[PATCH] fix BUG using smp_processor_id() in preemptiblethermal_throttle_add_dev

From: Sergey Senozhatsky
Date: Fri Aug 20 2010 - 03:36:07 EST


Fix: using smp_processor_id() in preemptible thermal_throttle_add_dev.
We know the cpu number when calling thermal_throttle_add_dev, so we can
remove smp_processor_id call in thermal_throttle_add_dev by supplying
the cpu number as argument.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>

---

diff --git a/arch/x86/kernel/cpu/mcheck/therm_throt.c b/arch/x86/kernel/cpu/mcheck/therm_throt.c
index c2a8b26..bcd8499 100644
--- a/arch/x86/kernel/cpu/mcheck/therm_throt.c
+++ b/arch/x86/kernel/cpu/mcheck/therm_throt.c
@@ -202,11 +202,12 @@ static int therm_throt_process(bool new_event, int event, int level)

#ifdef CONFIG_SYSFS
/* Add/Remove thermal_throttle interface for CPU device: */
-static __cpuinit int thermal_throttle_add_dev(struct sys_device *sys_dev)
+static __cpuinit int thermal_throttle_add_dev(struct sys_device *sys_dev,
+ unsigned int cpu)
{
int err;
- struct cpuinfo_x86 *c = &cpu_data(smp_processor_id());
-
+ struct cpuinfo_x86 *c = &cpu_data(cpu);
+
err = sysfs_create_group(&sys_dev->kobj, &thermal_attr_group);
if (err)
return err;
@@ -251,7 +252,7 @@ thermal_throttle_cpu_callback(struct notifier_block *nfb,
case CPU_UP_PREPARE:
case CPU_UP_PREPARE_FROZEN:
mutex_lock(&therm_cpu_lock);
- err = thermal_throttle_add_dev(sys_dev);
+ err = thermal_throttle_add_dev(sys_dev, cpu);
mutex_unlock(&therm_cpu_lock);
WARN_ON(err);
break;
@@ -287,7 +288,7 @@ static __init int thermal_throttle_init_device(void)
#endif
/* connect live CPUs to sysfs */
for_each_online_cpu(cpu) {
- err = thermal_throttle_add_dev(get_cpu_sysdev(cpu));
+ err = thermal_throttle_add_dev(get_cpu_sysdev(cpu), cpu);
WARN_ON(err);
}
#ifdef CONFIG_HOTPLUG_CPU

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