From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Laight Subject: RE: [PATCH RFC net-next 2/2] tcp: Add Redundant Data Bundling (RDB) Date: Mon, 2 Nov 2015 09:18:20 +0000 Message-ID: <063D6719AE5E284EB5DD2968C1650D6D1CBC86C4@AcuExch.aculab.com> References: <1445633413-3532-1-git-send-email-bro.devel+kernel@gmail.com> <3710572.sJUWpao1xp@bro-compal> Mime-Version: 1.0 Content-Type: text/plain; charset=Windows-1252 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Andreas Petlund , Neal Cardwell , "David S. Miller" , "Alexey Kuznetsov" , James Morris , "Hideaki YOSHIFUJI" , Patrick McHardy , Jonathan Corbet , Eric Dumazet , "Tom Herbert" , Paolo Abeni , Erik Kline , Hannes Frederic Sowa , Al Viro , Jiri Pirko , Alexander Duyck , Florian Westphal , Daniel Lee , Marcelo Ricardo Leitner , "Daniel Borkmann" , Willem de Bruijn , =?Windows-1252?Q?Linus_L=FCssing?= , "linux- To: "'bro.devel+kernel@gmail.com'" , Yuchung Cheng Return-path: In-Reply-To: <3710572.sJUWpao1xp@bro-compal> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org =46rom: Bendik R=F8nning Opstad > Sent: 29 October 2015 22:54 =2E.. > > > > The semantics of the tp->nonagle bits are already a bit complex= =2E My > > > > sense is that having a setsockopt of TCP_RDB transparently modi= fy the > > > > nagle behavior is going to add more extra complexity and unanti= cipated > > > > behavior than is warranted given the slight possible gain in > > > > convenience to the app writer. What about a model where the > > > > application user just needs to remember to call > > > > setsockopt(TCP_NODELAY) if they want the TCP_RDB behavior to be > > > > sensible? I see your nice tests at > > > > > > > > https://github.com/bendikro/packetdrill/commit/9916b6c53e33dd= 04329d29b > > > > 7d8baf703b2c2ac1b> > > > > > are already doing that. And my sense is that likewise most > > > > well-engineered "thin stream" apps will already be using > > > > setsockopt(TCP_NODELAY). Is that workable? >=20 > This is definitely workable. I agree that it may not be an ideal solu= tion to > have TCP_RDB disable Nagle, however, it would be useful with a way to= easily > enable RDB and disable Nagle. If enabling RDB disables Nagle, then what happens when you turn RDB bac= k off? David