[PATCH 44/50] intel_idle: disable auto_demotion for hotplugged CPUs

From: Len Brown
Date: Tue Jan 17 2012 - 08:22:27 EST


From: Shaohua Li <shaohua.li@xxxxxxxxx>

auto_demotion_disable is called only for online CPUs. For hotplugged
CPUs, we should disable it too.

Signed-off-by: Shaohua Li <shaohua.li@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Len Brown <len.brown@xxxxxxxxx>
---
drivers/idle/intel_idle.c | 53 ++++++++++++++++++++++++++++-----------------
1 files changed, 33 insertions(+), 20 deletions(-)

diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index af0b4a5..38da9f8 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -297,33 +297,42 @@ static void __setup_broadcast_timer(void *arg)
clockevents_notify(reason, &cpu);
}

-static int setup_broadcast_cpuhp_notify(struct notifier_block *n,
+static void auto_demotion_disable(void *dummy)
+{
+ unsigned long long msr_bits;
+
+ rdmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr_bits);
+ msr_bits &= ~auto_demotion_disable_flags;
+ wrmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr_bits);
+}
+
+static void __intel_idle_notify_handler(void *arg)
+{
+ if (auto_demotion_disable_flags)
+ auto_demotion_disable(NULL);
+
+ if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)
+ __setup_broadcast_timer((void *)true);
+}
+
+static int setup_intelidle_cpuhp_notify(struct notifier_block *n,
unsigned long action, void *hcpu)
{
int hotcpu = (unsigned long)hcpu;

switch (action & 0xf) {
case CPU_ONLINE:
- smp_call_function_single(hotcpu, __setup_broadcast_timer,
- (void *)true, 1);
+ smp_call_function_single(hotcpu, __intel_idle_notify_handler,
+ NULL, 1);
break;
}
return NOTIFY_OK;
}

-static struct notifier_block setup_broadcast_notifier = {
- .notifier_call = setup_broadcast_cpuhp_notify,
+static struct notifier_block setup_intelidle_notifier = {
+ .notifier_call = setup_intelidle_cpuhp_notify,
};

-static void auto_demotion_disable(void *dummy)
-{
- unsigned long long msr_bits;
-
- rdmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr_bits);
- msr_bits &= ~auto_demotion_disable_flags;
- wrmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr_bits);
-}
-
/*
* intel_idle_probe()
*/
@@ -393,10 +402,8 @@ static int intel_idle_probe(void)

if (boot_cpu_has(X86_FEATURE_ARAT)) /* Always Reliable APIC Timer */
lapic_timer_reliable_states = LAPIC_TIMER_ALWAYS_RELIABLE;
- else {
+ else
on_each_cpu(__setup_broadcast_timer, (void *)true, 1);
- register_cpu_notifier(&setup_broadcast_notifier);
- }

pr_debug(PREFIX "v" INTEL_IDLE_VERSION
" model 0x%X\n", boot_cpu_data.x86_model);
@@ -559,6 +566,10 @@ static int __init intel_idle_init(void)
return retval;
}

+ if (auto_demotion_disable_flags || lapic_timer_reliable_states !=
+ LAPIC_TIMER_ALWAYS_RELIABLE)
+ register_cpu_notifier(&setup_intelidle_notifier);
+
return 0;
}

@@ -567,10 +578,12 @@ static void __exit intel_idle_exit(void)
intel_idle_cpuidle_devices_uninit();
cpuidle_unregister_driver(&intel_idle_driver);

- if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE) {
+ if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)
on_each_cpu(__setup_broadcast_timer, (void *)false, 1);
- unregister_cpu_notifier(&setup_broadcast_notifier);
- }
+
+ if (auto_demotion_disable_flags || lapic_timer_reliable_states !=
+ LAPIC_TIMER_ALWAYS_RELIABLE)
+ unregister_cpu_notifier(&setup_intelidle_notifier);

return;
}
--
1.7.9.rc1

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