drivers/base/node.c: reduce stack usage of node_read_meminfo()
[sfrench/cifs-2.6.git] / drivers / base / node.c
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/compaction.h>
13 #include <linux/cpumask.h>
14 #include <linux/topology.h>
15 #include <linux/nodemask.h>
16 #include <linux/cpu.h>
17 #include <linux/device.h>
18 #include <linux/swap.h>
19 #include <linux/slab.h>
20
21 static struct sysdev_class_attribute *node_state_attrs[];
22
23 static struct sysdev_class node_class = {
24         .name = "node",
25         .attrs = node_state_attrs,
26 };
27
28
29 static ssize_t node_read_cpumap(struct sys_device *dev, int type, char *buf)
30 {
31         struct node *node_dev = to_node(dev);
32         const struct cpumask *mask = cpumask_of_node(node_dev->sysdev.id);
33         int len;
34
35         /* 2008/04/07: buf currently PAGE_SIZE, need 9 chars per 32 bits. */
36         BUILD_BUG_ON((NR_CPUS/32 * 9) > (PAGE_SIZE-1));
37
38         len = type?
39                 cpulist_scnprintf(buf, PAGE_SIZE-2, mask) :
40                 cpumask_scnprintf(buf, PAGE_SIZE-2, mask);
41         buf[len++] = '\n';
42         buf[len] = '\0';
43         return len;
44 }
45
46 static inline ssize_t node_read_cpumask(struct sys_device *dev,
47                                 struct sysdev_attribute *attr, char *buf)
48 {
49         return node_read_cpumap(dev, 0, buf);
50 }
51 static inline ssize_t node_read_cpulist(struct sys_device *dev,
52                                 struct sysdev_attribute *attr, char *buf)
53 {
54         return node_read_cpumap(dev, 1, buf);
55 }
56
57 static SYSDEV_ATTR(cpumap,  S_IRUGO, node_read_cpumask, NULL);
58 static SYSDEV_ATTR(cpulist, S_IRUGO, node_read_cpulist, NULL);
59
60 #define K(x) ((x) << (PAGE_SHIFT - 10))
61 static ssize_t node_read_meminfo(struct sys_device * dev,
62                         struct sysdev_attribute *attr, char * buf)
63 {
64         int n;
65         int nid = dev->id;
66         struct sysinfo i;
67
68         si_meminfo_node(&i, nid);
69         n = sprintf(buf,
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                        nid, K(i.totalram),
82                        nid, K(i.freeram),
83                        nid, K(i.totalram - i.freeram),
84                        nid, K(node_page_state(nid, NR_ACTIVE_ANON) +
85                                 node_page_state(nid, NR_ACTIVE_FILE)),
86                        nid, K(node_page_state(nid, NR_INACTIVE_ANON) +
87                                 node_page_state(nid, NR_INACTIVE_FILE)),
88                        nid, K(node_page_state(nid, NR_ACTIVE_ANON)),
89                        nid, K(node_page_state(nid, NR_INACTIVE_ANON)),
90                        nid, K(node_page_state(nid, NR_ACTIVE_FILE)),
91                        nid, K(node_page_state(nid, NR_INACTIVE_FILE)),
92                        nid, K(node_page_state(nid, NR_UNEVICTABLE)),
93                        nid, K(node_page_state(nid, NR_MLOCK)));
94
95 #ifdef CONFIG_HIGHMEM
96         n += sprintf(buf + n,
97                        "Node %d HighTotal:      %8lu kB\n"
98                        "Node %d HighFree:       %8lu kB\n"
99                        "Node %d LowTotal:       %8lu kB\n"
100                        "Node %d LowFree:        %8lu kB\n",
101                        nid, K(i.totalhigh),
102                        nid, K(i.freehigh),
103                        nid, K(i.totalram - i.totalhigh),
104                        nid, K(i.freeram - i.freehigh));
105 #endif
106         n += sprintf(buf + n,
107                        "Node %d Dirty:          %8lu kB\n"
108                        "Node %d Writeback:      %8lu kB\n"
109                        "Node %d FilePages:      %8lu kB\n"
110                        "Node %d Mapped:         %8lu kB\n"
111                        "Node %d AnonPages:      %8lu kB\n"
112                        "Node %d Shmem:          %8lu kB\n"
113                        "Node %d KernelStack:    %8lu kB\n"
