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authorLee Schermerhorn <lee.schermerhorn@hp.com>2010-05-26 14:44:56 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-05-27 09:12:57 -0700
commit7281201922a0063fa60804ce39c277fc98142a47 (patch)
tree4bf089d077b1055e54bc1411dcc0db121d01d9fa
parent866707fc2721df8fee637fcf0239628b9231f9ea (diff)
downloadkernel-7281201922a0063fa60804ce39c277fc98142a47.tar.gz
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>
-rw-r--r--arch/x86/include/asm/topology.h4
-rw-r--r--include/linux/topology.h51
-rw-r--r--mm/page_alloc.c5
3 files changed, 55 insertions, 5 deletions
diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h
index c5087d796587..a2e629476b0e 100644
--- a/arch/x86/include/asm/topology.h
+++ b/arch/x86/include/asm/topology.h
@@ -170,6 +170,10 @@ static inline int numa_node_id(void)
{
return 0;
}
+/*
+ * indicate override:
+ */
+#define numa_node_id numa_node_id
static inline int early_cpu_to_node(int cpu)
{
diff --git a/include/linux/topology.h b/include/linux/topology.h
index 5b81156780b1..2e5518f46571 100644
--- a/include/linux/topology.h
+++ b/include/linux/topology.h
@@ -31,6 +31,7 @@
#include <linux/bitops.h>
#include <linux/mmzone.h>
#include <linux/smp.h>
+#include <linux/percpu.h>
#include <asm/topology.h>
#ifndef node_has_online_mem
@@ -203,8 +204,53 @@ int arch_update_cpu_topology(void);
#ifndef SD_NODE_INIT
#error Please define an appropriate SD_NODE_INIT in include/asm/topology.h!!!
#endif
+
#endif /* CONFIG_NUMA */
+#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
+DECLARE_PER_CPU(int, numa_node);
+
+#ifndef numa_node_id
+/* Returns the number of the current Node. */
+static inline int numa_node_id(void)
+{
+ return __this_cpu_read(numa_node);
+}
+#endif
+
+#ifndef cpu_to_node
+static inline int cpu_to_node(int cpu)
+{
+ return per_cpu(numa_node, cpu);
+}
+#endif
+
+#ifndef set_numa_node
+static inline void set_numa_node(int node)
+{
+ percpu_write(numa_node, node);
+}
+#endif
+
+#ifndef set_cpu_numa_node
+static inline void set_cpu_numa_node(int cpu, int node)
+{
+ per_cpu(numa_node, cpu) = node;
+}
+#endif
+
+#else /* !CONFIG_USE_PERCPU_NUMA_NODE_ID */
+
+/* Returns the number of the current Node. */
+#ifndef numa_node_id
+static inline int numa_node_id(void)
+{
+ return cpu_to_node(raw_smp_processor_id());
+}
+#endif
+
+#endif /* [!]CONFIG_USE_PERCPU_NUMA_NODE_ID */
+
#ifndef topology_physical_package_id
#define topology_physical_package_id(cpu) ((void)(cpu), -1)
#endif
@@ -218,9 +264,4 @@ int arch_update_cpu_topology(void);
#define topology_core_cpumask(cpu) cpumask_of(cpu)
#endif
-/* Returns the number of the current Node. */
-#ifndef numa_node_id
-#define numa_node_id() (cpu_to_node(raw_smp_processor_id()))
-#endif
-
#endif /* _LINUX_TOPOLOGY_H */
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 @@
#include <asm/div64.h>
#include "internal.h"
+#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
+DEFINE_PER_CPU(int, numa_node);
+EXPORT_PER_CPU_SYMBOL(numa_node);
+#endif
+
/*
* Array of node states.
*/