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_numa_state(dev->id, NUMA_HIT), 164 sum_zone_numa_state(dev->id, NUMA_MISS), 165 sum_zone_numa_state(dev->id, NUMA_FOREIGN), 166 sum_zone_numa_state(dev->id, NUMA_INTERLEAVE_HIT), 167 sum_zone_numa_state(dev->id, NUMA_LOCAL), 168 sum_zone_numa_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 #ifdef CONFIG_NUMA 185 for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++) 186 n += sprintf(buf+n, "%s %lu\n", 187 vmstat_text[i + NR_VM_ZONE_STAT_ITEMS], 188 sum_zone_numa_state(nid, i)); 189 #endif 190 191 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) 192 n += sprintf(buf+n, "%s %lu\n", 193 vmstat_text[i + NR_VM_ZONE_STAT_ITEMS + 194 NR_VM_NUMA_STAT_ITEMS], 195 node_page_state(pgdat, i)); 196 197 return n; 198 } 199 static DEVICE_ATTR(vmstat, S_IRUGO, node_read_vmstat, NULL); 200 201 static ssize_t node_read_distance(struct device *dev, 202 struct device_attribute *attr, char *buf) 203 { 204 int nid = dev->id; 205 int len = 0; 206 int i; 207 208 /* 209 * buf is currently PAGE_SIZE in length and each node needs 4 chars 210 * at the most (distance + space or newline). 211 */ 212 BUILD_BUG_ON(MAX_NUMNODES * 4 > PAGE_SIZE); 213 214 for_each_online_node(i) 215 len += sprintf(buf + len, "%s%d", i ? " " : "", node_distance(nid, i)); 216 217 len += sprintf(buf + len, "\n"); 218 return len; 219 } 220 static DEVICE_ATTR(distance, S_IRUGO, node_read_distance, NULL); 221 222 static struct attribute *node_dev_attrs[] = { 223 &dev_attr_cpumap.attr, 224 &dev_attr_cpulist.attr, 225 &dev_attr_meminfo.attr, 226 &dev_attr_numastat.attr, 227 &dev_attr_distance.attr, 228 &dev_attr_vmstat.attr, 229 NULL 230 }; 231 ATTRIBUTE_GROUPS(node_dev); 232 233 #ifdef CONFIG_HUGETLBFS 234 /* 235 * hugetlbfs per node attributes registration interface: 236 * When/if hugetlb[fs] subsystem initializes [sometime after this module], 237 * it will register its per node attributes for all online nodes with 238 * memory. It will also call register_hugetlbfs_with_node(), below, to 239 * register its attribute registration functions with this node driver. 240 * Once these hooks have been initialized, the node driver will call into 241 * the hugetlb module to [un]register attributes for hot-plugged nodes. 242 */ 243 static node_registration_func_t __hugetlb_register_node; 244 static node_registration_func_t __hugetlb_unregister_node; 245 246 static inline bool hugetlb_register_node(struct node *node) 247 { 248 if (__hugetlb_register_node && 249 node_state(node->dev.id, N_MEMORY)) { 250 __hugetlb_register_node(node); 251 return true; 252 } 253 return false; 254 } 255 256 static inline void hugetlb_unregister_node(struct node *node) 257 { 258 if (__hugetlb_unregister_node) 259 __hugetlb_unregister_node(node); 260 } 261 262 void register_hugetlbfs_with_node(node_registration_func_t doregister, 263 node_registration_func_t unregister) 264 { 265 __hugetlb_register_node = doregister; 266 __hugetlb_unregister_node = unregister; 267 } 268 #else 269 static inline void hugetlb_register_node(struct node *node) {} 270 271 static inline void hugetlb_unregister_node(struct node *node) {} 272 #endif 273 274 static void node_device_release(struct device *dev) 275 { 276 struct node *node = to_node(dev); 277 278 #if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HUGETLBFS) 279 /* 280 * We schedule the work only when a memory section is 281 * onlined/offlined on this node. When we come here, 282 * all the memory on this node has been offlined, 283 * so we won't enqueue new work to this work. 284 * 285 * The work is using node->node_work, so we should 286 * flush work before freeing the memory. 