From mboxrd@z Thu Jan 1 00:00:00 1970 From: Flavio Leitner Subject: Re: [PATCH] net: reset gso header when the copied skb is linearized Date: Thu, 4 Nov 2010 18:35:27 -0200 Message-ID: <20101104203527.GA21935@redhat.com> References: <1288045398-3110-1-git-send-email-fleitner@redhat.com> <20101026.113157.233700961.davem@davemloft.net> <20101026192511.GA3494@redhat.com> <20101026.122801.52191238.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org, herbert@gondor.hengli.com.au To: David Miller Return-path: Received: from mx1.redhat.com ([209.132.183.28]:48025 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752305Ab0KDUff (ORCPT ); Thu, 4 Nov 2010 16:35:35 -0400 Content-Disposition: inline In-Reply-To: <20101026.122801.52191238.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On Tue, Oct 26, 2010 at 12:28:01PM -0700, David Miller wrote: > From: Flavio Leitner > Date: Tue, 26 Oct 2010 17:25:11 -0200 > > > If I understand that correctly, the gso_segs is the number > > of GSO segments which are divided in non-linear way. When the > > copy is made using that function, the skb turns into a big > > one segment inlined. So, the idea of segments is lost and > > I'm not seeing how it is going to be divided again. > > Later the NIC drives does, for example: > > GSO has nothing to do with linearity, although it just so happens > to be that GSO packets tend to be non-linear due to the way > TCP builds such frames. > > The GSO segment count is the number of MSS sized frames are > contained inside of a larger than MSS sized SKB. > > That is it. So the definition and meaning is independent of > linearity. > > Thus, if we linearize a larger than MSS sized frame, it should still > have the same GSO attributes. It makes sense, thanks for the explanation. Please ignore the proposed patch. thanks again, -- Flavio