diff options
| author | Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> | 2015-12-01 09:06:45 +0530 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2015-12-14 15:19:10 +1100 |
| commit | bf680d51605662aae5482d87e0e0a54ba6db056b (patch) | |
| tree | db17e9a9754e2f9fc10daa3bbb30ece19d21ba88 /arch/powerpc/include/asm/book3s/64/hash-4k.h | |
| parent | 106713a14590cd7b223db000f4f47f7d1d898153 (diff) | |
powerpc/mm: Don't track subpage valid bit in pte_t
This free up 11 bits in pte_t. In the later patch we also change
the pte_t format so that we can start supporting migration pte
at pmd level. We now track 4k subpage valid bit as below
If we have _PAGE_COMBO set, we override the _PAGE_F_GIX_SHIFT
and _PAGE_F_SECOND. Together we have 4 bits, each of them
used to indicate whether any of the 4 4k subpage in that group
is valid. ie,
[ group 1 bit ] [ group 2 bit ] ..... [ group 4 ]
[ subpage 1 - 4] [ subpage 5- 8] ..... [ subpage 13 - 16]
We still track each 4k subpage slot number and secondary hash
information in the second half of pgtable_t. Removing the subpage
tracking have some significant overhead on aim9 and ebizzy benchmark and
to support THP with 4K subpage, we do need a pgtable_t of 4096 bytes.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/include/asm/book3s/64/hash-4k.h')
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/hash-4k.h | 10 |
1 files changed, 1 insertions, 9 deletions
diff --git a/arch/powerpc/include/asm/book3s/64/hash-4k.h b/arch/powerpc/include/asm/book3s/64/hash-4k.h index 537eacecf6e9..75e8b9326e4b 100644 --- a/arch/powerpc/include/asm/book3s/64/hash-4k.h +++ b/arch/powerpc/include/asm/book3s/64/hash-4k.h @@ -47,17 +47,9 @@ /* Bits to mask out from a PGD to get to the PUD page */ #define PGD_MASKED_BITS 0 -/* PTE bits */ -#define _PAGE_HASHPTE 0x0400 /* software: pte has an associated HPTE */ -#define _PAGE_SECONDARY 0x8000 /* software: HPTE is in secondary group */ -#define _PAGE_GROUP_IX 0x7000 /* software: HPTE index within group */ -#define _PAGE_F_SECOND _PAGE_SECONDARY -#define _PAGE_F_GIX _PAGE_GROUP_IX -#define _PAGE_SPECIAL 0x10000 /* software: special page */ - /* PTE flags to conserve for HPTE identification */ #define _PAGE_HPTEFLAGS (_PAGE_BUSY | _PAGE_HASHPTE | \ - _PAGE_SECONDARY | _PAGE_GROUP_IX) + _PAGE_F_SECOND | _PAGE_F_GIX) /* shift to put page number into pte */ #define PTE_RPN_SHIFT (17) |