Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933140Ab2EYNJ4 (ORCPT ); Fri, 25 May 2012 09:09:56 -0400 Received: from mailhub.sw.ru ([195.214.232.25]:10261 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757761Ab2EYNJx (ORCPT ); Fri, 25 May 2012 09:09:53 -0400 From: Glauber Costa To: Cc: , , , Tejun Heo , Li Zefan , Greg Thelen , Suleiman Souhlal , Michal Hocko , Johannes Weiner , , David Rientjes , Glauber Costa , Christoph Lameter , Pekka Enberg Subject: [PATCH v3 26/28] slub: track all children of a kmem cache Date: Fri, 25 May 2012 17:03:46 +0400 Message-Id: <1337951028-3427-27-git-send-email-glommer@parallels.com> X-Mailer: git-send-email 1.7.7.6 In-Reply-To: <1337951028-3427-1-git-send-email-glommer@parallels.com> References: <1337951028-3427-1-git-send-email-glommer@parallels.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3796 Lines: 124 When we destroy a cache (like for instance, if we're unloading a module) we need to go through the list of memcg caches and destroy them as well. The caches are expected to be empty by themselves, so nothing is changed here. All previous guarantees are kept and no new guarantees are given. So given all memcg caches are expected to be empty - even though they are likely to be hanging around in the system, we just need to scan a list of sibling caches, and destroy each one of them. This is very similar to the work done by Suleiman for the slab. Signed-off-by: Glauber Costa CC: Christoph Lameter CC: Pekka Enberg CC: Michal Hocko CC: Kamezawa Hiroyuki CC: Johannes Weiner CC: Suleiman Souhlal --- mm/slub.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++++-------- 1 files changed, 55 insertions(+), 9 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index 4c29e5f..8151353 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -3254,6 +3254,54 @@ static inline int kmem_cache_close(struct kmem_cache *s) return 0; } +static void kmem_cache_destroy_unlocked(struct kmem_cache *s) +{ + mem_cgroup_release_cache(s); + if (kmem_cache_close(s)) { + printk(KERN_ERR + "SLUB %s: %s called for cache that still has objects.\n", + s->name, __func__); + dump_stack(); + } + + if (s->flags & SLAB_DESTROY_BY_RCU) + rcu_barrier(); + sysfs_slab_remove(s); +} + +static void kmem_cache_destroy_memcg_children(struct kmem_cache *s) +{ +#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM + struct mem_cgroup_cache_params *p, *tmp, *this; + struct kmem_cache *c; + int id = s->memcg_params.id; + + /* Not a parent cache */ + if (id == -1) + return ; + + this = &s->memcg_params; + mem_cgroup_flush_cache_create_queue(); + list_for_each_entry_safe(p, tmp, &this->sibling_list, sibling_list) { + c = container_of(p, struct kmem_cache, memcg_params); + /* We never added the main cache to the sibling list */ + if (WARN_ON(c == s)) + continue; + + c->refcount--; + if (c->refcount) + continue; + + list_del(&c->list); + list_del(&c->memcg_params.sibling_list); + s->refcount--; /* parent reference */ + up_write(&slub_lock); + mem_cgroup_remove_child_kmem_cache(c, id); + kmem_cache_destroy_unlocked(c); + down_write(&slub_lock); + } +#endif +} /* * Close a cache and release the kmem_cache structure * (must be used for caches created using kmem_cache_create) @@ -3261,19 +3309,15 @@ static inline int kmem_cache_close(struct kmem_cache *s) void kmem_cache_destroy(struct kmem_cache *s) { down_write(&slub_lock); + kmem_cache_destroy_memcg_children(s); s->refcount--; if (!s->refcount) { list_del(&s->list); - mem_cgroup_release_cache(s); +#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM + list_del(&s->memcg_params.sibling_list); +#endif up_write(&slub_lock); - if (kmem_cache_close(s)) { - printk(KERN_ERR "SLUB %s: %s called for cache that " - "still has objects.\n", s->name, __func__); - dump_stack(); - } - if (s->flags & SLAB_DESTROY_BY_RCU) - rcu_barrier(); - sysfs_slab_remove(s); + kmem_cache_destroy_unlocked(s); } else up_write(&slub_lock); } @@ -4102,6 +4146,8 @@ struct kmem_cache *kmem_cache_dup(struct mem_cgroup *memcg, */ if (new) { down_write(&slub_lock); + list_add(&new->memcg_params.sibling_list, + &s->memcg_params.sibling_list); s->refcount++; up_write(&slub_lock); slab_set_parent(new, s); -- 1.7.7.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/