lkml.org 
[lkml]   [2004]   [Jun]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [discuss] Re: 32-bit dma allocations on 64-bit platforms
    On Thu, Jun 24, 2004 at 02:54:41PM -0700, Andrew Morton wrote:
    > First thing to do is to identify some workload which needs the patch.

    that's quite trivial, boot a 2G box, malloc(1G), bzero(1GB), swapoff -a,
    then the machine will lockup.

    Depending on the architecture (more precisely depending if it starts
    allocating ram from the end or from the start of the physical memory),
    you may have to load 1G of data into pagecache first, like reading from
    /dev/hda 1G (without closing the file) will work fine, then run the
    above malloc + bzero + swapoff.

    Most people will never report this because everybody has swap and they
    simply run a lot slower than they could run if they didn't need to pass
    through the swap device to relocate memory because memory would been allocated
    in the right place in the first place. this plus the various oom killer
    breakages that gets dominated by the nr_swap_pages > 0 check, are the
    reasons 2.6 is unusable w/o swap.
    -
    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 14:04    [W:5.836 / U:0.552 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site