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authorChristoph Lameter <clameter@sgi.com>2007-10-16 01:24:15 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-16 09:42:51 -0700
commit0889eba5b38f66d7d892a167d88284daddd3d43b (patch)
treeadb578bb92cc18dbf842a9bde67e3861db030557 /arch/x86_64
parent29c71111d0557385328211b130246a90f9223b46 (diff)
downloadlinux-linaro-stable-0889eba5b38f66d7d892a167d88284daddd3d43b.tar.gz
x86_64: SPARSEMEM_VMEMMAP 2M page size support
x86_64 uses 2M page table entries to map its 1-1 kernel space. We also implement the virtual memmap using 2M page table entries. So there is no additional runtime overhead over FLATMEM, initialisation is slightly more complex. As FLATMEM still references memory to obtain the mem_map pointer and SPARSEMEM_VMEMMAP uses a compile time constant, SPARSEMEM_VMEMMAP should be superior. With this SPARSEMEM becomes the most efficient way of handling virt_to_page, pfn_to_page and friends for UP, SMP and NUMA on x86_64. [apw@shadowen.org: code resplit, style fixups] [apw@shadowen.org: vmemmap x86_64: ensure end of section memmap is initialised] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andy Whitcroft <apw@shadowen.org> Acked-by: Mel Gorman <mel@csn.ul.ie> Cc: Andi Kleen <ak@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86_64')
-rw-r--r--arch/x86_64/Kconfig1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index cf013cb85ea4..8c83dbe4c4d0 100644
--- a/arch/x86_64/Kconfig
+++ b/arch/x86_64/Kconfig
@@ -409,6 +409,7 @@ config ARCH_DISCONTIGMEM_DEFAULT
config ARCH_SPARSEMEM_ENABLE
def_bool y
depends on (NUMA || EXPERIMENTAL)
+ select SPARSEMEM_VMEMMAP_ENABLE
config ARCH_MEMORY_PROBE
def_bool y