xref: /linux/init/Kconfig (revision 509d3f45847627f4c5cdce004c3ec79262b5239c)
1ec8f24b7SThomas Gleixner# SPDX-License-Identifier: GPL-2.0-only
28b59cd81SMasahiro Yamadaconfig CC_VERSION_TEXT
38b59cd81SMasahiro Yamada	string
48b59cd81SMasahiro Yamada	default "$(CC_VERSION_TEXT)"
58b59cd81SMasahiro Yamada	help
68b59cd81SMasahiro Yamada	  This is used in unclear ways:
78b59cd81SMasahiro Yamada
88b59cd81SMasahiro Yamada	  - Re-run Kconfig when the compiler is updated
98b59cd81SMasahiro Yamada	    The 'default' property references the environment variable,
108b59cd81SMasahiro Yamada	    CC_VERSION_TEXT so it is recorded in include/config/auto.conf.cmd.
118b59cd81SMasahiro Yamada	    When the compiler is updated, Kconfig will be invoked.
128b59cd81SMasahiro Yamada
13f9c8bc46SBhaskar Chowdhury	  - Ensure full rebuild when the compiler is updated
14ce6ed1c4SMasahiro Yamada	    include/linux/compiler-version.h contains this option in the comment
150e0345b7SAlexey Dobriyan	    line so fixdep adds include/config/CC_VERSION_TEXT into the
16ce6ed1c4SMasahiro Yamada	    auto-generated dependency. When the compiler is updated, syncconfig
17ce6ed1c4SMasahiro Yamada	    will touch it and then every file will be rebuilt.
188b59cd81SMasahiro Yamada
19a4353898SMasahiro Yamadaconfig CC_IS_GCC
20aec6c60aSMasahiro Yamada	def_bool $(success,test "$(cc-name)" = GCC)
21a4353898SMasahiro Yamada
22a4353898SMasahiro Yamadaconfig GCC_VERSION
23a4353898SMasahiro Yamada	int
24aec6c60aSMasahiro Yamada	default $(cc-version) if CC_IS_GCC
25a4353898SMasahiro Yamada	default 0
26a4353898SMasahiro Yamada
27469cb737SMasahiro Yamadaconfig CC_IS_CLANG
28aec6c60aSMasahiro Yamada	def_bool $(success,test "$(cc-name)" = Clang)
29b744b43fSSami Tolvanen
30469cb737SMasahiro Yamadaconfig CLANG_VERSION
31469cb737SMasahiro Yamada	int
32aec6c60aSMasahiro Yamada	default $(cc-version) if CC_IS_CLANG
33aec6c60aSMasahiro Yamada	default 0
34469cb737SMasahiro Yamada
35ba64beb1SMasahiro Yamadaconfig AS_IS_GNU
36ba64beb1SMasahiro Yamada	def_bool $(success,test "$(as-name)" = GNU)
37ba64beb1SMasahiro Yamada
38ba64beb1SMasahiro Yamadaconfig AS_IS_LLVM
39ba64beb1SMasahiro Yamada	def_bool $(success,test "$(as-name)" = LLVM)
40ba64beb1SMasahiro Yamada
41ba64beb1SMasahiro Yamadaconfig AS_VERSION
42ba64beb1SMasahiro Yamada	int
43ba64beb1SMasahiro Yamada	# Use clang version if this is the integrated assembler
44ba64beb1SMasahiro Yamada	default CLANG_VERSION if AS_IS_LLVM
45ba64beb1SMasahiro Yamada	default $(as-version)
46ba64beb1SMasahiro Yamada
4702aff859SMasahiro Yamadaconfig LD_IS_BFD
4802aff859SMasahiro Yamada	def_bool $(success,test "$(ld-name)" = BFD)
4902aff859SMasahiro Yamada
5002aff859SMasahiro Yamadaconfig LD_VERSION
5102aff859SMasahiro Yamada	int
5202aff859SMasahiro Yamada	default $(ld-version) if LD_IS_BFD
5302aff859SMasahiro Yamada	default 0
5402aff859SMasahiro Yamada
5502aff859SMasahiro Yamadaconfig LD_IS_LLD
5602aff859SMasahiro Yamada	def_bool $(success,test "$(ld-name)" = LLD)
57c65eacbeSAndy Lutomirski
58d5750cd3SNathan Chancellorconfig LLD_VERSION
59d5750cd3SNathan Chancellor	int
6002aff859SMasahiro Yamada	default $(ld-version) if LD_IS_LLD
6102aff859SMasahiro Yamada	default 0
62d5750cd3SNathan Chancellor
636e74c6b5SMiguel Ojedaconfig RUSTC_VERSION
646e74c6b5SMiguel Ojeda	int
65af0121c2SGary Guo	default $(rustc-version)
666e74c6b5SMiguel Ojeda	help
676e74c6b5SMiguel Ojeda	  It does not depend on `RUST` since that one may need to use the version
686e74c6b5SMiguel Ojeda	  in a `depends on`.
