From patchwork Tue Apr 30 02:52:58 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Simon Horman X-Patchwork-Id: 240539 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 441062C00C6 for ; Tue, 30 Apr 2013 12:54:17 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759213Ab3D3CxN (ORCPT ); Mon, 29 Apr 2013 22:53:13 -0400 Received: from kirsty.vergenet.net ([202.4.237.240]:47757 "EHLO kirsty.vergenet.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760576Ab3D3CxG (ORCPT ); Mon, 29 Apr 2013 22:53:06 -0400 Received: from ayumi.akashicho.tokyo.vergenet.net (p5212-ipbfp1903kobeminato.hyogo.ocn.ne.jp [114.172.132.212]) by kirsty.vergenet.net (Postfix) with ESMTP id F3B7325BF6F; Tue, 30 Apr 2013 12:53:04 +1000 (EST) Received: by ayumi.akashicho.tokyo.vergenet.net (Postfix, from userid 7100) id 85F72EDE7CD; Tue, 30 Apr 2013 11:53:03 +0900 (JST) From: Simon Horman To: Eric Dumazet , Julian Anastasov , Ingo Molnar , Peter Zijlstra , "Paul E. McKenney" Cc: lvs-devel@vger.kernel.org, netdev@vger.kernel.org, netfilter-devel@vger.kernel.org, linux-kernel@vger.kernel.org, Pablo Neira Ayuso , Dipankar Sarma , Simon Horman , Ingo Molnar Subject: [PATCH v2 2/2] ipvs: Use cond_resched_rcu_lock() helper when dumping connections Date: Tue, 30 Apr 2013 11:52:58 +0900 Message-Id: <1367290378-29224-3-git-send-email-horms@verge.net.au> X-Mailer: git-send-email 1.8.2.1 In-Reply-To: <1367290378-29224-1-git-send-email-horms@verge.net.au> References: <1367290378-29224-1-git-send-email-horms@verge.net.au> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This avoids the situation where a dump of a large number of connections may prevent scheduling for a long time while also avoiding excessive calls to rcu_read_unlock() and rcu_read_lock(). Note that in the case of !CONFIG_PREEMPT_RCU this will add a call to cond_resched(). Compile tested only. Cc: Eric Dumazet Cc: Julian Anastasov Cc: Ingo Molnar Signed-off-by: Simon Horman --- net/netfilter/ipvs/ip_vs_conn.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/net/netfilter/ipvs/ip_vs_conn.c b/net/netfilter/ipvs/ip_vs_conn.c index a083bda..42a7b33 100644 --- a/net/netfilter/ipvs/ip_vs_conn.c +++ b/net/netfilter/ipvs/ip_vs_conn.c @@ -975,8 +975,7 @@ static void *ip_vs_conn_array(struct seq_file *seq, loff_t pos) return cp; } } - rcu_read_unlock(); - rcu_read_lock(); + cond_resched_rcu_lock(); } return NULL; @@ -1015,8 +1014,7 @@ static void *ip_vs_conn_seq_next(struct seq_file *seq, void *v, loff_t *pos) iter->l = &ip_vs_conn_tab[idx]; return cp; } - rcu_read_unlock(); - rcu_read_lock(); + cond_resched_rcu_lock(); } iter->l = NULL; return NULL;