Re: [PATCH v3 1/6] net: pad skb data and shinfo as a whole rather than individually

[Eric Dumazet <eric.dumazet@gmail.com>]

Le mardi 31 janvier 2012 à 14:35 +0000, Ian Campbell a écrit :
> Hi Eric,
> 
> On Wed, 2012-01-25 at 13:12 +0000, Eric Dumazet wrote:
> > Le mercredi 25 janvier 2012 à 13:09 +0000, Ian Campbell a écrit :
> > 
> > > Can you elaborate on the specific benchmark you used there?
> > 
> > One machine was sending udp frames on my target (using pktgen)
> > 
> > Target was running a mono threaded udp receiver (one socket)
> 
> I've been playing with pktgen and I'm seeing more like 81,600-81,800 pps
> from a UDP transmitter, measuring on the rx side using "bwm-ng -u
> packets" and sinking the traffic with "nc -l -u -p 9 > /dev/null". The
> numbers are the same with or without this series.
> 
> You mentioned numbers in the 820pps region -- is that really kilo-pps
> (in which case I'm an order of magnitude down) or actually 820pps (in
> which case I'm somehow a couple of orders of magnitude up).
> 
> I'm using a single NIC transmitter, no delay, 1000000 clones of each skb
> and I've tried 60 and 1500 byte packets. In the 60 byte case I see more
> like 50k pps
> 
> I'm in the process of setting up a receiver with a bnx2 but in the
> meantime I feel like I'm making some obvious or fundamental flaw in my
> method...
> 
> Any tips greatly appreciated.

I confirm I reach 820.000 packets per second, on a Gigabit link.

Sender can easily reach line rate (more than 1.000.000 packets per
second)

Check how many packet drops you have on receiver ?

ifconfig eth0

or "ethtool -S eth0"