From 3588494159eef67d73199ee1035347b5e78b2cfb Mon Sep 17 00:00:00 2001 From: suter Date: Tue, 13 May 2014 09:24:58 +0200 Subject: [PATCH] merge Fred and Henri description of the same stuff --- doc/doxygen/options.doc | 37 ++++++++++++++----------------------- 1 file changed, 14 insertions(+), 23 deletions(-) diff --git a/doc/doxygen/options.doc b/doc/doxygen/options.doc index 39d052fefc..1e39adae97 100644 --- a/doc/doxygen/options.doc +++ b/doc/doxygen/options.doc @@ -518,15 +518,20 @@ second) under which the execution chunks are not reported to the simulation kernel (default value: 1e-6). Please note that in some circonstances, this optimization can hinder the simulation accuracy. -If the "application" is in fact doing a "live replay" of another MPI -app (e.g., ScalaTrace's replay tool, various on-line simulators that -run an app at scale), the computation due to the replay logic should -not be simulated by SMPI. In that case the \b -smpi/simulation_computation item can be set to 'no' causing all the -compute bursts between MPI calls to be ignored by SMPI. Then only the -communications are simulated. This implies to add explicit calls to \c -smpi_execute() in the "application" to simulate computations. - + In some cases, however, one may wish to disable simulation of +application computation. This is the case when SMPI is used not to +simulate an MPI applications, but instead an MPI code that performs +"live replay" of another MPI app (e.g., ScalaTrace's replay tool, +various on-line simulators that run an app at scale). In this case the +computation of the replay/simulation logic should not be simulated by +SMPI. Instead, the replay tool or on-line simulator will issue +"computation events", which correspond to the actual MPI simulation +being replayed/simulated. At the moment, these computation events can +be simulated using SMPI by calling internal smpi_execute*() functions. + +To disable the benchmarking/simulation of computation in the simulated +application via this runtime automatic switching, the variable \b +smpi/privatize_global_variables should be set to no \subsection options_smpi_timing Reporting simulation time @@ -586,20 +591,6 @@ simulate the behavior of most of the existing MPI libraries. The \b smpi/coll_se uses naive version of collective operations). Each collective operation can be manually selected with a \b smpi/collective_name:algo_name. Available algorithms are listed in \ref SMPI_collective_algorithms . -\subsection options_model_smpi_computation_simulation Benchmarking/simulating application computation - -By default, SMPI benchmarks computational phases of the simulated application (i.e., CPU bursts in -between MPI calls) so that these phases can be simulated. In some cases, however, one may wish to -disable simulation of application computation. This is the case when SMPI is used not to simulate -an MPI applications, but instead an MPI code that performs "live replay" of another MPI app (e.g., -ScalaTrace's replay tool, various on-line simulators that run an app at scale). In this case the -computation of the replay/simulation logic should not be simulated by SMPI. Instead, the replay -tool or on-line simulator will issue "computation events", which correspond to the actual MPI simulation -being replayed/simulated. At the moment, these computation events can be simulated using SMPI by -calling internal smpi_execute*() functions. - -To disable the benchmarking/simulation of computation in the simulated application via this runtime automatic -switching, the variable \b smpi/privatize_global_variables should be set to no \section options_generic Configuring other aspects of SimGrid -- 2.20.1