xref: /linux/init/Kconfig (revision 3ad66a34cce2c5a6532ac0b979fdf58677193c67)
1ec8f24b7SThomas Gleixner# SPDX-License-Identifier: GPL-2.0-only
28b59cd81SMasahiro Yamadaconfig CC_VERSION_TEXT
38b59cd81SMasahiro Yamada	string
48b59cd81SMasahiro Yamada	default "$(CC_VERSION_TEXT)"
58b59cd81SMasahiro Yamada	help
68b59cd81SMasahiro Yamada	  This is used in unclear ways:
78b59cd81SMasahiro Yamada
88b59cd81SMasahiro Yamada	  - Re-run Kconfig when the compiler is updated
98b59cd81SMasahiro Yamada	    The 'default' property references the environment variable,
108b59cd81SMasahiro Yamada	    CC_VERSION_TEXT so it is recorded in include/config/auto.conf.cmd.
118b59cd81SMasahiro Yamada	    When the compiler is updated, Kconfig will be invoked.
128b59cd81SMasahiro Yamada
13f9c8bc46SBhaskar Chowdhury	  - Ensure full rebuild when the compiler is updated
14ce6ed1c4SMasahiro Yamada	    include/linux/compiler-version.h contains this option in the comment
150e0345b7SAlexey Dobriyan	    line so fixdep adds include/config/CC_VERSION_TEXT into the
16ce6ed1c4SMasahiro Yamada	    auto-generated dependency. When the compiler is updated, syncconfig
17ce6ed1c4SMasahiro Yamada	    will touch it and then every file will be rebuilt.
188b59cd81SMasahiro Yamada
19a4353898SMasahiro Yamadaconfig CC_IS_GCC
20aec6c60aSMasahiro Yamada	def_bool $(success,test "$(cc-name)" = GCC)
21a4353898SMasahiro Yamada
22a4353898SMasahiro Yamadaconfig GCC_VERSION
23a4353898SMasahiro Yamada	int
24aec6c60aSMasahiro Yamada	default $(cc-version) if CC_IS_GCC
25a4353898SMasahiro Yamada	default 0
26a4353898SMasahiro Yamada
27469cb737SMasahiro Yamadaconfig CC_IS_CLANG
28aec6c60aSMasahiro Yamada	def_bool $(success,test "$(cc-name)" = Clang)
29b744b43fSSami Tolvanen
30469cb737SMasahiro Yamadaconfig CLANG_VERSION
31469cb737SMasahiro Yamada	int
32aec6c60aSMasahiro Yamada	default $(cc-version) if CC_IS_CLANG
33aec6c60aSMasahiro Yamada	default 0
34469cb737SMasahiro Yamada
35ba64beb1SMasahiro Yamadaconfig AS_IS_GNU
36ba64beb1SMasahiro Yamada	def_bool $(success,test "$(as-name)" = GNU)
37ba64beb1SMasahiro Yamada
38ba64beb1SMasahiro Yamadaconfig AS_IS_LLVM
39ba64beb1SMasahiro Yamada	def_bool $(success,test "$(as-name)" = LLVM)
40ba64beb1SMasahiro Yamada
41ba64beb1SMasahiro Yamadaconfig AS_VERSION
42ba64beb1SMasahiro Yamada	int
43ba64beb1SMasahiro Yamada	# Use clang version if this is the integrated assembler
44ba64beb1SMasahiro Yamada	default CLANG_VERSION if AS_IS_LLVM
45ba64beb1SMasahiro Yamada	default $(as-version)
46ba64beb1SMasahiro Yamada
4702aff859SMasahiro Yamadaconfig LD_IS_BFD
4802aff859SMasahiro Yamada	def_bool $(success,test "$(ld-name)" = BFD)
4902aff859SMasahiro Yamada
5002aff859SMasahiro Yamadaconfig LD_VERSION
5102aff859SMasahiro Yamada	int
5202aff859SMasahiro Yamada	default $(ld-version) if LD_IS_BFD
5302aff859SMasahiro Yamada	default 0
5402aff859SMasahiro Yamada
5502aff859SMasahiro Yamadaconfig LD_IS_LLD
5602aff859SMasahiro Yamada	def_bool $(success,test "$(ld-name)" = LLD)
57c65eacbeSAndy Lutomirski
58d5750cd3SNathan Chancellorconfig LLD_VERSION
59d5750cd3SNathan Chancellor	int
6002aff859SMasahiro Yamada	default $(ld-version) if LD_IS_LLD
6102aff859SMasahiro Yamada	default 0
62d5750cd3SNathan Chancellor
636e74c6b5SMiguel Ojedaconfig RUSTC_VERSION
646e74c6b5SMiguel Ojeda	int
65af0121c2SGary Guo	default $(rustc-version)
666e74c6b5SMiguel Ojeda	help
676e74c6b5SMiguel Ojeda	  It does not depend on `RUST` since that one may need to use the version
686e74c6b5SMiguel Ojeda	  in a `depends on`.
696e74c6b5SMiguel Ojeda
702f7ab126SMiguel Ojedaconfig RUST_IS_AVAILABLE
712f7ab126SMiguel Ojeda	def_bool $(success,$(srctree)/scripts/rust_is_available.sh)
722f7ab126SMiguel Ojeda	help
732f7ab126SMiguel Ojeda	  This shows whether a suitable Rust toolchain is available (found).
742f7ab126SMiguel Ojeda
752f7ab126SMiguel Ojeda	  Please see Documentation/rust/quick-start.rst for instructions on how
76eacf96d2SColin Ian King	  to satisfy the build requirements of Rust support.
772f7ab126SMiguel Ojeda
782f7ab126SMiguel Ojeda	  In particular, the Makefile target 'rustavailable' is useful to check
792f7ab126SMiguel Ojeda	  why the Rust toolchain is not being detected.
802f7ab126SMiguel Ojeda
81af0121c2SGary Guoconfig RUSTC_LLVM_VERSION
82af0121c2SGary Guo	int
83af0121c2SGary Guo	default $(rustc-llvm-version)
84af0121c2SGary Guo
85deab487eSThomas Weißschuhconfig ARCH_HAS_CC_CAN_LINK
86deab487eSThomas Weißschuh	bool
87deab487eSThomas Weißschuh
881a927fd3SMasahiro Yamadaconfig CC_CAN_LINK
899371f86eSMasahiro Yamada	bool
90deab487eSThomas Weißschuh	default ARCH_CC_CAN_LINK if ARCH_HAS_CC_CAN_LINK
9180623f2cSThomas Weißschuh	default $(cc_can_link_user,$(m64-flag)) if 64BIT
9280623f2cSThomas Weißschuh	default $(cc_can_link_user,$(m32-flag))
931a927fd3SMasahiro Yamada
94f2f6a8e8SMark Rutland# Fixed in GCC 14, 13.3, 12.4 and 11.5
95f2f6a8e8SMark Rutland# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113921
96f2f6a8e8SMark Rutlandconfig GCC_ASM_GOTO_OUTPUT_BROKEN
97f2f6a8e8SMark Rutland	bool
98f2f6a8e8SMark Rutland	depends on CC_IS_GCC
99f2f6a8e8SMark Rutland	default y if GCC_VERSION < 110500
100f2f6a8e8SMark Rutland	default y if GCC_VERSION >= 120000 && GCC_VERSION < 120400
101f2f6a8e8SMark Rutland	default y if GCC_VERSION >= 130000 && GCC_VERSION < 130300
102f2f6a8e8SMark Rutland
103587f1701SNick Desaulniersconfig CC_HAS_ASM_GOTO_OUTPUT
104f2f6a8e8SMark Rutland	def_bool y
105f2f6a8e8SMark Rutland	depends on !GCC_ASM_GOTO_OUTPUT_BROKEN
106e2ffa15bSThomas Gleixner	# Detect basic support
107f2f6a8e8SMark Rutland	depends on $(success,echo 'int foo(int x) { asm goto ("": "=r"(x) ::: bar); return x; bar: return 0; }' | $(CC) -x c - -c -o /dev/null)
108e2ffa15bSThomas Gleixner	# Detect clang (< v17) scoped label issues
109fde0ab43SLinus Torvalds	depends on $(success,echo 'void b(void **);void* c(void);int f(void){{asm goto(""::::l0);return 0;l0:return 1;}void *x __attribute__((cleanup(b)))=c();{asm goto(""::::l1);return 2;l1:return 3;}}' | $(CC) -x c - -c -o /dev/null)
110587f1701SNick Desaulniers
1111aa0e8b1SSean Christophersonconfig CC_HAS_ASM_GOTO_TIED_OUTPUT
1121aa0e8b1SSean Christopherson	depends on CC_HAS_ASM_GOTO_OUTPUT
1131aa0e8b1SSean Christopherson	# Detect buggy gcc and clang, fixed in gcc-11 clang-14.
114534bd703SAlexandre Belloni	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)
1151aa0e8b1SSean Christopherson
1165cf896fbSPeter Collingbourneconfig TOOLS_SUPPORT_RELR
1172d122942SWill Deacon	def_bool $(success,env "CC=$(CC)" "LD=$(LD)" "NM=$(NM)" "OBJCOPY=$(OBJCOPY)" $(srctree)/scripts/tools-support-relr.sh)
1185cf896fbSPeter Collingbourne
119eb111869SRasmus Villemoesconfig CC_HAS_ASM_INLINE
120eb111869SRasmus Villemoes	def_bool $(success,echo 'void foo(void) { asm inline (""); }' | $(CC) -x c - -c -o /dev/null)
121eb111869SRasmus Villemoes
122f72e2cffSHeiko Carstensconfig CC_HAS_ASSUME
123f72e2cffSHeiko Carstens	bool
124f72e2cffSHeiko Carstens	# clang needs to be at least 19.1.0 since the meaning of the assume
125f72e2cffSHeiko Carstens	# attribute changed:
126f72e2cffSHeiko Carstens	# https://github.com/llvm/llvm-project/commit/c44fa3e8a9a44c2e9a575768a3c185354b9f6c17
127f72e2cffSHeiko Carstens	default y if CC_IS_CLANG && CLANG_VERSION >= 190100
128f72e2cffSHeiko Carstens	# supported since gcc 13.1.0
129f72e2cffSHeiko Carstens	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106654
130f72e2cffSHeiko Carstens	default y if CC_IS_GCC && GCC_VERSION >= 130100
131f72e2cffSHeiko Carstens
13251c2ee6dSNick Desaulniersconfig CC_HAS_NO_PROFILE_FN_ATTR
13351c2ee6dSNick Desaulniers	def_bool $(success,echo '__attribute__((no_profile_instrument_function)) int x();' | $(CC) -x c - -c -o /dev/null -Werror)
13451c2ee6dSNick Desaulniers
135f06e108aSJan Hendrik Farrconfig CC_HAS_COUNTED_BY
1365106c650SJan Hendrik Farr	bool
13786a9b125SNathan Chancellor	# clang needs to be at least 20.1.0 to avoid potential crashes
13886a9b125SNathan Chancellor	# when building structures that contain __counted_by
13986a9b125SNathan Chancellor	# https://github.com/ClangBuiltLinux/linux/issues/2114
14086a9b125SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/160fb1121cdf703c3ef5e61fb26c5659eb581489
14186a9b125SNathan Chancellor	default y if CC_IS_CLANG && CLANG_VERSION >= 200100
1425106c650SJan Hendrik Farr	# supported since gcc 15.1.0
1435106c650SJan Hendrik Farr	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108896
1445106c650SJan Hendrik Farr	default y if CC_IS_GCC && GCC_VERSION >= 150100
145f06e108aSJan Hendrik Farr
146150a04d8SBill Wendlingconfig CC_HAS_COUNTED_BY_PTR
147150a04d8SBill Wendling	bool
148150a04d8SBill Wendling	# supported since clang 22
149150a04d8SBill Wendling	default y if CC_IS_CLANG && CLANG_VERSION >= 220000
150150a04d8SBill Wendling	# supported since gcc 16.0.0
151150a04d8SBill Wendling	default y if CC_IS_GCC && GCC_VERSION >= 160000
152150a04d8SBill Wendling
153d39a1d74SKees Cookconfig CC_HAS_BROKEN_COUNTED_BY_REF
154d39a1d74SKees Cook	bool
155d39a1d74SKees Cook	# https://github.com/llvm/llvm-project/issues/182575
156f709859fSNathan Chancellor	default y if CC_IS_CLANG && CLANG_VERSION < 220100
157d39a1d74SKees Cook
158b688f369SKees Cookconfig CC_HAS_MULTIDIMENSIONAL_NONSTRING
159b688f369SKees Cook	def_bool $(success,echo 'char tag[][4] __attribute__((__nonstring__)) = { };' | $(CC) $(CLANG_FLAGS) -x c - -c -o /dev/null -Werror)
160b688f369SKees Cook
161e7607f7dSNathan Chancellorconfig LD_CAN_USE_KEEP_IN_OVERLAY
162e7607f7dSNathan Chancellor	# ld.lld prior to 21.0.0 did not support KEEP within an overlay description
163e7607f7dSNathan Chancellor	# https://github.com/llvm/llvm-project/pull/130661
164e7607f7dSNathan Chancellor	def_bool LD_IS_BFD || LLD_VERSION >= 210000
165e7607f7dSNathan Chancellor
16688622323SAlexandre Courbotconfig RUSTC_HAS_SLICE_AS_FLATTENED
16788622323SAlexandre Courbot	def_bool RUSTC_VERSION >= 108000
16888622323SAlexandre Courbot
16947cb6bf7SXiangfei Dingconfig RUSTC_HAS_COERCE_POINTEE
17047cb6bf7SXiangfei Ding	def_bool RUSTC_VERSION >= 108400
17147cb6bf7SXiangfei Ding
17236174d16SMiguel Ojedaconfig RUSTC_HAS_SPAN_FILE
17336174d16SMiguel Ojeda	def_bool RUSTC_VERSION >= 108800
17436174d16SMiguel Ojeda
1757129ea6eSMiguel Ojedaconfig RUSTC_HAS_UNNECESSARY_TRANSMUTES
1767129ea6eSMiguel Ojeda	def_bool RUSTC_VERSION >= 108800
1777129ea6eSMiguel Ojeda
1780aa2b78cSBoqun Fengconfig RUSTC_HAS_FILE_WITH_NUL
1790aa2b78cSBoqun Feng	def_bool RUSTC_VERSION >= 108900
1800aa2b78cSBoqun Feng
181c09461a0SAlice Ryhlconfig RUSTC_HAS_FILE_AS_C_STR
182c09461a0SAlice Ryhl	def_bool RUSTC_VERSION >= 109100
183c09461a0SAlice Ryhl
184613fe169SNathan Chancellorconfig PAHOLE_VERSION
185613fe169SNathan Chancellor	int
18690e5b38aSIhor Solodrai	default "$(PAHOLE_VERSION)"
187613fe169SNathan Chancellor
188b99b87f7SPeter Oberparleiterconfig CONSTRUCTORS
189b99b87f7SPeter Oberparleiter	bool
190b99b87f7SPeter Oberparleiter
191e360adbeSPeter Zijlstraconfig IRQ_WORK
192fd0a68a2STejun Heo	def_bool y if SMP
193e360adbeSPeter Zijlstra
19410916706SShile Zhangconfig BUILDTIME_TABLE_SORT
1951dbdc6f1SDavid Daney	bool
1961dbdc6f1SDavid Daney
197c65eacbeSAndy Lutomirskiconfig THREAD_INFO_IN_TASK
198c65eacbeSAndy Lutomirski	bool
199c65eacbeSAndy Lutomirski	help
200c65eacbeSAndy Lutomirski	  Select this to move thread_info off the stack into task_struct.  To
201c65eacbeSAndy Lutomirski	  make this work, an arch will need to remove all thread_info fields
202c65eacbeSAndy Lutomirski	  except flags and fix any runtime bugs.
203c65eacbeSAndy Lutomirski
204c6c314a6SAndy Lutomirski	  One subtle change that will be needed is to use try_get_task_stack()
205c6c314a6SAndy Lutomirski	  and put_task_stack() in save_thread_stack_tsk() and get_wchan().
206c6c314a6SAndy Lutomirski
207ff0cfc66SAl Boldimenu "General setup"
2081da177e4SLinus Torvalds
2091da177e4SLinus Torvaldsconfig BROKEN
2101da177e4SLinus Torvalds	bool
211fefbeed8SAndrew Morton	help
212fefbeed8SAndrew Morton	  This option allows you to choose whether you want to try to
213fefbeed8SAndrew Morton	  compile (and fix) old drivers that haven't been updated to
214fefbeed8SAndrew Morton	  new infrastructure.
2151da177e4SLinus Torvalds
2161da177e4SLinus Torvaldsconfig BROKEN_ON_SMP
2171da177e4SLinus Torvalds	bool
2181da177e4SLinus Torvalds	depends on BROKEN || !SMP
2191da177e4SLinus Torvalds	default y
2201da177e4SLinus Torvalds
2211da177e4SLinus Torvaldsconfig INIT_ENV_ARG_LIMIT
2221da177e4SLinus Torvalds	int
223dd673bcaSAdrian Bunk	default 32 if !UML
224dd673bcaSAdrian Bunk	default 128 if UML
2251da177e4SLinus Torvalds	help
22634ad92c2SRandy Dunlap	  Maximum of each of the number of arguments and environment
22734ad92c2SRandy Dunlap	  variables passed to init from the kernel command line.
2281da177e4SLinus Torvalds
2294bb16672SJiri Slabyconfig COMPILE_TEST
2304bb16672SJiri Slaby	bool "Compile also drivers which will not load"
231ea29b20aSMasahiro Yamada	depends on HAS_IOMEM
2324bb16672SJiri Slaby	help
2334bb16672SJiri Slaby	  Some drivers can be compiled on a different platform than they are
2344bb16672SJiri Slaby	  intended to be run on. Despite they cannot be loaded there (or even
2354bb16672SJiri Slaby	  when they load they cannot be used due to missing HW support),
2364bb16672SJiri Slaby	  developers still, opposing to distributors, might want to build such
2374bb16672SJiri Slaby	  drivers to compile-test them.
2384bb16672SJiri Slaby
2394bb16672SJiri Slaby	  If you are a developer and want to build everything available, say Y
2404bb16672SJiri Slaby	  here. If you are a user/distributor, say N here to exclude useless
2414bb16672SJiri Slaby	  drivers to be distributed.
2424bb16672SJiri Slaby
2433fe617ccSLinus Torvaldsconfig WERROR
2443fe617ccSLinus Torvalds	bool "Compile the kernel with warnings as errors"
245b339ec9cSMarco Elver	default COMPILE_TEST
2463fe617ccSLinus Torvalds	help
2473fe617ccSLinus Torvalds	  A kernel build should not cause any compiler warnings, and this
2482f7ab126SMiguel Ojeda	  enables the '-Werror' (for C) and '-Dwarnings' (for Rust) flags
249e1789d7cSXin Li	  to enforce that rule by default. Certain warnings from other tools
250e1789d7cSXin Li	  such as the linker may be upgraded to errors with this option as
251e1789d7cSXin Li	  well.
2523fe617ccSLinus Torvalds
253e1789d7cSXin Li	  However, if you have a new (or very old) compiler or linker with odd
254e1789d7cSXin Li	  and unusual warnings, or you have some architecture with problems,
2553fe617ccSLinus Torvalds	  you may need to disable this config option in order to
2563fe617ccSLinus Torvalds	  successfully build the kernel.
2573fe617ccSLinus Torvalds
2583fe617ccSLinus Torvalds	  If in doubt, say Y.
2593fe617ccSLinus Torvalds
260d6fc9fcbSMasahiro Yamadaconfig UAPI_HEADER_TEST
261d6fc9fcbSMasahiro Yamada	bool "Compile test UAPI headers"
2622a0a3080SThomas Weißschuh	depends on HEADERS_INSTALL
263d6fc9fcbSMasahiro Yamada	help
264d6fc9fcbSMasahiro Yamada	  Compile test headers exported to user-space to ensure they are
265d6fc9fcbSMasahiro Yamada	  self-contained, i.e. compilable as standalone units.
266d6fc9fcbSMasahiro Yamada
267d6fc9fcbSMasahiro Yamada	  If you are a developer or tester and want to ensure the exported
268d6fc9fcbSMasahiro Yamada	  headers are self-contained, say Y here. Otherwise, choose N.
269d6fc9fcbSMasahiro Yamada
2701da177e4SLinus Torvaldsconfig LOCALVERSION
2711da177e4SLinus Torvalds	string "Local version - append to kernel release"
2721da177e4SLinus Torvalds	help
2731da177e4SLinus Torvalds	  Append an extra string to the end of your kernel version.
