Pileus Git - ~andy/linux/blob - 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 /* __alloc_bootmem...() is protected by !slab_available() */
 134 static int __init_refok init_section_page_cgroup(unsigned long pfn)
 135 {
 136         struct page_cgroup *base, *pc;
 137         struct mem_section *section;
 138         unsigned long table_size;
 139         unsigned long nr;
 140         int nid, index;
 141
 142         nr = pfn_to_section_nr(pfn);
 143         section = __nr_to_section(nr);
 144
 145         if (section->page_cgroup)
 146                 return 0;
 147
 148         nid = page_to_nid(pfn_to_page(pfn));
 149         table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
 150         VM_BUG_ON(!slab_is_available());
 151         if (node_state(nid, N_HIGH_MEMORY)) {
 152                 base = kmalloc_node(table_size,
 153                                     GFP_KERNEL | __GFP_NOWARN, nid);
 154                 if (!base)
 155                         base = vmalloc_node(table_size, nid);
 156         } else {
 157                 base = kmalloc(table_size, GFP_KERNEL | __GFP_NOWARN);
 158                 if (!base)
 159                         base = vmalloc(table_size);
 160         }
 161         /*
 162          * The value stored in section->page_cgroup is (base - pfn)
 163          * and it does not point to the memory block allocated above,
 164          * causing kmemleak false positives.
 165          */
 166         kmemleak_not_leak(base);
 167
 168         if (!base) {
 169                 printk(KERN_ERR "page cgroup allocation failure\n");
 170                 return -ENOMEM;
 171         }
 172
 173         for (index = 0; index < PAGES_PER_SECTION; index++) {
 174                 pc = base + index;
 175                 init_page_cgroup(pc, nr);
 176         }
 177
 178         section->page_cgroup = base - pfn;
 179         total_usage += table_size;
 180         return 0;
 181 }
 182 #ifdef CONFIG_MEMORY_HOTPLUG
 183 void __free_page_cgroup(unsigned long pfn)
 184 {
 185         struct mem_section *ms;
 186         struct page_cgroup *base;
 187
 188         ms = __pfn_to_section(pfn);
 189         if (!ms || !ms->page_cgroup)
 190                 return;
 191         base = ms->page_cgroup + pfn;
 192         if (is_vmalloc_addr(base)) {
 193                 vfree(base);
 194                 ms->page_cgroup = NULL;
 195         } else {
 196                 struct page *page = virt_to_page(base);
 197                 if (!PageReserved(page)) { /* Is bootmem ? */
 198                         kfree(base);
 199                         ms->page_cgroup = NULL;
 200                 }
 201         }
 202 }
 203
 204 int __meminit online_page_cgroup(unsigned long start_pfn,
 205                         unsigned long nr_pages,
 206                         int nid)
 207 {
 208         unsigned long start, end, pfn;
 209         int fail = 0;
 210
 211         start = start_pfn & ~(PAGES_PER_SECTION - 1);
 212         end = ALIGN(start_pfn + nr_pages, PAGES_PER_SECTION);
 213
 214         for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION) {
 215                 if (!pfn_present(pfn))
 216                         continue;
 217                 fail = init_section_page_cgroup(pfn);
 218         }
 219         if (!fail)
 220                 return 0;
 221
 222         /* rollback */
 223         for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
 224                 __free_page_cgroup(pfn);
 225
 226         return -ENOMEM;
 227 }
 228
 229 int __meminit offline_page_cgroup(unsigned long start_pfn,
 230                 unsigned long nr_pages, int nid)
 231 {
 232         unsigned long start, end, pfn;
 233
 234         start = start_pfn & ~(PAGES_PER_SECTION - 1);
 235         end = ALIGN(start_pfn + nr_pages, PAGES_PER_SECTION);
 236
 237         for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
 238                 __free_page_cgroup(pfn);
 239         return 0;
 240
 241 }
 242
 243 static int __meminit page_cgroup_callback(struct notifier_block *self,
 244                                unsigned long action, void *arg)
 245 {
 246         struct memory_notify *mn = arg;
 247         int ret = 0;
 248         switch (action) {
 249         case MEM_GOING_ONLINE:
 250                 ret = online_page_cgroup(mn->start_pfn,
 251                                    mn->nr_pages, mn->status_change_nid);
 252                 break;
 253         case MEM_OFFLINE:
 254                 offline_page_cgroup(mn->start_pfn,
 255                                 mn->nr_pages, mn->status_change_nid);
