Re: Some interrupt latency figures for 2.3.99-pre3

From: Albert D. Cahalan (acahalan@cs.uml.edu)
Date: Sat Mar 25 2000 - 18:01:53 EST

  • Next message: David Whysong: "Re: Virtual vs. physical swap & shared memory forks (clone)"

    Andrew Morton writes:

    > 400MHz uniprocessor Celeron. I am using non-DMA IDE, networking and
    > very little else.
    >
    > The workload involved compiling a kernel, starting X, some NFS client
    > activity and a fair bit of paging. All times in microseconds.
    >
    > file-n-line Count Min Max Avg
    >
    > console.c:2015 -> console.c:2039 224 .88 2068.86 21.90
    > console.c:1857 -> console.c:1975 3283 .74 1943.17 15.80
    > cs89x0.c:1186 -> cs89x0.c:1207 504 43.82 1280.56 143.47
    > vt.c:810 -> vt.c:812 1 982.32 982.32 982.32
    > ide-disk.c:451 -> ll_rw_blk.c:277 157 126.23 959.35 334.22
    > ide-disk.c:451 -> ide.c:1622 1718 118.94 956.99 277.61
    > ide.c:1533 -> ide.c:1622 8911 14.52 952.61 606.20
    > ide.c:1533 -> ide.c:1298 3904 10.79 884.30 202.74
    ...
    > I would be interested in hearing views on how significant a 2 msec
    > interrupt blockage really is. Can it cause serial Rx overruns? GigE
    > problems?

    Viewing the worst case as 483 HZ makes it look awful.
    You could lose 3 clock ticks with a 1024 HZ clock.

    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.rutgers.edu
    Please read the FAQ at http://www.tux.org/lkml/

    This archive was generated by hypermail 2b29 : Sat Mar 25 2000 - 18:03:44 EST