2741da177e4SLinus Torvalds	  This will show up when you type uname, for example.
2751da177e4SLinus Torvalds	  The string you set here will be appended after the contents of
2761da177e4SLinus Torvalds	  any files with a filename matching localversion* in your
2771da177e4SLinus Torvalds	  object and source tree, in that order.  Your total string can
2781da177e4SLinus Torvalds	  be a maximum of 64 characters.
2791da177e4SLinus Torvalds
280aaebf433SRyan Andersonconfig LOCALVERSION_AUTO
281aaebf433SRyan Anderson	bool "Automatically append version information to the version string"
282aaebf433SRyan Anderson	default y
283ac3339baSAlexey Dobriyan	depends on !COMPILE_TEST
284aaebf433SRyan Anderson	help
285aaebf433SRyan Anderson	  This will try to automatically determine if the current tree is a
2866e5a5420SRobert P. J. Day	  release tree by looking for git tags that belong to the current
2876e5a5420SRobert P. J. Day	  top of tree revision.
288aaebf433SRyan Anderson
289aaebf433SRyan Anderson	  A string of the format -gxxxxxxxx will be added to the localversion
2906e5a5420SRobert P. J. Day	  if a git-based tree is found.  The string generated by this will be
291aaebf433SRyan Anderson	  appended after any matching localversion* files, and after the value
2926e5a5420SRobert P. J. Day	  set in CONFIG_LOCALVERSION.
293aaebf433SRyan Anderson
2940f9c608dSRasmus Villemoes	  (The actual string used here is the first 12 characters produced
2956e5a5420SRobert P. J. Day	  by running the command:
2966e5a5420SRobert P. J. Day
2976e5a5420SRobert P. J. Day	    $ git rev-parse --verify HEAD
2986e5a5420SRobert P. J. Day
2996e5a5420SRobert P. J. Day	  which is done within the script "scripts/setlocalversion".)
300aaebf433SRyan Anderson
3019afb719eSLaura Abbottconfig BUILD_SALT
3029afb719eSLaura Abbott	string "Build ID Salt"
3039afb719eSLaura Abbott	default ""
3049afb719eSLaura Abbott	help
3059afb719eSLaura Abbott	  The build ID is used to link binaries and their debug info. Setting
3069afb719eSLaura Abbott	  this option will use the value in the calculation of the build id.
3079afb719eSLaura Abbott	  This is mostly useful for distributions which want to ensure the
3089afb719eSLaura Abbott	  build is unique between builds. It's safe to leave the default.
3099afb719eSLaura Abbott
3102e9f3bddSH. Peter Anvinconfig HAVE_KERNEL_GZIP
3112e9f3bddSH. Peter Anvin	bool
3122e9f3bddSH. Peter Anvin
3132e9f3bddSH. Peter Anvinconfig HAVE_KERNEL_BZIP2
3142e9f3bddSH. Peter Anvin	bool
3152e9f3bddSH. Peter Anvin
3162e9f3bddSH. Peter Anvinconfig HAVE_KERNEL_LZMA
3172e9f3bddSH. Peter Anvin	bool
3182e9f3bddSH. Peter Anvin
3193ebe1243SLasse Collinconfig HAVE_KERNEL_XZ
3203ebe1243SLasse Collin	bool
3213ebe1243SLasse Collin
3227dd65febSAlbin Tonnerreconfig HAVE_KERNEL_LZO
3237dd65febSAlbin Tonnerre	bool
3247dd65febSAlbin Tonnerre
325e76e1fdfSKyungsik Leeconfig HAVE_KERNEL_LZ4
326e76e1fdfSKyungsik Lee	bool
327e76e1fdfSKyungsik Lee
32848f7ddf7SNick Terrellconfig HAVE_KERNEL_ZSTD
32948f7ddf7SNick Terrell	bool
33048f7ddf7SNick Terrell
331f16466afSVasily Gorbikconfig HAVE_KERNEL_UNCOMPRESSED
332f16466afSVasily Gorbik	bool
333f16466afSVasily Gorbik
33430d65dbfSAlain Knaffchoice
33530d65dbfSAlain Knaff	prompt "Kernel compression mode"
33630d65dbfSAlain Knaff	default KERNEL_GZIP
33748f7ddf7SNick Terrell	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
33830d65dbfSAlain Knaff	help
33930d65dbfSAlain Knaff	  The linux kernel is a kind of self-extracting executable.
34030d65dbfSAlain Knaff	  Several compression algorithms are available, which differ
34130d65dbfSAlain Knaff	  in efficiency, compression and decompression speed.
34230d65dbfSAlain Knaff	  Compression speed is only relevant when building a kernel.
34330d65dbfSAlain Knaff	  Decompression speed is relevant at each boot.
34430d65dbfSAlain Knaff
34530d65dbfSAlain Knaff	  If you have any problems with bzip2 or lzma compressed
34630d65dbfSAlain Knaff	  kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
34730d65dbfSAlain Knaff	  version of this functionality (bzip2 only), for 2.4, was
34830d65dbfSAlain Knaff	  supplied by Christian Ludwig)
34930d65dbfSAlain Knaff
35030d65dbfSAlain Knaff	  High compression options are mostly useful for users, who
35130d65dbfSAlain Knaff	  are low on disk space (embedded systems), but for whom ram
35230d65dbfSAlain Knaff	  size matters less.
35330d65dbfSAlain Knaff
35430d65dbfSAlain Knaff	  If in doubt, select 'gzip'
35530d65dbfSAlain Knaff
35630d65dbfSAlain Knaffconfig KERNEL_GZIP
35730d65dbfSAlain Knaff	bool "Gzip"
3582e9f3bddSH. Peter Anvin	depends on HAVE_KERNEL_GZIP
35930d65dbfSAlain Knaff	help
3607dd65febSAlbin Tonnerre	  The old and tried gzip compression. It provides a good balance
3617dd65febSAlbin Tonnerre	  between compression ratio and decompression speed.
36230d65dbfSAlain Knaff
36330d65dbfSAlain Knaffconfig KERNEL_BZIP2
36430d65dbfSAlain Knaff	bool "Bzip2"
3652e9f3bddSH. Peter Anvin	depends on HAVE_KERNEL_BZIP2
36630d65dbfSAlain Knaff	help
36730d65dbfSAlain Knaff	  Its compression ratio and speed is intermediate.
3680a4dd35cSRandy Dunlap	  Decompression speed is slowest among the choices.  The kernel
3692e9f3bddSH. Peter Anvin	  size is about 10% smaller with bzip2, in comparison to gzip.
3702e9f3bddSH. Peter Anvin	  Bzip2 uses a large amount of memory. For modern kernels you
3712e9f3bddSH. Peter Anvin	  will need at least 8MB RAM or more for booting.
37230d65dbfSAlain Knaff
37330d65dbfSAlain Knaffconfig KERNEL_LZMA
37430d65dbfSAlain Knaff	bool "LZMA"
3752e9f3bddSH. Peter Anvin	depends on HAVE_KERNEL_LZMA
37630d65dbfSAlain Knaff	help
3770a4dd35cSRandy Dunlap	  This compression algorithm's ratio is best.  Decompression speed
3780a4dd35cSRandy Dunlap	  is between gzip and bzip2.  Compression is slowest.
3790a4dd35cSRandy Dunlap	  The kernel size is about 33% smaller with LZMA in comparison to gzip.
38030d65dbfSAlain Knaff
3813ebe1243SLasse Collinconfig KERNEL_XZ
3823ebe1243SLasse Collin	bool "XZ"
3833ebe1243SLasse Collin	depends on HAVE_KERNEL_XZ
3843ebe1243SLasse Collin	help
3853ebe1243SLasse Collin	  XZ uses the LZMA2 algorithm and instruction set specific
3863ebe1243SLasse Collin	  BCJ filters which can improve compression ratio of executable
3873ebe1243SLasse Collin	  code. The size of the kernel is about 30% smaller with XZ in
3883ebe1243SLasse Collin	  comparison to gzip. On architectures for which there is a BCJ
3897472ff8aSLasse Collin	  filter (i386, x86_64, ARM, ARM64, RISC-V, big endian PowerPC,
3907472ff8aSLasse Collin	  and SPARC), XZ will create a few percent smaller kernel than
3917472ff8aSLasse Collin	  plain LZMA.
3923ebe1243SLasse Collin
3933ebe1243SLasse Collin	  The speed is about the same as with LZMA: The decompression
3943ebe1243SLasse Collin	  speed of XZ is better than that of bzip2 but worse than gzip
3953ebe1243SLasse Collin	  and LZO. Compression is slow.
3963ebe1243SLasse Collin
3977dd65febSAlbin Tonnerreconfig KERNEL_LZO
3987dd65febSAlbin Tonnerre	bool "LZO"
3997dd65febSAlbin Tonnerre	depends on HAVE_KERNEL_LZO
4007dd65febSAlbin Tonnerre	help
4010a4dd35cSRandy Dunlap	  Its compression ratio is the poorest among the choices. The kernel
402681b3049SStephan Sperber	  size is about 10% bigger than gzip; however its speed
4037dd65febSAlbin Tonnerre	  (both compression and decompression) is the fastest.
4047dd65febSAlbin Tonnerre
405e76e1fdfSKyungsik Leeconfig KERNEL_LZ4
406e76e1fdfSKyungsik Lee	bool "LZ4"
407e76e1fdfSKyungsik Lee	depends on HAVE_KERNEL_LZ4
408e76e1fdfSKyungsik Lee	help
409e76e1fdfSKyungsik Lee	  LZ4 is an LZ77-type compressor with a fixed, byte-oriented encoding.
410e76e1fdfSKyungsik Lee	  A preliminary version of LZ4 de/compression tool is available at
411e76e1fdfSKyungsik Lee	  <https://code.google.com/p/lz4/>.
412e76e1fdfSKyungsik Lee
413e76e1fdfSKyungsik Lee	  Its compression ratio is worse than LZO. The size of the kernel
414e76e1fdfSKyungsik Lee	  is about 8% bigger than LZO. But the decompression speed is
415e76e1fdfSKyungsik Lee	  faster than LZO.
416e76e1fdfSKyungsik Lee
41748f7ddf7SNick Terrellconfig KERNEL_ZSTD
41848f7ddf7SNick Terrell	bool "ZSTD"
41948f7ddf7SNick Terrell	depends on HAVE_KERNEL_ZSTD
42048f7ddf7SNick Terrell	help
42148f7ddf7SNick Terrell	  ZSTD is a compression algorithm targeting intermediate compression
42248f7ddf7SNick Terrell	  with fast decompression speed. It will compress better than GZIP and
42348f7ddf7SNick Terrell	  decompress around the same speed as LZO, but slower than LZ4. You
42448f7ddf7SNick Terrell	  will need at least 192 KB RAM or more for booting. The zstd command
42548f7ddf7SNick Terrell	  line tool is required for compression.
42648f7ddf7SNick Terrell
427f16466afSVasily Gorbikconfig KERNEL_UNCOMPRESSED
428f16466afSVasily Gorbik	bool "None"
429f16466afSVasily Gorbik	depends on HAVE_KERNEL_UNCOMPRESSED
430f16466afSVasily Gorbik	help
431f16466afSVasily Gorbik	  Produce uncompressed kernel image. This option is usually not what
432f16466afSVasily Gorbik	  you want. It is useful for debugging the kernel in slow simulation
433f16466afSVasily Gorbik	  environments, where decompressing and moving the kernel is awfully
434f16466afSVasily Gorbik	  slow. This option allows early boot code to skip the decompressor
435f16466afSVasily Gorbik	  and jump right at uncompressed kernel image.
436f16466afSVasily Gorbik
43730d65dbfSAlain Knaffendchoice
43830d65dbfSAlain Knaff
439ada4ab7aSChris Downconfig DEFAULT_INIT
440ada4ab7aSChris Down	string "Default init path"
441ada4ab7aSChris Down	default ""
442ada4ab7aSChris Down	help
443ada4ab7aSChris Down	  This option determines the default init for the system if no init=
444ada4ab7aSChris Down	  option is passed on the kernel command line. If the requested path is
445ada4ab7aSChris Down	  not present, we will still then move on to attempting further
446ada4ab7aSChris Down	  locations (e.g. /sbin/init, etc). If this is empty, we will just use
447ada4ab7aSChris Down	  the fallback list when init= is not passed.
448ada4ab7aSChris Down
449bd5dc17bSJosh Triplettconfig DEFAULT_HOSTNAME
450bd5dc17bSJosh Triplett	string "Default hostname"
451bd5dc17bSJosh Triplett	default "(none)"
452bd5dc17bSJosh Triplett	help
453bd5dc17bSJosh Triplett	  This option determines the default system hostname before userspace
454bd5dc17bSJosh Triplett	  calls sethostname(2). The kernel traditionally uses "(none)" here,
455bd5dc17bSJosh Triplett	  but you may wish to use a different default here to make a minimal
456bd5dc17bSJosh Triplett	  system more usable with less configuration.
457bd5dc17bSJosh Triplett
4581da177e4SLinus Torvaldsconfig SYSVIPC
4591da177e4SLinus Torvalds	bool "System V IPC"
460a7f7f624SMasahiro Yamada	help
4611da177e4SLinus Torvalds	  Inter Process Communication is a suite of library functions and
4621da177e4SLinus Torvalds	  system calls which let processes (running programs) synchronize and
4631da177e4SLinus Torvalds	  exchange information. It is generally considered to be a good thing,
4641da177e4SLinus Torvalds	  and some programs won't run unless you say Y here. In particular, if
4651da177e4SLinus Torvalds	  you want to run the DOS emulator dosemu under Linux (read the
4661da177e4SLinus Torvalds	  DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
4671da177e4SLinus Torvalds	  you'll need to say Y here.
4681da177e4SLinus Torvalds
4691da177e4SLinus Torvalds	  You can find documentation about IPC with "info ipc" and also in
4701da177e4SLinus Torvalds	  section 6.4 of the Linux Programmer's Guide, available from
4711da177e4SLinus Torvalds	  <http://www.tldp.org/guides.html>.
4721da177e4SLinus Torvalds
473a5494dcdSEric W. Biedermanconfig SYSVIPC_SYSCTL
474a5494dcdSEric W. Biederman	bool
475a5494dcdSEric W. Biederman	depends on SYSVIPC
476a5494dcdSEric W. Biederman	depends on SYSCTL
477a5494dcdSEric W. Biederman	default y
478a5494dcdSEric W. Biederman
4790cbed0eeSGuo Renconfig SYSVIPC_COMPAT
4800cbed0eeSGuo Ren	def_bool y
4810cbed0eeSGuo Ren	depends on COMPAT && SYSVIPC
4820cbed0eeSGuo Ren
4831da177e4SLinus Torvaldsconfig POSIX_MQUEUE
4841da177e4SLinus Torvalds	bool "POSIX Message Queues"
48519c92399SKees Cook	depends on NET
486a7f7f624SMasahiro Yamada	help
4871da177e4SLinus Torvalds	  POSIX variant of message queues is a part of IPC. In POSIX message
4881da177e4SLinus Torvalds	  queues every message has a priority which decides about succession
4891da177e4SLinus Torvalds	  of receiving it by a process. If you want to compile and run
4901da177e4SLinus Torvalds	  programs written e.g. for Solaris with use of its POSIX message
491b0e37650SRobert P. J. Day	  queues (functions mq_*) say Y here.
4921da177e4SLinus Torvalds
4931da177e4SLinus Torvalds	  POSIX message queues are visible as a filesystem called 'mqueue'
4941da177e4SLinus Torvalds	  and can be mounted somewhere if you want to do filesystem
4951da177e4SLinus Torvalds	  operations on message queues.
4961da177e4SLinus Torvalds
4971da177e4SLinus Torvalds	  If unsure, say Y.
4981da177e4SLinus Torvalds
499bdc8e5f8SSerge E. Hallynconfig POSIX_MQUEUE_SYSCTL
500bdc8e5f8SSerge E. Hallyn	bool
501bdc8e5f8SSerge E. Hallyn	depends on POSIX_MQUEUE
502bdc8e5f8SSerge E. Hallyn	depends on SYSCTL
503bdc8e5f8SSerge E. Hallyn	default y
504bdc8e5f8SSerge E. Hallyn
505c73be61cSDavid Howellsconfig WATCH_QUEUE
506c73be61cSDavid Howells	bool "General notification queue"
507c73be61cSDavid Howells	default n
508c73be61cSDavid Howells	help
509c73be61cSDavid Howells
510c73be61cSDavid Howells	  This is a general notification queue for the kernel to pass events to
511c73be61cSDavid Howells	  userspace by splicing them into pipes.  It can be used in conjunction
512c73be61cSDavid Howells	  with watches for key/keyring change notifications and device
513c73be61cSDavid Howells	  notifications.
514c73be61cSDavid Howells
515c02b872aSMauro Carvalho Chehab	  See Documentation/core-api/watch_queue.rst
516c73be61cSDavid Howells
517226b4ccdSKonstantin Khlebnikovconfig CROSS_MEMORY_ATTACH
518226b4ccdSKonstantin Khlebnikov	bool "Enable process_vm_readv/writev syscalls"
519226b4ccdSKonstantin Khlebnikov	depends on MMU
520226b4ccdSKonstantin Khlebnikov	default y
521226b4ccdSKonstantin Khlebnikov	help
522226b4ccdSKonstantin Khlebnikov	  Enabling this option adds the system calls process_vm_readv and
523226b4ccdSKonstantin Khlebnikov	  process_vm_writev which allow a process with the correct privileges
524a2a368d9SGeert Uytterhoeven	  to directly read from or write to another process' address space.
525226b4ccdSKonstantin Khlebnikov	  See the man page for more details.
526226b4ccdSKonstantin Khlebnikov
5271da177e4SLinus Torvaldsconfig AUDIT
5281da177e4SLinus Torvalds	bool "Auditing support"
529804a6a49SChris Wright	depends on NET
5301da177e4SLinus Torvalds	help
5311da177e4SLinus Torvalds	  Enable auditing infrastructure that can be used with another
5321da177e4SLinus Torvalds	  kernel subsystem, such as SELinux (which requires this for
533cb74ed27SPaul Moore	  logging of avc messages output).  System call auditing is included
534cb74ed27SPaul Moore	  on architectures which support it.
5351da177e4SLinus Torvalds
5367a017721SAKASHI Takahiroconfig HAVE_ARCH_AUDITSYSCALL
5377a017721SAKASHI Takahiro	bool
5387a017721SAKASHI Takahiro
5391da177e4SLinus Torvaldsconfig AUDITSYSCALL
540cb74ed27SPaul Moore	def_bool y
5417a017721SAKASHI Takahiro	depends on AUDIT && HAVE_ARCH_AUDITSYSCALL
54228a3a7ebSEric Paris	select FSNOTIFY
54374c3cbe3SAl Viro
544d9817ebeSThomas Gleixnersource "kernel/irq/Kconfig"
545764e0da1SThomas Gleixnersource "kernel/time/Kconfig"
546b24abcffSDaniel Borkmannsource "kernel/bpf/Kconfig"
54787a4c375SChristoph Hellwigsource "kernel/Kconfig.preempt"
548d9817ebeSThomas Gleixner
549391dc69cSFrederic Weisbeckermenu "CPU/Task time and stats accounting"
550391dc69cSFrederic Weisbecker
551abf917cdSFrederic Weisbeckerconfig VIRT_CPU_ACCOUNTING
552abf917cdSFrederic Weisbecker	bool
553abf917cdSFrederic Weisbecker
554fdf9c356SFrederic Weisbeckerchoice
555fdf9c356SFrederic Weisbecker	prompt "Cputime accounting"
55602382affSNicholas Piggin	default TICK_CPU_ACCOUNTING
557fdf9c356SFrederic Weisbecker
558fdf9c356SFrederic Weisbecker# Kind of a stub config for the pure tick based cputime accounting
559fdf9c356SFrederic Weisbeckerconfig TICK_CPU_ACCOUNTING
560fdf9c356SFrederic Weisbecker	bool "Simple tick based cputime accounting"
561c58b0df1SFrederic Weisbecker	depends on !S390 && !NO_HZ_FULL
562fdf9c356SFrederic Weisbecker	help
563fdf9c356SFrederic Weisbecker	  This is the basic tick based cputime accounting that maintains
564fdf9c356SFrederic Weisbecker	  statistics about user, system and idle time spent on per jiffies
565fdf9c356SFrederic Weisbecker	  granularity.
566fdf9c356SFrederic Weisbecker
567fdf9c356SFrederic Weisbecker	  If unsure, say Y.
