Re: [PATCH v5 6/6] PM: EM: Use scope-based cleanup helper
From: "Rafael J. Wysocki" <rafael@kernel.org>
Date: 2025-09-05 19:46:56
Also in:
dri-devel, imx, intel-gfx, linux-acpi, linux-arm-kernel, linux-omap, linux-pm, lkml
On Fri, Sep 5, 2025 at 3:25 PM Zihuan Zhang [off-list ref] wrote:
quoted hunk ↗ jump to hunk
Replace the manual cpufreq_cpu_put() with __free(put_cpufreq_policy) annotation for policy references. This reduces the risk of reference counting mistakes and aligns the code with the latest kernel style. No functional change intended. Signed-off-by: Zihuan Zhang <redacted> --- kernel/power/energy_model.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-)diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c index ea7995a25780..5ec63b3e7d85 100644 --- a/kernel/power/energy_model.c +++ b/kernel/power/energy_model.c@@ -451,7 +451,6 @@ static void em_cpufreq_update_efficiencies(struct device *dev, struct em_perf_state *table) { struct em_perf_domain *pd = dev->em_pd; - struct cpufreq_policy *policy; int found = 0; int i, cpu;@@ -465,7 +464,7 @@ em_cpufreq_update_efficiencies(struct device *dev, struct em_perf_state *table) return; } - policy = cpufreq_cpu_get(cpu); + struct cpufreq_policy *policy __free(put_cpufreq_policy) = cpufreq_cpu_get(cpu); if (!policy) { dev_warn(dev, "EM: Access to CPUFreq policy failed\n"); return;@@ -479,8 +478,6 @@ em_cpufreq_update_efficiencies(struct device *dev, struct em_perf_state *table) found++; } - cpufreq_cpu_put(policy); - if (!found) return;
The above changes are fine now and can be a separate patch.
quoted hunk ↗ jump to hunk
@@ -787,21 +784,19 @@ static void em_check_capacity_update(void) /* Check if CPUs capacity has changed than update EM */ for_each_possible_cpu(cpu) {
But I'd prefer the code in this loop to be moved into a separate function, in a separate patch, before the __free()-based simplification of it.
- struct cpufreq_policy *policy;
struct em_perf_domain *pd;
struct device *dev;
if (cpumask_test_cpu(cpu, cpu_done_mask))
continue;
- policy = cpufreq_cpu_get(cpu);
+ struct cpufreq_policy *policy __free(put_cpufreq_policy) = cpufreq_cpu_get(cpu);
if (!policy) {
pr_debug("Accessing cpu%d policy failed\n", cpu);
schedule_delayed_work(&em_update_work,
msecs_to_jiffies(1000));
break;
}
- cpufreq_cpu_put(policy);
dev = get_cpu_device(cpu);
pd = em_pd_get(dev);
--