Re: [for-next][PATCH 08/20] tracing: Warn if a tracepoint is not set via debugfs

From: Mathieu Desnoyers
Date: Wed Mar 12 2014 - 16:47:14 EST


----- Original Message -----
> From: "Andi Kleen" <andi@xxxxxxxxxxxxxx>
> To: "Mathieu Desnoyers" <mathieu.desnoyers@xxxxxxxxxxxx>
> Cc: "Steven Rostedt" <rostedt@xxxxxxxxxxx>, "Frank Ch. Eigler" <fche@xxxxxxxxxx>, linux-kernel@xxxxxxxxxxxxxxx, "Ingo
> Molnar" <mingo@xxxxxxxxxx>, "Frederic Weisbecker" <fweisbec@xxxxxxxxx>, "Andrew Morton" <akpm@xxxxxxxxxxxxxxxxxxxx>,
> "Johannes Berg" <johannes.berg@xxxxxxxxx>, "Linus Torvalds" <torvalds@xxxxxxxxxxxxxxxxxxxx>, "Peter Zijlstra"
> <peterz@xxxxxxxxxxxxx>, "Thomas Gleixner" <tglx@xxxxxxxxxxxxx>, "Greg Kroah-Hartman" <gregkh@xxxxxxxxxxxxxxxxxxx>,
> "lttng-dev" <lttng-dev@xxxxxxxxxxxxxxx>, "Rusty Russell" <rusty@xxxxxxxxxxxxxxx>, "Andi Kleen" <andi@xxxxxxxxxxxxxx>
> Sent: Wednesday, March 12, 2014 4:35:15 PM
> Subject: Re: [for-next][PATCH 08/20] tracing: Warn if a tracepoint is not set via debugfs
>
> > So I understand that you wish to banish tracepoints from static inline
> > functions within headers to ensure they only appear within a single module.
> > This seems to be a step backward, but let's assume we stick to that rule.
> > Then how do you envision dealing with Link-Time Optimisations (LTO) ?
>
> I assume it uses the file name defines set by Kbuild?

Just to make sure I understand your question: I understand that you are asking
whether tracepoints use file name defines at all in the naming of a tracepoint.
The answer to this question is: No, they do not.

> These don't change with
> LTO. It's whatever was specified at compile time. Also LTO doesn't
> inline over module boundaries (if the module is not built in)

Good to know. Can it inline core kernel functions into a module ?

Thanks,

Mathieu

>
> -Andi
>

--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
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