1 /* 2 * Basic Node interface support 3 */ 4 5 #include <linux/module.h> 6 #include <linux/init.h> 7 #include <linux/mm.h> 8 #include <linux/memory.h> 9 #include <linux/vmstat.h> 10 #include <linux/notifier.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 bus_type node_subsys = { 23 .name = "node", 24 .dev_name = "node", 25 }; 26 27 28 static ssize_t node_read_cpumap(struct device *dev, bool list, char *buf) 29 { 30 struct node *node_dev = to_node(dev); 31 const struct cpumask *mask = cpumask_of_node(node_dev->dev.id); 32 33 /* 2008/04/07: buf currently PAGE_SIZE, need 9 chars per 32 bits. */ 34 BUILD_BUG_ON((NR_CPUS/32 * 9) > (PAGE_SIZE-1)); 35 36 return cpumap_print_to_pagebuf(list, buf, mask); 37 } 38 39 static inline ssize_t node_read_cpumask(struct device *dev, 40 struct device_attribute *attr, char *buf) 41 { 42 return node_read_cpumap(dev, false, buf); 43 } 44 static inline ssize_t node_read_cpulist(struct device *dev, 45 struct device_attribute *attr, char *buf) 46 { 47 return node_read_cpumap(dev, true, buf); 48 } 49 50 static DEVICE_ATTR(cpumap, S_IRUGO, node_read_cpumask, NULL); 51 static DEVICE_ATTR(cpulist, S_IRUGO, node_read_cpulist, NULL); 52 53 #define K(x) ((x) << (PAGE_SHIFT - 10)) 54 static ssize_t node_read_meminfo(struct device *dev, 55 struct device_attribute *attr, char *buf) 56 { 57 int n; 58 int nid = dev->id; 59 struct pglist_data *pgdat = NODE_DATA(nid); 60 struct sysinfo i; 61 62 si_meminfo_node(&i, nid); 63 n = sprintf(buf, 64 "Node %d MemTotal: %8lu kB\n" 65 "Node %d MemFree: %8lu kB\n" 66 "Node %d MemUsed: %8lu kB\n" 67 "Node %d Active: %8lu kB\n" 68 "Node %d Inactive: %8lu kB\n" 69 "Node %d Active(anon): %8lu kB\n" 70 "Node %d Inactive(anon): %8lu kB\n" 71 "Node %d Active(file): %8lu kB\n" 72 "Node %d Inactive(file): %8lu kB\n" 73 "Node %d Unevictable: %8lu kB\n" 74 "Node %d Mlocked: %8lu kB\n", 75 nid, K(i.totalram), 76 nid, K(i.freeram), 77 nid, K(i.totalram - i.freeram), 78 nid, K(node_page_state(pgdat, NR_ACTIVE_ANON) + 79 node_page_state(pgdat, NR_ACTIVE_FILE)), 80 nid, K(node_page_state(pgdat, NR_INACTIVE_ANON) + 81 node_page_state(pgdat, NR_INACTIVE_FILE)), 82 nid, K(node_page_state(pgdat, NR_ACTIVE_ANON)), 83 nid, K(node_page_state(pgdat, NR_INACTIVE_ANON)), 84 nid, K(node_page_state(pgdat, NR_ACTIVE_FILE)), 85 nid, K(node_page_state(pgdat, NR_INACTIVE_FILE)), 86 nid, K(node_page_state(pgdat, NR_UNEVICTABLE)), 87 nid, K(sum_zone_node_page_state(nid, NR_MLOCK))); 88 89 #ifdef CONFIG_HIGHMEM 90 n += sprintf(buf + n, 91 "Node %d HighTotal: %8lu kB\n" 92 "Node %d HighFree: %8lu kB\n" 93 "Node %d LowTotal: %8lu kB\n" 94 "Node %d LowFree: %8lu kB\n", 95 nid, K(i.totalhigh), 96 nid, K(i.freehigh), 97 nid, K(i.totalram - i.totalhigh), 98 nid, K(i.freeram - i.freehigh)); 99 #endif 100 n += sprintf(buf + n, 101 "Node %d Dirty: %8lu kB\n" 102 "Node %d Writeback: %8lu kB\n" 103 "Node %d FilePages: %8lu kB\n" 104 "Node %d Mapped: %8lu kB\n" 105 "Node %d AnonPages: %8lu kB\n" 106 "Node %d Shmem: %8lu kB\n" 107 "Node %d KernelStack: %8lu kB\n" 108 "Node %d PageTables: %8lu kB\n" 109 "Node %d NFS_Unstable: %8lu kB\n" 110 "Node %d Bounce: %8lu kB\n" 111 "Node %d WritebackTmp: %8lu kB\n" 112 "Node %d Slab: %8lu kB\n" 113 "Node %d SReclaimable: %8lu kB\n" 114 "Node %d SUnreclaim: %8lu kB\n" 115 