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Commit 6bb2ff84 authored by Fenghua Yu's avatar Fenghua Yu Committed by Tony Luck
Browse files

x86 thermal: Disable power limit notification interrupt by default 

The package power limit notification interrupt is primarily for
system diagnosis, and should not be blindly enabled on every
system by default -- particuarly since Linux does nothing in the
handler except count how many times it has been called...

Add a new kernel cmdline parameter "int_pln_enable" for situations where
users want to oberve these events via existing system counters:

$ grep TRM /proc/interrupts

$ grep . /sys/devices/system/cpu/cpu*/thermal_throttle/*

https://bugzilla.kernel.org/show_bug.cgi?id=36182



Signed-off-by: default avatarFenghua Yu <fenghua.yu@intel.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
parent c8114748

Documentation/kernel-parameters.txt

+2 −0
Original line number Diff line number Diff line
@@ -1158,6 +1158,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. 
	inport.irq=	[HW] Inport (ATI XL and Microsoft) busmouse driver

			Format: <irq>



	int_pln_enable  [x86] Enable power limit notification interrupt



	intel_iommu=	[DMAR] Intel IOMMU driver (DMAR) option

		on

			Enable intel iommu driver.

arch/x86/kernel/cpu/mcheck/therm_throt.c

+26 −8
Original line number Diff line number Diff line
@@ -210,6 +210,15 @@ static int thresh_event_valid(int event) 
	return 1;

}



static bool int_pln_enable;

static int __init int_pln_enable_setup(char *s)

{

	int_pln_enable = true;



	return 1;

}

__setup("int_pln_enable", int_pln_enable_setup);



#ifdef CONFIG_SYSFS

/* Add/Remove thermal_throttle interface for CPU device: */

static __cpuinit int thermal_throttle_add_dev(struct device *dev,
@@ -222,7 +231,7 @@ static __cpuinit int thermal_throttle_add_dev(struct device *dev, 
	if (err)

		return err;



	if (cpu_has(c, X86_FEATURE_PLN))

	if (cpu_has(c, X86_FEATURE_PLN) && int_pln_enable)

		err = sysfs_add_file_to_group(&dev->kobj,

					      &dev_attr_core_power_limit_count.attr,

					      thermal_attr_group.name);
@@ -230,7 +239,7 @@ static __cpuinit int thermal_throttle_add_dev(struct device *dev, 
		err = sysfs_add_file_to_group(&dev->kobj,

					      &dev_attr_package_throttle_count.attr,

					      thermal_attr_group.name);

		if (cpu_has(c, X86_FEATURE_PLN))

		if (cpu_has(c, X86_FEATURE_PLN) && int_pln_enable)

			err = sysfs_add_file_to_group(&dev->kobj,

					&dev_attr_package_power_limit_count.attr,

					thermal_attr_group.name);
@@ -343,7 +352,7 @@ static void intel_thermal_interrupt(void) 
				CORE_LEVEL) != 0)

		mce_log_therm_throt_event(msr_val);



	if (this_cpu_has(X86_FEATURE_PLN))

	if (this_cpu_has(X86_FEATURE_PLN) && int_pln_enable)

		therm_throt_process(msr_val & THERM_STATUS_POWER_LIMIT,

					POWER_LIMIT_EVENT,

					CORE_LEVEL);
@@ -353,7 +362,7 @@ static void intel_thermal_interrupt(void) 
		therm_throt_process(msr_val & PACKAGE_THERM_STATUS_PROCHOT,

					THERMAL_THROTTLING_EVENT,

					PACKAGE_LEVEL);

		if (this_cpu_has(X86_FEATURE_PLN))

		if (this_cpu_has(X86_FEATURE_PLN) && int_pln_enable)

			therm_throt_process(msr_val &

					PACKAGE_THERM_STATUS_POWER_LIMIT,

					POWER_LIMIT_EVENT,
@@ -461,7 +470,11 @@ void intel_init_thermal(struct cpuinfo_x86 *c) 
	apic_write(APIC_LVTTHMR, h);



	rdmsr(MSR_IA32_THERM_INTERRUPT, l, h);

	if (cpu_has(c, X86_FEATURE_PLN))

	if (cpu_has(c, X86_FEATURE_PLN) && !int_pln_enable)

		wrmsr(MSR_IA32_THERM_INTERRUPT,

			(l | (THERM_INT_LOW_ENABLE

			| THERM_INT_HIGH_ENABLE)) & ~THERM_INT_PLN_ENABLE, h);

	else if (cpu_has(c, X86_FEATURE_PLN) && int_pln_enable)

		wrmsr(MSR_IA32_THERM_INTERRUPT,

			l | (THERM_INT_LOW_ENABLE

			| THERM_INT_HIGH_ENABLE | THERM_INT_PLN_ENABLE), h);
@@ -471,7 +484,12 @@ void intel_init_thermal(struct cpuinfo_x86 *c) 


	if (cpu_has(c, X86_FEATURE_PTS)) {

		rdmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);

		if (cpu_has(c, X86_FEATURE_PLN))

		if (cpu_has(c, X86_FEATURE_PLN) && !int_pln_enable)

			wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,

				(l | (PACKAGE_THERM_INT_LOW_ENABLE

				| PACKAGE_THERM_INT_HIGH_ENABLE))

				& ~PACKAGE_THERM_INT_PLN_ENABLE, h);

		else if (cpu_has(c, X86_FEATURE_PLN) && int_pln_enable)

			wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,

				l | (PACKAGE_THERM_INT_LOW_ENABLE

				| PACKAGE_THERM_INT_HIGH_ENABLE