@@ -271,3 +271,72 @@ Description: Parameters for the CPU cache attributes
- WriteBack: data is written only to the cache line and
the modified cache line is written to main
memory only when it is replaced
+
+What: /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats
+ /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/turbo_stat
+ /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/sub_turbo_stat
+ /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/unthrottle
+ /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/powercap
+ /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/overtemp
+ /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/supply_fault
+ /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/overcurrent
+ /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/occ_reset
+Date: March 2016
+Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
+ Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org>
+Description: POWERNV CPUFreq driver's frequency throttle stats directory and
+ attributes
+
+ 'cpuX/cpufreq/throttle_stats' directory contains the CPU frequency
+ throttle stat attributes for the chip. The throttle stats of a cpu
+ is common across all the cpus belonging to a chip. Below are the
+ throttle attributes exported in the 'throttle_stats' directory:
+
+ - turbo_stat : This file gives the total number of times the max
+ frequency is throttled to lower frequency in turbo (at and above
+ nominal frequency) range of frequencies.
+
+ - sub_turbo_stat : This file gives the total number of times the
+ max frequency is throttled to lower frequency in sub-turbo(below
+ nominal frequency) range of frequencies.
+
+ - unthrottle : This file gives the total number of times the max
+ frequency is unthrottled after being throttled.
+
+ - powercap : This file gives the total number of times the max
+ frequency is throttled due to 'Power Capping'.
+
+ - overtemp : This file gives the total number of times the max
+ frequency is throttled due to 'CPU Over Temperature'.
+
+ - supply_fault : This file gives the total number of times the
+ max frequency is throttled due to 'Power Supply Failure'.
+
+ - overcurrent : This file gives the total number of times the
+ max frequency is throttled due to 'Overcurrent'.
+
+ - occ_reset : This file gives the total number of times the max
+ frequency is throttled due to 'OCC Reset'.
+
+ The sysfs attributes representing different throttle reasons like
+ powercap, overtemp, supply_fault, overcurrent and occ_reset map to
+ the reasons provided by OCC firmware for throttling the frequency.
+
+What: /sys/devices/system/cpu/cpufreq/policyX/throttle_stats
+ /sys/devices/system/cpu/cpufreq/policyX/throttle_stats/turbo_stat
+ /sys/devices/system/cpu/cpufreq/policyX/throttle_stats/sub_turbo_stat
+ /sys/devices/system/cpu/cpufreq/policyX/throttle_stats/unthrottle
+ /sys/devices/system/cpu/cpufreq/policyX/throttle_stats/powercap
+ /sys/devices/system/cpu/cpufreq/policyX/throttle_stats/overtemp
+ /sys/devices/system/cpu/cpufreq/policyX/throttle_stats/supply_fault
+ /sys/devices/system/cpu/cpufreq/policyX/throttle_stats/overcurrent
+ /sys/devices/system/cpu/cpufreq/policyX/throttle_stats/occ_reset
+Date: March 2016
+Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
+ Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org>
+Description: POWERNV CPUFreq driver's frequency throttle stats directory and
+ attributes
+
+ 'policyX/throttle_stats' directory and all the attributes are same as
+ the /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats directory and
+ attributes which give the frequency throttle information of the chip.
@@ -44,6 +44,7 @@
static struct cpufreq_frequency_table powernv_freqs[POWERNV_MAX_PSTATES+1];
static bool rebooting, throttled, occ_reset;
+static bool *create_throttle_sysfs;
static const char * const throttle_reason[] = {
"No throttling",
@@ -54,6 +55,16 @@ static const char * const throttle_reason[] = {
"OCC Reset"
};
+enum throttle_reason_type {
+ NO_THROTTLE = 0,
+ POWERCAP,
+ CPU_OVERTEMP,
+ POWER_SUPPLY_FAILURE,
+ OVERCURRENT,
+ OCC_RESET_THROTTLE,
+ OCC_MAX_REASON
+};
+
static struct chip {
unsigned int id;
bool throttled;
@@ -61,6 +72,9 @@ static struct chip {
u8 throttle_reason;
cpumask_t mask;
struct work_struct throttle;
+ int throttle_turbo;
+ int throttle_sub_turbo;
+ int reason[OCC_MAX_REASON];
} *chips;
static int nr_chips;
@@ -196,6 +210,42 @@ static struct freq_attr *powernv_cpu_freq_attr[] = {
NULL,
};
+#define throttle_attr(name, member) \
+static ssize_t name##_show(struct cpufreq_policy *policy, char *buf) \
+{ \
+ struct chip *chip = per_cpu(chip_info, policy->cpu); \
+ \
+ return sprintf(buf, "%u\n", chip->member); \
+} \
