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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
22static struct bus_type node_subsys = {
23 .name = "node",
24 .dev_name = "node",
25};
26
27
28static 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
39static 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}
44static 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
50static DEVICE_ATTR(cpumap, S_IRUGO, node_read_cpumask, NULL);
51static DEVICE_ATTR(cpulist, S_IRUGO, node_read_cpulist, NULL);
52
53#define K(x) ((x) << (PAGE_SHIFT - 10))
54static 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 sysinfo i;
60
61 si_meminfo_node(&i, nid);
62 n = sprintf(buf,
63 "Node %d MemTotal: %8lu kB\n"
64 "Node %d MemFree: %8lu kB\n"
65 "Node %d MemUsed: %8lu kB\n"
66 "Node %d Active: %8lu kB\n"
67 "Node %d Inactive: %8lu kB\n"
68 "Node %d Active(anon): %8lu kB\n"
69 "Node %d Inactive(anon): %8lu kB\n"
70 "Node %d Active(file): %8lu kB\n"
71 "Node %d Inactive(file): %8lu kB\n"
72 "Node %d Unevictable: %8lu kB\n"
73 "Node %d Mlocked: %8lu kB\n",
74 nid, K(i.totalram),
75 nid, K(i.freeram),
76 nid, K(i.totalram - i.freeram),
77 nid, K(node_page_state(nid, NR_ACTIVE_ANON) +
78 node_page_state(nid, NR_ACTIVE_FILE)),
79 nid, K(node_page_state(nid, NR_INACTIVE_ANON) +
80 node_page_state(nid, NR_INACTIVE_FILE)),
81 nid, K(node_page_state(nid, NR_ACTIVE_ANON)),
82 nid, K(node_page_state(nid, NR_INACTIVE_ANON)),
83 nid, K(node_page_state(nid, NR_ACTIVE_FILE)),
84 nid, K(node_page_state(nid, NR_INACTIVE_FILE)),
85 nid, K(node_page_state(nid, NR_UNEVICTABLE)),
86 nid, K(node_page_state(nid, NR_MLOCK)));
87
88#ifdef CONFIG_HIGHMEM
89 n += sprintf(buf + n,
90 "Node %d HighTotal: %8lu kB\n"
91 "Node %d HighFree: %8lu kB\n"
92 "Node %d LowTotal: %8lu kB\n"
93 "Node %d LowFree: %8lu kB\n",
94 nid, K(i.totalhigh),
95 nid, K(i.freehigh),
96 nid, K(i.totalram - i.totalhigh),
97 nid, K(i.freeram - i.freehigh));
98#endif
99 n += sprintf(buf + n,
100 "Node %d Dirty: %8lu kB\n"
101 "Node %d Writeback: %8lu kB\n"
102 "Node %d FilePages: %8lu kB\n"
103 "Node %d Mapped: %8lu kB\n"
104 "Node %d AnonPages: %8lu kB\n"
105 "Node %d Shmem: %8lu kB\n"
106 "Node %d KernelStack: %8lu kB\n"
107 "Node %d PageTables: %8lu kB\n"
108 "Node %d NFS_Unstable: %8lu kB\n"
109 "Node %d Bounce: %8lu kB\n"
110 "Node %d WritebackTmp: %8lu kB\n"
111 "Node %d Slab: %8lu kB\n"
112 "Node %d SReclaimable: %8lu kB\n"
113 "Node %d SUnreclaim: %8lu kB\n"
114#ifdef CONFIG_TRANSPARENT_HUGEPAGE
115 "Node %d AnonHugePages: %8lu kB\n"
116#endif
117 ,
118 nid, K(node_page_state(nid, NR_FILE_DIRTY)),
119 nid, K(node_page_state(nid, NR_WRITEBACK)),
120 nid, K(node_page_state(nid, NR_FILE_PAGES)),
121 nid, K(node_page_state(nid, NR_FILE_MAPPED)),
122 nid, K(node_page_state(nid, NR_ANON_PAGES)),
123 nid, K(i.sharedram),
124 nid, node_page_state(nid, NR_KERNEL_STACK) *
125 THREAD_SIZE / 1024,
126 nid, K(node_page_state(nid, NR_PAGETABLE)),
127 nid, K(node_page_state(nid, NR_UNSTABLE_NFS)),
128 nid, K(node_page_state(nid, NR_BOUNCE)),
129 nid, K(node_page_state(nid, NR_WRITEBACK_TEMP)),
130 nid, K(node_page_state(nid, NR_SLAB_RECLAIMABLE) +
131 node_page_state(nid, NR_SLAB_UNRECLAIMABLE)),
132 nid, K(node_page_state(nid, NR_SLAB_RECLAIMABLE)),
133#ifdef CONFIG_TRANSPARENT_HUGEPAGE
134 nid, K(node_page_state(nid, NR_SLAB_UNRECLAIMABLE))
