drivers/base/node.c

   1 /*
   2  * drivers/base/node.c - basic Node class support
   3  */
   4
   5 #include <linux/sysdev.h>
   6 #include <linux/module.h>
   7 #include <linux/init.h>
   8 #include <linux/mm.h>
   9 #include <linux/memory.h>
  10 #include <linux/vmstat.h>
  11 #include <linux/node.h>
  12 #include <linux/hugetlb.h>
  13 #include <linux/compaction.h>
  14 #include <linux/cpumask.h>
  15 #include <linux/topology.h>
  16 #include <linux/nodemask.h>
  17 #include <linux/cpu.h>
  18 #include <linux/device.h>
  19 #include <linux/swap.h>
  20 #include <linux/slab.h>
  21
  22 static struct sysdev_class_attribute *node_state_attrs[];
  23
  24 static struct sysdev_class node_class = {
  25         .name = "node",
  26         .attrs = node_state_attrs,
  27 };
  28
  29
  30 static ssize_t node_read_cpumap(struct sys_device *dev, int type, char *buf)
  31 {
  32         struct node *node_dev = to_node(dev);
  33         const struct cpumask *mask = cpumask_of_node(node_dev->sysdev.id);
  34         int len;
  35
  36         /* 2008/04/07: buf currently PAGE_SIZE, need 9 chars per 32 bits. */
  37         BUILD_BUG_ON((NR_CPUS/32 * 9) > (PAGE_SIZE-1));
  38
  39         len = type?
  40                 cpulist_scnprintf(buf, PAGE_SIZE-2, mask) :
  41                 cpumask_scnprintf(buf, PAGE_SIZE-2, mask);
  42         buf[len++] = '\n';
  43         buf[len] = '\0';
  44         return len;
  45 }
  46
  47 static inline ssize_t node_read_cpumask(struct sys_device *dev,
  48                                 struct sysdev_attribute *attr, char *buf)
  49 {
  50         return node_read_cpumap(dev, 0, buf);
  51 }
  52 static inline ssize_t node_read_cpulist(struct sys_device *dev,
  53                                 struct sysdev_attribute *attr, char *buf)
  54 {
  55         return node_read_cpumap(dev, 1, buf);
  56 }
  57
  58 static SYSDEV_ATTR(cpumap,  S_IRUGO, node_read_cpumask, NULL);
  59 static SYSDEV_ATTR(cpulist, S_IRUGO, node_read_cpulist, NULL);
  60
  61 #define K(x) ((x) << (PAGE_SHIFT - 10))
  62 static ssize_t node_read_meminfo(struct sys_device * dev,
  63                         struct sysdev_attribute *attr, char * buf)
  64 {
  65         int n;
  66         int nid = dev->id;
  67         struct sysinfo i;
  68
  69         si_meminfo_node(&i, nid);
  70         n = sprintf(buf,
  71                        "Node %d MemTotal:       %8lu kB\n"
  72                        "Node %d MemFree:        %8lu kB\n"
  73                        "Node %d MemUsed:        %8lu kB\n"
  74                        "Node %d Active:         %8lu kB\n"
  75                        "Node %d Inactive:       %8lu kB\n"
  76                        "Node %d Active(anon):   %8lu kB\n"
  77                        "Node %d Inactive(anon): %8lu kB\n"
  78                        "Node %d Active(file):   %8lu kB\n"
  79                        "Node %d Inactive(file): %8lu kB\n"
  80                        "Node %d Unevictable:    %8lu kB\n"
  81                        "Node %d Mlocked:        %8lu kB\n",
  82                        nid, K(i.totalram),
  83                        nid, K(i.freeram),
  84                        nid, K(i.totalram - i.freeram),
  85                        nid, K(node_page_state(nid, NR_ACTIVE_ANON) +
  86                                 node_page_state(nid, NR_ACTIVE_FILE)),
  87                        nid, K(node_page_state(nid, NR_INACTIVE_ANON) +
  88                                 node_page_state(nid, NR_INACTIVE_FILE)),
  89                        nid, K(node_page_state(nid, NR_ACTIVE_ANON)),
  90                        nid, K(node_page_state(nid, NR_INACTIVE_ANON)),
  91                        nid, K(node_page_state(nid, NR_ACTIVE_FILE)),
  92                        nid, K(node_page_state(nid, NR_INACTIVE_FILE)),
  93                        nid, K(node_page_state(nid, NR_UNEVICTABLE)),
  94                        nid, K(node_page_state(nid, NR_MLOCK)));
  95
  96 #ifdef CONFIG_HIGHMEM
  97         n += sprintf(buf + n,
  98                        "Node %d HighTotal:      %8lu kB\n"
  99                        "Node %d HighFree:       %8lu kB\n"
 100                        "Node %d LowTotal:       %8lu kB\n"
 101                        "Node %d LowFree:        %8lu kB\n",
 102                        nid, K(i.totalhigh),
 103                        nid, K(i.freehigh),
 104                        nid, K(i.totalram - i.totalhigh),
 105                        nid, K(i.freeram - i.freehigh));
 106 #endif
 107         n += sprintf(buf + n,
 108                        "Node %d Dirty:          %8lu kB\n"
 109                        "Node %d Writeback:      %8lu kB\n"
