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