Re: [dpdk-dev] [RFC 0/8] eal: dynamic logs

[Thomas Monjalon <thomas.monjalon@6wind.com>]

2017-02-06 14:29, Olivier Matz:
> The objective of this RFC patchset is to introduce a framework to
> support dynamic log types in EAL. It also provides one example of use
> (in i40e).
> 
> Features:
> - log types are identified by a string
> - at registration, a uniq identifier is associated to a log type
> - each log type can have its level changed dynamically
> - extend command line parameters to set the log level of a specific
>   type, or logs matching a regular expression
> - keep compat with other legacy types (eal, malloc, ring, user*,
>   etc... keep their hardcoded log type value)
> 
> At the end, when, we can expect that all non-dataplane logs are moved to
> be dynamic, so we can enable/disable them at runtime, without
> recompiling. Many debug options can probably be removed from
> configuration:
>   $ git grep DEBUG config/common_base | wc -l
>   89

I think it would be a very nice cleanup and usability improvement.

It seems that everybody agrees that dynamic logging config is better.
There were 2 comments that I want to sum up here:

1/ Why not use an external log library?

It is not obvious that there is a real benefit to use another system.
And Olivier already wrote the code for this system.
If someone writes the integration of another log system, we could
consider it.

2/ Why filtering by log type instead of file/function?

File/function filtering targets DPDK debug use cases.
For application developers or system integrators, the log type seems
a good level of abstraction for logging part of the system.
Anyway, the file/function filtering could be added later if
someone integrates it in the dynamic logging configuration system.

The conclusion is that this series seems good to integrate.
As it is a RFC, do you plan to send a refresh or can we merge it as is?