linux/drivers/base/node.c
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   1/*
   2 * Basic Node interface support
   3 */
   4
   5#include <linux/module.h>
   6#include <linux/init.h>
   7#include <linux/mm.h>
   8#include <linux/memory.h>
   9#include <linux/vmstat.h>
  10#include <linux/node.h>
  11#include <linux/hugetlb.h>
  12#include <linux/compaction.h>
  13#include <linux/cpumask.h>
  14#include <linux/topology.h>
  15#include <linux/nodemask.h>
  16#include <linux/cpu.h>
  17#include <linux/device.h>
  18#include <linux/swap.h>
  19#include <linux/slab.h>
  20
  21static struct bus_type node_subsys = {
  22        .name = "node",
  23        .dev_name = "node",
  24};
  25
  26
  27static ssize_t node_read_cpumap(struct device *dev, int type, char *buf)
  28{
  29        struct node *node_dev = to_node(dev);
  30        const struct cpumask *mask = cpumask_of_node(node_dev->dev.id);
  31        int len;
  32
  33        /* 2008/04/07: buf currently PAGE_SIZE, need 9 chars per 32 bits. */
  34        BUILD_BUG_ON((NR_CPUS/32 * 9) > (PAGE_SIZE-1));
  35
  36        len = type?
  37                cpulist_scnprintf(buf, PAGE_SIZE-2, mask) :
  38                cpumask_scnprintf(buf, PAGE_SIZE-2, mask);
  39        buf[len++] = '\n';
  40        buf[len] = '\0';
  41        return len;
  42}
  43
  44static inline ssize_t node_read_cpumask(struct device *dev,
  45                                struct device_attribute *attr, char *buf)
  46{
  47        return node_read_cpumap(dev, 0, buf);
  48}
  49static inline ssize_t node_read_cpulist(struct device *dev,
  50                                struct device_attribute *attr, char *buf)
  51{
  52        return node_read_cpumap(dev, 1, buf);
  53}
  54
  55static DEVICE_ATTR(cpumap,  S_IRUGO, node_read_cpumask, NULL);
  56static DEVICE_ATTR(cpulist, S_IRUGO, node_read_cpulist, NULL);
  57
  58#define K(x) ((x) << (PAGE_SHIFT - 10))
  59static ssize_t node_read_meminfo(struct device *dev,
  60                        struct device_attribute *attr, char *buf)
  61{
  62        int n;
  63        int nid = dev->id;
  64        struct sysinfo i;
  65
  66        si_meminfo_node(&i, nid);
  67        n = sprintf(buf,
  68                       "Node %d MemTotal:       %8lu kB\n"
  69                       "Node %d MemFree:        %8lu kB\n"
  70                       "Node %d MemUsed:        %8lu kB\n"
  71                       "Node %d Active:         %8lu kB\n"
  72                       "Node %d Inactive:       %8lu kB\n"
  73                       "Node %d Active(anon):   %8lu kB\n"
  74                       "Node %d Inactive(anon): %8lu kB\n"
  75                       "Node %d Active(file):   %8lu kB\n"
  76                       "Node %d Inactive(file): %8lu kB\n"
  77                       "Node %d Unevictable:    %8lu kB\n"
  78                       "Node %d Mlocked:        %8lu kB\n",
  79                       nid, K(i.totalram),
  80                       nid, K(i.freeram),
  81                       nid, K(i.totalram - i.freeram),
  82                       nid, K(node_page_state(nid, NR_ACTIVE_ANON) +
  83                                node_page_state(nid, NR_ACTIVE_FILE)),
  84                       nid, K(node_page_state(nid, NR_INACTIVE_ANON) +
  85                                node_page_state(nid, NR_INACTIVE_FILE)),
  86                       nid, K(node_page_state(nid, NR_ACTIVE_ANON)),
  87                       nid, K(node_page_state(nid, NR_INACTIVE_ANON)),
  88                       nid, K(node_page_state(nid, NR_ACTIVE_FILE)),
  89                       nid, K(node_page_state(nid, NR_INACTIVE_FILE)),
  90                       nid, K(node_page_state(nid, NR_UNEVICTABLE)),
  91                       nid, K(node_page_state(nid, NR_MLOCK)));
  92
  93#ifdef CONFIG_HIGHMEM
  94        n += sprintf(buf + n,