135 , nid,
136 K(node_page_state(nid, NR_ANON_TRANSPARENT_HUGEPAGES) *
137 HPAGE_PMD_NR));
138#else
139 nid, K(node_page_state(nid, NR_SLAB_UNRECLAIMABLE)));
140#endif
141 n += hugetlb_report_node_meminfo(nid, buf + n);
142 return n;
143}
144
145#undef K
146static DEVICE_ATTR(meminfo, S_IRUGO, node_read_meminfo, NULL);
147
148static ssize_t node_read_numastat(struct device *dev,
149 struct device_attribute *attr, char *buf)
150{
151 return sprintf(buf,
152 "numa_hit %lu\n"
153 "numa_miss %lu\n"
154 "numa_foreign %lu\n"
155 "interleave_hit %lu\n"
156 "local_node %lu\n"
157 "other_node %lu\n",
158 node_page_state(dev->id, NUMA_HIT),
159 node_page_state(dev->id, NUMA_MISS),
160 node_page_state(dev->id, NUMA_FOREIGN),
161 node_page_state(dev->id, NUMA_INTERLEAVE_HIT),
162 node_page_state(dev->id, NUMA_LOCAL),
163 node_page_state(dev->id, NUMA_OTHER));
164}
165static DEVICE_ATTR(numastat, S_IRUGO, node_read_numastat, NULL);
166
167static ssize_t node_read_vmstat(struct device *dev,
168 struct device_attribute *attr, char *buf)
169{
170 int nid = dev->id;
171 int i;
172 int n = 0;
173
174 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
175 n += sprintf(buf+n, "%s %lu\n", vmstat_text[i],
176 node_page_state(nid, i));
177
178 return n;
179}
180static DEVICE_ATTR(vmstat, S_IRUGO, node_read_vmstat, NULL);
181
182static ssize_t node_read_distance(struct device *dev,
183 struct device_attribute *attr, char *buf)
184{
185 int nid = dev->id;
186 int len = 0;
187 int i;
188
189 /*
190 * buf is currently PAGE_SIZE in length and each node needs 4 chars
191 * at the most (distance + space or newline).
192 */
193 BUILD_BUG_ON(MAX_NUMNODES * 4 > PAGE_SIZE);
194
195 for_each_online_node(i)
196 len += sprintf(buf + len, "%s%d", i ? " " : "", node_distance(nid, i));
197
198 len += sprintf(buf + len, "\n");
199 return len;
200}
201static DEVICE_ATTR(distance, S_IRUGO, node_read_distance, NULL);
202
203static struct attribute *node_dev_attrs[] = {
204 &dev_attr_cpumap.attr,
205 &dev_attr_cpulist.attr,
206 &dev_attr_meminfo.attr,
207 &dev_attr_numastat.attr,
208 &dev_attr_distance.attr,
209 &dev_attr_vmstat.attr,
210 NULL
211};
212ATTRIBUTE_GROUPS(node_dev);
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 */
224static node_registration_func_t __hugetlb_register_node;
225static node_registration_func_t __hugetlb_unregister_node;
226
227static 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
237static inline void hugetlb_unregister_node(struct node *node)
238{
239 if (__hugetlb_unregister_node)
240 __hugetlb_unregister_node(node);
241}
242
243void 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
250static inline void hugetlb_register_node(struct node *node) {}
251
252static inline void hugetlb_unregister_node(struct node *node) {}
253#endif
254
255static 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 */
280static 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 node->dev.groups = node_dev_groups;
288 error = device_register(&node->dev);
289
290 if (!error){
291 hugetlb_register_node(node);
292
293 compaction_register_node(node);
294 }
295 return error;
296}
297
298/**
299 * unregister_node - unregister a node device
300 * @node: node going away
301 *
302 * Unregisters a node device @node. All the devices on the node must be
303 * unregistered before calling this function.
