[PATCH v1 3/3] cpufreq: intel_pstate: Adjust frequency percentage computations

From: Rafael J. Wysocki
Date: Fri Sep 05 2025 - 09:54:28 EST


From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

Adjust frequency percentage computations in update_cpu_qos_request() to
avoid going above the exact numerical percentage in the FREQ_QOS_MAX
case.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/cpufreq/intel_pstate.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)

--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -1696,8 +1696,8 @@ unlock_driver:
static void update_cpu_qos_request(int cpunum, enum freq_qos_req_type type)
{
struct cpudata *cpu = all_cpu_data[cpunum];
+ unsigned int freq = cpu->pstate.turbo_freq;
struct freq_qos_request *req;
- unsigned int freq, perf_pct;

struct cpufreq_policy *policy __free(put_cpufreq_policy) = cpufreq_cpu_get(cpunum);
if (!policy)
@@ -1711,14 +1711,12 @@ static void update_cpu_qos_request(int c
intel_pstate_get_hwp_cap(cpu);

if (type == FREQ_QOS_MIN) {
- perf_pct = global.min_perf_pct;
+ freq = DIV_ROUND_UP(freq * global.min_perf_pct, 100);
} else {
req++;
- perf_pct = global.max_perf_pct;
+ freq = (freq * global.max_perf_pct) / 100;
}

- freq = DIV_ROUND_UP(cpu->pstate.turbo_freq * perf_pct, 100);
-
if (freq_qos_update_request(req, freq) < 0)
pr_warn("Failed to update freq constraint: CPU%d\n", cpunum);
}