From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [RFC] Wild and crazy ideas involving struct sk_buff Date: Wed, 22 Aug 2007 14:08:05 -0700 (PDT) Message-ID: <20070822.140805.54950393.davem@davemloft.net> References: <200708221631.34234.paul.moore@hp.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, jmorris@namei.org To: paul.moore@hp.com Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:43606 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1764207AbXHVVII (ORCPT ); Wed, 22 Aug 2007 17:08:08 -0400 In-Reply-To: <200708221631.34234.paul.moore@hp.com> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: Paul Moore Date: Wed, 22 Aug 2007 16:31:34 -0400 > We're currently talking about several different ideas to solve the problem, > including leveraging the sk_buff.secmark field, and one of the ideas was to > add an additional field to the sk_buff structure. Knowing how well that idea > would go over (lead balloon is probably an understatement at best) I started > looking at what I might be able to remove from the sk_buff struct to make > room for a new field (the new field would be a u32). Looking at the sk_buff > structure it appears that the sk_buff.dev and sk_buff.iif fields are a bit > redundant and removing the sk_buff.dev field could free 32/64 bits depending > on the platform. Is there any reason (performance?) for keeping the > sk_buff.dev field around? Would the community be open to patches which > removed it and transition users over to the sk_buff.iif field? Finally, > assuming the sk_buff.dev field was removed, would the community be open to > adding a new LSM/SELinux related u32 field to the sk_buff struct? It's there for performance, and I bet there might be some semantic issues involved. And ironically James Morris still owes me a struct sk_buff removal from when I let him put the "secmark" thing in there! Stop spending money you guys haven't earned yet :-)