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Commit 99b72508 authored by Thomas Renninger's avatar Thomas Renninger Committed by Len Brown
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ACPI processor hotplug: Delay acpi_processor_start() call for hotplugged cores 



Delay the setting up of features (cpuidle, throttling by calling
acpi_processor_start()) to the time when the hotplugged
core got onlined the first time and got fully
initialized.

Signed-off-by: default avatarThomas Renninger <trenn@suse.de>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 54d5dcc4

drivers/acpi/processor_driver.c

+65 −7
Original line number Diff line number Diff line
@@ -84,7 +84,7 @@ static int acpi_processor_remove(struct acpi_device *device, int type); 
static void acpi_processor_notify(struct acpi_device *device, u32 event);

static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr);

static int acpi_processor_handle_eject(struct acpi_processor *pr);



static int acpi_processor_start(struct acpi_processor *pr);



static const struct acpi_device_id processor_device_ids[] = {

	{ACPI_PROCESSOR_OBJECT_HID, 0},
@@ -423,11 +423,30 @@ static int acpi_cpu_soft_notify(struct notifier_block *nfb, 
	struct acpi_processor *pr = per_cpu(processors, cpu);



	if (action == CPU_ONLINE && pr) {

		/* CPU got physically hotplugged and onlined the first time:

		 * Initialize missing things

		 */

		if (pr->flags.need_hotplug_init) {

			struct cpuidle_driver *idle_driver =

				cpuidle_get_driver();



			printk(KERN_INFO "Will online and init hotplugged "

			       "CPU: %d\n", pr->id);

			WARN(acpi_processor_start(pr), "Failed to start CPU:"

				" %d\n", pr->id);

			pr->flags.need_hotplug_init = 0;

			if (idle_driver && !strcmp(idle_driver->name,

						   "intel_idle")) {

				intel_idle_cpu_init(pr->id);

			}

		/* Normal CPU soft online event */

		} else {

			acpi_processor_ppc_has_changed(pr, 0);

		acpi_processor_hotplug(pr);

			acpi_processor_cst_has_changed(pr);

			acpi_processor_reevaluate_tstate(pr, action);

			acpi_processor_tstate_has_changed(pr);

		}

	}

	if (action == CPU_DEAD && pr) {

		/* invalidate the flag.throttling after one CPU is offline */

		acpi_processor_reevaluate_tstate(pr, action);
@@ -440,7 +459,15 @@ static struct notifier_block acpi_cpu_notifier = 
	    .notifier_call = acpi_cpu_soft_notify,

};



static int __cpuinit acpi_processor_start(struct acpi_processor *pr)

/*

 * acpi_processor_start() is called by the cpu_hotplug_notifier func:

 * acpi_cpu_soft_notify(). Getting it __cpuinit{data} is difficult, the

 * root cause seem to be that acpi_processor_uninstall_hotplug_notify()

 * is in the module_exit (__exit) func. Allowing acpi_processor_start()

 * to not be in __cpuinit section, but being called from __cpuinit funcs

 * via __ref looks like the right thing to do here.

 */

static __ref int acpi_processor_start(struct acpi_processor *pr)

{

	struct acpi_device *device = per_cpu(processor_device_array, pr->id);

	int result = 0;
@@ -491,7 +518,12 @@ static int __cpuinit acpi_processor_start(struct acpi_processor *pr) 
	return result;

}





/*

 * Do not put anything in here which needs the core to be online.

 * For example MSR access or setting up things which check for cpuinfo_x86

 * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc.

 * Such things have to be put in and set up above in acpi_processor_start()

 */

static int __cpuinit acpi_processor_add(struct acpi_device *device)

{

	struct acpi_processor *pr = NULL;
@@ -546,6 +578,21 @@ static int __cpuinit acpi_processor_add(struct acpi_device *device) 
		result = -EFAULT;

		goto err_free_cpumask;

	}



	/*

	 * Do not start hotplugged CPUs now, but when they

	 * are onlined the first time

	 */

	if (pr->flags.need_hotplug_init)

		return 0;



	/*

	 * Do not start hotplugged CPUs now, but when they

	 * are onlined the first time

	 */

	if (pr->flags.need_hotplug_init)

		return 0;



	result = acpi_processor_start(pr);

	if (result)

		goto err_remove_sysfs;
@@ -751,6 +798,17 @@ static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr) 
		return AE_ERROR;

	}



	/* CPU got hot-plugged, but cpu_data is not initialized yet

	 * Set flag to delay cpu_idle/throttling initialization

	 * in:

	 * acpi_processor_add()

	 *   acpi_processor_get_info()

	 * and do it when the CPU gets online the first time

	 * TBD: Cleanup above functions and try to do this more elegant.

	 */

	printk(KERN_INFO "CPU %d got hotplugged\n", pr->id);

	pr->flags.need_hotplug_init = 1;



	return AE_OK;

}

drivers/idle/intel_idle.c

+1 −1
Original line number Diff line number Diff line
@@ -527,7 +527,7 @@ int intel_idle_cpu_init(int cpu) 


	return 0;

}



EXPORT_SYMBOL_GPL(intel_idle_cpu_init);



static int __init intel_idle_init(void)

{

include/acpi/processor.h

+1 −0
Original line number Diff line number Diff line
@@ -195,6 +195,7 @@ struct acpi_processor_flags { 
	u8 has_cst:1;

	u8 power_setup_done:1;

	u8 bm_rld_set:1;

	u8 need_hotplug_init:1;

};



struct acpi_processor {