linux/arch/x86/mm/numa.c

824 lines
20 KiB
C

/* Common code for 32 and 64-bit NUMA */
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/memblock.h>
#include <linux/mmzone.h>
#include <linux/ctype.h>
#include <linux/module.h>
#include <linux/nodemask.h>
#include <linux/sched.h>
#include <linux/topology.h>
#include <asm/e820.h>
#include <asm/proto.h>
#include <asm/dma.h>
#include <asm/acpi.h>
#include <asm/amd_nb.h>
#include "numa_internal.h"
int __initdata numa_off;
nodemask_t numa_nodes_parsed __initdata;
struct pglist_data *node_data[MAX_NUMNODES] __read_mostly;
EXPORT_SYMBOL(node_data);
static struct numa_meminfo numa_meminfo
#ifndef CONFIG_MEMORY_HOTPLUG
__initdata
#endif
;
static int numa_distance_cnt;
static u8 *numa_distance;
static __init int numa_setup(char *opt)
{
if (!opt)
return -EINVAL;
if (!strncmp(opt, "off", 3))
numa_off = 1;
#ifdef CONFIG_NUMA_EMU
if (!strncmp(opt, "fake=", 5))
numa_emu_cmdline(opt + 5);
#endif
#ifdef CONFIG_ACPI_NUMA
if (!strncmp(opt, "noacpi", 6))
acpi_numa = -1;
#endif
return 0;
}
early_param("numa", numa_setup);
/*
* apicid, cpu, node mappings
*/
s16 __apicid_to_node[MAX_LOCAL_APIC] = {
[0 ... MAX_LOCAL_APIC-1] = NUMA_NO_NODE
};
int __cpuinit numa_cpu_node(int cpu)
{
int apicid = early_per_cpu(x86_cpu_to_apicid, cpu);
if (apicid != BAD_APICID)
return __apicid_to_node[apicid];
return NUMA_NO_NODE;
}
cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
EXPORT_SYMBOL(node_to_cpumask_map);
/*
* Map cpu index to node index
*/
DEFINE_EARLY_PER_CPU(int, x86_cpu_to_node_map, NUMA_NO_NODE);
EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_node_map);
void numa_set_node(int cpu, int node)
{
int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map);
/* early setting, no percpu area yet */
if (cpu_to_node_map) {
cpu_to_node_map[cpu] = node;
return;
}
#ifdef CONFIG_DEBUG_PER_CPU_MAPS
if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) {
printk(KERN_ERR "numa_set_node: invalid cpu# (%d)\n", cpu);
dump_stack();
return;
}
#endif
per_cpu(x86_cpu_to_node_map, cpu) = node;
set_cpu_numa_node(cpu, node);
}
void numa_clear_node(int cpu)
{
numa_set_node(cpu, NUMA_NO_NODE);
}
/*
* Allocate node_to_cpumask_map based on number of available nodes
* Requires node_possible_map to be valid.
*
* Note: cpumask_of_node() is not valid until after this is done.
* (Use CONFIG_DEBUG_PER_CPU_MAPS to check this.)
*/
void __init setup_node_to_cpumask_map(void)
{
unsigned int node, num = 0;
/* setup nr_node_ids if not done yet */
if (nr_node_ids == MAX_NUMNODES) {
for_each_node_mask(node, node_possible_map)
num = node;
nr_node_ids = num + 1;
}
/* allocate the map */
for (node = 0; node < nr_node_ids; node++)
alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
/* cpumask_of_node() will now work */
pr_debug("Node to cpumask map for %d nodes\n", nr_node_ids);
}
static int __init numa_add_memblk_to(int nid, u64 start, u64 end,
struct numa_meminfo *mi)
{
/* ignore zero length blks */
if (start == end)
return 0;
/* whine about and ignore invalid blks */
if (start > end || nid < 0 || nid >= MAX_NUMNODES) {
pr_warning("NUMA: Warning: invalid memblk node %d [mem %#010Lx-%#010Lx]\n",
nid, start, end - 1);
return 0;
}
if (mi->nr_blks >= NR_NODE_MEMBLKS) {
pr_err("NUMA: too many memblk ranges\n");
return -EINVAL;
}
mi->blk[mi->nr_blks].start = start;
mi->blk[mi->nr_blks].end = end;
mi->blk[mi->nr_blks].nid = nid;
mi->nr_blks++;
return 0;
}
/**
* numa_remove_memblk_from - Remove one numa_memblk from a numa_meminfo
* @idx: Index of memblk to remove
* @mi: numa_meminfo to remove memblk from
*
* Remove @idx'th numa_memblk from @mi by shifting @mi->blk[] and
* decrementing @mi->nr_blks.
