diff options
Diffstat (limited to 'arch/x86/include/asm/pgtable_types.h')
| -rw-r--r-- | arch/x86/include/asm/pgtable_types.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h index c98ac63aae48..5e8442f178f9 100644 --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -67,6 +67,19 @@ #define _PAGE_SOFT_DIRTY (_AT(pteval_t, 0)) #endif +/* + * Tracking soft dirty bit when a page goes to a swap is tricky. + * We need a bit which can be stored in pte _and_ not conflict + * with swap entry format. On x86 bits 6 and 7 are *not* involved + * into swap entry computation, but bit 6 is used for nonlinear + * file mapping, so we borrow bit 7 for soft dirty tracking. + */ +#ifdef CONFIG_MEM_SOFT_DIRTY +#define _PAGE_SWP_SOFT_DIRTY _PAGE_PSE +#else +#define _PAGE_SWP_SOFT_DIRTY (_AT(pteval_t, 0)) +#endif + #if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE) #define _PAGE_NX (_AT(pteval_t, 1) << _PAGE_BIT_NX) #else |