+ \
+static struct freq_attr throttle_attr_##name = __ATTR_RO(name) \
+
+throttle_attr(unthrottle, reason[NO_THROTTLE]);
+throttle_attr(powercap, reason[POWERCAP]);
+throttle_attr(overtemp, reason[CPU_OVERTEMP]);
+throttle_attr(supply_fault, reason[POWER_SUPPLY_FAILURE]);
+throttle_attr(overcurrent, reason[OVERCURRENT]);
+throttle_attr(occ_reset, reason[OCC_RESET_THROTTLE]);
+throttle_attr(turbo_stat, throttle_turbo);
+throttle_attr(sub_turbo_stat, throttle_sub_turbo);
+
+static struct attribute *throttle_attrs[] = {
+ &throttle_attr_unthrottle.attr,
+ &throttle_attr_powercap.attr,
+ &throttle_attr_overtemp.attr,
+ &throttle_attr_supply_fault.attr,
+ &throttle_attr_overcurrent.attr,
+ &throttle_attr_occ_reset.attr,
+ &throttle_attr_turbo_stat.attr,
+ &throttle_attr_sub_turbo_stat.attr,
+ NULL,
+};
+
+static const struct attribute_group throttle_attr_grp = {
+ .name = "throttle_stats",
+ .attrs = throttle_attrs,
+};
+
/* Helper routines */
/* Access helpers to power mgt SPR */
@@ -338,10 +388,14 @@ static void powernv_cpufreq_throttle_check(void *data)
if (chip->throttled)
goto next;
chip->throttled = true;
- if (pmsr_pmax < powernv_pstate_info.nominal)
+ if (pmsr_pmax < powernv_pstate_info.nominal) {
pr_warn_once("CPU %d on Chip %u has Pmax reduced below nominal frequency (%d < %d)\n",
cpu, chip->id, pmsr_pmax,
powernv_pstate_info.nominal);
+ chip->throttle_sub_turbo++;
+ } else {
+ chip->throttle_turbo++;
+ }
trace_powernv_throttle(chip->id,
throttle_reason[chip->throttle_reason],
pmsr_pmax);
@@ -401,13 +455,23 @@ static int powernv_cpufreq_target_index(struct cpufreq_policy *policy,
static int powernv_cpufreq_cpu_init(struct cpufreq_policy *policy)
{
- int base, i;
+ int base, i, ret;
base = cpu_first_thread_sibling(policy->cpu);
for (i = 0; i < threads_per_core; i++)
cpumask_set_cpu(base + i, policy->cpus);
+ i = cpu_core_index_of_thread(policy->cpu);
+ if (!create_throttle_sysfs[i]) {
+ ret = sysfs_create_group(&policy->kobj, &throttle_attr_grp);
+ if (ret) {
+ pr_info("Failed to create throttle stats directory for cpu %d\n",
+ policy->cpu);
+ return ret;
+ }
+ create_throttle_sysfs[i] = true;
+ }
return cpufreq_table_validate_and_show(policy, powernv_freqs);
}
@@ -514,8 +578,10 @@ static int powernv_cpufreq_occ_msg(struct notifier_block *nb,
break;
if (omsg.throttle_status >= 0 &&
- omsg.throttle_status <= OCC_MAX_THROTTLE_STATUS)
+ omsg.throttle_status <= OCC_MAX_THROTTLE_STATUS) {
chips[i].throttle_reason = omsg.throttle_status;
+ chips[i].reason[omsg.throttle_status]++;
+ }
if (!omsg.throttle_status)
chips[i].restore = true;
@@ -569,6 +635,13 @@ static int init_chip_info(void)
if (!chips)
return -ENOMEM;
+ create_throttle_sysfs = kcalloc(cpu_nr_cores(), sizeof(bool),
+ GFP_KERNEL);
+ if (!create_throttle_sysfs) {
+ kfree(chips);
+ return -ENOMEM;
+ }
+
for (i = 0; i < nr_chips; i++) {
chips[i].id = chip[i];
cpumask_copy(&chips[i].mask, cpumask_of_node(chip[i]));
@@ -582,6 +655,7 @@ static int init_chip_info(void)
static inline void clean_chip_info(void)
{
+ kfree(create_throttle_sysfs);
kfree(chips);
}
Create sysfs attributes to export throttle information in /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats directory. The newly added sysfs files are as follows: 1)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/turbo_stat 2)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/sub-turbo_stat 3)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/unthrottle 4)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/powercap 5)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/overtemp 6)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/supply_fault 7)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/overcurrent 8)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/occ_reset Detailed explanation of each attribute is added to Documentation/ABI/testing/sysfs-devices-system-cpu CC: linux-api@vger.kernel.org Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> --- Changes from v10: - Removed policy_notifiers to use driver->init() instead to create sysfs - sysfs attributes are removed by kobject_put(policy->kobj) - Rebased on top of http://lkml.iu.edu/hypermail/linux/kernel/1603.2/02268.html Changes from v9: - Modified documentation. - s/throttle_nominal/throttle_sub_turbo Changes from v8: - Moved the sysfs attributes from cpu/cpufreq/chipX to cpuX/cpufreq/throttle_stats - Adhering to one-value-per-file, replace throttle_table with multiple sysfs files. - Using CPUFREQ_POLICY_NOTIFIER to add/remove attribute_group. Documentation/ABI/testing/sysfs-devices-system-cpu | 69 +++++++++++++++++++ drivers/cpufreq/powernv-cpufreq.c | 80 +++++++++++++++++++++- 2 files changed, 146 insertions(+), 3 deletions(-)