// SPDX-License-Identifier: GPL-2.0 /* * Basic Node interface support */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static struct bus_type node_subsys = { .name = "node", .dev_name = "node", }; static ssize_t node_read_cpumap(struct device *dev, bool list, char *buf) { ssize_t n; cpumask_var_t mask; struct node *node_dev = to_node(dev); /* 2008/04/07: buf currently PAGE_SIZE, need 9 chars per 32 bits. */ BUILD_BUG_ON((NR_CPUS/32 * 9) > (PAGE_SIZE-1)); if (!alloc_cpumask_var(&mask, GFP_KERNEL)) return 0; cpumask_and(mask, cpumask_of_node(node_dev->dev.id), cpu_online_mask); n = cpumap_print_to_pagebuf(list, buf, mask); free_cpumask_var(mask); return n; } static inline ssize_t node_read_cpumask(struct device *dev, struct device_attribute *attr, char *buf) { return node_read_cpumap(dev, false, buf); } static inline ssize_t node_read_cpulist(struct device *dev, struct device_attribute *attr, char *buf) { return node_read_cpumap(dev, true, buf); } static DEVICE_ATTR(cpumap, S_IRUGO, node_read_cpumask, NULL); static DEVICE_ATTR(cpulist, S_IRUGO, node_read_cpulist, NULL); /** * struct node_access_nodes - Access class device to hold user visible * relationships to other nodes. * @dev: Device for this memory access class * @list_node: List element in the node's access list * @access: The access class rank */ struct node_access_nodes { struct device dev; struct list_head list_node; unsigned access; #ifdef CONFIG_HMEM_REPORTING struct node_hmem_attrs hmem_attrs; #endif }; #define to_access_nodes(dev) container_of(dev, struct node_access_nodes, dev) static struct attribute *node_init_access_node_attrs[] = { NULL, }; static struct attribute *node_targ_access_node_attrs[] = { NULL, }; static const struct attribute_group initiators = { .name = "initiators", .attrs = node_init_access_node_attrs, }; static const struct attribute_group targets = { .name = "targets", .attrs = node_targ_access_node_attrs, }; static const struct attribute_group *node_access_node_groups[] = { &initiators, &targets, NULL, }; static void node_remove_accesses(struct node *node) { struct node_access_nodes *c, *cnext; list_for_each_entry_safe(c, cnext, &node->access_list, list_node) { list_del(&c->list_node); device_unregister(&c->dev); } } static void node_access_release(struct device *dev) { kfree(to_access_nodes(dev)); } static struct node_access_nodes *node_init_node_access(struct node *node, unsigned access) { struct node_access_nodes *access_node; struct device *dev; list_for_each_entry(access_node, &node->access_list, list_node) if (access_node->access == access) return access_node; access_node = kzalloc(sizeof(*access_node), GFP_KERNEL); if (!access_node) return NULL; access_node->access = access; dev = &access_node->dev; dev->parent = &node->dev; dev->release = node_access_release; dev->groups = node_access_node_groups; if (dev_set_name(dev, "access%u", access)) goto free; if (device_register(dev)) goto free_name; pm_runtime_no_callbacks(dev); list_add_tail(&access_node->list_node, &node->access_list); return access_node; free_name: kfree_const(dev->kobj.name); free: kfree(access_node); return NULL; } #ifdef CONFIG_HMEM_REPORTING #define ACCESS_ATTR(name) \ static ssize_t name##_show(struct device *dev, \ struct device_attribute *attr, \ char *buf) \ { \ return sprintf(buf, "%u\n", to_access_nodes(dev)->hmem_attrs.name); \ } \ static DEVICE_ATTR_RO(name); ACCESS_ATTR(read_bandwidth) ACCESS_ATTR(read_latency) ACCESS_ATTR(write_bandwidth) ACCESS_ATTR(write_latency) static struct attribute *access_attrs[] = { &dev_attr_read_bandwidth.attr, &dev_attr_read_latency.attr, &dev_attr_write_bandwidth.attr, &dev_attr_write_latency.attr, NULL, }; /** * node_set_perf_attrs - Set the performance values for given access class * @nid: Node identifier to be set * @hmem_attrs: Heterogeneous memory performance attributes * @access: The access class the for the given attributes */ void node_set_perf_attrs(unsigned int nid, struct node_hmem_attrs *hmem_attrs, unsigned access) { struct node_access_nodes *c; struct node *node; int i; if (WARN_ON_ONCE(!node_online(nid))) return; node = node_devices[nid]; c = node_init_node_access(node, access); if (!c) return; c->hmem_attrs = *hmem_attrs; for (i = 0; access_attrs[i] != NULL; i++) { if (sysfs_add_file_to_group(&c->dev.kobj, access_attrs[i], "initiators")) { pr_info("failed to add performance attribute to node %d\n", nid); break; } } } #endif #define K(x) ((x) << (PAGE_SHIFT - 10)) static ssize_t node_read_meminfo(struct device *dev, struct device_attribute *attr, char *buf) { int n; int nid = dev->id; struct pglist_data *pgdat = NODE_DATA(nid); struct sysinfo i; unsigned long sreclaimable, sunreclaimable; si_meminfo_node(&i, nid); sreclaimable = node_page_state(pgdat, NR_SLAB_RECLAIMABLE); sunreclaimable = node_page_state(pgdat, NR_SLAB_UNRECLAIMABLE); n = sprintf(buf, "Node %d MemTotal: %8lu kB\n" "Node %d MemFree: %8lu kB\n" "Node %d MemUsed: %8lu kB\n" "Node %d Active: %8lu kB\n" "Node %d Inactive: %8lu kB\n" "Node %d Active(anon): %8lu kB\n" "Node %d Inactive(anon): %8lu kB\n" "Node %d Active(file): %8lu kB\n" "Node %d Inactive(file): %8lu kB\n" "Node %d Unevictable: %8lu kB\n" "Node %d Mlocked: %8lu kB\n", nid, K(i.totalram), nid, K(i.freeram), nid, K(i.totalram - i.freeram), nid, K(node_page_state(pgdat, NR_ACTIVE_ANON) + node_page_state(pgdat, NR_ACTIVE_FILE)), nid, K(node_page_state(pgdat, NR_INACTIVE_ANON) + node_page_state(pgdat, NR_INACTIVE_FILE)), nid, K(node_page_state(pgdat, NR_ACTIVE_ANON)), nid, K(node_page_state(pgdat, NR_INACTIVE_ANON)), nid, K(node_page_state(pgdat, NR_ACTIVE_FILE)), nid, K(node_page_state(pgdat, NR_INACTIVE_FILE)), nid, K(node_page_state(pgdat, NR_UNEVICTABLE)), nid, K(sum_zone_node_page_state(nid, NR_MLOCK))); #ifdef CONFIG_HIGHMEM n += sprintf(buf + n, "Node %d HighTotal: %8lu kB\n" "Node %d HighFree: %8lu kB\n" "Node %d LowTotal: %8lu kB\n" "Node %d LowFree: %8lu kB\n", nid, K(i.totalhigh), nid, K(i.freehigh), nid, K(i.totalram - i.totalhigh), nid, K(i.freeram - i.freehigh)); #endif n += sprintf(buf + n, "Node %d Dirty: %8lu kB\n" "Node %d Writeback: %8lu kB\n" "Node %d FilePages: %8lu kB\n" "Node %d Mapped: %8lu kB\n" "Node %d AnonPages: %8lu kB\n" "Node %d Shmem: %8lu kB\n" "Node %d KernelStack: %8lu kB\n" "Node %d PageTables: %8lu kB\n" "Node %d NFS_Unstable: %8lu kB\n" "Node %d Bounce: %8lu kB\n" "Node %d WritebackTmp: %8lu kB\n" "Node %d KReclaimable: %8lu kB\n" "Node %d Slab: %8lu kB\n" "Node %d SReclaimable: %8lu kB\n" "Node %d SUnreclaim: %8lu kB\n" #ifdef CONFIG_TRANSPARENT_HUGEPAGE "Node %d AnonHugePages: %8lu kB\n" "Node %d ShmemHugePages: %8lu kB\n" "Node %d ShmemPmdMapped: %8lu kB\n" #endif , nid, K(node_page_state(pgdat, NR_FILE_DIRTY)), nid, K(node_page_state(pgdat, NR_WRITEBACK)), nid, K(node_page_state(pgdat, NR_FILE_PAGES)), nid, K(node_page_state(pgdat, NR_FILE_MAPPED)), nid, K(node_page_state(pgdat, NR_ANON_MAPPED)), nid, K(i.sharedram), nid, sum_zone_node_page_state(nid, NR_KERNEL_STACK_KB), nid, K(sum_zone_node_page_state(nid, NR_PAGETABLE)), nid, K(node_page_state(pgdat, NR_UNSTABLE_NFS)), nid, K(sum_zone_node_page_state(nid, NR_BOUNCE)), nid, K(node_page_state(pgdat, NR_WRITEBACK_TEMP)), nid, K(sreclaimable + node_page_state(pgdat, NR_KERNEL_MISC_RECLAIMABLE)), nid, K(sreclaimable + sunreclaimable), nid, K(sreclaimable), nid, K(sunreclaimable) #ifdef CONFIG_TRANSPARENT_HUGEPAGE , nid, K(node_page_state(pgdat, NR_ANON_THPS) * HPAGE_PMD_NR), nid, K(node_page_state(pgdat, NR_SHMEM_THPS) * HPAGE_PMD_NR), nid, K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED) * HPAGE_PMD_NR) #endif ); n += hugetlb_report_node_meminfo(nid, buf + n); return n; } #undef K static DEVICE_ATTR(meminfo, S_IRUGO, node_read_meminfo, NULL); static ssize_t node_read_numastat(struct device *dev, struct device_attribute *attr, char *buf) { return sprintf(buf, "numa_hit %lu\n" "numa_miss %lu\n" "numa_foreign %lu\n" "interleave_hit %lu\n" "local_node %lu\n" "other_node %lu\n", sum_zone_numa_state(dev->id, NUMA_HIT), sum_zone_numa_state(dev->id, NUMA_MISS), sum_zone_numa_state(dev->id, NUMA_FOREIGN), sum_zone_numa_state(dev->id, NUMA_INTERLEAVE_HIT), sum_zone_numa_state(dev->id, NUMA_LOCAL), sum_zone_numa_state(dev->id, NUMA_OTHER)); } static DEVICE_ATTR(numastat, S_IRUGO, node_read_numastat, NULL); static ssize_t node_read_vmstat(struct device *dev, struct device_attribute *attr, char *buf) { int nid = dev->id; struct pglist_data *pgdat = NODE_DATA(nid); int i; int n = 0; for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) n += sprintf(buf+n, "%s %lu\n", vmstat_text[i], sum_zone_node_page_state(nid, i)); #ifdef CONFIG_NUMA for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++) n += sprintf(buf+n, "%s %lu\n", vmstat_text[i + NR_VM_ZONE_STAT_ITEMS], sum_zone_numa_state(nid, i)); #endif for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) n += sprintf(buf+n, "%s %lu\n", vmstat_text[i + NR_VM_ZONE_STAT_ITEMS + NR_VM_NUMA_STAT_ITEMS], node_page_state(pgdat, i)); return n; } static DEVICE_ATTR(vmstat, S_IRUGO, node_read_vmstat, NULL); static ssize_t node_read_distance(struct device *dev, struct device_attribute *attr, char *buf) { int nid = dev->id; int len = 0; int i; /* * buf is currently PAGE_SIZE in length and each node needs 4 chars * at the most (distance + space or newline). */ BUILD_BUG_ON(MAX_NUMNODES * 4 > PAGE_SIZE); for_each_online_node(i) len += sprintf(buf + len, "%s%d", i ? " " : "", node_distance(nid, i)); len += sprintf(buf + len, "\n"); return len; } static DEVICE_ATTR(distance, S_IRUGO, node_read_distance, NULL); static struct attribute *node_dev_attrs[] = { &dev_attr_cpumap.attr, &dev_attr_cpulist.attr, &dev_attr_meminfo.attr, &dev_attr_numastat.attr, &dev_attr_distance.attr, &dev_attr_vmstat.attr, NULL }; ATTRIBUTE_GROUPS(node_dev); #ifdef CONFIG_HUGETLBFS /* * hugetlbfs per node attributes registration interface: * When/if hugetlb[fs] subsystem initializes [sometime after this module], * it will register its per node attributes for all online nodes with * memory. It will also call register_hugetlbfs_with_node(), below, to * register its attribute registration functions with this node driver. * Once these hooks have been initialized, the node driver will call into * the hugetlb module to [un]register attributes for hot-plugged nodes. */ static node_registration_func_t __hugetlb_register_node; static node_registration_func_t __hugetlb_unregister_node; static inline bool hugetlb_register_node(struct node *node) { if (__hugetlb_register_node && node_state(node->dev.id, N_MEMORY)) { __hugetlb_register_node(node); return true; } return false; } static inline void hugetlb_unregister_node(struct node *node) { if (__hugetlb_unregister_node) __hugetlb_unregister_node(node); } void register_hugetlbfs_with_node(node_registration_func_t doregister, node_registration_func_t