[lttv.git] / trunk / tests / kernel / test-fair-rwlock.c

/* test-fair-rwlock.c
 *
 */

#include <linux/module.h>
#include <linux/proc_fs.h>
#include <linux/sched.h>
#include <linux/timex.h>
#include <linux/fair-rwlock.h>
#include <linux/kthread.h>
#include <linux/delay.h>
#include <linux/hardirq.h>
#include <linux/module.h>
#include <linux/percpu.h>
#include <asm/ptrace.h>

#if (NR_CPUS > 64 && (BITS_PER_LONG == 32 || NR_CPUS > 32768))
#error "fair rwlock needs more bits per long to deal with that many CPUs"
#endif

/* Test duration, in seconds */
#define TEST_DURATION 60

#define THREAD_ROFFSET	1UL
#define THREAD_RMASK	((NR_CPUS - 1) * THREAD_ROFFSET)
#define SOFTIRQ_ROFFSET	(THREAD_RMASK + 1)
#define SOFTIRQ_RMASK	((NR_CPUS - 1) * SOFTIRQ_ROFFSET)
#define HARDIRQ_ROFFSET	((SOFTIRQ_RMASK | THREAD_RMASK) + 1)
#define HARDIRQ_RMASK	((NR_CPUS - 1) * HARDIRQ_ROFFSET)

#define SUBSCRIBERS_WOFFSET	\
	((HARDIRQ_RMASK | SOFTIRQ_RMASK | THREAD_RMASK) + 1)
#define SUBSCRIBERS_WMASK	\
	((NR_CPUS - 1) * SUBSCRIBERS_WOFFSET)
#define WRITER_MUTEX		\
	((SUBSCRIBERS_WMASK | HARDIRQ_RMASK | SOFTIRQ_RMASK | THREAD_RMASK) + 1)
#define SOFTIRQ_WMASK	(WRITER_MUTEX << 1)
#define SOFTIRQ_WOFFSET	SOFTIRQ_WMASK
#define HARDIRQ_WMASK	(SOFTIRQ_WMASK << 1)
#define HARDIRQ_WOFFSET	HARDIRQ_WMASK

#define NR_VARS 100
#define NR_WRITERS 2
#define NR_TRYLOCK_WRITERS 2
#define NR_READERS 4
#define NR_TRYLOCK_READERS 2
#define NR_INTERRUPT_READERS 1
#define NR_TRYLOCK_INTERRUPT_READERS 1

/* Writer iteration delay, in ms. 0 for busy loop. */
#define WRITER_DELAY 1

static int var[NR_VARS];
static struct task_struct *reader_threads[NR_READERS];
static struct task_struct *trylock_reader_threads[NR_TRYLOCK_READERS];
static struct task_struct *writer_threads[NR_WRITERS];
static struct task_struct *trylock_writer_threads[NR_TRYLOCK_WRITERS];
static struct task_struct *interrupt_reader;
static struct task_struct *trylock_interrupt_reader;

static struct fair_rwlock frwlock = {
	.value = ATOMIC_LONG_INIT(0),
};

struct proc_dir_entry *pentry = NULL;

static int reader_thread(void *data)
{
	int i;
	int prev, cur;
	unsigned long iter = 0;
	cycles_t time1, time2, delaymax = 0;

	printk("reader_thread/%lu runnning\n", (unsigned long)data);
	do {
		iter++;
		preempt_disable();	/* for get_cycles accuracy */
		time1 = get_cycles();
		fair_read_lock(&frwlock);
		time2 = get_cycles();
		delaymax = max(delaymax, time2 - time1);
		prev = var[0];
		for (i = 1; i < NR_VARS; i++) {
			cur = var[i];
			if (cur != prev)
				printk(KERN_ALERT
				"Unequal cur %d/prev %d at i %d, iter %lu "
				"in thread\n", cur, prev, i, iter);
		}
		fair_read_unlock(&frwlock);
		preempt_enable();	/* for get_cycles accuracy */
		//msleep(100);
	} while (!kthread_should_stop());
	printk("reader_thread/%lu iterations : %lu, "
		"max contention %llu cycles\n",
		(unsigned long)data, iter, delaymax);
	return 0;
}

