From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759884Ab3GaN0E (ORCPT ); Wed, 31 Jul 2013 09:26:04 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:47000 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759769Ab3GaNZ6 (ORCPT ); Wed, 31 Jul 2013 09:25:58 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "dingtianhong" , "David S. Miller" Date: Wed, 31 Jul 2013 15:23:09 +0200 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [15/84] ifb: fix rcu_sched self-detected stalls In-Reply-To: X-SA-Exim-Connect-IP: 151.216.67.181 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.50-rc1 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 Signed-off-by: Ben Hutchings --- drivers/net/ifb.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/net/ifb.c b/drivers/net/ifb.c index 46b5f5f..4924a1e 100644 --- a/drivers/net/ifb.c +++ b/drivers/net/ifb.c @@ -291,8 +291,10 @@ 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();