mm: vmalloc: check for page allocation failure before vmlist insertion
[linux-2.6.git] / mm / page_cgroup.c
1 #include <linux/mm.h>
2 #include <linux/mmzone.h>
3 #include <linux/bootmem.h>
4 #include <linux/bit_spinlock.h>
5 #include <linux/page_cgroup.h>
6 #include <linux/hash.h>
7 #include <linux/slab.h>
8 #include <linux/memory.h>
9 #include <linux/vmalloc.h>
10 #include <linux/cgroup.h>
11 #include <linux/swapops.h>
12 #include <linux/kmemleak.h>
13
14 static void __meminit init_page_cgroup(struct page_cgroup *pc, unsigned long id)
15 {
16         pc->flags = 0;
17         set_page_cgroup_array_id(pc, id);
18         pc->mem_cgroup = NULL;
19         INIT_LIST_HEAD(&pc->lru);
20 }
21 static unsigned long total_usage;
22
23 #if !defined(CONFIG_SPARSEMEM)
24
25
26 void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
27 {
28         pgdat->node_page_cgroup = NULL;
29 }
30
31 struct page_cgroup *lookup_page_cgroup(struct page *page)
32 {
33         unsigned long pfn = page_to_pfn(page);
34         unsigned long offset;
35         struct page_cgroup *base;
36
37         base = NODE_DATA(page_to_nid(page))->node_page_cgroup;
38         if (unlikely(!base))
39                 return NULL;
40
41         offset = pfn - NODE_DATA(page_to_nid(page))->node_start_pfn;
42         return base + offset;
43 }
44
45 struct page *lookup_cgroup_page(struct page_cgroup *pc)
46 {
47         unsigned long pfn;
48         struct page *page;
49         pg_data_t *pgdat;
50
51         pgdat = NODE_DATA(page_cgroup_array_id(pc));
52         pfn = pc - pgdat->node_page_cgroup + pgdat->node_start_pfn;
53         page = pfn_to_page(pfn);
54         VM_BUG_ON(pc != lookup_page_cgroup(page));
55         return page;
56 }
57
58 static int __init alloc_node_page_cgroup(int nid)
59 {
60         struct page_cgroup *base, *pc;
61         unsigned long table_size;
62         unsigned long start_pfn, nr_pages, index;
63
64         start_pfn = NODE_DATA(nid)->node_start_pfn;
65         nr_pages = NODE_DATA(nid)->node_spanned_pages;
66
67         if (!nr_pages)
68                 return 0;
69
70         table_size = sizeof(struct page_cgroup) * nr_pages;
71
72         base = __alloc_bootmem_node_nopanic(NODE_DATA(nid),
73                         table_size, PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
74         if (!base)
75                 return -ENOMEM;
76         for (index = 0; index < nr_pages; index++) {
77                 pc = base + index;
78                 init_page_cgroup(pc, nid);
79         }
80         NODE_DATA(nid)->node_page_cgroup = base;
81         total_usage += table_size;
82         return 0;
83 }
84
85 void __init page_cgroup_init_flatmem(void)
86 {
87
88         int nid, fail;
89
90         if (mem_cgroup_disabled())
91                 return;
92
93         for_each_online_node(nid)  {
94                 fail = alloc_node_page_cgroup(nid);
95                 if (fail)
96                         goto fail;
97         }
98         printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
99         printk(KERN_INFO "please try 'cgroup_disable=memory' option if you"
100         " don't want memory cgroups\n");
101         return;
102 fail:
103         printk(KERN_CRIT "allocation of page_cgroup failed.\n");
104         printk(KERN_CRIT "please try 'cgroup_disable=memory' boot option\n");
105         panic("Out of memory");
106 }
107
108 #else /* CONFIG_FLAT_NODE_MEM_MAP */
109
110 struct page_cgroup *lookup_page_cgroup(struct page *page)
111 {
112         unsigned long pfn = page_to_pfn(page);
113         struct mem_section *section = __pfn_to_section(pfn);
114
115         if (!section->page_cgroup)
116                 return NULL;
117         return section->page_cgroup + pfn;
118 }
119
120 struct page *lookup_cgroup_page(struct page_cgroup *pc)
121 {
122         struct mem_section *section;
123         struct page *page;
124         unsigned long nr;
125
126         nr = page_cgroup_array_id(pc);
127         section = __nr_to_section(nr);
128         page = pfn_to_page(pc - section->page_cgroup);
129         VM_BUG_ON(pc != lookup_page_cgroup(page));
130         return page;
131 }
132
133 static void *__meminit alloc_page_cgroup(size_t size, int nid)
134 {
135         void *addr = NULL;
136
137         addr = alloc_pages_exact_nid(nid, size, GFP_KERNEL | __GFP_NOWARN);
138         if (addr)
139                 return addr;
140
141         if (node_state(nid, N_HIGH_MEMORY))
142                 addr = vmalloc_node(size, nid);
143         else
144                 addr = vmalloc(size);
145
146         return addr;
147 }
148
149 #ifdef CONFIG_MEMORY_HOTPLUG
150 static void free_page_cgroup(void *addr)
151 {
152         if (is_vmalloc_addr(addr)) {
153                 vfree(addr);
154         } else {
155                 struct page *page = virt_to_page(addr);
156                 size_t table_size =
157                         sizeof(struct page_cgroup) * PAGES_PER_SECTION;
158
159                 BUG_ON(PageReserved(page));
160                 free_pages_exact(addr, table_size);
161         }
162 }
163 #endif
