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