[Pw_forum] PW taskgroups and a large run on a BG/P

[David Farrell]

OK, I tried the Jan 12 2009 snapshot from the website with the BG/P  
scalapack, blacs, goto and lapack. Things compiled fine.

When I ran on 128 cores in vn mode with -ntg 4 -ndiag 121, I got a  
cholesky error:

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
%%%%%%%
      task #       103
      from  rdiaghg  : error #       102
       problems computing cholesky
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
%%%%%%%%%

When I ran on 128 cores in dual mode with -ntg 4 -ndiag 121, I got the  
cholesky error:

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
%%%%%%%
      task #       118
      from  rdiaghg  : error #       102
       problems computing cholesky
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
%%%%%%%%%


When I ran on 128 cores in smp mode with -ntg 4 -ndiag 121, it ran fine.


I am going to pull down the latest CVS version and see if that changes  
anything. It sounds like this shouldn't be a memory issue (and I don't  
get any memory errors in stderr), but I may have to see if I can  
reproduce this on a very small scale to see if it is something else.  
Something that according to the memory output should only use a couple  
hundred MB at most shouldn't require more than 1 GB to run.

Dave

On Feb 12, 2009, at 10:51 AM, Paolo Giannozzi wrote:

> On Feb 12, 2009, at 16:18 , David Farrell wrote:
>
>> OK - so perhaps I should try this same run with scalapack enabled
>> instead
>> just to be sure of what happens and that I haven't miscompiled
>> anything.
>> That is only available in the latest CVS versions right?
>
> right. You need option "-D__SCALAPACK" and to link to blacs and
> scalapack
>
> Paolo
> ---
> Paolo Giannozzi, Democritos and University of Udine, Italy
>
>
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David E. Farrell
Post-Doctoral Fellow
Department of Materials Science and Engineering
Northwestern University
email: d-farrell2 at northwestern.edu

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