[dpdk-users] How to show debug log in DPDK and DPDK application

[Stephen Hemminger]

On Fri, 21 Dec 2018 09:48:04 +0900
Hideyuki Yamashita <yamashita.hideyuki at po.ntt-tx.co.jp> wrote:

> Hello 
> 
> I am a developer for DPDK application(SPP).
> And I have a very basic question how to debug by
> increasing log level.
> 
> Q1.Are thre any documents those describe the following?
> - how to output debug log of DPDK
> - how to output debut log of DPDK application
> 
> As I did quick search on Google, no official documents found.
> If above is yes.
> Please let me know how to achieve those.
> 
> Thanks in advance for your guidance to newbie!
> 
> BR,
> Hideyuki Yamashita
> NTT TechnoCross
> 
> 

logging in current DPDK is controlled per subsystem.

See: rte_log_set_level_pattern and rte_set_level

This can be set on command line or with API.

The default log output on DPDK is to stdout of the application.
This is not useful for a long running service like a daemon,
but the log can be captured by either opening a file and using:
 rte_openlog_stream

Or also by using glibc stdio function open_memstream to make a memory stream
and pass that. This requires a bit more setup.