[lttng-dev] [PATCH lttng-ust] Improve tracelog handling, reduce exported functions

[Norbert Lange]

Am Do., 20. Mai 2021 um 16:19 Uhr schrieb Mathieu Desnoyers
<mathieu.desnoyers at efficios.com>:
>
> ----- On May 20, 2021, at 8:18 AM, lttng-dev lttng-dev at lists.lttng.org wrote:
>
> > Instead of creating functions for each loglevel, simply pass the
> > callback as argument.
> >
> > Further pack all preprocessor information into a struct that
> > the compiler already can prepare.
>
> This introduces an ABI break too late in the cycle.

So 2.14 would be the next chance I guess

> Also, I'm not so keen on adding an indirect call on the fast-path
> when it's not absolutely needed.

Code seems pretty similar: https://godbolt.org/z/oK1WhWqGT

> What is wrong with having one symbol per loglevel ?

Macro-magic is cumbersome to edit, more code, more relocations.

Easier to adapt aswell, could roll my own tracelog functions while
using lttng_ust__tracelog_printf (started soind that as I don't want
to link to lttng-ust.so)

Norbert