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Commit 7aac7898 authored by Lee Schermerhorn's avatar Lee Schermerhorn Committed by Linus Torvalds
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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 <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

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: default avatarLee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: default avatarChristoph Lameter <cl@linux-foundation.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3bccd996

include/asm-generic/topology.h

+3 −0
Original line number Diff line number Diff line
@@ -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

include/linux/mmzone.h

+6 −0
Original line number Diff line number Diff line
@@ -671,6 +671,12 @@ void memory_present(int nid, unsigned long start, unsigned long end); 
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

include/linux/topology.h

+61 −0
Original line number Diff line number Diff line
@@ -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

mm/page_alloc.c

+44 −1
Original line number Diff line number Diff line
@@ -62,6 +62,17 @@ DEFINE_PER_CPU(int, numa_node); 
EXPORT_PER_CPU_SYMBOL(numa_node);

#endif



#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()

 * defined in <linux/topology.h>.

 */

DEFINE_PER_CPU(int, _numa_mem_);		/* Kernel "local memory" node */

EXPORT_PER_CPU_SYMBOL(_numa_mem_);

#endif



/*

 * Array of node states.

 */
@@ -2861,6 +2872,24 @@ static void build_zonelist_cache(pg_data_t *pgdat) 
		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 */
@@ -2975,9 +3004,23 @@ static __init_refok int __build_all_zonelists(void *data) 
	 * 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))

			set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));

#endif

	}



	return 0;

}