static int trylock_reader_thread(void *data)
{
	int i;
	int prev, cur;
	unsigned long iter = 0, success_iter = 0;

	printk("trylock_reader_thread/%lu runnning\n", (unsigned long)data);
	do {
		while (!fair_read_trylock(&frwlock))
			iter++;
		success_iter++;
		prev = var[0];
		for (i = 1; i < NR_VARS; i++) {
			cur = var[i];
			if (cur != prev)
				printk(KERN_ALERT
				"Unequal cur %d/prev %d at i %d, iter %lu "
				"in thread\n", cur, prev, i, iter);
		}
		fair_read_unlock(&frwlock);
		//msleep(100);
	} while (!kthread_should_stop());
	printk("trylock_reader_thread/%lu iterations : %lu, "
		"successful iterations : %lu\n",
		(unsigned long)data, iter, success_iter);
	return 0;
}

DEFINE_PER_CPU(cycles_t, int_delaymax);

static void interrupt_reader_ipi(void *data)
{
	int i;
	int prev, cur;
	cycles_t time1, time2;
	cycles_t *delaymax;

	/*
	 * Skip the ipi caller, not in irq context.
	 */
	if (!in_irq())
		return;

	delaymax = &per_cpu(int_delaymax, smp_processor_id());
	time1 = get_cycles();
	fair_read_lock(&frwlock);
	time2 = get_cycles();
	*delaymax = max(*delaymax, time2 - time1);
	prev = var[0];
	for (i = 1; i < NR_VARS; i++) {
		cur = var[i];
		if (cur != prev)
			printk(KERN_ALERT
			"Unequal cur %d/prev %d at i %d in interrupt\n",
				cur, prev, i);
	}
	fair_read_unlock(&frwlock);
}

DEFINE_PER_CPU(unsigned long, trylock_int_iter);
DEFINE_PER_CPU(unsigned long, trylock_int_success);

static void trylock_interrupt_reader_ipi(void *data)
{
	int i;
	int prev, cur;

	/*
	 * Skip the ipi caller, not in irq context.
	 */
	if (!in_irq())
		return;

	per_cpu(trylock_int_iter, smp_processor_id())++;
	while (!fair_read_trylock(&frwlock))
		per_cpu(trylock_int_iter, smp_processor_id())++;
	per_cpu(trylock_int_success, smp_processor_id())++;
	prev = var[0];
	for (i = 1; i < NR_VARS; i++) {
		cur = var[i];
		if (cur != prev)
			printk(KERN_ALERT
			"Unequal cur %d/prev %d at i %d in interrupt\n",
				cur, prev, i);
	}
	fair_read_unlock(&frwlock);
}


static int interrupt_reader_thread(void *data)
{
	unsigned long iter = 0;
	int i;

	do {
		iter++;
		on_each_cpu(interrupt_reader_ipi, NULL, 0);
		msleep(100);
	} while (!kthread_should_stop());
	printk("interrupt_reader_thread/%lu iterations : %lu\n",
			(unsigned long)data, iter);
	for_each_online_cpu(i) {
		printk("interrupt readers on CPU %i, "
			"max contention : %llu cycles\n",
			i, per_cpu(int_delaymax, i));
	}
	return 0;
}

static int trylock_interrupt_reader_thread(void *data)
{
	unsigned long iter = 0;
	int i;

	do {
		iter++;
		on_each_cpu(trylock_interrupt_reader_ipi, NULL, 0);
		msleep(100);
	} while (!kthread_should_stop());
	printk("trylock_interrupt_reader_thread/%lu iterations : %lu\n",
			(unsigned long)data, iter);
	for_each_online_cpu(i) {
		printk("trylock interrupt readers on CPU %i, "
			"iterations %lu, "
			"successful iterations : %lu\n",
			i, per_cpu(trylock_int_iter, i),
			per_cpu(trylock_int_success, i));
	}
	return 0;
}

