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v6.2
  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/pm_runtime.h>
 21#include <linux/swap.h>
 22#include <linux/slab.h>
 23#include <linux/hugetlb.h>
 24
 25static struct bus_type node_subsys = {
 26	.name = "node",
 27	.dev_name = "node",
 28};
 29
 30static inline ssize_t cpumap_read(struct file *file, struct kobject *kobj,
 31				  struct bin_attribute *attr, char *buf,
 32				  loff_t off, size_t count)
 33{
 34	struct device *dev = kobj_to_dev(kobj);
 35	struct node *node_dev = to_node(dev);
 36	cpumask_var_t mask;
 37	ssize_t n;
 
 
 
 
 
 38
 39	if (!alloc_cpumask_var(&mask, GFP_KERNEL))
 40		return 0;
 41
 42	cpumask_and(mask, cpumask_of_node(node_dev->dev.id), cpu_online_mask);
 43	n = cpumap_print_bitmask_to_buf(buf, mask, off, count);
 44	free_cpumask_var(mask);
 45
 46	return n;
 47}
 48
 49static BIN_ATTR_RO(cpumap, CPUMAP_FILE_MAX_BYTES);
 50
 51static inline ssize_t cpulist_read(struct file *file, struct kobject *kobj,
 52				   struct bin_attribute *attr, char *buf,
 53				   loff_t off, size_t count)
 54{
 55	struct device *dev = kobj_to_dev(kobj);
 56	struct node *node_dev = to_node(dev);
 57	cpumask_var_t mask;
 58	ssize_t n;
 59
 60	if (!alloc_cpumask_var(&mask, GFP_KERNEL))
 61		return 0;
 62
 63	cpumask_and(mask, cpumask_of_node(node_dev->dev.id), cpu_online_mask);
 64	n = cpumap_print_list_to_buf(buf, mask, off, count);
 65	free_cpumask_var(mask);
 66
 67	return n;
 68}
 69
 70static BIN_ATTR_RO(cpulist, CPULIST_FILE_MAX_BYTES);
 71
 72/**
 73 * struct node_access_nodes - Access class device to hold user visible
 74 * 			      relationships to other nodes.
 75 * @dev:	Device for this memory access class
 76 * @list_node:	List element in the node's access list
 77 * @access:	The access class rank
 78 * @hmem_attrs: Heterogeneous memory performance attributes
 79 */
 80struct node_access_nodes {
 81	struct device		dev;
 82	struct list_head	list_node;
 83	unsigned int		access;
 84#ifdef CONFIG_HMEM_REPORTING
 85	struct node_hmem_attrs	hmem_attrs;
 86#endif
 87};
 88#define to_access_nodes(dev) container_of(dev, struct node_access_nodes, dev)
 89
 90static struct attribute *node_init_access_node_attrs[] = {
 91	NULL,
 92};
 93
 94static struct attribute *node_targ_access_node_attrs[] = {
 95	NULL,
 96};
 97
 98static const struct attribute_group initiators = {
 99	.name	= "initiators",
100	.attrs	= node_init_access_node_attrs,
101};
102
103static const struct attribute_group targets = {
104	.name	= "targets",
105	.attrs	= node_targ_access_node_attrs,
106};
107
108static const struct attribute_group *node_access_node_groups[] = {
109	&initiators,
110	&targets,
111	NULL,
112};
113
114static void node_remove_accesses(struct node *node)
115{
116	struct node_access_nodes *c, *cnext;
117
118	list_for_each_entry_safe(c, cnext, &node->access_list, list_node) {
119		list_del(&c->list_node);
120		device_unregister(&c->dev);
121	}
122}
123
124static void node_access_release(struct device *dev)
125{
126	kfree(to_access_nodes(dev));
127}
128
129static struct node_access_nodes *node_init_node_access(struct node *node,
130						       unsigned int access)
131{
132	struct node_access_nodes *access_node;
133	struct device *dev;
134
135	list_for_each_entry(access_node, &node->access_list, list_node)
136		if (access_node->access == access)
137			return access_node;
138
139	access_node = kzalloc(sizeof(*access_node), GFP_KERNEL);
140	if (!access_node)
141		return NULL;
142
143	access_node->access = access;
144	dev = &access_node->dev;
145	dev->parent = &node->dev;
146	dev->release = node_access_release;
147	dev->groups = node_access_node_groups;
148	if (dev_set_name(dev, "access%u", access))
149		goto free;
150
151	if (device_register(dev))
152		goto free_name;
153
154	pm_runtime_no_callbacks(dev);
155	list_add_tail(&access_node->list_node, &node->access_list);
156	return access_node;
157free_name:
158	kfree_const(dev->kobj.name);
159free:
160	kfree(access_node);
161	return NULL;
162}
163
164#ifdef CONFIG_HMEM_REPORTING
165#define ACCESS_ATTR(name)						\
166static ssize_t name##_show(struct device *dev,				\
167			   struct device_attribute *attr,		\
168			   char *buf)					\
169{									\
170	return sysfs_emit(buf, "%u\n",					\
171			  to_access_nodes(dev)->hmem_attrs.name);	\
172}									\
173static DEVICE_ATTR_RO(name)
174
175ACCESS_ATTR(read_bandwidth);
176ACCESS_ATTR(read_latency);
177ACCESS_ATTR(write_bandwidth);
178ACCESS_ATTR(write_latency);
179
180static struct attribute *access_attrs[] = {
181	&dev_attr_read_bandwidth.attr,
182	&dev_attr_read_latency.attr,
183	&dev_attr_write_bandwidth.attr,
184	&dev_attr_write_latency.attr,
185	NULL,
186};
187
188/**
189 * node_set_perf_attrs - Set the performance values for given access class
190 * @nid: Node identifier to be set
191 * @hmem_attrs: Heterogeneous memory performance attributes
192 * @access: The access class the for the given attributes
193 */
194void node_set_perf_attrs(unsigned int nid, struct node_hmem_attrs *hmem_attrs,
195			 unsigned int access)
196{
197	struct node_access_nodes *c;
198	struct node *node;
199	int i;
200
201	if (WARN_ON_ONCE(!node_online(nid)))
202		return;
203
204	node = node_devices[nid];
205	c = node_init_node_access(node, access);
206	if (!c)
207		return;
208
209	c->hmem_attrs = *hmem_attrs;
210	for (i = 0; access_attrs[i] != NULL; i++) {
211		if (sysfs_add_file_to_group(&c->dev.kobj, access_attrs[i],
212					    "initiators")) {
213			pr_info("failed to add performance attribute to node %d\n",
214				nid);
215			break;
216		}
217	}
218}
219
220/**
221 * struct node_cache_info - Internal tracking for memory node caches
222 * @dev:	Device represeting the cache level
223 * @node:	List element for tracking in the node
224 * @cache_attrs:Attributes for this cache level
225 */
226struct node_cache_info {
227	struct device dev;
228	struct list_head node;
229	struct node_cache_attrs cache_attrs;
230};
231#define to_cache_info(device) container_of(device, struct node_cache_info, dev)
232
233#define CACHE_ATTR(name, fmt) 						\
234static ssize_t name##_show(struct device *dev,				\
235			   struct device_attribute *attr,		\
236			   char *buf)					\
237{									\
238	return sysfs_emit(buf, fmt "\n",				\
239			  to_cache_info(dev)->cache_attrs.name);	\
240}									\
241static DEVICE_ATTR_RO(name);
242
243CACHE_ATTR(size, "%llu")
244CACHE_ATTR(line_size, "%u")
245CACHE_ATTR(indexing, "%u")
246CACHE_ATTR(write_policy, "%u")
247
248static struct attribute *cache_attrs[] = {
249	&dev_attr_indexing.attr,
250	&dev_attr_size.attr,
251	&dev_attr_line_size.attr,
252	&dev_attr_write_policy.attr,
253	NULL,
254};
255ATTRIBUTE_GROUPS(cache);
256
257static void node_cache_release(struct device *dev)
258{
259	kfree(dev);
260}
261
262static void node_cacheinfo_release(struct device *dev)
263{
264	struct node_cache_info *info = to_cache_info(dev);
265	kfree(info);
266}
267
268static void node_init_cache_dev(struct node *node)
269{
270	struct device *dev;
271
272	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
273	if (!dev)
274		return;
275
276	device_initialize(dev);
277	dev->parent = &node->dev;
278	dev->release = node_cache_release;
279	if (dev_set_name(dev, "memory_side_cache"))
280		goto put_device;
281
282	if (device_add(dev))
283		goto put_device;
284
285	pm_runtime_no_callbacks(dev);
286	node->cache_dev = dev;
287	return;
288put_device:
289	put_device(dev);
290}
291
292/**
293 * node_add_cache() - add cache attribute to a memory node
294 * @nid: Node identifier that has new cache attributes
295 * @cache_attrs: Attributes for the cache being added
296 */
297void node_add_cache(unsigned int nid, struct node_cache_attrs *cache_attrs)
298{
299	struct node_cache_info *info;
300	struct device *dev;
301	struct node *node;
302
303	if (!node_online(nid) || !node_devices[nid])
304		return;
305
306	node = node_devices[nid];
307	list_for_each_entry(info, &node->cache_attrs, node) {
308		if (info->cache_attrs.level == cache_attrs->level) {
309			dev_warn(&node->dev,
310				"attempt to add duplicate cache level:%d\n",
311				cache_attrs->level);
312			return;
313		}
314	}
315
316	if (!node->cache_dev)
317		node_init_cache_dev(node);
318	if (!node->cache_dev)
319		return;
320
321	info = kzalloc(sizeof(*info), GFP_KERNEL);
322	if (!info)
323		return;
324
325	dev = &info->dev;
326	device_initialize(dev);
327	dev->parent = node->cache_dev;
328	dev->release = node_cacheinfo_release;
