lkml.org 
[lkml]   [2003]   [Sep]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: x86, ARM, PARISC, PPC, MIPS and Sparc folks please run this
    On Mon, 1 Sep 2003, Jamie Lokier wrote:
    > Geert Uytterhoeven wrote:
    > > Are you also interested in m68k? ;-)
    > >
    > > cassandra:/tmp# time ./test
    > > Test separation: 4096 bytes: FAIL - store buffer not coherent
    >
    > Especially! I hadn't expected to see any machine that would print
    > "store buffer not coherent". It means that if there's an L1 cache, it
    > is coherent, but any store-then-load bypass in the CPU pipeline is
    > using the virtual address with no rollback after MMU translation.
    >
    > I had thought it would only be the case with chips using an external
    > MMU, but now that I think about it, the older simpler chips aren't
    > going to bother with things like pipeline rollback wherever they can
    > get away without it!

    As you probably know the 68020 had an external MMU (68551, or Sun-3 or Apollo
    MMU). Probably Motorola didn't bother to change the behavior when the MMU got
    integrated in later generations (68030 and up).

    BTW, probably you want us to run your test program on other m68k boxes? Mine
    got a 68040, that leaves us with:
    - 68020+68551
    - 68020+Sun-3 MMU
    - 68030
    - 68060

    For linux-m68k: You can find the test program source in Jamie's original
    posting on lkml. For your convenience, I put a binary for m68k at
    http://home.tvd.be/cr26864/Linux/m68k/jamie_test.gz. Just tell us the
    program's output and give us a copy of your /proc/cpuinfo. Thanks!

    Gr{oetje,eeting}s,

    Geert

    --
    Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

    In personal conversations with technical people, I call myself a hacker. But
    when I'm talking to journalists I just say "programmer" or something like that.
    -- Linus Torvalds

    -
    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: 2005-03-22 13:48    [W:0.023 / U:62.884 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site