VM and classzone

From: Carlo Wood (carlo@alinoe.com)
Date: Sat May 20 2000 - 02:52:21 EDT

  • Next message: G. Hugh Song: "Re: NFS & module"

    On Fri, May 19, 2000 at 09:16:35AM -0700, Andrea Arcangeli wrote:
    > On Fri, 19 May 2000, Rik van Riel wrote:
    >
    > >varying loads (but that's orthagonal, except for the fact
    > >that it would automagically solve the last 2 problems with
    > >pre9-2 + quintela).
    >
    > This make no sense to me. It it fixes two problems that doesn't mean it's
    > not orthogonal.
    >
    > I'm not sure about the problems you're talking about. And I'm not
    > convinced that waiting I/O completation during shink_mmap will be
    > successfully.
    >
    > Andrea

    I know I am pretty new to this list, but allow me to put
    an observation into a summary:

    The were problems with VM - also known as 'kswapd problem'
    because it showed itself mainly as a stall of the kernel
    while kswapd was consuming often, and a lot, cpu.

    Andrea Arcangeli has been working on what is known as the
    "class zone" patch(es) - which is a structural redesign
    related to how VM works (correct me if I am wrong).
    Linus didn't add this to the kernel because he thinks that
    Andreas (re)design has flaws.

    Rik van Riel also worked on VM, but more from the point of
    view of 'how to fix the kswapd bug', and he succeeded
    (at least partly, perhaps completely): reports have been
    posted that this bug is now gone - which is also my own
    humble observation.

    Nevertheless, the discussion about Andreas design continues
    as if it had to do with the bug - which is not true (I agree
    with Linus on this).

    In order to come to a solution, I'd like to suggest the
    following:

    - Linus makes a short list of what he thinks are the
      pros and cons of Andreas design, so it is more clear
      to Andrea what is the reason for the rejection so far;
      and if his design will ever make a chance to get into
      the kernel at all.
    - If there is chance that after possible improvements
      the patch will be added to a future kernel, then a series
      of benchmark tests if proposed by all parties that will
      produce *numbers* - so we will be able to actually see
      the impact of Andreas patch (with and without).

    $0.02 of a neutral party,

    -- 
    Carlo Wood <carlo@alinoe.com>
    

    - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/



    This archive was generated by hypermail 2b29 : Sat May 20 2000 - 02:55:10 EDT