xref: /linux/init/Kconfig (revision 2e05544060b9fef5d4d0e0172944e6956c55080f)
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
85e90f97ceSGary Guoconfig RUSTC_LLVM_MAJOR_VERSION
86e90f97ceSGary Guo	int
87e90f97ceSGary Guo	default $(shell,expr $(rustc-llvm-version) / 10000)
88e90f97ceSGary Guo
89e90f97ceSGary Guoconfig RUSTC_CLANG_LLVM_COMPATIBLE
90e90f97ceSGary Guo	bool
91e90f97ceSGary Guo	default y if CC_IS_CLANG && RUSTC_LLVM_MAJOR_VERSION = $(shell,expr $(cc-version) / 10000)
92e90f97ceSGary Guo	help
93e90f97ceSGary Guo	  This indicates whether Rust and Clang use LLVM of the same major
94e90f97ceSGary Guo	  version.
95e90f97ceSGary Guo
96e90f97ceSGary Guo	  Operations involving handling LLVM IR or bitcode (e.g. cross-language
97e90f97ceSGary Guo	  LTO) require the same LLVM major version to work properly. For best
98e90f97ceSGary Guo	  compatibility it is recommended that the exact same LLVM is used.
99e90f97ceSGary Guo
100deab487eSThomas Weißschuhconfig ARCH_HAS_CC_CAN_LINK
101deab487eSThomas Weißschuh	bool
102deab487eSThomas Weißschuh
1031a927fd3SMasahiro Yamadaconfig CC_CAN_LINK
1049371f86eSMasahiro Yamada	bool
105deab487eSThomas Weißschuh	default ARCH_CC_CAN_LINK if ARCH_HAS_CC_CAN_LINK
10680623f2cSThomas Weißschuh	default $(cc_can_link_user,$(m64-flag)) if 64BIT
10780623f2cSThomas Weißschuh	default $(cc_can_link_user,$(m32-flag))
1081a927fd3SMasahiro Yamada
109f2f6a8e8SMark Rutland# Fixed in GCC 14, 13.3, 12.4 and 11.5
110f2f6a8e8SMark Rutland# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113921
111f2f6a8e8SMark Rutlandconfig GCC_ASM_GOTO_OUTPUT_BROKEN
112f2f6a8e8SMark Rutland	bool
113f2f6a8e8SMark Rutland	depends on CC_IS_GCC
114f2f6a8e8SMark Rutland	default y if GCC_VERSION < 110500
115f2f6a8e8SMark Rutland	default y if GCC_VERSION >= 120000 && GCC_VERSION < 120400
116f2f6a8e8SMark Rutland	default y if GCC_VERSION >= 130000 && GCC_VERSION < 130300
117f2f6a8e8SMark Rutland
118587f1701SNick Desaulniersconfig CC_HAS_ASM_GOTO_OUTPUT
119f2f6a8e8SMark Rutland	def_bool y
120f2f6a8e8SMark Rutland	depends on !GCC_ASM_GOTO_OUTPUT_BROKEN
121f2f6a8e8SMark 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)
122587f1701SNick Desaulniers
1231aa0e8b1SSean Christophersonconfig CC_HAS_ASM_GOTO_TIED_OUTPUT
1241aa0e8b1SSean Christopherson	depends on CC_HAS_ASM_GOTO_OUTPUT
1251aa0e8b1SSean Christopherson	# Detect buggy gcc and clang, fixed in gcc-11 clang-14.
126534bd703SAlexandre 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)
1271aa0e8b1SSean Christopherson
1285cf896fbSPeter Collingbourneconfig TOOLS_SUPPORT_RELR
1292d122942SWill Deacon	def_bool $(success,env "CC=$(CC)" "LD=$(LD)" "NM=$(NM)" "OBJCOPY=$(OBJCOPY)" $(srctree)/scripts/tools-support-relr.sh)
1305cf896fbSPeter Collingbourne
131eb111869SRasmus Villemoesconfig CC_HAS_ASM_INLINE
132eb111869SRasmus Villemoes	def_bool $(success,echo 'void foo(void) { asm inline (""); }' | $(CC) -x c - -c -o /dev/null)
133eb111869SRasmus Villemoes
134f72e2cffSHeiko Carstensconfig CC_HAS_ASSUME
135f72e2cffSHeiko Carstens	bool
136f72e2cffSHeiko Carstens	# clang needs to be at least 19.1.0 since the meaning of the assume
137f72e2cffSHeiko Carstens	# attribute changed:
138f72e2cffSHeiko Carstens	# https://github.com/llvm/llvm-project/commit/c44fa3e8a9a44c2e9a575768a3c185354b9f6c17
139f72e2cffSHeiko Carstens	default y if CC_IS_CLANG && CLANG_VERSION >= 190100
140f72e2cffSHeiko Carstens	# supported since gcc 13.1.0
141f72e2cffSHeiko Carstens	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106654
142f72e2cffSHeiko Carstens	default y if CC_IS_GCC && GCC_VERSION >= 130100
143f72e2cffSHeiko Carstens
14451c2ee6dSNick Desaulniersconfig CC_HAS_NO_PROFILE_FN_ATTR
14551c2ee6dSNick Desaulniers	def_bool $(success,echo '__attribute__((no_profile_instrument_function)) int x();' | $(CC) -x c - -c -o /dev/null -Werror)
14651c2ee6dSNick Desaulniers
147f06e108aSJan Hendrik Farrconfig CC_HAS_COUNTED_BY
1485106c650SJan Hendrik Farr	bool
14986a9b125SNathan Chancellor	# clang needs to be at least 20.1.0 to avoid potential crashes
15086a9b125SNathan Chancellor	# when building structures that contain __counted_by
15186a9b125SNathan Chancellor	# https://github.com/ClangBuiltLinux/linux/issues/2114
15286a9b125SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/160fb1121cdf703c3ef5e61fb26c5659eb581489
15386a9b125SNathan Chancellor	default y if CC_IS_CLANG && CLANG_VERSION >= 200100
1545106c650SJan Hendrik Farr	# supported since gcc 15.1.0
1555106c650SJan Hendrik Farr	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108896
1565106c650SJan Hendrik Farr	default y if CC_IS_GCC && GCC_VERSION >= 150100
157f06e108aSJan Hendrik Farr
158150a04d8SBill Wendlingconfig CC_HAS_COUNTED_BY_PTR
159150a04d8SBill Wendling	bool
160150a04d8SBill Wendling	# supported since clang 22
1617a618ca9SNathan Chancellor	default y if CC_IS_CLANG && CLANG_VERSION >= 220100
162150a04d8SBill Wendling	# supported since gcc 16.0.0
163150a04d8SBill Wendling	default y if CC_IS_GCC && GCC_VERSION >= 160000
164150a04d8SBill Wendling
165d39a1d74SKees Cookconfig CC_HAS_BROKEN_COUNTED_BY_REF
166d39a1d74SKees Cook	bool
167d39a1d74SKees Cook	# https://github.com/llvm/llvm-project/issues/182575
168f709859fSNathan Chancellor	default y if CC_IS_CLANG && CLANG_VERSION < 220100
169d39a1d74SKees Cook
170feb662d9SMarco Elverconfig CC_HAS_ALLOC_TOKEN
171feb662d9SMarco Elver	def_bool $(cc-option,-falloc-token-max=123)
172feb662d9SMarco Elver
173b688f369SKees Cookconfig CC_HAS_MULTIDIMENSIONAL_NONSTRING
174b688f369SKees Cook	def_bool $(success,echo 'char tag[][4] __attribute__((__nonstring__)) = { };' | $(CC) $(CLANG_FLAGS) -x c - -c -o /dev/null -Werror)
175b688f369SKees Cook
176e7607f7dSNathan Chancellorconfig LD_CAN_USE_KEEP_IN_OVERLAY
177e7607f7dSNathan Chancellor	# ld.lld prior to 21.0.0 did not support KEEP within an overlay description
178e7607f7dSNathan Chancellor	# https://github.com/llvm/llvm-project/pull/130661
179e7607f7dSNathan Chancellor	def_bool LD_IS_BFD || LLD_VERSION >= 210000
180e7607f7dSNathan Chancellor
18136174d16SMiguel Ojedaconfig RUSTC_HAS_SPAN_FILE
18236174d16SMiguel Ojeda	def_bool RUSTC_VERSION >= 108800
18336174d16SMiguel Ojeda
1847129ea6eSMiguel Ojedaconfig RUSTC_HAS_UNNECESSARY_TRANSMUTES
1857129ea6eSMiguel Ojeda	def_bool RUSTC_VERSION >= 108800
1867129ea6eSMiguel Ojeda
1870aa2b78cSBoqun Fengconfig RUSTC_HAS_FILE_WITH_NUL
1880aa2b78cSBoqun Feng	def_bool RUSTC_VERSION >= 108900
1890aa2b78cSBoqun Feng
190c09461a0SAlice Ryhlconfig RUSTC_HAS_FILE_AS_C_STR
191c09461a0SAlice Ryhl	def_bool RUSTC_VERSION >= 109100
192c09461a0SAlice Ryhl
193613fe169SNathan Chancellorconfig PAHOLE_VERSION
194613fe169SNathan Chancellor	int
19590e5b38aSIhor Solodrai	default "$(PAHOLE_VERSION)"
196613fe169SNathan Chancellor
197b99b87f7SPeter Oberparleiterconfig CONSTRUCTORS
198b99b87f7SPeter Oberparleiter	bool
199b99b87f7SPeter Oberparleiter
200e360adbeSPeter Zijlstraconfig IRQ_WORK
201fd0a68a2STejun Heo	def_bool y if SMP
202e360adbeSPeter Zijlstra
20310916706SShile Zhangconfig BUILDTIME_TABLE_SORT
2041dbdc6f1SDavid Daney	bool
2051dbdc6f1SDavid Daney
206c65eacbeSAndy Lutomirskiconfig THREAD_INFO_IN_TASK
207c65eacbeSAndy Lutomirski	bool
208c65eacbeSAndy Lutomirski	help
209c65eacbeSAndy Lutomirski	  Select this to move thread_info off the stack into task_struct.  To
210c65eacbeSAndy Lutomirski	  make this work, an arch will need to remove all thread_info fields
211c65eacbeSAndy Lutomirski	  except flags and fix any runtime bugs.
212c65eacbeSAndy Lutomirski
213c6c314a6SAndy Lutomirski	  One subtle change that will be needed is to use try_get_task_stack()
214c6c314a6SAndy Lutomirski	  and put_task_stack() in save_thread_stack_tsk() and get_wchan().
215c6c314a6SAndy Lutomirski
216ff0cfc66SAl Boldimenu "General setup"
2171da177e4SLinus Torvalds
2181da177e4SLinus Torvaldsconfig BROKEN
2191da177e4SLinus Torvalds	bool
220fefbeed8SAndrew Morton	help
221fefbeed8SAndrew Morton	  This option allows you to choose whether you want to try to
222fefbeed8SAndrew Morton	  compile (and fix) old drivers that haven't been updated to
223fefbeed8SAndrew Morton	  new infrastructure.
2241da177e4SLinus Torvalds
2251da177e4SLinus Torvaldsconfig BROKEN_ON_SMP
2261da177e4SLinus Torvalds	bool
2271da177e4SLinus Torvalds	depends on BROKEN || !SMP
2281da177e4SLinus Torvalds	default y
2291da177e4SLinus Torvalds
2301da177e4SLinus Torvaldsconfig INIT_ENV_ARG_LIMIT
2311da177e4SLinus Torvalds	int
232dd673bcaSAdrian Bunk	default 32 if !UML
233dd673bcaSAdrian Bunk	default 128 if UML
2341da177e4SLinus Torvalds	help
23534ad92c2SRandy Dunlap	  Maximum of each of the number of arguments and environment
23634ad92c2SRandy Dunlap	  variables passed to init from the kernel command line.
2371da177e4SLinus Torvalds
2384bb16672SJiri Slabyconfig COMPILE_TEST
2394bb16672SJiri Slaby	bool "Compile also drivers which will not load"
240ea29b20aSMasahiro Yamada	depends on HAS_IOMEM
2414bb16672SJiri Slaby	help
2424bb16672SJiri Slaby	  Some drivers can be compiled on a different platform than they are
2434bb16672SJiri Slaby	  intended to be run on. Despite they cannot be loaded there (or even
2444bb16672SJiri Slaby	  when they load they cannot be used due to missing HW support),
2454bb16672SJiri Slaby	  developers still, opposing to distributors, might want to build such
2464bb16672SJiri Slaby	  drivers to compile-test them.
2474bb16672SJiri Slaby
2484bb16672SJiri Slaby	  If you are a developer and want to build everything available, say Y
2494bb16672SJiri Slaby	  here. If you are a user/distributor, say N here to exclude useless
2504bb16672SJiri Slaby	  drivers to be distributed.
2514bb16672SJiri Slaby
2523fe617ccSLinus Torvaldsconfig WERROR
2533fe617ccSLinus Torvalds	bool "Compile the kernel with warnings as errors"
254b339ec9cSMarco Elver	default COMPILE_TEST
2553fe617ccSLinus Torvalds	help
2563fe617ccSLinus Torvalds	  A kernel build should not cause any compiler warnings, and this
2572f7ab126SMiguel Ojeda	  enables the '-Werror' (for C) and '-Dwarnings' (for Rust) flags
258e1789d7cSXin Li	  to enforce that rule by default. Certain warnings from other tools
259e1789d7cSXin Li	  such as the linker may be upgraded to errors with this option as
260e1789d7cSXin Li	  well.
2613fe617ccSLinus Torvalds
262e1789d7cSXin Li	  However, if you have a new (or very old) compiler or linker with odd
263e1789d7cSXin Li	  and unusual warnings, or you have some architecture with problems,
2643fe617ccSLinus Torvalds	  you may need to disable this config option in order to
2653fe617ccSLinus Torvalds	  successfully build the kernel.
2663fe617ccSLinus Torvalds
2673fe617ccSLinus Torvalds	  If in doubt, say Y.
2683fe617ccSLinus Torvalds
269d6fc9fcbSMasahiro Yamadaconfig UAPI_HEADER_TEST
270d6fc9fcbSMasahiro Yamada	bool "Compile test UAPI headers"
2712a0a3080SThomas Weißschuh	depends on HEADERS_INSTALL
272d6fc9fcbSMasahiro Yamada	help
273d6fc9fcbSMasahiro Yamada	  Compile test headers exported to user-space to ensure they are
274d6fc9fcbSMasahiro Yamada	  self-contained, i.e. compilable as standalone units.
275d6fc9fcbSMasahiro Yamada
276d6fc9fcbSMasahiro Yamada	  If you are a developer or tester and want to ensure the exported
277d6fc9fcbSMasahiro Yamada	  headers are self-contained, say Y here. Otherwise, choose N.
278d6fc9fcbSMasahiro Yamada
2791da177e4SLinus Torvaldsconfig LOCALVERSION
2801da177e4SLinus Torvalds	string "Local version - append to kernel release"
2811da177e4SLinus Torvalds	help
2821da177e4SLinus Torvalds	  Append an extra string to the end of your kernel version.
2831da177e4SLinus Torvalds	  This will show up when you type uname, for example.
2841da177e4SLinus Torvalds	  The string you set here will be appended after the contents of
2851da177e4SLinus Torvalds	  any files with a filename matching localversion* in your
2861da177e4SLinus Torvalds	  object and source tree, in that order.  Your total string can
2871da177e4SLinus Torvalds	  be a maximum of 64 characters.
2881da177e4SLinus Torvalds
289aaebf433SRyan Andersonconfig LOCALVERSION_AUTO
290aaebf433SRyan Anderson	bool "Automatically append version information to the version string"
291aaebf433SRyan Anderson	default y
292ac3339baSAlexey Dobriyan	depends on !COMPILE_TEST
293aaebf433SRyan Anderson	help
294aaebf433SRyan Anderson	  This will try to automatically determine if the current tree is a
2956e5a5420SRobert P. J. Day	  release tree by looking for git tags that belong to the current
2966e5a5420SRobert P. J. Day	  top of tree revision.
297aaebf433SRyan Anderson
298aaebf433SRyan Anderson	  A string of the format -gxxxxxxxx will be added to the localversion
2996e5a5420SRobert P. J. Day	  if a git-based tree is found.  The string generated by this will be
300aaebf433SRyan Anderson	  appended after any matching localversion* files, and after the value
3016e5a5420SRobert P. J. Day	  set in CONFIG_LOCALVERSION.
302aaebf433SRyan Anderson
3030f9c608dSRasmus Villemoes	  (The actual string used here is the first 12 characters produced
3046e5a5420SRobert P. J. Day	  by running the command:
3056e5a5420SRobert P. J. Day
3066e5a5420SRobert P. J. Day	    $ git rev-parse --verify HEAD
3076e5a5420SRobert P. J. Day
3086e5a5420SRobert P. J. Day	  which is done within the script "scripts/setlocalversion".)
309aaebf433SRyan Anderson
3109afb719eSLaura Abbottconfig BUILD_SALT
3119afb719eSLaura Abbott	string "Build ID Salt"
3129afb719eSLaura Abbott	default ""
3139afb719eSLaura Abbott	help
3149afb719eSLaura Abbott	  The build ID is used to link binaries and their debug info. Setting
3159afb719eSLaura Abbott	  this option will use the value in the calculation of the build id.
3169afb719eSLaura Abbott	  This is mostly useful for distributions which want to ensure the
3179afb719eSLaura Abbott	  build is unique between builds. It's safe to leave the default.
3189afb719eSLaura Abbott
3192e9f3bddSH. Peter Anvinconfig HAVE_KERNEL_GZIP
3202e9f3bddSH. Peter Anvin	bool
3212e9f3bddSH. Peter Anvin
3222e9f3bddSH. Peter Anvinconfig HAVE_KERNEL_BZIP2
3232e9f3bddSH. Peter Anvin	bool
3242e9f3bddSH. Peter Anvin
3252e9f3bddSH. Peter Anvinconfig HAVE_KERNEL_LZMA
3262e9f3bddSH. Peter Anvin	bool
3272e9f3bddSH. Peter Anvin
3283ebe1243SLasse Collinconfig HAVE_KERNEL_XZ
3293ebe1243SLasse Collin	bool
3303ebe1243SLasse Collin
3317dd65febSAlbin Tonnerreconfig HAVE_KERNEL_LZO
3327dd65febSAlbin Tonnerre	bool
3337dd65febSAlbin Tonnerre
334e76e1fdfSKyungsik Leeconfig HAVE_KERNEL_LZ4
335e76e1fdfSKyungsik Lee	bool
336e76e1fdfSKyungsik Lee
33748f7ddf7SNick Terrellconfig HAVE_KERNEL_ZSTD
33848f7ddf7SNick Terrell	bool
33948f7ddf7SNick Terrell
340f16466afSVasily Gorbikconfig HAVE_KERNEL_UNCOMPRESSED
341f16466afSVasily Gorbik	bool
342f16466afSVasily Gorbik
34330d65dbfSAlain Knaffchoice
34430d65dbfSAlain Knaff	prompt "Kernel compression mode"
34530d65dbfSAlain Knaff	default KERNEL_GZIP
34648f7ddf7SNick 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
34730d65dbfSAlain Knaff	help
34830d65dbfSAlain Knaff	  The linux kernel is a kind of self-extracting executable.
34930d65dbfSAlain Knaff	  Several compression algorithms are available, which differ
35030d65dbfSAlain Knaff	  in efficiency, compression and decompression speed.
35130d65dbfSAlain Knaff	  Compression speed is only relevant when building a kernel.
35230d65dbfSAlain Knaff	  Decompression speed is relevant at each boot.
35330d65dbfSAlain Knaff
35430d65dbfSAlain Knaff	  If you have any problems with bzip2 or lzma compressed
35530d65dbfSAlain Knaff	  kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
35630d65dbfSAlain Knaff	  version of this functionality (bzip2 only), for 2.4, was
35730d65dbfSAlain Knaff	  supplied by Christian Ludwig)
35830d65dbfSAlain Knaff
35930d65dbfSAlain Knaff	  High compression options are mostly useful for users, who
36030d65dbfSAlain Knaff	  are low on disk space (embedded systems), but for whom ram
36130d65dbfSAlain Knaff	  size matters less.
