diff options
| -rw-r--r-- | Documentation/memory-hotplug.txt | 23 | ||||
| -rw-r--r-- | drivers/base/memory.c | 34 | ||||
| -rw-r--r-- | drivers/xen/balloon.c | 2 | ||||
| -rw-r--r-- | include/linux/memory.h | 3 | ||||
| -rw-r--r-- | include/linux/memory_hotplug.h | 4 | ||||
| -rw-r--r-- | mm/memory_hotplug.c | 17 |
6 files changed, 75 insertions, 8 deletions
diff --git a/Documentation/memory-hotplug.txt b/Documentation/memory-hotplug.txt index ce2cfcf35c27..443f4b44ad97 100644 --- a/Documentation/memory-hotplug.txt +++ b/Documentation/memory-hotplug.txt @@ -256,10 +256,27 @@ If the memory block is offline, you'll read "offline". 5.2. How to online memory ------------ -Even if the memory is hot-added, it is not at ready-to-use state. -For using newly added memory, you have to "online" the memory block. +When the memory is hot-added, the kernel decides whether or not to "online" +it according to the policy which can be read from "auto_online_blocks" file: -For onlining, you have to write "online" to the memory block's state file as: +% cat /sys/devices/system/memory/auto_online_blocks + +The default is "offline" which means the newly added memory is not in a +ready-to-use state and you have to "online" the newly added memory blocks +manually. Automatic onlining can be requested by writing "online" to +"auto_online_blocks" file: + +% echo online > /sys/devices/system/memory/auto_online_blocks + +This sets a global policy and impacts all memory blocks that will subsequently +be hotplugged. Currently offline blocks keep their state. It is possible, under +certain circumstances, that some memory blocks will be added but will fail to +online. User space tools can check their "state" files +(/sys/devices/system/memory/memoryXXX/state) and try to online them manually. + +If the automatic onlining wasn't requested, failed, or some memory block was +offlined it is possible to change the individual block's state by writing to the +"state" file: % echo online > /sys/devices/system/memory/memoryXXX/state diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 213456c2b123..f46dba8b7092 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -251,7 +251,7 @@ memory_block_action(unsigned long phys_index, unsigned long action, int online_t return ret; } -static int memory_block_change_state(struct memory_block *mem, +int memory_block_change_state(struct memory_block *mem, unsigned long to_state, unsigned long from_state_req) { int ret = 0; @@ -439,6 +439,37 @@ print_block_size(struct device *dev, struct device_attribute *attr, static DEVICE_ATTR(block_size_bytes, 0444, print_block_size, NULL); /* + * Memory auto online policy. + */ + +static ssize_t +show_auto_online_blocks(struct device *dev, struct device_attribute *attr, + char *buf) +{ + if (memhp_auto_online) + return sprintf(buf, "online\n"); + else + return sprintf(buf, "offline\n"); +} + +static ssize_t +store_auto_online_blocks(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + if (sysfs_streq(buf, "online")) + memhp_auto_online = true; + else if (sysfs_streq(buf, "offline")) + memhp_auto_online = false; + else + return -EINVAL; + + return count; +} + +static DEVICE_ATTR(auto_online_blocks, 0644, show_auto_online_blocks, + store_auto_online_blocks); + +/* * Some architectures will have custom drivers to do this, and * will not need to do it from userspace. The fake hot-add code * as well as ppc64 will do all of their discovery in userspace @@ -746,6 +777,7 @@ static struct attribute *memory_root_attrs[] = { #endif &dev_attr_block_size_bytes.attr, + &dev_attr_auto_online_blocks.attr, NULL }; diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index dc4305b407bf..e6058debd01b 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -338,7 +338,7 @@ static enum bp_state reserve_additional_memory(void) } #endif - rc = add_memory_resource(nid, resource); + rc = add_memory_resource(nid, resource, false); if (rc) { pr_warn("Cannot add additional memory (%i)\n", rc); goto err; diff --git a/include/linux/memory.h b/include/linux/memory.h index 8b8d8d12348e..82730adba950 100644 --- a/include/linux/memory.h +++ b/include/linux/memory.h @@ -109,6 +109,9 @@ extern void unregister_memory_notifier(struct notifier_block *nb); extern int register_memory_isolate_notifier(struct notifier_block *nb); extern void unregister_memory_isolate_notifier(struct notifier_block *nb); extern int register_new_memory(int, struct mem_section *); +extern int memory_block_change_state(struct memory_block *mem, + unsigned long to_state, + unsigned long from_state_req); #ifdef CONFIG_MEMORY_HOTREMOVE extern int unregister_memory_section(struct mem_section *); #endif diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 43405992d027..769d76870550 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -99,6 +99,8 @@ extern void __online_page_free(struct page *page); extern int try_online_node(int nid); +extern bool memhp_auto_online; + #ifdef CONFIG_MEMORY_HOTREMOVE extern bool is_pageblock_removable_nolock(struct page *page); extern int arch_remove_memory(u64 start, u64 size); @@ -267,7 +269,7 @@ static inline void remove_memory(int nid, u64 start, u64 size) {} extern int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn, void *arg, int (*func)(struct memory_block *, void *)); extern int add_memory(int nid, u64 start, u64 size); -extern int add_memory_resource(int nid, struct resource *resource); +extern int add_memory_resource(int nid, struct resource *resource, bool online); extern int zone_for_memory(int nid, u64 start, u64 size, int zone_default, bool for_device); extern int arch_add_memory(int nid, u64 start, u64 size, bool for_device); diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 979b18cbd343..484e86761b3e 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -77,6 +77,9 @@ static struct { #define memhp_lock_acquire() lock_map_acquire(&mem_hotplug.dep_map) #define memhp_lock_release() lock_map_release(&mem_hotplug.dep_map) +bool memhp_auto_online; +EXPORT_SYMBOL_GPL(memhp_auto_online); + void get_online_mems(void) { might_sleep(); @@ -1261,8 +1264,13 @@ int zone_for_memory(int nid, u64 start, u64 size, int zone_default, return zone_default; } +static int online_memory_block(struct memory_block *mem, void *arg) +{ + return memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE); +} + /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ -int __ref add_memory_resource(int nid, struct resource *res) +int __ref add_memory_resource(int nid, struct resource *res, bool online) { u64 start, size; pg_data_t *pgdat = NULL; @@ -1322,6 +1330,11 @@ int __ref add_memory_resource(int nid, struct resource *res) /* create new memmap entry */ firmware_map_add_hotplug(start, start + size, "System RAM"); + /* online pages if requested */ + if (online) + walk_memory_range(PFN_DOWN(start), PFN_UP(start + size - 1), + NULL, online_memory_block); + goto out; error: @@ -1345,7 +1358,7 @@ int __ref add_memory(int nid, u64 start, u64 size) if (IS_ERR(res)) return PTR_ERR(res); - ret = add_memory_resource(nid, res); + ret = add_memory_resource(nid, res, memhp_auto_online); if (ret < 0) release_memory_resource(res); return ret; |