mm/page_cgroup.c: quiet sparse noise
[linux-3.10.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         gfp_t flags = GFP_KERNEL | __GFP_NOWARN;
137
138         addr = alloc_pages_exact_nid(nid, size, flags);
139         if (addr) {
140                 kmemleak_alloc(addr, size, 1, flags);
141                 return addr;
142         }
143
144         if (node_state(nid, N_HIGH_MEMORY))
145                 addr = vmalloc_node(size, nid);
146         else
147                 addr = vmalloc(size);
148
149         return addr;
150 }
151
152 #ifdef CONFIG_MEMORY_HOTPLUG
153 static void free_page_cgroup(void *addr)
154 {
155         if (is_vmalloc_addr(addr)) {
156                 vfree(addr);
157         } else {
158                 struct page *page = virt_to_page(addr);
159                 size_t table_size =
160                         sizeof(struct page_cgroup) * PAGES_PER_SECTION;
161
162                 BUG_ON(PageReserved(page));
163                 free_pages_exact(addr, table_size);
164         }
165 }
166 #endif
167
168 static int __meminit init_section_page_cgroup(unsigned long pfn, int nid)
169 {
170         struct page_cgroup *base, *pc;
171         struct mem_section *section;
172         unsigned long table_size;
173         unsigned long nr;
174         int index;
175
176         nr = pfn_to_section_nr(pfn);
177         section = __nr_to_section(nr);
178
179         if (section->page_cgroup)
180                 return 0;
181
182         table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
183         base = alloc_page_cgroup(table_size, nid);
184
185         /*
186          * The value stored in section->page_cgroup is (base - pfn)
187          * and it does not point to the memory block allocated above,
188          * causing kmemleak false positives.
189          */
190         kmemleak_not_leak(base);
191
192         if (!base) {
193                 printk(KERN_ERR "page cgroup allocation failure\n");
194                 return -ENOMEM;
195         }
196
197         for (index = 0; index < PAGES_PER_SECTION; index++) {
198                 pc = base + index;
199                 init_page_cgroup(pc, nr);
200         }
201         /*
202          * The passed "pfn" may not be aligned to SECTION.  For the calculation
203          * we need to apply a mask.
204          */
205         pfn &= PAGE_SECTION_MASK;
206         section->page_cgroup = base - pfn;
207         total_usage += table_size;
208         return 0;
209 }
210 #ifdef CONFIG_MEMORY_HOTPLUG
211 void __free_page_cgroup(unsigned long pfn)
212 {
213         struct mem_section *ms;
214         struct page_cgroup *base;
215
216         ms = __pfn_to_section(pfn);
217         if (!ms || !ms->page_cgroup)
218                 return;
219         base = ms->page_cgroup + pfn;
220         free_page_cgroup(base);
221         ms->page_cgroup = NULL;
222 }
223
224 int __meminit online_page_cgroup(unsigned long start_pfn,
225                         unsigned long nr_pages,
226                         int nid)
227 {
228         unsigned long start, end, pfn;
229         int fail = 0;
230
231         start = SECTION_ALIGN_DOWN(start_pfn);
232         end = SECTION_ALIGN_UP(start_pfn + nr_pages);
233
234         if (nid == -1) {
235                 /*
236                  * In this case, "nid" already exists and contains valid memory.
237                  * "start_pfn" passed to us is a pfn which is an arg for
238                  * online__pages(), and start_pfn should exist.
239                  */
240                 nid = pfn_to_nid(start_pfn);
241                 VM_BUG_ON(!node_state(nid, N_ONLINE));
242         }
243
244         for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION) {
245                 if (!pfn_present(pfn))
246                         continue;
247                 fail = init_section_page_cgroup(pfn, nid);
248         }
249         if (!fail)
250                 return 0;
251
252         /* rollback */
253         for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
254                 __free_page_cgroup(pfn);
255
256         return -ENOMEM;
257 }
258
259 int __meminit offline_page_cgroup(unsigned long start_pfn,
260                 unsigned long nr_pages, int nid)
261 {
262         unsigned long start, end, pfn;
263
264         start = SECTION_ALIGN_DOWN(start_pfn);
265         end = SECTION_ALIGN_UP(start_pfn + nr_pages);
266
267         for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
268                 __free_page_cgroup(pfn);
269         return 0;
270
271 }
272
273 static int __meminit page_cgroup_callback(struct notifier_block *self,
274                                unsigned long action, void *arg)
275 {
276         struct memory_notify *mn = arg;
277         int ret = 0;
278         switch (action) {
279         case MEM_GOING_ONLINE:
280                 ret = online_page_cgroup(mn->start_pfn,
281                                    mn->nr_pages, mn->status_change_nid);
282                 break;
283         case MEM_OFFLINE:
284                 offline_page_cgroup(mn->start_pfn,
285                                 mn->nr_pages, mn->status_change_nid);
286                 break;
287         case MEM_CANCEL_ONLINE:
288         case MEM_GOING_OFFLINE:
289                 break;
290         case MEM_ONLINE:
291         case MEM_CANCEL_OFFLINE:
292                 break;
293         }
294
295         return notifier_from_errno(ret);
296 }
297
298 #endif
299
300 void __init page_cgroup_init(void)
301 {
302         unsigned long pfn;
303         int nid;
304
305         if (mem_cgroup_disabled())
306                 return;
307
308         for_each_node_state(nid, N_HIGH_MEMORY) {
309                 unsigned long start_pfn, end_pfn;
310
311                 start_pfn = node_start_pfn(nid);
312                 end_pfn = node_end_pfn(nid);
313                 /*
314                  * start_pfn and end_pfn may not be aligned to SECTION and the
315                  * page->flags of out of node pages are not initialized.  So we
316                  * scan [start_pfn, the biggest section's pfn < end_pfn) here.
