1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Basic Node interface support 4 */ 5 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/notifier.h> 12 #include <linux/node.h> 13 #include <linux/hugetlb.h> 14 #include <linux/compaction.h> 15 #include <linux/cpumask.h> 16 #include <linux/topology.h> 17 #include <linux/nodemask.h> 18 #include <linux/cpu.h> 19 #include <linux/device.h> 20 #include <linux/swap.h> 21 #include <linux/slab.h> 22 23 static struct bus_type node_subsys = { 24 .name = "node", 25 .dev_name = "node", 26 }; 27 28 29 static ssize_t node_read_cpumap(struct device *dev, bool list, char *buf) 30 { 31 ssize_t n; 32 cpumask_var_t mask; 33 struct node *node_dev = to_node(dev); 34 35 /* 2008/04/07: buf currently PAGE_SIZE, need 9 chars per 32 bits. */ 36 BUILD_BUG_ON((NR_CPUS/32 * 9) > (PAGE_SIZE-1)); 37 38 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) 39 return 0; 40 41 cpumask_and(mask, cpumask_of_node(node_dev->dev.id), cpu_online_mask); 42 n = cpumap_print_to_pagebuf(list, buf, mask); 43 free_cpumask_var(mask); 44 45 return n; 46 } 47 48 static inline ssize_t node_read_cpumask(struct device *dev, 49 struct device_attribute *attr, char *buf) 50 { 51 return node_read_cpumap(dev, false, buf); 52 } 53 static inline ssize_t node_read_cpulist(struct device *dev, 54 struct device_attribute *attr, char *buf) 55 { 56 return node_read_cpumap(dev, true, buf); 57 } 58 59 static DEVICE_ATTR(cpumap, S_IRUGO, node_read_cpumask, NULL); 60 static DEVICE_ATTR(cpulist, S_IRUGO, node_read_cpulist, NULL); 61 62 #define K(x) ((x) << (PAGE_SHIFT - 10)) 63 static ssize_t node_read_meminfo(struct device *dev, 64 struct device_attribute *attr, char *buf) 65 { 66 int n; 67 int nid = dev->id; 68 struct pglist_data *pgdat = NODE_DATA(nid); 69 struct sysinfo i; 70 71 si_meminfo_node(&i, nid); 72 n = sprintf(buf, 73 "Node %d MemTotal: %8lu kB\n" 74 "Node %d MemFree: %8lu kB\n" 75 "Node %d MemUsed: %8lu kB\n" 76 "Node %d Active: %8lu kB\n" 77 "Node %d Inactive: %8lu kB\n" 78 "Node %d Active(anon): %8lu kB\n" 79 "Node %d Inactive(anon): %8lu kB\n" 80 "Node %d Active(file): %8lu kB\n" 81 "Node %d Inactive(file): %8lu kB\n" 82 "Node %d Unevictable: %8lu kB\n" 83 "Node %d Mlocked: %8lu kB\n", 84 nid, K(i.totalram), 85 nid, K(i.freeram), 86 nid, K(i.totalram - i.freeram), 87 nid, K(node_page_state(pgdat, NR_ACTIVE_ANON) + 88 node_page_state(pgdat, NR_ACTIVE_FILE)), 89 nid, K(node_page_state(pgdat, NR_INACTIVE_ANON) + 90 node_page_state(pgdat, NR_INACTIVE_FILE)), 91 nid, K(node_page_state(pgdat, NR_ACTIVE_ANON)), 92 nid, K(node_page_state(pgdat, NR_INACTIVE_ANON)), 93 nid, K(node_page_state(pgdat, NR_ACTIVE_FILE)), 94 nid, K(node_page_state(pgdat, NR_INACTIVE_FILE)), 95 nid, K(node_page_state(pgdat, NR_UNEVICTABLE)), 96 nid, K(sum_zone_node_page_state(nid, NR_MLOCK))); 97 98 #ifdef CONFIG_HIGHMEM 99 n += sprintf(buf + n, 100 "Node %d HighTotal: %8lu kB\n" 101 "Node %d HighFree: %8lu kB\n" 102 "Node %d LowTotal: %8lu kB\n" 103 "Node %d LowFree: %8lu kB\n", 104 nid, K(i.totalhigh), 105 nid, K(i.freehigh), 106 nid, K(i.totalram - i.totalhigh), 107 nid, K(i.freeram - i.freehigh)); 108 #endif 109 n += sprintf(buf + n, 110 "Node %d Dirty: %8lu kB\n" 111 "Node %d Writeback: %8lu kB\n" 112 "Node %d FilePages: %8lu kB\n" 113 "Node %d Mapped: %8lu kB\n" 114 "Node %d AnonPages: %8lu kB\n" 115 "Node %d Shmem: %8lu kB\n" 116 "Node %d KernelStack: %8lu kB\n" 117 "Node %d PageTables: %8lu kB\n" 118 "Node %d NFS_Unstable: %8lu kB\n" 119 "Node %d Bounce: %8lu kB\n" 120 "Node %d WritebackTmp: %8lu kB\n" 121 "Node %d Slab: %8lu kB\n" 122 "Node %d SReclaimable: %8lu kB\n" 123 "Node %d SUnreclaim: %8lu kB\n" 124 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 125 "Node %d AnonHugePages: %8lu kB\n" 126 "Node %d ShmemHugePages: %8lu kB\n" 127 "Node %d ShmemPmdMapped: %8lu kB\n" 128 #endif 129 , 130 nid, K(node_page_state(pgdat, NR_FILE_DIRTY)), 131 nid, K(node_page_state(pgdat, NR_WRITEBACK)), 132 nid, K(node_page_state(pgdat, NR_FILE_PAGES)), 133 nid, K(node_page_state(pgdat, NR_FILE_MAPPED)), 134 nid, K(node_page_state(pgdat, NR_ANON_MAPPED)), 135 nid, K(i.sharedram), 136 nid, sum_zone_node_page_state(nid, NR_KERNEL_STACK_KB), 137 nid, K(sum_zone_node_page_state(nid, NR_PAGETABLE)), 138 nid, K(node_page_state(pgdat, NR_UNSTABLE_NFS)), 139 nid, K(sum_zone_node_page_state(nid, NR_BOUNCE)), 140 nid, K(node_page_state(pgdat, NR_WRITEBACK_TEMP)), 141 nid, K(node_page_state(pgdat, NR_SLAB_RECLAIMABLE) + 142 node_page_state(pgdat, NR_SLAB_UNRECLAIMABLE)), 143 nid, K(node_page_state(pgdat, NR_SLAB_RECLAIMABLE)), 144 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 145 nid, K(node_page_state(pgdat, NR_SLAB_UNRECLAIMABLE)), 146 nid, K(node_page_state(pgdat, NR_ANON_THPS) * 147 HPAGE_PMD_NR), 148 nid, K(node_page_state(pgdat, NR_SHMEM_THPS) * 149 HPAGE_PMD_NR), 150 nid, K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED) * 151 HPAGE_PMD_NR)); 152 #else 153 nid, K(node_page_state(pgdat, NR_SLAB_UNRECLAIMABLE))); 154 #endif 155 n += hugetlb_report_node_meminfo(nid, buf + n); 156 return n; 157 } 158 159 #undef K 160 static DEVICE_ATTR(meminfo, S_IRUGO, node_read_meminfo, NULL); 161 162 static ssize_t node_read_numastat(struct device *dev, 163 struct device_attribute *attr, char *buf) 164 { 165 return sprintf(buf, 166 "numa_hit %lu\n" 167 "numa_miss %lu\n" 168 "numa_foreign %lu\n" 169 "interleave_hit %lu\n" 170 "local_node %lu\n" 171 "other_node %lu\n", 172 sum_zone_numa_state(dev->id, NUMA_HIT), 173 sum_zone_numa_state(dev->id, NUMA_MISS), 174 sum_zone_numa_state(dev->id, NUMA_FOREIGN), 175 sum_zone_numa_state(dev->id, NUMA_INTERLEAVE_HIT), 176 sum_zone_numa_state(dev->id, NUMA_LOCAL), 177 sum_zone_numa_state(dev->id, NUMA_OTHER)); 178 } 179 static DEVICE_ATTR(numastat, S_IRUGO, node_read_numastat, NULL); 180 181 static ssize_t node_read_vmstat(struct device *dev, 182 struct device_attribute *attr, char *buf) 183 { 184 int nid = dev->id; 185 struct pglist_data *pgdat = NODE_DATA(nid); 186 int i; 187 int n = 0; 188 189 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) 190 n += sprintf(buf+n, "%s %lu\n", vmstat_text[i], 191 sum_zone_node_page_state(nid, i)); 192 193 #ifdef CONFIG_NUMA 194 for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++) 195 n += sprintf(buf+n, "%s %lu\n", 196 vmstat_text[i + NR_VM_ZONE_STAT_ITEMS], 197 sum_zone_numa_state(nid, i)); 198 #endif 199 200 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) 201 n += sprintf(buf+n, "%s %lu\n", 202 vmstat_text[i + NR_VM_ZONE_STAT_ITEMS + 203 NR_VM_NUMA_STAT_ITEMS], 204 node_page_state(pgdat, i)); 205 206 return n; 207 } 208 static DEVICE_ATTR(vmstat, S_IRUGO, node_read_vmstat, NULL); 209 210 static ssize_t node_read_distance(struct device *dev, 211 struct device_attribute *attr, char *buf) 212 { 213 int nid = dev->id; 214 int len = 0; 215 int i; 216 217 /* 218 * buf is currently PAGE_SIZE in length and each node needs 4 chars 219 * at the most (distance + space or newline). 