node.c revision 5a0e3ad6af8660be21ca98a971cd00f331318c05 
1/*
2 * drivers/base/node.c - basic Node class support
3 */
4
5#include <linux/sysdev.h>
6#include <linux/module.h>
7#include <linux/init.h>
8#include <linux/mm.h>
9#include <linux/memory.h>
10#include <linux/node.h>
11#include <linux/hugetlb.h>
12#include <linux/cpumask.h>
13#include <linux/topology.h>
14#include <linux/nodemask.h>
15#include <linux/cpu.h>
16#include <linux/device.h>
17#include <linux/swap.h>
18#include <linux/gfp.h>
19
20static struct sysdev_class_attribute *node_state_attrs[];
21
22static struct sysdev_class node_class = {
23	.name = "node",
24	.attrs = node_state_attrs,
25};
26
27
28static ssize_t node_read_cpumap(struct sys_device *dev, int type, char *buf)
29{
30	struct node *node_dev = to_node(dev);
31	const struct cpumask *mask = cpumask_of_node(node_dev->sysdev.id);
32	int len;
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	len = type?
38		cpulist_scnprintf(buf, PAGE_SIZE-2, mask) :
39		cpumask_scnprintf(buf, PAGE_SIZE-2, mask);
40 	buf[len++] = '\n';
41 	buf[len] = '\0';
42	return len;
43}
44
45static inline ssize_t node_read_cpumask(struct sys_device *dev,
46				struct sysdev_attribute *attr, char *buf)
47{
48	return node_read_cpumap(dev, 0, buf);
49}
50static inline ssize_t node_read_cpulist(struct sys_device *dev,
51				struct sysdev_attribute *attr, char *buf)
52{
53	return node_read_cpumap(dev, 1, buf);
54}
55
56static SYSDEV_ATTR(cpumap,  S_IRUGO, node_read_cpumask, NULL);
57static SYSDEV_ATTR(cpulist, S_IRUGO, node_read_cpulist, NULL);
58
59#define K(x) ((x) << (PAGE_SHIFT - 10))
60static ssize_t node_read_meminfo(struct sys_device * dev,
61			struct sysdev_attribute *attr, char * buf)
62{
63	int n;
64	int nid = dev->id;
65	struct sysinfo i;
66
67	si_meminfo_node(&i, nid);
68
69	n = sprintf(buf, "\n"
70		       "Node %d MemTotal:       %8lu kB\n"
71		       "Node %d MemFree:        %8lu kB\n"
72		       "Node %d MemUsed:        %8lu kB\n"
73		       "Node %d Active:         %8lu kB\n"
74		       "Node %d Inactive:       %8lu kB\n"
75		       "Node %d Active(anon):   %8lu kB\n"
76		       "Node %d Inactive(anon): %8lu kB\n"
77		       "Node %d Active(file):   %8lu kB\n"
78		       "Node %d Inactive(file): %8lu kB\n"
79		       "Node %d Unevictable:    %8lu kB\n"
80		       "Node %d Mlocked:        %8lu kB\n"
81#ifdef CONFIG_HIGHMEM
82		       "Node %d HighTotal:      %8lu kB\n"
83		       "Node %d HighFree:       %8lu kB\n"
84		       "Node %d LowTotal:       %8lu kB\n"
85		       "Node %d LowFree:        %8lu kB\n"
86#endif
87		       "Node %d Dirty:          %8lu kB\n"
88		       "Node %d Writeback:      %8lu kB\n"
89		       "Node %d FilePages:      %8lu kB\n"
90		       "Node %d Mapped:         %8lu kB\n"
91		       "Node %d AnonPages:      %8lu kB\n"
92		       "Node %d Shmem:          %8lu kB\n"
93		       "Node %d KernelStack:    %8lu kB\n"
94		       "Node %d PageTables:     %8lu kB\n"
95		       "Node %d NFS_Unstable:   %8lu kB\n"
96		       "Node %d Bounce:         %8lu kB\n"
97		       "Node %d WritebackTmp:   %8lu kB\n"
98		       "Node %d Slab:           %8lu kB\n"
99		       "Node %d SReclaimable:   %8lu kB\n"
100		       "Node %d SUnreclaim:     %8lu kB\n",
101		       nid, K(i.totalram),
102		       nid, K(i.freeram),
103		       nid, K(i.totalram - i.freeram),
104		       nid, K(node_page_state(nid, NR_ACTIVE_ANON) +
105				node_page_state(nid, NR_ACTIVE_FILE)),
106		       nid, K(node_page_state(nid, NR_INACTIVE_ANON) +