317                  */
318                 for (pfn = start_pfn;
319                      pfn < end_pfn;
320                      pfn = ALIGN(pfn + 1, PAGES_PER_SECTION)) {
321
322                         if (!pfn_valid(pfn))
323                                 continue;
324                         /*
325                          * Nodes's pfns can be overlapping.
326                          * We know some arch can have a nodes layout such as
327                          * -------------pfn-------------->
328                          * N0 | N1 | N2 | N0 | N1 | N2|....
329                          */
330                         if (pfn_to_nid(pfn) != nid)
331                                 continue;
332                         if (init_section_page_cgroup(pfn, nid))
333                                 goto oom;
334                 }
335         }
336         hotplug_memory_notifier(page_cgroup_callback, 0);
337         printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
338         printk(KERN_INFO "please try 'cgroup_disable=memory' option if you "
339                          "don't want memory cgroups\n");
340         return;
341 oom:
342         printk(KERN_CRIT "try 'cgroup_disable=memory' boot option\n");
343         panic("Out of memory");
344 }
345
346 void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
347 {
348         return;
349 }
350
351 #endif
352
353
354 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
355
356 static DEFINE_MUTEX(swap_cgroup_mutex);
357 struct swap_cgroup_ctrl {
358         struct page **map;
359         unsigned long length;
360         spinlock_t      lock;
361 };
362
363 static struct swap_cgroup_ctrl swap_cgroup_ctrl[MAX_SWAPFILES];
364
365 struct swap_cgroup {
366         unsigned short          id;
367 };
368 #define SC_PER_PAGE     (PAGE_SIZE/sizeof(struct swap_cgroup))
369 #define SC_POS_MASK     (SC_PER_PAGE - 1)
370
371 /*
372  * SwapCgroup implements "lookup" and "exchange" operations.
373  * In typical usage, this swap_cgroup is accessed via memcg's charge/uncharge
374  * against SwapCache. At swap_free(), this is accessed directly from swap.
375  *
376  * This means,
377  *  - we have no race in "exchange" when we're accessed via SwapCache because
378  *    SwapCache(and its swp_entry) is under lock.
379  *  - When called via swap_free(), there is no user of this entry and no race.
380  * Then, we don't need lock around "exchange".
381  *
382  * TODO: we can push these buffers out to HIGHMEM.
383  */
384
385 /*
386  * allocate buffer for swap_cgroup.
387  */
388 static int swap_cgroup_prepare(int type)
389 {
390         struct page *page;
391         struct swap_cgroup_ctrl *ctrl;
392         unsigned long idx, max;
393
394         ctrl = &swap_cgroup_ctrl[type];
395
396         for (idx = 0; idx < ctrl->length; idx++) {
397                 page = alloc_page(GFP_KERNEL | __GFP_ZERO);
398                 if (!page)
399                         goto not_enough_page;
400                 ctrl->map[idx] = page;
401         }
402         return 0;
403 not_enough_page:
404         max = idx;
405         for (idx = 0; idx < max; idx++)
406                 __free_page(ctrl->map[idx]);
407
408         return -ENOMEM;
409 }
410
411 /**
412  * swap_cgroup_cmpxchg - cmpxchg mem_cgroup's id for this swp_entry.
413  * @end: swap entry to be cmpxchged
414  * @old: old id
415  * @new: new id
416  *
417  * Returns old id at success, 0 at failure.