329	dev->groups = cache_groups;
330	if (dev_set_name(dev, "index%d", cache_attrs->level))
331		goto put_device;
332
333	info->cache_attrs = *cache_attrs;
334	if (device_add(dev)) {
335		dev_warn(&node->dev, "failed to add cache level:%d\n",
336			 cache_attrs->level);
337		goto put_device;
338	}
339	pm_runtime_no_callbacks(dev);
340	list_add_tail(&info->node, &node->cache_attrs);
341	return;
342put_device:
343	put_device(dev);
344}
345
346static void node_remove_caches(struct node *node)
347{
348	struct node_cache_info *info, *next;
349
350	if (!node->cache_dev)
351		return;
352
353	list_for_each_entry_safe(info, next, &node->cache_attrs, node) {
354		list_del(&info->node);
355		device_unregister(&info->dev);
356	}
357	device_unregister(node->cache_dev);
358}
359
360static void node_init_caches(unsigned int nid)
361{
362	INIT_LIST_HEAD(&node_devices[nid]->cache_attrs);
363}
364#else
365static void node_init_caches(unsigned int nid) { }
366static void node_remove_caches(struct node *node) { }
367#endif
368
369#define K(x) ((x) << (PAGE_SHIFT - 10))
370static ssize_t node_read_meminfo(struct device *dev,
371			struct device_attribute *attr, char *buf)
372{
373	int len = 0;
374	int nid = dev->id;
375	struct pglist_data *pgdat = NODE_DATA(nid);
376	struct sysinfo i;
377	unsigned long sreclaimable, sunreclaimable;
378	unsigned long swapcached = 0;
379
380	si_meminfo_node(&i, nid);
381	sreclaimable = node_page_state_pages(pgdat, NR_SLAB_RECLAIMABLE_B);
382	sunreclaimable = node_page_state_pages(pgdat, NR_SLAB_UNRECLAIMABLE_B);
383#ifdef CONFIG_SWAP
384	swapcached = node_page_state_pages(pgdat, NR_SWAPCACHE);
385#endif
386	len = sysfs_emit_at(buf, len,
387			    "Node %d MemTotal:       %8lu kB\n"
388			    "Node %d MemFree:        %8lu kB\n"
389			    "Node %d MemUsed:        %8lu kB\n"
390			    "Node %d SwapCached:     %8lu kB\n"
391			    "Node %d Active:         %8lu kB\n"
392			    "Node %d Inactive:       %8lu kB\n"
393			    "Node %d Active(anon):   %8lu kB\n"
394			    "Node %d Inactive(anon): %8lu kB\n"
395			    "Node %d Active(file):   %8lu kB\n"
396			    "Node %d Inactive(file): %8lu kB\n"
397			    "Node %d Unevictable:    %8lu kB\n"
398			    "Node %d Mlocked:        %8lu kB\n",
399			    nid, K(i.totalram),
400			    nid, K(i.freeram),
401			    nid, K(i.totalram - i.freeram),
402			    nid, K(swapcached),
403			    nid, K(node_page_state(pgdat, NR_ACTIVE_ANON) +
404				   node_page_state(pgdat, NR_ACTIVE_FILE)),
405			    nid, K(node_page_state(pgdat, NR_INACTIVE_ANON) +
406				   node_page_state(pgdat, NR_INACTIVE_FILE)),
407			    nid, K(node_page_state(pgdat, NR_ACTIVE_ANON)),
408			    nid, K(node_page_state(pgdat, NR_INACTIVE_ANON)),
409			    nid, K(node_page_state(pgdat, NR_ACTIVE_FILE)),
410			    nid, K(node_page_state(pgdat, NR_INACTIVE_FILE)),
411			    nid, K(node_page_state(pgdat, NR_UNEVICTABLE)),
412			    nid, K(sum_zone_node_page_state(nid, NR_MLOCK)));
413
414#ifdef CONFIG_HIGHMEM
415	len += sysfs_emit_at(buf, len,
416			     "Node %d HighTotal:      %8lu kB\n"
417			     "Node %d HighFree:       %8lu kB\n"
418			     "Node %d LowTotal:       %8lu kB\n"
419			     "Node %d LowFree:        %8lu kB\n",
420			     nid, K(i.totalhigh),
421			     nid, K(i.freehigh),
422			     nid, K(i.totalram - i.totalhigh),
423			     nid, K(i.freeram - i.freehigh));
424#endif
425	len += sysfs_emit_at(buf, len,
426			     "Node %d Dirty:          %8lu kB\n"
427			     "Node %d Writeback:      %8lu kB\n"
428			     "Node %d FilePages:      %8lu kB\n"
429			     "Node %d Mapped:         %8lu kB\n"
430			     "Node %d AnonPages:      %8lu kB\n"
431			     "Node %d Shmem:          %8lu kB\n"
432			     "Node %d KernelStack:    %8lu kB\n"
433#ifdef CONFIG_SHADOW_CALL_STACK
434			     "Node %d ShadowCallStack:%8lu kB\n"
435#endif
436			     "Node %d PageTables:     %8lu kB\n"
437			     "Node %d SecPageTables:  %8lu kB\n"
438			     "Node %d NFS_Unstable:   %8lu kB\n"
439			     "Node %d Bounce:         %8lu kB\n"
440			     "Node %d WritebackTmp:   %8lu kB\n"
441			     "Node %d KReclaimable:   %8lu kB\n"
442			     "Node %d Slab:           %8lu kB\n"
443			     "Node %d SReclaimable:   %8lu kB\n"
444			     "Node %d SUnreclaim:     %8lu kB\n"
445#ifdef CONFIG_TRANSPARENT_HUGEPAGE
446			     "Node %d AnonHugePages:  %8lu kB\n"
447			     "Node %d ShmemHugePages: %8lu kB\n"
448			     "Node %d ShmemPmdMapped: %8lu kB\n"
449			     "Node %d FileHugePages: %8lu kB\n"
450			     "Node %d FilePmdMapped: %8lu kB\n"
451#endif
452			     ,
453			     nid, K(node_page_state(pgdat, NR_FILE_DIRTY)),
454			     nid, K(node_page_state(pgdat, NR_WRITEBACK)),
455			     nid, K(node_page_state(pgdat, NR_FILE_PAGES)),
456			     nid, K(node_page_state(pgdat, NR_FILE_MAPPED)),
457			     nid, K(node_page_state(pgdat, NR_ANON_MAPPED)),
458			     nid, K(i.sharedram),
459			     nid, node_page_state(pgdat, NR_KERNEL_STACK_KB),
460#ifdef CONFIG_SHADOW_CALL_STACK
461			     nid, node_page_state(pgdat, NR_KERNEL_SCS_KB),
462#endif
463			     nid, K(node_page_state(pgdat, NR_PAGETABLE)),
464			     nid, K(node_page_state(pgdat, NR_SECONDARY_PAGETABLE)),
465			     nid, 0UL,
466			     nid, K(sum_zone_node_page_state(nid, NR_BOUNCE)),
467			     nid, K(node_page_state(pgdat, NR_WRITEBACK_TEMP)),
468			     nid, K(sreclaimable +
469				    node_page_state(pgdat, NR_KERNEL_MISC_RECLAIMABLE)),
470			     nid, K(sreclaimable + sunreclaimable),
471			     nid, K(sreclaimable),
472			     nid, K(sunreclaimable)
473#ifdef CONFIG_TRANSPARENT_HUGEPAGE
474			     ,
475			     nid, K(node_page_state(pgdat, NR_ANON_THPS)),
476			     nid, K(node_page_state(pgdat, NR_SHMEM_THPS)),
477			     nid, K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED)),
478			     nid, K(node_page_state(pgdat, NR_FILE_THPS)),
479			     nid, K(node_page_state(pgdat, NR_FILE_PMDMAPPED))
480#endif
481			    );
482	len += hugetlb_report_node_meminfo(buf, len, nid);
483	return len;
484}
485
486#undef K
487static DEVICE_ATTR(meminfo, 0444, node_read_meminfo, NULL);
488
489static ssize_t node_read_numastat(struct device *dev,
490				  struct device_attribute *attr, char *buf)
491{
492	fold_vm_numa_events();
493	return sysfs_emit(buf,
494			  "numa_hit %lu\n"
495			  "numa_miss %lu\n"
496			  "numa_foreign %lu\n"
497			  "interleave_hit %lu\n"
498			  "local_node %lu\n"
499			  "other_node %lu\n",
500			  sum_zone_numa_event_state(dev->id, NUMA_HIT),
501			  sum_zone_numa_event_state(dev->id, NUMA_MISS),
502			  sum_zone_numa_event_state(dev->id, NUMA_FOREIGN),
503			  sum_zone_numa_event_state(dev->id, NUMA_INTERLEAVE_HIT),
504			  sum_zone_numa_event_state(dev->id, NUMA_LOCAL),
505			  sum_zone_numa_event_state(dev->id, NUMA_OTHER));
506}
507static DEVICE_ATTR(numastat, 0444, node_read_numastat, NULL);
508
509static ssize_t node_read_vmstat(struct device *dev,
510				struct device_attribute *attr, char *buf)
511{
512	int nid = dev->id;
513	struct pglist_data *pgdat = NODE_DATA(nid);
514	int i;
515	int len = 0;
516
517	for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
518		len += sysfs_emit_at(buf, len, "%s %lu\n",
519				     zone_stat_name(i),
520				     sum_zone_node_page_state(nid, i));
521
522#ifdef CONFIG_NUMA
523	fold_vm_numa_events();
524	for (i = 0; i < NR_VM_NUMA_EVENT_ITEMS; i++)
525		len += sysfs_emit_at(buf, len, "%s %lu\n",
526				     numa_stat_name(i),
527				     sum_zone_numa_event_state(nid, i));
528
529#endif
530	for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
531		unsigned long pages = node_page_state_pages(pgdat, i);
532
533		if (vmstat_item_print_in_thp(i))
534			pages /= HPAGE_PMD_NR;
535		len += sysfs_emit_at(buf, len, "%s %lu\n", node_stat_name(i),
536				     pages);
537	}
538
539	return len;
540}
541static DEVICE_ATTR(vmstat, 0444, node_read_vmstat, NULL);
542
543static ssize_t node_read_distance(struct device *dev,
544				  struct device_attribute *attr, char *buf)
545{
546	int nid = dev->id;
547	int len = 0;
548	int i;
549
550	/*
551	 * buf is currently PAGE_SIZE in length and each node needs 4 chars
552	 * at the most (distance + space or newline).
553	 */
554	BUILD_BUG_ON(MAX_NUMNODES * 4 > PAGE_SIZE);
555
556	for_each_online_node(i) {
557		len += sysfs_emit_at(buf, len, "%s%d",
558				     i ? " " : "", node_distance(nid, i));
559	}
560
561	len += sysfs_emit_at(buf, len, "\n");
562	return len;
563}
564static DEVICE_ATTR(distance, 0444, node_read_distance, NULL);
565
566static struct attribute *node_dev_attrs[] = {
 