static int writer_thread(void *data)
{
	int i;
	int new;
	unsigned long iter = 0;
	cycles_t time1, time2, delaymax = 0;

	printk("writer_thread/%lu runnning\n", (unsigned long)data);
	do {
		iter++;
		preempt_disable();	/* for get_cycles accuracy */
		time1 = get_cycles();
		fair_write_lock_irq(&frwlock);
		//fair_write_lock(&frwlock);
		time2 = get_cycles();
		delaymax = max(delaymax, time2 - time1);
		new = (int)get_cycles();
		for (i = 0; i < NR_VARS; i++) {
			var[i] = new;
		}
		//fair_write_unlock(&frwlock);
		fair_write_unlock_irq(&frwlock);
		preempt_enable();	/* for get_cycles accuracy */
		if (WRITER_DELAY > 0)
			msleep(WRITER_DELAY);
	} while (!kthread_should_stop());
	printk("writer_thread/%lu iterations : %lu, "
		"max contention %llu cycles\n",
		(unsigned long)data, iter, delaymax);
	return 0;
}

static int trylock_writer_thread(void *data)
{
	int i;
	int new;
	unsigned long iter = 0, success = 0;

	printk("trylock_writer_thread/%lu runnning\n", (unsigned long)data);
	do {
		fair_write_subscribe(&frwlock);
		while (!fair_write_trylock_subscribed_irq(&frwlock)) {
			iter++;
			continue;
		}
		success++;
		//fair_write_lock(&frwlock);
		new = (int)get_cycles();
		for (i = 0; i < NR_VARS; i++) {
			var[i] = new;
		}
		//fair_write_unlock(&frwlock);
		fair_write_unlock_irq(&frwlock);
		if (WRITER_DELAY > 0)
			msleep(WRITER_DELAY);
	} while (!kthread_should_stop());
	printk("trylock_writer_thread/%lu iterations : %lu, "
		"successful iterations : %lu\n",
		(unsigned long)data, iter, success);
	return 0;
}

static void fair_rwlock_create(void)
{
	unsigned long i;

	for (i = 0; i < NR_READERS; i++) {
		printk("starting reader thread %lu\n", i);
		reader_threads[i] = kthread_run(reader_thread, (void *)i,
			"frwlock_reader");
		BUG_ON(!reader_threads[i]);
	}

	for (i = 0; i < NR_TRYLOCK_READERS; i++) {
		printk("starting trylock reader thread %lu\n", i);
		trylock_reader_threads[i] = kthread_run(trylock_reader_thread,
			(void *)i, "frwlock_trylock_reader");
		BUG_ON(!trylock_reader_threads[i]);
	}


	printk("starting interrupt reader %lu\n", i);
	interrupt_reader = kthread_run(interrupt_reader_thread, NULL,
		"frwlock_interrupt_reader");
	printk("starting trylock interrupt reader %lu\n", i);
	trylock_interrupt_reader = kthread_run(trylock_interrupt_reader_thread,
		NULL, "frwlock_trylock_interrupt_reader");

	for (i = 0; i < NR_WRITERS; i++) {
		printk("starting writer thread %lu\n", i);
		writer_threads[i] = kthread_run(writer_thread, (void *)i,
			"frwlock_writer");
		BUG_ON(!writer_threads[i]);
	}
	for (i = 0; i < NR_TRYLOCK_WRITERS; i++) {
		printk("starting trylock writer thread %lu\n", i);
		trylock_writer_threads[i] = kthread_run(trylock_writer_thread,
			(void *)i, "frwlock_trylock_writer");
		BUG_ON(!trylock_writer_threads[i]);
	}

