shinys000114/linux
1
0
Fork 0
mirror of https://github.com/hardkernel/linux.git synced 2026-03-24 19:40:21 +09:00
Code Issues Packages Projects Releases Wiki Activity

trace: Use -mcount-record for dynamic ftrace

Browse Source 
commit 96f60dfa58 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>
This commit is contained in:
Andi Kleen
2017-11-27 13:34:13 -08:00
committed by Chris
parent d919a7fb82
commit 66a86355ff
1 changed files with 6 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
scripts/Makefile.build
View File

@@ -242,6 +242,11 @@ endif
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
@@ -296,6 +301,7 @@ endif
ifdef CONFIG_GCOV_KERNEL
objtool_args += --no-unreachable
endif
endif
# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file