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/node.h> 11 #include <linux/hugetlb.h> 12 #include <linux/compaction.h> 13 #include <linux/cpumask.h> 14 #include <linux/topology.h> 15 #include <linux/nodemask.h> 16 #include <linux/cpu.h> 17 #include <linux/device.h> 18 #include <linux/swap.h> 19 #include <linux/slab.h> 20 21 static struct bus_type node_subsys = { 22 .name = "node", 23 .dev_name = "node", 24 }; 25 26 27 static ssize_t node_read_cpumap(struct device *dev, int type, char *buf) 28 { 29 struct node *node_dev = to_node(dev); 30 const struct cpumask *mask = cpumask_of_node(node_dev->dev.id); 31 int len; 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 len = type? 37 cpulist_scnprintf(buf, PAGE_SIZE-2, mask) : 38 cpumask_scnprintf(buf, PAGE_SIZE-2, mask); 39 buf[len++] = '\n'; 40 buf[len] = '\0'; 41 return len; 42 } 43 44 static inline ssize_t node_read_cpumask(struct device *dev, 45 struct device_attribute *attr, char *buf) 46 { 47 return node_read_cpumap(dev, 0, buf); 48 } 49 static inline ssize_t node_read_cpulist(struct device *dev, 50 struct device_attribute *attr, char *buf) 51 { 52 return node_read_cpumap(dev, 1, buf); 53 } 54 55 static DEVICE_ATTR(cpumap, S_IRUGO, node_read_cpumask, NULL); 56 static DEVICE_ATTR(cpulist, S_IRUGO, node_read_cpulist, NULL); 57 58 #define K(x) ((x) << (PAGE_SHIFT - 10)) 59 static ssize_t node_read_meminfo(struct device *dev, 60 struct device_attribute *attr, char *buf) 61 { 62 int n; 63 int nid = dev->id; 64 struct sysinfo i; 65 66 si_meminfo_node(&i, nid); 67 n = sprintf(buf, 68 "Node %d MemTotal: %8lu kB\n" 69 "Node %d MemFree: %8lu kB\n" 70 "Node %d MemUsed: %8lu kB\n" 71 "Node %d Active: %8lu kB\n" 72 "Node %d Inactive: %8lu kB\n" 73 "Node %d Active(anon): %8lu kB\n" 74 "Node %d Inactive(anon): %8lu kB\n" 75 "Node %d Active(file): %8lu kB\n" 76 "Node %d Inactive(file): %8lu kB\n" 77 "Node %d Unevictable: %8lu kB\n" 78 "Node %d Mlocked: %8lu kB\n", 79 nid, K(i.totalram), 80 nid, K(i.freeram), 81 nid, K(i.totalram - i.freeram), 82 nid, K(node_page_state(nid, NR_ACTIVE_ANON) + 83 node_page_state(nid, NR_ACTIVE_FILE)), 84 nid, K(node_page_state(nid, NR_INACTIVE_ANON) + 85 node_page_state(nid, NR_INACTIVE_FILE)), 86 nid, K(node_page_state(nid, NR_ACTIVE_ANON)), 87 nid, K(node_page_state(nid, NR_INACTIVE_ANON)), 88 nid, K(node_page_state(nid, NR_ACTIVE_FILE)), 89 nid, K(node_page_state(nid, NR_INACTIVE_FILE)), 90 nid, K(node_page_state(nid, NR_UNEVICTABLE)), 91 nid, K(node_page_state(nid, NR_MLOCK))); 92 93 #ifdef CONFIG_HIGHMEM 94 n += sprintf(buf + n, 95 "Node %d HighTotal: %8lu kB\n" 96 "Node %d HighFree: %8lu kB\n" 97 "Node %d LowTotal: %8lu kB\n" 98 "Node %d LowFree: %8lu kB\n", 99 nid, K(i.totalhigh), 100 nid, K(i.freehigh), 101 nid, K(i.totalram - i.totalhigh), 102 nid, K(i.freeram - i.freehigh)); 103 #endif 104 n += sprintf(buf + n, 105 "Node %d Dirty: %8lu kB\n" 106 "Node %d Writeback: %8lu kB\n" 107 "Node %d FilePages: %8lu kB\n" 108 "Node %d Mapped: %8lu kB\n" 109 "Node %d AnonPages: %8lu kB\n" 110 "Node %d Shmem: %8lu kB\n" 111 "Node %d KernelStack: %8lu kB\n" 112 "Node %d PageTables: %8lu kB\n" 113 "Node %d NFS_Unstable: %8lu kB\n" 114 "Node %d Bounce: %8lu kB\n" 115 "Node %d WritebackTmp: %8lu kB\n" 