107				node_page_state(nid, NR_INACTIVE_FILE)),
108		       nid, K(node_page_state(nid, NR_ACTIVE_ANON)),
109		       nid, K(node_page_state(nid, NR_INACTIVE_ANON)),
110		       nid, K(node_page_state(nid, NR_ACTIVE_FILE)),
111		       nid, K(node_page_state(nid, NR_INACTIVE_FILE)),
112		       nid, K(node_page_state(nid, NR_UNEVICTABLE)),
113		       nid, K(node_page_state(nid, NR_MLOCK)),
114#ifdef CONFIG_HIGHMEM
115		       nid, K(i.totalhigh),
116		       nid, K(i.freehigh),
117		       nid, K(i.totalram - i.totalhigh),
118		       nid, K(i.freeram - i.freehigh),
119#endif
120		       nid, K(node_page_state(nid, NR_FILE_DIRTY)),
121		       nid, K(node_page_state(nid, NR_WRITEBACK)),
122		       nid, K(node_page_state(nid, NR_FILE_PAGES)),
123		       nid, K(node_page_state(nid, NR_FILE_MAPPED)),
124		       nid, K(node_page_state(nid, NR_ANON_PAGES)),
125		       nid, K(node_page_state(nid, NR_SHMEM)),
126		       nid, node_page_state(nid, NR_KERNEL_STACK) *
127				THREAD_SIZE / 1024,
128		       nid, K(node_page_state(nid, NR_PAGETABLE)),
129		       nid, K(node_page_state(nid, NR_UNSTABLE_NFS)),
130		       nid, K(node_page_state(nid, NR_BOUNCE)),
131		       nid, K(node_page_state(nid, NR_WRITEBACK_TEMP)),
132		       nid, K(node_page_state(nid, NR_SLAB_RECLAIMABLE) +
133				node_page_state(nid, NR_SLAB_UNRECLAIMABLE)),
134		       nid, K(node_page_state(nid, NR_SLAB_RECLAIMABLE)),
135		       nid, K(node_page_state(nid, NR_SLAB_UNRECLAIMABLE)));
136	n += hugetlb_report_node_meminfo(nid, buf + n);
137	return n;
138}
139
140#undef K
141static SYSDEV_ATTR(meminfo, S_IRUGO, node_read_meminfo, NULL);
142
143static ssize_t node_read_numastat(struct sys_device * dev,
144				struct sysdev_attribute *attr, char * buf)
145{
146	return sprintf(buf,
147		       "numa_hit %lu\n"
148		       "numa_miss %lu\n"
149		       "numa_foreign %lu\n"
150		       "interleave_hit %lu\n"
151		       "local_node %lu\n"
152		       "other_node %lu\n",
153		       node_page_state(dev->id, NUMA_HIT),
154		       node_page_state(dev->id, NUMA_MISS),
155		       node_page_state(dev->id, NUMA_FOREIGN),
156		       node_page_state(dev->id, NUMA_INTERLEAVE_HIT),
157		       node_page_state(dev->id, NUMA_LOCAL),
158		       node_page_state(dev->id, NUMA_OTHER));
159}
160static SYSDEV_ATTR(numastat, S_IRUGO, node_read_numastat, NULL);
161
162static ssize_t node_read_distance(struct sys_device * dev,
163			struct sysdev_attribute *attr, char * buf)
164{
165	int nid = dev->id;
166	int len = 0;
167	int i;
168
169	/*
170	 * buf is currently PAGE_SIZE in length and each node needs 4 chars
171	 * at the most (distance + space or newline).
172	 */
173	BUILD_BUG_ON(MAX_NUMNODES * 4 > PAGE_SIZE);
174
175	for_each_online_node(i)
176		len += sprintf(buf + len, "%s%d", i ? " " : "", node_distance(nid, i));
177
178	len += sprintf(buf + len, "\n");
179	return len;
180}
181static SYSDEV_ATTR(distance, S_IRUGO, node_read_distance, NULL);
182
183#ifdef CONFIG_HUGETLBFS
184/*
185 * hugetlbfs per node attributes registration interface:
186 * When/if hugetlb[fs] subsystem initializes [sometime after this module],
187 * it will register its per node attributes for all online nodes with
188 * memory.  It will also call register_hugetlbfs_with_node(), below, to
189 * register its attribute registration functions with this node driver.
190 * Once these hooks have been initialized, the node driver will call into
191 * the hugetlb module to [un]register attributes for hot-plugged nodes.
