Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uunet!mcsun!hp4nl!dutrun!duteca4!mars
From: mars@duteca (mars@duteca.tudelft.nl)
Newsgroups: comp.sys.ibm.pc.rt
Subject: Problems with swap space??
Message-ID: <728@duteca4.UUCP>
Date: 26 Feb 90 08:58:54 GMT
Reply-To: mars@duteca.tudelft.nl ()
Organization: Delft University of Technology, Dep. of Electrotechnical engineering.
Lines: 34

We have a 4 RT PCs running under AIX 2.2.1 and have had a large amount of
crashes lately. It appeared that whenever I executed a really large
executable >1M, one of the RTs always crashed, whereas on the other RTs
it could be executed without problems. The same problem occured when
two or more applications such as large compilations where executed 
simultaneously. To locate the cause of this I wrote a program that:
1. allocated 20M
2. wrote data (!= 0) in the 20 M buffer
3. read the data
It appeared that when this program was executed, the RT always crashed.

It seems to me that the problem is caused by a problem with the swap space,
so I tried the program on the other RTs and it appeared that the same
problem occured (although at least one of them didn't crash until at least
one other extra application was running). I also tried the program on a
SUN, but couldn't crash it.

If anybody has noticed the same problem and found a solution to it,
please email me. Maybe a larger swap space is the solution, but
even if the swap space (+/- 22M) was chosen too small, at least an
error message could be expected when too much memory has been allocated.
I'm not really a RT expert, but when I had to make a guess about the
cause of this, I would say that the swap space that is reserved for the
vital AIX applications has been chosen to small. Please email suggestions
to mars@duteca.tudelft.nl, thanx in advance.

-- 
***************************************************************************
* Gert-Jan Tromp                                                         *
* Delft University of Technology                                        *
* Dept. of Elect. Engineering, room 10.04                              *
* P.O. Box 5031, 2600 GA Delft, The Netherlands                         *
* Email: mars@duteca.tudelft.nl                                          *
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