From owner-freebsd-net@FreeBSD.ORG Fri Aug 16 17:06:24 2013 Return-Path: Delivered-To: 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 ESMTP id F36C479B; Fri, 16 Aug 2013 17:06:23 +0000 (UTC) (envelope-from rizzo.unipi@gmail.com) Received: from mail-la0-x22d.google.com (mail-la0-x22d.google.com [IPv6:2a00:1450:4010:c03::22d]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id C11782494; Fri, 16 Aug 2013 17:06:22 +0000 (UTC) Received: by mail-la0-f45.google.com with SMTP id eh20so1678267lab.18 for ; Fri, 16 Aug 2013 10:06:20 -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; bh=XOdkJtOatgfP643zGiwSeS5LXtbY1VR6D1DYweeYWdo=; b=ZMF/1mizW2UjfEmcUdd6QQ/NNaTGLnDI8LwFJoEBtzGzDg6Xvrfs/h3u3Y4ovJEm+6 i464HAWlPzrvswPecUipha860bN/q5zYplLCkPT9WoG0v/2mTTxXwWVaWZ7F7MOkLs1t QFIQ/GBrR3kNNd3SmJDDRdupsRLt0Oajs9aPHo5BJFkXBUotQWSbsmEZP6d4MNU2Z61r TACYcmOR/92nWR7ABhkuwHqZfxYmXA1qqGayDjG3LsVvPAthEcfiPI+IN2jDeEQ2eLP7 YMszodLuGH5JR3rQ14bpPCm1bUXIz+OfjiLujFOJLTiU84Wf5S2cuPcLO1n8SuqYLAOL cotw== MIME-Version: 1.0 X-Received: by 10.112.0.173 with SMTP id 13mr3063592lbf.8.1376672780437; Fri, 16 Aug 2013 10:06:20 -0700 (PDT) Sender: rizzo.unipi@gmail.com Received: by 10.114.200.165 with HTTP; Fri, 16 Aug 2013 10:06:20 -0700 (PDT) In-Reply-To: References: <520A6D07.5080106@freebsd.org> <520AFBE8.1090109@freebsd.org> <520B24A0.4000706@freebsd.org> <520B3056.1000804@freebsd.org> <20130814102109.GA63246@onelab2.iet.unipi.it> <587579055.20130814154713@serebryakov.spb.ru> Date: Fri, 16 Aug 2013 19:06:20 +0200 X-Google-Sender-Auth: 0EcKRT-rFCN6SMjG8QK0FyHc4Co Message-ID: Subject: Re: it's the output, not ack coalescing (Re: TSO and FreeBSD vs Linux) From: Luigi Rizzo To: Adrian Chadd Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.14 Cc: Lawrence Stewart , Lev Serebryakov , FreeBSD Net , Vijay Singh X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 16 Aug 2013 17:06:24 -0000 the usenix paper and talk https://www.usenix.org/conference/usenixfederatedconferencesweek/netmap-novel-framework-fast-packet-io should give a short description of what i did. Basically i manually insert returns (and free mbufs and resources) in some place in the path and then compute the time consumed by the code as the inverse of the average pps over 0.1 .. 1s intervals. By moving the point where i place the return, i can estimate the cost of the various sections of code involved. cheers luigi On Fri, Aug 16, 2013 at 6:59 PM, Adrian Chadd wrote: > Luigi, > > Did you ever publish your patches or methodology for doing sampling? > > > > -adrian > > > On 14 August 2013 21:00, Vijay Singh wrote: > >> Is that what FLOWTABLE does? Also we need a mechanism to record time >> spent at various layers in the stack. Luigi has used his own methods but >> we're lacking something more generic. At work we have some crude tools that >> use mcount information to indirectly measure costs but they are not >> reliable and only provide partial information. >> >> Sent from my iPhone >> >> On Aug 14, 2013, at 11:11 AM, Adrian Chadd wrote: >> >> > On 14 August 2013 04:47, Lev Serebryakov wrote: >> > >> > >> >> And we should invalidate this info on ARP/route changes, or connection >> >> will be lost in such cases, am I right?.. So, on each such event code >> >> should look into all sockets and check, if routing/ARP information is >> >> still >> >> valid for them. Or we should store lists of sockets in routing and ARP >> >> tables... I don't know, what is worse. >> > >> > .. or per-CPU copies of the ARP table.. ? >> > >> > >> > >> > -adrian >> > _______________________________________________ >> > freebsd-net@freebsd.org mailing list >> > http://lists.freebsd.org/mailman/listinfo/freebsd-net >> > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org" >> > > -- -----------------------------------------+------------------------------- Prof. Luigi RIZZO, rizzo@iet.unipi.it . Dip. di Ing. dell'Informazione http://www.iet.unipi.it/~luigi/ . Universita` di Pisa TEL +39-050-2211611 . via Diotisalvi 2 Mobile +39-338-6809875 . 56122 PISA (Italy) -----------------------------------------+-------------------------------