 256                 break;
 257         case MEM_CANCEL_ONLINE:
 258         case MEM_GOING_OFFLINE:
 259                 break;
 260         case MEM_ONLINE:
 261         case MEM_CANCEL_OFFLINE:
 262                 break;
 263         }
 264
 265         return notifier_from_errno(ret);
 266 }
 267
 268 #endif
 269
 270 void __init page_cgroup_init(void)
 271 {
 272         unsigned long pfn;
 273         int fail = 0;
 274
 275         if (mem_cgroup_disabled())
 276                 return;
 277
 278         for (pfn = 0; !fail && pfn < max_pfn; pfn += PAGES_PER_SECTION) {
 279                 if (!pfn_present(pfn))
 280                         continue;
 281                 fail = init_section_page_cgroup(pfn);
 282         }
 283         if (fail) {
 284                 printk(KERN_CRIT "try 'cgroup_disable=memory' boot option\n");
 285                 panic("Out of memory");
 286         } else {
 287                 hotplug_memory_notifier(page_cgroup_callback, 0);
 288         }
 289         printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
 290         printk(KERN_INFO "please try 'cgroup_disable=memory' option if you don't"
 291         " want memory cgroups\n");
 292 }
 293
 294 void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
 295 {
 296         return;
 297 }
 298
 299 #endif
 300
 301
 302 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
 303
 304 static DEFINE_MUTEX(swap_cgroup_mutex);
 305 struct swap_cgroup_ctrl {
 306         struct page **map;
 307         unsigned long length;
 308         spinlock_t      lock;
 309 };
 310
 311 struct swap_cgroup_ctrl swap_cgroup_ctrl[MAX_SWAPFILES];
 312
 313 struct swap_cgroup {
 314         unsigned short          id;
 315 };
 316 #define SC_PER_PAGE     (PAGE_SIZE/sizeof(struct swap_cgroup))
 317 #define SC_POS_MASK     (SC_PER_PAGE - 1)
 318
 319 /*
 320  * SwapCgroup implements "lookup" and "exchange" operations.
 321  * In typical usage, this swap_cgroup is accessed via memcg's charge/uncharge
 322  * against SwapCache. At swap_free(), this is accessed directly from swap.
 323  *
 324  * This means,
 325  *  - we have no race in "exchange" when we're accessed via SwapCache because
 326  *    SwapCache(and its swp_entry) is under lock.
 327  *  - When called via swap_free(), there is no user of this entry and no race.
 328  * Then, we don't need lock around "exchange".
 329  *
 330  * TODO: we can push these buffers out to HIGHMEM.
 331  */
 332
 333 /*
 334  * allocate buffer for swap_cgroup.
 335  */
 336 static int swap_cgroup_prepare(int type)
 337 {
 338         struct page *page;
 339         struct swap_cgroup_ctrl *ctrl;
 340         unsigned long idx, max;
 341
 342         ctrl = &swap_cgroup_ctrl[type];
 343
 344         for (idx = 0; idx < ctrl->length; idx++) {
 345                 page = alloc_page(GFP_KERNEL | __GFP_ZERO);
 346                 if (!page)
 347                         goto not_enough_page;
 348                 ctrl->map[idx] = page;
 349         }
 350         return 0;
 351 not_enough_page:
 352         max = idx;
 353         for (idx = 0; idx < max; idx++)
 354                 __free_page(ctrl->map[idx]);
 355
 356         return -ENOMEM;
 357 }
 358
 359 /**
 360  * swap_cgroup_cmpxchg - cmpxchg mem_cgroup's id for this swp_entry.
 361  * @end: swap entry to be cmpxchged
 362  * @old: old id
 363  * @new: new id
 364  *
 365  * Returns old id at success, 0 at failure.
 366  * (There is no mem_cgroup useing 0 as its id)
 367  */
 368 unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
 369                                         unsigned short old, unsigned short new)
 370 {
 371         int type = swp_type(ent);
 372         unsigned long offset = swp_offset(ent);
 373         unsigned long idx = offset / SC_PER_PAGE;
 374         unsigned long pos = offset & SC_POS_MASK;
 375         struct swap_cgroup_ctrl *ctrl;
 376         struct page *mappage;
 377         struct swap_cgroup *sc;
 378         unsigned long flags;
 379         unsigned short retval;
 380
 381         ctrl = &swap_cgroup_ctrl[type];
 382
 383         mappage = ctrl->map[idx];
 384         sc = page_address(mappage);
 385         sc += pos;
 386         spin_lock_irqsave(&ctrl->lock, flags);
 387         retval = sc->id;
 388         if (retval == old)
 389                 sc->id = new;
 390         else
 391                 retval = 0;
 392         spin_unlock_irqrestore(&ctrl->lock, flags);
 393         return retval;
 394 }
 395
 396 /**
 397  * swap_cgroup_record - record mem_cgroup for this swp_entry.
