[1/3] thermal: cpufreq_cooling: Update also offline CPUs per-cpu thermal_pressure

Message ID 20210614191030.22241-1-lukasz.luba@arm.com
State Accepted
Commit 2ad8ccc17d1e4270cf65a3f2a07a7534aa23e3fb
Headers show
  • Add allowed CPU capacity knowledge to EAS
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Commit Message

Lukasz Luba June 14, 2021, 7:10 p.m.
The thermal pressure signal gives information to the scheduler about
reduced CPU capacity due to thermal. It is based on a value stored in a
per-cpu 'thermal_pressure' variable. The online CPUs will get the new
value there, while the offline won't. Unfortunately, when the CPU is back
online, the value read from per-cpu variable might be wrong (stale data).
This might affect the scheduler decisions, since it sees the CPU capacity
differently than what is actually available.

Fix it by making sure that all online+offline CPUs would get the proper
value in their per-cpu variable when thermal framework sets capping.

Fixes: f12e4f66ab6a3 ("thermal/cpu-cooling: Update thermal pressure in case of a maximum frequency capping")
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
 drivers/thermal/cpufreq_cooling.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)


diff --git a/drivers/thermal/cpufreq_cooling.c b/drivers/thermal/cpufreq_cooling.c
index eeb4e4b76c0b..43b1ae8a7789 100644
--- a/drivers/thermal/cpufreq_cooling.c
+++ b/drivers/thermal/cpufreq_cooling.c
@@ -478,7 +478,7 @@  static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev,
 	ret = freq_qos_update_request(&cpufreq_cdev->qos_req, frequency);
 	if (ret >= 0) {
 		cpufreq_cdev->cpufreq_state = state;
-		cpus = cpufreq_cdev->policy->cpus;
+		cpus = cpufreq_cdev->policy->related_cpus;
 		max_capacity = arch_scale_cpu_capacity(cpumask_first(cpus));
 		capacity = frequency * max_capacity;
 		capacity /= cpufreq_cdev->policy->cpuinfo.max_freq;