116 "Node %d Slab: %8lu kB\n" 117 "Node %d SReclaimable: %8lu kB\n" 118 "Node %d SUnreclaim: %8lu kB\n" 119 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 120 "Node %d AnonHugePages: %8lu kB\n" 121 #endif 122 , 123 nid, K(node_page_state(nid, NR_FILE_DIRTY)), 124 nid, K(node_page_state(nid, NR_WRITEBACK)), 125 nid, K(node_page_state(nid, NR_FILE_PAGES)), 126 nid, K(node_page_state(nid, NR_FILE_MAPPED)), 127 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 128 nid, K(node_page_state(nid, NR_ANON_PAGES) 129 + node_page_state(nid, NR_ANON_TRANSPARENT_HUGEPAGES) * 130 HPAGE_PMD_NR), 131 #else 132 nid, K(node_page_state(nid, NR_ANON_PAGES)), 133 #endif 134 nid, K(node_page_state(nid, NR_SHMEM)), 135 nid, node_page_state(nid, NR_KERNEL_STACK) * 136 THREAD_SIZE / 1024, 137 nid, K(node_page_state(nid, NR_PAGETABLE)), 138 nid, K(node_page_state(nid, NR_UNSTABLE_NFS)), 139 nid, K(node_page_state(nid, NR_BOUNCE)), 140 nid, K(node_page_state(nid, NR_WRITEBACK_TEMP)), 141 nid, K(node_page_state(nid, NR_SLAB_RECLAIMABLE) + 142 node_page_state(nid, NR_SLAB_UNRECLAIMABLE)), 143 nid, K(node_page_state(nid, NR_SLAB_RECLAIMABLE)), 144 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 145 nid, K(node_page_state(nid, NR_SLAB_UNRECLAIMABLE)) 146 , nid, 147 K(node_page_state(nid, NR_ANON_TRANSPARENT_HUGEPAGES) * 148 HPAGE_PMD_NR)); 149 #else 150 nid, K(node_page_state(nid, NR_SLAB_UNRECLAIMABLE))); 151 #endif 152 n += hugetlb_report_node_meminfo(nid, buf + n); 153 return n; 154 } 155 156 #undef K 157 static DEVICE_ATTR(meminfo, S_IRUGO, node_read_meminfo, NULL); 158 159 static ssize_t node_read_numastat(struct device *dev, 160 struct device_attribute *attr, char *buf) 161 { 162 return sprintf(buf, 163 "numa_hit %lu\n" 164 "numa_miss %lu\n" 165 "numa_foreign %lu\n" 166 "interleave_hit %lu\n" 167 "local_node %lu\n" 168 "other_node %lu\n", 169 node_page_state(dev->id, NUMA_HIT), 170 node_page_state(dev->id, NUMA_MISS), 171 node_page_state(dev->id, NUMA_FOREIGN), 172 node_page_state(dev->id, NUMA_INTERLEAVE_HIT), 173 node_page_state(dev->id, NUMA_LOCAL), 174 node_page_state(dev->id, NUMA_OTHER)); 175 } 176 static DEVICE_ATTR(numastat, S_IRUGO, node_read_numastat, NULL); 177 178 static ssize_t node_read_vmstat(struct device *dev, 179 struct device_attribute *attr, char *buf) 180 { 181 int nid = dev->id; 182 int i; 183 int n = 0; 184 185 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) 186 n += sprintf(buf+n, "%s %lu\n", vmstat_text[i], 187 node_page_state(nid, 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 #ifdef CONFIG_HUGETLBFS 215 /* 216 * hugetlbfs per node attributes registration interface: 217 * When/if hugetlb[fs] subsystem initializes [sometime after this module], 218 * it will register its per node attributes for all online nodes with 219 * memory. It will also call register_hugetlbfs_with_node(), below, to 220 * register its attribute registration functions with this node driver. 221 * Once these hooks have been initialized, the node driver will call into 222 * the hugetlb module to [un]register attributes for hot-plugged nodes. 