lkml.org 
[lkml]   [2002]   [Dec]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: Intel P6 vs P7 system call performance

    On Tue, 17 Dec 2002, Ulrich Drepper wrote:

    > > - 0x55, /* push %ebp */
    > > + 0x55, /* push %ebp */
    > > + 0x5d, /* pop %ebp */
    > > - 0x5d, /* pop %ebp */
    >
    > Instead of duplicating the push/pop %ebp just use the first one by using

    No, it's not duplicating it. Look closer. It's just _moving_ it, so that
    the old %ebp value will naturally be pointed to by %esp, which is what we
    want.

    Anyway, I reverted the %ebp games from my kernel, because they are
    fundamentally not restartable and thus not really a good idea. Besides, it
    might be wrong to try to optimize the fast system calls to handle six
    arguments too, if that makes the (much more common case) the other system
    calls slower. So the six-argument case might as well just continue to use
    "int 0x80".

    Linus


    -
    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 13:31    [W:0.022 / U:32.324 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site