From: Jesper Dangaard Brouer <brouer@redhat•com>
To: "Md. Islam" <mislam4@kent•edu>
Cc: netdev@vger•kernel.org, David Miller <davem@davemloft•net>,
David Ahern <dsahern@gmail•com>,
stephen@networkplumber•org, agaceph@gmail•com,
Pavel Emelyanov <xemul@openvz•org>,
Eric Dumazet <edumazet@google•com>,
alexei.starovoitov@gmail•com, brouer@redhat•com
Subject: Re: [PATCH v15 ] net/veth/XDP: Line-rate packet forwarding in kernel
Date: Wed, 4 Apr 2018 08:16:04 +0200 [thread overview]
Message-ID: <20180404081604.422e8a97@redhat.com> (raw)
In-Reply-To: <CAFgPn1DX9cOpDRGj=wFwvZq_bpq6VFnEOzR1YbMuC0+=DFEWxA@mail.gmail.com>
On Sun, 1 Apr 2018 20:47:28 -0400 Md. Islam" <mislam4@kent•edu> wrote:
> [...] More specifically, header parsing and fib
> lookup only takes around 82 ns. This shows that this could be used to
> implement linerate packet forwarding in kernel.
I cannot resist correcting you...
You didn't specify the link speed, but assuming 10Gbit/s, then the
linerate is 14.88Mpps, which is 67.2 ns between arriving packets. Thus,
if the lookup cost is 82 ns, thus you cannot claim linerate performance
with these numbers.
Details:
This is calculated based on the the minimum Ethernet frame size
84-bytes, see https://en.wikipedia.org/wiki/Ethernet_frame for why this
is the minimum size.
10*10^9/(84*8) = 14,880,952 pps
1/last*10^9 = 67.2 ns
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer
next prev parent reply other threads:[~2018-04-04 6:16 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-02 0:47 [PATCH v15 ] net/veth/XDP: Line-rate packet forwarding in kernel Md. Islam
2018-04-02 16:51 ` Stephen Hemminger
2018-04-02 18:03 ` John Fastabend
2018-04-02 18:09 ` David Ahern
2018-04-02 18:16 ` Alexei Starovoitov
2018-04-03 15:07 ` David Ahern
2018-04-03 16:41 ` John Fastabend
2018-04-03 16:45 ` David Miller
2018-04-03 17:00 ` David Ahern
2018-04-03 17:06 ` Alexei Starovoitov
2018-04-03 17:14 ` David Ahern
2018-04-03 17:37 ` Alexei Starovoitov
2018-04-04 1:09 ` David Ahern
2018-04-03 18:21 ` Jesper Dangaard Brouer
2018-04-04 1:16 ` David Ahern
2018-04-04 3:15 ` Md. Islam
2018-04-06 2:55 ` David Ahern
2018-04-10 4:27 ` Md. Islam
2018-04-04 6:16 ` Jesper Dangaard Brouer [this message]
2018-04-04 21:09 ` Md. Islam
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