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

On 13 May 2014 16:31, Christopher Covington [off-list ref] wrote:

Hi Steve,

On 05/06/2014 11:30 AM, Steve Capper wrote:

quoted

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.

quoted

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

--
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