164
165 static int __meminit init_section_page_cgroup(unsigned long pfn, int nid)
166 {
167         struct page_cgroup *base, *pc;
168         struct mem_section *section;
169         unsigned long table_size;
170         unsigned long nr;
171         int index;
172
173         nr = pfn_to_section_nr(pfn);
174         section = __nr_to_section(nr);
175
176         if (section->page_cgroup)
177                 return 0;
178
179         table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
180         base = alloc_page_cgroup(table_size, nid);
181
182         /*
183          * The value stored in section->page_cgroup is (base - pfn)
184          * and it does not point to the memory block allocated above,
185          * causing kmemleak false positives.
186          */
187         kmemleak_not_leak(base);
188
189         if (!base) {
190                 printk(KERN_ERR "page cgroup allocation failure\n");
191                 return -ENOMEM;
192         }
193
194         for (index = 0; index < PAGES_PER_SECTION; index++) {
195                 pc = base + index;
196                 init_page_cgroup(pc, nr);
197         }
198         /*
199          * The passed "pfn" may not be aligned to SECTION.  For the calculation
200          * we need to apply a mask.
201          */
202         pfn &= PAGE_SECTION_MASK;
203         section->page_cgroup = base - pfn;
204         total_usage += table_size;
205         return 0;
206 }
207 #ifdef CONFIG_MEMORY_HOTPLUG
208 void __free_page_cgroup(unsigned long pfn)
209 {
210         struct mem_section *ms;
211         struct page_cgroup *base;
212
213         ms = __pfn_to_section(pfn);
214         if (!ms || !ms->page_cgroup)
215                 return;
216         base = ms->page_cgroup + pfn;
217         free_page_cgroup(base);
218         ms->page_cgroup = NULL;
219 }
220
221 int __meminit online_page_cgroup(unsigned long start_pfn,
222                         unsigned long nr_pages,
223                         int nid)
224 {
225         unsigned long start, end, pfn;
226         int fail = 0;
227
228         start = SECTION_ALIGN_DOWN(start_pfn);
229         end = SECTION_ALIGN_UP(start_pfn + nr_pages);
230
231         if (nid == -1) {
232                 /*
233                  * In this case, "nid" already exists and contains valid memory.
234                  * "start_pfn" passed to us is a pfn which is an arg for
235                  * online__pages(), and start_pfn should exist.
236                  */
237                 nid = pfn_to_nid(start_pfn);
238                 VM_BUG_ON(!node_state(nid, N_ONLINE));
239         }
240
241         for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION) {
242                 if (!pfn_present(pfn))
243                         continue;
244                 fail = init_section_page_cgroup(pfn, nid);
245         }
246         if (!fail)
247                 return 0;
248
249         /* rollback */
250         for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
251                 __free_page_cgroup(pfn);
252
253         return -ENOMEM;
254 }
255
256 int __meminit offline_page_cgroup(unsigned long start_pfn,
257                 unsigned long nr_pages, int nid)
258 {
259         unsigned long start, end, pfn;
260
261         start = SECTION_ALIGN_DOWN(start_pfn);
262         end = SECTION_ALIGN_UP(start_pfn + nr_pages);
263
264         for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
265                 __free_page_cgroup(pfn);
266         return 0;
267
268 }
269
270 static int __meminit page_cgroup_callback(struct notifier_block *self,
271                                unsigned long action, void *arg)
272 {
273         struct memory_notify *mn = arg;
274         int ret = 0;
275         switch (action) {
276         case MEM_GOING_ONLINE:
277                 ret = online_page_cgroup(mn->start_pfn,
278                                    mn->nr_pages, mn->status_change_nid);
279                 break;
280         case MEM_OFFLINE:
281                 offline_page_cgroup(mn->start_pfn,
282                                 mn->nr_pages, mn->status_change_nid);
283                 break;
284         case MEM_CANCEL_ONLINE:
285         case MEM_GOING_OFFLINE:
286                 break;
287         case MEM_ONLINE:
288         case MEM_CANCEL_OFFLINE:
289                 break;
290         }
291
292         return notifier_from_errno(ret);
293 }
294
295 #endif
296
297 void __init page_cgroup_init(void)
298 {
299         unsigned long pfn;
300         int nid;
301
302         if (mem_cgroup_disabled())
303                 return;
304
305         for_each_node_state(nid, N_HIGH_MEMORY) {
306                 unsigned long start_pfn, end_pfn;
307
308                 start_pfn = node_start_pfn(nid);
309                 end_pfn = node_end_pfn(nid);
310                 /*
311                  * start_pfn and end_pfn may not be aligned to SECTION and the
312                  * page->flags of out of node pages are not initialized.  So we
313                  * scan [start_pfn, the biggest section's pfn < end_pfn) here.
