From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: pktgen: tricks Date: Tue, 22 Sep 2009 22:49:02 -0700 Message-ID: <20090922224902.17ed6cc4@nehalam> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: Jesper Dangaard Brouer , Robert Olsson Return-path: Received: from mail.vyatta.com ([76.74.103.46]:43111 "EHLO mail.vyatta.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751477AbZIWFtG (ORCPT ); Wed, 23 Sep 2009 01:49:06 -0400 Sender: netdev-owner@vger.kernel.org List-ID: I thought others want to know how to get maximum speed of pktgen. 1. Run nothing else (even X11), just a command line 2. Make sure ethernet flow control is disabled ethtool -A eth0 autoneg off rx off tx off 3. Make sure clocksource is TSC. On my old SMP Opteron's needed to get patch since in 2.6.30 or later, the clock guru's decided to remove it on all non Intel machines. Look for patch than enables "tsc=reliable" 4. Compile Ethernet drivers in, the overhead of the indirect function call required for modules (or cache footprint), slows things down. 5. Increase transmit ring size to 1000 ethtool -G eth0 tx 1000 Result: OK: 70408581(c70405979+d2602) nsec, 100000000 (60byte,0frags) 1420281pps 681Mb/sec (681734880bps) errors: 0