From: Christian Borntraeger <borntraeger@xxxxxxxxxx> We dont need the dirty bit if a write access is done via the kernel mapping. In that case SetPageDirty and friends are used anyway, no need to do that a second time. We can use the change-recording overide function for the kernel mapping, if available. Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx> Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx> --- arch/s390/include/asm/pgtable.h | 4 +++- arch/s390/mm/vmem.c | 11 ++++++++--- 2 files changed, 11 insertions(+), 4 deletions(-) Index: quilt-2.6/arch/s390/include/asm/pgtable.h =================================================================== --- quilt-2.6.orig/arch/s390/include/asm/pgtable.h 2009-11-13 15:48:32.000000000 +0100 +++ quilt-2.6/arch/s390/include/asm/pgtable.h 2009-11-13 16:08:17.000000000 +0100 @@ -169,12 +169,13 @@ * STL Segment-Table-Length: Segment-table length (STL+1*16 entries -> up to 2048) * * A 64 bit pagetable entry of S390 has following format: - * | PFRA |0IP0| OS | + * | PFRA |0IPC| OS | * 0000000000111111111122222222223333333333444444444455555555556666 * 0123456789012345678901234567890123456789012345678901234567890123 * * I Page-Invalid Bit: Page is not available for address-translation * P Page-Protection Bit: Store access not possible for page + * C Change-bit override: HW is not required to set change bit * * A 64 bit segmenttable entry of S390 has following format: * | P-table origin | TT @@ -218,6 +219,7 @@ */ /* Hardware bits in the page table entry */ +#define _PAGE_CO 0x100 /* HW Change-bit override */ #define _PAGE_RO 0x200 /* HW read-only bit */ #define _PAGE_INVALID 0x400 /* HW invalid bit */ Index: quilt-2.6/arch/s390/mm/vmem.c =================================================================== --- quilt-2.6.orig/arch/s390/mm/vmem.c 2009-11-13 15:48:32.000000000 +0100 +++ quilt-2.6/arch/s390/mm/vmem.c 2009-11-13 16:08:17.000000000 +0100 @@ -70,8 +70,12 @@ pte = alloc_bootmem(PTRS_PER_PTE * sizeof(pte_t)); if (!pte) return NULL; - clear_table((unsigned long *) pte, _PAGE_TYPE_EMPTY, - PTRS_PER_PTE * sizeof(pte_t)); + if (MACHINE_HAS_HPAGE) + clear_table((unsigned long *) pte, _PAGE_TYPE_EMPTY | _PAGE_CO, + PTRS_PER_PTE * sizeof(pte_t)); + else + clear_table((unsigned long *) pte, _PAGE_TYPE_EMPTY, + PTRS_PER_PTE * sizeof(pte_t)); return pte; } @@ -112,7 +116,8 @@ if (MACHINE_HAS_HPAGE && !(address & ~HPAGE_MASK) && (address + HPAGE_SIZE <= start + size) && (address >= HPAGE_SIZE)) { - pte_val(pte) |= _SEGMENT_ENTRY_LARGE; + pte_val(pte) |= _SEGMENT_ENTRY_LARGE | + _SEGMENT_ENTRY_CO; pmd_val(*pm_dir) = pte_val(pte); address += HPAGE_SIZE - PAGE_SIZE; continue; -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html