diff options
| author | Deepthi Dharwar | 2012-05-20 18:34:27 +0000 |
|---|---|---|
| committer | Benjamin Herrenschmidt | 2012-07-03 14:14:40 +1000 |
| commit | 16aaaff68440dd95de98adb075303355814be6e0 (patch) | |
| tree | f7ea14e9be10224e398aa8398ddd00db10ff112b | |
| parent | 25ebc45b93452d0bc60271f178237123c4b26808 (diff) | |
powerpc/pseries/cpuidle: Replace pseries_notify_cpuidle_add call with notifier
The following patch is to remove the pseries_notify_add_cpu() call
and replace it by a hot plug notifier.
This would prevent cpuidle resources being released and allocated each
time cpu comes online on pseries.
The earlier design was causing a lockdep problem
in start_secondary as reported on this thread
-https://lkml.org/lkml/2012/5/17/2
This applies on 3.4-rc7
Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| -rw-r--r-- | arch/powerpc/include/asm/processor.h | 2 | ||||
| -rw-r--r-- | arch/powerpc/platforms/pseries/processor_idle.c | 25 | ||||
| -rw-r--r-- | arch/powerpc/platforms/pseries/smp.c | 1 |
3 files changed, 19 insertions, 9 deletions
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h index 413a5eaef56c..53b6dfa83344 100644 --- a/arch/powerpc/include/asm/processor.h +++ b/arch/powerpc/include/asm/processor.h @@ -389,10 +389,8 @@ extern int powersave_nap; /* set if nap mode can be used in idle loop */ #ifdef CONFIG_PSERIES_IDLE extern void update_smt_snooze_delay(int snooze); -extern int pseries_notify_cpuidle_add_cpu(int cpu); #else static inline void update_smt_snooze_delay(int snooze) {} -static inline int pseries_notify_cpuidle_add_cpu(int cpu) { return 0; } #endif extern void flush_instruction_cache(void); diff --git a/arch/powerpc/platforms/pseries/processor_idle.c b/arch/powerpc/platforms/pseries/processor_idle.c index e61483e8e960..a97ef6692dad 100644 --- a/arch/powerpc/platforms/pseries/processor_idle.c +++ b/arch/powerpc/platforms/pseries/processor_idle.c @@ -11,6 +11,7 @@ #include <linux/moduleparam.h> #include <linux/cpuidle.h> #include <linux/cpu.h> +#include <linux/notifier.h> #include <asm/paca.h> #include <asm/reg.h> @@ -186,17 +187,28 @@ static struct cpuidle_state shared_states[MAX_IDLE_STATE_COUNT] = { .enter = &shared_cede_loop }, }; -int pseries_notify_cpuidle_add_cpu(int cpu) +static int pseries_cpuidle_add_cpu_notifier(struct notifier_block *n, + unsigned long action, void *hcpu) { + int hotcpu = (unsigned long)hcpu; struct cpuidle_device *dev = - per_cpu_ptr(pseries_cpuidle_devices, cpu); - if (dev && cpuidle_get_driver()) { - cpuidle_disable_device(dev); - cpuidle_enable_device(dev); + per_cpu_ptr(pseries_cpuidle_devices, hotcpu); + + switch (action & 0xf) { + case CPU_ONLINE: + if (dev && cpuidle_get_driver()) { + cpuidle_disable_device(dev); + cpuidle_enable_device(dev); + } + break; } - return 0; + return NOTIFY_OK; } +static struct notifier_block setup_hotplug_notifier = { + .notifier_call = pseries_cpuidle_add_cpu_notifier, +}; + /* * pseries_cpuidle_driver_init() */ @@ -321,6 +333,7 @@ static int __init pseries_processor_idle_init(void) return retval; } + register_cpu_notifier(&setup_hotplug_notifier); printk(KERN_DEBUG "pseries_idle_driver registered\n"); return 0; diff --git a/arch/powerpc/platforms/pseries/smp.c b/arch/powerpc/platforms/pseries/smp.c index e16bb8d48550..71706bc34a0d 100644 --- a/arch/powerpc/platforms/pseries/smp.c +++ b/arch/powerpc/platforms/pseries/smp.c @@ -147,7 +147,6 @@ static void __devinit smp_xics_setup_cpu(int cpu) set_cpu_current_state(cpu, CPU_STATE_ONLINE); set_default_offline_state(cpu); #endif - pseries_notify_cpuidle_add_cpu(cpu); } static int __devinit smp_pSeries_kick_cpu(int nr) |