Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!uunet!husc6!rutgers!clyde!cbosgd!mandrill!hal!ncoast!allbery
From: allbery@ncoast.UUCP (Brandon Allbery)
Newsgroups: comp.sys.att
Subject: Re: Re: Adding extra console window gettys: maybe not a good idea
Message-ID: <6318@ncoast.UUCP>
Date: Wed, 2-Dec-87 00:22:33 EST
Article-I.D.: ncoast.6318
Posted: Wed Dec  2 00:22:33 1987
Date-Received: Mon, 7-Dec-87 06:46:38 EST
References: <750@neoucom.UUCP> <47@cjsa.UUCP> <1810@ukecc.engr.uky.edu>
Reply-To: allbery@ncoast.UUCP (Brandon Allbery)
Followup-To: comp.sys.att
Organization: Cleveland Public Access UN*X, Cleveland, Oh
Lines: 34
Summary: Check your printer.  Yes, I said *printer*.

As quoted from <1810@ukecc.engr.uky.edu> by lynn@engr.uky.edu (H. Lynn Tilley):
+---------------
| >The only recourse is to reboot the system.  There is no indication in the
| >adm logs of a problem and I have been unable to locate any other signs of 
| >distress.  After reboot, the system runs fine for one or more days and then
| >the problem repeats.  
| 
| The error message you are getting and the fact that rebooting clears
| the problem up may indicate that the problem stems from having excess
| tmp files or very large log entries.  The 7300's (3b1's) keep a complete
+---------------

I was using my 3B1 yesterday to do word processing, so I turned on the printer
and then left it on later.  A few hours after I was done printing, the
system suddenly slowed down and smgr began reading the disk and updating the
status line once per second.  Also, the "windaemon" process (pid == 3) began
racking up enormous amounts of CPU time.  This went on for about an hour,
during which I checked everything I could think of; then gave up and went to
bed, expecting the computer to have crashed in the morning... got up again
and shut off the printer.  And the computer quieted down.  I let it sit for
a few minutes, then powered up the printer again... the disk started "ticking"
again, once per second, and smgr began updating once/second again; and it
stopped when I powered the printer down again.  For those interested, I use
a Tandy DMP105 (for final copies, I create a floppy and print it on my boss's
LaserJet+).

Anyway, I suspect that the parallel printer driver sends some unexpected
interrupts which tickle the kernel in some strange ways.  It is possible,
given the effect on "windaemon"'s CPU time, that this might be a cause for
peoples' spurious "too many windows open" crashes as well.
-- 
Brandon S. Allbery		      necntc!ncoast!allbery@harvard.harvard.edu
 {hoptoad,harvard!necntc,cbosgd,sun!mandrill!hal,uunet!hnsurg3}!ncoast!allbery
			Moderator of comp.sources.misc