mutex: make 0/1 FIO_MUTEX_LOCKED and FIO_MUTEX_UNLOCKED

[fio.git] / gettime.c

diff --git a/gettime.c b/gettime.c
index 72fda3f8597e335be2fc4677a208f02db9fa62b7..5b4928758b47f83c729082e399820ae2edc09a26 100644 (file)
--- a/gettime.c
+++ b/gettime.c
@@ -22,8 +22,9 @@ static int last_tv_valid;
 static struct timeval *fio_tv;
 int fio_gtod_offload = 0;
 int fio_gtod_cpu = -1;
+static pthread_t gtod_thread;
 
-enum fio_cs fio_clock_source = CS_GTOD;
+enum fio_cs fio_clock_source = FIO_PREFERRED_CLOCK_SOURCE;
 
 #ifdef FIO_DEBUG_TIME
 
@@ -140,7 +141,11 @@ void fio_gettime(struct timeval *tp, void fio_unused *caller)
        case CS_CGETTIME: {
                struct timespec ts;
 
+#ifdef FIO_HAVE_CLOCK_MONOTONIC
+               if (clock_gettime(CLOCK_MONOTONIC, &ts) < 0) {
+#else
                if (clock_gettime(CLOCK_REALTIME, &ts) < 0) {
+#endif
                        log_err("fio: clock_gettime fails\n");
                        assert(0);
                }
@@ -268,7 +273,60 @@ void fio_gtod_init(void)
        assert(fio_tv);
 }
 
-void fio_gtod_update(void)
+static void fio_gtod_update(void)
 {
        gettimeofday(fio_tv, NULL);
 }
+
+static void *gtod_thread_main(void *data)
+{
+       struct fio_mutex *mutex = data;
+
+       fio_mutex_up(mutex);
+
+       /*
+        * As long as we have jobs around, update the clock. It would be nice
+        * to have some way of NOT hammering that CPU with gettimeofday(),
+        * but I'm not sure what to use outside of a simple CPU nop to relax
+        * it - we don't want to lose precision.
+        */
+       while (threads) {
+               fio_gtod_update();
+               nop;
+       }
+
+       return NULL;
+}
+
+int fio_start_gtod_thread(void)
+{
+       struct fio_mutex *mutex;
+       pthread_attr_t attr;
+       int ret;
+
+       mutex = fio_mutex_init(FIO_MUTEX_LOCKED);
+       if (!mutex)
+               return 1;
+
+       pthread_attr_init(&attr);
+       pthread_attr_setstacksize(&attr, PTHREAD_STACK_MIN);
+       ret = pthread_create(&gtod_thread, &attr, gtod_thread_main, NULL);
+       pthread_attr_destroy(&attr);
+       if (ret) {
+               log_err("Can't create gtod thread: %s\n", strerror(ret));
+               goto err;
+       }
+
+       ret = pthread_detach(gtod_thread);
+       if (ret) {
+               log_err("Can't detatch gtod thread: %s\n", strerror(ret));
+               goto err;
+       }
+
+       dprint(FD_MUTEX, "wait on startup_mutex\n");
+       fio_mutex_down(mutex);
+       dprint(FD_MUTEX, "done waiting on startup_mutex\n");
+err:
+       fio_mutex_remove(mutex);
+       return ret;
+}