From owner-freebsd-net@FreeBSD.ORG Sat May 17 14:49:34 2014 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 59830169 for ; Sat, 17 May 2014 14:49:34 +0000 (UTC) Received: from mail-qg0-x22c.google.com (mail-qg0-x22c.google.com [IPv6:2607:f8b0:400d:c04::22c]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 1AAFB2956 for ; Sat, 17 May 2014 14:49:34 +0000 (UTC) Received: by mail-qg0-f44.google.com with SMTP id i50so6165310qgf.3 for ; Sat, 17 May 2014 07:49:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type:content-transfer-encoding; bh=LGI70hRahlmuTHVBA9oyG63DFLNh3aOEXjW6fqFFsUo=; b=atYybAjgebbWZIxXD6p9+Mlus/UkhcXy2gJroMmdIq6w8+euQ7qrvYxRZEvONj6/La IiktixCl8VO3QIqjFiZWhmszRrHTleDxfiVHUhzMHUl4trGzTi5FBnCu7OwekjUzQvpL /FOkKVPz+kN+DIZMdX5MN5jEonDalsCJRr5s1qG8ivTYwgjreuucS+0xXSY4dLAlCuP9 3JGyPsOR5NbEujgxmol3/C1OE1oYrDFDeMULMTEobvvgdDxuAjoeEXq53nn1Y9MJsogf bLEnfMcNwyvX5V2DGes2PQenhJUzzIPDothujvQYQnmRg/TmQ+/RFTTnTTaQ6D8kIkI8 W0eA== MIME-Version: 1.0 X-Received: by 10.229.198.2 with SMTP id em2mr25059252qcb.21.1400338173323; Sat, 17 May 2014 07:49:33 -0700 (PDT) Sender: adrian.chadd@gmail.com Received: by 10.224.191.201 with HTTP; Sat, 17 May 2014 07:49:33 -0700 (PDT) In-Reply-To: <080FBD5B7A09F845842100A6DE79623346F2EB44@BRN1WNEXMBX01.vcorp.ad.vrsn.com> References: <080FBD5B7A09F845842100A6DE79623346F2EB44@BRN1WNEXMBX01.vcorp.ad.vrsn.com> Date: Sat, 17 May 2014 07:49:33 -0700 X-Google-Sender-Auth: ojuNHsG-CKArJNxHqN1db7oeaK4 Message-ID: Subject: Re: [rfc] tcp timer update for RSS From: Adrian Chadd To: "Bentkofsky, Michael" Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: "freebsd-net@freebsd.org" X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 17 May 2014 14:49:34 -0000 On 17 May 2014 07:44, Bentkofsky, Michael wrote: > Hi Adrian, > > > > I haven=E2=80=99t had the chance to look this over carefully yet as we=E2= =80=99re at BSDCan. > I think I understand what you=E2=80=99re trying to achieve by aligning th= e per-CPU > timer processing per core. In principal that sounds reasonable, although = I > am unsure if you were trying to solve a particular performance issue with > this particular change. My sense is this is all preparatory with the goal= of > all inp processing to become per core. Could you comment on the general > evolution you=E2=80=99re considering? Do most of the PCB structures becom= e per-core, > as in PCB groups? > > > > If you=E2=80=99d like us to test this change, I=E2=80=99m happy to do so.= At the moment I > don=E2=80=99t know if we=E2=80=99d expect to see any benefit =E2=80=93 do= you have any traffic > conditions for which this showed any difference? But we can certainly dri= ve > many hundreds of thousands of connections at reasonably high connection > rates if that will help. Hi! Yes, the aim is to provide RSS support in the RSS model of "align everything to a specific core." The goal for RSS is to remove both lock contention between cores and keep data CPU/cache local to improve efficiency there. There's nothing obvious that'll be beneficial right now. The items at https://wiki.freebsd.org/NetworkRSS have to occur before it is beneficial to anyone. -a