Initial import

1 files changed, 194 insertions, 0 deletions

diff --git a/tools/power/cpupower/bench/benchmark.c b/tools/power/cpupower/bench/benchmark.c
new file mode 100644
index 000000000..81b1c4860
--- /dev/null
+++ b/tools/power/cpupower/bench/benchmark.c
@@ -0,0 +1,194 @@
+/*  cpufreq-bench CPUFreq microbenchmark
+ *
+ *  Copyright (C) 2008 Christian Kornacker <ckornacker@suse.de>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <math.h>
+
+#include "config.h"
+#include "system.h"
+#include "benchmark.h"
+
+/* Print out progress if we log into a file */
+#define show_progress(total_time, progress_time)	\
+if (config->output != stdout) {				\
+	fprintf(stdout, "Progress: %02lu %%\r",		\
+		(progress_time * 100) / total_time);	\
+	fflush(stdout);					\
+}
+
+/**
+ * compute how many rounds of calculation we should do
+ * to get the given load time
+ *
+ * @param load aimed load time in µs
+ *
+ * @retval rounds of calculation
+ **/
+
+unsigned int calculate_timespace(long load, struct config *config)
+{
+	int i;
+	long long now, then;
+	unsigned int estimated = GAUGECOUNT;
+	unsigned int rounds = 0;
+	unsigned int timed = 0;
+
+	if (config->verbose)
+		printf("calibrating load of %lius, please wait...\n", load);
+
+	/* get the initial calculation time for a specific number of rounds */
+	now = get_time();
+	ROUNDS(estimated);
+	then = get_time();
+
+	timed = (unsigned int)(then - now);
+
+	/* approximation of the wanted load time by comparing with the
+	 * initial calculation time */
+	for (i = 0; i < 4; i++) {
+		rounds = (unsigned int)(load * estimated / timed);
+		dprintf("calibrating with %u rounds\n", rounds);
+		now = get_time();
+		ROUNDS(rounds);
+		then = get_time();
+
+		timed = (unsigned int)(then - now);
+		estimated = rounds;
+	}
+	if (config->verbose)
+		printf("calibration done\n");
+
+	return estimated;
+}
+
+/**
+ * benchmark
+ * generates a specific sleep an load time with the performance
+ * governor and compares the used time for same calculations done
+ * with the configured powersave governor
+ *
+ * @param config config values for the benchmark
+ *
+ **/
+
+void start_benchmark(struct config *config)
+{
+	unsigned int _round, cycle;
+	long long now, then;
+	long sleep_time = 0, load_time = 0;
+	long performance_time = 0, powersave_time = 0;
+	unsigned int calculations;
+	unsigned long total_time = 0, progress_time = 0;
+
+	sleep_time = config->sleep;
+	load_time = config->load;
+
+	/* For the progress bar */
+	for (_round = 1; _round <= config->rounds; _round++)
+		total_time += _round * (config->sleep + config->load);
+	total_time *= 2; /* powersave and performance cycles */
+
+	for (_round = 0; _round < config->rounds; _round++) {
+		performance_time = 0LL;
+		powersave_time = 0LL;
+
+		show_progress(total_time, progress_time);
+
+		/* set the cpufreq governor to "performance" which disables
+		 * P-State switching. */
+		if (set_cpufreq_governor("performance", config->cpu) != 0)
+			return;
+
+		/* calibrate the calculation time. the resulting calculation
+		 * _rounds should produce a load which matches the configured
+		 * load time */
+		calculations = calculate_timespace(load_time, config);
+
+		if (config->verbose)
+			printf("_round %i: doing %u cycles with %u calculations"
+			       " for %lius\n", _round + 1, config->cycles,
+			       calculations, load_time);
+
+		fprintf(config->output, "%u %li %li ",
+			_round, load_time, sleep_time);
+
+		if (config->verbose)
+			printf("avarage: %lius, rps:%li\n",
+				load_time / calculations,
+				1000000 * calculations / load_time);
+
+		/* do some sleep/load cycles with the performance governor */
+		for (cycle = 0; cycle < config->cycles; cycle++) {
+			now = get_time();
+			usleep(sleep_time);
+			ROUNDS(calculations);
+			then = get_time();
+			performance_time += then - now - sleep_time;
+			if (config->verbose)
+				printf("performance cycle took %lius, "
+					"sleep: %lius, "
+					"load: %lius, rounds: %u\n",
+					(long)(then - now), sleep_time,
+					load_time, calculations);
+		}
+		fprintf(config->output, "%li ",
+			performance_time / config->cycles);
+
+		progress_time += sleep_time + load_time;
+		show_progress(total_time, progress_time);
+
+		/* set the powersave governor which activates P-State switching
+		 * again */
+		if (set_cpufreq_governor(config->governor, config->cpu) != 0)
+			return;
+
+		/* again, do some sleep/load cycles with the
+		 * powersave governor */
+		for (cycle = 0; cycle < config->cycles; cycle++) {
+			now = get_time();
+			usleep(sleep_time);
+			ROUNDS(calculations);
+			then = get_time();
+			powersave_time += then - now - sleep_time;
+			if (config->verbose)
+				printf("powersave cycle took %lius, "
+					"sleep: %lius, "
+					"load: %lius, rounds: %u\n",
+					(long)(then - now), sleep_time,
+					load_time, calculations);
+		}
+
+		progress_time += sleep_time + load_time;
+
+		/* compare the avarage sleep/load cycles  */
+		fprintf(config->output, "%li ",
+			powersave_time / config->cycles);
+		fprintf(config->output, "%.3f\n",
+			performance_time * 100.0 / powersave_time);
+		fflush(config->output);
+
+		if (config->verbose)
+			printf("performance is at %.2f%%\n",
+				performance_time * 100.0 / powersave_time);
+
+		sleep_time += config->sleep_step;
+		load_time += config->load_step;
+	}
+}