[PATCH] powerpc/mm/4k: don't allocate larger pmd page table for 4k

[PATCH] powerpc/mm/4k: don't allocate larger pmd page table for 4k

[Aneesh Kumar K.V]

We now support THP with both 64k and 4K page size configuration
for radix. (hash only support THP with 64K page size). Hence we
will have CONFIG_TRANSPARENT_HUGEPAGE enabled for both PPC_64K
and PPC_4K config. Since we only need large pmd page table
with hash configuration (to store the slot information
in the second half of the table) restrict the large pmd page table
to THP and 64K configs.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/book3s/64/hash.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/hash.h b/arch/powerpc/include/asm/book3s/64/hash.h
index f61cad3de4e6..5ae0596aa7e0 100644
--- a/arch/powerpc/include/asm/book3s/64/hash.h
+++ b/arch/powerpc/include/asm/book3s/64/hash.h
@@ -33,9 +33,9 @@
 				 H_PUD_INDEX_SIZE + H_PGD_INDEX_SIZE + PAGE_SHIFT)
 #define H_PGTABLE_RANGE		(ASM_CONST(1) << H_PGTABLE_EADDR_SIZE)
 
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+#if defined(CONFIG_TRANSPARENT_HUGEPAGE) &&  defined(CONFIG_PPC_64K_PAGES)
 /*
- * only with hash we need to use the second half of pmd page table
+ * only with hash 64k we need to use the second half of pmd page table
  * to store pointer to deposited pgtable_t
  */
 #define H_PMD_CACHE_INDEX	(H_PMD_INDEX_SIZE + 1)
-- 
2.10.2

Re: [PATCH] powerpc/mm/4k: don't allocate larger pmd page table for 4k

[Anshuman Khandual]

On 01/04/2017 08:19 AM, Aneesh Kumar K.V wrote:
> We now support THP with both 64k and 4K page size configuration
> for radix. (hash only support THP with 64K page size). Hence we

Can be a different sentence ^^^^^^^ as well. Small nit.

> will have CONFIG_TRANSPARENT_HUGEPAGE enabled for both PPC_64K
> and PPC_4K config. Since we only need large pmd page table
> with hash configuration (to store the slot information
> in the second half of the table) restrict the large pmd page table
> to THP and 64K configs.
> 
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

Reviewed-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>

Re: powerpc/mm/4k: don't allocate larger pmd page table for 4k

[Michael Ellerman]

On Wed, 2017-01-04 at 02:49:12 UTC, "Aneesh Kumar K.V" wrote:
> We now support THP with both 64k and 4K page size configuration
> for radix. (hash only support THP with 64K page size). Hence we
> will have CONFIG_TRANSPARENT_HUGEPAGE enabled for both PPC_64K
> and PPC_4K config. Since we only need large pmd page table
> with hash configuration (to store the slot information
> in the second half of the table) restrict the large pmd page table
> to THP and 64K configs.
> 
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> Reviewed-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/8ad43336b5c1ad9ac945148cb5e26a

cheers