Merge tag 'stable/for-linus-3.6-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel...
[platform/adaptation/renesas_rcar/renesas_kernel.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 unsigned long total_usage;
15
16 #if !defined(CONFIG_SPARSEMEM)
17
18
19 void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
20 {
21         pgdat->node_page_cgroup = NULL;
22 }
23
24 struct page_cgroup *lookup_page_cgroup(struct page *page)
25 {
26         unsigned long pfn = page_to_pfn(page);
27         unsigned long offset;
28         struct page_cgroup *base;
29
30         base = NODE_DATA(page_to_nid(page))->node_page_cgroup;
31 #ifdef CONFIG_DEBUG_VM
32         /*
33          * The sanity checks the page allocator does upon freeing a
34          * page can reach here before the page_cgroup arrays are
35          * allocated when feeding a range of pages to the allocator
36          * for the first time during bootup or memory hotplug.
37          */
38         if (unlikely(!base))
39                 return NULL;
40 #endif
41         offset = pfn - NODE_DATA(page_to_nid(page))->node_start_pfn;
42         return base + offset;
43 }
44
45 static int __init alloc_node_page_cgroup(int nid)
46 {
47         struct page_cgroup *base;
48         unsigned long table_size;
49         unsigned long nr_pages;
50
51         nr_pages = NODE_DATA(nid)->node_spanned_pages;
52         if (!nr_pages)
53                 return 0;
54
55         table_size = sizeof(struct page_cgroup) * nr_pages;
56
57         base = __alloc_bootmem_node_nopanic(NODE_DATA(nid),
58                         table_size, PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
59         if (!base)
60                 return -ENOMEM;
61         NODE_DATA(nid)->node_page_cgroup = base;
62         total_usage += table_size;
63         return 0;
64 }
65
66 void __init page_cgroup_init_flatmem(void)
67 {
68
69         int nid, fail;
70
71         if (mem_cgroup_disabled())
72                 return;
73
74         for_each_online_node(nid)  {
75                 fail = alloc_node_page_cgroup(nid);
76                 if (fail)
77                         goto fail;
78         }
79         printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
80         printk(KERN_INFO "please try 'cgroup_disable=memory' option if you"
81         " don't want memory cgroups\n");
82         return;
83 fail:
84         printk(KERN_CRIT "allocation of page_cgroup failed.\n");
85         printk(KERN_CRIT "please try 'cgroup_disable=memory' boot option\n");
86         panic("Out of memory");
87 }
88
89 #else /* CONFIG_FLAT_NODE_MEM_MAP */
90
91 struct page_cgroup *lookup_page_cgroup(struct page *page)
92 {
93         unsigned long pfn = page_to_pfn(page);
94         struct mem_section *section = __pfn_to_section(pfn);
95 #ifdef CONFIG_DEBUG_VM
96         /*
97          * The sanity checks the page allocator does upon freeing a
98          * page can reach here before the page_cgroup arrays are
99          * allocated when feeding a range of pages to the allocator
100          * for the first time during bootup or memory hotplug.
101          */
102         if (!section->page_cgroup)
103                 return NULL;
104 #endif
105         return section->page_cgroup + pfn;
106 }
107
108 static void *__meminit alloc_page_cgroup(size_t size, int nid)
109 {
110         gfp_t flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN;
111         void *addr = NULL;
112
113         addr = alloc_pages_exact_nid(nid, size, flags);
114         if (addr) {
115                 kmemleak_alloc(addr, size, 1, flags);
116                 return addr;
117         }
118
119         if (node_state(nid, N_HIGH_MEMORY))
120                 addr = vzalloc_node(size, nid);
121         else
122                 addr = vzalloc(size);
123
124         return addr;
125 }
126
127 static int __meminit init_section_page_cgroup(unsigned long pfn, int nid)
128 {
129         struct mem_section *section;
130         struct page_cgroup *base;
131         unsigned long table_size;
132
133         section = __pfn_to_section(pfn);
134
135         if (section->page_cgroup)
136                 return 0;
137
138         table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
139         base = alloc_page_cgroup(table_size, nid);
140
141         /*
142          * The value stored in section->page_cgroup is (base - pfn)
143          * and it does not point to the memory block allocated above,
144          * causing kmemleak false positives.
