On 6/22/21 10:32 AM, Viresh Kumar wrote:

Not commenting on the idea itself but just the code changes here.

On 22-06-21, 08:59, Lukasz Luba wrote:

quoted

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 802abc925b2a..d79cb9310572 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c

@@ -14,6 +14,7 @@
  
  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  
+#include <linux/active_stats.h>
  #include <linux/cpu.h>
  #include <linux/cpufreq.h>
  #include <linux/cpu_cooling.h>

@@ -387,6 +388,8 @@ static void cpufreq_notify_transition(struct cpufreq_policy *policy,
  
  		cpufreq_stats_record_transition(policy, freqs->new);
  		policy->cur = freqs->new;
+
+		active_stats_cpu_freq_change(policy->cpu, freqs->new);
  	}
  }
  

@@ -2085,6 +2088,8 @@ unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy,
  			    policy->cpuinfo.max_freq);
  	cpufreq_stats_record_transition(policy, freq);
  
+	active_stats_cpu_freq_fast_change(policy->cpu, freq);
+

It would have been better if you would have modified
cpufreq_stats_record_transition() instead, since that is there for
similar kind of stats.

That cpufreq_stats_record_transition() is present only if
CONFIG_CPU_FREQ_STAT is set. I didn't wanted to be dependent on
this config.

Plus don't you need to record this for all policy->cpus instead of
just policy->cpu ?

It will be accounted for all cpus in that freq domain. The
active_stats_cpu_freq_fast_change() implementation uses
a shared structure (single for whole domain) 'shared_ast':
_active_stats_cpu_freq_change(ast->shared_ast, freq, ts)
(from patch 1/4)