From owner-freebsd-net@FreeBSD.ORG Thu May 24 22:55:16 2012 Return-Path: Delivered-To: net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 28805106566C for ; Thu, 24 May 2012 22:55:16 +0000 (UTC) (envelope-from kob6558@gmail.com) Received: from mail-wg0-f50.google.com (mail-wg0-f50.google.com [74.125.82.50]) by mx1.freebsd.org (Postfix) with ESMTP id B3BF68FC0C for ; Thu, 24 May 2012 22:55:15 +0000 (UTC) Received: by wgbds11 with SMTP id ds11so289250wgb.31 for ; Thu, 24 May 2012 15:55:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:date:message-id:subject:from:to:content-type; bh=kA5lVNqxAyttO1VHCNb+H1lJPqjxEE0CQfhWsxyx9II=; b=QsbXx2LRjqMUczfo9adTvH9KvncAdsldbVhIiTF+ubfHVLWcXXCJ1Pletth0f5uNgT pqCX2+LGJiddhyomezo7NrG1d7oZaSqTTU04KET/Jug4AFEyUk89bST2lkSflOt2hG1A aFDGYBGYvOqRJC6YhE6SdFc1QCrgz5mjIHaOe1F6uoUEI9n7yMg78Ns7wCVjGa44TkWY SpCeMjBuibtaeZv8KdTeSX0YH3UdrvlUnXFl/kCz2K6gRwL9DuJxddJyAvMlJOdKF+9Y fRkL0o5ZN8pQZuycsu7NLJZYQvkXJN2Lgki5cHQuPoYeZz6ivuRQOinn7SqPrBK06IPv xOaA== MIME-Version: 1.0 Received: by 10.216.134.145 with SMTP id s17mr588859wei.22.1337900114545; Thu, 24 May 2012 15:55:14 -0700 (PDT) Received: by 10.223.155.4 with HTTP; Thu, 24 May 2012 15:55:14 -0700 (PDT) Date: Thu, 24 May 2012 15:55:14 -0700 Message-ID: From: Kevin Oberman To: net@freebsd.org Content-Type: text/plain; charset=ISO-8859-1 Cc: Subject: Major performance hit with ToS setting 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: Thu, 24 May 2012 22:55:16 -0000 When we set the ToS bits for less than best effort (also called scavenger) on packets (ToS=32), performance on FreeBSD 8.2 is terrible. It was as good as best effort on FreeBSD 7.3 (assuming no congestion). I will look into what 9 does, but does anyone have an idea of why 8.2 behaves so badly when ToS is set to 32? Here is an example of what happens to performance: nuttcp with ToS=0: 622.5000 MB / 1.00 sec = 5221.7570 Mbps 623.3125 MB / 1.00 sec = 5228.5883 Mbps 624.0000 MB / 1.00 sec = 5234.4495 Mbps With ToS=32 (0x20): 0.3750 MB / 1.00 sec = 3.1457 Mbps 0.5000 MB / 1.00 sec = 4.1942 Mbps 0.5000 MB / 1.00 sec = 4.1942 Mbps This is,of course, on a 10G interface. On 7.3 there is little difference between the two. We are using cubic CC on the 8.2 system. -- R. Kevin Oberman, Network Engineer E-mail: kob6558@gmail.com