114                        "Node %d PageTables:     %8lu kB\n"
115                        "Node %d NFS_Unstable:   %8lu kB\n"
116                        "Node %d Bounce:         %8lu kB\n"
117                        "Node %d WritebackTmp:   %8lu kB\n"
118                        "Node %d Slab:           %8lu kB\n"
119                        "Node %d SReclaimable:   %8lu kB\n"
120                        "Node %d SUnreclaim:     %8lu kB\n",
121                        nid, K(node_page_state(nid, NR_FILE_DIRTY)),
122                        nid, K(node_page_state(nid, NR_WRITEBACK)),
123                        nid, K(node_page_state(nid, NR_FILE_PAGES)),
124                        nid, K(node_page_state(nid, NR_FILE_MAPPED)),
125                        nid, K(node_page_state(nid, NR_ANON_PAGES)),
126                        nid, K(node_page_state(nid, NR_SHMEM)),
127                        nid, node_page_state(nid, NR_KERNEL_STACK) *
128                                 THREAD_SIZE / 1024,
129                        nid, K(node_page_state(nid, NR_PAGETABLE)),
130                        nid, K(node_page_state(nid, NR_UNSTABLE_NFS)),
131                        nid, K(node_page_state(nid, NR_BOUNCE)),
132                        nid, K(node_page_state(nid, NR_WRITEBACK_TEMP)),
133                        nid, K(node_page_state(nid, NR_SLAB_RECLAIMABLE) +
134                                 node_page_state(nid, NR_SLAB_UNRECLAIMABLE)),
135                        nid, K(node_page_state(nid, NR_SLAB_RECLAIMABLE)),
136                        nid, K(node_page_state(nid, NR_SLAB_UNRECLAIMABLE)));
137         n += hugetlb_report_node_meminfo(nid, buf + n);
138         return n;
139 }
140
141 #undef K
142 static SYSDEV_ATTR(meminfo, S_IRUGO, node_read_meminfo, NULL);
143
144 static ssize_t node_read_numastat(struct sys_device * dev,
145                                 struct sysdev_attribute *attr, char * buf)
146 {
147         return sprintf(buf,
148                        "numa_hit %lu\n"
149                        "numa_miss %lu\n"
150                        "numa_foreign %lu\n"
151                        "interleave_hit %lu\n"
152                        "local_node %lu\n"
153                        "other_node %lu\n",
154                        node_page_state(dev->id, NUMA_HIT),
155                        node_page_state(dev->id, NUMA_MISS),
156                        node_page_state(dev->id, NUMA_FOREIGN),
157                        node_page_state(dev->id, NUMA_INTERLEAVE_HIT),
158                        node_page_state(dev->id, NUMA_LOCAL),
159                        node_page_state(dev->id, NUMA_OTHER));
160 }
161 static SYSDEV_ATTR(numastat, S_IRUGO, node_read_numastat, NULL);
162
163 static ssize_t node_read_distance(struct sys_device * dev,
164                         struct sysdev_attribute *attr, char * buf)
165 {
166         int nid = dev->id;
167         int len = 0;
168         int i;
169
170         /*
171          * buf is currently PAGE_SIZE in length and each node needs 4 chars
172          * at the most (distance + space or newline).
173          */
174         BUILD_BUG_ON(MAX_NUMNODES * 4 > PAGE_SIZE);
175
176         for_each_online_node(i)
177                 len += sprintf(buf + len, "%s%d", i ? " " : "", node_distance(nid, i));
178
179         len += sprintf(buf + len, "\n");
180         return len;
181 }
182 static SYSDEV_ATTR(distance, S_IRUGO, node_read_distance, NULL);
183
184 #ifdef CONFIG_HUGETLBFS
185 /*
186  * hugetlbfs per node attributes registration interface:
187  * When/if hugetlb[fs] subsystem initializes [sometime after this module],
188  * it will register its per node attributes for all online nodes with
189  * memory.  It will also call register_hugetlbfs_with_node(), below, to
190  * register its attribute registration functions with this node driver.
191  * Once these hooks have been initialized, the node driver will call into
192  * the hugetlb module to [un]register attributes for hot-plugged nodes.
