Re: [PATCH v1 5/7] docs: mark intention to deprecate TCG tracing functionality
Daniel P. Berrangé <berrange(a)redhat.com> writes:
On Wed, May 05, 2021 at 11:41:46AM +0100, Alex Bennée wrote:
>
> Alex Bennée <alex.bennee(a)linaro.org> writes:
>
> > Daniel P. Berrangé <berrange(a)redhat.com> writes:
> >
> >> On Wed, May 05, 2021 at 10:22:57AM +0100, Alex Bennée wrote:
> <snip>
> >>> +TCG introspection features
> >>> +--------------------------
> >>> +
> >>> +TCG trace-events (since 6.1)
> >>>
+''''''''''''''''''''''''''''
> >>> +
> >>> +The ability to add new TCG trace points has bit rotted and as the
> >>
> >> When you say this "has bit rotted", just how bad is the situation
?
> >>
> >> Is the TCG tracing still usable at all, or is is fully broken
> >> already ?
> >
> > Well patches 6/7 got it working for generic TCG things. I haven't been
> > able to get the architecture one working but I suspect that is some sort
> > of interaction between the per-arch trace header generation that I
> > haven't quite figured out yet.
>
> Ahh it's since 7609ffb919 (trace: fix tcg tracing build breakage) which
> limited tcg/vcpu events to the root trace-events file.
That commit is from release 2.10.0.
The other commit mentioned in patch 6 (73ff061032) is from 2.12.0.
So no one has been able to use this feature for 3+ years already.
Is it actually worth fixing and then deprecating for 2 releases before
deleting, as opposed to just deleting the broken code today on basis
that it can't have any current users ?
Well I can get it up and running with the aforementioned patches and it
seems reasonable to give some notice. I'm happy to defer to Stefan here
though as it's his sub-system.
Regards,
Daniel
--
Alex Bennée