2029 lines
		
	
	
		
			64 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
			
		
		
	
	
			2029 lines
		
	
	
		
			64 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
| # SPDX-License-Identifier: GPL-2.0-only
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| config CC_VERSION_TEXT
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| 	string
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| 	default "$(CC_VERSION_TEXT)"
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| 	help
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| 	  This is used in unclear ways:
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| 
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| 	  - Re-run Kconfig when the compiler is updated
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| 	    The 'default' property references the environment variable,
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| 	    CC_VERSION_TEXT so it is recorded in include/config/auto.conf.cmd.
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| 	    When the compiler is updated, Kconfig will be invoked.
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| 
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| 	  - Ensure full rebuild when the compiler is updated
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| 	    include/linux/compiler-version.h contains this option in the comment
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| 	    line so fixdep adds include/config/CC_VERSION_TEXT into the
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| 	    auto-generated dependency. When the compiler is updated, syncconfig
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| 	    will touch it and then every file will be rebuilt.
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| 
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| config CC_IS_GCC
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| 	def_bool $(success,test "$(cc-name)" = GCC)
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| 
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| config GCC_VERSION
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| 	int
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| 	default $(cc-version) if CC_IS_GCC
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| 	default 0
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| 
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| config CC_IS_CLANG
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| 	def_bool $(success,test "$(cc-name)" = Clang)
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| 
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| config CLANG_VERSION
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| 	int
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| 	default $(cc-version) if CC_IS_CLANG
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| 	default 0
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| 
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| config AS_IS_GNU
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| 	def_bool $(success,test "$(as-name)" = GNU)
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| 
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| config AS_IS_LLVM
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| 	def_bool $(success,test "$(as-name)" = LLVM)
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| 
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| config AS_VERSION
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| 	int
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| 	# Use clang version if this is the integrated assembler
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| 	default CLANG_VERSION if AS_IS_LLVM
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| 	default $(as-version)
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| 
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| config LD_IS_BFD
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| 	def_bool $(success,test "$(ld-name)" = BFD)
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| 
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| config LD_VERSION
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| 	int
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| 	default $(ld-version) if LD_IS_BFD
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| 	default 0
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| 
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| config LD_IS_LLD
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| 	def_bool $(success,test "$(ld-name)" = LLD)
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| 
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| config LLD_VERSION
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| 	int
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| 	default $(ld-version) if LD_IS_LLD
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| 	default 0
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| 
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| config RUST_IS_AVAILABLE
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| 	def_bool $(success,$(srctree)/scripts/rust_is_available.sh)
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| 	help
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| 	  This shows whether a suitable Rust toolchain is available (found).
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| 
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| 	  Please see Documentation/rust/quick-start.rst for instructions on how
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| 	  to satisfy the build requirements of Rust support.
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| 
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| 	  In particular, the Makefile target 'rustavailable' is useful to check
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| 	  why the Rust toolchain is not being detected.
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| 
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| config CC_CAN_LINK
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| 	bool
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| 	default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag)) if 64BIT
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| 	default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m32-flag))
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| 
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| config CC_CAN_LINK_STATIC
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| 	bool
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| 	default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag) -static) if 64BIT
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| 	default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m32-flag) -static)
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| 
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| config CC_HAS_ASM_GOTO_OUTPUT
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| 	def_bool $(success,echo 'int foo(int x) { asm goto ("": "=r"(x) ::: bar); return x; bar: return 0; }' | $(CC) -x c - -c -o /dev/null)
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| 
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| config CC_HAS_ASM_GOTO_TIED_OUTPUT
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| 	depends on CC_HAS_ASM_GOTO_OUTPUT
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| 	# Detect buggy gcc and clang, fixed in gcc-11 clang-14.
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| 	def_bool $(success,echo 'int foo(int *x) { asm goto (".long (%l[bar]) - .": "+m"(*x) ::: bar); return *x; bar: return 0; }' | $CC -x c - -c -o /dev/null)
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| 
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| config GCC_ASM_GOTO_OUTPUT_WORKAROUND
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| 	bool
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| 	depends on CC_IS_GCC && CC_HAS_ASM_GOTO_OUTPUT
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| 	# Fixed in GCC 14, 13.3, 12.4 and 11.5
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| 	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113921
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| 	default y if GCC_VERSION < 110500
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| 	default y if GCC_VERSION >= 120000 && GCC_VERSION < 120400
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| 	default y if GCC_VERSION >= 130000 && GCC_VERSION < 130300
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| 
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| config TOOLS_SUPPORT_RELR
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| 	def_bool $(success,env "CC=$(CC)" "LD=$(LD)" "NM=$(NM)" "OBJCOPY=$(OBJCOPY)" $(srctree)/scripts/tools-support-relr.sh)
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| 
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| config CC_HAS_ASM_INLINE
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| 	def_bool $(success,echo 'void foo(void) { asm inline (""); }' | $(CC) -x c - -c -o /dev/null)
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| 
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| config CC_HAS_NO_PROFILE_FN_ATTR
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| 	def_bool $(success,echo '__attribute__((no_profile_instrument_function)) int x();' | $(CC) -x c - -c -o /dev/null -Werror)
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| 
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| config PAHOLE_VERSION
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| 	int
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| 	default $(shell,$(srctree)/scripts/pahole-version.sh $(PAHOLE))
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| 
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| config CONSTRUCTORS
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| 	bool
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| 
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| config IRQ_WORK
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| 	bool
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| 
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| config BUILDTIME_TABLE_SORT
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| 	bool
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| 
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| config THREAD_INFO_IN_TASK
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| 	bool
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| 	help
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| 	  Select this to move thread_info off the stack into task_struct.  To
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| 	  make this work, an arch will need to remove all thread_info fields
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| 	  except flags and fix any runtime bugs.
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| 
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| 	  One subtle change that will be needed is to use try_get_task_stack()
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| 	  and put_task_stack() in save_thread_stack_tsk() and get_wchan().
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| 
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| menu "General setup"
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| 
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| config BROKEN
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| 	bool
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| 
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| config BROKEN_ON_SMP
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| 	bool
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| 	depends on BROKEN || !SMP
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| 	default y
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| 
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| config INIT_ENV_ARG_LIMIT
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| 	int
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| 	default 32 if !UML
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| 	default 128 if UML
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| 	help
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| 	  Maximum of each of the number of arguments and environment
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| 	  variables passed to init from the kernel command line.
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| 
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| config COMPILE_TEST
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| 	bool "Compile also drivers which will not load"
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| 	depends on HAS_IOMEM
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| 	help
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| 	  Some drivers can be compiled on a different platform than they are
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| 	  intended to be run on. Despite they cannot be loaded there (or even
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| 	  when they load they cannot be used due to missing HW support),
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| 	  developers still, opposing to distributors, might want to build such
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| 	  drivers to compile-test them.
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| 
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| 	  If you are a developer and want to build everything available, say Y
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| 	  here. If you are a user/distributor, say N here to exclude useless
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| 	  drivers to be distributed.
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| 
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| config WERROR
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| 	bool "Compile the kernel with warnings as errors"
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| 	default COMPILE_TEST
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| 	help
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| 	  A kernel build should not cause any compiler warnings, and this
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| 	  enables the '-Werror' (for C) and '-Dwarnings' (for Rust) flags
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| 	  to enforce that rule by default.
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| 
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| 	  However, if you have a new (or very old) compiler with odd and
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| 	  unusual warnings, or you have some architecture with problems,
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| 	  you may need to disable this config option in order to
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| 	  successfully build the kernel.
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| 
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| 	  If in doubt, say Y.
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| 
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| config UAPI_HEADER_TEST
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| 	bool "Compile test UAPI headers"
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| 	depends on HEADERS_INSTALL && CC_CAN_LINK
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| 	help
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| 	  Compile test headers exported to user-space to ensure they are
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| 	  self-contained, i.e. compilable as standalone units.
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| 
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| 	  If you are a developer or tester and want to ensure the exported
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| 	  headers are self-contained, say Y here. Otherwise, choose N.
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| 
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| config LOCALVERSION
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| 	string "Local version - append to kernel release"
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| 	help
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| 	  Append an extra string to the end of your kernel version.
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| 	  This will show up when you type uname, for example.
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| 	  The string you set here will be appended after the contents of
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| 	  any files with a filename matching localversion* in your
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| 	  object and source tree, in that order.  Your total string can
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| 	  be a maximum of 64 characters.
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| 
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| config LOCALVERSION_AUTO
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| 	bool "Automatically append version information to the version string"
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| 	default y
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| 	depends on !COMPILE_TEST
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| 	help
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| 	  This will try to automatically determine if the current tree is a
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| 	  release tree by looking for git tags that belong to the current
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| 	  top of tree revision.
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| 
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| 	  A string of the format -gxxxxxxxx will be added to the localversion
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| 	  if a git-based tree is found.  The string generated by this will be
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| 	  appended after any matching localversion* files, and after the value
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| 	  set in CONFIG_LOCALVERSION.
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| 
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| 	  (The actual string used here is the first eight characters produced
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| 	  by running the command:
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| 
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| 	    $ git rev-parse --verify HEAD
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| 
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| 	  which is done within the script "scripts/setlocalversion".)
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| 
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| config BUILD_SALT
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| 	string "Build ID Salt"
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| 	default ""
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| 	help
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| 	  The build ID is used to link binaries and their debug info. Setting
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| 	  this option will use the value in the calculation of the build id.
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| 	  This is mostly useful for distributions which want to ensure the
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| 	  build is unique between builds. It's safe to leave the default.
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| 
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| config HAVE_KERNEL_GZIP
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| 	bool
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| 
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| config HAVE_KERNEL_BZIP2
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| 	bool
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| 
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| config HAVE_KERNEL_LZMA
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| 	bool
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| 
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| config HAVE_KERNEL_XZ
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| 	bool
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| 
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| config HAVE_KERNEL_LZO
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| 	bool
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| 
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| config HAVE_KERNEL_LZ4
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| 	bool
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| 
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| config HAVE_KERNEL_ZSTD
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| 	bool
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| 
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| config HAVE_KERNEL_UNCOMPRESSED
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| 	bool
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| 
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| choice
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| 	prompt "Kernel compression mode"
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| 	default KERNEL_GZIP
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| 	depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO || HAVE_KERNEL_LZ4 || HAVE_KERNEL_ZSTD || HAVE_KERNEL_UNCOMPRESSED
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| 	help
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| 	  The linux kernel is a kind of self-extracting executable.
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| 	  Several compression algorithms are available, which differ
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| 	  in efficiency, compression and decompression speed.
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| 	  Compression speed is only relevant when building a kernel.
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| 	  Decompression speed is relevant at each boot.
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| 
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| 	  If you have any problems with bzip2 or lzma compressed
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| 	  kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
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| 	  version of this functionality (bzip2 only), for 2.4, was
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| 	  supplied by Christian Ludwig)
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| 
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| 	  High compression options are mostly useful for users, who
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| 	  are low on disk space (embedded systems), but for whom ram
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| 	  size matters less.
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| 
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| 	  If in doubt, select 'gzip'
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| 
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| config KERNEL_GZIP
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| 	bool "Gzip"
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| 	depends on HAVE_KERNEL_GZIP
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| 	help
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| 	  The old and tried gzip compression. It provides a good balance
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| 	  between compression ratio and decompression speed.
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| 
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| config KERNEL_BZIP2
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| 	bool "Bzip2"
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| 	depends on HAVE_KERNEL_BZIP2
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| 	help
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| 	  Its compression ratio and speed is intermediate.
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| 	  Decompression speed is slowest among the choices.  The kernel
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| 	  size is about 10% smaller with bzip2, in comparison to gzip.
