![Harvey Harrison](/assets/img/avatar_default.png)
arch/x86/kernel/cpu/mcheck/therm_throt.c:121:2: warning: returning void-valued expression Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
189 lines
5.9 KiB
C
189 lines
5.9 KiB
C
/*
|
|
* linux/arch/i386/kernel/cpu/mcheck/therm_throt.c
|
|
*
|
|
* Thermal throttle event support code (such as syslog messaging and rate
|
|
* limiting) that was factored out from x86_64 (mce_intel.c) and i386 (p4.c).
|
|
* This allows consistent reporting of CPU thermal throttle events.
|
|
*
|
|
* Maintains a counter in /sys that keeps track of the number of thermal
|
|
* events, such that the user knows how bad the thermal problem might be
|
|
* (since the logging to syslog and mcelog is rate limited).
|
|
*
|
|
* Author: Dmitriy Zavin (dmitriyz@google.com)
|
|
*
|
|
* Credits: Adapted from Zwane Mwaikambo's original code in mce_intel.c.
|
|
* Inspired by Ross Biro's and Al Borchers' counter code.
|
|
*/
|
|
|
|
#include <linux/percpu.h>
|
|
#include <linux/sysdev.h>
|
|
#include <linux/cpu.h>
|
|
#include <asm/cpu.h>
|
|
#include <linux/notifier.h>
|
|
#include <linux/jiffies.h>
|
|
#include <asm/therm_throt.h>
|
|
|
|
/* How long to wait between reporting thermal events */
|
|
#define CHECK_INTERVAL (300 * HZ)
|
|
|
|
static DEFINE_PER_CPU(__u64, next_check) = INITIAL_JIFFIES;
|
|
static DEFINE_PER_CPU(unsigned long, thermal_throttle_count);
|
|
atomic_t therm_throt_en = ATOMIC_INIT(0);
|
|
|
|
#ifdef CONFIG_SYSFS
|
|
#define define_therm_throt_sysdev_one_ro(_name) \
|
|
static SYSDEV_ATTR(_name, 0444, therm_throt_sysdev_show_##_name, NULL)
|
|
|
|
#define define_therm_throt_sysdev_show_func(name) \
|
|
static ssize_t therm_throt_sysdev_show_##name(struct sys_device *dev, \
|
|
char *buf) \
|
|
{ \
|
|
unsigned int cpu = dev->id; \
|
|
ssize_t ret; \
|
|
\
|
|
preempt_disable(); /* CPU hotplug */ \
|
|
if (cpu_online(cpu)) \
|
|
ret = sprintf(buf, "%lu\n", \
|
|
per_cpu(thermal_throttle_##name, cpu)); \
|
|
else \
|
|
ret = 0; \
|
|
preempt_enable(); \
|
|
\
|
|
return ret; \
|
|
}
|
|
|
|
define_therm_throt_sysdev_show_func(count);
|
|
define_therm_throt_sysdev_one_ro(count);
|
|
|
|
static struct attribute *thermal_throttle_attrs[] = {
|
|
&attr_count.attr,
|
|
NULL
|
|
};
|
|
|
|
static struct attribute_group thermal_throttle_attr_group = {
|
|
.attrs = thermal_throttle_attrs,
|
|
.name = "thermal_throttle"
|
|
};
|
|
#endif /* CONFIG_SYSFS */
|
|
|
|
/***
|
|
* therm_throt_process - Process thermal throttling event from interrupt
|
|
* @curr: Whether the condition is current or not (boolean), since the
|
|
* thermal interrupt normally gets called both when the thermal
|
|
* event begins and once the event has ended.
|
|
*
|
|
* This function is called by the thermal interrupt after the
|
|
* IRQ has been acknowledged.
|
|
*
|
|
* It will take care of rate limiting and printing messages to the syslog.
|
|
*
|
|
* Returns: 0 : Event should NOT be further logged, i.e. still in
|
|
* "timeout" from previous log message.
|
|
* 1 : Event should be logged further, and a message has been
|
|
* printed to the syslog.
