/* * This file is part of the StarPU Handbook. * Copyright (C) 2009--2011 Universit@'e de Bordeaux 1 * Copyright (C) 2010, 2011, 2012, 2013 Centre National de la Recherche Scientifique * Copyright (C) 2011, 2012, 2013 Institut National de Recherche en Informatique et Automatique * See the file version.doxy for copying conditions. */ /*! \defgroup API_Scheduling_Context_Hypervisor_usage Scheduling Context Hypervisor - Regular usage \fn void *sc_hypervisor_init(struct sc_hypervisor_policy *policy) \ingroup API_Scheduling_Context_Hypervisor_usage There is a single hypervisor that is in charge of resizing contexts and the resizing strategy is chosen at the initialization of the hypervisor. A single resize can be done at a time. The Scheduling Context Hypervisor Plugin provides a series of performance counters to StarPU. By incrementing them, StarPU can help the hypervisor in the resizing decision making process. This function initializes the hypervisor to use the strategy provided as parameter and creates the performance counters (see starpu_sched_ctx_performance_counters). These performance counters represent actually some callbacks that will be used by the contexts to notify the information needed by the hypervisor. Note: The Hypervisor is actually a worker that takes this role once certain conditions trigger the resizing process (there is no additional thread assigned to the hypervisor). \fn void sc_hypervisor_shutdown(void) \ingroup API_Scheduling_Context_Hypervisor_usage The hypervisor and all information concerning it is cleaned. There is no synchronization between this function and starpu_shutdown(). Thus, this should be called after starpu_shutdown(), because the performance counters will still need allocated callback functions. \fn void sc_hypervisor_register_ctx(unsigned sched_ctx, double total_flops) \ingroup API_Scheduling_Context_Hypervisor_usage Scheduling Contexts that have to be resized by the hypervisor must be first registered to the hypervisor. This function registers the context to the hypervisor, and indicate the number of flops the context will execute (used for Gflops rate based strategy or any other custom strategy needing it, for the others we can pass 0.0) \fn void sc_hypervisor_unregister_ctx(unsigned sched_ctx) \ingroup API_Scheduling_Context_Hypervisor_usage Whenever we want to exclude contexts from the resizing process we have to unregister them from the hypervisor. \fn void sc_hypervisor_resize_ctxs(int *sched_ctxs, int nsched_ctxs , int *workers, int nworkers) \ingroup API_Scheduling_Context_Hypervisor_usage Requires reconsidering the distribution of ressources over the indicated scheduling contexts \fn void sc_hypervisor_stop_resize(unsigned sched_ctx) \ingroup API_Scheduling_Context_Hypervisor_usage The user can totally forbid the resizing of a certain context or can then change his mind and allow it (in this case the resizing is managed by the hypervisor, that can forbid it or allow it) \fn void sc_hypervisor_start_resize(unsigned sched_ctx) \ingroup API_Scheduling_Context_Hypervisor_usage Allow resizing of a context. The user can then provide information to the hypervisor concerning the conditions of resizing. \fn char *sc_hypervisor_get_policy(); \ingroup API_Scheduling_Context_Hypervisor_usage Returns the name of the resizing policy the hypervisor uses \fn void sc_hypervisor_add_workers_to_sched_ctx(int* workers_to_add, unsigned nworkers_to_add, unsigned sched_ctx) \ingroup API_Scheduling_Context_Hypervisor_usage Ask the hypervisor to add workers to a sched_ctx \fn void sc_hypervisor_remove_workers_from_sched_ctx(int* workers_to_remove, unsigned nworkers_to_remove, unsigned sched_ctx, unsigned now) \ingroup API_Scheduling_Context_Hypervisor_usage Ask the hypervisor to remove workers from a sched_ctx \fn void sc_hypervisor_move_workers(unsigned sender_sched_ctx, unsigned receiver_sched_ctx, int *workers_to_move, unsigned nworkers_to_move, unsigned now) \ingroup API_Scheduling_Context_Hypervisor_usage Moves workers from one context to another \fn void sc_hypervisor_size_ctxs(unsigned *sched_ctxs, int nsched_ctxs, int *workers, int nworkers) \ingroup API_Scheduling_Context_Hypervisor_usage Ask the hypervisor to chose a distribution of workers in the required contexts \fn void sc_hypervisor_set_type_of_task(struct starpu_codelet *cl, unsigned sched_ctx, uint32_t footprint, size_t data_size) \ingroup API_Scheduling_Context_Hypervisor_usage Indicate the types of tasks a context will execute in order to better decide the sizing of ctxs \fn void sc_hypervisor_update_diff_total_flops(unsigned sched_ctx, double diff_total_flops) \ingroup API_Scheduling_Context_Hypervisor_usage Change dynamically the total number of flops of a