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| 	  Bzip2 uses a large amount of memory. For modern kernels you
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| 	  will need at least 8MB RAM or more for booting.
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| 
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| config KERNEL_LZMA
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| 	bool "LZMA"
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| 	depends on HAVE_KERNEL_LZMA
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| 	help
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| 	  This compression algorithm's ratio is best.  Decompression speed
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| 	  is between gzip and bzip2.  Compression is slowest.
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| 	  The kernel size is about 33% smaller with LZMA in comparison to gzip.
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| 
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| config KERNEL_XZ
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| 	bool "XZ"
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| 	depends on HAVE_KERNEL_XZ
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| 	help
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| 	  XZ uses the LZMA2 algorithm and instruction set specific
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| 	  BCJ filters which can improve compression ratio of executable
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| 	  code. The size of the kernel is about 30% smaller with XZ in
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| 	  comparison to gzip. On architectures for which there is a BCJ
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| 	  filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
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| 	  will create a few percent smaller kernel than plain LZMA.
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| 
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| 	  The speed is about the same as with LZMA: The decompression
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| 	  speed of XZ is better than that of bzip2 but worse than gzip
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| 	  and LZO. Compression is slow.
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| 
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| config KERNEL_LZO
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| 	bool "LZO"
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| 	depends on HAVE_KERNEL_LZO
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| 	help
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| 	  Its compression ratio is the poorest among the choices. The kernel
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| 	  size is about 10% bigger than gzip; however its speed
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| 	  (both compression and decompression) is the fastest.
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| 
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| config KERNEL_LZ4
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| 	bool "LZ4"
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| 	depends on HAVE_KERNEL_LZ4
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| 	help
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| 	  LZ4 is an LZ77-type compressor with a fixed, byte-oriented encoding.
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| 	  A preliminary version of LZ4 de/compression tool is available at
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| 	  <https://code.google.com/p/lz4/>.
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| 
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| 	  Its compression ratio is worse than LZO. The size of the kernel
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| 	  is about 8% bigger than LZO. But the decompression speed is
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| 	  faster than LZO.
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| 
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| config KERNEL_ZSTD
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| 	bool "ZSTD"
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| 	depends on HAVE_KERNEL_ZSTD
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| 	help
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| 	  ZSTD is a compression algorithm targeting intermediate compression
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| 	  with fast decompression speed. It will compress better than GZIP and
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| 	  decompress around the same speed as LZO, but slower than LZ4. You
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| 	  will need at least 192 KB RAM or more for booting. The zstd command
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| 	  line tool is required for compression.
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| 
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| config KERNEL_UNCOMPRESSED
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| 	bool "None"
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| 	depends on HAVE_KERNEL_UNCOMPRESSED
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| 	help
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| 	  Produce uncompressed kernel image. This option is usually not what
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| 	  you want. It is useful for debugging the kernel in slow simulation
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| 	  environments, where decompressing and moving the kernel is awfully
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| 	  slow. This option allows early boot code to skip the decompressor
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| 	  and jump right at uncompressed kernel image.
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| 
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| endchoice
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| 
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| config DEFAULT_INIT
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| 	string "Default init path"
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| 	default ""
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| 	help
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| 	  This option determines the default init for the system if no init=
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| 	  option is passed on the kernel command line. If the requested path is
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| 	  not present, we will still then move on to attempting further
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| 	  locations (e.g. /sbin/init, etc). If this is empty, we will just use
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| 	  the fallback list when init= is not passed.
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| 
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| config DEFAULT_HOSTNAME
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| 	string "Default hostname"
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| 	default "(none)"
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| 	help
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| 	  This option determines the default system hostname before userspace
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| 	  calls sethostname(2). The kernel traditionally uses "(none)" here,
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| 	  but you may wish to use a different default here to make a minimal
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| 	  system more usable with less configuration.
 | |
| 
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| config SYSVIPC
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| 	bool "System V IPC"
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| 	help
 | |
| 	  Inter Process Communication is a suite of library functions and
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| 	  system calls which let processes (running programs) synchronize and
 | |
| 	  exchange information. It is generally considered to be a good thing,
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| 	  and some programs won't run unless you say Y here. In particular, if
 | |
| 	  you want to run the DOS emulator dosemu under Linux (read the
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| 	  DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
 | |
| 	  you'll need to say Y here.
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| 
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| 	  You can find documentation about IPC with "info ipc" and also in
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| 	  section 6.4 of the Linux Programmer's Guide, available from
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| 	  <http://www.tldp.org/guides.html>.
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| 
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| config SYSVIPC_SYSCTL
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| 	bool
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| 	depends on SYSVIPC
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| 	depends on SYSCTL
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| 	default y
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| 
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| config SYSVIPC_COMPAT
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| 	def_bool y
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| 	depends on COMPAT && SYSVIPC
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| 
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| config POSIX_MQUEUE
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| 	bool "POSIX Message Queues"
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| 	depends on NET
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| 	help
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| 	  POSIX variant of message queues is a part of IPC. In POSIX message
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| 	  queues every message has a priority which decides about succession
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| 	  of receiving it by a process. If you want to compile and run
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| 	  programs written e.g. for Solaris with use of its POSIX message
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| 	  queues (functions mq_*) say Y here.
 | |
| 
 | |
| 	  POSIX message queues are visible as a filesystem called 'mqueue'
 | |
| 	  and can be mounted somewhere if you want to do filesystem
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| 	  operations on message queues.
 | |
| 
 | |
| 	  If unsure, say Y.
 | |
| 
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| config POSIX_MQUEUE_SYSCTL
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| 	bool
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| 	depends on POSIX_MQUEUE
 | |
| 	depends on SYSCTL
 | |
| 	default y
 | |
| 
 | |
| config WATCH_QUEUE
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| 	bool "General notification queue"
 | |
| 	default n
 | |
| 	help
 | |
| 
 | |
| 	  This is a general notification queue for the kernel to pass events to
 | |
| 	  userspace by splicing them into pipes.  It can be used in conjunction
 | |
| 	  with watches for key/keyring change notifications and device
 | |
| 	  notifications.
 | |
| 
 | |
| 	  See Documentation/core-api/watch_queue.rst
 | |
| 
 | |
| config CROSS_MEMORY_ATTACH
 | |
| 	bool "Enable process_vm_readv/writev syscalls"
 | |
| 	depends on MMU
 | |
| 	default y
 | |
| 	help
 | |
| 	  Enabling this option adds the system calls process_vm_readv and
 | |
| 	  process_vm_writev which allow a process with the correct privileges
 | |
| 	  to directly read from or write to another process' address space.
 | |
| 	  See the man page for more details.
 | |
| 
 | |
| config USELIB
 | |
| 	bool "uselib syscall (for libc5 and earlier)"
 | |
| 	default ALPHA || M68K || SPARC
 | |
| 	help
 | |
| 	  This option enables the uselib syscall, a system call used in the
 | |
| 	  dynamic linker from libc5 and earlier.  glibc does not use this
 | |
| 	  system call.  If you intend to run programs built on libc5 or
 | |
| 	  earlier, you may need to enable this syscall.  Current systems
 | |
| 	  running glibc can safely disable this.
 | |
| 
 | |
| config AUDIT
 | |
| 	bool "Auditing support"
 | |
| 	depends on NET
 | |
| 	help
 | |
| 	  Enable auditing infrastructure that can be used with another
 | |
| 	  kernel subsystem, such as SELinux (which requires this for
 | |
| 	  logging of avc messages output).  System call auditing is included
 | |
| 	  on architectures which support it.
 | |
| 
 | |
| config HAVE_ARCH_AUDITSYSCALL
 | |
| 	bool
 | |
| 
 | |
| config AUDITSYSCALL
 | |
| 	def_bool y
 | |
| 	depends on AUDIT && HAVE_ARCH_AUDITSYSCALL
 | |
| 	select FSNOTIFY
 | |
| 
 | |
| source "kernel/irq/Kconfig"
 | |
| source "kernel/time/Kconfig"
 | |
| source "kernel/bpf/Kconfig"
 | |
| source "kernel/Kconfig.preempt"
 | |
| 
 | |
| menu "CPU/Task time and stats accounting"
 | |
| 
 | |
| config VIRT_CPU_ACCOUNTING
 | |
| 	bool
 | |
| 
 | |
| choice
 | |
| 	prompt "Cputime accounting"
 | |
| 	default TICK_CPU_ACCOUNTING
 | |
| 
 | |
| # Kind of a stub config for the pure tick based cputime accounting
 | |
| config TICK_CPU_ACCOUNTING
 | |
| 	bool "Simple tick based cputime accounting"
 | |
| 	depends on !S390 && !NO_HZ_FULL
 | |
| 	help
 | |
| 	  This is the basic tick based cputime accounting that maintains
 | |
| 	  statistics about user, system and idle time spent on per jiffies
 | |
| 	  granularity.
 | |
| 
 | |
| 	  If unsure, say Y.
 | |
| 
 | |
| config VIRT_CPU_ACCOUNTING_NATIVE
 | |
| 	bool "Deterministic task and CPU time accounting"
 | |
| 	depends on HAVE_VIRT_CPU_ACCOUNTING && !NO_HZ_FULL
 | |
| 	select VIRT_CPU_ACCOUNTING
 | |
| 	help
 | |
| 	  Select this option to enable more accurate task and CPU time
 | |
| 	  accounting.  This is done by reading a CPU counter on each
 | |
| 	  kernel entry and exit and on transitions within the kernel
 | |
| 	  between system, softirq and hardirq state, so there is a
 | |
| 	  small performance impact.  In the case of s390 or IBM POWER > 5,
 | |
| 	  this also enables accounting of stolen time on logically-partitioned
 | |
| 	  systems.
 | |
| 
 | |
| config VIRT_CPU_ACCOUNTING_GEN
 | |
| 	bool "Full dynticks CPU time accounting"
 | |
| 	depends on HAVE_CONTEXT_TRACKING_USER
 | |
| 	depends on HAVE_VIRT_CPU_ACCOUNTING_GEN
 | |
| 	depends on GENERIC_CLOCKEVENTS
 | |
| 	select VIRT_CPU_ACCOUNTING
 | |
| 	select CONTEXT_TRACKING_USER
 | |
| 	help
 | |
| 	  Select this option to enable task and CPU time accounting on full
 | |
| 	  dynticks systems. This accounting is implemented by watching every
 | |
| 	  kernel-user boundaries using the context tracking subsystem.
 | |
| 	  The accounting is thus performed at the expense of some significant
 | |
| 	  overhead.
 | |
| 
 | |
| 	  For now this is only useful if you are working on the full
 | |
| 	  dynticks subsystem development.
 | |
| 
 | |
| 	  If unsure, say N.
 | |
| 
 | |
| endchoice
 | |
| 
 | |
| config IRQ_TIME_ACCOUNTING
 | |
| 	bool "Fine granularity task level IRQ time accounting"
 | |
| 	depends on HAVE_IRQ_TIME_ACCOUNTING && !VIRT_CPU_ACCOUNTING_NATIVE
 | |
| 	help
 | |
| 	  Select this option to enable fine granularity task irq time
 | |
| 	  accounting. This is done by reading a timestamp on each
 | |
| 	  transitions between softirq and hardirq state, so there can be a
 | |
| 	  small performance impact.
 | |
| 
 | |
| 	  If in doubt, say N here.
