@@ -215,6 +215,18 @@ static struct scale_freq_data amu_sfd = {
.set_freq_scale = amu_scale_freq_tick,
};
+void arch_cpu_idle_enter(void)
+{
+ unsigned int cpu = smp_processor_id();
+
+ if (!cpumask_test_cpu(cpu, amu_fie_cpus))
+ return;
+
+ /* Kick in AMU update but only if one has not happned already */
+ if (time_is_before_jiffies(per_cpu(cpu_amu_samples.last_update, cpu)))
+ amu_scale_freq_tick();
+}
+
#define AMU_SAMPLE_EXP_MS 20
unsigned int arch_freq_get_on_cpu(int cpu)
@@ -242,7 +254,8 @@ unsigned int arch_freq_get_on_cpu(int cpu)
* try an alternative source for the counters (and thus freq scale),
* if available for given policy
*/
- if (time_is_before_jiffies(last_update + msecs_to_jiffies(AMU_SAMPLE_EXP_MS))) {
+ if (!idle_cpu(cpu) &&
+ time_is_before_jiffies(last_update + msecs_to_jiffies(AMU_SAMPLE_EXP_MS))) {
struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
int ref_cpu = nr_cpu_ids;
Now that the frequency scale factor has been activated for retrieving current frequency on a given CPU, trigger its update upon entering idle. This will, to an extent, allow querying last known frequency in a non-invasive way. It will also improve the frequency scale factor accuracy when a CPU entering idle did not receive a tick for a while. Suggested-by: Vanshidhar Konda <vanshikonda@os.amperecomputing.com> Signed-off-by: Beata Michalska <beata.michalska@arm.com> --- arch/arm64/kernel/topology.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-)