kernel/gcov/Kconfig

   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 !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
  38 config ARCH_HAS_GCOV_PROFILE_ALL
  39         def_bool n
  40
  41 config 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
  56 endmenu