220 */ 221 BUILD_BUG_ON(MAX_NUMNODES * 4 > PAGE_SIZE); 222 223 for_each_online_node(i) 224 len += sprintf(buf + len, "%s%d", i ? " " : "", node_distance(nid, i)); 225 226 len += sprintf(buf + len, "\n"); 227 return len; 228 } 229 static DEVICE_ATTR(distance, S_IRUGO, node_read_distance, NULL); 230 231 static struct attribute *node_dev_attrs[] = { 232 &dev_attr_cpumap.attr, 233 &dev_attr_cpulist.attr, 234 &dev_attr_meminfo.attr, 235 &dev_attr_numastat.attr, 236 &dev_attr_distance.attr, 237 &dev_attr_vmstat.attr, 238 NULL 239 }; 240 ATTRIBUTE_GROUPS(node_dev); 241 242 #ifdef CONFIG_HUGETLBFS 243 /* 244 * hugetlbfs per node attributes registration interface: 245 * When/if hugetlb[fs] subsystem initializes [sometime after this module], 246 * it will register its per node attributes for all online nodes with 247 * memory. It will also call register_hugetlbfs_with_node(), below, to 248 * register its attribute registration functions with this node driver. 249 * Once these hooks have been initialized, the node driver will call into 250 * the hugetlb module to [un]register attributes for hot-plugged nodes. 251 */ 252 static node_registration_func_t __hugetlb_register_node; 253 static node_registration_func_t __hugetlb_unregister_node; 254 255 static inline bool hugetlb_register_node(struct node *node) 256 { 257 if (__hugetlb_register_node && 258 node_state(node->dev.id, N_MEMORY)) { 259 __hugetlb_register_node(node); 260 return true; 261 } 262 return false; 263 } 264 265 static inline void hugetlb_unregister_node(struct node *node) 266 { 267 if (__hugetlb_unregister_node) 268 __hugetlb_unregister_node(node); 269 } 270 271 void register_hugetlbfs_with_node(node_registration_func_t doregister, 272 node_registration_func_t unregister) 273 { 274 __hugetlb_register_node = doregister; 275 __hugetlb_unregister_node = unregister; 276 } 277 #else 278 static inline void hugetlb_register_node(struct node *node) {} 279 280 static inline void hugetlb_unregister_node(struct node *node) {} 281 #endif 282 283 static void node_device_release(struct device *dev) 284 { 285 struct node *node = to_node(dev); 286 287 #if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HUGETLBFS) 288 /* 289 * We schedule the work only when a memory section is 290 * onlined/offlined on this node. When we come here, 291 * all the memory on this node has been offlined, 292 * so we won't enqueue new work to this work. 293 * 294 * The work is using node->node_work, so we should 295 * flush work before freeing the memory. 296 */ 297 flush_work(&node->node_work); 298 #endif 299 kfree(node); 300 } 301 302 /* 303 * register_node - Setup a sysfs device for a node. 304 * @num - Node number to use when creating the device. 305 * 306 * Initialize and register the node device. 307 */ 308 static int register_node(struct node *node, int num) 309 { 310 int error; 311 312 node->dev.id = num; 313 node->dev.bus = &node_subsys; 314 node->dev.release = node_device_release; 315 node->dev.groups = node_dev_groups; 316 error = device_register(&node->dev); 317 318 if (!error){ 319 hugetlb_register_node(node); 320 321 compaction_register_node(node); 322 } 323 return error; 324 } 325 326 /** 327 * unregister_node - unregister a node device 328 * @node: node going away 329 * 330 * Unregisters a node device @node. All the devices on the node must be 331 * unregistered before calling this function. 