On 15/4/2021 6:59 AM, Richael Zhuang wrote:
For some platforms the newly-set frequency may not be effective
immediately. If we didn't get the right value from cpuinfo_cur_freq
immediately, add 10ms delay each time before rechecking until
timeout.
From our test, for some arm platforms, it requires up to 700ms when
going from a minimum to a maximum frequency. And it's not the
driver/software issue.
Fixes: ed7c51a6a680 ("app/test: vm power management")
Cc: alan.ca...@intel.com
Cc: sta...@dpdk.org
Signed-off-by: Richael Zhuang <richael.zhu...@arm.com>
---
app/test/test_power_cpufreq.c | 27 ++++++++++++++++++++++-----
1 file changed, 22 insertions(+), 5 deletions(-)
diff --git a/app/test/test_power_cpufreq.c b/app/test/test_power_cpufreq.c
index 731c6b4dc..d47b3e0a1 100644
--- a/app/test/test_power_cpufreq.c
+++ b/app/test/test_power_cpufreq.c
@@ -8,6 +8,7 @@
#include <limits.h>
#include <string.h>
#include <inttypes.h>
+#include <rte_cycles.h>
#include "test.h"
@@ -44,11 +45,13 @@ static int
check_cur_freq(unsigned lcore_id, uint32_t idx)
{
#define TEST_POWER_CONVERT_TO_DECIMAL 10
+#define MAX_LOOP 100
FILE *f;
char fullpath[PATH_MAX];
char buf[BUFSIZ];
uint32_t cur_freq;
int ret = -1;
+ int i;
if (snprintf(fullpath, sizeof(fullpath),
TEST_POWER_SYSFILE_CUR_FREQ, lcore_id) < 0) {
@@ -58,13 +61,27 @@ check_cur_freq(unsigned lcore_id, uint32_t idx)
if (f == NULL) {
return 0;
}
- if (fgets(buf, sizeof(buf), f) == NULL) {
- goto fail_get_cur_freq;
+ for (i = 0; i < MAX_LOOP; i++) {
+ fflush(f);
+ if (fgets(buf, sizeof(buf), f) == NULL)
+ goto fail_all;
+
+ cur_freq = strtoul(buf, NULL, TEST_POWER_CONVERT_TO_DECIMAL);
+ ret = (freqs[idx] == cur_freq ? 0 : -1);
+
+ if (ret == 0)
+ break;
+
+ if (fseek(f, 0, SEEK_SET) < 0) {
+ printf("Fail to set file position indicator to 0\n");
+ goto fail_all;
+ }
+
+ /* wait for the value to be updated */
+ rte_delay_ms(10);
}
- cur_freq = strtoul(buf, NULL, TEST_POWER_CONVERT_TO_DECIMAL);
- ret = (freqs[idx] == cur_freq ? 0 : -1);
-fail_get_cur_freq:
+fail_all:
fclose(f);
return ret;
Hi Richael
On your system, is the current cpu frequency found in cpuinfo_cur_freq
or in scaling_cur_freq? On my system, which uses intel_pstate driver,
there is no file called cpuinfo_cur_freq, but the test works when I
change TEST_POWER_SYSFILE_CUR_FREQ to scaling_cur_freq.
I know that's unrelated to your patch above, but it migth be worth using
a file common to all platforms, or else attempting to open one, and if
that fails, try open the other.
Rgds,
Dave.
