On 07.09.15 15:42, Petri Savolainen wrote:
Use CPU cycle count API instead of time API to measure CPU
cycles.
Signed-off-by: Petri Savolainen <[email protected]>
---
test/performance/odp_scheduling.c | 132 ++++++++++++++++----------------------
1 file changed, 57 insertions(+), 75 deletions(-)
diff --git a/test/performance/odp_scheduling.c
b/test/performance/odp_scheduling.c
index 2a7e531..b1206e8 100644
--- a/test/performance/odp_scheduling.c
+++ b/test/performance/odp_scheduling.c
@@ -183,9 +183,9 @@ static int test_alloc_single(int thr, odp_pool_t pool)
{
int i;
odp_buffer_t temp_buf;
- uint64_t t1, t2, cycles, ns;
+ uint64_t c1, c2, cycles;
- t1 = odp_time_cycles();
+ c1 = odp_cpu_cycles();
for (i = 0; i < ALLOC_ROUNDS; i++) {
temp_buf = odp_buffer_alloc(pool);
@@ -198,12 +198,11 @@ static int test_alloc_single(int thr, odp_pool_t pool)
odp_buffer_free(temp_buf);
}
- t2 = odp_time_cycles();
- cycles = odp_time_diff_cycles(t1, t2);
- ns = odp_time_cycles_to_ns(cycles);
+ c2 = odp_cpu_cycles();
+ cycles = odp_cpu_cycles_diff(c1, c2);
- printf(" [%i] alloc_sng alloc+free %"PRIu64" cycles, %"PRIu64" ns\n",
- thr, cycles/ALLOC_ROUNDS, ns/ALLOC_ROUNDS);
+ printf(" [%i] alloc_sng alloc+free %4" PRIu64 " CPU cycles\n",
+ thr, cycles / ALLOC_ROUNDS);
return 0;
}
@@ -220,9 +219,9 @@ static int test_alloc_multi(int thr, odp_pool_t pool)
{
int i, j;
odp_buffer_t temp_buf[MAX_ALLOCS];
- uint64_t t1, t2, cycles, ns;
+ uint64_t c1, c2, cycles;
- t1 = odp_time_cycles();
+ c1 = odp_cpu_cycles();
for (i = 0; i < ALLOC_ROUNDS; i++) {
for (j = 0; j < MAX_ALLOCS; j++) {
@@ -238,13 +237,11 @@ static int test_alloc_multi(int thr, odp_pool_t pool)
odp_buffer_free(temp_buf[j-1]);
}
- t2 = odp_time_cycles();
- cycles = odp_time_diff_cycles(t1, t2);
- ns = odp_time_cycles_to_ns(cycles);
+ c2 = odp_cpu_cycles();
+ cycles = odp_cpu_cycles_diff(c1, c2);
- printf(" [%i] alloc_multi alloc+free %"PRIu64" cycles, %"PRIu64" ns\n",
- thr, cycles/(ALLOC_ROUNDS*MAX_ALLOCS),
- ns/(ALLOC_ROUNDS*MAX_ALLOCS));
+ printf(" [%i] alloc_multi alloc+free %4" PRIu64 " CPU cycles\n",
I'd rather not limit it to 4 (%4) and leave as is, as we never can be sure that
test works as expected. I mean all printfs in this patch.
+ thr, cycles / (ALLOC_ROUNDS * MAX_ALLOCS));
return 0;
}
@@ -265,7 +262,7 @@ static int test_poll_queue(int thr, odp_pool_t msg_pool)
odp_buffer_t buf;
test_message_t *t_msg;
odp_queue_t queue;
- uint64_t t1, t2, cycles, ns;
+ uint64_t c1, c2, cycles;
int i;
/* Alloc test message */
@@ -289,7 +286,7 @@ static int test_poll_queue(int thr, odp_pool_t msg_pool)
return -1;
}
- t1 = odp_time_cycles();
+ c1 = odp_cpu_cycles();
for (i = 0; i < QUEUE_ROUNDS; i++) {
ev = odp_buffer_to_event(buf);
@@ -310,12 +307,11 @@ static int test_poll_queue(int thr, odp_pool_t msg_pool)
}
}
- t2 = odp_time_cycles();
- cycles = odp_time_diff_cycles(t1, t2);
- ns = odp_time_cycles_to_ns(cycles);
+ c2 = odp_cpu_cycles();
+ cycles = odp_cpu_cycles_diff(c1, c2);
- printf(" [%i] poll_queue enq+deq %"PRIu64" cycles, %"PRIu64" ns\n",
- thr, cycles/QUEUE_ROUNDS, ns/QUEUE_ROUNDS);
+ printf(" [%i] poll_queue enq+deq %4" PRIu64 " CPU cycles\n",
+ thr, cycles / QUEUE_ROUNDS);
odp_buffer_free(buf);
return 0;
@@ -341,14 +337,14 @@ static int test_schedule_single(const char *str, int thr,
