``MPI_Fortran_COMPILER`` to the full path of smpicc, smpicxx and smpiff (or
smpif90), respectively. Example:
-.. code-block:: shell
+.. code-block:: console
- cmake -DMPI_C_COMPILER=/opt/simgrid/bin/smpicc -DMPI_CXX_COMPILER=/opt/simgrid/bin/smpicxx -DMPI_Fortran_COMPILER=/opt/simgrid/bin/smpiff .
+ $ cmake -DMPI_C_COMPILER=/opt/simgrid/bin/smpicc -DMPI_CXX_COMPILER=/opt/simgrid/bin/smpicxx -DMPI_Fortran_COMPILER=/opt/simgrid/bin/smpiff .
....................
Simulating your Code
Use the ``smpirun`` script as follows:
-.. code-block:: shell
+.. code-block:: console
- smpirun -hostfile my_hostfile.txt -platform my_platform.xml ./program -blah
+ $ smpirun -hostfile my_hostfile.txt -platform my_platform.xml ./program -blah
- ``my_hostfile.txt`` is a classical MPI hostfile (that is, this file
lists the machines on which the processes must be dispatched, one
a regular thread, and you can explore the state of each of them as
usual.
-.. code-block:: shell
+.. code-block:: console
- smpirun -wrapper valgrind ...other args...
- smpirun -wrapper "gdb --args" --cfg=contexts/factory:thread ...other args...
+ $ smpirun -wrapper valgrind ...other args...
+ $ smpirun -wrapper "gdb --args" --cfg=contexts/factory:thread ...other args...
Some shortcuts are available:
- ``-gdb`` is equivalent to ``-wrapper "gdb --args" -keep-temps``, to run within gdb debugger
- ``-lldb`` is equivalent to ``-wrapper "lldb --" -keep-temps``, to run within lldb debugger
-- ``-vgdb`` is equivalent to ``-wrapper "valgrind --vgdb=yes --vgdb-error=0"
--keep-temps``, to run within valgrind and allow to attach a debugger
+- ``-vgdb`` is equivalent to ``-wrapper "valgrind --vgdb=yes --vgdb-error=0" -keep-temps``,
+ to run within valgrind and allow to attach a debugger
To help locate bottlenecks and largest allocations in the simulated application,
the -analyze flag can be passed to smpirun. It will activate
- automatic (experimental): use an automatic self-benchmarking algorithm
- ompi_basic_linear: basic linear scatter
- ompi_binomial: binomial tree scatter
- - mvapich2_two_level_direct: SMP aware algorithm, with an intra-node stage (default set to mpich selector), and then a basic linear inter node stage. Use mvapich2 selector to change these to tuned algorithms for Stampede cluster.
+ - mvapich2_two_level_direct: SMP aware algorithm, with an intra-node stage (default set to mpich selector), and then a basic linear inter node stage. Use mvapich2 selector to change these to tuned algorithms for Stampede cluster.
- mvapich2_two_level_binomial: SMP aware algorithm, with an intra-node stage (default set to mpich selector), and then a binomial phase. Use mvapich2 selector to change these to tuned algorithms for Stampede cluster.
MPI_Reduce
iterations. These samples are done per processor with
SMPI_SAMPLE_LOCAL, and shared between all processors with
SMPI_SAMPLE_GLOBAL. Of course, none of this will work if the execution
-time of your loop iteration are not stable.
+time of your loop iteration are not stable. If some parameters have an
+incidence on the timing of a kernel, and if they are reused often
+(same kernel launched with a few different sizes during the run, for example),
+SMPI_SAMPLE_LOCAL_TAG and SMPI_SAMPLE_GLOBAL_TAG can be used, with a tag
+as last parameter, to differentiate between calls. The tag is a character
+chain crafted by the user, with a maximum size of 128, and should include
+what is necessary to group calls of a given size together.
This feature is demoed by the example file
`examples/smpi/NAS/ep.c <https://framagit.org/simgrid/simgrid/tree/master/examples/smpi/NAS/ep.c>`_
tracing/replay mechanism or how to use plugins written in S4U to
extend the simulator abilities.
-Another source of examples lay in the SimGrid archive, under
+Another source of examples lay in the SimGrid archive, under
`teshsuite/smpi <https://framagit.org/simgrid/simgrid/-/tree/master/examples/smpi>`_.
They are not in the ``examples`` directory because they probably don't
constitute pedagogical examples. Instead, they are intended to stress
our implementation during the tests. Some of you may be interested
anyway.
-
+
But the best source of SMPI examples is certainly the `proxy app
<https://framagit.org/simgrid/SMPI-proxy-apps>`_ external project.
Proxy apps are scale models of real, massive HPC applications: each of
``SMPI_PRETEND_CC`` environment variable before running the
configuration.
-.. code-block:: shell
+.. code-block:: console
- SMPI_PRETEND_CC=1 ./configure # here come the configure parameters
- make
+ $ SMPI_PRETEND_CC=1 ./configure # here come the configure parameters
+ $ make
Indeed, the programs compiled with ``smpicc`` cannot be executed
without ``smpirun`` (they are shared libraries and do weird things on
In addition to the previous answers, some projects also need to be
explicitly told what compiler to use, as follows:
-.. code-block:: shell
+.. code-block:: console
- SMPI_PRETEND_CC=1 ./configure CC=smpicc # here come the other configure parameters
- make
+ $ SMPI_PRETEND_CC=1 ./configure CC=smpicc # here come the other configure parameters
+ $ make
Maybe your configure is using another variable, such as ``cc`` (in
lower case) or similar. Just check the logs.
script of the actions to do sequentially. These trace files can
actually be captured with the online version of SMPI, as follows:
-.. code-block:: shell
+.. code-block:: console
$ smpirun -trace-ti --cfg=tracing/filename:LU.A.32 -np 32 -platform ../cluster_backbone.xml bin/lu.A.32
`simgrid/examples/smpi/replay
<https://framagit.org/simgrid/simgrid/tree/master/examples/smpi/replay>`_.
-.. code-block:: shell
+.. code-block:: console
$ smpicxx ../replay.cpp -O3 -o ../smpi_replay
Afterward, you can replay your trace in SMPI as follows:
+.. code-block:: console
+
$ smpirun -np 32 -platform ../cluster_torus.xml -ext smpi_replay ../smpi_replay LU.A.32
All the outputs are gone, as the application is not really simulated
