Re: [PATCH V3 5/5] cpufreq: postfix policy directory with the first CPU in related_cpus

On 10/16/2015 12:11 AM, Viresh Kumar wrote:

The sysfs policy directory is postfixed currently with the CPU number for which the policy was created, which isn't necessarily the first CPU in related_cpus mask.

To make it more consistent and predictable, lets postfix the policy with the first cpu in related-cpus mask.

Suggested-by: Saravana Kannan skannan@codeaurora.org Signed-off-by: Viresh Kumar viresh.kumar@linaro.org

---

V2->V3:

• Fix error path where we may try to put an uninitialized kobject.

• Break kobject_init_and_add() to kobject_init() and kobject_add().

  drivers/cpufreq/cpufreq.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 4fa2215cc6ec..7c48e7316d91 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1022,7 +1022,6 @@ static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu) { struct device *dev = get_cpu_device(cpu); struct cpufreq_policy *policy;

• int ret;

  if (WARN_ON(!dev)) return NULL;

@@ -1040,13 +1039,7 @@ static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu) if (!zalloc_cpumask_var(&policy->real_cpus, GFP_KERNEL)) goto err_free_rcpumask;

• ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq,

• 		   cpufreq_global_kobject, "policy%u", cpu);
  

• if (ret) {

• pr_err("%s: failed to init policy->kobj: %d\n", __func__, ret);
  

• goto err_free_real_cpus;
  

• }

• kobject_init(&policy->kobj, &ktype_cpufreq);

Oh yeah, this works better. I forgot kobject has a separate init and add fuctions.

INIT_LIST_HEAD(&policy->policy_list); init_rwsem(&policy->rwsem); spin_lock_init(&policy->transition_lock); @@ -1057,8 +1050,6 @@ static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu) policy->cpu = cpu; return policy;

-err_free_real_cpus:

• free_cpumask_var(policy->real_cpus); err_free_rcpumask: free_cpumask_var(policy->related_cpus); err_free_cpumask:

@@ -1163,6 +1154,16 @@ static int cpufreq_online(unsigned int cpu) cpumask_copy(policy->related_cpus, policy->cpus); /* Remember CPUs present at the policy creation time. */ cpumask_and(policy->real_cpus, policy->cpus, cpu_present_mask);

• /* Name and add the kobject */
  

• ret = kobject_add(&policy->kobj, cpufreq_global_kobject,
  

• 		  "policy%u",
  

• 		  cpumask_first(policy->related_cpus));
  

• if (ret) {
  

• 	pr_err("%s: failed to add policy->kobj: %d\n", __func__,
  

• 	       ret);
  

• 	goto out_exit_policy;
  

• }
  

Another out of patch issue that I see while reviewing this patch:

I think the existing error handling gotos aren't really cleaning things up well.

In the lines that follow this code we set the per_cpu(cpufreq_cpu_data) to point to the new policy. But if the subsequent cpu->get() fails, we goto out_exit_policy. But that label doesn't clean up the per_cpu(cpufreq_cpu_data). So, I think we need another label to jump to if ->get() fails

}

/*

Reviewed-by: Saravana Kannan skannan@codeaurora.org

-Saravana