145          */
146         kmemleak_not_leak(base);
147
148         if (!base) {
149                 printk(KERN_ERR "page cgroup allocation failure\n");
150                 return -ENOMEM;
151         }
152
153         /*
154          * The passed "pfn" may not be aligned to SECTION.  For the calculation
155          * we need to apply a mask.
156          */
157         pfn &= PAGE_SECTION_MASK;
158         section->page_cgroup = base - pfn;
159         total_usage += table_size;
160         return 0;
161 }
162 #ifdef CONFIG_MEMORY_HOTPLUG
163 static void free_page_cgroup(void *addr)
164 {
165         if (is_vmalloc_addr(addr)) {
166                 vfree(addr);
167         } else {
168                 struct page *page = virt_to_page(addr);
169                 size_t table_size =
170                         sizeof(struct page_cgroup) * PAGES_PER_SECTION;
171
172                 BUG_ON(PageReserved(page));
173                 free_pages_exact(addr, table_size);
174         }
175 }
176
177 void __free_page_cgroup(unsigned long pfn)
178 {
179         struct mem_section *ms;
180         struct page_cgroup *base;
181
182         ms = __pfn_to_section(pfn);
183         if (!ms || !ms->page_cgroup)
184                 return;
185         base = ms->page_cgroup + pfn;
186         free_page_cgroup(base);
187         ms->page_cgroup = NULL;
188 }
189
190 int __meminit online_page_cgroup(unsigned long start_pfn,
191                         unsigned long nr_pages,
192                         int nid)
193 {
194         unsigned long start, end, pfn;
195         int fail = 0;
196
197         start = SECTION_ALIGN_DOWN(start_pfn);
198         end = SECTION_ALIGN_UP(start_pfn + nr_pages);
199
200         if (nid == -1) {
201                 /*
202                  * In this case, "nid" already exists and contains valid memory.
203                  * "start_pfn" passed to us is a pfn which is an arg for
204                  * online__pages(), and start_pfn should exist.
205                  */
206                 nid = pfn_to_nid(start_pfn);
207                 VM_BUG_ON(!node_state(nid, N_ONLINE));
208         }
209
210         for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION) {
211                 if (!pfn_present(pfn))
212                         continue;
213                 fail = init_section_page_cgroup(pfn, nid);
214         }
215         if (!fail)
216                 return 0;
217
218         /* rollback */
219         for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
220                 __free_page_cgroup(pfn);
221
222         return -ENOMEM;
223 }
224
225 int __meminit offline_page_cgroup(unsigned long start_pfn,
226                 unsigned long nr_pages, int nid)
227 {
228         unsigned long start, end, pfn;
229
230         start = SECTION_ALIGN_DOWN(start_pfn);
231         end = SECTION_ALIGN_UP(start_pfn + nr_pages);
232
233         for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
234                 __free_page_cgroup(pfn);
235         return 0;
236
237 }
238
239 static int __meminit page_cgroup_callback(struct notifier_block *self,
240                                unsigned long action, void *arg)
241 {
242         struct memory_notify *mn = arg;
243         int ret = 0;
244         switch (action) {
245         case MEM_GOING_ONLINE:
246                 ret = online_page_cgroup(mn->start_pfn,
247                                    mn->nr_pages, mn->status_change_nid);
248                 break;
249         case MEM_OFFLINE:
250                 offline_page_cgroup(mn->start_pfn,
251                                 mn->nr_pages, mn->status_change_nid);
252                 break;
253         case MEM_CANCEL_ONLINE:
254         case MEM_GOING_OFFLINE:
255                 break;
256         case MEM_ONLINE:
257         case MEM_CANCEL_OFFLINE:
258                 break;
259         }
260
261         return notifier_from_errno(ret);
262 }
263
264 #endif
265
266 void __init page_cgroup_init(void)
267 {
268         unsigned long pfn;
269         int nid;
270
271         if (mem_cgroup_disabled())
272                 return;
273
274         for_each_node_state(nid, N_HIGH_MEMORY) {
275                 unsigned long start_pfn, end_pfn;
276
277                 start_pfn = node_start_pfn(nid);
278                 end_pfn = node_end_pfn(nid);
279                 /*
280                  * start_pfn and end_pfn may not be aligned to SECTION and the
281                  * page->flags of out of node pages are not initialized.  So we
282                  * scan [start_pfn, the biggest section's pfn < end_pfn) here.
