[mirror_ubuntu-eoan-kernel.git] / kernel / trace / ring_buffer_benchmark.c

/*
 * ring buffer tester and benchmark
 *
 * Copyright (C) 2009 Steven Rostedt <srostedt@redhat.com>
 */
#include <linux/ring_buffer.h>
#include <linux/completion.h>
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/time.h>

struct rb_page {
	u64		ts;
	local_t		commit;
	char		data[4080];
};

/* run time and sleep time in seconds */
#define RUN_TIME	10
#define SLEEP_TIME	10

/* number of events for writer to wake up the reader */
static int wakeup_interval = 100;

static int reader_finish;
static struct completion read_start;
static struct completion read_done;

static struct ring_buffer *buffer;
static struct task_struct *producer;
static struct task_struct *consumer;
static unsigned long read;

static int disable_reader;
module_param(disable_reader, uint, 0644);
MODULE_PARM_DESC(disable_reader, "only run producer");

static int read_events;

static int kill_test;

#define KILL_TEST()				\
	do {					\
		if (!kill_test) {		\
			kill_test = 1;		\
			WARN_ON(1);		\
		}				\
	} while (0)

enum event_status {
	EVENT_FOUND,
	EVENT_DROPPED,
};

static enum event_status read_event(int cpu)
{
	struct ring_buffer_event *event;
	int *entry;
	u64 ts;

	event = ring_buffer_consume(buffer, cpu, &ts);
	if (!event)
		return EVENT_DROPPED;

	entry = ring_buffer_event_data(event);
	if (*entry != cpu) {
		KILL_TEST();
		return EVENT_DROPPED;
	}

	read++;
	return EVENT_FOUND;
}

static enum event_status read_page(int cpu)
{
	struct ring_buffer_event *event;
	struct rb_page *rpage;
	unsigned long commit;
	void *bpage;
	int *entry;
	int ret;
	int inc;
	int i;

	bpage = ring_buffer_alloc_read_page(buffer);
	if (!bpage)
		return EVENT_DROPPED;

	ret = ring_buffer_read_page(buffer, &bpage, PAGE_SIZE, cpu, 1);
	if (ret >= 0) {
		rpage = bpage;
		commit = local_read(&rpage->commit);
		for (i = 0; i < commit && !kill_test; i += inc) {

			if (i >= (PAGE_SIZE - offsetof(struct rb_page, data))) {
				KILL_TEST();
				break;
			}

			inc = -1;
			event = (void *)&rpage->data[i];
			switch (event->type_len) {
			case RINGBUF_TYPE_PADDING:
				/* We don't expect any padding */
				KILL_TEST();
				break;
			case RINGBUF_TYPE_TIME_EXTEND:
				inc = 8;
				break;
			case 0:
				entry = ring_buffer_event_data(event);
				if (*entry != cpu) {
					KILL_TEST();
					break;
				}
				read++;
				if (!event->array[0]) {
					KILL_TEST();
					break;
				}
				inc = event->array[0];
				break;
			default:
				entry = ring_buffer_event_data(event);
				if (*entry != cpu) {
					KILL_TEST();
					break;
				}
				read++;
				inc = ((event->type_len + 1) * 4);
			}
			if (kill_test)
				break;

			if (inc <= 0) {
				KILL_TEST();
				break;
			}
		}
	}
	ring_buffer_free_read_page(buffer, bpage);

	if (ret < 0)
		return EVENT_DROPPED;
	return EVENT_FOUND;
}

static void ring_buffer_consumer(void)
{
	/* toggle between reading pages and events */
	read_events ^= 1;

	read = 0;
	while (!reader_finish && !kill_test) {
		int found;

		do {
			int cpu;

			found = 0;
			for_each_online_cpu(cpu) {
				enum event_status stat;

				if (read_events)
					stat = read_event(cpu);
				else
					stat = read_page(cpu);

