[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)
#ifndef ARCH_CPU_CLOCK_CYCLES_PER_USEC
static unsigned long cycles_per_usec;
static unsigned long inv_cycles_per_usec;
static uint64_t max_cycles_for_mult;
#endif
#ifdef ARCH_CPU_CLOCK_WRAPS
static unsigned long long cycles_start, cycles_wrap;
#endif
#endif
int tsc_reliable = 0;

struct tv_valid {
	uint64_t last_cycles;
	int last_tv_valid;
	int warned;
};
#ifdef ARCH_HAVE_CPU_CLOCK
#ifdef CONFIG_TLS_THREAD
static __thread struct tv_valid static_tv_valid;
#else
static pthread_key_t tv_tls_key;
#endif
#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 void inc_caller(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]);
	}

	log->calls++;
}

static void gtod_log_caller(void *caller)
{
	if (gtod_inited)
		inc_caller(caller);
}

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)
{
#if defined(CONFIG_CLOCK_MONOTONIC_RAW)
	return clock_gettime(CLOCK_MONOTONIC_RAW, ts);
#elif defined(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)
{
	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;
		struct tv_valid *tv;

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

		t = get_cpu_clock();
#ifdef ARCH_CPU_CLOCK_WRAPS
		if (t < cycles_start && !cycles_wrap)
			cycles_wrap = 1;
		else if (cycles_wrap && t >= cycles_start && !tv->warned) {
			log_err("fio: double CPU clock wrap\n");
			tv->warned = 1;
		}

		t -= cycles_start;
#endif
		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
		if (t < max_cycles_for_mult)
			usecs = (t * inv_cycles_per_usec) / 16777216UL;
		else
			usecs = t / cycles_per_usec;
#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_gettime_offload(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;
	uint64_t elapsed;

#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 {
		__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) / elapsed;
}

#define NR_TIME_ITERS	50

static int calibrate_cpu_clock(void)
{
	double delta, mean, S;
	uint64_t minc, maxc, 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));

	minc = -1ULL;
	maxc = samples = avg = 0;
	for (i = 0; i < NR_TIME_ITERS; i++) {
		double this = cycles[i];

		minc = min(cycles[i], minc);
		maxc = max(cycles[i], maxc);

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

	S /= (double) NR_TIME_ITERS;

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

	avg /= samples;
	dprint(FD_TIME, "avg: %llu\n", (unsigned long long) avg);
	dprint(FD_TIME, "min=%llu, max=%llu, mean=%f, S=%f\n",
			(unsigned long long) minc,
			(unsigned long long) maxc, mean, S);

	cycles_per_usec = avg;
	inv_cycles_per_usec = 16777216UL / cycles_per_usec;
	max_cycles_for_mult = ~0ULL / inv_cycles_per_usec;
	dprint(FD_TIME, "inv_cycles_per_usec=%lu\n", inv_cycles_per_usec);
#ifdef ARCH_CPU_CLOCK_WRAPS
	cycles_start = get_cpu_clock();
	dprint(FD_TIME, "cycles_start=%llu\n", cycles_start);
#endif
	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_monotonic_clocktest(0))
			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)
{
	int64_t sec, usec;

	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;

	return usec + (sec * 1000000);
}

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;

	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 *= 1000;
	usec /= 1000;
	return sec + usec;
}

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_DEBUG	100000
#define CLOCK_ENTRIES_TEST	10000

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

struct clock_thread {
	pthread_t thread;
	int cpu;
	int debug;
	pthread_mutex_t lock;
	pthread_mutex_t started;
	unsigned long nr_entries;
	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;
	unsigned long long first;
	int i;

	if (fio_cpuset_init(&cpu_mask)) {
		int __err = errno;

		log_err("clock cpuset init failed: %s\n", strerror(__err));
		goto err_out;
	}

	fio_cpu_set(&cpu_mask, t->cpu);

	if (fio_setaffinity(gettid(), cpu_mask) == -1) {
		int __err = errno;

		log_err("clock setaffinity failed: %s\n", strerror(__err));
		goto err;
	}

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

	first = get_cpu_clock();
	last_seq = 0;
	c = &t->entries[0];
	for (i = 0; i < t->nr_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;
	}

	if (t->debug) {
		unsigned long long clocks;