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 116 "Node %d AnonHugePages: %8lu kB\n" 117 "Node %d ShmemHugePages: %8lu kB\n" 118 "Node %d ShmemPmdMapped: %8lu kB\n" 119 #endif 120 , 121 nid, K(node_page_state(pgdat, NR_FILE_DIRTY)), 122 nid, K(node_page_state(pgdat, NR_WRITEBACK)), 123 nid, K(node_page_state(pgdat, NR_FILE_PAGES)), 124 nid, K(node_page_state(pgdat, NR_FILE_MAPPED)), 125 nid, K(node_page_state(pgdat, NR_ANON_MAPPED)), 126 nid, K(i.sharedram), 127 nid, sum_zone_node_page_state(nid, NR_KERNEL_STACK_KB), 128 nid, K(sum_zone_node_page_state(nid, NR_PAGETABLE)), 129 nid, K(node_page_state(pgdat, NR_UNSTABLE_NFS)), 130 nid, K(sum_zone_node_page_state(nid, NR_BOUNCE)), 131 nid, K(node_page_state(pgdat, NR_WRITEBACK_TEMP)), 132 nid, K(node_page_state(pgdat, NR_SLAB_RECLAIMABLE) + 133 node_page_state(pgdat, NR_SLAB_UNRECLAIMABLE)), 134 nid, K(node_page_state(pgdat, NR_SLAB_RECLAIMABLE)), 135 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 136 nid, K(node_page_state(pgdat, NR_SLAB_UNRECLAIMABLE)), 137 nid, K(node_page_state(pgdat, NR_ANON_THPS) * 138 HPAGE_PMD_NR), 139 nid, K(node_page_state(pgdat, NR_SHMEM_THPS) * 140 HPAGE_PMD_NR), 141 nid, K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED) * 142 HPAGE_PMD_NR)); 143 #else 144 nid, K(node_page_state(pgdat, NR_SLAB_UNRECLAIMABLE))); 145 #endif 146 n += hugetlb_report_node_meminfo(nid, buf + n); 147 return n; 148 } 149 150 #undef K 151 static DEVICE_ATTR(meminfo, S_IRUGO, node_read_meminfo, NULL); 152 153 static ssize_t node_read_numastat(struct device *dev, 154 struct device_attribute *attr, char *buf) 155 { 156 return sprintf(buf, 157 "numa_hit %lu\n" 158 "numa_miss %lu\n" 159 "numa_foreign %lu\n" 160 "interleave_hit %lu\n" 161 "local_node %lu\n" 162 "other_node %lu\n", 163 sum_zone_node_page_state(dev->id, NUMA_HIT), 164 sum_zone_node_page_state(dev->id, NUMA_MISS), 165 sum_zone_node_page_state(dev->id, NUMA_FOREIGN), 166 sum_zone_node_page_state(dev->id, NUMA_INTERLEAVE_HIT), 167 sum_zone_node_page_state(dev->id, NUMA_LOCAL), 168 sum_zone_node_page_state(dev->id, NUMA_OTHER)); 169 } 170 static DEVICE_ATTR(numastat, S_IRUGO, node_read_numastat, NULL); 171 172 static ssize_t node_read_vmstat(struct device *dev, 173 struct device_attribute *attr, char *buf) 174 { 175 int nid = dev->id; 176 struct pglist_data *pgdat = NODE_DATA(nid); 177 int i; 178 int n = 0; 179 180 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) 181 n += sprintf(buf+n, "%s %lu\n", vmstat_text[i], 182 sum_zone_node_page_state(nid, i)); 183 184 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) 185 n += sprintf(buf+n, "%s %lu\n", 186 vmstat_text[i + NR_VM_ZONE_STAT_ITEMS], 187 node_page_state(pgdat, i)); 188 189 return n; 190 } 191 static DEVICE_ATTR(vmstat, S_IRUGO, node_read_vmstat, NULL); 192 193 static ssize_t node_read_distance(struct device *dev, 194 struct device_attribute *attr, char *buf) 195 { 196 int nid = dev->id; 197 int len = 0; 198 int i; 199 200 /* 201 * buf is currently PAGE_SIZE in length and each node needs 4 chars 202 * at the most (distance + space or newline). 