287 */ 288 flush_work(&node->node_work); 289 #endif 290 kfree(node); 291 } 292 293 /* 294 * register_node - Setup a sysfs device for a node. 295 * @num - Node number to use when creating the device. 296 * 297 * Initialize and register the node device. 298 */ 299 static int register_node(struct node *node, int num) 300 { 301 int error; 302 303 node->dev.id = num; 304 node->dev.bus = &node_subsys; 305 node->dev.release = node_device_release; 306 node->dev.groups = node_dev_groups; 307 error = device_register(&node->dev); 308 309 if (!error){ 310 hugetlb_register_node(node); 311 312 compaction_register_node(node); 313 } 314 return error; 315 } 316 317 /** 318 * unregister_node - unregister a node device 319 * @node: node going away 320 * 321 * Unregisters a node device @node. All the devices on the node must be 322 * unregistered before calling this function. 323 */ 324 void unregister_node(struct node *node) 325 { 326 hugetlb_unregister_node(node); /* no-op, if memoryless node */ 327 328 device_unregister(&node->dev); 329 } 330 331 struct node *node_devices[MAX_NUMNODES]; 332 333 /* 334 * register cpu under node 335 */ 336 int register_cpu_under_node(unsigned int cpu, unsigned int nid) 337 { 338 int ret; 339 struct device *obj; 340 341 if (!node_online(nid)) 342 return 0; 343 344 obj = get_cpu_device(cpu); 345 if (!obj) 346 return 0; 347 348 ret = sysfs_create_link(&node_devices[nid]->dev.kobj, 349 &obj->kobj, 350 kobject_name(&obj->kobj)); 351 if (ret) 352 return ret; 353 354 return sysfs_create_link(&obj->kobj, 355 &node_devices[nid]->dev.kobj, 356 kobject_name(&node_devices[nid]->dev.kobj)); 357 } 358 359 int unregister_cpu_under_node(unsigned int cpu, unsigned int nid) 360 { 361 struct device *obj; 362 363 if (!node_online(nid)) 364 return 0; 365 366 obj = get_cpu_device(cpu); 367 if (!obj) 368 return 0; 369 370 sysfs_remove_link(&node_devices[nid]->dev.kobj, 371 kobject_name(&obj->kobj)); 372 sysfs_remove_link(&obj->kobj, 373 kobject_name(&node_devices[nid]->dev.kobj)); 374 375 return 0; 376 } 377 378 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE 379 static int __ref get_nid_for_pfn(unsigned long pfn) 380 { 381 if (!pfn_valid_within(pfn)) 382 return -1; 383 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT 384 if (system_state < SYSTEM_RUNNING) 385 return early_pfn_to_nid(pfn); 386 #endif 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 /* 408 * memory block could have several absent sections from start. 409 * skip pfn range from absent section 410 */ 411 if (!pfn_present(pfn)) { 412 pfn = round_down(pfn + PAGES_PER_SECTION, 413 PAGES_PER_SECTION) - 1; 414 continue; 415 } 416 417 page_nid = get_nid_for_pfn(pfn); 418 if (page_nid < 0) 419 continue; 420 if (page_nid != nid) 421 continue; 422 ret = sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj, 423 &mem_blk->dev.kobj, 424 kobject_name(&mem_blk->dev.kobj)); 425 if (ret) 426 return ret; 427 428 return sysfs_create_link_nowarn(&mem_blk->dev.kobj, 429 &node_devices[nid]->dev.kobj, 430 kobject_name(&node_devices[nid]->dev.kobj)); 431 } 432 /* mem section does not span the specified node */ 433 return 0; 434 } 435 436 /* unregister memory section under all nodes that it spans */ 437 int unregister_mem_sect_under_nodes(struct memory_block *mem_blk, 438 unsigned long