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    SubjectRe: [resent PATCH] Re: very slow parallel read performance
    On Mon, 27 Aug 2001, Alex Bligh - linux-kernel wrote:

    > A nit: I think it's a MRU list you want.

    Absolutely, however ...

    > If you are reading
    > ahead (let's have caps for a page that has been used for reading,
    > as well as read from the disk, and lowercase for read-ahead that
    > has not been used):
    > ABCDefghijklmnopq
    > | |
    > read disk
    > ptr head
    > and you want to reclaim memory, you want to drop (say) 'pq'
    > to get
    > ABCDefghijklmno
    > for two reasons: firstly because 'efg' etc. are most likely
    > to be used NEXT, and secondly because the diskhead is nearer
    > 'pq' when you (inevitably) have to read it again.

    This is NOT MRU, since p and q have not been used yet.
    In this example you really want to drop D and C instead.

    regards,

    Rik
    --
    IA64: a worthy successor to i860.

    http://www.surriel.com/ http://distro.conectiva.com/

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