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    SubjectRe: Very aggressive memory reclaim
    [ Add Cc's of those that may help you ]

    -- Steve

    On Mon, Mar 28, 2011 at 08:39:29PM +0400, John Lepikhin wrote:
    > Hello,
    >
    > I use high-loaded machine with 10M+ inodes inside XFS, 50+ GB of
    > memory, intensive HDD traffic and 20..50 forks per second. Vanilla
    > kernel 2.6.37.4. The problem is that kernel frees memory very
    > aggressively.
    >
    > For example:
    >
    > 25% of memory is used by processes
    > 50% for page caches
    > 7% for slabs, etc.
    > 18% free.
    >
    > That's bad but works. After few hours:
    >
    > 25% of memory is used by processes
    > 62% for page caches
    > 7% for slabs, etc.
    > 5% free.
    >
    > Most of files are cached, works perfectly. This is the moment when
    > kernel decides to free some memory. After memory reclaim:
    >
    > 25% of memory is used by processes
    > 25% for page caches(!)
    > 7% for slabs, etc.
    > 43% free(!)
    >
    > Page cache is dropped, server becomes too slow. This is the beginning
    > of new cycle.
    >
    > I didn't found any huge mallocs at that moment. Looks like because of
    > large number of small mallocs (forks) kernel have pessimistic forecast
    > about future memory usage and frees too much memory. Is there any
    > options of tuning this? Any other variants?
    >
    > Thanks!
    > --
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