314                  */
315                 for (pfn = start_pfn;
316                      pfn < end_pfn;
317                      pfn = ALIGN(pfn + 1, PAGES_PER_SECTION)) {
318
319                         if (!pfn_valid(pfn))
320                                 continue;
321                         /*
322                          * Nodes's pfns can be overlapping.
323                          * We know some arch can have a nodes layout such as
324                          * -------------pfn-------------->
325                          * N0 | N1 | N2 | N0 | N1 | N2|....
326                          */
327                         if (pfn_to_nid(pfn) != nid)
328                                 continue;
329                         if (init_section_page_cgroup(pfn, nid))
330                                 goto oom;
331                 }
332         }
333         hotplug_memory_notifier(page_cgroup_callback, 0);
334         printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
335         printk(KERN_INFO "please try 'cgroup_disable=memory' option if you "
336                          "don't want memory cgroups\n");
337         return;
338 oom:
339         printk(KERN_CRIT "try 'cgroup_disable=memory' boot option\n");
340         panic("Out of memory");
341 }
342
343 void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
344 {
345         return;
346 }
347
348 #endif
349
350
351 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
352
353 static DEFINE_MUTEX(swap_cgroup_mutex);
354 struct swap_cgroup_ctrl {
355         struct page **map;
356         unsigned long length;
357         spinlock_t      lock;
358 };
359
360 struct swap_cgroup_ctrl swap_cgroup_ctrl[MAX_SWAPFILES];
361
362 struct swap_cgroup {
363         unsigned short          id;
364 };
365 #define SC_PER_PAGE     (PAGE_SIZE/sizeof(struct swap_cgroup))
366 #define SC_POS_MASK     (SC_PER_PAGE - 1)
367
368 /*
369  * SwapCgroup implements "lookup" and "exchange" operations.
370  * In typical usage, this swap_cgroup is accessed via memcg's charge/uncharge
371  * against SwapCache. At swap_free(), this is accessed directly from swap.
372  *
373  * This means,
374  *  - we have no race in "exchange" when we're accessed via SwapCache because
375  *    SwapCache(and its swp_entry) is under lock.
376  *  - When called via swap_free(), there is no user of this entry and no race.
377  * Then, we don't need lock around "exchange".
378  *
379  * TODO: we can push these buffers out to HIGHMEM.
380  */
381
382 /*
383  * allocate buffer for swap_cgroup.
384  */
385 static int swap_cgroup_prepare(int type)
386 {
387         struct page *page;
388         struct swap_cgroup_ctrl *ctrl;
389         unsigned long idx, max;
390
391         ctrl = &swap_cgroup_ctrl[type];
392
393         for (idx = 0; idx < ctrl->length; idx++) {
394                 page = alloc_page(GFP_KERNEL | __GFP_ZERO);
395                 if (!page)
396                         goto not_enough_page;
397                 ctrl->map[idx] = page;
398         }
399         return 0;
400 not_enough_page:
401         max = idx;
402         for (idx = 0; idx < max; idx++)
403                 __free_page(ctrl->map[idx]);
404
405         return -ENOMEM;
406 }
407
408 /**
409  * swap_cgroup_cmpxchg - cmpxchg mem_cgroup's id for this swp_entry.
410  * @end: swap entry to be cmpxchged
411  * @old: old id
412  * @new: new id
413  *
414  * Returns old id at success, 0 at failure.
