[tip:x86/asm] x86/doc: Correct limits in Documentation/x86/x86_64/mm.txt

From: tip-bot for Juergen Gross
Date: Fri Apr 22 2016 - 05:49:13 EST


Commit-ID: 78b0634d2851d30ec5d289aefbae23b141de67f0
Gitweb: http://git.kernel.org/tip/78b0634d2851d30ec5d289aefbae23b141de67f0
Author: Juergen Gross <jgross@xxxxxxxx>
AuthorDate: Fri, 22 Apr 2016 09:35:04 +0200
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Fri, 22 Apr 2016 10:03:24 +0200

x86/doc: Correct limits in Documentation/x86/x86_64/mm.txt

Correct the size of the module mapping space and the maximum available
physical memory size of current processors.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: corbet@xxxxxxx
Cc: linux-doc@xxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/1461310504-15977-1-git-send-email-jgross@xxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
Documentation/x86/x86_64/mm.txt | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Documentation/x86/x86_64/mm.txt b/Documentation/x86/x86_64/mm.txt
index c518dce..5aa7383 100644
--- a/Documentation/x86/x86_64/mm.txt
+++ b/Documentation/x86/x86_64/mm.txt
@@ -19,7 +19,7 @@ ffffff0000000000 - ffffff7fffffffff (=39 bits) %esp fixup stacks
ffffffef00000000 - ffffffff00000000 (=64 GB) EFI region mapping space
... unused hole ...
ffffffff80000000 - ffffffffa0000000 (=512 MB) kernel text mapping, from phys 0
-ffffffffa0000000 - ffffffffff5fffff (=1525 MB) module mapping space
+ffffffffa0000000 - ffffffffff5fffff (=1526 MB) module mapping space
ffffffffff600000 - ffffffffffdfffff (=8 MB) vsyscalls
ffffffffffe00000 - ffffffffffffffff (=2 MB) unused hole

@@ -31,8 +31,8 @@ vmalloc space is lazily synchronized into the different PML4 pages of
the processes using the page fault handler, with init_level4_pgt as
reference.

-Current X86-64 implementations only support 40 bits of address space,
-but we support up to 46 bits. This expands into MBZ space in the page tables.
+Current X86-64 implementations support up to 46 bits of address space (64 TB),
+which is our current limit. This expands into MBZ space in the page tables.

We map EFI runtime services in the 'efi_pgd' PGD in a 64Gb large virtual
memory window (this size is arbitrary, it can be raised later if needed).