diff options
Diffstat (limited to 'Documentation/x86_64/mm.txt')
| -rw-r--r-- | Documentation/x86_64/mm.txt | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/Documentation/x86_64/mm.txt b/Documentation/x86_64/mm.txt index 133561b9cb0c..f42798ed1c54 100644 --- a/Documentation/x86_64/mm.txt +++ b/Documentation/x86_64/mm.txt | |||
| @@ -3,26 +3,26 @@ | |||
| 3 | 3 | ||
| 4 | Virtual memory map with 4 level page tables: | 4 | Virtual memory map with 4 level page tables: |
| 5 | 5 | ||
| 6 | 0000000000000000 - 00007fffffffffff (=47bits) user space, different per mm | 6 | 0000000000000000 - 00007fffffffffff (=47 bits) user space, different per mm |
| 7 | hole caused by [48:63] sign extension | 7 | hole caused by [48:63] sign extension |
| 8 | ffff800000000000 - ffff80ffffffffff (=40bits) guard hole | 8 | ffff800000000000 - ffff80ffffffffff (=40 bits) guard hole |
| 9 | ffff810000000000 - ffffc0ffffffffff (=46bits) direct mapping of all phys. memory | 9 | ffff810000000000 - ffffc0ffffffffff (=46 bits) direct mapping of all phys. memory |
| 10 | ffffc10000000000 - ffffc1ffffffffff (=40bits) hole | 10 | ffffc10000000000 - ffffc1ffffffffff (=40 bits) hole |
| 11 | ffffc20000000000 - ffffe1ffffffffff (=45bits) vmalloc/ioremap space | 11 | ffffc20000000000 - ffffe1ffffffffff (=45 bits) vmalloc/ioremap space |
| 12 | ... unused hole ... | 12 | ... unused hole ... |
| 13 | ffffffff80000000 - ffffffff82800000 (=40MB) kernel text mapping, from phys 0 | 13 | ffffffff80000000 - ffffffff82800000 (=40 MB) kernel text mapping, from phys 0 |
| 14 | ... unused hole ... | 14 | ... unused hole ... |
| 15 | ffffffff88000000 - fffffffffff00000 (=1919MB) module mapping space | 15 | ffffffff88000000 - fffffffffff00000 (=1919 MB) module mapping space |
| 16 | 16 | ||
| 17 | The direct mapping covers all memory in the system upto the highest | 17 | The direct mapping covers all memory in the system up to the highest |
| 18 | memory address (this means in some cases it can also include PCI memory | 18 | memory address (this means in some cases it can also include PCI memory |
| 19 | holes) | 19 | holes). |
| 20 | 20 | ||
| 21 | vmalloc space is lazily synchronized into the different PML4 pages of | 21 | vmalloc space is lazily synchronized into the different PML4 pages of |
| 22 | the processes using the page fault handler, with init_level4_pgt as | 22 | the processes using the page fault handler, with init_level4_pgt as |
| 23 | reference. | 23 | reference. |
| 24 | 24 | ||
| 25 | Current X86-64 implementations only support 40 bit of address space, | 25 | Current X86-64 implementations only support 40 bits of address space, |
| 26 | but we support upto 46bits. This expands into MBZ space in the page tables. | 26 | but we support up to 46 bits. This expands into MBZ space in the page tables. |
| 27 | 27 | ||
| 28 | -Andi Kleen, Jul 2004 | 28 | -Andi Kleen, Jul 2004 |