304 */
305void unregister_node(struct node *node)
306{
307 hugetlb_unregister_node(node); /* no-op, if memoryless node */
308
309 device_unregister(&node->dev);
310}
311
312struct node *node_devices[MAX_NUMNODES];
313
314/*
315 * register cpu under node
316 */
317int register_cpu_under_node(unsigned int cpu, unsigned int nid)
318{
319 int ret;
320 struct device *obj;
321
322 if (!node_online(nid))
323 return 0;
324
325 obj = get_cpu_device(cpu);
326 if (!obj)
327 return 0;
328
329 ret = sysfs_create_link(&node_devices[nid]->dev.kobj,
330 &obj->kobj,
331 kobject_name(&obj->kobj));
332 if (ret)
333 return ret;
334
335 return sysfs_create_link(&obj->kobj,
336 &node_devices[nid]->dev.kobj,
337 kobject_name(&node_devices[nid]->dev.kobj));
338}
339
340int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
341{
342 struct device *obj;
343
344 if (!node_online(nid))
345 return 0;
346
347 obj = get_cpu_device(cpu);
348 if (!obj)
349 return 0;
350
351 sysfs_remove_link(&node_devices[nid]->dev.kobj,
352 kobject_name(&obj->kobj));
353 sysfs_remove_link(&obj->kobj,
354 kobject_name(&node_devices[nid]->dev.kobj));
355
356 return 0;
357}
358
359#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
360#define page_initialized(page) (page->lru.next)
361
362static int __init_refok get_nid_for_pfn(unsigned long pfn)
363{
364 struct page *page;
365
366 if (!pfn_valid_within(pfn))
367 return -1;
368#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
369 if (system_state == SYSTEM_BOOTING)
370 return early_pfn_to_nid(pfn);
371#endif
372 page = pfn_to_page(pfn);
373 if (!page_initialized(page))
374 return -1;
375 return pfn_to_nid(pfn);
376}
377
378/* register memory section under specified node if it spans that node */
379int register_mem_sect_under_node(struct memory_block *mem_blk, int nid)
380{
381 int ret;
382 unsigned long pfn, sect_start_pfn, sect_end_pfn;
383
384 if (!mem_blk)
385 return -EFAULT;
386 if (!node_online(nid))
387 return 0;
388
389 sect_start_pfn = section_nr_to_pfn(mem_blk->start_section_nr);
390 sect_end_pfn = section_nr_to_pfn(mem_blk->end_section_nr);
391 sect_end_pfn += PAGES_PER_SECTION - 1;
392 for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
393 int page_nid;
394
395 /*
396 * memory block could have several absent sections from start.
397 * skip pfn range from absent section
398 */
399 if (!pfn_present(pfn)) {
400 pfn = round_down(pfn + PAGES_PER_SECTION,
401 PAGES_PER_SECTION) - 1;
402 continue;
403 }
404
405 page_nid = get_nid_for_pfn(pfn);
406 if (page_nid < 0)
407 continue;
408 if (page_nid != nid)
409 continue;
410 ret = sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj,
411 &mem_blk->dev.kobj,
412 kobject_name(&mem_blk->dev.kobj));
413 if (ret)
414 return ret;
415
416 return sysfs_create_link_nowarn(&mem_blk->dev.kobj,
417 &node_devices[nid]->dev.kobj,
418 kobject_name(&node_devices[nid]->dev.kobj));
419 }
420 /* mem section does not span the specified node */
421 return 0;
422}
423
424/* unregister memory section under all nodes that it spans */
425int unregister_mem_sect_under_nodes(struct memory_block *mem_blk,
426 unsigned long phys_index)
427{
428 NODEMASK_ALLOC(nodemask_t, unlinked_nodes, GFP_KERNEL);
429 unsigned long pfn, sect_start_pfn, sect_end_pfn;
430
431 if (!mem_blk) {
432 NODEMASK_FREE(unlinked_nodes);
433 return -EFAULT;
434 }
435 if (!unlinked_nodes)
436 return -ENOMEM;
437 nodes_clear(*unlinked_nodes);
438
439 sect_start_pfn = section_nr_to_pfn(phys_index);