696e74c6b5SMiguel Ojeda
702f7ab126SMiguel Ojedaconfig RUST_IS_AVAILABLE
712f7ab126SMiguel Ojeda	def_bool $(success,$(srctree)/scripts/rust_is_available.sh)
722f7ab126SMiguel Ojeda	help
732f7ab126SMiguel Ojeda	  This shows whether a suitable Rust toolchain is available (found).
742f7ab126SMiguel Ojeda
752f7ab126SMiguel Ojeda	  Please see Documentation/rust/quick-start.rst for instructions on how
76eacf96d2SColin Ian King	  to satisfy the build requirements of Rust support.
772f7ab126SMiguel Ojeda
782f7ab126SMiguel Ojeda	  In particular, the Makefile target 'rustavailable' is useful to check
792f7ab126SMiguel Ojeda	  why the Rust toolchain is not being detected.
802f7ab126SMiguel Ojeda
81af0121c2SGary Guoconfig RUSTC_LLVM_VERSION
82af0121c2SGary Guo	int
83af0121c2SGary Guo	default $(rustc-llvm-version)
84af0121c2SGary Guo
85deab487eSThomas Weißschuhconfig ARCH_HAS_CC_CAN_LINK
86deab487eSThomas Weißschuh	bool
87deab487eSThomas Weißschuh
881a927fd3SMasahiro Yamadaconfig CC_CAN_LINK
899371f86eSMasahiro Yamada	bool
90deab487eSThomas Weißschuh	default ARCH_CC_CAN_LINK if ARCH_HAS_CC_CAN_LINK
9180623f2cSThomas Weißschuh	default $(cc_can_link_user,$(m64-flag)) if 64BIT
9280623f2cSThomas Weißschuh	default $(cc_can_link_user,$(m32-flag))
931a927fd3SMasahiro Yamada
94f2f6a8e8SMark Rutland# Fixed in GCC 14, 13.3, 12.4 and 11.5
95f2f6a8e8SMark Rutland# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113921
96f2f6a8e8SMark Rutlandconfig GCC_ASM_GOTO_OUTPUT_BROKEN
97f2f6a8e8SMark Rutland	bool
98f2f6a8e8SMark Rutland	depends on CC_IS_GCC
99f2f6a8e8SMark Rutland	default y if GCC_VERSION < 110500
100f2f6a8e8SMark Rutland	default y if GCC_VERSION >= 120000 && GCC_VERSION < 120400
101f2f6a8e8SMark Rutland	default y if GCC_VERSION >= 130000 && GCC_VERSION < 130300
102f2f6a8e8SMark Rutland
103587f1701SNick Desaulniersconfig CC_HAS_ASM_GOTO_OUTPUT
104f2f6a8e8SMark Rutland	def_bool y
105f2f6a8e8SMark Rutland	depends on !GCC_ASM_GOTO_OUTPUT_BROKEN
106e2ffa15bSThomas Gleixner	# Detect basic support
107f2f6a8e8SMark Rutland	depends on $(success,echo 'int foo(int x) { asm goto ("": "=r"(x) ::: bar); return x; bar: return 0; }' | $(CC) -x c - -c -o /dev/null)
108e2ffa15bSThomas Gleixner	# Detect clang (< v17) scoped label issues
109fde0ab43SLinus Torvalds	depends on $(success,echo 'void b(void **);void* c(void);int f(void){{asm goto(""::::l0);return 0;l0:return 1;}void *x __attribute__((cleanup(b)))=c();{asm goto(""::::l1);return 2;l1:return 3;}}' | $(CC) -x c - -c -o /dev/null)
110587f1701SNick Desaulniers
1111aa0e8b1SSean Christophersonconfig CC_HAS_ASM_GOTO_TIED_OUTPUT
1121aa0e8b1SSean Christopherson	depends on CC_HAS_ASM_GOTO_OUTPUT
1131aa0e8b1SSean Christopherson	# Detect buggy gcc and clang, fixed in gcc-11 clang-14.
