diff options
| author | Andi Kleen <ak@linux.intel.com> | 2017-11-27 22:34:13 +0100 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2018-05-28 18:49:51 +0200 |
| commit | 96f60dfa5819a065bfdd2f2ba0df7d9cbce7f4dd (patch) | |
| tree | 98102816257e20f2be705a016b7049d16b159636 /scripts/Makefile.build | |
| parent | tracing: Make the snapshot trigger work with instances (diff) | |
| download | linux-96f60dfa5819a065bfdd2f2ba0df7d9cbce7f4dd.tar.xz linux-96f60dfa5819a065bfdd2f2ba0df7d9cbce7f4dd.zip | |
trace: Use -mcount-record for dynamic ftrace
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>
Diffstat (limited to 'scripts/Makefile.build')
| -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 8bdb1dc4072c..dcbca18011bb 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -207,6 +207,11 @@ 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 @@ -259,6 +264,7 @@ ifneq ($(RETPOLINE_CFLAGS),) objtool_args += --retpoline endif endif +endif ifdef CONFIG_MODVERSIONS |