Re: [PATCH v2 0/3] logging enhancements

[Thomas Monjalon <thomas@monjalon.net>]

23/02/2018 22:17, Stephen Hemminger:
> The current dynamic logging has some awkward user interface choices.
> It uses integers for log levels which requires user to know the
> mapping between numeric and symbolic values.
> 
> A bigger problem was the choice of regular expressions and option
> format for dynamic logging. Dynamic log names are seperated with
> a period and the wildcard character for regular expressions is
> a period. It is just a happy accident the expressions like:
>         "pmd.net.virtio.*"
> work as expected. This patch set adds a more usable solution
> with filename style matching.
> 
> Also, the choice of comma as seperator for log-level option was
> not consistent with other options. For other options, comma is
> used to seperate list of equal values as in:
>         -l 1,2,3
> Since new match required a backwards compatiable option the
> colon is now used to seperate name and value.
> 
> So:
>         --log-level='pmd.net.virtio.*,7'
> still works as expected. But the prefered syntax is:
>         --log-level='pmd.net.virtio.*:info'

+1
This syntax looks better.

> If this is accepted, I think we should mark the old regex style
> matching as deprecated and remove it in 18.11??

Good question. Do we want to deprecate the regex style?

> Also, the dynamic log level pattern stuff is not adaquately
> documented right now. There are only a couple of vague references
> in the current documentation (which this updates).

I think you should document the symbolic log levels in the guide
and in the --help.