Re: [tip:x86/mm] percpu: Introduce a read-mostly percpu API

H. Peter Anvin
2010-10-21T06:10:11Z

On 10/20/2010 11:07 PM, Eric Dumazet wrote:
> Le mercredi 20 octobre 2010 à 22:54 -0700, H. Peter Anvin a écrit :
>
>> L1_CACHE_BYTES is completely pointless, since if there is sharing to
>> worry about *at all*, it's probably at the L2 or L3 cache levels.
>>
>
> I see, and we dont have better way to express this hint/requirement than
> using PAGE_SIZE or INTERNODE_CACHE_SHIFT ?
>
> In your patch you force a PAGE_SIZE alignement *before*
> *(.data..percpu..page_aligned)
>
> If this alignment is really needed, this should be part of another
> patch, since this fixes a previous bug in 2.6.36 ?
>

It was part of Shaohua's patch... I don't know if it does anything
useful, but it also doesn't hurt.

-hpa

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