 | |
| 
 | |
| config HAVE_SCHED_AVG_IRQ
 | |
| 	def_bool y
 | |
| 	depends on IRQ_TIME_ACCOUNTING || PARAVIRT_TIME_ACCOUNTING
 | |
| 	depends on SMP
 | |
| 
 | |
| config SCHED_THERMAL_PRESSURE
 | |
| 	bool
 | |
| 	default y if ARM && ARM_CPU_TOPOLOGY
 | |
| 	default y if ARM64
 | |
| 	depends on SMP
 | |
| 	depends on CPU_FREQ_THERMAL
 | |
| 	help
 | |
| 	  Select this option to enable thermal pressure accounting in the
 | |
| 	  scheduler. Thermal pressure is the value conveyed to the scheduler
 | |
| 	  that reflects the reduction in CPU compute capacity resulted from
 | |
| 	  thermal throttling. Thermal throttling occurs when the performance of
 | |
| 	  a CPU is capped due to high operating temperatures.
 | |
| 
 | |
| 	  If selected, the scheduler will be able to balance tasks accordingly,
 | |
| 	  i.e. put less load on throttled CPUs than on non/less throttled ones.
 | |
| 
 | |
| 	  This requires the architecture to implement
 | |
| 	  arch_update_thermal_pressure() and arch_scale_thermal_pressure().
 | |
| 
 | |
| config BSD_PROCESS_ACCT
 | |
| 	bool "BSD Process Accounting"
 | |
| 	depends on MULTIUSER
 | |
| 	help
 | |
| 	  If you say Y here, a user level program will be able to instruct the
 | |
| 	  kernel (via a special system call) to write process accounting
 | |
| 	  information to a file: whenever a process exits, information about
 | |
| 	  that process will be appended to the file by the kernel.  The
 | |
| 	  information includes things such as creation time, owning user,
 | |
| 	  command name, memory usage, controlling terminal etc. (the complete
 | |
| 	  list is in the struct acct in <file:include/linux/acct.h>).  It is
 | |
| 	  up to the user level program to do useful things with this
 | |
| 	  information.  This is generally a good idea, so say Y.
 | |
| 
 | |
| config BSD_PROCESS_ACCT_V3
 | |
| 	bool "BSD Process Accounting version 3 file format"
 | |
| 	depends on BSD_PROCESS_ACCT
 | |
| 	default n
 | |
| 	help
 | |
| 	  If you say Y here, the process accounting information is written
 | |
| 	  in a new file format that also logs the process IDs of each
 | |
| 	  process and its parent. Note that this file format is incompatible
 | |
| 	  with previous v0/v1/v2 file formats, so you will need updated tools
 | |
| 	  for processing it. A preliminary version of these tools is available
 | |
| 	  at <http://www.gnu.org/software/acct/>.
 | |
| 
 | |
| config TASKSTATS
 | |
| 	bool "Export task/process statistics through netlink"
 | |
| 	depends on NET
 | |
| 	depends on MULTIUSER
 | |
| 	default n
 | |
| 	help
 | |
| 	  Export selected statistics for tasks/processes through the
 | |
| 	  generic netlink interface. Unlike BSD process accounting, the
 | |
| 	  statistics are available during the lifetime of tasks/processes as
 | |
| 	  responses to commands. Like BSD accounting, they are sent to user
 | |
| 	  space on task exit.
 | |
| 
 | |
| 	  Say N if unsure.
 | |
| 
 | |
| config TASK_DELAY_ACCT
 | |
| 	bool "Enable per-task delay accounting"
 | |
| 	depends on TASKSTATS
 | |
| 	select SCHED_INFO
 | |
| 	help
 | |
| 	  Collect information on time spent by a task waiting for system
 | |
| 	  resources like cpu, synchronous block I/O completion and swapping
 | |
| 	  in pages. Such statistics can help in setting a task's priorities
 | |
| 	  relative to other tasks for cpu, io, rss limits etc.
 | |
| 
 | |
| 	  Say N if unsure.
 | |
| 
 | |
| config TASK_XACCT
 | |
| 	bool "Enable extended accounting over taskstats"
 | |
| 	depends on TASKSTATS
 | |
| 	help
 | |
| 	  Collect extended task accounting data and send the data
 | |
| 	  to userland for processing over the taskstats interface.
 | |
| 
 | |
| 	  Say N if unsure.
 | |
| 
 | |
| config TASK_IO_ACCOUNTING
 | |
| 	bool "Enable per-task storage I/O accounting"
 | |
| 	depends on TASK_XACCT
 | |
| 	help
 | |
| 	  Collect information on the number of bytes of storage I/O which this
 | |
| 	  task has caused.
 | |
| 
 | |
| 	  Say N if unsure.
 | |
| 
 | |
| config PSI
 | |
| 	bool "Pressure stall information tracking"
 | |
| 	select KERNFS
 | |
| 	help
 | |
| 	  Collect metrics that indicate how overcommitted the CPU, memory,
 | |
| 	  and IO capacity are in the system.
 | |
| 
 | |
| 	  If you say Y here, the kernel will create /proc/pressure/ with the
 | |
| 	  pressure statistics files cpu, memory, and io. These will indicate
 | |
| 	  the share of walltime in which some or all tasks in the system are
 | |
| 	  delayed due to contention of the respective resource.
 | |
| 
 | |
| 	  In kernels with cgroup support, cgroups (cgroup2 only) will
 | |
| 	  have cpu.pressure, memory.pressure, and io.pressure files,
 | |
| 	  which aggregate pressure stalls for the grouped tasks only.
 | |
| 
 | |
| 	  For more details see Documentation/accounting/psi.rst.
 | |
| 
 | |
| 	  Say N if unsure.
 | |
| 
 | |
| config PSI_DEFAULT_DISABLED
 | |
| 	bool "Require boot parameter to enable pressure stall information tracking"
 | |
| 	default n
 | |
| 	depends on PSI
 | |
| 	help
 | |
| 	  If set, pressure stall information tracking will be disabled
 | |
| 	  per default but can be enabled through passing psi=1 on the
 | |
| 	  kernel commandline during boot.
 | |
| 
 | |
| 	  This feature adds some code to the task wakeup and sleep
 | |
| 	  paths of the scheduler. The overhead is too low to affect
 | |
| 	  common scheduling-intense workloads in practice (such as
 | |
| 	  webservers, memcache), but it does show up in artificial
 | |
| 	  scheduler stress tests, such as hackbench.
 | |
| 
 | |
| 	  If you are paranoid and not sure what the kernel will be
 | |
| 	  used for, say Y.
 | |
| 
 | |
| 	  Say N if unsure.
 | |
| 
 | |
| endmenu # "CPU/Task time and stats accounting"
 | |
| 
 | |
| config CPU_ISOLATION
 | |
| 	bool "CPU isolation"
 | |
| 	depends on SMP || COMPILE_TEST
 | |
| 	default y
 | |
| 	help
 | |
| 	  Make sure that CPUs running critical tasks are not disturbed by
 | |
| 	  any source of "noise" such as unbound workqueues, timers, kthreads...
 | |
| 	  Unbound jobs get offloaded to housekeeping CPUs. This is driven by
 | |
| 	  the "isolcpus=" boot parameter.
 | |
| 
 | |
| 	  Say Y if unsure.
 | |
| 
 | |
| source "kernel/rcu/Kconfig"
 | |
| 
 | |
| config BUILD_BIN2C
 | |
| 	bool
 | |
| 	default n
 | |
| 
 | |
| config IKCONFIG
 | |
| 	tristate "Kernel .config support"
 | |
| 	help
 | |
| 	  This option enables the complete Linux kernel ".config" file
 | |
| 	  contents to be saved in the kernel. It provides documentation
 | |
| 	  of which kernel options are used in a running kernel or in an
 | |
| 	  on-disk kernel.  This information can be extracted from the kernel
 | |
| 	  image file with the script scripts/extract-ikconfig and used as
 | |
| 	  input to rebuild the current kernel or to build another kernel.
 | |
| 	  It can also be extracted from a running kernel by reading
 | |
| 	  /proc/config.gz if enabled (below).
 | |
| 
 | |
| config IKCONFIG_PROC
 | |
| 	bool "Enable access to .config through /proc/config.gz"
 | |
| 	depends on IKCONFIG && PROC_FS
 | |
| 	help
 | |
| 	  This option enables access to the kernel configuration file
 | |
| 	  through /proc/config.gz.
 | |
| 
 | |
| config IKHEADERS
 | |
| 	tristate "Enable kernel headers through /sys/kernel/kheaders.tar.xz"
 | |
| 	depends on SYSFS
 | |
| 	help
 | |
| 	  This option enables access to the in-kernel headers that are generated during
 | |
| 	  the build process. These can be used to build eBPF tracing programs,
 | |
| 	  or similar programs.  If you build the headers as a module, a module called
 | |
| 	  kheaders.ko is built which can be loaded on-demand to get access to headers.
 | |
| 
 | |
| config LOG_BUF_SHIFT
 | |
| 	int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
 | |
| 	range 12 25
 | |
| 	default 17
 | |
| 	depends on PRINTK
 | |
| 	help
 | |
| 	  Select the minimal kernel log buffer size as a power of 2.
 | |
| 	  The final size is affected by LOG_CPU_MAX_BUF_SHIFT config
 | |
| 	  parameter, see below. Any higher size also might be forced
 | |
| 	  by "log_buf_len" boot parameter.
 | |
| 
 | |
| 	  Examples:
 | |
| 		     17 => 128 KB
 | |
| 		     16 => 64 KB
 | |
| 		     15 => 32 KB
 | |
| 		     14 => 16 KB
 | |
| 		     13 =>  8 KB
 | |
| 		     12 =>  4 KB
 | |
| 
 | |
| config LOG_CPU_MAX_BUF_SHIFT
 | |
| 	int "CPU kernel log buffer size contribution (13 => 8 KB, 17 => 128KB)"
 | |
| 	depends on SMP
 | |
| 	range 0 21
 | |
| 	default 12 if !BASE_SMALL
 | |
| 	default 0 if BASE_SMALL
 | |
| 	depends on PRINTK
 | |
| 	help
 | |
| 	  This option allows to increase the default ring buffer size
 | |
| 	  according to the number of CPUs. The value defines the contribution
 | |
| 	  of each CPU as a power of 2. The used space is typically only few
 | |
| 	  lines however it might be much more when problems are reported,
 | |
| 	  e.g. backtraces.
 | |
| 
 | |
| 	  The increased size means that a new buffer has to be allocated and
 | |
| 	  the original static one is unused. It makes sense only on systems
 | |
| 	  with more CPUs. Therefore this value is used only when the sum of
 | |
| 	  contributions is greater than the half of the default kernel ring
 | |
| 	  buffer as defined by LOG_BUF_SHIFT. The default values are set
 | |
| 	  so that more than 16 CPUs are needed to trigger the allocation.
 | |
| 
 | |
| 	  Also this option is ignored when "log_buf_len" kernel parameter is
 | |
| 	  used as it forces an exact (power of two) size of the ring buffer.
 | |
| 
 | |
| 	  The number of possible CPUs is used for this computation ignoring
 | |
| 	  hotplugging making the computation optimal for the worst case
 | |
| 	  scenario while allowing a simple algorithm to be used from bootup.
 | |
| 
 | |
| 	  Examples shift values and their meaning:
 | |
| 		     17 => 128 KB for each CPU
 | |
| 		     16 =>  64 KB for each CPU
 | |
| 		     15 =>  32 KB for each CPU
 | |
| 		     14 =>  16 KB for each CPU
 | |
| 		     13 =>   8 KB for each CPU
 | |
| 		     12 =>   4 KB for each CPU
 | |
| 
 | |
| config PRINTK_SAFE_LOG_BUF_SHIFT
 | |
| 	int "Temporary per-CPU printk log buffer size (12 => 4KB, 13 => 8KB)"
 | |
| 	range 10 21
 | |
| 	default 13
 | |
| 	depends on PRINTK
 | |
| 	help
 | |
| 	  Select the size of an alternate printk per-CPU buffer where messages
 | |
| 	  printed from usafe contexts are temporary stored. One example would
 | |
| 	  be NMI messages, another one - printk recursion. The messages are
 | |
| 	  copied to the main log buffer in a safe context to avoid a deadlock.
