powerpc64: port of the function graph tracer

This is a port of the function graph tracer that was written by
Frederic Weisbecker for the x86.

This only works for PPC64 at the moment and only for static tracing.
PPC32 and dynamic function graph tracing support will come later.

The trace produces a visual calling of functions:

 # tracer: function_graph
 #
 # CPU  DURATION                  FUNCTION CALLS
 # |     |   |                     |   |   |   |
  0)   2.224 us    |                        }
  0) ! 271.024 us  |                      }
  0) ! 320.080 us  |                    }
  0) ! 324.656 us  |                  }
  0) ! 329.136 us  |                }
  0)               |                .put_prev_task_fair() {
  0)               |                  .update_curr() {
  0)   2.240 us    |                    .update_min_vruntime();
  0)   6.512 us    |                  }
  0)   2.528 us    |                  .__enqueue_entity();
  0) + 15.536 us   |                }
  0)               |                .pick_next_task_fair() {
  0)   2.032 us    |                  .__pick_next_entity();
  0)   2.064 us    |                  .__clear_buddies();
  0)               |                  .set_next_entity() {
  0)   2.672 us    |                    .__dequeue_entity();
  0)   6.864 us    |                  }

Geoff Lavand tested on PS3.

Tested-by: Geoff Levand <geoffrey.levand@am.sony.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 4 insertions, 5 deletions

diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index d15992119085..583ba6493a62 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -18,12 +18,10 @@ CFLAGS_REMOVE_cputable.o = -pg -mno-sched-epilog
 CFLAGS_REMOVE_prom_init.o = -pg -mno-sched-epilog
 CFLAGS_REMOVE_btext.o = -pg -mno-sched-epilog
 CFLAGS_REMOVE_prom.o = -pg -mno-sched-epilog
-
-ifdef CONFIG_DYNAMIC_FTRACE
-# dynamic ftrace setup.
+# do not trace tracer code
 CFLAGS_REMOVE_ftrace.o = -pg -mno-sched-epilog
-endif
-
+# timers used by tracing
+CFLAGS_REMOVE_time.o = -pg -mno-sched-epilog
 endif
 
 obj-y                           := cputable.o ptrace.o syscalls.o \
@@ -95,6 +93,7 @@ obj-$(CONFIG_AUDIT)		+= audit.o
 obj64-$(CONFIG_AUDIT)           += compat_audit.o
 
 obj-$(CONFIG_DYNAMIC_FTRACE)    += ftrace.o
+obj-$(CONFIG_FUNCTION_GRAPH_TRACER)     += ftrace.o
 
 obj-$(CONFIG_8XX_MINIMAL_FPEMU) += softemu8xx.o