[fio.git] / gettime.c

/*
 * Clock functions
 */

#include <unistd.h>
#include <math.h>
#include <sys/time.h>
#include <time.h>

#include "fio.h"
#include "smalloc.h"

#include "hash.h"
#include "os/os.h"

#if defined(ARCH_HAVE_CPU_CLOCK) && !defined(ARCH_CPU_CLOCK_CYCLES_PER_USEC)
static unsigned long cycles_per_usec;
static unsigned long inv_cycles_per_usec;
#endif
int tsc_reliable = 0;

struct tv_valid {
	uint64_t last_cycles;
	uint64_t last_tv_valid;
};
#ifdef CONFIG_TLS_THREAD
static __thread struct tv_valid static_tv_valid;
#else
static pthread_key_t tv_tls_key;
#endif

enum fio_cs fio_clock_source = FIO_PREFERRED_CLOCK_SOURCE;
int fio_clock_source_set = 0;
static enum fio_cs fio_clock_source_inited = CS_INVAL;

#ifdef FIO_DEBUG_TIME

#define HASH_BITS	8
#define HASH_SIZE	(1 << HASH_BITS)

static struct flist_head hash[HASH_SIZE];
static int gtod_inited;

struct gtod_log {
	struct flist_head list;
	void *caller;
	unsigned long calls;
};

static struct gtod_log *find_hash(void *caller)
{
	unsigned long h = hash_ptr(caller, HASH_BITS);
	struct flist_head *entry;

	flist_for_each(entry, &hash[h]) {
		struct gtod_log *log = flist_entry(entry, struct gtod_log,
									list);

		if (log->caller == caller)
			return log;
	}

	return NULL;
}

static struct gtod_log *find_log(void *caller)
{
	struct gtod_log *log = find_hash(caller);

	if (!log) {
		unsigned long h;

		log = malloc(sizeof(*log));
		INIT_FLIST_HEAD(&log->list);
		log->caller = caller;
		log->calls = 0;

		h = hash_ptr(caller, HASH_BITS);
		flist_add_tail(&log->list, &hash[h]);
	}

	return log;
}

static void gtod_log_caller(void *caller)
{
	if (gtod_inited) {
		struct gtod_log *log = find_log(caller);

		log->calls++;
	}
}

static void fio_exit fio_dump_gtod(void)
{
	unsigned long total_calls = 0;
	int i;

	for (i = 0; i < HASH_SIZE; i++) {
		struct flist_head *entry;
		struct gtod_log *log;

		flist_for_each(entry, &hash[i]) {
			log = flist_entry(entry, struct gtod_log, list);

			printf("function %p, calls %lu\n", log->caller,
								log->calls);
			total_calls += log->calls;
		}
	}

	printf("Total %lu gettimeofday\n", total_calls);
}

static void fio_init gtod_init(void)
{
	int i;

	for (i = 0; i < HASH_SIZE; i++)
		INIT_FLIST_HEAD(&hash[i]);

	gtod_inited = 1;
}

#endif /* FIO_DEBUG_TIME */

#ifdef CONFIG_CLOCK_GETTIME
static int fill_clock_gettime(struct timespec *ts)
{
#ifdef CONFIG_CLOCK_MONOTONIC
	return clock_gettime(CLOCK_MONOTONIC, ts);
#else
	return clock_gettime(CLOCK_REALTIME, ts);
#endif
}
#endif

static void __fio_gettime(struct timeval *tp)
{
	struct tv_valid *tv;

#ifdef CONFIG_TLS_THREAD
	tv = &static_tv_valid;
#else
	tv = pthread_getspecific(tv_tls_key);
#endif

	switch (fio_clock_source) {
#ifdef CONFIG_GETTIMEOFDAY
	case CS_GTOD:
		gettimeofday(tp, NULL);
		break;
#endif
#ifdef CONFIG_CLOCK_GETTIME
	case CS_CGETTIME: {
		struct timespec ts;

		if (fill_clock_gettime(&ts) < 0) {
			log_err("fio: clock_gettime fails\n");
			assert(0);
		}

		tp->tv_sec = ts.tv_sec;
		tp->tv_usec = ts.tv_nsec / 1000;
		break;
		}
#endif
#ifdef ARCH_HAVE_CPU_CLOCK
	case CS_CPUCLOCK: {
		uint64_t usecs, t;

		t = get_cpu_clock();
		if (t < tv->last_cycles && tv->last_tv_valid)
			log_err("fio: CPU clock going back in time\n");

		tv->last_cycles = t;
		tv->last_tv_valid = 1;
#ifdef ARCH_CPU_CLOCK_CYCLES_PER_USEC
		usecs = t / ARCH_CPU_CLOCK_CYCLES_PER_USEC;
#else
		usecs = (t * inv_cycles_per_usec) / 16777216UL;
#endif
		tp->tv_sec = usecs / 1000000;
		tp->tv_usec = usecs % 1000000;
		break;
		}
#endif
	default:
		log_err("fio: invalid clock source %d\n", fio_clock_source);
		break;
	}
}

