[PATCH -V8 16/18] powerpc/THP: Enable THP on PPC64
From: Aneesh Kumar K.V <hidden>
Date: 2013-05-12 16:14:44
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
From: "Aneesh Kumar K.V" <redacted> We enable only if the we support 16MB page size. Reviewed-by: David Gibson <redacted> Signed-off-by: Aneesh Kumar K.V <redacted> --- 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 69cb52b..d046289 100644
--- a/arch/powerpc/include/asm/pgtable-ppc64.h
+++ b/arch/powerpc/include/asm/pgtable-ppc64.h@@ -429,8 +429,7 @@ 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 2ff92aa..1abf9cd 100644
--- a/arch/powerpc/mm/pgtable_64.c
+++ b/arch/powerpc/mm/pgtable_64.c@@ -818,4 +818,33 @@ 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 */
--
1.8.1.2