[net-next-2.6.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 write_iteration = 50;
module_param(write_iteration, uint, 0644);
MODULE_PARM_DESC(write_iteration, "# of writes between timestamp readings");

static int producer_nice = 19;
static int consumer_nice = 19;

static int producer_fifo = -1;
static int consumer_fifo = -1;

module_param(producer_nice, uint, 0644);
MODULE_PARM_DESC(producer_nice, "nice prio for producer");

module_param(consumer_nice, uint, 0644);
MODULE_PARM_DESC(consumer_nice, "nice prio for consumer");

module_param(producer_fifo, uint, 0644);
MODULE_PARM_DESC(producer_fifo, "fifo prio for producer");

module_param(consumer_fifo, uint, 0644);
MODULE_PARM_DESC(consumer_fifo, "fifo prio for consumer");

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:
				/* failed writes may be discarded events */
				if (!event->time_delta)
					KILL_TEST();
				inc = event->array[0] + 4;
				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] + 4;
				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)
	 */
	trace_printk("Starting ring buffer hammer\n");
	do_gettimeofday(&start_tv);
	do {
		struct ring_buffer_event *event;
		int *entry;
		int i;

		for (i = 0; i < write_iteration; i++) {
			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);
	trace_printk("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)
		trace_printk("ERROR!\n");

	if (!disable_reader) {
		if (consumer_fifo < 0)
			trace_printk("Running Consumer at nice: %d\n",
				     consumer_nice);
		else
			trace_printk("Running Consumer at SCHED_FIFO %d\n",
				     consumer_fifo);
	}
	if (producer_fifo < 0)
		trace_printk("Running Producer at nice: %d\n",
			     producer_nice);
	else
		trace_printk("Running Producer at SCHED_FIFO %d\n",
			     producer_fifo);

	/* Let the user know that the test is running at low priority */
	if (producer_fifo < 0 && consumer_fifo < 0 &&
	    producer_nice == 19 && consumer_nice == 19)
		trace_printk("WARNING!!! This test is running at lowest priority.\n");

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

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

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

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

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

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

		/* it is possible that hit + missed will overflow and be zero */
		if (!(hit + missed)) {
			trace_printk("hit + missed overflowed and totalled zero!\n");
			hit--; /* make it non zero */
		}

		/* Caculate the average time in nanosecs */
		avg = NSEC_PER_MSEC / (hit + missed);
		trace_printk("%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();

		trace_printk("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;

	/*
	 * Run them as low-prio background tasks by default:
	 */
	if (!disable_reader) {
		if (consumer_fifo >= 0) {
			struct sched_param param = {
				.sched_priority = consumer_fifo
			};
			sched_setscheduler(consumer, SCHED_FIFO, &param);
		} else
			set_user_nice(consumer, consumer_nice);
	}

	if (producer_fifo >= 0) {
		struct sched_param param = {
			.sched_priority = consumer_fifo
		};
		sched_setscheduler(producer, SCHED_FIFO, &param);
	} else
		set_user_nice(producer, producer_nice);

