Serious telnetd/rlogin/telnet performance bug

[Brian Thomson]

>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