				if (kill_test)
					break;
				if (stat == EVENT_FOUND)
					found = 1;
			}
		} while (found && !kill_test);

		set_current_state(TASK_INTERRUPTIBLE);
		if (reader_finish)
			break;

		schedule();
		__set_current_state(TASK_RUNNING);
	}
	reader_finish = 0;
	complete(&read_done);
}

static void ring_buffer_producer(void)
{
	struct timeval start_tv;
	struct timeval end_tv;
	unsigned long long time;
	unsigned long long entries;
	unsigned long long overruns;
	unsigned long missed = 0;
	unsigned long hit = 0;
	unsigned long avg;
	int cnt = 0;

	/*
	 * Hammer the buffer for 10 secs (this may
	 * make the system stall)
	 */
	pr_info("Starting ring buffer hammer\n");
	do_gettimeofday(&start_tv);
	do {
		struct ring_buffer_event *event;
		int *entry;

		event = ring_buffer_lock_reserve(buffer, 10);
		if (!event) {
			missed++;
		} else {
			hit++;
			entry = ring_buffer_event_data(event);
			*entry = smp_processor_id();
			ring_buffer_unlock_commit(buffer, event);
		}
		do_gettimeofday(&end_tv);

		cnt++;
		if (consumer && !(cnt % wakeup_interval))
			wake_up_process(consumer);

#ifndef CONFIG_PREEMPT
		/*
		 * If we are a non preempt kernel, the 10 second run will
		 * stop everything while it runs. Instead, we will call
		 * cond_resched and also add any time that was lost by a
		 * rescedule.
		 *
		 * Do a cond resched at the same frequency we would wake up
		 * the reader.
		 */
		if (cnt % wakeup_interval)
			cond_resched();
#endif

	} while (end_tv.tv_sec < (start_tv.tv_sec + RUN_TIME) && !kill_test);
	pr_info("End ring buffer hammer\n");

	if (consumer) {
		/* Init both completions here to avoid races */
		init_completion(&read_start);
		init_completion(&read_done);
		/* the completions must be visible before the finish var */
		smp_wmb();
		reader_finish = 1;
		/* finish var visible before waking up the consumer */
		smp_wmb();
		wake_up_process(consumer);
		wait_for_completion(&read_done);
	}

	time = end_tv.tv_sec - start_tv.tv_sec;
	time *= USEC_PER_SEC;
	time += (long long)((long)end_tv.tv_usec - (long)start_tv.tv_usec);

	entries = ring_buffer_entries(buffer);
	overruns = ring_buffer_overruns(buffer);

	if (kill_test)
		pr_info("ERROR!\n");
	pr_info("Time:     %lld (usecs)\n", time);
	pr_info("Overruns: %lld\n", overruns);
	if (disable_reader)
		pr_info("Read:     (reader disabled)\n");
	else
		pr_info("Read:     %ld  (by %s)\n", read,
			read_events ? "events" : "pages");
	pr_info("Entries:  %lld\n", entries);
	pr_info("Total:    %lld\n", entries + overruns + read);
	pr_info("Missed:   %ld\n", missed);
	pr_info("Hit:      %ld\n", hit);

	/* Convert time from usecs to millisecs */
	do_div(time, USEC_PER_MSEC);
	if (time)
		hit /= (long)time;
	else
		pr_info("TIME IS ZERO??\n");

	pr_info("Entries per millisec: %ld\n", hit);

	if (hit) {
		/* Calculate the average time in nanosecs */
		avg = NSEC_PER_MSEC / hit;
		pr_info("%ld ns per entry\n", avg);
	}

	if (missed) {
		if (time)
			missed /= (long)time;

		pr_info("Total iterations per millisec: %ld\n", hit + missed);