}

static void fair_rwlock_stop(void)
{
	unsigned long i;

	for (i = 0; i < NR_WRITERS; i++)
		kthread_stop(writer_threads[i]);
	for (i = 0; i < NR_TRYLOCK_WRITERS; i++)
		kthread_stop(trylock_writer_threads[i]);
	for (i = 0; i < NR_READERS; i++)
		kthread_stop(reader_threads[i]);
	for (i = 0; i < NR_TRYLOCK_READERS; i++)
		kthread_stop(trylock_reader_threads[i]);
	kthread_stop(interrupt_reader);
	kthread_stop(trylock_interrupt_reader);
}


static void perform_test(const char *name, void (*callback)(void))
{
	printk("%s\n", name);
	callback();
}

static int my_open(struct inode *inode, struct file *file)
{
	perform_test("fair-rwlock-create", fair_rwlock_create);
	ssleep(TEST_DURATION);
	perform_test("fair-rwlock-stop", fair_rwlock_stop);

	return -EPERM;
}


static struct file_operations my_operations = {
	.open = my_open,
};

int init_module(void)
{
	pentry = create_proc_entry("testfrwlock", 0444, NULL);
	if (pentry)
		pentry->proc_fops = &my_operations;

	printk("NR_CPUS : %d\n", NR_CPUS);
	printk("THREAD_ROFFSET : %lX\n", THREAD_ROFFSET);
	printk("THREAD_RMASK : %lX\n", THREAD_RMASK);
	printk("SOFTIRQ_ROFFSET : %lX\n", SOFTIRQ_ROFFSET);
	printk("SOFTIRQ_RMASK : %lX\n", SOFTIRQ_RMASK);
	printk("HARDIRQ_ROFFSET : %lX\n", HARDIRQ_ROFFSET);
	printk("HARDIRQ_RMASK : %lX\n", HARDIRQ_RMASK);
	printk("SUBSCRIBERS_WOFFSET : %lX\n", SUBSCRIBERS_WOFFSET);
	printk("SUBSCRIBERS_WMASK : %lX\n", SUBSCRIBERS_WMASK);
	printk("WRITER_MUTEX : %lX\n", WRITER_MUTEX);
	printk("SOFTIRQ_WMASK : %lX\n", SOFTIRQ_WMASK);
	printk("HARDIRQ_WMASK : %lX\n", HARDIRQ_WMASK);

