X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/a0bf088c008c5f07ac578f488aa11173e955a7c0..fcb5d351a63c53030b694087b299fc199ca5898d:/doc/doxygen/options.doc diff --git a/doc/doxygen/options.doc b/doc/doxygen/options.doc index cdb3654b27..5adc3817b0 100644 --- a/doc/doxygen/options.doc +++ b/doc/doxygen/options.doc @@ -139,7 +139,8 @@ when using SimDag. - \b compound: Host model that is automatically chosen if you change the network and CPU models - \b ptask_L07: Host model somehow similar to Cas01+CM02 but - allowing parallel tasks + allowing "parallel tasks", that are intended to model the moldable + tasks of the grid scheduling literature. \subsection options_generic_plugin Plugins @@ -198,16 +199,10 @@ the \b maxmin/precision item (default value: 0.00001). Changing it may speedup the simulation by discarding very small actions, at the price of a reduced numerical precision. -\subsection options_model_nthreads Parallel threads for model updates +\subsection options_concurrency_limit Concurrency limit -By default, Surf computes the analytical models sequentially to share their -resources and update their actions. It is possible to run them in parallel, -using the \b surf/nthreads item (default value: 1). If you use a -negative or null value, the amount of available cores is automatically -detected and used instead. - -Depending on the workload of the models and their complexity, you may get a -speedup or a slowdown because of the synchronization costs of threads. +The maximum number of variables in a system can be tuned through +the \b maxmin/concurrency_limit item (default value: 100). Setting a higher value can lift some limitations, such as the number of concurrent processes running on a single host. \subsection options_model_network Configuring the Network model @@ -317,6 +312,15 @@ corresponding to the ns3::TcpL4Protocol::SocketType configuration item in NS3. The only valid values (enforced on the SimGrid side) are 'NewReno' or 'Reno' or 'Tahoe'. +\subsection options_model_storage Configuring the Storage model + +\subsubsection option_model_storage_maxfd Maximum amount of file descriptors per host + +Each host maintains a fixed-size array of its file descriptors. You +can change its size (1024 by default) through the \b +storage/max_file_descriptors item to either enlarge it if your +application requires it or to reduce it to save memory space. + \section options_modelchecking Configuring the Model-Checking To enable the SimGrid model-checking support the program should @@ -719,8 +723,8 @@ say that if you have a large computation between a \c MPI_Recv() and a code, and create an execution task within the simulator to take this into account. For that, the actual duration is measured on the host machine and then scaled to the power of the corresponding simulated -machine. The variable \b smpi/running-power allows to specify the -computational power of the host machine (in flop/s) to use when +machine. The variable \b smpi/host-speed allows to specify the +computational speed of the host machine (in flop/s) to use when scaling the execution times. It defaults to 20000, but you really want to update it to get accurate simulation results. @@ -731,7 +735,6 @@ impacts badly the simulation performance. It specifies a threshold (in seconds) below which the execution chunks are not reported to the simulation kernel (default value: 1e-6). - \note The option smpi/cpu-threshold ignores any computation time spent below this threshold. SMPI does not consider the \a amount of these @@ -739,7 +742,7 @@ simulation kernel (default value: 1e-6). value that is too low, you may end up with unreliable simulation results. - In some cases, however, one may wish to disable simulation of +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, @@ -752,15 +755,19 @@ be simulated using SMPI by calling internal smpi_execute*() functions. To disable the benchmarking/simulation of computation in the simulated application, the variable \b smpi/simulate-computation should be set to no. -Equivalently, setting \b smpi/cpu-threshold to -1 also ignores all -computation. \note This option just ignores the timings in your simulation; it still executes the computations itself. If you want to stop SMPI from doing that, - you should check the SMPI_SAMPLE macros, documented in the chapter + you should check the SMPI_SAMPLE macros, documented in the section \ref SMPI_adapting_speed. +Solution | Computations actually executed? | Computations simulated ? +---------------------------------- | ------------------------------- | ------------------------ +--cfg=smpi/simulate-computation:no | Yes | No, never +--cfg=smpi/cpu-threshold:42 | Yes, in all cases | Only if it lasts more than 42 seconds +SMPI_SAMPLE() macro | Only once per loop nest (see @ref SMPI_adapting_speed "documentation") | Always + \subsection options_model_smpi_adj_file smpi/comp-adjustment-file: Slow-down or speed-up parts of your code. This option allows you to pass a file that contains two columns: The first column @@ -1174,7 +1181,8 @@ silently overflow on other parts of the memory. - \c path: \ref options_generic_path - \c plugin: \ref options_generic_plugin -- \c surf/nthreads: \ref options_model_nthreads +- \c storage/max_file_descriptors: \ref option_model_storage_maxfd + - \c surf/precision: \ref options_model_precision - \c For collective operations of SMPI, please refer to Section \ref options_index_smpi_coll @@ -1184,16 +1192,16 @@ silently overflow on other parts of the memory. - \c smpi/comp-adjustment-file: \ref options_model_smpi_adj_file - \c smpi/cpu-threshold: \ref options_smpi_bench - \c smpi/display-timing: \ref options_smpi_timing -- \c smpi/lat-factor: \ref options_model_smpi_lat_factor +- \c smpi/host-speed: \ref options_smpi_bench - \c smpi/IB-penalty-factors: \ref options_model_network_coefs - \c smpi/iprobe: \ref options_model_smpi_iprobe - \c smpi/init: \ref options_model_smpi_init +- \c smpi/lat-factor: \ref options_model_smpi_lat_factor - \c smpi/ois: \ref options_model_smpi_ois - \c smpi/or: \ref options_model_smpi_or - \c smpi/os: \ref options_model_smpi_os - \c smpi/papi-events: \ref options_smpi_papi_events - \c smpi/privatize-global-variables: \ref options_smpi_global -- \c smpi/running-power: \ref options_smpi_bench - \c smpi/send-is-detached-thresh: \ref options_model_smpi_detached - \c smpi/simulate-computation: \ref options_smpi_bench - \c smpi/test: \ref options_model_smpi_test