From mboxrd@z Thu Jan 1 00:00:00 1970 From: "David S. Miller" Subject: Re: skb diet Date: Sun, 16 Apr 2006 22:25:51 -0700 (PDT) Message-ID: <20060416.222551.46522402.davem@davemloft.net> References: <200604152122.01914.ak@suse.de> <200604161716.31276.ak@suse.de> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: hkotry@gmail.com, netdev@vger.kernel.org Return-path: Received: from dsl027-180-168.sfo1.dsl.speakeasy.net ([216.27.180.168]:2505 "EHLO sunset.davemloft.net") by vger.kernel.org with ESMTP id S1750705AbWDQFZ2 (ORCPT ); Mon, 17 Apr 2006 01:25:28 -0400 To: ak@suse.de In-Reply-To: <200604161716.31276.ak@suse.de> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: Andi Kleen Date: Sun, 16 Apr 2006 17:16:31 +0200 > On Sunday 16 April 2006 14:56, Hisham Kotry wrote: > > > Linux 2.0 did something like this, but that was removed for good > > > reasons. Now TCP always clones skbs before sending it out. > > > > Do you remember what those reasons were? I couldn't find a related > > discussion in the archives. I think the BSD mbuf tags approach is > > sound enough to justify the move. > > From your description so far it seems to only have disadvantages. I totally agree, tags are very stupid. I only brought them up long as food-for-thought, not as a very serious candidate for implementation. Indirection is a performance killer, and we've seen this time and time again in the past. Tags add more indirection for questionable gains.