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 }
  20 static unsigned long total_usage;
  21
  22 #if !defined(CONFIG_SPARSEMEM)
  23
  24
  25 void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
  26 {
  27         pgdat->node_page_cgroup = NULL;
  28 }
  29
  30 struct page_cgroup *lookup_page_cgroup(struct page *page)
  31 {
  32         unsigned long pfn = page_to_pfn(page);
  33         unsigned long offset;
  34         struct page_cgroup *base;
  35
  36         base = NODE_DATA(page_to_nid(page))->node_page_cgroup;
  37         if (unlikely(!base))
  38                 return NULL;
  39
  40         offset = pfn - NODE_DATA(page_to_nid(page))->node_start_pfn;
  41         return base + offset;
  42 }
  43
  44 static int __init alloc_node_page_cgroup(int nid)
  45 {
  46         struct page_cgroup *base, *pc;
  47         unsigned long table_size;
  48         unsigned long start_pfn, nr_pages, index;
  49
  50         start_pfn = NODE_DATA(nid)->node_start_pfn;
  51         nr_pages = NODE_DATA(nid)->node_spanned_pages;
  52
  53         if (!nr_pages)
  54                 return 0;
  55
  56         table_size = sizeof(struct page_cgroup) * nr_pages;
  57
  58         base = __alloc_bootmem_node_nopanic(NODE_DATA(nid),
  59                         table_size, PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
  60         if (!base)
  61                 return -ENOMEM;
  62         for (index = 0; index < nr_pages; index++) {
  63                 pc = base + index;
  64                 __init_page_cgroup(pc, start_pfn + index);
  65         }
  66         NODE_DATA(nid)->node_page_cgroup = base;
  67         total_usage += table_size;
  68         return 0;
  69 }
  70
  71 void __init page_cgroup_init(void)
  72 {
  73
  74         int nid, fail;
  75
  76         if (mem_cgroup_subsys.disabled)
  77                 return;
  78
  79         for_each_online_node(nid)  {
  80                 fail = alloc_node_page_cgroup(nid);
  81                 if (fail)
  82                         goto fail;
  83         }
  84         printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
  85         printk(KERN_INFO "please try cgroup_disable=memory option if you"
  86         " don't want\n");
  87         return;
  88 fail:
  89         printk(KERN_CRIT "allocation of page_cgroup was failed.\n");
  90         printk(KERN_CRIT "please try cgroup_disable=memory boot option\n");
  91         panic("Out of memory");
  92 }
  93
  94 #else /* CONFIG_FLAT_NODE_MEM_MAP */
  95
  96 struct page_cgroup *lookup_page_cgroup(struct page *page)
  97 {
  98         unsigned long pfn = page_to_pfn(page);
  99         struct mem_section *section = __pfn_to_section(pfn);
 100
 101         return section->page_cgroup + pfn;
 102 }
 103
 104 /* __alloc_bootmem...() is protected by !slab_available() */
 105 static int __init_refok init_section_page_cgroup(unsigned long pfn)
 106 {
 107         struct mem_section *section = __pfn_to_section(pfn);
 108         struct page_cgroup *base, *pc;
 109         unsigned long table_size;
 110         int nid, index;
 111
 112         if (!section->page_cgroup) {
 113                 nid = page_to_nid(pfn_to_page(pfn));
 114                 table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
 115                 if (slab_is_available()) {
 116                         base = kmalloc_node(table_size, GFP_KERNEL, nid);
 117                         if (!base)
 118                                 base = vmalloc_node(table_size, nid);
 119                 } else {
 120                         base = __alloc_bootmem_node_nopanic(NODE_DATA(nid),
 121                                 table_size,
 122                                 PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
 123                 }
 124         } else {
 125                 /*
 126                  * We don't have to allocate page_cgroup again, but
 127                  * address of memmap may be changed. So, we have to initialize
 128                  * again.
