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* [dpdk-users] mlx5 / tcpdump: packet drop
@ 2020-07-23 21:10 PATRICK KEROULAS
  2020-07-23 23:57 ` Stephen Hemminger
  0 siblings, 1 reply; 3+ messages in thread
From: PATRICK KEROULAS @ 2020-07-23 21:10 UTC (permalink / raw)
  To: users

Hello,

I'm trying to use tcpdump with dpdk support in order to benefit from
dpdk performance and nice features from tcpdump, like filters etc.
Traffic is constant but quite significant, 6 Gbps, captured by Mellanox
ConnectX-5.

DPDK standalone works like a charm, no packet drop.
$ testpmd -w 0000:01:00.0 -w 0000:01:00.1 -- --enable-rx-timestamp
$ dpdk-pdump -- --pdump 'port=0,queue=*,rx-dev=/tmp/test.pcap'

However,when using libpcap/tcpdump on exact same hardware and
dpdk version, 15% of the pkts are dropped by interface:
$ DPDK_CFG="-dlibrte_mempool_ring.so -dlibrte_common_mlx5.so \
    -dlibrte_pmd_mlx5.so " ./tcpdump -i dpdk:0 -w /tmp/test.pcap
[...]
tcpdump: listening on dpdk:0, link-type EN10MB (Ethernet), snapshot
length 262144 bytes
t
^CUSER1: portid:0, RX-packets: 3778136     RX-errors:  0
RX-bytes:  4767864278  RX-Imissed:  215784
USER1: portid:0, RX-PPS: 613698     RX-Mbps: 6195.72
3778136 packets captured
3778136 packets received by filter
0 packets dropped by kernel
215784 packets dropped by interface

What should I look at first? mempool, queue, dev init sequence?

dpdk v20.05
libpcap 1.8.1

Best regards,

Patrick

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [dpdk-users] mlx5 / tcpdump: packet drop
  2020-07-23 21:10 [dpdk-users] mlx5 / tcpdump: packet drop PATRICK KEROULAS
@ 2020-07-23 23:57 ` Stephen Hemminger
  2020-07-24 13:32   ` PATRICK KEROULAS
  0 siblings, 1 reply; 3+ messages in thread
From: Stephen Hemminger @ 2020-07-23 23:57 UTC (permalink / raw)
  To: PATRICK KEROULAS; +Cc: users

On Thu, 23 Jul 2020 17:10:31 -0400
PATRICK KEROULAS <patrick.keroulas@radio-canada.ca> wrote:

> Hello,
> 
> I'm trying to use tcpdump with dpdk support in order to benefit from
> dpdk performance and nice features from tcpdump, like filters etc.
> Traffic is constant but quite significant, 6 Gbps, captured by Mellanox
> ConnectX-5.
> 
> DPDK standalone works like a charm, no packet drop.
> $ testpmd -w 0000:01:00.0 -w 0000:01:00.1 -- --enable-rx-timestamp
> $ dpdk-pdump -- --pdump 'port=0,queue=*,rx-dev=/tmp/test.pcap'
> 
> However,when using libpcap/tcpdump on exact same hardware and
> dpdk version, 15% of the pkts are dropped by interface:

The libpcap version of packet capture has many copies, and lots
of extra system calls. The performance is likely to be less than doing
a native solution with the kernel.

It may get better in the future.

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [dpdk-users] mlx5 / tcpdump: packet drop
  2020-07-23 23:57 ` Stephen Hemminger
@ 2020-07-24 13:32   ` PATRICK KEROULAS
  0 siblings, 0 replies; 3+ messages in thread
From: PATRICK KEROULAS @ 2020-07-24 13:32 UTC (permalink / raw)
  To: Stephen Hemminger; +Cc: users

> The libpcap version of packet capture has many copies, and lots
> of extra system calls. The performance is likely to be less than doing
> a native solution with the kernel.
>
> It may get better in the future.

OK.
Then, I'll evaluate this one: https://github.com/marty90/DPDK-Dump
Thanks,
PK

^ permalink raw reply	[flat|nested] 3+ messages in thread

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Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2020-07-23 21:10 [dpdk-users] mlx5 / tcpdump: packet drop PATRICK KEROULAS
2020-07-23 23:57 ` Stephen Hemminger
2020-07-24 13:32   ` PATRICK KEROULAS

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