From owner-freebsd-net@freebsd.org Tue Nov 7 17:29:49 2017 Return-Path: Delivered-To: freebsd-net@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id E34ABE5ECCB for ; Tue, 7 Nov 2017 17:29:49 +0000 (UTC) (envelope-from v.maffione@gmail.com) Received: from mail-it0-x234.google.com (mail-it0-x234.google.com [IPv6:2607:f8b0:4001:c0b::234]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id A9FA57906E for ; Tue, 7 Nov 2017 17:29:49 +0000 (UTC) (envelope-from v.maffione@gmail.com) Received: by mail-it0-x234.google.com with SMTP id f187so3400543itb.1 for ; Tue, 07 Nov 2017 09:29:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=s2qWDL4DET0mFk2PfISh6sUoCx04+IG2HMUToQhPNpk=; b=p4siHjEnEJOHND3Bp0qhZBcqZUfOG773iFGLGx6aD1gySMIhhFOp2UyT8CMJ89H0tw iOPwBEmG4n1SsmlbAUrmfc/lZDgGta7zzYko0nlmgnFt3jtgTRqTWFqwhhM6GLuZYFds ENGctPq+yxrjd6iHhYks678loMk8L20sY0eF1g8GttrQ5h0R2O8Jy7NOkfCxP4p0Lwc8 m5zMOqspkqvNlAkRcrhuN6c5cmK2eLpV3I2RhQnIuuguZoSICSgLz1lTNT7xNDDD+0kV CDLmqd3RiBknDLzRHTcsKTAS6NlIXYdEsqdCYlGghYUKcez8O7ITvFGm6YgtY/HGdxD9 BBmA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=s2qWDL4DET0mFk2PfISh6sUoCx04+IG2HMUToQhPNpk=; b=Zird6NwY4Z4Sdyf2k4p2xKP0kn/ZvM9AjraGsMWJmrA2yeYPKIFolbdO3yJ8OAGrQR 3l5USWKQrOYaWUYVI64cnB2dqfjPtvgtt/Ps2tA9rRmoLh9DaU15aH3t2y4Rw2bWA7O1 i3REhmh9HOjXN8LsiR9M22KV4jNWz+OdBmsFo4mwWVmJGnKaOp87ZDkHTEbiT80oTEaG CVAiIY29soqMF27oPLOBjWzVYlK53Sc0luNZhmL4NI7aq5ef0ZsptowW9WzB143/2WKZ 6twR30mbUh3w9wguu+oTQn5gf327EH4plaY2a2Ouf9x7Tam1dJLTrzOyuNjbtKJld3xc HVsA== X-Gm-Message-State: AJaThX7iZrJQZB/1+C1DH/wMwQ1MkJb0FZmtPAAJXgMrlOCvI+mEOwD0 x5sMHsphf6NNnfjILUvJVUek0WEe4z18gpJXjUw= X-Google-Smtp-Source: ABhQp+RAVN7JV6n/WWDWli7rBoN7guL/OlIWY4XaMklNAguSWCLtigmFj1wX+KLqtKCATS27bZwXXfE/YGleq9EVREM= X-Received: by 10.36.85.139 with SMTP id e133mr3083495itb.147.1510075788856; Tue, 07 Nov 2017 09:29:48 -0800 (PST) MIME-Version: 1.0 Received: by 10.2.176.143 with HTTP; Tue, 7 Nov 2017 09:29:48 -0800 (PST) In-Reply-To: <5A01EC84.80703@cox.net> References: <59F0FBEE.6030008@cox.net> <59F1F1BA.3020608@cox.net> <59F214F6.9060905@cox.net> <59F223C3.5040907@cox.net> <5A01EC84.80703@cox.net> From: Vincenzo Maffione Date: Tue, 7 Nov 2017 18:29:48 +0100 Message-ID: Subject: Re: virtio_net / netmap RX dropping frames To: Joe Buehler Cc: FreeBSD Net Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.23 X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.23 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, 07 Nov 2017 17:29:50 -0000 I understand. My point was simply to make sure your performance problems here are not netmap's fault. Cheers, Vincenzo 2017-11-07 18:25 GMT+01:00 Joe Buehler : > I believe the frame drop is due to the nature of my KVM setup. There > are large latencies in processing incoming frames due to the vagaries of > the LINUX kernel. Moving to the RT kernel helped, host tuning is also > needed to eliminate large latencies in processing frames. There is good > information on real-time KVM on the net that explains how to achieve > what I want. > > Joe Buehler > > -- Vincenzo Maffione