[lkml]   [2000]   [Dec]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: bigphysarea support in 2.2.19 and 2.4.0 kernels
    Jes Sorensen writes:
    > Albert D Cahalan <> writes:

    [about using huge physical allocations for number crunching]

    >> 2. Programming a DMA controller with multiple addresses isn't
    >> as fast as programming it with one.
    > LOL
    > Consider that allocating the larger block of memory is going
    > to take a lot longer than it will take for the DMA engine to
    > read the scatter/gather table entries and fetch a new address
    > word now and then.

    Say it takes a whole minute to allocate the memory. It wouldn't
    of course, because you'd allocate memory at boot, but anyway...
    Then the app runs, using that memory, for a multi-hour surgery.
    The allocation happens once; the inter-node DMA transfers occur
    dozens or hundreds of times per second.
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    Please read the FAQ at

     \ /
      Last update: 2005-03-22 12:52    [W:0.027 / U:2.512 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site