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

[Jerin Jacob]

> > >
> > > 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.

>
> > i.e
> >
> > 1) Each log/trace has a  "level"
> > 2) There is a global level. See [1]
> > 3) The trace will be emitted when
> > a) When it is enabled(not applicable for log as it is always enabled)
> > AND
> > b) it is less than the global level.
>
> When it is less than both global and logtype level.
> See rte_log_can_log().

OK.

>
> The global level is just disabling some logs even if it is enabled
> in the logtype level.
> It only makes usage complicate.
> We should consider only logtype levels.

OK.  Do we care about the following use case?
# Trace only specific types of events(example, DEBUG or CRITICAL)?

IF NOT,

There is no need for,
# rte_trace_global_* API
# No need to introduce trace type(ie DEBUG or CRITICAL) i.e remove
rte_trace_level_set() API etc


# In summary:
~~~~~~~~~~~~~
# In the existing code:
The trace will be emitted when
 a) When the trace is enabled
 AND
b) trace level than the global level.

# in new suggestion
The trace will be emitted when
 a) When it is enabled

And the EAL argument will be --trace=regex/globbing, This EAL argument
will call rte_trace_regexp() and enable the selected tracepoints.

The downside will be it will not be similar to log API. I am fine with
either way.

@Mattias Rönnblom, Do you have any thoughts as you spend some time
reviewing the public API.

Thoughts in general?