Add some additional debug to capture failures in the locking scheme for cpufreq. Instead of just a NULL pointer, these warnings will capture failure points if the locking scheme for cpufreq is broken.
Cc: "Rafael J. Wysocki" <[email protected]> Cc: Viresh Kumar <[email protected]> Cc: [email protected] Signed-off-by: Prarit Bhargava <[email protected]> --- drivers/cpufreq/cpufreq_governor.c | 32 +++++++++++++++++++++++++++----- 1 file changed, 27 insertions(+), 5 deletions(-) diff --git a/drivers/cpufreq/cpufreq_governor.c b/drivers/cpufreq/cpufreq_governor.c index b1ee597..f158882 100644 --- a/drivers/cpufreq/cpufreq_governor.c +++ b/drivers/cpufreq/cpufreq_governor.c @@ -161,9 +161,18 @@ void dbs_check_cpu(struct dbs_data *dbs_data, int cpu) EXPORT_SYMBOL_GPL(dbs_check_cpu); static inline void __gov_queue_work(int cpu, struct dbs_data *dbs_data, - unsigned int delay) + unsigned int delay, + struct cpufreq_policy *policy) { - struct cpu_dbs_common_info *cdbs = dbs_data->cdata->get_cpu_cdbs(cpu); + struct cpu_dbs_common_info *cdbs; + + if (!dbs_data->cdata) { + pr_emerg("common_dbs_data is NULL for %s but initialized = %d", + policy->governor->name, + atomic_read(&policy->governor->initialized)); + BUG(); + } + cdbs = dbs_data->cdata->get_cpu_cdbs(cpu); mod_delayed_work_on(cpu, system_wq, &cdbs->work, delay); } @@ -185,10 +194,11 @@ void gov_queue_work(struct dbs_data *dbs_data, struct cpufreq_policy *policy, * those works are canceled during CPU_DOWN_PREPARE so they * can't possibly run on any other CPU. */ - __gov_queue_work(raw_smp_processor_id(), dbs_data, delay); + __gov_queue_work(raw_smp_processor_id(), dbs_data, delay, + policy); } else { for_each_cpu(i, policy->cpus) - __gov_queue_work(i, dbs_data, delay); + __gov_queue_work(i, dbs_data, delay, policy); } out_unlock: @@ -258,7 +268,13 @@ int cpufreq_governor_dbs(struct cpufreq_policy *policy, else dbs_data = cdata->gdbs_data; - WARN_ON(!dbs_data && (event != CPUFREQ_GOV_POLICY_INIT)); + if (!dbs_data && (event != CPUFREQ_GOV_POLICY_INIT)) { + pr_emerg("governor_data is NULL but governor %s is initialized = %d [governor_enabled = %d event = %u]\n", + policy->governor->name, + atomic_read(&policy->governor->initialized), + policy->governor_enabled, event); + BUG(); + } switch (event) { case CPUFREQ_GOV_POLICY_INIT: @@ -329,6 +345,12 @@ int cpufreq_governor_dbs(struct cpufreq_policy *policy, case CPUFREQ_GOV_POLICY_EXIT: mutex_lock(&dbs_data->usage_count_mutex); if (atomic_dec_and_test(&dbs_data->usage_count)) { + if (atomic_read(&policy->governor->initialized) > 1) { + pr_emerg("Removing governor %s but initialized = %d, dbs_data->usage_count = 0\n", + policy->governor->name, + atomic_read(&policy->governor->initialized)); + BUG(); + } sysfs_remove_group(get_governor_parent_kobj(policy), get_sysfs_attr(dbs_data)); -- 1.7.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
