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Path: utzoo!utcsri!utai!uthub!thomson
From: thomson@uthub.UUCP (Brian Thomson)
Newsgroups: net.unix-wizards,net.lan,net.bugs.4bsd
Subject: Re: Serious telnetd/rlogin/telnet performance bug
Message-ID: <288@uthub.UUCP>
Date: Thu, 17-Apr-86 14:56:55 EST
Article-I.D.: uthub.288
Posted: Thu Apr 17 14:56:55 1986
Date-Received: Thu, 17-Apr-86 16:28:42 EST
References: <380@quest.UUCP>
Distribution: net
Organization: CSRI, University of Toronto
Lines: 19

From Stuart Levy:
> Select() indicates that a file descriptor can be written to if ANY
> buffer space is available; but a write() with the
> non-blocking mode set will return EWOULDBLOCK unless there is enough room
> for the entire write buffer.  
[...]
> The REAL way to fix this problem would be to redefine non-blocking
> I/O, I think, to make it possible to indicate a partial read or write
> accompanied by an error, such as EWOULDBLOCK or EINTR.

I submitted such a fix in December 1983.  It has, I believe, been adopted
in 4.3; in any case, we have been running happily with partial reads/writes
for over three years.  Check your Mt. Xinu buglist, or send me a note if
you want a copy of the fix.
I also have a performance fix for pseudo-ttys that originally went out
in June 1984.  You may want that, too.
-- 
		    Brian Thomson,	    CSRI Univ. of Toronto
		    {linus,ihnp4,uw-beaver,floyd,utzoo}!utcsrgv!uthub!thomson