Thanks Ralph. It worked. Regards, Rajesh
On Sat, Jun 20, 2009 at 10:28 AM, Ralph Castain<r...@open-mpi.org> wrote: > Ah, yes - that is definitely true. What you need to use is the "seq" (for > "sequential") mapper. Do the following on your cmd line: > --hostfile hostfile -mca rmaps seq > This will cause OMPI to map the process ranks according to the order in the > hostfile. You need to specify one line for each node/rank, just as you have > done. > Ralph > > On Fri, Jun 19, 2009 at 10:24 PM, Rajesh Sudarsan <rsudar...@gmail.com> > wrote: >> >> Hi Ralph, >> >> Thanks for the reply. The default mapper does round-robin assignment >> as long as I do not specify the machinefile in the following format: >> >> n1 >> n2 >> n2 >> n1 where, n1 and n2 are two nodes in the cluster and I use two >> slots within each node. >> >> >> I have pasted the output and the display map for execution on 2, 4,8 >> and 16 processors. The mapper does not use the nodes in which it is >> listed in the file. >> >> The machinefile that I tested with uses two nodes n105 and n106 with 8 >> cores in each node. >> >> n105 >> n105 >> n105 >> n105 >> n106 >> n106 >> n106 >> n106 >> n106 >> n106 >> n106 >> n106 >> n105 >> n105 >> n105 >> n105 >> >> When I run a hello world program on 2 processors which prints the >> hostname, the output and the display map are as follows: >> >> >> $ mpiexec --display-map -machinefile m3 -np 2 ./hello >> >> ======================== JOB MAP ======================== >> >> Data for node: Name: n106 Num procs: 2 >> Process OMPI jobid: [7838,1] Process rank: 0 >> Process OMPI jobid: [7838,1] Process rank: 1 >> >> ============================================================= >> Rank 0 is present in C version of Hello World...hostname = n106 >> Rank 1 of C version says: Hello world!..hostname = n106 >> >> >> >> >> On 4 processors the output is as follows >> >> $ mpiexec --display-map -machinefile m3 -np 4 ./hello >> >> ======================== JOB MAP ======================== >> >> Data for node: Name: n106 Num procs: 4 >> Process OMPI jobid: [7294,1] Process rank: 0 >> Process OMPI jobid: [7294,1] Process rank: 1 >> Process OMPI jobid: [7294,1] Process rank: 2 >> Process OMPI jobid: [7294,1] Process rank: 3 >> >> ============================================================= >> Rank 0 is present in C version of Hello World...hostname = n106 >> Rank 1 of C version says: Hello world!..hostname = n106 >> Rank 3 of C version says: Hello world!..hostname = n106 >> Rank 2 of C version says: Hello world!..hostname = n106 >> >> >> >> >> On 8 processors the output is as follows: >> >> $ mpiexec --display-map -machinefile m3 -np 8 ./hello >> >> ======================== JOB MAP ======================== >> >> Data for node: Name: n106 Num procs: 8 >> Process OMPI jobid: [7264,1] Process rank: 0 >> Process OMPI jobid: [7264,1] Process rank: 1 >> Process OMPI jobid: [7264,1] Process rank: 2 >> Process OMPI jobid: [7264,1] Process rank: 3 >> Process OMPI jobid: [7264,1] Process rank: 4 >> Process OMPI jobid: [7264,1] Process rank: 5 >> Process OMPI jobid: [7264,1] Process rank: 6 >> Process OMPI jobid: [7264,1] Process rank: 7 >> >> ============================================================= >> Rank 3 of C version says: Hello world!..hostname = n106 >> Rank 7 of C version says: Hello world!..hostname = n106 >> Rank 0 is present in C version of Hello World...hostname = n106 >> Rank 2 of C version says: Hello world!..hostname = n106 >> Rank 4 of C version says: Hello world!..hostname = n106 >> Rank 6 of C version says: Hello world!..hostname = n106 >> Rank 5 of C version says: Hello world!..hostname = n106 >> Rank 1 of C version says: Hello world!..hostname = n106 >> >> >> >> On 16 nodes