From 78b0634d2851d30ec5d289aefbae23b141de67f0 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Fri, 22 Apr 2016 09:35:04 +0200 Subject: [PATCH] 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 Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: corbet@lwn.net Cc: linux-doc@vger.kernel.org Link: http://lkml.kernel.org/r/1461310504-15977-1-git-send-email-jgross@suse.com Signed-off-by: Ingo Molnar --- 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 c518dce7da4d..5aa738346062 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). -- 2.30.2