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
  13 static void __meminit
  14 __init_page_cgroup(struct page_cgroup *pc, unsigned long pfn)
  15 {
  16         pc->flags = 0;
  17         pc->mem_cgroup = NULL;
  18         pc->page = pfn_to_page(pfn);
  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 static int __init alloc_node_page_cgroup(int nid)
  46 {
  47         struct page_cgroup *base, *pc;
  48         unsigned long table_size;
  49         unsigned long start_pfn, nr_pages, index;
  50         struct page *page;
  51         unsigned int order;
  52
  53         start_pfn = NODE_DATA(nid)->node_start_pfn;
  54         nr_pages = NODE_DATA(nid)->node_spanned_pages;
  55
  56         if (!nr_pages)
  57                 return 0;
  58
  59         table_size = sizeof(struct page_cgroup) * nr_pages;
  60         order = get_order(table_size);
  61         page = alloc_pages_node(nid, GFP_NOWAIT | __GFP_ZERO, order);
  62         if (!page)
  63                 page = alloc_pages_node(-1, GFP_NOWAIT | __GFP_ZERO, order);
  64         if (!page)
  65                 return -ENOMEM;
  66         base = page_address(page);
  67         for (index = 0; index < nr_pages; index++) {
  68                 pc = base + index;
  69                 __init_page_cgroup(pc, start_pfn + index);
  70         }
  71         NODE_DATA(nid)->node_page_cgroup = base;
  72         total_usage += table_size;
  73         return 0;
  74 }
  75
  76 void __init page_cgroup_init(void)
  77 {
  78
  79         int nid, fail;
  80
  81         if (mem_cgroup_disabled())
  82                 return;
  83
  84         for_each_online_node(nid)  {
  85                 fail = alloc_node_page_cgroup(nid);
  86                 if (fail)
  87                         goto fail;
  88         }
  89         printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
  90         printk(KERN_INFO "please try cgroup_disable=memory option if you"
  91         " don't want\n");
  92         return;
  93 fail:
  94         printk(KERN_CRIT "allocation of page_cgroup was failed.\n");
  95         printk(KERN_CRIT "please try cgroup_disable=memory boot option\n");
  96         panic("Out of memory");
  97 }
  98
  99 #else /* CONFIG_FLAT_NODE_MEM_MAP */
 100
 101 struct page_cgroup *lookup_page_cgroup(struct page *page)
 102 {
 103         unsigned long pfn = page_to_pfn(page);
 104         struct mem_section *section = __pfn_to_section(pfn);
 105
 106         return section->page_cgroup + pfn;
 107 }
 108
 109 /* __alloc_bootmem...() is protected by !slab_available() */
 110 static int __init_refok init_section_page_cgroup(unsigned long pfn)
 111 {
 112         struct mem_section *section = __pfn_to_section(pfn);
 113         struct page_cgroup *base, *pc;
 114         unsigned long table_size;
 115         int nid, index;
 116
 117         if (!section->page_cgroup) {
 118                 nid = page_to_nid(pfn_to_page(pfn));
 119                 table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
 120                 if (slab_is_available()) {
 121                         base = kmalloc_node(table_size,
 122                                         GFP_KERNEL | __GFP_NOWARN, nid);
 123                         if (!base)
 124                                 base = vmalloc_node(table_size, nid);
 125                 } else {
 126                         base = __alloc_bootmem_node_nopanic(NODE_DATA(nid),
 127                                 table_size,
 128                                 PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
 129                 }
 130         } else {
 131                 /*
 132                  * We don't have to allocate page_cgroup again, but
 133                  * address of memmap may be changed. So, we have to initialize
 134                  * again.
