From patchwork Thu Nov 12 23:41:22 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johannes Weiner X-Patchwork-Id: 544003 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 49DBE141434 for ; Fri, 13 Nov 2015 10:46:48 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933101AbbKLXmM (ORCPT ); Thu, 12 Nov 2015 18:42:12 -0500 Received: from gum.cmpxchg.org ([85.214.110.215]:43148 "EHLO gum.cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933097AbbKLXmK (ORCPT ); Thu, 12 Nov 2015 18:42:10 -0500 From: Johannes Weiner To: David Miller , Andrew Morton Cc: Vladimir Davydov , Tejun Heo , Michal Hocko , netdev@vger.kernel.org, linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com Subject: [PATCH 03/14] net: tcp_memcontrol: properly detect ancestor socket pressure Date: Thu, 12 Nov 2015 18:41:22 -0500 Message-Id: <1447371693-25143-4-git-send-email-hannes@cmpxchg.org> X-Mailer: git-send-email 2.6.2 In-Reply-To: <1447371693-25143-1-git-send-email-hannes@cmpxchg.org> References: <1447371693-25143-1-git-send-email-hannes@cmpxchg.org> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org When charging socket memory, the code currently checks only the local page counter for excess to determine whether the memcg is under socket pressure. But even if the local counter is fine, one of the ancestors could have breached its limit, which should also force this child to enter socket pressure. This currently doesn't happen. Fix this by using page_counter_try_charge() first. If that fails, it means that either the local counter or one of the ancestors are in excess of their limit, and the child should enter socket pressure. Signed-off-by: Johannes Weiner Acked-by: David S. Miller Reviewed-by: Vladimir Davydov --- include/net/sock.h | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/include/net/sock.h b/include/net/sock.h index bbf7c2c..c4b33c9 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1190,11 +1190,13 @@ static inline void memcg_memory_allocated_add(struct cg_proto *prot, unsigned long amt, int *parent_status) { - page_counter_charge(&prot->memory_allocated, amt); + struct page_counter *counter; + + if (page_counter_try_charge(&prot->memory_allocated, amt, &counter)) + return; - if (page_counter_read(&prot->memory_allocated) > - prot->memory_allocated.limit) - *parent_status = OVER_LIMIT; + page_counter_charge(&prot->memory_allocated, amt); + *parent_status = OVER_LIMIT; } static inline void memcg_memory_allocated_sub(struct cg_proto *prot,