phys_index) 439 { 440 NODEMASK_ALLOC(nodemask_t, unlinked_nodes, GFP_KERNEL); 441 unsigned long pfn, sect_start_pfn, sect_end_pfn; 442 443 if (!mem_blk) { 444 NODEMASK_FREE(unlinked_nodes); 445 return -EFAULT; 446 } 447 if (!unlinked_nodes) 448 return -ENOMEM; 449 nodes_clear(*unlinked_nodes); 450 451 sect_start_pfn = section_nr_to_pfn(phys_index); 452 sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1; 453 for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) { 454 int nid; 455 456 nid = get_nid_for_pfn(pfn); 457 if (nid < 0) 458 continue; 459 if (!node_online(nid)) 460 continue; 461 if (node_test_and_set(nid, *unlinked_nodes)) 462 continue; 463 sysfs_remove_link(&node_devices[nid]->dev.kobj, 464 kobject_name(&mem_blk->dev.kobj)); 465 sysfs_remove_link(&mem_blk->dev.kobj, 466 kobject_name(&node_devices[nid]->dev.kobj)); 467 } 468 NODEMASK_FREE(unlinked_nodes); 469 return 0; 470 } 471 472 int link_mem_sections(int nid, unsigned long start_pfn, unsigned long nr_pages) 473 { 474 unsigned long end_pfn = start_pfn + nr_pages; 475 unsigned long pfn; 476 struct memory_block *mem_blk = NULL; 477 int err = 0; 478 479 for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { 480 unsigned long section_nr = pfn_to_section_nr(pfn); 481 struct mem_section *mem_sect; 482 int ret; 483 484 if (!present_section_nr(section_nr)) 485 continue; 486 mem_sect = __nr_to_section(section_nr); 487 488 /* same memblock ? */ 489 if (mem_blk) 490 if ((section_nr >= mem_blk->start_section_nr) && 491 (section_nr <= mem_blk->end_section_nr)) 492 continue; 493 494 mem_blk = find_memory_block_hinted(mem_sect, mem_blk); 495 496 ret = register_mem_sect_under_node(mem_blk, nid); 497 if (!err) 498 err = ret; 499 500 /* discard ref obtained in find_memory_block() */ 501 } 502 503 if (mem_blk) 504 kobject_put(&mem_blk->dev.kobj); 505 return err; 506 } 507 508 #ifdef CONFIG_HUGETLBFS 509 /* 510 * Handle per node hstate attribute [un]registration on transistions 511 * to/from memoryless state. 512 */ 513 static void node_hugetlb_work(struct work_struct *work) 514 { 515 struct node *node = container_of(work, struct node, node_work); 516 517 /* 518 * We only get here when a node transitions to/from memoryless state. 519 * We can detect which transition occurred by examining whether the 520 * node has memory now. hugetlb_register_node() already check this 521 * so we try to register the attributes. If that fails, then the 522 * node has transitioned to memoryless, try to unregister the 523 * attributes. 524 */ 525 if (!hugetlb_register_node(node)) 526 hugetlb_unregister_node(node); 527 } 528 529 static void init_node_hugetlb_work(int nid) 530 { 531 INIT_WORK(&node_devices[nid]->node_work, node_hugetlb_work); 532 } 533 534 static int node_memory_callback(struct notifier_block *self, 535 unsigned long action, void *arg) 536 { 537 struct memory_notify *mnb = arg; 538 int nid = mnb->status_change_nid; 539 540 switch (action) { 541 case MEM_ONLINE: 542 case MEM_OFFLINE: 543 /* 544 * offload per node hstate [un]registration to a work thread 545 * when transitioning to/from memoryless state. 