 110                        "Node %d FilePages:      %8lu kB\n"
 111                        "Node %d Mapped:         %8lu kB\n"
 112                        "Node %d AnonPages:      %8lu kB\n"
 113                        "Node %d Shmem:          %8lu kB\n"
 114                        "Node %d KernelStack:    %8lu kB\n"
 115                        "Node %d PageTables:     %8lu kB\n"
 116                        "Node %d NFS_Unstable:   %8lu kB\n"
 117                        "Node %d Bounce:         %8lu kB\n"
 118                        "Node %d WritebackTmp:   %8lu kB\n"
 119                        "Node %d Slab:           %8lu kB\n"
 120                        "Node %d SReclaimable:   %8lu kB\n"
 121                        "Node %d SUnreclaim:     %8lu kB\n"
 122 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 123                        "Node %d AnonHugePages:  %8lu kB\n"
 124 #endif
 125                         ,
 126                        nid, K(node_page_state(nid, NR_FILE_DIRTY)),
 127                        nid, K(node_page_state(nid, NR_WRITEBACK)),
 128                        nid, K(node_page_state(nid, NR_FILE_PAGES)),
 129                        nid, K(node_page_state(nid, NR_FILE_MAPPED)),
 130                        nid, K(node_page_state(nid, NR_ANON_PAGES)
 131 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 132                         + node_page_state(nid, NR_ANON_TRANSPARENT_HUGEPAGES) *
 133                         HPAGE_PMD_NR
 134 #endif
 135                        ),
 136                        nid, K(node_page_state(nid, NR_SHMEM)),
 137                        nid, node_page_state(nid, NR_KERNEL_STACK) *
 138                                 THREAD_SIZE / 1024,
 139                        nid, K(node_page_state(nid, NR_PAGETABLE)),
 140                        nid, K(node_page_state(nid, NR_UNSTABLE_NFS)),
 141                        nid, K(node_page_state(nid, NR_BOUNCE)),
 142                        nid, K(node_page_state(nid, NR_WRITEBACK_TEMP)),
 143                        nid, K(node_page_state(nid, NR_SLAB_RECLAIMABLE) +
 144                                 node_page_state(nid, NR_SLAB_UNRECLAIMABLE)),
 145                        nid, K(node_page_state(nid, NR_SLAB_RECLAIMABLE)),
 146                        nid, K(node_page_state(nid, NR_SLAB_UNRECLAIMABLE))
 147 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 148                         , nid,
 149                         K(node_page_state(nid, NR_ANON_TRANSPARENT_HUGEPAGES) *
 150                         HPAGE_PMD_NR)
 151 #endif
 152                        );
 153         n += hugetlb_report_node_meminfo(nid, buf + n);
 154         return n;
 155 }
 156
 157 #undef K
 158 static SYSDEV_ATTR(meminfo, S_IRUGO, node_read_meminfo, NULL);
 159
 160 static ssize_t node_read_numastat(struct sys_device * dev,
 161                                 struct sysdev_attribute *attr, char * buf)
 162 {
 163         return sprintf(buf,
 164                        "numa_hit %lu\n"
 165                        "numa_miss %lu\n"
 166                        "numa_foreign %lu\n"
 167                        "interleave_hit %lu\n"
 168                        "local_node %lu\n"
 169                        "other_node %lu\n",
 170                        node_page_state(dev->id, NUMA_HIT),
 171                        node_page_state(dev->id, NUMA_MISS),
 172                        node_page_state(dev->id, NUMA_FOREIGN),
 173                        node_page_state(dev->id, NUMA_INTERLEAVE_HIT),
 174                        node_page_state(dev->id, NUMA_LOCAL),
 175                        node_page_state(dev->id, NUMA_OTHER));
 176 }
 177 static SYSDEV_ATTR(numastat, S_IRUGO, node_read_numastat, NULL);
 178
 179 static ssize_t node_read_vmstat(struct sys_device *dev,
 180                                 struct sysdev_attribute *attr, char *buf)
 181 {
 182         int nid = dev->id;
 183         int i;
 184         int n = 0;
 185
 186         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
 187                 n += sprintf(buf+n, "%s %lu\n", vmstat_text[i],
 188                              node_page_state(nid, i));
 189
 190         return n;
 191 }
 192 static SYSDEV_ATTR(vmstat, S_IRUGO, node_read_vmstat, NULL);
 193
 194 static ssize_t node_read_distance(struct sys_device * dev,
 195                         struct sysdev_attribute *attr, char * buf)
 196 {
 197         int nid = dev->id;
 198         int len = 0;
 199         int i;
 200
 201         /*
 202          * buf is currently PAGE_SIZE in length and each node needs 4 chars
 203          * at the most (distance + space or newline).