 
567	&dev_attr_meminfo.attr,
568	&dev_attr_numastat.attr,
569	&dev_attr_distance.attr,
570	&dev_attr_vmstat.attr,
571	NULL
572};
 
573
574static struct bin_attribute *node_dev_bin_attrs[] = {
575	&bin_attr_cpumap,
576	&bin_attr_cpulist,
577	NULL
578};
 
 
 
 
 
 
 
579
580static const struct attribute_group node_dev_group = {
581	.attrs = node_dev_attrs,
582	.bin_attrs = node_dev_bin_attrs
583};
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
584
585static const struct attribute_group *node_dev_groups[] = {
586	&node_dev_group,
587#ifdef CONFIG_HAVE_ARCH_NODE_DEV_GROUP
588	&arch_node_dev_group,
589#endif
590	NULL
591};
592
593static void node_device_release(struct device *dev)
594{
595	kfree(to_node(dev));
 
 
 
 
 
 
 
 
 
 
 
 
 
 
596}
597
598/*
599 * register_node - Setup a sysfs device for a node.
600 * @num - Node number to use when creating the device.
601 *
602 * Initialize and register the node device.
603 */
604static int register_node(struct node *node, int num)
605{
606	int error;
607
608	node->dev.id = num;
609	node->dev.bus = &node_subsys;
610	node->dev.release = node_device_release;
611	node->dev.groups = node_dev_groups;
612	error = device_register(&node->dev);
613
614	if (error) {
615		put_device(&node->dev);
616	} else {
617		hugetlb_register_node(node);
 
618		compaction_register_node(node);
619	}
620
621	return error;
622}
623
624/**
625 * unregister_node - unregister a node device
626 * @node: node going away
627 *
628 * Unregisters a node device @node.  All the devices on the node must be
629 * unregistered before calling this function.
630 */
631void unregister_node(struct node *node)
632{
633	hugetlb_unregister_node(node);
634	compaction_unregister_node(node);
635	node_remove_accesses(node);
636	node_remove_caches(node);
637	device_unregister(&node->dev);
638}
639
640struct node *node_devices[MAX_NUMNODES];
641
642/*
643 * register cpu under node
644 */
645int register_cpu_under_node(unsigned int cpu, unsigned int nid)
646{
647	int ret;
648	struct device *obj;
649
650	if (!node_online(nid))
651		return 0;
652
653	obj = get_cpu_device(cpu);
654	if (!obj)
655		return 0;
656
657	ret = sysfs_create_link(&node_devices[nid]->dev.kobj,
658				&obj->kobj,
659				kobject_name(&obj->kobj));
660	if (ret)
661		return ret;
662
663	return sysfs_create_link(&obj->kobj,
664				 &node_devices[nid]->dev.kobj,
665				 kobject_name(&node_devices[nid]->dev.kobj));
666}
667
668/**
669 * register_memory_node_under_compute_node - link memory node to its compute
670 *					     node for a given access class.
671 * @mem_nid:	Memory node number
672 * @cpu_nid:	Cpu  node number
673 * @access:	Access class to register
674 *
675 * Description:
676 * 	For use with platforms that may have separate memory and compute nodes.
677 * 	This function will export node relationships linking which memory
678 * 	initiator nodes can access memory targets at a given ranked access
679 * 	class.
680 */
681int register_memory_node_under_compute_node(unsigned int mem_nid,
682					    unsigned int cpu_nid,
683					    unsigned int access)
684{
685	struct node *init_node, *targ_node;
686	struct node_access_nodes *initiator, *target;
687	int ret;
688
689	if (!node_online(cpu_nid) || !node_online(mem_nid))
690		return -ENODEV;
691
692	init_node = node_devices[cpu_nid];
693	targ_node = node_devices[mem_nid];
694	initiator = node_init_node_access(init_node, access);
695	target = node_init_node_access(targ_node, access);
696	if (!initiator || !target)
697		return -ENOMEM;
698
699	ret = sysfs_add_link_to_group(&initiator->dev.kobj, "targets",
700				      &targ_node->dev.kobj,
701				      dev_name(&targ_node->dev));
702	if (ret)
703		return ret;
704
705	ret = sysfs_add_link_to_group(&target->dev.kobj, "initiators",
706				      &init_node->dev.kobj,
707				      dev_name(&init_node->dev));
708	if (ret)
709		goto err;
710
711	return 0;
712 err:
713	sysfs_remove_link_from_group(&initiator->dev.kobj, "targets",
714				     dev_name(&targ_node->dev));
715	return ret;
716}
717
718int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
719{
720	struct device *obj;
721
722	if (!node_online(nid))
723		return 0;
724
725	obj = get_cpu_device(cpu);
726	if (!obj)
727		return 0;
728
729	sysfs_remove_link(&node_devices[nid]->dev.kobj,
730			  kobject_name(&obj->kobj));
731	sysfs_remove_link(&obj->kobj,
732			  kobject_name(&node_devices[nid]->dev.kobj));
733
734	return 0;
735}
736
737#ifdef CONFIG_MEMORY_HOTPLUG
738static int __ref get_nid_for_pfn(unsigned long pfn)
739{
 
 
740#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
741	if (system_state < SYSTEM_RUNNING)
742		return early_pfn_to_nid(pfn);
743#endif
744	return pfn_to_nid(pfn);
745}
746
747static void do_register_memory_block_under_node(int nid,
748						struct memory_block *mem_blk,
749						enum meminit_context context)
750{
751	int ret;
752
753	memory_block_add_nid(mem_blk, nid, context);
 
 
 