	return 0;
}

void cleanup_module(void)
{
	remove_proc_entry("testfrwlock", NULL);
}

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Mathieu Desnoyers");
MODULE_DESCRIPTION("Fair rwlock test");
Commit	Line	Data
f0a36bb1	1	/* test-fair-rwlock.c
	2	*
	3	*/
	4
	5	#include <linux/module.h>
	6	#include <linux/proc_fs.h>
	7	#include <linux/sched.h>
	8	#include <linux/timex.h>
	9	#include <linux/fair-rwlock.h>
	10	#include <linux/kthread.h>
	11	#include <linux/delay.h>
	12	#include <linux/hardirq.h>
	13	#include <linux/module.h>
7f563886	14	#include <linux/percpu.h>
f0a36bb1	15	#include <asm/ptrace.h>
f0a36bb1	16
7f563886	17	#if (NR_CPUS > 64 && (BITS_PER_LONG == 32 \|\| NR_CPUS > 32768))
f0a36bb1	18	#error "fair rwlock needs more bits per long to deal with that many CPUs"
	19	#endif
	20
89889f86	21	/* Test duration, in seconds */
f36c4112	22	#define TEST_DURATION 60
89889f86	23
f0a36bb1	24	#define THREAD_ROFFSET 1UL
	25	#define THREAD_RMASK ((NR_CPUS - 1) * THREAD_ROFFSET)
	26	#define SOFTIRQ_ROFFSET (THREAD_RMASK + 1)
	27	#define SOFTIRQ_RMASK ((NR_CPUS - 1) * SOFTIRQ_ROFFSET)
	28	#define HARDIRQ_ROFFSET ((SOFTIRQ_RMASK \| THREAD_RMASK) + 1)
	29	#define HARDIRQ_RMASK ((NR_CPUS - 1) * HARDIRQ_ROFFSET)
	30
7f563886	31	#define SUBSCRIBERS_WOFFSET \
	32	((HARDIRQ_RMASK \| SOFTIRQ_RMASK \| THREAD_RMASK) + 1)
	33	#define SUBSCRIBERS_WMASK \
	34	((NR_CPUS - 1) * SUBSCRIBERS_WOFFSET)
	35	#define WRITER_MUTEX \
	36	((SUBSCRIBERS_WMASK \| HARDIRQ_RMASK \| SOFTIRQ_RMASK \| THREAD_RMASK) + 1)
	37	#define SOFTIRQ_WMASK (WRITER_MUTEX << 1)
	38	#define SOFTIRQ_WOFFSET SOFTIRQ_WMASK
426d6b67	39	#define HARDIRQ_WMASK (SOFTIRQ_WMASK << 1)
7f563886	40	#define HARDIRQ_WOFFSET HARDIRQ_WMASK
f0a36bb1	41
f0a36bb1	42	#define NR_VARS 100
1c21e42c	43	#define NR_WRITERS 2
	44	#define NR_TRYLOCK_WRITERS 2
	45	#define NR_READERS 4
	46	#define NR_TRYLOCK_READERS 2
	47	#define NR_INTERRUPT_READERS 1
	48	#define NR_TRYLOCK_INTERRUPT_READERS 1
f0a36bb1	49
89889f86	50	/* Writer iteration delay, in ms. 0 for busy loop. */
1c21e42c	51	#define WRITER_DELAY 1
89889f86	52
f0a36bb1	53	static int var[NR_VARS];
f0a36bb1	54	static struct task_struct *reader_threads[NR_READERS];
1c21e42c	55	static struct task_struct *trylock_reader_threads[NR_TRYLOCK_READERS];
f0a36bb1	56	static struct task_struct *writer_threads[NR_WRITERS];
1c21e42c	57	static struct task_struct *trylock_writer_threads[NR_TRYLOCK_WRITERS];
f0a36bb1	58	static struct task_struct *interrupt_reader;
1c21e42c	59	static struct task_struct *trylock_interrupt_reader;
f0a36bb1	60
	61	static struct fair_rwlock frwlock = {
	62	.value = ATOMIC_LONG_INIT(0),
f0a36bb1	63	};
	64
	65	struct proc_dir_entry *pentry = NULL;
	66
	67	static int reader_thread(void *data)
	68	{
	69	int i;
	70	int prev, cur;
	71	unsigned long iter = 0;
7f563886	72	cycles_t time1, time2, delaymax = 0;
f0a36bb1	73
	74	printk("reader_thread/%lu runnning\n", (unsigned long)data);
	75	do {
	76	iter++;
7f563886	77	preempt_disable(); /* for get_cycles accuracy */
7f563886	78	time1 = get_cycles();
f0a36bb1	79	fair_read_lock(&frwlock);
7f563886	80	time2 = get_cycles();
7f563886	81	delaymax = max(delaymax, time2 - time1);
f0a36bb1	82	prev = var[0];
	83	for (i = 1; i < NR_VARS; i++) {