 | |
| 	  The value defines the size as a power of 2.
 | |
| 
 | |
| 	  Those messages are rare and limited. The largest one is when
 | |
| 	  a backtrace is printed. It usually fits into 4KB. Select
 | |
| 	  8KB if you want to be on the safe side.
 | |
| 
 | |
| 	  Examples:
 | |
| 		     17 => 128 KB for each CPU
 | |
| 		     16 =>  64 KB for each CPU
 | |
| 		     15 =>  32 KB for each CPU
 | |
| 		     14 =>  16 KB for each CPU
 | |
| 		     13 =>   8 KB for each CPU
 | |
| 		     12 =>   4 KB for each CPU
 | |
| 
 | |
| config PRINTK_INDEX
 | |
| 	bool "Printk indexing debugfs interface"
 | |
| 	depends on PRINTK && DEBUG_FS
 | |
| 	help
 | |
| 	  Add support for indexing of all printk formats known at compile time
 | |
| 	  at <debugfs>/printk/index/<module>.
 | |
| 
 | |
| 	  This can be used as part of maintaining daemons which monitor
 | |
| 	  /dev/kmsg, as it permits auditing the printk formats present in a
 | |
| 	  kernel, allowing detection of cases where monitored printks are
 | |
| 	  changed or no longer present.
 | |
| 
 | |
| 	  There is no additional runtime cost to printk with this enabled.
 | |
| 
 | |
| #
 | |
| # Architectures with an unreliable sched_clock() should select this:
 | |
| #
 | |
| config HAVE_UNSTABLE_SCHED_CLOCK
 | |
| 	bool
 | |
| 
 | |
| config GENERIC_SCHED_CLOCK
 | |
| 	bool
 | |
| 
 | |
| menu "Scheduler features"
 | |
| 
 | |
| config UCLAMP_TASK
 | |
| 	bool "Enable utilization clamping for RT/FAIR tasks"
 | |
| 	depends on CPU_FREQ_GOV_SCHEDUTIL
 | |
| 	help
 | |
| 	  This feature enables the scheduler to track the clamped utilization
 | |
| 	  of each CPU based on RUNNABLE tasks scheduled on that CPU.
 | |
| 
 | |
| 	  With this option, the user can specify the min and max CPU
 | |
| 	  utilization allowed for RUNNABLE tasks. The max utilization defines
 | |
| 	  the maximum frequency a task should use while the min utilization
 | |
| 	  defines the minimum frequency it should use.
 | |
| 
 | |
| 	  Both min and max utilization clamp values are hints to the scheduler,
 | |
| 	  aiming at improving its frequency selection policy, but they do not
 | |
| 	  enforce or grant any specific bandwidth for tasks.
 | |
| 
 | |
| 	  If in doubt, say N.
 | |
| 
 | |
| config UCLAMP_BUCKETS_COUNT
 | |
| 	int "Number of supported utilization clamp buckets"
 | |
| 	range 5 20
 | |
| 	default 5
 | |
| 	depends on UCLAMP_TASK
 | |
| 	help
 | |
| 	  Defines the number of clamp buckets to use. The range of each bucket
 | |
| 	  will be SCHED_CAPACITY_SCALE/UCLAMP_BUCKETS_COUNT. The higher the
 | |
| 	  number of clamp buckets the finer their granularity and the higher
 | |
| 	  the precision of clamping aggregation and tracking at run-time.
 | |
| 
 | |
| 	  For example, with the minimum configuration value we will have 5
 | |
| 	  clamp buckets tracking 20% utilization each. A 25% boosted tasks will
 | |
| 	  be refcounted in the [20..39]% bucket and will set the bucket clamp
 | |
| 	  effective value to 25%.
 | |
| 	  If a second 30% boosted task should be co-scheduled on the same CPU,
 | |
| 	  that task will be refcounted in the same bucket of the first task and
 | |
| 	  it will boost the bucket clamp effective value to 30%.
 | |
| 	  The clamp effective value of a bucket is reset to its nominal value
 | |
| 	  (20% in the example above) when there are no more tasks refcounted in
 | |
| 	  that bucket.
 | |
| 
 | |
| 	  An additional boost/capping margin can be added to some tasks. In the
 | |
| 	  example above the 25% task will be boosted to 30% until it exits the
 | |
| 	  CPU. If that should be considered not acceptable on certain systems,
 | |
| 	  it's always possible to reduce the margin by increasing the number of
 | |
| 	  clamp buckets to trade off used memory for run-time tracking
 | |
| 	  precision.
 | |
| 
 | |
| 	  If in doubt, use the default value.
 | |
| 
 | |
| endmenu
 | |
| 
 | |
| #
 | |
| # For architectures that want to enable the support for NUMA-affine scheduler
 | |
| # balancing logic:
 | |
| #
 | |
| config ARCH_SUPPORTS_NUMA_BALANCING
 | |
| 	bool
 | |
| 
 | |
| #
 | |
| # For architectures that prefer to flush all TLBs after a number of pages
 | |
| # are unmapped instead of sending one IPI per page to flush. The architecture
 | |
| # must provide guarantees on what happens if a clean TLB cache entry is
 | |
| # written after the unmap. Details are in mm/rmap.c near the check for
 | |
| # should_defer_flush. The architecture should also consider if the full flush
 | |
| # and the refill costs are offset by the savings of sending fewer IPIs.
 | |
| config ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
 | |
| 	bool
 | |
| 
 | |
| config CC_HAS_INT128
 | |
| 	def_bool !$(cc-option,$(m64-flag) -D__SIZEOF_INT128__=0) && 64BIT
 | |
| 
 | |
| config CC_IMPLICIT_FALLTHROUGH
 | |
| 	string
 | |
| 	default "-Wimplicit-fallthrough=5" if CC_IS_GCC && $(cc-option,-Wimplicit-fallthrough=5)
 | |
| 	default "-Wimplicit-fallthrough" if CC_IS_CLANG && $(cc-option,-Wunreachable-code-fallthrough)
 | |
| 
 | |
| # Currently, disable gcc-10+ array-bounds globally.
 | |
| # It's still broken in gcc-13, so no upper bound yet.
 | |
| config GCC10_NO_ARRAY_BOUNDS
 | |
| 	def_bool y
 | |
| 
 | |
| config CC_NO_ARRAY_BOUNDS
 | |
| 	bool
 | |
| 	default y if CC_IS_GCC && GCC_VERSION >= 100000 && GCC10_NO_ARRAY_BOUNDS
 | |
| 
 | |
| #
 | |
| # For architectures that know their GCC __int128 support is sound
 | |
| #
 | |
| config ARCH_SUPPORTS_INT128
 | |
| 	bool
 | |
| 
 | |
| # For architectures that (ab)use NUMA to represent different memory regions
 | |
| # all cpu-local but of different latencies, such as SuperH.
 | |
| #
 | |
| config ARCH_WANT_NUMA_VARIABLE_LOCALITY
 | |
| 	bool
 | |
| 
 | |
| config NUMA_BALANCING
 | |
| 	bool "Memory placement aware NUMA scheduler"
 | |
| 	depends on ARCH_SUPPORTS_NUMA_BALANCING
 | |
| 	depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
 | |
| 	depends on SMP && NUMA && MIGRATION && !PREEMPT_RT
 | |
| 	help
 | |
| 	  This option adds support for automatic NUMA aware memory/task placement.
 | |
| 	  The mechanism is quite primitive and is based on migrating memory when
 | |
| 	  it has references to the node the task is running on.
 | |
| 
 | |
| 	  This system will be inactive on UMA systems.
 | |
| 
 | |
| config NUMA_BALANCING_DEFAULT_ENABLED
 | |
| 	bool "Automatically enable NUMA aware memory/task placement"
 | |
| 	default y
 | |
| 	depends on NUMA_BALANCING
 | |
| 	help
 | |
| 	  If set, automatic NUMA balancing will be enabled if running on a NUMA
 | |
| 	  machine.
 | |
| 
 | |
| menuconfig CGROUPS
 | |
| 	bool "Control Group support"
 | |
| 	select KERNFS
 | |
| 	help
 | |
| 	  This option adds support for grouping sets of processes together, for
 | |
| 	  use with process control subsystems such as Cpusets, CFS, memory
 | |
| 	  controls or device isolation.
 | |
| 	  See
 | |
| 		- Documentation/scheduler/sched-design-CFS.rst	(CFS)
 | |
| 		- Documentation/admin-guide/cgroup-v1/ (features for grouping, isolation
 | |
| 					  and resource control)
 | |
| 
 | |
| 	  Say N if unsure.
 | |
| 
 | |
| if CGROUPS
 | |
| 
 | |
| config PAGE_COUNTER
 | |
| 	bool
 | |
| 
 | |
| config CGROUP_FAVOR_DYNMODS
 | |
|         bool "Favor dynamic modification latency reduction by default"
 | |
|         help
 | |
|           This option enables the "favordynmods" mount option by default
 | |
|           which reduces the latencies of dynamic cgroup modifications such
 | |
|           as task migrations and controller on/offs at the cost of making
 | |
|           hot path operations such as forks and exits more expensive.
 | |
| 
 | |
|           Say N if unsure.
 | |
| 
 | |
| config MEMCG
 | |
| 	bool "Memory controller"
 | |
| 	select PAGE_COUNTER
 | |
| 	select EVENTFD
 | |
| 	help
 | |
| 	  Provides control over the memory footprint of tasks in a cgroup.
 | |
| 
 | |
| config MEMCG_KMEM
 | |
| 	bool
 | |
| 	depends on MEMCG && !SLOB
 | |
| 	default y
 | |
| 
 | |
| config BLK_CGROUP
 | |
| 	bool "IO controller"
 | |
| 	depends on BLOCK
 | |
| 	default n
 | |
| 	help
 | |
| 	Generic block IO controller cgroup interface. This is the common
 | |
| 	cgroup interface which should be used by various IO controlling
 | |
| 	policies.
 | |
| 
 | |
| 	Currently, CFQ IO scheduler uses it to recognize task groups and
 | |
| 	control disk bandwidth allocation (proportional time slice allocation)
 | |
| 	to such task groups. It is also used by bio throttling logic in
 | |
| 	block layer to implement upper limit in IO rates on a device.
 | |
| 
 | |
| 	This option only enables generic Block IO controller infrastructure.
 | |
| 	One needs to also enable actual IO controlling logic/policy. For
 | |
| 	enabling proportional weight division of disk bandwidth in CFQ, set
 | |
| 	CONFIG_BFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
 | |
| 	CONFIG_BLK_DEV_THROTTLING=y.
 | |
| 
 | |
| 	See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information.
 | |
| 
 | |
| config CGROUP_WRITEBACK
 | |
| 	bool
 | |
| 	depends on MEMCG && BLK_CGROUP
 | |
| 	default y
 | |
| 
 | |
| menuconfig CGROUP_SCHED
 | |
| 	bool "CPU controller"
 | |
| 	default n
 | |
| 	help
 | |
| 	  This feature lets CPU scheduler recognize task groups and control CPU
 | |
| 	  bandwidth allocation to such task groups. It uses cgroups to group
 | |
| 	  tasks.