192 */
193static node_registration_func_t __hugetlb_register_node;
194static node_registration_func_t __hugetlb_unregister_node;
195
196static inline bool hugetlb_register_node(struct node *node)
197{
198	if (__hugetlb_register_node &&
199			node_state(node->sysdev.id, N_HIGH_MEMORY)) {
200		__hugetlb_register_node(node);
201		return true;
202	}
203	return false;
204}
205
206static inline void hugetlb_unregister_node(struct node *node)
207{
208	if (__hugetlb_unregister_node)
209		__hugetlb_unregister_node(node);
210}
211
212void register_hugetlbfs_with_node(node_registration_func_t doregister,
213				  node_registration_func_t unregister)
214{
215	__hugetlb_register_node   = doregister;
216	__hugetlb_unregister_node = unregister;
217}
218#else
219static inline void hugetlb_register_node(struct node *node) {}
220
221static inline void hugetlb_unregister_node(struct node *node) {}
222#endif
223
224
225/*
226 * register_node - Setup a sysfs device for a node.
227 * @num - Node number to use when creating the device.
228 *
229 * Initialize and register the node device.
230 */
231int register_node(struct node *node, int num, struct node *parent)
232{
233	int error;
234
235	node->sysdev.id = num;
236	node->sysdev.cls = &node_class;
237	error = sysdev_register(&node->sysdev);
238
239	if (!error){
240		sysdev_create_file(&node->sysdev, &attr_cpumap);
241		sysdev_create_file(&node->sysdev, &attr_cpulist);
242		sysdev_create_file(&node->sysdev, &attr_meminfo);
243		sysdev_create_file(&node->sysdev, &attr_numastat);
244		sysdev_create_file(&node->sysdev, &attr_distance);
245
246		scan_unevictable_register_node(node);
247
248		hugetlb_register_node(node);
249	}
250	return error;
251}
252
253/**
254 * unregister_node - unregister a node device
255 * @node: node going away
256 *
257 * Unregisters a node device @node.  All the devices on the node must be
258 * unregistered before calling this function.
259 */
260void unregister_node(struct node *node)
261{
262	sysdev_remove_file(&node->sysdev, &attr_cpumap);
263	sysdev_remove_file(&node->sysdev, &attr_cpulist);
264	sysdev_remove_file(&node->sysdev, &attr_meminfo);
265	sysdev_remove_file(&node->sysdev, &attr_numastat);
266	sysdev_remove_file(&node->sysdev, &attr_distance);
267
268	scan_unevictable_unregister_node(node);
269	hugetlb_unregister_node(node);		/* no-op, if memoryless node */
270
271	sysdev_unregister(&node->sysdev);
272}
273
274struct node node_devices[MAX_NUMNODES];
275
276/*
277 * register cpu under node
278 */
279int register_cpu_under_node(unsigned int cpu, unsigned int nid)
280{
281	int ret;
282	struct sys_device *obj;
283
284	if (!node_online(nid))
285		return 0;
286
287	obj = get_cpu_sysdev(cpu);
288	if (!obj)
289		return 0;
290
291	ret = sysfs_create_link(&node_devices[nid].sysdev.kobj,
292				&obj->kobj,
293				kobject_name(&obj->kobj));
294	if (ret)
295		return ret;
296
297	return sysfs_create_link(&obj->kobj,
298				 &node_devices[nid].sysdev.kobj,
299				 kobject_name(&node_devices[nid].sysdev.kobj));
300}
301
302int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
303{
304	struct sys_device *obj;
305
306	if (!node_online(nid))
307		return 0;
308
309	obj = get_cpu_sysdev(cpu);
310	if (!obj)
311		return 0;
312
313	sysfs_remove_link(&node_devices[nid].sysdev.kobj,
314			  kobject_name(&obj->kobj));
315	sysfs_remove_link(&obj->kobj,
316			  kobject_name(&node_devices[nid].sysdev.kobj));
317
318	return 0;
319}
320
321#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
322#define page_initialized(page)  (page->lru.next)
323
324static int get_nid_for_pfn(unsigned long pfn)
325{
326	struct page *page;
327
328	if (!pfn_valid_within(pfn))
329		return -1;
330	page = pfn_to_page(pfn);
331	if (!page_initialized(page))
332		return -1;
333	return pfn_to_nid(pfn);
334}
335
336/* register memory section under specified node if it spans that node */
337int register_mem_sect_under_node(struct memory_block *mem_blk, int nid)
338{
339	int ret;
