This reverts commit f22980954a2d765ca6ca03c11b2eac8f3fe1d105. This commit is deadly broken - it frees pages allocated with alloc_kmem_pages using put_page instead of free_kmem_pages. As a result, kmem counter of the cgroup the page is charged to won't be uncharged and therefore will be leaked. What is worse, if such a page then gets reused for a thread info or slab page, there is a chance that the order of the new page will be greater than it used to be, as a result the mem_cgroup->kmem counter can be under-uncharged:
WARNING: at kernel/res_counter.c:91 res_counter_uncharge_locked+0x2f/0x40() CPU: 0 PID: 19 Comm: rcuos/1 ve: 0 Tainted: G W -------------- 3.10.0-123.1.2.vz7.5.18 #1 5.18 ffffffff817e8e14 00000000a31483c6 ffff8804090c1c98 ffffffff815ca9ea ffff8804090c1cd0 ffffffff8105e091 ffff8800ceadf150 0000000000000000 ffff8800ceadf150 0000000000000000 ffff8800ceadf178 ffff8804090c1ce0 Call Trace: [<ffffffff815ca9ea>] dump_stack+0x19/0x1b [<ffffffff8105e091>] warn_slowpath_common+0x61/0x80 [<ffffffff8105e1ba>] warn_slowpath_null+0x1a/0x20 [<ffffffff810edfdf>] res_counter_uncharge_locked+0x2f/0x40 [<ffffffff810ee1e5>] res_counter_uncharge_until+0x55/0xb0 [<ffffffff810ee253>] res_counter_uncharge+0x13/0x20 [<ffffffff811b2ba4>] memcg_uncharge_kmem+0x34/0x80 [<ffffffff811b2ebd>] __memcg_kmem_uncharge_pages+0x5d/0x70 [<ffffffff8114fe28>] free_kmem_pages+0x68/0x80 [<ffffffff8105aed2>] free_task+0x32/0x60 [<ffffffff8105af9b>] __put_task_struct+0x9b/0x140 [<ffffffff81062b6c>] delayed_put_task_struct+0x3c/0x80 [<ffffffff811034d9>] rcu_nocb_kthread+0x229/0x370 [<ffffffff810883a0>] ? wake_up_bit+0x30/0x30 [<ffffffff811032b0>] ? rcu_start_gp+0x40/0x40 [<ffffffff8108723f>] kthread+0xcf/0xe0 [<ffffffff81087170>] ? create_kthread+0x60/0x60 [<ffffffff815db0ac>] ret_from_fork+0x7c/0xb0 [<ffffffff81087170>] ? create_kthread+0x60/0x60 This will probably eventually lead to the cgroup being freed when there are still active objects in one or more of its kmem caches: BUG buffer_head(39:101) (Tainted: G W -------------- ): Objects remaining in buffer_head(39:101) on kmem_cache_close() kernel BUG at mm/slab_common.c:493! This patch therefore reverts the above mentioned commit. We will rework it later. https://jira.sw.ru/browse/PSBM-34492 Signed-off-by: Vladimir Davydov <vdavy...@parallels.com> Conflicts: net/core/sock.c --- net/core/sock.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/core/sock.c b/net/core/sock.c index 10b4362f59fa..03f4b236476b 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1780,7 +1780,7 @@ struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len, while (order) { if (npages >= 1 << order) { - page = alloc_kmem_pages(sk->sk_allocation | + page = alloc_pages(sk->sk_allocation | __GFP_COMP | __GFP_NOWARN, order); if (page) @@ -1788,7 +1788,7 @@ struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len, } order--; } - page = alloc_kmem_pages(sk->sk_allocation, 0); + page = alloc_page(sk->sk_allocation); if (!page) goto failure; fill_page: -- 2.1.4 _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel
