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Based on kernel version 3.16. Page generated on 2014-08-06 21:41 EST.

1	
2	<previous description obsolete, deleted>
3	
4	Virtual memory map with 4 level page tables:
5	
6	0000000000000000 - 00007fffffffffff (=47 bits) user space, different per mm
7	hole caused by [48:63] sign extension
8	ffff800000000000 - ffff80ffffffffff (=40 bits) guard hole
9	ffff880000000000 - ffffc7ffffffffff (=64 TB) direct mapping of all phys. memory
10	ffffc80000000000 - ffffc8ffffffffff (=40 bits) hole
11	ffffc90000000000 - ffffe8ffffffffff (=45 bits) vmalloc/ioremap space
12	ffffe90000000000 - ffffe9ffffffffff (=40 bits) hole
13	ffffea0000000000 - ffffeaffffffffff (=40 bits) virtual memory map (1TB)
14	... unused hole ...
15	ffffff0000000000 - ffffff7fffffffff (=39 bits) %esp fixup stacks
16	... unused hole ...
17	ffffffff80000000 - ffffffffa0000000 (=512 MB)  kernel text mapping, from phys 0
18	ffffffffa0000000 - ffffffffff5fffff (=1525 MB) module mapping space
19	ffffffffff600000 - ffffffffffdfffff (=8 MB) vsyscalls
20	ffffffffffe00000 - ffffffffffffffff (=2 MB) unused hole
21	
22	The direct mapping covers all memory in the system up to the highest
23	memory address (this means in some cases it can also include PCI memory
24	holes).
25	
26	vmalloc space is lazily synchronized into the different PML4 pages of
27	the processes using the page fault handler, with init_level4_pgt as
28	reference.
29	
30	Current X86-64 implementations only support 40 bits of address space,
31	but we support up to 46 bits. This expands into MBZ space in the page tables.
32	
33	->trampoline_pgd:
34	
35	We map EFI runtime services in the aforementioned PGD in the virtual
36	range of 64Gb (arbitrarily set, can be raised if needed)
37	
38	0xffffffef00000000 - 0xffffffff00000000
39	
40	-Andi Kleen, Jul 2004
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