the output is as follows: >> >> $ mpiexec --display-map -machinefile m3 -np 16 ./hello >> >> ======================== JOB MAP ======================== >> >> Data for node: Name: n106 Num procs: 8 >> Process OMPI jobid: [7266,1] Process rank: 0 >> Process OMPI jobid: [7266,1] Process rank: 1 >> Process OMPI jobid: [7266,1] Process rank: 2 >> Process OMPI jobid: [7266,1] Process rank: 3 >> Process OMPI jobid: [7266,1] Process rank: 4 >> Process OMPI jobid: [7266,1] Process rank: 5 >> Process OMPI jobid: [7266,1] Process rank: 6 >> Process OMPI jobid: [7266,1] Process rank: 7 >> >> Data for node: Name: n105 Num procs: 8 >> Process OMPI jobid: [7266,1] Process rank: 8 >> Process OMPI jobid: [7266,1] Process rank: 9 >> Process OMPI jobid: [7266,1] Process rank: 10 >> Process OMPI jobid: [7266,1] Process rank: 11 >> Process OMPI jobid: [7266,1] Process rank: 12 >> Process OMPI jobid: [7266,1] Process rank: 13 >> Process OMPI jobid: [7266,1] Process rank: 14 >> Process OMPI jobid: [7266,1] Process rank: 15 >> >> ============================================================= >> Rank 10 of C version says: Hello world!..hostname = n105 >> Rank 12 of C version says: Hello world!..hostname = n105 >> Rank 13 of C version says: Hello world!..hostname = n105 >> Rank 14 of C version says: Hello world!..hostname = n105 >> Rank 0 is present in C version of Hello World...hostname = n106 >> Rank 1 of C version says: Hello world!..hostname = n106 >> Rank 3 of C version says: Hello world!..hostname = n106 >> Rank 6 of C version says: Hello world!..hostname = n106 >> Rank 7 of C version says: Hello world!..hostname = n106 >> Rank 15 of C version says: Hello world!..hostname = n105 >> Rank 8 of C version says: Hello world!..hostname = n105 >> Rank 11 of C version says: Hello world!..hostname = n105 >> Rank 4 of C version says: Hello world!..hostname = n106 >> Rank 2 of C version says: Hello world!..hostname = n106 >> Rank 5 of C version says: Hello world!..hostname = n106 >> Rank 9 of C version says: Hello world!..hostname = n105 >> >> >> >> Thanks, >> Rajesh >> >> >> >> >> >> On Fri, Jun 19, 2009 at 10:40 PM, Ralph Castain<r...@open-mpi.org> wrote: >> > If you do "man orte_hosts", you'll see a full explanation of how the >> > various >> > machinefile options work. >> > The default mapper doesn't do any type of sorting - it is a round-robin >> > mapper that just works its way through the provided nodes. We don't >> > reorder >> > them in any way. >> > However, it does depend on the number of slots we are told each node >> > has, so >> > that might be what you are encountering. If you do a --display-map and >> > send >> > it along, I might be able to spot the issue. >> > Thanks >> > Ralph >> > >> > On Fri, Jun 19, 2009 at 1:35 PM, Rajesh Sudarsan <rsudar...@gmail.com> >> > wrote: >> >> >> >> Hi, >> >> >> >> I tested a simple hello world program on 5 nodes each with dual >> >> quad-core processors. I noticed that openmpi does not always follow >> >> the order of the processors indicated in the machinefile. Depending >> >> upon the number of processors requested, openmpi does some type of >> >> sorting to find the best node fit for a particular job and runs on >> >> them. Is there a way to make openmpi to turn off this sorting and >> >> strictly follow the order indicated in the machinefile? >> >> >> >> mpiexec supports three options to specify the machinefile - >> >> default-machinefile, hostfile, and machinefile. Can anyone tell what >> >> is the difference between these three options? >> >> >> >> Any help would be greatly appreciated. >> >> >> >> Thanks, >> >> Rajesh >> >> _______________________________________________ >> >> 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 >