36230d65dbfSAlain Knaff
36330d65dbfSAlain Knaff	  If in doubt, select 'gzip'
36430d65dbfSAlain Knaff
36530d65dbfSAlain Knaffconfig KERNEL_GZIP
36630d65dbfSAlain Knaff	bool "Gzip"
3672e9f3bddSH. Peter Anvin	depends on HAVE_KERNEL_GZIP
36830d65dbfSAlain Knaff	help
3697dd65febSAlbin Tonnerre	  The old and tried gzip compression. It provides a good balance
3707dd65febSAlbin Tonnerre	  between compression ratio and decompression speed.
37130d65dbfSAlain Knaff
37230d65dbfSAlain Knaffconfig KERNEL_BZIP2
37330d65dbfSAlain Knaff	bool "Bzip2"
3742e9f3bddSH. Peter Anvin	depends on HAVE_KERNEL_BZIP2
37530d65dbfSAlain Knaff	help
37630d65dbfSAlain Knaff	  Its compression ratio and speed is intermediate.
3770a4dd35cSRandy Dunlap	  Decompression speed is slowest among the choices.  The kernel
3782e9f3bddSH. Peter Anvin	  size is about 10% smaller with bzip2, in comparison to gzip.
3792e9f3bddSH. Peter Anvin	  Bzip2 uses a large amount of memory. For modern kernels you
3802e9f3bddSH. Peter Anvin	  will need at least 8MB RAM or more for booting.
38130d65dbfSAlain Knaff
38230d65dbfSAlain Knaffconfig KERNEL_LZMA
38330d65dbfSAlain Knaff	bool "LZMA"
3842e9f3bddSH. Peter Anvin	depends on HAVE_KERNEL_LZMA
38530d65dbfSAlain Knaff	help
3860a4dd35cSRandy Dunlap	  This compression algorithm's ratio is best.  Decompression speed
3870a4dd35cSRandy Dunlap	  is between gzip and bzip2.  Compression is slowest.
3880a4dd35cSRandy Dunlap	  The kernel size is about 33% smaller with LZMA in comparison to gzip.
38930d65dbfSAlain Knaff
3903ebe1243SLasse Collinconfig KERNEL_XZ
3913ebe1243SLasse Collin	bool "XZ"
3923ebe1243SLasse Collin	depends on HAVE_KERNEL_XZ
3933ebe1243SLasse Collin	help
3943ebe1243SLasse Collin	  XZ uses the LZMA2 algorithm and instruction set specific
3953ebe1243SLasse Collin	  BCJ filters which can improve compression ratio of executable
3963ebe1243SLasse Collin	  code. The size of the kernel is about 30% smaller with XZ in
3973ebe1243SLasse Collin	  comparison to gzip. On architectures for which there is a BCJ
3987472ff8aSLasse Collin	  filter (i386, x86_64, ARM, ARM64, RISC-V, big endian PowerPC,
3997472ff8aSLasse Collin	  and SPARC), XZ will create a few percent smaller kernel than
4007472ff8aSLasse Collin	  plain LZMA.
4013ebe1243SLasse Collin
4023ebe1243SLasse Collin	  The speed is about the same as with LZMA: The decompression
4033ebe1243SLasse Collin	  speed of XZ is better than that of bzip2 but worse than gzip
4043ebe1243SLasse Collin	  and LZO. Compression is slow.
4053ebe1243SLasse Collin
4067dd65febSAlbin Tonnerreconfig KERNEL_LZO
4077dd65febSAlbin Tonnerre	bool "LZO"
4087dd65febSAlbin Tonnerre	depends on HAVE_KERNEL_LZO
4097dd65febSAlbin Tonnerre	help
4100a4dd35cSRandy Dunlap	  Its compression ratio is the poorest among the choices. The kernel
411681b3049SStephan Sperber	  size is about 10% bigger than gzip; however its speed
4127dd65febSAlbin Tonnerre	  (both compression and decompression) is the fastest.
4137dd65febSAlbin Tonnerre
414e76e1fdfSKyungsik Leeconfig KERNEL_LZ4
415e76e1fdfSKyungsik Lee	bool "LZ4"
416e76e1fdfSKyungsik Lee	depends on HAVE_KERNEL_LZ4
417e76e1fdfSKyungsik Lee	help
418e76e1fdfSKyungsik Lee	  LZ4 is an LZ77-type compressor with a fixed, byte-oriented encoding.
419e76e1fdfSKyungsik Lee	  A preliminary version of LZ4 de/compression tool is available at
420e76e1fdfSKyungsik Lee	  <https://code.google.com/p/lz4/>.
421e76e1fdfSKyungsik Lee
422e76e1fdfSKyungsik Lee	  Its compression ratio is worse than LZO. The size of the kernel
423e76e1fdfSKyungsik Lee	  is about 8% bigger than LZO. But the decompression speed is
424e76e1fdfSKyungsik Lee	  faster than LZO.
425e76e1fdfSKyungsik Lee
42648f7ddf7SNick Terrellconfig KERNEL_ZSTD
42748f7ddf7SNick Terrell	bool "ZSTD"
42848f7ddf7SNick Terrell	depends on HAVE_KERNEL_ZSTD
42948f7ddf7SNick Terrell	help
43048f7ddf7SNick Terrell	  ZSTD is a compression algorithm targeting intermediate compression
43148f7ddf7SNick Terrell	  with fast decompression speed. It will compress better than GZIP and
43248f7ddf7SNick Terrell	  decompress around the same speed as LZO, but slower than LZ4. You
43348f7ddf7SNick Terrell	  will need at least 192 KB RAM or more for booting. The zstd command
43448f7ddf7SNick Terrell	  line tool is required for compression.
43548f7ddf7SNick Terrell
436f16466afSVasily Gorbikconfig KERNEL_UNCOMPRESSED
437f16466afSVasily Gorbik	bool "None"
438f16466afSVasily Gorbik	depends on HAVE_KERNEL_UNCOMPRESSED
439f16466afSVasily Gorbik	help
440f16466afSVasily Gorbik	  Produce uncompressed kernel image. This option is usually not what
441f16466afSVasily Gorbik	  you want. It is useful for debugging the kernel in slow simulation
442f16466afSVasily Gorbik	  environments, where decompressing and moving the kernel is awfully
443f16466afSVasily Gorbik	  slow. This option allows early boot code to skip the decompressor
444f16466afSVasily Gorbik	  and jump right at uncompressed kernel image.
445f16466afSVasily Gorbik
44630d65dbfSAlain Knaffendchoice
44730d65dbfSAlain Knaff
448ada4ab7aSChris Downconfig DEFAULT_INIT
449ada4ab7aSChris Down	string "Default init path"
450ada4ab7aSChris Down	default ""
451ada4ab7aSChris Down	help
452ada4ab7aSChris Down	  This option determines the default init for the system if no init=
453ada4ab7aSChris Down	  option is passed on the kernel command line. If the requested path is
454ada4ab7aSChris Down	  not present, we will still then move on to attempting further
455ada4ab7aSChris Down	  locations (e.g. /sbin/init, etc). If this is empty, we will just use
456ada4ab7aSChris Down	  the fallback list when init= is not passed.
457ada4ab7aSChris Down
458bd5dc17bSJosh Triplettconfig DEFAULT_HOSTNAME
459bd5dc17bSJosh Triplett	string "Default hostname"
460bd5dc17bSJosh Triplett	default "(none)"
461bd5dc17bSJosh Triplett	help
462bd5dc17bSJosh Triplett	  This option determines the default system hostname before userspace
463bd5dc17bSJosh Triplett	  calls sethostname(2). The kernel traditionally uses "(none)" here,
464bd5dc17bSJosh Triplett	  but you may wish to use a different default here to make a minimal
465bd5dc17bSJosh Triplett	  system more usable with less configuration.
466bd5dc17bSJosh Triplett
4671da177e4SLinus Torvaldsconfig SYSVIPC
4681da177e4SLinus Torvalds	bool "System V IPC"
469a7f7f624SMasahiro Yamada	help
4701da177e4SLinus Torvalds	  Inter Process Communication is a suite of library functions and
4711da177e4SLinus Torvalds	  system calls which let processes (running programs) synchronize and
4721da177e4SLinus Torvalds	  exchange information. It is generally considered to be a good thing,
4731da177e4SLinus Torvalds	  and some programs won't run unless you say Y here. In particular, if
4741da177e4SLinus Torvalds	  you want to run the DOS emulator dosemu under Linux (read the
4751da177e4SLinus Torvalds	  DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
4761da177e4SLinus Torvalds	  you'll need to say Y here.
4771da177e4SLinus Torvalds
4781da177e4SLinus Torvalds	  You can find documentation about IPC with "info ipc" and also in
4791da177e4SLinus Torvalds	  section 6.4 of the Linux Programmer's Guide, available from
4801da177e4SLinus Torvalds	  <http://www.tldp.org/guides.html>.
4811da177e4SLinus Torvalds
482a5494dcdSEric W. Biedermanconfig SYSVIPC_SYSCTL
483a5494dcdSEric W. Biederman	bool
484a5494dcdSEric W. Biederman	depends on SYSVIPC
485a5494dcdSEric W. Biederman	depends on SYSCTL
486a5494dcdSEric W. Biederman	default y
487a5494dcdSEric W. Biederman
4880cbed0eeSGuo Renconfig SYSVIPC_COMPAT
4890cbed0eeSGuo Ren	def_bool y
4900cbed0eeSGuo Ren	depends on COMPAT && SYSVIPC
4910cbed0eeSGuo Ren
4921da177e4SLinus Torvaldsconfig POSIX_MQUEUE
4931da177e4SLinus Torvalds	bool "POSIX Message Queues"
49419c92399SKees Cook	depends on NET
495a7f7f624SMasahiro Yamada	help
4961da177e4SLinus Torvalds	  POSIX variant of message queues is a part of IPC. In POSIX message
4971da177e4SLinus Torvalds	  queues every message has a priority which decides about succession
4981da177e4SLinus Torvalds	  of receiving it by a process. If you want to compile and run
4991da177e4SLinus Torvalds	  programs written e.g. for Solaris with use of its POSIX message
500b0e37650SRobert P. J. Day	  queues (functions mq_*) say Y here.
5011da177e4SLinus Torvalds
5021da177e4SLinus Torvalds	  POSIX message queues are visible as a filesystem called 'mqueue'
5031da177e4SLinus Torvalds	  and can be mounted somewhere if you want to do filesystem
5041da177e4SLinus Torvalds	  operations on message queues.
5051da177e4SLinus Torvalds
5061da177e4SLinus Torvalds	  If unsure, say Y.
5071da177e4SLinus Torvalds
508bdc8e5f8SSerge E. Hallynconfig POSIX_MQUEUE_SYSCTL
509bdc8e5f8SSerge E. Hallyn	bool
510bdc8e5f8SSerge E. Hallyn	depends on POSIX_MQUEUE
511bdc8e5f8SSerge E. Hallyn	depends on SYSCTL
512bdc8e5f8SSerge E. Hallyn	default y
513bdc8e5f8SSerge E. Hallyn
514c73be61cSDavid Howellsconfig WATCH_QUEUE
515c73be61cSDavid Howells	bool "General notification queue"
516c73be61cSDavid Howells	default n
517c73be61cSDavid Howells	help
518c73be61cSDavid Howells
519c73be61cSDavid Howells	  This is a general notification queue for the kernel to pass events to
520c73be61cSDavid Howells	  userspace by splicing them into pipes.  It can be used in conjunction
521c73be61cSDavid Howells	  with watches for key/keyring change notifications and device
522c73be61cSDavid Howells	  notifications.
523c73be61cSDavid Howells
524c02b872aSMauro Carvalho Chehab	  See Documentation/core-api/watch_queue.rst
525c73be61cSDavid Howells
526226b4ccdSKonstantin Khlebnikovconfig CROSS_MEMORY_ATTACH
527226b4ccdSKonstantin Khlebnikov	bool "Enable process_vm_readv/writev syscalls"
528226b4ccdSKonstantin Khlebnikov	depends on MMU
529226b4ccdSKonstantin Khlebnikov	default y
530226b4ccdSKonstantin Khlebnikov	help
531226b4ccdSKonstantin Khlebnikov	  Enabling this option adds the system calls process_vm_readv and
532226b4ccdSKonstantin Khlebnikov	  process_vm_writev which allow a process with the correct privileges
533a2a368d9SGeert Uytterhoeven	  to directly read from or write to another process' address space.
534226b4ccdSKonstantin Khlebnikov	  See the man page for more details.
535226b4ccdSKonstantin Khlebnikov
5361da177e4SLinus Torvaldsconfig AUDIT
5371da177e4SLinus Torvalds	bool "Auditing support"
538804a6a49SChris Wright	depends on NET
5391da177e4SLinus Torvalds	help
5401da177e4SLinus Torvalds	  Enable auditing infrastructure that can be used with another
5411da177e4SLinus Torvalds	  kernel subsystem, such as SELinux (which requires this for
542cb74ed27SPaul Moore	  logging of avc messages output).  System call auditing is included
543cb74ed27SPaul Moore	  on architectures which support it.
5441da177e4SLinus Torvalds
5457a017721SAKASHI Takahiroconfig HAVE_ARCH_AUDITSYSCALL
5467a017721SAKASHI Takahiro	bool
5477a017721SAKASHI Takahiro
5481da177e4SLinus Torvaldsconfig AUDITSYSCALL
549cb74ed27SPaul Moore	def_bool y
5507a017721SAKASHI Takahiro	depends on AUDIT && HAVE_ARCH_AUDITSYSCALL
55128a3a7ebSEric Paris	select FSNOTIFY
55274c3cbe3SAl Viro
553d9817ebeSThomas Gleixnersource "kernel/irq/Kconfig"
554764e0da1SThomas Gleixnersource "kernel/time/Kconfig"
555b24abcffSDaniel Borkmannsource "kernel/bpf/Kconfig"
55687a4c375SChristoph Hellwigsource "kernel/Kconfig.preempt"
557d9817ebeSThomas Gleixner
558391dc69cSFrederic Weisbeckermenu "CPU/Task time and stats accounting"
559391dc69cSFrederic Weisbecker
560abf917cdSFrederic Weisbeckerconfig VIRT_CPU_ACCOUNTING
561abf917cdSFrederic Weisbecker	bool
562abf917cdSFrederic Weisbecker
563fdf9c356SFrederic Weisbeckerchoice
564fdf9c356SFrederic Weisbecker	prompt "Cputime accounting"
56502382affSNicholas Piggin	default TICK_CPU_ACCOUNTING
566fdf9c356SFrederic Weisbecker
567fdf9c356SFrederic Weisbecker# Kind of a stub config for the pure tick based cputime accounting
568fdf9c356SFrederic Weisbeckerconfig TICK_CPU_ACCOUNTING
569fdf9c356SFrederic Weisbecker	bool "Simple tick based cputime accounting"
570c58b0df1SFrederic Weisbecker	depends on !S390 && !NO_HZ_FULL
571fdf9c356SFrederic Weisbecker	help
572fdf9c356SFrederic Weisbecker	  This is the basic tick based cputime accounting that maintains
573fdf9c356SFrederic Weisbecker	  statistics about user, system and idle time spent on per jiffies
574fdf9c356SFrederic Weisbecker	  granularity.
575fdf9c356SFrederic Weisbecker
576fdf9c356SFrederic Weisbecker	  If unsure, say Y.
577fdf9c356SFrederic Weisbecker
578abf917cdSFrederic Weisbeckerconfig VIRT_CPU_ACCOUNTING_NATIVE
579391dc69cSFrederic Weisbecker	bool "Deterministic task and CPU time accounting"
580c58b0df1SFrederic Weisbecker	depends on HAVE_VIRT_CPU_ACCOUNTING && !NO_HZ_FULL
581abf917cdSFrederic Weisbecker	select VIRT_CPU_ACCOUNTING
582391dc69cSFrederic Weisbecker	help
583391dc69cSFrederic Weisbecker	  Select this option to enable more accurate task and CPU time
584391dc69cSFrederic Weisbecker	  accounting.  This is done by reading a CPU counter on each
585391dc69cSFrederic Weisbecker	  kernel entry and exit and on transitions within the kernel
586391dc69cSFrederic Weisbecker	  between system, softirq and hardirq state, so there is a
587391dc69cSFrederic Weisbecker	  small performance impact.  In the case of s390 or IBM POWER > 5,
588391dc69cSFrederic Weisbecker	  this also enables accounting of stolen time on logically-partitioned
589391dc69cSFrederic Weisbecker	  systems.
590391dc69cSFrederic Weisbecker
591abf917cdSFrederic Weisbeckerconfig VIRT_CPU_ACCOUNTING_GEN
592abf917cdSFrederic Weisbecker	bool "Full dynticks CPU time accounting"
59324a9c541SFrederic Weisbecker	depends on HAVE_CONTEXT_TRACKING_USER
594554b0004SKevin Hilman	depends on HAVE_VIRT_CPU_ACCOUNTING_GEN
595041a1574SArnd Bergmann	depends on GENERIC_CLOCKEVENTS
596abf917cdSFrederic Weisbecker	select VIRT_CPU_ACCOUNTING
59724a9c541SFrederic Weisbecker	select CONTEXT_TRACKING_USER
598abf917cdSFrederic Weisbecker	help
599abf917cdSFrederic Weisbecker	  Select this option to enable task and CPU time accounting on full
600abf917cdSFrederic Weisbecker	  dynticks systems. This accounting is implemented by watching every
601abf917cdSFrederic Weisbecker	  kernel-user boundaries using the context tracking subsystem.
602abf917cdSFrederic Weisbecker	  The accounting is thus performed at the expense of some significant
603abf917cdSFrederic Weisbecker	  overhead.
604abf917cdSFrederic Weisbecker
605abf917cdSFrederic Weisbecker	  For now this is only useful if you are working on the full
606abf917cdSFrederic Weisbecker	  dynticks subsystem development.
607abf917cdSFrederic Weisbecker
608abf917cdSFrederic Weisbecker	  If unsure, say N.
609abf917cdSFrederic Weisbecker
610b58c3584SRik van Rielendchoice
611b58c3584SRik van Riel
612fdf9c356SFrederic Weisbeckerconfig IRQ_TIME_ACCOUNTING
613fdf9c356SFrederic Weisbecker	bool "Fine granularity task level IRQ time accounting"
614b58c3584SRik van Riel	depends on HAVE_IRQ_TIME_ACCOUNTING && !VIRT_CPU_ACCOUNTING_NATIVE
615fdf9c356SFrederic Weisbecker	help
616fdf9c356SFrederic Weisbecker	  Select this option to enable fine granularity task irq time
617fdf9c356SFrederic Weisbecker	  accounting. This is done by reading a timestamp on each
618fdf9c356SFrederic Weisbecker	  transitions between softirq and hardirq state, so there can be a
619fdf9c356SFrederic Weisbecker	  small performance impact.
620fdf9c356SFrederic Weisbecker
621fdf9c356SFrederic Weisbecker	  If in doubt, say N here.
622fdf9c356SFrederic Weisbecker
62311d4afd4SVincent Guittotconfig HAVE_SCHED_AVG_IRQ
62411d4afd4SVincent Guittot	def_bool y
62511d4afd4SVincent Guittot	depends on IRQ_TIME_ACCOUNTING || PARAVIRT_TIME_ACCOUNTING
62611d4afd4SVincent Guittot	depends on SMP
62711d4afd4SVincent Guittot
628d4dbc991SVincent Guittotconfig SCHED_HW_PRESSURE
62998eb401dSValentin Schneider	bool
630fcd7c9c3SValentin Schneider	default y if ARM && ARM_CPU_TOPOLOGY
631fcd7c9c3SValentin Schneider	default y if ARM64
63276504793SThara Gopinath	depends on SMP
63398eb401dSValentin Schneider	depends on CPU_FREQ_THERMAL
63498eb401dSValentin Schneider	help
635d4dbc991SVincent Guittot	  Select this option to enable HW pressure accounting in the
636d4dbc991SVincent Guittot	  scheduler. HW pressure is the value conveyed to the scheduler
63798eb401dSValentin Schneider	  that reflects the reduction in CPU compute capacity resulted from
638d4dbc991SVincent Guittot	  HW throttling. HW throttling occurs when the performance of
639d4dbc991SVincent Guittot	  a CPU is capped due to high operating temperatures as an example.
