Illustrate how to use profiling capabilities

examples/Makefile.am

@@ -516,3 +516,16 @@ if STARPU_USE_OPENCL
 nobase_STARPU_OPENCL_DATA_DATA += \
 	block/block_kernel.cl
 endif
+
+#####################
+# profiling example #
+#####################
+
+check_PROGRAMS +=				\
+	profiling/profiling
+
+examplebin_PROGRAMS +=				\
+	profiling/profiling
+
+profiling_profiling_SOURCES =			\
+	profiling/profiling.c

examples/profiling/profiling.c

@@ -0,0 +1,102 @@
+/*
+ * StarPU
+ * Copyright (C) INRIA 2008-2010 (see AUTHORS file)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * See the GNU Lesser General Public License in COPYING.LGPL for more details.
+ */
+
+#include <starpu.h>
+#include <starpu_profiling.h>
+#include <assert.h>
+
+static unsigned niter = 50;
+
+void sleep_codelet(__attribute__ ((unused)) void *descr[],
+			__attribute__ ((unused)) void *_args)
+{
+	usleep(1000);
+}
+
+int main(int argc, char **argv)
+{
+	if (argc == 2)
+		niter = atoi(argv[1]);
+
+	starpu_init(NULL);
+
+	/* Enable profiling */
+	starpu_enable_profiling();
+
+	starpu_codelet cl =
+	{
+		.where = STARPU_CPU|STARPU_CUDA|STARPU_OPENCL,
+		.cpu_func = sleep_codelet,
+		.cuda_func = sleep_codelet,
+		.opencl_func = sleep_codelet,
+		.nbuffers = 0
+	};
+
+	struct starpu_task **tasks = malloc(niter*sizeof(struct starpu_task *));
+	assert(tasks);
+
+	unsigned i;
+	for (i = 0; i < niter; i++)
+	{
+		struct starpu_task *task = starpu_task_create();
+
+		task->cl = &cl;
+
+		/* We will destroy the task structure by hand so that we can
+		 * query the profiling info before the task is destroyed. */
+		task->destroy = 0;
+		
+		tasks[i] = task;
+
+		int ret = starpu_task_submit(task);
+		if (STARPU_UNLIKELY(ret == -ENODEV))
+		{
+			fprintf(stderr, "No worker may execute this task\n");
+			exit(0);
+		}
+	}
+
+	starpu_task_wait_for_all();
+
+	int64_t delay_sum = 0;
+	int64_t length_sum = 0;
+
+	for (i = 0; i < niter; i++)
+	{
+		struct starpu_task *task = tasks[i];
+		struct starpu_task_profiling_info *info = task->profiling_info;
+
+		/* How much time did it take before the task started ? */
+		int64_t delay = (info->start_time - info->submit_time);
+		delay_sum += delay;
+
+		/* How long was the task execution ? */
+		int64_t length = (info->end_time - info->start_time);
+		length_sum += length;
+
+		/* We don't need the task structure anymore */
+		starpu_task_destroy(task);
+	}
+
+	free(tasks);
+
+	fprintf(stderr, "Avg. delay : %2.2f us\n", ((double)delay_sum)/niter);
+	fprintf(stderr, "Avg. length : %2.2f us\n", ((double)length_sum)/niter);
+
+	starpu_shutdown();
+
+	return 0;
+}