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
  51         start_pfn = NODE_DATA(nid)->node_start_pfn;
  52         nr_pages = NODE_DATA(nid)->node_spanned_pages;
  53
  54         if (!nr_pages)
  55                 return 0;
  56
  57         table_size = sizeof(struct page_cgroup) * nr_pages;
  58
  59         base = __alloc_bootmem_node_nopanic(NODE_DATA(nid),
  60                         table_size, PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
  61         if (!base)
  62                 return -ENOMEM;
  63         for (index = 0; index < nr_pages; index++) {
  64                 pc = base + index;
  65                 __init_page_cgroup(pc, start_pfn + index);
  66         }
  67         NODE_DATA(nid)->node_page_cgroup = base;
  68         total_usage += table_size;
  69         return 0;
  70 }
  71
  72 void __init page_cgroup_init_flatmem(void)
  73 {
  74
  75         int nid, fail;
  76
  77         if (mem_cgroup_disabled())
  78                 return;
  79
  80         for_each_online_node(nid)  {
  81                 fail = alloc_node_page_cgroup(nid);
  82                 if (fail)
  83                         goto fail;
  84         }
  85         printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
  86         printk(KERN_INFO "please try 'cgroup_disable=memory' option if you"
  87         " don't want memory cgroups\n");
  88         return;
  89 fail:
  90         printk(KERN_CRIT "allocation of page_cgroup failed.\n");
  91         printk(KERN_CRIT "please try 'cgroup_disable=memory' boot option\n");
  92         panic("Out of memory");
  93 }
  94
  95 #else /* CONFIG_FLAT_NODE_MEM_MAP */
  96
  97 struct page_cgroup *lookup_page_cgroup(struct page *page)
  98 {
  99         unsigned long pfn = page_to_pfn(page);
 100         struct mem_section *section = __pfn_to_section(pfn);
 101
 102         if (!section->page_cgroup)
 103                 return NULL;
 104         return section->page_cgroup + pfn;
 105 }
 106
 107 /* __alloc_bootmem...() is protected by !slab_available() */
 108 static int __init_refok init_section_page_cgroup(unsigned long pfn)
 109 {
 110         struct mem_section *section = __pfn_to_section(pfn);
 111         struct page_cgroup *base, *pc;
 112         unsigned long table_size;
 113         int nid, index;
 114
 115         if (!section->page_cgroup) {
 116                 nid = page_to_nid(pfn_to_page(pfn));
 117                 table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
 118                 VM_BUG_ON(!slab_is_available());
 119                 if (node_state(nid, N_HIGH_MEMORY)) {
 120                         base = kmalloc_node(table_size,
 121                                 GFP_KERNEL | __GFP_NOWARN, nid);
 122                         if (!base)
 123                                 base = vmalloc_node(table_size, nid);
 124                 } else {
 125                         base = kmalloc(table_size, GFP_KERNEL | __GFP_NOWARN);
 126                         if (!base)
 127                                 base = vmalloc(table_size);
 128                 }
 129         } else {
 130                 /*
 131                  * We don't have to allocate page_cgroup again, but
 132                  * address of memmap may be changed. So, we have to initialize
 133                  * again.
