From 7281201922a0063fa60804ce39c277fc98142a47 Mon Sep 17 00:00:00 2001 From: Lee Schermerhorn Date: Wed, 26 May 2010 14:44:56 -0700 Subject: 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 Cc: Tejun Heo Cc: Mel Gorman Reviewed-by: Christoph Lameter Cc: Nick Piggin Cc: David Rientjes Cc: Eric Whitney Cc: KAMEZAWA Hiroyuki Cc: Ingo Molnar Cc: Thomas Gleixner Cc: "H. Peter Anvin" Cc: "Luck, Tony" Cc: Pekka Enberg Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/topology.h | 51 +++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 46 insertions(+), 5 deletions(-) (limited to 'include/linux/topology.h') 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 #include #include +#include #include #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 */ -- cgit v1.2.2 From 7aac789885512388a66d47280d7e7777ffba1e59 Mon Sep 17 00:00:00 2001 From: Lee Schermerhorn Date: Wed, 26 May 2010 14:45:00 -0700 Subject: numa: introduce numa_mem_id()- effective local memory node id Introduce numa_mem_id(), based on generic percpu variable infrastructure to track "nearest node with memory" for archs that support memoryless nodes. Define API in when CONFIG_HAVE_MEMORYLESS_NODES defined, else stubs. Architectures will define HAVE_MEMORYLESS_NODES if/when they support them. Archs can override definitions of: numa_mem_id() - returns node number of "local memory" node set_numa_mem() - initialize [this cpus'] per cpu variable 'numa_mem' cpu_to_mem() - return numa_mem for specified cpu; may be used as lvalue Generic initialization of 'numa_mem' occurs in __build_all_zonelists(). This will initialize the boot cpu at boot time, and all cpus on change of numa_zonelist_order, or when node or memory hot-plug requires zonelist rebuild. Archs that support memoryless nodes will need to initialize 'numa_mem' for secondary cpus as they're brought on-line. [akpm@linux-foundation.org: fix build] Signed-off-by: Lee Schermerhorn Signed-off-by: Christoph Lameter Cc: Tejun Heo Cc: Mel Gorman Cc: Christoph Lameter Cc: Nick Piggin Cc: David Rientjes Cc: Eric Whitney Cc: KAMEZAWA Hiroyuki Cc: Ingo Molnar Cc: Thomas Gleixner Cc: "H. Peter Anvin" Cc: "Luck, Tony" Cc: Pekka Enberg Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/topology.h | 61 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) (limited to 'include/linux/topology.h') diff --git a/include/linux/topology.h b/include/linux/topology.h index 2e5518f46571..c44df50a05ab 100644 --- a/include/linux/topology.h +++ b/include/linux/topology.h @@ -251,6 +251,67 @@ static inline int numa_node_id(void) #endif /* [!]CONFIG_USE_PERCPU_NUMA_NODE_ID */ +#ifdef CONFIG_HAVE_MEMORYLESS_NODES + +/* + * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly. + * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined. + * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem(). + */ +DECLARE_PER_CPU(int, _numa_mem_); + +#ifndef set_numa_mem +static inline void set_numa_mem(int node) +{ + percpu_write(_numa_mem_, node); +} +#endif + +#ifndef numa_mem_id +/* Returns the number of the nearest Node with memory */ +static inline int numa_mem_id(void) +{ + return __this_cpu_read(_numa_mem_); +} +#endif + +#ifndef cpu_to_mem +static inline int cpu_to_mem(int cpu) +{ + return per_cpu(_numa_mem_, cpu); +} +#endif + +#ifndef set_cpu_numa_mem +static inline void set_cpu_numa_mem(int cpu, int node) +{ + per_cpu(_numa_mem_, cpu) = node; +} +#endif + +#else /* !CONFIG_HAVE_MEMORYLESS_NODES */ + +static inline void set_numa_mem(int node) {} + +static inline void set_cpu_numa_mem(int cpu, int node) {} + +#ifndef numa_mem_id +/* Returns the number of the nearest Node with memory */ +static inline int numa_mem_id(void) +{ + return numa_node_id(); +} +#endif + +#ifndef cpu_to_mem +static inline int cpu_to_mem(int cpu) +{ + return cpu_to_node(cpu); +} +#endif + +#endif /* [!]CONFIG_HAVE_MEMORYLESS_NODES */ + #ifndef topology_physical_package_id #define topology_physical_package_id(cpu) ((void)(cpu), -1) #endif -- cgit v1.2.2