[PATCH] cpufreq : powernv: Report Pmax throttling if capped below nominal frequency

Log a 'critical' message if the max frequency is reduced below nominal
frequency. We already log 'info' message if the max frequency is
capped below turbo frequency. CPU should guarantee atleast nominal
frequency, but not turbo frequency in all system configurations and
environments. So report the pmax throttling with severity when Pmax is
dipped below nominal frequency.

Signed-off-by: Shilpasri G Bhat <redacted>
---
 drivers/cpufreq/powernv-cpufreq.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
index 64994e1..2d9ed42 100644
--- a/drivers/cpufreq/powernv-cpufreq.c
+++ b/drivers/cpufreq/powernv-cpufreq.c

@@ -327,8 +327,13 @@ static void powernv_cpufreq_throttle_check(void *data)
 		if (chips[i].throttled)
 			goto next;
 		chips[i].throttled = true;
-		pr_info("CPU %d on Chip %u has Pmax reduced to %d\n", cpu,
-			chips[i].id, pmsr_pmax);
+		if (pmsr_pmax < powernv_pstate_info.nominal)
+			pr_crit("CPU %d on Chip %u has Pmax reduced to %d\n",
+				cpu, chips[i].id, pmsr_pmax);
+		else
+			pr_info("CPU %d on Chip %u has Pmax reduced to %d\n",
+				cpu, chips[i].id, pmsr_pmax);
+
 	} else if (chips[i].throttled) {
 		chips[i].throttled = false;
 		pr_info("CPU %d on Chip %u has Pmax restored to %d\n", cpu,

-- 
1.9.3

On 14-09-15, 10:47, Shilpasri G Bhat wrote:

I think the messages here can be improved a bit here to something
like:

			pr_warn("CPU %d on Chip %u has Pmax reduced below nominal freq (%d < %d)\n",
                                 cpu, chips[i].id, pmsr_pmax, powernv_pstate_info.nominal);

And similarly for the pr_info case as well.

-- 
viresh

Log a 'critical' message if the max frequency is reduced below nominal
frequency. We already log 'info' message if the max frequency is
capped below turbo frequency. CPU should guarantee atleast nominal
frequency, but not turbo frequency in all system configurations and
environments. So report the pmax throttling with severity when Pmax is
dipped below nominal frequency.

Signed-off-by: Shilpasri G Bhat <redacted>
---
Changes from v1:
- Modified the printk messages as per Viresh's suggestion.

 drivers/cpufreq/powernv-cpufreq.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
index 64994e1..cb50138 100644
--- a/drivers/cpufreq/powernv-cpufreq.c
+++ b/drivers/cpufreq/powernv-cpufreq.c

@@ -327,8 +327,14 @@ static void powernv_cpufreq_throttle_check(void *data)
 		if (chips[i].throttled)
 			goto next;
 		chips[i].throttled = true;
-		pr_info("CPU %d on Chip %u has Pmax reduced to %d\n", cpu,
-			chips[i].id, pmsr_pmax);
+		if (pmsr_pmax < powernv_pstate_info.nominal)
+			pr_crit("CPU %d on Chip %u has Pmax reduced below nominal frequency (%d < %d)\n",
+				cpu, chips[i].id, pmsr_pmax,
+				powernv_pstate_info.nominal);
+		else
+			pr_info("CPU %d on Chip %u has Pmax reduced below turbo frequency (%d < %d)\n",
+				cpu, chips[i].id, pmsr_pmax,
+				powernv_pstate_info.max);
 	} else if (chips[i].throttled) {
 		chips[i].throttled = false;
 		pr_info("CPU %d on Chip %u has Pmax restored to %d\n", cpu,

-- 
1.9.3

On 14-09-15, 14:01, Shilpasri G Bhat wrote:

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
-- 
viresh

On Monday, September 14, 2015 03:58:09 PM Viresh Kumar wrote:

On 14-09-15, 14:01, Shilpasri G Bhat wrote:

quoted

Log a 'critical' message if the max frequency is reduced below nominal
frequency. We already log 'info' message if the max frequency is
capped below turbo frequency. CPU should guarantee atleast nominal
frequency, but not turbo frequency in all system configurations and
environments. So report the pmax throttling with severity when Pmax is
dipped below nominal frequency.

Signed-off-by: Shilpasri G Bhat <redacted>
---
Changes from v1:
- Modified the printk messages as per Viresh's suggestion.

 drivers/cpufreq/powernv-cpufreq.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
index 64994e1..cb50138 100644
--- a/drivers/cpufreq/powernv-cpufreq.c
+++ b/drivers/cpufreq/powernv-cpufreq.c

@@ -327,8 +327,14 @@ static void powernv_cpufreq_throttle_check(void *data)
 		if (chips[i].throttled)
 			goto next;
 		chips[i].throttled = true;
-		pr_info("CPU %d on Chip %u has Pmax reduced to %d\n", cpu,
-			chips[i].id, pmsr_pmax);
+		if (pmsr_pmax < powernv_pstate_info.nominal)
+			pr_crit("CPU %d on Chip %u has Pmax reduced below nominal frequency (%d < %d)\n",
+				cpu, chips[i].id, pmsr_pmax,
+				powernv_pstate_info.nominal);
+		else
+			pr_info("CPU %d on Chip %u has Pmax reduced below turbo frequency (%d < %d)\n",
+				cpu, chips[i].id, pmsr_pmax,
+				powernv_pstate_info.max);
 	} else if (chips[i].throttled) {
 		chips[i].throttled = false;
 		pr_info("CPU %d on Chip %u has Pmax restored to %d\n", cpu,

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

Applied, thanks!

Rafael