settings (accurate modeling of slow start with correction factors on
three intervals: < 1KiB, < 64 KiB, >= 64 KiB). See also \ref
options_model_network_coefs "this section" for more info.
+ - \b IB: Realistic network model specifically tailored for HPC
+ settings with InfiniBand networks (accurate modeling contention
+ behavior, based on the model explained in
+ http://mescal.imag.fr/membres/jean-marc.vincent/index.html/PhD/Vienne.pdf).
+ See also \ref options_model_network_coefs "this section" for more info.
- \b CM02: Legacy network analytic model (Very similar to LV08, but
without corrective factors. The timings of small messages are thus
poorly modeled)
themselves corrected by constant values depending on the size of the
exchange. Again, only hardcore experts should bother about this fact.
+InfiniBand network behavior can be modeled through 3 parameters, as explained in
+http://mescal.imag.fr/membres/jean-marc.vincent/index.html/PhD/Vienne.pdf . These
+factors can be changed through option smpi/IB_penalty_factors:"βe;βs;γs". By
+default SMPI uses factors computed one Stampede cluster from TACC, with optimal
+deployment of processes on nodes.
+
\subsubsection options_model_network_crosstraffic Simulating cross-traffic
As of SimGrid v3.7, cross-traffic effects can be taken into account in
The only reason to change this setting is when the debugging tools get
fooled by the optimized context factories. Threads are the most
-debugging-friendly contextes.
+debugging-friendly contextes, as they allow to set breakpoints anywhere with gdb
+ and visualize backtraces for all processes, in order to debug concurrency issues.
+Valgrind is also more comfortable with threads, but it should be usable with all factories.
\subsection options_virt_stacksize Adapting the used stack size
In some cases, no stack guard page is used and the stack will silently
overflow on other parts of the memory if the stack size is too small
-for your application. This happens :
+for your application. This happens :
- on Windows systems;
- when the model checker is enabled;
\subsection options_generic_exit Behavior on Ctrl-C
By default, when Ctrl-C is pressed, the status of all existing
-simulated processes is displayed. This is very useful to debug your
+simulated processes is displayed before exiting the simulation. This is very useful to debug your
code, but it can reveal troublesome in some cases (such as when the
amount of processes becomes really big). This behavior is disabled
when \b verbose-exit is set to 0 (it is to 1 by default).