	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
a6f0eb6a SR	38	static int write_iteration = 50;
	39	module_param(write_iteration, uint, 0644);
	40	MODULE_PARM_DESC(write_iteration, "# of writes between timestamp readings");
	41
7ac07434 SR	42	static int producer_nice = 19;
	43	static int consumer_nice = 19;
	44
	45	static int producer_fifo = -1;
	46	static int consumer_fifo = -1;
	47
	48	module_param(producer_nice, uint, 0644);
	49	MODULE_PARM_DESC(producer_nice, "nice prio for producer");
	50
	51	module_param(consumer_nice, uint, 0644);
	52	MODULE_PARM_DESC(consumer_nice, "nice prio for consumer");
	53
	54	module_param(producer_fifo, uint, 0644);
	55	MODULE_PARM_DESC(producer_fifo, "fifo prio for producer");
	56
	57	module_param(consumer_fifo, uint, 0644);
	58	MODULE_PARM_DESC(consumer_fifo, "fifo prio for consumer");
	59
5092dbc9 SR	60	static int read_events;
	61
	62	static int kill_test;
	63
	64	#define KILL_TEST() \
	65	do { \
	66	if (!kill_test) { \
	67	kill_test = 1; \
	68	WARN_ON(1); \
	69	} \
	70	} while (0)
	71
	72	enum event_status {
	73	EVENT_FOUND,
	74	EVENT_DROPPED,
	75	};
	76
	77	static enum event_status read_event(int cpu)
	78	{
	79	struct ring_buffer_event *event;
	80	int *entry;
	81	u64 ts;
	82
	83	event = ring_buffer_consume(buffer, cpu, &ts);
	84	if (!event)
	85	return EVENT_DROPPED;
	86
	87	entry = ring_buffer_event_data(event);
	88	if (*entry != cpu) {
	89	KILL_TEST();
	90	return EVENT_DROPPED;
	91	}
	92
	93	read++;
	94	return EVENT_FOUND;
	95	}
	96
	97	static enum event_status read_page(int cpu)
	98	{
	99	struct ring_buffer_event *event;
	100	struct rb_page *rpage;
	101	unsigned long commit;
	102	void *bpage;
	103	int *entry;
	104	int ret;
	105	int inc;
	106	int i;
	107
	108	bpage = ring_buffer_alloc_read_page(buffer);
00c81a58 SR	109	if (!bpage)
	110	return EVENT_DROPPED;
	111
5092dbc9 SR	112	ret = ring_buffer_read_page(buffer, &bpage, PAGE_SIZE, cpu, 1);
	113	if (ret >= 0) {
	114	rpage = bpage;
	115	commit = local_read(&rpage->commit);
	116	for (i = 0; i < commit && !kill_test; i += inc) {
	117
	118	if (i >= (PAGE_SIZE - offsetof(struct rb_page, data))) {
	119	KILL_TEST();
	120	break;
	121	}
	122
	123	inc = -1;
	124	event = (void *)&rpage->data[i];
	125	switch (event->type_len) {
	126	case RINGBUF_TYPE_PADDING:
9086c7b9 SR	127	/* failed writes may be discarded events */
	128	if (!event->time_delta)
	129	KILL_TEST();
	130	inc = event->array[0] + 4;
5092dbc9 SR	131	break;
	132	case RINGBUF_TYPE_TIME_EXTEND:
	133	inc = 8;
	134	break;
	135	case 0:
	136	entry = ring_buffer_event_data(event);
	137	if (*entry != cpu) {
	138	KILL_TEST();
	139	break;
	140	}
	141	read++;
	142	if (!event->array[0]) {
	143	KILL_TEST();
	144	break;
	145	}
9086c7b9	146	inc = event->array[0] + 4;
5092dbc9 SR	147	break;
	148	default:
	149	entry = ring_buffer_event_data(event);
	150	if (*entry != cpu) {
	151	KILL_TEST();
	152	break;
	153	}
	154	read++;
	155	inc = ((event->type_len + 1) * 4);
	156	}
	157	if (kill_test)
	158	break;
	159
	160	if (inc <= 0) {
	161	KILL_TEST();
	162	break;
	163	}
	164	}
	165	}
	166	ring_buffer_free_read_page(buffer, bpage);
	167
	168	if (ret < 0)
	169	return EVENT_DROPPED;
	170	return EVENT_FOUND;
	171	}
	172
	173	static void ring_buffer_consumer(void)
	174	{
	175	/* toggle between reading pages and events */
	176	read_events ^= 1;
	177
	178	read = 0;
	179	while (!reader_finish && !kill_test) {
	180	int found;
	181
	182	do {
	183	int cpu;
	184
	185	found = 0;
	186	for_each_online_cpu(cpu) {
	187	enum event_status stat;
	188
	189	if (read_events)
	190	stat = read_event(cpu);
	191	else
	192	stat = read_page(cpu);
	193
	194	if (kill_test)
	195	break;
	196	if (stat == EVENT_FOUND)
	197	found = 1;
	198	}
	199	} while (found && !kill_test);
	200
	201	set_current_state(TASK_INTERRUPTIBLE);
	202	if (reader_finish)
	203	break;
	204
	205	schedule();
	206	__set_current_state(TASK_RUNNING);
	207	}
	208	reader_finish = 0;
	209	complete(&read_done);
	210	}
211
