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authorChristoph Lameter <clameter@sgi.com>2008-01-30 13:30:47 +0100
committerIngo Molnar <mingo@elte.hu>2008-01-30 13:30:47 +0100
commitb263295dbffd33b0fbff670720fa178c30e3392a (patch)
tree014b402cb65b17e1521ed356e5c225083ea578dd /arch/x86/Kconfig
parent4ebd1290ba12121d66285cc06987ca97bcdfc55b (diff)
x86: 64-bit, make sparsemem vmemmap the only memory model
Use sparsemem as the only memory model for UP, SMP and NUMA. Measurements indicate that DISCONTIGMEM has a higher overhead than sparsemem. And FLATMEMs benefits are minimal. So I think its best to simply standardize on sparsemem. Results of page allocator tests (test can be had via git from slab git tree branch tests) Measurements in cycle counts. 1000 allocations were performed and then the average cycle count was calculated. Order FlatMem Discontig SparseMem 0 639 665 641 1 567 647 593 2 679 774 692 3 763 967 781 4 961 1501 962 5 1356 2344 1392 6 2224 3982 2336 7 4869 7225 5074 8 12500 14048 12732 9 27926 28223 28165 10 58578 58714 58682 (Note that FlatMem is an SMP config and the rest NUMA configurations) Memory use: SMP Sparsemem ------------- Kernel size: text data bss dec hex filename 3849268 397739 1264856 5511863 541ab7 vmlinux total used free shared buffers cached Mem: 8242252 41164 8201088 0 352 11512 -/+ buffers/cache: 29300 8212952 Swap: 9775512 0 9775512 SMP Flatmem ----------- Kernel size: text data bss dec hex filename 3844612 397739 1264536 5506887 540747 vmlinux So 4.5k growth in text size vs. FLATMEM. total used free shared buffers cached Mem: 8244052 40544 8203508 0 352 11484 -/+ buffers/cache: 28708 8215344 2k growth in overall memory use after boot. NUMA discontig: text data bss dec hex filename 3888124 470659 1276504 5635287 55fcd7 vmlinux total used free shared buffers cached Mem: 8256256 56908 8199348 0 352 11496 -/+ buffers/cache: 45060 8211196 Swap: 9775512 0 9775512 NUMA sparse: text data bss dec hex filename 3896428 470659 1276824 5643911 561e87 vmlinux 8k text growth. Given that we fully inline virt_to_page and friends now that is rather good. total used free shared buffers cached Mem: 8264720 57240 8207480 0 352 11516 -/+ buffers/cache: 45372 8219348 Swap: 9775512 0 9775512 The total available memory is increased by 8k. This patch makes sparsemem the default and removes discontig and flatmem support from x86. [ akpm@linux-foundation.org: allnoconfig build fix ] Acked-by: Andi Kleen <ak@suse.de> Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/Kconfig')
-rw-r--r--arch/x86/Kconfig22
1 files changed, 9 insertions, 13 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 2f4d88babd36..da98368f66af 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -891,25 +891,29 @@ config HAVE_ARCH_ALLOC_REMAP
config ARCH_FLATMEM_ENABLE
def_bool y
- depends on (X86_32 && ARCH_SELECT_MEMORY_MODEL && X86_PC) || (X86_64 && !NUMA)
+ depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && X86_PC
config ARCH_DISCONTIGMEM_ENABLE
def_bool y
- depends on NUMA
+ depends on NUMA && X86_32
config ARCH_DISCONTIGMEM_DEFAULT
def_bool y
- depends on NUMA
+ depends on NUMA && X86_32
+
+config ARCH_SPARSEMEM_DEFAULT
+ def_bool y
+ depends on X86_64
config ARCH_SPARSEMEM_ENABLE
def_bool y
- depends on NUMA || (EXPERIMENTAL && (X86_PC || X86_64))
+ depends on X86_64 || NUMA || (EXPERIMENTAL && X86_PC)
select SPARSEMEM_STATIC if X86_32
select SPARSEMEM_VMEMMAP_ENABLE if X86_64
config ARCH_SELECT_MEMORY_MODEL
def_bool y
- depends on X86_32 && ARCH_SPARSEMEM_ENABLE
+ depends on ARCH_SPARSEMEM_ENABLE
config ARCH_MEMORY_PROBE
def_bool X86_64
@@ -1207,18 +1211,10 @@ config ARCH_ENABLE_MEMORY_HOTPLUG
def_bool y
depends on X86_64 || (X86_32 && HIGHMEM)
-config MEMORY_HOTPLUG_RESERVE
- def_bool X86_64
- depends on (MEMORY_HOTPLUG && DISCONTIGMEM)
-
config HAVE_ARCH_EARLY_PFN_TO_NID
def_bool X86_64
depends on NUMA
-config OUT_OF_LINE_PFN_TO_PAGE
- def_bool X86_64
- depends on DISCONTIGMEM
-
menu "Power management options"
depends on !X86_VOYAGER