Re: reaction to a smaller buffer size

From: abel deuring (a.deuring@satzbau-gmbh.de)
Date: Sun Nov 19 2000 - 14:55:54 PST

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    Oliver Neukum wrote:
    >
    > > Oliver,
    > >
    > > agreed, it is really not likely that we get different amount of memory
    > > after different open calls. But exactly this can be a problem: Imagine a
    > > Sane user working on an ooverloaded Linux box, who gets from time to
    > > time segfaults, and that [s]he can't reproduce this behaviuor reliably.
    > > How someone get the idea that this behaviour might be caused by a
    > > changing sanei_scsi_max_request_size?
    >
    > There must be a misunderstanding.
    >
    > There are situations where it's almost _certain_ that the
    > kernel _will_ give out buffers of _different_ sizes.
    >
    > If you have one host adaptor which does scatter/gather and
    > a second host adaptor which does no scatter/gather,
    > the first will result in a buffer of 128K and the second a
    > buffer of 32K.

    I didn't see this point. But then again: If sanei_scsi_max_request_size
    is not constant, things might be messed up -- not necessarily for the
    Microtek2 backend, but perhaps for the backend of a second scanner
    conncted to the same machine.

    Abel

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