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x86: mce: Clean up thermal throttling state tracking code

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Instead of a mess of three separate percpu variables, consolidate
the state into a single structure.

Also clean up therm_throt_process(), use cleaner and more
understandable variable names and a clearer logic.

This, without changing the logic, makes the code more
streamlined, more readable and smaller as well:

   text	   data	    bss	    dec	    hex	filename
   1487	    169	      4	   1660	    67c	therm_throt.o.before
   1432	    176	      4	   1612	    64c	therm_throt.o.after

Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Ingo Molnar 2009-09-22 15:50:24 +02:00
parent b8c7f1dc5c
commit 3967684006
1 changed files with 39 additions and 24 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

63
arch/x86/kernel/cpu/mcheck/therm_throt.c
View file

@ -34,20 +34,30 @@
/* How long to wait between reporting thermal events */ /* How long to wait between reporting thermal events */
#define CHECK_INTERVAL (300 * HZ) #define CHECK_INTERVAL (300 * HZ)
static DEFINE_PER_CPU(__u64, next_check) = INITIAL_JIFFIES; /*
static DEFINE_PER_CPU(unsigned long, thermal_throttle_count); * Current thermal throttling state:
static DEFINE_PER_CPU(bool, thermal_throttle_active); */
struct thermal_state {
bool is_throttled;
static atomic_t therm_throt_en = ATOMIC_INIT(0); u64 next_check;
unsigned long throttle_count;
};
static DEFINE_PER_CPU(struct thermal_state, thermal_state);
static atomic_t therm_throt_en = ATOMIC_INIT(0);
#ifdef CONFIG_SYSFS #ifdef CONFIG_SYSFS
#define define_therm_throt_sysdev_one_ro(_name) \ #define define_therm_throt_sysdev_one_ro(_name) \
static SYSDEV_ATTR(_name, 0444, therm_throt_sysdev_show_##_name, NULL) static SYSDEV_ATTR(_name, 0444, therm_throt_sysdev_show_##_name, NULL)
#define define_therm_throt_sysdev_show_func(name) \ #define define_therm_throt_sysdev_show_func(name) \
static ssize_t therm_throt_sysdev_show_##name(struct sys_device *dev, \ \
struct sysdev_attribute *attr, \ static ssize_t therm_throt_sysdev_show_##name( \
char *buf) \ struct sys_device *dev, \
struct sysdev_attribute *attr, \
char *buf) \
{ \ { \
unsigned int cpu = dev->id; \ unsigned int cpu = dev->id; \
ssize_t ret; \ ssize_t ret; \
@ -55,7 +65,7 @@ static ssize_t therm_throt_sysdev_show_##name(struct sys_device *dev, \
preempt_disable(); /* CPU hotplug */ \ preempt_disable(); /* CPU hotplug */ \
if (cpu_online(cpu)) \ if (cpu_online(cpu)) \
ret = sprintf(buf, "%lu\n", \ ret = sprintf(buf, "%lu\n", \
per_cpu(thermal_throttle_##name, cpu)); \ per_cpu(thermal_state, cpu).name); \
else \ else \
ret = 0; \ ret = 0; \
preempt_enable(); \ preempt_enable(); \
@ -63,11 +73,11 @@ static ssize_t therm_throt_sysdev_show_##name(struct sys_device *dev, \
return ret; \ return ret; \
} }
define_therm_throt_sysdev_show_func(count); define_therm_throt_sysdev_show_func(throttle_count);
define_therm_throt_sysdev_one_ro(count); define_therm_throt_sysdev_one_ro(throttle_count);
static struct attribute *thermal_throttle_attrs[] = { static struct attribute *thermal_throttle_attrs[] = {
&attr_count.attr, &attr_throttle_count.attr,
NULL NULL
}; };
@ -93,33 +103,38 @@ static struct attribute_group thermal_throttle_attr_group = {
* 1 : Event should be logged further, and a message has been * 1 : Event should be logged further, and a message has been
* printed to the syslog. * printed to the syslog.
*/ */
static int therm_throt_process(int curr) static int therm_throt_process(bool is_throttled)
{ {
unsigned int cpu = smp_processor_id(); struct thermal_state *state;
__u64 tmp_jiffs = get_jiffies_64(); unsigned int this_cpu;
bool was_throttled = __get_cpu_var(thermal_throttle_active); bool was_throttled;
bool is_throttled = __get_cpu_var(thermal_throttle_active) = curr; u64 now;
this_cpu = smp_processor_id();
now = get_jiffies_64();
state = &per_cpu(thermal_state, this_cpu);
was_throttled = state->is_throttled;
state->is_throttled = is_throttled;
if (is_throttled) if (is_throttled)
__get_cpu_var(thermal_throttle_count)++; state->throttle_count++;
if (!(was_throttled ^ is_throttled) && if (!(was_throttled ^ is_throttled) &&
time_before64(tmp_jiffs, __get_cpu_var(next_check))) time_before64(now, state->next_check))
return 0; return 0;
__get_cpu_var(next_check) = tmp_jiffs + CHECK_INTERVAL; state->next_check = now + CHECK_INTERVAL;
/* if we just entered the thermal event */ /* if we just entered the thermal event */
if (is_throttled) { if (is_throttled) {
printk(KERN_CRIT "CPU%d: Temperature above threshold, " printk(KERN_CRIT "CPU%d: Temperature above threshold, cpu clock throttled (total events = %lu)\n", this_cpu, state->throttle_count);
"cpu clock throttled (total events = %lu)\n",
cpu, __get_cpu_var(thermal_throttle_count));
add_taint(TAINT_MACHINE_CHECK); add_taint(TAINT_MACHINE_CHECK);
return 1; return 1;
} }
if (was_throttled) { if (was_throttled) {
printk(KERN_INFO "CPU%d: Temperature/speed normal\n", cpu); printk(KERN_INFO "CPU%d: Temperature/speed normal\n", this_cpu);
return 1; return 1;
} }
@ -213,7 +228,7 @@ static void intel_thermal_interrupt(void)
__u64 msr_val; __u64 msr_val;
rdmsrl(MSR_IA32_THERM_STATUS, msr_val); rdmsrl(MSR_IA32_THERM_STATUS, msr_val);
if (therm_throt_process(msr_val & THERM_STATUS_PROCHOT)) if (therm_throt_process((msr_val & THERM_STATUS_PROCHOT) != 0))
mce_log_therm_throt_event(msr_val); mce_log_therm_throt_event(msr_val);
} }