332 */ 333 void unregister_node(struct node *node) 334 { 335 hugetlb_unregister_node(node); /* no-op, if memoryless node */ 336 337 device_unregister(&node->dev); 338 } 339 340 struct node *node_devices[MAX_NUMNODES]; 341 342 /* 343 * register cpu under node 344 */ 345 int register_cpu_under_node(unsigned int cpu, unsigned int nid) 346 { 347 int ret; 348 struct device *obj; 349 350 if (!node_online(nid)) 351 return 0; 352 353 obj = get_cpu_device(cpu); 354 if (!obj) 355 return 0; 356 357 ret = sysfs_create_link(&node_devices[nid]->dev.kobj, 358 &obj->kobj, 359 kobject_name(&obj->kobj)); 360 if (ret) 361 return ret; 362 363 return sysfs_create_link(&obj->kobj, 364 &node_devices[nid]->dev.kobj, 365 kobject_name(&node_devices[nid]->dev.kobj)); 366 } 367 368 int unregister_cpu_under_node(unsigned int cpu, unsigned int nid) 369 { 370 struct device *obj; 371 372 if (!node_online(nid)) 373 return 0; 374 375 obj = get_cpu_device(cpu); 376 if (!obj) 377 return 0; 378 379 sysfs_remove_link(&node_devices[nid]->dev.kobj, 380 kobject_name(&obj->kobj)); 381 sysfs_remove_link(&obj->kobj, 382 kobject_name(&node_devices[nid]->dev.kobj)); 383 384 return 0; 385 } 386 387 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE 388 static int __ref get_nid_for_pfn(unsigned long pfn) 389 { 390 if (!pfn_valid_within(pfn)) 391 return -1; 392 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT 393 if (system_state < SYSTEM_RUNNING) 394 return early_pfn_to_nid(pfn); 395 #endif 396 return pfn_to_nid(pfn); 397 } 398 399 /* register memory section under specified node if it spans that node */ 400 int register_mem_sect_under_node(struct memory_block *mem_blk, int nid) 401 { 402 int ret; 403 unsigned long pfn, sect_start_pfn, sect_end_pfn; 404 405 if (!mem_blk) 406 return -EFAULT; 407 if (!node_online(nid)) 408 return 0; 409 410 sect_start_pfn = section_nr_to_pfn(mem_blk->start_section_nr); 411 sect_end_pfn = section_nr_to_pfn(mem_blk->end_section_nr); 412 sect_end_pfn += PAGES_PER_SECTION - 1; 413 for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) { 414 int page_nid; 415 416 /* 417 * memory block could have several absent sections from start. 418 * skip pfn range from absent section 419 */ 420 if (!pfn_present(pfn)) { 421 pfn = round_down(pfn + PAGES_PER_SECTION, 422 PAGES_PER_SECTION) - 1; 423 continue; 424 } 425 426 page_nid = get_nid_for_pfn(pfn); 427 if (page_nid < 0) 428 continue; 429 if (page_nid != nid) 430 continue; 431 ret = sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj, 432 &mem_blk->dev.kobj, 433 kobject_name(&mem_blk->dev.kobj)); 434 if (ret) 435 return ret; 436 437 return sysfs_create_link_nowarn(&mem_blk->dev.kobj, 438 &node_devices[nid]->dev.kobj, 439 kobject_name(&node_devices[nid]->dev.kobj)); 440 } 441 /* mem section does not span the specified node */ 442 return 0; 443 } 444 445 /* unregister memory section under all nodes that it spans */ 446 int unregister_mem_sect_under_nodes(struct memory_block *mem_blk, 447 unsigned long phys_index) 448 { 449 NODEMASK_ALLOC(nodemask_t, unlinked_nodes, GFP_KERNEL); 450 unsigned long pfn, sect_start_pfn, sect_end_pfn; 451 452 if (!mem_blk) { 453 NODEMASK_FREE(unlinked_nodes); 454 return -EFAULT; 455 } 456 if (!unlinked_nodes) 457 return -ENOMEM; 458 nodes_clear(*unlinked_nodes); 459 460 sect_start_pfn = section_nr_to_pfn(phys_index); 461 sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1; 462 for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) { 463 int nid; 464 465 nid = get_nid_for_pfn(pfn); 466 if (nid < 0) 467 continue; 468 if (!node_online(nid)) 469 continue; 470 if (node_test_and_set(nid, *unlinked_nodes)) 471 continue; 472 sysfs_remove_link(&node_devices[nid]->dev.kobj, 473 kobject_name(&mem_blk->dev.kobj)); 474 sysfs_remove_link(&mem_blk->dev.kobj, 475 kobject_name(&node_devices[nid]->dev.kobj)); 476 } 477 NODEMASK_FREE(unlinked_nodes); 478 return 0; 479 } 480 481 int link_mem_sections(int nid, unsigned long start_pfn, unsigned long nr_pages) 482 { 483 unsigned long end_pfn = start_pfn + nr_pages; 484 unsigned long pfn; 485 struct memory_block *mem_blk = NULL; 486 int err = 0; 487 488 for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { 489 unsigned long section_nr = pfn_to_section_nr(pfn); 490 struct mem_section *mem_sect; 491 int ret; 492 493 if (!present_section_nr(section_nr)) 494 continue; 495 mem_sect = __nr_to_section(section_nr); 496 497 /* same memblock ? */ 498 if (mem_blk) 499 if ((section_nr >= mem_blk->start_section_nr) && 500 (section_nr <= mem_blk->end_section_nr)) 501 continue; 502 503 mem_blk = find_memory_block_hinted(mem_sect, mem_blk); 504 505 ret = register_mem_sect_under_node(mem_blk, nid); 506 if (!err) 507 err = ret; 508 509 /* discard ref obtained in find_memory_block() */ 510 } 511 512 if (mem_blk) 513 kobject_put(&mem_blk->dev.kobj); 514 return err; 515 } 516 517 #ifdef CONFIG_HUGETLBFS 518 /* 519 * Handle per node hstate attribute [un]registration on transistions 520 * to/from memoryless state. 521 */ 522 static void node_hugetlb_work(struct work_struct *work) 523 { 524 struct node *node = container_of(work, struct node, node_work); 525 526 /* 527 * We only get here when a node transitions to/from memoryless state. 528 * We can detect which transition occurred by examining whether the 529 * node has memory now. hugetlb_register_node() already check this 530 * so we try to register the attributes. If that fails, then the 531 * node has transitioned to memoryless, try to unregister the 532 * attributes. 533 */ 534 if (!hugetlb_register_node(node)) 535 hugetlb_unregister_node(node); 536 } 537 538 static void init_node_hugetlb_work(int nid) 539 { 540 INIT_WORK(&node_devices[nid]->node_work, node_hugetlb_work); 541 } 542 543 static int node_memory_callback(struct notifier_block *self, 544 unsigned long action, void *arg) 545 { 546 struct memory_notify *mnb = arg; 547 int nid = mnb->status_change_nid; 548 549 switch (action) { 550 case MEM_ONLINE: 551 case MEM_OFFLINE: 552 /* 553 * offload per node hstate [un]registration to a work thread 554 * when transitioning to/from memoryless state. 