Messages in this thread Patch in this message | | | From | Andi Kleen <> | Subject | [PATCH] Use -mcount-record for dynamic ftrace | Date | Sun, 12 Apr 2015 17:54:27 -0700 |
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From: Andi Kleen <ak@linux.intel.com>
gcc 5 supports a new -mcount-record option to generate ftrace tables directly. This avoids the need to run record_mcount manually.
Use this option when available.
It also has a -mcount-nop option to generate the mcount calls as nops. So far that is not implemented, but it could be used to optimize patching at boot up.
Signed-off-by: Andi Kleen <ak@linux.intel.com> --- scripts/Makefile.build | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 01df30a..f258e9b 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -210,6 +210,11 @@ cmd_modversions = \ fi; endif +# gcc 5 supports generating the mcount tables directly +ifneq ($(call cc-option,-mrecord-mcount,y),y) +KBUILD_CFLAGS += -mrecord-mcount +else +# else do it all manually ifdef CONFIG_FTRACE_MCOUNT_RECORD ifdef BUILD_C_RECORDMCOUNT ifeq ("$(origin RECORDMCOUNT_WARN)", "command line") @@ -240,6 +245,7 @@ cmd_record_mcount = \ $(sub_cmd_record_mcount) \ fi; endif +endif define rule_cc_o_c $(call echo-cmd,checksrc) $(cmd_checksrc) \ -- 2.3.3
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