203 */ 204 BUILD_BUG_ON(MAX_NUMNODES * 4 > PAGE_SIZE); 205 206 for_each_online_node(i) 207 len += sprintf(buf + len, "%s%d", i ? " " : "", node_distance(nid, i)); 208 209 len += sprintf(buf + len, "\n"); 210 return len; 211 } 212 static DEVICE_ATTR(distance, S_IRUGO, node_read_distance, NULL); 213 214 static struct attribute *node_dev_attrs[] = { 215 &dev_attr_cpumap.attr, 216 &dev_attr_cpulist.attr, 217 &dev_attr_meminfo.attr, 218 &dev_attr_numastat.attr, 219 &dev_attr_distance.attr, 220 &dev_attr_vmstat.attr, 221 NULL 222 }; 223 ATTRIBUTE_GROUPS(node_dev); 224 225 #ifdef CONFIG_HUGETLBFS 226 /* 227 * hugetlbfs per node attributes registration interface: 228 * When/if hugetlb[fs] subsystem initializes [sometime after this module], 229 * it will register its per node attributes for all online nodes with 230 * memory. It will also call register_hugetlbfs_with_node(), below, to 231 * register its attribute registration functions with this node driver. 232 * Once these hooks have been initialized, the node driver will call into 233 * the hugetlb module to [un]register attributes for hot-plugged nodes. 234 */ 235 static node_registration_func_t __hugetlb_register_node; 236 static node_registration_func_t __hugetlb_unregister_node; 237 238 static inline bool hugetlb_register_node(struct node *node) 239 { 240 if (__hugetlb_register_node && 241 node_state(node->dev.id, N_MEMORY)) { 242 __hugetlb_register_node(node); 243 return true; 244 } 245 return false; 246 } 247 248 static inline void hugetlb_unregister_node(struct node *node) 249 { 250 if (__hugetlb_unregister_node) 251 __hugetlb_unregister_node(node); 252 } 253 254 void register_hugetlbfs_with_node(node_registration_func_t doregister, 255 node_registration_func_t unregister) 256 { 257 __hugetlb_register_node = doregister; 258 __hugetlb_unregister_node = unregister; 259 } 260 #else 261 static inline void hugetlb_register_node(struct node *node) {} 262 263 static inline void hugetlb_unregister_node(struct node *node) {} 264 #endif 265 266 static void node_device_release(struct device *dev) 267 { 268 struct node *node = to_node(dev); 269 270 #if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HUGETLBFS) 271 /* 272 * We schedule the work only when a memory section is 273 * onlined/offlined on this node. When we come here, 274 * all the memory on this node has been offlined, 275 * so we won't enqueue new work to this work. 276 * 277 * The work is using node->node_work, so we should 278 * flush work before freeing the memory. 279 */ 280 flush_work(&node->node_work); 281 #endif 282 kfree(node); 283 } 284 285 /* 286 * register_node - Setup a sysfs device for a node. 287 * @num - Node number to use when creating the device. 288 * 289 * Initialize and register the node device. 290 */ 291 static int register_node(struct node *node, int num) 292 { 293 int error; 294 295 node->dev.id = num; 296 node->dev.bus = &node_subsys; 297 node->dev.release = node_device_release; 298 node->dev.groups = node_dev_groups; 299 error = device_register(&node->dev); 300 301 if (!error){ 302 hugetlb_register_node(node); 303 304 compaction_register_node(node); 305 } 306 return error; 307 } 308 309 /** 310 * unregister_node - unregister a node device 311 * @node: node going away 312 * 313 * Unregisters a node device @node. All the devices on the node must be 314 * unregistered before calling this function. 