440 sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
441 for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
442 int nid;
443
444 nid = get_nid_for_pfn(pfn);
445 if (nid < 0)
446 continue;
447 if (!node_online(nid))
448 continue;
449 if (node_test_and_set(nid, *unlinked_nodes))
450 continue;
451 sysfs_remove_link(&node_devices[nid]->dev.kobj,
452 kobject_name(&mem_blk->dev.kobj));
453 sysfs_remove_link(&mem_blk->dev.kobj,
454 kobject_name(&node_devices[nid]->dev.kobj));
455 }
456 NODEMASK_FREE(unlinked_nodes);
457 return 0;
458}
459
460static int link_mem_sections(int nid)
461{
462 unsigned long start_pfn = NODE_DATA(nid)->node_start_pfn;
463 unsigned long end_pfn = start_pfn + NODE_DATA(nid)->node_spanned_pages;
464 unsigned long pfn;
465 struct memory_block *mem_blk = NULL;
466 int err = 0;
467
468 for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
469 unsigned long section_nr = pfn_to_section_nr(pfn);
470 struct mem_section *mem_sect;
471 int ret;
472
473 if (!present_section_nr(section_nr))
474 continue;
475 mem_sect = __nr_to_section(section_nr);
476
477 /* same memblock ? */
478 if (mem_blk)
479 if ((section_nr >= mem_blk->start_section_nr) &&
480 (section_nr <= mem_blk->end_section_nr))
481 continue;
482
483 mem_blk = find_memory_block_hinted(mem_sect, mem_blk);
484
485 ret = register_mem_sect_under_node(mem_blk, nid);
486 if (!err)
487 err = ret;
488
489 /* discard ref obtained in find_memory_block() */
490 }
491
492 if (mem_blk)
493 kobject_put(&mem_blk->dev.kobj);
494 return err;
495}
496
497#ifdef CONFIG_HUGETLBFS
498/*
499 * Handle per node hstate attribute [un]registration on transistions
500 * to/from memoryless state.
501 */
502static void node_hugetlb_work(struct work_struct *work)
503{
504 struct node *node = container_of(work, struct node, node_work);
505
506 /*
507 * We only get here when a node transitions to/from memoryless state.
508 * We can detect which transition occurred by examining whether the
509 * node has memory now. hugetlb_register_node() already check this
510 * so we try to register the attributes. If that fails, then the
511 * node has transitioned to memoryless, try to unregister the
512 * attributes.
513 */
514 if (!hugetlb_register_node(node))
515 hugetlb_unregister_node(node);
516}
517
518static void init_node_hugetlb_work(int nid)
519{
520 INIT_WORK(&node_devices[nid]->node_work, node_hugetlb_work);
521}
522
523static int node_memory_callback(struct notifier_block *self,
524 unsigned long action, void *arg)
525{
526 struct memory_notify *mnb = arg;
527 int nid = mnb->status_change_nid;
528
529 switch (action) {
530 case MEM_ONLINE:
531 case MEM_OFFLINE:
532 /*
533 * offload per node hstate [un]registration to a work thread
534 * when transitioning to/from memoryless state.
535 */
536 if (nid != NUMA_NO_NODE)
537 schedule_work(&node_devices[nid]->node_work);
538 break;
539
540 case MEM_GOING_ONLINE:
541 case MEM_GOING_OFFLINE:
542 case MEM_CANCEL_ONLINE:
543 case MEM_CANCEL_OFFLINE:
544 default:
545 break;
546 }
547
548 return NOTIFY_OK;
549}
550#endif /* CONFIG_HUGETLBFS */
551#else /* !CONFIG_MEMORY_HOTPLUG_SPARSE */
552
553static int link_mem_sections(int nid) { return 0; }
554#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
555
556#if !defined(CONFIG_MEMORY_HOTPLUG_SPARSE) || \
557 !defined(CONFIG_HUGETLBFS)
558static inline int node_memory_callback(struct notifier_block *self,
559 unsigned long action, void *arg)
560{
561 return NOTIFY_OK;
562}
563
