# SPDX-License-Identifier: GPL-2.0-only menu "GCOV-based kernel profiling" config GCOV_KERNEL bool "Enable gcov-based kernel profiling" depends on DEBUG_FS depends on !ARCH_WANTS_NO_INSTR || CC_HAS_NO_PROFILE_FN_ATTR select CONSTRUCTORS default n help This option enables gcov-based code profiling (e.g. for code coverage measurements). If unsure, say N. Additionally specify CONFIG_GCOV_PROFILE_ALL=y to get profiling data for the entire kernel. To enable profiling for specific files or directories, add a line similar to the following to the respective Makefile: For a single file (e.g. main.o): GCOV_PROFILE_main.o := y For all files in one directory: GCOV_PROFILE := y To exclude files from being profiled even when CONFIG_GCOV_PROFILE_ALL is specified, use: GCOV_PROFILE_main.o := n and: GCOV_PROFILE := n Note that the debugfs filesystem has to be mounted to access profiling data. config ARCH_HAS_GCOV_PROFILE_ALL def_bool n config GCOV_PROFILE_ALL bool "Profile entire Kernel" depends on !COMPILE_TEST depends on GCOV_KERNEL depends on ARCH_HAS_GCOV_PROFILE_ALL default n help This options activates profiling for the entire kernel. If unsure, say N. Note that a kernel compiled with profiling flags will be significantly larger and run slower. Also be sure to exclude files from profiling which are not linked to the kernel image to prevent linker errors. endmenu