven Rostedt <rostedt@goodmis.org> wrote:
    > On Tue, 2005-11-01 at 21:55 -0500, Carlos Antunes wrote:
    >
    > >
    > > Fernando,
    > >
    > > I'm also having some when using SCHED_FIFO and SCHED_RR. When running
    > > several hundred threads, each sleeping on a loop for 20ms, SCHED_OTHER
    > > performs ok with latencies of less than 10ms while with SCHED_FIFO or
    > > SCHED_RR, I see latencies exceeding 1 full second!
    >
    > Are you saying that you have several hundred threads in SCHED_FIFO or
    > SCHED_RR? Or is just Jack as that.
    >

    It's a simple program I put together to test wakeup latency. Each
    thread basically sleeps for 20ms, wakes up and executes a couple of
    instructions and goes back to sleep for another 20ms. Multiply this by
    a thousand. What I found out is that, inthis situation, and using
    realtime-preempt, SCHED_OTHER offers 3 orders of magnitude less
    latency than SCHED_FIFO or SCHED_RR. Which suggests to me there is
    something fishy going on.

    Carlos


    --
    "We hold [...] that all men are created equal; that they are
    endowed [...] with certain inalienable rights; that among
    these are life, liberty, and the pursuit of happiness"
    -- Thomas Jefferson
    -
    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: 2005-11-02 04:32    [W:0.021 / U:60.452 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site