114534bd703SAlexandre Belloni	def_bool $(success,echo 'int foo(int *x) { asm goto (".long (%l[bar]) - .": "+m"(*x) ::: bar); return *x; bar: return 0; }' | $CC -x c - -c -o /dev/null)
1151aa0e8b1SSean Christopherson
1165cf896fbSPeter Collingbourneconfig TOOLS_SUPPORT_RELR
1172d122942SWill Deacon	def_bool $(success,env "CC=$(CC)" "LD=$(LD)" "NM=$(NM)" "OBJCOPY=$(OBJCOPY)" $(srctree)/scripts/tools-support-relr.sh)
1185cf896fbSPeter Collingbourne
119eb111869SRasmus Villemoesconfig CC_HAS_ASM_INLINE
120eb111869SRasmus Villemoes	def_bool $(success,echo 'void foo(void) { asm inline (""); }' | $(CC) -x c - -c -o /dev/null)
121eb111869SRasmus Villemoes
122f72e2cffSHeiko Carstensconfig CC_HAS_ASSUME
123f72e2cffSHeiko Carstens	bool
124f72e2cffSHeiko Carstens	# clang needs to be at least 19.1.0 since the meaning of the assume
125f72e2cffSHeiko Carstens	# attribute changed:
126f72e2cffSHeiko Carstens	# https://github.com/llvm/llvm-project/commit/c44fa3e8a9a44c2e9a575768a3c185354b9f6c17
127f72e2cffSHeiko Carstens	default y if CC_IS_CLANG && CLANG_VERSION >= 190100
128f72e2cffSHeiko Carstens	# supported since gcc 13.1.0
129f72e2cffSHeiko Carstens	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106654
130f72e2cffSHeiko Carstens	default y if CC_IS_GCC && GCC_VERSION >= 130100
131f72e2cffSHeiko Carstens
13251c2ee6dSNick Desaulniersconfig CC_HAS_NO_PROFILE_FN_ATTR
13351c2ee6dSNick Desaulniers	def_bool $(success,echo '__attribute__((no_profile_instrument_function)) int x();' | $(CC) -x c - -c -o /dev/null -Werror)
13451c2ee6dSNick Desaulniers
135f06e108aSJan Hendrik Farrconfig CC_HAS_COUNTED_BY
1365106c650SJan Hendrik Farr	bool
13786a9b125SNathan Chancellor	# clang needs to be at least 20.1.0 to avoid potential crashes
13886a9b125SNathan Chancellor	# when building structures that contain __counted_by
13986a9b125SNathan Chancellor	# https://github.com/ClangBuiltLinux/linux/issues/2114
14086a9b125SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/160fb1121cdf703c3ef5e61fb26c5659eb581489
14186a9b125SNathan Chancellor	default y if CC_IS_CLANG && CLANG_VERSION >= 200100
1425106c650SJan Hendrik Farr	# supported since gcc 15.1.0
1435106c650SJan Hendrik Farr	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108896
1445106c650SJan Hendrik Farr	default y if CC_IS_GCC && GCC_VERSION >= 150100
145f06e108aSJan Hendrik Farr
146b688f369SKees Cookconfig CC_HAS_MULTIDIMENSIONAL_NONSTRING
147b688f369SKees Cook	def_bool $(success,echo 'char tag[][4] __attribute__((__nonstring__)) = { };' | $(CC) $(CLANG_FLAGS) -x c - -c -o /dev/null -Werror)
148b688f369SKees Cook
149e7607f7dSNathan Chancellorconfig LD_CAN_USE_KEEP_IN_OVERLAY
150e7607f7dSNathan Chancellor	# ld.lld prior to 21.0.0 did not support KEEP within an overlay description
151e7607f7dSNathan Chancellor	# https://github.com/llvm/llvm-project/pull/130661
152e7607f7dSNathan Chancellor	def_bool LD_IS_BFD || LLD_VERSION >= 210000
153e7607f7dSNathan Chancellor
15488622323SAlexandre Courbotconfig RUSTC_HAS_SLICE_AS_FLATTENED
