From: Lee Schermerhorn <lee.schermerhorn@xxxxxx> 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@xxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Cc: Mel Gorman <mel@xxxxxxxxx> Reviewed-by: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx> Cc: Nick Piggin <npiggin@xxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Eric Whitney <eric.whitney@xxxxxx> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: "Luck, Tony" <tony.luck@xxxxxxxxx> Cc: Pekka Enberg <penberg@xxxxxxxxxxxxxx> Cc: <linux-arch@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/x86/include/asm/topology.h | 4 ++ include/linux/topology.h | 51 +++++++++++++++++++++++++++--- mm/page_alloc.c | 5 ++ 3 files changed, 55 insertions(+), 5 deletions(-) diff -puN arch/x86/include/asm/topology.h~numa-add-generic-percpu-var-numa_node_id-implementation arch/x86/include/asm/topology.h --- a/arch/x86/include/asm/topology.h~numa-add-generic-percpu-var-numa_node_id-implementation +++ a/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 -puN include/linux/topology.h~numa-add-generic-percpu-var-numa_node_id-implementation include/linux/topology.h --- a/include/linux/topology.h~numa-add-generic-percpu-var-numa_node_id-implementation +++ a/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 -puN mm/page_alloc.c~numa-add-generic-percpu-var-numa_node_id-implementation mm/page_alloc.c --- a/mm/page_alloc.c~numa-add-generic-percpu-var-numa_node_id-implementation +++ a/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. */ _ -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html