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

	/*
	 * 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)
		goto err;

	fio_cpuset_exit(&cpu_mask);
	return NULL;
err:
	fio_cpuset_exit(&cpu_mask);
err_out:
	return (void *) 1;
}

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

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

#ifdef FIO_INC_DEBUG
		fio_debug |= 1U << FD_TIME;
#endif
		nr_entries = CLOCK_ENTRIES_DEBUG;
	} else
		nr_entries = CLOCK_ENTRIES_TEST;

	calibrate_cpu_clock();

	if (debug) {
#ifdef FIO_INC_DEBUG
		fio_debug &= ~(1U << FD_TIME);
#endif
	}

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

	if (debug)
		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->debug = debug;
		t->seq = &seq;
		t->nr_entries = nr_entries;
		t->entries = &entries[i * nr_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) {
		if (debug)
			log_err("Clocksource test: %lu threads failed\n", failed);
		goto err;
	}

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

	/* silence silly gcc */
	prev = NULL;
	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;

			if (!debug) {
				failed++;
				break;
			}

			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 (debug) {
		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(int debug)
{
	if (debug)
		log_info("cs: current platform does not support CPU clocks\n");
	return 1;
}

#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)
	17	#ifndef ARCH_CPU_CLOCK_CYCLES_PER_USEC
	18	static unsigned long cycles_per_usec;
	19	static unsigned long inv_cycles_per_usec;
	20	static uint64_t max_cycles_for_mult;
	21	#endif
	22	#ifdef ARCH_CPU_CLOCK_WRAPS
	23	static unsigned long long cycles_start, cycles_wrap;
	24	#endif
	25	#endif
	26	int tsc_reliable = 0;
	27
	28	struct tv_valid {
	29	uint64_t last_cycles;
	30	int last_tv_valid;
	31	int warned;
	32	};
	33	#ifdef ARCH_HAVE_CPU_CLOCK
	34	#ifdef CONFIG_TLS_THREAD
	35	static __thread struct tv_valid static_tv_valid;
	36	#else
	37	static pthread_key_t tv_tls_key;
	38	#endif
	39	#endif
	40
	41	enum fio_cs fio_clock_source = FIO_PREFERRED_CLOCK_SOURCE;
	42	int fio_clock_source_set = 0;
	43	static enum fio_cs fio_clock_source_inited = CS_INVAL;
	44
	45	#ifdef FIO_DEBUG_TIME
	46
	47	#define HASH_BITS 8
	48	#define HASH_SIZE (1 << HASH_BITS)
	49
	50	static struct flist_head hash[HASH_SIZE];
	51	static int gtod_inited;
	52
	53	struct gtod_log {
	54	struct flist_head list;
	55	void *caller;
	56	unsigned long calls;
	57	};
	58
	59	static struct gtod_log find_hash(void caller)
	60	{
	61	unsigned long h = hash_ptr(caller, HASH_BITS);
	62	struct flist_head *entry;
	63
	64	flist_for_each(entry, &hash[h]) {
	65	struct gtod_log *log = flist_entry(entry, struct gtod_log,
	66	list);
	67
	68	if (log->caller == caller)
	69	return log;
	70	}
	71
	72	return NULL;
	73	}