unregister) { __hugetlb_register_node = doregister; __hugetlb_unregister_node = unregister; } #else static inline void hugetlb_register_node(struct node *node) {} static inline void hugetlb_unregister_node(struct node *node) {} #endif static void node_device_release(struct device *dev) { struct node *node = to_node(dev); #if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HUGETLBFS) /* * We schedule the work only when a memory section is * onlined/offlined on this node. When we come here, * all the memory on this node has been offlined, * so we won't enqueue new work to this work. * * The work is using node->node_work, so we should * flush work before freeing the memory. */ flush_work(&node->node_work); #endif kfree(node); } /* * register_node - Setup a sysfs device for a node. * @num - Node number to use when creating the device. * * Initialize and register the node device. */ static int register_node(struct node *node, int num) { int error; node->dev.id = num; node->dev.bus = &node_subsys; node->dev.release = node_device_release; node->dev.groups = node_dev_groups; error = device_register(&node->dev); if (error) put_device(&node->dev); else { hugetlb_register_node(node); compaction_register_node(node); } return error; } /** * unregister_node - unregister a node device * @node: node going away * * Unregisters a node device @node. All the devices on the node must be * unregistered before calling this function. */ void unregister_node(struct node *node) { hugetlb_unregister_node(node); /* no-op, if memoryless node */ node_remove_accesses(node); device_unregister(&node->dev); } struct node *node_devices[MAX_NUMNODES]; /* * register cpu under node */ int register_cpu_under_node(unsigned int cpu, unsigned int nid) { int ret; struct device *obj; if (!node_online(nid)) return 0; obj = get_cpu_device(cpu); if (!obj) return 0; ret = sysfs_create_link(&node_devices[nid]->dev.kobj, &obj->kobj, kobject_name(&obj->kobj)); if (ret) return ret; return sysfs_create_link(&obj->kobj, &node_devices[nid]->dev.kobj, kobject_name(&node_devices[nid]->dev.kobj)); } /** * register_memory_node_under_compute_node - link memory node to its compute * node for a given access class. * @mem_node: Memory node number * @cpu_node: Cpu node number * @access: Access class to register * * Description: * For use with platforms that may have separate memory and compute nodes. * This function will export node relationships linking which memory * initiator nodes can access memory targets at a given ranked access * class. */ int register_memory_node_under_compute_node(unsigned int mem_nid, unsigned int cpu_nid, unsigned access) { struct node *init_node, *targ_node; struct node_access_nodes *initiator, *target; int ret; if (!node_online(cpu_nid) || !node_online(mem_nid)) return -ENODEV; init_node = node_devices[cpu_nid]; targ_node = node_devices[mem_nid]; initiator = node_init_node_access(init_node, access); target = node_init_node_access(targ_node, access); if (!initiator || !target) return -ENOMEM; ret = sysfs_add_link_to_group(&initiator->dev.kobj, "targets", &targ_node->dev.kobj, dev_name(&targ_node->dev)); if (ret) return ret; ret = sysfs_add_link_to_group(&target->dev.kobj, "initiators", &init_node->dev.kobj, dev_name(&init_node->dev)); if (ret) goto err; return 0; err: sysfs_remove_link_from_group(&initiator->dev.kobj, "targets", dev_name(&targ_node->dev)); return ret; } int unregister_cpu_under_node(unsigned int cpu, unsigned int nid) { struct device *obj; if (!node_online(nid)) return 0; obj = get_cpu_device(cpu); if (!obj) return 