193  */
194 static node_registration_func_t __hugetlb_register_node;
195 static node_registration_func_t __hugetlb_unregister_node;
196
197 static inline bool hugetlb_register_node(struct node *node)
198 {
199         if (__hugetlb_register_node &&
200                         node_state(node->sysdev.id, N_HIGH_MEMORY)) {
201                 __hugetlb_register_node(node);
202                 return true;
203         }
204         return false;
205 }
206
207 static inline void hugetlb_unregister_node(struct node *node)
208 {
209         if (__hugetlb_unregister_node)
210                 __hugetlb_unregister_node(node);
211 }
212
213 void register_hugetlbfs_with_node(node_registration_func_t doregister,
214                                   node_registration_func_t unregister)
215 {
216         __hugetlb_register_node   = doregister;
217         __hugetlb_unregister_node = unregister;
218 }
219 #else
220 static inline void hugetlb_register_node(struct node *node) {}
221
222 static inline void hugetlb_unregister_node(struct node *node) {}
223 #endif
224
225
226 /*
227  * register_node - Setup a sysfs device for a node.
228  * @num - Node number to use when creating the device.
229  *
230  * Initialize and register the node device.
231  */
232 int register_node(struct node *node, int num, struct node *parent)
233 {
234         int error;
235
236         node->sysdev.id = num;
237         node->sysdev.cls = &node_class;
238         error = sysdev_register(&node->sysdev);
239
240         if (!error){
241                 sysdev_create_file(&node->sysdev, &attr_cpumap);
242                 sysdev_create_file(&node->sysdev, &attr_cpulist);
243                 sysdev_create_file(&node->sysdev, &attr_meminfo);
244                 sysdev_create_file(&node->sysdev, &attr_numastat);
245                 sysdev_create_file(&node->sysdev, &attr_distance);
246
247                 scan_unevictable_register_node(node);
248
249                 hugetlb_register_node(node);
250
251                 compaction_register_node(node);
252         }
253         return error;
254 }
255
256 /**
257  * unregister_node - unregister a node device
258  * @node: node going away
259  *
260  * Unregisters a node device @node.  All the devices on the node must be
261  * unregistered before calling this function.
262  */
263 void unregister_node(struct node *node)
264 {
265         sysdev_remove_file(&node->sysdev, &attr_cpumap);
266         sysdev_remove_file(&node->sysdev, &attr_cpulist);
267         sysdev_remove_file(&node->sysdev, &attr_meminfo);
268         sysdev_remove_file(&node->sysdev, &attr_numastat);
269         sysdev_remove_file(&node->sysdev, &attr_distance);
270
271         scan_unevictable_unregister_node(node);
272         hugetlb_unregister_node(node);          /* no-op, if memoryless node */
273
274         sysdev_unregister(&node->sysdev);
275 }
276
277 struct node node_devices[MAX_NUMNODES];
278
279 /*
280  * register cpu under node
281  */
282 int register_cpu_under_node(unsigned int cpu, unsigned int nid)
283 {
284         int ret;
285         struct sys_device *obj;
286
287         if (!node_online(nid))
288                 return 0;
289
290         obj = get_cpu_sysdev(cpu);
291         if (!obj)
292                 return 0;
293
294         ret = sysfs_create_link(&node_devices[nid].sysdev.kobj,
295                                 &obj->kobj,
296                                 kobject_name(&obj->kobj));
297         if (ret)
298                 return ret;
299
300         return sysfs_create_link(&obj->kobj,
301                                  &node_devices[nid].sysdev.kobj,
302                                  kobject_name(&node_devices[nid].sysdev.kobj));
303 }
304
305 int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
306 {
307         struct sys_device *obj;
308
309         if (!node_online(nid))
310                 return 0;
311
312         obj = get_cpu_sysdev(cpu);
313         if (!obj)
314                 return 0;
315
316         sysfs_remove_link(&node_devices[nid].sysdev.kobj,
317                           kobject_name(&obj->kobj));
318         sysfs_remove_link(&obj->kobj,
319                           kobject_name(&node_devices[nid].sysdev.kobj));
320
321         return 0;
322 }
323
324 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
325 #define page_initialized(page)  (page->lru.next)
326
327 static int get_nid_for_pfn(unsigned long pfn)
328 {
329         struct page *page;
330
331         if (!pfn_valid_within(pfn))
332                 return -1;
333         page = pfn_to_page(pfn);
334         if (!page_initialized(page))
335                 return -1;
336         return pfn_to_nid(pfn);
337 }
338
339 /* register memory section under specified node if it spans that node */
340 int register_mem_sect_under_node(struct memory_block *mem_blk, int nid)
341 {
342         int ret;
343         unsigned long pfn, sect_start_pfn, sect_end_pfn;
344
345         if (!mem_blk)
346                 return -EFAULT;
347         if (!node_online(nid))
348                 return 0;