*/
void __init numa_remove_memblk_from(int idx, struct numa_meminfo *mi)
{
mi->nr_blks--;
memmove(&mi->blk[idx], &mi->blk[idx + 1],
(mi->nr_blks - idx) * sizeof(mi->blk[0]));
}
/**
* numa_add_memblk - Add one numa_memblk to numa_meminfo
* @nid: NUMA node ID of the new memblk
* @start: Start address of the new memblk
* @end: End address of the new memblk
*
* Add a new memblk to the default numa_meminfo.
*
* RETURNS:
* 0 on success, -errno on failure.
*/
int __init numa_add_memblk(int nid, u64 start, u64 end)
{
return numa_add_memblk_to(nid, start, end, &numa_meminfo);
}
/* Initialize NODE_DATA for a node on the local memory */
static void __init setup_node_data(int nid, u64 start, u64 end)
{
const size_t nd_size = roundup(sizeof(pg_data_t), PAGE_SIZE);
u64 nd_pa;
void *nd;
int tnid;
/*
* Don't confuse VM with a node that doesn't have the
* minimum amount of memory:
*/
if (end && (end - start) < NODE_MIN_SIZE)
return;
start = roundup(start, ZONE_ALIGN);
printk(KERN_INFO "Initmem setup node %d [mem %#010Lx-%#010Lx]\n",
nid, start, end - 1);
/*
* Allocate node data. Try node-local memory and then any node.
* Never allocate in DMA zone.
*/
nd_pa = memblock_alloc_nid(nd_size, SMP_CACHE_BYTES, nid);
if (!nd_pa) {
pr_err("Cannot find %zu bytes in node %d\n",
nd_size, nid);
return;
}
nd = __va(nd_pa);
/* report and initialize */
printk(KERN_INFO " NODE_DATA [mem %#010Lx-%#010Lx]\n",
nd_pa, nd_pa + nd_size - 1);
tnid = early_pfn_to_nid(nd_pa >> PAGE_SHIFT);
if (tnid != nid)
printk(KERN_INFO " NODE_DATA(%d) on node %d\n", nid, tnid);
node_data[nid] = nd;
memset(NODE_DATA(nid), 0, sizeof(pg_data_t));
NODE_DATA(nid)->node_id = nid;
NODE_DATA(nid)->node_start_pfn = start >> PAGE_SHIFT;
NODE_DATA(nid)->node_spanned_pages = (end - start) >> PAGE_SHIFT;
node_set_online(nid);
}
/**
* numa_cleanup_meminfo - Cleanup a numa_meminfo
* @mi: numa_meminfo to clean up
*
* Sanitize @mi by merging and removing unncessary memblks. Also check for
* conflicts and clear unused memblks.
*
* RETURNS:
* 0 on success, -errno on failure.
*/
int __init numa_cleanup_meminfo(struct numa_meminfo *mi)
{
const u64 low = 0;
const u64 high = PFN_PHYS(max_pfn);
int i, j, k;
/* first, trim all entries */
for (i = 0; i < mi->nr_blks; i++) {
struct numa_memblk *bi = &mi->blk[i];
/* make sure all blocks are inside the limits */
bi->start = max(bi->start, low);
bi->end = min(bi->end, high);
/* and there's no empty block */
if (bi->start >= bi->end)
numa_remove_memblk_from(i--, mi);
}
/* merge neighboring / overlapping entries */
for (i = 0; i < mi->nr_blks; i++) {
struct numa_memblk *bi = &mi->blk[i];
for (j = i + 1; j < mi->nr_blks; j++) {
struct numa_memblk *bj = &mi->blk[j];
u64 start, end;
/*
* See whether there are overlapping blocks. Whine
* about but allow overlaps of the same nid. They
* will be merged below.
