Against: 2.6.33-mmotm-100302-1838 Introduce numa_mem_id(), based on generic percpu variable infrastructure to track "effective local memory node" for archs that support memoryless nodes. Define API in <linux/topology.h> 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 if they don't want to use the generic version, but want to support memoryless nodes. 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 use this implementation will need to initialize 'numa_mem' for secondary cpus as they're brought on-line. Question: Is it worth adding a generic initialization of per cpu numa_mem? E.g., built only when CONFIG_HAVE_MEMORYLESS_NODES defined? Or leave it to the archs? Signed-off-by: Lee Schermerhorn <lee.schermerhorn@xxxxxx> Signed-off-by: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx> V2: + split this out of Christoph's incomplete "starter patch" + flesh out the definition include/asm-generic/topology.h | 3 +++ include/linux/mmzone.h | 6 ++++++ include/linux/topology.h | 24 ++++++++++++++++++++++++ mm/page_alloc.c | 39 ++++++++++++++++++++++++++++++++++++++- 4 files changed, 71 insertions(+), 1 deletion(-) Index: linux-2.6.33-mmotm-100302-1838/include/linux/topology.h =================================================================== --- linux-2.6.33-mmotm-100302-1838.orig/include/linux/topology.h 2010-03-03 16:28:53.000000000 -0500 +++ linux-2.6.33-mmotm-100302-1838/include/linux/topology.h 2010-03-03 16:28:55.000000000 -0500 @@ -233,6 +233,30 @@ DECLARE_PER_CPU(int, numa_node); #endif /* [!]CONFIG_USE_PERCPU_NUMA_NODE_ID */ +#ifdef CONFIG_HAVE_MEMORYLESS_NODES + +DECLARE_PER_CPU(int, numa_mem); + +#ifndef set_numa_mem +#define set_numa_mem(__node) percpu_write(numa_mem, __node) +#endif + +#else /* !CONFIG_HAVE_MEMORYLESS_NODES */ + +#define numa_mem numa_node +static inline void set_numa_mem(int node) {} + +#endif /* [!]CONFIG_HAVE_MEMORYLESS_NODES */ + +#ifndef numa_mem_id +/* Returns the number of the nearest Node with memory */ +#define numa_mem_id() __this_cpu_read(numa_mem) +#endif + +#ifndef cpu_to_mem +#define cpu_to_mem(__cpu) per_cpu(numa_mem, (__cpu)) +#endif + #ifndef topology_physical_package_id #define topology_physical_package_id(cpu) ((void)(cpu), -1) #endif Index: linux-2.6.33-mmotm-100302-1838/mm/page_alloc.c =================================================================== --- linux-2.6.33-mmotm-100302-1838.orig/mm/page_alloc.c 2010-03-03 16:28:53.000000000 -0500 +++ linux-2.6.33-mmotm-100302-1838/mm/page_alloc.c 2010-03-03 16:28:55.000000000 -0500 @@ -61,6 +61,11 @@ DEFINE_PER_CPU(int, numa_node); EXPORT_PER_CPU_SYMBOL(numa_node); #endif +#ifdef CONFIG_HAVE_MEMORYLESS_NODES +DEFINE_PER_CPU(int, numa_mem); /* Kernel "local memory" node */ +EXPORT_PER_CPU_SYMBOL(numa_mem); +#endif + /* * Array of node states. */ @@ -2733,6 +2738,24 @@ static void build_zonelist_cache(pg_data zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z); } +#ifdef CONFIG_HAVE_MEMORYLESS_NODES +/* + * Return node id of node used for "local" allocations. + * I.e., first node id of first zone in arg node's generic zonelist. + * Used for initializing percpu 'numa_mem', which is used primarily + * for kernel allocations, so use GFP_KERNEL flags to locate zonelist. + */ +int local_memory_node(int node) +{ + struct zone *zone; + + (void)first_zones_zonelist(node_zonelist(node, GFP_KERNEL), + gfp_zone(GFP_KERNEL), + NULL, + &zone); + return zone->node; +} +#endif #else /* CONFIG_NUMA */ @@ -2832,9 +2855,23 @@ static int __build_all_zonelists(void *d * needs the percpu allocator in order to allocate its pagesets * (a chicken-egg dilemma). */ - for_each_possible_cpu(cpu) + for_each_possible_cpu(cpu) { setup_pageset(&per_cpu(boot_pageset, cpu), 0); +#ifdef CONFIG_HAVE_MEMORYLESS_NODES + /* + * We now know the "local memory node" for each node-- + * i.e., the node of the first zone in the generic zonelist. + * Set up numa_mem percpu variable for on-line cpus. During + * boot, only the boot cpu should be on-line; we'll init the + * secondary cpus' numa_mem as they come on-line. During + * node/memory hotplug, we'll fixup all on-line cpus. + */ + if (cpu_online(cpu)) + cpu_to_mem(cpu) = local_memory_node(cpu_to_node(cpu)); +#endif + } + return 0; } Index: linux-2.6.33-mmotm-100302-1838/include/linux/mmzone.h =================================================================== --- linux-2.6.33-mmotm-100302-1838.orig/include/linux/mmzone.h 2010-03-03 16:28:53.000000000 -0500 +++ linux-2.6.33-mmotm-100302-1838/include/linux/mmzone.h 2010-03-03 16:28:55.000000000 -0500 @@ -661,6 +661,12 @@ void memory_present(int nid, unsigned lo static inline void memory_present(int nid, unsigned long start, unsigned long end) {} #endif +#ifdef CONFIG_HAVE_MEMORYLESS_NODES +int local_memory_node(int node_id); +#else +static inline int local_memory_node(int node_id) { return node_id; }; +#endif + #ifdef CONFIG_NEED_NODE_MEMMAP_SIZE unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long); #endif Index: linux-2.6.33-mmotm-100302-1838/include/asm-generic/topology.h =================================================================== --- linux-2.6.33-mmotm-100302-1838.orig/include/asm-generic/topology.h 2010-03-03 16:28:53.000000000 -0500 +++ linux-2.6.33-mmotm-100302-1838/include/asm-generic/topology.h 2010-03-03 16:28:55.000000000 -0500 @@ -34,6 +34,9 @@ #ifndef cpu_to_node #define cpu_to_node(cpu) ((void)(cpu),0) #endif +#ifndef cpu_to_mem +#define cpu_to_mem(cpu) (void)(cpu),0) +#endif #ifndef parent_node #define parent_node(node) ((void)(node),0) #endif -- 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