564static void init_node_hugetlb_work(int nid) { }
565
566#endif
567
568int register_one_node(int nid)
569{
570 int error = 0;
571 int cpu;
572
573 if (node_online(nid)) {
574 int p_node = parent_node(nid);
575 struct node *parent = NULL;
576
577 if (p_node != nid)
578 parent = node_devices[p_node];
579
580 node_devices[nid] = kzalloc(sizeof(struct node), GFP_KERNEL);
581 if (!node_devices[nid])
582 return -ENOMEM;
583
584 error = register_node(node_devices[nid], nid, parent);
585
586 /* link cpu under this node */
587 for_each_present_cpu(cpu) {
588 if (cpu_to_node(cpu) == nid)
589 register_cpu_under_node(cpu, nid);
590 }
591
592 /* link memory sections under this node */
593 error = link_mem_sections(nid);
594
595 /* initialize work queue for memory hot plug */
596 init_node_hugetlb_work(nid);
597 }
598
599 return error;
600
601}
602
603void unregister_one_node(int nid)
604{
605 if (!node_devices[nid])
606 return;
607
608 unregister_node(node_devices[nid]);
609 node_devices[nid] = NULL;
610}
611
612/*
613 * node states attributes
614 */
615
616static ssize_t print_nodes_state(enum node_states state, char *buf)
617{
618 int n;
619
620 n = scnprintf(buf, PAGE_SIZE - 1, "%*pbl",
621 nodemask_pr_args(&node_states[state]));
622 buf[n++] = '\n';
623 buf[n] = '\0';
624 return n;
625}
626
627struct node_attr {
628 struct device_attribute attr;
629 enum node_states state;
630};
631
632static ssize_t show_node_state(struct device *dev,
633 struct device_attribute *attr, char *buf)
634{
635 struct node_attr *na = container_of(attr, struct node_attr, attr);
636 return print_nodes_state(na->state, buf);
637}
638
639#define _NODE_ATTR(name, state) \
640 { __ATTR(name, 0444, show_node_state, NULL), state }
641
642static struct node_attr node_state_attr[] = {
643 [N_POSSIBLE] = _NODE_ATTR(possible, N_POSSIBLE),
644 [N_ONLINE] = _NODE_ATTR(online, N_ONLINE),
645 [N_NORMAL_MEMORY] = _NODE_ATTR(has_normal_memory, N_NORMAL_MEMORY),
646#ifdef CONFIG_HIGHMEM
647 [N_HIGH_MEMORY] = _NODE_ATTR(has_high_memory, N_HIGH_MEMORY),
648#endif
649#ifdef CONFIG_MOVABLE_NODE
650 [N_MEMORY] = _NODE_ATTR(has_memory, N_MEMORY),
651#endif
652 [N_CPU] = _NODE_ATTR(has_cpu, N_CPU),
653};
654
655static struct attribute *node_state_attrs[] = {
656 &node_state_attr[N_POSSIBLE].attr.attr,
657 &node_state_attr[N_ONLINE].attr.attr,
658 &node_state_attr[N_NORMAL_MEMORY].attr.attr,
659#ifdef CONFIG_HIGHMEM
660 &node_state_attr[N_HIGH_MEMORY].attr.attr,
661#endif
662#ifdef CONFIG_MOVABLE_NODE
663 &node_state_attr[N_MEMORY].attr.attr,
664#endif
665 &node_state_attr[N_CPU].attr.attr,
666 NULL
667};
668
669static struct attribute_group memory_root_attr_group = {
670 .attrs = node_state_attrs,
671};
672
673static const struct attribute_group *cpu_root_attr_groups[] = {
674 &memory_root_attr_group,
675 NULL,
676};
677
678#define NODE_CALLBACK_PRI 2 /* lower than SLAB */
679static int __init register_node_type(void)
680{
681 int ret;
682
683 BUILD_BUG_ON(ARRAY_SIZE(node_state_attr) != NR_NODE_STATES);
684 BUILD_BUG_ON(ARRAY_SIZE(node_state_attrs)-1 != NR_NODE_STATES);
685
686 ret = subsys_system_register(&node_subsys, cpu_root_attr_groups);
687 if (!ret) {
688 static struct notifier_block node_memory_callback_nb = {
689 .notifier_call = node_memory_callback,
690 .priority = NODE_CALLBACK_PRI,
691 };
692 register_hotmemory_notifier(&node_memory_callback_nb);
693 }
694
695 /*
696 * Note: we're not going to unregister the node class if we fail
697 * to register the node state class attribute files.