*/
if (bi->end > bj->start && bi->start < bj->end) {
if (bi->nid != bj->nid) {
pr_err("NUMA: node %d [mem %#010Lx-%#010Lx] overlaps with node %d [mem %#010Lx-%#010Lx]\n",
bi->nid, bi->start, bi->end - 1,
bj->nid, bj->start, bj->end - 1);
return -EINVAL;
}
pr_warning("NUMA: Warning: node %d [mem %#010Lx-%#010Lx] overlaps with itself [mem %#010Lx-%#010Lx]\n",
bi->nid, bi->start, bi->end - 1,
bj->start, bj->end - 1);
}
/*
* Join together blocks on the same node, holes
* between which don't overlap with memory on other
* nodes.
*/
if (bi->nid != bj->nid)
continue;
start = min(bi->start, bj->start);
end = max(bi->end, bj->end);
for (k = 0; k < mi->nr_blks; k++) {
struct numa_memblk *bk = &mi->blk[k];
if (bi->nid == bk->nid)
continue;
if (start < bk->end && end > bk->start)
break;
}
if (k < mi->nr_blks)
continue;
printk(KERN_INFO "NUMA: Node %d [mem %#010Lx-%#010Lx] + [mem %#010Lx-%#010Lx] -> [mem %#010Lx-%#010Lx]\n",
bi->nid, bi->start, bi->end - 1, bj->start,
bj->end - 1, start, end - 1);
bi->start = start;
bi->end = end;
numa_remove_memblk_from(j--, mi);
}
}
/* clear unused ones */
for (i = mi->nr_blks; i < ARRAY_SIZE(mi->blk); i++) {
mi->blk[i].start = mi->blk[i].end = 0;
mi->blk[i].nid = NUMA_NO_NODE;
}
return 0;
}
/*
* Set nodes, which have memory in @mi, in *@nodemask.
*/
static void __init numa_nodemask_from_meminfo(nodemask_t *nodemask,
const struct numa_meminfo *mi)
{
int i;
for (i = 0; i < ARRAY_SIZE(mi->blk); i++)
if (mi->blk[i].start != mi->blk[i].end &&
mi->blk[i].nid != NUMA_NO_NODE)
node_set(mi->blk[i].nid, *nodemask);
}
/**
* numa_reset_distance - Reset NUMA distance table
*
* The current table is freed. The next numa_set_distance() call will
* create a new one.
*/
void __init numa_reset_distance(void)
{
size_t size = numa_distance_cnt * numa_distance_cnt * sizeof(numa_distance[0]);
/* numa_distance could be 1LU marking allocation failure, test cnt */
if (numa_distance_cnt)
memblock_free(__pa(numa_distance), size);
numa_distance_cnt = 0;
numa_distance = NULL; /* enable table creation */
}
static int __init numa_alloc_distance(void)
{
nodemask_t nodes_parsed;
size_t size;
int i, j, cnt = 0;
u64 phys;
/* size the new table and allocate it */
nodes_parsed = numa_nodes_parsed;
numa_nodemask_from_meminfo(&nodes_parsed, &numa_meminfo);
for_each_node_mask(i, nodes_parsed)
cnt = i;
cnt++;
size = cnt * cnt * sizeof(numa_distance[0]);
phys = memblock_find_in_range(0, PFN_PHYS(max_pfn_mapped),
size, PAGE_SIZE);
if (!phys) {
pr_warning("NUMA: Warning: can't allocate distance table!\n");
/* don't retry until explicitly reset */
numa_distance = (void *)1LU;
return -ENOMEM;
}
memblock_reserve(phys, size);
numa_distance = __va(phys);
numa_distance_cnt = cnt;
/* fill with the default distances */
for (i = 0; i < cnt; i++)
for (j = 0; j < cnt; j++)
numa_distance[i * cnt + j] = i == j ?
LOCAL_DISTANCE : REMOTE_DISTANCE;
printk(KERN_DEBUG "NUMA: Initialized distance table, cnt=%d\n", cnt);
return 0;
}
/**
* numa_set_distance - Set NUMA distance from one NUMA to another
* @from: the 'from' node to set distance
* @to: the 'to' node to set distance
* @distance: NUMA distance
*
* Set the distance from node @from to @to to @distance. If distance table
* doesn't exist, one which is large enough to accommodate all the currently
* known nodes will be created.
