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    SubjectRe: [PATCH] slub: reduce overhead of slub_debug
    Christoph Lameter <> writes:

    > +#ifdef __HAVE_ARCH_INV_MEMSCAN
    > +void *inv_memscan(void *addr, int c, size_t size)
    > +{
    > + if (!size)
    > + return addr;
    > + asm volatile("repz; scasb\n\t"

    This will just do the slow byte accesses again internally.
    scasb is not normally very optimized in microcode as far
    as I know.

    Also rep has quite some startup overhead which makes
    it a bad idea for small sizes (<16-20 or so)

    I would stay with the C version. I bet that one is


    -- -- Speaking for myself only

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      Last update: 2011-07-08 07:27    [W:0.020 / U:22.132 seconds]
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