From: Stephen Hemminger <stephen@networkplumber.org>
To: Antonio Di Bacco <a.dibacco.ks@gmail.com>
Cc: users@dpdk.org
Subject: Re: tap device speed
Date: Mon, 2 Oct 2023 14:21:33 -0700 [thread overview]
Message-ID: <20231002142133.27590624@hermes.local> (raw)
In-Reply-To: <CAO8pfFmA4-brn3zKBqxmVfauxHm+uvhFBAkxn667dgoBQX3hSg@mail.gmail.com>
On Mon, 2 Oct 2023 21:13:03 +0200
Antonio Di Bacco <a.dibacco.ks@gmail.com> wrote:
> I'm doing a test where we have a couple of tap devices, the two
> devices are seen by testpmd that is setup in forward mode.
>
> On the linux side, the two tap devices are confined in different
> network namespaces and in one namespace we have an iperf server while
> on the other namespace the iperf client sending either UDP or TCP.
>
> I expected a bandwidth in the range of few gpbs while the actual
> measured bandwidth is a few gigabits.
>
> I suppose I need to configure the tap devices with optimized
> parameters but I don't know where to look for advice.
>
> If I try to use the loopback interface I can get something 40 gbps
> with a command like this:
>
> iperf -c 127.0.0.1 -u -i 1 -b 40g -t 10 -l 40000
>
> .
Sorry TAP device is inherently slow. It requires copies to/from Linux
kernel. You are doing well if you get 1 million packets per second.
One thing to check is that checksum is not being done twice.
next prev parent reply other threads:[~2023-10-02 21:21 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-02 19:13 Antonio Di Bacco
2023-10-02 21:21 ` Stephen Hemminger [this message]
2023-10-03 8:49 ` Antonio Di Bacco
2023-10-03 16:01 ` Stephen Hemminger
2023-10-04 6:17 ` David Marchand
2023-10-04 7:08 ` Maxime Coquelin
2023-10-04 7:42 ` Antonio Di Bacco
2023-10-04 7:49 ` Maxime Coquelin
2023-10-09 17:48 ` Antonio Di Bacco
2023-10-09 18:42 ` Maxime Coquelin
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