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[mirror_ubuntu-artful-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 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