From c0ba10b512eb2e2a3888b6e6cc0e089f5e7a191b Mon Sep 17 00:00:00 2001 From: Russell King Date: Sun, 21 Nov 2010 14:42:47 +0000 Subject: [PATCH] ARM: improve compiler's ability to optimize page tables Allow the compiler to better optimize the page table walking code by avoiding over-complex pmd_addr_end() calculations. These calculations prevent the compiler spotting that we'll never iterate over the PMD table, causing it to create double nested loops where a single loop will do. Signed-off-by: Russell King --- arch/arm/include/asm/pgtable.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h index b155414192d..53d1d5deb11 100644 --- a/arch/arm/include/asm/pgtable.h +++ b/arch/arm/include/asm/pgtable.h @@ -374,6 +374,9 @@ static inline pte_t *pmd_page_vaddr(pmd_t pmd) #define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd))) +/* we don't need complex calculations here as the pmd is folded into the pgd */ +#define pmd_addr_end(addr,end) (end) + /* * Conversion functions: convert a page and protection to a page entry, * and a page entry and page directory to the page they refer to. -- 2.20.1