	74
	75	static void inc_caller(void *caller)
	76	{
	77	struct gtod_log *log = find_hash(caller);
	78
	79	if (!log) {
	80	unsigned long h;
	81
	82	log = malloc(sizeof(*log));
	83	INIT_FLIST_HEAD(&log->list);
	84	log->caller = caller;
	85	log->calls = 0;
	86
	87	h = hash_ptr(caller, HASH_BITS);
	88	flist_add_tail(&log->list, &hash[h]);
	89	}
	90
	91	log->calls++;
	92	}
	93
	94	static void gtod_log_caller(void *caller)
	95	{
	96	if (gtod_inited)
	97	inc_caller(caller);
	98	}
	99
	100	static void fio_exit fio_dump_gtod(void)
	101	{
	102	unsigned long total_calls = 0;
	103	int i;
	104
	105	for (i = 0; i < HASH_SIZE; i++) {
	106	struct flist_head *entry;
	107	struct gtod_log *log;
	108
	109	flist_for_each(entry, &hash[i]) {
	110	log = flist_entry(entry, struct gtod_log, list);
	111
	112	printf("function %p, calls %lu\n", log->caller,
	113	log->calls);
	114	total_calls += log->calls;
	115	}
	116	}
	117
	118	printf("Total %lu gettimeofday\n", total_calls);
	119	}
	120
	121	static void fio_init gtod_init(void)
	122	{
	123	int i;
	124
	125	for (i = 0; i < HASH_SIZE; i++)
	126	INIT_FLIST_HEAD(&hash[i]);
	127
	128	gtod_inited = 1;
	129	}
	130
	131	#endif /* FIO_DEBUG_TIME */
	132
	133	#ifdef CONFIG_CLOCK_GETTIME
	134	static int fill_clock_gettime(struct timespec *ts)
	135	{
	136	#if defined(CONFIG_CLOCK_MONOTONIC_RAW)
	137	return clock_gettime(CLOCK_MONOTONIC_RAW, ts);
	138	#elif defined(CONFIG_CLOCK_MONOTONIC)
	139	return clock_gettime(CLOCK_MONOTONIC, ts);
	140	#else
	141	return clock_gettime(CLOCK_REALTIME, ts);
	142	#endif
	143	}
	144	#endif
	145
	146	static void __fio_gettime(struct timeval *tp)
	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	struct tv_valid *tv;
	172
	173	#ifdef CONFIG_TLS_THREAD
	174	tv = &static_tv_valid;
	175	#else
	176	tv = pthread_getspecific(tv_tls_key);
	177	#endif
	178
	179	t = get_cpu_clock();
	180	#ifdef ARCH_CPU_CLOCK_WRAPS
	181	if (t < cycles_start && !cycles_wrap)
	182	cycles_wrap = 1;
	183	else if (cycles_wrap && t >= cycles_start && !tv->warned) {
	184	log_err("fio: double CPU clock wrap\n");
	185	tv->warned = 1;
	186	}
	187
	188	t -= cycles_start;
	189	#endif
	190	tv->last_cycles = t;
	191	tv->last_tv_valid = 1;
	192	#ifdef ARCH_CPU_CLOCK_CYCLES_PER_USEC
	193	usecs = t / ARCH_CPU_CLOCK_CYCLES_PER_USEC;
	194	#else
	195	if (t < max_cycles_for_mult)
	196	usecs = (t * inv_cycles_per_usec) / 16777216UL;
	197	else
	198	usecs = t / cycles_per_usec;
	199	#endif
	200	tp->tv_sec = usecs / 1000000;
	201	tp->tv_usec = usecs % 1000000;
	202	break;
	203	}
	204	#endif
	205	default:
	206	log_err("fio: invalid clock source %d\n", fio_clock_source);
	207	break;
	208	}
	209	}
	210
	211	#ifdef FIO_DEBUG_TIME
	212	void fio_gettime(struct timeval tp, void caller)
	213	#else
	214	void fio_gettime(struct timeval tp, void fio_unused caller)
	215	#endif
	216	{
