On Thu, 17 May 2007, Matt Mackall wrote:

quoted text
> 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.

quoted text
> 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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