#ifdef FIO_DEBUG_TIME
void fio_gettime(struct timeval *tp, void *caller)
#else
void fio_gettime(struct timeval *tp, void fio_unused *caller)
#endif
{
#ifdef FIO_DEBUG_TIME
	if (!caller)
		caller = __builtin_return_address(0);

	gtod_log_caller(caller);
#endif
	if (fio_unlikely(fio_tv)) {
		memcpy(tp, fio_tv, sizeof(*tp));
		return;
	}

	__fio_gettime(tp);
}

#if defined(ARCH_HAVE_CPU_CLOCK) && !defined(ARCH_CPU_CLOCK_CYCLES_PER_USEC)
static unsigned long get_cycles_per_usec(void)
{
	struct timeval s, e;
	uint64_t c_s, c_e;
	enum fio_cs old_cs = fio_clock_source;

#ifdef CONFIG_CLOCK_GETTIME
	fio_clock_source = CS_CGETTIME;
#else
	fio_clock_source = CS_GTOD;
#endif
	__fio_gettime(&s);

	c_s = get_cpu_clock();
	do {
		uint64_t elapsed;

		__fio_gettime(&e);

		elapsed = utime_since(&s, &e);
		if (elapsed >= 1280) {
			c_e = get_cpu_clock();
			break;
		}
	} while (1);

	fio_clock_source = old_cs;
	return (c_e - c_s + 127) >> 7;
}

#define NR_TIME_ITERS	50

static int calibrate_cpu_clock(void)
{
	double delta, mean, S;
	uint64_t avg, cycles[NR_TIME_ITERS];
	int i, samples;

	cycles[0] = get_cycles_per_usec();
	S = delta = mean = 0.0;
	for (i = 0; i < NR_TIME_ITERS; i++) {
		cycles[i] = get_cycles_per_usec();
		delta = cycles[i] - mean;
		if (delta) {
			mean += delta / (i + 1.0);
			S += delta * (cycles[i] - mean);
		}
	}

	/*
	 * The most common platform clock breakage is returning zero
	 * indefinitely. Check for that and return failure.
	 */
	if (!cycles[0] && !cycles[NR_TIME_ITERS - 1])
		return 1;

	S = sqrt(S / (NR_TIME_ITERS - 1.0));

	samples = avg = 0;
	for (i = 0; i < NR_TIME_ITERS; i++) {
		double this = cycles[i];

		if ((fmax(this, mean) - fmin(this, mean)) > S)
			continue;
		samples++;
		avg += this;
	}

	S /= (double) NR_TIME_ITERS;
	mean /= 10.0;

	for (i = 0; i < NR_TIME_ITERS; i++)
		dprint(FD_TIME, "cycles[%d]=%llu\n", i,
					(unsigned long long) cycles[i] / 10);

	avg /= samples;
	avg = (avg + 5) / 10;
	dprint(FD_TIME, "avg: %llu\n", (unsigned long long) avg);
	dprint(FD_TIME, "mean=%f, S=%f\n", mean, S);

	cycles_per_usec = avg;
	inv_cycles_per_usec = 16777216UL / cycles_per_usec;
	dprint(FD_TIME, "inv_cycles_per_usec=%lu\n", inv_cycles_per_usec);
	return 0;
}
#else
static int calibrate_cpu_clock(void)
{
#ifdef ARCH_CPU_CLOCK_CYCLES_PER_USEC
	return 0;
#else
	return 1;
#endif
}
#endif // ARCH_HAVE_CPU_CLOCK

#ifndef CONFIG_TLS_THREAD
void fio_local_clock_init(int is_thread)
{
	struct tv_valid *t;

	t = calloc(1, sizeof(*t));
	if (pthread_setspecific(tv_tls_key, t)) {
		log_err("fio: can't set TLS key\n");
		assert(0);
	}
}

static void kill_tv_tls_key(void *data)
{
	free(data);
}
#else
void fio_local_clock_init(int is_thread)
{
}
#endif

void fio_clock_init(void)
{
	if (fio_clock_source == fio_clock_source_inited)
		return;

#ifndef CONFIG_TLS_THREAD
	if (pthread_key_create(&tv_tls_key, kill_tv_tls_key))
		log_err("fio: can't create TLS key\n");
#endif

	fio_clock_source_inited = fio_clock_source;

	if (calibrate_cpu_clock())
		tsc_reliable = 0;

