Hi Steve,
On Wed, Dec 9, 2015 at 2:19 PM, Steve Muckle <steve.muc...@linaro.org> wrote:
[snip...]
> +static int cpufreq_sched_policy_init(struct cpufreq_policy *policy)
> +{
> + struct gov_data *gd;
> + int cpu;
> +
> + for_each_cpu(cpu, policy->cpus)
> + memset(&per_cpu(cpu_sched_capacity_reqs, cpu), 0,
> + sizeof(struct sched_capacity_reqs));
> +
> + gd = kzalloc(sizeof(*gd), GFP_KERNEL);
> + if (!gd)
> + return -ENOMEM;
> +
> + gd->throttle_nsec = policy->cpuinfo.transition_latency ?
> + policy->cpuinfo.transition_latency :
> + THROTTLE_NSEC;
> + pr_debug("%s: throttle threshold = %u [ns]\n",
> + __func__, gd->throttle_nsec);
> +
> + if (cpufreq_driver_is_slow()) {
> + cpufreq_driver_slow = true;
> + gd->task = kthread_create(cpufreq_sched_thread, policy,
> + "kschedfreq:%d",
> +
> cpumask_first(policy->related_cpus));
> + if (IS_ERR_OR_NULL(gd->task)) {
> + pr_err("%s: failed to create kschedfreq thread\n",
> + __func__);
> + goto err;
> + }
> + get_task_struct(gd->task);
> + kthread_bind_mask(gd->task, policy->related_cpus);
> + wake_up_process(gd->task);
> + init_irq_work(&gd->irq_work, cpufreq_sched_irq_work);
> + }
> +
> + policy->governor_data = gd;
This should be moved before if(cpufreq_driver_is_slow()) {...}. I've
seen NULL pointer deference at boot in cpufreq_sched_thread() when it
tried to run sched_setscheduler_nocheck(gd->task, SCHED_FIFO, ¶m).
> + set_sched_freq();
> +
> + return 0;
> +
> +err:
And probably also set policy->governor_data to NULL here.
> + kfree(gd);
> + return -ENOMEM;
> +}
[snip...]
Best,
Ricky
