X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=gettime.c;h=172b4782b722fed95da4aadd456716cfdabae9eb;hp=e2746711d2e4e2b51b914a98a2c9d30e914beeda;hb=03be65c96360db94cde247bd46f523dfe5e61d12;hpb=27325ed5a4f770b681c6847352c547d51dbdeb62

diff --git a/gettime.c b/gettime.c
index e2746711..172b4782 100644
--- a/gettime.c
+++ b/gettime.c
@@ -16,6 +16,8 @@
 #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;
+static uint64_t max_cycles_for_mult;
+static unsigned long long cycles_start, cycles_wrap;
 #endif
 int tsc_reliable = 0;
 
@@ -24,11 +26,13 @@ struct tv_valid {
 	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;
@@ -64,7 +68,7 @@ static struct gtod_log *find_hash(void *caller)
 	return NULL;
 }
 
-static struct gtod_log *find_log(void *caller)
+static void inc_caller(void *caller)
 {
 	struct gtod_log *log = find_hash(caller);
 
@@ -80,16 +84,13 @@ static struct gtod_log *find_log(void *caller)
 		flist_add_tail(&log->list, &hash[h]);
 	}
 
-	return log;
+	log->calls++;
 }
 
 static void gtod_log_caller(void *caller)
 {
-	if (gtod_inited) {
-		struct gtod_log *log = find_log(caller);
-
-		log->calls++;
-	}
+	if (gtod_inited)
+		inc_caller(caller);
 }
 
 static void fio_exit fio_dump_gtod(void)
@@ -138,14 +139,6 @@ static int fill_clock_gettime(struct timespec *ts)
 
 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:
@@ -169,20 +162,32 @@ static void __fio_gettime(struct timeval *tp)
 #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();
-		if (t < tv->last_cycles && tv->last_tv_valid &&
-		    !tv->warned) {
-			log_err("fio: CPU clock going back in time\n");
+		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;
 		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;
+		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;
@@ -296,7 +301,10 @@ static int calibrate_cpu_clock(void)
 
 	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);
+	cycles_start = get_cpu_clock();
+	dprint(FD_TIME, "cycles_start=%llu\n", cycles_start);
 	return 0;
 }
 #else