349         sect_start_pfn = section_nr_to_pfn(mem_blk->phys_index);
350         sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
351         for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
352                 int page_nid;
353
354                 page_nid = get_nid_for_pfn(pfn);
355                 if (page_nid < 0)
356                         continue;
357                 if (page_nid != nid)
358                         continue;
359                 ret = sysfs_create_link_nowarn(&node_devices[nid].sysdev.kobj,
360                                         &mem_blk->sysdev.kobj,
361                                         kobject_name(&mem_blk->sysdev.kobj));
362                 if (ret)
363                         return ret;
364
365                 return sysfs_create_link_nowarn(&mem_blk->sysdev.kobj,
366                                 &node_devices[nid].sysdev.kobj,
367                                 kobject_name(&node_devices[nid].sysdev.kobj));
368         }
369         /* mem section does not span the specified node */
370         return 0;
371 }
372
373 /* unregister memory section under all nodes that it spans */
374 int unregister_mem_sect_under_nodes(struct memory_block *mem_blk)
375 {
376         NODEMASK_ALLOC(nodemask_t, unlinked_nodes, GFP_KERNEL);
377         unsigned long pfn, sect_start_pfn, sect_end_pfn;
378
379         if (!mem_blk) {
380                 NODEMASK_FREE(unlinked_nodes);
381                 return -EFAULT;
382         }
383         if (!unlinked_nodes)
384                 return -ENOMEM;
385         nodes_clear(*unlinked_nodes);
386         sect_start_pfn = section_nr_to_pfn(mem_blk->phys_index);
387         sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
388         for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
389                 int nid;
390
391                 nid = get_nid_for_pfn(pfn);
392                 if (nid < 0)
393                         continue;
394                 if (!node_online(nid))
395                         continue;
396                 if (node_test_and_set(nid, *unlinked_nodes))
397                         continue;
398                 sysfs_remove_link(&node_devices[nid].sysdev.kobj,
399                          kobject_name(&mem_blk->sysdev.kobj));
400                 sysfs_remove_link(&mem_blk->sysdev.kobj,
401                          kobject_name(&node_devices[nid].sysdev.kobj));
402         }
403         NODEMASK_FREE(unlinked_nodes);
404         return 0;
405 }
406
407 static int link_mem_sections(int nid)
408 {
409         unsigned long start_pfn = NODE_DATA(nid)->node_start_pfn;
410         unsigned long end_pfn = start_pfn + NODE_DATA(nid)->node_spanned_pages;
411         unsigned long pfn;
412         int err = 0;
413
414         for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
415                 unsigned long section_nr = pfn_to_section_nr(pfn);
416                 struct mem_section *mem_sect;
417                 struct memory_block *mem_blk;
418                 int ret;
419
420                 if (!present_section_nr(section_nr))
421                         continue;
422                 mem_sect = __nr_to_section(section_nr);
423                 mem_blk = find_memory_block(mem_sect);
424                 ret = register_mem_sect_under_node(mem_blk, nid);
425                 if (!err)
426                         err = ret;
427
428                 /* discard ref obtained in find_memory_block() */
429                 kobject_put(&mem_blk->sysdev.kobj);
430         }
431         return err;
432 }
433
434 #ifdef CONFIG_HUGETLBFS
435 /*
436  * Handle per node hstate attribute [un]registration on transistions
437  * to/from memoryless state.
438  */
439 static void node_hugetlb_work(struct work_struct *work)
440 {
441         struct node *node = container_of(work, struct node, node_work);
442
443         /*
444          * We only get here when a node transitions to/from memoryless state.
445          * We can detect which transition occurred by examining whether the
446          * node has memory now.  hugetlb_register_node() already check this
447          * so we try to register the attributes.  If that fails, then the
448          * node has transitioned to memoryless, try to unregister the
449          * attributes.
450          */
451         if (!hugetlb_register_node(node))
452                 hugetlb_unregister_node(node);
453 }
454
455 static void init_node_hugetlb_work(int nid)
456 {
457         INIT_WORK(&node_devices[nid].node_work, node_hugetlb_work);
458 }
459
460 static int node_memory_callback(struct notifier_block *self,
461                                 unsigned long action, void *arg)
462 {
463         struct memory_notify *mnb = arg;
464         int nid = mnb->status_change_nid;
465
466         switch (action) {
467         case MEM_ONLINE:
468         case MEM_OFFLINE:
469                 /*
470                  * offload per node hstate [un]registration to a work thread
471                  * when transitioning to/from memoryless state.
