diff options
| author | Andi Kleen <ak@linux.intel.com> | 2017-11-27 13:34:13 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-02-23 13:58:13 +0100 |
| commit | 86cb8d448d99cef3e4425683296dff3a4d2d75a8 (patch) | |
| tree | 82544742aca062161d1e768bb2250c896c7fc849 /scripts | |
| parent | 0769ec67ae0a37a1ae4bbcb709bcb20e7cbbffce (diff) | |
trace: Use -mcount-record for dynamic ftrace
commit 96f60dfa5819a065bfdd2f2ba0df7d9cbce7f4dd upstream.
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.
So far doesn't use -mcount-nop, which also exists now.
This is needed to make ftrace work with LTO because the
normal record-mcount script doesn't run over the link
time output.
It should also improve build times slightly in the general
case.
Link: http://lkml.kernel.org/r/20171127213423.27218-12-andi@firstfloor.org
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'scripts')
| -rw-r--r-- | scripts/Makefile.build | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 42aef001dfdd..fff1452cb76e 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -221,6 +221,11 @@ cmd_modversions_c = \ endif ifdef CONFIG_FTRACE_MCOUNT_RECORD +# gcc 5 supports generating the mcount tables directly +ifneq ($(call cc-option,-mrecord-mcount,y),y) +KBUILD_CFLAGS += -mrecord-mcount +else +# else do it all manually ifdef BUILD_C_RECORDMCOUNT ifeq ("$(origin RECORDMCOUNT_WARN)", "command line") RECORDMCOUNT_FLAGS = -w @@ -250,6 +255,7 @@ cmd_record_mcount = \ $(sub_cmd_record_mcount) \ fi; endif +endif define rule_cc_o_c $(call echo-cmd,checksrc) $(cmd_checksrc) \ |