 204          */
 205         BUILD_BUG_ON(MAX_NUMNODES * 4 > PAGE_SIZE);
 206
 207         for_each_online_node(i)
 208                 len += sprintf(buf + len, "%s%d", i ? " " : "", node_distance(nid, i));
 209
 210         len += sprintf(buf + len, "\n");
 211         return len;
 212 }
 213 static SYSDEV_ATTR(distance, S_IRUGO, node_read_distance, NULL);
 214
 215 #ifdef CONFIG_HUGETLBFS
 216 /*
 217  * hugetlbfs per node attributes registration interface:
 218  * When/if hugetlb[fs] subsystem initializes [sometime after this module],
 219  * it will register its per node attributes for all online nodes with
 220  * memory.  It will also call register_hugetlbfs_with_node(), below, to
 221  * register its attribute registration functions with this node driver.
 222  * Once these hooks have been initialized, the node driver will call into
 223  * the hugetlb module to [un]register attributes for hot-plugged nodes.
 224  */
 225 static node_registration_func_t __hugetlb_register_node;
 226 static node_registration_func_t __hugetlb_unregister_node;
 227
 228 static inline bool hugetlb_register_node(struct node *node)
 229 {
 230         if (__hugetlb_register_node &&
 231                         node_state(node->sysdev.id, N_HIGH_MEMORY)) {
 232                 __hugetlb_register_node(node);
 233                 return true;
 234         }
 235         return false;
 236 }
 237
 238 static inline void hugetlb_unregister_node(struct node *node)
 239 {
 240         if (__hugetlb_unregister_node)
 241                 __hugetlb_unregister_node(node);
 242 }
 243
 244 void register_hugetlbfs_with_node(node_registration_func_t doregister,
 245                                   node_registration_func_t unregister)
 246 {
 247         __hugetlb_register_node   = doregister;
 248         __hugetlb_unregister_node = unregister;
 249 }
 250 #else
 251 static inline void hugetlb_register_node(struct node *node) {}
 252
 253 static inline void hugetlb_unregister_node(struct node *node) {}
 254 #endif
 255
 256
 257 /*
 258  * register_node - Setup a sysfs device for a node.
 259  * @num - Node number to use when creating the device.
 260  *
 261  * Initialize and register the node device.
 262  */
 263 int register_node(struct node *node, int num, struct node *parent)
 264 {
 265         int error;
 266
 267         node->sysdev.id = num;
 268         node->sysdev.cls = &node_class;
 269         error = sysdev_register(&node->sysdev);
 270
 271         if (!error){
 272                 sysdev_create_file(&node->sysdev, &attr_cpumap);
 273                 sysdev_create_file(&node->sysdev, &attr_cpulist);
 274                 sysdev_create_file(&node->sysdev, &attr_meminfo);
 275                 sysdev_create_file(&node->sysdev, &attr_numastat);
 276                 sysdev_create_file(&node->sysdev, &attr_distance);
 277                 sysdev_create_file(&node->sysdev, &attr_vmstat);
 278
 279                 scan_unevictable_register_node(node);
 280
 281                 hugetlb_register_node(node);
 282
 283                 compaction_register_node(node);
 284         }
 285         return error;
 286 }
 287
 288 /**
 289  * unregister_node - unregister a node device
 290  * @node: node going away
 291  *
 292  * Unregisters a node device @node.  All the devices on the node must be
 293  * unregistered before calling this function.
