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    SubjectRe: Major regression on hackbench with SLUB (more numbers)
    On Tue, 11 Dec 2007, Ingo Molnar wrote:

    > hackbench-10: 1.12 2.99 (166%)
    > hackbench-20: 2.04 6.67 (226%)
    > hackbench-50: 5.03 17.50 (247%)
    >
    > and hackbench overhead stands out, by a huge margin. Other stuff is
    > within measurement noise. Neither SLUB nor SLAB debugging was turned on,
    > all other debugging options were off too.

    I just came back from vacation. The non linear growth of regression
    indicates lock contention somewhere. Must be something special that was
    triggered by hackbench.

    We have had a regression like that in 2.6.24 before due to order 1 allocs
    in the network layer. The .24 modifications for SLUB introduced page
    allocator pass through for allocations > PAGESIZE/2. Order 1 allocs could
    serialize on zone locks.


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