[PATCH] Improve rate functionality
usec_sleep() now takes into account the granularity of nanosleep().
Also stop using the remainder returned by nanosleep(), it doesn't
appear to always be accurate. Instead just check the elapsed time
manually.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fio.c b/fio.c
index 84819d9..225aaa4 100644
--- a/fio.c
+++ b/fio.c
@@ -449,7 +449,7 @@
if (check_min_rate(td, &icd.time)) {
if (exitall_on_terminate)
terminate_threads(td->groupid, 0);
- td_verror(td, ENOMEM);
+ td_verror(td, ENODATA);
break;
}
diff --git a/time.c b/time.c
index d0ecbe5..08ef078 100644
--- a/time.c
+++ b/time.c
@@ -4,6 +4,7 @@
#include "fio.h"
static struct timeval genesis;
+static unsigned long ns_granularity;
unsigned long utime_since(struct timeval *s, struct timeval *e)
{
@@ -74,28 +75,36 @@
void usec_sleep(struct thread_data *td, unsigned long usec)
{
- struct timespec req, rem;
-
- req.tv_sec = usec / 1000000;
- req.tv_nsec = usec * 1000 - req.tv_sec * 1000000;
+ struct timespec req;
+ struct timeval tv;
do {
- if (usec < 5000) {
+ unsigned long ts = usec;
+
+ if (usec < ns_granularity) {
__usec_sleep(usec);
break;
}
- rem.tv_sec = rem.tv_nsec = 0;
- if (nanosleep(&req, &rem) < 0)
+ ts = usec - ns_granularity;
+
+ if (ts >= 1000000) {
+ req.tv_sec = ts / 1000000;
+ ts -= 1000000 * req.tv_sec;
+ } else
+ req.tv_sec = 0;
+
+ req.tv_nsec = ts * 1000;
+ fio_gettime(&tv, NULL);
+
+ if (nanosleep(&req, NULL) < 0)
break;
- if ((rem.tv_sec + rem.tv_nsec) == 0)
+ ts = utime_since_now(&tv);
+ if (ts >= usec)
break;
- req.tv_nsec = rem.tv_nsec;
- req.tv_sec = rem.tv_sec;
-
- usec = rem.tv_sec * 1000000 + rem.tv_nsec / 1000;
+ usec -= ts;
} while (!td->terminate);
}
@@ -131,7 +140,28 @@
static void fio_init time_init(void)
{
+ int i;
+
fio_gettime(&genesis, NULL);
+
+ /*
+ * Check the granularity of the nanosleep function
+ */
+ for (i = 0; i < 10; i++) {
+ struct timeval tv;
+ struct timespec ts;
+ unsigned long elapsed;
+
+ fio_gettime(&tv, NULL);
+ ts.tv_sec = 0;
+ ts.tv_nsec = 1000;
+
+ nanosleep(&ts, NULL);
+ elapsed = utime_since_now(&tv);
+
+ if (elapsed > ns_granularity)
+ ns_granularity = elapsed;
+ }
}
void fill_start_time(struct timeval *t)