 294  */
 295 void unregister_node(struct node *node)
 296 {
 297         sysdev_remove_file(&node->sysdev, &attr_cpumap);
 298         sysdev_remove_file(&node->sysdev, &attr_cpulist);
 299         sysdev_remove_file(&node->sysdev, &attr_meminfo);
 300         sysdev_remove_file(&node->sysdev, &attr_numastat);
 301         sysdev_remove_file(&node->sysdev, &attr_distance);
 302         sysdev_remove_file(&node->sysdev, &attr_vmstat);
 303
 304         scan_unevictable_unregister_node(node);
 305         hugetlb_unregister_node(node);          /* no-op, if memoryless node */
 306
 307         sysdev_unregister(&node->sysdev);
 308 }
 309
 310 struct node node_devices[MAX_NUMNODES];
 311
 312 /*
 313  * register cpu under node
 314  */
 315 int register_cpu_under_node(unsigned int cpu, unsigned int nid)
 316 {
 317         int ret;
 318         struct sys_device *obj;
 319
 320         if (!node_online(nid))
 321                 return 0;
 322
 323         obj = get_cpu_sysdev(cpu);
 324         if (!obj)
 325                 return 0;
 326
 327         ret = sysfs_create_link(&node_devices[nid].sysdev.kobj,
 328                                 &obj->kobj,
 329                                 kobject_name(&obj->kobj));
 330         if (ret)
 331                 return ret;
 332
 333         return sysfs_create_link(&obj->kobj,
 334                                  &node_devices[nid].sysdev.kobj,
 335                                  kobject_name(&node_devices[nid].sysdev.kobj));
 336 }
 337
 338 int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
 339 {
 340         struct sys_device *obj;
 341
 342         if (!node_online(nid))
 343                 return 0;
 344
 345         obj = get_cpu_sysdev(cpu);
 346         if (!obj)
 347                 return 0;
 348
 349         sysfs_remove_link(&node_devices[nid].sysdev.kobj,
 350                           kobject_name(&obj->kobj));
 351         sysfs_remove_link(&obj->kobj,
 352                           kobject_name(&node_devices[nid].sysdev.kobj));
 353
 354         return 0;
 355 }
 356
 357 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
 358 #define page_initialized(page)  (page->lru.next)
 359
 360 static int get_nid_for_pfn(unsigned long pfn)
 361 {
 362         struct page *page;
 363
 364         if (!pfn_valid_within(pfn))
 365                 return -1;
 366         page = pfn_to_page(pfn);
 367         if (!page_initialized(page))
 368                 return -1;
 369         return pfn_to_nid(pfn);
 370 }
 371
 372 /* register memory section under specified node if it spans that node */
 373 int register_mem_sect_under_node(struct memory_block *mem_blk, int nid)
 374 {
 375         int ret;
 376         unsigned long pfn, sect_start_pfn, sect_end_pfn;
 377
 378         if (!mem_blk)
 379                 return -EFAULT;
 380         if (!node_online(nid))
 381                 return 0;
 382
 383         sect_start_pfn = section_nr_to_pfn(mem_blk->start_section_nr);
 384         sect_end_pfn = section_nr_to_pfn(mem_blk->end_section_nr);
 385         sect_end_pfn += PAGES_PER_SECTION - 1;
 386         for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
 387                 int page_nid;
 388
 389                 page_nid = get_nid_for_pfn(pfn);
 390                 if (page_nid < 0)
 391                         continue;
 392                 if (page_nid != nid)
 393                         continue;
 394                 ret = sysfs_create_link_nowarn(&node_devices[nid].sysdev.kobj,
 395                                         &mem_blk->sysdev.kobj,
 396                                         kobject_name(&mem_blk->sysdev.kobj));
 397                 if (ret)
 398                         return ret;
 399
 400                 return sysfs_create_link_nowarn(&mem_blk->sysdev.kobj,
 401                                 &node_devices[nid].sysdev.kobj,
 402                                 kobject_name(&node_devices[nid].sysdev.kobj));
 403         }
 404         /* mem section does not span the specified node */
 405         return 0;
 406 }
 407
 408 /* unregister memory section under all nodes that it spans */
