From: Jesper Dangaard Brouer <brouer@redhat•com>
To: Eric Dumazet <eric.dumazet@gmail•com>
Cc: "David S. Miller" <davem@davemloft•net>,
netdev@vger•kernel.org, Ben Greear <greearb@candelatech•com>,
Robert Olsson <robert@herjulf•se>,
brouer@redhat•com
Subject: Re: [net-next PATCH] pktgen: add flag NO_TIMESTAMP to disable timestamping
Date: Fri, 29 Aug 2014 21:02:54 +0200 [thread overview]
Message-ID: <20140829210254.360f74bf@redhat.com> (raw)
In-Reply-To: <1409329026.3173.93.camel@edumazet-glaptop2.roam.corp.google.com>
On Fri, 29 Aug 2014 09:17:06 -0700
Eric Dumazet <eric.dumazet@gmail•com> wrote:
> On Thu, 2014-08-28 at 18:14 +0200, 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.
>
> I guess using local_clock() would provide an accurate and less expensive
> timestamp, if a timestamp is needed.
Sure, but I don't need this timestamp, thus I added an option to disable it.
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Sr. Network Kernel Developer at Red Hat
Author of http://www.iptv-analyzer.org
LinkedIn: http://www.linkedin.com/in/brouer
next prev parent reply other threads:[~2014-08-29 19:03 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-28 16:14 [net-next PATCH] pktgen: add flag NO_TIMESTAMP to disable timestamping Jesper Dangaard Brouer
2014-08-29 16:17 ` Eric Dumazet
2014-08-29 19:02 ` Jesper Dangaard Brouer [this message]
2014-09-02 1:07 ` David Miller
2015-04-01 16:48 ` Ben Greear
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