 135                  */
 136                 base = section->page_cgroup + pfn;
 137                 table_size = 0;
 138                 /* check address of memmap is changed or not. */
 139                 if (base->page == pfn_to_page(pfn))
 140                         return 0;
 141         }
 142
 143         if (!base) {
 144                 printk(KERN_ERR "page cgroup allocation failure\n");
 145                 return -ENOMEM;
 146         }
 147
 148         for (index = 0; index < PAGES_PER_SECTION; index++) {
 149                 pc = base + index;
 150                 __init_page_cgroup(pc, pfn + index);
 151         }
 152
 153         section->page_cgroup = base - pfn;
 154         total_usage += table_size;
 155         return 0;
 156 }
 157 #ifdef CONFIG_MEMORY_HOTPLUG
 158 void __free_page_cgroup(unsigned long pfn)
 159 {
 160         struct mem_section *ms;
 161         struct page_cgroup *base;
 162
 163         ms = __pfn_to_section(pfn);
 164         if (!ms || !ms->page_cgroup)
 165                 return;
 166         base = ms->page_cgroup + pfn;
 167         if (is_vmalloc_addr(base)) {
 168                 vfree(base);
 169                 ms->page_cgroup = NULL;
 170         } else {
 171                 struct page *page = virt_to_page(base);
 172                 if (!PageReserved(page)) { /* Is bootmem ? */
 173                         kfree(base);
 174                         ms->page_cgroup = NULL;
 175                 }
 176         }
 177 }
 178
 179 int __meminit online_page_cgroup(unsigned long start_pfn,
 180                         unsigned long nr_pages,
 181                         int nid)
 182 {
 183         unsigned long start, end, pfn;
 184         int fail = 0;
 185
 186         start = start_pfn & ~(PAGES_PER_SECTION - 1);
 187         end = ALIGN(start_pfn + nr_pages, PAGES_PER_SECTION);
 188
 189         for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION) {
 190                 if (!pfn_present(pfn))
 191                         continue;
 192                 fail = init_section_page_cgroup(pfn);
 193         }
 194         if (!fail)
 195                 return 0;
 196
 197         /* rollback */
 198         for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
 199                 __free_page_cgroup(pfn);
 200
 201         return -ENOMEM;
 202 }
 203
 204 int __meminit offline_page_cgroup(unsigned long start_pfn,
 205                 unsigned long nr_pages, int nid)
 206 {
 207         unsigned long start, end, pfn;
 208
 209         start = start_pfn & ~(PAGES_PER_SECTION - 1);
 210         end = ALIGN(start_pfn + nr_pages, PAGES_PER_SECTION);
 211
 212         for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
 213                 __free_page_cgroup(pfn);
 214         return 0;
 215
 216 }
 217
 218 static int __meminit page_cgroup_callback(struct notifier_block *self,
 219                                unsigned long action, void *arg)
 220 {
 221         struct memory_notify *mn = arg;
 222         int ret = 0;
 223         switch (action) {
 224         case MEM_GOING_ONLINE:
 225                 ret = online_page_cgroup(mn->start_pfn,
 226                                    mn->nr_pages, mn->status_change_nid);
 227                 break;
 228         case MEM_OFFLINE:
 229                 offline_page_cgroup(mn->start_pfn,
 230                                 mn->nr_pages, mn->status_change_nid);
 231                 break;
 232         case MEM_CANCEL_ONLINE:
 233         case MEM_GOING_OFFLINE:
 234                 break;
 235         case MEM_ONLINE:
 236         case MEM_CANCEL_OFFLINE:
 237                 break;
 238         }
 239
 240         if (ret)
 241                 ret = notifier_from_errno(ret);
 242         else
 243                 ret = NOTIFY_OK;
 244
 245         return ret;
 246 }
 247
 248 #endif
 249
 250 void __init page_cgroup_init(void)
 251 {
 252         unsigned long pfn;
 253         int fail = 0;
 254
 255         if (mem_cgroup_disabled())
 256                 return;
 257
 258         for (pfn = 0; !fail && pfn < max_pfn; pfn += PAGES_PER_SECTION) {
 259                 if (!pfn_present(pfn))
 260                         continue;
 261                 fail = init_section_page_cgroup(pfn);
 262         }
 263         if (fail) {
 264                 printk(KERN_CRIT "try cgroup_disable=memory boot option\n");
 265                 panic("Out of memory");
 266         } else {
 267                 hotplug_memory_notifier(page_cgroup_callback, 0);
 268         }
 269         printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
 270         printk(KERN_INFO "please try cgroup_disable=memory option if you don't"
 271         " want\n");
 272 }
 273
 274 void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
 275 {
 276         return;
 277 }
 278
 279 #endif
 280
 281
 282 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
 283
 284 static DEFINE_MUTEX(swap_cgroup_mutex);
 285 struct swap_cgroup_ctrl {
 286         struct page **map;
 287         unsigned long length;
 288 };
 289
 290 struct swap_cgroup_ctrl swap_cgroup_ctrl[MAX_SWAPFILES];
 291
 292 struct swap_cgroup {
 293         unsigned short          id;
 294 };
 295 #define SC_PER_PAGE     (PAGE_SIZE/sizeof(struct swap_cgroup))
 296 #define SC_POS_MASK     (SC_PER_PAGE - 1)
 297
 298 /*
 299  * SwapCgroup implements "lookup" and "exchange" operations.
 300  * In typical usage, this swap_cgroup is accessed via memcg's charge/uncharge
 301  * against SwapCache. At swap_free(), this is accessed directly from swap.
 302  *
 303  * This means,
 304  *  - we have no race in "exchange" when we're accessed via SwapCache because
 305  *    SwapCache(and its swp_entry) is under lock.
 306  *  - When called via swap_free(), there is no user of this entry and no race.
 307  * Then, we don't need lock around "exchange".
 308  *
 309  * TODO: we can push these buffers out to HIGHMEM.
 310  */
 311
 312 /*
 313  * allocate buffer for swap_cgroup.