	84	cur = var[i];
	85	if (cur != prev)
	86	printk(KERN_ALERT
	87	"Unequal cur %d/prev %d at i %d, iter %lu "
	88	"in thread\n", cur, prev, i, iter);
	89	}
	90	fair_read_unlock(&frwlock);
7f563886	91	preempt_enable(); /* for get_cycles accuracy */
f0a36bb1	92	//msleep(100);
f0a36bb1	93	} while (!kthread_should_stop());
7f563886	94	printk("reader_thread/%lu iterations : %lu, "
	95	"max contention %llu cycles\n",
	96	(unsigned long)data, iter, delaymax);
f0a36bb1	97	return 0;
	98	}
	99
1c21e42c	100	static int trylock_reader_thread(void *data)
	101	{
	102	int i;
	103	int prev, cur;
	104	unsigned long iter = 0, success_iter = 0;
	105
	106	printk("trylock_reader_thread/%lu runnning\n", (unsigned long)data);
	107	do {
	108	while (!fair_read_trylock(&frwlock))
	109	iter++;
	110	success_iter++;
	111	prev = var[0];
	112	for (i = 1; i < NR_VARS; i++) {
	113	cur = var[i];
	114	if (cur != prev)
	115	printk(KERN_ALERT
	116	"Unequal cur %d/prev %d at i %d, iter %lu "
	117	"in thread\n", cur, prev, i, iter);
	118	}
	119	fair_read_unlock(&frwlock);
	120	//msleep(100);
	121	} while (!kthread_should_stop());
	122	printk("trylock_reader_thread/%lu iterations : %lu, "
	123	"successful iterations : %lu\n",
	124	(unsigned long)data, iter, success_iter);
	125	return 0;
	126	}
	127
7f563886	128	DEFINE_PER_CPU(cycles_t, int_delaymax);
7f563886	129
f0a36bb1	130	static void interrupt_reader_ipi(void *data)
	131	{
	132	int i;
	133	int prev, cur;
7f563886	134	cycles_t time1, time2;
	135	cycles_t *delaymax;
	136
	137	/*
	138	* Skip the ipi caller, not in irq context.
	139	*/
	140	if (!in_irq())
	141	return;
f0a36bb1	142
7f563886	143	delaymax = &per_cpu(int_delaymax, smp_processor_id());
7f563886	144	time1 = get_cycles();
f0a36bb1	145	fair_read_lock(&frwlock);
7f563886	146	time2 = get_cycles();
7f563886	147	delaymax = max(delaymax, time2 - time1);
f0a36bb1	148	prev = var[0];
	149	for (i = 1; i < NR_VARS; i++) {
	150	cur = var[i];
	151	if (cur != prev)
	152	printk(KERN_ALERT
	153	"Unequal cur %d/prev %d at i %d in interrupt\n",
	154	cur, prev, i);
	155	}
	156	fair_read_unlock(&frwlock);
	157	}
	158
1c21e42c	159	DEFINE_PER_CPU(unsigned long, trylock_int_iter);
	160	DEFINE_PER_CPU(unsigned long, trylock_int_success);
	161
	162	static void trylock_interrupt_reader_ipi(void *data)
	163	{
	164	int i;
	165	int prev, cur;
	166
	167	/*
	168	* Skip the ipi caller, not in irq context.
	169	*/
	170	if (!in_irq())
	171	return;
	172
	173	per_cpu(trylock_int_iter, smp_processor_id())++;
	174	while (!fair_read_trylock(&frwlock))
	175	per_cpu(trylock_int_iter, smp_processor_id())++;
	176	per_cpu(trylock_int_success, smp_processor_id())++;
	177	prev = var[0];
	178	for (i = 1; i < NR_VARS; i++) {
	179	cur = var[i];
	180	if (cur != prev)
	181	printk(KERN_ALERT
	182	"Unequal cur %d/prev %d at i %d in interrupt\n",
	183	cur, prev, i);
	184	}
	185	fair_read_unlock(&frwlock);
	186	}
	187
	188
f0a36bb1	189	static int interrupt_reader_thread(void *data)
	190	{
	191	unsigned long iter = 0;
7f563886	192	int i;
7f563886	193
f0a36bb1	194	do {
	195	iter++;
	196	on_each_cpu(interrupt_reader_ipi, NULL, 0);
	197	msleep(100);
	198	} while (!kthread_should_stop());