	/*
	 * If the arch sets tsc_reliable != 0, then it must be good enough
	 * to use as THE clock source. For x86 CPUs, this means the TSC
	 * runs at a constant rate and is synced across CPU cores.
	 */
	if (tsc_reliable) {
		if (!fio_clock_source_set)
			fio_clock_source = CS_CPUCLOCK;
	} else if (fio_clock_source == CS_CPUCLOCK)
		log_info("fio: clocksource=cpu may not be reliable\n");
}

uint64_t utime_since(const struct timeval *s, const struct timeval *e)
{
	long sec, usec;
	uint64_t ret;

	sec = e->tv_sec - s->tv_sec;
	usec = e->tv_usec - s->tv_usec;
	if (sec > 0 && usec < 0) {
		sec--;
		usec += 1000000;
	}

	/*
	 * time warp bug on some kernels?
	 */
	if (sec < 0 || (sec == 0 && usec < 0))
		return 0;

	ret = sec * 1000000ULL + usec;

	return ret;
}

uint64_t utime_since_now(const struct timeval *s)
{
	struct timeval t;

	fio_gettime(&t, NULL);
	return utime_since(s, &t);
}

uint64_t mtime_since(const struct timeval *s, const struct timeval *e)
{
	long sec, usec, ret;

	sec = e->tv_sec - s->tv_sec;
	usec = e->tv_usec - s->tv_usec;
	if (sec > 0 && usec < 0) {
		sec--;
		usec += 1000000;
	}

	if (sec < 0 || (sec == 0 && usec < 0))
		return 0;

	sec *= 1000UL;
	usec /= 1000UL;
	ret = sec + usec;

	return ret;
}

uint64_t mtime_since_now(const struct timeval *s)
{
	struct timeval t;
	void *p = __builtin_return_address(0);

	fio_gettime(&t, p);
	return mtime_since(s, &t);
}

uint64_t time_since_now(const struct timeval *s)
{
	return mtime_since_now(s) / 1000;
}

#if defined(FIO_HAVE_CPU_AFFINITY) && defined(ARCH_HAVE_CPU_CLOCK)  && \
    defined(CONFIG_SFAA)

#define CLOCK_ENTRIES	100000

struct clock_entry {
	uint32_t seq;
	uint32_t cpu;
	uint64_t tsc;
};

struct clock_thread {
	pthread_t thread;
	int cpu;
	pthread_mutex_t lock;
	pthread_mutex_t started;
	uint32_t *seq;
	struct clock_entry *entries;
};

static inline uint32_t atomic32_inc_return(uint32_t *seq)
{
	return 1 + __sync_fetch_and_add(seq, 1);
}

static void *clock_thread_fn(void *data)
{
	struct clock_thread *t = data;
	struct clock_entry *c;
	os_cpu_mask_t cpu_mask;
	uint32_t last_seq;
	int i;

	memset(&cpu_mask, 0, sizeof(cpu_mask));
	fio_cpu_set(&cpu_mask, t->cpu);

	if (fio_setaffinity(gettid(), cpu_mask) == -1) {
		log_err("clock setaffinity failed\n");
		return (void *) 1;
	}

	pthread_mutex_lock(&t->lock);
	pthread_mutex_unlock(&t->started);

	last_seq = 0;
	c = &t->entries[0];
	for (i = 0; i < CLOCK_ENTRIES; i++, c++) {
		uint32_t seq;
		uint64_t tsc;

		c->cpu = t->cpu;
		do {
			seq = atomic32_inc_return(t->seq);
			if (seq < last_seq)
				break;
			tsc = get_cpu_clock();
		} while (seq != *t->seq);

		c->seq = seq;
		c->tsc = tsc;
	}

	log_info("cs: cpu%3d: %llu clocks seen\n", t->cpu,
		(unsigned long long) t->entries[i - 1].tsc - t->entries[0].tsc);

	/*
	 * The most common platform clock breakage is returning zero
	 * indefinitely. Check for that and return failure.
	 */
	if (!t->entries[i - 1].tsc && !t->entries[0].tsc)
		return (void *) 1;

	return NULL;
}

static int clock_cmp(const void *p1, const void *p2)
{
	const struct clock_entry *c1 = p1;
	const struct clock_entry *c2 = p2;

	if (c1->seq == c2->seq)
		log_err("cs: bug in atomic sequence!\n");

	return c1->seq - c2->seq;
}

int fio_monotonic_clocktest(void)
{
	struct clock_thread *cthreads;
	unsigned int nr_cpus = cpus_online();
	struct clock_entry *entries;
	unsigned long tentries, failed = 0;
	struct clock_entry *prev, *this;
	uint32_t seq = 0;
	unsigned int i;

	log_info("cs: reliable_tsc: %s\n", tsc_reliable ? "yes" : "no");

