Commit 5720821b authored by Frederic Weisbecker's avatar Frederic Weisbecker Committed by Ingo Molnar
Browse files

cpufreq: Use vtime aware kcpustat accessors for user time 



We can now safely read user and guest kcpustat fields on nohz_full CPUs.
Use the appropriate accessors.

Reported-by: default avatarYauheni Kaliuta <yauheni.kaliuta@redhat.com>
Signed-off-by: default avatarFrederic Weisbecker <frederic@kernel.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wanpeng Li <wanpengli@tencent.com>
Link: https://lkml.kernel.org/r/20191121024430.19938-5-frederic@kernel.org


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 26dae145

drivers/cpufreq/cpufreq.c

+10 −7
Original line number Diff line number Diff line
@@ -113,18 +113,21 @@ EXPORT_SYMBOL_GPL(get_governor_parent_kobj); 


static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall)

{

	u64 idle_time;

	struct kernel_cpustat kcpustat;

	u64 cur_wall_time;

	u64 idle_time;

	u64 busy_time;



	cur_wall_time = jiffies64_to_nsecs(get_jiffies_64());



	busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER];

	busy_time += kcpustat_field(&kcpustat_cpu(cpu), CPUTIME_SYSTEM, cpu);

	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ];

	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ];

	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL];

	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE];

	kcpustat_cpu_fetch(&kcpustat, cpu);



	busy_time = kcpustat.cpustat[CPUTIME_USER];

	busy_time += kcpustat.cpustat[CPUTIME_SYSTEM];

	busy_time += kcpustat.cpustat[CPUTIME_IRQ];

	busy_time += kcpustat.cpustat[CPUTIME_SOFTIRQ];

	busy_time += kcpustat.cpustat[CPUTIME_STEAL];

	busy_time += kcpustat.cpustat[CPUTIME_NICE];



	idle_time = cur_wall_time - busy_time;

	if (wall)

drivers/cpufreq/cpufreq_governor.c

+3 −3
Original line number Diff line number Diff line
@@ -105,7 +105,7 @@ void gov_update_cpu_data(struct dbs_data *dbs_data) 
			j_cdbs->prev_cpu_idle = get_cpu_idle_time(j, &j_cdbs->prev_update_time,

								  dbs_data->io_is_busy);

			if (dbs_data->ignore_nice_load)

				j_cdbs->prev_cpu_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE];

				j_cdbs->prev_cpu_nice = kcpustat_field(&kcpustat_cpu(j), CPUTIME_NICE, j);

		}

	}

}
@@ -149,7 +149,7 @@ unsigned int dbs_update(struct cpufreq_policy *policy) 
		j_cdbs->prev_cpu_idle = cur_idle_time;



		if (ignore_nice) {

			u64 cur_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE];

			u64 cur_nice = kcpustat_field(&kcpustat_cpu(j), CPUTIME_NICE, j);



			idle_time += div_u64(cur_nice - j_cdbs->prev_cpu_nice, NSEC_PER_USEC);

			j_cdbs->prev_cpu_nice = cur_nice;
@@ -530,7 +530,7 @@ int cpufreq_dbs_governor_start(struct cpufreq_policy *policy) 
		j_cdbs->prev_load = 0;



		if (ignore_nice)

			j_cdbs->prev_cpu_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE];

			j_cdbs->prev_cpu_nice = kcpustat_field(&kcpustat_cpu(j), CPUTIME_NICE, j);

	}



	gov->start(policy);

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