----- Original Message ----- > From: "Andi Kleen" <a...@firstfloor.org> > To: "Mathieu Desnoyers" <mathieu.desnoy...@efficios.com> > Cc: "Andi Kleen" <a...@firstfloor.org>, "Steven Rostedt" > <rost...@goodmis.org>, "Frank Ch. Eigler" <f...@redhat.com>, > linux-kernel@vger.kernel.org, "Ingo Molnar" <mi...@kernel.org>, "Frederic > Weisbecker" <fweis...@gmail.com>, "Andrew > Morton" <a...@linux-foundation.org>, "Johannes Berg" > <johannes.b...@intel.com>, "Linus Torvalds" > <torva...@linux-foundation.org>, "Peter Zijlstra" <pet...@infradead.org>, > "Thomas Gleixner" <t...@linutronix.de>, > "Greg Kroah-Hartman" <gre...@linuxfoundation.org>, "lttng-dev" > <lttng-...@lists.lttng.org>, "Rusty Russell" > <ru...@rustcorp.com.au> > Sent: Wednesday, March 12, 2014 11:15:01 PM > Subject: Re: [for-next][PATCH 08/20] tracing: Warn if a tracepoint is not set > via debugfs > > On Wed, Mar 12, 2014 at 08:47:07PM +0000, Mathieu Desnoyers wrote: > > ----- Original Message ----- > > > From: "Andi Kleen" <a...@firstfloor.org> > > > To: "Mathieu Desnoyers" <mathieu.desnoy...@efficios.com> > > > Cc: "Steven Rostedt" <rost...@goodmis.org>, "Frank Ch. Eigler" > > > <f...@redhat.com>, linux-kernel@vger.kernel.org, "Ingo > > > Molnar" <mi...@kernel.org>, "Frederic Weisbecker" <fweis...@gmail.com>, > > > "Andrew Morton" <a...@linux-foundation.org>, > > > "Johannes Berg" <johannes.b...@intel.com>, "Linus Torvalds" > > > <torva...@linux-foundation.org>, "Peter Zijlstra" > > > <pet...@infradead.org>, "Thomas Gleixner" <t...@linutronix.de>, "Greg > > > Kroah-Hartman" <gre...@linuxfoundation.org>, > > > "lttng-dev" <lttng-...@lists.lttng.org>, "Rusty Russell" > > > <ru...@rustcorp.com.au>, "Andi Kleen" <a...@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. > > Ok. It uses kallsyms? That can change of course.
As I just replied to Steven, I now see that I mixed up concerns about static keys, and the prior kernel markers, with tracepoint concerns. The way they are implemented are very much different (Hey! I should know, I wrote that code some 6 years ago!) ;) > > > > > 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 ? > > Each module and the main kernel are currently LTO'ed separately. > > In theory it would be possible to change this, but likely at some > compile time cost. OK, thanks for the explanations! Mathieu > > -Andi > -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
