Merge branch 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[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 *__init_refok 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 __init_refok init_section_page_cgroup(unsigned long pfn)
166 {
167         struct page_cgroup *base, *pc;
168         struct mem_section *section;
169         unsigned long table_size;
170         unsigned long nr;
171         int nid, 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         nid = page_to_nid(pfn_to_page(pfn));
180         table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
181         base = alloc_page_cgroup(table_size, nid);
182
183         /*
184          * The value stored in section->page_cgroup is (base - pfn)
185          * and it does not point to the memory block allocated above,
186          * causing kmemleak false positives.
187          */
188         kmemleak_not_leak(base);
189
190         if (!base) {
191                 printk(KERN_ERR "page cgroup allocation failure\n");
192                 return -ENOMEM;
193         }
194
195         for (index = 0; index < PAGES_PER_SECTION; index++) {
196                 pc = base + index;
197                 init_page_cgroup(pc, nr);
198         }
199
200         section->page_cgroup = base - pfn;
201         total_usage += table_size;
202         return 0;
203 }
204 #ifdef CONFIG_MEMORY_HOTPLUG
205 void __free_page_cgroup(unsigned long pfn)
206 {
207         struct mem_section *ms;
208         struct page_cgroup *base;
209
210         ms = __pfn_to_section(pfn);
211         if (!ms || !ms->page_cgroup)
212                 return;
213         base = ms->page_cgroup + pfn;
214         free_page_cgroup(base);
215         ms->page_cgroup = NULL;
216 }
217
218 int __meminit online_page_cgroup(unsigned long start_pfn,
219                         unsigned long nr_pages,
220                         int nid)
221 {
222         unsigned long start, end, pfn;
223         int fail = 0;
224
225         start = start_pfn & ~(PAGES_PER_SECTION - 1);
226         end = ALIGN(start_pfn + nr_pages, PAGES_PER_SECTION);
227
228         for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION) {
229                 if (!pfn_present(pfn))
230                         continue;
231                 fail = init_section_page_cgroup(pfn);
232         }
233         if (!fail)
234                 return 0;
235
236         /* rollback */
237         for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
238                 __free_page_cgroup(pfn);
239
240         return -ENOMEM;
241 }
242
243 int __meminit offline_page_cgroup(unsigned long start_pfn,
244                 unsigned long nr_pages, int nid)
245 {
246         unsigned long start, end, pfn;
247
248         start = start_pfn & ~(PAGES_PER_SECTION - 1);
249         end = ALIGN(start_pfn + nr_pages, PAGES_PER_SECTION);
250
251         for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
252                 __free_page_cgroup(pfn);
253         return 0;
254
255 }
256
257 static int __meminit page_cgroup_callback(struct notifier_block *self,
258                                unsigned long action, void *arg)
259 {
260         struct memory_notify *mn = arg;
261         int ret = 0;
262         switch (action) {
263         case MEM_GOING_ONLINE:
264                 ret = online_page_cgroup(mn->start_pfn,
265                                    mn->nr_pages, mn->status_change_nid);
266                 break;
267         case MEM_OFFLINE:
268                 offline_page_cgroup(mn->start_pfn,
269                                 mn->nr_pages, mn->status_change_nid);
270                 break;
271         case MEM_CANCEL_ONLINE:
272         case MEM_GOING_OFFLINE:
273                 break;
274         case MEM_ONLINE:
275         case MEM_CANCEL_OFFLINE:
276                 break;
277         }
278
279         return notifier_from_errno(ret);
280 }
281
282 #endif
283
284 void __init page_cgroup_init(void)
285 {
286         unsigned long pfn;
287         int fail = 0;
288
289         if (mem_cgroup_disabled())
290                 return;
291
292         for (pfn = 0; !fail && pfn < max_pfn; pfn += PAGES_PER_SECTION) {
293                 if (!pfn_present(pfn))
294                         continue;
295                 fail = init_section_page_cgroup(pfn);
296         }
297         if (fail) {
298                 printk(KERN_CRIT "try 'cgroup_disable=memory' boot option\n");
299                 panic("Out of memory");
300         } else {
301                 hotplug_memory_notifier(page_cgroup_callback, 0);
302         }
303         printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
304         printk(KERN_INFO "please try 'cgroup_disable=memory' option if you don't"
305         " want memory cgroups\n");
306 }
307
308 void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
309 {
310         return;
311 }
312
313 #endif
314
315
316 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
317
318 static DEFINE_MUTEX(swap_cgroup_mutex);
319 struct swap_cgroup_ctrl {
320         struct page **map;
321         unsigned long length;
322         spinlock_t      lock;
323 };
324
325 struct swap_cgroup_ctrl swap_cgroup_ctrl[MAX_SWAPFILES];
326
327 struct swap_cgroup {
328         unsigned short          id;
329 };
330 #define SC_PER_PAGE     (PAGE_SIZE/sizeof(struct swap_cgroup))
331 #define SC_POS_MASK     (SC_PER_PAGE - 1)
332
333 /*
334  * SwapCgroup implements "lookup" and "exchange" operations.
335  * In typical usage, this swap_cgroup is accessed via memcg's charge/uncharge
336  * against SwapCache. At swap_free(), this is accessed directly from swap.
337  *
338  * This means,
339  *  - we have no race in "exchange" when we're accessed via SwapCache because
340  *    SwapCache(and its swp_entry) is under lock.
341  *  - When called via swap_free(), there is no user of this entry and no race.
342  * Then, we don't need lock around "exchange".
343  *
344  * TODO: we can push these buffers out to HIGHMEM.