 134                  */
 135                 base = section->page_cgroup + pfn;
 136                 table_size = 0;
 137                 /* check address of memmap is changed or not. */
 138                 if (base->page == pfn_to_page(pfn))
 139                         return 0;
 140         }
 141
 142         if (!base) {
 143                 printk(KERN_ERR "page cgroup allocation failure\n");
 144                 return -ENOMEM;
 145         }
 146
 147         for (index = 0; index < PAGES_PER_SECTION; index++) {
 148                 pc = base + index;
 149                 __init_page_cgroup(pc, pfn + index);
 150         }
 151
 152         section->page_cgroup = base - pfn;
 153         total_usage += table_size;
 154         return 0;
 155 }
 156 #ifdef CONFIG_MEMORY_HOTPLUG
 157 void __free_page_cgroup(unsigned long pfn)
 158 {
 159         struct mem_section *ms;
 160         struct page_cgroup *base;
 161
 162         ms = __pfn_to_section(pfn);
 163         if (!ms || !ms->page_cgroup)
 164                 return;
 165         base = ms->page_cgroup + pfn;
 166         if (is_vmalloc_addr(base)) {
 167                 vfree(base);
 168                 ms->page_cgroup = NULL;
 169         } else {
 170                 struct page *page = virt_to_page(base);
 171                 if (!PageReserved(page)) { /* Is bootmem ? */
 172                         kfree(base);
 173                         ms->page_cgroup = NULL;
 174                 }
 175         }
 176 }
 177
 178 int __meminit online_page_cgroup(unsigned long start_pfn,
 179                         unsigned long nr_pages,
 180                         int nid)
 181 {
 182         unsigned long start, end, pfn;
 183         int fail = 0;
 184
 185         start = start_pfn & ~(PAGES_PER_SECTION - 1);
 186         end = ALIGN(start_pfn + nr_pages, PAGES_PER_SECTION);
 187
 188         for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION) {
 189                 if (!pfn_present(pfn))
 190                         continue;
 191                 fail = init_section_page_cgroup(pfn);
 192         }
 193         if (!fail)
 194                 return 0;
 195
 196         /* rollback */
 197         for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
 198                 __free_page_cgroup(pfn);
 199
 200         return -ENOMEM;
 201 }
 202
 203 int __meminit offline_page_cgroup(unsigned long start_pfn,
 204                 unsigned long nr_pages, int nid)
 205 {
 206         unsigned long start, end, pfn;
 207
 208         start = start_pfn & ~(PAGES_PER_SECTION - 1);
 209         end = ALIGN(start_pfn + nr_pages, PAGES_PER_SECTION);
 210
 211         for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
 212                 __free_page_cgroup(pfn);
 213         return 0;
 214
 215 }
 216
 217 static int __meminit page_cgroup_callback(struct notifier_block *self,
 218                                unsigned long action, void *arg)
 219 {
 220         struct memory_notify *mn = arg;
 221         int ret = 0;
 222         switch (action) {
 223         case MEM_GOING_ONLINE:
 224                 ret = online_page_cgroup(mn->start_pfn,
 225                                    mn->nr_pages, mn->status_change_nid);
 226                 break;
 227         case MEM_OFFLINE:
 228                 offline_page_cgroup(mn->start_pfn,
 229                                 mn->nr_pages, mn->status_change_nid);
 230                 break;
 231         case MEM_CANCEL_ONLINE:
 232         case MEM_GOING_OFFLINE:
 233                 break;
 234         case MEM_ONLINE:
 235         case MEM_CANCEL_OFFLINE:
 236                 break;
 237         }
 238
 239         if (ret)
 240                 ret = notifier_from_errno(ret);
 241         else
 242                 ret = NOTIFY_OK;
 243
 244         return ret;
 245 }
 246
 247 #endif
 248
 249 void __init page_cgroup_init(void)
 250 {
 251         unsigned long pfn;
 252         int fail = 0;
 253
 254         if (mem_cgroup_disabled())
 255                 return;
 256
 257         for (pfn = 0; !fail && pfn < max_pfn; pfn += PAGES_PER_SECTION) {
 258                 if (!pfn_present(pfn))
 259                         continue;
 260                 fail = init_section_page_cgroup(pfn);
 261         }
 262         if (fail) {
 263                 printk(KERN_CRIT "try 'cgroup_disable=memory' boot option\n");
 264                 panic("Out of memory");
 265         } else {
 266                 hotplug_memory_notifier(page_cgroup_callback, 0);
 267         }
 268         printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
 269         printk(KERN_INFO "please try 'cgroup_disable=memory' option if you don't"
 270         " want memory cgroups\n");
 271 }
 272
 273 void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
 274 {
 275         return;
 276 }
 277
 278 #endif
 279
 280
 281 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
 282
 283 static DEFINE_MUTEX(swap_cgroup_mutex);
 284 struct swap_cgroup_ctrl {
 285         struct page **map;
 286         unsigned long length;
 287         spinlock_t      lock;
 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         ctrl = &swap_cgroup_ctrl[type];
 322
 323         for (idx = 0; idx < ctrl->length; idx++) {
 324                 page = alloc_page(GFP_KERNEL | __GFP_ZERO);
 325                 if (!page)
 326                         goto not_enough_page;
 327                 ctrl->map[idx] = page;
 328         }
 329         return 0;
 330 not_enough_page:
 331         max = idx;
 332         for (idx = 0; idx < max; idx++)
 333                 __free_page(ctrl->map[idx]);
 334
 335         return -ENOMEM;
 336 }
 337
 338 /**
 339  * swap_cgroup_cmpxchg - cmpxchg mem_cgroup's id for this swp_entry.
 340  * @end: swap entry to be cmpxchged
 341  * @old: old id
 342  * @new: new id
 343  *
 344  * Returns old id at success, 0 at failure.
