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    SubjectRe: [PATCH 0/5] make slab gfp fair
    On Thu, 17 May 2007, Matt Mackall wrote:

    > Simply stated, the problem is sometimes it's impossible to free memory
    > without allocating more memory. Thus we must keep enough protected
    > reserve that we can guarantee progress. This is what mempools are for
    > in the regular I/O stack. Unfortunately, mempools are a bad match for
    > network I/O.
    > It's absolutely correct that performance doesn't matter in the case
    > this patch is addressing. All that matters is digging ourselves out of
    > OOM. The box either survives the crisis or it doesn't.

    Well we fail allocations in order to do so and these allocations may be
    even nonatomic allocs. Pretty dangerous approach.

    > It's also correct that we should hardly ever get into a situation
    > where we trigger this problem. But such cases are still fairly easy to
    > trigger in some workloads. Swap over network is an excellent example,
    > because we typically don't start swapping heavily until we're quite
    > low on freeable memory.

    Is it not possible to avoid failing allocs? Instead put processes to
    sleep? Run synchrononous reclaim?

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      Last update: 2007-05-17 20:05    [W:0.019 / U:7.040 seconds]
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