*
* If such table cannot be allocated, a warning is printed and further
* calls are ignored until the distance table is reset with
* numa_reset_distance().
*
* If @from or @to is higher than the highest known node or lower than zero
* at the time of table creation or @distance doesn't make sense, the call
* is ignored.
* This is to allow simplification of specific NUMA config implementations.
*/
void __init numa_set_distance(int from, int to, int distance)
{
if (!numa_distance && numa_alloc_distance() < 0)
return;
if (from >= numa_distance_cnt || to >= numa_distance_cnt ||
from < 0 || to < 0) {
pr_warn_once("NUMA: Warning: node ids are out of bound, from=%d to=%d distance=%d\n",
from, to, distance);
return;
}
if ((u8)distance != distance ||
(from == to && distance != LOCAL_DISTANCE)) {
pr_warn_once("NUMA: Warning: invalid distance parameter, from=%d to=%d distance=%d\n",
from, to, distance);
return;
}
numa_distance[from * numa_distance_cnt + to] = distance;
}
int __node_distance(int from, int to)
{
if (from >= numa_distance_cnt || to >= numa_distance_cnt)
return from == to ? LOCAL_DISTANCE : REMOTE_DISTANCE;
return numa_distance[from * numa_distance_cnt + to];
}
EXPORT_SYMBOL(__node_distance);
/*
* Sanity check to catch more bad NUMA configurations (they are amazingly
* common). Make sure the nodes cover all memory.
*/
static bool __init numa_meminfo_cover_memory(const struct numa_meminfo *mi)
{
u64 numaram, e820ram;
int i;
numaram = 0;
for (i = 0; i < mi->nr_blks; i++) {
u64 s = mi->blk[i].start >> PAGE_SHIFT;
u64 e = mi->blk[i].end >> PAGE_SHIFT;
numaram += e - s;
numaram -= __absent_pages_in_range(mi->blk[i].nid, s, e);
if ((s64)numaram < 0)
numaram = 0;
}
e820ram = max_pfn - absent_pages_in_range(0, max_pfn);
/* We seem to lose 3 pages somewhere. Allow 1M of slack. */
if ((s64)(e820ram - numaram) >= (1 << (20 - PAGE_SHIFT))) {
printk(KERN_ERR "NUMA: nodes only cover %LuMB of your %LuMB e820 RAM. Not used.\n",
(numaram << PAGE_SHIFT) >> 20,
(e820ram << PAGE_SHIFT) >> 20);
return false;
}
return true;
}
static int __init numa_register_memblks(struct numa_meminfo *mi)
{
unsigned long uninitialized_var(pfn_align);
int i, nid;
/* Account for nodes with cpus and no memory */
node_possible_map = numa_nodes_parsed;
numa_nodemask_from_meminfo(&node_possible_map, mi);
if (WARN_ON(nodes_empty(node_possible_map)))
return -EINVAL;
for (i = 0; i < mi->nr_blks; i++) {
struct numa_memblk *mb = &mi->blk[i];
memblock_set_node(mb->start, mb->end - mb->start, mb->nid);
}
/*
* If sections array is gonna be used for pfn -> nid mapping, check
* whether its granularity is fine enough.
*/
#ifdef NODE_NOT_IN_PAGE_FLAGS
pfn_align = node_map_pfn_alignment();
if (pfn_align && pfn_align < PAGES_PER_SECTION) {
printk(KERN_WARNING "Node alignment %LuMB < min %LuMB, rejecting NUMA config\n",
PFN_PHYS(pfn_align) >> 20,
PFN_PHYS(PAGES_PER_SECTION) >> 20);
return -EINVAL;
}
#endif
if (!numa_meminfo_cover_memory(mi))
return -EINVAL;
/* Finally register nodes. */
for_each_node_mask(nid, node_possible_map) {
u64 start = PFN_PHYS(max_pfn);
u64 end = 0;
for (i = 0; i < mi->nr_blks; i++) {
if (nid != mi->blk[i].nid)
continue;
start = min(mi->blk[i].start, start);
end = max(mi->blk[i].end, end);
}
if (start < end)
setup_node_data(nid, start, end);
}
/* Dump memblock with node info and return. */
memblock_dump_all();
return 0;
}
/*
* There are unfortunately some poorly designed mainboards around that
* only connect memory to a single CPU. This breaks the 1:1 cpu->node
* mapping. To avoid this fill in the mapping for all possible CPUs,
* as the number of CPUs is not known yet. We round robin the existing
* nodes.
