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