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