From: Rusty Russell From: Ed L Cashin This small patch documents that bits 9, 10, and 11 are unused by the Linux kernel. The IA-32 Intel Architecture Software Developer's Manual says that these bits are available for programmer use. --- 25-akpm/include/asm-i386/pgtable.h | 6 ++++++ 1 files changed, 6 insertions(+) diff -puN include/asm-i386/pgtable.h~document-unused-i386-pte-bits include/asm-i386/pgtable.h --- 25/include/asm-i386/pgtable.h~document-unused-i386-pte-bits 2004-04-03 02:59:59.969236232 -0800 +++ 25-akpm/include/asm-i386/pgtable.h 2004-04-03 02:59:59.972235776 -0800 @@ -107,6 +107,9 @@ void paging_init(void); #define _PAGE_BIT_DIRTY 6 #define _PAGE_BIT_PSE 7 /* 4 MB (or 2MB) page, Pentium+, if present.. */ #define _PAGE_BIT_GLOBAL 8 /* Global TLB entry PPro+ */ +#define _PAGE_BIT_UNUSED1 9 /* available for programmer */ +#define _PAGE_BIT_UNUSED2 10 +#define _PAGE_BIT_UNUSED3 11 #define _PAGE_PRESENT 0x001 #define _PAGE_RW 0x002 @@ -117,6 +120,9 @@ void paging_init(void); #define _PAGE_DIRTY 0x040 #define _PAGE_PSE 0x080 /* 4 MB (or 2MB) page, Pentium+, if present.. */ #define _PAGE_GLOBAL 0x100 /* Global TLB entry PPro+ */ +#define _PAGE_UNUSED1 0x200 /* available for programmer */ +#define _PAGE_UNUSED2 0x400 +#define _PAGE_UNUSED3 0x800 #define _PAGE_FILE 0x040 /* set:pagecache unset:swap */ #define _PAGE_PROTNONE 0x080 /* If not present */ _