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

Shilpasri G Bhat shilpa.bhat at linux.vnet.ibm.com
Mon Sep 14 15:17:54 AEST 2015


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 <shilpa.bhat at linux.vnet.ibm.com>
---
 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



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