15588622323SAlexandre Courbot	def_bool RUSTC_VERSION >= 108000
15688622323SAlexandre Courbot
15747cb6bf7SXiangfei Dingconfig RUSTC_HAS_COERCE_POINTEE
15847cb6bf7SXiangfei Ding	def_bool RUSTC_VERSION >= 108400
15947cb6bf7SXiangfei Ding
16036174d16SMiguel Ojedaconfig RUSTC_HAS_SPAN_FILE
16136174d16SMiguel Ojeda	def_bool RUSTC_VERSION >= 108800
16236174d16SMiguel Ojeda
1637129ea6eSMiguel Ojedaconfig RUSTC_HAS_UNNECESSARY_TRANSMUTES
1647129ea6eSMiguel Ojeda	def_bool RUSTC_VERSION >= 108800
1657129ea6eSMiguel Ojeda
1660aa2b78cSBoqun Fengconfig RUSTC_HAS_FILE_WITH_NUL
1670aa2b78cSBoqun Feng	def_bool RUSTC_VERSION >= 108900
1680aa2b78cSBoqun Feng
169c09461a0SAlice Ryhlconfig RUSTC_HAS_FILE_AS_C_STR
170c09461a0SAlice Ryhl	def_bool RUSTC_VERSION >= 109100
171c09461a0SAlice Ryhl
172613fe169SNathan Chancellorconfig PAHOLE_VERSION
173613fe169SNathan Chancellor	int
174613fe169SNathan Chancellor	default $(shell,$(srctree)/scripts/pahole-version.sh $(PAHOLE))
175613fe169SNathan Chancellor
176b99b87f7SPeter Oberparleiterconfig CONSTRUCTORS
177b99b87f7SPeter Oberparleiter	bool
178b99b87f7SPeter Oberparleiter
179e360adbeSPeter Zijlstraconfig IRQ_WORK
180fd0a68a2STejun Heo	def_bool y if SMP
181e360adbeSPeter Zijlstra
18210916706SShile Zhangconfig BUILDTIME_TABLE_SORT
1831dbdc6f1SDavid Daney	bool
1841dbdc6f1SDavid Daney
185c65eacbeSAndy Lutomirskiconfig THREAD_INFO_IN_TASK
186c65eacbeSAndy Lutomirski	bool
187c65eacbeSAndy Lutomirski	help
188c65eacbeSAndy Lutomirski	  Select this to move thread_info off the stack into task_struct.  To
189c65eacbeSAndy Lutomirski	  make this work, an arch will need to remove all thread_info fields
190c65eacbeSAndy Lutomirski	  except flags and fix any runtime bugs.
191c65eacbeSAndy Lutomirski
192c6c314a6SAndy Lutomirski	  One subtle change that will be needed is to use try_get_task_stack()
193c6c314a6SAndy Lutomirski	  and put_task_stack() in save_thread_stack_tsk() and get_wchan().
194c6c314a6SAndy Lutomirski
195ff0cfc66SAl Boldimenu "General setup"
1961da177e4SLinus Torvalds
1971da177e4SLinus Torvaldsconfig BROKEN
1981da177e4SLinus Torvalds	bool
199fefbeed8SAndrew Morton	help
200fefbeed8SAndrew Morton	  This option allows you to choose whether you want to try to
201fefbeed8SAndrew Morton	  compile (and fix) old drivers that haven't been updated to
202fefbeed8SAndrew Morton	  new infrastructure.
2031da177e4SLinus Torvalds
2041da177e4SLinus Torvaldsconfig BROKEN_ON_SMP
2051da177e4SLinus Torvalds	bool
2061da177e4SLinus Torvalds	depends on BROKEN || !SMP
2071da177e4SLinus Torvalds	default y
2081da177e4SLinus Torvalds
2091da177e4SLinus Torvaldsconfig INIT_ENV_ARG_LIMIT
2101da177e4SLinus Torvalds	int
211dd673bcaSAdrian Bunk	default 32 if !UML
212dd673bcaSAdrian Bunk	default 128 if UML
2131da177e4SLinus Torvalds	help
21434ad92c2SRandy Dunlap	  Maximum of each of the number of arguments and environment
21534ad92c2SRandy Dunlap	  variables passed to init from the kernel command line.