  95                       "Node %d HighTotal:      %8lu kB\n"
  96                       "Node %d HighFree:       %8lu kB\n"
  97                       "Node %d LowTotal:       %8lu kB\n"
  98                       "Node %d LowFree:        %8lu kB\n",
  99                       nid, K(i.totalhigh),
 100                       nid, K(i.freehigh),
 101                       nid, K(i.totalram - i.totalhigh),
 102                       nid, K(i.freeram - i.freehigh));
 103#endif
 104        n += sprintf(buf + n,
 105                       "Node %d Dirty:          %8lu kB\n"
 106                       "Node %d Writeback:      %8lu kB\n"
 107                       "Node %d FilePages:      %8lu kB\n"
 108                       "Node %d Mapped:         %8lu kB\n"
 109                       "Node %d AnonPages:      %8lu kB\n"
 110                       "Node %d Shmem:          %8lu kB\n"
 111                       "Node %d KernelStack:    %8lu kB\n"
 112                       "Node %d PageTables:     %8lu kB\n"
 113                       "Node %d NFS_Unstable:   %8lu kB\n"
 114                       "Node %d Bounce:         %8lu kB\n"
 115                       "Node %d WritebackTmp:   %8lu kB\n"
 116                       "Node %d Slab:           %8lu kB\n"
 117                       "Node %d SReclaimable:   %8lu kB\n"
 118                       "Node %d SUnreclaim:     %8lu kB\n"
 119#ifdef CONFIG_TRANSPARENT_HUGEPAGE
 120                       "Node %d AnonHugePages:  %8lu kB\n"
 121#endif
 122                        ,
 123                       nid, K(node_page_state(nid, NR_FILE_DIRTY)),
 124                       nid, K(node_page_state(nid, NR_WRITEBACK)),
 125                       nid, K(node_page_state(nid, NR_FILE_PAGES)),
 126                       nid, K(node_page_state(nid, NR_FILE_MAPPED)),
 127#ifdef CONFIG_TRANSPARENT_HUGEPAGE
 128                       nid, K(node_page_state(nid, NR_ANON_PAGES)
 129                        + node_page_state(nid, NR_ANON_TRANSPARENT_HUGEPAGES) *
 130                        HPAGE_PMD_NR),
 131#else
 132                       nid, K(node_page_state(nid, NR_ANON_PAGES)),
 133#endif
 134                       nid, K(node_page_state(nid, NR_SHMEM)),
 135                       nid, node_page_state(nid, NR_KERNEL_STACK) *
 136                                THREAD_SIZE / 1024,
 137                       nid, K(node_page_state(nid, NR_PAGETABLE)),
 138                       nid, K(node_page_state(nid, NR_UNSTABLE_NFS)),
 139                       nid, K(node_page_state(nid, NR_BOUNCE)),
 140                       nid, K(node_page_state(nid, NR_WRITEBACK_TEMP)),
 141                       nid, K(node_page_state(nid, NR_SLAB_RECLAIMABLE) +
 142                                node_page_state(nid, NR_SLAB_UNRECLAIMABLE)),
 143                       nid, K(node_page_state(nid, NR_SLAB_RECLAIMABLE)),
 144#ifdef CONFIG_TRANSPARENT_HUGEPAGE
 145                       nid, K(node_page_state(nid, NR_SLAB_UNRECLAIMABLE))
 146                        , nid,
 147                        K(node_page_state(nid, NR_ANON_TRANSPARENT_HUGEPAGES) *
 148                        HPAGE_PMD_NR));
 149#else
 150                       nid, K(node_page_state(nid, NR_SLAB_UNRECLAIMABLE)));
 151#endif
 152        n += hugetlb_report_node_meminfo(nid, buf + n);
 153        return n;
 154}
 155
 156#undef K
 157static DEVICE_ATTR(meminfo, S_IRUGO, node_read_meminfo, NULL);
 158
 159static ssize_t node_read_numastat(struct device *dev,
 160                                struct device_attribute *attr, char *buf)
 161{
 162        return sprintf(buf,
 163                       "numa_hit %lu\n"
 164                       "numa_miss %lu\n"
 165                       "numa_foreign %lu\n"
 166                       "interleave_hit %lu\n"
 167                       "local_node %lu\n"
