[PATCH] Configurable NODES_SHIFT

Current implementations define NODES_SHIFT in include/asm-xxx/numnodes.h for
each arch.  Its definition is sometimes configurable.  Indeed, ia64 defines 5
NODES_SHIFT values in the current git tree.  But it looks a bit messy.

SGI-SN2(ia64) system requires 1024 nodes, and the number of nodes already has
been changeable by config.  Suitable node's number may be changed in the
future even if it is other architecture.  So, I wrote configurable node's
number.

This patch set defines just default value for each arch which needs multi
nodes except ia64.  But, it is easy to change to configurable if necessary.

On ia64 the number of nodes can be already configured in generic ia64 and SN2
config.  But, NODES_SHIFT is defined for DIG64 and HP'S machine too.  So, I
changed it so that all platforms can be configured via CONFIG_NODES_SHIFT.  It
would be simpler.

See also: http://marc.theaimsgroup.com/?l=linux-kernel&m=114358010523896&w=2

Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/arch/i386/Kconfig b/arch/i386/Kconfig
index 57301db056f5..18ec9fe6deb6 100644
--- a/arch/i386/Kconfig
+++ b/arch/i386/Kconfig
@@ -522,6 +522,12 @@ config NUMA
 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
         depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI)
 
+config NODES_SHIFT
+        int
+        default "4" if X86_NUMAQ
+        default "3"
+        depends on NEED_MULTIPLE_NODES
+
 config HAVE_ARCH_BOOTMEM_NODE
         bool
         depends on NUMA