From 437d496457a30ce9ccccb94b2373c201b2558392 Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Thu, 20 Jun 2013 14:30:26 +0530 Subject: [PATCH] powerpc/THP: Enable THP on PPC64 We enable only if the we support 16MB page size. Reviewed-by: David Gibson Signed-off-by: Aneesh Kumar K.V Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/pgtable-ppc64.h | 3 +-- arch/powerpc/mm/pgtable_64.c | 29 ++++++++++++++++++++++++ 2 files changed, 30 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/include/asm/pgtable-ppc64.h b/arch/powerpc/include/asm/pgtable-ppc64.h index e71bd25d62d7..46db09414a10 100644 --- a/arch/powerpc/include/asm/pgtable-ppc64.h +++ b/arch/powerpc/include/asm/pgtable-ppc64.h @@ -444,8 +444,7 @@ static inline int pmd_trans_splitting(pmd_t pmd) return 0; } -/* We will enable it in the last patch */ -#define has_transparent_hugepage() 0 +extern int has_transparent_hugepage(void); #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ static inline pte_t pmd_pte(pmd_t pmd) diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c index e4d3e9fb59be..074a4a225054 100644 --- a/arch/powerpc/mm/pgtable_64.c +++ b/arch/powerpc/mm/pgtable_64.c @@ -831,4 +831,33 @@ pmd_t pmdp_get_and_clear(struct mm_struct *mm, memset(pgtable, 0, PTE_FRAG_SIZE); return old_pmd; } + +int has_transparent_hugepage(void) +{ + if (!mmu_has_feature(MMU_FTR_16M_PAGE)) + return 0; + /* + * We support THP only if PMD_SIZE is 16MB. + */ + if (mmu_psize_defs[MMU_PAGE_16M].shift != PMD_SHIFT) + return 0; + /* + * We need to make sure that we support 16MB hugepage in a segement + * with base page size 64K or 4K. We only enable THP with a PAGE_SIZE + * of 64K. + */ + /* + * If we have 64K HPTE, we will be using that by default + */ + if (mmu_psize_defs[MMU_PAGE_64K].shift && + (mmu_psize_defs[MMU_PAGE_64K].penc[MMU_PAGE_16M] == -1)) + return 0; + /* + * Ok we only have 4K HPTE + */ + if (mmu_psize_defs[MMU_PAGE_4K].penc[MMU_PAGE_16M] == -1) + return 0; + + return 1; +} #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ -- 2.20.1