numa: add generic percpu var numa_node_id() implementation (72812019) · Commits · 戴 / test

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>

arch/x86/include/asm/topology.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -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)
		{

include/linux/topology.h

+46 −5

Original line number	Diff line number	Diff line
		@@ -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 */

mm/page_alloc.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -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.
		*/

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