315 */ 316 void unregister_node(struct node *node) 317 { 318 hugetlb_unregister_node(node); /* no-op, if memoryless node */ 319 320 device_unregister(&node->dev); 321 } 322 323 struct node *node_devices[MAX_NUMNODES]; 324 325 /* 326 * register cpu under node 327 */ 328 int register_cpu_under_node(unsigned int cpu, unsigned int nid) 329 { 330 int ret; 331 struct device *obj; 332 333 if (!node_online(nid)) 334 return 0; 335 336 obj = get_cpu_device(cpu); 337 if (!obj) 338 return 0; 339 340 ret = sysfs_create_link(&node_devices[nid]->dev.kobj, 341 &obj->kobj, 342 kobject_name(&obj->kobj)); 343 if (ret) 344 return ret; 345 346 return sysfs_create_link(&obj->kobj, 347 &node_devices[nid]->dev.kobj, 348 kobject_name(&node_devices[nid]->dev.kobj)); 349 } 350 351 int unregister_cpu_under_node(unsigned int cpu, unsigned int nid) 352 { 353 struct device *obj; 354 355 if (!node_online(nid)) 356 return 0; 357 358 obj = get_cpu_device(cpu); 359 if (!obj) 360 return 0; 361 362 sysfs_remove_link(&node_devices[nid]->dev.kobj, 363 kobject_name(&obj->kobj)); 364 sysfs_remove_link(&obj->kobj, 365 kobject_name(&node_devices[nid]->dev.kobj)); 366 367 return 0; 368 } 369 370 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE 371 static int __ref get_nid_for_pfn(unsigned long pfn) 372 { 373 if (!pfn_valid_within(pfn)) 374 return -1; 375 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT 376 if (system_state < SYSTEM_RUNNING) 377 return early_pfn_to_nid(pfn); 378 #endif 379 return pfn_to_nid(pfn); 380 } 381 382 /* register memory section under specified node if it spans that node */ 383 int register_mem_sect_under_node(struct memory_block *mem_blk, int nid) 384 { 385 int ret; 386 unsigned long pfn, sect_start_pfn, sect_end_pfn; 387 388 if (!mem_blk) 389 return -EFAULT; 390 if (!node_online(nid)) 391 return 0; 392 393 sect_start_pfn = section_nr_to_pfn(mem_blk->start_section_nr); 394 sect_end_pfn = section_nr_to_pfn(mem_blk->end_section_nr); 395 sect_end_pfn += PAGES_PER_SECTION - 1; 396 for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) { 397 int page_nid; 398 399 /* 400 * memory block could have several absent sections from start. 401 * skip pfn range from absent section 402 */ 403 if (!pfn_present(pfn)) { 404 pfn = round_down(pfn + PAGES_PER_SECTION, 405 PAGES_PER_SECTION) - 1; 406 continue; 407 } 408 409 page_nid = get_nid_for_pfn(pfn); 410 if (page_nid < 0) 411 continue; 412 if (page_nid != nid) 413 continue; 414 ret = sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj, 415 &mem_blk->dev.kobj, 416 kobject_name(&mem_blk->dev.kobj)); 417 if (ret) 418 return ret; 419 420 return sysfs_create_link_nowarn(&mem_blk->dev.kobj, 421 &node_devices[nid]->dev.kobj, 422 kobject_name(&node_devices[nid]->dev.kobj)); 423 } 424 /* mem section does not span the specified node */ 425 return 0; 426 } 427 428 /* unregister memory section under all nodes that it spans */ 429 int unregister_mem_sect_under_nodes(struct memory_block *mem_blk, 430 unsigned long phys_index) 431 { 432 NODEMASK_ALLOC(nodemask_t, unlinked_nodes, GFP_KERNEL); 433 unsigned long pfn, sect_start_pfn, sect_end_pfn; 434 435 if (!mem_blk) { 436 NODEMASK_FREE(unlinked_nodes); 437 return -EFAULT; 438 } 439 if (!unlinked_nodes) 440 return -ENOMEM; 441 nodes_clear(*unlinked_nodes); 442 443 sect_start_pfn = section_nr_to_pfn(phys_index); 444 sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1; 