568fdf9c356SFrederic Weisbecker
569abf917cdSFrederic Weisbeckerconfig VIRT_CPU_ACCOUNTING_NATIVE
570391dc69cSFrederic Weisbecker	bool "Deterministic task and CPU time accounting"
571c58b0df1SFrederic Weisbecker	depends on HAVE_VIRT_CPU_ACCOUNTING && !NO_HZ_FULL
572abf917cdSFrederic Weisbecker	select VIRT_CPU_ACCOUNTING
573391dc69cSFrederic Weisbecker	help
574391dc69cSFrederic Weisbecker	  Select this option to enable more accurate task and CPU time
575391dc69cSFrederic Weisbecker	  accounting.  This is done by reading a CPU counter on each
576391dc69cSFrederic Weisbecker	  kernel entry and exit and on transitions within the kernel
577391dc69cSFrederic Weisbecker	  between system, softirq and hardirq state, so there is a
578391dc69cSFrederic Weisbecker	  small performance impact.  In the case of s390 or IBM POWER > 5,
579391dc69cSFrederic Weisbecker	  this also enables accounting of stolen time on logically-partitioned
580391dc69cSFrederic Weisbecker	  systems.
581391dc69cSFrederic Weisbecker
582abf917cdSFrederic Weisbeckerconfig VIRT_CPU_ACCOUNTING_GEN
583abf917cdSFrederic Weisbecker	bool "Full dynticks CPU time accounting"
58424a9c541SFrederic Weisbecker	depends on HAVE_CONTEXT_TRACKING_USER
585554b0004SKevin Hilman	depends on HAVE_VIRT_CPU_ACCOUNTING_GEN
586041a1574SArnd Bergmann	depends on GENERIC_CLOCKEVENTS
587abf917cdSFrederic Weisbecker	select VIRT_CPU_ACCOUNTING
58824a9c541SFrederic Weisbecker	select CONTEXT_TRACKING_USER
589abf917cdSFrederic Weisbecker	help
590abf917cdSFrederic Weisbecker	  Select this option to enable task and CPU time accounting on full
591abf917cdSFrederic Weisbecker	  dynticks systems. This accounting is implemented by watching every
592abf917cdSFrederic Weisbecker	  kernel-user boundaries using the context tracking subsystem.
593abf917cdSFrederic Weisbecker	  The accounting is thus performed at the expense of some significant
594abf917cdSFrederic Weisbecker	  overhead.
595abf917cdSFrederic Weisbecker
596abf917cdSFrederic Weisbecker	  For now this is only useful if you are working on the full
597abf917cdSFrederic Weisbecker	  dynticks subsystem development.
598abf917cdSFrederic Weisbecker
599abf917cdSFrederic Weisbecker	  If unsure, say N.
600abf917cdSFrederic Weisbecker
601b58c3584SRik van Rielendchoice
602b58c3584SRik van Riel
603fdf9c356SFrederic Weisbeckerconfig IRQ_TIME_ACCOUNTING
604fdf9c356SFrederic Weisbecker	bool "Fine granularity task level IRQ time accounting"
605b58c3584SRik van Riel	depends on HAVE_IRQ_TIME_ACCOUNTING && !VIRT_CPU_ACCOUNTING_NATIVE
606fdf9c356SFrederic Weisbecker	help
607fdf9c356SFrederic Weisbecker	  Select this option to enable fine granularity task irq time
608fdf9c356SFrederic Weisbecker	  accounting. This is done by reading a timestamp on each
609fdf9c356SFrederic Weisbecker	  transitions between softirq and hardirq state, so there can be a
610fdf9c356SFrederic Weisbecker	  small performance impact.
611fdf9c356SFrederic Weisbecker
612fdf9c356SFrederic Weisbecker	  If in doubt, say N here.
613fdf9c356SFrederic Weisbecker
61411d4afd4SVincent Guittotconfig HAVE_SCHED_AVG_IRQ
61511d4afd4SVincent Guittot	def_bool y
61611d4afd4SVincent Guittot	depends on IRQ_TIME_ACCOUNTING || PARAVIRT_TIME_ACCOUNTING
61711d4afd4SVincent Guittot	depends on SMP
61811d4afd4SVincent Guittot
619d4dbc991SVincent Guittotconfig SCHED_HW_PRESSURE
62098eb401dSValentin Schneider	bool
621fcd7c9c3SValentin Schneider	default y if ARM && ARM_CPU_TOPOLOGY
622fcd7c9c3SValentin Schneider	default y if ARM64
62376504793SThara Gopinath	depends on SMP
62498eb401dSValentin Schneider	depends on CPU_FREQ_THERMAL
62598eb401dSValentin Schneider	help
626d4dbc991SVincent Guittot	  Select this option to enable HW pressure accounting in the
627d4dbc991SVincent Guittot	  scheduler. HW pressure is the value conveyed to the scheduler
62898eb401dSValentin Schneider	  that reflects the reduction in CPU compute capacity resulted from
629d4dbc991SVincent Guittot	  HW throttling. HW throttling occurs when the performance of
630d4dbc991SVincent Guittot	  a CPU is capped due to high operating temperatures as an example.
63198eb401dSValentin Schneider
63298eb401dSValentin Schneider	  If selected, the scheduler will be able to balance tasks accordingly,
63398eb401dSValentin Schneider	  i.e. put less load on throttled CPUs than on non/less throttled ones.
63498eb401dSValentin Schneider
63598eb401dSValentin Schneider	  This requires the architecture to implement
636d4dbc991SVincent Guittot	  arch_update_hw_pressure() and arch_scale_thermal_pressure().
63776504793SThara Gopinath
638391dc69cSFrederic Weisbeckerconfig BSD_PROCESS_ACCT
63946329a9dSJeff Layton	bool "BSD Process Accounting (DEPRECATED)"
6402813893fSIulia Manda	depends on MULTIUSER
64146329a9dSJeff Layton	default n
642391dc69cSFrederic Weisbecker	help
643391dc69cSFrederic Weisbecker	  If you say Y here, a user level program will be able to instruct the
644391dc69cSFrederic Weisbecker	  kernel (via a special system call) to write process accounting
645391dc69cSFrederic Weisbecker	  information to a file: whenever a process exits, information about
646391dc69cSFrederic Weisbecker	  that process will be appended to the file by the kernel.  The
647391dc69cSFrederic Weisbecker	  information includes things such as creation time, owning user,
648391dc69cSFrederic Weisbecker	  command name, memory usage, controlling terminal etc. (the complete
649391dc69cSFrederic Weisbecker	  list is in the struct acct in <file:include/linux/acct.h>).  It is
650391dc69cSFrederic Weisbecker	  up to the user level program to do useful things with this
65146329a9dSJeff Layton	  information.  This mechanism is antiquated and has significant
65246329a9dSJeff Layton	  scalability issues.  You probably want to use eBPF instead.  Say
65346329a9dSJeff Layton	  N unless you really need this.
654391dc69cSFrederic Weisbecker
655391dc69cSFrederic Weisbeckerconfig BSD_PROCESS_ACCT_V3
656391dc69cSFrederic Weisbecker	bool "BSD Process Accounting version 3 file format"
657391dc69cSFrederic Weisbecker	depends on BSD_PROCESS_ACCT
658391dc69cSFrederic Weisbecker	default n
659391dc69cSFrederic Weisbecker	help
660391dc69cSFrederic Weisbecker	  If you say Y here, the process accounting information is written
661391dc69cSFrederic Weisbecker	  in a new file format that also logs the process IDs of each
6623903bf94SRandy Dunlap	  process and its parent. Note that this file format is incompatible
663391dc69cSFrederic Weisbecker	  with previous v0/v1/v2 file formats, so you will need updated tools
664391dc69cSFrederic Weisbecker	  for processing it. A preliminary version of these tools is available
665391dc69cSFrederic Weisbecker	  at <http://www.gnu.org/software/acct/>.
666391dc69cSFrederic Weisbecker
667391dc69cSFrederic Weisbeckerconfig TASKSTATS
66819c92399SKees Cook	bool "Export task/process statistics through netlink"
669391dc69cSFrederic Weisbecker	depends on NET
6702813893fSIulia Manda	depends on MULTIUSER
671391dc69cSFrederic Weisbecker	default n
672391dc69cSFrederic Weisbecker	help
673391dc69cSFrederic Weisbecker	  Export selected statistics for tasks/processes through the
674391dc69cSFrederic Weisbecker	  generic netlink interface. Unlike BSD process accounting, the
675391dc69cSFrederic Weisbecker	  statistics are available during the lifetime of tasks/processes as
676391dc69cSFrederic Weisbecker	  responses to commands. Like BSD accounting, they are sent to user
677391dc69cSFrederic Weisbecker	  space on task exit.
678391dc69cSFrederic Weisbecker
679391dc69cSFrederic Weisbecker	  Say N if unsure.
680391dc69cSFrederic Weisbecker
681391dc69cSFrederic Weisbeckerconfig TASK_DELAY_ACCT
68219c92399SKees Cook	bool "Enable per-task delay accounting"
683391dc69cSFrederic Weisbecker	depends on TASKSTATS
684f6db8347SNaveen N. Rao	select SCHED_INFO
685391dc69cSFrederic Weisbecker	help
686391dc69cSFrederic Weisbecker	  Collect information on time spent by a task waiting for system
687391dc69cSFrederic Weisbecker	  resources like cpu, synchronous block I/O completion and swapping
688391dc69cSFrederic Weisbecker	  in pages. Such statistics can help in setting a task's priorities
689391dc69cSFrederic Weisbecker	  relative to other tasks for cpu, io, rss limits etc.
690391dc69cSFrederic Weisbecker
691391dc69cSFrederic Weisbecker	  Say N if unsure.
692391dc69cSFrederic Weisbecker
693391dc69cSFrederic Weisbeckerconfig TASK_XACCT
69419c92399SKees Cook	bool "Enable extended accounting over taskstats"
695391dc69cSFrederic Weisbecker	depends on TASKSTATS
696391dc69cSFrederic Weisbecker	help
697391dc69cSFrederic Weisbecker	  Collect extended task accounting data and send the data
698391dc69cSFrederic Weisbecker	  to userland for processing over the taskstats interface.
699391dc69cSFrederic Weisbecker
700391dc69cSFrederic Weisbecker	  Say N if unsure.
701391dc69cSFrederic Weisbecker
702391dc69cSFrederic Weisbeckerconfig TASK_IO_ACCOUNTING
70319c92399SKees Cook	bool "Enable per-task storage I/O accounting"
704391dc69cSFrederic Weisbecker	depends on TASK_XACCT
705391dc69cSFrederic Weisbecker	help
706391dc69cSFrederic Weisbecker	  Collect information on the number of bytes of storage I/O which this
707391dc69cSFrederic Weisbecker	  task has caused.
708391dc69cSFrederic Weisbecker
709391dc69cSFrederic Weisbecker	  Say N if unsure.
710391dc69cSFrederic Weisbecker
711eb414681SJohannes Weinerconfig PSI
712eb414681SJohannes Weiner	bool "Pressure stall information tracking"
71398dfdd9eSRandy Dunlap	select KERNFS
714eb414681SJohannes Weiner	help
715eb414681SJohannes Weiner	  Collect metrics that indicate how overcommitted the CPU, memory,
716eb414681SJohannes Weiner	  and IO capacity are in the system.
717eb414681SJohannes Weiner
718eb414681SJohannes Weiner	  If you say Y here, the kernel will create /proc/pressure/ with the
719eb414681SJohannes Weiner	  pressure statistics files cpu, memory, and io. These will indicate
720eb414681SJohannes Weiner	  the share of walltime in which some or all tasks in the system are
721eb414681SJohannes Weiner	  delayed due to contention of the respective resource.
722eb414681SJohannes Weiner
7232ce7135aSJohannes Weiner	  In kernels with cgroup support, cgroups (cgroup2 only) will
7242ce7135aSJohannes Weiner	  have cpu.pressure, memory.pressure, and io.pressure files,
7252ce7135aSJohannes Weiner	  which aggregate pressure stalls for the grouped tasks only.
7262ce7135aSJohannes Weiner
727c3123552SMauro Carvalho Chehab	  For more details see Documentation/accounting/psi.rst.
728eb414681SJohannes Weiner
729eb414681SJohannes Weiner	  Say N if unsure.
730eb414681SJohannes Weiner
731e0c27447SJohannes Weinerconfig PSI_DEFAULT_DISABLED
732e0c27447SJohannes Weiner	bool "Require boot parameter to enable pressure stall information tracking"
733e0c27447SJohannes Weiner	default n
734e0c27447SJohannes Weiner	depends on PSI
735e0c27447SJohannes Weiner	help
736e0c27447SJohannes Weiner	  If set, pressure stall information tracking will be disabled
737428a1cb4SBaruch Siach	  per default but can be enabled through passing psi=1 on the
738428a1cb4SBaruch Siach	  kernel commandline during boot.
739e0c27447SJohannes Weiner
7407b2489d3SJohannes Weiner	  This feature adds some code to the task wakeup and sleep
7417b2489d3SJohannes Weiner	  paths of the scheduler. The overhead is too low to affect
7427b2489d3SJohannes Weiner	  common scheduling-intense workloads in practice (such as
7437b2489d3SJohannes Weiner	  webservers, memcache), but it does show up in artificial
7447b2489d3SJohannes Weiner	  scheduler stress tests, such as hackbench.
7457b2489d3SJohannes Weiner
7467b2489d3SJohannes Weiner	  If you are paranoid and not sure what the kernel will be
7477b2489d3SJohannes Weiner	  used for, say Y.
7487b2489d3SJohannes Weiner
7497b2489d3SJohannes Weiner	  Say N if unsure.
7507b2489d3SJohannes Weiner
751391dc69cSFrederic Weisbeckerendmenu # "CPU/Task time and stats accounting"
752391dc69cSFrederic Weisbecker
7535c4991e2SFrederic Weisbeckerconfig CPU_ISOLATION
7545c4991e2SFrederic Weisbecker	bool "CPU isolation"
75597577684SOleg Nesterov	depends on SMP
7562c43838cSFrederic Weisbecker	default y
7575c4991e2SFrederic Weisbecker	help
7585c4991e2SFrederic Weisbecker	  Make sure that CPUs running critical tasks are not disturbed by
7595c4991e2SFrederic Weisbecker	  any source of "noise" such as unbound workqueues, timers, kthreads...
7602c43838cSFrederic Weisbecker	  Unbound jobs get offloaded to housekeeping CPUs. This is driven by
7612c43838cSFrederic Weisbecker	  the "isolcpus=" boot parameter.
7622c43838cSFrederic Weisbecker
7632c43838cSFrederic Weisbecker	  Say Y if unsure.
7645c4991e2SFrederic Weisbecker
7650af92d46SPaul E. McKenneysource "kernel/rcu/Kconfig"
766c903ff83SMike Travis
7671da177e4SLinus Torvaldsconfig IKCONFIG
768f2443ab6SRoss Biro	tristate "Kernel .config support"
769a7f7f624SMasahiro Yamada	help
7701da177e4SLinus Torvalds	  This option enables the complete Linux kernel ".config" file
7711da177e4SLinus Torvalds	  contents to be saved in the kernel. It provides documentation
7721da177e4SLinus Torvalds	  of which kernel options are used in a running kernel or in an
7731da177e4SLinus Torvalds	  on-disk kernel.  This information can be extracted from the kernel
7741da177e4SLinus Torvalds	  image file with the script scripts/extract-ikconfig and used as
7751da177e4SLinus Torvalds	  input to rebuild the current kernel or to build another kernel.
7761da177e4SLinus Torvalds	  It can also be extracted from a running kernel by reading
7771da177e4SLinus Torvalds	  /proc/config.gz if enabled (below).
7781da177e4SLinus Torvalds
7791da177e4SLinus Torvaldsconfig IKCONFIG_PROC
7801da177e4SLinus Torvalds	bool "Enable access to .config through /proc/config.gz"
7811da177e4SLinus Torvalds	depends on IKCONFIG && PROC_FS
782a7f7f624SMasahiro Yamada	help
7831da177e4SLinus Torvalds	  This option enables access to the kernel configuration file
7841da177e4SLinus Torvalds	  through /proc/config.gz.
7851da177e4SLinus Torvalds
786f7b101d3SJoel Fernandes (Google)config IKHEADERS
787f7b101d3SJoel Fernandes (Google)	tristate "Enable kernel headers through /sys/kernel/kheaders.tar.xz"
788f7b101d3SJoel Fernandes (Google)	depends on SYSFS
78943d8ce9dSJoel Fernandes (Google)	help
790f7b101d3SJoel Fernandes (Google)	  This option enables access to the in-kernel headers that are generated during
791f7b101d3SJoel Fernandes (Google)	  the build process. These can be used to build eBPF tracing programs,
792f7b101d3SJoel Fernandes (Google)	  or similar programs.  If you build the headers as a module, a module called
793f7b101d3SJoel Fernandes (Google)	  kheaders.ko is built which can be loaded on-demand to get access to headers.
79443d8ce9dSJoel Fernandes (Google)
795794543a2SAlistair John Strachanconfig LOG_BUF_SHIFT
796794543a2SAlistair John Strachan	int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
7971c4b5ecbSChristoph Hellwig	range 12 25
798f17a32e9SAdrian Bunk	default 17
799361e9dfbSJosh Triplett	depends on PRINTK
800794543a2SAlistair John Strachan	help
80123b2899fSLuis R. Rodriguez	  Select the minimal kernel log buffer size as a power of 2.
80223b2899fSLuis R. Rodriguez	  The final size is affected by LOG_CPU_MAX_BUF_SHIFT config
80323b2899fSLuis R. Rodriguez	  parameter, see below. Any higher size also might be forced
80423b2899fSLuis R. Rodriguez	  by "log_buf_len" boot parameter.
80523b2899fSLuis R. Rodriguez
806f17a32e9SAdrian Bunk	  Examples:
807f17a32e9SAdrian Bunk		     17 => 128 KB
808f17a32e9SAdrian Bunk		     16 => 64 KB
809f17a32e9SAdrian Bunk		     15 => 32 KB
810f17a32e9SAdrian Bunk		     14 => 16 KB
811794543a2SAlistair John Strachan		     13 =>  8 KB
812794543a2SAlistair John Strachan		     12 =>  4 KB
813794543a2SAlistair John Strachan
81423b2899fSLuis R. Rodriguezconfig LOG_CPU_MAX_BUF_SHIFT
81523b2899fSLuis R. Rodriguez	int "CPU kernel log buffer size contribution (13 => 8 KB, 17 => 128KB)"
8162240a31dSGeert Uytterhoeven	depends on SMP
81723b2899fSLuis R. Rodriguez	range 0 21
81823b2899fSLuis R. Rodriguez	default 0 if BASE_SMALL
819320bf431SYoann Congal	default 12
820361e9dfbSJosh Triplett	depends on PRINTK
82123b2899fSLuis R. Rodriguez	help
82223b2899fSLuis R. Rodriguez	  This option allows to increase the default ring buffer size
82323b2899fSLuis R. Rodriguez	  according to the number of CPUs. The value defines the contribution
82423b2899fSLuis R. Rodriguez	  of each CPU as a power of 2. The used space is typically only few
82523b2899fSLuis R. Rodriguez	  lines however it might be much more when problems are reported,
82623b2899fSLuis R. Rodriguez	  e.g. backtraces.
82723b2899fSLuis R. Rodriguez
82823b2899fSLuis R. Rodriguez	  The increased size means that a new buffer has to be allocated and
82923b2899fSLuis R. Rodriguez	  the original static one is unused. It makes sense only on systems
83023b2899fSLuis R. Rodriguez	  with more CPUs. Therefore this value is used only when the sum of
83123b2899fSLuis R. Rodriguez	  contributions is greater than the half of the default kernel ring
83223b2899fSLuis R. Rodriguez	  buffer as defined by LOG_BUF_SHIFT. The default values are set
8330f7636e1SPaul Menzel	  so that more than 16 CPUs are needed to trigger the allocation.
83423b2899fSLuis R. Rodriguez
83523b2899fSLuis R. Rodriguez	  Also this option is ignored when "log_buf_len" kernel parameter is
83623b2899fSLuis R. Rodriguez	  used as it forces an exact (power of two) size of the ring buffer.
83723b2899fSLuis R. Rodriguez
83823b2899fSLuis R. Rodriguez	  The number of possible CPUs is used for this computation ignoring
8395e0d8d59SGeert Uytterhoeven	  hotplugging making the computation optimal for the worst case
8405e0d8d59SGeert Uytterhoeven	  scenario while allowing a simple algorithm to be used from bootup.