223 */ 224 static node_registration_func_t __hugetlb_register_node; 225 static node_registration_func_t __hugetlb_unregister_node; 226 227 static inline bool hugetlb_register_node(struct node *node) 228 { 229 if (__hugetlb_register_node && 230 node_state(node->dev.id, N_MEMORY)) { 231 __hugetlb_register_node(node); 232 return true; 233 } 234 return false; 235 } 236 237 static inline void hugetlb_unregister_node(struct node *node) 238 { 239 if (__hugetlb_unregister_node) 240 __hugetlb_unregister_node(node); 241 } 242 243 void register_hugetlbfs_with_node(node_registration_func_t doregister, 244 node_registration_func_t unregister) 245 { 246 __hugetlb_register_node = doregister; 247 __hugetlb_unregister_node = unregister; 248 } 249 #else 250 static inline void hugetlb_register_node(struct node *node) {} 251 252 static inline void hugetlb_unregister_node(struct node *node) {} 253 #endif 254 255 static void node_device_release(struct device *dev) 256 { 257 struct node *node = to_node(dev); 258 259 #if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HUGETLBFS) 260 /* 261 * We schedule the work only when a memory section is 262 * onlined/offlined on this node. When we come here, 263 * all the memory on this node has been offlined, 264 * so we won't enqueue new work to this work. 265 * 266 * The work is using node->node_work, so we should 267 * flush work before freeing the memory. 268 */ 269 flush_work(&node->node_work); 270 #endif 271 kfree(node); 272 } 273 274 /* 275 * register_node - Setup a sysfs device for a node. 276 * @num - Node number to use when creating the device. 277 * 278 * Initialize and register the node device. 279 */ 280 static int register_node(struct node *node, int num, struct node *parent) 281 { 282 int error; 283 284 node->dev.id = num; 285 node->dev.bus = &node_subsys; 286 node->dev.release = node_device_release; 287 error = device_register(&node->dev); 288 289 if (!error){ 290 device_create_file(&node->dev, &dev_attr_cpumap); 291 device_create_file(&node->dev, &dev_attr_cpulist); 292 device_create_file(&node->dev, &dev_attr_meminfo); 293 device_create_file(&node->dev, &dev_attr_numastat); 294 device_create_file(&node->dev, &dev_attr_distance); 295 device_create_file(&node->dev, &dev_attr_vmstat); 296 297 scan_unevictable_register_node(node); 298 299 hugetlb_register_node(node); 300 301 compaction_register_node(node); 302 } 303 return error; 304 } 305 306 /** 307 * unregister_node - unregister a node device 308 * @node: node going away 309 * 310 * Unregisters a node device @node. All the devices on the node must be 311 * unregistered before calling this function. 312 */ 313 void unregister_node(struct node *node) 314 { 315 device_remove_file(&node->dev, &dev_attr_cpumap); 316 device_remove_file(&node->dev, &dev_attr_cpulist); 317 device_remove_file(&node->dev, &dev_attr_meminfo); 318 device_remove_file(&node->dev, &dev_attr_numastat); 319 device_remove_file(&node->dev, &dev_attr_distance); 320 device_remove_file(&node->dev, &dev_attr_vmstat); 321 322 scan_unevictable_unregister_node(node); 323 hugetlb_unregister_node(node); /* no-op, if memoryless node */ 324 325 device_unregister(&node->dev); 326 } 327 328 struct node *node_devices[MAX_NUMNODES]; 329 330 /* 331 * register cpu under node 332 */ 333 int register_cpu_under_node(unsigned int cpu, unsigned int nid) 334 { 335 int