546 */ 547 if (nid != NUMA_NO_NODE) 548 schedule_work(&node_devices[nid]->node_work); 549 break; 550 551 case MEM_GOING_ONLINE: 552 case MEM_GOING_OFFLINE: 553 case MEM_CANCEL_ONLINE: 554 case MEM_CANCEL_OFFLINE: 555 default: 556 break; 557 } 558 559 return NOTIFY_OK; 560 } 561 #endif /* CONFIG_HUGETLBFS */ 562 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ 563 564 #if !defined(CONFIG_MEMORY_HOTPLUG_SPARSE) || \ 565 !defined(CONFIG_HUGETLBFS) 566 static inline int node_memory_callback(struct notifier_block *self, 567 unsigned long action, void *arg) 568 { 569 return NOTIFY_OK; 570 } 571 572 static void init_node_hugetlb_work(int nid) { } 573 574 #endif 575 576 int __register_one_node(int nid) 577 { 578 int error; 579 int cpu; 580 581 node_devices[nid] = kzalloc(sizeof(struct node), GFP_KERNEL); 582 if (!node_devices[nid]) 583 return -ENOMEM; 584 585 error = register_node(node_devices[nid], nid); 586 587 /* link cpu under this node */ 588 for_each_present_cpu(cpu) { 589 if (cpu_to_node(cpu) == nid) 590 register_cpu_under_node(cpu, nid); 591 } 592 593 /* initialize work queue for memory hot plug */ 594 init_node_hugetlb_work(nid); 595 596 return error; 597 } 598 599 void unregister_one_node(int nid) 600 { 601 if (!node_devices[nid]) 602 return; 603 604 unregister_node(node_devices[nid]); 605 node_devices[nid] = NULL; 606 } 607 608 /* 609 * node states attributes 610 */ 611 612 static ssize_t print_nodes_state(enum node_states state, char *buf) 613 { 614 int n; 615 616 n = scnprintf(buf, PAGE_SIZE - 1, "%*pbl", 617 nodemask_pr_args(&node_states[state])); 618 buf[n++] = '\n'; 619 buf[n] = '\0'; 620 return n; 621 } 622 623 struct node_attr { 624 struct device_attribute attr; 625 enum node_states state; 626 }; 627 628 static ssize_t show_node_state(struct device *dev, 629 struct device_attribute *attr, char *buf) 630 { 631 struct node_attr *na = container_of(attr, struct node_attr, attr); 632 return print_nodes_state(na->state, buf); 633 } 634 635 #define _NODE_ATTR(name, state) \ 636 { __ATTR(name, 0444, show_node_state, NULL), state } 637 638 static struct node_attr node_state_attr[] = { 639 [N_POSSIBLE] = _NODE_ATTR(possible, N_POSSIBLE), 640 [N_ONLINE] = _NODE_ATTR(online, N_ONLINE), 641 [N_NORMAL_MEMORY] = _NODE_ATTR(has_normal_memory, N_NORMAL_MEMORY), 642 #ifdef CONFIG_HIGHMEM 643 [N_HIGH_MEMORY] = _NODE_ATTR(has_high_memory, N_HIGH_MEMORY), 644 #endif 645 [N_MEMORY] = _NODE_ATTR(has_memory, N_MEMORY), 646 [N_CPU] = _NODE_ATTR(has_cpu, N_CPU), 647 }; 648 649 static struct attribute *node_state_attrs[] = { 650 &node_state_attr[N_POSSIBLE].attr.attr, 651 &node_state_attr[N_ONLINE].attr.attr, 652 &node_state_attr[N_NORMAL_MEMORY].attr.attr, 653 #ifdef CONFIG_HIGHMEM 654 &node_state_attr[N_HIGH_MEMORY].attr.attr, 655 #endif 656 &node_state_attr[N_MEMORY].attr.attr, 657 &node_state_attr[N_CPU].attr.attr, 658 NULL 659 }; 660 661 static struct attribute_group memory_root_attr_group = { 662 .attrs = node_state_attrs, 663 }; 664 665 static const struct attribute_group *cpu_root_attr_groups[] = { 666 &memory_root_attr_group, 667 NULL, 668 }; 669 670 #define NODE_CALLBACK_PRI 2 /* lower than SLAB */ 671 static int __init register_node_type(void) 672 { 673 int ret; 674 675 BUILD_BUG_ON(ARRAY_SIZE(node_state_attr) != NR_NODE_STATES); 676 BUILD_BUG_ON(ARRAY_SIZE(node_state_attrs)-1 != NR_NODE_STATES); 677 678 ret = subsys_system_register(&node_subsys, cpu_root_attr_groups); 679 if (!ret) { 680 static struct notifier_block node_memory_callback_nb = { 681 .notifier_call = node_memory_callback, 682 .priority = NODE_CALLBACK_PRI, 683 }; 684 register_hotmemory_notifier(&node_memory_callback_nb); 685 } 686 687 /* 688 * Note: we're not going to unregister the node class if we fail 689 * to register the node state class attribute files. 690 */ 691 return ret; 692 } 693 postcore_initcall(register_node_type); 694