	199	printk("interrupt_reader_thread/%lu iterations : %lu\n",
	200	(unsigned long)data, iter);
7f563886	201	for_each_online_cpu(i) {
	202	printk("interrupt readers on CPU %i, "
	203	"max contention : %llu cycles\n",
	204	i, per_cpu(int_delaymax, i));
	205	}
f0a36bb1	206	return 0;
	207	}
	208
1c21e42c	209	static int trylock_interrupt_reader_thread(void *data)
	210	{
	211	unsigned long iter = 0;
	212	int i;
	213
	214	do {
	215	iter++;
	216	on_each_cpu(trylock_interrupt_reader_ipi, NULL, 0);
	217	msleep(100);
	218	} while (!kthread_should_stop());
	219	printk("trylock_interrupt_reader_thread/%lu iterations : %lu\n",
	220	(unsigned long)data, iter);
	221	for_each_online_cpu(i) {
	222	printk("trylock interrupt readers on CPU %i, "
	223	"iterations %lu, "
	224	"successful iterations : %lu\n",
	225	i, per_cpu(trylock_int_iter, i),
	226	per_cpu(trylock_int_success, i));
	227	}
	228	return 0;
	229	}
	230
f0a36bb1	231	static int writer_thread(void *data)
	232	{
	233	int i;
	234	int new;
	235	unsigned long iter = 0;
7f563886	236	cycles_t time1, time2, delaymax = 0;
f0a36bb1	237
	238	printk("writer_thread/%lu runnning\n", (unsigned long)data);
	239	do {
	240	iter++;
7f563886	241	preempt_disable(); /* for get_cycles accuracy */
7f563886	242	time1 = get_cycles();
f0a36bb1	243	fair_write_lock_irq(&frwlock);
f0a36bb1	244	//fair_write_lock(&frwlock);
7f563886	245	time2 = get_cycles();
7f563886	246	delaymax = max(delaymax, time2 - time1);
f0a36bb1	247	new = (int)get_cycles();
	248	for (i = 0; i < NR_VARS; i++) {
	249	var[i] = new;
	250	}
	251	//fair_write_unlock(&frwlock);
	252	fair_write_unlock_irq(&frwlock);
7f563886	253	preempt_enable(); /* for get_cycles accuracy */
89889f86	254	if (WRITER_DELAY > 0)
89889f86	255	msleep(WRITER_DELAY);
f0a36bb1	256	} while (!kthread_should_stop());
7f563886	257	printk("writer_thread/%lu iterations : %lu, "
	258	"max contention %llu cycles\n",
	259	(unsigned long)data, iter, delaymax);
f0a36bb1	260	return 0;
	261	}
	262
1c21e42c	263	static int trylock_writer_thread(void *data)
	264	{
	265	int i;
	266	int new;
	267	unsigned long iter = 0, success = 0;
	268
	269	printk("trylock_writer_thread/%lu runnning\n", (unsigned long)data);
	270	do {
	271	fair_write_subscribe(&frwlock);
	272	while (!fair_write_trylock_subscribed_irq(&frwlock)) {
	273	iter++;
	274	continue;
	275	}
	276	success++;
	277	//fair_write_lock(&frwlock);
	278	new = (int)get_cycles();
	279	for (i = 0; i < NR_VARS; i++) {
	280	var[i] = new;
	281	}
	282	//fair_write_unlock(&frwlock);
	283	fair_write_unlock_irq(&frwlock);
	284	if (WRITER_DELAY > 0)
	285	msleep(WRITER_DELAY);
	286	} while (!kthread_should_stop());
	287	printk("trylock_writer_thread/%lu iterations : %lu, "
	288	"successful iterations : %lu\n",
	289	(unsigned long)data, iter, success);
	290	return 0;
	291	}
	292
f0a36bb1	293	static void fair_rwlock_create(void)
	294	{
	295	unsigned long i;
	296
	297	for (i = 0; i < NR_READERS; i++) {
	298	printk("starting reader thread %lu\n", i);
	299	reader_threads[i] = kthread_run(reader_thread, (void *)i,
	300	"frwlock_reader");
	301	BUG_ON(!reader_threads[i]);
	302	}
	303
1c21e42c	304	for (i = 0; i < NR_TRYLOCK_READERS; i++) {
	305	printk("starting trylock reader thread %lu\n", i);