0; sysfs_remove_link(&node_devices[nid]->dev.kobj, kobject_name(&obj->kobj)); sysfs_remove_link(&obj->kobj, kobject_name(&node_devices[nid]->dev.kobj)); return 0; } #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE static int __ref get_nid_for_pfn(unsigned long pfn) { if (!pfn_valid_within(pfn)) return -1; #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT if (system_state < SYSTEM_RUNNING) return early_pfn_to_nid(pfn); #endif return pfn_to_nid(pfn); } /* register memory section under specified node if it spans that node */ int register_mem_sect_under_node(struct memory_block *mem_blk, void *arg) { int ret, nid = *(int *)arg; unsigned long pfn, sect_start_pfn, sect_end_pfn; mem_blk->nid = nid; sect_start_pfn = section_nr_to_pfn(mem_blk->start_section_nr); sect_end_pfn = section_nr_to_pfn(mem_blk->end_section_nr); sect_end_pfn += PAGES_PER_SECTION - 1; for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) { int page_nid; /* * memory block could have several absent sections from start. * skip pfn range from absent section */ if (!pfn_present(pfn)) { pfn = round_down(pfn + PAGES_PER_SECTION, PAGES_PER_SECTION) - 1; continue; } /* * We need to check if page belongs to nid only for the boot * case, during hotplug we know that all pages in the memory * block belong to the same node. */ if (system_state == SYSTEM_BOOTING) { page_nid = get_nid_for_pfn(pfn); if (page_nid < 0) continue; if (page_nid != nid) continue; } ret = sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj, &mem_blk->dev.kobj, kobject_name(&mem_blk->dev.kobj)); if (ret) return ret; return sysfs_create_link_nowarn(&mem_blk->dev.kobj, &node_devices[nid]->dev.kobj, kobject_name(&node_devices[nid]->dev.kobj)); } /* mem section does not span the specified node */ return 0; } /* unregister memory section under all nodes that it spans */ int unregister_mem_sect_under_nodes(struct memory_block *mem_blk, unsigned long phys_index) { NODEMASK_ALLOC(nodemask_t, unlinked_nodes, GFP_KERNEL); unsigned long pfn, sect_start_pfn, sect_end_pfn; if (!mem_blk) { NODEMASK_FREE(unlinked_nodes); return -EFAULT; } if (!unlinked_nodes) return -ENOMEM; nodes_clear(*unlinked_nodes); sect_start_pfn = section_nr_to_pfn(phys_index); sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1; for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) { int nid; nid = get_nid_for_pfn(pfn); if (nid < 0) continue; if (!node_online(nid)) continue; if (node_test_and_set(nid, *unlinked_nodes)) continue; sysfs_remove_link(&node_devices[nid]->dev.kobj, kobject_name(&mem_blk->dev.kobj)); sysfs_remove_link(&mem_blk->dev.kobj, kobject_name(&node_devices[nid]->dev.kobj)); } NODEMASK_FREE(unlinked_nodes); return 0; } int link_mem_sections(int nid, unsigned long start_pfn, unsigned long end_pfn) { return walk_memory_range(start_pfn, end_pfn, (void *)&nid, register_mem_sect_under_node); } #ifdef CONFIG_HUGETLBFS /* * Handle per node hstate attribute [un]registration on transistions * to/from memoryless state. */ static void node_hugetlb_work(struct work_struct *work) { struct node *node = container_of(work, struct node, node_work); /* * We only get here when a node transitions to/from memoryless state. * We can detect which transition occurred by examining whether the * node has memory now. hugetlb_register_node() already check this * so we try to register the attributes. If that fails, then the * node has transitioned to memoryless, try to unregister the * attributes. */ if (!hugetlb_register_node(node)) hugetlb_unregister_node(node); } static void init_node_hugetlb_work(int nid) { INIT_WORK(&node_devices[nid]->node_work, node_hugetlb_work); } static int node_memory_callback(struct