drivers/base/node.c

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