64098eb401dSValentin Schneider
64198eb401dSValentin Schneider	  If selected, the scheduler will be able to balance tasks accordingly,
64298eb401dSValentin Schneider	  i.e. put less load on throttled CPUs than on non/less throttled ones.
64398eb401dSValentin Schneider
64498eb401dSValentin Schneider	  This requires the architecture to implement
645d4dbc991SVincent Guittot	  arch_update_hw_pressure() and arch_scale_thermal_pressure().
64676504793SThara Gopinath
647391dc69cSFrederic Weisbeckerconfig BSD_PROCESS_ACCT
64846329a9dSJeff Layton	bool "BSD Process Accounting (DEPRECATED)"
6492813893fSIulia Manda	depends on MULTIUSER
65046329a9dSJeff Layton	default n
651391dc69cSFrederic Weisbecker	help
652391dc69cSFrederic Weisbecker	  If you say Y here, a user level program will be able to instruct the
653391dc69cSFrederic Weisbecker	  kernel (via a special system call) to write process accounting
654391dc69cSFrederic Weisbecker	  information to a file: whenever a process exits, information about
655391dc69cSFrederic Weisbecker	  that process will be appended to the file by the kernel.  The
656391dc69cSFrederic Weisbecker	  information includes things such as creation time, owning user,
657391dc69cSFrederic Weisbecker	  command name, memory usage, controlling terminal etc. (the complete
658391dc69cSFrederic Weisbecker	  list is in the struct acct in <file:include/linux/acct.h>).  It is
659391dc69cSFrederic Weisbecker	  up to the user level program to do useful things with this
66046329a9dSJeff Layton	  information.  This mechanism is antiquated and has significant
66146329a9dSJeff Layton	  scalability issues.  You probably want to use eBPF instead.  Say
66246329a9dSJeff Layton	  N unless you really need this.
663391dc69cSFrederic Weisbecker
664391dc69cSFrederic Weisbeckerconfig BSD_PROCESS_ACCT_V3
665391dc69cSFrederic Weisbecker	bool "BSD Process Accounting version 3 file format"
666391dc69cSFrederic Weisbecker	depends on BSD_PROCESS_ACCT
667391dc69cSFrederic Weisbecker	default n
668391dc69cSFrederic Weisbecker	help
669391dc69cSFrederic Weisbecker	  If you say Y here, the process accounting information is written
670391dc69cSFrederic Weisbecker	  in a new file format that also logs the process IDs of each
6713903bf94SRandy Dunlap	  process and its parent. Note that this file format is incompatible
672391dc69cSFrederic Weisbecker	  with previous v0/v1/v2 file formats, so you will need updated tools
673391dc69cSFrederic Weisbecker	  for processing it. A preliminary version of these tools is available
674391dc69cSFrederic Weisbecker	  at <http://www.gnu.org/software/acct/>.
675391dc69cSFrederic Weisbecker
676391dc69cSFrederic Weisbeckerconfig TASKSTATS
67719c92399SKees Cook	bool "Export task/process statistics through netlink"
678391dc69cSFrederic Weisbecker	depends on NET
6792813893fSIulia Manda	depends on MULTIUSER
680391dc69cSFrederic Weisbecker	default n
681391dc69cSFrederic Weisbecker	help
682391dc69cSFrederic Weisbecker	  Export selected statistics for tasks/processes through the
683391dc69cSFrederic Weisbecker	  generic netlink interface. Unlike BSD process accounting, the
684391dc69cSFrederic Weisbecker	  statistics are available during the lifetime of tasks/processes as
685391dc69cSFrederic Weisbecker	  responses to commands. Like BSD accounting, they are sent to user
686391dc69cSFrederic Weisbecker	  space on task exit.
687391dc69cSFrederic Weisbecker
688391dc69cSFrederic Weisbecker	  Say N if unsure.
689391dc69cSFrederic Weisbecker
690391dc69cSFrederic Weisbeckerconfig TASK_DELAY_ACCT
69119c92399SKees Cook	bool "Enable per-task delay accounting"
692391dc69cSFrederic Weisbecker	depends on TASKSTATS
693f6db8347SNaveen N. Rao	select SCHED_INFO
694391dc69cSFrederic Weisbecker	help
695391dc69cSFrederic Weisbecker	  Collect information on time spent by a task waiting for system
696391dc69cSFrederic Weisbecker	  resources like cpu, synchronous block I/O completion and swapping
697391dc69cSFrederic Weisbecker	  in pages. Such statistics can help in setting a task's priorities
698391dc69cSFrederic Weisbecker	  relative to other tasks for cpu, io, rss limits etc.
699391dc69cSFrederic Weisbecker
700391dc69cSFrederic Weisbecker	  Say N if unsure.
701391dc69cSFrederic Weisbecker
702391dc69cSFrederic Weisbeckerconfig TASK_XACCT
70319c92399SKees Cook	bool "Enable extended accounting over taskstats"
704391dc69cSFrederic Weisbecker	depends on TASKSTATS
705391dc69cSFrederic Weisbecker	help
706391dc69cSFrederic Weisbecker	  Collect extended task accounting data and send the data
707391dc69cSFrederic Weisbecker	  to userland for processing over the taskstats interface.
708391dc69cSFrederic Weisbecker
709391dc69cSFrederic Weisbecker	  Say N if unsure.
710391dc69cSFrederic Weisbecker
711391dc69cSFrederic Weisbeckerconfig TASK_IO_ACCOUNTING
71219c92399SKees Cook	bool "Enable per-task storage I/O accounting"
713391dc69cSFrederic Weisbecker	depends on TASK_XACCT
714391dc69cSFrederic Weisbecker	help
715391dc69cSFrederic Weisbecker	  Collect information on the number of bytes of storage I/O which this
716391dc69cSFrederic Weisbecker	  task has caused.
717391dc69cSFrederic Weisbecker
718391dc69cSFrederic Weisbecker	  Say N if unsure.
719391dc69cSFrederic Weisbecker
720eb414681SJohannes Weinerconfig PSI
721eb414681SJohannes Weiner	bool "Pressure stall information tracking"
72298dfdd9eSRandy Dunlap	select KERNFS
723eb414681SJohannes Weiner	help
724eb414681SJohannes Weiner	  Collect metrics that indicate how overcommitted the CPU, memory,
725eb414681SJohannes Weiner	  and IO capacity are in the system.
726eb414681SJohannes Weiner
727eb414681SJohannes Weiner	  If you say Y here, the kernel will create /proc/pressure/ with the
728eb414681SJohannes Weiner	  pressure statistics files cpu, memory, and io. These will indicate
729eb414681SJohannes Weiner	  the share of walltime in which some or all tasks in the system are
730eb414681SJohannes Weiner	  delayed due to contention of the respective resource.
731eb414681SJohannes Weiner
7322ce7135aSJohannes Weiner	  In kernels with cgroup support, cgroups (cgroup2 only) will
7332ce7135aSJohannes Weiner	  have cpu.pressure, memory.pressure, and io.pressure files,
7342ce7135aSJohannes Weiner	  which aggregate pressure stalls for the grouped tasks only.
7352ce7135aSJohannes Weiner
736c3123552SMauro Carvalho Chehab	  For more details see Documentation/accounting/psi.rst.
737eb414681SJohannes Weiner
738eb414681SJohannes Weiner	  Say N if unsure.
739eb414681SJohannes Weiner
740e0c27447SJohannes Weinerconfig PSI_DEFAULT_DISABLED
741e0c27447SJohannes Weiner	bool "Require boot parameter to enable pressure stall information tracking"
742e0c27447SJohannes Weiner	default n
743e0c27447SJohannes Weiner	depends on PSI
744e0c27447SJohannes Weiner	help
745e0c27447SJohannes Weiner	  If set, pressure stall information tracking will be disabled
746428a1cb4SBaruch Siach	  per default but can be enabled through passing psi=1 on the
747428a1cb4SBaruch Siach	  kernel commandline during boot.
748e0c27447SJohannes Weiner
7497b2489d3SJohannes Weiner	  This feature adds some code to the task wakeup and sleep
7507b2489d3SJohannes Weiner	  paths of the scheduler. The overhead is too low to affect
7517b2489d3SJohannes Weiner	  common scheduling-intense workloads in practice (such as
7527b2489d3SJohannes Weiner	  webservers, memcache), but it does show up in artificial
7537b2489d3SJohannes Weiner	  scheduler stress tests, such as hackbench.
7547b2489d3SJohannes Weiner
7557b2489d3SJohannes Weiner	  If you are paranoid and not sure what the kernel will be
7567b2489d3SJohannes Weiner	  used for, say Y.
7577b2489d3SJohannes Weiner
7587b2489d3SJohannes Weiner	  Say N if unsure.
7597b2489d3SJohannes Weiner
760391dc69cSFrederic Weisbeckerendmenu # "CPU/Task time and stats accounting"
761391dc69cSFrederic Weisbecker
7625c4991e2SFrederic Weisbeckerconfig CPU_ISOLATION
7635c4991e2SFrederic Weisbecker	bool "CPU isolation"
76497577684SOleg Nesterov	depends on SMP
7652c43838cSFrederic Weisbecker	default y
7665c4991e2SFrederic Weisbecker	help
7675c4991e2SFrederic Weisbecker	  Make sure that CPUs running critical tasks are not disturbed by
7685c4991e2SFrederic Weisbecker	  any source of "noise" such as unbound workqueues, timers, kthreads...
7692c43838cSFrederic Weisbecker	  Unbound jobs get offloaded to housekeeping CPUs. This is driven by
7702c43838cSFrederic Weisbecker	  the "isolcpus=" boot parameter.
7712c43838cSFrederic Weisbecker
7722c43838cSFrederic Weisbecker	  Say Y if unsure.
7735c4991e2SFrederic Weisbecker
7740af92d46SPaul E. McKenneysource "kernel/rcu/Kconfig"
775c903ff83SMike Travis
7761da177e4SLinus Torvaldsconfig IKCONFIG
777f2443ab6SRoss Biro	tristate "Kernel .config support"
778a7f7f624SMasahiro Yamada	help
7791da177e4SLinus Torvalds	  This option enables the complete Linux kernel ".config" file
7801da177e4SLinus Torvalds	  contents to be saved in the kernel. It provides documentation
7811da177e4SLinus Torvalds	  of which kernel options are used in a running kernel or in an
7821da177e4SLinus Torvalds	  on-disk kernel.  This information can be extracted from the kernel
7831da177e4SLinus Torvalds	  image file with the script scripts/extract-ikconfig and used as
7841da177e4SLinus Torvalds	  input to rebuild the current kernel or to build another kernel.
7851da177e4SLinus Torvalds	  It can also be extracted from a running kernel by reading
7861da177e4SLinus Torvalds	  /proc/config.gz if enabled (below).
7871da177e4SLinus Torvalds
7881da177e4SLinus Torvaldsconfig IKCONFIG_PROC
7891da177e4SLinus Torvalds	bool "Enable access to .config through /proc/config.gz"
7901da177e4SLinus Torvalds	depends on IKCONFIG && PROC_FS
791a7f7f624SMasahiro Yamada	help
7921da177e4SLinus Torvalds	  This option enables access to the kernel configuration file
7931da177e4SLinus Torvalds	  through /proc/config.gz.
7941da177e4SLinus Torvalds
795f7b101d3SJoel Fernandes (Google)config IKHEADERS
796f7b101d3SJoel Fernandes (Google)	tristate "Enable kernel headers through /sys/kernel/kheaders.tar.xz"
797f7b101d3SJoel Fernandes (Google)	depends on SYSFS
79843d8ce9dSJoel Fernandes (Google)	help
799f7b101d3SJoel Fernandes (Google)	  This option enables access to the in-kernel headers that are generated during
800f7b101d3SJoel Fernandes (Google)	  the build process. These can be used to build eBPF tracing programs,
801f7b101d3SJoel Fernandes (Google)	  or similar programs.  If you build the headers as a module, a module called
802f7b101d3SJoel Fernandes (Google)	  kheaders.ko is built which can be loaded on-demand to get access to headers.
80343d8ce9dSJoel Fernandes (Google)
804794543a2SAlistair John Strachanconfig LOG_BUF_SHIFT
805794543a2SAlistair John Strachan	int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
8061c4b5ecbSChristoph Hellwig	range 12 25
807f17a32e9SAdrian Bunk	default 17
808361e9dfbSJosh Triplett	depends on PRINTK
809794543a2SAlistair John Strachan	help
81023b2899fSLuis R. Rodriguez	  Select the minimal kernel log buffer size as a power of 2.
81123b2899fSLuis R. Rodriguez	  The final size is affected by LOG_CPU_MAX_BUF_SHIFT config
81223b2899fSLuis R. Rodriguez	  parameter, see below. Any higher size also might be forced
81323b2899fSLuis R. Rodriguez	  by "log_buf_len" boot parameter.
81423b2899fSLuis R. Rodriguez
815f17a32e9SAdrian Bunk	  Examples:
816f17a32e9SAdrian Bunk		     17 => 128 KB
817f17a32e9SAdrian Bunk		     16 => 64 KB
818f17a32e9SAdrian Bunk		     15 => 32 KB
819f17a32e9SAdrian Bunk		     14 => 16 KB
820794543a2SAlistair John Strachan		     13 =>  8 KB
821794543a2SAlistair John Strachan		     12 =>  4 KB
822794543a2SAlistair John Strachan
82323b2899fSLuis R. Rodriguezconfig LOG_CPU_MAX_BUF_SHIFT
82423b2899fSLuis R. Rodriguez	int "CPU kernel log buffer size contribution (13 => 8 KB, 17 => 128KB)"
8252240a31dSGeert Uytterhoeven	depends on SMP
82623b2899fSLuis R. Rodriguez	range 0 21
82723b2899fSLuis R. Rodriguez	default 0 if BASE_SMALL
828320bf431SYoann Congal	default 12
829361e9dfbSJosh Triplett	depends on PRINTK
83023b2899fSLuis R. Rodriguez	help
83123b2899fSLuis R. Rodriguez	  This option allows to increase the default ring buffer size
83223b2899fSLuis R. Rodriguez	  according to the number of CPUs. The value defines the contribution
83323b2899fSLuis R. Rodriguez	  of each CPU as a power of 2. The used space is typically only few
83423b2899fSLuis R. Rodriguez	  lines however it might be much more when problems are reported,
83523b2899fSLuis R. Rodriguez	  e.g. backtraces.
83623b2899fSLuis R. Rodriguez
83723b2899fSLuis R. Rodriguez	  The increased size means that a new buffer has to be allocated and
83823b2899fSLuis R. Rodriguez	  the original static one is unused. It makes sense only on systems
83923b2899fSLuis R. Rodriguez	  with more CPUs. Therefore this value is used only when the sum of
84023b2899fSLuis R. Rodriguez	  contributions is greater than the half of the default kernel ring
84123b2899fSLuis R. Rodriguez	  buffer as defined by LOG_BUF_SHIFT. The default values are set
8420f7636e1SPaul Menzel	  so that more than 16 CPUs are needed to trigger the allocation.
84323b2899fSLuis R. Rodriguez
84423b2899fSLuis R. Rodriguez	  Also this option is ignored when "log_buf_len" kernel parameter is
84523b2899fSLuis R. Rodriguez	  used as it forces an exact (power of two) size of the ring buffer.
84623b2899fSLuis R. Rodriguez
84723b2899fSLuis R. Rodriguez	  The number of possible CPUs is used for this computation ignoring
8485e0d8d59SGeert Uytterhoeven	  hotplugging making the computation optimal for the worst case
8495e0d8d59SGeert Uytterhoeven	  scenario while allowing a simple algorithm to be used from bootup.
85023b2899fSLuis R. Rodriguez
85123b2899fSLuis R. Rodriguez	  Examples shift values and their meaning:
85223b2899fSLuis R. Rodriguez		     17 => 128 KB for each CPU
85323b2899fSLuis R. Rodriguez		     16 =>  64 KB for each CPU
85423b2899fSLuis R. Rodriguez		     15 =>  32 KB for each CPU
85523b2899fSLuis R. Rodriguez		     14 =>  16 KB for each CPU
85623b2899fSLuis R. Rodriguez		     13 =>   8 KB for each CPU
85723b2899fSLuis R. Rodriguez		     12 =>   4 KB for each CPU
85823b2899fSLuis R. Rodriguez
85933701557SChris Downconfig PRINTK_INDEX
86033701557SChris Down	bool "Printk indexing debugfs interface"
86133701557SChris Down	depends on PRINTK && DEBUG_FS
86233701557SChris Down	help
86333701557SChris Down	  Add support for indexing of all printk formats known at compile time
86433701557SChris Down	  at <debugfs>/printk/index/<module>.
86533701557SChris Down
86633701557SChris Down	  This can be used as part of maintaining daemons which monitor
86733701557SChris Down	  /dev/kmsg, as it permits auditing the printk formats present in a
86833701557SChris Down	  kernel, allowing detection of cases where monitored printks are
86933701557SChris Down	  changed or no longer present.
87033701557SChris Down
87133701557SChris Down	  There is no additional runtime cost to printk with this enabled.
87233701557SChris Down
8735cdc38f9SKAMEZAWA Hiroyuki#
8745cdc38f9SKAMEZAWA Hiroyuki# Architectures with an unreliable sched_clock() should select this:
8755cdc38f9SKAMEZAWA Hiroyuki#
8765cdc38f9SKAMEZAWA Hiroyukiconfig HAVE_UNSTABLE_SCHED_CLOCK
8775cdc38f9SKAMEZAWA Hiroyuki	bool
8785cdc38f9SKAMEZAWA Hiroyuki
87938ff87f7SStephen Boydconfig GENERIC_SCHED_CLOCK
88038ff87f7SStephen Boyd	bool
88138ff87f7SStephen Boyd
88269842cbaSPatrick Bellasimenu "Scheduler features"
88369842cbaSPatrick Bellasi
88469842cbaSPatrick Bellasiconfig UCLAMP_TASK
88569842cbaSPatrick Bellasi	bool "Enable utilization clamping for RT/FAIR tasks"
88669842cbaSPatrick Bellasi	depends on CPU_FREQ_GOV_SCHEDUTIL
88769842cbaSPatrick Bellasi	help
88869842cbaSPatrick Bellasi	  This feature enables the scheduler to track the clamped utilization
88969842cbaSPatrick Bellasi	  of each CPU based on RUNNABLE tasks scheduled on that CPU.
89069842cbaSPatrick Bellasi
89169842cbaSPatrick Bellasi	  With this option, the user can specify the min and max CPU
89269842cbaSPatrick Bellasi	  utilization allowed for RUNNABLE tasks. The max utilization defines
89369842cbaSPatrick Bellasi	  the maximum frequency a task should use while the min utilization
89469842cbaSPatrick Bellasi	  defines the minimum frequency it should use.
89569842cbaSPatrick Bellasi
89669842cbaSPatrick Bellasi	  Both min and max utilization clamp values are hints to the scheduler,
89769842cbaSPatrick Bellasi	  aiming at improving its frequency selection policy, but they do not
89869842cbaSPatrick Bellasi	  enforce or grant any specific bandwidth for tasks.
89969842cbaSPatrick Bellasi
90069842cbaSPatrick Bellasi	  If in doubt, say N.
90169842cbaSPatrick Bellasi
90269842cbaSPatrick Bellasiconfig UCLAMP_BUCKETS_COUNT
90369842cbaSPatrick Bellasi	int "Number of supported utilization clamp buckets"
90469842cbaSPatrick Bellasi	range 5 20
90569842cbaSPatrick Bellasi	default 5
90669842cbaSPatrick Bellasi	depends on UCLAMP_TASK
90769842cbaSPatrick Bellasi	help
90869842cbaSPatrick Bellasi	  Defines the number of clamp buckets to use. The range of each bucket
90969842cbaSPatrick Bellasi	  will be SCHED_CAPACITY_SCALE/UCLAMP_BUCKETS_COUNT. The higher the
91069842cbaSPatrick Bellasi	  number of clamp buckets the finer their granularity and the higher
91169842cbaSPatrick Bellasi	  the precision of clamping aggregation and tracking at run-time.
