Commit 72812019 authored by Lee Schermerhorn's avatar Lee Schermerhorn Committed by Linus Torvalds

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: default avatarLee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: default avatarChristoph 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 866707fc
...@@ -170,6 +170,10 @@ static inline int numa_node_id(void) ...@@ -170,6 +170,10 @@ static inline int numa_node_id(void)
{ {
return 0; return 0;
} }
/*
* indicate override:
*/
#define numa_node_id numa_node_id
static inline int early_cpu_to_node(int cpu) static inline int early_cpu_to_node(int cpu)
{ {
......
...@@ -31,6 +31,7 @@ ...@@ -31,6 +31,7 @@
#include <linux/bitops.h> #include <linux/bitops.h>
#include <linux/mmzone.h> #include <linux/mmzone.h>
#include <linux/smp.h> #include <linux/smp.h>
#include <linux/percpu.h>
#include <asm/topology.h> #include <asm/topology.h>
#ifndef node_has_online_mem #ifndef node_has_online_mem
...@@ -203,8 +204,53 @@ int arch_update_cpu_topology(void); ...@@ -203,8 +204,53 @@ int arch_update_cpu_topology(void);
#ifndef SD_NODE_INIT #ifndef SD_NODE_INIT
#error Please define an appropriate SD_NODE_INIT in include/asm/topology.h!!! #error Please define an appropriate SD_NODE_INIT in include/asm/topology.h!!!
#endif #endif
#endif /* CONFIG_NUMA */ #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 #ifndef topology_physical_package_id
#define topology_physical_package_id(cpu) ((void)(cpu), -1) #define topology_physical_package_id(cpu) ((void)(cpu), -1)
#endif #endif
...@@ -218,9 +264,4 @@ int arch_update_cpu_topology(void); ...@@ -218,9 +264,4 @@ int arch_update_cpu_topology(void);
#define topology_core_cpumask(cpu) cpumask_of(cpu) #define topology_core_cpumask(cpu) cpumask_of(cpu)
#endif #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 */ #endif /* _LINUX_TOPOLOGY_H */
...@@ -57,6 +57,11 @@ ...@@ -57,6 +57,11 @@
#include <asm/div64.h> #include <asm/div64.h>
#include "internal.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. * Array of node states.
*/ */
......
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