ret; 336 struct device *obj; 337 338 if (!node_online(nid)) 339 return 0; 340 341 obj = get_cpu_device(cpu); 342 if (!obj) 343 return 0; 344 345 ret = sysfs_create_link(&node_devices[nid]->dev.kobj, 346 &obj->kobj, 347 kobject_name(&obj->kobj)); 348 if (ret) 349 return ret; 350 351 return sysfs_create_link(&obj->kobj, 352 &node_devices[nid]->dev.kobj, 353 kobject_name(&node_devices[nid]->dev.kobj)); 354 } 355 356 int unregister_cpu_under_node(unsigned int cpu, unsigned int nid) 357 { 358 struct device *obj; 359 360 if (!node_online(nid)) 361 return 0; 362 363 obj = get_cpu_device(cpu); 364 if (!obj) 365 return 0; 366 367 sysfs_remove_link(&node_devices[nid]->dev.kobj, 368 kobject_name(&obj->kobj)); 369 sysfs_remove_link(&obj->kobj, 370 kobject_name(&node_devices[nid]->dev.kobj)); 371 372 return 0; 373 } 374 375 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE 376 #define page_initialized(page) (page->lru.next) 377 378 static int get_nid_for_pfn(unsigned long pfn) 379 { 380 struct page *page; 381 382 if (!pfn_valid_within(pfn)) 383 return -1; 384 page = pfn_to_page(pfn); 385 if (!page_initialized(page)) 386 return -1; 387 return pfn_to_nid(pfn); 388 } 389 390 /* register memory section under specified node if it spans that node */ 391 int register_mem_sect_under_node(struct memory_block *mem_blk, int nid) 392 { 393 int ret; 394 unsigned long pfn, sect_start_pfn, sect_end_pfn; 395 396 if (!mem_blk) 397 return -EFAULT; 398 if (!node_online(nid)) 399 return 0; 400 401 sect_start_pfn = section_nr_to_pfn(mem_blk->start_section_nr); 402 sect_end_pfn = section_nr_to_pfn(mem_blk->end_section_nr); 403 sect_end_pfn += PAGES_PER_SECTION - 1; 404 for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) { 405 int page_nid; 406 407 page_nid = get_nid_for_pfn(pfn); 408 if (page_nid < 0) 409 continue; 410 if (page_nid != nid) 411 continue; 412 ret = sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj, 413 &mem_blk->dev.kobj, 414 kobject_name(&mem_blk->dev.kobj)); 415 if (ret) 416 return ret; 417 418 return sysfs_create_link_nowarn(&mem_blk->dev.kobj, 419 &node_devices[nid]->dev.kobj, 420 kobject_name(&node_devices[nid]->dev.kobj)); 421 } 422 /* mem section does not span the specified node */ 423 return 0; 424 } 425 426 /* unregister memory section under all nodes that it spans */ 427 int unregister_mem_sect_under_nodes(struct memory_block *mem_blk, 428 unsigned long phys_index) 429 { 430 NODEMASK_ALLOC(nodemask_t, unlinked_nodes, GFP_KERNEL); 431 unsigned long pfn, sect_start_pfn, sect_end_pfn; 432 433 if (!mem_blk) { 434 NODEMASK_FREE(unlinked_nodes); 435 return -EFAULT; 436 } 437 if (!unlinked_nodes) 438 return -ENOMEM; 439 nodes_clear(*unlinked_nodes); 440 441 sect_start_pfn = section_nr_to_pfn(phys_index); 442 sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1; 443 for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) { 444 int nid; 445 446 nid = get_nid_for_pfn(pfn); 447 if (nid < 0) 448 continue; 449 if (!node_online(nid)) 450 continue; 451 if (node_test_and_set(nid, *unlinked_nodes)) 452 continue; 453 sysfs_remove_link(&node_devices[nid]->dev.kobj, 454 kobject_name(&mem_blk->dev.kobj)); 455 sysfs_remove_link(&mem_blk->dev.kobj, 456 kobject_name(&node_devices[nid]->dev.kobj)); 