91269842cbaSPatrick Bellasi
91369842cbaSPatrick Bellasi	  For example, with the minimum configuration value we will have 5
91469842cbaSPatrick Bellasi	  clamp buckets tracking 20% utilization each. A 25% boosted tasks will
91569842cbaSPatrick Bellasi	  be refcounted in the [20..39]% bucket and will set the bucket clamp
91669842cbaSPatrick Bellasi	  effective value to 25%.
91769842cbaSPatrick Bellasi	  If a second 30% boosted task should be co-scheduled on the same CPU,
91869842cbaSPatrick Bellasi	  that task will be refcounted in the same bucket of the first task and
91969842cbaSPatrick Bellasi	  it will boost the bucket clamp effective value to 30%.
92069842cbaSPatrick Bellasi	  The clamp effective value of a bucket is reset to its nominal value
92169842cbaSPatrick Bellasi	  (20% in the example above) when there are no more tasks refcounted in
92269842cbaSPatrick Bellasi	  that bucket.
92369842cbaSPatrick Bellasi
92469842cbaSPatrick Bellasi	  An additional boost/capping margin can be added to some tasks. In the
92569842cbaSPatrick Bellasi	  example above the 25% task will be boosted to 30% until it exits the
92669842cbaSPatrick Bellasi	  CPU. If that should be considered not acceptable on certain systems,
92769842cbaSPatrick Bellasi	  it's always possible to reduce the margin by increasing the number of
92869842cbaSPatrick Bellasi	  clamp buckets to trade off used memory for run-time tracking
92969842cbaSPatrick Bellasi	  precision.
93069842cbaSPatrick Bellasi
93169842cbaSPatrick Bellasi	  If in doubt, use the default value.
93269842cbaSPatrick Bellasi
93325c411fcSJohn Stultzconfig SCHED_PROXY_EXEC
93425c411fcSJohn Stultz	bool "Proxy Execution"
93525c411fcSJohn Stultz	# Avoid some build failures w/ PREEMPT_RT until it can be fixed
93625c411fcSJohn Stultz	depends on !PREEMPT_RT
93725c411fcSJohn Stultz	# Need to investigate how to inform sched_ext of split contexts
93825c411fcSJohn Stultz	depends on !SCHED_CLASS_EXT
93925c411fcSJohn Stultz	# Not particularly useful until we get to multi-rq proxying
94025c411fcSJohn Stultz	depends on EXPERT
94125c411fcSJohn Stultz	help
94225c411fcSJohn Stultz	  This option enables proxy execution, a mechanism for mutex-owning
94325c411fcSJohn Stultz	  tasks to inherit the scheduling context of higher priority waiters.
94425c411fcSJohn Stultz
94569842cbaSPatrick Bellasiendmenu
94669842cbaSPatrick Bellasi
947be3a7284SAndrea Arcangeli#
948be3a7284SAndrea Arcangeli# For architectures that want to enable the support for NUMA-affine scheduler
949be3a7284SAndrea Arcangeli# balancing logic:
950be3a7284SAndrea Arcangeli#
951be3a7284SAndrea Arcangeliconfig ARCH_SUPPORTS_NUMA_BALANCING
952be3a7284SAndrea Arcangeli	bool
953be3a7284SAndrea Arcangeli
954be5e610cSPeter Zijlstra#
95572b252aeSMel Gorman# For architectures that prefer to flush all TLBs after a number of pages
95672b252aeSMel Gorman# are unmapped instead of sending one IPI per page to flush. The architecture
95772b252aeSMel Gorman# must provide guarantees on what happens if a clean TLB cache entry is
95872b252aeSMel Gorman# written after the unmap. Details are in mm/rmap.c near the check for
95972b252aeSMel Gorman# should_defer_flush. The architecture should also consider if the full flush
96072b252aeSMel Gorman# and the refill costs are offset by the savings of sending fewer IPIs.
96172b252aeSMel Gormanconfig ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
96272b252aeSMel Gorman	bool
96372b252aeSMel Gorman
964c12d3362SArd Biesheuvelconfig CC_HAS_INT128
9653a7c7331SMasahiro Yamada	def_bool !$(cc-option,$(m64-flag) -D__SIZEOF_INT128__=0) && 64BIT
966c12d3362SArd Biesheuvel
967dee2b702SGustavo A. R. Silvaconfig CC_IMPLICIT_FALLTHROUGH
968dee2b702SGustavo A. R. Silva	string
969158ea2d2SGustavo A. R. Silva	default "-Wimplicit-fallthrough=5" if CC_IS_GCC && $(cc-option,-Wimplicit-fallthrough=5)
970dee2b702SGustavo A. R. Silva	default "-Wimplicit-fallthrough" if CC_IS_CLANG && $(cc-option,-Wunreachable-code-fallthrough)
971dee2b702SGustavo A. R. Silva
9720d3fccf6SNathan Chancellorconfig CC_MS_EXTENSIONS
9730d3fccf6SNathan Chancellor	string
9740d3fccf6SNathan Chancellor	default "-fms-anonymous-structs" if $(cc-option,-fms-anonymous-structs)
9750d3fccf6SNathan Chancellor	default "-fms-extensions"
9760d3fccf6SNathan Chancellor
9773e00f580SKees Cook# Currently, disable gcc-10+ array-bounds globally.
9780da6e5fdSLinus Torvalds# It's still broken in gcc-13, so no upper bound yet.
9793e00f580SKees Cookconfig GCC10_NO_ARRAY_BOUNDS
9805a41237aSLinus Torvalds	def_bool y
9815a41237aSLinus Torvalds
982f0be87c4SLinus Torvaldsconfig CC_NO_ARRAY_BOUNDS
983f0be87c4SLinus Torvalds	bool
9848e5bd4eaSYury Norov	default y if CC_IS_GCC && GCC_VERSION >= 90000 && GCC10_NO_ARRAY_BOUNDS
985f0be87c4SLinus Torvalds
98602153319SLinus Torvalds# Currently, disable -Wstringop-overflow for GCC globally.
98702153319SLinus Torvaldsconfig GCC_NO_STRINGOP_OVERFLOW
988a5e0ace0SGustavo A. R. Silva	def_bool y
989a5e0ace0SGustavo A. R. Silva
990a5e0ace0SGustavo A. R. Silvaconfig CC_NO_STRINGOP_OVERFLOW
991a5e0ace0SGustavo A. R. Silva	bool
99202153319SLinus Torvalds	default y if CC_IS_GCC && GCC_NO_STRINGOP_OVERFLOW
993a5e0ace0SGustavo A. R. Silva
994a5e0ace0SGustavo A. R. Silvaconfig CC_STRINGOP_OVERFLOW
995a5e0ace0SGustavo A. R. Silva	bool
996a5e0ace0SGustavo A. R. Silva	default y if CC_IS_GCC && !CC_NO_STRINGOP_OVERFLOW
997a5e0ace0SGustavo A. R. Silva
99872b252aeSMel Gorman#
999be5e610cSPeter Zijlstra# For architectures that know their GCC __int128 support is sound
1000be5e610cSPeter Zijlstra#
1001be5e610cSPeter Zijlstraconfig ARCH_SUPPORTS_INT128
1002be5e610cSPeter Zijlstra	bool
1003be5e610cSPeter Zijlstra
1004be3a7284SAndrea Arcangeli# For architectures that (ab)use NUMA to represent different memory regions
1005be3a7284SAndrea Arcangeli# all cpu-local but of different latencies, such as SuperH.
1006be3a7284SAndrea Arcangeli#
1007be3a7284SAndrea Arcangeliconfig ARCH_WANT_NUMA_VARIABLE_LOCALITY
1008be3a7284SAndrea Arcangeli	bool
1009be3a7284SAndrea Arcangeli
1010be3a7284SAndrea Arcangeliconfig NUMA_BALANCING
1011be3a7284SAndrea Arcangeli	bool "Memory placement aware NUMA scheduler"
1012be3a7284SAndrea Arcangeli	depends on ARCH_SUPPORTS_NUMA_BALANCING
1013be3a7284SAndrea Arcangeli	depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
10146ebf98d7SDavid Hildenbrand (Arm)	depends on SMP && NUMA_MIGRATION && !PREEMPT_RT
1015be3a7284SAndrea Arcangeli	help
1016be3a7284SAndrea Arcangeli	  This option adds support for automatic NUMA aware memory/task placement.
1017be3a7284SAndrea Arcangeli	  The mechanism is quite primitive and is based on migrating memory when
10186d56a410SPaul Gortmaker	  it has references to the node the task is running on.
1019be3a7284SAndrea Arcangeli
1020be3a7284SAndrea Arcangeli	  This system will be inactive on UMA systems.
1021be3a7284SAndrea Arcangeli
1022df0d9847SPeter Zijlstra (Intel)config SCHED_CACHE
1023df0d9847SPeter Zijlstra (Intel)	bool "Cache aware load balance"
1024df0d9847SPeter Zijlstra (Intel)	default y
1025df0d9847SPeter Zijlstra (Intel)	depends on SMP
1026df0d9847SPeter Zijlstra (Intel)	help
1027df0d9847SPeter Zijlstra (Intel)	  When enabled, the scheduler will attempt to aggregate tasks from
1028df0d9847SPeter Zijlstra (Intel)	  the same process onto a single Last Level Cache (LLC) domain when
1029df0d9847SPeter Zijlstra (Intel)	  possible. This improves cache locality by keeping tasks that share
1030df0d9847SPeter Zijlstra (Intel)	  resources within the same cache domain, reducing cache misses and
1031df0d9847SPeter Zijlstra (Intel)	  lowering data access latency.
1032df0d9847SPeter Zijlstra (Intel)
10336f7c97e8SAneesh Kumar K.Vconfig NUMA_BALANCING_DEFAULT_ENABLED
10346f7c97e8SAneesh Kumar K.V	bool "Automatically enable NUMA aware memory/task placement"
10356f7c97e8SAneesh Kumar K.V	default y
10366f7c97e8SAneesh Kumar K.V	depends on NUMA_BALANCING
10376f7c97e8SAneesh Kumar K.V	help
10386f7c97e8SAneesh Kumar K.V	  If set, automatic NUMA balancing will be enabled if running on a NUMA
10396f7c97e8SAneesh Kumar K.V	  machine.
10406f7c97e8SAneesh Kumar K.V
104121c690a3SSuren Baghdasaryanconfig SLAB_OBJ_EXT
104221c690a3SSuren Baghdasaryan	bool
104321c690a3SSuren Baghdasaryan
104423964d2dSLi Zefanmenuconfig CGROUPS
10456341e62bSChristoph Jaeger	bool "Control Group support"
10462bd59d48STejun Heo	select KERNFS
1047ddbcc7e8SPaul Menage	help
104823964d2dSLi Zefan	  This option adds support for grouping sets of processes together, for
10495cdc38f9SKAMEZAWA Hiroyuki	  use with process control subsystems such as Cpusets, CFS, memory
10505cdc38f9SKAMEZAWA Hiroyuki	  controls or device isolation.
10515cdc38f9SKAMEZAWA Hiroyuki	  See
1052d6a3b247SMauro Carvalho Chehab		- Documentation/scheduler/sched-design-CFS.rst	(CFS)
1053da82c92fSMauro Carvalho Chehab		- Documentation/admin-guide/cgroup-v1/ (features for grouping, isolation
105445ce80fbSLi Zefan					  and resource control)
1055ddbcc7e8SPaul Menage
1056ddbcc7e8SPaul Menage	  Say N if unsure.
1057ddbcc7e8SPaul Menage
105823964d2dSLi Zefanif CGROUPS
105923964d2dSLi Zefan
10603e32cb2eSJohannes Weinerconfig PAGE_COUNTER
10613e32cb2eSJohannes Weiner	bool
10623e32cb2eSJohannes Weiner
10636a010a49STejun Heoconfig CGROUP_FAVOR_DYNMODS
10646a010a49STejun Heo	bool "Favor dynamic modification latency reduction by default"
10656a010a49STejun Heo	help
10666a010a49STejun Heo	  This option enables the "favordynmods" mount option by default
10676a010a49STejun Heo	  which reduces the latencies of dynamic cgroup modifications such
10686a010a49STejun Heo	  as task migrations and controller on/offs at the cost of making
10696a010a49STejun Heo	  hot path operations such as forks and exits more expensive.
10706a010a49STejun Heo
10716a010a49STejun Heo	  Say N if unsure.
10726a010a49STejun Heo
1073c255a458SAndrew Mortonconfig MEMCG
1074a0166ec4SJohannes Weiner	bool "Memory controller"
10753e32cb2eSJohannes Weiner	select PAGE_COUNTER
107679bd9814STejun Heo	select EVENTFD
107721c690a3SSuren Baghdasaryan	select SLAB_OBJ_EXT
1078fdc5001bSKirill A. Shutemov	select VM_EVENT_COUNTERS
107900f0b825SBalbir Singh	help
1080a0166ec4SJohannes Weiner	  Provides control over the memory footprint of tasks in a cgroup.
108100f0b825SBalbir Singh
108225352d2fSShakeel Buttconfig MEMCG_NMI_UNSAFE
108325352d2fSShakeel Butt	bool
108425352d2fSShakeel Butt	depends on MEMCG
108525352d2fSShakeel Butt	depends on HAVE_NMI
108625352d2fSShakeel Butt	depends on !ARCH_HAS_NMI_SAFE_THIS_CPU_OPS && !ARCH_HAVE_NMI_SAFE_CMPXCHG
108725352d2fSShakeel Butt	default y
108825352d2fSShakeel Butt
1089940b01fcSShakeel Buttconfig MEMCG_NMI_SAFETY_REQUIRES_ATOMIC
1090940b01fcSShakeel Butt	bool
1091940b01fcSShakeel Butt	depends on MEMCG
1092940b01fcSShakeel Butt	depends on HAVE_NMI
1093940b01fcSShakeel Butt	depends on !ARCH_HAS_NMI_SAFE_THIS_CPU_OPS && ARCH_HAVE_NMI_SAFE_CMPXCHG
1094940b01fcSShakeel Butt	default y
1095940b01fcSShakeel Butt
1096e93d4166SRoman Gushchinconfig MEMCG_V1
1097e93d4166SRoman Gushchin	bool "Legacy cgroup v1 memory controller"
1098c9929f0eSVlastimil Babka	depends on MEMCG
1099e93d4166SRoman Gushchin	default n
1100e93d4166SRoman Gushchin	help
1101e93d4166SRoman Gushchin	  Legacy cgroup v1 memory controller which has been deprecated by
1102e93d4166SRoman Gushchin	  cgroup v2 implementation. The v1 is there for legacy applications
1103e93d4166SRoman Gushchin	  which haven't migrated to the new cgroup v2 interface yet. If you
1104e93d4166SRoman Gushchin	  do not have any such application then you are completely fine leaving
1105e93d4166SRoman Gushchin	  this option disabled.
1106e93d4166SRoman Gushchin
1107e93d4166SRoman Gushchin	  Please note that feature set of the legacy memory controller is likely
1108e93d4166SRoman Gushchin	  going to shrink due to deprecation process. New deployments with v1
1109e93d4166SRoman Gushchin	  controller are highly discouraged.
1110e93d4166SRoman Gushchin
1111fcb4824bSValdis Kletnieks	  Say N if unsure.
111284c07d11SKirill Tkhai
11136bf024e6SJohannes Weinerconfig BLK_CGROUP
11146bf024e6SJohannes Weiner	bool "IO controller"
11156bf024e6SJohannes Weiner	depends on BLOCK
11162bc64a20SAneesh Kumar K.V	default n
1117a7f7f624SMasahiro Yamada	help
11186bf024e6SJohannes Weiner	Generic block IO controller cgroup interface. This is the common
11196bf024e6SJohannes Weiner	cgroup interface which should be used by various IO controlling
11206bf024e6SJohannes Weiner	policies.
11212bc64a20SAneesh Kumar K.V
11226bf024e6SJohannes Weiner	Currently, CFQ IO scheduler uses it to recognize task groups and
11236bf024e6SJohannes Weiner	control disk bandwidth allocation (proportional time slice allocation)
11246bf024e6SJohannes Weiner	to such task groups. It is also used by bio throttling logic in
11256bf024e6SJohannes Weiner	block layer to implement upper limit in IO rates on a device.
1126e5d1367fSStephane Eranian
11276bf024e6SJohannes Weiner	This option only enables generic Block IO controller infrastructure.
11286bf024e6SJohannes Weiner	One needs to also enable actual IO controlling logic/policy. For
11296bf024e6SJohannes Weiner	enabling proportional weight division of disk bandwidth in CFQ, set
11307baf2199SKrzysztof Kozlowski	CONFIG_BFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
11316bf024e6SJohannes Weiner	CONFIG_BLK_DEV_THROTTLING=y.
11326bf024e6SJohannes Weiner
1133da82c92fSMauro Carvalho Chehab	See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information.
11346bf024e6SJohannes Weiner
11356bf024e6SJohannes Weinerconfig CGROUP_WRITEBACK
11366bf024e6SJohannes Weiner	bool
11376bf024e6SJohannes Weiner	depends on MEMCG && BLK_CGROUP
11386bf024e6SJohannes Weiner	default y
1139e5d1367fSStephane Eranian
11407c941438SDhaval Gianimenuconfig CGROUP_SCHED
1141a0166ec4SJohannes Weiner	bool "CPU controller"
11427c941438SDhaval Giani	default n
11437c941438SDhaval Giani	help
11447c941438SDhaval Giani	  This feature lets CPU scheduler recognize task groups and control CPU
11457c941438SDhaval Giani	  bandwidth allocation to such task groups. It uses cgroups to group
11467c941438SDhaval Giani	  tasks.
11477c941438SDhaval Giani
11487c941438SDhaval Gianiif CGROUP_SCHED
1149e179e80cSTejun Heoconfig GROUP_SCHED_WEIGHT
1150e179e80cSTejun Heo	def_bool n
1151e179e80cSTejun Heo
1152ddceadceSTejun Heoconfig GROUP_SCHED_BANDWIDTH
1153ddceadceSTejun Heo	def_bool n
1154ddceadceSTejun Heo
11557c941438SDhaval Gianiconfig FAIR_GROUP_SCHED
11567c941438SDhaval Giani	bool "Group scheduling for SCHED_OTHER"
11577c941438SDhaval Giani	depends on CGROUP_SCHED
1158e179e80cSTejun Heo	select GROUP_SCHED_WEIGHT
11597c941438SDhaval Giani	default CGROUP_SCHED
11607c941438SDhaval Giani
1161ab84d31eSPaul Turnerconfig CFS_BANDWIDTH
1162ab84d31eSPaul Turner	bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
1163ab84d31eSPaul Turner	depends on FAIR_GROUP_SCHED
1164ddceadceSTejun Heo	select GROUP_SCHED_BANDWIDTH
1165ab84d31eSPaul Turner	default n
1166ab84d31eSPaul Turner	help
1167ab84d31eSPaul Turner	  This option allows users to define CPU bandwidth rates (limits) for
1168ab84d31eSPaul Turner	  tasks running within the fair group scheduler.  Groups with no limit
1169ab84d31eSPaul Turner	  set are considered to be unconstrained and will run with no
1170ab84d31eSPaul Turner	  restriction.
1171d6a3b247SMauro Carvalho Chehab	  See Documentation/scheduler/sched-bwc.rst for more information.
1172ab84d31eSPaul Turner
11737c941438SDhaval Gianiconfig RT_GROUP_SCHED
11747c941438SDhaval Giani	bool "Group scheduling for SCHED_RR/FIFO"
11757c941438SDhaval Giani	depends on CGROUP_SCHED
11767c941438SDhaval Giani	default n
11777c941438SDhaval Giani	help
11787c941438SDhaval Giani	  This feature lets you explicitly allocate real CPU bandwidth
117932bd7eb5SLi Zefan	  to task groups. If enabled, it will also make it impossible to
11807c941438SDhaval Giani	  schedule realtime tasks for non-root users until you allocate
11817c941438SDhaval Giani	  realtime bandwidth for them.
