[RFC PATCH V5 4/6] arm: mm: Enable RCU fast_gup

[Steve Capper]

On 13 May 2014 16:31, Christopher Covington <cov at codeaurora.org> wrote:
> Hi Steve,
>
> On 05/06/2014 11:30 AM, Steve Capper wrote:
>> Activate the RCU fast_gup for ARM. We also need to force THP splits to
>> broadcast an IPI s.t. we block in the fast_gup page walker. As THP
>> splits are comparatively rare, this should not lead to a noticeable
>> performance degradation.
>
>> diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c
>> index 3387e60..91a2b59 100644
>> --- a/arch/arm/mm/flush.c
>> +++ b/arch/arm/mm/flush.c
>> @@ -377,3 +377,22 @@ void __flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned l
>>        */
>>       __cpuc_flush_dcache_area(page_address(page), PAGE_SIZE);
>>  }
>> +
>> +#ifdef CONFIG_TRANSPARENT_HUGEPAGE
>> +#ifdef CONFIG_HAVE_RCU_TABLE_FREE
>
> This is trivia, but I for one find the form #if defined(a) && defined(b)
> easier to read. (Applies to the A64 version as well).
>

Thank you Christopher, I agree that looks nicer.

Cheers,
-- 
Steve

> Christopher
>
> --
> Employee of Qualcomm Innovation Center, Inc.
> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
> hosted by the Linux Foundation.