X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=gettime.c;h=e2746711d2e4e2b51b914a98a2c9d30e914beeda;hp=d56045c58919812df17d46dd8148b78471810190;hb=27325ed5a4f770b681c6847352c547d51dbdeb62;hpb=e259879ea353f5695a8be662b2748c4f4d0918d9

diff --git a/gettime.c b/gettime.c
index d56045c5..e2746711 100644
--- a/gettime.c
+++ b/gettime.c
@@ -13,26 +13,26 @@
 #include "hash.h"
 #include "os/os.h"
 
-#ifdef ARCH_HAVE_CPU_CLOCK
+#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 {
-	struct timeval last_tv;
 	uint64_t last_cycles;
 	int last_tv_valid;
+	int warned;
 };
 #ifdef CONFIG_TLS_THREAD
-static struct tv_valid __thread static_tv_valid;
+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;
-enum fio_cs fio_clock_source_inited = CS_INVAL;
+static enum fio_cs fio_clock_source_inited = CS_INVAL;
 
 #ifdef FIO_DEBUG_TIME
 
@@ -136,7 +136,7 @@ static int fill_clock_gettime(struct timespec *ts)
 }
 #endif
 
-static void *__fio_gettime(struct timeval *tp)
+static void __fio_gettime(struct timeval *tp)
 {
 	struct tv_valid *tv;
 
@@ -171,13 +171,19 @@ static void *__fio_gettime(struct timeval *tp)
 		uint64_t usecs, t;
 
 		t = get_cpu_clock();
-		if (tv && t < tv->last_cycles) {
-			dprint(FD_TIME, "CPU clock going back in time\n");
-			t = tv->last_cycles;
-		} else if (tv)
-			tv->last_cycles = t;
+		if (t < tv->last_cycles && tv->last_tv_valid &&
+		    !tv->warned) {
+			log_err("fio: CPU clock going back in time\n");
+			tv->warned = 1;
+		}
 
+		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;
@@ -187,8 +193,6 @@ static void *__fio_gettime(struct timeval *tp)
 		log_err("fio: invalid clock source %d\n", fio_clock_source);
 		break;
 	}
-
-	return tv;
 }
 
 #ifdef FIO_DEBUG_TIME
@@ -197,39 +201,19 @@ void fio_gettime(struct timeval *tp, void *caller)
 void fio_gettime(struct timeval *tp, void fio_unused *caller)
 #endif
 {
-	struct tv_valid *tv;
-
 #ifdef FIO_DEBUG_TIME
 	if (!caller)
 		caller = __builtin_return_address(0);
 
 	gtod_log_caller(caller);
 #endif
-	if (fio_tv) {
-		memcpy(tp, fio_tv, sizeof(*tp));
+	if (fio_unlikely(fio_gettime_offload(tp)))
 		return;
-	}
-
-	tv = __fio_gettime(tp);
 
-	/*
-	 * If Linux is using the tsc clock on non-synced processors,
-	 * sometimes time can appear to drift backwards. Fix that up.
-	 */
-	if (tv) {
-		if (tv->last_tv_valid) {
-			if (tp->tv_sec < tv->last_tv.tv_sec)
-				tp->tv_sec = tv->last_tv.tv_sec;
-			else if (tv->last_tv.tv_sec == tp->tv_sec &&
-				 tp->tv_usec < tv->last_tv.tv_usec)
-				tp->tv_usec = tv->last_tv.tv_usec;
-		}
-		tv->last_tv_valid = 1;
-		memcpy(&tv->last_tv, tp, sizeof(*tp));
-	}
+	__fio_gettime(tp);
 }
 
-#ifdef ARCH_HAVE_CPU_CLOCK
+#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;
@@ -302,11 +286,12 @@ static int calibrate_cpu_clock(void)
 	mean /= 10.0;
 
 	for (i = 0; i < NR_TIME_ITERS; i++)
-		dprint(FD_TIME, "cycles[%d]=%lu\n", i, cycles[i] / 10);
+		dprint(FD_TIME, "cycles[%d]=%llu\n", i,
+					(unsigned long long) cycles[i] / 10);
 
 	avg /= samples;
 	avg = (avg + 5) / 10;
-	dprint(FD_TIME, "avg: %lu\n", avg);
+	dprint(FD_TIME, "avg: %llu\n", (unsigned long long) avg);
 	dprint(FD_TIME, "mean=%f, S=%f\n", mean, S);
 
 	cycles_per_usec = avg;
@@ -317,18 +302,24 @@ static int calibrate_cpu_clock(void)
 #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(sizeof(*t), 1);
-	if (pthread_setspecific(tv_tls_key, 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)
@@ -368,7 +359,7 @@ void fio_clock_init(void)
 		log_info("fio: clocksource=cpu may not be reliable\n");
 }
 
-uint64_t utime_since(struct timeval *s, struct timeval *e)
+uint64_t utime_since(const struct timeval *s, const struct timeval *e)
 {
 	long sec, usec;
 	uint64_t ret;
@@ -391,7 +382,7 @@ uint64_t utime_since(struct timeval *s, struct timeval *e)
 	return ret;
 }
 
-uint64_t utime_since_now(struct timeval *s)
+uint64_t utime_since_now(const struct timeval *s)
 {
 	struct timeval t;
 
@@ -399,7 +390,7 @@ uint64_t utime_since_now(struct timeval *s)
 	return utime_since(s, &t);
 }
 