 168                       "other_node %lu\n",
 169                       node_page_state(dev->id, NUMA_HIT),
 170                       node_page_state(dev->id, NUMA_MISS),
 171                       node_page_state(dev->id, NUMA_FOREIGN),
 172                       node_page_state(dev->id, NUMA_INTERLEAVE_HIT),
 173                       node_page_state(dev->id, NUMA_LOCAL),
 174                       node_page_state(dev->id, NUMA_OTHER));
 175}
 176static DEVICE_ATTR(numastat, S_IRUGO, node_read_numastat, NULL);
 177
 178static ssize_t node_read_vmstat(struct device *dev,
 179                                struct device_attribute *attr, char *buf)
 180{
 181        int nid = dev->id;
 182        int i;
 183        int n = 0;
 184
 185        for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
 186                n += sprintf(buf+n, "%s %lu\n", vmstat_text[i],
 187                             node_page_state(nid, i));
 188
 189        return n;
 190}
 191static DEVICE_ATTR(vmstat, S_IRUGO, node_read_vmstat, NULL);
 192
 193static ssize_t node_read_distance(struct device *dev,
 194                        struct device_attribute *attr, char * buf)
 195{
 196        int nid = dev->id;
 197        int len = 0;
 198        int i;
 199
 200        /*
 201         * buf is currently PAGE_SIZE in length and each node needs 4 chars
 202         * at the most (distance + space or newline).
 203         */
 204        BUILD_BUG_ON(MAX_NUMNODES * 4 > PAGE_SIZE);
 205
 206        for_each_online_node(i)
 207                len += sprintf(buf + len, "%s%d", i ? " " : "", node_distance(nid, i));
 208
 209        len += sprintf(buf + len, "\n");
 210        return len;
 211}
 212static DEVICE_ATTR(distance, S_IRUGO, node_read_distance, NULL);
 213
 214#ifdef CONFIG_HUGETLBFS
 215/*
 216 * hugetlbfs per node attributes registration interface:
 217 * When/if hugetlb[fs] subsystem initializes [sometime after this module],
 218 * it will register its per node attributes for all online nodes with
 219 * memory.  It will also call register_hugetlbfs_with_node(), below, to
 220 * register its attribute registration functions with this node driver.
 221 * Once these hooks have been initialized, the node driver will call into
 222 * the hugetlb module to [un]register attributes for hot-plugged nodes.
 223 */
 224static node_registration_func_t __hugetlb_register_node;
 225static node_registration_func_t __hugetlb_unregister_node;
 226
 227static inline bool hugetlb_register_node(struct node *node)
 228{
 229        if (__hugetlb_register_node &&
 230                        node_state(node->dev.id, N_MEMORY)) {
 231                __hugetlb_register_node(node);
 232                return true;
 233        }
 234        return false;
 235}
 236
 237static inline void hugetlb_unregister_node(struct node *node)
 238{
 239        if (__hugetlb_unregister_node)
 240                __hugetlb_unregister_node(node);
 241}
 242
 243void register_hugetlbfs_with_node(node_registration_func_t doregister,
 244                                  node_registration_func_t unregister)
 245{
 246        __hugetlb_register_node   = doregister;
 247        __hugetlb_unregister_node = unregister;
 248}
 249#else
 250static inline void hugetlb_register_node(struct node *node) {}
 251
 252static inline void hugetlb_unregister_node(struct node *node) {}
 253#endif
 254
 255static void node_device_release(struct device *dev)
 256{
 257        struct node *node = to_node(dev);
 258
 259#if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HUGETLBFS)
 260        /*
 261         * We schedule the work only when a memory section is
 262         * onlined/offlined on this node. When we come here,
 263         * all the memory on this node has been offlined,
 264         * so we won't enqueue new work to this work.
