[dpdk-dev] [PATCH v4 00/33] DPDK Trace support

[Jerin Jacob]

On Thu, Apr 9, 2020 at 11:57 PM Jerin Jacob <jerinjacobk at gmail.com> wrote:
>
> > > >
> > > > They are setting levels with regex or globbing.
> > > > --log-level supports 3 syntaxes today:
> > > >         - int (global level)
> > > >         - globbing:int
> > > >         - regex,int
> > >
> > > Here is my understanding.
> > >
> > > IMO, Actual Syntax is
> > >          - int (global level)
> > >          - globbing: int (global level)
> > >          - regex: int (global level)
> >
> > The level apply to the logs matching the pattern (globbing or regex)
> > so I don't understand why you call it "global".
>
> What I meant is, if there is no global, what is the point of changing
> the trace level with EAL command-line argument with globbing and regex.

Self reply on this:

I understood where is the disconnect is:

In case of log:
~~~~~~~~~~~
It will be printed when:
a) When it is less than both the "global" and "log level"

NOTE: in case of log, log level passed on to log function (see
rte_log(uint32_t level..)

In case of trace:
~~~~~~~~~~~~
it will be emitted when:
a) The trace is enabled (rte_trace_enable() called on the tracepoint)
b) When it is less than the global level.

NOTE: in case of trace, Nothing like log level passed to trace emit
function. The control lies with a slow path enable/disable
decision(item (a)) due to performance requirements
to instrumentation overhead.