cvs commit: src/sys/sys buf.h

Alexander Leidinger Alexander at Leidinger.net
Sat Nov 6 04:06:08 PST 2004


On Fri, 05 Nov 2004 11:42:14 -0800
Julian Elischer <julian at elischer.org> wrote:

[buf-junta work]

> >Do you have an outline where this heads to and why?
> >
> 
> when systems were smaller the number of cached bufs was small, and bufs
> represented 'buffers' likely to used soon fo rIO and IO requests were 
> simple,
> it made sence to combine the IO request and the storage descriptor (buf).
> 
> Since then, storage is done via the vm system, IO requests have gotten 
> bigger,
> and the number of IO requests needed at any time has remained small. it 
> makes less
> sense to have an IO request with every buf storage descriptor.

You haven't said it explicitly, but I assume there are cases where an IO
request doesn't need a buf storage descriptor. Is this correct?

I was asking for something like an annotated roadmap. Something like
"After X will be done, we need to look at Y, X is an infrastructure
change for Y and we want Y because it allows us to do Z." This would
allow those who are reading cvs-all to see where we are standing and
where we are heading (and to applaud when we reach milestones).

Bye,
Alexander.

-- 
              The best things in life are free, but the
                expensive ones are still worth a look.

http://www.Leidinger.net                       Alexander @ Leidinger.net
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