		/* Caculate the average time in nanosecs */
		avg = NSEC_PER_MSEC / (hit + missed);
		pr_info("%ld ns per entry\n", avg);
	}
}

static void wait_to_die(void)
{
	set_current_state(TASK_INTERRUPTIBLE);
	while (!kthread_should_stop()) {
		schedule();
		set_current_state(TASK_INTERRUPTIBLE);
	}
	__set_current_state(TASK_RUNNING);
}

static int ring_buffer_consumer_thread(void *arg)
{
	while (!kthread_should_stop() && !kill_test) {
		complete(&read_start);

		ring_buffer_consumer();

		set_current_state(TASK_INTERRUPTIBLE);
		if (kthread_should_stop() || kill_test)
			break;

		schedule();
		__set_current_state(TASK_RUNNING);
	}
	__set_current_state(TASK_RUNNING);

	if (kill_test)
		wait_to_die();

	return 0;
}

static int ring_buffer_producer_thread(void *arg)
{
	init_completion(&read_start);

	while (!kthread_should_stop() && !kill_test) {
		ring_buffer_reset(buffer);

		if (consumer) {
			smp_wmb();
			wake_up_process(consumer);
			wait_for_completion(&read_start);
		}

		ring_buffer_producer();

		pr_info("Sleeping for 10 secs\n");
		set_current_state(TASK_INTERRUPTIBLE);
		schedule_timeout(HZ * SLEEP_TIME);
		__set_current_state(TASK_RUNNING);
	}

	if (kill_test)
		wait_to_die();

	return 0;
}

static int __init ring_buffer_benchmark_init(void)
{
	int ret;

	/* make a one meg buffer in overwite mode */
	buffer = ring_buffer_alloc(1000000, RB_FL_OVERWRITE);
	if (!buffer)
		return -ENOMEM;

	if (!disable_reader) {
		consumer = kthread_create(ring_buffer_consumer_thread,
					  NULL, "rb_consumer");
		ret = PTR_ERR(consumer);
		if (IS_ERR(consumer))
			goto out_fail;
	}

	producer = kthread_run(ring_buffer_producer_thread,
			       NULL, "rb_producer");
	ret = PTR_ERR(producer);

	if (IS_ERR(producer))
		goto out_kill;

	return 0;

 out_kill:
	if (consumer)
		kthread_stop(consumer);

 out_fail:
	ring_buffer_free(buffer);
	return ret;
}

static void __exit ring_buffer_benchmark_exit(void)
{
	kthread_stop(producer);
	if (consumer)
		kthread_stop(consumer);
	ring_buffer_free(buffer);
}

module_init(ring_buffer_benchmark_init);
module_exit(ring_buffer_benchmark_exit);

