From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Gruenbacher Subject: Re: [RFC] [TCP 1/3] tcp: Add MSG_NEW_PACKET flag to indicate preferable packet boundaries Date: Mon, 02 Jul 2012 13:00:56 +0200 Message-ID: <1341226856.29646.8.camel@gurkel.linbit> References: <1340981690.25226.3.camel@gurkel.linbit> <1340982666.21162.3.camel@edumazet-glaptop> <1340984335.25450.24.camel@gurkel.linbit> <1340990157.21162.5.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Herbert Xu , "David S. Miller" To: Eric Dumazet Return-path: In-Reply-To: <1340990157.21162.5.camel@edumazet-glaptop> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Fri, 2012-06-29 at 19:15 +0200, Eric Dumazet wrote: > 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. That's alright as long as we'll get "back to normal" eventually; the only effect will be that we'll copy data out of the socket receive buffers for a while. There will be extremely little packet loss on the kinds of networks that we want to use this on. Thanks, Andreas