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   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(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\n");
  88         return;
  89 fail:
  90         printk(KERN_CRIT "allocation of page_cgroup was 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         return section->page_cgroup + pfn;
 103 }
 104
 105 /* __alloc_bootmem...() is protected by !slab_available() */
 106 static int __init_refok init_section_page_cgroup(unsigned long pfn)
 107 {
 108         struct mem_section *section = __pfn_to_section(pfn);
 109         struct page_cgroup *base, *pc;
 110         unsigned long table_size;
 111         int nid, index;
 112
 113         if (!section->page_cgroup) {
 114                 nid = page_to_nid(pfn_to_page(pfn));
 115                 table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
 116                 if (slab_is_available()) {
 117                         base = kmalloc_node(table_size, GFP_KERNEL, nid);
 118                         if (!base)
 119                                 base = vmalloc_node(table_size, nid);
 120                 } else {
 121                         base = __alloc_bootmem_node_nopanic(NODE_DATA(nid),
 122                                 table_size,
 123                                 PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
 124                 }
 125         } else {
 126                 /*
 127                  * We don't have to allocate page_cgroup again, but
 128                  * address of memmap may be changed. So, we have to initialize
 129                  * again.
 130                  */
 131                 base = section->page_cgroup + pfn;
 132                 table_size = 0;
 133                 /* check address of memmap is changed or not. */
 134                 if (base->page == pfn_to_page(pfn))
 135                         return 0;
 136         }
 137
 138         if (!base) {
 139                 printk(KERN_ERR "page cgroup allocation failure\n");
 140                 return -ENOMEM;
 141         }
 142
 143         for (index = 0; index < PAGES_PER_SECTION; index++) {
 144                 pc = base + index;
 145                 __init_page_cgroup(pc, pfn + index);
 146         }
 147
 148         section->page_cgroup = base - pfn;
 149         total_usage += table_size;
 150         return 0;
 151 }
 152 #ifdef CONFIG_MEMORY_HOTPLUG
 153 void __free_page_cgroup(unsigned long pfn)
 154 {
 155         struct mem_section *ms;
 156         struct page_cgroup *base;
 157
 158         ms = __pfn_to_section(pfn);
 159         if (!ms || !ms->page_cgroup)
 160                 return;
 161         base = ms->page_cgroup + pfn;
 162         if (is_vmalloc_addr(base)) {
 163                 vfree(base);
 164                 ms->page_cgroup = NULL;
 165         } else {
 166                 struct page *page = virt_to_page(base);
 167                 if (!PageReserved(page)) { /* Is bootmem ? */
 168                         kfree(base);
 169                         ms->page_cgroup = NULL;
 170                 }
 171         }
 172 }
 173
 174 int __meminit online_page_cgroup(unsigned long start_pfn,
 175                         unsigned long nr_pages,
 176                         int nid)
 177 {
 178         unsigned long start, end, pfn;
 179         int fail = 0;
 180
 181         start = start_pfn & ~(PAGES_PER_SECTION - 1);
 182         end = ALIGN(start_pfn + nr_pages, PAGES_PER_SECTION);
 183
 184         for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION) {
 185                 if (!pfn_present(pfn))
 186                         continue;
 187                 fail = init_section_page_cgroup(pfn);
 188         }
 189         if (!fail)
 190                 return 0;
 191
 192         /* rollback */
 193         for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
 194                 __free_page_cgroup(pfn);
 195
 196         return -ENOMEM;
 197 }
 198
 199 int __meminit offline_page_cgroup(unsigned long start_pfn,
 200                 unsigned long nr_pages, int nid)
 201 {
 202         unsigned long start, end, pfn;
 203
 204         start = start_pfn & ~(PAGES_PER_SECTION - 1);
 205         end = ALIGN(start_pfn + nr_pages, PAGES_PER_SECTION);
 206
 207         for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
 208                 __free_page_cgroup(pfn);