context, move the deadline of the finishing time of the context \fn void sc_hypervisor_update_diff_elapsed_flops(unsigned sched_ctx, double diff_task_flops) \ingroup API_Scheduling_Context_Hypervisor_usage Change dynamically the number of the elapsed flops in a context, modify the past in order to better compute the speed \fn int *sc_hypervisor_get_sched_ctxs() \ingroup API_Scheduling_Context_Hypervisor_usage Gets the contexts managed by the hypervisor \fn int sc_hypervisor_get_nsched_ctxs() \ingroup API_Scheduling_Context_Hypervisor_usage Gets the number of contexts managed by the hypervisor \fn void sc_hypervisor_ctl(unsigned sched_ctx, ...) \ingroup API_Scheduling_Context_Hypervisor_usage Inputs conditions to the context sched_ctx with the following arguments. The argument list must be zero-terminated. \def SC_HYPERVISOR_MAX_IDLE \ingroup API_Scheduling_Context_Hypervisor_usage This macro is used when calling sc_hypervisor_ctl() and must be followed by 3 arguments: an array of int for the workerids to apply the condition, an int to indicate the size of the array, and a double value indicating the maximum idle time allowed for a worker before the resizing process should be triggered \def SC_HYPERVISOR_PRIORITY \ingroup API_Scheduling_Context_Hypervisor_usage This macro is used when calling sc_hypervisor_ctl() and must be followed by 3 arguments: an array of int for the workerids to apply the condition, an int to indicate the size of the array, and an int value indicating the priority of the workers previously mentioned. The workers with the smallest priority are moved the first. \def SC_HYPERVISOR_MIN_WORKERS \ingroup API_Scheduling_Context_Hypervisor_usage This macro is used when calling sc_hypervisor_ctl() and must be followed by 1 argument(int) indicating the minimum number of workers a context should have, underneath this limit the context cannot execute. \def SC_HYPERVISOR_MAX_WORKERS \ingroup API_Scheduling_Context_Hypervisor_usage This macro is used when calling sc_hypervisor_ctl() and must be followed by 1 argument(int) indicating the maximum number of workers a context should have, above this limit the context would not be able to scale \def SC_HYPERVISOR_GRANULARITY \ingroup API_Scheduling_Context_Hypervisor_usage This macro is used when calling sc_hypervisor_ctl() and must be followed by 1 argument(int) indicating the granularity of the resizing process (the number of workers should be moved from the context once it is resized) This parameter is ignore for the Gflops rate based strategy (see \ref ResizingStrategies), the number of workers that have to be moved is calculated by the strategy. \def SC_HYPERVISOR_FIXED_WORKERS \ingroup API_Scheduling_Context_Hypervisor_usage This macro is used when calling sc_hypervisor_ctl() and must be followed by 2 arguments: an array of int for the workerids to apply the condition and an int to indicate the size of the array. These workers are not allowed to be moved from the context. \def SC_HYPERVISOR_MIN_TASKS \ingroup API_Scheduling_Context_Hypervisor_usage This macro is used when calling sc_hypervisor_ctl() and must be followed by 1 argument (int) that indicated the minimum number of tasks that have to be executed before the context could be resized. This parameter is ignored for the Application Driven strategy (see \ref ResizingStrategies) where the user indicates exactly when the resize should be done. \def SC_HYPERVISOR_NEW_WORKERS_MAX_IDLE \ingroup API_Scheduling_Context_Hypervisor_usage This macro is used when calling sc_hypervisor_ctl() and must be followed by 1 argument, a double value indicating the maximum idle time allowed for workers that have just been moved from other contexts in the current context. \def SC_HYPERVISOR_TIME_TO_APPLY \ingroup API_Scheduling_Context_Hypervisor_usage This macro is used when calling sc_hypervisor_ctl() and must be followed by 1 argument (int) indicating the tag an executed task should have such that this configuration should be taken into account. \def SC_HYPERVISOR_ISPEED_W_SAMPLE \ingroup API_Scheduling_Context_Hypervisor_usage This macro is used when calling sc_hypervisor_ctl() and must be followed by 1 argument, a double, that indicates the number of flops needed to be executed before computing the speed of a worker \def SC_HYPERVISOR_ISPEED_CTX_SAMPLE \ingroup API_Scheduling_Context_Hypervisor_usage This macro is used when calling sc_hypervisor_ctl() and must be followed by 1 argument, a double, that indicates the number of flops needed to be executed before computing the speed of a context \def SC_HYPERVISOR_NULL \ingroup API_Scheduling_Context_Hypervisor_usage This macro is used when calling sc_hypervisor_ctl() and must be followed by 1 arguments */