2161da177e4SLinus Torvalds
2174bb16672SJiri Slabyconfig COMPILE_TEST
2184bb16672SJiri Slaby	bool "Compile also drivers which will not load"
219ea29b20aSMasahiro Yamada	depends on HAS_IOMEM
2204bb16672SJiri Slaby	help
2214bb16672SJiri Slaby	  Some drivers can be compiled on a different platform than they are
2224bb16672SJiri Slaby	  intended to be run on. Despite they cannot be loaded there (or even
2234bb16672SJiri Slaby	  when they load they cannot be used due to missing HW support),
2244bb16672SJiri Slaby	  developers still, opposing to distributors, might want to build such
2254bb16672SJiri Slaby	  drivers to compile-test them.
2264bb16672SJiri Slaby
2274bb16672SJiri Slaby	  If you are a developer and want to build everything available, say Y
2284bb16672SJiri Slaby	  here. If you are a user/distributor, say N here to exclude useless
2294bb16672SJiri Slaby	  drivers to be distributed.
2304bb16672SJiri Slaby
2313fe617ccSLinus Torvaldsconfig WERROR
2323fe617ccSLinus Torvalds	bool "Compile the kernel with warnings as errors"
233b339ec9cSMarco Elver	default COMPILE_TEST
2343fe617ccSLinus Torvalds	help
2353fe617ccSLinus Torvalds	  A kernel build should not cause any compiler warnings, and this
2362f7ab126SMiguel Ojeda	  enables the '-Werror' (for C) and '-Dwarnings' (for Rust) flags
237e1789d7cSXin Li	  to enforce that rule by default. Certain warnings from other tools
238e1789d7cSXin Li	  such as the linker may be upgraded to errors with this option as
239e1789d7cSXin Li	  well.
2403fe617ccSLinus Torvalds
241e1789d7cSXin Li	  However, if you have a new (or very old) compiler or linker with odd
242e1789d7cSXin Li	  and unusual warnings, or you have some architecture with problems,
2433fe617ccSLinus Torvalds	  you may need to disable this config option in order to
2443fe617ccSLinus Torvalds	  successfully build the kernel.
2453fe617ccSLinus Torvalds
2463fe617ccSLinus Torvalds	  If in doubt, say Y.
2473fe617ccSLinus Torvalds
248d6fc9fcbSMasahiro Yamadaconfig UAPI_HEADER_TEST
249d6fc9fcbSMasahiro Yamada	bool "Compile test UAPI headers"
250fcbb8461SMasahiro Yamada	depends on HEADERS_INSTALL && CC_CAN_LINK
251d6fc9fcbSMasahiro Yamada	help
252d6fc9fcbSMasahiro Yamada	  Compile test headers exported to user-space to ensure they are
253d6fc9fcbSMasahiro Yamada	  self-contained, i.e. compilable as standalone units.
254d6fc9fcbSMasahiro Yamada
255d6fc9fcbSMasahiro Yamada	  If you are a developer or tester and want to ensure the exported
256d6fc9fcbSMasahiro Yamada	  headers are self-contained, say Y here. Otherwise, choose N.
257d6fc9fcbSMasahiro Yamada
2581da177e4SLinus Torvaldsconfig LOCALVERSION
2591da177e4SLinus Torvalds	string "Local version - append to kernel release"
2601da177e4SLinus Torvalds	help
2611da177e4SLinus Torvalds	  Append an extra string to the end of your kernel version.
2621da177e4SLinus Torvalds	  This will show up when you type uname, for example.
2631da177e4SLinus Torvalds	  The string you set here will be appended after the contents of
2641da177e4SLinus Torvalds	  any files with a filename matching localversion* in your
2651da177e4SLinus Torvalds	  object and source tree, in that order.  Your total string can
2661da177e4SLinus Torvalds	  be a maximum of 64 characters.