#ifdef FIO_INC_DEBUG
	fio_debug |= 1U << FD_TIME;
#endif
	calibrate_cpu_clock();
#ifdef FIO_INC_DEBUG
	fio_debug &= ~(1U << FD_TIME);
#endif

	cthreads = malloc(nr_cpus * sizeof(struct clock_thread));
	tentries = CLOCK_ENTRIES * nr_cpus;
	entries = malloc(tentries * sizeof(struct clock_entry));

	log_info("cs: Testing %u CPUs\n", nr_cpus);

	for (i = 0; i < nr_cpus; i++) {
		struct clock_thread *t = &cthreads[i];

		t->cpu = i;
		t->seq = &seq;
		t->entries = &entries[i * CLOCK_ENTRIES];
		pthread_mutex_init(&t->lock, NULL);
		pthread_mutex_init(&t->started, NULL);
		pthread_mutex_lock(&t->lock);
		if (pthread_create(&t->thread, NULL, clock_thread_fn, t)) {
			failed++;
			nr_cpus = i;
			break;
		}
	}

	for (i = 0; i < nr_cpus; i++) {
		struct clock_thread *t = &cthreads[i];

		pthread_mutex_lock(&t->started);
	}

	for (i = 0; i < nr_cpus; i++) {
		struct clock_thread *t = &cthreads[i];

		pthread_mutex_unlock(&t->lock);
	}

	for (i = 0; i < nr_cpus; i++) {
		struct clock_thread *t = &cthreads[i];
		void *ret;

		pthread_join(t->thread, &ret);
		if (ret)
			failed++;
	}
	free(cthreads);

	if (failed) {
		log_err("Clocksource test: %lu threads failed\n", failed);
		goto err;
	}

	qsort(entries, tentries, sizeof(struct clock_entry), clock_cmp);

	for (failed = i = 0; i < tentries; i++) {
		this = &entries[i];

		if (!i) {
			prev = this;
			continue;
		}

		if (prev->tsc > this->tsc) {
			uint64_t diff = prev->tsc - this->tsc;

			log_info("cs: CPU clock mismatch (diff=%llu):\n",
						(unsigned long long) diff);
			log_info("\t CPU%3u: TSC=%llu, SEQ=%u\n", prev->cpu, (unsigned long long) prev->tsc, prev->seq);
			log_info("\t CPU%3u: TSC=%llu, SEQ=%u\n", this->cpu, (unsigned long long) this->tsc, this->seq);
			failed++;
		}

		prev = this;
	}

	if (failed)
		log_info("cs: Failed: %lu\n", failed);
	else
		log_info("cs: Pass!\n");

err:
	free(entries);
	return !!failed;
}

#else /* defined(FIO_HAVE_CPU_AFFINITY) && defined(ARCH_HAVE_CPU_CLOCK) */

int fio_monotonic_clocktest(void)
{
	log_info("cs: current platform does not support CPU clocks\n");
	return 0;
}

