From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754034Ab2GIOiU (ORCPT ); Mon, 9 Jul 2012 10:38:20 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:38236 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754302Ab2GIOiP (ORCPT ); Mon, 9 Jul 2012 10:38:15 -0400 Message-Id: <20120709143121.743971024@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Mon, 09 Jul 2012 15:31:51 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Eric Dumazet , "David S. Miller" Subject: [ 35/48] dummy: fix rcu_sched self-detected stalls In-Reply-To: <20120709143116.348975190@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:21c:bfff:fe03:f805 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-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 16b0dc29c1af9df341428f4c49ada4f626258082 ] Trying to "modprobe dummy numdummies=30000" triggers : INFO: rcu_sched self-detected stall on CPU { 8} (t=60000 jiffies) After this splat, RTNL is locked and reboot is needed. We must call cond_resched() to avoid this, even holding RTNL. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- drivers/net/dummy.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/net/dummy.c b/drivers/net/dummy.c index eeac9ca..87e4632 100644 --- a/drivers/net/dummy.c +++ b/drivers/net/dummy.c @@ -186,8 +186,10 @@ static int __init dummy_init_module(void) rtnl_lock(); err = __rtnl_link_register(&dummy_link_ops); - for (i = 0; i < numdummies && !err; i++) + for (i = 0; i < numdummies && !err; i++) { err = dummy_init_one(); + cond_resched(); + } if (err < 0) __rtnl_link_unregister(&dummy_link_ops); rtnl_unlock();