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[PATCH 02/20 -v5] Add basic support for gcc profiler instrumentation

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From: Steven Rostedt <rostedt@...>
To: LKML <linux-kernel@...>
Cc: Ingo Molnar <mingo@...>, Linus Torvalds <torvalds@...>, Andrew Morton <akpm@...>, Peter Zijlstra <a.p.zijlstra@...>, Christoph Hellwig <hch@...>, Mathieu Desnoyers <mathieu.desnoyers@...>, Gregory Haskins <ghaskins@...>, Arnaldo Carvalho de Melo <acme@...>, Thomas Gleixner <tglx@...>, Tim Bird <tim.bird@...>, Sam Ravnborg <sam@...>, Frank Ch. Eigler <fche@...>, Jan Kiszka <jan.kiszka@...>, John Stultz <johnstul@...>, Arjan van de Ven <arjan@...>, Steven Rostedt <srostedt@...>
Subject: [PATCH 02/20 -v5] Add basic support for gcc profiler instrumentation
Date: Wednesday, January 23, 2008 - 12:02 pm

If CONFIG_MCOUNT is selected and /proc/sys/kernel/mcount_enabled is set to a

non-zero value the mcount routine will be called everytime we enter a kernel

function that is not marked with the "notrace" attribute.


The mcount routine will then call a registered function if a function

happens to be registered.


[This code has been highly hacked by Steven Rostedt, so don't

 blame Arnaldo for all of this ;-) ]


Update:

  It is now possible to register more than one mcount function.

  If only one mcount function is registered, that will be the

  function that mcount calls directly. If more than one function

  is registered, then mcount will call a function that will loop

  through the functions to call.


Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>

Signed-off-by: Steven Rostedt <srostedt@redhat.com>

---

 Makefile                   |    3

 arch/x86/Kconfig           |    1

 arch/x86/kernel/entry_32.S |   25 +++++++

 arch/x86/kernel/entry_64.S |   36 +++++++++++

 include/linux/linkage.h    |    2

 include/linux/mcount.h     |   38 ++++++++++++

 kernel/sysctl.c            |   11 +++

 lib/Kconfig.debug          |    2

 lib/Makefile               |    2

 lib/tracing/Kconfig        |   10 +++

 lib/tracing/Makefile       |    3

 lib/tracing/mcount.c       |  141 +++++++++++++++++++++++++++++++++++++++++++++

 12 files changed, 274 insertions(+)


Index: linux-mcount.git/Makefile

===================================================================

--- linux-mcount.git.orig/Makefile	2008-01-23 10:26:31.000000000 -0500

+++ linux-mcount.git/Makefile	2008-01-23 10:26:34.000000000 -0500

@@ -509,6 +509,9 @@ endif


 include $(srctree)/arch/$(SRCARCH)/Makefile


+ifdef CONFIG_MCOUNT

+KBUILD_CFLAGS	+= -pg

+endif

 ifdef CONFIG_FRAME_POINTER

 KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls

 else

Index: linux-mcount.git/arch/x86/Kconfig

===================================================================

--- linux-mcount.git.orig/arc...
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