#endif
Commit	Line	Data
	1	/*
	2	* Clock functions
	3	*/
	4
	5	#include <unistd.h>
	6	#include <math.h>
	7	#include <sys/time.h>
	8	#include <time.h>
	9
	10	#include "fio.h"
	11	#include "smalloc.h"
	12
	13	#include "hash.h"
	14	#include "os/os.h"
	15
	16	#if defined(ARCH_HAVE_CPU_CLOCK) && !defined(ARCH_CPU_CLOCK_CYCLES_PER_USEC)
	17	static unsigned long cycles_per_usec;
	18	static unsigned long inv_cycles_per_usec;
	19	#endif
	20	int tsc_reliable = 0;
	21
	22	struct tv_valid {
	23	uint64_t last_cycles;
	24	uint64_t last_tv_valid;
	25	};
	26	#ifdef CONFIG_TLS_THREAD
	27	static __thread struct tv_valid static_tv_valid;
	28	#else
	29	static pthread_key_t tv_tls_key;
	30	#endif
	31
	32	enum fio_cs fio_clock_source = FIO_PREFERRED_CLOCK_SOURCE;
	33	int fio_clock_source_set = 0;
	34	static enum fio_cs fio_clock_source_inited = CS_INVAL;
	35
	36	#ifdef FIO_DEBUG_TIME
	37
	38	#define HASH_BITS 8
	39	#define HASH_SIZE (1 << HASH_BITS)
	40
	41	static struct flist_head hash[HASH_SIZE];
	42	static int gtod_inited;
	43
	44	struct gtod_log {
	45	struct flist_head list;
	46	void *caller;
	47	unsigned long calls;
	48	};
	49
	50	static struct gtod_log find_hash(void caller)
	51	{
	52	unsigned long h = hash_ptr(caller, HASH_BITS);
	53	struct flist_head *entry;
	54
	55	flist_for_each(entry, &hash[h]) {
	56	struct gtod_log *log = flist_entry(entry, struct gtod_log,
	57	list);
	58
	59	if (log->caller == caller)
	60	return log;
	61	}
	62
	63	return NULL;
	64	}
	65
	66	static struct gtod_log find_log(void caller)
	67	{
	68	struct gtod_log *log = find_hash(caller);
	69
	70	if (!log) {
	71	unsigned long h;
	72
	73	log = malloc(sizeof(*log));
	74	INIT_FLIST_HEAD(&log->list);
	75	log->caller = caller;
	76	log->calls = 0;
	77
	78	h = hash_ptr(caller, HASH_BITS);
	79	flist_add_tail(&log->list, &hash[h]);
	80	}
	81
	82	return log;
	83	}
	84
	85	static void gtod_log_caller(void *caller)
	86	{
	87	if (gtod_inited) {
	88	struct gtod_log *log = find_log(caller);
	89
	90	log->calls++;
	91	}
	92	}
	93
	94	static void fio_exit fio_dump_gtod(void)
	95	{
	96	unsigned long total_calls = 0;
	97	int i;
	98
	99	for (i = 0; i < HASH_SIZE; i++) {
	100	struct flist_head *entry;
	101	struct gtod_log *log;
	102
	103	flist_for_each(entry, &hash[i]) {
	104	log = flist_entry(entry, struct gtod_log, list);
	105
	106	printf("function %p, calls %lu\n", log->caller,
	107	log->calls);
	108	total_calls += log->calls;
	109	}
	110	}
	111
	112	printf("Total %lu gettimeofday\n", total_calls);
	113	}
	114
	115	static void fio_init gtod_init(void)
	116	{
	117	int i;
	118
	119	for (i = 0; i < HASH_SIZE; i++)
	120	INIT_FLIST_HEAD(&hash[i]);
	121
	122	gtod_inited = 1;
	123	}
	124
	125	#endif /* FIO_DEBUG_TIME */
	126
	127	#ifdef CONFIG_CLOCK_GETTIME
	128	static int fill_clock_gettime(struct timespec *ts)
	129	{
	130	#ifdef CONFIG_CLOCK_MONOTONIC
	131	return clock_gettime(CLOCK_MONOTONIC, ts);
	132	#else
	133	return clock_gettime(CLOCK_REALTIME, ts);
	134	#endif
	135	}
	136	#endif
	137
	138	static void __fio_gettime(struct timeval *tp)
	139	{
	140	struct tv_valid *tv;
	141
	142	#ifdef CONFIG_TLS_THREAD
	143	tv = &static_tv_valid;
	144	#else
	145	tv = pthread_getspecific(tv_tls_key);
	146	#endif
	147
	148	switch (fio_clock_source) {
	149	#ifdef CONFIG_GETTIMEOFDAY
	150	case CS_GTOD:
	151	gettimeofday(tp, NULL);
	152	break;
	153	#endif
	154	#ifdef CONFIG_CLOCK_GETTIME
	155	case CS_CGETTIME: {
	156	struct timespec ts;
	157
	158	if (fill_clock_gettime(&ts) < 0) {
	159	log_err("fio: clock_gettime fails\n");
	160	assert(0);
	161	}
	162
	163	tp->tv_sec = ts.tv_sec;
	164	tp->tv_usec = ts.tv_nsec / 1000;
	165	break;
	166	}
	167	#endif
	168	#ifdef ARCH_HAVE_CPU_CLOCK