	217	#ifdef FIO_DEBUG_TIME
	218	if (!caller)
	219	caller = __builtin_return_address(0);
	220
	221	gtod_log_caller(caller);
	222	#endif
	223	if (fio_unlikely(fio_gettime_offload(tp)))
	224	return;
	225
	226	__fio_gettime(tp);
	227	}
	228
	229	#if defined(ARCH_HAVE_CPU_CLOCK) && !defined(ARCH_CPU_CLOCK_CYCLES_PER_USEC)
	230	static unsigned long get_cycles_per_usec(void)
	231	{
	232	struct timeval s, e;
	233	uint64_t c_s, c_e;
	234	enum fio_cs old_cs = fio_clock_source;
	235	uint64_t elapsed;
	236
	237	#ifdef CONFIG_CLOCK_GETTIME
	238	fio_clock_source = CS_CGETTIME;
	239	#else
	240	fio_clock_source = CS_GTOD;
	241	#endif
	242	__fio_gettime(&s);
	243
	244	c_s = get_cpu_clock();
	245	do {
	246	__fio_gettime(&e);
	247
	248	elapsed = utime_since(&s, &e);
	249	if (elapsed >= 1280) {
	250	c_e = get_cpu_clock();
	251	break;
	252	}
	253	} while (1);
	254
	255	fio_clock_source = old_cs;
	256	return (c_e - c_s) / elapsed;
	257	}
	258
	259	#define NR_TIME_ITERS 50
	260
	261	static int calibrate_cpu_clock(void)
	262	{
	263	double delta, mean, S;
	264	uint64_t minc, maxc, avg, cycles[NR_TIME_ITERS];
	265	int i, samples;
	266
	267	cycles[0] = get_cycles_per_usec();
	268	S = delta = mean = 0.0;
	269	for (i = 0; i < NR_TIME_ITERS; i++) {
	270	cycles[i] = get_cycles_per_usec();
	271	delta = cycles[i] - mean;
	272	if (delta) {
	273	mean += delta / (i + 1.0);
	274	S += delta * (cycles[i] - mean);
	275	}
	276	}
	277
	278	/*
	279	* The most common platform clock breakage is returning zero
	280	* indefinitely. Check for that and return failure.
	281	*/
	282	if (!cycles[0] && !cycles[NR_TIME_ITERS - 1])
	283	return 1;
	284
	285	S = sqrt(S / (NR_TIME_ITERS - 1.0));
	286
	287	minc = -1ULL;
	288	maxc = samples = avg = 0;
	289	for (i = 0; i < NR_TIME_ITERS; i++) {
	290	double this = cycles[i];
	291
	292	minc = min(cycles[i], minc);
	293	maxc = max(cycles[i], maxc);
	294
	295	if ((fmax(this, mean) - fmin(this, mean)) > S)
	296	continue;
	297	samples++;
	298	avg += this;
	299	}
	300
	301	S /= (double) NR_TIME_ITERS;
	302
	303	for (i = 0; i < NR_TIME_ITERS; i++)
	304	dprint(FD_TIME, "cycles[%d]=%llu\n", i, (unsigned long long) cycles[i]);
	305
	306	avg /= samples;
	307	dprint(FD_TIME, "avg: %llu\n", (unsigned long long) avg);
	308	dprint(FD_TIME, "min=%llu, max=%llu, mean=%f, S=%f\n",
	309	(unsigned long long) minc,
	310	(unsigned long long) maxc, mean, S);
	311
	312	cycles_per_usec = avg;
	313	inv_cycles_per_usec = 16777216UL / cycles_per_usec;
	314	max_cycles_for_mult = ~0ULL / inv_cycles_per_usec;
	315	dprint(FD_TIME, "inv_cycles_per_usec=%lu\n", inv_cycles_per_usec);
	316	#ifdef ARCH_CPU_CLOCK_WRAPS
	317	cycles_start = get_cpu_clock();
	318	dprint(FD_TIME, "cycles_start=%llu\n", cycles_start);
	319	#endif
	320	return 0;
	321	}
	322	#else
	323	static int calibrate_cpu_clock(void)
	324	{
