Re: [RFC PATCH 2/3] tracing: Introduce "rel_stack" option

[Masami Hiramatsu (Google) <mhiramat@kernel.org>]

On Tue, 28 Jan 2025 11:07:00 -0500
Steven Rostedt <rostedt@goodmis.org> wrote:

> On Wed, 29 Jan 2025 00:37:15 +0900
> "Masami Hiramatsu (Google)" <mhiramat@kernel.org> wrote:
> 
> > From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> > 
> > Since the relative offset stacktrace requires a special module loading
> > events to decode binary, it should be an optional for normal use case.
> > User can enable this feature via `options/relative-stacktrace`.
> > 
> 
> Let's make this an entirely new event and not based on an option. Reason
> being, there's no way for libtraceevent to know which this is. We could
> even have a mixture of these in the trace.
> 
> Instead of an option, we can add a new trigger: stacktrace_rel that will do
> a relative stack trace. And the event can be kernel_stack_rel
> 
> Then it can be enabled via:
> 
>   echo 'stacktrace_rel if prev_state & 3' > events/sched/sched_switch/trigger

Oh, I thought this was another feature, adding a new trigger action.
Can't we do this with the event defined by FTRACE_ENTRY_DUP()?

Thank you,

> 
> -- Steve


-- 
Masami Hiramatsu (Google) <mhiramat@kernel.org>