 409 int unregister_mem_sect_under_nodes(struct memory_block *mem_blk,
 410                                     unsigned long phys_index)
 411 {
 412         NODEMASK_ALLOC(nodemask_t, unlinked_nodes, GFP_KERNEL);
 413         unsigned long pfn, sect_start_pfn, sect_end_pfn;
 414
 415         if (!mem_blk) {
 416                 NODEMASK_FREE(unlinked_nodes);
 417                 return -EFAULT;
 418         }
 419         if (!unlinked_nodes)
 420                 return -ENOMEM;
 421         nodes_clear(*unlinked_nodes);
 422
 423         sect_start_pfn = section_nr_to_pfn(phys_index);
 424         sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
 425         for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
 426                 int nid;
 427
 428                 nid = get_nid_for_pfn(pfn);
 429                 if (nid < 0)
 430                         continue;
 431                 if (!node_online(nid))
 432                         continue;
 433                 if (node_test_and_set(nid, *unlinked_nodes))
 434                         continue;
 435                 sysfs_remove_link(&node_devices[nid].sysdev.kobj,
 436                          kobject_name(&mem_blk->sysdev.kobj));
 437                 sysfs_remove_link(&mem_blk->sysdev.kobj,
 438                          kobject_name(&node_devices[nid].sysdev.kobj));
 439         }
 440         NODEMASK_FREE(unlinked_nodes);
 441         return 0;
 442 }
 443
 444 static int link_mem_sections(int nid)
 445 {
 446         unsigned long start_pfn = NODE_DATA(nid)->node_start_pfn;
 447         unsigned long end_pfn = start_pfn + NODE_DATA(nid)->node_spanned_pages;
 448         unsigned long pfn;
 449         struct memory_block *mem_blk = NULL;
 450         int err = 0;
 451
 452         for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
 453                 unsigned long section_nr = pfn_to_section_nr(pfn);
 454                 struct mem_section *mem_sect;
 455                 int ret;
 456
 457                 if (!present_section_nr(section_nr))
 458                         continue;
 459                 mem_sect = __nr_to_section(section_nr);
 460                 mem_blk = find_memory_block_hinted(mem_sect, mem_blk);
 461                 ret = register_mem_sect_under_node(mem_blk, nid);
 462                 if (!err)
 463                         err = ret;
 464
 465                 /* discard ref obtained in find_memory_block() */
 466         }
 467
 468         if (mem_blk)
 469                 kobject_put(&mem_blk->sysdev.kobj);
 470         return err;
 471 }
 472
 473 #ifdef CONFIG_HUGETLBFS
 474 /*
 475  * Handle per node hstate attribute [un]registration on transistions
 476  * to/from memoryless state.
 477  */
 478 static void node_hugetlb_work(struct work_struct *work)
 479 {
 480         struct node *node = container_of(work, struct node, node_work);
 481
 482         /*
 483          * We only get here when a node transitions to/from memoryless state.
 484          * We can detect which transition occurred by examining whether the
 485          * node has memory now.  hugetlb_register_node() already check this
 486          * so we try to register the attributes.  If that fails, then the
 487          * node has transitioned to memoryless, try to unregister the
 488          * attributes.
 489          */
 490         if (!hugetlb_register_node(node))
 491                 hugetlb_unregister_node(node);
 492 }
 493
 494 static void init_node_hugetlb_work(int nid)
 495 {
 496         INIT_WORK(&node_devices[nid].node_work, node_hugetlb_work);
 497 }
 498
 499 static int node_memory_callback(struct notifier_block *self,
 500                                 unsigned long action, void *arg)
 501 {
 502         struct memory_notify *mnb = arg;
 503         int nid = mnb->status_change_nid;
 504
 505         switch (action) {
 506         case MEM_ONLINE:
 507         case MEM_OFFLINE:
 508                 /*
 509                  * offload per node hstate [un]registration to a work thread
 510                  * when transitioning to/from memoryless state.