 129                  */
 130                 base = section->page_cgroup + pfn;
 131                 table_size = 0;
 132                 /* check address of memmap is changed or not. */
 133                 if (base->page == pfn_to_page(pfn))
 134                         return 0;
 135         }
 136
 137         if (!base) {
 138                 printk(KERN_ERR "page cgroup allocation failure\n");
 139                 return -ENOMEM;
 140         }
 141
 142         for (index = 0; index < PAGES_PER_SECTION; index++) {
 143                 pc = base + index;
 144                 __init_page_cgroup(pc, pfn + index);
 145         }
 146
 147         section->page_cgroup = base - pfn;
 148         total_usage += table_size;
 149         return 0;
 150 }
 151 #ifdef CONFIG_MEMORY_HOTPLUG
 152 void __free_page_cgroup(unsigned long pfn)
 153 {
 154         struct mem_section *ms;
 155         struct page_cgroup *base;
 156
 157         ms = __pfn_to_section(pfn);
 158         if (!ms || !ms->page_cgroup)
 159                 return;
 160         base = ms->page_cgroup + pfn;
 161         if (is_vmalloc_addr(base)) {
 162                 vfree(base);
 163                 ms->page_cgroup = NULL;
 164         } else {
 165                 struct page *page = virt_to_page(base);
 166                 if (!PageReserved(page)) { /* Is bootmem ? */
 167                         kfree(base);
 168                         ms->page_cgroup = NULL;
 169                 }
 170         }
 171 }
 172
 173 int __meminit online_page_cgroup(unsigned long start_pfn,
 174                         unsigned long nr_pages,
 175                         int nid)
 176 {
 177         unsigned long start, end, pfn;
 178         int fail = 0;
 179
 180         start = start_pfn & ~(PAGES_PER_SECTION - 1);
 181         end = ALIGN(start_pfn + nr_pages, PAGES_PER_SECTION);
 182
 183         for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION) {
 184                 if (!pfn_present(pfn))
 185                         continue;
 186                 fail = init_section_page_cgroup(pfn);
 187         }
 188         if (!fail)
 189                 return 0;
 190
 191         /* rollback */
 192         for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
 193                 __free_page_cgroup(pfn);
 194
 195         return -ENOMEM;
 196 }
 197
 198 int __meminit offline_page_cgroup(unsigned long start_pfn,
 199                 unsigned long nr_pages, int nid)
 200 {
 201         unsigned long start, end, pfn;
 202
 203         start = start_pfn & ~(PAGES_PER_SECTION - 1);
 204         end = ALIGN(start_pfn + nr_pages, PAGES_PER_SECTION);
 205
 206         for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
 207                 __free_page_cgroup(pfn);
 208         return 0;
 209
 210 }
 211
 212 static int __meminit page_cgroup_callback(struct notifier_block *self,
 213                                unsigned long action, void *arg)
 214 {
 215         struct memory_notify *mn = arg;
 216         int ret = 0;
 217         switch (action) {
 218         case MEM_GOING_ONLINE:
 219                 ret = online_page_cgroup(mn->start_pfn,
 220                                    mn->nr_pages, mn->status_change_nid);
 221                 break;
 222         case MEM_OFFLINE:
 223                 offline_page_cgroup(mn->start_pfn,
 224                                 mn->nr_pages, mn->status_change_nid);
 225                 break;
 226         case MEM_CANCEL_ONLINE:
 227         case MEM_GOING_OFFLINE:
 228                 break;
 229         case MEM_ONLINE:
 230         case MEM_CANCEL_OFFLINE:
 231                 break;
 232         }
 233
 234         if (ret)
 235                 ret = notifier_from_errno(ret);
 236         else
 237                 ret = NOTIFY_OK;
 238
 239         return ret;
 240 }
 241
 242 #endif
 243
 244 void __init page_cgroup_init(void)
 245 {
 246         unsigned long pfn;
 247         int fail = 0;
 248
 249         if (mem_cgroup_subsys.disabled)
 250                 return;
 251
 252         for (pfn = 0; !fail && pfn < max_pfn; pfn += PAGES_PER_SECTION) {
 253                 if (!pfn_present(pfn))
 254                         continue;
 255                 fail = init_section_page_cgroup(pfn);
 256         }
 257         if (fail) {
 258                 printk(KERN_CRIT "try cgroup_disable=memory boot option\n");
 259                 panic("Out of memory");
 260         } else {
 261                 hotplug_memory_notifier(page_cgroup_callback, 0);
 262         }
 263         printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
 264         printk(KERN_INFO "please try cgroup_disable=memory option if you don't"
 265         " want\n");
 266 }
 267
 268 void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
 269 {
 270         return;
 271 }
 272
 273 #endif
 274
 275
 276 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
 277
 278 static DEFINE_MUTEX(swap_cgroup_mutex);
 279 struct swap_cgroup_ctrl {
 280         struct page **map;
 281         unsigned long length;
 282 };
 283
 284 struct swap_cgroup_ctrl swap_cgroup_ctrl[MAX_SWAPFILES];
 285
 286 /*
 287  * This 8bytes seems big..maybe we can reduce this when we can use "id" for
 288  * cgroup rather than pointer.
 289  */
 290 struct swap_cgroup {
 291         struct mem_cgroup       *val;
 292 };
 293 #define SC_PER_PAGE     (PAGE_SIZE/sizeof(struct swap_cgroup))
 294 #define SC_POS_MASK     (SC_PER_PAGE - 1)
 295
 296 /*
 297  * SwapCgroup implements "lookup" and "exchange" operations.
 298  * In typical usage, this swap_cgroup is accessed via memcg's charge/uncharge
 299  * against SwapCache. At swap_free(), this is accessed directly from swap.
 300  *
 301  * This means,
 302  *  - we have no race in "exchange" when we're accessed via SwapCache because
 303  *    SwapCache(and its swp_entry) is under lock.
 304  *  - When called via swap_free(), there is no user of this entry and no race.
 305  * Then, we don't need lock around "exchange".
 306  *
 307  * TODO: we can push these buffers out to HIGHMEM.
 308  */
 309
 310 /*
 311  * allocate buffer for swap_cgroup.
