From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755024AbYCZDOh (ORCPT ); Tue, 25 Mar 2008 23:14:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752813AbYCZDOR (ORCPT ); Tue, 25 Mar 2008 23:14:17 -0400 Received: from srv5.dvmed.net ([207.36.208.214]:59825 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752660AbYCZDOQ (ORCPT ); Tue, 25 Mar 2008 23:14:16 -0400 Message-ID: <47E9BF83.8070006@pobox.com> Date: Tue, 25 Mar 2008 23:14:11 -0400 From: Jeff Garzik User-Agent: Thunderbird 2.0.0.12 (X11/20080226) MIME-Version: 1.0 To: yshi CC: David Miller , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] Improvev netconsole support for RTL8139 NIC driver References: <47E9B115.9060109@windriver.com> <47E9B39C.5010502@pobox.com> <20080325.194221.16658596.davem@davemloft.net> <47E9BA6C.2010502@windriver.com> In-Reply-To: <47E9BA6C.2010502@windriver.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Score: -4.4 (----) X-Spam-Report: SpamAssassin version 3.2.4 on srv5.dvmed.net summary: Content analysis details: (-4.4 points, 5.0 required) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org yshi wrote: > David Miller 写道: >> From: Jeff Garzik >> Date: Tue, 25 Mar 2008 22:23:24 -0400 >> >> >>> This is bogus -- you should never need to slow down the hot path in >>> such a way. >>> >> >> Slow down in what way? Even on x86 saving the flags is just >> about as expensive as a plain sti/cli. >> >> I would in fact prefer to see drivers unconditionally use >> spin_lock_irqsave() et al. in the interrupt handler, for >> consistency. >> > Yes, I agree. Many NIC drivers do the same thing, like Gianfar, E1000, etc. No, I just looked. Neither gianfar nor e1000 nor e1000e does this. In fact, gfar_transmit() is precisely an example of what I'm talking about: you only need to use spin_lock() there. Jeff