[PATCH v3] cpufreq: stats: Add 'load_table' debugfs file to showaccumulated data of CPUs
From: Chanwoo Choi
Date: Mon Jun 24 2013 - 05:02:47 EST
This patch add new 'load_table' debugfs file to show previous accumulated data
of CPUs load as following path and add CPUFREQ_LOADCHECK notification to
CPUFREQ_TRANSITION_NOTIFIER notifier chain.
- /sys/kernel/debug/cpufreq/cpuX/load_table
When governor calculates CPUs load on dbs_check_cpu(), governor send
CPUFREQ_LOADCHECK notification with CPUs load, so that cpufreq_stats
accumulates calculated CPUs load on 'load_table' storage.
This debugfs file is used to judge the correct system state or determine
suitable system resource according to current CPUs load on user-space.
This debugfs file include following data:
- Measurement point of time
- CPU frequency
- Per-CPU load
Signed-off-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
Signed-off-by: Myungjoo Ham <myungjoo.ham@xxxxxxxxxxx>
---
Changes since v2:
- Code clean according to Viresh Kumar's comment
- Show both old frequency and new frequency on 'load_table' debugfs file
- Change debufs file patch as below
old: /sys/kernel/debugfs/cpufreq/load_table
new: /sys/kernel/debugfs/cpufreq/cpuX/load_table
Changes since v1:
- Set maximum storage size to save CPUs load on Kconfig
- Use spinlock to synchronize read/write operation for CPUs load
- Use local variable instead of global variable(struct cpufreq_freqs *freqs)
- Use pointer of data structure to get correct size of data structure
in sizeof() macro instead of structure name
: sizeof(struct cpufreq_freqs) -> sizeof(*stat->load_table)
- Change time unit from nanosecond to microsecond
- Remove unnecessary memory copy
Following Test result :
- Cpufreq governor : ondemand governor
- Test application : MP3 play + Picture Audo-slide application
- NR_CPU_LOAD_STORAGE is 50
Time Old Frequency New Frequency CPU0 CPU1 CPU2 CPU3
347000 1600000 1600000 12 33 86 8
347100 1600000 1600000 4 30 72 4
347200 1600000 1600000 20 18 15 80
347300 1600000 1500000 61 20 56 66
347400 1500000 1300000 64 5 58 52
347500 1300000 1100000 39 19 57 59
347600 1100000 1100000 73 2 77 49
347700 1100000 1600000 70 40 84 58
347800 1600000 1600000 98 95 45 25
347900 1600000 1200000 39 30 16 53
348000 1200000 600000 37 7 1 3
348100 600000 200000 6 0 18 5
348200 200000 200000 22 8 5 23
348300 200000 200000 43 3 75 13
348400 200000 1600000 43 12 100 16
348500 1600000 700000 19 7 17 30
348600 700000 400000 31 12 37 2
348705 400000 1600000 67 53 83 18
348800 1600000 600000 26 7 7 17
348900 600000 600000 16 3 0 3
349000 200000 200000 42 9 9 48
349100 200000 1600000 19 11 26 84
349200 1600000 400000 17 9 15 15
349300 400000 300000 38 27 6 7
349400 300000 300000 53 11 2 21
349500 300000 300000 56 19 16 38
349600 300000 300000 58 32 7 40
349700 300000 300000 54 39 12 21
349800 300000 1600000 91 70 85 67
349900 1600000 900000 42 2 42 23
350000 900000 400000 30 3 2 5
350100 400000 200000 15 15 3 8
350200 200000 200000 37 33 1 26
350300 200000 1600000 10 95 0 4
350400 1600000 500000 20 10 1 13
350500 500000 300000 31 8 1 25
350600 300000 200000 36 10 10 6
350700 200000 200000 65 9 23 45
350800 200000 200000 68 40 63 44
350900 200000 1600000 95 73 84 89
351000 1600000 1600000 35 81 5 1
351100 1600000 600000 26 3 7 7
351200 600000 200000 13 6 8 23
351300 200000 200000 36 9 2 16
351400 200000 200000 60 53 0 57
351500 200000 200000 36 21 11 31
351600 200000 200000 54 1 33 34
351700 200000 200000 60 1 30 59
351800 200000 200000 36 18 9 16
351900 200000 1600000 84 12 46 17
drivers/cpufreq/Kconfig | 6 +
drivers/cpufreq/cpufreq.c | 4 +
drivers/cpufreq/cpufreq_governor.c | 19 +++-
drivers/cpufreq/cpufreq_stats.c | 227 +++++++++++++++++++++++++++++++++----
include/linux/cpufreq.h | 6 +
5 files changed, 242 insertions(+), 20 deletions(-)
diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
index 534fcb8..8a429b3 100644
--- a/drivers/cpufreq/Kconfig
+++ b/drivers/cpufreq/Kconfig
@@ -45,6 +45,12 @@ config CPU_FREQ_STAT_DETAILS
If in doubt, say N.