340	unsigned long pfn, sect_start_pfn, sect_end_pfn;
341
342	if (!mem_blk)
343		return -EFAULT;
344	if (!node_online(nid))
345		return 0;
346	sect_start_pfn = section_nr_to_pfn(mem_blk->phys_index);
347	sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
348	for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
349		int page_nid;
350
351		page_nid = get_nid_for_pfn(pfn);
352		if (page_nid < 0)
353			continue;
354		if (page_nid != nid)
355			continue;
356		ret = sysfs_create_link_nowarn(&node_devices[nid].sysdev.kobj,
357					&mem_blk->sysdev.kobj,
358					kobject_name(&mem_blk->sysdev.kobj));
359		if (ret)
360			return ret;
361
362		return sysfs_create_link_nowarn(&mem_blk->sysdev.kobj,
363				&node_devices[nid].sysdev.kobj,
364				kobject_name(&node_devices[nid].sysdev.kobj));
365	}
366	/* mem section does not span the specified node */
367	return 0;
368}
369
370/* unregister memory section under all nodes that it spans */
371int unregister_mem_sect_under_nodes(struct memory_block *mem_blk)
372{
373	NODEMASK_ALLOC(nodemask_t, unlinked_nodes, GFP_KERNEL);
374	unsigned long pfn, sect_start_pfn, sect_end_pfn;
375
376	if (!mem_blk) {
377		NODEMASK_FREE(unlinked_nodes);
378		return -EFAULT;
379	}
380	if (!unlinked_nodes)
381		return -ENOMEM;
382	nodes_clear(*unlinked_nodes);
383	sect_start_pfn = section_nr_to_pfn(mem_blk->phys_index);
384	sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
385	for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
386		int nid;
387
388		nid = get_nid_for_pfn(pfn);
389		if (nid < 0)
390			continue;
391		if (!node_online(nid))
392			continue;
393		if (node_test_and_set(nid, *unlinked_nodes))
394			continue;
395		sysfs_remove_link(&node_devices[nid].sysdev.kobj,
396			 kobject_name(&mem_blk->sysdev.kobj));
397		sysfs_remove_link(&mem_blk->sysdev.kobj,
398			 kobject_name(&node_devices[nid].sysdev.kobj));
399	}
400	NODEMASK_FREE(unlinked_nodes);
401	return 0;
402}
403
404static int link_mem_sections(int nid)
405{
406	unsigned long start_pfn = NODE_DATA(nid)->node_start_pfn;
407	unsigned long end_pfn = start_pfn + NODE_DATA(nid)->node_spanned_pages;
408	unsigned long pfn;
409	int err = 0;
410
411	for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
412		unsigned long section_nr = pfn_to_section_nr(pfn);
413		struct mem_section *mem_sect;
414		struct memory_block *mem_blk;
415		int ret;
416
417		if (!present_section_nr(section_nr))
418			continue;
419		mem_sect = __nr_to_section(section_nr);
420		mem_blk = find_memory_block(mem_sect);
421		ret = register_mem_sect_under_node(mem_blk, nid);
422		if (!err)
423			err = ret;
424
425		/* discard ref obtained in find_memory_block() */
426		kobject_put(&mem_blk->sysdev.kobj);
427	}
428	return err;
429}
430
431#ifdef CONFIG_HUGETLBFS
432/*
433 * Handle per node hstate attribute [un]registration on transistions
434 * to/from memoryless state.
435 */
436static void node_hugetlb_work(struct work_struct *work)
437{
438	struct node *node = container_of(work, struct node, node_work);
439
440	/*
441	 * We only get here when a node transitions to/from memoryless state.
442	 * We can detect which transition occurred by examining whether the
443	 * node has memory now.  hugetlb_register_node() already check this
444	 * so we try to register the attributes.  If that fails, then the
445	 * node has transitioned to memoryless, try to unregister the
446	 * attributes.
447	 */
448	if (!hugetlb_register_node(node))
449		hugetlb_unregister_node(node);
450}
451
452static void init_node_hugetlb_work(int nid)
453{
454	INIT_WORK(&node_devices[nid].node_work, node_hugetlb_work);
455}
456
457static int node_memory_callback(struct notifier_block *self,
458				unsigned long action, void *arg)
459{
460	struct memory_notify *mnb = arg;
461	int nid = mnb->status_change_nid;
462
463	switch (action) {
464	case MEM_ONLINE:
465	case MEM_OFFLINE:
466		/*
467		 * offload per node hstate [un]registration to a work thread
468		 * when transitioning to/from memoryless state.