698 */
699 return ret;
700}
701postcore_initcall(register_node_type);
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
23static struct bus_type node_subsys = {
24 .name = "node",
25 .dev_name = "node",
26};
27
28
29static 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
48static 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}
53static 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
59static DEVICE_ATTR(cpumap, S_IRUGO, node_read_cpumask, NULL);
60static DEVICE_ATTR(cpulist, S_IRUGO, node_read_cpulist, NULL);
61
62#define K(x) ((x) << (PAGE_SHIFT - 10))
63static 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
160static DEVICE_ATTR(meminfo, S_IRUGO, node_read_meminfo, NULL);
161
162static 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}
179static DEVICE_ATTR(numastat, S_IRUGO, node_read_numastat, NULL);
180
181static 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}
208static DEVICE_ATTR(vmstat, S_IRUGO, node_read_vmstat, NULL);
209
210static 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}
229static DEVICE_ATTR(distance, S_IRUGO, node_read_distance, NULL);
230
231static 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};
240ATTRIBUTE_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 */
252static node_registration_func_t __hugetlb_register_node;
253static node_registration_func_t __hugetlb_unregister_node;
254
255static 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
265static inline void hugetlb_unregister_node(struct node *node)
266{
267 if (__hugetlb_unregister_node)
268 __hugetlb_unregister_node(node);
269}
270
271void 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
278static inline void hugetlb_register_node(struct node *node) {}
279
280static inline void hugetlb_unregister_node(struct node *node) {}
281#endif
282
283static 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 */
308static 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 put_device(&node->dev);
320 else {
321 hugetlb_register_node(node);
322
323 compaction_register_node(node);
324 }
325 return error;
326}
327
328/**
329 * unregister_node - unregister a node device
330 * @node: node going away
331 *
332 * Unregisters a node device @node. All the devices on the node must be
333 * unregistered before calling this function.
334 */
335void unregister_node(struct node *node)
336{
337 hugetlb_unregister_node(node); /* no-op, if memoryless node */
338
339 device_unregister(&node->dev);
340}
341
342struct node *node_devices[MAX_NUMNODES];
343
344/*
345 * register cpu under node
346 */
347int register_cpu_under_node(unsigned int cpu, unsigned int nid)
348{
349 int ret;
350 struct device *obj;
351
352 if (!node_online(nid))
353 return 0;
354
355 obj = get_cpu_device(cpu);
356 if (!obj)
357 return 0;
358
359 ret = sysfs_create_link(&node_devices[nid]->dev.kobj,
360 &obj->kobj,
361 kobject_name(&obj->kobj));
362 if (ret)
363 return ret;
364
365 return sysfs_create_link(&obj->kobj,
366 &node_devices[nid]->dev.kobj,
367 kobject_name(&node_devices[nid]->dev.kobj));
368}
369
370int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
371{
372 struct device *obj;
373
374 if (!node_online(nid))
375 return 0;
376
377 obj = get_cpu_device(cpu);
378 if (!obj)
379 return 0;
380
381 sysfs_remove_link(&node_devices[nid]->dev.kobj,
382 kobject_name(&obj->kobj));
383 sysfs_remove_link(&obj->kobj,
384 kobject_name(&node_devices[nid]->dev.kobj));
385
386 return 0;
387}
388
389#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
390static int __ref get_nid_for_pfn(unsigned long pfn)
391{
392 if (!pfn_valid_within(pfn))
393 return -1;
394#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
395 if (system_state < SYSTEM_RUNNING)
396 return early_pfn_to_nid(pfn);
397#endif
398 return pfn_to_nid(pfn);
399}
400
401/* register memory section under specified node if it spans that node */
402int register_mem_sect_under_node(struct memory_block *mem_blk, int nid,
403 bool check_nid)
404{
405 int ret;
406 unsigned long pfn, sect_start_pfn, sect_end_pfn;
407
408 if (!mem_blk)
409 return -EFAULT;
410
411 mem_blk->nid = nid;
412 if (!node_online(nid))
413 return 0;
414
415 sect_start_pfn = section_nr_to_pfn(mem_blk->start_section_nr);
416 sect_end_pfn = section_nr_to_pfn(mem_blk->end_section_nr);
417 sect_end_pfn += PAGES_PER_SECTION - 1;
418 for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
419 int page_nid;
420
421 /*
422 * memory block could have several absent sections from start.
423 * skip pfn range from absent section
424 */
425 if (!pfn_present(pfn)) {
426 pfn = round_down(pfn + PAGES_PER_SECTION,
427 PAGES_PER_SECTION) - 1;
428 continue;
429 }
430
431 /*
432 * We need to check if page belongs to nid only for the boot
433 * case, during hotplug we know that all pages in the memory
434 * block belong to the same node.