 
754
755	ret = sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj,
756				       &mem_blk->dev.kobj,
757				       kobject_name(&mem_blk->dev.kobj));
758	if (ret && ret != -EEXIST)
759		dev_err_ratelimited(&node_devices[nid]->dev,
760				    "can't create link to %s in sysfs (%d)\n",
761				    kobject_name(&mem_blk->dev.kobj), ret);
762
763	ret = sysfs_create_link_nowarn(&mem_blk->dev.kobj,
764				&node_devices[nid]->dev.kobj,
765				kobject_name(&node_devices[nid]->dev.kobj));
766	if (ret && ret != -EEXIST)
767		dev_err_ratelimited(&mem_blk->dev,
768				    "can't create link to %s in sysfs (%d)\n",
769				    kobject_name(&node_devices[nid]->dev.kobj),
770				    ret);
771}
772
773/* register memory section under specified node if it spans that node */
774static int register_mem_block_under_node_early(struct memory_block *mem_blk,
775					       void *arg)
776{
777	unsigned long memory_block_pfns = memory_block_size_bytes() / PAGE_SIZE;
778	unsigned long start_pfn = section_nr_to_pfn(mem_blk->start_section_nr);
779	unsigned long end_pfn = start_pfn + memory_block_pfns - 1;
780	int nid = *(int *)arg;
781	unsigned long pfn;
782
783	for (pfn = start_pfn; pfn <= end_pfn; pfn++) {
784		int page_nid;
785
786		/*
787		 * memory block could have several absent sections from start.
788		 * skip pfn range from absent section
789		 */
790		if (!pfn_in_present_section(pfn)) {
791			pfn = round_down(pfn + PAGES_PER_SECTION,
792					 PAGES_PER_SECTION) - 1;
793			continue;
794		}
795
796		/*
797		 * We need to check if page belongs to nid only at the boot
798		 * case because node's ranges can be interleaved.
799		 */
800		page_nid = get_nid_for_pfn(pfn);
801		if (page_nid < 0)
802			continue;
803		if (page_nid != nid)
804			continue;
805
806		do_register_memory_block_under_node(nid, mem_blk, MEMINIT_EARLY);
807		return 0;
808	}
809	/* mem section does not span the specified node */
810	return 0;
811}
812
813/*
814 * During hotplug we know that all pages in the memory block belong to the same
815 * node.
816 */
817static int register_mem_block_under_node_hotplug(struct memory_block *mem_blk,
818						 void *arg)
819{
820	int nid = *(int *)arg;
821
822	do_register_memory_block_under_node(nid, mem_blk, MEMINIT_HOTPLUG);
823	return 0;
824}
825
826/*
827 * Unregister a memory block device under the node it spans. Memory blocks
828 * with multiple nodes cannot be offlined and therefore also never be removed.
829 */
830void unregister_memory_block_under_nodes(struct memory_block *mem_blk)
831{
832	if (mem_blk->nid == NUMA_NO_NODE)
833		return;
834
835	sysfs_remove_link(&node_devices[mem_blk->nid]->dev.kobj,
836			  kobject_name(&mem_blk->dev.kobj));
837	sysfs_remove_link(&mem_blk->dev.kobj,
838			  kobject_name(&node_devices[mem_blk->nid]->dev.kobj));
839}
840
841void register_memory_blocks_under_node(int nid, unsigned long start_pfn,
842				       unsigned long end_pfn,
843				       enum meminit_context context)
844{
845	walk_memory_blocks_func_t func;
846
847	if (context == MEMINIT_HOTPLUG)
848		func = register_mem_block_under_node_hotplug;
849	else
850		func = register_mem_block_under_node_early;
851
852	walk_memory_blocks(PFN_PHYS(start_pfn), PFN_PHYS(end_pfn - start_pfn),
853			   (void *)&nid, func);
854	return;
855}
856#endif /* CONFIG_MEMORY_HOTPLUG */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
857
858int __register_one_node(int nid)
859{
860	int error;
861	int cpu;
862
863	node_devices[nid] = kzalloc(sizeof(struct node), GFP_KERNEL);
864	if (!node_devices[nid])
865		return -ENOMEM;
866
867	error = register_node(node_devices[nid], nid);
868
869	/* link cpu under this node */
870	for_each_present_cpu(cpu) {
871		if (cpu_to_node(cpu) == nid)
872			register_cpu_under_node(cpu, nid);
873	}
874
875	INIT_LIST_HEAD(&node_devices[nid]->access_list);
 
 
876	node_init_caches(nid);
877
878	return error;
879}
880
881void unregister_one_node(int nid)
882{
883	if (!node_devices[nid])
884		return;
885
886	unregister_node(node_devices[nid]);
887	node_devices[nid] = NULL;
888}
889
890/*
891 * node states attributes
892 */
893
894struct node_attr {
895	struct device_attribute attr;
896	enum node_states state;
897};
898
899static ssize_t show_node_state(struct device *dev,
900			       struct device_attribute *attr, char *buf)
901{
902	struct node_attr *na = container_of(attr, struct node_attr, attr);
903
904	return sysfs_emit(buf, "%*pbl\n",
905			  nodemask_pr_args(&node_states[na->state]));
906}
907
908#define _NODE_ATTR(name, state) \
909	{ __ATTR(name, 0444, show_node_state, NULL), state }
910
911static struct node_attr node_state_attr[] = {
912	[N_POSSIBLE] = _NODE_ATTR(possible, N_POSSIBLE),
913	[N_ONLINE] = _NODE_ATTR(online, N_ONLINE),
914	[N_NORMAL_MEMORY] = _NODE_ATTR(has_normal_memory, N_NORMAL_MEMORY),
915#ifdef CONFIG_HIGHMEM
916	[N_HIGH_MEMORY] = _NODE_ATTR(has_high_memory, N_HIGH_MEMORY),
917#endif
918	[N_MEMORY] = _NODE_ATTR(has_memory, N_MEMORY),
919	[N_CPU] = _NODE_ATTR(has_cpu, N_CPU),
920	[N_GENERIC_INITIATOR] = _NODE_ATTR(has_generic_initiator,
921					   N_GENERIC_INITIATOR),
922};
923
924static struct attribute *node_state_attrs[] = {
925	&node_state_attr[N_POSSIBLE].attr.attr,
926	&node_state_attr[N_ONLINE].attr.attr,
927	&node_state_attr[N_NORMAL_MEMORY].attr.attr,
928#ifdef CONFIG_HIGHMEM
929	&node_state_attr[N_HIGH_MEMORY].attr.attr,
930#endif
931	&node_state_attr[N_MEMORY].attr.attr,
932	&node_state_attr[N_CPU].attr.attr,
933	&node_state_attr[N_GENERIC_INITIATOR].attr.attr,
934	NULL
935};
936
937static const struct attribute_group memory_root_attr_group = {
938	.attrs = node_state_attrs,
939};
940
941static const struct attribute_group *cpu_root_attr_groups[] = {
942	&memory_root_attr_group,
943	NULL,
944};
945
946void __init node_dev_init(void)
 
947{
948	int ret, i;
949
950 	BUILD_BUG_ON(ARRAY_SIZE(node_state_attr) != NR_NODE_STATES);
951 	BUILD_BUG_ON(ARRAY_SIZE(node_state_attrs)-1 != NR_NODE_STATES);
952
953	ret = subsys_system_register(&node_subsys, cpu_root_attr_groups);
954	if (ret)
955		panic("%s() failed to register subsystem: %d\n", __func__, ret);
 
 
 
 
 
956
957	/*
958	 * Create all node devices, which will properly link the node
959	 * to applicable memory block devices and already created cpu devices.
960	 */
961	for_each_online_node(i) {
962		ret = register_one_node(i);
963		if (ret)
964			panic("%s() failed to add node: %d\n", __func__, ret);
965	}
966}
v5.14.15
   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/pm_runtime.h>
  21#include <linux/swap.h>
  22#include <linux/slab.h>
 
  23
  24static struct bus_type node_subsys = {
  25	.name = "node",
  26	.dev_name = "node",
  27};
  28
  29
  30static ssize_t node_read_cpumap(struct device *dev, bool list, char *buf)
 
  31{
 
 
 
  32	ssize_t n;
  33	cpumask_var_t mask;
  34	struct node *node_dev = to_node(dev);
  35
  36	/* 2008/04/07: buf currently PAGE_SIZE, need 9 chars per 32 bits. */
  37	BUILD_BUG_ON((NR_CPUS/32 * 9) > (PAGE_SIZE-1));
  38
  39	if (!alloc_cpumask_var(&mask, GFP_KERNEL))
  40		return 0;
  41
  42	cpumask_and(mask, cpumask_of_node(node_dev->dev.id), cpu_online_mask);
  43	n = cpumap_print_to_pagebuf(list, buf, mask);
  44	free_cpumask_var(mask);
  45
  46	return n;
  47}
  48
  49static inline ssize_t cpumap_show(struct device *dev,
  50				  struct device_attribute *attr,
  51				  char *buf)
 
 
  52{
  53	return node_read_cpumap(dev, false, buf);
  54}
 
 
  55
  56static DEVICE_ATTR_RO(cpumap);
 
