lkml.org 
[lkml]   [2002]   [Mar]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: fadvise syscall?
    On Sun, Mar 17, 2002 at 01:41:37PM +0000, Anton Altaparmakov wrote:
    > When you want large data streaming, i.e. you start getting worried about
    > memory pressure, then you want open(2) + O_DIRECT. No caching done. Perfect
    > for large data streams and we have that already. I agree that you may want
    > some form of asynchronous read ahead with passed pages being dropped from
    > the cache but that could be just a open(2) + O_SEQUENTIAL (doesn't exist yet).

    O_DIRECT isn't the right thing for large streaming. You want
    readahead and dropbehind. O_DIRECT takes substantial penalties for its
    lack of copy/cacheing. This works fine in certain circumstances
    (applications that keep their own caching), but for something like a
    video or mp3, you'll win with working dropbehind easily.

    Joel

    --

    Life's Little Instruction Book #444

    "Never underestimate the power of a kind word or deed."

    http://www.jlbec.org/
    jlbec@evilplan.org
    -
    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 13:25    [W:0.022 / U:31.284 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site