	306	trylock_reader_threads[i] = kthread_run(trylock_reader_thread,
	307	(void *)i, "frwlock_trylock_reader");
	308	BUG_ON(!trylock_reader_threads[i]);
	309	}
	310
	311
f0a36bb1	312	printk("starting interrupt reader %lu\n", i);
	313	interrupt_reader = kthread_run(interrupt_reader_thread, NULL,
	314	"frwlock_interrupt_reader");
1c21e42c	315	printk("starting trylock interrupt reader %lu\n", i);
	316	trylock_interrupt_reader = kthread_run(trylock_interrupt_reader_thread,
	317	NULL, "frwlock_trylock_interrupt_reader");
f0a36bb1	318
	319	for (i = 0; i < NR_WRITERS; i++) {
	320	printk("starting writer thread %lu\n", i);
	321	writer_threads[i] = kthread_run(writer_thread, (void *)i,
	322	"frwlock_writer");
	323	BUG_ON(!writer_threads[i]);
	324	}
1c21e42c	325	for (i = 0; i < NR_TRYLOCK_WRITERS; i++) {
	326	printk("starting trylock writer thread %lu\n", i);
	327	trylock_writer_threads[i] = kthread_run(trylock_writer_thread,
	328	(void *)i, "frwlock_trylock_writer");
	329	BUG_ON(!trylock_writer_threads[i]);
	330	}
	331
f0a36bb1	332	}
	333
	334	static void fair_rwlock_stop(void)
	335	{
	336	unsigned long i;
	337
1c21e42c	338	for (i = 0; i < NR_WRITERS; i++)
7f563886	339	kthread_stop(writer_threads[i]);
1c21e42c	340	for (i = 0; i < NR_TRYLOCK_WRITERS; i++)
	341	kthread_stop(trylock_writer_threads[i]);
	342	for (i = 0; i < NR_READERS; i++)
f0a36bb1	343	kthread_stop(reader_threads[i]);
1c21e42c	344	for (i = 0; i < NR_TRYLOCK_READERS; i++)
1c21e42c	345	kthread_stop(trylock_reader_threads[i]);
7f563886	346	kthread_stop(interrupt_reader);
1c21e42c	347	kthread_stop(trylock_interrupt_reader);
f0a36bb1	348	}
	349
	350
	351	static void perform_test(const char name, void (callback)(void))
	352	{
	353	printk("%s\n", name);
	354	callback();
	355	}
	356
	357	static int my_open(struct inode inode, struct file file)
	358	{
	359	perform_test("fair-rwlock-create", fair_rwlock_create);
f36c4112	360	ssleep(TEST_DURATION);
f0a36bb1	361	perform_test("fair-rwlock-stop", fair_rwlock_stop);
	362
	363	return -EPERM;
	364	}
	365
	366
	367	static struct file_operations my_operations = {
	368	.open = my_open,
	369	};
	370
	371	int init_module(void)
	372	{
	373	pentry = create_proc_entry("testfrwlock", 0444, NULL);
	374	if (pentry)
	375	pentry->proc_fops = &my_operations;
	376
	377	printk("NR_CPUS : %d\n", NR_CPUS);
	378	printk("THREAD_ROFFSET : %lX\n", THREAD_ROFFSET);
	379	printk("THREAD_RMASK : %lX\n", THREAD_RMASK);
f0a36bb1	380	printk("SOFTIRQ_ROFFSET : %lX\n", SOFTIRQ_ROFFSET);
f0a36bb1	381	printk("SOFTIRQ_RMASK : %lX\n", SOFTIRQ_RMASK);
f0a36bb1	382	printk("HARDIRQ_ROFFSET : %lX\n", HARDIRQ_ROFFSET);
f0a36bb1	383	printk("HARDIRQ_RMASK : %lX\n", HARDIRQ_RMASK);
7f563886	384	printk("SUBSCRIBERS_WOFFSET : %lX\n", SUBSCRIBERS_WOFFSET);
	385	printk("SUBSCRIBERS_WMASK : %lX\n", SUBSCRIBERS_WMASK);
	386	printk("WRITER_MUTEX : %lX\n", WRITER_MUTEX);
	387	printk("SOFTIRQ_WMASK : %lX\n", SOFTIRQ_WMASK);
f0a36bb1	388	printk("HARDIRQ_WMASK : %lX\n", HARDIRQ_WMASK);
	389
	390	return 0;
	391	}
	392
	393	void cleanup_module(void)
	394	{
	395	remove_proc_entry("testfrwlock", NULL);
	396	}
	397
	398	MODULE_LICENSE("GPL");
	399	MODULE_AUTHOR("Mathieu Desnoyers");
	400	MODULE_DESCRIPTION("Fair rwlock test");