perf events: Do not generate function trace entries in perf code

Decreases perf overhead when function tracing is enabled,
by about 50%.

Cc: Peter Zijlstra <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <[email protected]>

diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index 68537e957a9b2cd621185e275103c201af9502e6..1d2cb383410ebef206fb48e2ccecbe8fd03f90ce 100644 (file)
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -5,6 +5,7 @@
 # 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/Makefile b/kernel/Makefile
index 17b575ec7d07aa001ff550f584dddb6d8aaf73e9..6b7ce8173dfdc063676dd6d2a565fbcc56cc7603 100644 (file)
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -21,6 +21,7 @@ CFLAGS_REMOVE_mutex-debug.o = -pg
 CFLAGS_REMOVE_rtmutex-debug.o = -pg
 CFLAGS_REMOVE_cgroup-debug.o = -pg
 CFLAGS_REMOVE_sched_clock.o = -pg
+CFLAGS_REMOVE_perf_event.o = -pg
 endif
 
 obj-$(CONFIG_FREEZER) += freezer.o