From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756249Ab2F2RQJ (ORCPT ); Fri, 29 Jun 2012 13:16:09 -0400 Received: from mail-bk0-f46.google.com ([209.85.214.46]:41670 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756040Ab2F2RQH (ORCPT ); Fri, 29 Jun 2012 13:16:07 -0400 Subject: Re: [RFC] [TCP 1/3] tcp: Add MSG_NEW_PACKET flag to indicate preferable packet boundaries From: Eric Dumazet To: Andreas Gruenbacher Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Herbert Xu , "David S. Miller" In-Reply-To: <1340984335.25450.24.camel@gurkel.linbit> References: <1340981690.25226.3.camel@gurkel.linbit> <1340982666.21162.3.camel@edumazet-glaptop> <1340984335.25450.24.camel@gurkel.linbit> Content-Type: text/plain; charset="UTF-8" Date: Fri, 29 Jun 2012 19:15:57 +0200 Message-ID: <1340990157.21162.5.camel@edumazet-glaptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2012-06-29 at 17:38 +0200, Andreas Gruenbacher wrote: > The primary use case is fast Gigabit (10 or more) Ethernet connections > with jumbo frames and switches that support them. There, frames will go > through unchanged and you can zero-copy receive all the time. > > Not sure how well the approach scales to other kinds of connections; it > may work often enough to be worth it. When things get distorted between > the sender and the receiver and tcp_recvbio() fails, the data can still > be copied out of the socket as before. If you have a packet loss, receiver can and will coalesce frames.