555 */ 556 if (nid != NUMA_NO_NODE) 557 schedule_work(&node_devices[nid]->node_work); 558 break; 559 560 case MEM_GOING_ONLINE: 561 case MEM_GOING_OFFLINE: 562 case MEM_CANCEL_ONLINE: 563 case MEM_CANCEL_OFFLINE: 564 default: 565 break; 566 } 567 568 return NOTIFY_OK; 569 } 570 #endif /* CONFIG_HUGETLBFS */ 571 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ 572 573 #if !defined(CONFIG_MEMORY_HOTPLUG_SPARSE) || \ 574 !defined(CONFIG_HUGETLBFS) 575 static inline int node_memory_callback(struct notifier_block *self, 576 unsigned long action, void *arg) 577 { 578 return NOTIFY_OK; 579 } 580 581 static void init_node_hugetlb_work(int nid) { } 582 583 #endif 584 585 int __register_one_node(int nid) 586 { 587 int error; 588 int cpu; 589 590 node_devices[nid] = kzalloc(sizeof(struct node), GFP_KERNEL); 591 if (!node_devices[nid]) 592 return -ENOMEM; 593 594 error = register_node(node_devices[nid], nid); 595 596 /* link cpu under this node */ 597 for_each_present_cpu(cpu) { 598 if (cpu_to_node(cpu) == nid) 599 register_cpu_under_node(cpu, nid); 600 } 601 602 /* initialize work queue for memory hot plug */ 603 init_node_hugetlb_work(nid); 604 605 return error; 606 } 607 608 void unregister_one_node(int nid) 609 { 610 if (!node_devices[nid]) 611 return; 612 613 unregister_node(node_devices[nid]); 614 node_devices[nid] = NULL; 615 } 616 617 /* 618 * node states attributes 619 */ 620 621 static ssize_t print_nodes_state(enum node_states state, char *buf) 622 { 623 int n; 624 625 n = scnprintf(buf, PAGE_SIZE - 1, "%*pbl", 626 nodemask_pr_args(&node_states[state])); 627 buf[n++] = '\n'; 628 buf[n] = '\0'; 629 return n; 630 } 631 632 struct node_attr { 633 struct device_attribute attr; 634 enum node_states state; 635 }; 636 637 static ssize_t show_node_state(struct device *dev, 638 struct device_attribute *attr, char *buf) 639 { 640 struct node_attr *na = container_of(attr, struct node_attr, attr); 641 return print_nodes_state(na->state, buf); 642 } 643 644 #define _NODE_ATTR(name, state) \ 645 { __ATTR(name, 0444, show_node_state, NULL), state } 646 647 static struct node_attr node_state_attr[] = { 648 [N_POSSIBLE] = _NODE_ATTR(possible, N_POSSIBLE), 649 [N_ONLINE] = _NODE_ATTR(online, N_ONLINE), 650 [N_NORMAL_MEMORY] = _NODE_ATTR(has_normal_memory, N_NORMAL_MEMORY), 651 #ifdef CONFIG_HIGHMEM 652 [N_HIGH_MEMORY] = _NODE_ATTR(has_high_memory, N_HIGH_MEMORY), 653 #endif 654 [N_MEMORY] = _NODE_ATTR(has_memory, N_MEMORY), 655 [N_CPU] = _NODE_ATTR(has_cpu, N_CPU), 656 }; 657 658 static struct attribute *node_state_attrs[] = { 659 &node_state_attr[N_POSSIBLE].attr.attr, 660 &node_state_attr[N_ONLINE].attr.attr, 661 &node_state_attr[N_NORMAL_MEMORY].attr.attr, 662 #ifdef CONFIG_HIGHMEM 663 &node_state_attr[N_HIGH_MEMORY].attr.attr, 664 #endif 665 &node_state_attr[N_MEMORY].attr.attr, 666 &node_state_attr[N_CPU].attr.attr, 667 NULL 668 }; 669 670 static struct attribute_group memory_root_attr_group = { 671 .attrs = node_state_attrs, 672 }; 673 674 static const struct attribute_group *cpu_root_attr_groups[] = { 675 &memory_root_attr_group, 676 NULL, 677 }; 678 679 #define NODE_CALLBACK_PRI 2 /* lower than SLAB */ 680 static int __init register_node_type(void) 681 { 682 int ret; 683 684 BUILD_BUG_ON(ARRAY_SIZE(node_state_attr) != NR_NODE_STATES); 685 BUILD_BUG_ON(ARRAY_SIZE(node_state_attrs)-1 != NR_NODE_STATES); 686 687 ret = subsys_system_register(&node_subsys, cpu_root_attr_groups); 688 if (!ret) { 689 static struct notifier_block node_memory_callback_nb = { 690 .notifier_call = node_memory_callback, 691 .priority = NODE_CALLBACK_PRI, 692 }; 693 register_hotmemory_notifier(&node_memory_callback_nb); 694 } 695 696 /* 697 * Note: we're not going to unregister the node class if we fail 698 * to register the node state class attribute files. 699 */ 700 return ret; 701 } 702 postcore_initcall(register_node_type); 703