lkml.org 
[lkml]   [2003]   [Dec]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: 2.6.0-test9 - poor swap performance on low end machines
    On Wed, 17 Dec 2003 13:53:28 -0500, Rik van Riel wrote:
    > On Tue, 16 Dec 2003, Roger Luethi wrote:
    >
    > > One potential problem with the benchmarks is that my test box has
    > > just one bar with 256 MB RAM. The kbuild and efax tests were run with
    > > mem=64M and mem=32M, respectively. If the difference between mem=32M
    >
    > OK, I found another difference with 2.4.
    >
    > Try "echo 256 > /proc/sys/vm/min_free_kbytes", I think
    > that should give the same free watermarks that 2.4 has.

    I played around with that knob after wli posted his findings in the
    "mem=16MB laptop testing" thread. IIRC tweaking min_free_kbytes didn't
    help nearly as much as I had hoped. I'm running the efax benchmark
    right now just to make sure. It's going to take a couple of hours,
    I'll follow up with results.

    FWIW akpm posted a patch to initialize min_free_kbytes depending on
    available RAM which seemed to make sense but it hasn't made it into
    mainline yet.

    > Using 1MB as the min free watermark for lowmem is bound
    > to result in more free (and less used) memory on systems
    > with less than 128 MB RAM ... significantly so on smaller
    > systems.

    Possibly. If memory pressure is high enough, though, the allocator
    ignores the watermarks. And on the other end kswapd seems to be pretty
    busy anyway during the benchmarks.

    Roger
    -
    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 13:59    [W:8.174 / U:0.056 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site