lkml.org 
[lkml]   [1999]   [Jan]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: Results: pre6 vs pre6+zlatko's_patch vs pre5 vs arcavm13


    On Sun, 10 Jan 1999, Andrea Arcangeli wrote:
    >
    > Steve, could you try the image test in 128Mbyte with this my new patch
    > (arca-vm-14) applyed against clean 2.2.0-pre6?

    Please don't do this.

    > do {
    > int result;
    > - tsk->swap_address = address + PAGE_SIZE;
    > result = try_to_swap_out(tsk, vma, address, pte, gfp_mask);
    > + address += PAGE_SIZE;
    > + tsk->swap_address = address;

    The above is horribly broken, and should be killed on sight.

    "swap_address" _must_ be set before try_to_swap_out(), because otherwise
    when try-to_swap_out() sleeps any other processes trying to free will
    start from the wrong address - unfairly penalizing the process in
    question, as the accessed bits have been cleared.

    If the above help, it only does so because it is unfair - which _can_ help
    simply because other processes run faster.

    It looks like you tried to optimize away one add, at the expense of
    getting the whole algorithm wrong.

    Linus


    -
    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/

    \
     
     \ /
      Last update: 2005-03-22 13:49    [W:0.022 / U:0.596 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site