1# SPDX-License-Identifier: GPL-2.0-only
2menu "GCOV-based kernel profiling"
3
4config GCOV_KERNEL
5	bool "Enable gcov-based kernel profiling"
6	depends on DEBUG_FS
7	depends on !CC_IS_CLANG || CLANG_VERSION >= 110000
8	depends on !ARCH_WANTS_NO_INSTR || CC_HAS_NO_PROFILE_FN_ATTR
9	select CONSTRUCTORS
10	default n
11	help
12	This option enables gcov-based code profiling (e.g. for code coverage
13	measurements).
14
15	If unsure, say N.
16
17	Additionally specify CONFIG_GCOV_PROFILE_ALL=y to get profiling data
18	for the entire kernel. To enable profiling for specific files or
19	directories, add a line similar to the following to the respective
20	Makefile:
21
22	For a single file (e.g. main.o):
23	        GCOV_PROFILE_main.o := y
24
25	For all files in one directory:
26	        GCOV_PROFILE := y
27
28	To exclude files from being profiled even when CONFIG_GCOV_PROFILE_ALL
29	is specified, use:
30
31	        GCOV_PROFILE_main.o := n
32	and:
33	        GCOV_PROFILE := n
34
35	Note that the debugfs filesystem has to be mounted to access
36	profiling data.
37
38config ARCH_HAS_GCOV_PROFILE_ALL
39	def_bool n
40
41config GCOV_PROFILE_ALL
42	bool "Profile entire Kernel"
43	depends on !COMPILE_TEST
44	depends on GCOV_KERNEL
45	depends on ARCH_HAS_GCOV_PROFILE_ALL
46	default n
47	help
48	This options activates profiling for the entire kernel.
49
50	If unsure, say N.
51
52	Note that a kernel compiled with profiling flags will be significantly
53	larger and run slower. Also be sure to exclude files from profiling
54	which are not linked to the kernel image to prevent linker errors.
55
56endmenu
57