Reducing the impact of the cntvct_el0 register and isb() operation
on microbenchmark test results to improve testing accuracy and reduce
latency in test results.
Signed-off-by: heqiong <heqiong1557@xxxxxxxxxxxxxx>
---
arm/micro-bench.c | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)
diff --git a/arm/micro-bench.c b/arm/micro-bench.c
index fbe59d03..22408955 100644
--- a/arm/micro-bench.c
+++ b/arm/micro-bench.c
@@ -24,7 +24,6 @@
#include <asm/gic-v3-its.h>
#include <asm/timer.h>
-#define NS_5_SECONDS (5 * 1000 * 1000 * 1000UL)
#define QEMU_MMIO_ADDR 0x0a000008
static u32 cntfrq;
@@ -346,17 +345,21 @@ static void loop_test(struct exit_test *test)
}
}
- while (ntimes < test->times && total_ns.ns < NS_5_SECONDS) {
- isb();
- start = read_sysreg(cntvct_el0);
+ dsb(ish);
+ isb();
+ start = read_sysreg(cntvct_el0);
+ isb();
+ while (ntimes < test->times) {
test->exec();
- isb();
- end = read_sysreg(cntvct_el0);
ntimes++;
- total_ticks += (end - start);
- ticks_to_ns_time(total_ticks, &total_ns);
}
+ dsb(ish);
+ isb();
+ end = read_sysreg(cntvct_el0);
+
+ total_ticks = end - start;
+ ticks_to_ns_time(total_ticks, &total_ns);
if (test->post) {
test->post(ntimes, &total_ticks);
--
2.39.3