	169	case CS_CPUCLOCK: {
	170	uint64_t usecs, t;
	171
	172	t = get_cpu_clock();
	173	if (t < tv->last_cycles && tv->last_tv_valid)
	174	log_err("fio: CPU clock going back in time\n");
	175
	176	tv->last_cycles = t;
	177	tv->last_tv_valid = 1;
	178	#ifdef ARCH_CPU_CLOCK_CYCLES_PER_USEC
	179	usecs = t / ARCH_CPU_CLOCK_CYCLES_PER_USEC;
	180	#else
	181	usecs = (t * inv_cycles_per_usec) / 16777216UL;
	182	#endif
	183	tp->tv_sec = usecs / 1000000;
	184	tp->tv_usec = usecs % 1000000;
	185	break;
	186	}
	187	#endif
	188	default:
	189	log_err("fio: invalid clock source %d\n", fio_clock_source);
	190	break;
	191	}
	192	}
	193
	194	#ifdef FIO_DEBUG_TIME
	195	void fio_gettime(struct timeval tp, void caller)
	196	#else
	197	void fio_gettime(struct timeval tp, void fio_unused caller)
	198	#endif
	199	{
	200	#ifdef FIO_DEBUG_TIME
	201	if (!caller)
	202	caller = __builtin_return_address(0);
	203
	204	gtod_log_caller(caller);
	205	#endif
	206	if (fio_unlikely(fio_tv)) {
	207	memcpy(tp, fio_tv, sizeof(*tp));
	208	return;
	209	}
	210
	211	__fio_gettime(tp);
	212	}
	213
	214	#if defined(ARCH_HAVE_CPU_CLOCK) && !defined(ARCH_CPU_CLOCK_CYCLES_PER_USEC)
	215	static unsigned long get_cycles_per_usec(void)
	216	{
	217	struct timeval s, e;
	218	uint64_t c_s, c_e;
	219	enum fio_cs old_cs = fio_clock_source;
	220
	221	#ifdef CONFIG_CLOCK_GETTIME
	222	fio_clock_source = CS_CGETTIME;
	223	#else
	224	fio_clock_source = CS_GTOD;
	225	#endif
	226	__fio_gettime(&s);
	227
	228	c_s = get_cpu_clock();
	229	do {
	230	uint64_t elapsed;
	231
	232	__fio_gettime(&e);
	233
	234	elapsed = utime_since(&s, &e);
	235	if (elapsed >= 1280) {
	236	c_e = get_cpu_clock();
	237	break;
	238	}
	239	} while (1);
	240
	241	fio_clock_source = old_cs;
	242	return (c_e - c_s + 127) >> 7;
	243	}
	244
	245	#define NR_TIME_ITERS 50
	246
	247	static int calibrate_cpu_clock(void)
	248	{
	249	double delta, mean, S;
	250	uint64_t avg, cycles[NR_TIME_ITERS];
	251	int i, samples;
	252
	253	cycles[0] = get_cycles_per_usec();
	254	S = delta = mean = 0.0;
	255	for (i = 0; i < NR_TIME_ITERS; i++) {
	256	cycles[i] = get_cycles_per_usec();
	257	delta = cycles[i] - mean;
	258	if (delta) {
	259	mean += delta / (i + 1.0);
	260	S += delta * (cycles[i] - mean);
	261	}
	262	}
	263
	264	/*
	265	* The most common platform clock breakage is returning zero
	266	* indefinitely. Check for that and return failure.
	267	*/
	268	if (!cycles[0] && !cycles[NR_TIME_ITERS - 1])
	269	return 1;
	270
	271	S = sqrt(S / (NR_TIME_ITERS - 1.0));
	272
	273	samples = avg = 0;
	274	for (i = 0; i < NR_TIME_ITERS; i++) {
	275	double this = cycles[i];
	276
	277	if ((fmax(this, mean) - fmin(this, mean)) > S)
	278	continue;
	279	samples++;
	280	avg += this;
	281	}
	282
	283	S /= (double) NR_TIME_ITERS;
	284	mean /= 10.0;
	285
	286	for (i = 0; i < NR_TIME_ITERS; i++)
	287	dprint(FD_TIME, "cycles[%d]=%llu\n", i,
	288	(unsigned long long) cycles[i] / 10);
	289
	290	avg /= samples;
	291	avg = (avg + 5) / 10;
	292	dprint(FD_TIME, "avg: %llu\n", (unsigned long long) avg);
	293	dprint(FD_TIME, "mean=%f, S=%f\n", mean, S);
	294
	295	cycles_per_usec = avg;
	296	inv_cycles_per_usec = 16777216UL / cycles_per_usec;
	297	dprint(FD_TIME, "inv_cycles_per_usec=%lu\n", inv_cycles_per_usec);
	298	return 0;
	299	}
	300	#else
	301	static int calibrate_cpu_clock(void)
	302	{
	303	#ifdef ARCH_CPU_CLOCK_CYCLES_PER_USEC
	304	return 0;
	305	#else
	306	return 1;
	307	#endif
	308	}
	309	#endif // ARCH_HAVE_CPU_CLOCK
	310
	311	#ifndef CONFIG_TLS_THREAD
	312	void fio_local_clock_init(int is_thread)
	313	{
	314	struct tv_valid *t;
	315
	316	t = calloc(1, sizeof(*t));
	317	if (pthread_setspecific(tv_tls_key, t)) {