84123b2899fSLuis R. Rodriguez
84223b2899fSLuis R. Rodriguez	  Examples shift values and their meaning:
84323b2899fSLuis R. Rodriguez		     17 => 128 KB for each CPU
84423b2899fSLuis R. Rodriguez		     16 =>  64 KB for each CPU
84523b2899fSLuis R. Rodriguez		     15 =>  32 KB for each CPU
84623b2899fSLuis R. Rodriguez		     14 =>  16 KB for each CPU
84723b2899fSLuis R. Rodriguez		     13 =>   8 KB for each CPU
84823b2899fSLuis R. Rodriguez		     12 =>   4 KB for each CPU
84923b2899fSLuis R. Rodriguez
85033701557SChris Downconfig PRINTK_INDEX
85133701557SChris Down	bool "Printk indexing debugfs interface"
85233701557SChris Down	depends on PRINTK && DEBUG_FS
85333701557SChris Down	help
85433701557SChris Down	  Add support for indexing of all printk formats known at compile time
85533701557SChris Down	  at <debugfs>/printk/index/<module>.
85633701557SChris Down
85733701557SChris Down	  This can be used as part of maintaining daemons which monitor
85833701557SChris Down	  /dev/kmsg, as it permits auditing the printk formats present in a
85933701557SChris Down	  kernel, allowing detection of cases where monitored printks are
86033701557SChris Down	  changed or no longer present.
86133701557SChris Down
86233701557SChris Down	  There is no additional runtime cost to printk with this enabled.
86333701557SChris Down
8645cdc38f9SKAMEZAWA Hiroyuki#
8655cdc38f9SKAMEZAWA Hiroyuki# Architectures with an unreliable sched_clock() should select this:
8665cdc38f9SKAMEZAWA Hiroyuki#
8675cdc38f9SKAMEZAWA Hiroyukiconfig HAVE_UNSTABLE_SCHED_CLOCK
8685cdc38f9SKAMEZAWA Hiroyuki	bool
8695cdc38f9SKAMEZAWA Hiroyuki
87038ff87f7SStephen Boydconfig GENERIC_SCHED_CLOCK
87138ff87f7SStephen Boyd	bool
87238ff87f7SStephen Boyd
87369842cbaSPatrick Bellasimenu "Scheduler features"
87469842cbaSPatrick Bellasi
87569842cbaSPatrick Bellasiconfig UCLAMP_TASK
87669842cbaSPatrick Bellasi	bool "Enable utilization clamping for RT/FAIR tasks"
87769842cbaSPatrick Bellasi	depends on CPU_FREQ_GOV_SCHEDUTIL
87869842cbaSPatrick Bellasi	help
87969842cbaSPatrick Bellasi	  This feature enables the scheduler to track the clamped utilization
88069842cbaSPatrick Bellasi	  of each CPU based on RUNNABLE tasks scheduled on that CPU.
88169842cbaSPatrick Bellasi
88269842cbaSPatrick Bellasi	  With this option, the user can specify the min and max CPU
88369842cbaSPatrick Bellasi	  utilization allowed for RUNNABLE tasks. The max utilization defines
88469842cbaSPatrick Bellasi	  the maximum frequency a task should use while the min utilization
88569842cbaSPatrick Bellasi	  defines the minimum frequency it should use.
88669842cbaSPatrick Bellasi
88769842cbaSPatrick Bellasi	  Both min and max utilization clamp values are hints to the scheduler,
88869842cbaSPatrick Bellasi	  aiming at improving its frequency selection policy, but they do not
88969842cbaSPatrick Bellasi	  enforce or grant any specific bandwidth for tasks.
89069842cbaSPatrick Bellasi
89169842cbaSPatrick Bellasi	  If in doubt, say N.
89269842cbaSPatrick Bellasi
89369842cbaSPatrick Bellasiconfig UCLAMP_BUCKETS_COUNT
89469842cbaSPatrick Bellasi	int "Number of supported utilization clamp buckets"
89569842cbaSPatrick Bellasi	range 5 20
89669842cbaSPatrick Bellasi	default 5
89769842cbaSPatrick Bellasi	depends on UCLAMP_TASK
89869842cbaSPatrick Bellasi	help
89969842cbaSPatrick Bellasi	  Defines the number of clamp buckets to use. The range of each bucket
90069842cbaSPatrick Bellasi	  will be SCHED_CAPACITY_SCALE/UCLAMP_BUCKETS_COUNT. The higher the
90169842cbaSPatrick Bellasi	  number of clamp buckets the finer their granularity and the higher
90269842cbaSPatrick Bellasi	  the precision of clamping aggregation and tracking at run-time.
90369842cbaSPatrick Bellasi
90469842cbaSPatrick Bellasi	  For example, with the minimum configuration value we will have 5
90569842cbaSPatrick Bellasi	  clamp buckets tracking 20% utilization each. A 25% boosted tasks will
90669842cbaSPatrick Bellasi	  be refcounted in the [20..39]% bucket and will set the bucket clamp
90769842cbaSPatrick Bellasi	  effective value to 25%.
90869842cbaSPatrick Bellasi	  If a second 30% boosted task should be co-scheduled on the same CPU,
90969842cbaSPatrick Bellasi	  that task will be refcounted in the same bucket of the first task and
91069842cbaSPatrick Bellasi	  it will boost the bucket clamp effective value to 30%.
91169842cbaSPatrick Bellasi	  The clamp effective value of a bucket is reset to its nominal value
91269842cbaSPatrick Bellasi	  (20% in the example above) when there are no more tasks refcounted in
91369842cbaSPatrick Bellasi	  that bucket.
91469842cbaSPatrick Bellasi
91569842cbaSPatrick Bellasi	  An additional boost/capping margin can be added to some tasks. In the
91669842cbaSPatrick Bellasi	  example above the 25% task will be boosted to 30% until it exits the
91769842cbaSPatrick Bellasi	  CPU. If that should be considered not acceptable on certain systems,
91869842cbaSPatrick Bellasi	  it's always possible to reduce the margin by increasing the number of
91969842cbaSPatrick Bellasi	  clamp buckets to trade off used memory for run-time tracking
92069842cbaSPatrick Bellasi	  precision.
92169842cbaSPatrick Bellasi
92269842cbaSPatrick Bellasi	  If in doubt, use the default value.
92369842cbaSPatrick Bellasi
92425c411fcSJohn Stultzconfig SCHED_PROXY_EXEC
92525c411fcSJohn Stultz	bool "Proxy Execution"
92625c411fcSJohn Stultz	# Avoid some build failures w/ PREEMPT_RT until it can be fixed
92725c411fcSJohn Stultz	depends on !PREEMPT_RT
92825c411fcSJohn Stultz	# Need to investigate how to inform sched_ext of split contexts
92925c411fcSJohn Stultz	depends on !SCHED_CLASS_EXT
93025c411fcSJohn Stultz	# Not particularly useful until we get to multi-rq proxying
93125c411fcSJohn Stultz	depends on EXPERT
93225c411fcSJohn Stultz	help
93325c411fcSJohn Stultz	  This option enables proxy execution, a mechanism for mutex-owning
93425c411fcSJohn Stultz	  tasks to inherit the scheduling context of higher priority waiters.
93525c411fcSJohn Stultz
93669842cbaSPatrick Bellasiendmenu
93769842cbaSPatrick Bellasi
938be3a7284SAndrea Arcangeli#
939be3a7284SAndrea Arcangeli# For architectures that want to enable the support for NUMA-affine scheduler
940be3a7284SAndrea Arcangeli# balancing logic:
941be3a7284SAndrea Arcangeli#
942be3a7284SAndrea Arcangeliconfig ARCH_SUPPORTS_NUMA_BALANCING
943be3a7284SAndrea Arcangeli	bool
944be3a7284SAndrea Arcangeli
945be5e610cSPeter Zijlstra#
94672b252aeSMel Gorman# For architectures that prefer to flush all TLBs after a number of pages
94772b252aeSMel Gorman# are unmapped instead of sending one IPI per page to flush. The architecture
94872b252aeSMel Gorman# must provide guarantees on what happens if a clean TLB cache entry is
94972b252aeSMel Gorman# written after the unmap. Details are in mm/rmap.c near the check for
95072b252aeSMel Gorman# should_defer_flush. The architecture should also consider if the full flush
95172b252aeSMel Gorman# and the refill costs are offset by the savings of sending fewer IPIs.
95272b252aeSMel Gormanconfig ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
95372b252aeSMel Gorman	bool
95472b252aeSMel Gorman
955c12d3362SArd Biesheuvelconfig CC_HAS_INT128
9563a7c7331SMasahiro Yamada	def_bool !$(cc-option,$(m64-flag) -D__SIZEOF_INT128__=0) && 64BIT
957c12d3362SArd Biesheuvel
958dee2b702SGustavo A. R. Silvaconfig CC_IMPLICIT_FALLTHROUGH
959dee2b702SGustavo A. R. Silva	string
960158ea2d2SGustavo A. R. Silva	default "-Wimplicit-fallthrough=5" if CC_IS_GCC && $(cc-option,-Wimplicit-fallthrough=5)
961dee2b702SGustavo A. R. Silva	default "-Wimplicit-fallthrough" if CC_IS_CLANG && $(cc-option,-Wunreachable-code-fallthrough)
962dee2b702SGustavo A. R. Silva
9633e00f580SKees Cook# Currently, disable gcc-10+ array-bounds globally.
9640da6e5fdSLinus Torvalds# It's still broken in gcc-13, so no upper bound yet.
9653e00f580SKees Cookconfig GCC10_NO_ARRAY_BOUNDS
9665a41237aSLinus Torvalds	def_bool y
9675a41237aSLinus Torvalds
968f0be87c4SLinus Torvaldsconfig CC_NO_ARRAY_BOUNDS
969f0be87c4SLinus Torvalds	bool
9708e5bd4eaSYury Norov	default y if CC_IS_GCC && GCC_VERSION >= 90000 && GCC10_NO_ARRAY_BOUNDS
971f0be87c4SLinus Torvalds
97202153319SLinus Torvalds# Currently, disable -Wstringop-overflow for GCC globally.
97302153319SLinus Torvaldsconfig GCC_NO_STRINGOP_OVERFLOW
974a5e0ace0SGustavo A. R. Silva	def_bool y
975a5e0ace0SGustavo A. R. Silva
976a5e0ace0SGustavo A. R. Silvaconfig CC_NO_STRINGOP_OVERFLOW
977a5e0ace0SGustavo A. R. Silva	bool
97802153319SLinus Torvalds	default y if CC_IS_GCC && GCC_NO_STRINGOP_OVERFLOW
979a5e0ace0SGustavo A. R. Silva
980a5e0ace0SGustavo A. R. Silvaconfig CC_STRINGOP_OVERFLOW
981a5e0ace0SGustavo A. R. Silva	bool
982a5e0ace0SGustavo A. R. Silva	default y if CC_IS_GCC && !CC_NO_STRINGOP_OVERFLOW
983a5e0ace0SGustavo A. R. Silva
98472b252aeSMel Gorman#
985be5e610cSPeter Zijlstra# For architectures that know their GCC __int128 support is sound
986be5e610cSPeter Zijlstra#
987be5e610cSPeter Zijlstraconfig ARCH_SUPPORTS_INT128
988be5e610cSPeter Zijlstra	bool
989be5e610cSPeter Zijlstra
990be3a7284SAndrea Arcangeli# For architectures that (ab)use NUMA to represent different memory regions
991be3a7284SAndrea Arcangeli# all cpu-local but of different latencies, such as SuperH.
992be3a7284SAndrea Arcangeli#
993be3a7284SAndrea Arcangeliconfig ARCH_WANT_NUMA_VARIABLE_LOCALITY
994be3a7284SAndrea Arcangeli	bool
995be3a7284SAndrea Arcangeli
996be3a7284SAndrea Arcangeliconfig NUMA_BALANCING
997be3a7284SAndrea Arcangeli	bool "Memory placement aware NUMA scheduler"
998be3a7284SAndrea Arcangeli	depends on ARCH_SUPPORTS_NUMA_BALANCING
999be3a7284SAndrea Arcangeli	depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
1000554b0f3cSSebastian Andrzej Siewior	depends on SMP && NUMA && MIGRATION && !PREEMPT_RT
1001be3a7284SAndrea Arcangeli	help
1002be3a7284SAndrea Arcangeli	  This option adds support for automatic NUMA aware memory/task placement.
1003be3a7284SAndrea Arcangeli	  The mechanism is quite primitive and is based on migrating memory when
10046d56a410SPaul Gortmaker	  it has references to the node the task is running on.
1005be3a7284SAndrea Arcangeli
1006be3a7284SAndrea Arcangeli	  This system will be inactive on UMA systems.
1007be3a7284SAndrea Arcangeli
10086f7c97e8SAneesh Kumar K.Vconfig NUMA_BALANCING_DEFAULT_ENABLED
10096f7c97e8SAneesh Kumar K.V	bool "Automatically enable NUMA aware memory/task placement"
10106f7c97e8SAneesh Kumar K.V	default y
10116f7c97e8SAneesh Kumar K.V	depends on NUMA_BALANCING
10126f7c97e8SAneesh Kumar K.V	help
10136f7c97e8SAneesh Kumar K.V	  If set, automatic NUMA balancing will be enabled if running on a NUMA
10146f7c97e8SAneesh Kumar K.V	  machine.
10156f7c97e8SAneesh Kumar K.V
101621c690a3SSuren Baghdasaryanconfig SLAB_OBJ_EXT
101721c690a3SSuren Baghdasaryan	bool
101821c690a3SSuren Baghdasaryan
101923964d2dSLi Zefanmenuconfig CGROUPS
10206341e62bSChristoph Jaeger	bool "Control Group support"
10212bd59d48STejun Heo	select KERNFS
1022ddbcc7e8SPaul Menage	help
102323964d2dSLi Zefan	  This option adds support for grouping sets of processes together, for
10245cdc38f9SKAMEZAWA Hiroyuki	  use with process control subsystems such as Cpusets, CFS, memory
10255cdc38f9SKAMEZAWA Hiroyuki	  controls or device isolation.
10265cdc38f9SKAMEZAWA Hiroyuki	  See
1027d6a3b247SMauro Carvalho Chehab		- Documentation/scheduler/sched-design-CFS.rst	(CFS)
1028da82c92fSMauro Carvalho Chehab		- Documentation/admin-guide/cgroup-v1/ (features for grouping, isolation
102945ce80fbSLi Zefan					  and resource control)
1030ddbcc7e8SPaul Menage
1031ddbcc7e8SPaul Menage	  Say N if unsure.
1032ddbcc7e8SPaul Menage
103323964d2dSLi Zefanif CGROUPS
103423964d2dSLi Zefan
10353e32cb2eSJohannes Weinerconfig PAGE_COUNTER
10363e32cb2eSJohannes Weiner	bool
10373e32cb2eSJohannes Weiner
10386a010a49STejun Heoconfig CGROUP_FAVOR_DYNMODS
10396a010a49STejun Heo        bool "Favor dynamic modification latency reduction by default"
10406a010a49STejun Heo        help
10416a010a49STejun Heo          This option enables the "favordynmods" mount option by default
10426a010a49STejun Heo          which reduces the latencies of dynamic cgroup modifications such
10436a010a49STejun Heo          as task migrations and controller on/offs at the cost of making
10446a010a49STejun Heo          hot path operations such as forks and exits more expensive.
10456a010a49STejun Heo
10466a010a49STejun Heo          Say N if unsure.
10476a010a49STejun Heo
1048c255a458SAndrew Mortonconfig MEMCG
1049a0166ec4SJohannes Weiner	bool "Memory controller"
10503e32cb2eSJohannes Weiner	select PAGE_COUNTER
105179bd9814STejun Heo	select EVENTFD
105221c690a3SSuren Baghdasaryan	select SLAB_OBJ_EXT
1053fdc5001bSKirill A. Shutemov	select VM_EVENT_COUNTERS
105400f0b825SBalbir Singh	help
1055a0166ec4SJohannes Weiner	  Provides control over the memory footprint of tasks in a cgroup.
105600f0b825SBalbir Singh
105725352d2fSShakeel Buttconfig MEMCG_NMI_UNSAFE
105825352d2fSShakeel Butt	bool
105925352d2fSShakeel Butt	depends on MEMCG
106025352d2fSShakeel Butt	depends on HAVE_NMI
106125352d2fSShakeel Butt	depends on !ARCH_HAS_NMI_SAFE_THIS_CPU_OPS && !ARCH_HAVE_NMI_SAFE_CMPXCHG
106225352d2fSShakeel Butt	default y
106325352d2fSShakeel Butt
1064940b01fcSShakeel Buttconfig MEMCG_NMI_SAFETY_REQUIRES_ATOMIC
1065940b01fcSShakeel Butt	bool
1066940b01fcSShakeel Butt	depends on MEMCG
1067940b01fcSShakeel Butt	depends on HAVE_NMI
1068940b01fcSShakeel Butt	depends on !ARCH_HAS_NMI_SAFE_THIS_CPU_OPS && ARCH_HAVE_NMI_SAFE_CMPXCHG
1069940b01fcSShakeel Butt	default y
1070940b01fcSShakeel Butt
1071e93d4166SRoman Gushchinconfig MEMCG_V1
1072e93d4166SRoman Gushchin	bool "Legacy cgroup v1 memory controller"
1073c9929f0eSVlastimil Babka	depends on MEMCG
1074e93d4166SRoman Gushchin	default n
1075e93d4166SRoman Gushchin	help
1076e93d4166SRoman Gushchin	  Legacy cgroup v1 memory controller which has been deprecated by
1077e93d4166SRoman Gushchin	  cgroup v2 implementation. The v1 is there for legacy applications
1078e93d4166SRoman Gushchin	  which haven't migrated to the new cgroup v2 interface yet. If you
1079e93d4166SRoman Gushchin	  do not have any such application then you are completely fine leaving
1080e93d4166SRoman Gushchin	  this option disabled.
1081e93d4166SRoman Gushchin
1082e93d4166SRoman Gushchin	  Please note that feature set of the legacy memory controller is likely
1083e93d4166SRoman Gushchin	  going to shrink due to deprecation process. New deployments with v1
1084e93d4166SRoman Gushchin	  controller are highly discouraged.
1085e93d4166SRoman Gushchin
1086fcb4824bSValdis Kletnieks	  Say N if unsure.
108784c07d11SKirill Tkhai
10886bf024e6SJohannes Weinerconfig BLK_CGROUP
10896bf024e6SJohannes Weiner	bool "IO controller"
10906bf024e6SJohannes Weiner	depends on BLOCK
10912bc64a20SAneesh Kumar K.V	default n
1092a7f7f624SMasahiro Yamada	help
10936bf024e6SJohannes Weiner	Generic block IO controller cgroup interface. This is the common
10946bf024e6SJohannes Weiner	cgroup interface which should be used by various IO controlling
10956bf024e6SJohannes Weiner	policies.
10962bc64a20SAneesh Kumar K.V
10976bf024e6SJohannes Weiner	Currently, CFQ IO scheduler uses it to recognize task groups and
10986bf024e6SJohannes Weiner	control disk bandwidth allocation (proportional time slice allocation)
10996bf024e6SJohannes Weiner	to such task groups. It is also used by bio throttling logic in
11006bf024e6SJohannes Weiner	block layer to implement upper limit in IO rates on a device.
1101e5d1367fSStephane Eranian
11026bf024e6SJohannes Weiner	This option only enables generic Block IO controller infrastructure.
11036bf024e6SJohannes Weiner	One needs to also enable actual IO controlling logic/policy. For
11046bf024e6SJohannes Weiner	enabling proportional weight division of disk bandwidth in CFQ, set
11057baf2199SKrzysztof Kozlowski	CONFIG_BFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
11066bf024e6SJohannes Weiner	CONFIG_BLK_DEV_THROTTLING=y.
11076bf024e6SJohannes Weiner
1108da82c92fSMauro Carvalho Chehab	See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information.
11096bf024e6SJohannes Weiner
11106bf024e6SJohannes Weinerconfig CGROUP_WRITEBACK
11116bf024e6SJohannes Weiner	bool
11126bf024e6SJohannes Weiner	depends on MEMCG && BLK_CGROUP
11136bf024e6SJohannes Weiner	default y
1114e5d1367fSStephane Eranian
11157c941438SDhaval Gianimenuconfig CGROUP_SCHED
1116a0166ec4SJohannes Weiner	bool "CPU controller"
11177c941438SDhaval Giani	default n
11187c941438SDhaval Giani	help
11197c941438SDhaval Giani	  This feature lets CPU scheduler recognize task groups and control CPU
11207c941438SDhaval Giani	  bandwidth allocation to such task groups. It uses cgroups to group
11217c941438SDhaval Giani	  tasks.