	325	#ifdef ARCH_CPU_CLOCK_CYCLES_PER_USEC
	326	return 0;
	327	#else
	328	return 1;
	329	#endif
	330	}
	331	#endif // ARCH_HAVE_CPU_CLOCK
	332
	333	#ifndef CONFIG_TLS_THREAD
	334	void fio_local_clock_init(int is_thread)
	335	{
	336	struct tv_valid *t;
	337
	338	t = calloc(1, sizeof(*t));
	339	if (pthread_setspecific(tv_tls_key, t)) {
	340	log_err("fio: can't set TLS key\n");
	341	assert(0);
	342	}
	343	}
	344
	345	static void kill_tv_tls_key(void *data)
	346	{
	347	free(data);
	348	}
	349	#else
	350	void fio_local_clock_init(int is_thread)
	351	{
	352	}
	353	#endif
	354
	355	void fio_clock_init(void)
	356	{
	357	if (fio_clock_source == fio_clock_source_inited)
	358	return;
	359
	360	#ifndef CONFIG_TLS_THREAD
	361	if (pthread_key_create(&tv_tls_key, kill_tv_tls_key))
	362	log_err("fio: can't create TLS key\n");
	363	#endif
	364
	365	fio_clock_source_inited = fio_clock_source;
	366
	367	if (calibrate_cpu_clock())
	368	tsc_reliable = 0;
	369
	370	/*
	371	* If the arch sets tsc_reliable != 0, then it must be good enough
	372	* to use as THE clock source. For x86 CPUs, this means the TSC
	373	* runs at a constant rate and is synced across CPU cores.
	374	*/
	375	if (tsc_reliable) {
	376	if (!fio_clock_source_set && !fio_monotonic_clocktest(0))
	377	fio_clock_source = CS_CPUCLOCK;
	378	} else if (fio_clock_source == CS_CPUCLOCK)
	379	log_info("fio: clocksource=cpu may not be reliable\n");
	380	}
	381
	382	uint64_t utime_since(const struct timeval s, const struct timeval e)
	383	{
	384	int64_t sec, usec;
	385
	386	sec = e->tv_sec - s->tv_sec;
	387	usec = e->tv_usec - s->tv_usec;
	388	if (sec > 0 && usec < 0) {
	389	sec--;
	390	usec += 1000000;
	391	}
	392
	393	/*
	394	* time warp bug on some kernels?
	395	*/
	396	if (sec < 0 \|\| (sec == 0 && usec < 0))
	397	return 0;
	398
	399	return usec + (sec * 1000000);
	400	}
	401
	402	uint64_t utime_since_now(const struct timeval *s)
	403	{
	404	struct timeval t;
	405
	406	fio_gettime(&t, NULL);
	407	return utime_since(s, &t);
	408	}
	409
	410	uint64_t mtime_since(const struct timeval s, const struct timeval e)
	411	{
	412	long sec, usec;
	413
	414	sec = e->tv_sec - s->tv_sec;
	415	usec = e->tv_usec - s->tv_usec;
	416	if (sec > 0 && usec < 0) {
	417	sec--;
	418	usec += 1000000;
	419	}
	420
	421	if (sec < 0 \|\| (sec == 0 && usec < 0))
	422	return 0;
	423
	424	sec *= 1000;
	425	usec /= 1000;
	426	return sec + usec;
	427	}
	428
	429	uint64_t mtime_since_now(const struct timeval *s)
	430	{
	431	struct timeval t;
	432	void *p = __builtin_return_address(0);
	433
	434	fio_gettime(&t, p);
	435	return mtime_since(s, &t);
	436	}
	437
	438	uint64_t time_since_now(const struct timeval *s)
	439	{
	440	return mtime_since_now(s) / 1000;
	441	}
	442
	443	#if defined(FIO_HAVE_CPU_AFFINITY) && defined(ARCH_HAVE_CPU_CLOCK) && \
	444	defined(CONFIG_SFAA)
	445