435 */
436 if (check_nid) {
437 page_nid = get_nid_for_pfn(pfn);
438 if (page_nid < 0)
439 continue;
440 if (page_nid != nid)
441 continue;
442 }
443 ret = sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj,
444 &mem_blk->dev.kobj,
445 kobject_name(&mem_blk->dev.kobj));
446 if (ret)
447 return ret;
448
449 return sysfs_create_link_nowarn(&mem_blk->dev.kobj,
450 &node_devices[nid]->dev.kobj,
451 kobject_name(&node_devices[nid]->dev.kobj));
452 }
453 /* mem section does not span the specified node */
454 return 0;
455}
456
457/* unregister memory section under all nodes that it spans */
458int unregister_mem_sect_under_nodes(struct memory_block *mem_blk,
459 unsigned long phys_index)
460{
461 NODEMASK_ALLOC(nodemask_t, unlinked_nodes, GFP_KERNEL);
462 unsigned long pfn, sect_start_pfn, sect_end_pfn;
463
464 if (!mem_blk) {
465 NODEMASK_FREE(unlinked_nodes);
466 return -EFAULT;
467 }
468 if (!unlinked_nodes)
469 return -ENOMEM;
470 nodes_clear(*unlinked_nodes);
471
472 sect_start_pfn = section_nr_to_pfn(phys_index);
473 sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
474 for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
475 int nid;
476
477 nid = get_nid_for_pfn(pfn);
478 if (nid < 0)
479 continue;
480 if (!node_online(nid))
481 continue;
482 if (node_test_and_set(nid, *unlinked_nodes))
483 continue;
484 sysfs_remove_link(&node_devices[nid]->dev.kobj,
485 kobject_name(&mem_blk->dev.kobj));
486 sysfs_remove_link(&mem_blk->dev.kobj,
487 kobject_name(&node_devices[nid]->dev.kobj));
488 }
489 NODEMASK_FREE(unlinked_nodes);
490 return 0;
491}
492
493int link_mem_sections(int nid, unsigned long start_pfn, unsigned long nr_pages,
494 bool check_nid)
495{
496 unsigned long end_pfn = start_pfn + nr_pages;
497 unsigned long pfn;
498 struct memory_block *mem_blk = NULL;
499 int err = 0;
500
501 for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
502 unsigned long section_nr = pfn_to_section_nr(pfn);
503 struct mem_section *mem_sect;
504 int ret;
505
506 if (!present_section_nr(section_nr))
507 continue;
508 mem_sect = __nr_to_section(section_nr);
509
510 /* same memblock ? */
511 if (mem_blk)
512 if ((section_nr >= mem_blk->start_section_nr) &&
513 (section_nr <= mem_blk->end_section_nr))
514 continue;
515
516 mem_blk = find_memory_block_hinted(mem_sect, mem_blk);
517
518 ret = register_mem_sect_under_node(mem_blk, nid, check_nid);
519 if (!err)
520 err = ret;
521
522 /* discard ref obtained in find_memory_block() */
523 }
524
525 if (mem_blk)
526 kobject_put(&mem_blk->dev.kobj);
527 return err;
528}
529
530#ifdef CONFIG_HUGETLBFS
531/*
532 * Handle per node hstate attribute [un]registration on transistions
533 * to/from memoryless state.
534 */
535static void node_hugetlb_work(struct work_struct *work)
536{
537 struct node *node = container_of(work, struct node, node_work);
538
539 /*
540 * We only get here when a node transitions to/from memoryless state.
541 * We can detect which transition occurred by examining whether the
542 * node has memory now. hugetlb_register_node() already check this
543 * so we try to register the attributes. If that fails, then the
544 * node has transitioned to memoryless, try to unregister the
545 * attributes.
546 */
547 if (!hugetlb_register_node(node))
548 hugetlb_unregister_node(node);
549}
550
551static void init_node_hugetlb_work(int nid)
552{
553 INIT_WORK(&node_devices[nid]->node_work, node_hugetlb_work);
554}
555
556static int node_memory_callback(struct notifier_block *self,
557 unsigned long action, void *arg)
558{
559 struct memory_notify *mnb = arg;
560 int nid = mnb->status_change_nid;
561
562 switch (action) {
563 case MEM_ONLINE:
564 case MEM_OFFLINE:
565 /*
566 * offload per node hstate [un]registration to a work thread
567 * when transitioning to/from memoryless state.
