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    SubjectRe: [patch] SLQB slab allocator
    On Wed, 14 Jan 2009, Nick Piggin wrote:

    > Right, but that regression isn't my only problem with SLUB. I think
    > higher order allocations could be much more damaging for more a wider
    > class of users. It is less common to see higher order allocation failure
    > reports in places other than lkml, where people tend to have systems
    > stay up longer and/or do a wider range of things with them.

    The higher orders can fail and will then result in the allocator doing
    order 0 allocs. It is not a failure condition. Higher orders are an
    advantage because they localize variables of the same type and therefore
    reduce TLB pressure.

    > The idea of removing queues doesn't seem so good to me. Queues are good.
    > You amortize or avoid all sorts of things with queues. We have them
    > everywhere in the kernel ;)

    Queues require maintenance which introduces variability because queue
    cleaning has to be done periodically and the queues grow in number if NUMA
    scenarios have to be handled effectively. This is a big problem for low
    latency applications (like in HPC). Spending far too much time optimizing
    queue cleaning in SLAB lead to the SLUB idea.

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      Last update: 2009-01-14 19:05    [W:0.030 / U:139.416 seconds]
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