 398  * @ent: swap entry to be recorded into
 399  * @mem: mem_cgroup to be recorded
 400  *
 401  * Returns old value at success, 0 at failure.
 402  * (Of course, old value can be 0.)
 403  */
 404 unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
 405 {
 406         int type = swp_type(ent);
 407         unsigned long offset = swp_offset(ent);
 408         unsigned long idx = offset / SC_PER_PAGE;
 409         unsigned long pos = offset & SC_POS_MASK;
 410         struct swap_cgroup_ctrl *ctrl;
 411         struct page *mappage;
 412         struct swap_cgroup *sc;
 413         unsigned short old;
 414         unsigned long flags;
 415
 416         ctrl = &swap_cgroup_ctrl[type];
 417
 418         mappage = ctrl->map[idx];
 419         sc = page_address(mappage);
 420         sc += pos;
 421         spin_lock_irqsave(&ctrl->lock, flags);
 422         old = sc->id;
 423         sc->id = id;
 424         spin_unlock_irqrestore(&ctrl->lock, flags);
 425
 426         return old;
 427 }
 428
 429 /**
 430  * lookup_swap_cgroup - lookup mem_cgroup tied to swap entry
 431  * @ent: swap entry to be looked up.
 432  *
 433  * Returns CSS ID of mem_cgroup at success. 0 at failure. (0 is invalid ID)
 434  */
 435 unsigned short lookup_swap_cgroup(swp_entry_t ent)
 436 {
 437         int type = swp_type(ent);
 438         unsigned long offset = swp_offset(ent);
 439         unsigned long idx = offset / SC_PER_PAGE;
 440         unsigned long pos = offset & SC_POS_MASK;
 441         struct swap_cgroup_ctrl *ctrl;
 442         struct page *mappage;
 443         struct swap_cgroup *sc;
 444         unsigned short ret;
 445
 446         ctrl = &swap_cgroup_ctrl[type];
 447         mappage = ctrl->map[idx];
 448         sc = page_address(mappage);
 449         sc += pos;
 450         ret = sc->id;
 451         return ret;
 452 }
 453
 454 int swap_cgroup_swapon(int type, unsigned long max_pages)
 455 {
 456         void *array;
 457         unsigned long array_size;
 458         unsigned long length;
 459         struct swap_cgroup_ctrl *ctrl;
 460
 461         if (!do_swap_account)
 462                 return 0;
 463
 464         length = ((max_pages/SC_PER_PAGE) + 1);
 465         array_size = length * sizeof(void *);
 466
 467         array = vmalloc(array_size);
 468         if (!array)
 469                 goto nomem;
 470
 471         memset(array, 0, array_size);
 472         ctrl = &swap_cgroup_ctrl[type];
 473         mutex_lock(&swap_cgroup_mutex);
 474         ctrl->length = length;
 475         ctrl->map = array;
 476         spin_lock_init(&ctrl->lock);
 477         if (swap_cgroup_prepare(type)) {
 478                 /* memory shortage */
 479                 ctrl->map = NULL;
 480                 ctrl->length = 0;
 481                 vfree(array);
 482                 mutex_unlock(&swap_cgroup_mutex);
 483                 goto nomem;
 484         }
 485         mutex_unlock(&swap_cgroup_mutex);
 486
 487         return 0;
 488 nomem:
 489         printk(KERN_INFO "couldn't allocate enough memory for swap_cgroup.\n");
 490         printk(KERN_INFO
 491                 "swap_cgroup can be disabled by noswapaccount boot option\n");
 492         return -ENOMEM;
 493 }
 494
 495 void swap_cgroup_swapoff(int type)
 496 {
 497         int i;
 498         struct swap_cgroup_ctrl *ctrl;
 499
 500         if (!do_swap_account)
 501                 return;
 502
 503         mutex_lock(&swap_cgroup_mutex);
 504         ctrl = &swap_cgroup_ctrl[type];
 505         if (ctrl->map) {
 506                 for (i = 0; i < ctrl->length; i++) {
 507                         struct page *page = ctrl->map[i];
 508                         if (page)
 509                                 __free_page(page);
 510                 }
 511                 vfree(ctrl->map);
 512                 ctrl->map = NULL;
 513                 ctrl->length = 0;
 514         }
 515         mutex_unlock(&swap_cgroup_mutex);
 516 }
 517
 518 #endif