Swapping in 2.6.10 and 2.6.11.11 on a desktop system

From: Alexander Gretencord (arutha_at_gmx.de)
Date: 06/14/05

  • Next message: Jon Smirl: "Re: Input sysbsystema and hotplug" 
    To: linux-kernel@vger.kernel.org
Date:	Tue, 14 Jun 2005 16:53:30 +0200

    Hi,

    [1] With swappiness = 60 I either get swap hell (2.6.10) or the oom killer
    kicks in (2.6.11.11)

    [2] I upgraded to 2.6.11.11 from 2.6.8.1 yesterday and tried to compile
    something. After some time I come back and the compile has aborted because
    the oom killer killed the compiler process. There is no additional use of
    swap space (although some applications that were also running could have been
    swapped out). There was a similar bugreport with this behaviour some time ago
    for 2.6.11.8 but that one included a swappiness value of 0, i got 60.

    Then I tried 2.6.10. The oom bugs were gone, the compile finished over night.
    About an hour ago I started a very RAM consuming application and at 2/3 RAM
    usage I get swap hell. The system constantly swaps, yet ram usage _and_ swap
    usage stay about the same. Even setting swappiness to 0 from an ssh login
    (switching to a console does not work) did not help, only killing the
    consuming application.

    I also applied the ck hard-swappiness Patch to my 2.6.10 and tested a bit
    further. Depending on the swappiness I get hellish swapping behaviour at
    different levels of RAM usage and even managed to get the oom killer to step
    in (at swappiness=20). I had about 250MB of RAM used and boom -> oom killer
    shoots down some bigger java processes. At swappiness=80 I get massive
    swapping with 250MB of RAM usage. When reaching that level, the fs cache goes
    up to 300MB while the applications that need the ram are left with about 120
    megs. Rest was buffers.

    I'm really out of ideas. 2.6.8.1 with swappiness=0 is by far the best I've
    managed to get by now. With that I can use my system until RAM and swap are
    completely full. No swap hell and no oom killer yet. Maybe I just have to
    search the lkml a bit more to find something usable. If someone else already
    has, please tell me (and tell me why it's not in the mainline kernel
    already :))

    I have 512MB of RAM and another 512MB of swap.

    Please cc me in replies as I'm not on the list.

    Alex
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  • Next message: Jon Smirl: "Re: Input sysbsystema and hotplug"

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