gettime: improve gettimeofday() offload support

[fio.git] / gettime.c

diff --git a/gettime.c b/gettime.c
index 9f8362090095c2d679c2b568274649d931aa8942..e2746711d2e4e2b51b914a98a2c9d30e914beeda 100644 (file)
--- a/gettime.c
+++ b/gettime.c
@@ -20,9 +20,9 @@ static unsigned long inv_cycles_per_usec;
 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 __thread struct tv_valid static_tv_valid;
@@ -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;
 
@@ -171,12 +171,14 @@ 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
@@ -191,8 +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
@@ -201,36 +201,16 @@ 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_unlikely(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);
 }
 
 #if defined(ARCH_HAVE_CPU_CLOCK) && !defined(ARCH_CPU_CLOCK_CYCLES_PER_USEC)
@@ -336,8 +316,10 @@ void fio_local_clock_init(int is_thread)
        struct tv_valid *t;
 
        t = calloc(1, sizeof(*t));
-       if (pthread_setspecific(tv_tls_key, 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)
@@ -531,7 +513,7 @@ 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 = 0;
@@ -549,14 +531,14 @@ int fio_monotonic_clocktest(void)
        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;
@@ -572,26 +554,26 @@ int fio_monotonic_clocktest(void)
        }
 
        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 (i = 0; i < nr_cpus; i++) {
-               struct clock_thread *t = &threads[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: %lu threads failed\n", failed);