NAME¶

likwid-mpirun - A tool to start and monitor MPI applications with LIKWID

SYNOPSIS¶

likwid-memsweeper [-hvdOm] [-n number_of_processes] [-hostfile filename] [-nperdomain number_of_processes_in_domain] [-pin expression] [-omp omptype] [-mpi mpitype] [-g eventset] [--mpiopts opts]

DESCRIPTION¶

likwid-mpirun is a command line application that wraps the vendor-specific mpirun tool and adds calls to likwid-perfctr(1) to the execution string. The user-given application is ran, measured and the results returned to the staring node.

OPTIONS¶

-h,--help

prints a help message to standard output, then exits

-v,--version

prints version information to standard output, then exits

-d,--debug

prints debug messages to standard output

-n,-np,--n,--np <number_of_processes>

specifies how many MPI processes should be started

-hostfile <filename>

specifies the nodes to schedule the MPI processes on. If not given, the environment variables PBS_NODEFILE, LOADL_HOSTFILE and SLURM_HOSTFILE are checked.

-nperdomain <number_of_processes_in_domain>

specifies the processes per affinity domain (see likwid-pin for info about affinity domains)

-pin <expression>

specifies the pinning for hybrid execution (see likwid-pin for info about affinity domains)

-s, --skip <mask>

Specify skip mask as HEX number. For each set bit the corresponding thread is skipped.

-omp <omptype>

enables hybrid setup. Likwid tries to determine OpenMP type automatically. The only possible value are intel and gnu

-mpi <mpitype>

specifies the MPI implementation that should be used by the wrapper. Possible values are intelmpi, openmpi, slurm and mvapich2

-m,--marker

activates the Marker API for the executed MPI processes

-O

prints output in CSV not ASCII tables

--mpiopts <opts>

adds options for the underlying MPI implementation. Please use proper quoting.

--

stops parsing arguments for likwid-mpirun.

EXAMPLE¶

1.

For standard application:

likwid-mpirun -np 32 ./myApp

Will run 32 MPI processes, each host is filled with as much processes as written in ppn

2.

With pinning:

likwid-mpirun -np 32 -nperdomain S:2 ./myApp

Will start 32 MPI processes with 2 processes per socket.

3.

For hybrid runs:

likwid-mpirun -np 32 -pin M0:0-3_M1:0-3 ./myApp

Will start 32 MPI processes with 2 processes per node. Threads of the first process are pinned to the hardware threads 0-3 in NUMA domain 0 (M0). The OpenMP threads of the second process are pinned to the first four hardware threads in NUMA domain 1 (M1)

BUGS¶

When measuring Uncore events it is not possible to select a cpu pin expression that covers multiple sockets, e.g. S0:0-1_S0:2@S1:2. This runs two processes, each running on two CPUs. But since the first CPU of the second expression is on socket 0, which is already handled by S0:0-1, the second MPI process gets a event set that does not contain Uncore counters although the second part of the second expression would measure the Uncore counters on socket 1.

AUTHOR¶

Written by Thomas Gruber <thomas.roehl@googlemail.com>.

BUGS¶

Report Bugs on <https://github.com/RRZE-HPC/likwid/issues>.

SEE ALSO¶

likwid-pin(1), likwid-perfctr(1), likwid-powermeter(1)