11227c941438SDhaval Giani
11237c941438SDhaval Gianiif CGROUP_SCHED
1124e179e80cSTejun Heoconfig GROUP_SCHED_WEIGHT
1125e179e80cSTejun Heo	def_bool n
1126e179e80cSTejun Heo
1127ddceadceSTejun Heoconfig GROUP_SCHED_BANDWIDTH
1128ddceadceSTejun Heo        def_bool n
1129ddceadceSTejun Heo
11307c941438SDhaval Gianiconfig FAIR_GROUP_SCHED
11317c941438SDhaval Giani	bool "Group scheduling for SCHED_OTHER"
11327c941438SDhaval Giani	depends on CGROUP_SCHED
1133e179e80cSTejun Heo	select GROUP_SCHED_WEIGHT
11347c941438SDhaval Giani	default CGROUP_SCHED
11357c941438SDhaval Giani
1136ab84d31eSPaul Turnerconfig CFS_BANDWIDTH
1137ab84d31eSPaul Turner	bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
1138ab84d31eSPaul Turner	depends on FAIR_GROUP_SCHED
1139ddceadceSTejun Heo	select GROUP_SCHED_BANDWIDTH
1140ab84d31eSPaul Turner	default n
1141ab84d31eSPaul Turner	help
1142ab84d31eSPaul Turner	  This option allows users to define CPU bandwidth rates (limits) for
1143ab84d31eSPaul Turner	  tasks running within the fair group scheduler.  Groups with no limit
1144ab84d31eSPaul Turner	  set are considered to be unconstrained and will run with no
1145ab84d31eSPaul Turner	  restriction.
1146d6a3b247SMauro Carvalho Chehab	  See Documentation/scheduler/sched-bwc.rst for more information.
1147ab84d31eSPaul Turner
11487c941438SDhaval Gianiconfig RT_GROUP_SCHED
11497c941438SDhaval Giani	bool "Group scheduling for SCHED_RR/FIFO"
11507c941438SDhaval Giani	depends on CGROUP_SCHED
11517c941438SDhaval Giani	default n
11527c941438SDhaval Giani	help
11537c941438SDhaval Giani	  This feature lets you explicitly allocate real CPU bandwidth
115432bd7eb5SLi Zefan	  to task groups. If enabled, it will also make it impossible to
11557c941438SDhaval Giani	  schedule realtime tasks for non-root users until you allocate
11567c941438SDhaval Giani	  realtime bandwidth for them.
1157d6a3b247SMauro Carvalho Chehab	  See Documentation/scheduler/sched-rt-group.rst for more information.
11587c941438SDhaval Giani
1159e34e0131SMichal Koutnýconfig RT_GROUP_SCHED_DEFAULT_DISABLED
1160e34e0131SMichal Koutný	bool "Require boot parameter to enable group scheduling for SCHED_RR/FIFO"
1161e34e0131SMichal Koutný	depends on RT_GROUP_SCHED
1162e34e0131SMichal Koutný	default n
1163e34e0131SMichal Koutný	help
1164e34e0131SMichal Koutný	  When set, the RT group scheduling is disabled by default. The option
1165e34e0131SMichal Koutný	  is in inverted form so that mere RT_GROUP_SCHED enables the group
1166e34e0131SMichal Koutný	  scheduling.
1167e34e0131SMichal Koutný
1168e34e0131SMichal Koutný	  Say N if unsure.
1169e34e0131SMichal Koutný
117081951366STejun Heoconfig EXT_GROUP_SCHED
117181951366STejun Heo	bool
117281951366STejun Heo	depends on SCHED_CLASS_EXT && CGROUP_SCHED
117381951366STejun Heo	select GROUP_SCHED_WEIGHT
1174ddceadceSTejun Heo	select GROUP_SCHED_BANDWIDTH
117581951366STejun Heo	default y
117681951366STejun Heo
11777c941438SDhaval Gianiendif #CGROUP_SCHED
11787c941438SDhaval Giani
1179af7f588dSMathieu Desnoyersconfig SCHED_MM_CID
1180af7f588dSMathieu Desnoyers	def_bool y
1181af7f588dSMathieu Desnoyers	depends on SMP && RSEQ
1182af7f588dSMathieu Desnoyers
11832480c093SPatrick Bellasiconfig UCLAMP_TASK_GROUP
11842480c093SPatrick Bellasi	bool "Utilization clamping per group of tasks"
11852480c093SPatrick Bellasi	depends on CGROUP_SCHED
11862480c093SPatrick Bellasi	depends on UCLAMP_TASK
11872480c093SPatrick Bellasi	default n
11882480c093SPatrick Bellasi	help
11892480c093SPatrick Bellasi	  This feature enables the scheduler to track the clamped utilization
11902480c093SPatrick Bellasi	  of each CPU based on RUNNABLE tasks currently scheduled on that CPU.
11912480c093SPatrick Bellasi
11922480c093SPatrick Bellasi	  When this option is enabled, the user can specify a min and max
11932480c093SPatrick Bellasi	  CPU bandwidth which is allowed for each single task in a group.
11942480c093SPatrick Bellasi	  The max bandwidth allows to clamp the maximum frequency a task
11952480c093SPatrick Bellasi	  can use, while the min bandwidth allows to define a minimum
11962480c093SPatrick Bellasi	  frequency a task will always use.
11972480c093SPatrick Bellasi
11982480c093SPatrick Bellasi	  When task group based utilization clamping is enabled, an eventually
11992480c093SPatrick Bellasi	  specified task-specific clamp value is constrained by the cgroup
12002480c093SPatrick Bellasi	  specified clamp value. Both minimum and maximum task clamping cannot
12012480c093SPatrick Bellasi	  be bigger than the corresponding clamping defined at task group level.
12022480c093SPatrick Bellasi
12032480c093SPatrick Bellasi	  If in doubt, say N.
12042480c093SPatrick Bellasi
12056bf024e6SJohannes Weinerconfig CGROUP_PIDS
12066bf024e6SJohannes Weiner	bool "PIDs controller"
12076bf024e6SJohannes Weiner	help
12086bf024e6SJohannes Weiner	  Provides enforcement of process number limits in the scope of a
12096bf024e6SJohannes Weiner	  cgroup. Any attempt to fork more processes than is allowed in the
12106bf024e6SJohannes Weiner	  cgroup will fail. PIDs are fundamentally a global resource because it
12116bf024e6SJohannes Weiner	  is fairly trivial to reach PID exhaustion before you reach even a
12126bf024e6SJohannes Weiner	  conservative kmemcg limit. As a result, it is possible to grind a
12136bf024e6SJohannes Weiner	  system to halt without being limited by other cgroup policies. The
12146cc578dfSParav Pandit	  PIDs controller is designed to stop this from happening.
12156bf024e6SJohannes Weiner
12166bf024e6SJohannes Weiner	  It should be noted that organisational operations (such as attaching
121798076833SJonathan Neuschäfer	  to a cgroup hierarchy) will *not* be blocked by the PIDs controller,
12186bf024e6SJohannes Weiner	  since the PIDs limit only affects a process's ability to fork, not to
12196bf024e6SJohannes Weiner	  attach to a cgroup.
12206bf024e6SJohannes Weiner
122139d3e758SParav Panditconfig CGROUP_RDMA
122239d3e758SParav Pandit	bool "RDMA controller"
122339d3e758SParav Pandit	help
122439d3e758SParav Pandit	  Provides enforcement of RDMA resources defined by IB stack.
122539d3e758SParav Pandit	  It is fairly easy for consumers to exhaust RDMA resources, which
122639d3e758SParav Pandit	  can result into resource unavailability to other consumers.
122739d3e758SParav Pandit	  RDMA controller is designed to stop this from happening.
122839d3e758SParav Pandit	  Attaching processes with active RDMA resources to the cgroup
122939d3e758SParav Pandit	  hierarchy is allowed even if can cross the hierarchy's limit.
123039d3e758SParav Pandit
1231b168ed45SMaarten Lankhorstconfig CGROUP_DMEM
1232b168ed45SMaarten Lankhorst	bool "Device memory controller (DMEM)"
1233e33b5149SMaxime Ripard	select PAGE_COUNTER
1234b168ed45SMaarten Lankhorst	help
1235b168ed45SMaarten Lankhorst	  The DMEM controller allows compatible devices to restrict device
1236b168ed45SMaarten Lankhorst	  memory usage based on the cgroup hierarchy.
1237b168ed45SMaarten Lankhorst
1238b168ed45SMaarten Lankhorst	  As an example, it allows you to restrict VRAM usage for applications
1239b168ed45SMaarten Lankhorst	  in the DRM subsystem.
1240b168ed45SMaarten Lankhorst
12416bf024e6SJohannes Weinerconfig CGROUP_FREEZER
12426bf024e6SJohannes Weiner	bool "Freezer controller"
12436bf024e6SJohannes Weiner	help
12446bf024e6SJohannes Weiner	  Provides a way to freeze and unfreeze all tasks in a
12456bf024e6SJohannes Weiner	  cgroup.
12466bf024e6SJohannes Weiner
1247489c2a20SJohannes Weiner	  This option affects the ORIGINAL cgroup interface. The cgroup2 memory
1248489c2a20SJohannes Weiner	  controller includes important in-kernel memory consumers per default.
1249489c2a20SJohannes Weiner
1250489c2a20SJohannes Weiner	  If you're using cgroup2, say N.
1251489c2a20SJohannes Weiner
12526bf024e6SJohannes Weinerconfig CGROUP_HUGETLB
12536bf024e6SJohannes Weiner	bool "HugeTLB controller"
12546bf024e6SJohannes Weiner	depends on HUGETLB_PAGE
12556bf024e6SJohannes Weiner	select PAGE_COUNTER
1256afc24d49SVivek Goyal	default n
12576bf024e6SJohannes Weiner	help
12586bf024e6SJohannes Weiner	  Provides a cgroup controller for HugeTLB pages.
12596bf024e6SJohannes Weiner	  When you enable this, you can put a per cgroup limit on HugeTLB usage.
12606bf024e6SJohannes Weiner	  The limit is enforced during page fault. Since HugeTLB doesn't
12616bf024e6SJohannes Weiner	  support page reclaim, enforcing the limit at page fault time implies
12626bf024e6SJohannes Weiner	  that, the application will get SIGBUS signal if it tries to access
12636bf024e6SJohannes Weiner	  HugeTLB pages beyond its limit. This requires the application to know
12646bf024e6SJohannes Weiner	  beforehand how much HugeTLB pages it would require for its use. The
12656bf024e6SJohannes Weiner	  control group is tracked in the third page lru pointer. This means
12666bf024e6SJohannes Weiner	  that we cannot use the controller with huge page less than 3 pages.
1267afc24d49SVivek Goyal
12686bf024e6SJohannes Weinerconfig CPUSETS
12696bf024e6SJohannes Weiner	bool "Cpuset controller"
1270e1d4eeecSNicolas Pitre	depends on SMP
1271bf9850f6SKuan-Wei Chiu	select UNION_FIND
127223f09dccSFrederic Weisbecker	select CPU_ISOLATION
12736bf024e6SJohannes Weiner	help
12746bf024e6SJohannes Weiner	  This option will let you create and manage CPUSETs which
12756bf024e6SJohannes Weiner	  allow dynamically partitioning a system into sets of CPUs and
12766bf024e6SJohannes Weiner	  Memory Nodes and assigning tasks to run only within those sets.
12776bf024e6SJohannes Weiner	  This is primarily useful on large SMP or NUMA systems.
1278afc24d49SVivek Goyal
12796bf024e6SJohannes Weiner	  Say N if unsure.
1280afc24d49SVivek Goyal
12811abab1baSChen Ridongconfig CPUSETS_V1
12821abab1baSChen Ridong	bool "Legacy cgroup v1 cpusets controller"
12831abab1baSChen Ridong	depends on CPUSETS
12841abab1baSChen Ridong	default n
12851abab1baSChen Ridong	help
12861abab1baSChen Ridong	  Legacy cgroup v1 cpusets controller which has been deprecated by
12871abab1baSChen Ridong	  cgroup v2 implementation. The v1 is there for legacy applications
1288dae68fbaSMichal Koutný	  which haven't migrated to the new cgroup v2 interface yet. Legacy
1289dae68fbaSMichal Koutný	  interface includes cpuset filesystem and /proc/<pid>/cpuset. If you
12901abab1baSChen Ridong	  do not have any such application then you are completely fine leaving
12911abab1baSChen Ridong	  this option disabled.
12921abab1baSChen Ridong
12931abab1baSChen Ridong	  Say N if unsure.
12941abab1baSChen Ridong
12956bf024e6SJohannes Weinerconfig PROC_PID_CPUSET
12966bf024e6SJohannes Weiner	bool "Include legacy /proc/<pid>/cpuset file"
1297dae68fbaSMichal Koutný	depends on CPUSETS_V1
129889e9b9e0STejun Heo	default y
129989e9b9e0STejun Heo
13006bf024e6SJohannes Weinerconfig CGROUP_DEVICE
13016bf024e6SJohannes Weiner	bool "Device controller"
13026bf024e6SJohannes Weiner	help
13036bf024e6SJohannes Weiner	  Provides a cgroup controller implementing whitelists for
13046bf024e6SJohannes Weiner	  devices which a process in the cgroup can mknod or open.
13056bf024e6SJohannes Weiner
13066bf024e6SJohannes Weinerconfig CGROUP_CPUACCT
13076bf024e6SJohannes Weiner	bool "Simple CPU accounting controller"
13086bf024e6SJohannes Weiner	help
13096bf024e6SJohannes Weiner	  Provides a simple controller for monitoring the
13106bf024e6SJohannes Weiner	  total CPU consumed by the tasks in a cgroup.
13116bf024e6SJohannes Weiner
13126bf024e6SJohannes Weinerconfig CGROUP_PERF
13136bf024e6SJohannes Weiner	bool "Perf controller"
13146bf024e6SJohannes Weiner	depends on PERF_EVENTS
13156bf024e6SJohannes Weiner	help
13166bf024e6SJohannes Weiner	  This option extends the perf per-cpu mode to restrict monitoring
13176bf024e6SJohannes Weiner	  to threads which belong to the cgroup specified and run on the
13186546b19fSNamhyung Kim	  designated cpu.  Or this can be used to have cgroup ID in samples
13196546b19fSNamhyung Kim	  so that it can monitor performance events among cgroups.
13206bf024e6SJohannes Weiner
13216bf024e6SJohannes Weiner	  Say N if unsure.
13226bf024e6SJohannes Weiner
132330070984SDaniel Mackconfig CGROUP_BPF
132430070984SDaniel Mack	bool "Support for eBPF programs attached to cgroups"
1325483c4933SAndy Lutomirski	depends on BPF_SYSCALL
1326483c4933SAndy Lutomirski	select SOCK_CGROUP_DATA
132730070984SDaniel Mack	help
132830070984SDaniel Mack	  Allow attaching eBPF programs to a cgroup using the bpf(2)
132930070984SDaniel Mack	  syscall command BPF_PROG_ATTACH.
133030070984SDaniel Mack
133130070984SDaniel Mack	  In which context these programs are accessed depends on the type
133230070984SDaniel Mack	  of attachment. For instance, programs that are attached using
133330070984SDaniel Mack	  BPF_CGROUP_INET_INGRESS will be executed on the ingress path of
133430070984SDaniel Mack	  inet sockets.
133530070984SDaniel Mack
1336a72232eaSVipin Sharmaconfig CGROUP_MISC
1337a72232eaSVipin Sharma	bool "Misc resource controller"
1338a72232eaSVipin Sharma	default n
1339a72232eaSVipin Sharma	help
1340a72232eaSVipin Sharma	  Provides a controller for miscellaneous resources on a host.
1341a72232eaSVipin Sharma
1342a72232eaSVipin Sharma	  Miscellaneous scalar resources are the resources on the host system
1343a72232eaSVipin Sharma	  which cannot be abstracted like the other cgroups. This controller
1344a72232eaSVipin Sharma	  tracks and limits the miscellaneous resources used by a process
1345a72232eaSVipin Sharma	  attached to a cgroup hierarchy.
1346a72232eaSVipin Sharma
1347a72232eaSVipin Sharma	  For more information, please check misc cgroup section in
1348a72232eaSVipin Sharma	  /Documentation/admin-guide/cgroup-v2.rst.
1349a72232eaSVipin Sharma
13506bf024e6SJohannes Weinerconfig CGROUP_DEBUG
135123b0be48SWaiman Long	bool "Debug controller"
13526bf024e6SJohannes Weiner	default n
135323b0be48SWaiman Long	depends on DEBUG_KERNEL
13546bf024e6SJohannes Weiner	help
13556bf024e6SJohannes Weiner	  This option enables a simple controller that exports
135623b0be48SWaiman Long	  debugging information about the cgroups framework. This
135723b0be48SWaiman Long	  controller is for control cgroup debugging only. Its
135823b0be48SWaiman Long	  interfaces are not stable.
13596bf024e6SJohannes Weiner
13606bf024e6SJohannes Weiner	  Say N.
13616bf024e6SJohannes Weiner
136273b35147SArnd Bergmannconfig SOCK_CGROUP_DATA
136373b35147SArnd Bergmann	bool
136473b35147SArnd Bergmann	default n
136573b35147SArnd Bergmann
136623964d2dSLi Zefanendif # CGROUPS
1367c077719bSKAMEZAWA Hiroyuki
13688dd2a82cSDaniel Lezcanomenuconfig NAMESPACES
13696a108a14SDavid Rientjes	bool "Namespaces support" if EXPERT
13702813893fSIulia Manda	depends on MULTIUSER
13716a108a14SDavid Rientjes	default !EXPERT
1372c5289a69SPavel Emelyanov	help
1373c5289a69SPavel Emelyanov	  Provides the way to make tasks work with different objects using
1374c5289a69SPavel Emelyanov	  the same id. For example same IPC id may refer to different objects
1375c5289a69SPavel Emelyanov	  or same user id or pid may refer to different tasks when used in
1376c5289a69SPavel Emelyanov	  different namespaces.
1377c5289a69SPavel Emelyanov
13788dd2a82cSDaniel Lezcanoif NAMESPACES
13798dd2a82cSDaniel Lezcano
138058bfdd6dSPavel Emelyanovconfig UTS_NS
138158bfdd6dSPavel Emelyanov	bool "UTS namespace"
138217a6d441SDaniel Lezcano	default y
138358bfdd6dSPavel Emelyanov	help
138458bfdd6dSPavel Emelyanov	  In this namespace tasks see different info provided with the
138558bfdd6dSPavel Emelyanov	  uname() system call
138658bfdd6dSPavel Emelyanov
1387769071acSAndrei Vaginconfig TIME_NS
1388769071acSAndrei Vagin	bool "TIME namespace"
1389bad53ae2SThomas Weißschuh	depends on GENERIC_GETTIMEOFDAY
1390769071acSAndrei Vagin	default y
1391769071acSAndrei Vagin	help
1392769071acSAndrei Vagin	  In this namespace boottime and monotonic clocks can be set.
1393769071acSAndrei Vagin	  The time will keep going with the same pace.
1394769071acSAndrei Vagin
1395ae5e1b22SPavel Emelyanovconfig IPC_NS
1396ae5e1b22SPavel Emelyanov	bool "IPC namespace"
13978dd2a82cSDaniel Lezcano	depends on (SYSVIPC || POSIX_MQUEUE)
139817a6d441SDaniel Lezcano	default y
1399ae5e1b22SPavel Emelyanov	help
1400ae5e1b22SPavel Emelyanov	  In this namespace tasks work with IPC ids which correspond to
1401614b84cfSSerge E. Hallyn	  different IPC objects in different namespaces.
1402ae5e1b22SPavel Emelyanov
1403aee16ce7SPavel Emelyanovconfig USER_NS
140419c92399SKees Cook	bool "User namespace"
14055673a94cSEric W. Biederman	default n
1406aee16ce7SPavel Emelyanov	help
1407aee16ce7SPavel Emelyanov	  This allows containers, i.e. vservers, to use user namespaces
1408aee16ce7SPavel Emelyanov	  to provide different user info for different servers.
1409e11f0ae3SEric W. Biederman
1410e11f0ae3SEric W. Biederman	  When user namespaces are enabled in the kernel it is
1411d886f4e4SJohannes Weiner	  recommended that the MEMCG option also be enabled and that
1412d886f4e4SJohannes Weiner	  user-space use the memory control groups to limit the amount
1413d886f4e4SJohannes Weiner	  of memory a memory unprivileged users can use.