 209         return 0;
 210
 211 }
 212
 213 static int __meminit page_cgroup_callback(struct notifier_block *self,
 214                                unsigned long action, void *arg)
 215 {
 216         struct memory_notify *mn = arg;
 217         int ret = 0;
 218         switch (action) {
 219         case MEM_GOING_ONLINE:
 220                 ret = online_page_cgroup(mn->start_pfn,
 221                                    mn->nr_pages, mn->status_change_nid);
 222                 break;
 223         case MEM_OFFLINE:
 224                 offline_page_cgroup(mn->start_pfn,
 225                                 mn->nr_pages, mn->status_change_nid);
 226                 break;
 227         case MEM_CANCEL_ONLINE:
 228         case MEM_GOING_OFFLINE:
 229                 break;
 230         case MEM_ONLINE:
 231         case MEM_CANCEL_OFFLINE:
 232                 break;
 233         }
 234
 235         if (ret)
 236                 ret = notifier_from_errno(ret);
 237         else
 238                 ret = NOTIFY_OK;
 239
 240         return ret;
 241 }
 242
 243 #endif
 244
 245 void __init page_cgroup_init(void)
 246 {
 247         unsigned long pfn;
 248         int fail = 0;
 249
 250         if (mem_cgroup_disabled())
 251                 return;
 252
 253         for (pfn = 0; !fail && pfn < max_pfn; pfn += PAGES_PER_SECTION) {
 254                 if (!pfn_present(pfn))
 255                         continue;
 256                 fail = init_section_page_cgroup(pfn);
 257         }
 258         if (fail) {
 259                 printk(KERN_CRIT "try cgroup_disable=memory boot option\n");
 260                 panic("Out of memory");
 261         } else {
 262                 hotplug_memory_notifier(page_cgroup_callback, 0);
 263         }
 264         printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
 265         printk(KERN_INFO "please try cgroup_disable=memory option if you don't"
 266         " want\n");
 267 }
 268
 269 void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
 270 {
 271         return;
 272 }
 273
 274 #endif
 275
 276
 277 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
 278
 279 static DEFINE_MUTEX(swap_cgroup_mutex);
 280 struct swap_cgroup_ctrl {
 281         struct page **map;
 282         unsigned long length;
 283 };
 284
 285 struct swap_cgroup_ctrl swap_cgroup_ctrl[MAX_SWAPFILES];
 286
 287 /*
 288  * This 8bytes seems big..maybe we can reduce this when we can use "id" for
 289  * cgroup rather than pointer.
 290  */
 291 struct swap_cgroup {
 292         struct mem_cgroup       *val;
 293 };
 294 #define SC_PER_PAGE     (PAGE_SIZE/sizeof(struct swap_cgroup))
 295 #define SC_POS_MASK     (SC_PER_PAGE - 1)
 296
 297 /*
 298  * SwapCgroup implements "lookup" and "exchange" operations.
 299  * In typical usage, this swap_cgroup is accessed via memcg's charge/uncharge
 300  * against SwapCache. At swap_free(), this is accessed directly from swap.
 301  *
 302  * This means,
 303  *  - we have no race in "exchange" when we're accessed via SwapCache because
 304  *    SwapCache(and its swp_entry) is under lock.
 305  *  - When called via swap_free(), there is no user of this entry and no race.
 306  * Then, we don't need lock around "exchange".
 307  *
 308  * TODO: we can push these buffers out to HIGHMEM.
 309  */
 310
 311 /*
 312  * allocate buffer for swap_cgroup.
 313  */
 314 static int swap_cgroup_prepare(int type)
 315 {
 316         struct page *page;
 317         struct swap_cgroup_ctrl *ctrl;
 318         unsigned long idx, max;
 319
 320         if (!do_swap_account)
 321                 return 0;
 322         ctrl = &swap_cgroup_ctrl[type];
 323
 324         for (idx = 0; idx < ctrl->length; idx++) {
 325                 page = alloc_page(GFP_KERNEL | __GFP_ZERO);
 326                 if (!page)
 327                         goto not_enough_page;
 328                 ctrl->map[idx] = page;
 329         }
 330         return 0;
 331 not_enough_page:
 332         max = idx;
 333         for (idx = 0; idx < max; idx++)
 334                 __free_page(ctrl->map[idx]);
 335
 336         return -ENOMEM;
 337 }
 338
 339 /**
 340  * swap_cgroup_record - record mem_cgroup for this swp_entry.
 341  * @ent: swap entry to be recorded into
 342  * @mem: mem_cgroup to be recorded
 343  *
 344  * Returns old value at success, NULL at failure.
 345  * (Of course, old value can be NULL.)