  57
  58static inline ssize_t cpulist_show(struct device *dev,
  59				   struct device_attribute *attr,
  60				   char *buf)
  61{
  62	return node_read_cpumap(dev, true, buf);
  63}
  64
  65static DEVICE_ATTR_RO(cpulist);
  66
  67/**
  68 * struct node_access_nodes - Access class device to hold user visible
  69 * 			      relationships to other nodes.
  70 * @dev:	Device for this memory access class
  71 * @list_node:	List element in the node's access list
  72 * @access:	The access class rank
  73 * @hmem_attrs: Heterogeneous memory performance attributes
  74 */
  75struct node_access_nodes {
  76	struct device		dev;
  77	struct list_head	list_node;
  78	unsigned		access;
  79#ifdef CONFIG_HMEM_REPORTING
  80	struct node_hmem_attrs	hmem_attrs;
  81#endif
  82};
  83#define to_access_nodes(dev) container_of(dev, struct node_access_nodes, dev)
  84
  85static struct attribute *node_init_access_node_attrs[] = {
  86	NULL,
  87};
  88
  89static struct attribute *node_targ_access_node_attrs[] = {
  90	NULL,
  91};
  92
  93static const struct attribute_group initiators = {
  94	.name	= "initiators",
  95	.attrs	= node_init_access_node_attrs,
  96};
  97
  98static const struct attribute_group targets = {
  99	.name	= "targets",
 100	.attrs	= node_targ_access_node_attrs,
 101};
 102
 103static const struct attribute_group *node_access_node_groups[] = {
 104	&initiators,
 105	&targets,
 106	NULL,
 107};
 108
 109static void node_remove_accesses(struct node *node)
 110{
 111	struct node_access_nodes *c, *cnext;
 112
 113	list_for_each_entry_safe(c, cnext, &node->access_list, list_node) {
 114		list_del(&c->list_node);
 115		device_unregister(&c->dev);
 116	}
 117}
 118
 119static void node_access_release(struct device *dev)
 120{
 121	kfree(to_access_nodes(dev));
 122}
 123
 124static struct node_access_nodes *node_init_node_access(struct node *node,
 125						       unsigned access)
 126{
 127	struct node_access_nodes *access_node;
 128	struct device *dev;
 129
 130	list_for_each_entry(access_node, &node->access_list, list_node)
 131		if (access_node->access == access)
 132			return access_node;
 133
 134	access_node = kzalloc(sizeof(*access_node), GFP_KERNEL);
 135	if (!access_node)
 136		return NULL;
 137
 138	access_node->access = access;
 139	dev = &access_node->dev;
 140	dev->parent = &node->dev;
 141	dev->release = node_access_release;
 142	dev->groups = node_access_node_groups;
 143	if (dev_set_name(dev, "access%u", access))
 144		goto free;
 145
 146	if (device_register(dev))
 147		goto free_name;
 148
 149	pm_runtime_no_callbacks(dev);
 150	list_add_tail(&access_node->list_node, &node->access_list);
 151	return access_node;
 152free_name:
 153	kfree_const(dev->kobj.name);
 154free:
 155	kfree(access_node);
 156	return NULL;
 157}
 158
 159#ifdef CONFIG_HMEM_REPORTING
 160#define ACCESS_ATTR(name)						\
 161static ssize_t name##_show(struct device *dev,				\
 162			   struct device_attribute *attr,		\
 163			   char *buf)					\
 164{									\
 165	return sysfs_emit(buf, "%u\n",					\
 166			  to_access_nodes(dev)->hmem_attrs.name);	\
 167}									\
 168static DEVICE_ATTR_RO(name)
 169
 170ACCESS_ATTR(read_bandwidth);
 171ACCESS_ATTR(read_latency);
 172ACCESS_ATTR(write_bandwidth);
 173ACCESS_ATTR(write_latency);
 174
 175static struct attribute *access_attrs[] = {
 176	&dev_attr_read_bandwidth.attr,
 177	&dev_attr_read_latency.attr,
 178	&dev_attr_write_bandwidth.attr,
 179	&dev_attr_write_latency.attr,
 180	NULL,
 181};
 182
 183/**
 184 * node_set_perf_attrs - Set the performance values for given access class
 185 * @nid: Node identifier to be set
 186 * @hmem_attrs: Heterogeneous memory performance attributes
 187 * @access: The access class the for the given attributes
 188 */
 189void node_set_perf_attrs(unsigned int nid, struct node_hmem_attrs *hmem_attrs,
 190			 unsigned access)
 191{
 192	struct node_access_nodes *c;
 193	struct node *node;
 194	int i;
 195
 196	if (WARN_ON_ONCE(!node_online(nid)))
 197		return;
 198
 199	node = node_devices[nid];
 200	c = node_init_node_access(node, access);
 201	if (!c)
 202		return;
 203
 204	c->hmem_attrs = *hmem_attrs;
 205	for (i = 0; access_attrs[i] != NULL; i++) {
 206		if (sysfs_add_file_to_group(&c->dev.kobj, access_attrs[i],
 207					    "initiators")) {
 208			pr_info("failed to add performance attribute to node %d\n",
 209				nid);
 210			break;
 211		}
 212	}
 213}
 214
 215/**
 216 * struct node_cache_info - Internal tracking for memory node caches
 217 * @dev:	Device represeting the cache level
 218 * @node:	List element for tracking in the node
 219 * @cache_attrs:Attributes for this cache level
 220 */
 221struct node_cache_info {
 222	struct device dev;
 223	struct list_head node;
 224	struct node_cache_attrs cache_attrs;
 225};
 226#define to_cache_info(device) container_of(device, struct node_cache_info, dev)
 227
 228#define CACHE_ATTR(name, fmt) 						\
 229static ssize_t name##_show(struct device *dev,				\
 230			   struct device_attribute *attr,		\
 231			   char *buf)					\
 232{									\
 233	return sysfs_emit(buf, fmt "\n",				\
 234			  to_cache_info(dev)->cache_attrs.name);	\
 235}									\
 236static DEVICE_ATTR_RO(name);
 237
 238CACHE_ATTR(size, "%llu")
 239CACHE_ATTR(line_size, "%u")
 240CACHE_ATTR(indexing, "%u")
 241CACHE_ATTR(write_policy, "%u")
 242
 243static struct attribute *cache_attrs[] = {
 244	&dev_attr_indexing.attr,
 245	&dev_attr_size.attr,
 246	&dev_attr_line_size.attr,
 247	&dev_attr_write_policy.attr,
 248	NULL,
 249};
 250ATTRIBUTE_GROUPS(cache);
 251
 252static void node_cache_release(struct device *dev)
 253{
 254	kfree(dev);
 255}
 256
 257static void node_cacheinfo_release(struct device *dev)
 258{
 259	struct node_cache_info *info = to_cache_info(dev);
 260	kfree(info);
 261}
 262
 263static void node_init_cache_dev(struct node *node)
 264{
 265	struct device *dev;
 266
 267	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 268	if (!dev)
 269		return;
 270
 271	device_initialize(dev);
 272	dev->parent = &node->dev;
 273	dev->release = node_cache_release;
 274	if (dev_set_name(dev, "memory_side_cache"))
 275		goto put_device;
 276
 277	if (device_add(dev))
 278		goto put_device;
 279
 280	pm_runtime_no_callbacks(dev);
 281	node->cache_dev = dev;
 282	return;
 283put_device:
 284	put_device(dev);
 285}
 286
 287/**
 288 * node_add_cache() - add cache attribute to a memory node
 289 * @nid: Node identifier that has new cache attributes
 290 * @cache_attrs: Attributes for the cache being added
 291 */
 292void node_add_cache(unsigned int nid, struct node_cache_attrs *cache_attrs)
 293{
 294	struct node_cache_info *info;
 295	struct device *dev;
 296	struct node *node;
 297
 298	if (!node_online(nid) || !node_devices[nid])
 299		return;
 300
 301	node = node_devices[nid];
 302	list_for_each_entry(info, &node->cache_attrs, node) {
 303		if (info->cache_attrs.level == cache_attrs->level) {
 304			dev_warn(&node->dev,
 305				"attempt to add duplicate cache level:%d\n",
 306				cache_attrs->level);
 307			return;
 308		}
 309	}
 310
 311	if (!node->cache_dev)
 312		node_init_cache_dev(node);
 313	if (!node->cache_dev)
 314		return;
 315
 316	info = kzalloc(sizeof(*info), GFP_KERNEL);
 317	if (!info)
 318		return;
 319
 320	dev = &info->dev;
 321	device_initialize(dev);
 322	dev->parent = node->cache_dev;
 323	dev->release = node_cacheinfo_release;
 324	dev->groups = cache_groups;
 325	if (dev_set_name(dev, "index%d", cache_attrs->level))
 326		goto put_device;
 327
 328	info->cache_attrs = *cache_attrs;
 329	if (device_add(dev)) {
 330		dev_warn(&node->dev, "failed to add cache level:%d\n",
 331			 cache_attrs->level);
 332		goto put_device;
 333	}
 334	pm_runtime_no_callbacks(dev);
 335	list_add_tail(&info->node, &node->cache_attrs);
 336	return;
 337put_device:
 338	put_device(dev);
 339}
 340
 341static void node_remove_caches(struct node *node)
 342{
 343	struct node_cache_info *info, *next;
 344
 345	if (!node->cache_dev)
 346		return;
 347
 348	list_for_each_entry_safe(info, next, &node->cache_attrs, node) {
 349		list_del(&info->node);
 350		device_unregister(&info->dev);
 351	}
 352	device_unregister(node->cache_dev);
 353}
 354
 355static void node_init_caches(unsigned int nid)
 356{
 357	INIT_LIST_HEAD(&node_devices[nid]->cache_attrs);
 358}
 359#else
 360static void node_init_caches(unsigned int nid) { }
 361static void node_remove_caches(struct node *node) { }
 362#endif
 363
 364#define K(x) ((x) << (PAGE_SHIFT - 10))
 365static ssize_t node_read_meminfo(struct device *dev,
 366			struct device_attribute *attr, char *buf)
 367{
 368	int len = 0;
 369	int nid = dev->id;
 370	struct pglist_data *pgdat = NODE_DATA(nid);
 371	struct sysinfo i;
 372	unsigned long sreclaimable, sunreclaimable;
 373	unsigned long swapcached = 0;
 374
 375	si_meminfo_node(&i, nid);
 376	sreclaimable = node_page_state_pages(pgdat, NR_SLAB_RECLAIMABLE_B);
 377	sunreclaimable = node_page_state_pages(pgdat, NR_SLAB_UNRECLAIMABLE_B);
 378#ifdef CONFIG_SWAP
 379	swapcached = node_page_state_pages(pgdat, NR_SWAPCACHE);
 380#endif
 381	len = sysfs_emit_at(buf, len,
 382			    "Node %d MemTotal:       %8lu kB\n"
 383			    "Node %d MemFree:        %8lu kB\n"
 384			    "Node %d MemUsed:        %8lu kB\n"
 385			    "Node %d SwapCached:     %8lu kB\n"
 386			    "Node %d Active:         %8lu kB\n"
 387			    "Node %d Inactive:       %8lu kB\n"
 388			    "Node %d Active(anon):   %8lu kB\n"
 389			    "Node %d Inactive(anon): %8lu kB\n"
 390			    "Node %d Active(file):   %8lu kB\n"
 391			    "Node %d Inactive(file): %8lu kB\n"
 392			    "Node %d Unevictable:    %8lu kB\n"
 393			    "Node %d Mlocked:        %8lu kB\n",
 394			    nid, K(i.totalram),
 395			    nid, K(i.freeram),
 396			    nid, K(i.totalram - i.freeram),
 397			    nid, K(swapcached),
 398			    nid, K(node_page_state(pgdat, NR_ACTIVE_ANON) +
 399				   node_page_state(pgdat, NR_ACTIVE_FILE)),
 400			    nid, K(node_page_state(pgdat, NR_INACTIVE_ANON) +
 401				   node_page_state(pgdat, NR_INACTIVE_FILE)),
 402			    nid, K(node_page_state(pgdat, NR_ACTIVE_ANON)),
 403			    nid, K(node_page_state(pgdat, NR_INACTIVE_ANON)),
 404			    nid, K(node_page_state(pgdat, NR_ACTIVE_FILE)),
 405			    nid, K(node_page_state(pgdat, NR_INACTIVE_FILE)),
 406			    nid, K(node_page_state(pgdat, NR_UNEVICTABLE)),
 407			    nid, K(sum_zone_node_page_state(nid, NR_MLOCK)));
 408
 409#ifdef CONFIG_HIGHMEM
 410	len += sysfs_emit_at(buf, len,
 411			     "Node %d HighTotal:      %8lu kB\n"
 412			     "Node %d HighFree:       %8lu kB\n"
 413			     "Node %d LowTotal:       %8lu kB\n"
 414			     "Node %d LowFree:        %8lu kB\n",
 415			     nid, K(i.totalhigh),
 416			     nid, K(i.freehigh),
 417			     nid, K(i.totalram - i.totalhigh),
 418			     nid, K(i.freeram - i.freehigh));
 419#endif
 420	len += sysfs_emit_at(buf, len,
 421			     "Node %d Dirty:          %8lu kB\n"
 422			     "Node %d Writeback:      %8lu kB\n"
 423			     "Node %d FilePages:      %8lu kB\n"
 424			     "Node %d Mapped:         %8lu kB\n"
 425			     "Node %d AnonPages:      %8lu kB\n"
 426			     "Node %d Shmem:          %8lu kB\n"
 427			     "Node %d KernelStack:    %8lu kB\n"
 428#ifdef CONFIG_SHADOW_CALL_STACK
 429			     "Node %d ShadowCallStack:%8lu kB\n"
 430#endif
 431			     "Node %d PageTables:     %8lu kB\n"
 