212	static void ring_buffer_producer(void)
213	{
214	struct timeval start_tv;
215	struct timeval end_tv;
216	unsigned long long time;
217	unsigned long long entries;
218	unsigned long long overruns;
219	unsigned long missed = 0;
220	unsigned long hit = 0;
221	unsigned long avg;
222	int cnt = 0;
223
224	/*
225	* Hammer the buffer for 10 secs (this may
226	* make the system stall)
227	*/
4b221f03	228	trace_printk("Starting ring buffer hammer\n");
5092dbc9 SR	229	do_gettimeofday(&start_tv);
	230	do {
	231	struct ring_buffer_event *event;
	232	int *entry;
a6f0eb6a SR	233	int i;
	234
	235	for (i = 0; i < write_iteration; i++) {
	236	event = ring_buffer_lock_reserve(buffer, 10);
	237	if (!event) {
	238	missed++;
	239	} else {
	240	hit++;
	241	entry = ring_buffer_event_data(event);
	242	*entry = smp_processor_id();
	243	ring_buffer_unlock_commit(buffer, event);
	244	}
5092dbc9 SR	245	}
	246	do_gettimeofday(&end_tv);
	247
0574ea42 SR	248	cnt++;
0574ea42 SR	249	if (consumer && !(cnt % wakeup_interval))
5092dbc9 SR	250	wake_up_process(consumer);
5092dbc9 SR	251
0574ea42	252	#ifndef CONFIG_PREEMPT
29c8000e SR	253	/*
	254	* If we are a non preempt kernel, the 10 second run will
	255	* stop everything while it runs. Instead, we will call
	256	* cond_resched and also add any time that was lost by a
	257	* rescedule.
0574ea42 SR	258	*
	259	* Do a cond resched at the same frequency we would wake up
	260	* the reader.
29c8000e	261	*/
0574ea42 SR	262	if (cnt % wakeup_interval)
	263	cond_resched();
	264	#endif
3e07a4f6	265
5092dbc9	266	} while (end_tv.tv_sec < (start_tv.tv_sec + RUN_TIME) && !kill_test);
4b221f03	267	trace_printk("End ring buffer hammer\n");
5092dbc9 SR	268
	269	if (consumer) {
	270	/* Init both completions here to avoid races */
	271	init_completion(&read_start);
	272	init_completion(&read_done);
	273	/* the completions must be visible before the finish var */
	274	smp_wmb();
	275	reader_finish = 1;
	276	/* finish var visible before waking up the consumer */
	277	smp_wmb();
	278	wake_up_process(consumer);
	279	wait_for_completion(&read_done);
	280	}
	281
	282	time = end_tv.tv_sec - start_tv.tv_sec;
5a772b2b	283	time *= USEC_PER_SEC;
5092dbc9 SR	284	time += (long long)((long)end_tv.tv_usec - (long)start_tv.tv_usec);
	285
	286	entries = ring_buffer_entries(buffer);
	287	overruns = ring_buffer_overruns(buffer);
	288
	289	if (kill_test)
4b221f03	290	trace_printk("ERROR!\n");
7ac07434 SR	291
	292	if (!disable_reader) {
	293	if (consumer_fifo < 0)
	294	trace_printk("Running Consumer at nice: %d\n",
	295	consumer_nice);
	296	else
	297	trace_printk("Running Consumer at SCHED_FIFO %d\n",
	298	consumer_fifo);
	299	}
	300	if (producer_fifo < 0)
	301	trace_printk("Running Producer at nice: %d\n",
	302	producer_nice);
	303	else
	304	trace_printk("Running Producer at SCHED_FIFO %d\n",
	305	producer_fifo);
	306
	307	/* Let the user know that the test is running at low priority */
	308	if (producer_fifo < 0 && consumer_fifo < 0 &&
	309	producer_nice == 19 && consumer_nice == 19)
	310	trace_printk("WARNING!!! This test is running at lowest priority.\n");
	311
4b221f03 SR	312	trace_printk("Time: %lld (usecs)\n", time);
4b221f03 SR	313	trace_printk("Overruns: %lld\n", overruns);
5092dbc9	314	if (disable_reader)
4b221f03	315	trace_printk("Read: (reader disabled)\n");
5092dbc9	316	else
4b221f03	317	trace_printk("Read: %ld (by %s)\n", read,
5092dbc9	318	read_events ? "events" : "pages");
4b221f03 SR	319	trace_printk("Entries: %lld\n", entries);
	320	trace_printk("Total: %lld\n", entries + overruns + read);
	321	trace_printk("Missed: %ld\n", missed);
	322	trace_printk("Hit: %ld\n", hit);
5092dbc9	323
5a772b2b SR	324	/* Convert time from usecs to millisecs */
5a772b2b SR	325	do_div(time, USEC_PER_MSEC);
5092dbc9 SR	326	if (time)
	327	hit /= (long)time;
	328	else
4b221f03	329	trace_printk("TIME IS ZERO??\n");
5092dbc9	330
4b221f03	331	trace_printk("Entries per millisec: %ld\n", hit);
5092dbc9 SR	332