MODULE_AUTHOR("Steven Rostedt");
MODULE_DESCRIPTION("ring_buffer_benchmark");
MODULE_LICENSE("GPL");
Commit	Line	Data
5092dbc9 SR	1	/*
	2	* ring buffer tester and benchmark
	3	*
	4	* Copyright (C) 2009 Steven Rostedt <srostedt@redhat.com>
	5	*/
	6	#include <linux/ring_buffer.h>
	7	#include <linux/completion.h>
	8	#include <linux/kthread.h>
	9	#include <linux/module.h>
	10	#include <linux/time.h>
	11
	12	struct rb_page {
	13	u64 ts;
	14	local_t commit;
	15	char data[4080];
	16	};
	17
	18	/* run time and sleep time in seconds */
	19	#define RUN_TIME 10
	20	#define SLEEP_TIME 10
	21
	22	/* number of events for writer to wake up the reader */
	23	static int wakeup_interval = 100;
	24
	25	static int reader_finish;
	26	static struct completion read_start;
	27	static struct completion read_done;
	28
	29	static struct ring_buffer *buffer;
	30	static struct task_struct *producer;
	31	static struct task_struct *consumer;
	32	static unsigned long read;
	33
	34	static int disable_reader;
	35	module_param(disable_reader, uint, 0644);
	36	MODULE_PARM_DESC(disable_reader, "only run producer");
	37
	38	static int read_events;
	39
	40	static int kill_test;
	41
	42	#define KILL_TEST() \
	43	do { \
	44	if (!kill_test) { \
	45	kill_test = 1; \
	46	WARN_ON(1); \
	47	} \
	48	} while (0)
	49
	50	enum event_status {
	51	EVENT_FOUND,
	52	EVENT_DROPPED,
	53	};
	54
	55	static enum event_status read_event(int cpu)
	56	{
	57	struct ring_buffer_event *event;
	58	int *entry;
	59	u64 ts;
	60
	61	event = ring_buffer_consume(buffer, cpu, &ts);
	62	if (!event)
	63	return EVENT_DROPPED;
	64
65	entry = ring_buffer_event_data(event);
66	if (*entry != cpu) {
67	KILL_TEST();
68	return EVENT_DROPPED;
69	}
70
71	read++;
72	return EVENT_FOUND;
73	}
74
75	static enum event_status read_page(int cpu)
76	{
77	struct ring_buffer_event *event;
78	struct rb_page *rpage;
79	unsigned long commit;
80	void *bpage;
81	int *entry;
82	int ret;
83	int inc;
84	int i;
85
86	bpage = ring_buffer_alloc_read_page(buffer);
00c81a58 SR	87	if (!bpage)
	88	return EVENT_DROPPED;
	89
5092dbc9 SR	90	ret = ring_buffer_read_page(buffer, &bpage, PAGE_SIZE, cpu, 1);
	91	if (ret >= 0) {
	92	rpage = bpage;
	93	commit = local_read(&rpage->commit);
	94	for (i = 0; i < commit && !kill_test; i += inc) {
	95
	96	if (i >= (PAGE_SIZE - offsetof(struct rb_page, data))) {
	97	KILL_TEST();
	98	break;
	99	}
	100
	101	inc = -1;
	102	event = (void *)&rpage->data[i];
	103	switch (event->type_len) {
	104	case RINGBUF_TYPE_PADDING:
	105	/* We don't expect any padding */
	106	KILL_TEST();
	107	break;
	108	case RINGBUF_TYPE_TIME_EXTEND:
	109	inc = 8;
	110	break;
	111	case 0:
	112	entry = ring_buffer_event_data(event);
	113	if (*entry != cpu) {
	114	KILL_TEST();
	115	break;
	116	}
	117	read++;
	118	if (!event->array[0]) {
	119	KILL_TEST();
	120	break;
	121	}
	122	inc = event->array[0];
	123	break;
	124	default:
	125	entry = ring_buffer_event_data(event);
	126	if (*entry != cpu) {
	127	KILL_TEST();
	128	break;
	129	}
	130	read++;
	131	inc = ((event->type_len + 1) * 4);
	132	}
	133	if (kill_test)
	134	break;
	135
	136	if (inc <= 0) {
	137	KILL_TEST();
	138	break;
	139	}
	140	}
	141	}
	142	ring_buffer_free_read_page(buffer, bpage);
	143
	144	if (ret < 0)
	145	return EVENT_DROPPED;
	146	return EVENT_FOUND;
	147	}
	148
	149	static void ring_buffer_consumer(void)
