Re: [PATCH v5] x86/hpet: Reduce HPET counter read contention

Waiman Long
2016-08-12T22:51:04Z

On 08/12/2016 05:38 PM, Dave Hansen wrote:
> On 08/12/2016 02:25 PM, Waiman Long wrote:
>> + * The lock and the hpet value are stored together and can be read in a
>> + * single atomic 64-bit read. It is explicitly assumed that the raw spinlock
>> + * size is 32-bit.
> So what happens when we have all the fun debugging options on?
>
>> typedef struct raw_spinlock {
>> arch_spinlock_t raw_lock;
>> #ifdef CONFIG_GENERIC_LOCKBREAK
>> unsigned int break_lock;
>> #endif
>> #ifdef CONFIG_DEBUG_SPINLOCK
>> unsigned int magic, owner_cpu;
>> void *owner;
>> #endif
>> #ifdef CONFIG_DEBUG_LOCK_ALLOC
>> struct lockdep_map dep_map;
>> #endif
>> } raw_spinlock_t;

Sorry, it should be arch_spinlock_t instead. Will fix that.

Cheers,
Longman