Hi Ralph, thank you for your comment.
I understand what you mean. As you pointed out, I have one process sleep before finalize. Then, mumps finalize might affect the behavior. I will remove mumps finalize (and/or initialize) function from my testing program ant try again on next Monday to make my point clear. Regards, tmishima > I'm not sure - just fishing for possible answers. When we see high cpu usage, it usually occurs during MPI communications - when a process is waiting for a message to arrive, it polls at a high rate > to keep the latency as low as possible. Since you have one process "sleep" before calling the finalize sequence, it could be that the other process is getting held up on a receive and thus eating the > cpu. > > There really isn't anything special going on during Init/Finalize, and OMPI itself doesn't have any MPI communications in there. I'm not familiar with MUMPS, but if MUMPS finalize is doing something > like an MPI_Barrier to ensure the procs finalize together, then that would explain what you see. The docs I could find imply there is some MPI embedded in MUMPS, but I couldn't find anything specific > about finalize. > > > On Oct 25, 2012, at 6:43 PM, tmish...@jcity.maeda.co.jp wrote: > > > > > > > Hi Ralph, > > > > do you really mean "MUMPS finalize"? I don't think it has much relation > > with > > this behavior? > > > > Anyway, I'm just a mumps user. I have to ask mumps developers about what > > MUMPS > > initailize and finalize does. > > > > Regartds, > > tmishima > > > >> Out of curiosity, what does MUMPS finalize do? Does it send a message or > > do a barrier operation? > >> > >> > >> On Oct 25, 2012, at 5:53 PM, tmish...@jcity.maeda.co.jp wrote: > >> > >>> > >>> > >>> Hi, > >>> > >>> I find that system CPU time of openmpi-1.7rc1 is quite different with > >>> that of openmpi-1.6.2 as shown in the attached ganglia display. > >>> > >>> About 2 years ago, I reported a similar behavior of openmpi-1.4.3. > >>> The testing method is what I used at that time. > >>> (please see my post entitled "SYSTEM CPU with OpenMPI 1.4.3") > >>> > >>> Is this due to a pre-released version's check routine or does > >>> something go wrong? > >>> > >>> Best regards, > >>> Tetsuya Mishima > >>> > >>> ------------------ > >>> Testing program: > >>> INCLUDE 'mpif.h' > >>> INCLUDE 'dmumps_struc.h' > >>> TYPE (DMUMPS_STRUC) MUMPS_PAR > >>> c > >>> MUMPS_PAR%COMM = MPI_COMM_WORLD > >>> MUMPS_PAR%SYM = 1 > >>> MUMPS_PAR%PAR = 1 > >>> MUMPS_PAR%JOB = -1 ! INITIALIZE MUMPS > >>> CALL MPI_INIT(IERR) > >>> CALL DMUMPS(MUMPS_PAR) > >>> c > >>> CALL MPI_COMM_RANK( MPI_COMM_WORLD, MYID, IERR ) > >>> IF ( MYID .EQ. 0 ) CALL SLEEP(180) ! WAIT 180 SEC. > >>> c > >>> MUMPS_PAR%JOB = -2 ! FINALIZE MUMPS > >>> CALL DMUMPS(MUMPS_PAR) > >>> CALL MPI_FINALIZE(IERR) > >>> c > >>> END > >>> ( This does nothing but just calls intialize & finalize > >>> routine of MUMPS & MPI) > >>> > >>> command line : mpirun -host node03 -np 16 ./testrun > >>> > >>> (See attached file: > > openmpi17rc1-cmp.bmp)<openmpi17rc1-cmp.bmp>_______________________________________________ > > > >>> users mailing list > >>> us...@open-mpi.org > >>> http://www.open-mpi.org/mailman/listinfo.cgi/users > >> > >> > >> _______________________________________________ > >> users mailing list > >> us...@open-mpi.org > >> http://www.open-mpi.org/mailman/listinfo.cgi/users > >> > > > > _______________________________________________ > > users mailing list > > us...@open-mpi.org > > http://www.open-mpi.org/mailman/listinfo.cgi/users > > > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users >