 265         *
 266         * The work is using node->node_work, so we should
 267         * flush work before freeing the memory.
 268         */
 269        flush_work(&node->node_work);
 270#endif
 271        kfree(node);
 272}
 273
 274/*
 275 * register_node - Setup a sysfs device for a node.
 276 * @num - Node number to use when creating the device.
 277 *
 278 * Initialize and register the node device.
 279 */
 280static int register_node(struct node *node, int num, struct node *parent)
 281{
 282        int error;
 283
 284        node->dev.id = num;
 285        node->dev.bus = &node_subsys;
 286        node->dev.release = node_device_release;
 287        error = device_register(&node->dev);
 288
 289        if (!error){
 290                device_create_file(&node->dev, &dev_attr_cpumap);
 291                device_create_file(&node->dev, &dev_attr_cpulist);
 292                device_create_file(&node->dev, &dev_attr_meminfo);
 293                device_create_file(&node->dev, &dev_attr_numastat);
 294                device_create_file(&node->dev, &dev_attr_distance);
 295                device_create_file(&node->dev, &dev_attr_vmstat);
 296
 297                scan_unevictable_register_node(node);
 298
 299                hugetlb_register_node(node);
 300
 301                compaction_register_node(node);
 302        }
 303        return error;
 304}
 305
 306/**
 307 * unregister_node - unregister a node device
 308 * @node: node going away
 309 *
 310 * Unregisters a node device @node.  All the devices on the node must be
 311 * unregistered before calling this function.
 312 */
 313void unregister_node(struct node *node)
 314{
 315        device_remove_file(&node->dev, &dev_attr_cpumap);
 316        device_remove_file(&node->dev, &dev_attr_cpulist);
 317        device_remove_file(&node->dev, &dev_attr_meminfo);
 318        device_remove_file(&node->dev, &dev_attr_numastat);
 319        device_remove_file(&node->dev, &dev_attr_distance);
 320        device_remove_file(&node->dev, &dev_attr_vmstat);
 321
 322        scan_unevictable_unregister_node(node);
 323        hugetlb_unregister_node(node);          /* no-op, if memoryless node */
 324
 325        device_unregister(&node->dev);
 326}
 327
 328struct node *node_devices[MAX_NUMNODES];
 329
 330/*
 331 * register cpu under node
 332 */
 333int register_cpu_under_node(unsigned int cpu, unsigned int nid)
 334{
 335        int ret;
 336        struct device *obj;
 337
 338        if (!node_online(nid))
 339                return 0;
 340
 341        obj = get_cpu_device(cpu);
 342        if (!obj)
 343                return 0;
 344
 345        ret = sysfs_create_link(&node_devices[nid]->dev.kobj,
 346                                &obj->kobj,
 347                                kobject_name(&obj->kobj));
 348        if (ret)
 349                return ret;
 350
 351        return sysfs_create_link(&obj->kobj,
 352                                 &node_devices[nid]->dev.kobj,
 353                                 kobject_name(&node_devices[nid]->dev.kobj));
 354}
 355
 356int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
 357{
 358        struct device *obj;
 359
 360        if (!node_online(nid))
 361                return 0;
 362
 363        obj = get_cpu_device(cpu);
 364        if (!obj)
 365                return 0;
 366
 367        sysfs_remove_link(&node_devices[nid]->dev.kobj,
 368                          kobject_name(&obj->kobj));
 369        sysfs_remove_link(&obj->kobj,
 370                          kobject_name(&node_devices[nid]->dev.kobj));
 371
 372        return 0;
 373}
 374
 375#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
 376#define page_initialized(page)  (page->lru.next)
 377
 378static int get_nid_for_pfn(unsigned long pfn)
 379{
 380        struct page *page;
 381
 382        if (!pfn_valid_within(pfn))
 383                return -1;
 384        page = pfn_to_page(pfn);
 385        if (!page_initialized(page))
 386                return -1;
 387        return pfn_to_nid(pfn);
 388}
 389
 390/* register memory section under specified node if it spans that node */
 391int register_mem_sect_under_node(struct memory_block *mem_blk, int nid)
 392{
 393        int ret;
 394        unsigned long pfn, sect_start_pfn, sect_end_pfn;