 | |
| 
 | |
| if CGROUP_SCHED
 | |
| config FAIR_GROUP_SCHED
 | |
| 	bool "Group scheduling for SCHED_OTHER"
 | |
| 	depends on CGROUP_SCHED
 | |
| 	default CGROUP_SCHED
 | |
| 
 | |
| config CFS_BANDWIDTH
 | |
| 	bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
 | |
| 	depends on FAIR_GROUP_SCHED
 | |
| 	default n
 | |
| 	help
 | |
| 	  This option allows users to define CPU bandwidth rates (limits) for
 | |
| 	  tasks running within the fair group scheduler.  Groups with no limit
 | |
| 	  set are considered to be unconstrained and will run with no
 | |
| 	  restriction.
 | |
| 	  See Documentation/scheduler/sched-bwc.rst for more information.
 | |
| 
 | |
| config RT_GROUP_SCHED
 | |
| 	bool "Group scheduling for SCHED_RR/FIFO"
 | |
| 	depends on CGROUP_SCHED
 | |
| 	default n
 | |
| 	help
 | |
| 	  This feature lets you explicitly allocate real CPU bandwidth
 | |
| 	  to task groups. If enabled, it will also make it impossible to
 | |
| 	  schedule realtime tasks for non-root users until you allocate
 | |
| 	  realtime bandwidth for them.
 | |
| 	  See Documentation/scheduler/sched-rt-group.rst for more information.
 | |
| 
 | |
| endif #CGROUP_SCHED
 | |
| 
 | |
| config UCLAMP_TASK_GROUP
 | |
| 	bool "Utilization clamping per group of tasks"
 | |
| 	depends on CGROUP_SCHED
 | |
| 	depends on UCLAMP_TASK
 | |
| 	default n
 | |
| 	help
 | |
| 	  This feature enables the scheduler to track the clamped utilization
 | |
| 	  of each CPU based on RUNNABLE tasks currently scheduled on that CPU.
 | |
| 
 | |
| 	  When this option is enabled, the user can specify a min and max
 | |
| 	  CPU bandwidth which is allowed for each single task in a group.
 | |
| 	  The max bandwidth allows to clamp the maximum frequency a task
 | |
| 	  can use, while the min bandwidth allows to define a minimum
 | |
| 	  frequency a task will always use.
 | |
| 
 | |
| 	  When task group based utilization clamping is enabled, an eventually
 | |
| 	  specified task-specific clamp value is constrained by the cgroup
 | |
| 	  specified clamp value. Both minimum and maximum task clamping cannot
 | |
| 	  be bigger than the corresponding clamping defined at task group level.
 | |
| 
 | |
| 	  If in doubt, say N.
 | |
| 
 | |
| config CGROUP_PIDS
 | |
| 	bool "PIDs controller"
 | |
| 	help
 | |
| 	  Provides enforcement of process number limits in the scope of a
 | |
| 	  cgroup. Any attempt to fork more processes than is allowed in the
 | |
| 	  cgroup will fail. PIDs are fundamentally a global resource because it
 | |
| 	  is fairly trivial to reach PID exhaustion before you reach even a
 | |
| 	  conservative kmemcg limit. As a result, it is possible to grind a
 | |
| 	  system to halt without being limited by other cgroup policies. The
 | |
| 	  PIDs controller is designed to stop this from happening.
 | |
| 
 | |
| 	  It should be noted that organisational operations (such as attaching
 | |
| 	  to a cgroup hierarchy) will *not* be blocked by the PIDs controller,
 | |
| 	  since the PIDs limit only affects a process's ability to fork, not to
 | |
| 	  attach to a cgroup.
 | |
| 
 | |
| config CGROUP_RDMA
 | |
| 	bool "RDMA controller"
 | |
| 	help
 | |
| 	  Provides enforcement of RDMA resources defined by IB stack.
 | |
| 	  It is fairly easy for consumers to exhaust RDMA resources, which
 | |
| 	  can result into resource unavailability to other consumers.
 | |
| 	  RDMA controller is designed to stop this from happening.
 | |
| 	  Attaching processes with active RDMA resources to the cgroup
 | |
| 	  hierarchy is allowed even if can cross the hierarchy's limit.
 | |
| 
 | |
| config CGROUP_FREEZER
 | |
| 	bool "Freezer controller"
 | |
| 	help
 | |
| 	  Provides a way to freeze and unfreeze all tasks in a
 | |
| 	  cgroup.
 | |
| 
 | |
| 	  This option affects the ORIGINAL cgroup interface. The cgroup2 memory
 | |
| 	  controller includes important in-kernel memory consumers per default.
 | |
| 
 | |
| 	  If you're using cgroup2, say N.
 | |
| 
 | |
| config CGROUP_HUGETLB
 | |
| 	bool "HugeTLB controller"
 | |
| 	depends on HUGETLB_PAGE
 | |
| 	select PAGE_COUNTER
 | |
| 	default n
 | |
| 	help
 | |
| 	  Provides a cgroup controller for HugeTLB pages.
 | |
| 	  When you enable this, you can put a per cgroup limit on HugeTLB usage.
 | |
| 	  The limit is enforced during page fault. Since HugeTLB doesn't
 | |
| 	  support page reclaim, enforcing the limit at page fault time implies
 | |
| 	  that, the application will get SIGBUS signal if it tries to access
 | |
| 	  HugeTLB pages beyond its limit. This requires the application to know
 | |
| 	  beforehand how much HugeTLB pages it would require for its use. The
 | |
| 	  control group is tracked in the third page lru pointer. This means
 | |
| 	  that we cannot use the controller with huge page less than 3 pages.
 | |
| 
 | |
| config CPUSETS
 | |
| 	bool "Cpuset controller"
 | |
| 	depends on SMP
 | |
| 	help
 | |
| 	  This option will let you create and manage CPUSETs which
 | |
| 	  allow dynamically partitioning a system into sets of CPUs and
 | |
| 	  Memory Nodes and assigning tasks to run only within those sets.
 | |
| 	  This is primarily useful on large SMP or NUMA systems.
 | |
| 
 | |
| 	  Say N if unsure.
 | |
| 
 | |
| config PROC_PID_CPUSET
 | |
| 	bool "Include legacy /proc/<pid>/cpuset file"
 | |
| 	depends on CPUSETS
 | |
| 	default y
 | |
| 
 | |
| config CGROUP_DEVICE
 | |
| 	bool "Device controller"
 | |
| 	help
 | |
| 	  Provides a cgroup controller implementing whitelists for
 | |
| 	  devices which a process in the cgroup can mknod or open.
 | |
| 
 | |
| config CGROUP_CPUACCT
 | |
| 	bool "Simple CPU accounting controller"
 | |
| 	help
 | |
| 	  Provides a simple controller for monitoring the
 | |
| 	  total CPU consumed by the tasks in a cgroup.
 | |
| 
 | |
| config CGROUP_PERF
 | |
| 	bool "Perf controller"
 | |
| 	depends on PERF_EVENTS
 | |
| 	help
 | |
| 	  This option extends the perf per-cpu mode to restrict monitoring
 | |
| 	  to threads which belong to the cgroup specified and run on the
 | |
| 	  designated cpu.  Or this can be used to have cgroup ID in samples
 | |
| 	  so that it can monitor performance events among cgroups.
 | |
| 
 | |
| 	  Say N if unsure.
 | |
| 
 | |
| config CGROUP_BPF
 | |
| 	bool "Support for eBPF programs attached to cgroups"
 | |
| 	depends on BPF_SYSCALL
 | |
| 	select SOCK_CGROUP_DATA
 | |
| 	help
 | |
| 	  Allow attaching eBPF programs to a cgroup using the bpf(2)
 | |
| 	  syscall command BPF_PROG_ATTACH.
 | |
| 
 | |
| 	  In which context these programs are accessed depends on the type
 | |
| 	  of attachment. For instance, programs that are attached using
 | |
| 	  BPF_CGROUP_INET_INGRESS will be executed on the ingress path of
 | |
| 	  inet sockets.
 | |
| 
 | |
| config CGROUP_MISC
 | |
| 	bool "Misc resource controller"
 | |
| 	default n
 | |
| 	help
 | |
| 	  Provides a controller for miscellaneous resources on a host.
 | |
| 
 | |
| 	  Miscellaneous scalar resources are the resources on the host system
 | |
| 	  which cannot be abstracted like the other cgroups. This controller
 | |
| 	  tracks and limits the miscellaneous resources used by a process
 | |
| 	  attached to a cgroup hierarchy.
 | |
| 
 | |
| 	  For more information, please check misc cgroup section in
 | |
| 	  /Documentation/admin-guide/cgroup-v2.rst.
 | |
| 
 | |
| config CGROUP_DEBUG
 | |
| 	bool "Debug controller"
 | |
| 	default n
 | |
| 	depends on DEBUG_KERNEL
 | |
| 	help
 | |
| 	  This option enables a simple controller that exports
 | |
| 	  debugging information about the cgroups framework. This
 | |
| 	  controller is for control cgroup debugging only. Its
 | |
| 	  interfaces are not stable.
 | |
| 
 | |
| 	  Say N.
 | |
| 
 | |
| config SOCK_CGROUP_DATA
 | |
| 	bool
 | |
| 	default n
 | |
| 
 | |
| endif # CGROUPS
 | |
| 
 | |
| menuconfig NAMESPACES
 | |
| 	bool "Namespaces support" if EXPERT
 | |
| 	depends on MULTIUSER
 | |
| 	default !EXPERT
 | |
| 	help
 | |
| 	  Provides the way to make tasks work with different objects using
 | |
| 	  the same id. For example same IPC id may refer to different objects
 | |
| 	  or same user id or pid may refer to different tasks when used in
 | |
| 	  different namespaces.
 | |
| 
 | |
| if NAMESPACES
 | |
| 
 | |
| config UTS_NS
 | |
| 	bool "UTS namespace"
 | |
| 	default y
 | |
| 	help
 | |
| 	  In this namespace tasks see different info provided with the
 | |
| 	  uname() system call
 | |
| 
 | |
| config TIME_NS
 | |
| 	bool "TIME namespace"
 | |
| 	depends on GENERIC_VDSO_TIME_NS
 | |
| 	default y
 | |
| 	help
 | |
| 	  In this namespace boottime and monotonic clocks can be set.
 | |
| 	  The time will keep going with the same pace.
 | |
| 
 | |
| config IPC_NS
 | |
| 	bool "IPC namespace"
 | |
| 	depends on (SYSVIPC || POSIX_MQUEUE)
 | |
| 	default y
 | |
| 	help
 | |
| 	  In this namespace tasks work with IPC ids which correspond to
 | |
| 	  different IPC objects in different namespaces.
 | |
| 
 | |
| config USER_NS
 | |
| 	bool "User namespace"
 | |
| 	default n
 | |
| 	help
 | |
| 	  This allows containers, i.e. vservers, to use user namespaces
 | |
| 	  to provide different user info for different servers.
 | |
| 
 | |
| 	  When user namespaces are enabled in the kernel it is
 | |
| 	  recommended that the MEMCG option also be enabled and that
 | |
| 	  user-space use the memory control groups to limit the amount
 | |
| 	  of memory a memory unprivileged users can use.
 | |
| 
 | |
| 	  If unsure, say N.
 | |
| 
 | |
| config PID_NS
 | |
| 	bool "PID Namespaces"
 | |
| 	default y
 | |
| 	help
 | |
| 	  Support process id namespaces.  This allows having multiple
 | |
| 	  processes with the same pid as long as they are in different
 | |
| 	  pid namespaces.  This is a building block of containers.
