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    SubjectRe: [PATCH/RFC] Simplified Readahead
    Ray Bryant wrote:

    > Hi Steve,
    > On question I have (and I'm sorry, I haven't had time to look at your
    > patch to sort this out) is what happens if the user supplies a rather
    > serious I/O size, will you read ahead multiples of that, or what
    > happens? Or, for that matter, how well will it perform?

    Same behavior as the old code. I/Os are broken up into at most
    max_readahead size pieces. In the case of the old code only 1 of these
    could be outstanding. In the new code there could be at most 2
    outstanding at any point in time.

    > I've heard about HPC applications for IRIX that issue a 2GB read. :-)

    This is why for these types of applications, especially on RAID arrays,
    you need to set max_readahead into the MBs. (But that is a different topic).


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