\section options_model Configuring the platform models
+\anchor options_storage_model
+\anchor options_vm_workstation_model
\subsection options_model_select Selecting the platform models
-SimGrid comes with several network and CPU models built in, and you
+SimGrid comes with several network, CPU and storage models built in, and you
can change the used model at runtime by changing the passed
configuration. The three main configuration items are given below.
For each of these items, passing the special \c help value gives
- \b network/model: specify the used network model
- \b cpu/model: specify the used CPU model
- \b workstation/model: specify the used workstation model
+ - \b storage/model: specify the used storage model (there is currently only one such model - this option is hence only useful for future releases)
+ - \b vm_workstation/model: specify the workstation model for virtual machines (there is currently only one such model - this option is hence only useful for future releases)
%As of writing, the following network models are accepted. Over
the time new models can be added, and some experimental models can be
By default, no state is snapshotted and cycles cannot be detected.
-\subsection options_modelchecking_termination, model-check/termination, Non termination detection
+\subsection options_modelchecking_termination model-check/termination, Non termination detection
The \b model-check/termination configuration item can be used to report if a
non-termination execution path has been found. This is a path with a cycle
simulations. For additional details about this and all tracing
options, check See the \ref tracing_tracing_options.
+\section options_msg Configuring MSG
+
+\subsection options_msg_debug_multiple_use Debugging MSG
+
+Sometimes your application may try to send a task that is still being
+executed somewhere else, making it impossible to send this task. However,
+for debugging purposes, one may want to know what the other host is/was
+doing. This option shows a backtrace of the other process.
+
+Enable this option by adding
+
+\verbatim
+--cfg=msg/debug_multiple_use:on
+\endverbatim
+
\section options_smpi Configuring SMPI
The SMPI interface provides several specific configuration items.
messages of size 15424 to 65471 will get MAX_BANDWIDTH*0.697866 and so on.
Here, MAX_BANDWIDTH denotes the bandwidth of the link.
+\note
+ The SimGrid-Team has developed a script to help you determine these
+ values. You can find more information and the download here:
+ 1. http://simgrid.gforge.inria.fr/contrib/smpi-calibration-doc.html
+ 2. http://simgrid.gforge.inria.fr/contrib/smpi-saturation-doc.html
+
\subsection options_smpi_timing smpi/display_timing: Reporting simulation time
+\b Default: 0 (false)
+
Most of the time, you run MPI code through SMPI to compute the time it
would take to run it on a platform that you don't have. But since the
code is run through the \c smpirun script, you don't have any control
65472:11.6436;15424:3.48845;9376:2.59299;5776:2.18796;3484:1.88101;1426:1.61075;732:1.9503;257:1.95341;0:2.01467
\endverbatim
+\note
+ The SimGrid-Team has developed a script to help you determine these
+ values. You can find more information and the download here:
+ 1. http://simgrid.gforge.inria.fr/contrib/smpi-calibration-doc.html
+ 2. http://simgrid.gforge.inria.fr/contrib/smpi-saturation-doc.html
+
\subsection options_smpi_global smpi/privatize_global_variables: Automatic privatization of global variables
MPI executables are meant to be executed in separated processes, but SMPI is
The behavior and motivation for this configuration option is identical with \a smpi/test, see
Section \ref options_model_smpi_test for details.
+\subsection options_model_smpi_ois smpi/ois: Inject constant times for asynchronous send operations
+
+This configuration option works exactly as \a smpi/os, see Section \ref options_model_smpi_os.
+Of course, \a smpi/ois is used to account for MPI_Isend instead of MPI_Send.
+
+\subsection options_model_smpi_os smpi/os: Inject constant times for send operations
+
+In several network models such as LogP, send (MPI_Send, MPI_Isend) and receive (MPI_Recv)
+operations incur costs (i.e., they consume CPU time). SMPI can factor these costs in as well, but the
+user has to configure SMPI accordingly as these values may vary by machine.