469		 */
470		if (nid != NUMA_NO_NODE)
471			schedule_work(&node_devices[nid].node_work);
472		break;
473
474	case MEM_GOING_ONLINE:
475	case MEM_GOING_OFFLINE:
476	case MEM_CANCEL_ONLINE:
477	case MEM_CANCEL_OFFLINE:
478	default:
479		break;
480	}
481
482	return NOTIFY_OK;
483}
484#endif	/* CONFIG_HUGETLBFS */
485#else	/* !CONFIG_MEMORY_HOTPLUG_SPARSE */
486
487static int link_mem_sections(int nid) { return 0; }
488#endif	/* CONFIG_MEMORY_HOTPLUG_SPARSE */
489
490#if !defined(CONFIG_MEMORY_HOTPLUG_SPARSE) || \
491    !defined(CONFIG_HUGETLBFS)
492static inline int node_memory_callback(struct notifier_block *self,
493				unsigned long action, void *arg)
494{
495	return NOTIFY_OK;
496}
497
498static void init_node_hugetlb_work(int nid) { }
499
500#endif
501
502int register_one_node(int nid)
503{
504	int error = 0;
505	int cpu;
506
507	if (node_online(nid)) {
508		int p_node = parent_node(nid);
509		struct node *parent = NULL;
510
511		if (p_node != nid)
512			parent = &node_devices[p_node];
513
514		error = register_node(&node_devices[nid], nid, parent);
515
516		/* link cpu under this node */
517		for_each_present_cpu(cpu) {
518			if (cpu_to_node(cpu) == nid)
519				register_cpu_under_node(cpu, nid);
520		}
521
522		/* link memory sections under this node */
523		error = link_mem_sections(nid);
524
525		/* initialize work queue for memory hot plug */
526		init_node_hugetlb_work(nid);
527	}
528
529	return error;
530
531}
532
533void unregister_one_node(int nid)
534{
535	unregister_node(&node_devices[nid]);
536}
537
538/*
539 * node states attributes
540 */
541
542static ssize_t print_nodes_state(enum node_states state, char *buf)
543{
544	int n;
545
546	n = nodelist_scnprintf(buf, PAGE_SIZE, node_states[state]);
547	if (n > 0 && PAGE_SIZE > n + 1) {
548		*(buf + n++) = '\n';
549		*(buf + n++) = '\0';
550	}
551	return n;
552}
553
554struct node_attr {
555	struct sysdev_class_attribute attr;
556	enum node_states state;
557};
558
559static ssize_t show_node_state(struct sysdev_class *class,
560			       struct sysdev_class_attribute *attr, char *buf)
561{
562	struct node_attr *na = container_of(attr, struct node_attr, attr);
563	return print_nodes_state(na->state, buf);
564}
565
566#define _NODE_ATTR(name, state) \
567	{ _SYSDEV_CLASS_ATTR(name, 0444, show_node_state, NULL), state }
568
569static struct node_attr node_state_attr[] = {
570	_NODE_ATTR(possible, N_POSSIBLE),
571	_NODE_ATTR(online, N_ONLINE),
572	_NODE_ATTR(has_normal_memory, N_NORMAL_MEMORY),
573	_NODE_ATTR(has_cpu, N_CPU),
574#ifdef CONFIG_HIGHMEM
575	_NODE_ATTR(has_high_memory, N_HIGH_MEMORY),
576#endif
577};
578
579static struct sysdev_class_attribute *node_state_attrs[] = {
580	&node_state_attr[0].attr,
581	&node_state_attr[1].attr,
582	&node_state_attr[2].attr,
583	&node_state_attr[3].attr,
584#ifdef CONFIG_HIGHMEM
585	&node_state_attr[4].attr,
586#endif
587	NULL
588};
589
590#define NODE_CALLBACK_PRI	2	/* lower than SLAB */
591static int __init register_node_type(void)
592{
593	int ret;
594
595 	BUILD_BUG_ON(ARRAY_SIZE(node_state_attr) != NR_NODE_STATES);
596 	BUILD_BUG_ON(ARRAY_SIZE(node_state_attrs)-1 != NR_NODE_STATES);
597
598	ret = sysdev_class_register(&node_class);
599	if (!ret) {
600		hotplug_memory_notifier(node_memory_callback,
601					NODE_CALLBACK_PRI);
602	}
603
604	/*
605	 * Note:  we're not going to unregister the node class if we fail
606	 * to register the node state class attribute files.
607	 */
608	return ret;
609}
610postcore_initcall(register_node_type);
611