[lkml]   [2004]   [Nov]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [patch] Real-Time Preemption, -RT-2.6.10-rc2-mm2-V0.7.30-2
    Ingo Molnar wrote:
    > * Eran Mann <> wrote:
    >>I´m seeing latencies of up to ~2000 microseconds. see attached traces
    >>file for a small sample. I think I´m missing something obvious
    >>config-wise but I don´t know what...

    > this seems to imply IDE DMA related hardware overhead. Apparently what
    > happens is that with certain motherboards/chipsets, if IDE DMA happens
    > then that DMA transfer _completely locks up_ the system bus. Nothing
    > happens, and the CPU is stalled in essence until the end of the DMA
    > request.
    > Ingo

    Right on.
    After hdparm -d0 I see maximum latency of 35 us after a full kernel
    build with a few GUI apps in the background. I´ll try to find a
    reasonable compromise.
    Eran Mann
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2005-03-22 14:08    [W:0.019 / U:10.180 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site