2671da177e4SLinus Torvalds
268aaebf433SRyan Andersonconfig LOCALVERSION_AUTO
269aaebf433SRyan Anderson	bool "Automatically append version information to the version string"
270aaebf433SRyan Anderson	default y
271ac3339baSAlexey Dobriyan	depends on !COMPILE_TEST
272aaebf433SRyan Anderson	help
273aaebf433SRyan Anderson	  This will try to automatically determine if the current tree is a
2746e5a5420SRobert P. J. Day	  release tree by looking for git tags that belong to the current
2756e5a5420SRobert P. J. Day	  top of tree revision.
276aaebf433SRyan Anderson
277aaebf433SRyan Anderson	  A string of the format -gxxxxxxxx will be added to the localversion
2786e5a5420SRobert P. J. Day	  if a git-based tree is found.  The string generated by this will be
279aaebf433SRyan Anderson	  appended after any matching localversion* files, and after the value
2806e5a5420SRobert P. J. Day	  set in CONFIG_LOCALVERSION.
281aaebf433SRyan Anderson
2820f9c608dSRasmus Villemoes	  (The actual string used here is the first 12 characters produced
2836e5a5420SRobert P. J. Day	  by running the command:
2846e5a5420SRobert P. J. Day
2856e5a5420SRobert P. J. Day	    $ git rev-parse --verify HEAD
2866e5a5420SRobert P. J. Day
2876e5a5420SRobert P. J. Day	  which is done within the script "scripts/setlocalversion".)
288aaebf433SRyan Anderson
2899afb719eSLaura Abbottconfig BUILD_SALT
2909afb719eSLaura Abbott	string "Build ID Salt"
2919afb719eSLaura Abbott	default ""
2929afb719eSLaura Abbott	help
2939afb719eSLaura Abbott	  The build ID is used to link binaries and their debug info. Setting
2949afb719eSLaura Abbott	  this option will use the value in the calculation of the build id.
2959afb719eSLaura Abbott	  This is mostly useful for distributions which want to ensure the
2969afb719eSLaura Abbott	  build is unique between builds. It's safe to leave the default.
2979afb719eSLaura Abbott
2982e9f3bddSH. Peter Anvinconfig HAVE_KERNEL_GZIP
2992e9f3bddSH. Peter Anvin	bool
3002e9f3bddSH. Peter Anvin
3012e9f3bddSH. Peter Anvinconfig HAVE_KERNEL_BZIP2
3022e9f3bddSH. Peter Anvin	bool
3032e9f3bddSH. Peter Anvin
3042e9f3bddSH. Peter Anvinconfig HAVE_KERNEL_LZMA
3052e9f3bddSH. Peter Anvin	bool
3062e9f3bddSH. Peter Anvin
3073ebe1243SLasse Collinconfig HAVE_KERNEL_XZ
3083ebe1243SLasse Collin	bool
3093ebe1243SLasse Collin
3107dd65febSAlbin Tonnerreconfig HAVE_KERNEL_LZO
3117dd65febSAlbin Tonnerre	bool
3127dd65febSAlbin Tonnerre
313e76e1fdfSKyungsik Leeconfig HAVE_KERNEL_LZ4
314e76e1fdfSKyungsik Lee	bool
315e76e1fdfSKyungsik Lee
31648f7ddf7SNick Terrellconfig HAVE_KERNEL_ZSTD
31748f7ddf7SNick Terrell	bool
31848f7ddf7SNick Terrell
319f16466afSVasily Gorbikconfig HAVE_KERNEL_UNCOMPRESSED
320f16466afSVasily Gorbik	bool
321f16466afSVasily Gorbik
32230d65dbfSAlain Knaffchoice
32330d65dbfSAlain Knaff	prompt "Kernel compression mode"
32430d65dbfSAlain Knaff	default KERNEL_GZIP
32548f7ddf7SNick 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
32630d65dbfSAlain Knaff	help
32730d65dbfSAlain Knaff	  The linux kernel is a kind of self-extracting executable.
32830d65dbfSAlain Knaff	  Several compression algorithms are available, which differ
32930d65dbfSAlain Knaff	  in efficiency, compression and decompression speed.
33030d65dbfSAlain Knaff	  Compression speed is only relevant when building a kernel.
33130d65dbfSAlain Knaff	  Decompression speed is relevant at each boot.