 346  */
 347 struct mem_cgroup *swap_cgroup_record(swp_entry_t ent, struct mem_cgroup *mem)
 348 {
 349         int type = swp_type(ent);
 350         unsigned long offset = swp_offset(ent);
 351         unsigned long idx = offset / SC_PER_PAGE;
 352         unsigned long pos = offset & SC_POS_MASK;
 353         struct swap_cgroup_ctrl *ctrl;
 354         struct page *mappage;
 355         struct swap_cgroup *sc;
 356         struct mem_cgroup *old;
 357
 358         if (!do_swap_account)
 359                 return NULL;
 360
 361         ctrl = &swap_cgroup_ctrl[type];
 362
 363         mappage = ctrl->map[idx];
 364         sc = page_address(mappage);
 365         sc += pos;
 366         old = sc->val;
 367         sc->val = mem;
 368
 369         return old;
 370 }
 371
 372 /**
 373  * lookup_swap_cgroup - lookup mem_cgroup tied to swap entry
 374  * @ent: swap entry to be looked up.
 375  *
 376  * Returns pointer to mem_cgroup at success. NULL at failure.
 377  */
 378 struct mem_cgroup *lookup_swap_cgroup(swp_entry_t ent)
 379 {
 380         int type = swp_type(ent);
 381         unsigned long offset = swp_offset(ent);
 382         unsigned long idx = offset / SC_PER_PAGE;
 383         unsigned long pos = offset & SC_POS_MASK;
 384         struct swap_cgroup_ctrl *ctrl;
 385         struct page *mappage;
 386         struct swap_cgroup *sc;
 387         struct mem_cgroup *ret;
 388
 389         if (!do_swap_account)
 390                 return NULL;
 391
 392         ctrl = &swap_cgroup_ctrl[type];
 393         mappage = ctrl->map[idx];
 394         sc = page_address(mappage);
 395         sc += pos;
 396         ret = sc->val;
 397         return ret;
 398 }
 399
 400 int swap_cgroup_swapon(int type, unsigned long max_pages)
 401 {
 402         void *array;
 403         unsigned long array_size;
 404         unsigned long length;
 405         struct swap_cgroup_ctrl *ctrl;
 406
 407         if (!do_swap_account)
 408                 return 0;
 409
 410         length = ((max_pages/SC_PER_PAGE) + 1);
 411         array_size = length * sizeof(void *);
 412
 413         array = vmalloc(array_size);
 414         if (!array)
 415                 goto nomem;
 416
 417         memset(array, 0, array_size);
 418         ctrl = &swap_cgroup_ctrl[type];
 419         mutex_lock(&swap_cgroup_mutex);
 420         ctrl->length = length;
 421         ctrl->map = array;
 422         if (swap_cgroup_prepare(type)) {
 423                 /* memory shortage */
 424                 ctrl->map = NULL;
 425                 ctrl->length = 0;
 426                 vfree(array);
 427                 mutex_unlock(&swap_cgroup_mutex);
 428                 goto nomem;
 429         }
 430         mutex_unlock(&swap_cgroup_mutex);
 431
 432         printk(KERN_INFO
 433                 "swap_cgroup: uses %ld bytes of vmalloc for pointer array space"
 434                 " and %ld bytes to hold mem_cgroup pointers on swap\n",
 435                 array_size, length * PAGE_SIZE);
 436         printk(KERN_INFO
 437         "swap_cgroup can be disabled by noswapaccount boot option.\n");
 438
 439         return 0;
 440 nomem:
 441         printk(KERN_INFO "couldn't allocate enough memory for swap_cgroup.\n");
 442         printk(KERN_INFO
 443                 "swap_cgroup can be disabled by noswapaccount boot option\n");
 444         return -ENOMEM;
 445 }
 446
 447 void swap_cgroup_swapoff(int type)
 448 {
 449         int i;
 450         struct swap_cgroup_ctrl *ctrl;
 451
 452         if (!do_swap_account)
 453                 return;
 454
 455         mutex_lock(&swap_cgroup_mutex);
 456         ctrl = &swap_cgroup_ctrl[type];
 457         if (ctrl->map) {
 458                 for (i = 0; i < ctrl->length; i++) {
 459                         struct page *page = ctrl->map[i];
 460                         if (page)
 461                                 __free_page(page);
 462                 }
 463                 vfree(ctrl->map);
 464                 ctrl->map = NULL;
 465                 ctrl->length = 0;
 466         }
 467         mutex_unlock(&swap_cgroup_mutex);
 468 }
 469
 470 #endif