lkml.org 
[lkml]   [2008]   [Apr]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: 2.6.25-mm1: not looking good
    On 4/18/08, Jason Wessel <jason.wessel@windriver.com> wrote:
    > Vegard Nossum wrote:
    > > On Fri, Apr 18, 2008 at 3:02 PM, Jason Wessel
    > > <jason.wessel@windriver.com> wrote:
    > >
    > >> Vegard Nossum wrote:
    > >> > On Fri, Apr 18, 2008 at 2:34 PM, Ingo Molnar <mingo@elte.hu> wrote:
    > >> >
    > >> >> * Vegard Nossum <vegard.nossum@gmail.com> wrote:
    > >> >>
    > >> >> > With the patch below, it seems 100% reproducible to me (7 out of 7
    > >> >> > bootups hung).
    > >> >> >
    > >> >> > The number of loops it could do before hanging were, in order:
    > 697,
    > >> >> > 898, 237, 55, 45, 92, 59
    > >> >>
    > >> >> cool! Jason: i think that particular self-test should be repeated
    > 1000
    > >> >> times before reporting success ;-)
    > >> >>
    > >> >
    > >> > BTW, I just tested a 32-bit config and it hung after 55 iterations as
    > well.
    > >> >
    > >> > Vegard
    > >> >
    > >> >
    > >> >
    > >> I assume this was SMP?
    > >>
    > >
    > > Yes. But now that I realize this, I tried running same kernel with
    > > qemu, using -smp 16, and it seems to be stuck here:
    > >
    > >
    >
    > Unless you have a qemu with the NMI patches, kgdb does not work on SMP
    > with qemu. The very first test is going to fail because the IPI sent by
    > the kernel is not handled in qemu's hardware emulation.

    Oops, no, and that makes sense.

    I now picked up qemu 0.9.1 and applied the three NMI/SMI patches by Jan Kiszka.

    So in qemu it seems to run fine now, except that I need to prod it
    sometimes (it gets stuck in cpu_clock() and I have to break/continue
    from gdb to make it proceed). Oh, there it made it to 1056, and gdb
    can't interrupt anymore. Hmm. This is probably not a very good
    testing/debugging environment if the qemu support is that bad. Sorry
    :-)

    But booting with nosmp on real hardware gets easily above 100,000
    iterations of the loop (before I reboot), so it seems to be related to
    that, anyway.

    Vegard

    --
    "The animistic metaphor of the bug that maliciously sneaked in while
    the programmer was not looking is intellectually dishonest as it
    disguises that the error is the programmer's own creation."
    -- E. W. Dijkstra, EWD1036


    \
     
     \ /
      Last update: 2008-04-18 16:49    [W:0.026 / U:1.096 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site