OpenMP compiling

Hi,

I just downloaded the 15-day evaluation version of the Linux amd64 compiler and I’m trying to get our cosmological code to run with OpenMP (the directives were already present and working fine with the Intel compiler).

The code compiles fine with pgf90 with the options:

-O2 -tp amd64 -mp -Minfo=mp -byteswapio

No warnings, just the parallelization diagnostics.

However when I run the code, I can see that only one processor is being used.

I’ve exported NCPUS and OMP_NUM_THREADS=4

Is explicit (OpenMP) parallelization forbidden in the demo version?

Hi franjesus,

The demo is a fully functional Workstation product which allows up to 4 processes. How are you determining the number of processes running? ‘top’ doesn’t always report multiple processes and can give the appearance that only a singe process is running. I have found that the utility “xosview” found in “/usr/X11R6/bin” more reliable in determining the number of processes used.

  • Mat

What I find is that running top and pressing “1” (this shows you the individual use of each processor) only one processor is running at 100%, while the rest are totally idle. The system load tops at ~1 (instead of ~4).

Moreover, the % of processor use of each process is additive, when one process is running in, say, 4 processors, the percentage of use is close to 400%. The top with pgf90 is 100%.

And the wallclock time spent at each iteration of the program also indicates that it’s only running in 1 processor.

PS: Sorry for the delay, but I was having problems accesing the website from Spain. When i entered http://www.pgroup.com, it was redirecting me to a page by networksolutions.com saying “This domain name expired on 03/01/2006 and is pending renewal or deletion.”. I was puzzled until i tried to enter the site by ip: http://192.124.124.21
DNS forgery??

Hi franjesus,

I sounds like your doing everything correctly so I’m not sure why your not seeing the multiple threads. Which OS are your using? Is this a program that you could send us so we can try and duplicate the behavior? If so, please send it to trs@pgroup.com. Also, we have a small test program that we could send you.

PS: Sorry for the delay, but I was having problems accesing the website from Spain. When i entered > http://www.pgroup.com> , it was redirecting me to a page by networksolutions.com saying “This domain name expired on 03/01/2006 and is pending renewal or deletion.”. I was puzzled until i tried to enter the site by ip: > http://192.124.124.21 >
DNS forgery??

No, just an embarassing oversite where our parent company forgot to renew the pgroup.com domain name. The problem was corrected and everything should be back to normal shortly.

Thanks,
Mat

It sounds like your doing everything correctly so I’m not sure why your not seeing the multiple threads. Which OS are your using? Is this a program that you could send us so we can try and duplicate the behavior? If so, please send it to > trs@pgroup.com> . Also, we have a small test program that we could send you.

I’m using Opensuse 10.0 w/ kernel 2.6.13-15.8-smp x86_64. I’m not authorized to send you the code, but I can run any tests you send me.

Thanks.