+config NR_CPU_LOAD_STORAGE
+ int "Maximum storage size to save CPU load (10-100)"
+ range 10 100
+ depends on CPU_FREQ_STAT_DETAILS
+ default "10"
+
choice
prompt "Default CPUFreq governor"
default CPU_FREQ_DEFAULT_GOV_USERSPACE if ARM_SA1100_CPUFREQ || ARM_SA1110_CPUFREQ
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 2d53f47..cbaaff0 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -292,6 +292,10 @@ void __cpufreq_notify_transition(struct cpufreq_policy *policy,
if (likely(policy) && likely(policy->cpu == freqs->cpu))
policy->cur = freqs->new;
break;
+ case CPUFREQ_LOADCHECK:
+ srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
+ CPUFREQ_LOADCHECK, freqs);
+ break;
}
}
/**
diff --git a/drivers/cpufreq/cpufreq_governor.c b/drivers/cpufreq/cpufreq_governor.c
index dc9b72e..7f19394 100644
--- a/drivers/cpufreq/cpufreq_governor.c
+++ b/drivers/cpufreq/cpufreq_governor.c
@@ -90,6 +90,9 @@ void dbs_check_cpu(struct dbs_data *dbs_data, int cpu)
unsigned int max_load = 0;
unsigned int ignore_nice;
unsigned int j;
+#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
+ struct cpufreq_freqs freq;
+#endif
if (dbs_data->cdata->governor == GOV_ONDEMAND)
ignore_nice = od_tuners->ignore_nice;
@@ -144,10 +147,17 @@ void dbs_check_cpu(struct dbs_data *dbs_data, int cpu)
idle_time += jiffies_to_usecs(cur_nice_jiffies);
}
- if (unlikely(!wall_time || wall_time < idle_time))
+ if (unlikely(!wall_time || wall_time < idle_time)) {
+#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
+ freq.load[j] = 0;
+#endif
continue;
+ }
load = 100 * (wall_time - idle_time) / wall_time;
+#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
+ freq.load[j] = load;
+#endif
if (dbs_data->cdata->governor == GOV_ONDEMAND) {
int freq_avg = __cpufreq_driver_getavg(policy, j);
@@ -161,6 +171,13 @@ void dbs_check_cpu(struct dbs_data *dbs_data, int cpu)
max_load = load;
}
+#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
+ freq.time = ktime_to_ms(ktime_get());
+ freq.old = freq.new = policy->cur;
+
+ cpufreq_notify_transition(policy, &freq, CPUFREQ_LOADCHECK);
+#endif
+
dbs_data->cdata->gov_check_cpu(cpu, max_load);
}
EXPORT_SYMBOL_GPL(dbs_check_cpu);
diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
index fb65dec..1b74b03 100644
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -12,6 +12,7 @@
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/cpu.h>
+#include <linux/debugfs.h>
#include <linux/sysfs.h>
#include <linux/cpufreq.h>
#include <linux/module.h>
@@ -24,6 +25,10 @@
static spinlock_t cpufreq_stats_lock;
+#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
+static struct dentry *debugfs_cpufreq;
+#endif
+
struct cpufreq_stats {
unsigned int cpu;
unsigned int total_trans;
@@ -35,6 +40,12 @@ struct cpufreq_stats {
unsigned int *freq_table;
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
unsigned int *trans_table;
+
+ /* debugfs file for load_table */
+ struct cpufreq_freqs *load_table;
+ unsigned int load_last_index;
+ unsigned int load_max_index;
+ struct dentry *debugfs_cpu;
#endif
};
@@ -149,6 +160,163 @@ static struct attribute_group stats_attr_group = {
.name = "stats"
};
+#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
+#define MAX_LINE_SIZE 255
+static ssize_t load_table_read(struct file *file, char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ struct cpufreq_policy *policy = file->private_data;
+ struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
+ struct cpufreq_freqs *load_table = stat->load_table;
+ ssize_t len = 0;
+ char *buf;
+ int i, cpu, ret;
+
+ buf = kzalloc(MAX_LINE_SIZE * stat->load_max_index, GFP_KERNEL);
+ if (!buf)
+ return 0;
+
+ spin_lock(&cpufreq_stats_lock);
+ len += sprintf(buf + len, "%10s %13s %13s", "Time", "Old Frequency",
+ "New Frequency");
+ for_each_present_cpu(cpu)
+ len += sprintf(buf + len, " %3s%d", "CPU", cpu);
+ len += sprintf(buf + len, "\n");
+
+ i = stat->load_last_index;
+ do {
+ len += sprintf(buf + len, "%10lld %13d %13d",
+ load_table[i].time,
+ load_table[i].old,
+ load_table[i].new);
+
+ for_each_present_cpu(cpu)
+ len += sprintf(buf + len, " %4d",
+ load_table[i].load[cpu]);
+ len += sprintf(buf + len, "\n");
+
+ if (++i == stat->load_max_index)
+ i = 0;
+ } while (i != stat->load_last_index);
+ spin_unlock(&cpufreq_stats_lock);
+
+ ret = simple_read_from_buffer(user_buf, count, ppos, buf, len);
+ kfree(buf);
+
+ return ret;
+}
+
+static const struct file_operations load_table_fops = {
+ .read = load_table_read,
+ .open = simple_open,
+ .llseek = no_llseek,
+};
+
+static void cpufreq_stats_store_load_table(struct cpufreq_freqs *freq,
+ unsigned long val)
+{
+ struct cpufreq_stats *stat;
+ int cpu, last_idx;
+
+ stat = per_cpu(cpufreq_stats_table, freq->cpu);
+ if (!stat)
+ return;
+
+ spin_lock(&cpufreq_stats_lock);
+
+ switch (val) {
+ case CPUFREQ_POSTCHANGE:
+ if (!stat->load_last_index)
+ last_idx = stat->load_max_index;
+ else
+ last_idx = stat->load_last_index - 1;
+
+ stat->load_table[last_idx].new = freq->new;
+ break;
+ case CPUFREQ_LOADCHECK:
+ last_idx = stat->load_last_index;
+
+ stat->load_table[last_idx].time = freq->time;
+ stat->load_table[last_idx].old = freq->old;
+ stat->load_table[last_idx].new = freq->old;
+ for_each_present_cpu(cpu)
+ stat->load_table[last_idx].load[cpu] = freq->load[cpu];
+
+ if (++stat->load_last_index == stat->load_max_index)
+ stat->load_last_index = 0;
+ break;
+ }
+
+ spin_unlock(&cpufreq_stats_lock);
+}
+
+static int cpufreq_stats_create_debugfs(struct cpufreq_policy *policy)
+{
+ struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
+ char buf[10];
+ int size, ret = 0;
+
+ if (!stat)
+ return -EINVAL;
+
+ stat->load_last_index = 0;
+ stat->load_max_index = CONFIG_NR_CPU_LOAD_STORAGE;
+
+ size = sizeof(*stat->load_table) * stat->load_max_index;
+ stat->load_table = kzalloc(size, GFP_KERNEL);
+ if (!stat->load_table) {
+ ret = -ENOMEM;
+ goto err_alloc;
+ }
+
+ /* Create debugfs root and file for cpufreq */
+ if (!debugfs_cpufreq) {
+ debugfs_cpufreq = debugfs_create_dir("cpufreq", NULL);
+ if (!debugfs_cpufreq) {
+ ret = -EINVAL;
+ goto err_alloc;
+ }
+ }
+
+ sprintf(buf, "cpu%d", policy->cpu);
+
+ stat->debugfs_cpu = debugfs_create_dir(buf, debugfs_cpufreq);
+ if (!stat->debugfs_cpu) {
+ ret = -EINVAL;
+ goto err_alloc;
+ }
+
+ debugfs_create_file("load_table", S_IWUSR, stat->debugfs_cpu,
+ (void *)policy, &load_table_fops);
+
+ return 0;
+
+err_alloc:
+ kfree(stat->load_table);
+
+ return ret;
+}
+
+static void cpufreq_stats_free_debugfs(unsigned int cpu)
+{
+ struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, cpu);
+
+ if (!stat)
+ return;
+
+ pr_debug("%s: Free debugfs stat\n", __func__);
+ debugfs_remove(debugfs_cpufreq);
+}
+#else
+static void cpufreq_stats_store_load_table(struct cpufreq_freqs *freq,
+ unsigned long val) { }
