tracing: Avoid calling cc-option -mrecord-mcount for every Makefile (07d04081) · Commits · 戴 / test

Currently if CONFIG_FTRACE_MCOUNT_RECORD is enabled -mrecord-mcount compiler flag support is tested for every Makefile. Top 4 cc-option usages: 511 -mrecord-mcount 11 -fno-stack-protector 9 -Wno-override-init 2 -fsched-pressure To address that move cc-option from scripts/Makefile.build to top Makefile and export CC_USING_RECORD_MCOUNT to be used in original place. While doing that also add -mrecord-mcount to CC_FLAGS_FTRACE (if gcc actually supports it). Link: http://lkml.kernel.org/r/patch-2.thread-aa7b8d.git-de935bace15a.your-ad-here.call-01533557518-ext-9465@work.hours Acked-by:

Andi Kleen <ak@linux.intel.com> Signed-off-by:

Vasily Gorbik <gor@linux.ibm.com> Signed-off-by:

Steven Rostedt (VMware) <rostedt@goodmis.org>

Makefile

+7 −0

Original line number	Diff line number	Diff line
		@@ -743,6 +743,13 @@ ifdef CONFIG_FUNCTION_TRACER
		ifndef CC_FLAGS_FTRACE
		CC_FLAGS_FTRACE := -pg
		endif
		ifdef CONFIG_FTRACE_MCOUNT_RECORD
		# gcc 5 supports generating the mcount tables directly
		ifeq ($(call cc-option-yn,-mrecord-mcount),y)
		CC_FLAGS_FTRACE += -mrecord-mcount
		export CC_USING_RECORD_MCOUNT := 1
		endif
		endif
		ifdef CONFIG_HAVE_FENTRY
		ifeq ($(call cc-option-yn, -mfentry),y)
		CC_FLAGS_FTRACE += -mfentry

scripts/Makefile.build

+3 −6

Original line number	Diff line number	Diff line
		@@ -206,11 +206,8 @@ cmd_modversions_c = \
		endif

		ifdef CONFIG_FTRACE_MCOUNT_RECORD
		# gcc 5 supports generating the mcount tables directly
		ifneq ($(call cc-option,-mrecord-mcount,y),y)
		KBUILD_CFLAGS += -mrecord-mcount
		else
		# else do it all manually
		ifndef CC_USING_RECORD_MCOUNT
		# compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
		ifdef BUILD_C_RECORDMCOUNT
		ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
		RECORDMCOUNT_FLAGS = -w
		@@ -239,7 +236,7 @@ cmd_record_mcount = \
		"$(CC_FLAGS_FTRACE)" ]; then \
		$(sub_cmd_record_mcount) \
		fi;
		endif # -record-mcount
		endif # CC_USING_RECORD_MCOUNT
		endif # CONFIG_FTRACE_MCOUNT_RECORD

		ifdef CONFIG_STACK_VALIDATION

Admin message