*/
static void __init numa_init_array(void)
{
int rr, i;
rr = first_node(node_online_map);
for (i = 0; i < nr_cpu_ids; i++) {
if (early_cpu_to_node(i) != NUMA_NO_NODE)
continue;
numa_set_node(i, rr);
rr = next_node(rr, node_online_map);
if (rr == MAX_NUMNODES)
rr = first_node(node_online_map);
}
}
static int __init numa_init(int (*init_func)(void))
{
int i;
int ret;
for (i = 0; i < MAX_LOCAL_APIC; i++)
set_apicid_to_node(i, NUMA_NO_NODE);
nodes_clear(numa_nodes_parsed);
nodes_clear(node_possible_map);
nodes_clear(node_online_map);
memset(&numa_meminfo, 0, sizeof(numa_meminfo));
WARN_ON(memblock_set_node(0, ULLONG_MAX, MAX_NUMNODES));
numa_reset_distance();
ret = init_func();
if (ret < 0)
return ret;
ret = numa_cleanup_meminfo(&numa_meminfo);
if (ret < 0)
return ret;
numa_emulation(&numa_meminfo, numa_distance_cnt);
ret = numa_register_memblks(&numa_meminfo);
if (ret < 0)
return ret;
for (i = 0; i < nr_cpu_ids; i++) {
int nid = early_cpu_to_node(i);
if (nid == NUMA_NO_NODE)
continue;
if (!node_online(nid))
numa_clear_node(i);
}
numa_init_array();
return 0;
}
/**
* dummy_numa_init - Fallback dummy NUMA init
*
* Used if there's no underlying NUMA architecture, NUMA initialization
* fails, or NUMA is disabled on the command line.
*
* Must online at least one node and add memory blocks that cover all
* allowed memory. This function must not fail.
*/
static int __init dummy_numa_init(void)
{
printk(KERN_INFO "%s\n",
numa_off ? "NUMA turned off" : "No NUMA configuration found");
printk(KERN_INFO "Faking a node at [mem %#018Lx-%#018Lx]\n",
0LLU, PFN_PHYS(max_pfn) - 1);
node_set(0, numa_nodes_parsed);
numa_add_memblk(0, 0, PFN_PHYS(max_pfn));
return 0;
}
/**
* x86_numa_init - Initialize NUMA
*
* Try each configured NUMA initialization method until one succeeds. The
* last fallback is dummy single node config encomapssing whole memory and
* never fails.
*/
void __init x86_numa_init(void)
{
if (!numa_off) {
#ifdef CONFIG_X86_NUMAQ
if (!numa_init(numaq_numa_init))
return;
#endif
#ifdef CONFIG_ACPI_NUMA
if (!numa_init(x86_acpi_numa_init))
return;
#endif
#ifdef CONFIG_AMD_NUMA
if (!numa_init(amd_numa_init))
return;
#endif
}
numa_init(dummy_numa_init);
}
static __init int find_near_online_node(int node)
{
int n, val;
int min_val = INT_MAX;
int best_node = -1;
for_each_online_node(n) {
val = node_distance(node, n);
if (val < min_val) {
min_val = val;
best_node = n;
}
}
return best_node;
}
/*
* Setup early cpu_to_node.
*
* Populate cpu_to_node[] only if x86_cpu_to_apicid[],
* and apicid_to_node[] tables have valid entries for a CPU.
* This means we skip cpu_to_node[] initialisation for NUMA
* emulation and faking node case (when running a kernel compiled
* for NUMA on a non NUMA box), which is OK as cpu_to_node[]
* is already initialized in a round robin manner at numa_init_array,
* prior to this call, and this initialization is good enough
* for the fake NUMA cases.
*
* Called before the per_cpu areas are setup.