1414e11f0ae3SEric W. Biederman
1415aee16ce7SPavel Emelyanov	  If unsure, say N.
1416aee16ce7SPavel Emelyanov
141774bd59bbSPavel Emelyanovconfig PID_NS
14189bd38c2cSDaniel Lezcano	bool "PID Namespaces"
141917a6d441SDaniel Lezcano	default y
142074bd59bbSPavel Emelyanov	help
142112d2b8f9SHeikki Orsila	  Support process id namespaces.  This allows having multiple
1422692105b8SMatt LaPlante	  processes with the same pid as long as they are in different
142374bd59bbSPavel Emelyanov	  pid namespaces.  This is a building block of containers.
142474bd59bbSPavel Emelyanov
1425d6eb633fSMatt Helsleyconfig NET_NS
1426d6eb633fSMatt Helsley	bool "Network namespace"
14278dd2a82cSDaniel Lezcano	depends on NET
142817a6d441SDaniel Lezcano	default y
1429d6eb633fSMatt Helsley	help
1430d6eb633fSMatt Helsley	  Allow user space to create what appear to be multiple instances
1431d6eb633fSMatt Helsley	  of the network stack.
1432d6eb633fSMatt Helsley
14338dd2a82cSDaniel Lezcanoendif # NAMESPACES
14348dd2a82cSDaniel Lezcano
14355cb366bbSAdrian Reberconfig CHECKPOINT_RESTORE
14365cb366bbSAdrian Reber	bool "Checkpoint/restore support"
143730341ec9SRen Zhijie	depends on PROC_FS
14385cb366bbSAdrian Reber	select PROC_CHILDREN
1439bfe3911aSChris Wilson	select KCMP
14405cb366bbSAdrian Reber	default n
14415cb366bbSAdrian Reber	help
14425cb366bbSAdrian Reber	  Enables additional kernel features in a sake of checkpoint/restore.
14435cb366bbSAdrian Reber	  In particular it adds auxiliary prctl codes to setup process text,
14445cb366bbSAdrian Reber	  data and heap segment sizes, and a few additional /proc filesystem
14455cb366bbSAdrian Reber	  entries.
14465cb366bbSAdrian Reber
14475cb366bbSAdrian Reber	  If unsure, say N here.
14485cb366bbSAdrian Reber
14495091faa4SMike Galbraithconfig SCHED_AUTOGROUP
14505091faa4SMike Galbraith	bool "Automatic process group scheduling"
14515091faa4SMike Galbraith	select CGROUPS
14525091faa4SMike Galbraith	select CGROUP_SCHED
14535091faa4SMike Galbraith	select FAIR_GROUP_SCHED
14545091faa4SMike Galbraith	help
14555091faa4SMike Galbraith	  This option optimizes the scheduler for common desktop workloads by
14565091faa4SMike Galbraith	  automatically creating and populating task groups.  This separation
14575091faa4SMike Galbraith	  of workloads isolates aggressive CPU burners (like build jobs) from
14585091faa4SMike Galbraith	  desktop applications.  Task group autogeneration is currently based
14595091faa4SMike Galbraith	  upon task session.
14605091faa4SMike Galbraith
14617af37becSDaniel Lezcanoconfig RELAY
14627af37becSDaniel Lezcano	bool "Kernel->user space relay support (formerly relayfs)"
146326b5679eSPeter Zijlstra	select IRQ_WORK
14647af37becSDaniel Lezcano	help
14657af37becSDaniel Lezcano	  This option enables support for relay interface support in
14667af37becSDaniel Lezcano	  certain file systems (such as debugfs).
14677af37becSDaniel Lezcano	  It is designed to provide an efficient mechanism for tools and
14687af37becSDaniel Lezcano	  facilities to relay large amounts of data from kernel space to
14697af37becSDaniel Lezcano	  user space.
14707af37becSDaniel Lezcano
14717af37becSDaniel Lezcano	  If unsure, say N.
14727af37becSDaniel Lezcano
1473f991633dSDimitri Gorokhovikconfig BLK_DEV_INITRD
1474f991633dSDimitri Gorokhovik	bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1475f991633dSDimitri Gorokhovik	help
1476f991633dSDimitri Gorokhovik	  The initial RAM filesystem is a ramfs which is loaded by the
1477f991633dSDimitri Gorokhovik	  boot loader (loadlin or lilo) and that is mounted as root
1478f991633dSDimitri Gorokhovik	  before the normal boot procedure. It is typically used to
1479f991633dSDimitri Gorokhovik	  load modules needed to mount the "real" root file system,
14808c27ceffSMauro Carvalho Chehab	  etc. See <file:Documentation/admin-guide/initrd.rst> for details.
1481f991633dSDimitri Gorokhovik
1482f991633dSDimitri Gorokhovik	  If RAM disk support (BLK_DEV_RAM) is also included, this
1483f991633dSDimitri Gorokhovik	  also enables initial RAM disk (initrd) support and adds
1484f991633dSDimitri Gorokhovik	  15 Kbytes (more on some other architectures) to the kernel size.
1485f991633dSDimitri Gorokhovik
1486f991633dSDimitri Gorokhovik	  If unsure say Y.
1487f991633dSDimitri Gorokhovik
1488c33df4eaSJean-Paul Samanif BLK_DEV_INITRD
1489c33df4eaSJean-Paul Saman
1490dbec4866SSam Ravnborgsource "usr/Kconfig"
1491dbec4866SSam Ravnborg
1492c33df4eaSJean-Paul Samanendif
1493c33df4eaSJean-Paul Saman
149476db5a27SMasami Hiramatsuconfig BOOT_CONFIG
149576db5a27SMasami Hiramatsu	bool "Boot config support"
1496a2a9d67aSMasami Hiramatsu	select BLK_DEV_INITRD if !BOOT_CONFIG_EMBED
149776db5a27SMasami Hiramatsu	help
149876db5a27SMasami Hiramatsu	  Extra boot config allows system admin to pass a config file as
149976db5a27SMasami Hiramatsu	  complemental extension of kernel cmdline when booting.
15000947db01SMasami Hiramatsu	  The boot config file must be attached at the end of initramfs
150185c46b78SMasami Hiramatsu	  with checksum, size and magic word.
15020947db01SMasami Hiramatsu	  See <file:Documentation/admin-guide/bootconfig.rst> for details.
150376db5a27SMasami Hiramatsu
150476db5a27SMasami Hiramatsu	  If unsure, say Y.
150576db5a27SMasami Hiramatsu
1506b743852cSPaul E. McKenneyconfig BOOT_CONFIG_FORCE
1507b743852cSPaul E. McKenney	bool "Force unconditional bootconfig processing"
1508b743852cSPaul E. McKenney	depends on BOOT_CONFIG
15096ded8a28SPaul E. McKenney	default y if BOOT_CONFIG_EMBED
1510b743852cSPaul E. McKenney	help
1511b743852cSPaul E. McKenney	  With this Kconfig option set, BOOT_CONFIG processing is carried
1512b743852cSPaul E. McKenney	  out even when the "bootconfig" kernel-boot parameter is omitted.
1513b743852cSPaul E. McKenney	  In fact, with this Kconfig option set, there is no way to
1514b743852cSPaul E. McKenney	  make the kernel ignore the BOOT_CONFIG-supplied kernel-boot
1515b743852cSPaul E. McKenney	  parameters.
1516b743852cSPaul E. McKenney
1517b743852cSPaul E. McKenney	  If unsure, say N.
1518b743852cSPaul E. McKenney
1519a2a9d67aSMasami Hiramatsuconfig BOOT_CONFIG_EMBED
1520a2a9d67aSMasami Hiramatsu	bool "Embed bootconfig file in the kernel"
1521a2a9d67aSMasami Hiramatsu	depends on BOOT_CONFIG
1522a2a9d67aSMasami Hiramatsu	help
1523a2a9d67aSMasami Hiramatsu	  Embed a bootconfig file given by BOOT_CONFIG_EMBED_FILE in the
1524a2a9d67aSMasami Hiramatsu	  kernel. Usually, the bootconfig file is loaded with the initrd
1525a2a9d67aSMasami Hiramatsu	  image. But if the system doesn't support initrd, this option will
1526a2a9d67aSMasami Hiramatsu	  help you by embedding a bootconfig file while building the kernel.
1527a2a9d67aSMasami Hiramatsu
1528a2a9d67aSMasami Hiramatsu	  If unsure, say N.
1529a2a9d67aSMasami Hiramatsu
1530a2a9d67aSMasami Hiramatsuconfig BOOT_CONFIG_EMBED_FILE
1531a2a9d67aSMasami Hiramatsu	string "Embedded bootconfig file path"
1532a2a9d67aSMasami Hiramatsu	depends on BOOT_CONFIG_EMBED
1533a2a9d67aSMasami Hiramatsu	help
1534a2a9d67aSMasami Hiramatsu	  Specify a bootconfig file which will be embedded to the kernel.
1535a2a9d67aSMasami Hiramatsu	  This bootconfig will be used if there is no initrd or no other
1536a2a9d67aSMasami Hiramatsu	  bootconfig in the initrd.
1537a2a9d67aSMasami Hiramatsu
1538032a7302SDouglas Andersonconfig CMDLINE_LOG_WRAP_IDEAL_LEN
1539032a7302SDouglas Anderson	int "Length to try to wrap the cmdline when logged at boot"
1540032a7302SDouglas Anderson	default 1021
1541032a7302SDouglas Anderson	range 0 1021
1542032a7302SDouglas Anderson	help
1543032a7302SDouglas Anderson	  At boot time, the kernel command line is logged to the console.
1544032a7302SDouglas Anderson	  The log message will start with the prefix "Kernel command line: ".
1545032a7302SDouglas Anderson	  The log message will attempt to be wrapped (split into multiple log
1546032a7302SDouglas Anderson	  messages) at spaces based on CMDLINE_LOG_WRAP_IDEAL_LEN characters.
1547032a7302SDouglas Anderson	  If wrapping happens, each log message will start with the prefix and
1548032a7302SDouglas Anderson	  all but the last message will end with " \". Messages may exceed the
1549032a7302SDouglas Anderson	  ideal length if a place to wrap isn't found before the specified
1550032a7302SDouglas Anderson	  number of characters.
1551032a7302SDouglas Anderson
1552032a7302SDouglas Anderson	  A value of 0 disables wrapping, though be warned that the maximum
1553032a7302SDouglas Anderson	  length of a log message (1021 characters) may cause the cmdline to
1554032a7302SDouglas Anderson	  be truncated.
1555032a7302SDouglas Anderson
15561274aea1SDavid Disseldorpconfig INITRAMFS_PRESERVE_MTIME
15571274aea1SDavid Disseldorp	bool "Preserve cpio archive mtimes in initramfs"
155874792608SGeert Uytterhoeven	depends on BLK_DEV_INITRD
15591274aea1SDavid Disseldorp	default y
15601274aea1SDavid Disseldorp	help
15611274aea1SDavid Disseldorp	  Each entry in an initramfs cpio archive carries an mtime value. When
15621274aea1SDavid Disseldorp	  enabled, extracted cpio items take this mtime, with directory mtime
15631274aea1SDavid Disseldorp	  setting deferred until after creation of any child entries.
15641274aea1SDavid Disseldorp
15651274aea1SDavid Disseldorp	  If unsure, say Y.
15661274aea1SDavid Disseldorp
156783c0b272SDavid Disseldorpconfig INITRAMFS_TEST
156883c0b272SDavid Disseldorp	bool "Test initramfs cpio archive extraction" if !KUNIT_ALL_TESTS
156983c0b272SDavid Disseldorp	depends on BLK_DEV_INITRD && KUNIT=y
157083c0b272SDavid Disseldorp	default KUNIT_ALL_TESTS
157183c0b272SDavid Disseldorp	help
157283c0b272SDavid Disseldorp	  Build KUnit tests for initramfs. See Documentation/dev-tools/kunit
157383c0b272SDavid Disseldorp
1574877417e6SArnd Bergmannchoice
1575877417e6SArnd Bergmann	prompt "Compiler optimization level"
15762cc3ce24SUlf Magnusson	default CC_OPTIMIZE_FOR_PERFORMANCE
1577877417e6SArnd Bergmann
1578877417e6SArnd Bergmannconfig CC_OPTIMIZE_FOR_PERFORMANCE
157915f5db60SMasahiro Yamada	bool "Optimize for performance (-O2)"
1580877417e6SArnd Bergmann	help
1581877417e6SArnd Bergmann	  This is the default optimization level for the kernel, building
1582877417e6SArnd Bergmann	  with the "-O2" compiler flag for best performance and most
1583877417e6SArnd Bergmann	  helpful compile-time warnings.
1584877417e6SArnd Bergmann
1585c45b4f1fSLinus Torvaldsconfig CC_OPTIMIZE_FOR_SIZE
158615f5db60SMasahiro Yamada	bool "Optimize for size (-Os)"
1587c45b4f1fSLinus Torvalds	help
1588ce3b487fSMasahiro Yamada	  Choosing this option will pass "-Os" to your compiler resulting
1589ce3b487fSMasahiro Yamada	  in a smaller kernel.
1590c45b4f1fSLinus Torvalds
1591877417e6SArnd Bergmannendchoice
1592877417e6SArnd Bergmann
15935d20ee31SNicholas Pigginconfig HAVE_LD_DEAD_CODE_DATA_ELIMINATION
15945d20ee31SNicholas Piggin	bool
15955d20ee31SNicholas Piggin	help
15965d20ee31SNicholas Piggin	  This requires that the arch annotates or otherwise protects
15975d20ee31SNicholas Piggin	  its external entry points from being discarded. Linker scripts
15985d20ee31SNicholas Piggin	  must also merge .text.*, .data.*, and .bss.* correctly into
15995d20ee31SNicholas Piggin	  output sections. Care must be taken not to pull in unrelated
16005d20ee31SNicholas Piggin	  sections (e.g., '.text.init'). Typically '.' in section names
16015d20ee31SNicholas Piggin	  is used to distinguish them from label names / C identifiers.
16025d20ee31SNicholas Piggin
16035d20ee31SNicholas Pigginconfig LD_DEAD_CODE_DATA_ELIMINATION
16045d20ee31SNicholas Piggin	bool "Dead code and data elimination (EXPERIMENTAL)"
16055d20ee31SNicholas Piggin	depends on HAVE_LD_DEAD_CODE_DATA_ELIMINATION
16065d20ee31SNicholas Piggin	depends on EXPERT
1607e85d1d65SMasahiro Yamada	depends on $(cc-option,-ffunction-sections -fdata-sections)
1608e85d1d65SMasahiro Yamada	depends on $(ld-option,--gc-sections)
16095d20ee31SNicholas Piggin	help
16108b9d2712SMasahiro Yamada	  Enable this if you want to do dead code and data elimination with
16118b9d2712SMasahiro Yamada	  the linker by compiling with -ffunction-sections -fdata-sections,
16128b9d2712SMasahiro Yamada	  and linking with --gc-sections.
16135d20ee31SNicholas Piggin
16145d20ee31SNicholas Piggin	  This can reduce on disk and in-memory size of the kernel
16155d20ee31SNicholas Piggin	  code and static data, particularly for small configs and
16165d20ee31SNicholas Piggin	  on small systems. This has the possibility of introducing
16175d20ee31SNicholas Piggin	  silently broken kernel if the required annotations are not
16185d20ee31SNicholas Piggin	  present. This option is not well tested yet, so use at your
16195d20ee31SNicholas Piggin	  own risk.
16205d20ee31SNicholas Piggin
162159612b24SNathan Chancellorconfig LD_ORPHAN_WARN
162259612b24SNathan Chancellor	def_bool y
162359612b24SNathan Chancellor	depends on ARCH_WANT_LD_ORPHAN_WARN
162459612b24SNathan Chancellor	depends on $(ld-option,--orphan-handling=warn)
1625e1789d7cSXin Li	depends on $(ld-option,--orphan-handling=error)
1626e1789d7cSXin Li
1627e1789d7cSXin Liconfig LD_ORPHAN_WARN_LEVEL
1628e1789d7cSXin Li        string
1629e1789d7cSXin Li        depends on LD_ORPHAN_WARN
1630e1789d7cSXin Li        default "error" if WERROR
1631e1789d7cSXin Li        default "warn"
163259612b24SNathan Chancellor
16330847062aSRandy Dunlapconfig SYSCTL
16340847062aSRandy Dunlap	bool
16350847062aSRandy Dunlap
1636657a5209SMike Frysingerconfig HAVE_UID16
1637657a5209SMike Frysinger	bool
1638657a5209SMike Frysinger
1639657a5209SMike Frysingerconfig SYSCTL_EXCEPTION_TRACE
1640657a5209SMike Frysinger	bool
1641657a5209SMike Frysinger	help
1642657a5209SMike Frysinger	  Enable support for /proc/sys/debug/exception-trace.
1643657a5209SMike Frysinger
1644657a5209SMike Frysingerconfig SYSCTL_ARCH_UNALIGN_NO_WARN
1645657a5209SMike Frysinger	bool
1646657a5209SMike Frysinger	help
1647657a5209SMike Frysinger	  Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
1648657a5209SMike Frysinger	  Allows arch to define/use @no_unaligned_warning to possibly warn
1649657a5209SMike Frysinger	  about unaligned access emulation going on under the hood.
1650657a5209SMike Frysinger
1651657a5209SMike Frysingerconfig SYSCTL_ARCH_UNALIGN_ALLOW
1652657a5209SMike Frysinger	bool
1653657a5209SMike Frysinger	help
1654657a5209SMike Frysinger	  Enable support for /proc/sys/kernel/unaligned-trap
1655657a5209SMike Frysinger	  Allows arches to define/use @unaligned_enabled to runtime toggle
1656657a5209SMike Frysinger	  the unaligned access emulation.
1657657a5209SMike Frysinger	  see arch/parisc/kernel/unaligned.c for reference
1658657a5209SMike Frysinger
1659c443279aSChristian Braunerconfig SYSFS_SYSCALL
1660c443279aSChristian Brauner	bool "Sysfs syscall support"
1661c443279aSChristian Brauner	default n
1662c443279aSChristian Brauner	help
1663c443279aSChristian Brauner	  sys_sysfs is an obsolete system call no longer supported in libc.
1664c443279aSChristian Brauner	  Note that disabling this option is more secure but might break
1665c443279aSChristian Brauner	  compatibility with some systems.
1666c443279aSChristian Brauner
1667c443279aSChristian Brauner	  If unsure say N here.
1668c443279aSChristian Brauner
1669657a5209SMike Frysingerconfig HAVE_PCSPKR_PLATFORM
1670657a5209SMike Frysinger	bool
1671657a5209SMike Frysinger
16726a108a14SDavid Rientjesmenuconfig EXPERT
16736a108a14SDavid Rientjes	bool "Configure standard kernel features (expert users)"
1674f505c553SJosh Triplett	# Unhide debug options, to make the on-by-default options visible
1675f505c553SJosh Triplett	select DEBUG_KERNEL
16761da177e4SLinus Torvalds	help
16771da177e4SLinus Torvalds	  This option allows certain base kernel options and settings
16781da177e4SLinus Torvalds	  to be disabled or tweaked. This is for specialized
16791da177e4SLinus Torvalds	  environments which can tolerate a "non-standard" kernel.
16801da177e4SLinus Torvalds	  Only use this if you really know what you are doing.
16811da177e4SLinus Torvalds
1682ae81f9e3SChuck Ebbertconfig UID16
16836a108a14SDavid Rientjes	bool "Enable 16-bit UID system calls" if EXPERT
16842813893fSIulia Manda	depends on HAVE_UID16 && MULTIUSER
1685ae81f9e3SChuck Ebbert	default y
1686ae81f9e3SChuck Ebbert	help
1687ae81f9e3SChuck Ebbert	  This enables the legacy 16-bit UID syscall wrappers.
1688ae81f9e3SChuck Ebbert
16892813893fSIulia Mandaconfig MULTIUSER
16902813893fSIulia Manda	bool "Multiple users, groups and capabilities support" if EXPERT
16912813893fSIulia Manda	default y
16922813893fSIulia Manda	help
16932813893fSIulia Manda	  This option enables support for non-root users, groups and
16942813893fSIulia Manda	  capabilities.
16952813893fSIulia Manda
16962813893fSIulia Manda	  If you say N here, all processes will run with UID 0, GID 0, and all
16972813893fSIulia Manda	  possible capabilities.  Saying N here also compiles out support for
16982813893fSIulia Manda	  system calls related to UIDs, GIDs, and capabilities, such as setuid,
16992813893fSIulia Manda	  setgid, and capset.
17002813893fSIulia Manda
17012813893fSIulia Manda	  If unsure, say Y here.
