From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: [RFC][PATCH 2/9] deadlock prevention core Date: Wed, 09 Aug 2006 18:19:54 +0200 Message-ID: <1155140394.12225.88.camel@twins> References: <20060808193345.1396.16773.sendpatchset@lappy> <20060808211731.GR14627@postel.suug.ch> <44D93BB3.5070507@google.com> <20060808.183920.41636471.davem@davemloft.net> <44D976E6.5010106@google.com> <20060809131942.GY14627@postel.suug.ch> <1155132440.12225.70.camel@twins> <20060809161816.GA14627@postel.suug.ch> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Daniel Phillips , David Miller , linux-mm@kvack.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Return-path: Received: from amsfep17-int.chello.nl ([213.46.243.15]:49064 "EHLO amsfep12-int.chello.nl") by vger.kernel.org with ESMTP id S1750767AbWHIQYZ (ORCPT ); Wed, 9 Aug 2006 12:24:25 -0400 To: Thomas Graf In-Reply-To: <20060809161816.GA14627@postel.suug.ch> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Wed, 2006-08-09 at 18:18 +0200, Thomas Graf wrote: > * Peter Zijlstra 2006-08-09 16:07 > > I think Daniel was thinking of adding struct net_device * > > sk_buff::alloc_dev, > > I know I was after reading the first few mails. However if adding a > > field > > there is strict no-no.... > > > > /me takes a look at struct sk_buff > > > > Hmm, what does sk_buff::input_dev do? That seems to store the initial > > device? > > No, skb->input_dev is used when redirecting packets around in the > stack and may change. Even if it would keep its value the reference > to the netdevice is not valid anymore when you free the skb as the > skb was queued and the refcnt acquired in __netifx_rx_schedule() > has been released again thus making it possible for the netdevice > to disappear. Bah, tricky stuff that. disregards this part from -v2 then :-(