1182d6a3b247SMauro Carvalho Chehab	  See Documentation/scheduler/sched-rt-group.rst for more information.
11837c941438SDhaval Giani
1184e34e0131SMichal Koutnýconfig RT_GROUP_SCHED_DEFAULT_DISABLED
1185e34e0131SMichal Koutný	bool "Require boot parameter to enable group scheduling for SCHED_RR/FIFO"
1186e34e0131SMichal Koutný	depends on RT_GROUP_SCHED
1187e34e0131SMichal Koutný	default n
1188e34e0131SMichal Koutný	help
1189e34e0131SMichal Koutný	  When set, the RT group scheduling is disabled by default. The option
1190e34e0131SMichal Koutný	  is in inverted form so that mere RT_GROUP_SCHED enables the group
1191e34e0131SMichal Koutný	  scheduling.
1192e34e0131SMichal Koutný
1193e34e0131SMichal Koutný	  Say N if unsure.
1194e34e0131SMichal Koutný
119581951366STejun Heoconfig EXT_GROUP_SCHED
119681951366STejun Heo	bool
119781951366STejun Heo	depends on SCHED_CLASS_EXT && CGROUP_SCHED
119881951366STejun Heo	select GROUP_SCHED_WEIGHT
1199ddceadceSTejun Heo	select GROUP_SCHED_BANDWIDTH
120081951366STejun Heo	default y
120181951366STejun Heo
12027c941438SDhaval Gianiendif #CGROUP_SCHED
12037c941438SDhaval Giani
1204ebeca1f9STejun Heoconfig EXT_SUB_SCHED
1205ebeca1f9STejun Heo        def_bool y
1206e73b1d72SCheng-Yang Chou        depends on SCHED_CLASS_EXT && CGROUPS
1207ebeca1f9STejun Heo
1208af7f588dSMathieu Desnoyersconfig SCHED_MM_CID
1209af7f588dSMathieu Desnoyers	def_bool y
1210af7f588dSMathieu Desnoyers	depends on SMP && RSEQ
1211af7f588dSMathieu Desnoyers
12122480c093SPatrick Bellasiconfig UCLAMP_TASK_GROUP
12132480c093SPatrick Bellasi	bool "Utilization clamping per group of tasks"
12142480c093SPatrick Bellasi	depends on CGROUP_SCHED
12152480c093SPatrick Bellasi	depends on UCLAMP_TASK
12162480c093SPatrick Bellasi	default n
12172480c093SPatrick Bellasi	help
12182480c093SPatrick Bellasi	  This feature enables the scheduler to track the clamped utilization
12192480c093SPatrick Bellasi	  of each CPU based on RUNNABLE tasks currently scheduled on that CPU.
12202480c093SPatrick Bellasi
12212480c093SPatrick Bellasi	  When this option is enabled, the user can specify a min and max
12222480c093SPatrick Bellasi	  CPU bandwidth which is allowed for each single task in a group.
12232480c093SPatrick Bellasi	  The max bandwidth allows to clamp the maximum frequency a task
12242480c093SPatrick Bellasi	  can use, while the min bandwidth allows to define a minimum
12252480c093SPatrick Bellasi	  frequency a task will always use.
12262480c093SPatrick Bellasi
12272480c093SPatrick Bellasi	  When task group based utilization clamping is enabled, an eventually
12282480c093SPatrick Bellasi	  specified task-specific clamp value is constrained by the cgroup
12292480c093SPatrick Bellasi	  specified clamp value. Both minimum and maximum task clamping cannot
12302480c093SPatrick Bellasi	  be bigger than the corresponding clamping defined at task group level.
12312480c093SPatrick Bellasi
12322480c093SPatrick Bellasi	  If in doubt, say N.
12332480c093SPatrick Bellasi
12346bf024e6SJohannes Weinerconfig CGROUP_PIDS
12356bf024e6SJohannes Weiner	bool "PIDs controller"
12366bf024e6SJohannes Weiner	help
12376bf024e6SJohannes Weiner	  Provides enforcement of process number limits in the scope of a
12386bf024e6SJohannes Weiner	  cgroup. Any attempt to fork more processes than is allowed in the
12396bf024e6SJohannes Weiner	  cgroup will fail. PIDs are fundamentally a global resource because it
12406bf024e6SJohannes Weiner	  is fairly trivial to reach PID exhaustion before you reach even a
12416bf024e6SJohannes Weiner	  conservative kmemcg limit. As a result, it is possible to grind a
12426bf024e6SJohannes Weiner	  system to halt without being limited by other cgroup policies. The
12436cc578dfSParav Pandit	  PIDs controller is designed to stop this from happening.
12446bf024e6SJohannes Weiner
12456bf024e6SJohannes Weiner	  It should be noted that organisational operations (such as attaching
124698076833SJonathan Neuschäfer	  to a cgroup hierarchy) will *not* be blocked by the PIDs controller,
12476bf024e6SJohannes Weiner	  since the PIDs limit only affects a process's ability to fork, not to
12486bf024e6SJohannes Weiner	  attach to a cgroup.
12496bf024e6SJohannes Weiner
125039d3e758SParav Panditconfig CGROUP_RDMA
125139d3e758SParav Pandit	bool "RDMA controller"
125239d3e758SParav Pandit	help
125339d3e758SParav Pandit	  Provides enforcement of RDMA resources defined by IB stack.
125439d3e758SParav Pandit	  It is fairly easy for consumers to exhaust RDMA resources, which
125539d3e758SParav Pandit	  can result into resource unavailability to other consumers.
125639d3e758SParav Pandit	  RDMA controller is designed to stop this from happening.
125739d3e758SParav Pandit	  Attaching processes with active RDMA resources to the cgroup
125839d3e758SParav Pandit	  hierarchy is allowed even if can cross the hierarchy's limit.
125939d3e758SParav Pandit
1260b168ed45SMaarten Lankhorstconfig CGROUP_DMEM
1261b168ed45SMaarten Lankhorst	bool "Device memory controller (DMEM)"
1262e33b5149SMaxime Ripard	select PAGE_COUNTER
1263b168ed45SMaarten Lankhorst	help
1264b168ed45SMaarten Lankhorst	  The DMEM controller allows compatible devices to restrict device
1265b168ed45SMaarten Lankhorst	  memory usage based on the cgroup hierarchy.
1266b168ed45SMaarten Lankhorst
1267b168ed45SMaarten Lankhorst	  As an example, it allows you to restrict VRAM usage for applications
1268b168ed45SMaarten Lankhorst	  in the DRM subsystem.
1269b168ed45SMaarten Lankhorst
12706bf024e6SJohannes Weinerconfig CGROUP_FREEZER
12716bf024e6SJohannes Weiner	bool "Freezer controller"
12726bf024e6SJohannes Weiner	help
12736bf024e6SJohannes Weiner	  Provides a way to freeze and unfreeze all tasks in a
12746bf024e6SJohannes Weiner	  cgroup.
12756bf024e6SJohannes Weiner
1276489c2a20SJohannes Weiner	  This option affects the ORIGINAL cgroup interface. The cgroup2 memory
1277489c2a20SJohannes Weiner	  controller includes important in-kernel memory consumers per default.
1278489c2a20SJohannes Weiner
1279489c2a20SJohannes Weiner	  If you're using cgroup2, say N.
1280489c2a20SJohannes Weiner
12816bf024e6SJohannes Weinerconfig CGROUP_HUGETLB
12826bf024e6SJohannes Weiner	bool "HugeTLB controller"
12836bf024e6SJohannes Weiner	depends on HUGETLB_PAGE
12846bf024e6SJohannes Weiner	select PAGE_COUNTER
1285afc24d49SVivek Goyal	default n
12866bf024e6SJohannes Weiner	help
12876bf024e6SJohannes Weiner	  Provides a cgroup controller for HugeTLB pages.
12886bf024e6SJohannes Weiner	  When you enable this, you can put a per cgroup limit on HugeTLB usage.
12896bf024e6SJohannes Weiner	  The limit is enforced during page fault. Since HugeTLB doesn't
12906bf024e6SJohannes Weiner	  support page reclaim, enforcing the limit at page fault time implies
12916bf024e6SJohannes Weiner	  that, the application will get SIGBUS signal if it tries to access
12926bf024e6SJohannes Weiner	  HugeTLB pages beyond its limit. This requires the application to know
12936bf024e6SJohannes Weiner	  beforehand how much HugeTLB pages it would require for its use. The
12946bf024e6SJohannes Weiner	  control group is tracked in the third page lru pointer. This means
12956bf024e6SJohannes Weiner	  that we cannot use the controller with huge page less than 3 pages.
1296afc24d49SVivek Goyal
12976bf024e6SJohannes Weinerconfig CPUSETS
12986bf024e6SJohannes Weiner	bool "Cpuset controller"
1299e1d4eeecSNicolas Pitre	depends on SMP
1300bf9850f6SKuan-Wei Chiu	select UNION_FIND
130123f09dccSFrederic Weisbecker	select CPU_ISOLATION
13026bf024e6SJohannes Weiner	help
13036bf024e6SJohannes Weiner	  This option will let you create and manage CPUSETs which
13046bf024e6SJohannes Weiner	  allow dynamically partitioning a system into sets of CPUs and
13056bf024e6SJohannes Weiner	  Memory Nodes and assigning tasks to run only within those sets.
13066bf024e6SJohannes Weiner	  This is primarily useful on large SMP or NUMA systems.
1307afc24d49SVivek Goyal
13086bf024e6SJohannes Weiner	  Say N if unsure.
1309afc24d49SVivek Goyal
13101abab1baSChen Ridongconfig CPUSETS_V1
13111abab1baSChen Ridong	bool "Legacy cgroup v1 cpusets controller"
13121abab1baSChen Ridong	depends on CPUSETS
13131abab1baSChen Ridong	default n
13141abab1baSChen Ridong	help
13151abab1baSChen Ridong	  Legacy cgroup v1 cpusets controller which has been deprecated by
13161abab1baSChen Ridong	  cgroup v2 implementation. The v1 is there for legacy applications
1317dae68fbaSMichal Koutný	  which haven't migrated to the new cgroup v2 interface yet. Legacy
1318dae68fbaSMichal Koutný	  interface includes cpuset filesystem and /proc/<pid>/cpuset. If you
13191abab1baSChen Ridong	  do not have any such application then you are completely fine leaving
13201abab1baSChen Ridong	  this option disabled.
13211abab1baSChen Ridong
13221abab1baSChen Ridong	  Say N if unsure.
13231abab1baSChen Ridong
13246bf024e6SJohannes Weinerconfig PROC_PID_CPUSET
13256bf024e6SJohannes Weiner	bool "Include legacy /proc/<pid>/cpuset file"
1326dae68fbaSMichal Koutný	depends on CPUSETS_V1
132789e9b9e0STejun Heo	default y
132889e9b9e0STejun Heo
13296bf024e6SJohannes Weinerconfig CGROUP_DEVICE
13306bf024e6SJohannes Weiner	bool "Device controller"
13316bf024e6SJohannes Weiner	help
13326bf024e6SJohannes Weiner	  Provides a cgroup controller implementing whitelists for
13336bf024e6SJohannes Weiner	  devices which a process in the cgroup can mknod or open.
13346bf024e6SJohannes Weiner
13356bf024e6SJohannes Weinerconfig CGROUP_CPUACCT
13366bf024e6SJohannes Weiner	bool "Simple CPU accounting controller"
13376bf024e6SJohannes Weiner	help
13386bf024e6SJohannes Weiner	  Provides a simple controller for monitoring the
13396bf024e6SJohannes Weiner	  total CPU consumed by the tasks in a cgroup.
13406bf024e6SJohannes Weiner
13416bf024e6SJohannes Weinerconfig CGROUP_PERF
13426bf024e6SJohannes Weiner	bool "Perf controller"
13436bf024e6SJohannes Weiner	depends on PERF_EVENTS
13446bf024e6SJohannes Weiner	help
13456bf024e6SJohannes Weiner	  This option extends the perf per-cpu mode to restrict monitoring
13466bf024e6SJohannes Weiner	  to threads which belong to the cgroup specified and run on the
13476546b19fSNamhyung Kim	  designated cpu.  Or this can be used to have cgroup ID in samples
13486546b19fSNamhyung Kim	  so that it can monitor performance events among cgroups.
13496bf024e6SJohannes Weiner
13506bf024e6SJohannes Weiner	  Say N if unsure.
13516bf024e6SJohannes Weiner
135230070984SDaniel Mackconfig CGROUP_BPF
135330070984SDaniel Mack	bool "Support for eBPF programs attached to cgroups"
1354483c4933SAndy Lutomirski	depends on BPF_SYSCALL
1355483c4933SAndy Lutomirski	select SOCK_CGROUP_DATA
135630070984SDaniel Mack	help
135730070984SDaniel Mack	  Allow attaching eBPF programs to a cgroup using the bpf(2)
135830070984SDaniel Mack	  syscall command BPF_PROG_ATTACH.
135930070984SDaniel Mack
136030070984SDaniel Mack	  In which context these programs are accessed depends on the type
136130070984SDaniel Mack	  of attachment. For instance, programs that are attached using
136230070984SDaniel Mack	  BPF_CGROUP_INET_INGRESS will be executed on the ingress path of
136330070984SDaniel Mack	  inet sockets.
136430070984SDaniel Mack
1365a72232eaSVipin Sharmaconfig CGROUP_MISC
1366a72232eaSVipin Sharma	bool "Misc resource controller"
1367a72232eaSVipin Sharma	default n
1368a72232eaSVipin Sharma	help
1369a72232eaSVipin Sharma	  Provides a controller for miscellaneous resources on a host.
1370a72232eaSVipin Sharma
1371a72232eaSVipin Sharma	  Miscellaneous scalar resources are the resources on the host system
1372a72232eaSVipin Sharma	  which cannot be abstracted like the other cgroups. This controller
1373a72232eaSVipin Sharma	  tracks and limits the miscellaneous resources used by a process
1374a72232eaSVipin Sharma	  attached to a cgroup hierarchy.
1375a72232eaSVipin Sharma
1376a72232eaSVipin Sharma	  For more information, please check misc cgroup section in
1377a72232eaSVipin Sharma	  /Documentation/admin-guide/cgroup-v2.rst.
1378a72232eaSVipin Sharma
13796bf024e6SJohannes Weinerconfig CGROUP_DEBUG
138023b0be48SWaiman Long	bool "Debug controller"
13816bf024e6SJohannes Weiner	default n
138223b0be48SWaiman Long	depends on DEBUG_KERNEL
13836bf024e6SJohannes Weiner	help
13846bf024e6SJohannes Weiner	  This option enables a simple controller that exports
138523b0be48SWaiman Long	  debugging information about the cgroups framework. This
138623b0be48SWaiman Long	  controller is for control cgroup debugging only. Its
138723b0be48SWaiman Long	  interfaces are not stable.
13886bf024e6SJohannes Weiner
13896bf024e6SJohannes Weiner	  Say N.
13906bf024e6SJohannes Weiner
139173b35147SArnd Bergmannconfig SOCK_CGROUP_DATA
139273b35147SArnd Bergmann	bool
139373b35147SArnd Bergmann	default n
139473b35147SArnd Bergmann
139523964d2dSLi Zefanendif # CGROUPS
1396c077719bSKAMEZAWA Hiroyuki
13978dd2a82cSDaniel Lezcanomenuconfig NAMESPACES
13986a108a14SDavid Rientjes	bool "Namespaces support" if EXPERT
13992813893fSIulia Manda	depends on MULTIUSER
14006a108a14SDavid Rientjes	default !EXPERT
1401c5289a69SPavel Emelyanov	help
1402c5289a69SPavel Emelyanov	  Provides the way to make tasks work with different objects using
1403c5289a69SPavel Emelyanov	  the same id. For example same IPC id may refer to different objects
1404c5289a69SPavel Emelyanov	  or same user id or pid may refer to different tasks when used in
1405c5289a69SPavel Emelyanov	  different namespaces.
1406c5289a69SPavel Emelyanov
14078dd2a82cSDaniel Lezcanoif NAMESPACES
14088dd2a82cSDaniel Lezcano
140958bfdd6dSPavel Emelyanovconfig UTS_NS
141058bfdd6dSPavel Emelyanov	bool "UTS namespace"
141117a6d441SDaniel Lezcano	default y
141258bfdd6dSPavel Emelyanov	help
141358bfdd6dSPavel Emelyanov	  In this namespace tasks see different info provided with the
141458bfdd6dSPavel Emelyanov	  uname() system call
141558bfdd6dSPavel Emelyanov
1416769071acSAndrei Vaginconfig TIME_NS
1417769071acSAndrei Vagin	bool "TIME namespace"
1418769071acSAndrei Vagin	default y
1419769071acSAndrei Vagin	help
1420769071acSAndrei Vagin	  In this namespace boottime and monotonic clocks can be set.
1421769071acSAndrei Vagin	  The time will keep going with the same pace.
1422769071acSAndrei Vagin
14231b6c8928SThomas Weißschuhconfig TIME_NS_VDSO
14241b6c8928SThomas Weißschuh	def_bool TIME_NS && GENERIC_GETTIMEOFDAY
14251b6c8928SThomas Weißschuh
1426ae5e1b22SPavel Emelyanovconfig IPC_NS
1427ae5e1b22SPavel Emelyanov	bool "IPC namespace"
14288dd2a82cSDaniel Lezcano	depends on (SYSVIPC || POSIX_MQUEUE)
142917a6d441SDaniel Lezcano	default y
1430ae5e1b22SPavel Emelyanov	help
1431ae5e1b22SPavel Emelyanov	  In this namespace tasks work with IPC ids which correspond to
1432614b84cfSSerge E. Hallyn	  different IPC objects in different namespaces.
1433ae5e1b22SPavel Emelyanov
1434aee16ce7SPavel Emelyanovconfig USER_NS
143519c92399SKees Cook	bool "User namespace"
14365673a94cSEric W. Biederman	default n
1437aee16ce7SPavel Emelyanov	help
1438aee16ce7SPavel Emelyanov	  This allows containers, i.e. vservers, to use user namespaces
1439aee16ce7SPavel Emelyanov	  to provide different user info for different servers.
1440e11f0ae3SEric W. Biederman
1441e11f0ae3SEric W. Biederman	  When user namespaces are enabled in the kernel it is
1442d886f4e4SJohannes Weiner	  recommended that the MEMCG option also be enabled and that
1443d886f4e4SJohannes Weiner	  user-space use the memory control groups to limit the amount
1444d886f4e4SJohannes Weiner	  of memory a memory unprivileged users can use.
1445e11f0ae3SEric W. Biederman
1446aee16ce7SPavel Emelyanov	  If unsure, say N.
1447aee16ce7SPavel Emelyanov
144874bd59bbSPavel Emelyanovconfig PID_NS
14499bd38c2cSDaniel Lezcano	bool "PID Namespaces"
145017a6d441SDaniel Lezcano	default y
145174bd59bbSPavel Emelyanov	help
145212d2b8f9SHeikki Orsila	  Support process id namespaces.  This allows having multiple
1453692105b8SMatt LaPlante	  processes with the same pid as long as they are in different
145474bd59bbSPavel Emelyanov	  pid namespaces.  This is a building block of containers.
145574bd59bbSPavel Emelyanov
1456d6eb633fSMatt Helsleyconfig NET_NS
1457d6eb633fSMatt Helsley	bool "Network namespace"
14588dd2a82cSDaniel Lezcano	depends on NET
145917a6d441SDaniel Lezcano	default y
1460d6eb633fSMatt Helsley	help
1461d6eb633fSMatt Helsley	  Allow user space to create what appear to be multiple instances
1462d6eb633fSMatt Helsley	  of the network stack.