	446	#define CLOCK_ENTRIES_DEBUG 100000
	447	#define CLOCK_ENTRIES_TEST 10000
	448
	449	struct clock_entry {
	450	uint32_t seq;
	451	uint32_t cpu;
	452	uint64_t tsc;
	453	};
	454
	455	struct clock_thread {
	456	pthread_t thread;
	457	int cpu;
	458	int debug;
	459	pthread_mutex_t lock;
	460	pthread_mutex_t started;
	461	unsigned long nr_entries;
	462	uint32_t *seq;
	463	struct clock_entry *entries;
	464	};
	465
	466	static inline uint32_t atomic32_inc_return(uint32_t *seq)
	467	{
	468	return 1 + __sync_fetch_and_add(seq, 1);
	469	}
	470
	471	static void clock_thread_fn(void data)
	472	{
	473	struct clock_thread *t = data;
	474	struct clock_entry *c;
	475	os_cpu_mask_t cpu_mask;
	476	uint32_t last_seq;
	477	unsigned long long first;
	478	int i;
	479
	480	if (fio_cpuset_init(&cpu_mask)) {
	481	int __err = errno;
	482
	483	log_err("clock cpuset init failed: %s\n", strerror(__err));
	484	goto err_out;
	485	}
	486
	487	fio_cpu_set(&cpu_mask, t->cpu);
	488
	489	if (fio_setaffinity(gettid(), cpu_mask) == -1) {
	490	int __err = errno;
	491
	492	log_err("clock setaffinity failed: %s\n", strerror(__err));
	493	goto err;
	494	}
	495
	496	pthread_mutex_lock(&t->lock);
	497	pthread_mutex_unlock(&t->started);
	498
	499	first = get_cpu_clock();
	500	last_seq = 0;
	501	c = &t->entries[0];
	502	for (i = 0; i < t->nr_entries; i++, c++) {
	503	uint32_t seq;
	504	uint64_t tsc;
	505
	506	c->cpu = t->cpu;
	507	do {
	508	seq = atomic32_inc_return(t->seq);
	509	if (seq < last_seq)
	510	break;
	511	tsc = get_cpu_clock();
	512	} while (seq != *t->seq);
	513
	514	c->seq = seq;
	515	c->tsc = tsc;
	516	}
	517
	518	if (t->debug) {
	519	unsigned long long clocks;
	520
	521	clocks = t->entries[i - 1].tsc - t->entries[0].tsc;
	522	log_info("cs: cpu%3d: %llu clocks seen, first %llu\n", t->cpu,
	523	clocks, first);
	524	}
	525
	526	/*
	527	* The most common platform clock breakage is returning zero
	528	* indefinitely. Check for that and return failure.
	529	*/
	530	if (!t->entries[i - 1].tsc && !t->entries[0].tsc)
	531	goto err;
	532
	533	fio_cpuset_exit(&cpu_mask);
	534	return NULL;
	535	err:
	536	fio_cpuset_exit(&cpu_mask);
	537	err_out:
	538	return (void *) 1;
	539	}
	540
	541	static int clock_cmp(const void p1, const void p2)
	542	{
	543	const struct clock_entry *c1 = p1;
	544	const struct clock_entry *c2 = p2;
	545
	546	if (c1->seq == c2->seq)
	547	log_err("cs: bug in atomic sequence!\n");
	548
	549	return c1->seq - c2->seq;
	550	}
	551
	552	int fio_monotonic_clocktest(int debug)
	553	{
	554	struct clock_thread *cthreads;
	555	unsigned int nr_cpus = cpus_online();
	556	struct clock_entry *entries;
	557	unsigned long nr_entries, tentries, failed = 0;
	558	struct clock_entry prev, this;
	559	uint32_t seq = 0;
	560	unsigned int i;
	561
	562	if (debug) {
	563	log_info("cs: reliable_tsc: %s\n", tsc_reliable ? "yes" : "no");
