mpiexec throws error "mkstemp failed No such file or directory"

Question

I have cross compiled MPICH for Android and configured it. It works fine when I spawn a single process as follows

$./mpiexec -n 1  -launcher=fork  ./mpi_hello_world                             
Hello world from processor zero, rank 0 out of 1 processors

However the Android System responds with following error if parameter "n" is greater than 1 as follows :

$./mpiexec -n 2  -launcher=fork  ./mpi_hello_world                                         
Fatal error in MPI_Init: Other MPI error, error stack:
MPIR_Init_thread(474).................: 
MPID_Init(190)........................: channel initialization failed
MPIDI_CH3_Init(89)....................: 
MPID_nem_init(272)....................: 
MPIDI_CH3I_Seg_commit(327)............: 
MPIU_SHMW_Seg_create_and_attach(897)..: 
MPIU_SHMW_Seg_create_attach_templ(610): mkstemp failed No such file or directory

It may be something related with name of temp file being created on android ? Please help.

Answer 1

The problem is that on Android file system you do not have /tmp and /dev/shm directories, which are crutial for creating temp files for shared-memory communication. Because of that, mkstemp() will fail. mkdir them while you are su, set up the permissions and ch3:nemesis will work.