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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: Thomas Renninger <trenn@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>
This commit is contained in:
Thomas Renninger 2012-01-19 18:18:43 +01:00 committed by Len Brown
parent 54d5dcc45a
commit 99b7250844
3 changed files with 67 additions and 8 deletions
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72
drivers/acpi/processor_driver.c
View File

@ -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},
@ -423,10 +423,29 @@ static int acpi_cpu_soft_notify(struct notifier_block *nfb,
struct acpi_processor *pr = per_cpu(processors, cpu);
if (action == CPU_ONLINE && pr) {
acpi_processor_ppc_has_changed(pr, 0);
acpi_processor_hotplug(pr);
acpi_processor_reevaluate_tstate(pr, action);
acpi_processor_tstate_has_changed(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_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 */
@ -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 @@ err_power_exit:
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;
}

2
drivers/idle/intel_idle.c
View File

@ -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)
{

1
include/acpi/processor.h
View File

@ -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 {