17022813893fSIulia Manda
1703f6187769SFabian Frederickconfig SGETMASK_SYSCALL
1704f6187769SFabian Frederick	bool "sgetmask/ssetmask syscalls support" if EXPERT
1705cd14b018SMasahiro Yamada	default PARISC || M68K || PPC || MIPS || X86 || SPARC || MICROBLAZE || SUPERH
1706a7f7f624SMasahiro Yamada	help
1707f6187769SFabian Frederick	  sys_sgetmask and sys_ssetmask are obsolete system calls
1708f6187769SFabian Frederick	  no longer supported in libc but still enabled by default in some
1709f6187769SFabian Frederick	  architectures.
1710f6187769SFabian Frederick
1711f6187769SFabian Frederick	  If unsure, leave the default option here.
1712f6187769SFabian Frederick
1713d1b069f5SRandy Dunlapconfig FHANDLE
1714d1b069f5SRandy Dunlap	bool "open by fhandle syscalls" if EXPERT
1715d1b069f5SRandy Dunlap	select EXPORTFS
1716d1b069f5SRandy Dunlap	default y
1717d1b069f5SRandy Dunlap	help
1718d1b069f5SRandy Dunlap	  If you say Y here, a user level program will be able to map
1719d1b069f5SRandy Dunlap	  file names to handle and then later use the handle for
1720d1b069f5SRandy Dunlap	  different file system operations. This is useful in implementing
1721d1b069f5SRandy Dunlap	  userspace file servers, which now track files using handles instead
1722d1b069f5SRandy Dunlap	  of names. The handle would remain the same even if file names
1723d1b069f5SRandy Dunlap	  get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
1724d1b069f5SRandy Dunlap	  syscalls.
1725d1b069f5SRandy Dunlap
1726baa73d9eSNicolas Pitreconfig POSIX_TIMERS
1727baa73d9eSNicolas Pitre	bool "Posix Clocks & timers" if EXPERT
1728baa73d9eSNicolas Pitre	default y
1729baa73d9eSNicolas Pitre	help
1730baa73d9eSNicolas Pitre	  This includes native support for POSIX timers to the kernel.
1731baa73d9eSNicolas Pitre	  Some embedded systems have no use for them and therefore they
1732baa73d9eSNicolas Pitre	  can be configured out to reduce the size of the kernel image.
1733baa73d9eSNicolas Pitre
1734baa73d9eSNicolas Pitre	  When this option is disabled, the following syscalls won't be
1735baa73d9eSNicolas Pitre	  available: timer_create, timer_gettime: timer_getoverrun,
1736baa73d9eSNicolas Pitre	  timer_settime, timer_delete, clock_adjtime, getitimer,
1737baa73d9eSNicolas Pitre	  setitimer, alarm. Furthermore, the clock_settime, clock_gettime,
1738baa73d9eSNicolas Pitre	  clock_getres and clock_nanosleep syscalls will be limited to
1739baa73d9eSNicolas Pitre	  CLOCK_REALTIME, CLOCK_MONOTONIC and CLOCK_BOOTTIME only.
1740baa73d9eSNicolas Pitre
1741baa73d9eSNicolas Pitre	  If unsure say y.
1742baa73d9eSNicolas Pitre
1743d59745ceSMatt Mackallconfig PRINTK
1744d59745ceSMatt Mackall	default y
17456a108a14SDavid Rientjes	bool "Enable support for printk" if EXPERT
174674876a98SFrederic Weisbecker	select IRQ_WORK
1747d59745ceSMatt Mackall	help
1748d59745ceSMatt Mackall	  This option enables normal printk support. Removing it
1749d59745ceSMatt Mackall	  eliminates most of the message strings from the kernel image
1750d59745ceSMatt Mackall	  and makes the kernel more or less silent. As this makes it
1751d59745ceSMatt Mackall	  very difficult to diagnose system problems, saying N here is
1752d59745ceSMatt Mackall	  strongly discouraged.
1753d59745ceSMatt Mackall
17545ea2bcdfSThomas Weißschuhconfig PRINTK_RINGBUFFER_KUNIT_TEST
17555ea2bcdfSThomas Weißschuh	tristate "KUnit Test for the printk ringbuffer" if !KUNIT_ALL_TESTS
17565ea2bcdfSThomas Weißschuh	depends on PRINTK && KUNIT
17575ea2bcdfSThomas Weißschuh	default KUNIT_ALL_TESTS
17585ea2bcdfSThomas Weißschuh	help
17595ea2bcdfSThomas Weißschuh	  This builds the printk ringbuffer KUnit test suite.
17605ea2bcdfSThomas Weißschuh
17615ea2bcdfSThomas Weißschuh	  For more information on KUnit and unit tests in general, please refer
17625ea2bcdfSThomas Weißschuh	  to the KUnit documentation.
17635ea2bcdfSThomas Weißschuh
17645ea2bcdfSThomas Weißschuh	  If unsure, say N.
17655ea2bcdfSThomas Weißschuh
1766c8538a7aSMatt Mackallconfig BUG
17676a108a14SDavid Rientjes	bool "BUG() support" if EXPERT
1768c8538a7aSMatt Mackall	default y
1769c8538a7aSMatt Mackall	help
1770c8538a7aSMatt Mackall	  Disabling this option eliminates support for BUG and WARN, reducing
1771c8538a7aSMatt Mackall	  the size of your kernel image and potentially quietly ignoring
1772c8538a7aSMatt Mackall	  numerous fatal conditions. You should only consider disabling this
1773c8538a7aSMatt Mackall	  option for embedded systems with no facilities for reporting errors.
1774c8538a7aSMatt Mackall	  Just say Y.
1775c8538a7aSMatt Mackall
1776708e9a79SMatt Mackallconfig ELF_CORE
1777046d662fSAlex Kelly	depends on COREDUMP
1778708e9a79SMatt Mackall	default y
17796a108a14SDavid Rientjes	bool "Enable ELF core dumps" if EXPERT
1780708e9a79SMatt Mackall	help
1781708e9a79SMatt Mackall	  Enable support for generating core dumps. Disabling saves about 4k.
1782708e9a79SMatt Mackall
17838761f1abSRalf Baechle
1784e5e1d3cbSStas Sergeevconfig PCSPKR_PLATFORM
17856a108a14SDavid Rientjes	bool "Enable PC-Speaker support" if EXPERT
17868761f1abSRalf Baechle	depends on HAVE_PCSPKR_PLATFORM
178715f304b6SRalf Baechle	select I8253_LOCK
1788e5e1d3cbSStas Sergeev	default y
1789e5e1d3cbSStas Sergeev	help
1790e5e1d3cbSStas Sergeev	  This option allows to disable the internal PC-Speaker
1791e5e1d3cbSStas Sergeev	  support, saving some memory.
1792e5e1d3cbSStas Sergeev
179327021649SYoann Congalconfig BASE_SMALL
179427021649SYoann Congal	bool "Enable smaller-sized data structures for core" if EXPERT
17951da177e4SLinus Torvalds	help
179627021649SYoann Congal	  Enabling this option reduces the size of miscellaneous core
17971da177e4SLinus Torvalds	  kernel data structures. This saves memory on small machines,
17981da177e4SLinus Torvalds	  but may reduce performance.
17991da177e4SLinus Torvalds
18001da177e4SLinus Torvaldsconfig FUTEX
18016a108a14SDavid Rientjes	bool "Enable futex support" if EXPERT
18023f2bedabSArnd Bergmann	depends on !(SPARC32 && SMP)
18031da177e4SLinus Torvalds	default y
1804bc2eecd7SNicolas Pitre	imply RT_MUTEXES
18051da177e4SLinus Torvalds	help
18061da177e4SLinus Torvalds	  Disabling this option will cause the kernel to be built without
18071da177e4SLinus Torvalds	  support for "fast userspace mutexes".  The resulting kernel may not
18081da177e4SLinus Torvalds	  run glibc-based applications correctly.
18091da177e4SLinus Torvalds
1810bc2eecd7SNicolas Pitreconfig FUTEX_PI
1811bc2eecd7SNicolas Pitre	bool
1812bc2eecd7SNicolas Pitre	depends on FUTEX && RT_MUTEXES
1813bc2eecd7SNicolas Pitre	default y
1814bc2eecd7SNicolas Pitre
181580367ad0SSebastian Andrzej Siewiorconfig FUTEX_PRIVATE_HASH
181680367ad0SSebastian Andrzej Siewior	bool
181780367ad0SSebastian Andrzej Siewior	depends on FUTEX && !BASE_SMALL && MMU
181880367ad0SSebastian Andrzej Siewior	default y
181980367ad0SSebastian Andrzej Siewior
1820c042c505SPeter Zijlstraconfig FUTEX_MPOL
1821c042c505SPeter Zijlstra	bool
1822c042c505SPeter Zijlstra	depends on FUTEX && NUMA
1823c042c505SPeter Zijlstra	default y
1824c042c505SPeter Zijlstra
18251da177e4SLinus Torvaldsconfig EPOLL
18266a108a14SDavid Rientjes	bool "Enable eventpoll support" if EXPERT
18271da177e4SLinus Torvalds	default y
18281da177e4SLinus Torvalds	help
18291da177e4SLinus Torvalds	  Disabling this option will cause the kernel to be built without
18301da177e4SLinus Torvalds	  support for epoll family of system calls.
18311da177e4SLinus Torvalds
1832fba2afaaSDavide Libenziconfig SIGNALFD
18336a108a14SDavid Rientjes	bool "Enable signalfd() system call" if EXPERT
1834fba2afaaSDavide Libenzi	default y
1835fba2afaaSDavide Libenzi	help
1836fba2afaaSDavide Libenzi	  Enable the signalfd() system call that allows to receive signals
1837fba2afaaSDavide Libenzi	  on a file descriptor.
1838fba2afaaSDavide Libenzi
1839fba2afaaSDavide Libenzi	  If unsure, say Y.
1840fba2afaaSDavide Libenzi
1841b215e283SDavide Libenziconfig TIMERFD
18426a108a14SDavid Rientjes	bool "Enable timerfd() system call" if EXPERT
1843b215e283SDavide Libenzi	default y
1844b215e283SDavide Libenzi	help
1845b215e283SDavide Libenzi	  Enable the timerfd() system call that allows to receive timer
1846b215e283SDavide Libenzi	  events on a file descriptor.
1847b215e283SDavide Libenzi
1848b215e283SDavide Libenzi	  If unsure, say Y.
1849b215e283SDavide Libenzi
1850e1ad7468SDavide Libenziconfig EVENTFD
18516a108a14SDavid Rientjes	bool "Enable eventfd() system call" if EXPERT
1852e1ad7468SDavide Libenzi	default y
1853e1ad7468SDavide Libenzi	help
1854e1ad7468SDavide Libenzi	  Enable the eventfd() system call that allows to receive both
1855e1ad7468SDavide Libenzi	  kernel notification (ie. KAIO) or userspace notifications.
1856e1ad7468SDavide Libenzi
1857e1ad7468SDavide Libenzi	  If unsure, say Y.
1858e1ad7468SDavide Libenzi
18591da177e4SLinus Torvaldsconfig SHMEM
18606a108a14SDavid Rientjes	bool "Use full shmem filesystem" if EXPERT
18611da177e4SLinus Torvalds	default y
18621da177e4SLinus Torvalds	depends on MMU
18631da177e4SLinus Torvalds	help
18641da177e4SLinus Torvalds	  The shmem is an internal filesystem used to manage shared memory.
18651da177e4SLinus Torvalds	  It is backed by swap and manages resource limits. It is also exported
18661da177e4SLinus Torvalds	  to userspace as tmpfs if TMPFS is enabled. Disabling this
18671da177e4SLinus Torvalds	  option replaces shmem and tmpfs with the much simpler ramfs code,
18681da177e4SLinus Torvalds	  which may be appropriate on small systems without swap.
18691da177e4SLinus Torvalds
1870ebf3f09cSThomas Petazzoniconfig AIO
18716a108a14SDavid Rientjes	bool "Enable AIO support" if EXPERT
1872ebf3f09cSThomas Petazzoni	default y
1873ebf3f09cSThomas Petazzoni	help
1874ebf3f09cSThomas Petazzoni	  This option enables POSIX asynchronous I/O which may by used
1875ebf3f09cSThomas Petazzoni	  by some high performance threaded applications. Disabling
1876ebf3f09cSThomas Petazzoni	  this option saves about 7k.
1877ebf3f09cSThomas Petazzoni
18782b188cc1SJens Axboeconfig IO_URING
18792b188cc1SJens Axboe	bool "Enable IO uring support" if EXPERT
1880561fb04aSJens Axboe	select IO_WQ
18812b188cc1SJens Axboe	default y
18822b188cc1SJens Axboe	help
18832b188cc1SJens Axboe	  This option enables support for the io_uring interface, enabling
18842b188cc1SJens Axboe	  applications to submit and complete IO through submission and
18852b188cc1SJens Axboe	  completion rings that are shared between the kernel and application.
18862b188cc1SJens Axboe
18871802656eSJens Axboeconfig GCOV_PROFILE_URING
18881802656eSJens Axboe	bool "Enable GCOV profiling on the io_uring subsystem"
1889d1fbe1ebSRandy Dunlap	depends on IO_URING && GCOV_KERNEL
18901802656eSJens Axboe	help
18911802656eSJens Axboe	  Enable GCOV profiling on the io_uring subsystem, to facilitate
18921802656eSJens Axboe	  code coverage testing.
18931802656eSJens Axboe
18941802656eSJens Axboe	  If unsure, say N.
18951802656eSJens Axboe
18961802656eSJens Axboe	  Note that this will have a negative impact on the performance of
18971802656eSJens Axboe	  the io_uring subsystem, hence this should only be enabled for
18981802656eSJens Axboe	  specific test purposes.
18991802656eSJens Axboe
19003a0ae385SPavel Begunkovconfig IO_URING_MOCK_FILE
19013a0ae385SPavel Begunkov	tristate "Enable io_uring mock files (Experimental)" if EXPERT
19023a0ae385SPavel Begunkov	default n
19033a0ae385SPavel Begunkov	depends on IO_URING
19043a0ae385SPavel Begunkov	help
1905*9e7dc228SJ. Neuschäfer	  Enable mock files for io_uring subsystem testing. The ABI might
19063a0ae385SPavel Begunkov	  still change, so it's still experimental and should only be enabled
19073a0ae385SPavel Begunkov	  for specific test purposes.
19083a0ae385SPavel Begunkov
19093a0ae385SPavel Begunkov	  If unsure, say N.
19103a0ae385SPavel Begunkov
1911d3ac21caSJosh Triplettconfig ADVISE_SYSCALLS
1912d3ac21caSJosh Triplett	bool "Enable madvise/fadvise syscalls" if EXPERT
1913d3ac21caSJosh Triplett	default y
1914d3ac21caSJosh Triplett	help
1915d3ac21caSJosh Triplett	  This option enables the madvise and fadvise syscalls, used by
1916d3ac21caSJosh Triplett	  applications to advise the kernel about their future memory or file
1917d3ac21caSJosh Triplett	  usage, improving performance. If building an embedded system where no
1918d3ac21caSJosh Triplett	  applications use these syscalls, you can disable this option to save
1919d3ac21caSJosh Triplett	  space.
1920d3ac21caSJosh Triplett
19215b25b13aSMathieu Desnoyersconfig MEMBARRIER
19225b25b13aSMathieu Desnoyers	bool "Enable membarrier() system call" if EXPERT
19235b25b13aSMathieu Desnoyers	default y
19245b25b13aSMathieu Desnoyers	help
19255b25b13aSMathieu Desnoyers	  Enable the membarrier() system call that allows issuing memory
19265b25b13aSMathieu Desnoyers	  barriers across all running threads, which can be used to distribute
19275b25b13aSMathieu Desnoyers	  the cost of user-space memory barriers asymmetrically by transforming
19285b25b13aSMathieu Desnoyers	  pairs of memory barriers into pairs consisting of membarrier() and a
19295b25b13aSMathieu Desnoyers	  compiler barrier.
19305b25b13aSMathieu Desnoyers
19315b25b13aSMathieu Desnoyers	  If unsure, say Y.
19325b25b13aSMathieu Desnoyers
1933a751ea34SRandy Dunlapconfig KCMP
1934a751ea34SRandy Dunlap	bool "Enable kcmp() system call" if EXPERT
1935a751ea34SRandy Dunlap	help
1936a751ea34SRandy Dunlap	  Enable the kernel resource comparison system call. It provides
1937a751ea34SRandy Dunlap	  user-space with the ability to compare two processes to see if they
1938a751ea34SRandy Dunlap	  share a common resource, such as a file descriptor or even virtual
1939a751ea34SRandy Dunlap	  memory space.
1940a751ea34SRandy Dunlap
1941a751ea34SRandy Dunlap	  If unsure, say N.
1942a751ea34SRandy Dunlap
1943a751ea34SRandy Dunlapconfig RSEQ
1944a751ea34SRandy Dunlap	bool "Enable rseq() system call" if EXPERT
1945a751ea34SRandy Dunlap	default y
1946a751ea34SRandy Dunlap	depends on HAVE_RSEQ
1947a751ea34SRandy Dunlap	select MEMBARRIER
1948a751ea34SRandy Dunlap	help
1949a751ea34SRandy Dunlap	  Enable the restartable sequences system call. It provides a
1950a751ea34SRandy Dunlap	  user-space cache for the current CPU number value, which
1951a751ea34SRandy Dunlap	  speeds up getting the current CPU number from user-space,
1952a751ea34SRandy Dunlap	  as well as an ABI to speed up user-space operations on
1953a751ea34SRandy Dunlap	  per-CPU data.
1954a751ea34SRandy Dunlap
1955a751ea34SRandy Dunlap	  If unsure, say Y.
1956a751ea34SRandy Dunlap
1957d7a5da7aSThomas Gleixnerconfig RSEQ_SLICE_EXTENSION
1958d7a5da7aSThomas Gleixner	bool "Enable rseq-based time slice extension mechanism"
1959d7a5da7aSThomas Gleixner	depends on RSEQ && HIGH_RES_TIMERS && GENERIC_ENTRY && HAVE_GENERIC_TIF_BITS
1960d7a5da7aSThomas Gleixner	help
1961d7a5da7aSThomas Gleixner	  Allows userspace to request a limited time slice extension when
1962d7a5da7aSThomas Gleixner	  returning from an interrupt to user space via the RSEQ shared
1963d7a5da7aSThomas Gleixner	  data ABI. If granted, that allows to complete a critical section,
1964d7a5da7aSThomas Gleixner	  so that other threads are not stuck on a conflicted resource,
1965d7a5da7aSThomas Gleixner	  while the task is scheduled out.
1966d7a5da7aSThomas Gleixner
1967d7a5da7aSThomas Gleixner	  If unsure, say N.
1968d7a5da7aSThomas Gleixner
196954129104SThomas Gleixnerconfig RSEQ_STATS
197054129104SThomas Gleixner	default n
197154129104SThomas Gleixner	bool "Enable lightweight statistics of restartable sequences" if EXPERT
197254129104SThomas Gleixner	depends on RSEQ && DEBUG_FS
197354129104SThomas Gleixner	help
197454129104SThomas Gleixner	  Enable lightweight counters which expose information about the
197554129104SThomas Gleixner	  frequency of RSEQ operations via debugfs. Mostly interesting for
197654129104SThomas Gleixner	  kernel debugging or performance analysis. While lightweight it's
197754129104SThomas Gleixner	  still adding code into the user/kernel mode transitions.
197854129104SThomas Gleixner
197954129104SThomas Gleixner	  If unsure, say N.
198054129104SThomas Gleixner
19819c37cb6eSThomas Gleixnerconfig RSEQ_DEBUG_DEFAULT_ENABLE
19829c37cb6eSThomas Gleixner	default n
19839c37cb6eSThomas Gleixner	bool "Enable restartable sequences debug mode by default" if EXPERT
19849c37cb6eSThomas Gleixner	depends on RSEQ
19859c37cb6eSThomas Gleixner	help
19869c37cb6eSThomas Gleixner	  This enables the static branch for debug mode of restartable
19879c37cb6eSThomas Gleixner	  sequences.
19889c37cb6eSThomas Gleixner
19899c37cb6eSThomas Gleixner	  This also can be controlled on the kernel command line via the
19909c37cb6eSThomas Gleixner	  command line parameter "rseq_debug=0/1" and through debugfs.
19919c37cb6eSThomas Gleixner
19929c37cb6eSThomas Gleixner	  If unsure, say N.
