All CPUs sharing a cpufreq policy share stats too. For this reason, add a stats pointer to struct cpufreq_policy and drop per-CPU variable cpufreq_stats_table used for accessing cpufreq stats so as to reduce code complexity.
Reviewed-by: Prarit Bhargava prarit@redhat.com Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- Resending only a single patch as found a issue with it while testing with my newly written cpufreq-test suite. The problem was that we haven't done cpufreq_cpu_put() for few failure cases and that restricts the cpufreq driver module to unload.
Here is the diff to V3:
@@ -265,14 +265,14 @@ static int cpufreq_stat_notifier_trans(struct notifier_block *nb, struct cpufreq_stats *stats; int old_index, new_index;
- if (val != CPUFREQ_POSTCHANGE) - return 0; - if (!policy) { pr_err("%s: No policy found\n", __func__); return 0; }
+ if (val != CPUFREQ_POSTCHANGE) + goto put_policy; + if (!policy->stats) { pr_debug("%s: No stats found\n", __func__); goto put_policy; @@ -285,10 +285,10 @@ static int cpufreq_stat_notifier_trans(struct notifier_block *nb,
/* We can't do stats->time_in_state[-1]= .. */ if (old_index == -1 || new_index == -1) - return 0; + goto put_policy;
if (old_index == new_index) - return 0; + goto put_policy;
cpufreq_stats_update(stats);
drivers/cpufreq/cpufreq_stats.c | 62 +++++++++++++++++++---------------------- include/linux/cpufreq.h | 3 ++ 2 files changed, 32 insertions(+), 33 deletions(-)
diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c index 6c234f548601..3792b2e2f4a8 100644 --- a/drivers/cpufreq/cpufreq_stats.c +++ b/drivers/cpufreq/cpufreq_stats.c @@ -31,8 +31,6 @@ struct cpufreq_stats { #endif };
-static DEFINE_PER_CPU(struct cpufreq_stats *, cpufreq_stats_table); - static int cpufreq_stats_update(struct cpufreq_stats *stat) { unsigned long long cur_time = get_jiffies_64(); @@ -48,20 +46,15 @@ static int cpufreq_stats_update(struct cpufreq_stats *stat)
static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf) { - struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu); - if (!stat) - return 0; - return sprintf(buf, "%d\n", - per_cpu(cpufreq_stats_table, stat->cpu)->total_trans); + return sprintf(buf, "%d\n", policy->stats->total_trans); }
static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf) { + struct cpufreq_stats *stat = policy->stats; ssize_t len = 0; int i; - struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu); - if (!stat) - return 0; + cpufreq_stats_update(stat); for (i = 0; i < stat->state_num; i++) { len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i], @@ -74,12 +67,10 @@ static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf) #ifdef CONFIG_CPU_FREQ_STAT_DETAILS static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf) { + struct cpufreq_stats *stat = policy->stats; ssize_t len = 0; int i, j;
- struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu); - if (!stat) - return 0; cpufreq_stats_update(stat); len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n"); len += snprintf(buf + len, PAGE_SIZE - len, " : "); @@ -145,8 +136,9 @@ static int freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
static void __cpufreq_stats_free_table(struct cpufreq_policy *policy) { - struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu); + struct cpufreq_stats *stat = policy->stats;
+ /* Already freed */ if (!stat) return;
@@ -155,7 +147,7 @@ static void __cpufreq_stats_free_table(struct cpufreq_policy *policy) sysfs_remove_group(&policy->kobj, &stats_attr_group); kfree(stat->time_in_state); kfree(stat); - per_cpu(cpufreq_stats_table, policy->cpu) = NULL; + policy->stats = NULL; }
static void cpufreq_stats_free_table(unsigned int cpu) @@ -184,7 +176,7 @@ static int __cpufreq_stats_create_table(struct cpufreq_policy *policy) return 0;
/* stats already initialized */ - if (per_cpu(cpufreq_stats_table, cpu)) + if (policy->stats) return -EEXIST;
stat = kzalloc(sizeof(*stat), GFP_KERNEL); @@ -196,7 +188,7 @@ static int __cpufreq_stats_create_table(struct cpufreq_policy *policy) goto error_out;
stat->cpu = cpu; - per_cpu(cpufreq_stats_table, cpu) = stat; + policy->stats = stat;
cpufreq_for_each_valid_entry(pos, table) count++; @@ -231,7 +223,7 @@ static int __cpufreq_stats_create_table(struct cpufreq_policy *policy) sysfs_remove_group(&policy->kobj, &stats_attr_group); error_out: kfree(stat); - per_cpu(cpufreq_stats_table, cpu) = NULL; + policy->stats = NULL; return ret; }
@@ -254,15 +246,7 @@ static void cpufreq_stats_create_table(unsigned int cpu)
static void cpufreq_stats_update_policy_cpu(struct cpufreq_policy *policy) { - struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, - policy->last_cpu); - - pr_debug("Updating stats_table for new_cpu %u from last_cpu %u\n", - policy->cpu, policy->last_cpu); - per_cpu(cpufreq_stats_table, policy->cpu) = per_cpu(cpufreq_stats_table, - policy->last_cpu); - per_cpu(cpufreq_stats_table, policy->last_cpu) = NULL; - stat->cpu = policy->cpu; + policy->stats->cpu = policy->cpu; }
static int cpufreq_stat_notifier_policy(struct notifier_block *nb, @@ -288,27 +272,36 @@ static int cpufreq_stat_notifier_trans(struct notifier_block *nb, unsigned long val, void *data) { struct cpufreq_freqs *freq = data; + struct cpufreq_policy *policy = cpufreq_cpu_get(freq->cpu); struct cpufreq_stats *stat; int old_index, new_index;
- if (val != CPUFREQ_POSTCHANGE) + if (!policy) { + pr_err("%s: No policy found\n", __func__); return 0; + }
- stat = per_cpu(cpufreq_stats_table, freq->cpu); - if (!stat) - return 0; + if (val != CPUFREQ_POSTCHANGE) + goto put_policy; + + if (!policy->stats) { + pr_debug("%s: No stats found\n", __func__); + goto put_policy; + } + + stat = policy->stats;
old_index = stat->last_index; new_index = freq_table_get_index(stat, freq->new);
/* We can't do stat->time_in_state[-1]= .. */ if (old_index == -1 || new_index == -1) - return 0; + goto put_policy;
cpufreq_stats_update(stat);
if (old_index == new_index) - return 0; + goto put_policy;
spin_lock(&cpufreq_stats_lock); stat->last_index = new_index; @@ -317,6 +310,9 @@ static int cpufreq_stat_notifier_trans(struct notifier_block *nb, #endif stat->total_trans++; spin_unlock(&cpufreq_stats_lock); + +put_policy: + cpufreq_cpu_put(policy); return 0; }
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 4d078cebafd2..60b7b496565d 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -113,6 +113,9 @@ struct cpufreq_policy { wait_queue_head_t transition_wait; struct task_struct *transition_task; /* Task which is doing the transition */
+ /* cpufreq-stats */ + struct cpufreq_stats *stats; + /* For cpufreq driver's internal use */ void *driver_data; };