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authorKonstantin Khlebnikov <khlebnikov@openvz.org>2013-03-08 12:43:36 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-03-08 15:05:34 -0800
commit15cf17d26e08ee95c2e392a3a71f55d32e99e971 (patch)
treee61f2c31bfa2b84a313b1b977bbd996be59f4d46
parent755727b7fb1e0ebe46824159107749cf635d43b1 (diff)
downloadlinaro-lsk-15cf17d26e08ee95c2e392a3a71f55d32e99e971.tar.gz
memcg: initialize kmem-cache destroying work earlier
Fix a warning from lockdep caused by calling cancel_work_sync() for uninitialized struct work. This path has been triggered by destructon kmem-cache hierarchy via destroying its root kmem-cache. cache ffff88003c072d80 obj ffff88003b410000 cache ffff88003c072d80 obj ffff88003b924000 cache ffff88003c20bd40 INFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. Pid: 2825, comm: insmod Tainted: G O 3.9.0-rc1-next-20130307+ #611 Call Trace: __lock_acquire+0x16a2/0x1cb0 lock_acquire+0x8a/0x120 flush_work+0x38/0x2a0 __cancel_work_timer+0x89/0xf0 cancel_work_sync+0xb/0x10 kmem_cache_destroy_memcg_children+0x81/0xb0 kmem_cache_destroy+0xf/0xe0 init_module+0xcb/0x1000 [kmem_test] do_one_initcall+0x11a/0x170 load_module+0x19b0/0x2320 SyS_init_module+0xc6/0xf0 system_call_fastpath+0x16/0x1b Example module to demonstrate: #include <linux/module.h> #include <linux/slab.h> #include <linux/mm.h> #include <linux/workqueue.h> int __init mod_init(void) { int size = 256; struct kmem_cache *cache; void *obj; struct page *page; cache = kmem_cache_create("kmem_cache_test", size, size, 0, NULL); if (!cache) return -ENOMEM; printk("cache %p\n", cache); obj = kmem_cache_alloc(cache, GFP_KERNEL); if (obj) { page = virt_to_head_page(obj); printk("obj %p cache %p\n", obj, page->slab_cache); kmem_cache_free(cache, obj); } flush_scheduled_work(); obj = kmem_cache_alloc(cache, GFP_KERNEL); if (obj) { page = virt_to_head_page(obj); printk("obj %p cache %p\n", obj, page->slab_cache); kmem_cache_free(cache, obj); } kmem_cache_destroy(cache); return -EBUSY; } module_init(mod_init); MODULE_LICENSE("GPL"); Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Glauber Costa <glommer@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/memcontrol.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 53b8201b31e..2b552224f5c 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3012,6 +3012,8 @@ void memcg_update_array_size(int num)
memcg_limited_groups_array_size = memcg_caches_array_size(num);
}
+static void kmem_cache_destroy_work_func(struct work_struct *w);
+
int memcg_update_cache_size(struct kmem_cache *s, int num_groups)
{
struct memcg_cache_params *cur_params = s->memcg_params;
@@ -3031,6 +3033,8 @@ int memcg_update_cache_size(struct kmem_cache *s, int num_groups)
return -ENOMEM;
}
+ INIT_WORK(&s->memcg_params->destroy,
+ kmem_cache_destroy_work_func);
s->memcg_params->is_root_cache = true;
/*
@@ -3078,6 +3082,8 @@ int memcg_register_cache(struct mem_cgroup *memcg, struct kmem_cache *s,
if (!s->memcg_params)
return -ENOMEM;
+ INIT_WORK(&s->memcg_params->destroy,
+ kmem_cache_destroy_work_func);
if (memcg) {
s->memcg_params->memcg = memcg;
s->memcg_params->root_cache = root_cache;
@@ -3358,8 +3364,6 @@ static void mem_cgroup_destroy_all_caches(struct mem_cgroup *memcg)
list_for_each_entry(params, &memcg->memcg_slab_caches, list) {
cachep = memcg_params_to_cache(params);
cachep->memcg_params->dead = true;
- INIT_WORK(&cachep->memcg_params->destroy,
- kmem_cache_destroy_work_func);
schedule_work(&cachep->memcg_params->destroy);
}
mutex_unlock(&memcg->slab_caches_mutex);