19939c37cb6eSThomas Gleixner
1994a751ea34SRandy Dunlapconfig DEBUG_RSEQ
1995a751ea34SRandy Dunlap	default n
1996a751ea34SRandy Dunlap	bool "Enable debugging of rseq() system call" if EXPERT
19973db6b38dSThomas Gleixner	depends on RSEQ && DEBUG_KERNEL && !GENERIC_ENTRY
19989c37cb6eSThomas Gleixner	select RSEQ_DEBUG_DEFAULT_ENABLE
1999a751ea34SRandy Dunlap	help
2000a751ea34SRandy Dunlap	  Enable extra debugging checks for the rseq system call.
2001a751ea34SRandy Dunlap
2002a751ea34SRandy Dunlap	  If unsure, say N.
2003a751ea34SRandy Dunlap
2004a751ea34SRandy Dunlapconfig CACHESTAT_SYSCALL
2005a751ea34SRandy Dunlap	bool "Enable cachestat() system call" if EXPERT
2006a751ea34SRandy Dunlap	default y
2007a751ea34SRandy Dunlap	help
2008a751ea34SRandy Dunlap	  Enable the cachestat system call, which queries the page cache
2009a751ea34SRandy Dunlap	  statistics of a file (number of cached pages, dirty pages,
2010a751ea34SRandy Dunlap	  pages marked for writeback, (recently) evicted pages).
2011a751ea34SRandy Dunlap
2012a751ea34SRandy Dunlap	  If unsure say Y here.
2013a751ea34SRandy Dunlap
2014d1b069f5SRandy Dunlapconfig KALLSYMS
2015d1b069f5SRandy Dunlap	bool "Load all symbols for debugging/ksymoops" if EXPERT
2016d1b069f5SRandy Dunlap	default y
2017d1b069f5SRandy Dunlap	help
2018d1b069f5SRandy Dunlap	  Say Y here to let the kernel print out symbolic crash information and
2019d1b069f5SRandy Dunlap	  symbolic stack backtraces. This increases the size of the kernel
2020d1b069f5SRandy Dunlap	  somewhat, as all symbols have to be loaded into the kernel image.
2021d1b069f5SRandy Dunlap
202230f3bb09SZhen Leiconfig KALLSYMS_SELFTEST
202330f3bb09SZhen Lei	bool "Test the basic functions and performance of kallsyms"
202430f3bb09SZhen Lei	depends on KALLSYMS
202530f3bb09SZhen Lei	default n
202630f3bb09SZhen Lei	help
202730f3bb09SZhen Lei	  Test the basic functions and performance of some interfaces, such as
202830f3bb09SZhen Lei	  kallsyms_lookup_name. It also calculates the compression rate of the
202930f3bb09SZhen Lei	  kallsyms compression algorithm for the current symbol set.
203030f3bb09SZhen Lei
203130f3bb09SZhen Lei	  Start self-test automatically after system startup. Suggest executing
203230f3bb09SZhen Lei	  "dmesg | grep kallsyms_selftest" to collect test results. "finish" is
203330f3bb09SZhen Lei	  displayed in the last line, indicating that the test is complete.
203430f3bb09SZhen Lei
2035d1b069f5SRandy Dunlapconfig KALLSYMS_ALL
2036d1b069f5SRandy Dunlap	bool "Include all symbols in kallsyms"
2037d1b069f5SRandy Dunlap	depends on DEBUG_KERNEL && KALLSYMS
2038d1b069f5SRandy Dunlap	help
2039d1b069f5SRandy Dunlap	  Normally kallsyms only contains the symbols of functions for nicer
2040d1b069f5SRandy Dunlap	  OOPS messages and backtraces (i.e., symbols from the text and inittext
2041bdf0fe33SBaruch Siach	  sections). This is sufficient for most cases. And only if you want to
2042bdf0fe33SBaruch Siach	  enable kernel live patching, or other less common use cases (e.g.,
2043bdf0fe33SBaruch Siach	  when a debugger is used) all symbols are required (i.e., names of
2044bdf0fe33SBaruch Siach	  variables from the data sections, etc).
2045d1b069f5SRandy Dunlap
2046d1b069f5SRandy Dunlap	  This option makes sure that all symbols are loaded into the kernel
2047d1b069f5SRandy Dunlap	  image (i.e., symbols from all sections) in cost of increased kernel
2048d1b069f5SRandy Dunlap	  size (depending on the kernel configuration, it may be 300KiB or
2049d1b069f5SRandy Dunlap	  something like this).
2050d1b069f5SRandy Dunlap
2051bdf0fe33SBaruch Siach	  Say N unless you really need all symbols, or kernel live patching.
2052d1b069f5SRandy Dunlap
2053d1b069f5SRandy Dunlap# end of the "standard kernel features (expert users)" menu
2054d1b069f5SRandy Dunlap
20553ccfebedSMathieu Desnoyersconfig ARCH_HAS_MEMBARRIER_CALLBACKS
20563ccfebedSMathieu Desnoyers	bool
20573ccfebedSMathieu Desnoyers
205870216e18SMathieu Desnoyersconfig ARCH_HAS_MEMBARRIER_SYNC_CORE
205970216e18SMathieu Desnoyers	bool
206070216e18SMathieu Desnoyers
20615796d396SJeff Xuconfig ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS
20625796d396SJeff Xu	bool
20635796d396SJeff Xu	help
20645796d396SJeff Xu	  Control MSEAL_SYSTEM_MAPPINGS access based on architecture.
20655796d396SJeff Xu
20665796d396SJeff Xu	  A 64-bit kernel is required for the memory sealing feature.
20675796d396SJeff Xu	  No specific hardware features from the CPU are needed.
20685796d396SJeff Xu
20695796d396SJeff Xu	  To enable this feature, the architecture needs to update their
20705796d396SJeff Xu	  special mappings calls to include the sealing flag and confirm
20715796d396SJeff Xu	  that it doesn't unmap/remap system mappings during the life
20725796d396SJeff Xu	  time of the process. The existence of this flag for an architecture
20735796d396SJeff Xu	  implies that it does not require the remapping of the system
20745796d396SJeff Xu	  mappings during process lifetime, so sealing these mappings is safe
20755796d396SJeff Xu	  from a kernel perspective.
20765796d396SJeff Xu
20775796d396SJeff Xu	  After the architecture enables this, a distribution can set
20785796d396SJeff Xu	  CONFIG_MSEAL_SYSTEM_MAPPING to manage access to the feature.
20795796d396SJeff Xu
20805796d396SJeff Xu	  For complete descriptions of memory sealing, please see
20815796d396SJeff Xu	  Documentation/userspace-api/mseal.rst
20825796d396SJeff Xu
2083cdd6c482SIngo Molnarconfig HAVE_PERF_EVENTS
20840793a61dSThomas Gleixner	bool
2085018df72dSMike Frysinger	help
2086018df72dSMike Frysinger	  See tools/perf/design.txt for details.
20870793a61dSThomas Gleixner
20882aef6f30SSean Christophersonconfig GUEST_PERF_EVENTS
20892aef6f30SSean Christopherson	bool
20902aef6f30SSean Christopherson	depends on HAVE_PERF_EVENTS
20912aef6f30SSean Christopherson
2092eff95e17SKan Liangconfig PERF_GUEST_MEDIATED_PMU
2093eff95e17SKan Liang	bool
2094eff95e17SKan Liang	depends on GUEST_PERF_EVENTS
2095eff95e17SKan Liang
2096906010b2SPeter Zijlstraconfig PERF_USE_VMALLOC
2097906010b2SPeter Zijlstra	bool
2098906010b2SPeter Zijlstra	help
2099906010b2SPeter Zijlstra	  See tools/perf/design.txt for details
2100906010b2SPeter Zijlstra
210157c0c15bSIngo Molnarmenu "Kernel Performance Events And Counters"
21020793a61dSThomas Gleixner
2103cdd6c482SIngo Molnarconfig PERF_EVENTS
210457c0c15bSIngo Molnar	bool "Kernel performance events and counters"
2105392d65a9SRobert Richter	default y if PROFILING
2106cdd6c482SIngo Molnar	depends on HAVE_PERF_EVENTS
2107e360adbeSPeter Zijlstra	select IRQ_WORK
21080793a61dSThomas Gleixner	help
210957c0c15bSIngo Molnar	  Enable kernel support for various performance events provided
211057c0c15bSIngo Molnar	  by software and hardware.
21110793a61dSThomas Gleixner
2112dd77038dSThadeu Lima de Souza Cascardo	  Software events are supported either built-in or via the
211357c0c15bSIngo Molnar	  use of generic tracepoints.
211457c0c15bSIngo Molnar
211557c0c15bSIngo Molnar	  Most modern CPUs support performance events via performance
211657c0c15bSIngo Molnar	  counter registers. These registers count the number of certain
21170793a61dSThomas Gleixner	  types of hw events: such as instructions executed, cachemisses
21180793a61dSThomas Gleixner	  suffered, or branches mis-predicted - without slowing down the
21190793a61dSThomas Gleixner	  kernel or applications. These registers can also trigger interrupts
21200793a61dSThomas Gleixner	  when a threshold number of events have passed - and can thus be
21210793a61dSThomas Gleixner	  used to profile the code that runs on that CPU.
21220793a61dSThomas Gleixner
212357c0c15bSIngo Molnar	  The Linux Performance Event subsystem provides an abstraction of
2124dd77038dSThadeu Lima de Souza Cascardo	  these software and hardware event capabilities, available via a
212557c0c15bSIngo Molnar	  system call and used by the "perf" utility in tools/perf/. It
21260793a61dSThomas Gleixner	  provides per task and per CPU counters, and it provides event
21270793a61dSThomas Gleixner	  capabilities on top of those.
21280793a61dSThomas Gleixner
21290793a61dSThomas Gleixner	  Say Y if unsure.
21300793a61dSThomas Gleixner
2131906010b2SPeter Zijlstraconfig DEBUG_PERF_USE_VMALLOC
2132906010b2SPeter Zijlstra	default n
2133906010b2SPeter Zijlstra	bool "Debug: use vmalloc to back perf mmap() buffers"
2134cb307113SMichael Ellerman	depends on PERF_EVENTS && DEBUG_KERNEL && !PPC
2135906010b2SPeter Zijlstra	select PERF_USE_VMALLOC
2136906010b2SPeter Zijlstra	help
2137906010b2SPeter Zijlstra	  Use vmalloc memory to back perf mmap() buffers.
2138906010b2SPeter Zijlstra
2139906010b2SPeter Zijlstra	  Mostly useful for debugging the vmalloc code on platforms
2140906010b2SPeter Zijlstra	  that don't require it.
2141906010b2SPeter Zijlstra
2142906010b2SPeter Zijlstra	  Say N if unsure.
2143906010b2SPeter Zijlstra
21440793a61dSThomas Gleixnerendmenu
21450793a61dSThomas Gleixner
2146091f6e26SDavid Howellsconfig SYSTEM_DATA_VERIFICATION
2147091f6e26SDavid Howells	def_bool n
2148091f6e26SDavid Howells	select SYSTEM_TRUSTED_KEYRING
2149091f6e26SDavid Howells	select KEYS
2150091f6e26SDavid Howells	select CRYPTO
2151d43de6c7SDavid Howells	select CRYPTO_RSA
2152091f6e26SDavid Howells	select ASYMMETRIC_KEY_TYPE
2153091f6e26SDavid Howells	select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
2154091f6e26SDavid Howells	select ASN1
2155091f6e26SDavid Howells	select OID_REGISTRY
2156091f6e26SDavid Howells	select X509_CERTIFICATE_PARSER
2157091f6e26SDavid Howells	select PKCS7_MESSAGE_PARSER
215882c04ff8SPeter Foley	help
2159091f6e26SDavid Howells	  Provide PKCS#7 message verification using the contents of the system
2160091f6e26SDavid Howells	  trusted keyring to provide public keys.  This then can be used for
2161091f6e26SDavid Howells	  module verification, kexec image verification and firmware blob
2162091f6e26SDavid Howells	  verification.
216382c04ff8SPeter Foley
2164125e5645SMathieu Desnoyersconfig PROFILING
2165b309a294SRobert Richter	bool "Profiling support"
2166125e5645SMathieu Desnoyers	help
2167125e5645SMathieu Desnoyers	  Say Y here to enable the extended profiling support mechanisms used
2168f8408264SViresh Kumar	  by profilers.
2169125e5645SMathieu Desnoyers
21702f7ab126SMiguel Ojedaconfig RUST
21712f7ab126SMiguel Ojeda	bool "Rust support"
21722f7ab126SMiguel Ojeda	depends on HAVE_RUST
21732f7ab126SMiguel Ojeda	depends on RUST_IS_AVAILABLE
2174ac61506bSSami Tolvanen	select EXTENDED_MODVERSIONS if MODVERSIONS
2175ac61506bSSami Tolvanen	depends on !MODVERSIONS || GENDWARFKSYMS
2176f1385dc6SNeal Gompa	depends on !GCC_PLUGIN_RANDSTRUCT
21772f7ab126SMiguel Ojeda	depends on !RANDSTRUCT
21785daa0c35SMatthew Maurer	depends on !DEBUG_INFO_BTF || (PAHOLE_HAS_LANG_EXCLUDE && !LTO)
217923ef9d43SKees Cook	depends on !CFI || HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC
218023ef9d43SKees Cook	select CFI_ICALL_NORMALIZE_INTEGERS if CFI
2181af6017b6SMiguel Ojeda	depends on !CALL_PADDING || RUSTC_VERSION >= 108100
2182f64e2f3aSMatthew Maurer	depends on !KASAN_SW_TAGS
218393e34a0bSAlice Ryhl	depends on !(MITIGATION_RETHUNK && KASAN) || RUSTC_VERSION >= 108300
21842f7ab126SMiguel Ojeda	help
21852f7ab126SMiguel Ojeda	  Enables Rust support in the kernel.
21862f7ab126SMiguel Ojeda
21872f7ab126SMiguel Ojeda	  This allows other Rust-related options, like drivers written in Rust,
21882f7ab126SMiguel Ojeda	  to be selected.
21892f7ab126SMiguel Ojeda
21902f7ab126SMiguel Ojeda	  It is also required to be able to load external kernel modules
21912f7ab126SMiguel Ojeda	  written in Rust.
21922f7ab126SMiguel Ojeda
21932f7ab126SMiguel Ojeda	  See Documentation/rust/ for more information.
21942f7ab126SMiguel Ojeda
21952f7ab126SMiguel Ojeda	  If unsure, say N.
21962f7ab126SMiguel Ojeda
21972f7ab126SMiguel Ojedaconfig RUSTC_VERSION_TEXT
21982f7ab126SMiguel Ojeda	string
21992f7ab126SMiguel Ojeda	depends on RUST
22005134a335SMiguel Ojeda	default "$(RUSTC_VERSION_TEXT)"
22015134a335SMiguel Ojeda	help
22025134a335SMiguel Ojeda	  See `CC_VERSION_TEXT`.
22032f7ab126SMiguel Ojeda
22042f7ab126SMiguel Ojedaconfig BINDGEN_VERSION_TEXT
22052f7ab126SMiguel Ojeda	string
22062f7ab126SMiguel Ojeda	depends on RUST
22079e98db17SMiguel Ojeda	# The dummy parameter `workaround-for-0.69.0` is required to support 0.69.0
2208c23d1f7eSMiguel Ojeda	# (https://github.com/rust-lang/rust-bindgen/pull/2678) and 0.71.0
2209c23d1f7eSMiguel Ojeda	# (https://github.com/rust-lang/rust-bindgen/pull/3040). It can be removed
2210c23d1f7eSMiguel Ojeda	# when the minimum version is upgraded past the latter (0.69.1 and 0.71.1
2211c23d1f7eSMiguel Ojeda	# both fixed the issue).
2212aacf93e8SMasahiro Yamada	default "$(shell,$(BINDGEN) --version workaround-for-0.69.0 2>/dev/null)"
22132f7ab126SMiguel Ojeda
22145f87f112SIngo Molnar#
22155f87f112SIngo Molnar# Place an empty function call at each tracepoint site. Can be
22165f87f112SIngo Molnar# dynamically changed for a probe function.
22175f87f112SIngo Molnar#
221897e1c18eSMathieu Desnoyersconfig TRACEPOINTS
22195f87f112SIngo Molnar	bool
2220a363d27cSMathieu Desnoyers	select TASKS_TRACE_RCU
222197e1c18eSMathieu Desnoyers
222289cde455SEric DeVoldersource "kernel/Kconfig.kexec"
222389cde455SEric DeVolder
222448a1b232SPasha Tatashinsource "kernel/liveupdate/Kconfig"
222548a1b232SPasha Tatashin
22261da177e4SLinus Torvaldsendmenu		# General setup
22271da177e4SLinus Torvalds
22281572497cSChristoph Hellwigsource "arch/Kconfig"
22291572497cSChristoph Hellwig
2230ae81f9e3SChuck Ebbertconfig RT_MUTEXES
22316341e62bSChristoph Jaeger	bool
22321c6f9ec0SSebastian Andrzej Siewior	default y if PREEMPT_RT
2233ae81f9e3SChuck Ebbert
2234c8424e77SThiago Jung Bauermannconfig MODULE_SIG_FORMAT
2235c8424e77SThiago Jung Bauermann	def_bool n
2236c8424e77SThiago Jung Bauermann	select SYSTEM_DATA_VERIFICATION
2237c8424e77SThiago Jung Bauermann
223873b4fc92SChristophe Leroysource "kernel/module/Kconfig"
22396c9692e2SPeter Zijlstra
224098a79d6aSRusty Russellconfig INIT_ALL_POSSIBLE
224198a79d6aSRusty Russell	bool
224298a79d6aSRusty Russell	help
22435f054e31SRusty Russell	  Back when each arch used to define their own cpu_online_mask and
22445f054e31SRusty Russell	  cpu_possible_mask, some of them chose to initialize cpu_possible_mask
224598a79d6aSRusty Russell	  with all 1s, and others with all 0s.  When they were centralised,
224698a79d6aSRusty Russell	  it was better to provide this option than to break all the archs
2247692105b8SMatt LaPlante	  and have several arch maintainers pursuing me down dark alleys.
224898a79d6aSRusty Russell
22493a65dfe8SJens Axboesource "block/Kconfig"
2250e98c3202SAvi Kivity
2251e98c3202SAvi Kivityconfig PREEMPT_NOTIFIERS
2252e98c3202SAvi Kivity	bool
2253e260be67SPaul E. McKenney
225416295becSSteffen Klassertconfig PADATA
225516295becSSteffen Klassert	depends on SMP
225616295becSSteffen Klassert	bool
225716295becSSteffen Klassert
22584520c6a4SDavid Howellsconfig ASN1
22594520c6a4SDavid Howells	tristate
22604520c6a4SDavid Howells	help
22614520c6a4SDavid Howells	  Build a simple ASN.1 grammar compiler that produces a bytecode output
22624520c6a4SDavid Howells	  that can be interpreted by the ASN.1 stream decoder and used to
22634520c6a4SDavid Howells	  inform it as to what tags are to be expected in a stream and what
22644520c6a4SDavid Howells	  functions to call on what tags.
22654520c6a4SDavid Howells
22666beb0009SThomas Gleixnersource "kernel/Kconfig.locks"
2267e61938a9SMathieu Desnoyers
22680ebeea8cSDaniel Borkmannconfig ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
22690ebeea8cSDaniel Borkmann	bool
22700ebeea8cSDaniel Borkmann
22714ff4c745SAndrea Parriconfig ARCH_HAS_PREPARE_SYNC_CORE_CMD
22724ff4c745SAndrea Parri	bool
22734ff4c745SAndrea Parri
2274e61938a9SMathieu Desnoyersconfig ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
2275e61938a9SMathieu Desnoyers	bool
22761bd21c6cSDominik Brodowski
22771bd21c6cSDominik Brodowski# It may be useful for an architecture to override the definitions of the
22787303e30eSDominik Brodowski# SYSCALL_DEFINE() and __SYSCALL_DEFINEx() macros in <linux/syscalls.h>
22797303e30eSDominik Brodowski# and the COMPAT_ variants in <linux/compat.h>, in particular to use a
22807303e30eSDominik Brodowski# different calling convention for syscalls. They can also override the
22817303e30eSDominik Brodowski# macros for not-implemented syscalls in kernel/sys_ni.c and
22827303e30eSDominik Brodowski# kernel/time/posix-stubs.c. All these overrides need to be available in
22837303e30eSDominik Brodowski# <asm/syscall_wrapper.h>.
22841bd21c6cSDominik Brodowskiconfig ARCH_HAS_SYSCALL_WRAPPER
22851bd21c6cSDominik Brodowski	def_bool n
2286