Streams message allocation

[Jim Hutchison]

I have been reading through the systemVr2 streams porting doc for the 3b2,
in an effort to better understand the streams code in Suns 4.1 source.

I noted that there is some logic to avoid deadlocks which result from all
the message buffer space being in use.  There is a pool, and a certain
amount which is reserved for high-priority messages.

Can someone with real-life experience tell me what the relationship is
between activity and the proportion of the size of the pool to the size of
the reserved high-priority part?  I'd imagine that by counting the high
priority sections (areas that can't sleep) which allocate buffers per
second, I'd get the number of high-priority buffers that would have to be
available in that second.  This number would rely on certain factors such
as the message rate and system load as seen by the streams.

Any takers?

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Jim Hutchison   	{dcdwest,ucbvax}!ucsd!fps!hutch
Disclaimer:  I am not an official spokesman for FPS computing