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    SubjectRe: 2.6.1-rc1-tiny2
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    På on , 07/01/2004 klokka 15:10, skreiv Matt Mackall:
    > NFS is a good example of why the guarantees of mempool are being
    > overstated - it still needs to allocate SKBs to make progress and
    > preallocating a pool for other data structures can make that fail
    > where it otherwise might not. The pool size for NFS (32) is also
    > completely arbitrary as far as I can tell.

    If you are in a hardware situation where you actually care about the
    permanent size of that mempool, then you're barking up entirely the
    wrong tree: there is a hell of a lot more memory to reclaim from not
    having to build up all those nfs_page lists in the first place.

    i.e. Rip out the entire asynchronous NFS read/write support, not just
    the mempools.

    As for the usefulness of the mempools in the situation where you have
    asynchronous I/O: I agree that the socket layer screws any chance of a
    guarantee. So does the server if it goes down, the network itself can
    screw you,.... All in all, it is surprising how few guarantees NFS
    offers you.
    I therefore see the mempools as more of an optimization that mainly
    avoid sleeping under a certain limited set of "reasonable"
    circumstances.

    Cheers,
    Trond
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