From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [PATCH] Improvev netconsole support for RTL8139 NIC driver Date: Tue, 25 Mar 2008 23:14:11 -0400 Message-ID: <47E9BF83.8070006@pobox.com> References: <47E9B115.9060109@windriver.com> <47E9B39C.5010502@pobox.com> <20080325.194221.16658596.davem@davemloft.net> <47E9BA6C.2010502@windriver.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: David Miller , netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: yshi Return-path: 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 In-Reply-To: <47E9BA6C.2010502@windriver.com> Sender: netdev-owner@vger.kernel.org List-ID: yshi wrote: > David Miller =E5=86=99=E9=81=93: >> From: Jeff Garzik >> Date: Tue, 25 Mar 2008 22:23:24 -0400 >> >> =20 >>> This is bogus -- you should never need to slow down the hot path in= =20 >>> such a way. >>> =20 >> >> 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. >> =20 > 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=20 about: you only need to use spin_lock() there. Jeff