From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751389AbZHXCuA (ORCPT ); Sun, 23 Aug 2009 22:50:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751313AbZHXCtz (ORCPT ); Sun, 23 Aug 2009 22:49:55 -0400 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:48221 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751181AbZHXCty (ORCPT ); Sun, 23 Aug 2009 22:49:54 -0400 Date: Sun, 23 Aug 2009 19:50:07 -0700 (PDT) Message-Id: <20090823.195007.192261442.davem@davemloft.net> To: Dongdong.deng@windriver.com Cc: mpm@selenic.com, nico@cam.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, jason.wessel@windriver.com Subject: Re: [PATCH 2/2] drivers/net: fixed drivers that support netpoll use ndo_start_xmit() From: David Miller In-Reply-To: <1250861693.24178.22.camel@dengdd-desktop> References: <1250861616.24178.20.camel@dengdd-desktop> <1250861693.24178.22.camel@dengdd-desktop> X-Mailer: Mew version 6.2.51 on Emacs 22.1 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: DDD Date: Fri, 21 Aug 2009 21:34:53 +0800 > The NETPOLL API requires that interrupts remain disabled in > netpoll_send_skb(). The use of "A functions set" in the NETPOLL API > callbacks causes the interrupts to get enabled and can lead to kernel > instability. > > The solution is to use "B functions set" to prevent the irqs from > getting enabled while in netpoll_send_skb(). > > A functions set: > local_irq_disable()/local_irq_enable() > spin_lock_irq()/spin_unlock_irq() > spin_trylock_irq()/spin_unlock_irq() > > B functions set: > local_irq_save()/local_irq_restore() > spin_lock_irqsave()/spin_unlock_irqrestore() > spin_trylock_irqsave()/spin_unlock_irqrestore() > > Signed-off-by: Dongdong Deng Applied.