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    SubjectRE: Cache coherency and snooping
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    Thanks Ralf and Alan,

    What if I allocate memory at boot-time using alloc_bootmem*(..)?

    Imran.


    -----Original Message-----
    From: Ralf Baechle [mailto:ralf@linux-mips.org]
    Sent: Tuesday, August 13, 2002 5:08 PM
    To: Imran Badr
    Cc: linux-kernel@vger.kernel.org
    Subject: Re: Cache coherency and snooping


    On Tue, Aug 13, 2002 at 04:22:31PM -0700, Imran Badr wrote:

    > How can I define a certain region of memory so that it is never cached? I
    > want to use non-cached region of memory to communicate to my PCI device to
    > avoid system overhead in cache snooping.

    On every sane platform the hardware performs better at keeping the
    coherency than software ever could. Don't even think about it unless
    you for some reason absolutely must disable caching. Aside and as Alan
    already mentioned the allocation of uncached memory isn't supported.

    Ralf

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