[dpdk-stable] patch 'test/power: add delay before checking CPU frequency' has been queued to stable release 19.11.9

[Christian Ehrhardt]

Hi,

FYI, your patch has been queued to stable release 19.11.9

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 05/19/21. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://github.com/cpaelzer/dpdk-stable-queue

This queued commit can be viewed at:
https://github.com/cpaelzer/dpdk-stable-queue/commit/002beb990e5dcfeca7ae73a5ad5505e19f729f7e
our

Thanks.

Christian Ehrhardt <christian.ehrhardt at canonical.com>

---
>From 002beb990e5dcfeca7ae73a5ad5505e19f729f7e Mon Sep 17 00:00:00 2001
From: Richael Zhuang <richael.zhuang at arm.com>
Date: Thu, 15 Apr 2021 13:59:29 +0800
Subject: [PATCH] test/power: add delay before checking CPU frequency

[ upstream commit 00456850be40d8b663d1066763ddedffe4346585 ]

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")

Signed-off-by: Richael Zhuang <richael.zhuang at arm.com>
Reviewed-by: David Hunt <david.hunt at intel.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 d203810da9..188d789e0a 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;
-- 
2.31.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2021-05-17 17:40:34.386989302 +0200
+++ 0127-test-power-add-delay-before-checking-CPU-frequency.patch	2021-05-17 17:40:29.355810924 +0200
@@ -1 +1 @@
-From 00456850be40d8b663d1066763ddedffe4346585 Mon Sep 17 00:00:00 2001
+From 002beb990e5dcfeca7ae73a5ad5505e19f729f7e Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit 00456850be40d8b663d1066763ddedffe4346585 ]
+
@@ -16 +17,0 @@
-Cc: stable at dpdk.org
@@ -25 +26 @@
-index 731c6b4dc8..d47b3e0a1a 100644
+index d203810da9..188d789e0a 100644