	150	{
	151	/* toggle between reading pages and events */
	152	read_events ^= 1;
	153
154	read = 0;
155	while (!reader_finish && !kill_test) {
156	int found;
157
158	do {
159	int cpu;
160
161	found = 0;
162	for_each_online_cpu(cpu) {
163	enum event_status stat;
164
165	if (read_events)
166	stat = read_event(cpu);
167	else
168	stat = read_page(cpu);
169
170	if (kill_test)
171	break;
172	if (stat == EVENT_FOUND)
173	found = 1;
174	}
175	} while (found && !kill_test);
176
177	set_current_state(TASK_INTERRUPTIBLE);
178	if (reader_finish)
179	break;
180
181	schedule();
182	__set_current_state(TASK_RUNNING);
183	}
184	reader_finish = 0;
185	complete(&read_done);
186	}
187
188	static void ring_buffer_producer(void)
189	{
190	struct timeval start_tv;
191	struct timeval end_tv;
192	unsigned long long time;
193	unsigned long long entries;
194	unsigned long long overruns;
195	unsigned long missed = 0;
196	unsigned long hit = 0;
197	unsigned long avg;
198	int cnt = 0;
199
200	/*
201	* Hammer the buffer for 10 secs (this may
202	* make the system stall)
203	*/
204	pr_info("Starting ring buffer hammer\n");
205	do_gettimeofday(&start_tv);
206	do {
207	struct ring_buffer_event *event;
208	int *entry;
209
210	event = ring_buffer_lock_reserve(buffer, 10);
211	if (!event) {
212	missed++;
213	} else {
214	hit++;
215	entry = ring_buffer_event_data(event);
216	*entry = smp_processor_id();
217	ring_buffer_unlock_commit(buffer, event);
218	}
219	do_gettimeofday(&end_tv);
220
0574ea42 SR	221	cnt++;
0574ea42 SR	222	if (consumer && !(cnt % wakeup_interval))
5092dbc9 SR	223	wake_up_process(consumer);
5092dbc9 SR	224
0574ea42	225	#ifndef CONFIG_PREEMPT
29c8000e SR	226	/*
	227	* If we are a non preempt kernel, the 10 second run will
	228	* stop everything while it runs. Instead, we will call
	229	* cond_resched and also add any time that was lost by a
	230	* rescedule.
0574ea42 SR	231	*
	232	* Do a cond resched at the same frequency we would wake up
	233	* the reader.
29c8000e	234	*/
0574ea42 SR	235	if (cnt % wakeup_interval)
	236	cond_resched();
	237	#endif
3e07a4f6	238
5092dbc9 SR	239	} while (end_tv.tv_sec < (start_tv.tv_sec + RUN_TIME) && !kill_test);
	240	pr_info("End ring buffer hammer\n");
	241
	242	if (consumer) {
	243	/* Init both completions here to avoid races */
	244	init_completion(&read_start);
	245	init_completion(&read_done);
	246	/* the completions must be visible before the finish var */
	247	smp_wmb();
	248	reader_finish = 1;
	249	/* finish var visible before waking up the consumer */
	250	smp_wmb();
	251	wake_up_process(consumer);
	252	wait_for_completion(&read_done);
	253	}
	254
	255	time = end_tv.tv_sec - start_tv.tv_sec;
5a772b2b	256	time *= USEC_PER_SEC;
5092dbc9 SR	257	time += (long long)((long)end_tv.tv_usec - (long)start_tv.tv_usec);
	258
	259	entries = ring_buffer_entries(buffer);
	260	overruns = ring_buffer_overruns(buffer);
	261
	262	if (kill_test)
	263	pr_info("ERROR!\n");
	264	pr_info("Time: %lld (usecs)\n", time);
	265	pr_info("Overruns: %lld\n", overruns);
	266	if (disable_reader)
	267	pr_info("Read: (reader disabled)\n");
	268	else
	269	pr_info("Read: %ld (by %s)\n", read,
	270	read_events ? "events" : "pages");
	271	pr_info("Entries: %lld\n", entries);
	272	pr_info("Total: %lld\n", entries + overruns + read);
