From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755548AbaELBvx (ORCPT ); Sun, 11 May 2014 21:51:53 -0400 Received: from 1wt.eu ([62.212.114.60]:34749 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754318AbaELBnx (ORCPT ); Sun, 11 May 2014 21:43:53 -0400 Message-Id: <20140512003202.877708998@1wt.eu> User-Agent: quilt/0.48-1 Date: Mon, 12 May 2014 02:32:54 +0200 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ding Tianhong , "David S. Miller" , Willy Tarreau Subject: [ 054/143] ifb: fix rcu_sched self-detected stalls In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let me know. ------------------ From: dingtianhong [ Upstream commit 440d57bc5ff55ec1efb3efc9cbe9420b4bbdfefa ] According to the commit 16b0dc29c1af9df341428f4c49ada4f626258082 (dummy: fix rcu_sched self-detected stalls) Eric Dumazet fix the problem in dummy, but the ifb will occur the same problem like the dummy modules. Trying to "modprobe ifb numifbs=30000" triggers : INFO: rcu_sched self-detected stall on CPU After this splat, RTNL is locked and reboot is needed. We must call cond_resched() to avoid this, even holding RTNL. Signed-off-by: Ding Tianhong Signed-off-by: David S. Miller [wt: 2.6.32: cond_resched() needs linux/sched.h] Signed-off-by: Willy Tarreau --- drivers/net/ifb.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/net/ifb.c b/drivers/net/ifb.c index 030913f..cfd5510 100644 --- a/drivers/net/ifb.c +++ b/drivers/net/ifb.c @@ -33,6 +33,7 @@ #include #include #include +#include #include #include @@ -269,8 +270,10 @@ static int __init ifb_init_module(void) rtnl_lock(); err = __rtnl_link_register(&ifb_link_ops); - for (i = 0; i < numifbs && !err; i++) + for (i = 0; i < numifbs && !err; i++) { err = ifb_init_one(i); + cond_resched(); + } if (err) __rtnl_link_unregister(&ifb_link_ops); rtnl_unlock(); -- 1.7.12.2.21.g234cd45.dirty