I neglected to include some pertinent information:
I'm using Open MPI 1.3.2. Here's a backtrace:
#0 0x0000002a95e6890c in epoll_wait () from /lib64/tls/libc.so.6
#1 0x0000002a9623a39c in epoll_dispatch ()
#2 0x0000002a96238f10 in opal_event_base_loop ()
#3 0x0000002a9622dfb0 in opal_progress ()
#4 0x0000002a989502c5 in mca_pml_ob1_send ()
#5 0x0000002a956c56f1 in PMPI_Send ()
Frames #0-#3 do return and loop. Frame #4 never returns.
Shaun Jackman wrote:
> I'm seeing MPI_Send block in mca_pml_ob1_send. The packet is shorter
> than the eager transmit limit for shared memory (3300 bytes < 4096
> bytes). I'm trying to determine if MPI_Send is blocking due to a
> deadlock. Will MPI_Send block even when sending a packet eagerly?