1463d6eb633fSMatt Helsley
14648dd2a82cSDaniel Lezcanoendif # NAMESPACES
14658dd2a82cSDaniel Lezcano
14665cb366bbSAdrian Reberconfig CHECKPOINT_RESTORE
14675cb366bbSAdrian Reber	bool "Checkpoint/restore support"
146830341ec9SRen Zhijie	depends on PROC_FS
14695cb366bbSAdrian Reber	select PROC_CHILDREN
1470bfe3911aSChris Wilson	select KCMP
14715cb366bbSAdrian Reber	default n
14725cb366bbSAdrian Reber	help
14735cb366bbSAdrian Reber	  Enables additional kernel features in a sake of checkpoint/restore.
14745cb366bbSAdrian Reber	  In particular it adds auxiliary prctl codes to setup process text,
14755cb366bbSAdrian Reber	  data and heap segment sizes, and a few additional /proc filesystem
14765cb366bbSAdrian Reber	  entries.
14775cb366bbSAdrian Reber
14785cb366bbSAdrian Reber	  If unsure, say N here.
14795cb366bbSAdrian Reber
14805091faa4SMike Galbraithconfig SCHED_AUTOGROUP
14815091faa4SMike Galbraith	bool "Automatic process group scheduling"
14825091faa4SMike Galbraith	select CGROUPS
14835091faa4SMike Galbraith	select CGROUP_SCHED
14845091faa4SMike Galbraith	select FAIR_GROUP_SCHED
14855091faa4SMike Galbraith	help
14865091faa4SMike Galbraith	  This option optimizes the scheduler for common desktop workloads by
14875091faa4SMike Galbraith	  automatically creating and populating task groups.  This separation
14885091faa4SMike Galbraith	  of workloads isolates aggressive CPU burners (like build jobs) from
14895091faa4SMike Galbraith	  desktop applications.  Task group autogeneration is currently based
14905091faa4SMike Galbraith	  upon task session.
14915091faa4SMike Galbraith
14927af37becSDaniel Lezcanoconfig RELAY
14937af37becSDaniel Lezcano	bool "Kernel->user space relay support (formerly relayfs)"
149426b5679eSPeter Zijlstra	select IRQ_WORK
14957af37becSDaniel Lezcano	help
14967af37becSDaniel Lezcano	  This option enables support for relay interface support in
14977af37becSDaniel Lezcano	  certain file systems (such as debugfs).
14987af37becSDaniel Lezcano	  It is designed to provide an efficient mechanism for tools and
14997af37becSDaniel Lezcano	  facilities to relay large amounts of data from kernel space to
15007af37becSDaniel Lezcano	  user space.
15017af37becSDaniel Lezcano
15027af37becSDaniel Lezcano	  If unsure, say N.
15037af37becSDaniel Lezcano
1504f991633dSDimitri Gorokhovikconfig BLK_DEV_INITRD
1505f991633dSDimitri Gorokhovik	bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1506f991633dSDimitri Gorokhovik	help
1507f991633dSDimitri Gorokhovik	  The initial RAM filesystem is a ramfs which is loaded by the
1508f991633dSDimitri Gorokhovik	  boot loader (loadlin or lilo) and that is mounted as root
1509f991633dSDimitri Gorokhovik	  before the normal boot procedure. It is typically used to
1510f991633dSDimitri Gorokhovik	  load modules needed to mount the "real" root file system,
15118c27ceffSMauro Carvalho Chehab	  etc. See <file:Documentation/admin-guide/initrd.rst> for details.
1512f991633dSDimitri Gorokhovik
1513f991633dSDimitri Gorokhovik	  If RAM disk support (BLK_DEV_RAM) is also included, this
1514f991633dSDimitri Gorokhovik	  also enables initial RAM disk (initrd) support and adds
1515f991633dSDimitri Gorokhovik	  15 Kbytes (more on some other architectures) to the kernel size.
1516f991633dSDimitri Gorokhovik
1517f991633dSDimitri Gorokhovik	  If unsure say Y.
1518f991633dSDimitri Gorokhovik
1519c33df4eaSJean-Paul Samanif BLK_DEV_INITRD
1520c33df4eaSJean-Paul Saman
1521dbec4866SSam Ravnborgsource "usr/Kconfig"
1522dbec4866SSam Ravnborg
1523c33df4eaSJean-Paul Samanendif
1524c33df4eaSJean-Paul Saman
152576db5a27SMasami Hiramatsuconfig BOOT_CONFIG
152676db5a27SMasami Hiramatsu	bool "Boot config support"
1527a2a9d67aSMasami Hiramatsu	select BLK_DEV_INITRD if !BOOT_CONFIG_EMBED
152876db5a27SMasami Hiramatsu	help
152976db5a27SMasami Hiramatsu	  Extra boot config allows system admin to pass a config file as
153076db5a27SMasami Hiramatsu	  complemental extension of kernel cmdline when booting.
15310947db01SMasami Hiramatsu	  The boot config file must be attached at the end of initramfs
153285c46b78SMasami Hiramatsu	  with checksum, size and magic word.
15330947db01SMasami Hiramatsu	  See <file:Documentation/admin-guide/bootconfig.rst> for details.
153476db5a27SMasami Hiramatsu
153576db5a27SMasami Hiramatsu	  If unsure, say Y.
153676db5a27SMasami Hiramatsu
1537b743852cSPaul E. McKenneyconfig BOOT_CONFIG_FORCE
1538b743852cSPaul E. McKenney	bool "Force unconditional bootconfig processing"
1539b743852cSPaul E. McKenney	depends on BOOT_CONFIG
15406ded8a28SPaul E. McKenney	default y if BOOT_CONFIG_EMBED
1541b743852cSPaul E. McKenney	help
1542b743852cSPaul E. McKenney	  With this Kconfig option set, BOOT_CONFIG processing is carried
1543b743852cSPaul E. McKenney	  out even when the "bootconfig" kernel-boot parameter is omitted.
1544b743852cSPaul E. McKenney	  In fact, with this Kconfig option set, there is no way to
1545b743852cSPaul E. McKenney	  make the kernel ignore the BOOT_CONFIG-supplied kernel-boot
1546b743852cSPaul E. McKenney	  parameters.
1547b743852cSPaul E. McKenney
1548b743852cSPaul E. McKenney	  If unsure, say N.
1549b743852cSPaul E. McKenney
1550a2a9d67aSMasami Hiramatsuconfig BOOT_CONFIG_EMBED
1551a2a9d67aSMasami Hiramatsu	bool "Embed bootconfig file in the kernel"
1552a2a9d67aSMasami Hiramatsu	depends on BOOT_CONFIG
1553a2a9d67aSMasami Hiramatsu	help
1554a2a9d67aSMasami Hiramatsu	  Embed a bootconfig file given by BOOT_CONFIG_EMBED_FILE in the
1555a2a9d67aSMasami Hiramatsu	  kernel. Usually, the bootconfig file is loaded with the initrd
1556a2a9d67aSMasami Hiramatsu	  image. But if the system doesn't support initrd, this option will
1557a2a9d67aSMasami Hiramatsu	  help you by embedding a bootconfig file while building the kernel.
1558a2a9d67aSMasami Hiramatsu
1559a2a9d67aSMasami Hiramatsu	  If unsure, say N.
1560a2a9d67aSMasami Hiramatsu
1561a2a9d67aSMasami Hiramatsuconfig BOOT_CONFIG_EMBED_FILE
1562a2a9d67aSMasami Hiramatsu	string "Embedded bootconfig file path"
1563a2a9d67aSMasami Hiramatsu	depends on BOOT_CONFIG_EMBED
1564a2a9d67aSMasami Hiramatsu	help
1565a2a9d67aSMasami Hiramatsu	  Specify a bootconfig file which will be embedded to the kernel.
1566a2a9d67aSMasami Hiramatsu	  This bootconfig will be used if there is no initrd or no other
1567a2a9d67aSMasami Hiramatsu	  bootconfig in the initrd.
1568a2a9d67aSMasami Hiramatsu
1569032a7302SDouglas Andersonconfig CMDLINE_LOG_WRAP_IDEAL_LEN
1570032a7302SDouglas Anderson	int "Length to try to wrap the cmdline when logged at boot"
1571032a7302SDouglas Anderson	default 1021
1572032a7302SDouglas Anderson	range 0 1021
1573032a7302SDouglas Anderson	help
1574032a7302SDouglas Anderson	  At boot time, the kernel command line is logged to the console.
1575032a7302SDouglas Anderson	  The log message will start with the prefix "Kernel command line: ".
1576032a7302SDouglas Anderson	  The log message will attempt to be wrapped (split into multiple log
1577032a7302SDouglas Anderson	  messages) at spaces based on CMDLINE_LOG_WRAP_IDEAL_LEN characters.
1578032a7302SDouglas Anderson	  If wrapping happens, each log message will start with the prefix and
1579032a7302SDouglas Anderson	  all but the last message will end with " \". Messages may exceed the
1580032a7302SDouglas Anderson	  ideal length if a place to wrap isn't found before the specified
1581032a7302SDouglas Anderson	  number of characters.
1582032a7302SDouglas Anderson
1583032a7302SDouglas Anderson	  A value of 0 disables wrapping, though be warned that the maximum
1584032a7302SDouglas Anderson	  length of a log message (1021 characters) may cause the cmdline to
1585032a7302SDouglas Anderson	  be truncated.
1586032a7302SDouglas Anderson
15871274aea1SDavid Disseldorpconfig INITRAMFS_PRESERVE_MTIME
15881274aea1SDavid Disseldorp	bool "Preserve cpio archive mtimes in initramfs"
158974792608SGeert Uytterhoeven	depends on BLK_DEV_INITRD
15901274aea1SDavid Disseldorp	default y
15911274aea1SDavid Disseldorp	help
15921274aea1SDavid Disseldorp	  Each entry in an initramfs cpio archive carries an mtime value. When
15931274aea1SDavid Disseldorp	  enabled, extracted cpio items take this mtime, with directory mtime
15941274aea1SDavid Disseldorp	  setting deferred until after creation of any child entries.
15951274aea1SDavid Disseldorp
15961274aea1SDavid Disseldorp	  If unsure, say Y.
15971274aea1SDavid Disseldorp
159883c0b272SDavid Disseldorpconfig INITRAMFS_TEST
159983c0b272SDavid Disseldorp	bool "Test initramfs cpio archive extraction" if !KUNIT_ALL_TESTS
160083c0b272SDavid Disseldorp	depends on BLK_DEV_INITRD && KUNIT=y
160183c0b272SDavid Disseldorp	default KUNIT_ALL_TESTS
160283c0b272SDavid Disseldorp	help
160383c0b272SDavid Disseldorp	  Build KUnit tests for initramfs. See Documentation/dev-tools/kunit
160483c0b272SDavid Disseldorp
1605877417e6SArnd Bergmannchoice
1606877417e6SArnd Bergmann	prompt "Compiler optimization level"
16072cc3ce24SUlf Magnusson	default CC_OPTIMIZE_FOR_PERFORMANCE
1608877417e6SArnd Bergmann
1609877417e6SArnd Bergmannconfig CC_OPTIMIZE_FOR_PERFORMANCE
161015f5db60SMasahiro Yamada	bool "Optimize for performance (-O2)"
1611877417e6SArnd Bergmann	help
1612877417e6SArnd Bergmann	  This is the default optimization level for the kernel, building
1613877417e6SArnd Bergmann	  with the "-O2" compiler flag for best performance and most
1614877417e6SArnd Bergmann	  helpful compile-time warnings.
1615877417e6SArnd Bergmann
1616c45b4f1fSLinus Torvaldsconfig CC_OPTIMIZE_FOR_SIZE
161715f5db60SMasahiro Yamada	bool "Optimize for size (-Os)"
1618c45b4f1fSLinus Torvalds	help
1619ce3b487fSMasahiro Yamada	  Choosing this option will pass "-Os" to your compiler resulting
1620ce3b487fSMasahiro Yamada	  in a smaller kernel.
1621c45b4f1fSLinus Torvalds
1622877417e6SArnd Bergmannendchoice
1623877417e6SArnd Bergmann
16245d20ee31SNicholas Pigginconfig HAVE_LD_DEAD_CODE_DATA_ELIMINATION
16255d20ee31SNicholas Piggin	bool
16265d20ee31SNicholas Piggin	help
16275d20ee31SNicholas Piggin	  This requires that the arch annotates or otherwise protects
16285d20ee31SNicholas Piggin	  its external entry points from being discarded. Linker scripts
16295d20ee31SNicholas Piggin	  must also merge .text.*, .data.*, and .bss.* correctly into
16305d20ee31SNicholas Piggin	  output sections. Care must be taken not to pull in unrelated
16315d20ee31SNicholas Piggin	  sections (e.g., '.text.init'). Typically '.' in section names
16325d20ee31SNicholas Piggin	  is used to distinguish them from label names / C identifiers.
16335d20ee31SNicholas Piggin
16345d20ee31SNicholas Pigginconfig LD_DEAD_CODE_DATA_ELIMINATION
16355d20ee31SNicholas Piggin	bool "Dead code and data elimination (EXPERIMENTAL)"
16365d20ee31SNicholas Piggin	depends on HAVE_LD_DEAD_CODE_DATA_ELIMINATION
16375d20ee31SNicholas Piggin	depends on EXPERT
1638e85d1d65SMasahiro Yamada	depends on $(cc-option,-ffunction-sections -fdata-sections)
1639e85d1d65SMasahiro Yamada	depends on $(ld-option,--gc-sections)
16405d20ee31SNicholas Piggin	help
16418b9d2712SMasahiro Yamada	  Enable this if you want to do dead code and data elimination with
16428b9d2712SMasahiro Yamada	  the linker by compiling with -ffunction-sections -fdata-sections,
16438b9d2712SMasahiro Yamada	  and linking with --gc-sections.
16445d20ee31SNicholas Piggin
16455d20ee31SNicholas Piggin	  This can reduce on disk and in-memory size of the kernel
16465d20ee31SNicholas Piggin	  code and static data, particularly for small configs and
16475d20ee31SNicholas Piggin	  on small systems. This has the possibility of introducing
16485d20ee31SNicholas Piggin	  silently broken kernel if the required annotations are not
16495d20ee31SNicholas Piggin	  present. This option is not well tested yet, so use at your
16505d20ee31SNicholas Piggin	  own risk.
16515d20ee31SNicholas Piggin
165259612b24SNathan Chancellorconfig LD_ORPHAN_WARN
165359612b24SNathan Chancellor	def_bool y
165459612b24SNathan Chancellor	depends on ARCH_WANT_LD_ORPHAN_WARN
165559612b24SNathan Chancellor	depends on $(ld-option,--orphan-handling=warn)
1656e1789d7cSXin Li	depends on $(ld-option,--orphan-handling=error)
1657e1789d7cSXin Li
1658e1789d7cSXin Liconfig LD_ORPHAN_WARN_LEVEL
1659e1789d7cSXin Li	string
1660e1789d7cSXin Li	depends on LD_ORPHAN_WARN
1661e1789d7cSXin Li	default "error" if WERROR
1662e1789d7cSXin Li	default "warn"
166359612b24SNathan Chancellor
16640847062aSRandy Dunlapconfig SYSCTL
16650847062aSRandy Dunlap	bool
16660847062aSRandy Dunlap
1667657a5209SMike Frysingerconfig HAVE_UID16
1668657a5209SMike Frysinger	bool
1669657a5209SMike Frysinger
1670657a5209SMike Frysingerconfig SYSCTL_EXCEPTION_TRACE
1671657a5209SMike Frysinger	bool
1672657a5209SMike Frysinger	help
1673657a5209SMike Frysinger	  Enable support for /proc/sys/debug/exception-trace.
1674657a5209SMike Frysinger
1675657a5209SMike Frysingerconfig SYSCTL_ARCH_UNALIGN_NO_WARN
1676657a5209SMike Frysinger	bool
1677657a5209SMike Frysinger	help
1678657a5209SMike Frysinger	  Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
1679657a5209SMike Frysinger	  Allows arch to define/use @no_unaligned_warning to possibly warn
1680657a5209SMike Frysinger	  about unaligned access emulation going on under the hood.
1681657a5209SMike Frysinger
1682657a5209SMike Frysingerconfig SYSCTL_ARCH_UNALIGN_ALLOW
1683657a5209SMike Frysinger	bool
1684657a5209SMike Frysinger	help
1685657a5209SMike Frysinger	  Enable support for /proc/sys/kernel/unaligned-trap
1686657a5209SMike Frysinger	  Allows arches to define/use @unaligned_enabled to runtime toggle
1687657a5209SMike Frysinger	  the unaligned access emulation.
1688657a5209SMike Frysinger	  see arch/parisc/kernel/unaligned.c for reference
1689657a5209SMike Frysinger
1690c443279aSChristian Braunerconfig SYSFS_SYSCALL
1691c443279aSChristian Brauner	bool "Sysfs syscall support"
1692c443279aSChristian Brauner	default n
1693c443279aSChristian Brauner	help
1694c443279aSChristian Brauner	  sys_sysfs is an obsolete system call no longer supported in libc.
1695c443279aSChristian Brauner	  Note that disabling this option is more secure but might break
1696c443279aSChristian Brauner	  compatibility with some systems.
1697c443279aSChristian Brauner
1698c443279aSChristian Brauner	  If unsure say N here.
1699c443279aSChristian Brauner
1700657a5209SMike Frysingerconfig HAVE_PCSPKR_PLATFORM
1701657a5209SMike Frysinger	bool
1702657a5209SMike Frysinger
17036a108a14SDavid Rientjesmenuconfig EXPERT
17046a108a14SDavid Rientjes	bool "Configure standard kernel features (expert users)"
1705f505c553SJosh Triplett	# Unhide debug options, to make the on-by-default options visible
1706f505c553SJosh Triplett	select DEBUG_KERNEL
17071da177e4SLinus Torvalds	help
17081da177e4SLinus Torvalds	  This option allows certain base kernel options and settings
17091da177e4SLinus Torvalds	  to be disabled or tweaked. This is for specialized
17101da177e4SLinus Torvalds	  environments which can tolerate a "non-standard" kernel.
17111da177e4SLinus Torvalds	  Only use this if you really know what you are doing.
17121da177e4SLinus Torvalds
1713ae81f9e3SChuck Ebbertconfig UID16
17146a108a14SDavid Rientjes	bool "Enable 16-bit UID system calls" if EXPERT
17152813893fSIulia Manda	depends on HAVE_UID16 && MULTIUSER
1716ae81f9e3SChuck Ebbert	default y
1717ae81f9e3SChuck Ebbert	help
1718ae81f9e3SChuck Ebbert	  This enables the legacy 16-bit UID syscall wrappers.
1719ae81f9e3SChuck Ebbert
17202813893fSIulia Mandaconfig MULTIUSER
17212813893fSIulia Manda	bool "Multiple users, groups and capabilities support" if EXPERT
17222813893fSIulia Manda	default y
17232813893fSIulia Manda	help
17242813893fSIulia Manda	  This option enables support for non-root users, groups and
17252813893fSIulia Manda	  capabilities.
17262813893fSIulia Manda
17272813893fSIulia Manda	  If you say N here, all processes will run with UID 0, GID 0, and all
17282813893fSIulia Manda	  possible capabilities.  Saying N here also compiles out support for
17292813893fSIulia Manda	  system calls related to UIDs, GIDs, and capabilities, such as setuid,
17302813893fSIulia Manda	  setgid, and capset.
17312813893fSIulia Manda
17322813893fSIulia Manda	  If unsure, say Y here.
17332813893fSIulia Manda
1734f6187769SFabian Frederickconfig SGETMASK_SYSCALL
1735f6187769SFabian Frederick	bool "sgetmask/ssetmask syscalls support" if EXPERT
1736cd14b018SMasahiro Yamada	default PARISC || M68K || PPC || MIPS || X86 || SPARC || MICROBLAZE || SUPERH
1737a7f7f624SMasahiro Yamada	help
1738f6187769SFabian Frederick	  sys_sgetmask and sys_ssetmask are obsolete system calls
1739f6187769SFabian Frederick	  no longer supported in libc but still enabled by default in some
1740f6187769SFabian Frederick	  architectures.
1741f6187769SFabian Frederick
1742f6187769SFabian Frederick	  If unsure, leave the default option here.
