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| author | Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> | 2013-06-20 11:00:26 +0200 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2013-06-21 08:01:58 +0200 |
| commit | 437d496457a30ce9ccccb94b2373c201b2558392 (patch) | |
| tree | 401857d741564eff170764518ed5acbeacc43f63 | |
| parent | powerpc: split hugepage when using subpage protection (diff) | |
| download | linux-437d496457a30ce9ccccb94b2373c201b2558392.tar.xz linux-437d496457a30ce9ccccb94b2373c201b2558392.zip | |
powerpc/THP: Enable THP on PPC64
We enable only if the we support 16MB page size.
Reviewed-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| -rw-r--r-- | arch/powerpc/include/asm/pgtable-ppc64.h | 3 | ||||
| -rw-r--r-- | 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 */ |