5092dbc9 SR	333	if (hit) {
5a772b2b SR	334	/* Calculate the average time in nanosecs */
5a772b2b SR	335	avg = NSEC_PER_MSEC / hit;
4b221f03	336	trace_printk("%ld ns per entry\n", avg);
5092dbc9	337	}
7da3046d	338
7da3046d SR	339	if (missed) {
	340	if (time)
	341	missed /= (long)time;
	342
4b221f03 SR	343	trace_printk("Total iterations per millisec: %ld\n",
4b221f03 SR	344	hit + missed);
7da3046d	345
d988ff94 SR	346	/* it is possible that hit + missed will overflow and be zero */
d988ff94 SR	347	if (!(hit + missed)) {
4b221f03	348	trace_printk("hit + missed overflowed and totalled zero!\n");
d988ff94 SR	349	hit--; /* make it non zero */
	350	}
	351
5a772b2b SR	352	/* Caculate the average time in nanosecs */
5a772b2b SR	353	avg = NSEC_PER_MSEC / (hit + missed);
4b221f03	354	trace_printk("%ld ns per entry\n", avg);
7da3046d	355	}
5092dbc9 SR	356	}
	357
	358	static void wait_to_die(void)
	359	{
	360	set_current_state(TASK_INTERRUPTIBLE);
	361	while (!kthread_should_stop()) {
	362	schedule();
	363	set_current_state(TASK_INTERRUPTIBLE);
	364	}
	365	__set_current_state(TASK_RUNNING);
	366	}
	367
	368	static int ring_buffer_consumer_thread(void *arg)
	369	{
	370	while (!kthread_should_stop() && !kill_test) {
	371	complete(&read_start);
	372
	373	ring_buffer_consumer();
	374
	375	set_current_state(TASK_INTERRUPTIBLE);
	376	if (kthread_should_stop() \|\| kill_test)
	377	break;
	378
	379	schedule();
	380	__set_current_state(TASK_RUNNING);
	381	}
	382	__set_current_state(TASK_RUNNING);
	383
	384	if (kill_test)
	385	wait_to_die();
	386
	387	return 0;
	388	}
	389
	390	static int ring_buffer_producer_thread(void *arg)
	391	{
	392	init_completion(&read_start);
	393
	394	while (!kthread_should_stop() && !kill_test) {
	395	ring_buffer_reset(buffer);
	396
	397	if (consumer) {
	398	smp_wmb();
	399	wake_up_process(consumer);
	400	wait_for_completion(&read_start);
	401	}
	402
	403	ring_buffer_producer();
	404
4b221f03	405	trace_printk("Sleeping for 10 secs\n");
5092dbc9 SR	406	set_current_state(TASK_INTERRUPTIBLE);
	407	schedule_timeout(HZ * SLEEP_TIME);
	408	__set_current_state(TASK_RUNNING);
	409	}
	410
	411	if (kill_test)
	412	wait_to_die();
	413
	414	return 0;
	415	}
	416
	417	static int __init ring_buffer_benchmark_init(void)
	418	{
	419	int ret;
	420
	421	/* make a one meg buffer in overwite mode */
	422	buffer = ring_buffer_alloc(1000000, RB_FL_OVERWRITE);
	423	if (!buffer)
	424	return -ENOMEM;
	425
	426	if (!disable_reader) {
	427	consumer = kthread_create(ring_buffer_consumer_thread,
	428	NULL, "rb_consumer");
	429	ret = PTR_ERR(consumer);
	430	if (IS_ERR(consumer))
	431	goto out_fail;
	432	}
	433
	434	producer = kthread_run(ring_buffer_producer_thread,
	435	NULL, "rb_producer");
	436	ret = PTR_ERR(producer);
	437
	438	if (IS_ERR(producer))
	439	goto out_kill;
	440
98e4833b IM	441	/*
	442	* Run them as low-prio background tasks by default:
	443	*/
7ac07434 SR	444	if (!disable_reader) {
	445	if (consumer_fifo >= 0) {
	446	struct sched_param param = {
	447	.sched_priority = consumer_fifo
	448	};
	449	sched_setscheduler(consumer, SCHED_FIFO, &param);
	450	} else
	451	set_user_nice(consumer, consumer_nice);
	452	}
	453
	454	if (producer_fifo >= 0) {
	455	struct sched_param param = {
	456	.sched_priority = consumer_fifo
	457	};
	458	sched_setscheduler(producer, SCHED_FIFO, &param);
	459	} else
	460	set_user_nice(producer, producer_nice);
98e4833b	461
5092dbc9 SR	462	return 0;
	463
	464	out_kill:
	465	if (consumer)
	466	kthread_stop(consumer);
	467
	468	out_fail:
	469	ring_buffer_free(buffer);
	470	return ret;
	471	}
	472
	473	static void __exit ring_buffer_benchmark_exit(void)
	474	{
	475	kthread_stop(producer);
	476	if (consumer)
	477	kthread_stop(consumer);
	478	ring_buffer_free(buffer);
	479	}
	480
	481	module_init(ring_buffer_benchmark_init);
	482	module_exit(ring_buffer_benchmark_exit);
	483
	484	MODULE_AUTHOR("Steven Rostedt");
	485	MODULE_DESCRIPTION("ring_buffer_benchmark");
	486	MODULE_LICENSE("GPL");