 511                  */
 512                 if (nid != NUMA_NO_NODE)
 513                         schedule_work(&node_devices[nid].node_work);
 514                 break;
 515
 516         case MEM_GOING_ONLINE:
 517         case MEM_GOING_OFFLINE:
 518         case MEM_CANCEL_ONLINE:
 519         case MEM_CANCEL_OFFLINE:
 520         default:
 521                 break;
 522         }
 523
 524         return NOTIFY_OK;
 525 }
 526 #endif  /* CONFIG_HUGETLBFS */
 527 #else   /* !CONFIG_MEMORY_HOTPLUG_SPARSE */
 528
 529 static int link_mem_sections(int nid) { return 0; }
 530 #endif  /* CONFIG_MEMORY_HOTPLUG_SPARSE */
 531
 532 #if !defined(CONFIG_MEMORY_HOTPLUG_SPARSE) || \
 533     !defined(CONFIG_HUGETLBFS)
 534 static inline int node_memory_callback(struct notifier_block *self,
 535                                 unsigned long action, void *arg)
 536 {
 537         return NOTIFY_OK;
 538 }
 539
 540 static void init_node_hugetlb_work(int nid) { }
 541
 542 #endif
 543
 544 int register_one_node(int nid)
 545 {
 546         int error = 0;
 547         int cpu;
 548
 549         if (node_online(nid)) {
 550                 int p_node = parent_node(nid);
 551                 struct node *parent = NULL;
 552
 553                 if (p_node != nid)
 554                         parent = &node_devices[p_node];
 555
 556                 error = register_node(&node_devices[nid], nid, parent);
 557
 558                 /* link cpu under this node */
 559                 for_each_present_cpu(cpu) {
 560                         if (cpu_to_node(cpu) == nid)
 561                                 register_cpu_under_node(cpu, nid);
 562                 }
 563
 564                 /* link memory sections under this node */
 565                 error = link_mem_sections(nid);
 566
 567                 /* initialize work queue for memory hot plug */
 568                 init_node_hugetlb_work(nid);
 569         }
 570
 571         return error;
 572
 573 }
 574
 575 void unregister_one_node(int nid)
 576 {
 577         unregister_node(&node_devices[nid]);
 578 }
 579
 580 /*
 581  * node states attributes
 582  */
 583
 584 static ssize_t print_nodes_state(enum node_states state, char *buf)
 585 {
 586         int n;
 587
 588         n = nodelist_scnprintf(buf, PAGE_SIZE, node_states[state]);
 589         if (n > 0 && PAGE_SIZE > n + 1) {
 590                 *(buf + n++) = '\n';
 591                 *(buf + n++) = '\0';
 592         }
 593         return n;
 594 }
 595
 596 struct node_attr {
 597         struct sysdev_class_attribute attr;
 598         enum node_states state;
 599 };
 600
 601 static ssize_t show_node_state(struct sysdev_class *class,
 602                                struct sysdev_class_attribute *attr, char *buf)
 603 {
 604         struct node_attr *na = container_of(attr, struct node_attr, attr);
 605         return print_nodes_state(na->state, buf);
 606 }
 607
 608 #define _NODE_ATTR(name, state) \
 609         { _SYSDEV_CLASS_ATTR(name, 0444, show_node_state, NULL), state }
 610
 611 static struct node_attr node_state_attr[] = {
 612         _NODE_ATTR(possible, N_POSSIBLE),
 613         _NODE_ATTR(online, N_ONLINE),
 614         _NODE_ATTR(has_normal_memory, N_NORMAL_MEMORY),
 615         _NODE_ATTR(has_cpu, N_CPU),
 616 #ifdef CONFIG_HIGHMEM
 617         _NODE_ATTR(has_high_memory, N_HIGH_MEMORY),
 618 #endif
 619 };
 620
 621 static struct sysdev_class_attribute *node_state_attrs[] = {
 622         &node_state_attr[0].attr,
 623         &node_state_attr[1].attr,
 624         &node_state_attr[2].attr,
 625         &node_state_attr[3].attr,
 626 #ifdef CONFIG_HIGHMEM
 627         &node_state_attr[4].attr,
 628 #endif
 629         NULL
 630 };
 631
 632 #define NODE_CALLBACK_PRI       2       /* lower than SLAB */
 633 static int __init register_node_type(void)
 634 {
 635         int ret;
 636
 637         BUILD_BUG_ON(ARRAY_SIZE(node_state_attr) != NR_NODE_STATES);
 638         BUILD_BUG_ON(ARRAY_SIZE(node_state_attrs)-1 != NR_NODE_STATES);
 639
 640         ret = sysdev_class_register(&node_class);
 641         if (!ret) {
 642                 hotplug_memory_notifier(node_memory_callback,
 643                                         NODE_CALLBACK_PRI);
 644         }
 645
 646         /*
 647          * Note:  we're not going to unregister the node class if we fail
 648          * to register the node state class attribute files.
 649          */
 650         return ret;
 651 }
 652 postcore_initcall(register_node_type);