 395
 396        if (!mem_blk)
 397                return -EFAULT;
 398        if (!node_online(nid))
 399                return 0;
 400
 401        sect_start_pfn = section_nr_to_pfn(mem_blk->start_section_nr);
 402        sect_end_pfn = section_nr_to_pfn(mem_blk->end_section_nr);
 403        sect_end_pfn += PAGES_PER_SECTION - 1;
 404        for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
 405                int page_nid;
 406
 407                page_nid = get_nid_for_pfn(pfn);
 408                if (page_nid < 0)
 409                        continue;
 410                if (page_nid != nid)
 411                        continue;
 412                ret = sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj,
 413                                        &mem_blk->dev.kobj,
 414                                        kobject_name(&mem_blk->dev.kobj));
 415                if (ret)
 416                        return ret;
 417
 418                return sysfs_create_link_nowarn(&mem_blk->dev.kobj,
 419                                &node_devices[nid]->dev.kobj,
 420                                kobject_name(&node_devices[nid]->dev.kobj));
 421        }
 422        /* mem section does not span the specified node */
 423        return 0;
 424}
 425
 426/* unregister memory section under all nodes that it spans */
 427int unregister_mem_sect_under_nodes(struct memory_block *mem_blk,
 428                                    unsigned long phys_index)
 429{
 430        NODEMASK_ALLOC(nodemask_t, unlinked_nodes, GFP_KERNEL);
 431        unsigned long pfn, sect_start_pfn, sect_end_pfn;
 432
 433        if (!mem_blk) {
 434                NODEMASK_FREE(unlinked_nodes);
 435                return -EFAULT;
 436        }
 437        if (!unlinked_nodes)
 438                return -ENOMEM;
 439        nodes_clear(*unlinked_nodes);
 440
 441        sect_start_pfn = section_nr_to_pfn(phys_index);
 442        sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
 443        for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
 444                int nid;
 445
 446                nid = get_nid_for_pfn(pfn);
 447                if (nid < 0)
 448                        continue;
 449                if (!node_online(nid))
 450                        continue;
 451                if (node_test_and_set(nid, *unlinked_nodes))
 452                        continue;
 453                sysfs_remove_link(&node_devices[nid]->dev.kobj,
 454                         kobject_name(&mem_blk->dev.kobj));
 455                sysfs_remove_link(&mem_blk->dev.kobj,
 456                         kobject_name(&node_devices[nid]->dev.kobj));
 457        }
 458        NODEMASK_FREE(unlinked_nodes);
 459        return 0;
 460}
 461
 462static int link_mem_sections(int nid)
 463{
 464        unsigned long start_pfn = NODE_DATA(nid)->node_start_pfn;
 465        unsigned long end_pfn = start_pfn + NODE_DATA(nid)->node_spanned_pages;
 466        unsigned long pfn;
 467        struct memory_block *mem_blk = NULL;
 468        int err = 0;
 469
 470        for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
 471                unsigned long section_nr = pfn_to_section_nr(pfn);
 472                struct mem_section *mem_sect;
 473                int ret;
 474
 475                if (!present_section_nr(section_nr))
 476                        continue;
 477                mem_sect = __nr_to_section(section_nr);
 478
 479                /* same memblock ? */
 480                if (mem_blk)
 481                        if ((section_nr >= mem_blk->start_section_nr) &&
 482                            (section_nr <= mem_blk->end_section_nr))
 483                                continue;
 484
 485                mem_blk = find_memory_block_hinted(mem_sect, mem_blk);
 486
 487                ret = register_mem_sect_under_node(mem_blk, nid);
 488                if (!err)
 489                        err = ret;
 490
 491                /* discard ref obtained in find_memory_block() */
 492        }
 493
 494        if (mem_blk)
 495                kobject_put(&mem_blk->dev.kobj);
 496        return err;
 497}
 498
 499#ifdef CONFIG_HUGETLBFS
 500/*
 501 * Handle per node hstate attribute [un]registration on transistions
 502 * to/from memoryless state.