472                  */
473                 if (nid != NUMA_NO_NODE)
474                         schedule_work(&node_devices[nid].node_work);
475                 break;
476
477         case MEM_GOING_ONLINE:
478         case MEM_GOING_OFFLINE:
479         case MEM_CANCEL_ONLINE:
480         case MEM_CANCEL_OFFLINE:
481         default:
482                 break;
483         }
484
485         return NOTIFY_OK;
486 }
487 #endif  /* CONFIG_HUGETLBFS */
488 #else   /* !CONFIG_MEMORY_HOTPLUG_SPARSE */
489
490 static int link_mem_sections(int nid) { return 0; }
491 #endif  /* CONFIG_MEMORY_HOTPLUG_SPARSE */
492
493 #if !defined(CONFIG_MEMORY_HOTPLUG_SPARSE) || \
494     !defined(CONFIG_HUGETLBFS)
495 static inline int node_memory_callback(struct notifier_block *self,
496                                 unsigned long action, void *arg)
497 {
498         return NOTIFY_OK;
499 }
500
501 static void init_node_hugetlb_work(int nid) { }
502
503 #endif
504
505 int register_one_node(int nid)
506 {
507         int error = 0;
508         int cpu;
509
510         if (node_online(nid)) {
511                 int p_node = parent_node(nid);
512                 struct node *parent = NULL;
513
514                 if (p_node != nid)
515                         parent = &node_devices[p_node];
516
517                 error = register_node(&node_devices[nid], nid, parent);
518
519                 /* link cpu under this node */
520                 for_each_present_cpu(cpu) {
521                         if (cpu_to_node(cpu) == nid)
522                                 register_cpu_under_node(cpu, nid);
523                 }
524
525                 /* link memory sections under this node */
526                 error = link_mem_sections(nid);
527
528                 /* initialize work queue for memory hot plug */
529                 init_node_hugetlb_work(nid);
530         }
531
532         return error;
533
534 }
535
536 void unregister_one_node(int nid)
537 {
538         unregister_node(&node_devices[nid]);
539 }
540
541 /*
542  * node states attributes
543  */
544
545 static ssize_t print_nodes_state(enum node_states state, char *buf)
546 {
547         int n;
548
549         n = nodelist_scnprintf(buf, PAGE_SIZE, node_states[state]);
550         if (n > 0 && PAGE_SIZE > n + 1) {
551                 *(buf + n++) = '\n';
552                 *(buf + n++) = '\0';
553         }
554         return n;
555 }
556
557 struct node_attr {
558         struct sysdev_class_attribute attr;
559         enum node_states state;
560 };
561
562 static ssize_t show_node_state(struct sysdev_class *class,
563                                struct sysdev_class_attribute *attr, char *buf)
564 {
565         struct node_attr *na = container_of(attr, struct node_attr, attr);
566         return print_nodes_state(na->state, buf);
567 }
568
569 #define _NODE_ATTR(name, state) \
570         { _SYSDEV_CLASS_ATTR(name, 0444, show_node_state, NULL), state }
571
572 static struct node_attr node_state_attr[] = {
573         _NODE_ATTR(possible, N_POSSIBLE),
574         _NODE_ATTR(online, N_ONLINE),
575         _NODE_ATTR(has_normal_memory, N_NORMAL_MEMORY),
576         _NODE_ATTR(has_cpu, N_CPU),
577 #ifdef CONFIG_HIGHMEM
578         _NODE_ATTR(has_high_memory, N_HIGH_MEMORY),
579 #endif
580 };
581
582 static struct sysdev_class_attribute *node_state_attrs[] = {
583         &node_state_attr[0].attr,
584         &node_state_attr[1].attr,
585         &node_state_attr[2].attr,
586         &node_state_attr[3].attr,
587 #ifdef CONFIG_HIGHMEM
588         &node_state_attr[4].attr,
589 #endif
590         NULL
591 };
592
593 #define NODE_CALLBACK_PRI       2       /* lower than SLAB */
594 static int __init register_node_type(void)
595 {
596         int ret;
597
598         BUILD_BUG_ON(ARRAY_SIZE(node_state_attr) != NR_NODE_STATES);
599         BUILD_BUG_ON(ARRAY_SIZE(node_state_attrs)-1 != NR_NODE_STATES);
600
601         ret = sysdev_class_register(&node_class);
602         if (!ret) {
603                 hotplug_memory_notifier(node_memory_callback,
604                                         NODE_CALLBACK_PRI);
605         }
606
607         /*
608          * Note:  we're not going to unregister the node class if we fail
609          * to register the node state class attribute files.
610          */
611         return ret;
612 }
613 postcore_initcall(register_node_type);