I am having a problem where the system locks up inside the MPI_Send() routine. In my test, each MPI rank has an additional pthread and system locks up when: - main thread does MPI_Recv from ANY rank - pthread does MPI_Send to another rank I verified with MPI_Init_thread() that I can run MPI_THREAD_MULTIPLE environment. The same thing happened on MPICH with Fedora 20 (3.0.4) and the one build from 3.2b3 sources. When building from sources I provided '--enable-threads=multiple' option. I also tried to play with '--enable-thread-cs' option but got build failure when 'per-object' was selected. Is this supposed to work? Thanks, Nenad I am attaching traces form GDB for the rank that locks up. (gdb) info thread Id Target Id Frame 2 Thread 0x7ffff6a5a700 (LWP 29570) "barrier_test" 0x0000003ef040bca0 in pthread_cond_wait@@GLIBC_2.3.2 () from /usr/lib64/libpthread.so.0 * 1 Thread 0x7ffff7a64b80 (LWP 29568) "barrier_test" 0x00007ffff7c58717 in MPIU_Thread_CS_yield_lockname_recursive_impl_ ( lockname=0x7ffff7cdc8b1 "global_mutex", mutex=<optimized out>, kind=MPIU_Nest_global_mutex) at ../src/src/include/mpiimplthreadpost.h:190 (gdb) where #0 0x00007ffff7c58717 in MPIU_Thread_CS_yield_lockname_recursive_impl_ (lockname=0x7ffff7cdc8b1 "global_mutex", mutex=<optimized out>, kind=MPIU_Nest_global_mutex) at ../src/src/include/mpiimplthreadpost.h:190 #1 0x00007ffff7c5db42 in MPIDI_CH3I_Progress (progress_state=progress_state@entry=0x7fffffffd2c0, is_blocking=is_blocking@entry=1) at ../src/src/mpid/ch3/channels/nemesis/src/ch3_progress.c:507 #2 0x00007ffff7b5e795 in PMPI_Recv (buf=0x7fffffffd61c, count=1, datatype=1275069445, source=-2, tag=299, comm=1140850688, status=0x7fffffffd620) at ../src/src/mpi/pt2pt/recv.c:157 #3 0x0000000000401732 in receive_int () at comm.c:52 #4 0x0000000000400bf2 in main (argc=1, argv=0x7fffffffd758) at barrier_test.c:39 (gdb) thread 2 [Switching to thread 2 (Thread 0x7ffff6a5a700 (LWP 29570))] #0 0x0000003ef040bca0 in pthread_cond_wait@@GLIBC_2.3.2 () from /usr/lib64/libpthread.so.0 (gdb) where #0 0x0000003ef040bca0 in pthread_cond_wait@@GLIBC_2.3.2 () from /usr/lib64/libpthread.so.0 #1 0x00007ffff7c5d614 in MPIDI_CH3I_Progress_delay (completion_count=<optimized out>) at ../src/src/mpid/ch3/channels/nemesis/src/ch3_progress.c:566 #2 MPIDI_CH3I_Progress (progress_state=progress_state@entry=0x7ffff6a59710, is_blocking=is_blocking@entry=1) at ../src/src/mpid/ch3/channels/nemesis/src/ch3_progress.c:347 #3 0x00007ffff7b632ec in PMPI_Send (buf=0x7ffff6a5985c, count=1, datatype=1275069445, dest=0, tag=199, comm=1140850688) at ../src/src/mpi/pt2pt/send.c:145 #4 0x0000000000400e42 in barrier_thread_release (id=0) at barrier.c:115 #5 0x0000000000401098 in barrier_helper (arg=0x0) at barrier.c:186 #6 0x0000003ef0407ee5 in start_thread () from /usr/lib64/libpthread.so.0 #7 0x0000003eef8f4d1d in clone () from /usr/lib64/libc.so.6 _______________________________________________ discuss mailing list [email protected] To manage subscription options or unsubscribe: https://lists.mpich.org/mailman/listinfo/discuss