 503 */
 504static void node_hugetlb_work(struct work_struct *work)
 505{
 506        struct node *node = container_of(work, struct node, node_work);
 507
 508        /*
 509         * We only get here when a node transitions to/from memoryless state.
 510         * We can detect which transition occurred by examining whether the
 511         * node has memory now.  hugetlb_register_node() already check this
 512         * so we try to register the attributes.  If that fails, then the
 513         * node has transitioned to memoryless, try to unregister the
 514         * attributes.
 515         */
 516        if (!hugetlb_register_node(node))
 517                hugetlb_unregister_node(node);
 518}
 519
 520static void init_node_hugetlb_work(int nid)
 521{
 522        INIT_WORK(&node_devices[nid]->node_work, node_hugetlb_work);
 523}
 524
 525static int node_memory_callback(struct notifier_block *self,
 526                                unsigned long action, void *arg)
 527{
 528        struct memory_notify *mnb = arg;
 529        int nid = mnb->status_change_nid;
 530
 531        switch (action) {
 532        case MEM_ONLINE:
 533        case MEM_OFFLINE:
 534                /*
 535                 * offload per node hstate [un]registration to a work thread
 536                 * when transitioning to/from memoryless state.
 537                 */
 538                if (nid != NUMA_NO_NODE)
 539                        schedule_work(&node_devices[nid]->node_work);
 540                break;
 541
 542        case MEM_GOING_ONLINE:
 543        case MEM_GOING_OFFLINE:
 544        case MEM_CANCEL_ONLINE:
 545        case MEM_CANCEL_OFFLINE:
 546        default:
 547                break;
 548        }
 549
 550        return NOTIFY_OK;
 551}
 552#endif  /* CONFIG_HUGETLBFS */
 553#else   /* !CONFIG_MEMORY_HOTPLUG_SPARSE */
 554
 555static int link_mem_sections(int nid) { return 0; }
 556#endif  /* CONFIG_MEMORY_HOTPLUG_SPARSE */
 557
 558#if !defined(CONFIG_MEMORY_HOTPLUG_SPARSE) || \
 559    !defined(CONFIG_HUGETLBFS)
 560static inline int node_memory_callback(struct notifier_block *self,
 561                                unsigned long action, void *arg)
 562{
 563        return NOTIFY_OK;
 564}
 565
 566static void init_node_hugetlb_work(int nid) { }
 567
 568#endif
 569
 570int register_one_node(int nid)
 571{
 572        int error = 0;
 573        int cpu;
 574
 575        if (node_online(nid)) {
 576                int p_node = parent_node(nid);
 577                struct node *parent = NULL;
 578
 579                if (p_node != nid)
 580                        parent = node_devices[p_node];
 581
 582                node_devices[nid] = kzalloc(sizeof(struct node), GFP_KERNEL);
 583                if (!node_devices[nid])
 584                        return -ENOMEM;
 585
 586                error = register_node(node_devices[nid], nid, parent);
 587
 588                /* link cpu under this node */
 589                for_each_present_cpu(cpu) {
 590                        if (cpu_to_node(cpu) == nid)
 591                                register_cpu_under_node(cpu, nid);
 592                }
 593
 594                /* link memory sections under this node */
 595                error = link_mem_sections(nid);
