Re: [PATCH 3/7] percpu: clean up percpu variable definitions

["H. Peter Anvin" <hpa@zytor.com>]

David Miller wrote:
> From: Tejun Heo <tj@kernel.org>
> Date: Mon,  1 Jun 2009 17:58:24 +0900
> 
>> --- a/arch/cris/include/asm/mmu_context.h
>> +++ b/arch/cris/include/asm/mmu_context.h
>> @@ -17,7 +17,7 @@ extern void switch_mm(struct mm_struct *prev, struct mm_struct *next,
>>   * registers like cr3 on the i386
>>   */
>>  
>> -extern volatile DEFINE_PER_CPU(pgd_t *,current_pgd); /* defined in arch/cris/mm/fault.c */
>> +DECLARE_PER_CPU(pgd_t *,current_pgd); /* defined in arch/cris/mm/fault.c */
>>  
>>  static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
>>  {
> 
> Yes volatile sucks, but might this break something?
> 
> Whether the volatile is actually needed or not, it's bad to have this
> kind of potential behavior changing nugget hidden in this seemingly
> inocuous change.  Especially if you're the poor soul who ends up
> having to debug it :-/

Shouldn't the "volatile" go inside the DECLARE_PER_CPU() with the rest
of the type?  [Disclaimer: I haven't actually looked.]

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

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