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

Mathieu Desnoyers mathieu.desnoyers at efficios.com
Wed Mar 12 16:47:07 EDT 2014


----- Original Message -----
> From: "Andi Kleen" <andi at firstfloor.org>
> To: "Mathieu Desnoyers" <mathieu.desnoyers at efficios.com>
> Cc: "Steven Rostedt" <rostedt at goodmis.org>, "Frank Ch. Eigler" <fche at redhat.com>, linux-kernel at vger.kernel.org, "Ingo
> Molnar" <mingo at kernel.org>, "Frederic Weisbecker" <fweisbec at gmail.com>, "Andrew Morton" <akpm at linux-foundation.org>,
> "Johannes Berg" <johannes.berg at intel.com>, "Linus Torvalds" <torvalds at linux-foundation.org>, "Peter Zijlstra"
> <peterz at infradead.org>, "Thomas Gleixner" <tglx at linutronix.de>, "Greg Kroah-Hartman" <gregkh at linuxfoundation.org>,
> "lttng-dev" <lttng-dev at lists.lttng.org>, "Rusty Russell" <rusty at rustcorp.com.au>, "Andi Kleen" <andi at firstfloor.org>
> 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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