 | |
| 
 | |
| config NET_NS
 | |
| 	bool "Network namespace"
 | |
| 	depends on NET
 | |
| 	default y
 | |
| 	help
 | |
| 	  Allow user space to create what appear to be multiple instances
 | |
| 	  of the network stack.
 | |
| 
 | |
| endif # NAMESPACES
 | |
| 
 | |
| config CHECKPOINT_RESTORE
 | |
| 	bool "Checkpoint/restore support"
 | |
| 	depends on PROC_FS
 | |
| 	select PROC_CHILDREN
 | |
| 	select KCMP
 | |
| 	default n
 | |
| 	help
 | |
| 	  Enables additional kernel features in a sake of checkpoint/restore.
 | |
| 	  In particular it adds auxiliary prctl codes to setup process text,
 | |
| 	  data and heap segment sizes, and a few additional /proc filesystem
 | |
| 	  entries.
 | |
| 
 | |
| 	  If unsure, say N here.
 | |
| 
 | |
| config SCHED_AUTOGROUP
 | |
| 	bool "Automatic process group scheduling"
 | |
| 	select CGROUPS
 | |
| 	select CGROUP_SCHED
 | |
| 	select FAIR_GROUP_SCHED
 | |
| 	help
 | |
| 	  This option optimizes the scheduler for common desktop workloads by
 | |
| 	  automatically creating and populating task groups.  This separation
 | |
| 	  of workloads isolates aggressive CPU burners (like build jobs) from
 | |
| 	  desktop applications.  Task group autogeneration is currently based
 | |
| 	  upon task session.
 | |
| 
 | |
| config SYSFS_DEPRECATED
 | |
| 	bool "Enable deprecated sysfs features to support old userspace tools"
 | |
| 	depends on SYSFS
 | |
| 	default n
 | |
| 	help
 | |
| 	  This option adds code that switches the layout of the "block" class
 | |
| 	  devices, to not show up in /sys/class/block/, but only in
 | |
| 	  /sys/block/.
 | |
| 
 | |
| 	  This switch is only active when the sysfs.deprecated=1 boot option is
 | |
| 	  passed or the SYSFS_DEPRECATED_V2 option is set.
 | |
| 
 | |
| 	  This option allows new kernels to run on old distributions and tools,
 | |
| 	  which might get confused by /sys/class/block/. Since 2007/2008 all
 | |
| 	  major distributions and tools handle this just fine.
 | |
| 
 | |
| 	  Recent distributions and userspace tools after 2009/2010 depend on
 | |
| 	  the existence of /sys/class/block/, and will not work with this
 | |
| 	  option enabled.
 | |
| 
 | |
| 	  Only if you are using a new kernel on an old distribution, you might
 | |
| 	  need to say Y here.
 | |
| 
 | |
| config SYSFS_DEPRECATED_V2
 | |
| 	bool "Enable deprecated sysfs features by default"
 | |
| 	default n
 | |
| 	depends on SYSFS
 | |
| 	depends on SYSFS_DEPRECATED
 | |
| 	help
 | |
| 	  Enable deprecated sysfs by default.
 | |
| 
 | |
| 	  See the CONFIG_SYSFS_DEPRECATED option for more details about this
 | |
| 	  option.
 | |
| 
 | |
| 	  Only if you are using a new kernel on an old distribution, you might
 | |
| 	  need to say Y here. Even then, odds are you would not need it
 | |
| 	  enabled, you can always pass the boot option if absolutely necessary.
 | |
| 
 | |
| config RELAY
 | |
| 	bool "Kernel->user space relay support (formerly relayfs)"
 | |
| 	select IRQ_WORK
 | |
| 	help
 | |
| 	  This option enables support for relay interface support in
 | |
| 	  certain file systems (such as debugfs).
 | |
| 	  It is designed to provide an efficient mechanism for tools and
 | |
| 	  facilities to relay large amounts of data from kernel space to
 | |
| 	  user space.
 | |
| 
 | |
| 	  If unsure, say N.
 | |
| 
 | |
| config BLK_DEV_INITRD
 | |
| 	bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
 | |
| 	help
 | |
| 	  The initial RAM filesystem is a ramfs which is loaded by the
 | |
| 	  boot loader (loadlin or lilo) and that is mounted as root
 | |
| 	  before the normal boot procedure. It is typically used to
 | |
| 	  load modules needed to mount the "real" root file system,
 | |
| 	  etc. See <file:Documentation/admin-guide/initrd.rst> for details.
 | |
| 
 | |
| 	  If RAM disk support (BLK_DEV_RAM) is also included, this
 | |
| 	  also enables initial RAM disk (initrd) support and adds
 | |
| 	  15 Kbytes (more on some other architectures) to the kernel size.
 | |
| 
 | |
| 	  If unsure say Y.
 | |
| 
 | |
| if BLK_DEV_INITRD
 | |
| 
 | |
| source "usr/Kconfig"
 | |
| 
 | |
| endif
 | |
| 
 | |
| config INITCALL_ASYNC
 | |
| 	bool "Call initcall async"
 | |
| 	depends on ROCKCHIP_THUNDER_BOOT
 | |
| 	help
 | |
| 	  Call same level initcall async in kthread.
 | |
| 	  Kernel parameter "initcall_nr_threads" control how many threads.
 | |
| 	  initcall_nr_threads default is 0, which disable intcall async.
 | |
| 	  initcall_nr_threads=-1, auto selected the number of threads.
 | |
| 
 | |
| config BOOT_CONFIG
 | |
| 	bool "Boot config support"
 | |
| 	select BLK_DEV_INITRD if !BOOT_CONFIG_EMBED
 | |
| 	help
 | |
| 	  Extra boot config allows system admin to pass a config file as
 | |
| 	  complemental extension of kernel cmdline when booting.
 | |
| 	  The boot config file must be attached at the end of initramfs
 | |
| 	  with checksum, size and magic word.
 | |
| 	  See <file:Documentation/admin-guide/bootconfig.rst> for details.
 | |
| 
 | |
| 	  If unsure, say Y.
 | |
| 
 | |
| config BOOT_CONFIG_EMBED
 | |
| 	bool "Embed bootconfig file in the kernel"
 | |
| 	depends on BOOT_CONFIG
 | |
| 	help
 | |
| 	  Embed a bootconfig file given by BOOT_CONFIG_EMBED_FILE in the
 | |
| 	  kernel. Usually, the bootconfig file is loaded with the initrd
 | |
| 	  image. But if the system doesn't support initrd, this option will
 | |
| 	  help you by embedding a bootconfig file while building the kernel.
 | |
| 
 | |
| 	  If unsure, say N.
 | |
| 
 | |
| config BOOT_CONFIG_EMBED_FILE
 | |
| 	string "Embedded bootconfig file path"
 | |
| 	depends on BOOT_CONFIG_EMBED
 | |
| 	help
 | |
| 	  Specify a bootconfig file which will be embedded to the kernel.
 | |
| 	  This bootconfig will be used if there is no initrd or no other
 | |
| 	  bootconfig in the initrd.
 | |
| 
 | |
| config INITRAMFS_PRESERVE_MTIME
 | |
| 	bool "Preserve cpio archive mtimes in initramfs"
 | |
| 	default y
 | |
| 	help
 | |
| 	  Each entry in an initramfs cpio archive carries an mtime value. When
 | |
| 	  enabled, extracted cpio items take this mtime, with directory mtime
 | |
| 	  setting deferred until after creation of any child entries.
 | |
| 
 | |
| 	  If unsure, say Y.
 | |
| 
 | |
| choice
 | |
| 	prompt "Compiler optimization level"
 | |
| 	default CC_OPTIMIZE_FOR_PERFORMANCE
 | |
| 
 | |
| config CC_OPTIMIZE_FOR_PERFORMANCE
 | |
| 	bool "Optimize for performance (-O2)"
 | |
| 	help
 | |
| 	  This is the default optimization level for the kernel, building
 | |
| 	  with the "-O2" compiler flag for best performance and most
 | |
| 	  helpful compile-time warnings.
 | |
| 
 | |
| config CC_OPTIMIZE_FOR_SIZE
 | |
| 	bool "Optimize for size (-Os)"
 | |
| 	help
 | |
| 	  Choosing this option will pass "-Os" to your compiler resulting
 | |
| 	  in a smaller kernel.
 | |
| 
 | |
| endchoice
 | |
| 
 | |
| config HAVE_LD_DEAD_CODE_DATA_ELIMINATION
 | |
| 	bool
 | |
| 	help
 | |
| 	  This requires that the arch annotates or otherwise protects
 | |
| 	  its external entry points from being discarded. Linker scripts
 | |
| 	  must also merge .text.*, .data.*, and .bss.* correctly into
 | |
| 	  output sections. Care must be taken not to pull in unrelated
 | |
| 	  sections (e.g., '.text.init'). Typically '.' in section names
 | |
| 	  is used to distinguish them from label names / C identifiers.
 | |
| 
 | |
| config LD_DEAD_CODE_DATA_ELIMINATION
 | |
| 	bool "Dead code and data elimination (EXPERIMENTAL)"
 | |
| 	depends on HAVE_LD_DEAD_CODE_DATA_ELIMINATION
 | |
| 	depends on EXPERT
 | |
| 	depends on $(cc-option,-ffunction-sections -fdata-sections)
 | |
| 	depends on $(ld-option,--gc-sections)
 | |
| 	help
 | |
| 	  Enable this if you want to do dead code and data elimination with
 | |
| 	  the linker by compiling with -ffunction-sections -fdata-sections,
 | |
| 	  and linking with --gc-sections.
 | |
| 
 | |
| 	  This can reduce on disk and in-memory size of the kernel
 | |
| 	  code and static data, particularly for small configs and
 | |
| 	  on small systems. This has the possibility of introducing
 | |
| 	  silently broken kernel if the required annotations are not
 | |
| 	  present. This option is not well tested yet, so use at your
 | |
| 	  own risk.
 | |
| 
 | |
| config LD_ORPHAN_WARN
 | |
| 	def_bool y
 | |
| 	depends on ARCH_WANT_LD_ORPHAN_WARN
 | |
| 	depends on $(ld-option,--orphan-handling=warn)
 | |
| 
 | |
| config SYSCTL
 | |
| 	bool
 | |
| 
 | |
| config HAVE_UID16
 | |
| 	bool
 | |
| 
 | |
| config SYSCTL_EXCEPTION_TRACE
 | |
| 	bool
 | |
| 	help
 | |
| 	  Enable support for /proc/sys/debug/exception-trace.
 | |
| 
 | |
| config SYSCTL_ARCH_UNALIGN_NO_WARN
 | |
| 	bool
 | |
| 	help
 | |
| 	  Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
 | |
| 	  Allows arch to define/use @no_unaligned_warning to possibly warn
 | |
| 	  about unaligned access emulation going on under the hood.
 | |
| 
 | |
| config SYSCTL_ARCH_UNALIGN_ALLOW
 | |
| 	bool
 | |
| 	help
 | |
| 	  Enable support for /proc/sys/kernel/unaligned-trap
 | |
| 	  Allows arches to define/use @unaligned_enabled to runtime toggle
 | |
| 	  the unaligned access emulation.
 | |
| 	  see arch/parisc/kernel/unaligned.c for reference
 | |
| 
 | |
| config HAVE_PCSPKR_PLATFORM
 | |
| 	bool
 | |
| 
 | |
| # interpreter that classic socket filters depend on
 | |
| config BPF
 | |
| 	bool
 | |
| 	select CRYPTO_LIB_SHA1
 | |
| 
 | |
| menuconfig EXPERT
 | |
| 	bool "Configure standard kernel features (expert users)"
 | |
| 	# Unhide debug options, to make the on-by-default options visible
 | |
| 	select DEBUG_KERNEL
 | |
| 	help
 | |
| 	  This option allows certain base kernel options and settings
 | |
| 	  to be disabled or tweaked. This is for specialized
 | |
| 	  environments which can tolerate a "non-standard" kernel.