|
|
*/
|
|
int therm_throt_process(int curr)
|
|
{
|
|
unsigned int cpu = smp_processor_id();
|
|
__u64 tmp_jiffs = get_jiffies_64();
|
|
|
|
if (curr)
|
|
__get_cpu_var(thermal_throttle_count)++;
|
|
|
|
if (time_before64(tmp_jiffs, __get_cpu_var(next_check)))
|
|
return 0;
|
|
|
|
__get_cpu_var(next_check) = tmp_jiffs + CHECK_INTERVAL;
|
|
|
|
/* if we just entered the thermal event */
|
|
if (curr) {
|
|
printk(KERN_CRIT "CPU%d: Temperature above threshold, "
|
|
"cpu clock throttled (total events = %lu)\n", cpu,
|
|
__get_cpu_var(thermal_throttle_count));
|
|
|
|
add_taint(TAINT_MACHINE_CHECK);
|
|
} else {
|
|
printk(KERN_CRIT "CPU%d: Temperature/speed normal\n", cpu);
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
#ifdef CONFIG_SYSFS
|
|
/* Add/Remove thermal_throttle interface for CPU device */
|
|
static __cpuinit int thermal_throttle_add_dev(struct sys_device *sys_dev)
|
|
{
|
|
return sysfs_create_group(&sys_dev->kobj, &thermal_throttle_attr_group);
|
|
}
|
|
|
|
static __cpuinit void thermal_throttle_remove_dev(struct sys_device *sys_dev)
|
|
{
|
|
sysfs_remove_group(&sys_dev->kobj, &thermal_throttle_attr_group);
|
|
}
|
|
|
|
/* Mutex protecting device creation against CPU hotplug */
|
|
static DEFINE_MUTEX(therm_cpu_lock);
|
|
|
|
/* Get notified when a cpu comes on/off. Be hotplug friendly. */
|
|
static __cpuinit int thermal_throttle_cpu_callback(struct notifier_block *nfb,
|
|
unsigned long action,
|
|
void *hcpu)
|
|
{
|
|
unsigned int cpu = (unsigned long)hcpu;
|
|
struct sys_device *sys_dev;
|
|
int err = 0;
|
|
|
|
sys_dev = get_cpu_sysdev(cpu);
|
|
switch (action) {
|
|
case CPU_UP_PREPARE:
|
|
case CPU_UP_PREPARE_FROZEN:
|
|
mutex_lock(&therm_cpu_lock);
|
|
err = thermal_throttle_add_dev(sys_dev);
|
|
mutex_unlock(&therm_cpu_lock);
|
|
WARN_ON(err);
|
|
break;
|
|
case CPU_UP_CANCELED:
|
|
case CPU_UP_CANCELED_FROZEN:
|
|
case CPU_DEAD:
|
|
case CPU_DEAD_FROZEN:
|
|
mutex_lock(&therm_cpu_lock);
|
|
thermal_throttle_remove_dev(sys_dev);
|
|
mutex_unlock(&therm_cpu_lock);
|
|
break;
|
|
}
|
|
return err ? NOTIFY_BAD : NOTIFY_OK;
|
|
}
|
|
|
|
static struct notifier_block thermal_throttle_cpu_notifier __cpuinitdata =
|
|
{
|
|
.notifier_call = thermal_throttle_cpu_callback,
|
|
};
|
|
|
|
static __init int thermal_throttle_init_device(void)
|
|
{
|
|
unsigned int cpu = 0;
|
|
int err;
|
|
|
|
if (!atomic_read(&therm_throt_en))
|
|
return 0;
|
|
|
|
register_hotcpu_notifier(&thermal_throttle_cpu_notifier);
|
|
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
mutex_lock(&therm_cpu_lock);
|
|
#endif
|
|
/* connect live CPUs to sysfs */
|
|
for_each_online_cpu(cpu) {
|
|
err = thermal_throttle_add_dev(get_cpu_sysdev(cpu));
|
|
WARN_ON(err);
|
|
}
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
mutex_unlock(&therm_cpu_lock);
|
|
#endif
|
|
|
|
return 0;
|
|
}
|
|
|
|
device_initcall(thermal_throttle_init_device);
|
|
#endif /* CONFIG_SYSFS */
|