From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ding Tianhong Subject: [PATCH] ifb: fix rcu_sched self-detected stalls Date: Wed, 10 Jul 2013 12:04:02 +0800 Message-ID: <51DCDD32.30102@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit To: Eric Dumazet , "David S. Miller" , Patrick McHardy , Netdev Return-path: Received: from szxga03-in.huawei.com ([119.145.14.66]:49029 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750710Ab3GJEGR (ORCPT ); Wed, 10 Jul 2013 00:06:17 -0400 Sender: netdev-owner@vger.kernel.org List-ID: 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 --- 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 dc9f6a4..a11f7a4 100644 --- a/drivers/net/ifb.c +++ b/drivers/net/ifb.c @@ -292,8 +292,10 @@ 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(); -- 1.8.0