[lkml]   [2008]   [Jan]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [RFC] mmaped copy too slow?
    KOSAKI Motohiro wrote:
    > Hi
    > at one point, I found the large file copy speed was different depending on
    > the copy method.
    > I compared below method
    > - read(2) and write(2).
    > - mmap(2) x2 and memcpy.
    > - mmap(2) and write(2).
    > in addition, effect of fadvice(2) and madvice(2) is checked.
    > to a strange thing,
    > - most faster method is read + write + fadvice.
    > - worst method is mmap + memcpy.

    One thing you could also try is to pass MAP_POPULATE to mmap so that the
    page tables are filled in at the time of the mmap, avoiding a lot of
    page faults later.

    Just my 2 cents,

    Paulo Marques -

    "All I ask is a chance to prove that money can't make me happy."

     \ /
      Last update: 2008-01-15 13:49    [W:0.021 / U:0.200 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site