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    SubjectRe: Machine's high load when HIGHMEM is enabled
    vasya vasyaev wrote:
    > Hello,
    >
    > I have some strange kind of problem:
    > When HIGHMEM-enabled kernel is used, there is too high
    > CPU load on any task - computer get loaded high while
    > it is doing some minor, usual jobs (load average grows
    > significantly).

    2.4 can only do I/O to and from lowmem. This means highmem pages have
    to use bounce buffers in lowmem, and th edata is copied to/from highmem
    which is causing the cpu load. This has been corrected in 2.5, which
    can do I/O to any page the device can DMA from.

    --
    Brian Gerst

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