418  * (There is no mem_cgroup using 0 as its id)
419  */
420 unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
421                                         unsigned short old, unsigned short new)
422 {
423         int type = swp_type(ent);
424         unsigned long offset = swp_offset(ent);
425         unsigned long idx = offset / SC_PER_PAGE;
426         unsigned long pos = offset & SC_POS_MASK;
427         struct swap_cgroup_ctrl *ctrl;
428         struct page *mappage;
429         struct swap_cgroup *sc;
430         unsigned long flags;
431         unsigned short retval;
432
433         ctrl = &swap_cgroup_ctrl[type];
434
435         mappage = ctrl->map[idx];
436         sc = page_address(mappage);
437         sc += pos;
438         spin_lock_irqsave(&ctrl->lock, flags);
439         retval = sc->id;
440         if (retval == old)
441                 sc->id = new;
442         else
443                 retval = 0;
444         spin_unlock_irqrestore(&ctrl->lock, flags);
445         return retval;
446 }
447
448 /**
449  * swap_cgroup_record - record mem_cgroup for this swp_entry.
450  * @ent: swap entry to be recorded into
451  * @mem: mem_cgroup to be recorded
452  *
453  * Returns old value at success, 0 at failure.
454  * (Of course, old value can be 0.)
455  */
456 unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
457 {
458         int type = swp_type(ent);
459         unsigned long offset = swp_offset(ent);
460         unsigned long idx = offset / SC_PER_PAGE;
461         unsigned long pos = offset & SC_POS_MASK;
462         struct swap_cgroup_ctrl *ctrl;
463         struct page *mappage;
464         struct swap_cgroup *sc;
465         unsigned short old;
466         unsigned long flags;
467
468         ctrl = &swap_cgroup_ctrl[type];
469
470         mappage = ctrl->map[idx];
471         sc = page_address(mappage);
472         sc += pos;
473         spin_lock_irqsave(&ctrl->lock, flags);
474         old = sc->id;
475         sc->id = id;
476         spin_unlock_irqrestore(&ctrl->lock, flags);
477
478         return old;
479 }
480
481 /**
482  * lookup_swap_cgroup - lookup mem_cgroup tied to swap entry
483  * @ent: swap entry to be looked up.
484  *
485  * Returns CSS ID of mem_cgroup at success. 0 at failure. (0 is invalid ID)
486  */
487 unsigned short lookup_swap_cgroup(swp_entry_t ent)
488 {
489         int type = swp_type(ent);
490         unsigned long offset = swp_offset(ent);
491         unsigned long idx = offset / SC_PER_PAGE;
492         unsigned long pos = offset & SC_POS_MASK;
493         struct swap_cgroup_ctrl *ctrl;
494         struct page *mappage;
495         struct swap_cgroup *sc;
496         unsigned short ret;
497
498         ctrl = &swap_cgroup_ctrl[type];
499         mappage = ctrl->map[idx];
500         sc = page_address(mappage);
501         sc += pos;
502         ret = sc->id;
503         return ret;
504 }
505
506 int swap_cgroup_swapon(int type, unsigned long max_pages)
507 {
508         void *array;
509         unsigned long array_size;
510         unsigned long length;
511         struct swap_cgroup_ctrl *ctrl;
512
513         if (!do_swap_account)
514                 return 0;
515
516         length = DIV_ROUND_UP(max_pages, SC_PER_PAGE);
517         array_size = length * sizeof(void *);
518
519         array = vzalloc(array_size);
520         if (!array)
521                 goto nomem;
522
523         ctrl = &swap_cgroup_ctrl[type];
524         mutex_lock(&swap_cgroup_mutex);
525         ctrl->length = length;
526         ctrl->map = array;
527         spin_lock_init(&ctrl->lock);
528         if (swap_cgroup_prepare(type)) {
529                 /* memory shortage */
530                 ctrl->map = NULL;
531                 ctrl->length = 0;
532                 mutex_unlock(&swap_cgroup_mutex);
533                 vfree(array);
534                 goto nomem;
535         }
536         mutex_unlock(&swap_cgroup_mutex);
537
538         return 0;
539 nomem:
540         printk(KERN_INFO "couldn't allocate enough memory for swap_cgroup.\n");
541         printk(KERN_INFO
542                 "swap_cgroup can be disabled by swapaccount=0 boot option\n");
543         return -ENOMEM;
544 }
545
546 void swap_cgroup_swapoff(int type)
547 {
548         struct page **map;
549         unsigned long i, length;
550         struct swap_cgroup_ctrl *ctrl;
551
552         if (!do_swap_account)
553                 return;
554
555         mutex_lock(&swap_cgroup_mutex);
556         ctrl = &swap_cgroup_ctrl[type];
557         map = ctrl->map;
558         length = ctrl->length;
559         ctrl->map = NULL;
560         ctrl->length = 0;
561         mutex_unlock(&swap_cgroup_mutex);
562
563         if (map) {
564                 for (i = 0; i < length; i++) {
565                         struct page *page = map[i];
566                         if (page)
567                                 __free_page(page);
568                 }
569                 vfree(map);
570         }
571 }
572
573 #endif