 314  */
 315 static int swap_cgroup_prepare(int type)
 316 {
 317         struct page *page;
 318         struct swap_cgroup_ctrl *ctrl;
 319         unsigned long idx, max;
 320
 321         if (!do_swap_account)
 322                 return 0;
 323         ctrl = &swap_cgroup_ctrl[type];
 324
 325         for (idx = 0; idx < ctrl->length; idx++) {
 326                 page = alloc_page(GFP_KERNEL | __GFP_ZERO);
 327                 if (!page)
 328                         goto not_enough_page;
 329                 ctrl->map[idx] = page;
 330         }
 331         return 0;
 332 not_enough_page:
 333         max = idx;
 334         for (idx = 0; idx < max; idx++)
 335                 __free_page(ctrl->map[idx]);
 336
 337         return -ENOMEM;
 338 }
 339
 340 /**
 341  * swap_cgroup_record - record mem_cgroup for this swp_entry.
 342  * @ent: swap entry to be recorded into
 343  * @mem: mem_cgroup to be recorded
 344  *
 345  * Returns old value at success, 0 at failure.
 346  * (Of course, old value can be 0.)
 347  */
 348 unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
 349 {
 350         int type = swp_type(ent);
 351         unsigned long offset = swp_offset(ent);
 352         unsigned long idx = offset / SC_PER_PAGE;
 353         unsigned long pos = offset & SC_POS_MASK;
 354         struct swap_cgroup_ctrl *ctrl;
 355         struct page *mappage;
 356         struct swap_cgroup *sc;
 357         unsigned short old;
 358
 359         if (!do_swap_account)
 360                 return 0;
 361
 362         ctrl = &swap_cgroup_ctrl[type];
 363
 364         mappage = ctrl->map[idx];
 365         sc = page_address(mappage);
 366         sc += pos;
 367         old = sc->id;
 368         sc->id = id;
 369
 370         return old;
 371 }
 372
 373 /**
 374  * lookup_swap_cgroup - lookup mem_cgroup tied to swap entry
 375  * @ent: swap entry to be looked up.
 376  *
 377  * Returns CSS ID of mem_cgroup at success. 0 at failure. (0 is invalid ID)
 378  */
 379 unsigned short lookup_swap_cgroup(swp_entry_t ent)
 380 {
 381         int type = swp_type(ent);
 382         unsigned long offset = swp_offset(ent);
 383         unsigned long idx = offset / SC_PER_PAGE;
 384         unsigned long pos = offset & SC_POS_MASK;
 385         struct swap_cgroup_ctrl *ctrl;
 386         struct page *mappage;
 387         struct swap_cgroup *sc;
 388         unsigned short ret;
 389
 390         if (!do_swap_account)
 391                 return 0;
 392
 393         ctrl = &swap_cgroup_ctrl[type];
 394         mappage = ctrl->map[idx];
 395         sc = page_address(mappage);
 396         sc += pos;
 397         ret = sc->id;
 398         return ret;
 399 }
 400
 401 int swap_cgroup_swapon(int type, unsigned long max_pages)
 402 {
 403         void *array;
 404         unsigned long array_size;
 405         unsigned long length;
 406         struct swap_cgroup_ctrl *ctrl;
 407
 408         if (!do_swap_account)
 409                 return 0;
 410
 411         length = ((max_pages/SC_PER_PAGE) + 1);
 412         array_size = length * sizeof(void *);
 413
 414         array = vmalloc(array_size);
 415         if (!array)
 416                 goto nomem;
 417
 418         memset(array, 0, array_size);
 419         ctrl = &swap_cgroup_ctrl[type];
 420         mutex_lock(&swap_cgroup_mutex);
 421         ctrl->length = length;
 422         ctrl->map = array;
 423         if (swap_cgroup_prepare(type)) {
 424                 /* memory shortage */
 425                 ctrl->map = NULL;
 426                 ctrl->length = 0;
 427                 vfree(array);
 428                 mutex_unlock(&swap_cgroup_mutex);
 429                 goto nomem;
 430         }
 431         mutex_unlock(&swap_cgroup_mutex);
 432
 433         return 0;
 434 nomem:
 435         printk(KERN_INFO "couldn't allocate enough memory for swap_cgroup.\n");
 436         printk(KERN_INFO
 437                 "swap_cgroup can be disabled by noswapaccount boot option\n");
 438         return -ENOMEM;
 439 }
 440
 441 void swap_cgroup_swapoff(int type)
 442 {
 443         int i;
 444         struct swap_cgroup_ctrl *ctrl;
 445
 446         if (!do_swap_account)
 447                 return;
 448
 449         mutex_lock(&swap_cgroup_mutex);
 450         ctrl = &swap_cgroup_ctrl[type];
 451         if (ctrl->map) {
 452                 for (i = 0; i < ctrl->length; i++) {
 453                         struct page *page = ctrl->map[i];
 454                         if (page)
 455                                 __free_page(page);
 456                 }
 457                 vfree(ctrl->map);
 458                 ctrl->map = NULL;
 459                 ctrl->length = 0;
 460         }
 461         mutex_unlock(&swap_cgroup_mutex);
 462 }
 463
 464 #endif