{
odp_event_t ev;
odp_queue_t queue;
- uint64_t t1, t2, cycles, ns;
+ uint64_t c1, c2, cycles;
uint32_t i;
uint32_t tot;
if (create_queue(thr, msg_pool, prio))
return -1;
- t1 = odp_time_cycles();
+ c1 = odp_cpu_cycles();
for (i = 0; i < QUEUE_ROUNDS; i++) {
ev = odp_schedule(&queue, ODP_SCHED_WAIT);
@@ -382,18 +378,15 @@ static int test_schedule_single(const char *str, int thr,
odp_schedule_resume();
- t2 = odp_time_cycles();
- cycles = odp_time_diff_cycles(t1, t2);
- ns = odp_time_cycles_to_ns(cycles);
+ c2 = odp_cpu_cycles();
+ cycles = odp_cpu_cycles_diff(c1, c2);
odp_barrier_wait(barrier);
clear_sched_queues();
cycles = cycles/tot;
- ns = ns/tot;
- printf(" [%i] %s enq+deq %"PRIu64" cycles, %"PRIu64" ns\n",
- thr, str, cycles, ns);
+ printf(" [%i] %s enq+deq %4" PRIu64 " CPU cycles\n", thr, str, cycles);
return 0;
}
@@ -419,9 +412,7 @@ static int test_schedule_many(const char *str, int thr,
{
odp_event_t ev;
odp_queue_t queue;
- uint64_t t1;
- uint64_t t2;
- uint64_t cycles, ns;
+ uint64_t c1, c2, cycles;
uint32_t i;
uint32_t tot;
@@ -429,7 +420,7 @@ static int test_schedule_many(const char *str, int thr,
return -1;
/* Start sched-enq loop */
- t1 = odp_time_cycles();
+ c1 = odp_cpu_cycles();
for (i = 0; i < QUEUE_ROUNDS; i++) {
ev = odp_schedule(&queue, ODP_SCHED_WAIT);
@@ -463,18 +454,15 @@ static int test_schedule_many(const char *str, int thr,
odp_schedule_resume();
- t2 = odp_time_cycles();
- cycles = odp_time_diff_cycles(t1, t2);
- ns = odp_time_cycles_to_ns(cycles);
+ c2 = odp_cpu_cycles();
+ cycles = odp_cpu_cycles_diff(c1, c2);
odp_barrier_wait(barrier);
clear_sched_queues();
cycles = cycles/tot;
I know that it's not from change, but printf is changed,
maybe in order to keep module style, put cycles / tot in printf.
- ns = ns/tot;
- printf(" [%i] %s enq+deq %"PRIu64" cycles, %"PRIu64" ns\n",
- thr, str, cycles, ns);
+ printf(" [%i] %s enq+deq %4" PRIu64 " CPU cycles\n", thr, str, cycles);
return 0;
}
@@ -496,9 +484,7 @@ static int test_schedule_multi(const char *str, int thr,
{
odp_event_t ev[MULTI_BUFS_MAX];
odp_queue_t queue;
- uint64_t t1;
- uint64_t t2;
- uint64_t cycles, ns;
+ uint64_t c1, c2, cycles;
int i, j;
int num;
uint32_t tot = 0;
@@ -547,7 +533,7 @@ static int test_schedule_multi(const char *str, int thr,
}
/* Start sched-enq loop */
- t1 = odp_time_cycles();
+ c1 = odp_cpu_cycles();
for (i = 0; i < QUEUE_ROUNDS; i++) {
num = odp_schedule_multi(&queue, ODP_SCHED_WAIT, ev,
@@ -584,23 +570,18 @@ static int test_schedule_multi(const char *str, int thr,
odp_schedule_resume();
- t2 = odp_time_cycles();
- cycles = odp_time_diff_cycles(t1, t2);
- ns = odp_time_cycles_to_ns(cycles);
+ c2 = odp_cpu_cycles();
+ cycles = odp_cpu_cycles_diff(c1, c2);
odp_barrier_wait(barrier);
clear_sched_queues();
- if (tot) {
+ if (tot)
cycles = cycles/tot;
- ns = ns/tot;
- } else {
+ else
cycles = 0;
- ns = 0;
- }
- printf(" [%i] %s enq+deq %"PRIu64" cycles, %"PRIu64" ns\n",
- thr, str, cycles, ns);
+ printf(" [%i] %s enq+deq %4" PRIu64 " CPU cycles\n", thr, str, cycles);
return 0;
}
@@ -714,21 +695,21 @@ static void *run_thread(void *arg)
}
/**
- * @internal Test cycle counter accuracy
+ * @internal Test cycle counter frequency
*/
-static void test_time(void)
+static void test_cpu_freq(void)
Why? maybe test_cpu_cycles*...