	273	pr_info("Missed: %ld\n", missed);
	274	pr_info("Hit: %ld\n", hit);
	275
5a772b2b SR	276	/* Convert time from usecs to millisecs */
5a772b2b SR	277	do_div(time, USEC_PER_MSEC);
5092dbc9 SR	278	if (time)
	279	hit /= (long)time;
	280	else
	281	pr_info("TIME IS ZERO??\n");
	282
	283	pr_info("Entries per millisec: %ld\n", hit);
	284
	285	if (hit) {
5a772b2b SR	286	/* Calculate the average time in nanosecs */
5a772b2b SR	287	avg = NSEC_PER_MSEC / hit;
5092dbc9 SR	288	pr_info("%ld ns per entry\n", avg);
5092dbc9 SR	289	}
7da3046d	290
7da3046d SR	291	if (missed) {
	292	if (time)
	293	missed /= (long)time;
	294
	295	pr_info("Total iterations per millisec: %ld\n", hit + missed);
	296
5a772b2b SR	297	/* Caculate the average time in nanosecs */
5a772b2b SR	298	avg = NSEC_PER_MSEC / (hit + missed);
7da3046d SR	299	pr_info("%ld ns per entry\n", avg);
7da3046d SR	300	}
5092dbc9 SR	301	}
	302
	303	static void wait_to_die(void)
	304	{
	305	set_current_state(TASK_INTERRUPTIBLE);
	306	while (!kthread_should_stop()) {
	307	schedule();
	308	set_current_state(TASK_INTERRUPTIBLE);
	309	}
	310	__set_current_state(TASK_RUNNING);
	311	}
	312
	313	static int ring_buffer_consumer_thread(void *arg)
	314	{
	315	while (!kthread_should_stop() && !kill_test) {
	316	complete(&read_start);
	317
	318	ring_buffer_consumer();
	319
	320	set_current_state(TASK_INTERRUPTIBLE);
	321	if (kthread_should_stop() \|\| kill_test)
	322	break;
	323
	324	schedule();
	325	__set_current_state(TASK_RUNNING);
	326	}
	327	__set_current_state(TASK_RUNNING);
	328
	329	if (kill_test)
	330	wait_to_die();
	331
	332	return 0;
	333	}
	334
	335	static int ring_buffer_producer_thread(void *arg)
	336	{
	337	init_completion(&read_start);
	338
	339	while (!kthread_should_stop() && !kill_test) {
	340	ring_buffer_reset(buffer);
	341
	342	if (consumer) {
	343	smp_wmb();
	344	wake_up_process(consumer);
	345	wait_for_completion(&read_start);
	346	}
	347
	348	ring_buffer_producer();
	349
	350	pr_info("Sleeping for 10 secs\n");
	351	set_current_state(TASK_INTERRUPTIBLE);
	352	schedule_timeout(HZ * SLEEP_TIME);
	353	__set_current_state(TASK_RUNNING);
	354	}
	355
	356	if (kill_test)
	357	wait_to_die();
	358
	359	return 0;
	360	}
	361
	362	static int __init ring_buffer_benchmark_init(void)
	363	{
	364	int ret;
365
366	/* make a one meg buffer in overwite mode */
367	buffer = ring_buffer_alloc(1000000, RB_FL_OVERWRITE);
368	if (!buffer)
369	return -ENOMEM;
370
371	if (!disable_reader) {
372	consumer = kthread_create(ring_buffer_consumer_thread,
373	NULL, "rb_consumer");
374	ret = PTR_ERR(consumer);
375	if (IS_ERR(consumer))
376	goto out_fail;
377	}
378
379	producer = kthread_run(ring_buffer_producer_thread,
380	NULL, "rb_producer");
381	ret = PTR_ERR(producer);
382
383	if (IS_ERR(producer))
384	goto out_kill;
385
386	return 0;
387
388	out_kill:
389	if (consumer)
390	kthread_stop(consumer);
391
392	out_fail:
393	ring_buffer_free(buffer);
394	return ret;
395	}
396
397	static void __exit ring_buffer_benchmark_exit(void)
398	{
399	kthread_stop(producer);
400	if (consumer)
401	kthread_stop(consumer);
402	ring_buffer_free(buffer);
403	}
404
405	module_init(ring_buffer_benchmark_init);
406	module_exit(ring_buffer_benchmark_exit);
407
408	MODULE_AUTHOR("Steven Rostedt");
409	MODULE_DESCRIPTION("ring_buffer_benchmark");
410	MODULE_LICENSE("GPL");