445 for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) { 446 int nid; 447 448 nid = get_nid_for_pfn(pfn); 449 if (nid < 0) 450 continue; 451 if (!node_online(nid)) 452 continue; 453 if (node_test_and_set(nid, *unlinked_nodes)) 454 continue; 455 sysfs_remove_link(&node_devices[nid]->dev.kobj, 456 kobject_name(&mem_blk->dev.kobj)); 457 sysfs_remove_link(&mem_blk->dev.kobj, 458 kobject_name(&node_devices[nid]->dev.kobj)); 459 } 460 NODEMASK_FREE(unlinked_nodes); 461 return 0; 462 } 463 464 int link_mem_sections(int nid, unsigned long start_pfn, unsigned long nr_pages) 465 { 466 unsigned long end_pfn = start_pfn + nr_pages; 467 unsigned long pfn; 468 struct memory_block *mem_blk = NULL; 469 int err = 0; 470 471 for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { 472 unsigned long section_nr = pfn_to_section_nr(pfn); 473 struct mem_section *mem_sect; 474 int ret; 475 476 if (!present_section_nr(section_nr)) 477 continue; 478 mem_sect = __nr_to_section(section_nr); 479 480 /* same memblock ? */ 481 if (mem_blk) 482 if ((section_nr >= mem_blk->start_section_nr) && 483 (section_nr <= mem_blk->end_section_nr)) 484 continue; 485 486 mem_blk = find_memory_block_hinted(mem_sect, mem_blk); 487 488 ret = register_mem_sect_under_node(mem_blk, nid); 489 if (!err) 490 err = ret; 491 492 /* discard ref obtained in find_memory_block() */ 493 } 494 495 if (mem_blk) 496 kobject_put(&mem_blk->dev.kobj); 497 return err; 498 } 499 500 #ifdef CONFIG_HUGETLBFS 501 /* 502 * Handle per node hstate attribute [un]registration on transistions 503 * to/from memoryless state. 504 */ 505 static void node_hugetlb_work(struct work_struct *work) 506 { 507 struct node *node = container_of(work, struct node, node_work); 508 509 /* 510 * We only get here when a node transitions to/from memoryless state. 511 * We can detect which transition occurred by examining whether the 512 * node has memory now. hugetlb_register_node() already check this 513 * so we try to register the attributes. If that fails, then the 514 * node has transitioned to memoryless, try to unregister the 515 * attributes. 516 */ 517 if (!hugetlb_register_node(node)) 518 hugetlb_unregister_node(node); 519 } 520 521 static void init_node_hugetlb_work(int nid) 522 { 523 INIT_WORK(&node_devices[nid]->node_work, node_hugetlb_work); 524 } 525 526 static int node_memory_callback(struct notifier_block *self, 527 unsigned long action, void *arg) 528 { 529 struct memory_notify *mnb = arg; 530 int nid = mnb->status_change_nid; 531 532 switch (action) { 533 case MEM_ONLINE: 534 case MEM_OFFLINE: 535 /* 536 * offload per node hstate [un]registration to a work thread 537 * when transitioning to/from memoryless state. 538 */ 539 if (nid != NUMA_NO_NODE) 540 schedule_work(&node_devices[nid]->node_work); 541 break; 542 543 case MEM_GOING_ONLINE: 544 case MEM_GOING_OFFLINE: 545 case MEM_CANCEL_ONLINE: 546 case MEM_CANCEL_OFFLINE: 547 default: 548 break; 549 } 550 551 return NOTIFY_OK; 552 } 553 #endif /* CONFIG_HUGETLBFS */ 554 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ 555 556 #if !defined(CONFIG_MEMORY_HOTPLUG_SPARSE) || \ 557 !defined(CONFIG_HUGETLBFS) 558 static inline int node_memory_callback(struct notifier_block *self, 559 unsigned long action, void *arg) 560 { 561 return