 596
 597                /* initialize work queue for memory hot plug */
 598                init_node_hugetlb_work(nid);
 599        }
 600
 601        return error;
 602
 603}
 604
 605void unregister_one_node(int nid)
 606{
 607        unregister_node(node_devices[nid]);
 608        node_devices[nid] = NULL;
 609}
 610
 611/*
 612 * node states attributes
 613 */
 614
 615static ssize_t print_nodes_state(enum node_states state, char *buf)
 616{
 617        int n;
 618
 619        n = nodelist_scnprintf(buf, PAGE_SIZE-2, node_states[state]);
 620        buf[n++] = '\n';
 621        buf[n] = '\0';
 622        return n;
 623}
 624
 625struct node_attr {
 626        struct device_attribute attr;
 627        enum node_states state;
 628};
 629
 630static ssize_t show_node_state(struct device *dev,
 631                               struct device_attribute *attr, char *buf)
 632{
 633        struct node_attr *na = container_of(attr, struct node_attr, attr);
 634        return print_nodes_state(na->state, buf);
 635}
 636
 637#define _NODE_ATTR(name, state) \
 638        { __ATTR(name, 0444, show_node_state, NULL), state }
 639
 640static struct node_attr node_state_attr[] = {
 641        [N_POSSIBLE] = _NODE_ATTR(possible, N_POSSIBLE),
 642        [N_ONLINE] = _NODE_ATTR(online, N_ONLINE),
 643        [N_NORMAL_MEMORY] = _NODE_ATTR(has_normal_memory, N_NORMAL_MEMORY),
 644#ifdef CONFIG_HIGHMEM
 645        [N_HIGH_MEMORY] = _NODE_ATTR(has_high_memory, N_HIGH_MEMORY),
 646#endif
 647#ifdef CONFIG_MOVABLE_NODE
 648        [N_MEMORY] = _NODE_ATTR(has_memory, N_MEMORY),
 649#endif
 650        [N_CPU] = _NODE_ATTR(has_cpu, N_CPU),
 651};
 652
 653static struct attribute *node_state_attrs[] = {
 654        &node_state_attr[N_POSSIBLE].attr.attr,
 655        &node_state_attr[N_ONLINE].attr.attr,
 656        &node_state_attr[N_NORMAL_MEMORY].attr.attr,
 657#ifdef CONFIG_HIGHMEM
 658        &node_state_attr[N_HIGH_MEMORY].attr.attr,
 659#endif
 660#ifdef CONFIG_MOVABLE_NODE
 661        &node_state_attr[N_MEMORY].attr.attr,
 662#endif
 663        &node_state_attr[N_CPU].attr.attr,
 664        NULL
 665};
 666
 667static struct attribute_group memory_root_attr_group = {
 668        .attrs = node_state_attrs,
 669};
 670
 671static const struct attribute_group *cpu_root_attr_groups[] = {
 672        &memory_root_attr_group,
 673        NULL,
 674};
 675
 676#define NODE_CALLBACK_PRI       2       /* lower than SLAB */
 677static int __init register_node_type(void)
 678{
 679        int ret;
 680
 681        BUILD_BUG_ON(ARRAY_SIZE(node_state_attr) != NR_NODE_STATES);
 682        BUILD_BUG_ON(ARRAY_SIZE(node_state_attrs)-1 != NR_NODE_STATES);
 683
 684        ret = subsys_system_register(&node_subsys, cpu_root_attr_groups);
 685        if (!ret) {
 686                hotplug_memory_notifier(node_memory_callback,
 687                                        NODE_CALLBACK_PRI);
 688        }
 689
 690        /*
 691         * Note:  we're not going to unregister the node class if we fail
 692         * to register the node state class attribute files.
 693         */
 694        return ret;
 695}
 696postcore_initcall(register_node_type);
 697
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