From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Greear Subject: Re: [net-next PATCH] pktgen: add flag NO_TIMESTAMP to disable timestamping Date: Wed, 01 Apr 2015 09:48:56 -0700 Message-ID: <551C2178.9070000@candelatech.com> References: <20140828161447.6652.59388.stgit@dragon> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: "David S. Miller" , netdev@vger.kernel.org, Robert Olsson To: Jesper Dangaard Brouer Return-path: Received: from mail2.candelatech.com ([208.74.158.173]:50252 "EHLO mail2.candelatech.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752042AbbDAQs5 (ORCPT ); Wed, 1 Apr 2015 12:48:57 -0400 In-Reply-To: <20140828161447.6652.59388.stgit@dragon> Sender: netdev-owner@vger.kernel.org List-ID: On 08/28/2014 09:14 AM, Jesper Dangaard Brouer wrote: > Then testing the TX limits of the stack, then it is useful to > be-able to disable the do_gettimeofday() timetamping on every packet. > > This implements a pktgen flag NO_TIMESTAMP which will disable this > call to do_gettimeofday(). > > The performance change on (my system E5-2695) with skb_clone=0, goes > from TX 2,423,751 pps to 2,567,165 pps with flag NO_TIMESTAMP. Thus, > the cost of do_gettimeofday() or saving is approx 23 nanosec. > > Signed-off-by: Jesper Dangaard Brouer > + else if (strcmp(f, "NO_TIMESTAMP") == 0) > + pkt_dev->flags |= F_NO_TIMESTAMP; > + While porting pktgen changes into my own modified pktgen logic, I noticed that there is no handling for !NO_TIMESTAMP, so it seems you cannot disable this once it is enabled? Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com