 312  */
 313 static int swap_cgroup_prepare(int type)
 314 {
 315         struct page *page;
 316         struct swap_cgroup_ctrl *ctrl;
 317         unsigned long idx, max;
 318
 319         if (!do_swap_account)
 320                 return 0;
 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_record - record mem_cgroup for this swp_entry.
 340  * @ent: swap entry to be recorded into
 341  * @mem: mem_cgroup to be recorded
 342  *
 343  * Returns old value at success, NULL at failure.
 344  * (Of course, old value can be NULL.)
 345  */
 346 struct mem_cgroup *swap_cgroup_record(swp_entry_t ent, struct mem_cgroup *mem)
 347 {
 348         int type = swp_type(ent);
 349         unsigned long offset = swp_offset(ent);
 350         unsigned long idx = offset / SC_PER_PAGE;
 351         unsigned long pos = offset & SC_POS_MASK;
 352         struct swap_cgroup_ctrl *ctrl;
 353         struct page *mappage;
 354         struct swap_cgroup *sc;
 355         struct mem_cgroup *old;
 356
 357         if (!do_swap_account)
 358                 return NULL;
 359
 360         ctrl = &swap_cgroup_ctrl[type];
 361
 362         mappage = ctrl->map[idx];
 363         sc = page_address(mappage);
 364         sc += pos;
 365         old = sc->val;
 366         sc->val = mem;
 367
 368         return old;
 369 }
 370
 371 /**
 372  * lookup_swap_cgroup - lookup mem_cgroup tied to swap entry
 373  * @ent: swap entry to be looked up.
 374  *
 375  * Returns pointer to mem_cgroup at success. NULL at failure.
 376  */
 377 struct mem_cgroup *lookup_swap_cgroup(swp_entry_t ent)
 378 {
 379         int type = swp_type(ent);
 380         unsigned long offset = swp_offset(ent);
 381         unsigned long idx = offset / SC_PER_PAGE;
 382         unsigned long pos = offset & SC_POS_MASK;
 383         struct swap_cgroup_ctrl *ctrl;
 384         struct page *mappage;
 385         struct swap_cgroup *sc;
 386         struct mem_cgroup *ret;
 387
 388         if (!do_swap_account)
 389                 return NULL;
 390
 391         ctrl = &swap_cgroup_ctrl[type];
 392         mappage = ctrl->map[idx];
 393         sc = page_address(mappage);
 394         sc += pos;
 395         ret = sc->val;
 396         return ret;
 397 }
 398
 399 int swap_cgroup_swapon(int type, unsigned long max_pages)
 400 {
 401         void *array;
 402         unsigned long array_size;
 403         unsigned long length;
 404         struct swap_cgroup_ctrl *ctrl;
 405
 406         if (!do_swap_account)
 407                 return 0;
 408
 409         length = ((max_pages/SC_PER_PAGE) + 1);
 410         array_size = length * sizeof(void *);
 411
 412         array = vmalloc(array_size);
 413         if (!array)
 414                 goto nomem;
 415
 416         memset(array, 0, array_size);
 417         ctrl = &swap_cgroup_ctrl[type];
 418         mutex_lock(&swap_cgroup_mutex);
 419         ctrl->length = length;
 420         ctrl->map = array;
 421         if (swap_cgroup_prepare(type)) {
 422                 /* memory shortage */
 423                 ctrl->map = NULL;
 424                 ctrl->length = 0;
 425                 vfree(array);
 426                 mutex_unlock(&swap_cgroup_mutex);
 427                 goto nomem;
 428         }
 429         mutex_unlock(&swap_cgroup_mutex);
 430
 431         printk(KERN_INFO
 432                 "swap_cgroup: uses %ld bytes of vmalloc for pointer array space"
 433                 " and %ld bytes to hold mem_cgroup pointers on swap\n",
 434                 array_size, length * PAGE_SIZE);
 435         printk(KERN_INFO
 436         "swap_cgroup can be disabled by noswapaccount boot option.\n");
 437
 438         return 0;
 439 nomem:
 440         printk(KERN_INFO "couldn't allocate enough memory for swap_cgroup.\n");
 441         printk(KERN_INFO
 442                 "swap_cgroup can be disabled by noswapaccount boot option\n");
 443         return -ENOMEM;
 444 }
 445
 446 void swap_cgroup_swapoff(int type)
 447 {
 448         int i;
 449         struct swap_cgroup_ctrl *ctrl;
 450
 451         if (!do_swap_account)
 452                 return;
 453
 454         mutex_lock(&swap_cgroup_mutex);
 455         ctrl = &swap_cgroup_ctrl[type];
 456         if (ctrl->map) {
 457                 for (i = 0; i < ctrl->length; i++) {
 458                         struct page *page = ctrl->map[i];
 459                         if (page)
 460                                 __free_page(page);
 461                 }
 462                 vfree(ctrl->map);
 463                 ctrl->map = NULL;
 464                 ctrl->length = 0;
 465         }
 466         mutex_unlock(&swap_cgroup_mutex);
 467 }
 468
 469 #endif