+This can be done by using smpi/os for MPI_Send operations; for MPI_Isend and
+MPI_Recv, use \a smpi/ois and \a smpi/or, respectively. These work exactly as
+\a smpi/ois.
+
+\a smpi/os can consist of multiple sections; each section takes three values, for example:
+
+\verbatim
+ 1:3:2;10:5:1
+\endverbatim
+
+Here, the sections are divided by ";" (that is, this example contains two sections).
+Furthermore, each section consists of three values.
+
+1. The first value denotes the minimum size for this section to take effect;
+ read it as "if message size is greater than this value (and other section has a larger
+ first value that is also smaller than the message size), use this".
+ In the first section above, this value is "1".
+
+2. The second value is the startup time; this is a constant value that will always
+ be charged, no matter what the size of the message. In the first section above,
+ this value is "3".
+
+3. The third value is the \a per-byte cost. That is, it is charged for every
+ byte of the message (incurring cost messageSize*cost_per_byte)
+ and hence accounts also for larger messages. In the first
+ section of the example above, this value is "2".
+
+Now, SMPI always checks which section it should take for a given message; that is,
+if a message of size 11 is sent with the configuration of the example above, only
+the second section will be used, not the first, as the first value of the second
+section is closer to the message size. Hence, a message of size 11 incurs the
+following cost inside MPI_Send:
+
+\verbatim
+ 5+11*1
+\endverbatim
+
+%As 5 is the startup cost and 1 is the cost per byte.
+
+\note
+ The order of sections can be arbitrary; they will be ordered internally.
+
+\subsection options_model_smpi_or smpi/or: Inject constant times for receive operations
+
+This configuration option works exactly as \a smpi/os, see Section \ref options_model_smpi_os.
+Of course, \a smpi/or is used to account for MPI_Recv instead of MPI_Send.
+
\subsection options_model_smpi_test smpi/test: Inject constant times for calls to MPI_Test
\b Default value: 0.0001
to sleep increases linearly with the number of previously failed testk.
+\subsection options_model_smpi_use_shared_malloc smpi/use_shared_malloc: Use shared memory
+
+\b Default: 1
+
+SMPI can use shared memory by calling shm_* functions; this might speed up the simulation.
+This opens or creates a new POSIX shared memory object, kept in RAM, in /dev/shm.
+
+If you want to disable this behavior, set the value to 0.
+
\subsection options_model_smpi_wtime smpi/wtime: Inject constant times for calls to MPI_Wtime
\b Default value: 0
for the moment (May 2015).
\note
- \b Please \b note: You can also pass the command-line option "\b --help" and
+ \b Please \b note: You can also pass the command-line option "--help" and
"--help-cfg" to an executable that uses simgrid.
- \c clean_atexit: \ref options_generic_clean_atexit
- \c workstation/model: \ref options_model_select
\subsection options_index_smpi_coll Index of SMPI collective algorithms options
-- \c smpi/allgather: \ref options_model_smpi_coll_allgather
-- \c smpi/allgatherv: \ref options_model_smpi_coll_allgatherv
-- \c smpi/allreduce: \ref options_model_smpi_coll_allreduce
-- \c smpi/alltoall: \ref options_model_smpi_coll_alltoall
-- \c smpi/alltoallv: \ref options_model_smpi_coll_alltoallv
-- \c smpi/barrier: \ref options_model_smpi_coll_barrier
-- \c smpi/bcast: \ref options_model_smpi_coll_bcast
-- \c smpi/gather: \ref options_model_smpi_coll_gather
-- \c smpi/reduce: \ref options_model_smpi_coll_reduce
-- \c smpi/reduce_scatter: \ref options_model_smpi_coll_reduce_scatter
-- \c smpi/scatter: \ref options_model_smpi_coll_scatter
+
+TODO: All available collective algorithms will be made available via the ``smpirun --help-coll`` command.
*/
