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![Masahiro Yamada](/assets/img/avatar_default.png)
CONFIG_GCOV_FORMAT_AUTODETECT compiles either gcc_3_4.c or gcc_4_7.c according to your GCC version. We can achieve the equivalent behavior by setting reasonable dependency with the knowledge of the compiler version. If GCC older than 4.7 is used, GCOV_FORMAT_3_4 is the default, but users are still allowed to select GCOV_FORMAT_4_7 in case the newer format is back-ported. On the other hand, If GCC 4.7 or newer is used, there is no reason to use GCOV_FORMAT_3_4, so it should be hidden. If you downgrade the compiler to GCC 4.7 or older, oldconfig/syncconfig will display a prompt for the choice because GCOV_FORMAT_3_4 becomes visible as a new symbol. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Reviewed-by: Kees Cook <keescook@chromium.org>
76 lines
2 KiB
Text
76 lines
2 KiB
Text
menu "GCOV-based kernel profiling"
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config GCOV_KERNEL
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bool "Enable gcov-based kernel profiling"
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depends on DEBUG_FS
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select CONSTRUCTORS if !UML
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default n
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---help---
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This option enables gcov-based code profiling (e.g. for code coverage
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measurements).
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If unsure, say N.
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Additionally specify CONFIG_GCOV_PROFILE_ALL=y to get profiling data
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for the entire kernel. To enable profiling for specific files or
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directories, add a line similar to the following to the respective
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Makefile:
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For a single file (e.g. main.o):
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GCOV_PROFILE_main.o := y
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For all files in one directory:
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GCOV_PROFILE := y
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To exclude files from being profiled even when CONFIG_GCOV_PROFILE_ALL
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is specified, use:
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GCOV_PROFILE_main.o := n
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and:
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GCOV_PROFILE := n
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Note that the debugfs filesystem has to be mounted to access
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profiling data.
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config ARCH_HAS_GCOV_PROFILE_ALL
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def_bool n
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config GCOV_PROFILE_ALL
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bool "Profile entire Kernel"
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depends on !COMPILE_TEST
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depends on GCOV_KERNEL
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depends on ARCH_HAS_GCOV_PROFILE_ALL
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default n
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---help---
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This options activates profiling for the entire kernel.
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If unsure, say N.
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Note that a kernel compiled with profiling flags will be significantly
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larger and run slower. Also be sure to exclude files from profiling
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which are not linked to the kernel image to prevent linker errors.
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choice
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prompt "Specify GCOV format"
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depends on GCOV_KERNEL
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---help---
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The gcov format is usually determined by the GCC version, and the
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default is chosen according to your GCC version. However, there are
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exceptions where format changes are integrated in lower-version GCCs.
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In such a case, change this option to adjust the format used in the
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kernel accordingly.
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config GCOV_FORMAT_3_4
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bool "GCC 3.4 format"
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depends on CC_IS_GCC && GCC_VERSION < 40700
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---help---
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Select this option to use the format defined by GCC 3.4.
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config GCOV_FORMAT_4_7
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bool "GCC 4.7 format"
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---help---
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Select this option to use the format defined by GCC 4.7.
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endchoice
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endmenu
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