diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 35b07b773e6c..864035fb8f8a 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -202,6 +202,7 @@ static inline int is_mem_section_removable(unsigned long pfn, } #endif /* CONFIG_MEMORY_HOTREMOVE */ +extern int mem_online_node(int nid); extern int add_memory(int nid, u64 start, u64 size); extern int arch_add_memory(int nid, u64 start, u64 size); extern int remove_memory(u64 start, u64 size); diff --git a/kernel/cpu.c b/kernel/cpu.c index 545777574779..a3fbcc0a0abc 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -326,6 +326,12 @@ out_notify: int __cpuinit cpu_up(unsigned int cpu) { int err = 0; + +#ifdef CONFIG_MEMORY_HOTPLUG + int nid; + pg_data_t *pgdat; +#endif + if (!cpu_possible(cpu)) { printk(KERN_ERR "can't online cpu %d because it is not " "configured as may-hotadd at boot time\n", cpu); @@ -336,6 +342,25 @@ int __cpuinit cpu_up(unsigned int cpu) return -EINVAL; } +#ifdef CONFIG_MEMORY_HOTPLUG + nid = cpu_to_node(cpu); + if (!node_online(nid)) { + err = mem_online_node(nid); + if (err) + return err; + } + + pgdat = NODE_DATA(nid); + if (!pgdat) { + printk(KERN_ERR + "Can't online cpu %d due to NULL pgdat\n", cpu); + return -ENOMEM; + } + + if (pgdat->node_zonelists->_zonerefs->zone == NULL) + build_all_zonelists(); +#endif + cpu_maps_update_begin(); if (cpu_hotplug_disabled) { diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index be211a582930..85eb4d342ac5 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -482,6 +482,29 @@ static void rollback_node_hotadd(int nid, pg_data_t *pgdat) } +/* + * called by cpu_up() to online a node without onlined memory. + */ +int mem_online_node(int nid) +{ + pg_data_t *pgdat; + int ret; + + lock_system_sleep(); + pgdat = hotadd_new_pgdat(nid, 0); + if (pgdat) { + ret = -ENOMEM; + goto out; + } + node_set_online(nid); + ret = register_one_node(nid); + BUG_ON(ret); + +out: + unlock_system_sleep(); + return ret; +} + /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ int __ref add_memory(int nid, u64 start, u64 size) {