This part contains the description of the launcher part of MALP. More...

This part contains the description of the launcher part of MALP.

The MPI application is set in the virtual MPI and instrumentation environment by preloading the libmalpinstrum.so library before launching the application (LD_PRELOAD).

For the profiled program, every MPI calls will then be overridden by calls to their instrumented versions in MALP.
For the analyzer program, they are not as is is directly linked to the Virtual MPI ones.

The analyzer and the instrumented MPI application are launched as parallel MPI applications. Communication between intrumentation and analyzer will be done using the PMPI interface with the MPI_COMM_UNIVERSE communicator.

The MPI application and the analyzer application are launched in the same MPI context within the "malpl" script.

The launching script is also used to manage the process number attribution and what portion of those is dedicated to analyze. The number of cores (process) to be used by the application and its analyzer is specified in the command arguments.

The main parameters to set are the number of cores/processes to be used, and the ratio of core to be dedicated to the analysis. Next parameters are the name of the MPI program and the list of this program parameters.

MALP launcher command line:

malp [CORES_NUMBER] [ANALYSIS_RATIO] [APP] [ARG1] [ARG2] ... [ARGN]

MALP launcher parameters:

[CORE_NUMBER:] Total number of processes to be used for running the MPI application launched with MALP (at least one).
[ANALYSIS_RATIO] The wanted ratio between number of cores in the application and the number of cores in the analyzer. N_INST_CORES=CORES_NUMBER/ANALYSIS_RATIO
[APP] The MPI program to be launched with MALP
[ARG1] .. [ARGN] The MPI program parameters