1743f6187769SFabian Frederick
1744d1b069f5SRandy Dunlapconfig FHANDLE
1745d1b069f5SRandy Dunlap	bool "open by fhandle syscalls" if EXPERT
1746d1b069f5SRandy Dunlap	select EXPORTFS
1747d1b069f5SRandy Dunlap	default y
1748d1b069f5SRandy Dunlap	help
1749d1b069f5SRandy Dunlap	  If you say Y here, a user level program will be able to map
1750d1b069f5SRandy Dunlap	  file names to handle and then later use the handle for
1751d1b069f5SRandy Dunlap	  different file system operations. This is useful in implementing
1752d1b069f5SRandy Dunlap	  userspace file servers, which now track files using handles instead
1753d1b069f5SRandy Dunlap	  of names. The handle would remain the same even if file names
1754d1b069f5SRandy Dunlap	  get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
1755d1b069f5SRandy Dunlap	  syscalls.
1756d1b069f5SRandy Dunlap
1757baa73d9eSNicolas Pitreconfig POSIX_TIMERS
1758baa73d9eSNicolas Pitre	bool "Posix Clocks & timers" if EXPERT
1759baa73d9eSNicolas Pitre	default y
1760baa73d9eSNicolas Pitre	help
1761baa73d9eSNicolas Pitre	  This includes native support for POSIX timers to the kernel.
1762baa73d9eSNicolas Pitre	  Some embedded systems have no use for them and therefore they
1763baa73d9eSNicolas Pitre	  can be configured out to reduce the size of the kernel image.
1764baa73d9eSNicolas Pitre
1765baa73d9eSNicolas Pitre	  When this option is disabled, the following syscalls won't be
1766baa73d9eSNicolas Pitre	  available: timer_create, timer_gettime: timer_getoverrun,
1767baa73d9eSNicolas Pitre	  timer_settime, timer_delete, clock_adjtime, getitimer,
1768baa73d9eSNicolas Pitre	  setitimer, alarm. Furthermore, the clock_settime, clock_gettime,
1769baa73d9eSNicolas Pitre	  clock_getres and clock_nanosleep syscalls will be limited to
1770baa73d9eSNicolas Pitre	  CLOCK_REALTIME, CLOCK_MONOTONIC and CLOCK_BOOTTIME only.
1771baa73d9eSNicolas Pitre
1772baa73d9eSNicolas Pitre	  If unsure say y.
1773baa73d9eSNicolas Pitre
1774d59745ceSMatt Mackallconfig PRINTK
1775d59745ceSMatt Mackall	default y
17766a108a14SDavid Rientjes	bool "Enable support for printk" if EXPERT
177774876a98SFrederic Weisbecker	select IRQ_WORK
1778d59745ceSMatt Mackall	help
1779d59745ceSMatt Mackall	  This option enables normal printk support. Removing it
1780d59745ceSMatt Mackall	  eliminates most of the message strings from the kernel image
1781d59745ceSMatt Mackall	  and makes the kernel more or less silent. As this makes it
1782d59745ceSMatt Mackall	  very difficult to diagnose system problems, saying N here is
1783d59745ceSMatt Mackall	  strongly discouraged.
1784d59745ceSMatt Mackall
17855ea2bcdfSThomas Weißschuhconfig PRINTK_RINGBUFFER_KUNIT_TEST
17865ea2bcdfSThomas Weißschuh	tristate "KUnit Test for the printk ringbuffer" if !KUNIT_ALL_TESTS
17875ea2bcdfSThomas Weißschuh	depends on PRINTK && KUNIT
17885ea2bcdfSThomas Weißschuh	default KUNIT_ALL_TESTS
17895ea2bcdfSThomas Weißschuh	help
17905ea2bcdfSThomas Weißschuh	  This builds the printk ringbuffer KUnit test suite.
17915ea2bcdfSThomas Weißschuh
17925ea2bcdfSThomas Weißschuh	  For more information on KUnit and unit tests in general, please refer
17935ea2bcdfSThomas Weißschuh	  to the KUnit documentation.
17945ea2bcdfSThomas Weißschuh
17955ea2bcdfSThomas Weißschuh	  If unsure, say N.
17965ea2bcdfSThomas Weißschuh
1797c8538a7aSMatt Mackallconfig BUG
17986a108a14SDavid Rientjes	bool "BUG() support" if EXPERT
1799c8538a7aSMatt Mackall	default y
1800c8538a7aSMatt Mackall	help
1801c8538a7aSMatt Mackall	  Disabling this option eliminates support for BUG and WARN, reducing
1802c8538a7aSMatt Mackall	  the size of your kernel image and potentially quietly ignoring
1803c8538a7aSMatt Mackall	  numerous fatal conditions. You should only consider disabling this
1804c8538a7aSMatt Mackall	  option for embedded systems with no facilities for reporting errors.
1805c8538a7aSMatt Mackall	  Just say Y.
1806c8538a7aSMatt Mackall
1807708e9a79SMatt Mackallconfig ELF_CORE
1808046d662fSAlex Kelly	depends on COREDUMP
1809708e9a79SMatt Mackall	default y
18106a108a14SDavid Rientjes	bool "Enable ELF core dumps" if EXPERT
1811708e9a79SMatt Mackall	help
1812708e9a79SMatt Mackall	  Enable support for generating core dumps. Disabling saves about 4k.
1813708e9a79SMatt Mackall
18148761f1abSRalf Baechle
1815e5e1d3cbSStas Sergeevconfig PCSPKR_PLATFORM
18166a108a14SDavid Rientjes	bool "Enable PC-Speaker support" if EXPERT
18178761f1abSRalf Baechle	depends on HAVE_PCSPKR_PLATFORM
181815f304b6SRalf Baechle	select I8253_LOCK
1819e5e1d3cbSStas Sergeev	default y
1820e5e1d3cbSStas Sergeev	help
1821e5e1d3cbSStas Sergeev	  This option allows to disable the internal PC-Speaker
1822e5e1d3cbSStas Sergeev	  support, saving some memory.
1823e5e1d3cbSStas Sergeev
182427021649SYoann Congalconfig BASE_SMALL
182527021649SYoann Congal	bool "Enable smaller-sized data structures for core" if EXPERT
18261da177e4SLinus Torvalds	help
182727021649SYoann Congal	  Enabling this option reduces the size of miscellaneous core
18281da177e4SLinus Torvalds	  kernel data structures. This saves memory on small machines,
18291da177e4SLinus Torvalds	  but may reduce performance.
18301da177e4SLinus Torvalds
18311da177e4SLinus Torvaldsconfig FUTEX
18326a108a14SDavid Rientjes	bool "Enable futex support" if EXPERT
18333f2bedabSArnd Bergmann	depends on !(SPARC32 && SMP)
18341da177e4SLinus Torvalds	default y
1835bc2eecd7SNicolas Pitre	imply RT_MUTEXES
18361da177e4SLinus Torvalds	help
18371da177e4SLinus Torvalds	  Disabling this option will cause the kernel to be built without
18381da177e4SLinus Torvalds	  support for "fast userspace mutexes".  The resulting kernel may not
18391da177e4SLinus Torvalds	  run glibc-based applications correctly.
18401da177e4SLinus Torvalds
1841bc2eecd7SNicolas Pitreconfig FUTEX_PI
1842bc2eecd7SNicolas Pitre	bool
1843bc2eecd7SNicolas Pitre	depends on FUTEX && RT_MUTEXES
1844bc2eecd7SNicolas Pitre	default y
1845bc2eecd7SNicolas Pitre
184680367ad0SSebastian Andrzej Siewiorconfig FUTEX_PRIVATE_HASH
184780367ad0SSebastian Andrzej Siewior	bool
184880367ad0SSebastian Andrzej Siewior	depends on FUTEX && !BASE_SMALL && MMU
184980367ad0SSebastian Andrzej Siewior	default y
185080367ad0SSebastian Andrzej Siewior
1851c042c505SPeter Zijlstraconfig FUTEX_MPOL
1852c042c505SPeter Zijlstra	bool
1853c042c505SPeter Zijlstra	depends on FUTEX && NUMA
1854c042c505SPeter Zijlstra	default y
1855c042c505SPeter Zijlstra
1856042df0c1SThomas Gleixnerconfig HAVE_FUTEX_ROBUST_UNLOCK
1857042df0c1SThomas Gleixner	bool
1858042df0c1SThomas Gleixner
1859042df0c1SThomas Gleixnerconfig FUTEX_ROBUST_UNLOCK
1860042df0c1SThomas Gleixner	def_bool FUTEX && HAVE_GENERIC_VDSO && GENERIC_IRQ_ENTRY && RSEQ && HAVE_FUTEX_ROBUST_UNLOCK
1861042df0c1SThomas Gleixner
18621da177e4SLinus Torvaldsconfig EPOLL
18636a108a14SDavid Rientjes	bool "Enable eventpoll support" if EXPERT
18641da177e4SLinus Torvalds	default y
18651da177e4SLinus Torvalds	help
18661da177e4SLinus Torvalds	  Disabling this option will cause the kernel to be built without
18671da177e4SLinus Torvalds	  support for epoll family of system calls.
18681da177e4SLinus Torvalds
1869fba2afaaSDavide Libenziconfig SIGNALFD
18706a108a14SDavid Rientjes	bool "Enable signalfd() system call" if EXPERT
1871fba2afaaSDavide Libenzi	default y
1872fba2afaaSDavide Libenzi	help
1873fba2afaaSDavide Libenzi	  Enable the signalfd() system call that allows to receive signals
1874fba2afaaSDavide Libenzi	  on a file descriptor.
1875fba2afaaSDavide Libenzi
1876fba2afaaSDavide Libenzi	  If unsure, say Y.
1877fba2afaaSDavide Libenzi
1878b215e283SDavide Libenziconfig TIMERFD
18796a108a14SDavid Rientjes	bool "Enable timerfd() system call" if EXPERT
1880b215e283SDavide Libenzi	default y
1881b215e283SDavide Libenzi	help
1882b215e283SDavide Libenzi	  Enable the timerfd() system call that allows to receive timer
1883b215e283SDavide Libenzi	  events on a file descriptor.
1884b215e283SDavide Libenzi
1885b215e283SDavide Libenzi	  If unsure, say Y.
1886b215e283SDavide Libenzi
1887e1ad7468SDavide Libenziconfig EVENTFD
18886a108a14SDavid Rientjes	bool "Enable eventfd() system call" if EXPERT
1889e1ad7468SDavide Libenzi	default y
1890e1ad7468SDavide Libenzi	help
1891e1ad7468SDavide Libenzi	  Enable the eventfd() system call that allows to receive both
1892e1ad7468SDavide Libenzi	  kernel notification (ie. KAIO) or userspace notifications.
1893e1ad7468SDavide Libenzi
1894e1ad7468SDavide Libenzi	  If unsure, say Y.
1895e1ad7468SDavide Libenzi
18961da177e4SLinus Torvaldsconfig SHMEM
18976a108a14SDavid Rientjes	bool "Use full shmem filesystem" if EXPERT
18981da177e4SLinus Torvalds	default y
18991da177e4SLinus Torvalds	depends on MMU
19001da177e4SLinus Torvalds	help
19011da177e4SLinus Torvalds	  The shmem is an internal filesystem used to manage shared memory.
19021da177e4SLinus Torvalds	  It is backed by swap and manages resource limits. It is also exported
19031da177e4SLinus Torvalds	  to userspace as tmpfs if TMPFS is enabled. Disabling this
19041da177e4SLinus Torvalds	  option replaces shmem and tmpfs with the much simpler ramfs code,
19051da177e4SLinus Torvalds	  which may be appropriate on small systems without swap.
19061da177e4SLinus Torvalds
1907ebf3f09cSThomas Petazzoniconfig AIO
19086a108a14SDavid Rientjes	bool "Enable AIO support" if EXPERT
1909ebf3f09cSThomas Petazzoni	default y
1910ebf3f09cSThomas Petazzoni	help
1911ebf3f09cSThomas Petazzoni	  This option enables POSIX asynchronous I/O which may by used
1912ebf3f09cSThomas Petazzoni	  by some high performance threaded applications. Disabling
1913ebf3f09cSThomas Petazzoni	  this option saves about 7k.
1914ebf3f09cSThomas Petazzoni
19152b188cc1SJens Axboeconfig IO_URING
19162b188cc1SJens Axboe	bool "Enable IO uring support" if EXPERT
1917561fb04aSJens Axboe	select IO_WQ
19182b188cc1SJens Axboe	default y
19192b188cc1SJens Axboe	help
19202b188cc1SJens Axboe	  This option enables support for the io_uring interface, enabling
19212b188cc1SJens Axboe	  applications to submit and complete IO through submission and
19222b188cc1SJens Axboe	  completion rings that are shared between the kernel and application.
19232b188cc1SJens Axboe
19241802656eSJens Axboeconfig GCOV_PROFILE_URING
19251802656eSJens Axboe	bool "Enable GCOV profiling on the io_uring subsystem"
1926d1fbe1ebSRandy Dunlap	depends on IO_URING && GCOV_KERNEL
19271802656eSJens Axboe	help
19281802656eSJens Axboe	  Enable GCOV profiling on the io_uring subsystem, to facilitate
19291802656eSJens Axboe	  code coverage testing.
19301802656eSJens Axboe
19311802656eSJens Axboe	  If unsure, say N.
19321802656eSJens Axboe
19331802656eSJens Axboe	  Note that this will have a negative impact on the performance of
19341802656eSJens Axboe	  the io_uring subsystem, hence this should only be enabled for
19351802656eSJens Axboe	  specific test purposes.
19361802656eSJens Axboe
19373a0ae385SPavel Begunkovconfig IO_URING_MOCK_FILE
19383a0ae385SPavel Begunkov	tristate "Enable io_uring mock files (Experimental)" if EXPERT
19393a0ae385SPavel Begunkov	default n
19403a0ae385SPavel Begunkov	depends on IO_URING
19413a0ae385SPavel Begunkov	help
19429e7dc228SJ. Neuschäfer	  Enable mock files for io_uring subsystem testing. The ABI might
19433a0ae385SPavel Begunkov	  still change, so it's still experimental and should only be enabled
19443a0ae385SPavel Begunkov	  for specific test purposes.
19453a0ae385SPavel Begunkov
19463a0ae385SPavel Begunkov	  If unsure, say N.
19473a0ae385SPavel Begunkov
1948d3ac21caSJosh Triplettconfig ADVISE_SYSCALLS
1949d3ac21caSJosh Triplett	bool "Enable madvise/fadvise syscalls" if EXPERT
1950d3ac21caSJosh Triplett	default y
1951d3ac21caSJosh Triplett	help
1952d3ac21caSJosh Triplett	  This option enables the madvise and fadvise syscalls, used by
1953d3ac21caSJosh Triplett	  applications to advise the kernel about their future memory or file
1954d3ac21caSJosh Triplett	  usage, improving performance. If building an embedded system where no
1955d3ac21caSJosh Triplett	  applications use these syscalls, you can disable this option to save
1956d3ac21caSJosh Triplett	  space.
1957d3ac21caSJosh Triplett
19585b25b13aSMathieu Desnoyersconfig MEMBARRIER
19595b25b13aSMathieu Desnoyers	bool "Enable membarrier() system call" if EXPERT
19605b25b13aSMathieu Desnoyers	default y
19615b25b13aSMathieu Desnoyers	help
19625b25b13aSMathieu Desnoyers	  Enable the membarrier() system call that allows issuing memory
19635b25b13aSMathieu Desnoyers	  barriers across all running threads, which can be used to distribute
19645b25b13aSMathieu Desnoyers	  the cost of user-space memory barriers asymmetrically by transforming
19655b25b13aSMathieu Desnoyers	  pairs of memory barriers into pairs consisting of membarrier() and a
19665b25b13aSMathieu Desnoyers	  compiler barrier.
19675b25b13aSMathieu Desnoyers
19685b25b13aSMathieu Desnoyers	  If unsure, say Y.
19695b25b13aSMathieu Desnoyers
1970a751ea34SRandy Dunlapconfig KCMP
1971a751ea34SRandy Dunlap	bool "Enable kcmp() system call" if EXPERT
1972a751ea34SRandy Dunlap	help
1973a751ea34SRandy Dunlap	  Enable the kernel resource comparison system call. It provides
1974a751ea34SRandy Dunlap	  user-space with the ability to compare two processes to see if they
1975a751ea34SRandy Dunlap	  share a common resource, such as a file descriptor or even virtual
1976a751ea34SRandy Dunlap	  memory space.
1977a751ea34SRandy Dunlap
1978a751ea34SRandy Dunlap	  If unsure, say N.
1979a751ea34SRandy Dunlap
1980a751ea34SRandy Dunlapconfig RSEQ
1981a751ea34SRandy Dunlap	bool "Enable rseq() system call" if EXPERT
1982a751ea34SRandy Dunlap	default y
1983a751ea34SRandy Dunlap	depends on HAVE_RSEQ
1984a751ea34SRandy Dunlap	select MEMBARRIER
1985a751ea34SRandy Dunlap	help
1986a751ea34SRandy Dunlap	  Enable the restartable sequences system call. It provides a
1987a751ea34SRandy Dunlap	  user-space cache for the current CPU number value, which
1988a751ea34SRandy Dunlap	  speeds up getting the current CPU number from user-space,
1989a751ea34SRandy Dunlap	  as well as an ABI to speed up user-space operations on
1990a751ea34SRandy Dunlap	  per-CPU data.
1991a751ea34SRandy Dunlap
1992a751ea34SRandy Dunlap	  If unsure, say Y.
1993a751ea34SRandy Dunlap
1994d7a5da7aSThomas Gleixnerconfig RSEQ_SLICE_EXTENSION
1995d7a5da7aSThomas Gleixner	bool "Enable rseq-based time slice extension mechanism"
1996d7a5da7aSThomas Gleixner	depends on RSEQ && HIGH_RES_TIMERS && GENERIC_ENTRY && HAVE_GENERIC_TIF_BITS
1997d7a5da7aSThomas Gleixner	help
1998d7a5da7aSThomas Gleixner	  Allows userspace to request a limited time slice extension when
1999d7a5da7aSThomas Gleixner	  returning from an interrupt to user space via the RSEQ shared
2000d7a5da7aSThomas Gleixner	  data ABI. If granted, that allows to complete a critical section,
2001d7a5da7aSThomas Gleixner	  so that other threads are not stuck on a conflicted resource,
2002d7a5da7aSThomas Gleixner	  while the task is scheduled out.
2003d7a5da7aSThomas Gleixner
2004d7a5da7aSThomas Gleixner	  If unsure, say N.
2005d7a5da7aSThomas Gleixner
200654129104SThomas Gleixnerconfig RSEQ_STATS
200754129104SThomas Gleixner	default n
200854129104SThomas Gleixner	bool "Enable lightweight statistics of restartable sequences" if EXPERT
200954129104SThomas Gleixner	depends on RSEQ && DEBUG_FS
201054129104SThomas Gleixner	help
201154129104SThomas Gleixner	  Enable lightweight counters which expose information about the
201254129104SThomas Gleixner	  frequency of RSEQ operations via debugfs. Mostly interesting for
201354129104SThomas Gleixner	  kernel debugging or performance analysis. While lightweight it's
201454129104SThomas Gleixner	  still adding code into the user/kernel mode transitions.
201554129104SThomas Gleixner
201654129104SThomas Gleixner	  If unsure, say N.
201754129104SThomas Gleixner
20189c37cb6eSThomas Gleixnerconfig RSEQ_DEBUG_DEFAULT_ENABLE
20199c37cb6eSThomas Gleixner	default n
20209c37cb6eSThomas Gleixner	bool "Enable restartable sequences debug mode by default" if EXPERT
20219c37cb6eSThomas Gleixner	depends on RSEQ
20229c37cb6eSThomas Gleixner	help
20239c37cb6eSThomas Gleixner	  This enables the static branch for debug mode of restartable
20249c37cb6eSThomas Gleixner	  sequences.
20259c37cb6eSThomas Gleixner
20269c37cb6eSThomas Gleixner	  This also can be controlled on the kernel command line via the
20279c37cb6eSThomas Gleixner	  command line parameter "rseq_debug=0/1" and through debugfs.
20289c37cb6eSThomas Gleixner
20299c37cb6eSThomas Gleixner	  If unsure, say N.
