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