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    SubjectRe: [patch] vmfixes-2.4.0-test9-B2 - fixing deadlocks
    On Tue, Sep 26, 2000 at 08:54:23AM +0200, Christoph Rohland wrote:
    > "Stephen C. Tweedie" <sct@redhat.com> writes:
    >
    > > Hi,
    > >
    > > On Mon, Sep 25, 2000 at 09:32:42PM +0200, Andrea Arcangeli wrote:
    > >
    > > > Having shrink_mmap that browse the mapped page cache is useless
    > > > as having shrink_mmap browsing kernel memory and anonymous pages
    > > > as it does in 2.2.x as far I can tell. It's an algorithm
    > > > complexity problem and it will waste lots of CPU.
    > >
    > > It's a compromise between CPU cost and Getting It Right. Ignoring the
    > > mmap is not a good solution either.
    > >
    > > > Now think this simple real life example. A 2G RAM machine running
    > > > an executable image of 1.5G, 300M in shm and 200M in cache.
    >
    > Hey that's ridiculous: 1.5G executable image and 300M shm? Take it
    > vice-versa and you are approaching real life.

    Could you tell me what's wrong in having an app with a 1.5G mapped executable
    (or a tiny executable but with a 1.5G shared/private file mapping if you
    prefer), 300M of shm (or 300M of anonymous memory if you prefer) and 200M as
    filesystem cache?

    The application have a misc I/O load that in some part will run out
    of the working set, what's wrong with this?

    What's ridiculous? Please elaborate.

    To emulate that workload we only need to mmap(1.5G, MAP_PRIVATE or MAP_SHARED),
    fault into it, and run bonnie.

    Andrea
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