Re: Bio pool & scsi scatter gather pool usage

From: arjan@fenrus.demon.nl
Date: Mon Apr 22 2002 - 02:06:47 EST


In article <3CC3B2AA.80217EA0@in.ibm.com> you wrote:

> or maybe have a way pass back an error to retry with smaller size.
> Maybe 2 limits (one that indicates that anything bigger than this is
> sure to
> get split, so always break it up, and another that says that anything
> smaller
> than this is sure not to be split, so use this size when you can't
> afford a
> split).

Unfortionatly it's not always size that's the issue. For example in my
code I need to split when a request crosses a certain boundary, and without
going into too much detail, that boundary is 62 Kb aligned, not 64
(for technical reasons ;().

Size won't catch this and while a 64Kb Kb block will always be split, that
you can be sure of, even a 4Kb request, if unlucky, can have the need to
split up.

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