{
struct timespec tp1, tp2;
- uint64_t t1, t2;
- uint64_t ns1, ns2, cycles;
- double err;
+ uint64_t c1, c2, cycles;
+ uint64_t nsec;
+ double diff_max_hz, max_cycles;
if (clock_gettime(CLOCK_MONOTONIC, &tp2)) {
LOG_ERR("clock_gettime failed.\n");
return;
}
- printf("\nTime accuracy test (%i sec)\n", TEST_SEC);
+ printf("\nCPU cycle count accuracy test (%i sec)\n", TEST_SEC);
Maybe beter to put this line under clock_gettime? In order to not miss
t1 == t2? Maybe here it's not so important but if it's going to be
replaced on odp_time, better to do it here, anyway printf is changed.
do {
if (clock_gettime(CLOCK_MONOTONIC, &tp1)) {
@@ -738,7 +719,7 @@ static void test_time(void)
} while (tp1.tv_sec == tp2.tv_sec);
- t1 = odp_time_cycles();
+ c1 = odp_cpu_cycles();
do {
if (clock_gettime(CLOCK_MONOTONIC, &tp2)) {
@@ -748,24 +729,25 @@ static void test_time(void)
} while ((tp2.tv_sec - tp1.tv_sec) < TEST_SEC);
- t2 = odp_time_cycles();
+ c2 = odp_cpu_cycles();
- ns1 = (tp2.tv_sec - tp1.tv_sec)*1000000000;
+ nsec = (tp2.tv_sec - tp1.tv_sec) * 1000000000;
Maybe better to use sec here? Then no need to divide on 10000000000 double
later.
Divide only in printf.
and maybe ODP_TIME_SEC?
Aslo is it correct to use clock_gettime here?
Better to replace on time API probably. (I am ready to do that after)
if (tp2.tv_nsec > tp1.tv_nsec)
- ns1 += tp2.tv_nsec - tp1.tv_nsec;
+ nsec += tp2.tv_nsec - tp1.tv_nsec;
else
- ns1 -= tp1.tv_nsec - tp2.tv_nsec;
+ nsec -= tp1.tv_nsec - tp2.tv_nsec;
- cycles = odp_time_diff_cycles(t1, t2);
- ns2 = odp_time_cycles_to_ns(cycles);
+ cycles = odp_cpu_cycles_diff(c1, c2);
+ max_cycles = (nsec * odp_sys_cpu_hz()) / 1000000000.0;
That case could be impacted by cpufreq change...I believe that it's static.
- err = ((double)(ns2) - (double)ns1) / (double)ns1;
+ /* Compare measured CPU cycles to maximum theoretical CPU cycle count */
+ diff_max_hz = ((double)(cycles) - max_cycles) / max_cycles;
It's expected here to be -X%, but due to "time measurement" can have resolution
impact,
can happen that it will be +X%...that is confusing. Is it OK?
- printf("clock_gettime %"PRIu64" ns\n", ns1);
- printf("odp_time_cycles %"PRIu64" cycles\n", cycles);
- printf("odp_time_cycles_to_ns %"PRIu64" ns\n", ns2);
- printf("odp get cycle error %f%%\n", err*100.0);
+ printf("clock_gettime %" PRIu64 " ns\n", nsec);
+ printf("odp_cpu_cycles %" PRIu64 " CPU cycles\n", cycles);
+ printf("odp_sys_cpu_hz %" PRIu64 " hz\n", odp_sys_cpu_hz());
+ printf("Diff from max CPU freq %f%%\n", diff_max_hz * 100.0);
printf("\n");
}
@@ -879,7 +861,7 @@ int main(int argc, char *argv[])
printf("---------------\n");
printf("ODP API version: %s\n", odp_version_api_str());
printf("CPU model: %s\n", odp_sys_cpu_model_str());
- printf("CPU freq (hz): %"PRIu64"\n", odp_sys_cpu_hz());
+ printf("CPU freq (hz): %" PRIu64 "\n", odp_sys_cpu_hz());
printf("Cache line size: %i\n", odp_sys_cache_line_size());
printf("Max CPU count: %i\n", odp_cpu_count());
@@ -898,8 +880,8 @@ int main(int argc, char *argv[])
printf("first CPU: %i\n", odp_cpumask_first(&cpumask));
printf("cpu mask: %s\n", cpumaskstr);
- /* Test cycle count accuracy */
- test_time();
+ /* Test cycle count frequency */
+ test_cpu_freq();
shm = odp_shm_reserve("test_globals",
sizeof(test_globals_t), ODP_CACHE_LINE_SIZE, 0);
--
Regards,
Ivan Khoronzhuk
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