linux-kernel - [PATCH v1 2/3] cpufreq: intel_pstate: Rearrange freq QoS updates using _

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Message-ID: <3026597.e9J7NaK4W3@rafael.j.wysocki>
Date: Fri, 05 Sep 2025 15:52:54 +0200
From: "Rafael J. Wysocki" <rafael@...nel.org>
To: Linux PM <linux-pm@...r.kernel.org>
Cc: Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
 LKML <linux-kernel@...r.kernel.org>, Viresh Kumar <viresh.kumar@...aro.org>,
 Zihuan Zhang <zhangzihuan@...inos.cn>,
 Jonathan Cameron <jonathan.cameron@...wei.com>
Subject:
 [PATCH v1 2/3] cpufreq: intel_pstate: Rearrange freq QoS updates using
 __free()

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

Move the code from the for_each_possible_cpu() loop in update_qos_request()
to a separate function and use __free() for cpufreq policy reference
counting in it to avoid having to call cpufreq_cpu_put() repeatedly (or
using goto).

While at it, rename update_qos_request() to update_qos_requests()
because it updates multiple requests in one go.

No intentional functional impact.

Link: https://lore.kernel.org/linux-pm/CAJZ5v0gN1T5woSF0tO=TbAh+2-sWzxFjWyDbB7wG2TFCOU01iQ@mail.gmail.com/
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
---
 drivers/cpufreq/intel_pstate.c |   65 ++++++++++++++++++++---------------------
 1 file changed, 32 insertions(+), 33 deletions(-)

--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -1693,43 +1693,42 @@ unlock_driver:
 	return count;
 }
 
-static void update_qos_request(enum freq_qos_req_type type)
+static void update_cpu_qos_request(int cpunum, enum freq_qos_req_type type)
 {
+	struct cpudata *cpu = all_cpu_data[cpunum];
 	struct freq_qos_request *req;
-	struct cpufreq_policy *policy;
-	int i;
+	unsigned int freq, perf_pct;
 
-	for_each_possible_cpu(i) {
-		struct cpudata *cpu = all_cpu_data[i];
-		unsigned int freq, perf_pct;
-
-		policy = cpufreq_cpu_get(i);
-		if (!policy)
-			continue;
-
-		req = policy->driver_data;
-		if (!req) {
-			cpufreq_cpu_put(policy);
-			continue;
-		}
-
-		if (hwp_active)
-			intel_pstate_get_hwp_cap(cpu);
-
-		if (type == FREQ_QOS_MIN) {
-			perf_pct = global.min_perf_pct;
-		} else {
-			req++;
-			perf_pct = global.max_perf_pct;
-		}
+	struct cpufreq_policy *policy __free(put_cpufreq_policy) = cpufreq_cpu_get(cpunum);
+	if (!policy)
+		return;
+
+	req = policy->driver_data;
+	if (!req)
+		return;
+
+	if (hwp_active)
+		intel_pstate_get_hwp_cap(cpu);
+
+	if (type == FREQ_QOS_MIN) {
+		perf_pct = global.min_perf_pct;
+	} else {
+		req++;
+		perf_pct = global.max_perf_pct;
+	}
 
-		freq = DIV_ROUND_UP(cpu->pstate.turbo_freq * 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", i);
+	if (freq_qos_update_request(req, freq) < 0)
+		pr_warn("Failed to update freq constraint: CPU%d\n", cpunum);
+}
 
-		cpufreq_cpu_put(policy);
-	}
+static void update_qos_requests(enum freq_qos_req_type type)
+{
+	int i;
+
+	for_each_possible_cpu(i)
+		update_cpu_qos_request(i, type);
 }
 
 static ssize_t store_max_perf_pct(struct kobject *a, struct kobj_attribute *b,
@@ -1758,7 +1757,7 @@ static ssize_t store_max_perf_pct(struct
 	if (intel_pstate_driver == &intel_pstate)
 		intel_pstate_update_policies();
 	else
-		update_qos_request(FREQ_QOS_MAX);
+		update_qos_requests(FREQ_QOS_MAX);
 
 	mutex_unlock(&intel_pstate_driver_lock);
 
@@ -1792,7 +1791,7 @@ static ssize_t store_min_perf_pct(struct
 	if (intel_pstate_driver == &intel_pstate)
 		intel_pstate_update_policies();
 	else
-		update_qos_request(FREQ_QOS_MIN);
+		update_qos_requests(FREQ_QOS_MIN);
 
 	mutex_unlock(&intel_pstate_driver_lock);