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From: dyer@spdcc.COM (Steve Dyer)
Newsgroups: comp.unix.wizards
Subject: Implementing 4.X TCP on non-VAXes
Message-ID: <203@spdcc.COM>
Date: Wed, 22-Jul-87 12:24:31 EDT
Article-I.D.: spdcc.203
Posted: Wed Jul 22 12:24:31 1987
Date-Received: Fri, 24-Jul-87 05:09:30 EDT
Organization: S.P. Dyer Computer Consulting, Cambridge MA
Lines: 15
Summary: software interrupts on machines without 'em

4.1BSD network code was switchable between having a network process
for consuming network input or using the VAX software interrupt system
to do this at interrupt level and avoid the overhead of a context switch.
The 4.2 and 4.3 network code assumes a software interrupt system.  Since
not every hardware architecture supports this feature and the code has
been ported to a wide variety of different machines, I was wondering what
the most common ways of implementing this were.  Do you examine the state of
the software interrupt flag upon returning from a hardware interrupt?
Check it during a timeout() routine?

Thanks,
-- 
Steve Dyer
dyer@harvard.harvard.edu
dyer@spdcc.COM aka {ihnp4,harvard,linus,ima,bbn,m2c}!spdcc!dyer