X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=gettime.c;h=4c998e5ff89f1dc72503f01f2552cdde78538437;hp=5c0e44576f2b3392fd0c982b2ee35a95c06cec3a;hb=0f78b22cb13d2e59b134ee80bafa669679504bd6;hpb=372fd659ee6a652d373ae0b4420c23c5fa9e4dc0

diff --git a/gettime.c b/gettime.c
index 5c0e4457..4c998e5f 100644
--- a/gettime.c
+++ b/gettime.c
@@ -262,7 +262,7 @@ static unsigned long get_cycles_per_usec(void)
 
 #define NR_TIME_ITERS	50
 
-static void calibrate_cpu_clock(void)
+static int calibrate_cpu_clock(void)
 {
 	double delta, mean, S;
 	uint64_t avg, cycles[NR_TIME_ITERS];
@@ -279,6 +279,13 @@ static void calibrate_cpu_clock(void)
 		}
 	}
 
+	/*
+	 * 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;
@@ -295,20 +302,23 @@ static void 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;
 	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 void calibrate_cpu_clock(void)
+static int calibrate_cpu_clock(void)
 {
+	return 1;
 }
 #endif
 
@@ -342,16 +352,10 @@ void fio_clock_init(void)
 		log_err("fio: can't create TLS key\n");
 #endif
 
-	/*
-	 * Probably an AMD issue, will need to investigate. Until that
-	 * is done, disable the CPU clock.
-	 */
-#if FIO_OS == os_solaris
-	tsc_reliable = 0;
-#endif
-
 	fio_clock_source_inited = fio_clock_source;
-	calibrate_cpu_clock();
+
+	if (calibrate_cpu_clock())
+		tsc_reliable = 0;
 
 	/*
 	 * If the arch sets tsc_reliable != 0, then it must be good enough
@@ -437,9 +441,9 @@ 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 {
@@ -447,11 +451,11 @@ 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);
 }
@@ -461,6 +465,7 @@ 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));
@@ -474,13 +479,17 @@ 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);
 
@@ -488,7 +497,16 @@ 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[i - 1].tsc && !t->entries[0].tsc)
+		return (void *) 1;
+
 	return NULL;
 }
 
@@ -509,7 +527,8 @@ int fio_monotonic_clocktest(void)
 	unsigned int nr_cpus = cpus_online();
 	struct clock_entry *entries;
 	unsigned long tentries, failed;
-	uint64_t seq = 0;
+	struct clock_entry *prev, *this;
+	uint32_t seq = 0;
 	int i;
 
 	log_info("cs: reliable_tsc: %s\n", tsc_reliable ? "yes" : "no");
@@ -566,7 +585,7 @@ int fio_monotonic_clocktest(void)
 	qsort(entries, tentries, sizeof(struct clock_entry), clock_cmp);
 
 	for (failed = i = 0; i < tentries; i++) {
-		struct clock_entry *prev, *this = &entries[i];
+		this = &entries[i];
 
 		if (!i) {
 			prev = this;