	318	log_err("fio: can't set TLS key\n");
	319	assert(0);
	320	}
	321	}
	322
	323	static void kill_tv_tls_key(void *data)
	324	{
	325	free(data);
	326	}
	327	#else
	328	void fio_local_clock_init(int is_thread)
	329	{
	330	}
	331	#endif
	332
	333	void fio_clock_init(void)
	334	{
	335	if (fio_clock_source == fio_clock_source_inited)
	336	return;
	337
	338	#ifndef CONFIG_TLS_THREAD
	339	if (pthread_key_create(&tv_tls_key, kill_tv_tls_key))
	340	log_err("fio: can't create TLS key\n");
	341	#endif
	342
	343	fio_clock_source_inited = fio_clock_source;
	344
	345	if (calibrate_cpu_clock())
	346	tsc_reliable = 0;
	347
	348	/*
	349	* If the arch sets tsc_reliable != 0, then it must be good enough
	350	* to use as THE clock source. For x86 CPUs, this means the TSC
	351	* runs at a constant rate and is synced across CPU cores.
	352	*/
	353	if (tsc_reliable) {
	354	if (!fio_clock_source_set)
	355	fio_clock_source = CS_CPUCLOCK;
	356	} else if (fio_clock_source == CS_CPUCLOCK)
	357	log_info("fio: clocksource=cpu may not be reliable\n");
	358	}
	359
	360	uint64_t utime_since(const struct timeval s, const struct timeval e)
	361	{
	362	long sec, usec;
	363	uint64_t ret;
	364
	365	sec = e->tv_sec - s->tv_sec;
	366	usec = e->tv_usec - s->tv_usec;
	367	if (sec > 0 && usec < 0) {
	368	sec--;
	369	usec += 1000000;
	370	}
	371
	372	/*
	373	* time warp bug on some kernels?
	374	*/
	375	if (sec < 0 \|\| (sec == 0 && usec < 0))
	376	return 0;
	377
	378	ret = sec * 1000000ULL + usec;
	379
	380	return ret;
	381	}
	382
	383	uint64_t utime_since_now(const struct timeval *s)
	384	{
	385	struct timeval t;
	386
	387	fio_gettime(&t, NULL);
	388	return utime_since(s, &t);
	389	}
	390
	391	uint64_t mtime_since(const struct timeval s, const struct timeval e)
	392	{
	393	long sec, usec, ret;
	394
	395	sec = e->tv_sec - s->tv_sec;
	396	usec = e->tv_usec - s->tv_usec;
	397	if (sec > 0 && usec < 0) {
	398	sec--;
	399	usec += 1000000;
	400	}
	401
	402	if (sec < 0 \|\| (sec == 0 && usec < 0))
	403	return 0;
	404
	405	sec *= 1000UL;
	406	usec /= 1000UL;
	407	ret = sec + usec;
	408
	409	return ret;
	410	}
	411
	412	uint64_t mtime_since_now(const struct timeval *s)
	413	{
	414	struct timeval t;
	415	void *p = __builtin_return_address(0);
	416
	417	fio_gettime(&t, p);
	418	return mtime_since(s, &t);
	419	}
	420
	421	uint64_t time_since_now(const struct timeval *s)
	422	{
	423	return mtime_since_now(s) / 1000;
	424	}
	425
	426	#if defined(FIO_HAVE_CPU_AFFINITY) && defined(ARCH_HAVE_CPU_CLOCK) && \
	427	defined(CONFIG_SFAA)
	428
	429	#define CLOCK_ENTRIES 100000
	430
	431	struct clock_entry {
	432	uint32_t seq;
	433	uint32_t cpu;
	434	uint64_t tsc;
	435	};
	436
	437	struct clock_thread {
	438	pthread_t thread;
	439	int cpu;
	440	pthread_mutex_t lock;
	441	pthread_mutex_t started;
	442	uint32_t *seq;
	443	struct clock_entry *entries;
	444	};
	445
	446	static inline uint32_t atomic32_inc_return(uint32_t *seq)
	447	{
	448	return 1 + __sync_fetch_and_add(seq, 1);
	449	}
	450
	451	static void clock_thread_fn(void data)
	452	{
	453	struct clock_thread *t = data;
	454	struct clock_entry *c;
	455	os_cpu_mask_t cpu_mask;
	456	uint32_t last_seq;
	457	int i;
	458
	459	memset(&cpu_mask, 0, sizeof(cpu_mask));
	460	fio_cpu_set(&cpu_mask, t->cpu);
	461
	462	if (fio_setaffinity(gettid(), cpu_mask) == -1) {
	463	log_err("clock setaffinity failed\n");
	464	return (void *) 1;
	465	}
	466
	467	pthread_mutex_lock(&t->lock);
	468	pthread_mutex_unlock(&t->started);
	469
	470	last_seq = 0;
	471	c = &t->entries[0];
	472	for (i = 0; i < CLOCK_ENTRIES; i++, c++) {
	473	uint32_t seq;
	474	uint64_t tsc;
	475
	476	c->cpu = t->cpu;
	477	do {
