linux-kernel - [PATCH] thermal: cpu_cooling: Actually trace CPU load in thermal_power_cpu_get

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Date:   Thu,  2 May 2019 11:32:38 -0700
From:   Matthias Kaehlcke <mka@...omium.org>
To:     Amit Daniel Kachhap <amit.kachhap@...il.com>,
        Viresh Kumar <viresh.kumar@...aro.org>,
        Javi Merino <javi.merino@...nel.org>,
        Zhang Rui <rui.zhang@...el.com>,
        Eduardo Valentin <edubezval@...il.com>,
        Daniel Lezcano <daniel.lezcano@...aro.org>
Cc:     linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org,
        Douglas Anderson <dianders@...omium.org>,
        Matthias Kaehlcke <mka@...omium.org>
Subject: [PATCH] thermal: cpu_cooling: Actually trace CPU load in thermal_power_cpu_get_power

The CPU load values passed to the thermal_power_cpu_get_power
tracepoint are zero for all CPUs, unless, unless the
thermal_power_cpu_limit tracepoint is enabled too:

  irq/41-rockchip-98    [000] ....   290.972410: thermal_power_cpu_get_power:
  cpus=0000000f freq=1800000 load={{0x0,0x0,0x0,0x0}} dynamic_power=4815

vs

  irq/41-rockchip-96    [000] ....    95.773585: thermal_power_cpu_get_power:
  cpus=0000000f freq=1800000 load={{0x56,0x64,0x64,0x5e}} dynamic_power=4959
  irq/41-rockchip-96    [000] ....    95.773596: thermal_power_cpu_limit:
  cpus=0000000f freq=408000 cdev_state=10 power=416

There seems to be no good reason for omitting the CPU load information
depending on another tracepoint. My guess is that the intention was to
check whether thermal_power_cpu_get_power is (still) enabled, however
'load_cpu != NULL' already indicates that it was at least enabled when
cpufreq_get_requested_power() was entered, there seems little gain
from omitting the assignment if the tracepoint was just disabled, so
just remove the check.

Fixes: 6828a4711f99 ("thermal: add trace events to the power allocator governor")
Signed-off-by: Matthias Kaehlcke <mka@...omium.org>
---
 drivers/thermal/cpu_cooling.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c
index f7c1f49ec87f..b437804e099b 100644
--- a/drivers/thermal/cpu_cooling.c
+++ b/drivers/thermal/cpu_cooling.c
@@ -458,7 +458,7 @@ static int cpufreq_get_requested_power(struct thermal_cooling_device *cdev,
 			load = 0;
 
 		total_load += load;
-		if (trace_thermal_power_cpu_limit_enabled() && load_cpu)
+		if (load_cpu)
 			load_cpu[i] = load;
 
 		i++;
-- 
2.21.0.593.g511ec345e18-goog