🚀 go-pugleaf

RetroBBS NetNews Server

Inspired by RockSolid Light RIP Retro Guy

4 total messages Started by James J Dempsey Wed, 26 Jul 1989 19:20
Runaway bash
#386
Author: James J Dempsey
Date: Wed, 26 Jul 1989 19:20
20 lines
1076 bytes
I use: Vax 8530, Ultrix 3.0, GCC 1.35, yacc, GNU make 1.35

I have had over a dozen cases where a bash of mine gets into some very
tight infinite loop and eats up gobs of cpu time.  I have tried to get
a core dump, but the only signal they will respond to is SIGKILL, so I
have been unsuccessful.

These runaway bashes must come from shells which are in the process of
exiting or X windows which are closing or something, because I never
notice when they get created.  Currently running interactive shells
don't go into this state.

This wouldn't bother me too much, except we are charged for cpu time
on this host.

Does anyone have any good ideas about how to debug this problem?

Thanks,

		--Jim--
Runaway bash
#388
Author: Brian Fox
Date: Thu, 27 Jul 1989 13:54
29 lines
1563 bytes
   Date: Wed, 26 Jul 89 15:20:30 -0400
   From: James J Dempsey <jjd@bbn.com>

   I use: Vax 8530, Ultrix 3.0, GCC 1.35, yacc, GNU make 1.35

   I have had over a dozen cases where a bash of mine gets into some very
   tight infinite loop and eats up gobs of cpu time.  I have tried to get
   a core dump, but the only signal they will respond to is SIGKILL, so I
   have been unsuccessful.

   These runaway bashes must come from shells which are in the process of
   exiting or X windows which are closing or something, because I never
   notice when they get created.  Currently running interactive shells
   don't go into this state.

   Does anyone have any good ideas about how to debug this problem?

The only thing that comes to mind is that bash is trying to do some
output, (or read some input) and just keeps trying instead of getting
blocked, or stopped, or something.

If these runaway shells won't respond to SIGTSTP or SIGSTOP, then it is
likely that they are login shells.

If anyone gets more information on this problem, I would like to hear
about it.

Brian
Re: Runaway bash
#397
Author: Jason S. Molenda
Date: Sun, 30 Jul 1989 18:47
55 lines
2712 bytes
bfox@AUREL.CALTECH.EDU (Brian Fox) writes:


>   Date: Wed, 26 Jul 89 15:20:30 -0400
>   From: James J Dempsey <jjd@bbn.com>

>   I have had over a dozen cases where a bash of mine gets into some very
>   tight infinite loop and eats up gobs of cpu time.  I have tried to get
>   a core dump, but the only signal they will respond to is SIGKILL, so I
>   have been unsuccessful.


>The only thing that comes to mind is that bash is trying to do some
>output, (or read some input) and just keeps trying instead of getting
>blocked, or stopped, or something.

>If these runaway shells won't respond to SIGTSTP or SIGSTOP, then it is
>likely that they are login shells.

>If anyone gets more information on this problem, I would like to hear
>about it.

>Brian

I've had this happen to me twice.  Once on our Sequent Symmetry S27
running a BSD 4.3-similar OS and once on one of our NeXT cubes.

As James noticed, it is not easy to notice when one of these processes
start..  If you're using a single-CPU machine it just starts to act
very sluggishly.

The only difference is that when it happened on the Sequent, the bash
process had no controlling terminal (e.g. there was a "?" reported for
the terminal by a "ps aux").  When it happened on the NeXT yesterday,
there was a controlling terminal (/dev/ttyp1).

The only similarity was that I'm pretty sure I was using windowing
systems both times (X on the sequent and the NeXT environment on the
NeXT), and as we all know occasionally something can go wrong when
you're working in one of those windowing environments and the whole
thing can crash really quickly...  so I'm thinking that maybe the
bash programs managed to ignore some kind of signal that they were
sent.

Both times they appear to be polling for input; they definitely
aren't blocked.  On the sequent where we have top, I saw the bash
process eating up 98% of the CPU time on one of our processors.  On
the NeXT it had accumulated about 27 minutes of cpu time before I
figured it out.

-------
Jason Molenda,  University of Minnesota, Computer Science dept.
Internet:       molenda@umn-cs.cs.umn.edu,
Uucp:           ..!rutgers!umn-cs!molenda
Real life:      "hey you!"
Re: Runaway bash
#402
Author: Andrew Thomas
Date: Mon, 31 Jul 1989 20:49
23 lines
1533 bytes
      I use: Vax 8530, Ultrix 3.0, GCC 1.35, yacc, GNU make 1.35

      I have had over a dozen cases where a bash of mine gets into some very
      tight infinite loop and eats up gobs of cpu time.  I have tried to get
      a core dump, but the only signal they will respond to is SIGKILL, so I
      have been unsuccessful.

   If anyone gets more information on this problem, I would like to hear
   about it.

   Brian

I use a uVaxII running Ultrix 2.0.  I have had this problem only once,
when the system was very heavily loaded.  There was a lot of swapping
going on, so I tried to ^C out of a program only to have bash hang.  I
did not manage to find out why, but I thought you would like to have a
confirmation of the problem.
--

Andrew Thomas
andrewt@watsnew.waterloo.edu	Systems Design Eng.	University of Waterloo
"If a million people do a stupid thing, it's still a stupid thing." - Opus
Thread Navigation

This is a paginated view of messages in the thread with full content displayed inline.

Messages are displayed in chronological order, with the original post highlighted in green.

Use pagination controls to navigate through all messages in large threads.

Back to All Threads