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authorLee Schermerhorn <lee.schermerhorn@hp.com>2010-05-26 17:44:56 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2010-05-27 12:12:57 -0400
commit7281201922a0063fa60804ce39c277fc98142a47 (patch)
tree4bf089d077b1055e54bc1411dcc0db121d01d9fa /mm/page_alloc.c
parent866707fc2721df8fee637fcf0239628b9231f9ea (diff)
numa: add generic percpu var numa_node_id() implementation
Rework the generic version of the numa_node_id() function to use the new generic percpu variable infrastructure. Guard the new implementation with a new config option: CONFIG_USE_PERCPU_NUMA_NODE_ID. Archs which support this new implemention will default this option to 'y' when NUMA is configured. This config option could be removed if/when all archs switch over to the generic percpu implementation of numa_node_id(). Arch support involves: 1) converting any existing per cpu variable implementations to use this implementation. x86_64 is an instance of such an arch. 2) archs that don't use a per cpu variable for numa_node_id() will need to initialize the new per cpu variable "numa_node" as cpus are brought on-line. ia64 is an example. 3) Defining USE_PERCPU_NUMA_NODE_ID in arch dependent Kconfig--e.g., when NUMA is configured. This is required because I have retained the old implementation by default to allow archs to be modified incrementally, as desired. Subsequent patches will convert x86_64 and ia64 to use this implemenation. Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Tejun Heo <tj@kernel.org> Cc: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Cc: Nick Piggin <npiggin@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Eric Whitney <eric.whitney@hp.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/page_alloc.c')
-rw-r--r--mm/page_alloc.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 08b349931ebc..6fe1b65ee1a8 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -57,6 +57,11 @@
57#include <asm/div64.h> 57#include <asm/div64.h>
58#include "internal.h" 58#include "internal.h"
59 59
60#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
61DEFINE_PER_CPU(int, numa_node);
62EXPORT_PER_CPU_SYMBOL(numa_node);
63#endif
64
60/* 65/*
61 * Array of node states. 66 * Array of node states.
62 */ 67 */