On Tue, Nov 8, 2011 at 1:49 PM, PEREZ CERQUERA MANUEL RICARDO < manuel.perezcerquera at polito.it> wrote:
> Hi all, > > I'm having problems with the efficiency of my code, I mean, it's taken so > much time when I'm running in 2 processors than in 1 Processor. My guess > is that the communications at low level inside PETSC Directives, because > I'm generating the elements on wrong processes and this is killing me, > moreover I'm over estimated my memory occupancy, so my questions are: > Please send the output of -log_summary with all performance questions. > 1. For The Memory Occupancy , I Know the NonZero Pattern of my Matrix, so > I'm calling > CALL MatCreateMPIAIJ(PETSC_COMM_**WORLD,LocalNOfBEMFunctions,** > LocalTotalRank,**NOfTotalBEMFunctions,**GlobalTotalRank,& > PETSC_NULL_INTEGER,NNZ_** > diagonal(:),& > PETSC_NULL_INTEGER,NNZ_** > outofdiagonal(:),UFar,ierr) > So I have a doubt if when I'm doing this Should I specify just one > NNZ_diagonal(:) or NNZ_outofdiagonal(:) ?, not both of them as I'm doing. > Use MatSetOption(MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_TRUE) to make sure you are not causing mallocs. > 2. For the time efficiency, When I'm calling, MatSetValues() The Global > Index is out of the range set in MatCreateMPIAIJ, I mean for example if the > range is between 1 and 10 in a Matrix of 100 The Global index are let's say > 1 20 25 2 5 60 85 90 100 3 so there are some elements out of the range, > moreover I ran with -info option and I got this: > [0] MatAssemblyBegin_MPIAIJ(): Stash has 84088 entries, uses 3 mallocs. > And in the manual is written this actually means I'm generating entries in > the wrong process,not because of the mollocs but because of the entries, Do > I'm right ? > You are sending a lot of values. I would reorganize my code to compute the values on the owner. Matt > So is this indeed not efficient?. If not, Can you suggest me a possible > way to improve it? , Or there are some special way for indexing the > elements in order to put them in order to solve the system? > > Thanks! > > Manuel. > > > > I realized with -info option in run time > > > > > > Eng. Manuel Ricardo Perez Cerquera. MSc. Ph.D student > Antenna and EMC Lab (LACE) > Istituto Superiore Mario Boella (ISMB) > Politecnico di Torino > Via Pier Carlo Boggio 61, Torino 10138, Italy > Email: manuel.perezcerquera at polito.it > Phone: +39 0112276704 > Fax: +39 011 2276 299 > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20111108/0b1d6904/attachment-0001.htm>