 | |
| 	  Only use this if you really know what you are doing.
 | |
| 
 | |
| config UID16
 | |
| 	bool "Enable 16-bit UID system calls" if EXPERT
 | |
| 	depends on HAVE_UID16 && MULTIUSER
 | |
| 	default y
 | |
| 	help
 | |
| 	  This enables the legacy 16-bit UID syscall wrappers.
 | |
| 
 | |
| config MULTIUSER
 | |
| 	bool "Multiple users, groups and capabilities support" if EXPERT
 | |
| 	default y
 | |
| 	help
 | |
| 	  This option enables support for non-root users, groups and
 | |
| 	  capabilities.
 | |
| 
 | |
| 	  If you say N here, all processes will run with UID 0, GID 0, and all
 | |
| 	  possible capabilities.  Saying N here also compiles out support for
 | |
| 	  system calls related to UIDs, GIDs, and capabilities, such as setuid,
 | |
| 	  setgid, and capset.
 | |
| 
 | |
| 	  If unsure, say Y here.
 | |
| 
 | |
| config SGETMASK_SYSCALL
 | |
| 	bool "sgetmask/ssetmask syscalls support" if EXPERT
 | |
| 	def_bool PARISC || M68K || PPC || MIPS || X86 || SPARC || MICROBLAZE || SUPERH
 | |
| 	help
 | |
| 	  sys_sgetmask and sys_ssetmask are obsolete system calls
 | |
| 	  no longer supported in libc but still enabled by default in some
 | |
| 	  architectures.
 | |
| 
 | |
| 	  If unsure, leave the default option here.
 | |
| 
 | |
| config SYSFS_SYSCALL
 | |
| 	bool "Sysfs syscall support" if EXPERT
 | |
| 	default y
 | |
| 	help
 | |
| 	  sys_sysfs is an obsolete system call no longer supported in libc.
 | |
| 	  Note that disabling this option is more secure but might break
 | |
| 	  compatibility with some systems.
 | |
| 
 | |
| 	  If unsure say Y here.
 | |
| 
 | |
| config FHANDLE
 | |
| 	bool "open by fhandle syscalls" if EXPERT
 | |
| 	select EXPORTFS
 | |
| 	default y
 | |
| 	help
 | |
| 	  If you say Y here, a user level program will be able to map
 | |
| 	  file names to handle and then later use the handle for
 | |
| 	  different file system operations. This is useful in implementing
 | |
| 	  userspace file servers, which now track files using handles instead
 | |
| 	  of names. The handle would remain the same even if file names
 | |
| 	  get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
 | |
| 	  syscalls.
 | |
| 
 | |
| config POSIX_TIMERS
 | |
| 	bool "Posix Clocks & timers" if EXPERT
 | |
| 	default y
 | |
| 	help
 | |
| 	  This includes native support for POSIX timers to the kernel.
 | |
| 	  Some embedded systems have no use for them and therefore they
 | |
| 	  can be configured out to reduce the size of the kernel image.
 | |
| 
 | |
| 	  When this option is disabled, the following syscalls won't be
 | |
| 	  available: timer_create, timer_gettime: timer_getoverrun,
 | |
| 	  timer_settime, timer_delete, clock_adjtime, getitimer,
 | |
| 	  setitimer, alarm. Furthermore, the clock_settime, clock_gettime,
 | |
| 	  clock_getres and clock_nanosleep syscalls will be limited to
 | |
| 	  CLOCK_REALTIME, CLOCK_MONOTONIC and CLOCK_BOOTTIME only.
 | |
| 
 | |
| 	  If unsure say y.
 | |
| 
 | |
| config PRINTK
 | |
| 	default y
 | |
| 	bool "Enable support for printk" if EXPERT
 | |
| 	select IRQ_WORK
 | |
| 	help
 | |
| 	  This option enables normal printk support. Removing it
 | |
| 	  eliminates most of the message strings from the kernel image
 | |
| 	  and makes the kernel more or less silent. As this makes it
 | |
| 	  very difficult to diagnose system problems, saying N here is
 | |
| 	  strongly discouraged.
 | |
| 
 | |
| config BUG
 | |
| 	bool "BUG() support" if EXPERT
 | |
| 	default y
 | |
| 	help
 | |
| 	  Disabling this option eliminates support for BUG and WARN, reducing
 | |
| 	  the size of your kernel image and potentially quietly ignoring
 | |
| 	  numerous fatal conditions. You should only consider disabling this
 | |
| 	  option for embedded systems with no facilities for reporting errors.
 | |
| 	  Just say Y.
 | |
| 
 | |
| config ELF_CORE
 | |
| 	depends on COREDUMP
 | |
| 	default y
 | |
| 	bool "Enable ELF core dumps" if EXPERT
 | |
| 	help
 | |
| 	  Enable support for generating core dumps. Disabling saves about 4k.
 | |
| 
 | |
| 
 | |
| config PCSPKR_PLATFORM
 | |
| 	bool "Enable PC-Speaker support" if EXPERT
 | |
| 	depends on HAVE_PCSPKR_PLATFORM
 | |
| 	select I8253_LOCK
 | |
| 	default y
 | |
| 	help
 | |
| 	  This option allows to disable the internal PC-Speaker
 | |
| 	  support, saving some memory.
 | |
| 
 | |
| config BASE_FULL
 | |
| 	default y
 | |
| 	bool "Enable full-sized data structures for core" if EXPERT
 | |
| 	help
 | |
| 	  Disabling this option reduces the size of miscellaneous core
 | |
| 	  kernel data structures. This saves memory on small machines,
 | |
| 	  but may reduce performance.
 | |
| 
 | |
| config FUTEX
 | |
| 	bool "Enable futex support" if EXPERT
 | |
| 	depends on !(SPARC32 && SMP)
 | |
| 	default y
 | |
| 	imply RT_MUTEXES
 | |
| 	help
 | |
| 	  Disabling this option will cause the kernel to be built without
 | |
| 	  support for "fast userspace mutexes".  The resulting kernel may not
 | |
| 	  run glibc-based applications correctly.
 | |
| 
 | |
| config FUTEX_PI
 | |
| 	bool
 | |
| 	depends on FUTEX && RT_MUTEXES
 | |
| 	default y
 | |
| 
 | |
| config EPOLL
 | |
| 	bool "Enable eventpoll support" if EXPERT
 | |
| 	default y
 | |
| 	help
 | |
| 	  Disabling this option will cause the kernel to be built without
 | |
| 	  support for epoll family of system calls.
 | |
| 
 | |
| config SIGNALFD
 | |
| 	bool "Enable signalfd() system call" if EXPERT
 | |
| 	default y
 | |
| 	help
 | |
| 	  Enable the signalfd() system call that allows to receive signals
 | |
| 	  on a file descriptor.
 | |
| 
 | |
| 	  If unsure, say Y.
 | |
| 
 | |
| config TIMERFD
 | |
| 	bool "Enable timerfd() system call" if EXPERT
 | |
| 	default y
 | |
| 	help
 | |
| 	  Enable the timerfd() system call that allows to receive timer
 | |
| 	  events on a file descriptor.
 | |
| 
 | |
| 	  If unsure, say Y.
 | |
| 
 | |
| config EVENTFD
 | |
| 	bool "Enable eventfd() system call" if EXPERT
 | |
| 	default y
 | |
| 	help
 | |
| 	  Enable the eventfd() system call that allows to receive both
 | |
| 	  kernel notification (ie. KAIO) or userspace notifications.
 | |
| 
 | |
| 	  If unsure, say Y.
 | |
| 
 | |
| config SHMEM
 | |
| 	bool "Use full shmem filesystem" if EXPERT
 | |
| 	default y
 | |
| 	depends on MMU
 | |
| 	help
 | |
| 	  The shmem is an internal filesystem used to manage shared memory.
 | |
| 	  It is backed by swap and manages resource limits. It is also exported
 | |
| 	  to userspace as tmpfs if TMPFS is enabled. Disabling this
 | |
| 	  option replaces shmem and tmpfs with the much simpler ramfs code,
 | |
| 	  which may be appropriate on small systems without swap.
 | |
| 
 | |
| config AIO
 | |
| 	bool "Enable AIO support" if EXPERT
 | |
| 	default y
 | |
| 	help
 | |
| 	  This option enables POSIX asynchronous I/O which may by used
 | |
| 	  by some high performance threaded applications. Disabling
 | |
| 	  this option saves about 7k.
 | |
| 
 | |
| config IO_URING
 | |
| 	bool "Enable IO uring support" if EXPERT
 | |
| 	select IO_WQ
 | |
| 	default y
 | |
| 	help
 | |
| 	  This option enables support for the io_uring interface, enabling
 | |
| 	  applications to submit and complete IO through submission and
 | |
| 	  completion rings that are shared between the kernel and application.
 | |
| 
 | |
| config ADVISE_SYSCALLS
 | |
| 	bool "Enable madvise/fadvise syscalls" if EXPERT
 | |
| 	default y
 | |
| 	help
 | |
| 	  This option enables the madvise and fadvise syscalls, used by
 | |
| 	  applications to advise the kernel about their future memory or file
 | |
| 	  usage, improving performance. If building an embedded system where no
 | |
| 	  applications use these syscalls, you can disable this option to save
 | |
| 	  space.
 | |
| 
 | |
| config MEMBARRIER
 | |
| 	bool "Enable membarrier() system call" if EXPERT
 | |
| 	default y
 | |
| 	help
 | |
| 	  Enable the membarrier() system call that allows issuing memory
 | |
| 	  barriers across all running threads, which can be used to distribute
 | |
| 	  the cost of user-space memory barriers asymmetrically by transforming
 | |
| 	  pairs of memory barriers into pairs consisting of membarrier() and a
 | |
| 	  compiler barrier.
 | |
| 
 | |
| 	  If unsure, say Y.
 | |
| 
 | |
| config KALLSYMS
 | |
| 	bool "Load all symbols for debugging/ksymoops" if EXPERT
 | |
| 	default y
 | |
| 	help
 | |
| 	  Say Y here to let the kernel print out symbolic crash information and
 | |
| 	  symbolic stack backtraces. This increases the size of the kernel
 | |
| 	  somewhat, as all symbols have to be loaded into the kernel image.
 | |
| 
 | |
| config KALLSYMS_ALL
 | |
| 	bool "Include all symbols in kallsyms"
 | |
| 	depends on DEBUG_KERNEL && KALLSYMS
 | |
| 	help
 | |
| 	  Normally kallsyms only contains the symbols of functions for nicer
 | |
| 	  OOPS messages and backtraces (i.e., symbols from the text and inittext
 | |
| 	  sections). This is sufficient for most cases. And only if you want to
 | |
| 	  enable kernel live patching, or other less common use cases (e.g.,
 | |
| 	  when a debugger is used) all symbols are required (i.e., names of
 | |
| 	  variables from the data sections, etc).
 | |
| 
 | |
| 	  This option makes sure that all symbols are loaded into the kernel
 | |
| 	  image (i.e., symbols from all sections) in cost of increased kernel
 | |
| 	  size (depending on the kernel configuration, it may be 300KiB or
 | |
| 	  something like this).
 | |
| 
 | |
| 	  Say N unless you really need all symbols, or kernel live patching.
