From mboxrd@z Thu Jan 1 00:00:00 1970 From: Willy Tarreau Subject: Re: [PATCH net-next 3/3] net/tcp-fastopen: Add new API support Date: Tue, 24 Jan 2017 19:43:45 +0100 Message-ID: <20170124184345.GF21921@1wt.eu> References: <20170123185922.48046-1-tracywwnj@gmail.com> <20170123185922.48046-4-tracywwnj@gmail.com> <20170124073043.GA21590@1wt.eu> <1485279727.16328.303.camel@edumazet-glaptop3.roam.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Yuchung Cheng , Wei Wang , netdev , David Miller , Eric Dumazet , Wei Wang To: Eric Dumazet Return-path: Received: from wtarreau.pck.nerim.net ([62.212.114.60]:65023 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751045AbdAXSnw (ORCPT ); Tue, 24 Jan 2017 13:43:52 -0500 Content-Disposition: inline In-Reply-To: <1485279727.16328.303.camel@edumazet-glaptop3.roam.corp.google.com> Sender: netdev-owner@vger.kernel.org List-ID: On Tue, Jan 24, 2017 at 09:42:07AM -0800, Eric Dumazet wrote: > On Tue, 2017-01-24 at 09:26 -0800, Yuchung Cheng wrote: > > > > > > > Do you think there's a compelling reason for adding a new option or > > > are you interested in a small patch to perform the change above ? > > I like the proposal especially other stack also uses TCP_FASTOPEN > > https://msdn.microsoft.com/en-us/library/windows/desktop/ms738596(v=vs.85).aspx > > > Problem is that might break existing applications that were using > TCP_FASTOPEN before a connect() (it was a NOP until now) > > I prefer we use a separate new option to be 100% safe, not adding > regressions. > > Only new applications, tested, will use this new feature at their risk. That's indeed a good point. I Yuchung's comment above made me wonder about application's portability but very few OSes will use this and in the end it might be that portable applications will just add : #define TCP_FASTOPEN_CONNECT TCP_FASTOPEN For other OSes and use TCP_FASTOPEN_CONNECT only for the connect() case. Willy