CFD Online Logo CFD Online URL
Home > Forums > Main CFD Forum

OpenMP and fortran

Register Blogs Members List Search Today's Posts Mark Forums Read

LinkBack Thread Tools Display Modes
Old   May 17, 2007, 16:53
Default OpenMP and fortran
John Deas
Posts: n/a
Hi, my configuration is

Red Hat Linux 9.0 Intel Fortran Compiler (and debugger) 9.1 Intel 2x3.6 ghz 3.6 gig of ram

I have a program which manipulate large arrays (speed vectors for direct numerical simulation, CFD), and I a trying to modify and debug it with ifort and idb. The code contains openmp sections. When compiled without the openmp option, everything looks fine, but when I try to compile it with openmp, and I run it, I had crash early in the run at trivial functions call. After some research, I thought it might be linked to the stack size. I set "ulimit -s 2000000" and "export KMP_STACKSIZE=2g" and the program get further when it run, but, I got segmentation fault at a point later (I run it with 2 threads). A step-by-step debugging show me that, inside an omp do loop, the values of some SHARED variables where modified, but no line inside the do loop does this modification. Since those variables store arrays boundaries, once they are modified the do loop get outside the corresponding array and I got segfault.

If you have any advice on this problem, I would really appreciate it, since I have no clue why the openmp version version modify those values.


  Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
How to parallelize this fortran code by openmp ronac Main CFD Forum 1 May 11, 2016 02:12
OpenMP maz Main CFD Forum 5 May 3, 2013 01:00
C++ Vs Fortran Dave Main CFD Forum 54 February 10, 2012 17:33
OpenMP in Junction Box Routine Hannes_Kiel CFX 10 September 21, 2010 13:51
OpenMP and shared memory programming rt Main CFD Forum 8 May 4, 2006 12:29

All times are GMT -4. The time now is 23:59.