*/
void __init init_cpu_to_node(void)
{
int cpu;
u16 *cpu_to_apicid = early_per_cpu_ptr(x86_cpu_to_apicid);
BUG_ON(cpu_to_apicid == NULL);
for_each_possible_cpu(cpu) {
int node = numa_cpu_node(cpu);
if (node == NUMA_NO_NODE)
continue;
if (!node_online(node))
node = find_near_online_node(node);
numa_set_node(cpu, node);
}
}
#ifndef CONFIG_DEBUG_PER_CPU_MAPS
# ifndef CONFIG_NUMA_EMU
void __cpuinit numa_add_cpu(int cpu)
{
cpumask_set_cpu(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
}
void __cpuinit numa_remove_cpu(int cpu)
{
cpumask_clear_cpu(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
}
# endif /* !CONFIG_NUMA_EMU */
#else /* !CONFIG_DEBUG_PER_CPU_MAPS */
int __cpu_to_node(int cpu)
{
if (early_per_cpu_ptr(x86_cpu_to_node_map)) {
printk(KERN_WARNING
"cpu_to_node(%d): usage too early!\n", cpu);
dump_stack();
return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
}
return per_cpu(x86_cpu_to_node_map, cpu);
}
EXPORT_SYMBOL(__cpu_to_node);
/*
* Same function as cpu_to_node() but used if called before the
* per_cpu areas are setup.
*/
int early_cpu_to_node(int cpu)
{
if (early_per_cpu_ptr(x86_cpu_to_node_map))
return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
if (!cpu_possible(cpu)) {
printk(KERN_WARNING
"early_cpu_to_node(%d): no per_cpu area!\n", cpu);
dump_stack();
return NUMA_NO_NODE;
}
return per_cpu(x86_cpu_to_node_map, cpu);
}
void debug_cpumask_set_cpu(int cpu, int node, bool enable)
{
struct cpumask *mask;
char buf[64];
if (node == NUMA_NO_NODE) {
/* early_cpu_to_node() already emits a warning and trace */
return;
}
mask = node_to_cpumask_map[node];
if (!mask) {
pr_err("node_to_cpumask_map[%i] NULL\n", node);
dump_stack();
return;
}
if (enable)
cpumask_set_cpu(cpu, mask);
else
cpumask_clear_cpu(cpu, mask);
cpulist_scnprintf(buf, sizeof(buf), mask);
printk(KERN_DEBUG "%s cpu %d node %d: mask now %s\n",
enable ? "numa_add_cpu" : "numa_remove_cpu",
cpu, node, buf);
return;
}
# ifndef CONFIG_NUMA_EMU
static void __cpuinit numa_set_cpumask(int cpu, bool enable)
{
debug_cpumask_set_cpu(cpu, early_cpu_to_node(cpu), enable);
}
void __cpuinit numa_add_cpu(int cpu)
{
numa_set_cpumask(cpu, true);
}
void __cpuinit numa_remove_cpu(int cpu)
{
numa_set_cpumask(cpu, false);
}
# endif /* !CONFIG_NUMA_EMU */
/*
* Returns a pointer to the bitmask of CPUs on Node 'node'.
*/
const struct cpumask *cpumask_of_node(int node)
{
if (node >= nr_node_ids) {
printk(KERN_WARNING
"cpumask_of_node(%d): node > nr_node_ids(%d)\n",
node, nr_node_ids);
dump_stack();
return cpu_none_mask;
}
if (node_to_cpumask_map[node] == NULL) {
printk(KERN_WARNING
"cpumask_of_node(%d): no node_to_cpumask_map!\n",
node);
dump_stack();
return cpu_online_mask;
}
return node_to_cpumask_map[node];
}
EXPORT_SYMBOL(cpumask_of_node);
#endif /* !CONFIG_DEBUG_PER_CPU_MAPS */
#ifdef CONFIG_MEMORY_HOTPLUG
int memory_add_physaddr_to_nid(u64 start)
{
struct numa_meminfo *mi = &numa_meminfo;
int nid = mi->blk[0].nid;
int i;
for (i = 0; i < mi->nr_blks; i++)
if (mi->blk[i].start <= start && mi->blk[i].end > start)
nid = mi->blk[i].nid;
return nid;
}
EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
#endif