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author | Ingo Molnar <mingo@elte.hu> | 2009-09-22 15:50:24 +0200 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@suse.de> | 2009-11-09 16:23:06 -0800 |
commit | fe2414ca987a3a49007bec6fd12254c7defae2a9 (patch) | |
tree | 6ed91ef964780a5ab2c1254fc91a68d064cf8a76 /arch | |
parent | 94f48f549e455e4abbb3f0d6e65185830cbec8f1 (diff) | |
download | lwn-fe2414ca987a3a49007bec6fd12254c7defae2a9.tar.gz lwn-fe2414ca987a3a49007bec6fd12254c7defae2a9.zip |
x86: mce: Clean up thermal throttling state tracking code
commit 3967684006f30c253bc6d4a6604d1bad4a7fc672 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/x86/kernel/cpu/mcheck/therm_throt.c | 63 |
1 files changed, 39 insertions, 24 deletions
diff --git a/arch/x86/kernel/cpu/mcheck/therm_throt.c b/arch/x86/kernel/cpu/mcheck/therm_throt.c index 5957a93e5173..2951436ac0e3 100644 --- a/arch/x86/kernel/cpu/mcheck/therm_throt.c +++ b/arch/x86/kernel/cpu/mcheck/therm_throt.c @@ -34,20 +34,30 @@ /* 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); -static DEFINE_PER_CPU(bool, thermal_throttle_active); +/* + * Current thermal throttling state: + */ +struct thermal_state { + bool is_throttled; + + 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); +static 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, \ - struct sysdev_attribute *attr, \ - char *buf) \ + \ +static ssize_t therm_throt_sysdev_show_##name( \ + struct sys_device *dev, \ + struct sysdev_attribute *attr, \ + char *buf) \ { \ unsigned int cpu = dev->id; \ ssize_t ret; \ @@ -55,7 +65,7 @@ static ssize_t therm_throt_sysdev_show_##name(struct sys_device *dev, \ preempt_disable(); /* CPU hotplug */ \ if (cpu_online(cpu)) \ ret = sprintf(buf, "%lu\n", \ - per_cpu(thermal_throttle_##name, cpu)); \ + per_cpu(thermal_state, cpu).name); \ else \ ret = 0; \ preempt_enable(); \ @@ -63,11 +73,11 @@ static ssize_t therm_throt_sysdev_show_##name(struct sys_device *dev, \ return ret; \ } -define_therm_throt_sysdev_show_func(count); -define_therm_throt_sysdev_one_ro(count); +define_therm_throt_sysdev_show_func(throttle_count); +define_therm_throt_sysdev_one_ro(throttle_count); static struct attribute *thermal_throttle_attrs[] = { - &attr_count.attr, + &attr_throttle_count.attr, NULL }; @@ -93,33 +103,38 @@ static struct attribute_group thermal_throttle_attr_group = { * 1 : Event should be logged further, and a message has been * 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(); - __u64 tmp_jiffs = get_jiffies_64(); - bool was_throttled = __get_cpu_var(thermal_throttle_active); - bool is_throttled = __get_cpu_var(thermal_throttle_active) = curr; + struct thermal_state *state; + unsigned int this_cpu; + bool was_throttled; + 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) - __get_cpu_var(thermal_throttle_count)++; + state->throttle_count++; if (!(was_throttled ^ is_throttled) && - time_before64(tmp_jiffs, __get_cpu_var(next_check))) + time_before64(now, state->next_check)) 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 (is_throttled) { - printk(KERN_CRIT "CPU%d: Temperature above threshold, " - "cpu clock throttled (total events = %lu)\n", - cpu, __get_cpu_var(thermal_throttle_count)); + printk(KERN_CRIT "CPU%d: Temperature above threshold, cpu clock throttled (total events = %lu)\n", this_cpu, state->throttle_count); add_taint(TAINT_MACHINE_CHECK); return 1; } 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; } @@ -213,7 +228,7 @@ static void intel_thermal_interrupt(void) __u64 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); } |