+static int cpufreq_stats_create_debugfs(struct cpufreq_policy *policy)
+{
+ return 0;
+}
+static void cpufreq_stats_free_debugfs(unsigned int cpu) { }
+#endif
+
static int freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
{
int index;
@@ -167,6 +335,9 @@ static void cpufreq_stats_free_table(unsigned int cpu)
if (stat) {
pr_debug("%s: Free stat table\n", __func__);
+#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
+ kfree(stat->load_table);
+#endif
kfree(stat->time_in_state);
kfree(stat);
per_cpu(cpufreq_stats_table, cpu) = NULL;
@@ -257,6 +428,14 @@ static int cpufreq_stats_create_table(struct cpufreq_policy *policy,
spin_lock(&cpufreq_stats_lock);
stat->last_time = get_jiffies_64();
stat->last_index = freq_table_get_index(stat, policy->cur);
+
+ ret = cpufreq_stats_create_debugfs(data);
+ if (ret) {
+ spin_unlock(&cpufreq_stats_lock);
+ ret = -EINVAL;
+ goto error_out;
+ }
+
spin_unlock(&cpufreq_stats_lock);
cpufreq_cpu_put(data);
return 0;
@@ -312,32 +491,40 @@ static int cpufreq_stat_notifier_trans(struct notifier_block *nb,
struct cpufreq_stats *stat;
int old_index, new_index;
- if (val != CPUFREQ_POSTCHANGE)
- return 0;
-
- stat = per_cpu(cpufreq_stats_table, freq->cpu);
- if (!stat)
- return 0;
+ switch (val) {
+ case CPUFREQ_POSTCHANGE:
+ stat = per_cpu(cpufreq_stats_table, freq->cpu);
+ if (!stat)
+ return 0;
- old_index = stat->last_index;
- new_index = freq_table_get_index(stat, freq->new);
+ 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;
+ /* We can't do stat->time_in_state[-1]= .. */
+ if (old_index == -1 || new_index == -1)
+ return 0;
- cpufreq_stats_update(freq->cpu);
+ cpufreq_stats_update(freq->cpu);
- if (old_index == new_index)
- return 0;
+ if (old_index == new_index)
+ return 0;
- spin_lock(&cpufreq_stats_lock);
- stat->last_index = new_index;
+ spin_lock(&cpufreq_stats_lock);
+ stat->last_index = new_index;
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
- stat->trans_table[old_index * stat->max_state + new_index]++;
+ stat->trans_table[old_index * stat->max_state + new_index]++;
#endif
- stat->total_trans++;
- spin_unlock(&cpufreq_stats_lock);
+ stat->total_trans++;
+ spin_unlock(&cpufreq_stats_lock);
+
+ cpufreq_stats_store_load_table(freq, CPUFREQ_POSTCHANGE);
+
+ break;
+ case CPUFREQ_LOADCHECK:
+ cpufreq_stats_store_load_table(freq, CPUFREQ_LOADCHECK);
+ break;
+ }
+
return 0;
}
@@ -352,12 +539,14 @@ static int __cpuinit cpufreq_stat_cpu_callback(struct notifier_block *nfb,
cpufreq_update_policy(cpu);
break;
case CPU_DOWN_PREPARE:
+ cpufreq_stats_free_debugfs(cpu);
cpufreq_stats_free_sysfs(cpu);
break;
case CPU_DEAD:
cpufreq_stats_free_table(cpu);
break;
case CPU_UP_CANCELED_FROZEN:
+ cpufreq_stats_free_debugfs(cpu);
cpufreq_stats_free_sysfs(cpu);
cpufreq_stats_free_table(cpu);
break;
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 037d36a..f780645 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -140,12 +140,18 @@ static inline bool policy_is_shared(struct cpufreq_policy *policy)
#define CPUFREQ_POSTCHANGE (1)
#define CPUFREQ_RESUMECHANGE (8)
#define CPUFREQ_SUSPENDCHANGE (9)
+#define CPUFREQ_LOADCHECK (10)
struct cpufreq_freqs {
unsigned int cpu; /* cpu nr */
unsigned int old;
unsigned int new;
u8 flags; /* flags of cpufreq_driver, see below. */
+
+#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
+ int64_t time;
+ unsigned int load[NR_CPUS];
+#endif
};
--
1.8.0
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