The best thing to do here is get a stack trace from the debugger. From the<br>
description, it is hard to tell what statement is trying to access which illegal<br>
memory.<br>
<br>
Matt<br><br><div><span class="gmail_quote">On 5/27/06, <b class="gmail_sendername">Randall Mackie</b> <<a href="mailto:randy@geosystem.us">randy@geosystem.us</a>> wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
In my PETSc based modeling code, I write out intermediate results to a scratch<br>file, and then read them back later. This has worked fine up until today,<br>when for a large model, this seems to be causing my program to crash with
<br>errors like:<br><br>------------------------------------------------------------------------<br>[9]PETSC ERROR: Caught signal number 11 SEGV: Segmentation Violation, probably memory access out of range<br><br><br>I've tracked down the offending code to:
<br><br> IF (rank == 0) THEN<br> irec=(iper-1)*2+ipol<br> write(7,rec=irec) (xvec(i),i=1,np)<br> END IF<br><br>It writes out xvec for the first record, but then on the second<br>
record my program is crashing.<br><br>The record length (from an inquire statement) is recl 22626552<br><br>The size of the scratch file when my program crashes is 98M.<br><br>PETSc is compiled using the intel compilers (
v9.0 for fortran),<br>and the users manual says that you can have record lengths of<br>up to 2 billion bytes.<br><br>I'm kind of stuck as to what might be the cause. Any ideas from anyone<br>would be greatly appreciated.<br>
<br>Randy Mackie<br><br>ps. I've tried both the optimized and debugging versions of the PETSc<br>libraries, with the same result.<br><br><br>--<br>Randall Mackie<br>GSY-USA, Inc.<br>PMB# 643<br>2261 Market St.,<br>San Francisco, CA 94114-1600
<br>Tel (415) 469-8649<br>Fax (415) 469-5044<br><br>California Registered Geophysicist<br>License No. GP 1034<br><br></blockquote></div><br><br clear="all"><br>-- <br>"Failure has a thousand explanations. Success doesn't need one" -- Sir Alec Guiness