	564
	565	#ifdef FIO_INC_DEBUG
	566	fio_debug \|= 1U << FD_TIME;
	567	#endif
	568	nr_entries = CLOCK_ENTRIES_DEBUG;
	569	} else
	570	nr_entries = CLOCK_ENTRIES_TEST;
	571
	572	calibrate_cpu_clock();
	573
	574	if (debug) {
	575	#ifdef FIO_INC_DEBUG
	576	fio_debug &= ~(1U << FD_TIME);
	577	#endif
	578	}
	579
	580	cthreads = malloc(nr_cpus * sizeof(struct clock_thread));
	581	tentries = nr_entries * nr_cpus;
	582	entries = malloc(tentries * sizeof(struct clock_entry));
	583
	584	if (debug)
	585	log_info("cs: Testing %u CPUs\n", nr_cpus);
	586
	587	for (i = 0; i < nr_cpus; i++) {
	588	struct clock_thread *t = &cthreads[i];
	589
	590	t->cpu = i;
	591	t->debug = debug;
	592	t->seq = &seq;
	593	t->nr_entries = nr_entries;
	594	t->entries = &entries[i * nr_entries];
	595	pthread_mutex_init(&t->lock, NULL);
	596	pthread_mutex_init(&t->started, NULL);
	597	pthread_mutex_lock(&t->lock);
	598	if (pthread_create(&t->thread, NULL, clock_thread_fn, t)) {
	599	failed++;
	600	nr_cpus = i;
	601	break;
	602	}
	603	}
	604
	605	for (i = 0; i < nr_cpus; i++) {
	606	struct clock_thread *t = &cthreads[i];
	607
	608	pthread_mutex_lock(&t->started);
	609	}
	610
	611	for (i = 0; i < nr_cpus; i++) {
	612	struct clock_thread *t = &cthreads[i];
	613
	614	pthread_mutex_unlock(&t->lock);
	615	}
	616
	617	for (i = 0; i < nr_cpus; i++) {
	618	struct clock_thread *t = &cthreads[i];
	619	void *ret;
	620
	621	pthread_join(t->thread, &ret);
	622	if (ret)
	623	failed++;
	624	}
	625	free(cthreads);
	626
	627	if (failed) {
	628	if (debug)
	629	log_err("Clocksource test: %lu threads failed\n", failed);
	630	goto err;
	631	}
	632
	633	qsort(entries, tentries, sizeof(struct clock_entry), clock_cmp);
	634
	635	/* silence silly gcc */
	636	prev = NULL;
	637	for (failed = i = 0; i < tentries; i++) {
	638	this = &entries[i];
	639
	640	if (!i) {
	641	prev = this;
	642	continue;
	643	}
	644
	645	if (prev->tsc > this->tsc) {
	646	uint64_t diff = prev->tsc - this->tsc;
	647
	648	if (!debug) {
	649	failed++;
	650	break;
	651	}
	652
	653	log_info("cs: CPU clock mismatch (diff=%llu):\n",
	654	(unsigned long long) diff);
	655	log_info("\t CPU%3u: TSC=%llu, SEQ=%u\n", prev->cpu, (unsigned long long) prev->tsc, prev->seq);
	656	log_info("\t CPU%3u: TSC=%llu, SEQ=%u\n", this->cpu, (unsigned long long) this->tsc, this->seq);
	657	failed++;
	658	}
	659
	660	prev = this;
	661	}
	662
	663	if (debug) {
	664	if (failed)
	665	log_info("cs: Failed: %lu\n", failed);
	666	else
	667	log_info("cs: Pass!\n");
	668	}
	669	err:
	670	free(entries);
	671	return !!failed;
	672	}
	673
	674	#else /* defined(FIO_HAVE_CPU_AFFINITY) && defined(ARCH_HAVE_CPU_CLOCK) */
	675
	676	int fio_monotonic_clocktest(int debug)
	677	{
	678	if (debug)
	679	log_info("cs: current platform does not support CPU clocks\n");
	680	return 1;
	681	}
	682
	683	#endif