 432			     "Node %d NFS_Unstable:   %8lu kB\n"
 433			     "Node %d Bounce:         %8lu kB\n"
 434			     "Node %d WritebackTmp:   %8lu kB\n"
 435			     "Node %d KReclaimable:   %8lu kB\n"
 436			     "Node %d Slab:           %8lu kB\n"
 437			     "Node %d SReclaimable:   %8lu kB\n"
 438			     "Node %d SUnreclaim:     %8lu kB\n"
 439#ifdef CONFIG_TRANSPARENT_HUGEPAGE
 440			     "Node %d AnonHugePages:  %8lu kB\n"
 441			     "Node %d ShmemHugePages: %8lu kB\n"
 442			     "Node %d ShmemPmdMapped: %8lu kB\n"
 443			     "Node %d FileHugePages: %8lu kB\n"
 444			     "Node %d FilePmdMapped: %8lu kB\n"
 445#endif
 446			     ,
 447			     nid, K(node_page_state(pgdat, NR_FILE_DIRTY)),
 448			     nid, K(node_page_state(pgdat, NR_WRITEBACK)),
 449			     nid, K(node_page_state(pgdat, NR_FILE_PAGES)),
 450			     nid, K(node_page_state(pgdat, NR_FILE_MAPPED)),
 451			     nid, K(node_page_state(pgdat, NR_ANON_MAPPED)),
 452			     nid, K(i.sharedram),
 453			     nid, node_page_state(pgdat, NR_KERNEL_STACK_KB),
 454#ifdef CONFIG_SHADOW_CALL_STACK
 455			     nid, node_page_state(pgdat, NR_KERNEL_SCS_KB),
 456#endif
 457			     nid, K(node_page_state(pgdat, NR_PAGETABLE)),
 
 458			     nid, 0UL,
 459			     nid, K(sum_zone_node_page_state(nid, NR_BOUNCE)),
 460			     nid, K(node_page_state(pgdat, NR_WRITEBACK_TEMP)),
 461			     nid, K(sreclaimable +
 462				    node_page_state(pgdat, NR_KERNEL_MISC_RECLAIMABLE)),
 463			     nid, K(sreclaimable + sunreclaimable),
 464			     nid, K(sreclaimable),
 465			     nid, K(sunreclaimable)
 466#ifdef CONFIG_TRANSPARENT_HUGEPAGE
 467			     ,
 468			     nid, K(node_page_state(pgdat, NR_ANON_THPS)),
 469			     nid, K(node_page_state(pgdat, NR_SHMEM_THPS)),
 470			     nid, K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED)),
 471			     nid, K(node_page_state(pgdat, NR_FILE_THPS)),
 472			     nid, K(node_page_state(pgdat, NR_FILE_PMDMAPPED))
 473#endif
 474			    );
 475	len += hugetlb_report_node_meminfo(buf, len, nid);
 476	return len;
 477}
 478
 479#undef K
 480static DEVICE_ATTR(meminfo, 0444, node_read_meminfo, NULL);
 481
 482static ssize_t node_read_numastat(struct device *dev,
 483				  struct device_attribute *attr, char *buf)
 484{
 485	fold_vm_numa_events();
 486	return sysfs_emit(buf,
 487			  "numa_hit %lu\n"
 488			  "numa_miss %lu\n"
 489			  "numa_foreign %lu\n"
 490			  "interleave_hit %lu\n"
 491			  "local_node %lu\n"
 492			  "other_node %lu\n",
 493			  sum_zone_numa_event_state(dev->id, NUMA_HIT),
 494			  sum_zone_numa_event_state(dev->id, NUMA_MISS),
 495			  sum_zone_numa_event_state(dev->id, NUMA_FOREIGN),
 496			  sum_zone_numa_event_state(dev->id, NUMA_INTERLEAVE_HIT),
 497			  sum_zone_numa_event_state(dev->id, NUMA_LOCAL),
 498			  sum_zone_numa_event_state(dev->id, NUMA_OTHER));
 499}
 500static DEVICE_ATTR(numastat, 0444, node_read_numastat, NULL);
 501
 502static ssize_t node_read_vmstat(struct device *dev,
 503				struct device_attribute *attr, char *buf)
 504{
 505	int nid = dev->id;
 506	struct pglist_data *pgdat = NODE_DATA(nid);
 507	int i;
 508	int len = 0;
 509
 510	for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
 511		len += sysfs_emit_at(buf, len, "%s %lu\n",
 512				     zone_stat_name(i),
 513				     sum_zone_node_page_state(nid, i));
 514
 515#ifdef CONFIG_NUMA
 516	fold_vm_numa_events();
 517	for (i = 0; i < NR_VM_NUMA_EVENT_ITEMS; i++)
 518		len += sysfs_emit_at(buf, len, "%s %lu\n",
 519				     numa_stat_name(i),
 520				     sum_zone_numa_event_state(nid, i));
 521
 522#endif
 523	for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
 524		unsigned long pages = node_page_state_pages(pgdat, i);
 525
 526		if (vmstat_item_print_in_thp(i))
 527			pages /= HPAGE_PMD_NR;
 528		len += sysfs_emit_at(buf, len, "%s %lu\n", node_stat_name(i),
 529				     pages);
 530	}
 531
 532	return len;
 533}
 534static DEVICE_ATTR(vmstat, 0444, node_read_vmstat, NULL);
 535
 536static ssize_t node_read_distance(struct device *dev,
 537				  struct device_attribute *attr, char *buf)
 538{
 539	int nid = dev->id;
 540	int len = 0;
 541	int i;
 542
 543	/*
 544	 * buf is currently PAGE_SIZE in length and each node needs 4 chars
 545	 * at the most (distance + space or newline).
 546	 */
 547	BUILD_BUG_ON(MAX_NUMNODES * 4 > PAGE_SIZE);
 548
 549	for_each_online_node(i) {
 550		len += sysfs_emit_at(buf, len, "%s%d",
 551				     i ? " " : "", node_distance(nid, i));
 552	}
 553
 554	len += sysfs_emit_at(buf, len, "\n");
 555	return len;
 556}
 557static DEVICE_ATTR(distance, 0444, node_read_distance, NULL);
 558
 559static struct attribute *node_dev_attrs[] = {
 560	&dev_attr_cpumap.attr,
 561	&dev_attr_cpulist.attr,
 562	&dev_attr_meminfo.attr,
 563	&dev_attr_numastat.attr,
 564	&dev_attr_distance.attr,
 565	&dev_attr_vmstat.attr,
 566	NULL
 567};
 568ATTRIBUTE_GROUPS(node_dev);
 569
 570#ifdef CONFIG_HUGETLBFS
 571/*
 572 * hugetlbfs per node attributes registration interface:
 573 * When/if hugetlb[fs] subsystem initializes [sometime after this module],
 574 * it will register its per node attributes for all online nodes with
 575 * memory.  It will also call register_hugetlbfs_with_node(), below, to
 576 * register its attribute registration functions with this node driver.
 577 * Once these hooks have been initialized, the node driver will call into
 578 * the hugetlb module to [un]register attributes for hot-plugged nodes.
 579 */
 580static node_registration_func_t __hugetlb_register_node;
 581static node_registration_func_t __hugetlb_unregister_node;
 582
 583static inline bool hugetlb_register_node(struct node *node)
 584{
 585	if (__hugetlb_register_node &&
 586			node_state(node->dev.id, N_MEMORY)) {
 587		__hugetlb_register_node(node);
 588		return true;
 589	}
 590	return false;
 591}
 592
 593static inline void hugetlb_unregister_node(struct node *node)
 594{
 595	if (__hugetlb_unregister_node)
 596		__hugetlb_unregister_node(node);
 597}
 598
 599void register_hugetlbfs_with_node(node_registration_func_t doregister,
 600				  node_registration_func_t unregister)
 601{
 602	__hugetlb_register_node   = doregister;
 603	__hugetlb_unregister_node = unregister;
 604}
 605#else
 606static inline void hugetlb_register_node(struct node *node) {}
 607
 608static inline void hugetlb_unregister_node(struct node *node) {}
 