283                  */
284                 for (pfn = start_pfn;
285                      pfn < end_pfn;
286                      pfn = ALIGN(pfn + 1, PAGES_PER_SECTION)) {
287
288                         if (!pfn_valid(pfn))
289                                 continue;
290                         /*
291                          * Nodes's pfns can be overlapping.
292                          * We know some arch can have a nodes layout such as
293                          * -------------pfn-------------->
294                          * N0 | N1 | N2 | N0 | N1 | N2|....
295                          */
296                         if (pfn_to_nid(pfn) != nid)
297                                 continue;
298                         if (init_section_page_cgroup(pfn, nid))
299                                 goto oom;
300                 }
301         }
302         hotplug_memory_notifier(page_cgroup_callback, 0);
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 "
305                          "don't want memory cgroups\n");
306         return;
307 oom:
308         printk(KERN_CRIT "try 'cgroup_disable=memory' boot option\n");
309         panic("Out of memory");
310 }
311
312 void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
313 {
314         return;
315 }
316
317 #endif
318
319
320 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
321
322 static DEFINE_MUTEX(swap_cgroup_mutex);
323 struct swap_cgroup_ctrl {
324         struct page **map;
325         unsigned long length;
326         spinlock_t      lock;
327 };
328
329 static struct swap_cgroup_ctrl swap_cgroup_ctrl[MAX_SWAPFILES];
330
331 struct swap_cgroup {
332         unsigned short          id;
333 };
334 #define SC_PER_PAGE     (PAGE_SIZE/sizeof(struct swap_cgroup))
335
336 /*
337  * SwapCgroup implements "lookup" and "exchange" operations.
338  * In typical usage, this swap_cgroup is accessed via memcg's charge/uncharge
339  * against SwapCache. At swap_free(), this is accessed directly from swap.
340  *
341  * This means,
342  *  - we have no race in "exchange" when we're accessed via SwapCache because
343  *    SwapCache(and its swp_entry) is under lock.
344  *  - When called via swap_free(), there is no user of this entry and no race.
345  * Then, we don't need lock around "exchange".
346  *
347  * TODO: we can push these buffers out to HIGHMEM.
348  */
349
350 /*
351  * allocate buffer for swap_cgroup.
352  */
353 static int swap_cgroup_prepare(int type)
354 {
355         struct page *page;
356         struct swap_cgroup_ctrl *ctrl;
357         unsigned long idx, max;
358
359         ctrl = &swap_cgroup_ctrl[type];
360
361         for (idx = 0; idx < ctrl->length; idx++) {
362                 page = alloc_page(GFP_KERNEL | __GFP_ZERO);
363                 if (!page)
364                         goto not_enough_page;
365                 ctrl->map[idx] = page;
366         }
367         return 0;
368 not_enough_page:
369         max = idx;
370         for (idx = 0; idx < max; idx++)
371                 __free_page(ctrl->map[idx]);
372
373         return -ENOMEM;
374 }
375
376 static struct swap_cgroup *lookup_swap_cgroup(swp_entry_t ent,
377                                         struct swap_cgroup_ctrl **ctrlp)
378 {
379         pgoff_t offset = swp_offset(ent);
380         struct swap_cgroup_ctrl *ctrl;
381         struct page *mappage;
382         struct swap_cgroup *sc;
383
384         ctrl = &swap_cgroup_ctrl[swp_type(ent)];
385         if (ctrlp)
386                 *ctrlp = ctrl;
387
388         mappage = ctrl->map[offset / SC_PER_PAGE];
389         sc = page_address(mappage);
390         return sc + offset % SC_PER_PAGE;
391 }
392
393 /**
394  * swap_cgroup_cmpxchg - cmpxchg mem_cgroup's id for this swp_entry.
