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    SubjectRe: [patch] 2.4.4 alpha semaphores optimization
    On Thu, May 03, 2001 at 07:28:48PM +0200, Andrea Arcangeli wrote:
    > I'd love if you could port it on top of this one and to fix it so that
    > it can handle up to 2^32 sleepers and not only 2^16 like we have to do
    > on the 32bit archs to get good performance:
    >
    > ftp://ftp.us.kernel.org/pub/linux/kernel/people/andrea/kernels/v2.4/2.4.4aa3/00_rwsem-11

    It could be done without much pain for both "official" and your rwsem
    implementations.
    However, there are 3 reasons why I prefer 16-bit counters:
    a. "max user processes" ulimit is much lower than 64K anyway;
    b. "long" count would cost extra 8 bytes in the struct rw_semaphore;
    c. I can use existing atomic routines which deal with ints.

    Actually I'm more anxious about a __builtin_expect() problem,
    and I'd like to hear Richard's comment on this...

    Ivan.
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