 
 
 609#endif
 
 
 610
 611static void node_device_release(struct device *dev)
 612{
 613	struct node *node = to_node(dev);
 614
 615#if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HUGETLBFS)
 616	/*
 617	 * We schedule the work only when a memory section is
 618	 * onlined/offlined on this node. When we come here,
 619	 * all the memory on this node has been offlined,
 620	 * so we won't enqueue new work to this work.
 621	 *
 622	 * The work is using node->node_work, so we should
 623	 * flush work before freeing the memory.
 624	 */
 625	flush_work(&node->node_work);
 626#endif
 627	kfree(node);
 628}
 629
 630/*
 631 * register_node - Setup a sysfs device for a node.
 632 * @num - Node number to use when creating the device.
 633 *
 634 * Initialize and register the node device.
 635 */
 636static int register_node(struct node *node, int num)
 637{
 638	int error;
 639
 640	node->dev.id = num;
 641	node->dev.bus = &node_subsys;
 642	node->dev.release = node_device_release;
 643	node->dev.groups = node_dev_groups;
 644	error = device_register(&node->dev);
 645
 646	if (error)
 647		put_device(&node->dev);
 648	else {
 649		hugetlb_register_node(node);
 650
 651		compaction_register_node(node);
 652	}
 
 653	return error;
 654}
 655
 656/**
 657 * unregister_node - unregister a node device
 658 * @node: node going away
 659 *
 660 * Unregisters a node device @node.  All the devices on the node must be
 661 * unregistered before calling this function.
 662 */
 663void unregister_node(struct node *node)
 664{
 665	hugetlb_unregister_node(node);		/* no-op, if memoryless node */
 
 666	node_remove_accesses(node);
 667	node_remove_caches(node);
 668	device_unregister(&node->dev);
 669}
 670
 671struct node *node_devices[MAX_NUMNODES];
 672
 673/*
 674 * register cpu under node
 675 */
 676int register_cpu_under_node(unsigned int cpu, unsigned int nid)
 677{
 678	int ret;
 679	struct device *obj;
 680
 681	if (!node_online(nid))
 682		return 0;
 683
 684	obj = get_cpu_device(cpu);
 685	if (!obj)
 686		return 0;
 687
 688	ret = sysfs_create_link(&node_devices[nid]->dev.kobj,
 689				&obj->kobj,
 690				kobject_name(&obj->kobj));
 691	if (ret)
 692		return ret;
 693
 694	return sysfs_create_link(&obj->kobj,
 695				 &node_devices[nid]->dev.kobj,
 696				 kobject_name(&node_devices[nid]->dev.kobj));
 697}
 698
 699/**
 700 * register_memory_node_under_compute_node - link memory node to its compute
 701 *					     node for a given access class.
 702 * @mem_nid:	Memory node number
 703 * @cpu_nid:	Cpu  node number
 704 * @access:	Access class to register
 705 *
 706 * Description:
 707 * 	For use with platforms that may have separate memory and compute nodes.
 708 * 	This function will export node relationships linking which memory
 709 * 	initiator nodes can access memory targets at a given ranked access
 710 * 	class.
 711 */
 712int register_memory_node_under_compute_node(unsigned int mem_nid,
 713					    unsigned int cpu_nid,
 714					    unsigned access)
 715{
 716	struct node *init_node, *targ_node;
 717	struct node_access_nodes *initiator, *target;
 718	int ret;
 719
 720	if (!node_online(cpu_nid) || !node_online(mem_nid))
 721		return -ENODEV;
 722
 723	init_node = node_devices[cpu_nid];
 724	targ_node = node_devices[mem_nid];
 725	initiator = node_init_node_access(init_node, access);
 726	target = node_init_node_access(targ_node, access);
 727	if (!initiator || !target)
 728		return -ENOMEM;
 729
 730	ret = sysfs_add_link_to_group(&initiator->dev.kobj, "targets",
 731				      &targ_node->dev.kobj,
 732				      dev_name(&targ_node->dev));
 733	if (ret)
 734		return ret;
 735
 736	ret = sysfs_add_link_to_group(&target->dev.kobj, "initiators",
 737				      &init_node->dev.kobj,
 738				      dev_name(&init_node->dev));
 739	if (ret)
 740		goto err;
 741
 742	return 0;
 743 err:
 744	sysfs_remove_link_from_group(&initiator->dev.kobj, "targets",
 745				     dev_name(&targ_node->dev));
 746	return ret;
 747}
 748
 749int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
 750{
 751	struct device *obj;
 752
 753	if (!node_online(nid))
 754		return 0;
 755
 756	obj = get_cpu_device(cpu);
 757	if (!obj)
 758		return 0;
 759
 760	sysfs_remove_link(&node_devices[nid]->dev.kobj,
 761			  kobject_name(&obj->kobj));
 762	sysfs_remove_link(&obj->kobj,
 763			  kobject_name(&node_devices[nid]->dev.kobj));
 764
 765	return 0;
 766}
 767
 768#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
 769static int __ref get_nid_for_pfn(unsigned long pfn)
 770{
 771	if (!pfn_valid_within(pfn))
 772		return -1;
 773#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
 774	if (system_state < SYSTEM_RUNNING)
 775		return early_pfn_to_nid(pfn);
 776#endif
 777	return pfn_to_nid(pfn);
 778}
 779
 780static void do_register_memory_block_under_node(int nid,
 781						struct memory_block *mem_blk)
 
