[PATCH] perf: Enable function tracing for perf core

[PATCH] perf: Enable function tracing for perf core

[Andi Kleen]

From: Andi Kleen <ak@linux.intel.com>

According to Steven R. there is no reason left to not support
function tracing for the perf core. This makes it easier to debug
perf.

Don't remove -pg for the x86 and generic perf core.

Cc: rostedt@goodmis.org
Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
 arch/x86/kernel/cpu/Makefile |    1 -
 kernel/events/Makefile       |    4 ----
 2 files changed, 0 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index a0e067d..8eb5d28 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -5,7 +5,6 @@
 # Don't trace early stages of a secondary CPU boot
 ifdef CONFIG_FUNCTION_TRACER
 CFLAGS_REMOVE_common.o = -pg
-CFLAGS_REMOVE_perf_event.o = -pg
 endif
 
 # Make sure load_percpu_segment has no stackprotector
diff --git a/kernel/events/Makefile b/kernel/events/Makefile
index 103f5d1..a630994 100644
--- a/kernel/events/Makefile
+++ b/kernel/events/Makefile
@@ -1,7 +1,3 @@
-ifdef CONFIG_FUNCTION_TRACER
-CFLAGS_REMOVE_core.o = -pg
-endif
-
 obj-y := core.o ring_buffer.o callchain.o
 
 obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
-- 
1.7.7.6

Re: [PATCH] perf: Enable function tracing for perf core

[Andi Kleen]

Andi Kleen <andi@firstfloor.org> writes:

> From: Andi Kleen <ak@linux.intel.com>
>
> According to Steven R. there is no reason left to not support
> function tracing for the perf core. This makes it easier to debug
> perf.
>
> Don't remove -pg for the x86 and generic perf core.

Ping! patch is missing review.


>
> Cc: rostedt@goodmis.org
> Signed-off-by: Andi Kleen <ak@linux.intel.com>
> ---
>  arch/x86/kernel/cpu/Makefile |    1 -
>  kernel/events/Makefile       |    4 ----
>  2 files changed, 0 insertions(+), 5 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
> index a0e067d..8eb5d28 100644
> --- a/arch/x86/kernel/cpu/Makefile
> +++ b/arch/x86/kernel/cpu/Makefile
> @@ -5,7 +5,6 @@
>  # Don't trace early stages of a secondary CPU boot
>  ifdef CONFIG_FUNCTION_TRACER
>  CFLAGS_REMOVE_common.o = -pg
> -CFLAGS_REMOVE_perf_event.o = -pg
>  endif
>  
>  # Make sure load_percpu_segment has no stackprotector
> diff --git a/kernel/events/Makefile b/kernel/events/Makefile
> index 103f5d1..a630994 100644
> --- a/kernel/events/Makefile
> +++ b/kernel/events/Makefile
> @@ -1,7 +1,3 @@
> -ifdef CONFIG_FUNCTION_TRACER
> -CFLAGS_REMOVE_core.o = -pg
> -endif
> -
>  obj-y := core.o ring_buffer.o callchain.o
>  
>  obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o

-- 
ak@linux.intel.com -- Speaking for myself only

Re: [PATCH] perf: Enable function tracing for perf core

[Steven Rostedt]

On Thu, 2013-03-28 at 08:45 -0700, Andi Kleen wrote:
> Andi Kleen <andi@firstfloor.org> writes:
> 
> > From: Andi Kleen <ak@linux.intel.com>
> >
> > According to Steven R. there is no reason left to not support
> > function tracing for the perf core. This makes it easier to debug
> > perf.
> >
> > Don't remove -pg for the x86 and generic perf core.
> 
> Ping! patch is missing review.
> 

This needs an acked-by from either Peter or Frederic.

-- Steve

> 
> >
> > Cc: rostedt@goodmis.org
> > Signed-off-by: Andi Kleen <ak@linux.intel.com>
> > ---
> >  arch/x86/kernel/cpu/Makefile |    1 -
> >  kernel/events/Makefile       |    4 ----
> >  2 files changed, 0 insertions(+), 5 deletions(-)
> >
> > diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
> > index a0e067d..8eb5d28 100644
> > --- a/arch/x86/kernel/cpu/Makefile
> > +++ b/arch/x86/kernel/cpu/Makefile
> > @@ -5,7 +5,6 @@
> >  # Don't trace early stages of a secondary CPU boot
> >  ifdef CONFIG_FUNCTION_TRACER
> >  CFLAGS_REMOVE_common.o = -pg
> > -CFLAGS_REMOVE_perf_event.o = -pg
> >  endif
> >  
> >  # Make sure load_percpu_segment has no stackprotector
> > diff --git a/kernel/events/Makefile b/kernel/events/Makefile
> > index 103f5d1..a630994 100644
> > --- a/kernel/events/Makefile
> > +++ b/kernel/events/Makefile
> > @@ -1,7 +1,3 @@
> > -ifdef CONFIG_FUNCTION_TRACER
> > -CFLAGS_REMOVE_core.o = -pg
> > -endif
> > -
> >  obj-y := core.o ring_buffer.o callchain.o
> >  
> >  obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
> 

Re: [PATCH] perf: Enable function tracing for perf core

[Ingo Molnar]

* Steven Rostedt <rostedt@goodmis.org> wrote:

> On Thu, 2013-03-28 at 08:45 -0700, Andi Kleen wrote:
> > Andi Kleen <andi@firstfloor.org> writes:
> > 
> > > From: Andi Kleen <ak@linux.intel.com>
> > >
> > > According to Steven R. there is no reason left to not support
> > > function tracing for the perf core. This makes it easier to debug
> > > perf.
> > >
> > > Don't remove -pg for the x86 and generic perf core.
> > 
> > Ping! patch is missing review.
> > 
> 
> This needs an acked-by from either Peter or Frederic.

I think this was mentioned before: there was measurable overhead due to this, so 
that has to be re-measured.

Thanks,

	Ingo