[PATCH] trace: take live traces via telemetry

[Bruce Richardson]

On Tue, Oct 18, 2022 at 04:33:49PM +0200, Morten Brørup wrote:
> > From: David Marchand [mailto:david.marchand at redhat.com]
> > Sent: Thursday, 13 October 2022 09.49
> > 
> > Register telemetry commands to list and configure trace points and
> > later
> > save traces for a running DPDK application.
> > 
> > Note: trace point names contain a '.', so the list of valid characters
> > used in telemetry commands and dictionary keys has been extended.
> 
> Regarding '.' in telemetry commands and dictionary keys, I agree with Bruce to allow it.
> 
> > 
> > Example with testpmd running with two net/null ports (startup command
> > from devtools/test-null.sh):
> > 
> > --> /trace/list,lib.ethdev.*
> > {"/trace/list": {"lib.ethdev.configure": "Disabled",
> >     "lib.ethdev.rxq.setup": "Disabled",
> >     "lib.ethdev.txq.setup": "Disabled",
> >     "lib.ethdev.start": "Disabled",
> >     "lib.ethdev.stop": "Disabled",
> >     "lib.ethdev.close": "Disabled",
> >     "lib.ethdev.rx.burst": "Disabled",
> >     "lib.ethdev.tx.burst": "Disabled"}}
> 
> Jerin commented that "Disabled"/"Enabled" are a bit verbose, and suggested shortening them.
> 
> It seems to me that these values are Boolean, and should be true or false (not surrounded by quotation marks), instead of some string representing a Boolean value. Note: This would require expanding the telemetry library with a Boolean type.
> 
> Alternatively, use integer values 0 or 1.
> 
> If we want to represent Boolean values as strings, I vote for "TRUE" and "FALSE", using all upper case to indicate that they are magic strings - and also to help avoid confusion with the JSON true/false Boolean values, which are all lower case.

+1 for integer values (at least in the short term). I don't think we want
these as strings.

/Bruce