 782{
 783	int ret;
 784
 785	/*
 786	 * If this memory block spans multiple nodes, we only indicate
 787	 * the last processed node.
 788	 */
 789	mem_blk->nid = nid;
 790
 791	ret = sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj,
 792				       &mem_blk->dev.kobj,
 793				       kobject_name(&mem_blk->dev.kobj));
 794	if (ret && ret != -EEXIST)
 795		dev_err_ratelimited(&node_devices[nid]->dev,
 796				    "can't create link to %s in sysfs (%d)\n",
 797				    kobject_name(&mem_blk->dev.kobj), ret);
 798
 799	ret = sysfs_create_link_nowarn(&mem_blk->dev.kobj,
 800				&node_devices[nid]->dev.kobj,
 801				kobject_name(&node_devices[nid]->dev.kobj));
 802	if (ret && ret != -EEXIST)
 803		dev_err_ratelimited(&mem_blk->dev,
 804				    "can't create link to %s in sysfs (%d)\n",
 805				    kobject_name(&node_devices[nid]->dev.kobj),
 806				    ret);
 807}
 808
 809/* register memory section under specified node if it spans that node */
 810static int register_mem_block_under_node_early(struct memory_block *mem_blk,
 811					       void *arg)
 812{
 813	unsigned long memory_block_pfns = memory_block_size_bytes() / PAGE_SIZE;
 814	unsigned long start_pfn = section_nr_to_pfn(mem_blk->start_section_nr);
 815	unsigned long end_pfn = start_pfn + memory_block_pfns - 1;
 816	int nid = *(int *)arg;
 817	unsigned long pfn;
 818
 819	for (pfn = start_pfn; pfn <= end_pfn; pfn++) {
 820		int page_nid;
 821
 822		/*
 823		 * memory block could have several absent sections from start.
 824		 * skip pfn range from absent section
 825		 */
 826		if (!pfn_in_present_section(pfn)) {
 827			pfn = round_down(pfn + PAGES_PER_SECTION,
 828					 PAGES_PER_SECTION) - 1;
 829			continue;
 830		}
 831
 832		/*
 833		 * We need to check if page belongs to nid only at the boot
 834		 * case because node's ranges can be interleaved.
 835		 */
 836		page_nid = get_nid_for_pfn(pfn);
 837		if (page_nid < 0)
 838			continue;
 839		if (page_nid != nid)
 840			continue;
 841
 842		do_register_memory_block_under_node(nid, mem_blk);
 843		return 0;
 844	}
 845	/* mem section does not span the specified node */
 846	return 0;
 847}
 848
 849/*
 850 * During hotplug we know that all pages in the memory block belong to the same
 851 * node.
 852 */
 853static int register_mem_block_under_node_hotplug(struct memory_block *mem_blk,
 854						 void *arg)
 855{
 856	int nid = *(int *)arg;
 857
 858	do_register_memory_block_under_node(nid, mem_blk);
 859	return 0;
 860}
 861
 862/*
 863 * Unregister a memory block device under the node it spans. Memory blocks
 864 * with multiple nodes cannot be offlined and therefore also never be removed.
 865 */
 866void unregister_memory_block_under_nodes(struct memory_block *mem_blk)
 867{
 868	if (mem_blk->nid == NUMA_NO_NODE)
 869		return;
 870
 871	sysfs_remove_link(&node_devices[mem_blk->nid]->dev.kobj,
 872			  kobject_name(&mem_blk->dev.kobj));
 873	sysfs_remove_link(&mem_blk->dev.kobj,
 874			  kobject_name(&node_devices[mem_blk->nid]->dev.kobj));
 875}
 876
 877void link_mem_sections(int nid, unsigned long start_pfn, unsigned long end_pfn,
 878		       enum meminit_context context)
 
 879{
 880	walk_memory_blocks_func_t func;
 881
 882	if (context == MEMINIT_HOTPLUG)
 883		func = register_mem_block_under_node_hotplug;
 884	else
 885		func = register_mem_block_under_node_early;
 886
 887	walk_memory_blocks(PFN_PHYS(start_pfn), PFN_PHYS(end_pfn - start_pfn),
 888			   (void *)&nid, func);
 889	return;
 890}
 891
 892#ifdef CONFIG_HUGETLBFS
 893/*
 894 * Handle per node hstate attribute [un]registration on transistions
 895 * to/from memoryless state.
 896 */
 897static void node_hugetlb_work(struct work_struct *work)
 898{
 899	struct node *node = container_of(work, struct node, node_work);
 900
 901	/*
 902	 * We only get here when a node transitions to/from memoryless state.
 903	 * We can detect which transition occurred by examining whether the
 904	 * node has memory now.  hugetlb_register_node() already check this
 905	 * so we try to register the attributes.  If that fails, then the
 906	 * node has transitioned to memoryless, try to unregister the
 907	 * attributes.
 908	 */
 909	if (!hugetlb_register_node(node))
 910		hugetlb_unregister_node(node);
 911}
 912
 913static void init_node_hugetlb_work(int nid)
 914{
 915	INIT_WORK(&node_devices[nid]->node_work, node_hugetlb_work);
 916}
 917
 918static int node_memory_callback(struct notifier_block *self,
 919				unsigned long action, void *arg)
 920{
 921	struct memory_notify *mnb = arg;
 922	int nid = mnb->status_change_nid;
 923
 924	switch (action) {
 925	case MEM_ONLINE:
 926	case MEM_OFFLINE:
 927		/*
 928		 * offload per node hstate [un]registration to a work thread
 929		 * when transitioning to/from memoryless state.
 930		 */
 931		if (nid != NUMA_NO_NODE)
 932			schedule_work(&node_devices[nid]->node_work);
 933		break;
 934
 935	case MEM_GOING_ONLINE:
 936	case MEM_GOING_OFFLINE:
 937	case MEM_CANCEL_ONLINE:
 938	case MEM_CANCEL_OFFLINE:
 939	default:
 940		break;
 941	}
 942
 943	return NOTIFY_OK;
 944}
 945#endif	/* CONFIG_HUGETLBFS */
 946#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
 947
 948#if !defined(CONFIG_MEMORY_HOTPLUG_SPARSE) || \
 949    !defined(CONFIG_HUGETLBFS)
 950static inline int node_memory_callback(struct notifier_block *self,
 951				unsigned long action, void *arg)
 952{
 953	return NOTIFY_OK;
 954}
 955
 956static void init_node_hugetlb_work(int nid) { }
 957
 958#endif
 959
 960int __register_one_node(int nid)
 961{
 962	int error;
 963	int cpu;
 964
 965	node_devices[nid] = kzalloc(sizeof(struct node), GFP_KERNEL);
 966	if (!node_devices[nid])
 967		return -ENOMEM;
 968
 969	error = register_node(node_devices[nid], nid);
 970
 971	/* link cpu under this node */
 972	for_each_present_cpu(cpu) {
 973		if (cpu_to_node(cpu) == nid)
 974			register_cpu_under_node(cpu, nid);
 975	}
 976
 977	INIT_LIST_HEAD(&node_devices[nid]->access_list);
 978	/* initialize work queue for memory hot plug */
 979	init_node_hugetlb_work(nid);
 980	node_init_caches(nid);
 981
 982	return error;
 983}
 984
 985void unregister_one_node(int nid)
 986{
 987	if (!node_devices[nid])
 988		return;
 989
 990	unregister_node(node_devices[nid]);
 991	node_devices[nid] = NULL;
 992}
 993
 994/*
 995 * node states attributes
 996 */
 997
 998struct node_attr {
 999	struct device_attribute attr;
1000	enum node_states state;
1001};
1002
1003static ssize_t show_node_state(struct device *dev,
1004			       struct device_attribute *attr, char *buf)
1005{
1006	struct node_attr *na = container_of(attr, struct node_attr, attr);
1007
1008	return sysfs_emit(buf, "%*pbl\n",
1009			  nodemask_pr_args(&node_states[na->state]));
1010}
1011
1012#define _NODE_ATTR(name, state) \
1013	{ __ATTR(name, 0444, show_node_state, NULL), state }
1014
1015static struct node_attr node_state_attr[] = {
1016	[N_POSSIBLE] = _NODE_ATTR(possible, N_POSSIBLE),
1017	[N_ONLINE] = _NODE_ATTR(online, N_ONLINE),
1018	[N_NORMAL_MEMORY] = _NODE_ATTR(has_normal_memory, N_NORMAL_MEMORY),
1019#ifdef CONFIG_HIGHMEM
1020	[N_HIGH_MEMORY] = _NODE_ATTR(has_high_memory, N_HIGH_MEMORY),
1021#endif
1022	[N_MEMORY] = _NODE_ATTR(has_memory, N_MEMORY),
1023	[N_CPU] = _NODE_ATTR(has_cpu, N_CPU),
1024	[N_GENERIC_INITIATOR] = _NODE_ATTR(has_generic_initiator,
1025					   N_GENERIC_INITIATOR),
1026};
1027
1028static struct attribute *node_state_attrs[] = {
1029	&node_state_attr[N_POSSIBLE].attr.attr,
1030	&node_state_attr[N_ONLINE].attr.attr,
1031	&node_state_attr[N_NORMAL_MEMORY].attr.attr,
1032#ifdef CONFIG_HIGHMEM
1033	&node_state_attr[N_HIGH_MEMORY].attr.attr,
1034#endif
1035	&node_state_attr[N_MEMORY].attr.attr,
1036	&node_state_attr[N_CPU].attr.attr,
1037	&node_state_attr[N_GENERIC_INITIATOR].attr.attr,
1038	NULL
1039};
1040
1041static const struct attribute_group memory_root_attr_group = {
1042	.attrs = node_state_attrs,
1043};
1044
1045static const struct attribute_group *cpu_root_attr_groups[] = {
1046	&memory_root_attr_group,
1047	NULL,
1048};
1049
1050#define NODE_CALLBACK_PRI	2	/* lower than SLAB */
1051static int __init register_node_type(void)
1052{
1053	int ret;
1054
1055 	BUILD_BUG_ON(ARRAY_SIZE(node_state_attr) != NR_NODE_STATES);
1056 	BUILD_BUG_ON(ARRAY_SIZE(node_state_attrs)-1 != NR_NODE_STATES);
1057
1058	ret = subsys_system_register(&node_subsys, cpu_root_attr_groups);
1059	if (!ret) {
1060		static struct notifier_block node_memory_callback_nb = {
1061			.notifier_call = node_memory_callback,
1062			.priority = NODE_CALLBACK_PRI,
1063		};
1064		register_hotmemory_notifier(&node_memory_callback_nb);
1065	}
1066
1067	/*
1068	 * Note:  we're not going to unregister the node class if we fail
1069	 * to register the node state class attribute files.
1070	 */
1071	return ret;
 
 
 
 
1072}
1073postcore_initcall(register_node_type);