Hi:
When running a simple MPI program in the form of:
int main()
{
...
MPI_Init();
...
sleep(10);
...
MPI_Finalize()
;
...
}
Two threads, additionally to the master, can be seen when using gstack:
Thread 3 (Thread 0x7f2238a6c700 (LWP 106578)):
#0 0x00007f223a869783 in epoll_wait () from /lib64/libc.so.6
#1 0x00007f223a268983 in epoll_dispatch (base=0x1be76c0, tv=<optimized
out>) at epoll.c:407
#2 0x00007f223a26c3d0 in opal_libevent2022_event_base_loop
(base=0x1be76c0, flags=1) at event.c:1630
#3 0x00007f2238a91b9d in progress_engine () from
../openmpi-2.0.0/lib/openmpi/mca_pmix_pmix112.so
#4 0x00007f223ab3bdf5 in start_thread () from /lib64/libpthread.so.0
#5 0x00007f223a8691ad in clone () from /lib64/libc.so.6
Thread 2 (Thread 0x7f2233fff700 (LWP 106579)):
#0 0x00007f223a85eb7d in poll () from /lib64/libc.so.6
#1 0x00007f223a274736 in poll_dispatch (base=0x1be8bd0, tv=0x7f2233ffeea0)
at poll.c:165
#2 0x00007f223a26c3d0 in opal_libevent2022_event_base_loop
(base=0x1be8bd0, flags=1) at event.c:1630
#3 0x00007f223a23115e in progress_engine () from
.../openmpi-2.0.0/lib/libopen-pal.so.20
#4 0x00007f223ab3bdf5 in start_thread () from /lib64/libpthread.so.0
#5 0x00007f223a8691ad in clone () from /lib64/libc.so.6
Thread 1 (Thread 0x7f223b23e740 (LWP 106577)):
#0 0x00007f223a83048d in nanosleep () from /lib64/libc.so.6
#1 0x00007f223a830324 in sleep () from /lib64/libc.so.6
#2 0x0000000000400acb in main (argc=1, argv=0x7fffd6e7b498)
What are these threads designation? Are they progress threads?
Also, if I'd wanted to disable the extra threads, so there was only one
thread (the master one), how could I do it?
Info:
OpenMPI used: 2.0.0
Command used: mpirun -machinefile ~/hostfile --n 2 --map-by node ./test
Thanks!
Jaime
_______________________________________________
users mailing list
users@lists.open-mpi.org
https://rfd.newmexicoconsortium.org/mailman/listinfo/users
