diff options
| -rw-r--r-- | include/linux/memory.h | 4 | ||||
| -rw-r--r-- | mm/slub.c | 118 |
2 files changed, 122 insertions, 0 deletions
diff --git a/include/linux/memory.h b/include/linux/memory.h index ec376e482ab..33f0ff0cf63 100644 --- a/include/linux/memory.h +++ b/include/linux/memory.h @@ -83,10 +83,14 @@ extern int memory_notify(unsigned long val, void *v); #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ +#ifdef CONFIG_MEMORY_HOTPLUG #define hotplug_memory_notifier(fn, pri) { \ static struct notifier_block fn##_mem_nb = \ { .notifier_call = fn, .priority = pri }; \ register_memory_notifier(&fn##_mem_nb); \ } +#else +#define hotplug_memory_notifier(fn, pri) do { } while (0) +#endif #endif /* _LINUX_MEMORY_H_ */ diff --git a/mm/slub.c b/mm/slub.c index e29a42988c7..aac1dd3c657 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -20,6 +20,7 @@ #include <linux/mempolicy.h> #include <linux/ctype.h> #include <linux/kallsyms.h> +#include <linux/memory.h> /* * Lock order: @@ -2694,6 +2695,121 @@ int kmem_cache_shrink(struct kmem_cache *s) } EXPORT_SYMBOL(kmem_cache_shrink); +#if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG) +static int slab_mem_going_offline_callback(void *arg) +{ + struct kmem_cache *s; + + down_read(&slub_lock); + list_for_each_entry(s, &slab_caches, list) + kmem_cache_shrink(s); + up_read(&slub_lock); + + return 0; +} + +static void slab_mem_offline_callback(void *arg) +{ + struct kmem_cache_node *n; + struct kmem_cache *s; + struct memory_notify *marg = arg; + int offline_node; + + offline_node = marg->status_change_nid; + + /* + * If the node still has available memory. we need kmem_cache_node + * for it yet. + */ + if (offline_node < 0) + return; + + down_read(&slub_lock); + list_for_each_entry(s, &slab_caches, list) { + n = get_node(s, offline_node); + if (n) { + /* + * if n->nr_slabs > 0, slabs still exist on the node + * that is going down. We were unable to free them, + * and offline_pages() function shoudn't call this + * callback. So, we must fail. + */ + BUG_ON(atomic_read(&n->nr_slabs)); + + s->node[offline_node] = NULL; + kmem_cache_free(kmalloc_caches, n); + } + } + up_read(&slub_lock); +} + +static int slab_mem_going_online_callback(void *arg) +{ + struct kmem_cache_node *n; + struct kmem_cache *s; + struct memory_notify *marg = arg; + int nid = marg->status_change_nid; + int ret = 0; + + /* + * If the node's memory is already available, then kmem_cache_node is + * already created. Nothing to do. + */ + if (nid < 0) + return 0; + + /* + * We are bringing a node online. No memory is availabe yet. We must + * allocate a kmem_cache_node structure in order to bring the node + * online. + */ + down_read(&slub_lock); + list_for_each_entry(s, &slab_caches, list) { + /* + * XXX: kmem_cache_alloc_node will fallback to other nodes + * since memory is not yet available from the node that + * is brought up. + */ + n = kmem_cache_alloc(kmalloc_caches, GFP_KERNEL); + if (!n) { + ret = -ENOMEM; + goto out; + } + init_kmem_cache_node(n); + s->node[nid] = n; + } +out: + up_read(&slub_lock); + return ret; +} + +static int slab_memory_callback(struct notifier_block *self, + unsigned long action, void *arg) +{ + int ret = 0; + + switch (action) { + case MEM_GOING_ONLINE: + ret = slab_mem_going_online_callback(arg); + break; + case MEM_GOING_OFFLINE: + ret = slab_mem_going_offline_callback(arg); + break; + case MEM_OFFLINE: + case MEM_CANCEL_ONLINE: + slab_mem_offline_callback(arg); + break; + case MEM_ONLINE: + case MEM_CANCEL_OFFLINE: + break; + } + + ret = notifier_from_errno(ret); + return ret; +} + +#endif /* CONFIG_MEMORY_HOTPLUG */ + /******************************************************************** * Basic setup of slabs *******************************************************************/ @@ -2715,6 +2831,8 @@ void __init kmem_cache_init(void) sizeof(struct kmem_cache_node), GFP_KERNEL); kmalloc_caches[0].refcount = -1; caches++; + + hotplug_memory_notifier(slab_memory_callback, 1); #endif /* Able to allocate the per node structures */ |