 345  * (There is no mem_cgroup useing 0 as its id)
 346  */
 347 unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
 348                                         unsigned short old, unsigned short new)
 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 long flags;
 358         unsigned short retval;
 359
 360         ctrl = &swap_cgroup_ctrl[type];
 361
 362         mappage = ctrl->map[idx];
 363         sc = page_address(mappage);
 364         sc += pos;
 365         spin_lock_irqsave(&ctrl->lock, flags);
 366         retval = sc->id;
 367         if (retval == old)
 368                 sc->id = new;
 369         else
 370                 retval = 0;
 371         spin_unlock_irqrestore(&ctrl->lock, flags);
 372         return retval;
 373 }
 374
 375 /**
 376  * swap_cgroup_record - record mem_cgroup for this swp_entry.
 377  * @ent: swap entry to be recorded into
 378  * @mem: mem_cgroup to be recorded
 379  *
 380  * Returns old value at success, 0 at failure.
 381  * (Of course, old value can be 0.)
 382  */
 383 unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
 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 short old;
 393         unsigned long flags;
 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         old = sc->id;
 402         sc->id = id;
 403         spin_unlock_irqrestore(&ctrl->lock, flags);
 404
 405         return old;
 406 }
 407
 408 /**
 409  * lookup_swap_cgroup - lookup mem_cgroup tied to swap entry
 410  * @ent: swap entry to be looked up.
 411  *
 412  * Returns CSS ID of mem_cgroup at success. 0 at failure. (0 is invalid ID)
 413  */
 414 unsigned short lookup_swap_cgroup(swp_entry_t ent)
 415 {
 416         int type = swp_type(ent);
 417         unsigned long offset = swp_offset(ent);
 418         unsigned long idx = offset / SC_PER_PAGE;
 419         unsigned long pos = offset & SC_POS_MASK;
 420         struct swap_cgroup_ctrl *ctrl;
 421         struct page *mappage;
 422         struct swap_cgroup *sc;
 423         unsigned short ret;
 424
 425         ctrl = &swap_cgroup_ctrl[type];
 426         mappage = ctrl->map[idx];
 427         sc = page_address(mappage);
 428         sc += pos;
 429         ret = sc->id;
 430         return ret;
 431 }
 432
 433 int swap_cgroup_swapon(int type, unsigned long max_pages)
 434 {
 435         void *array;
 436         unsigned long array_size;
 437         unsigned long length;
 438         struct swap_cgroup_ctrl *ctrl;
 439
 440         if (!do_swap_account)
 441                 return 0;
 442
 443         length = ((max_pages/SC_PER_PAGE) + 1);
 444         array_size = length * sizeof(void *);
 445
 446         array = vmalloc(array_size);
 447         if (!array)
 448                 goto nomem;
 449
 450         memset(array, 0, array_size);
 451         ctrl = &swap_cgroup_ctrl[type];
 452         mutex_lock(&swap_cgroup_mutex);
 453         ctrl->length = length;
 454         ctrl->map = array;
 455         spin_lock_init(&ctrl->lock);
 456         if (swap_cgroup_prepare(type)) {
 457                 /* memory shortage */
 458                 ctrl->map = NULL;
 459                 ctrl->length = 0;
 460                 vfree(array);
 461                 mutex_unlock(&swap_cgroup_mutex);
 462                 goto nomem;
 463         }
 464         mutex_unlock(&swap_cgroup_mutex);
 465
 466         return 0;
 467 nomem:
 468         printk(KERN_INFO "couldn't allocate enough memory for swap_cgroup.\n");
 469         printk(KERN_INFO
 470                 "swap_cgroup can be disabled by noswapaccount boot option\n");
 471         return -ENOMEM;
 472 }
 473
 474 void swap_cgroup_swapoff(int type)
 475 {
 476         int i;
 477         struct swap_cgroup_ctrl *ctrl;
 478
 479         if (!do_swap_account)
 480                 return;
 481
 482         mutex_lock(&swap_cgroup_mutex);
 483         ctrl = &swap_cgroup_ctrl[type];
 484         if (ctrl->map) {
 485                 for (i = 0; i < ctrl->length; i++) {
 486                         struct page *page = ctrl->map[i];
 487                         if (page)
 488                                 __free_page(page);
 489                 }
 490                 vfree(ctrl->map);
 491                 ctrl->map = NULL;
 492                 ctrl->length = 0;
 493         }
 494         mutex_unlock(&swap_cgroup_mutex);
 495 }
 496
 497 #endif