From patchwork Wed Mar 6 06:10:26 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [-V2,25/26] powerpc/THP: Enable THP on PPC64 From: "Aneesh Kumar K.V" X-Patchwork-Id: 225365 Message-Id: <1362550227-575-26-git-send-email-aneesh.kumar@linux.vnet.ibm.com> To: benh@kernel.crashing.org, paulus@samba.org Cc: linuxppc-dev@lists.ozlabs.org, "Aneesh Kumar K.V" Date: Wed, 6 Mar 2013 11:40:26 +0530 From: "Aneesh Kumar K.V" We enable only if the we support 16MB page size. Signed-off-by: Aneesh Kumar K.V --- arch/powerpc/include/asm/pgtable.h | 30 ++++++++++++++++++++++++++++-- 1 file changed, 28 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h index 09f3a77..17120c3 100644 --- a/arch/powerpc/include/asm/pgtable.h +++ b/arch/powerpc/include/asm/pgtable.h @@ -107,8 +107,34 @@ static inline int pmd_trans_huge(pmd_t pmd) return ((pmd_val(pmd) & PMD_ISHUGE) == PMD_ISHUGE); } -/* We will enable it in the last patch */ -#define has_transparent_hugepage() 0 +static inline int has_transparent_hugepage(void) +{ + if (!mmu_has_feature(MMU_FTR_16M_PAGE)) + return 0; + /* + * We support THP only if HPAGE_SHIFT is 16MB. + */ + if (!HPAGE_SHIFT || (HPAGE_SHIFT != mmu_psize_defs[MMU_PAGE_16M].shift)) + return 0; + /* + * We need to make sure that we support 16MB huge page 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 && + ((signed int)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; +} static inline pmd_t pmd_mkold(pmd_t pmd) {