-uint64_t mtime_since(struct timeval *s, struct timeval *e)
+uint64_t mtime_since(const struct timeval *s, const struct timeval *e)
 {
 	long sec, usec, ret;
 
@@ -420,7 +411,7 @@ uint64_t mtime_since(struct timeval *s, struct timeval *e)
 	return ret;
 }
 
-uint64_t mtime_since_now(struct timeval *s)
+uint64_t mtime_since_now(const struct timeval *s)
 {
 	struct timeval t;
 	void *p = __builtin_return_address(0);
@@ -429,7 +420,7 @@ uint64_t mtime_since_now(struct timeval *s)
 	return mtime_since(s, &t);
 }
 
-uint64_t time_since_now(struct timeval *s)
+uint64_t time_since_now(const struct timeval *s)
 {
 	return mtime_since_now(s) / 1000;
 }
@@ -440,9 +431,9 @@ uint64_t time_since_now(struct timeval *s)
 #define CLOCK_ENTRIES	100000
 
 struct clock_entry {
-	uint64_t seq;
+	uint32_t seq;
+	uint32_t cpu;
 	uint64_t tsc;
-	uint64_t cpu;
 };
 
 struct clock_thread {
@@ -450,11 +441,11 @@ struct clock_thread {
 	int cpu;
 	pthread_mutex_t lock;
 	pthread_mutex_t started;
-	uint64_t *seq;
+	uint32_t *seq;
 	struct clock_entry *entries;
 };
 
-static inline uint64_t atomic64_inc_return(uint64_t *seq)
+static inline uint32_t atomic32_inc_return(uint32_t *seq)
 {
 	return 1 + __sync_fetch_and_add(seq, 1);
 }
@@ -464,6 +455,7 @@ 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));
@@ -477,13 +469,17 @@ static void *clock_thread_fn(void *data)
 	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++) {
-		uint64_t seq, tsc;
+		uint32_t seq;
+		uint64_t tsc;
 
 		c->cpu = t->cpu;
 		do {
-			seq = atomic64_inc_return(t->seq);
+			seq = atomic32_inc_return(t->seq);
+			if (seq < last_seq)
+				break;
 			tsc = get_cpu_clock();
 		} while (seq != *t->seq);
 
@@ -491,12 +487,14 @@ static void *clock_thread_fn(void *data)
 		c->tsc = tsc;
 	}
 
-	log_info("cs: cpu%3d: %lu clocks seen\n", t->cpu, t->entries[CLOCK_ENTRIES - 1].tsc - t->entries[0].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[CLOCK_ENTRIES - 1].tsc && !t->entries[0].tsc)
+	if (!t->entries[i - 1].tsc && !t->entries[0].tsc)
 		return (void *) 1;
 
 	return NULL;
@@ -515,28 +513,32 @@ static int clock_cmp(const void *p1, const void *p2)
 
 int fio_monotonic_clocktest(void)
 {
-	struct clock_thread *threads;
+	struct clock_thread *cthreads;
 	unsigned int nr_cpus = cpus_online();
 	struct clock_entry *entries;
-	unsigned long tentries, failed;
+	unsigned long tentries, failed = 0;
 	struct clock_entry *prev, *this;
-	uint64_t seq = 0;
-	int i;
+	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
 
-	threads = malloc(nr_cpus * sizeof(struct clock_thread));
+	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 = &threads[i];
+		struct clock_thread *t = &cthreads[i];
 
 		t->cpu = i;
 		t->seq = &seq;
@@ -544,33 +546,37 @@ int fio_monotonic_clocktest(void)
 		pthread_mutex_init(&t->lock, NULL);
 		pthread_mutex_init(&t->started, NULL);
 		pthread_mutex_lock(&t->lock);
-		pthread_create(&t->thread, NULL, clock_thread_fn, t);
+		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 = &threads[i];
+		struct clock_thread *t = &cthreads[i];
 
 		pthread_mutex_lock(&t->started);
 	}
 
 	for (i = 0; i < nr_cpus; i++) {
-		struct clock_thread *t = &threads[i];
+		struct clock_thread *t = &cthreads[i];
 
 		pthread_mutex_unlock(&t->lock);
 	}
 
-	for (failed = i = 0; i < nr_cpus; i++) {
-		struct clock_thread *t = &threads[i];
+	for (i = 0; i < nr_cpus; i++) {
+		struct clock_thread *t = &cthreads[i];
 		void *ret;
 
 		pthread_join(t->thread, &ret);
 		if (ret)
 			failed++;
 	}
-	free(threads);
+	free(cthreads);
 
 	if (failed) {
-		log_err("Clocksource test: %u threads failed\n", failed);
+		log_err("Clocksource test: %lu threads failed\n", failed);
 		goto err;
 	}
 
@@ -587,9 +593,10 @@ int fio_monotonic_clocktest(void)
 		if (prev->tsc > this->tsc) {
 			uint64_t diff = prev->tsc - this->tsc;
 
-			log_info("cs: CPU clock mismatch (diff=%lu):\n", diff);
-			log_info("\t CPU%3lu: TSC=%lu, SEQ=%lu\n", prev->cpu, prev->tsc, prev->seq);
-			log_info("\t CPU%3lu: TSC=%lu, SEQ=%lu\n", this->cpu, this->tsc, this->seq);
+			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++;
 		}