	478	seq = atomic32_inc_return(t->seq);
	479	if (seq < last_seq)
	480	break;
	481	tsc = get_cpu_clock();
	482	} while (seq != *t->seq);
	483
	484	c->seq = seq;
	485	c->tsc = tsc;
	486	}
	487
	488	log_info("cs: cpu%3d: %llu clocks seen\n", t->cpu,
	489	(unsigned long long) t->entries[i - 1].tsc - t->entries[0].tsc);
	490
	491	/*
	492	* The most common platform clock breakage is returning zero
	493	* indefinitely. Check for that and return failure.
	494	*/
	495	if (!t->entries[i - 1].tsc && !t->entries[0].tsc)
	496	return (void *) 1;
	497
	498	return NULL;
	499	}
	500
	501	static int clock_cmp(const void p1, const void p2)
	502	{
	503	const struct clock_entry *c1 = p1;
	504	const struct clock_entry *c2 = p2;
	505
	506	if (c1->seq == c2->seq)
	507	log_err("cs: bug in atomic sequence!\n");
	508
	509	return c1->seq - c2->seq;
	510	}
	511
	512	int fio_monotonic_clocktest(void)
	513	{
	514	struct clock_thread *cthreads;
	515	unsigned int nr_cpus = cpus_online();
	516	struct clock_entry *entries;
	517	unsigned long tentries, failed = 0;
	518	struct clock_entry prev, this;
	519	uint32_t seq = 0;
	520	unsigned int i;
	521
	522	log_info("cs: reliable_tsc: %s\n", tsc_reliable ? "yes" : "no");
	523
	524	#ifdef FIO_INC_DEBUG
	525	fio_debug \|= 1U << FD_TIME;
	526	#endif
	527	calibrate_cpu_clock();
	528	#ifdef FIO_INC_DEBUG
	529	fio_debug &= ~(1U << FD_TIME);
	530	#endif
	531
	532	cthreads = malloc(nr_cpus * sizeof(struct clock_thread));
	533	tentries = CLOCK_ENTRIES * nr_cpus;
	534	entries = malloc(tentries * sizeof(struct clock_entry));
	535
	536	log_info("cs: Testing %u CPUs\n", nr_cpus);
	537
	538	for (i = 0; i < nr_cpus; i++) {
	539	struct clock_thread *t = &cthreads[i];
	540
	541	t->cpu = i;
	542	t->seq = &seq;
	543	t->entries = &entries[i * CLOCK_ENTRIES];
	544	pthread_mutex_init(&t->lock, NULL);
	545	pthread_mutex_init(&t->started, NULL);
	546	pthread_mutex_lock(&t->lock);
	547	if (pthread_create(&t->thread, NULL, clock_thread_fn, t)) {
	548	failed++;
	549	nr_cpus = i;
	550	break;
	551	}
	552	}
	553
	554	for (i = 0; i < nr_cpus; i++) {
	555	struct clock_thread *t = &cthreads[i];
	556
	557	pthread_mutex_lock(&t->started);
	558	}
	559
	560	for (i = 0; i < nr_cpus; i++) {
	561	struct clock_thread *t = &cthreads[i];
	562
	563	pthread_mutex_unlock(&t->lock);
	564	}
	565
	566	for (i = 0; i < nr_cpus; i++) {
	567	struct clock_thread *t = &cthreads[i];
	568	void *ret;
	569
	570	pthread_join(t->thread, &ret);
	571	if (ret)
	572	failed++;
	573	}
	574	free(cthreads);
	575
	576	if (failed) {
	577	log_err("Clocksource test: %lu threads failed\n", failed);
	578	goto err;
	579	}
	580
	581	qsort(entries, tentries, sizeof(struct clock_entry), clock_cmp);
	582
	583	for (failed = i = 0; i < tentries; i++) {
	584	this = &entries[i];
	585
	586	if (!i) {
	587	prev = this;
	588	continue;
	589	}
	590
	591	if (prev->tsc > this->tsc) {
	592	uint64_t diff = prev->tsc - this->tsc;
	593
	594	log_info("cs: CPU clock mismatch (diff=%llu):\n",
	595	(unsigned long long) diff);
	596	log_info("\t CPU%3u: TSC=%llu, SEQ=%u\n", prev->cpu, (unsigned long long) prev->tsc, prev->seq);
	597	log_info("\t CPU%3u: TSC=%llu, SEQ=%u\n", this->cpu, (unsigned long long) this->tsc, this->seq);
	598	failed++;
	599	}
	600
	601	prev = this;
	602	}
	603
	604	if (failed)
	605	log_info("cs: Failed: %lu\n", failed);
	606	else
	607	log_info("cs: Pass!\n");
	608
	609	err:
	610	free(entries);
	611	return !!failed;
	612	}
	613
	614	#else /* defined(FIO_HAVE_CPU_AFFINITY) && defined(ARCH_HAVE_CPU_CLOCK) */
	615
	616	int fio_monotonic_clocktest(void)
	617	{
	618	log_info("cs: current platform does not support CPU clocks\n");
	619	return 0;
	620	}
	621
	622	#endif