415  * (There is no mem_cgroup using 0 as its id)
416  */
417 unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
418                                         unsigned short old, unsigned short new)
419 {
420         int type = swp_type(ent);
421         unsigned long offset = swp_offset(ent);
422         unsigned long idx = offset / SC_PER_PAGE;
423         unsigned long pos = offset & SC_POS_MASK;
424         struct swap_cgroup_ctrl *ctrl;
425         struct page *mappage;
426         struct swap_cgroup *sc;
427         unsigned long flags;
428         unsigned short retval;
429
430         ctrl = &swap_cgroup_ctrl[type];
431
432         mappage = ctrl->map[idx];
433         sc = page_address(mappage);
434         sc += pos;
435         spin_lock_irqsave(&ctrl->lock, flags);
436         retval = sc->id;
437         if (retval == old)
438                 sc->id = new;
439         else
440                 retval = 0;
441         spin_unlock_irqrestore(&ctrl->lock, flags);
442         return retval;
443 }
444
445 /**
446  * swap_cgroup_record - record mem_cgroup for this swp_entry.
447  * @ent: swap entry to be recorded into
448  * @mem: mem_cgroup to be recorded
449  *
450  * Returns old value at success, 0 at failure.
451  * (Of course, old value can be 0.)
452  */
453 unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
454 {
455         int type = swp_type(ent);
456         unsigned long offset = swp_offset(ent);
457         unsigned long idx = offset / SC_PER_PAGE;
458         unsigned long pos = offset & SC_POS_MASK;
459         struct swap_cgroup_ctrl *ctrl;
460         struct page *mappage;
461         struct swap_cgroup *sc;
462         unsigned short old;
463         unsigned long flags;
464
465         ctrl = &swap_cgroup_ctrl[type];
466
467         mappage = ctrl->map[idx];
468         sc = page_address(mappage);
469         sc += pos;
470         spin_lock_irqsave(&ctrl->lock, flags);
471         old = sc->id;
472         sc->id = id;
473         spin_unlock_irqrestore(&ctrl->lock, flags);
474
475         return old;
476 }
477
478 /**
479  * lookup_swap_cgroup - lookup mem_cgroup tied to swap entry
480  * @ent: swap entry to be looked up.
481  *
482  * Returns CSS ID of mem_cgroup at success. 0 at failure. (0 is invalid ID)
483  */
484 unsigned short lookup_swap_cgroup(swp_entry_t ent)
485 {
486         int type = swp_type(ent);
487         unsigned long offset = swp_offset(ent);
488         unsigned long idx = offset / SC_PER_PAGE;
489         unsigned long pos = offset & SC_POS_MASK;
490         struct swap_cgroup_ctrl *ctrl;
491         struct page *mappage;
492         struct swap_cgroup *sc;
493         unsigned short ret;
494
495         ctrl = &swap_cgroup_ctrl[type];
496         mappage = ctrl->map[idx];
497         sc = page_address(mappage);
498         sc += pos;
499         ret = sc->id;
500         return ret;
501 }
502
503 int swap_cgroup_swapon(int type, unsigned long max_pages)
504 {
505         void *array;
506         unsigned long array_size;
507         unsigned long length;
508         struct swap_cgroup_ctrl *ctrl;
509
510         if (!do_swap_account)
511                 return 0;
512
513         length = DIV_ROUND_UP(max_pages, SC_PER_PAGE);
514         array_size = length * sizeof(void *);
515
516         array = vmalloc(array_size);
517         if (!array)
518                 goto nomem;
519
520         memset(array, 0, array_size);
521         ctrl = &swap_cgroup_ctrl[type];
522         mutex_lock(&swap_cgroup_mutex);
523         ctrl->length = length;
524         ctrl->map = array;
525         spin_lock_init(&ctrl->lock);
526         if (swap_cgroup_prepare(type)) {
527                 /* memory shortage */
528                 ctrl->map = NULL;
529                 ctrl->length = 0;
530                 mutex_unlock(&swap_cgroup_mutex);
531                 vfree(array);
532                 goto nomem;
533         }
534         mutex_unlock(&swap_cgroup_mutex);
535
536         return 0;
537 nomem:
538         printk(KERN_INFO "couldn't allocate enough memory for swap_cgroup.\n");
539         printk(KERN_INFO
540                 "swap_cgroup can be disabled by swapaccount=0 boot option\n");
541         return -ENOMEM;
542 }
543
544 void swap_cgroup_swapoff(int type)
545 {
546         struct page **map;
547         unsigned long i, length;
548         struct swap_cgroup_ctrl *ctrl;
549
550         if (!do_swap_account)
551                 return;
552
553         mutex_lock(&swap_cgroup_mutex);
554         ctrl = &swap_cgroup_ctrl[type];
555         map = ctrl->map;
556         length = ctrl->length;
557         ctrl->map = NULL;
558         ctrl->length = 0;
559         mutex_unlock(&swap_cgroup_mutex);
560
561         if (map) {
562                 for (i = 0; i < length; i++) {
563                         struct page *page = map[i];
564                         if (page)
565                                 __free_page(page);
566                 }
567                 vfree(map);
568         }
569 }
570
571 #endif