568 */
569 if (nid != NUMA_NO_NODE)
570 schedule_work(&node_devices[nid]->node_work);
571 break;
572
573 case MEM_GOING_ONLINE:
574 case MEM_GOING_OFFLINE:
575 case MEM_CANCEL_ONLINE:
576 case MEM_CANCEL_OFFLINE:
577 default:
578 break;
579 }
580
581 return NOTIFY_OK;
582}
583#endif /* CONFIG_HUGETLBFS */
584#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
585
586#if !defined(CONFIG_MEMORY_HOTPLUG_SPARSE) || \
587 !defined(CONFIG_HUGETLBFS)
588static inline int node_memory_callback(struct notifier_block *self,
589 unsigned long action, void *arg)
590{
591 return NOTIFY_OK;
592}
593
594static void init_node_hugetlb_work(int nid) { }
595
596#endif
597
598int __register_one_node(int nid)
599{
600 int error;
601 int cpu;
602
603 node_devices[nid] = kzalloc(sizeof(struct node), GFP_KERNEL);
604 if (!node_devices[nid])
605 return -ENOMEM;
606
607 error = register_node(node_devices[nid], nid);
608
609 /* link cpu under this node */
610 for_each_present_cpu(cpu) {
611 if (cpu_to_node(cpu) == nid)
612 register_cpu_under_node(cpu, nid);
613 }
614
615 /* initialize work queue for memory hot plug */
616 init_node_hugetlb_work(nid);
617
618 return error;
619}
620
621void unregister_one_node(int nid)
622{
623 if (!node_devices[nid])
624 return;
625
626 unregister_node(node_devices[nid]);
627 node_devices[nid] = NULL;
628}
629
630/*
631 * node states attributes
632 */
633
634static ssize_t print_nodes_state(enum node_states state, char *buf)
635{
636 int n;
637
638 n = scnprintf(buf, PAGE_SIZE - 1, "%*pbl",
639 nodemask_pr_args(&node_states[state]));
640 buf[n++] = '\n';
641 buf[n] = '\0';
642 return n;
643}
644
645struct node_attr {
646 struct device_attribute attr;
647 enum node_states state;
648};
649
650static ssize_t show_node_state(struct device *dev,
651 struct device_attribute *attr, char *buf)
652{
653 struct node_attr *na = container_of(attr, struct node_attr, attr);
654 return print_nodes_state(na->state, buf);
655}
656
657#define _NODE_ATTR(name, state) \
658 { __ATTR(name, 0444, show_node_state, NULL), state }
659
660static struct node_attr node_state_attr[] = {
661 [N_POSSIBLE] = _NODE_ATTR(possible, N_POSSIBLE),
662 [N_ONLINE] = _NODE_ATTR(online, N_ONLINE),
663 [N_NORMAL_MEMORY] = _NODE_ATTR(has_normal_memory, N_NORMAL_MEMORY),
664#ifdef CONFIG_HIGHMEM
665 [N_HIGH_MEMORY] = _NODE_ATTR(has_high_memory, N_HIGH_MEMORY),
666#endif
667 [N_MEMORY] = _NODE_ATTR(has_memory, N_MEMORY),
668 [N_CPU] = _NODE_ATTR(has_cpu, N_CPU),
669};
670
671static struct attribute *node_state_attrs[] = {
672 &node_state_attr[N_POSSIBLE].attr.attr,
673 &node_state_attr[N_ONLINE].attr.attr,
674 &node_state_attr[N_NORMAL_MEMORY].attr.attr,
675#ifdef CONFIG_HIGHMEM
676 &node_state_attr[N_HIGH_MEMORY].attr.attr,
677#endif
678 &node_state_attr[N_MEMORY].attr.attr,
679 &node_state_attr[N_CPU].attr.attr,
680 NULL
681};
682
683static struct attribute_group memory_root_attr_group = {
684 .attrs = node_state_attrs,
685};
686
687static const struct attribute_group *cpu_root_attr_groups[] = {
688 &memory_root_attr_group,
689 NULL,
690};
691
692#define NODE_CALLBACK_PRI 2 /* lower than SLAB */
693static int __init register_node_type(void)
694{
695 int ret;
696
697 BUILD_BUG_ON(ARRAY_SIZE(node_state_attr) != NR_NODE_STATES);
698 BUILD_BUG_ON(ARRAY_SIZE(node_state_attrs)-1 != NR_NODE_STATES);
699
700 ret = subsys_system_register(&node_subsys, cpu_root_attr_groups);
701 if (!ret) {
702 static struct notifier_block node_memory_callback_nb = {
703 .notifier_call = node_memory_callback,
704 .priority = NODE_CALLBACK_PRI,
705 };
706 register_hotmemory_notifier(&node_memory_callback_nb);
707 }
708
709 /*
710 * Note: we're not going to unregister the node class if we fail
711 * to register the node state class attribute files.
712 */
713 return ret;
714}
715postcore_initcall(register_node_type);