jeff@uhccux.UUCP (Jeffrey Blomberg) (11/13/87)
Reply-Path:
We often encounter a situation where a user on our system manages to get
the mail program into a CPU run state, and although the user drops their
modem line the process remains on the system. In cases like this, the
sys admin must kill the process. When the user gets their billing report,
they are often surprised to see the cost....
Anyway, I have not been able to reproduce the problem, but still see several
occurrances a week and have been unsuccessful in getting a problem description
from the users. Just curious if any other Ultrix sites have observed
this problem. Is 'mail' sensitive to typical line garbage?
Configuration info: Utrix 1.2 (8650), dhu-11 lines to Gandalf PACX, all lines
configured for modem control, standard 'mail' program.
stty -nohang is the default.
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Jeffrey Blomberg, University of Hawaii Computing Center 808/948-7351
Internet: jeff@uhccux.uhcc.hawaii.edu BITNET: jeff@uhccux.BITNET
UUCP: ..!{ihnp4,ucbvax,dcdwest}!sdcsvax!nosc!uhccux!jeffchuck@felix.UUCP (11/18/87)
Reply-Path: We have seen simliar behavior under Ultrix 2.0-1. A user will get disconnected, and then his/her active process will run wild trying to read from the tty. We've seen mail, emacs, and others all do this. We also see peoples lines not drop (modem lines) when they log out, which might be a related problem. ------------------------------------------------------------ Howie Kaye howie@columbia.edu Columbia University hlkcu@cuvma.bitnet Systems Group ...!rutgers!columbia!howie
chuck@felix.UUCP (11/19/87)
Reply-Path: On occasion I have found mail processes 'running away'. The user has logged out and he has a mail process that he owns that is cranking up the CPU. I end up killing it when someone points it out. I have not been able to force it to happen. Rob
chuck@felix.UUCP (12/03/87)
Reply-Path: In article <12684@felix.UUCP> jeff@uhccux.UUCP (Jeffrey Blomberg) writes: >We often encounter a situation where a user on our system manages to get >the mail program into a CPU run state, and although the user drops their >modem line the process remains on the system. In cases like this, the >sys admin must kill the process. When the user gets their billing report, >they are often surprised to see the cost.... I too have observed this, ever since the initial release of Ultrix. I think I have tracked this down to the "mail" command's improper handling of EOF! That is, if you are at the mail command prompt (?), and then type a Control-D (or something else generates a EOF), then mail will loop forever, burning up CPU. [Note that dropping the modem line results in EOF on the input device]. I suspect EOF because we run Untamo, which attempts to kill idle processies by closing stdin and stdout for the process. I _beleive_ that mail handles properly a SIGHUP. Anybody else? barry -- LIVE: Barry A. Burke, (617) 499-6370 USPS: Adelie Corporation, 125 CambridgePark Drive Cambridge, MA 02140 UUCP: barry@adelie.Adelie.COM / ..!{harvard,ll-xn,necntc,mirror}!adelie!barry ARPA: barry@adelie.Adelie.COM (via MX) / barry%adelie@harvard.Harvard.EDU