Commit 437d4964 authored by Aneesh Kumar K.V's avatar Aneesh Kumar K.V Committed by Benjamin Herrenschmidt
Browse files

powerpc/THP: Enable THP on PPC64 



We enable only if the we support 16MB page size.

Reviewed-by: default avatarDavid Gibson <dwg@au1.ibm.com>
Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent d8e355a2

arch/powerpc/include/asm/pgtable-ppc64.h

+1 −2
Original line number Diff line number Diff line
@@ -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)

arch/powerpc/mm/pgtable_64.c

+29 −0
Original line number Diff line number Diff line
@@ -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 */