From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx128.postini.com [74.125.245.128]) by kanga.kvack.org (Postfix) with SMTP id 310096B0005 for ; Thu, 7 Mar 2013 02:48:58 -0500 (EST) Received: by mail-lb0-f177.google.com with SMTP id go11so214792lbb.36 for ; Wed, 06 Mar 2013 23:48:56 -0800 (PST) Subject: [PATCH for 3.9] memcg: initialize kmem-cache destroying work earlier From: Konstantin Khlebnikov Date: Thu, 07 Mar 2013 11:48:53 +0400 Message-ID: <20130307074853.26272.83618.stgit@zurg> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Andrew Morton , Glauber Costa This patch fixes 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. Signed-off-by: Konstantin Khlebnikov Cc: Glauber Costa Cc: Andrew Morton --- [ 250.781400] cache ffff88003c072d80 [ 250.783706] obj ffff88003b410000 cache ffff88003c072d80 [ 250.786312] obj ffff88003b924000 cache ffff88003c20bd40 [ 250.787233] INFO: trying to register non-static key. [ 250.788046] the code is fine but needs lockdep annotation. [ 250.788184] turning off the locking correctness validator. [ 250.788184] Pid: 2825, comm: insmod Tainted: G O 3.9.0-rc1-next-20130307+ #611 [ 250.788184] Call Trace: [ 250.788184] [] __lock_acquire+0x16a2/0x1cb0 [ 250.788184] [] lock_acquire+0x8a/0x120 [ 250.788184] [] ? cancel_delayed_work+0xb0/0xb0 [ 250.788184] [] flush_work+0x38/0x2a0 [ 250.788184] [] ? cancel_delayed_work+0xb0/0xb0 [ 250.788184] [] ? mark_held_locks+0xae/0x120 [ 250.788184] [] ? __cancel_work_timer+0x7d/0xf0 [ 250.788184] [] ? trace_hardirqs_on_caller+0x105/0x1d0 [ 250.788184] [] __cancel_work_timer+0x89/0xf0 [ 250.788184] [] cancel_work_sync+0xb/0x10 [ 250.788184] [] kmem_cache_destroy_memcg_children+0x81/0xb0 [ 250.788184] [] kmem_cache_destroy+0xf/0xe0 [ 250.788184] [] init_module+0xcb/0x1000 [kmem_test] [ 250.788184] [] ? 0xffffffffa0009fff [ 250.788184] [] do_one_initcall+0x11a/0x170 [ 250.788184] [] load_module+0x19b0/0x2320 [ 250.788184] [] ? __unlink_module+0x30/0x30 [ 250.788184] [] ? retint_restore_args+0xe/0xe [ 250.788184] [] ? retint_restore_args+0xe/0xe [ 250.788184] [] SyS_init_module+0xc6/0xf0 [ 250.788184] [] system_call_fastpath+0x16/0x1b --- #include #include #include #include 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"); --- mm/memcontrol.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 669d16a..690fa8c 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3078,6 +3078,8 @@ 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; @@ -3097,6 +3099,8 @@ 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; /* @@ -3144,6 +3148,8 @@ 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; @@ -3424,8 +3430,6 @@ 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); -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org