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