NOTIFY_OK; 562 } 563 564 static void init_node_hugetlb_work(int nid) { } 565 566 #endif 567 568 int __register_one_node(int nid) 569 { 570 int error; 571 int cpu; 572 573 node_devices[nid] = kzalloc(sizeof(struct node), GFP_KERNEL); 574 if (!node_devices[nid]) 575 return -ENOMEM; 576 577 error = register_node(node_devices[nid], nid); 578 579 /* link cpu under this node */ 580 for_each_present_cpu(cpu) { 581 if (cpu_to_node(cpu) == nid) 582 register_cpu_under_node(cpu, nid); 583 } 584 585 /* initialize work queue for memory hot plug */ 586 init_node_hugetlb_work(nid); 587 588 return error; 589 } 590 591 void unregister_one_node(int nid) 592 { 593 if (!node_devices[nid]) 594 return; 595 596 unregister_node(node_devices[nid]); 597 node_devices[nid] = NULL; 598 } 599 600 /* 601 * node states attributes 602 */ 603 604 static ssize_t print_nodes_state(enum node_states state, char *buf) 605 { 606 int n; 607 608 n = scnprintf(buf, PAGE_SIZE - 1, "%*pbl", 609 nodemask_pr_args(&node_states[state])); 610 buf[n++] = '\n'; 611 buf[n] = '\0'; 612 return n; 613 } 614 615 struct node_attr { 616 struct device_attribute attr; 617 enum node_states state; 618 }; 619 620 static ssize_t show_node_state(struct device *dev, 621 struct device_attribute *attr, char *buf) 622 { 623 struct node_attr *na = container_of(attr, struct node_attr, attr); 624 return print_nodes_state(na->state, buf); 625 } 626 627 #define _NODE_ATTR(name, state) \ 628 { __ATTR(name, 0444, show_node_state, NULL), state } 629 630 static struct node_attr node_state_attr[] = { 631 [N_POSSIBLE] = _NODE_ATTR(possible, N_POSSIBLE), 632 [N_ONLINE] = _NODE_ATTR(online, N_ONLINE), 633 [N_NORMAL_MEMORY] = _NODE_ATTR(has_normal_memory, N_NORMAL_MEMORY), 634 #ifdef CONFIG_HIGHMEM 635 [N_HIGH_MEMORY] = _NODE_ATTR(has_high_memory, N_HIGH_MEMORY), 636 #endif 637 [N_MEMORY] = _NODE_ATTR(has_memory, N_MEMORY), 638 [N_CPU] = _NODE_ATTR(has_cpu, N_CPU), 639 }; 640 641 static struct attribute *node_state_attrs[] = { 642 &node_state_attr[N_POSSIBLE].attr.attr, 643 &node_state_attr[N_ONLINE].attr.attr, 644 &node_state_attr[N_NORMAL_MEMORY].attr.attr, 645 #ifdef CONFIG_HIGHMEM 646 &node_state_attr[N_HIGH_MEMORY].attr.attr, 647 #endif 648 &node_state_attr[N_MEMORY].attr.attr, 649 &node_state_attr[N_CPU].attr.attr, 650 NULL 651 }; 652 653 static struct attribute_group memory_root_attr_group = { 654 .attrs = node_state_attrs, 655 }; 656 657 static const struct attribute_group *cpu_root_attr_groups[] = { 658 &memory_root_attr_group, 659 NULL, 660 }; 661 662 #define NODE_CALLBACK_PRI 2 /* lower than SLAB */ 663 static int __init register_node_type(void) 664 { 665 int ret; 666 667 BUILD_BUG_ON(ARRAY_SIZE(node_state_attr) != NR_NODE_STATES); 668 BUILD_BUG_ON(ARRAY_SIZE(node_state_attrs)-1 != NR_NODE_STATES); 669 670 ret = subsys_system_register(&node_subsys, cpu_root_attr_groups); 671 if (!ret) { 672 static struct notifier_block node_memory_callback_nb = { 673 .notifier_call = node_memory_callback, 674 .priority = NODE_CALLBACK_PRI, 675 }; 676 register_hotmemory_notifier(&node_memory_callback_nb); 677 } 678 679 /* 680 * Note: we're not going to unregister the node class if we fail 681 * to register the node state class attribute files. 682 */ 683 return ret; 684 } 685 postcore_initcall(register_node_type); 686