[PATCH v4 4/4] cpufreq: Use arch specific feedback for cpuinfo_cur_freq

From: Beata Michalska
Date: Fri Apr 05 2024 - 09:34:42 EST


Some architectures provide a way to determine an average frequency over
a certain period of time based on available performance monitors (AMU on
ARM or APERF/MPERf on x86). With those at hand, enroll arch_freq_get_on_cpu
into cpuinfo_cur_freq policy sysfs attribute handler, which is expected to
represent the current frequency of a given CPU, as obtained by the hardware.
This is the type of feedback that counters do provide.

Signed-off-by: Beata Michalska <beata.michalska@xxxxxxx>
---
drivers/cpufreq/cpufreq.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 66e10a19d76a..603533b2608f 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -795,8 +795,10 @@ store_one(scaling_max_freq, max);
static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy,
char *buf)
{
- unsigned int cur_freq = __cpufreq_get(policy);
+ unsigned int cur_freq = arch_freq_get_on_cpu(policy->cpu);

+ if (!cur_freq)
+ cur_freq = __cpufreq_get(policy);
if (cur_freq)
return sprintf(buf, "%u\n", cur_freq);

--
2.25.1