Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site down.FUN Path: utzoo!watmath!clyde!burl!ulysses!allegra!princeton!down!honey From: honey@down.FUN (code 101) Newsgroups: net.bugs.uucp Subject: Re: 4.2 uucp performance problems? Message-ID: <443@down.FUN> Date: Mon, 11-Feb-85 22:44:15 EST Article-I.D.: down.443 Posted: Mon Feb 11 22:44:15 1985 Date-Received: Tue, 12-Feb-85 06:39:45 EST References: <438@down.FUN> <548@vortex.UUCP> Organization: Princeton University, EECS Lines: 22 i recommend the pkspeedup code for all versions of uucp and unix, at all baudrates. it is simply the correct thing to do. lauren and others have observed that short reads are more frequent in 4.2. the obvious conclusion is that 4.2 has a smaller system call overhead, but this goes against my religion. in any case, we have ample evidence that the speedup is useful in 4.2: mark plotnick tested a number of cases and pkspeedup beat them all on throughput *and* cpu overhead. some versions of uucp use the system v VMIN/VTIME trick; as such, the pkspeedup line will usually not be reached. on those (rare) instances when the read returns short, pkspeedup remains the best thing to do. v7 based systems (e.g. 4.1bsd) don't have VMIN. v8 has a buffering line discpline that you push on top of of the ld stack; this makes it look look vaguely like the system v VMIN. i posted a 4.2 nap() here the other day (today?). i have seen nap() hacks for other unix versions in net.sources in the past -- consult net.wanted.sources.