345  */
346
347 /*
348  * allocate buffer for swap_cgroup.
349  */
350 static int swap_cgroup_prepare(int type)
351 {
352         struct page *page;
353         struct swap_cgroup_ctrl *ctrl;
354         unsigned long idx, max;
355
356         ctrl = &swap_cgroup_ctrl[type];
357
358         for (idx = 0; idx < ctrl->length; idx++) {
359                 page = alloc_page(GFP_KERNEL | __GFP_ZERO);
360                 if (!page)
361                         goto not_enough_page;
362                 ctrl->map[idx] = page;
363         }
364         return 0;
365 not_enough_page:
366         max = idx;
367         for (idx = 0; idx < max; idx++)
368                 __free_page(ctrl->map[idx]);
369
370         return -ENOMEM;
371 }
372
373 /**
374  * swap_cgroup_cmpxchg - cmpxchg mem_cgroup's id for this swp_entry.
375  * @end: swap entry to be cmpxchged
376  * @old: old id
377  * @new: new id
378  *
379  * Returns old id at success, 0 at failure.
380  * (There is no mem_cgroup using 0 as its id)
381  */
382 unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
383                                         unsigned short old, unsigned short new)
384 {
385         int type = swp_type(ent);
386         unsigned long offset = swp_offset(ent);
387         unsigned long idx = offset / SC_PER_PAGE;
388         unsigned long pos = offset & SC_POS_MASK;
389         struct swap_cgroup_ctrl *ctrl;
390         struct page *mappage;
391         struct swap_cgroup *sc;
392         unsigned long flags;
393         unsigned short retval;
394
395         ctrl = &swap_cgroup_ctrl[type];
396
397         mappage = ctrl->map[idx];
398         sc = page_address(mappage);
399         sc += pos;
400         spin_lock_irqsave(&ctrl->lock, flags);
401         retval = sc->id;
402         if (retval == old)
403                 sc->id = new;
404         else
405                 retval = 0;
406         spin_unlock_irqrestore(&ctrl->lock, flags);
407         return retval;
408 }
409
410 /**
411  * swap_cgroup_record - record mem_cgroup for this swp_entry.
412  * @ent: swap entry to be recorded into
413  * @mem: mem_cgroup to be recorded
414  *
415  * Returns old value at success, 0 at failure.
416  * (Of course, old value can be 0.)
417  */
418 unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
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 short old;
428         unsigned long flags;
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         old = sc->id;
437         sc->id = id;
438         spin_unlock_irqrestore(&ctrl->lock, flags);
439
440         return old;
441 }
442
443 /**
444  * lookup_swap_cgroup - lookup mem_cgroup tied to swap entry
445  * @ent: swap entry to be looked up.
446  *
447  * Returns CSS ID of mem_cgroup at success. 0 at failure. (0 is invalid ID)
448  */
449 unsigned short lookup_swap_cgroup(swp_entry_t ent)
450 {
451         int type = swp_type(ent);
452         unsigned long offset = swp_offset(ent);
453         unsigned long idx = offset / SC_PER_PAGE;
454         unsigned long pos = offset & SC_POS_MASK;
455         struct swap_cgroup_ctrl *ctrl;
456         struct page *mappage;
457         struct swap_cgroup *sc;
458         unsigned short ret;
459
460         ctrl = &swap_cgroup_ctrl[type];
461         mappage = ctrl->map[idx];
462         sc = page_address(mappage);
463         sc += pos;
464         ret = sc->id;
465         return ret;
466 }
467
468 int swap_cgroup_swapon(int type, unsigned long max_pages)
469 {
470         void *array;
471         unsigned long array_size;
472         unsigned long length;
473         struct swap_cgroup_ctrl *ctrl;
474
475         if (!do_swap_account)
476                 return 0;
477
478         length = ((max_pages/SC_PER_PAGE) + 1);
479         array_size = length * sizeof(void *);
480
481         array = vmalloc(array_size);
482         if (!array)
483                 goto nomem;
484
485         memset(array, 0, array_size);
486         ctrl = &swap_cgroup_ctrl[type];
487         mutex_lock(&swap_cgroup_mutex);
488         ctrl->length = length;
489         ctrl->map = array;
490         spin_lock_init(&ctrl->lock);
491         if (swap_cgroup_prepare(type)) {
492                 /* memory shortage */
493                 ctrl->map = NULL;
494                 ctrl->length = 0;
495                 vfree(array);
496                 mutex_unlock(&swap_cgroup_mutex);
497                 goto nomem;
498         }
499         mutex_unlock(&swap_cgroup_mutex);
500
501         return 0;
502 nomem:
503         printk(KERN_INFO "couldn't allocate enough memory for swap_cgroup.\n");
504         printk(KERN_INFO
505                 "swap_cgroup can be disabled by noswapaccount boot option\n");
506         return -ENOMEM;
507 }
508
509 void swap_cgroup_swapoff(int type)
510 {
511         int i;
512         struct swap_cgroup_ctrl *ctrl;
513
514         if (!do_swap_account)
515                 return;
516
517         mutex_lock(&swap_cgroup_mutex);
518         ctrl = &swap_cgroup_ctrl[type];
519         if (ctrl->map) {
520                 for (i = 0; i < ctrl->length; i++) {
521                         struct page *page = ctrl->map[i];
522                         if (page)
523                                 __free_page(page);
524                 }
525                 vfree(ctrl->map);
526                 ctrl->map = NULL;
527                 ctrl->length = 0;
528         }
529         mutex_unlock(&swap_cgroup_mutex);
530 }
531
532 #endif