notifier_block *self, unsigned long action, void *arg) { struct memory_notify *mnb = arg; int nid = mnb->status_change_nid; switch (action) { case MEM_ONLINE: case MEM_OFFLINE: /* * offload per node hstate [un]registration to a work thread * when transitioning to/from memoryless state. */ if (nid != NUMA_NO_NODE) schedule_work(&node_devices[nid]->node_work); break; case MEM_GOING_ONLINE: case MEM_GOING_OFFLINE: case MEM_CANCEL_ONLINE: case MEM_CANCEL_OFFLINE: default: break; } return NOTIFY_OK; } #endif /* CONFIG_HUGETLBFS */ #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ #if !defined(CONFIG_MEMORY_HOTPLUG_SPARSE) || \ !defined(CONFIG_HUGETLBFS) static inline int node_memory_callback(struct notifier_block *self, unsigned long action, void *arg) { return NOTIFY_OK; } static void init_node_hugetlb_work(int nid) { } #endif int __register_one_node(int nid) { int error; int cpu; node_devices[nid] = kzalloc(sizeof(struct node), GFP_KERNEL); if (!node_devices[nid]) return -ENOMEM; error = register_node(node_devices[nid], nid); /* link cpu under this node */ for_each_present_cpu(cpu) { if (cpu_to_node(cpu) == nid) register_cpu_under_node(cpu, nid); } INIT_LIST_HEAD(&node_devices[nid]->access_list); /* initialize work queue for memory hot plug */ init_node_hugetlb_work(nid); return error; } void unregister_one_node(int nid) { if (!node_devices[nid]) return; unregister_node(node_devices[nid]); node_devices[nid] = NULL; } /* * node states attributes */ static ssize_t print_nodes_state(enum node_states state, char *buf) { int n; n = scnprintf(buf, PAGE_SIZE - 1, "%*pbl", nodemask_pr_args(&node_states[state])); buf[n++] = '\n'; buf[n] = '\0'; return n; } struct node_attr { struct device_attribute attr; enum node_states state; }; static ssize_t show_node_state(struct device *dev, struct device_attribute *attr, char *buf) { struct node_attr *na = container_of(attr, struct node_attr, attr); return print_nodes_state(na->state, buf); } #define _NODE_ATTR(name, state) \ { __ATTR(name, 0444, show_node_state, NULL), state } static struct node_attr node_state_attr[] = { [N_POSSIBLE] = _NODE_ATTR(possible, N_POSSIBLE), [N_ONLINE] = _NODE_ATTR(online, N_ONLINE), [N_NORMAL_MEMORY] = _NODE_ATTR(has_normal_memory, N_NORMAL_MEMORY), #ifdef CONFIG_HIGHMEM [N_HIGH_MEMORY] = _NODE_ATTR(has_high_memory, N_HIGH_MEMORY), #endif [N_MEMORY] = _NODE_ATTR(has_memory, N_MEMORY), [N_CPU] = _NODE_ATTR(has_cpu, N_CPU), }; static struct attribute *node_state_attrs[] = { &node_state_attr[N_POSSIBLE].attr.attr, &node_state_attr[N_ONLINE].attr.attr, &node_state_attr[N_NORMAL_MEMORY].attr.attr, #ifdef CONFIG_HIGHMEM &node_state_attr[N_HIGH_MEMORY].attr.attr, #endif &node_state_attr[N_MEMORY].attr.attr, &node_state_attr[N_CPU].attr.attr, NULL }; static struct attribute_group memory_root_attr_group = { .attrs = node_state_attrs, }; static const struct attribute_group *cpu_root_attr_groups[] = { &memory_root_attr_group, NULL, }; #define NODE_CALLBACK_PRI 2 /* lower than SLAB */ static int __init register_node_type(void) { int ret; BUILD_BUG_ON(ARRAY_SIZE(node_state_attr) != NR_NODE_STATES); BUILD_BUG_ON(ARRAY_SIZE(node_state_attrs)-1 != NR_NODE_STATES); ret = subsys_system_register(&node_subsys, cpu_root_attr_groups); if (!ret) { static struct notifier_block node_memory_callback_nb = { .notifier_call = node_memory_callback, .priority = NODE_CALLBACK_PRI, }; register_hotmemory_notifier(&node_memory_callback_nb); } /* * Note: we're not going to unregister the node class if we fail * to register the node state class attribute files. */ return ret; } postcore_initcall(register_node_type);