From owner-freebsd-net@FreeBSD.ORG Tue Jul 8 16:34:50 2008 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 3CA261065678 for ; Tue, 8 Jul 2008 16:34:50 +0000 (UTC) (envelope-from artemb@gmail.com) Received: from fg-out-1718.google.com (fg-out-1718.google.com [72.14.220.157]) by mx1.freebsd.org (Postfix) with ESMTP id B37D18FC20 for ; Tue, 8 Jul 2008 16:34:49 +0000 (UTC) (envelope-from artemb@gmail.com) Received: by fg-out-1718.google.com with SMTP id l26so1416235fgb.35 for ; Tue, 08 Jul 2008 09:34:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:sender :to:subject:cc:in-reply-to:mime-version:content-type :content-transfer-encoding:content-disposition:references :x-google-sender-auth; bh=RY55Q2hmv0SnI445CM2qjgOXbNCneXIPNRw4FrxRzvE=; b=l83cC7MeBHjTtagBAR9mS2EKoyMySANrCzJyZmd0lk2g911W80yLJVK2DAi6pUwCcx he0Hx90rcVf5vBrP/rP6bCTanVeN0Y8tg8r+aHM6hStlaxNCNNwk6zubRynNuQnVEIxA VIISINgxk9+T9vGFop3oXOQH15O05NTynTg0k= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:sender:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references:x-google-sender-auth; b=PzWJru1DJ6yVRGXHbUVgoF7b1+8uppsGcCbDsYmuJZnZY+GWbUerWVKG35aBz98A6y JPxz6viCTfe52g6RD2miI7/NYW6O7MejP/YRCMYman5PwJrh5w+qdNV0PJvn0zKXRmaM mOAy/mOtzCGa3HLMeCXoyoKYU2LtfQcbMxEbk= Received: by 10.86.91.12 with SMTP id o12mr5754710fgb.1.1215534888241; Tue, 08 Jul 2008 09:34:48 -0700 (PDT) Received: by 10.86.83.19 with HTTP; Tue, 8 Jul 2008 09:34:48 -0700 (PDT) Message-ID: Date: Tue, 8 Jul 2008 09:34:48 -0700 From: "Artem Belevich" Sender: artemb@gmail.com To: "Robert Watson" In-Reply-To: <20080708085227.J31157@fledge.watson.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <4867420D.7090406@gtcomm.net> <486FFF70.3090402@gtcomm.net> <48701921.7090107@gtcomm.net> <4871E618.1080500@freebsd.org> <20080708002228.G680@besplex.bde.org> <48724238.2020103@freebsd.org> <20080708034304.R21502@delplex.bde.org> <20080708045135.V1022@besplex.bde.org> <20080708085227.J31157@fledge.watson.org> X-Google-Sender-Auth: 40aab35622524a80 Cc: FreeBSD Net Subject: Re: Freebsd IP Forwarding performance (question, and some info) [7-stable, current, em, smp] X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 08 Jul 2008 16:34:50 -0000 On 7/8/08, Robert Watson wrote: > There were some patches floating around for if_em to do a prefetch of the > first bit of packet data on packets before handing them up the stack. My I found Andre Oppermann's optimization patch mentioned in july 2005 status report: http://lists.freebsd.org/pipermail/freebsd-announce/2005-July/001012.html http://www.nrg4u.com/freebsd/tcp_reass+prefetch-20041216.patch Is that the patch you had in mind? In the report Andre says: "Use [of prefetch] in both of these places show a very significant performance gain but not yet fully quantified." "very significant" bit looks promising. Unfortunately, it does not look like prefetch changes in the patch made it into official kernel. I wonder why. It should be easy enough to apply prefetch-related changes and see if/how it affects forwarding performance. --Artem