457 } 458 NODEMASK_FREE(unlinked_nodes); 459 return 0; 460 } 461 462 static int link_mem_sections(int nid) 463 { 464 unsigned long start_pfn = NODE_DATA(nid)->node_start_pfn; 465 unsigned long end_pfn = start_pfn + NODE_DATA(nid)->node_spanned_pages; 466 unsigned long pfn; 467 struct memory_block *mem_blk = NULL; 468 int err = 0; 469 470 for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { 471 unsigned long section_nr = pfn_to_section_nr(pfn); 472 struct mem_section *mem_sect; 473 int ret; 474 475 if (!present_section_nr(section_nr)) 476 continue; 477 mem_sect = __nr_to_section(section_nr); 478 479 /* same memblock ? */ 480 if (mem_blk) 481 if ((section_nr >= mem_blk->start_section_nr) && 482 (section_nr <= mem_blk->end_section_nr)) 483 continue; 484 485 mem_blk = find_memory_block_hinted(mem_sect, mem_blk); 486 487 ret = register_mem_sect_under_node(mem_blk, nid); 488 if (!err) 489 err = ret; 490 491 /* discard ref obtained in find_memory_block() */ 492 } 493 494 if (mem_blk) 495 kobject_put(&mem_blk->dev.kobj); 496 return err; 497 } 498 499 #ifdef CONFIG_HUGETLBFS 500 /* 501 * Handle per node hstate attribute [un]registration on transistions 502 * to/from memoryless state. 503 */ 504 static void node_hugetlb_work(struct work_struct *work) 505 { 506 struct node *node = container_of(work, struct node, node_work); 507 508 /* 509 * We only get here when a node transitions to/from memoryless state. 510 * We can detect which transition occurred by examining whether the 511 * node has memory now. hugetlb_register_node() already check this 512 * so we try to register the attributes. If that fails, then the 513 * node has transitioned to memoryless, try to unregister the 514 * attributes. 515 */ 516 if (!hugetlb_register_node(node)) 517 hugetlb_unregister_node(node); 518 } 519 520 static void init_node_hugetlb_work(int nid) 521 { 522 INIT_WORK(&node_devices[nid]->node_work, node_hugetlb_work); 523 } 524 525 static int node_memory_callback(struct notifier_block *self, 526 unsigned long action, void *arg) 527 { 528 struct memory_notify *mnb = arg; 529 int nid = mnb->status_change_nid; 530 531 switch (action) { 532 case MEM_ONLINE: 533 case MEM_OFFLINE: 534 /* 535 * offload per node hstate [un]registration to a work thread 536 * when transitioning to/from memoryless state. 537 */ 538 if (nid != NUMA_NO_NODE) 539 schedule_work(&node_devices[nid]->node_work); 540 break; 541 542 case MEM_GOING_ONLINE: 543 case MEM_GOING_OFFLINE: 544 case MEM_CANCEL_ONLINE: 545 case MEM_CANCEL_OFFLINE: 546 default: 547 break; 548 } 549 550 return NOTIFY_OK; 551 } 552 #endif /* CONFIG_HUGETLBFS */ 553 #else /* !CONFIG_MEMORY_HOTPLUG_SPARSE */ 554 555 static int link_mem_sections(int nid) { return 0; } 556 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ 557 558 #if !defined(CONFIG_MEMORY_HOTPLUG_SPARSE) || \ 559 !defined(CONFIG_HUGETLBFS) 560 static inline int node_memory_callback(struct notifier_block *self, 561 unsigned long action, void *arg) 562 { 563 return NOTIFY_OK; 564 } 565 566 static void init_node_hugetlb_work(int nid) { } 567 568 #endif 569 570 int register_one_node(int nid) 571 { 572 int error = 0; 573 int cpu; 574 575 if (node_online(nid)) { 576 int p_node = parent_node(nid); 577 struct node *parent = NULL; 578 579 if (p_node != nid) 580 parent = node_devices[p_node]; 581 582 node_devices[nid] = kzalloc(sizeof(struct node), GFP_KERNEL); 583 if (!node_devices[nid]) 584 return -ENOMEM; 585 586 error = register_node(node_devices[nid], nid, parent); 587 588 /* link cpu under this node */ 589 for_each_present_cpu(cpu) { 590 if (cpu_to_node(cpu) == nid) 591 register_cpu_under_node(cpu, nid); 592 } 593 594 /* link memory sections under this node */ 595 error = link_mem_sections(nid); 596 597 /* initialize work queue for memory hot plug */ 598 init_node_hugetlb_work(nid); 599 } 600 601 return error; 602 603 } 604 605 void unregister_one_node(int nid) 606 { 607 unregister_node(node_devices[nid]); 608 node_devices[nid] = NULL; 609 } 610 611 /* 612 * node states attributes 613 */ 614 615 static ssize_t print_nodes_state(enum node_states state, char *buf) 616 { 617 int n; 618 619 n = nodelist_scnprintf(buf, PAGE_SIZE-2, node_states[state]); 620 buf[n++] = '\n'; 621 buf[n] = '\0'; 622 return n; 623 } 624 625 struct node_attr { 626 struct device_attribute attr; 627 enum node_states state; 628 }; 629 630 static ssize_t show_node_state(struct device *dev, 631 struct device_attribute *attr, char *buf) 632 { 633 struct node_attr *na = container_of(attr, struct node_attr, attr); 634 return print_nodes_state(na->state, buf); 635 } 636 637 #define _NODE_ATTR(name, state) \ 638 { __ATTR(name, 0444, show_node_state, NULL), state } 639 640 static struct node_attr node_state_attr[] = { 641 [N_POSSIBLE] = _NODE_ATTR(possible, N_POSSIBLE), 642 [N_ONLINE] = _NODE_ATTR(online, N_ONLINE), 643 [N_NORMAL_MEMORY] = _NODE_ATTR(has_normal_memory, N_NORMAL_MEMORY), 644 #ifdef CONFIG_HIGHMEM 645 [N_HIGH_MEMORY] = _NODE_ATTR(has_high_memory, N_HIGH_MEMORY), 646 #endif 647 #ifdef CONFIG_MOVABLE_NODE 648 [N_MEMORY] = _NODE_ATTR(has_memory, N_MEMORY), 649 #endif 650 [N_CPU] = _NODE_ATTR(has_cpu, N_CPU), 651 }; 652 653 static struct attribute *node_state_attrs[] = { 654 &node_state_attr[N_POSSIBLE].attr.attr, 655 &node_state_attr[N_ONLINE].attr.attr, 656 &node_state_attr[N_NORMAL_MEMORY].attr.attr, 657 #ifdef CONFIG_HIGHMEM 658 &node_state_attr[N_HIGH_MEMORY].attr.attr, 659 #endif 660 #ifdef CONFIG_MOVABLE_NODE 661 &node_state_attr[N_MEMORY].attr.attr, 662 #endif 663 &node_state_attr[N_CPU].attr.attr, 664 NULL 665 }; 666 667 static struct attribute_group memory_root_attr_group = { 668 .attrs = node_state_attrs, 669 }; 670 671 static const struct attribute_group *cpu_root_attr_groups[] = { 672 &memory_root_attr_group, 673 NULL, 674 }; 675 676 #define NODE_CALLBACK_PRI 2 /* lower than SLAB */ 677 static int __init register_node_type(void) 678 { 679 int ret; 680 681 BUILD_BUG_ON(ARRAY_SIZE(node_state_attr) != NR_NODE_STATES); 682 BUILD_BUG_ON(ARRAY_SIZE(node_state_attrs)-1 != NR_NODE_STATES); 683 684 ret = subsys_system_register(&node_subsys, cpu_root_attr_groups); 685 if (!ret) { 686 hotplug_memory_notifier(node_memory_callback, 687 NODE_CALLBACK_PRI); 688 } 689 690 /* 691 * Note: we're not going to unregister the node class if we fail 692 * to register the node state class attribute files. 693 */ 694 return ret; 695 } 696 postcore_initcall(register_node_type); 697