20309c37cb6eSThomas Gleixner
2031a751ea34SRandy Dunlapconfig DEBUG_RSEQ
2032a751ea34SRandy Dunlap	default n
2033a751ea34SRandy Dunlap	bool "Enable debugging of rseq() system call" if EXPERT
20343db6b38dSThomas Gleixner	depends on RSEQ && DEBUG_KERNEL && !GENERIC_ENTRY
20359c37cb6eSThomas Gleixner	select RSEQ_DEBUG_DEFAULT_ENABLE
2036a751ea34SRandy Dunlap	help
2037a751ea34SRandy Dunlap	  Enable extra debugging checks for the rseq system call.
2038a751ea34SRandy Dunlap
2039a751ea34SRandy Dunlap	  If unsure, say N.
2040a751ea34SRandy Dunlap
2041a751ea34SRandy Dunlapconfig CACHESTAT_SYSCALL
2042a751ea34SRandy Dunlap	bool "Enable cachestat() system call" if EXPERT
2043a751ea34SRandy Dunlap	default y
2044a751ea34SRandy Dunlap	help
2045a751ea34SRandy Dunlap	  Enable the cachestat system call, which queries the page cache
2046a751ea34SRandy Dunlap	  statistics of a file (number of cached pages, dirty pages,
2047a751ea34SRandy Dunlap	  pages marked for writeback, (recently) evicted pages).
2048a751ea34SRandy Dunlap
2049a751ea34SRandy Dunlap	  If unsure say Y here.
2050a751ea34SRandy Dunlap
2051d1b069f5SRandy Dunlapconfig KALLSYMS
2052d1b069f5SRandy Dunlap	bool "Load all symbols for debugging/ksymoops" if EXPERT
2053d1b069f5SRandy Dunlap	default y
2054d1b069f5SRandy Dunlap	help
2055d1b069f5SRandy Dunlap	  Say Y here to let the kernel print out symbolic crash information and
2056d1b069f5SRandy Dunlap	  symbolic stack backtraces. This increases the size of the kernel
2057d1b069f5SRandy Dunlap	  somewhat, as all symbols have to be loaded into the kernel image.
2058d1b069f5SRandy Dunlap
205930f3bb09SZhen Leiconfig KALLSYMS_SELFTEST
206030f3bb09SZhen Lei	bool "Test the basic functions and performance of kallsyms"
206130f3bb09SZhen Lei	depends on KALLSYMS
206230f3bb09SZhen Lei	default n
206330f3bb09SZhen Lei	help
206430f3bb09SZhen Lei	  Test the basic functions and performance of some interfaces, such as
206530f3bb09SZhen Lei	  kallsyms_lookup_name. It also calculates the compression rate of the
206630f3bb09SZhen Lei	  kallsyms compression algorithm for the current symbol set.
206730f3bb09SZhen Lei
206830f3bb09SZhen Lei	  Start self-test automatically after system startup. Suggest executing
206930f3bb09SZhen Lei	  "dmesg | grep kallsyms_selftest" to collect test results. "finish" is
207030f3bb09SZhen Lei	  displayed in the last line, indicating that the test is complete.
207130f3bb09SZhen Lei
2072d1b069f5SRandy Dunlapconfig KALLSYMS_ALL
2073d1b069f5SRandy Dunlap	bool "Include all symbols in kallsyms"
2074d1b069f5SRandy Dunlap	depends on DEBUG_KERNEL && KALLSYMS
2075d1b069f5SRandy Dunlap	help
2076d1b069f5SRandy Dunlap	  Normally kallsyms only contains the symbols of functions for nicer
2077d1b069f5SRandy Dunlap	  OOPS messages and backtraces (i.e., symbols from the text and inittext
2078bdf0fe33SBaruch Siach	  sections). This is sufficient for most cases. And only if you want to
2079bdf0fe33SBaruch Siach	  enable kernel live patching, or other less common use cases (e.g.,
2080bdf0fe33SBaruch Siach	  when a debugger is used) all symbols are required (i.e., names of
2081bdf0fe33SBaruch Siach	  variables from the data sections, etc).
2082d1b069f5SRandy Dunlap
2083d1b069f5SRandy Dunlap	  This option makes sure that all symbols are loaded into the kernel
2084d1b069f5SRandy Dunlap	  image (i.e., symbols from all sections) in cost of increased kernel
2085d1b069f5SRandy Dunlap	  size (depending on the kernel configuration, it may be 300KiB or
2086d1b069f5SRandy Dunlap	  something like this).
2087d1b069f5SRandy Dunlap
2088bdf0fe33SBaruch Siach	  Say N unless you really need all symbols, or kernel live patching.
2089d1b069f5SRandy Dunlap
2090d1b069f5SRandy Dunlap# end of the "standard kernel features (expert users)" menu
2091d1b069f5SRandy Dunlap
20923ccfebedSMathieu Desnoyersconfig ARCH_HAS_MEMBARRIER_CALLBACKS
20933ccfebedSMathieu Desnoyers	bool
20943ccfebedSMathieu Desnoyers
209570216e18SMathieu Desnoyersconfig ARCH_HAS_MEMBARRIER_SYNC_CORE
209670216e18SMathieu Desnoyers	bool
209770216e18SMathieu Desnoyers
20985796d396SJeff Xuconfig ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS
20995796d396SJeff Xu	bool
21005796d396SJeff Xu	help
21015796d396SJeff Xu	  Control MSEAL_SYSTEM_MAPPINGS access based on architecture.
21025796d396SJeff Xu
21035796d396SJeff Xu	  A 64-bit kernel is required for the memory sealing feature.
21045796d396SJeff Xu	  No specific hardware features from the CPU are needed.
21055796d396SJeff Xu
21065796d396SJeff Xu	  To enable this feature, the architecture needs to update their
21075796d396SJeff Xu	  special mappings calls to include the sealing flag and confirm
21085796d396SJeff Xu	  that it doesn't unmap/remap system mappings during the life
21095796d396SJeff Xu	  time of the process. The existence of this flag for an architecture
21105796d396SJeff Xu	  implies that it does not require the remapping of the system
21115796d396SJeff Xu	  mappings during process lifetime, so sealing these mappings is safe
21125796d396SJeff Xu	  from a kernel perspective.
21135796d396SJeff Xu
21145796d396SJeff Xu	  After the architecture enables this, a distribution can set
21155796d396SJeff Xu	  CONFIG_MSEAL_SYSTEM_MAPPING to manage access to the feature.
21165796d396SJeff Xu
21175796d396SJeff Xu	  For complete descriptions of memory sealing, please see
21185796d396SJeff Xu	  Documentation/userspace-api/mseal.rst
21195796d396SJeff Xu
2120cdd6c482SIngo Molnarconfig HAVE_PERF_EVENTS
21210793a61dSThomas Gleixner	bool
2122018df72dSMike Frysinger	help
2123018df72dSMike Frysinger	  See tools/perf/design.txt for details.
21240793a61dSThomas Gleixner
21252aef6f30SSean Christophersonconfig GUEST_PERF_EVENTS
21262aef6f30SSean Christopherson	bool
21272aef6f30SSean Christopherson	depends on HAVE_PERF_EVENTS
21282aef6f30SSean Christopherson
2129eff95e17SKan Liangconfig PERF_GUEST_MEDIATED_PMU
2130eff95e17SKan Liang	bool
2131eff95e17SKan Liang	depends on GUEST_PERF_EVENTS
2132eff95e17SKan Liang
2133906010b2SPeter Zijlstraconfig PERF_USE_VMALLOC
2134906010b2SPeter Zijlstra	bool
2135906010b2SPeter Zijlstra	help
2136906010b2SPeter Zijlstra	  See tools/perf/design.txt for details
2137906010b2SPeter Zijlstra
213857c0c15bSIngo Molnarmenu "Kernel Performance Events And Counters"
21390793a61dSThomas Gleixner
2140cdd6c482SIngo Molnarconfig PERF_EVENTS
214157c0c15bSIngo Molnar	bool "Kernel performance events and counters"
2142392d65a9SRobert Richter	default y if PROFILING
2143cdd6c482SIngo Molnar	depends on HAVE_PERF_EVENTS
2144e360adbeSPeter Zijlstra	select IRQ_WORK
21450793a61dSThomas Gleixner	help
214657c0c15bSIngo Molnar	  Enable kernel support for various performance events provided
214757c0c15bSIngo Molnar	  by software and hardware.
21480793a61dSThomas Gleixner
2149dd77038dSThadeu Lima de Souza Cascardo	  Software events are supported either built-in or via the
215057c0c15bSIngo Molnar	  use of generic tracepoints.
215157c0c15bSIngo Molnar
215257c0c15bSIngo Molnar	  Most modern CPUs support performance events via performance
215357c0c15bSIngo Molnar	  counter registers. These registers count the number of certain
21540793a61dSThomas Gleixner	  types of hw events: such as instructions executed, cachemisses
21550793a61dSThomas Gleixner	  suffered, or branches mis-predicted - without slowing down the
21560793a61dSThomas Gleixner	  kernel or applications. These registers can also trigger interrupts
21570793a61dSThomas Gleixner	  when a threshold number of events have passed - and can thus be
21580793a61dSThomas Gleixner	  used to profile the code that runs on that CPU.
21590793a61dSThomas Gleixner
216057c0c15bSIngo Molnar	  The Linux Performance Event subsystem provides an abstraction of
2161dd77038dSThadeu Lima de Souza Cascardo	  these software and hardware event capabilities, available via a
216257c0c15bSIngo Molnar	  system call and used by the "perf" utility in tools/perf/. It
21630793a61dSThomas Gleixner	  provides per task and per CPU counters, and it provides event
21640793a61dSThomas Gleixner	  capabilities on top of those.
21650793a61dSThomas Gleixner
21660793a61dSThomas Gleixner	  Say Y if unsure.
21670793a61dSThomas Gleixner
2168906010b2SPeter Zijlstraconfig DEBUG_PERF_USE_VMALLOC
2169906010b2SPeter Zijlstra	default n
2170906010b2SPeter Zijlstra	bool "Debug: use vmalloc to back perf mmap() buffers"
2171cb307113SMichael Ellerman	depends on PERF_EVENTS && DEBUG_KERNEL && !PPC
2172906010b2SPeter Zijlstra	select PERF_USE_VMALLOC
2173906010b2SPeter Zijlstra	help
2174906010b2SPeter Zijlstra	  Use vmalloc memory to back perf mmap() buffers.
2175906010b2SPeter Zijlstra
2176906010b2SPeter Zijlstra	  Mostly useful for debugging the vmalloc code on platforms
2177906010b2SPeter Zijlstra	  that don't require it.
2178906010b2SPeter Zijlstra
2179906010b2SPeter Zijlstra	  Say N if unsure.
2180906010b2SPeter Zijlstra
21810793a61dSThomas Gleixnerendmenu
21820793a61dSThomas Gleixner
2183091f6e26SDavid Howellsconfig SYSTEM_DATA_VERIFICATION
2184091f6e26SDavid Howells	def_bool n
2185091f6e26SDavid Howells	select SYSTEM_TRUSTED_KEYRING
2186091f6e26SDavid Howells	select KEYS
2187091f6e26SDavid Howells	select CRYPTO
2188d43de6c7SDavid Howells	select CRYPTO_RSA
2189091f6e26SDavid Howells	select ASYMMETRIC_KEY_TYPE
2190091f6e26SDavid Howells	select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
2191091f6e26SDavid Howells	select ASN1
2192091f6e26SDavid Howells	select OID_REGISTRY
2193091f6e26SDavid Howells	select X509_CERTIFICATE_PARSER
2194091f6e26SDavid Howells	select PKCS7_MESSAGE_PARSER
219582c04ff8SPeter Foley	help
2196091f6e26SDavid Howells	  Provide PKCS#7 message verification using the contents of the system
2197091f6e26SDavid Howells	  trusted keyring to provide public keys.  This then can be used for
2198091f6e26SDavid Howells	  module verification, kexec image verification and firmware blob
2199091f6e26SDavid Howells	  verification.
220082c04ff8SPeter Foley
2201125e5645SMathieu Desnoyersconfig PROFILING
2202b309a294SRobert Richter	bool "Profiling support"
2203125e5645SMathieu Desnoyers	help
2204125e5645SMathieu Desnoyers	  Say Y here to enable the extended profiling support mechanisms used
2205f8408264SViresh Kumar	  by profilers.
2206125e5645SMathieu Desnoyers
22072f7ab126SMiguel Ojedaconfig RUST
22082f7ab126SMiguel Ojeda	bool "Rust support"
22092f7ab126SMiguel Ojeda	depends on HAVE_RUST
22102f7ab126SMiguel Ojeda	depends on RUST_IS_AVAILABLE
2211ac61506bSSami Tolvanen	select EXTENDED_MODVERSIONS if MODVERSIONS
2212ac61506bSSami Tolvanen	depends on !MODVERSIONS || GENDWARFKSYMS
2213f1385dc6SNeal Gompa	depends on !GCC_PLUGIN_RANDSTRUCT
22142f7ab126SMiguel Ojeda	depends on !RANDSTRUCT
22155daa0c35SMatthew Maurer	depends on !DEBUG_INFO_BTF || (PAHOLE_HAS_LANG_EXCLUDE && !LTO)
221623ef9d43SKees Cook	depends on !CFI || HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC
221723ef9d43SKees Cook	select CFI_ICALL_NORMALIZE_INTEGERS if CFI
22185b271543SAlice Ryhl	depends on !KASAN || CC_IS_CLANG
221972d33b8bSAlice Ryhl	depends on !KASAN_SW_TAGS || RUSTC_VERSION >= 109600
22202f7ab126SMiguel Ojeda	help
22212f7ab126SMiguel Ojeda	  Enables Rust support in the kernel.
22222f7ab126SMiguel Ojeda
22232f7ab126SMiguel Ojeda	  This allows other Rust-related options, like drivers written in Rust,
22242f7ab126SMiguel Ojeda	  to be selected.
22252f7ab126SMiguel Ojeda
22262f7ab126SMiguel Ojeda	  It is also required to be able to load external kernel modules
22272f7ab126SMiguel Ojeda	  written in Rust.
22282f7ab126SMiguel Ojeda
22292f7ab126SMiguel Ojeda	  See Documentation/rust/ for more information.
22302f7ab126SMiguel Ojeda
22312f7ab126SMiguel Ojeda	  If unsure, say N.
22322f7ab126SMiguel Ojeda
2233*e74b7a3fSYury Norovsource "rust/kernel/Kconfig.test"
2234*e74b7a3fSYury Norov
22352f7ab126SMiguel Ojedaconfig RUSTC_VERSION_TEXT
22362f7ab126SMiguel Ojeda	string
22372f7ab126SMiguel Ojeda	depends on RUST
22385134a335SMiguel Ojeda	default "$(RUSTC_VERSION_TEXT)"
22395134a335SMiguel Ojeda	help
22405134a335SMiguel Ojeda	  See `CC_VERSION_TEXT`.
22412f7ab126SMiguel Ojeda
22422f7ab126SMiguel Ojedaconfig BINDGEN_VERSION_TEXT
22432f7ab126SMiguel Ojeda	string
22442f7ab126SMiguel Ojeda	depends on RUST
224593553d99SMiguel Ojeda	default "$(shell,$(BINDGEN) --version 2>/dev/null)"
22462f7ab126SMiguel Ojeda
22475f87f112SIngo Molnar#
22485f87f112SIngo Molnar# Place an empty function call at each tracepoint site. Can be
22495f87f112SIngo Molnar# dynamically changed for a probe function.
22505f87f112SIngo Molnar#
225197e1c18eSMathieu Desnoyersconfig TRACEPOINTS
22525f87f112SIngo Molnar	bool
2253a363d27cSMathieu Desnoyers	select TASKS_TRACE_RCU
225497e1c18eSMathieu Desnoyers
225589cde455SEric DeVoldersource "kernel/Kconfig.kexec"
225689cde455SEric DeVolder
225748a1b232SPasha Tatashinsource "kernel/liveupdate/Kconfig"
225848a1b232SPasha Tatashin
22591da177e4SLinus Torvaldsendmenu		# General setup
22601da177e4SLinus Torvalds
22611572497cSChristoph Hellwigsource "arch/Kconfig"
22621572497cSChristoph Hellwig
2263ae81f9e3SChuck Ebbertconfig RT_MUTEXES
22646341e62bSChristoph Jaeger	bool
22651c6f9ec0SSebastian Andrzej Siewior	default y if PREEMPT_RT
2266ae81f9e3SChuck Ebbert
2267c8424e77SThiago Jung Bauermannconfig MODULE_SIG_FORMAT
2268c8424e77SThiago Jung Bauermann	def_bool n
2269c8424e77SThiago Jung Bauermann	select SYSTEM_DATA_VERIFICATION
2270c8424e77SThiago Jung Bauermann
227173b4fc92SChristophe Leroysource "kernel/module/Kconfig"
22726c9692e2SPeter Zijlstra
227398a79d6aSRusty Russellconfig INIT_ALL_POSSIBLE
227498a79d6aSRusty Russell	bool
227598a79d6aSRusty Russell	help
22765f054e31SRusty Russell	  Back when each arch used to define their own cpu_online_mask and
22775f054e31SRusty Russell	  cpu_possible_mask, some of them chose to initialize cpu_possible_mask
227898a79d6aSRusty Russell	  with all 1s, and others with all 0s.  When they were centralised,
227998a79d6aSRusty Russell	  it was better to provide this option than to break all the archs
2280692105b8SMatt LaPlante	  and have several arch maintainers pursuing me down dark alleys.
228198a79d6aSRusty Russell
22823a65dfe8SJens Axboesource "block/Kconfig"
2283e98c3202SAvi Kivity
2284e98c3202SAvi Kivityconfig PREEMPT_NOTIFIERS
2285e98c3202SAvi Kivity	bool
2286e260be67SPaul E. McKenney
228716295becSSteffen Klassertconfig PADATA
228816295becSSteffen Klassert	depends on SMP
228916295becSSteffen Klassert	bool
229016295becSSteffen Klassert
22914520c6a4SDavid Howellsconfig ASN1
22924520c6a4SDavid Howells	tristate
22934520c6a4SDavid Howells	help
22944520c6a4SDavid Howells	  Build a simple ASN.1 grammar compiler that produces a bytecode output
22954520c6a4SDavid Howells	  that can be interpreted by the ASN.1 stream decoder and used to
22964520c6a4SDavid Howells	  inform it as to what tags are to be expected in a stream and what
22974520c6a4SDavid Howells	  functions to call on what tags.
22984520c6a4SDavid Howells
22996beb0009SThomas Gleixnersource "kernel/Kconfig.locks"
2300e61938a9SMathieu Desnoyers
23010ebeea8cSDaniel Borkmannconfig ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
23020ebeea8cSDaniel Borkmann	bool
23030ebeea8cSDaniel Borkmann
23044ff4c745SAndrea Parriconfig ARCH_HAS_PREPARE_SYNC_CORE_CMD
23054ff4c745SAndrea Parri	bool
23064ff4c745SAndrea Parri
2307e61938a9SMathieu Desnoyersconfig ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
2308e61938a9SMathieu Desnoyers	bool
23091bd21c6cSDominik Brodowski
23101bd21c6cSDominik Brodowski# It may be useful for an architecture to override the definitions of the
23117303e30eSDominik Brodowski# SYSCALL_DEFINE() and __SYSCALL_DEFINEx() macros in <linux/syscalls.h>
23127303e30eSDominik Brodowski# and the COMPAT_ variants in <linux/compat.h>, in particular to use a
23137303e30eSDominik Brodowski# different calling convention for syscalls. They can also override the
23147303e30eSDominik Brodowski# macros for not-implemented syscalls in kernel/sys_ni.c and
23157303e30eSDominik Brodowski# kernel/time/posix-stubs.c. All these overrides need to be available in
23167303e30eSDominik Brodowski# <asm/syscall_wrapper.h>.
23171bd21c6cSDominik Brodowskiconfig ARCH_HAS_SYSCALL_WRAPPER
23181bd21c6cSDominik Brodowski	def_bool n
2319