| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame] | 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 | select CONSTRUCTORS if !UML |
| 8 | default n |
| 9 | ---help--- |
| 10 | This option enables gcov-based code profiling (e.g. for code coverage |
| 11 | measurements). |
| 12 | |
| 13 | If unsure, say N. |
| 14 | |
| 15 | Additionally specify CONFIG_GCOV_PROFILE_ALL=y to get profiling data |
| 16 | for the entire kernel. To enable profiling for specific files or |
| 17 | directories, add a line similar to the following to the respective |
| 18 | Makefile: |
| 19 | |
| 20 | For a single file (e.g. main.o): |
| 21 | GCOV_PROFILE_main.o := y |
| 22 | |
| 23 | For all files in one directory: |
| 24 | GCOV_PROFILE := y |
| 25 | |
| 26 | To exclude files from being profiled even when CONFIG_GCOV_PROFILE_ALL |
| 27 | is specified, use: |
| 28 | |
| 29 | GCOV_PROFILE_main.o := n |
| 30 | and: |
| 31 | GCOV_PROFILE := n |
| 32 | |
| 33 | Note that the debugfs filesystem has to be mounted to access |
| 34 | profiling data. |
| 35 | |
| 36 | config ARCH_HAS_GCOV_PROFILE_ALL |
| 37 | def_bool n |
| 38 | |
| 39 | config GCOV_PROFILE_ALL |
| 40 | bool "Profile entire Kernel" |
| 41 | depends on !COMPILE_TEST |
| 42 | depends on GCOV_KERNEL |
| 43 | depends on ARCH_HAS_GCOV_PROFILE_ALL |
| 44 | default n |
| 45 | ---help--- |
| 46 | This options activates profiling for the entire kernel. |
| 47 | |
| 48 | If unsure, say N. |
| 49 | |
| 50 | Note that a kernel compiled with profiling flags will be significantly |
| 51 | larger and run slower. Also be sure to exclude files from profiling |
| 52 | which are not linked to the kernel image to prevent linker errors. |
| 53 | |
| 54 | choice |
| 55 | prompt "Specify GCOV format" |
| 56 | depends on GCOV_KERNEL |
| 57 | depends on CC_IS_GCC |
| 58 | ---help--- |
| 59 | The gcov format is usually determined by the GCC version, and the |
| 60 | default is chosen according to your GCC version. However, there are |
| 61 | exceptions where format changes are integrated in lower-version GCCs. |
| 62 | In such a case, change this option to adjust the format used in the |
| 63 | kernel accordingly. |
| 64 | |
| 65 | config GCOV_FORMAT_3_4 |
| 66 | bool "GCC 3.4 format" |
| 67 | depends on GCC_VERSION < 40700 |
| 68 | ---help--- |
| 69 | Select this option to use the format defined by GCC 3.4. |
| 70 | |
| 71 | config GCOV_FORMAT_4_7 |
| 72 | bool "GCC 4.7 format" |
| 73 | ---help--- |
| 74 | Select this option to use the format defined by GCC 4.7. |
| 75 | |
| 76 | endchoice |
| 77 | |
| 78 | endmenu |