 | |
| 
 | |
| config KALLSYMS_ABSOLUTE_PERCPU
 | |
| 	bool
 | |
| 	depends on KALLSYMS
 | |
| 	default X86_64 && SMP
 | |
| 
 | |
| config KALLSYMS_BASE_RELATIVE
 | |
| 	bool
 | |
| 	depends on KALLSYMS
 | |
| 	default !IA64
 | |
| 	help
 | |
| 	  Instead of emitting them as absolute values in the native word size,
 | |
| 	  emit the symbol references in the kallsyms table as 32-bit entries,
 | |
| 	  each containing a relative value in the range [base, base + U32_MAX]
 | |
| 	  or, when KALLSYMS_ABSOLUTE_PERCPU is in effect, each containing either
 | |
| 	  an absolute value in the range [0, S32_MAX] or a relative value in the
 | |
| 	  range [base, base + S32_MAX], where base is the lowest relative symbol
 | |
| 	  address encountered in the image.
 | |
| 
 | |
| 	  On 64-bit builds, this reduces the size of the address table by 50%,
 | |
| 	  but more importantly, it results in entries whose values are build
 | |
| 	  time constants, and no relocation pass is required at runtime to fix
 | |
| 	  up the entries based on the runtime load address of the kernel.
 | |
| 
 | |
| # end of the "standard kernel features (expert users)" menu
 | |
| 
 | |
| # syscall, maps, verifier
 | |
| 
 | |
| config ARCH_HAS_MEMBARRIER_CALLBACKS
 | |
| 	bool
 | |
| 
 | |
| config ARCH_HAS_MEMBARRIER_SYNC_CORE
 | |
| 	bool
 | |
| 
 | |
| config KCMP
 | |
| 	bool "Enable kcmp() system call" if EXPERT
 | |
| 	help
 | |
| 	  Enable the kernel resource comparison system call. It provides
 | |
| 	  user-space with the ability to compare two processes to see if they
 | |
| 	  share a common resource, such as a file descriptor or even virtual
 | |
| 	  memory space.
 | |
| 
 | |
| 	  If unsure, say N.
 | |
| 
 | |
| config RSEQ
 | |
| 	bool "Enable rseq() system call" if EXPERT
 | |
| 	default y
 | |
| 	depends on HAVE_RSEQ
 | |
| 	select MEMBARRIER
 | |
| 	help
 | |
| 	  Enable the restartable sequences system call. It provides a
 | |
| 	  user-space cache for the current CPU number value, which
 | |
| 	  speeds up getting the current CPU number from user-space,
 | |
| 	  as well as an ABI to speed up user-space operations on
 | |
| 	  per-CPU data.
 | |
| 
 | |
| 	  If unsure, say Y.
 | |
| 
 | |
| config DEBUG_RSEQ
 | |
| 	default n
 | |
| 	bool "Enabled debugging of rseq() system call" if EXPERT
 | |
| 	depends on RSEQ && DEBUG_KERNEL
 | |
| 	help
 | |
| 	  Enable extra debugging checks for the rseq system call.
 | |
| 
 | |
| 	  If unsure, say N.
 | |
| 
 | |
| config EMBEDDED
 | |
| 	bool "Embedded system"
 | |
| 	select EXPERT
 | |
| 	help
 | |
| 	  This option should be enabled if compiling the kernel for
 | |
| 	  an embedded system so certain expert options are available
 | |
| 	  for configuration.
 | |
| 
 | |
| config HAVE_PERF_EVENTS
 | |
| 	bool
 | |
| 	help
 | |
| 	  See tools/perf/design.txt for details.
 | |
| 
 | |
| config GUEST_PERF_EVENTS
 | |
| 	bool
 | |
| 	depends on HAVE_PERF_EVENTS
 | |
| 
 | |
| config PERF_USE_VMALLOC
 | |
| 	bool
 | |
| 	help
 | |
| 	  See tools/perf/design.txt for details
 | |
| 
 | |
| config PC104
 | |
| 	bool "PC/104 support" if EXPERT
 | |
| 	help
 | |
| 	  Expose PC/104 form factor device drivers and options available for
 | |
| 	  selection and configuration. Enable this option if your target
 | |
| 	  machine has a PC/104 bus.
 | |
| 
 | |
| menu "Kernel Performance Events And Counters"
 | |
| 
 | |
| config PERF_EVENTS
 | |
| 	bool "Kernel performance events and counters"
 | |
| 	default y if PROFILING
 | |
| 	depends on HAVE_PERF_EVENTS
 | |
| 	select IRQ_WORK
 | |
| 	select SRCU
 | |
| 	help
 | |
| 	  Enable kernel support for various performance events provided
 | |
| 	  by software and hardware.
 | |
| 
 | |
| 	  Software events are supported either built-in or via the
 | |
| 	  use of generic tracepoints.
 | |
| 
 | |
| 	  Most modern CPUs support performance events via performance
 | |
| 	  counter registers. These registers count the number of certain
 | |
| 	  types of hw events: such as instructions executed, cachemisses
 | |
| 	  suffered, or branches mis-predicted - without slowing down the
 | |
| 	  kernel or applications. These registers can also trigger interrupts
 | |
| 	  when a threshold number of events have passed - and can thus be
 | |
| 	  used to profile the code that runs on that CPU.
 | |
| 
 | |
| 	  The Linux Performance Event subsystem provides an abstraction of
 | |
| 	  these software and hardware event capabilities, available via a
 | |
| 	  system call and used by the "perf" utility in tools/perf/. It
 | |
| 	  provides per task and per CPU counters, and it provides event
 | |
| 	  capabilities on top of those.
 | |
| 
 | |
| 	  Say Y if unsure.
 | |
| 
 | |
| config DEBUG_PERF_USE_VMALLOC
 | |
| 	default n
 | |
| 	bool "Debug: use vmalloc to back perf mmap() buffers"
 | |
| 	depends on PERF_EVENTS && DEBUG_KERNEL && !PPC
 | |
| 	select PERF_USE_VMALLOC
 | |
| 	help
 | |
| 	  Use vmalloc memory to back perf mmap() buffers.
 | |
| 
 | |
| 	  Mostly useful for debugging the vmalloc code on platforms
 | |
| 	  that don't require it.
 | |
| 
 | |
| 	  Say N if unsure.
 | |
| 
 | |
| endmenu
 | |
| 
 | |
| config SYSTEM_DATA_VERIFICATION
 | |
| 	def_bool n
 | |
| 	select SYSTEM_TRUSTED_KEYRING
 | |
| 	select KEYS
 | |
| 	select CRYPTO
 | |
| 	select CRYPTO_RSA
 | |
| 	select ASYMMETRIC_KEY_TYPE
 | |
| 	select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
 | |
| 	select ASN1
 | |
| 	select OID_REGISTRY
 | |
| 	select X509_CERTIFICATE_PARSER
 | |
| 	select PKCS7_MESSAGE_PARSER
 | |
| 	help
 | |
| 	  Provide PKCS#7 message verification using the contents of the system
 | |
| 	  trusted keyring to provide public keys.  This then can be used for
 | |
| 	  module verification, kexec image verification and firmware blob
 | |
| 	  verification.
 | |
| 
 | |
| config PROFILING
 | |
| 	bool "Profiling support"
 | |
| 	help
 | |
| 	  Say Y here to enable the extended profiling support mechanisms used
 | |
| 	  by profilers.
 | |
| 
 | |
| config RUST
 | |
| 	bool "Rust support"
 | |
| 	depends on HAVE_RUST
 | |
| 	depends on RUST_IS_AVAILABLE
 | |
| 	depends on !CFI_CLANG
 | |
| 	depends on !MODVERSIONS
 | |
| 	depends on !GCC_PLUGINS
 | |
| 	depends on !RANDSTRUCT
 | |
| 	depends on !DEBUG_INFO_BTF || PAHOLE_HAS_LANG_EXCLUDE
 | |
| 	help
 | |
| 	  Enables Rust support in the kernel.
 | |
| 
 | |
| 	  This allows other Rust-related options, like drivers written in Rust,
 | |
| 	  to be selected.
 | |
| 
 | |
| 	  It is also required to be able to load external kernel modules
 | |
| 	  written in Rust.
 | |
| 
 | |
| 	  See Documentation/rust/ for more information.
 | |
| 
 | |
| 	  If unsure, say N.
 | |
| 
 | |
| config RUSTC_VERSION_TEXT
 | |
| 	string
 | |
| 	depends on RUST
 | |
| 	default $(shell,command -v $(RUSTC) >/dev/null 2>&1 && $(RUSTC) --version || echo n)
 | |
| 
 | |
| config BINDGEN_VERSION_TEXT
 | |
| 	string
 | |
| 	depends on RUST
 | |
| 	default $(shell,command -v $(BINDGEN) >/dev/null 2>&1 && $(BINDGEN) --version || echo n)
 | |
| 
 | |
| #
 | |
| # Place an empty function call at each tracepoint site. Can be
 | |
| # dynamically changed for a probe function.
 | |
| #
 | |
| config TRACEPOINTS
 | |
| 	bool
 | |
| 
 | |
| endmenu		# General setup
 | |
| 
 | |
| source "arch/Kconfig"
 | |
| 
 | |
| config RT_MUTEXES
 | |
| 	bool
 | |
| 	default y if PREEMPT_RT
 | |
| 
 | |
| config BASE_SMALL
 | |
| 	int
 | |
| 	default 0 if BASE_FULL
 | |
| 	default 1 if !BASE_FULL
 | |
| 
 | |
| config MODULE_SIG_FORMAT
 | |
| 	def_bool n
 | |
| 	select SYSTEM_DATA_VERIFICATION
 | |
| 
 | |
| source "kernel/module/Kconfig"
 | |
| 
 | |
| config INIT_ALL_POSSIBLE
 | |
| 	bool
 | |
| 	help
 | |
| 	  Back when each arch used to define their own cpu_online_mask and
 | |
| 	  cpu_possible_mask, some of them chose to initialize cpu_possible_mask
 | |
| 	  with all 1s, and others with all 0s.  When they were centralised,
 | |
| 	  it was better to provide this option than to break all the archs
 | |
| 	  and have several arch maintainers pursuing me down dark alleys.
 | |
| 
 | |
| source "block/Kconfig"
 | |
| 
 | |
| config PREEMPT_NOTIFIERS
 | |
| 	bool
 | |
| 
 | |
| config PADATA
 | |
| 	depends on SMP
 | |
| 	bool
 | |
| 
 | |
| config ASN1
 | |
| 	tristate
 | |
| 	help
 | |
| 	  Build a simple ASN.1 grammar compiler that produces a bytecode output
 | |
| 	  that can be interpreted by the ASN.1 stream decoder and used to
 | |
| 	  inform it as to what tags are to be expected in a stream and what
 | |
| 	  functions to call on what tags.
 | |
| 
 | |
| source "kernel/Kconfig.locks"
 | |
| 
 | |
| config ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
 | |
| 	bool
 | |
| 
 | |
| config ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
 | |
| 	bool
 | |
| 
 | |
| # It may be useful for an architecture to override the definitions of the
 | |
| # SYSCALL_DEFINE() and __SYSCALL_DEFINEx() macros in <linux/syscalls.h>
 | |
| # and the COMPAT_ variants in <linux/compat.h>, in particular to use a
 | |
| # different calling convention for syscalls. They can also override the
 | |
| # macros for not-implemented syscalls in kernel/sys_ni.c and
 | |
| # kernel/time/posix-stubs.c. All these overrides need to be available in
 | |
| # <asm/syscall_wrapper.h>.
 | |
| config ARCH_HAS_SYSCALL_WRAPPER
 | |
| 	def_bool n
 |