395  * @ent: swap entry to be cmpxchged
396  * @old: old id
397  * @new: new id
398  *
399  * Returns old id at success, 0 at failure.
400  * (There is no mem_cgroup using 0 as its id)
401  */
402 unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
403                                         unsigned short old, unsigned short new)
404 {
405         struct swap_cgroup_ctrl *ctrl;
406         struct swap_cgroup *sc;
407         unsigned long flags;
408         unsigned short retval;
409
410         sc = lookup_swap_cgroup(ent, &ctrl);
411
412         spin_lock_irqsave(&ctrl->lock, flags);
413         retval = sc->id;
414         if (retval == old)
415                 sc->id = new;
416         else
417                 retval = 0;
418         spin_unlock_irqrestore(&ctrl->lock, flags);
419         return retval;
420 }
421
422 /**
423  * swap_cgroup_record - record mem_cgroup for this swp_entry.
424  * @ent: swap entry to be recorded into
425  * @id: mem_cgroup to be recorded
426  *
427  * Returns old value at success, 0 at failure.
428  * (Of course, old value can be 0.)
429  */
430 unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
431 {
432         struct swap_cgroup_ctrl *ctrl;
433         struct swap_cgroup *sc;
434         unsigned short old;
435         unsigned long flags;
436
437         sc = lookup_swap_cgroup(ent, &ctrl);
438
439         spin_lock_irqsave(&ctrl->lock, flags);
440         old = sc->id;
441         sc->id = id;
442         spin_unlock_irqrestore(&ctrl->lock, flags);
443
444         return old;
445 }
446
447 /**
448  * lookup_swap_cgroup_id - lookup mem_cgroup id tied to swap entry
449  * @ent: swap entry to be looked up.
450  *
451  * Returns CSS ID of mem_cgroup at success. 0 at failure. (0 is invalid ID)
452  */
453 unsigned short lookup_swap_cgroup_id(swp_entry_t ent)
454 {
455         return lookup_swap_cgroup(ent, NULL)->id;
456 }
457
458 int swap_cgroup_swapon(int type, unsigned long max_pages)
459 {
460         void *array;
461         unsigned long array_size;
462         unsigned long length;
463         struct swap_cgroup_ctrl *ctrl;
464
465         if (!do_swap_account)
466                 return 0;
467
468         length = DIV_ROUND_UP(max_pages, SC_PER_PAGE);
469         array_size = length * sizeof(void *);
470
471         array = vzalloc(array_size);
472         if (!array)
473                 goto nomem;
474
475         ctrl = &swap_cgroup_ctrl[type];
476         mutex_lock(&swap_cgroup_mutex);
477         ctrl->length = length;
478         ctrl->map = array;
479         spin_lock_init(&ctrl->lock);
480         if (swap_cgroup_prepare(type)) {
481                 /* memory shortage */
482                 ctrl->map = NULL;
483                 ctrl->length = 0;
484                 mutex_unlock(&swap_cgroup_mutex);
485                 vfree(array);
486                 goto nomem;
487         }
488         mutex_unlock(&swap_cgroup_mutex);
489
490         return 0;
491 nomem:
492         printk(KERN_INFO "couldn't allocate enough memory for swap_cgroup.\n");
493         printk(KERN_INFO
494                 "swap_cgroup can be disabled by swapaccount=0 boot option\n");
495         return -ENOMEM;
496 }
497
498 void swap_cgroup_swapoff(int type)
499 {
500         struct page **map;
501         unsigned long i, length;
502         struct swap_cgroup_ctrl *ctrl;
503
504         if (!do_swap_account)
505                 return;
506
507         mutex_lock(&swap_cgroup_mutex);
508         ctrl = &swap_cgroup_ctrl[type];
509         map = ctrl->map;
510         length = ctrl->length;
511         ctrl->map = NULL;
512         ctrl->length = 0;
513         mutex_unlock(&swap_cgroup_mutex);
514
515         if (map) {
516                 for (i = 0; i < length; i++) {
517                         struct page *page = map[i];
518                         if (page)
519                                 __free_page(page);
520                 }
521                 vfree(map);
522         }
523 }
524
525 #endif