33230d65dbfSAlain Knaff
33330d65dbfSAlain Knaff	  If you have any problems with bzip2 or lzma compressed
33430d65dbfSAlain Knaff	  kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
33530d65dbfSAlain Knaff	  version of this functionality (bzip2 only), for 2.4, was
33630d65dbfSAlain Knaff	  supplied by Christian Ludwig)
33730d65dbfSAlain Knaff
33830d65dbfSAlain Knaff	  High compression options are mostly useful for users, who
33930d65dbfSAlain Knaff	  are low on disk space (embedded systems), but for whom ram
34030d65dbfSAlain Knaff	  size matters less.
34130d65dbfSAlain Knaff
34230d65dbfSAlain Knaff	  If in doubt, select 'gzip'
34330d65dbfSAlain Knaff
34430d65dbfSAlain Knaffconfig KERNEL_GZIP
34530d65dbfSAlain Knaff	bool "Gzip"
3462e9f3bddSH. Peter Anvin	depends on HAVE_KERNEL_GZIP
34730d65dbfSAlain Knaff	help
3487dd65febSAlbin Tonnerre	  The old and tried gzip compression. It provides a good balance
3497dd65febSAlbin Tonnerre	  between compression ratio and decompression speed.
35030d65dbfSAlain Knaff
35130d65dbfSAlain Knaffconfig KERNEL_BZIP2
35230d65dbfSAlain Knaff	bool "Bzip2"
3532e9f3bddSH. Peter Anvin	depends on HAVE_KERNEL_BZIP2
35430d65dbfSAlain Knaff	help
35530d65dbfSAlain Knaff	  Its compression ratio and speed is intermediate.
3560a4dd35cSRandy Dunlap	  Decompression speed is slowest among the choices.  The kernel
3572e9f3bddSH. Peter Anvin	  size is about 10% smaller with bzip2, in comparison to gzip.
3582e9f3bddSH. Peter Anvin	  Bzip2 uses a large amount of memory. For modern kernels you
3592e9f3bddSH. Peter Anvin	  will need at least 8MB RAM or more for booting.
36030d65dbfSAlain Knaff
36130d65dbfSAlain Knaffconfig KERNEL_LZMA
36230d65dbfSAlain Knaff	bool "LZMA"
3632e9f3bddSH. Peter Anvin	depends on HAVE_KERNEL_LZMA
36430d65dbfSAlain Knaff	help
3650a4dd35cSRandy Dunlap	  This compression algorithm's ratio is best.  Decompression speed
3660a4dd35cSRandy Dunlap	  is between gzip and bzip2.  Compression is slowest.
3670a4dd35cSRandy Dunlap	  The kernel size is about 33% smaller with LZMA in comparison to gzip.
36830d65dbfSAlain Knaff
3693ebe1243SLasse Collinconfig KERNEL_XZ
3703ebe1243SLasse Collin	bool "XZ"
3713ebe1243SLasse Collin	depends on HAVE_KERNEL_XZ
3723ebe1243SLasse Collin	help
3733ebe1243SLasse Collin	  XZ uses the LZMA2 algorithm and instruction set specific
3743ebe1243SLasse Collin	  BCJ filters which can improve compression ratio of executable
3753ebe1243SLasse Collin	  code. The size of the kernel is about 30% smaller with XZ in
3763ebe1243SLasse Collin	  comparison to gzip. On architectures for which there is a BCJ
3777472ff8aSLasse Collin	  filter (i386, x86_64, ARM, ARM64, RISC-V, big endian PowerPC,
3787472ff8aSLasse Collin	  and SPARC), XZ will create a few percent smaller kernel than
3797472ff8aSLasse Collin	  plain LZMA.
3803ebe1243SLasse Collin
3813ebe1243SLasse Collin	  The speed is about the same as with LZMA: The decompression
3823ebe1243SLasse Collin	  speed of XZ is better than that of bzip2 but worse than gzip
3833ebe1243SLasse Collin	  and LZO. Compression is slow.
3843ebe1243SLasse Collin
3857dd65febSAlbin Tonnerreconfig KERNEL_LZO
3867dd65febSAlbin Tonnerre	bool "LZO"
3877dd65febSAlbin Tonnerre	depends on HAVE_KERNEL_LZO
3887dd65febSAlbin Tonnerre	help
3890a4dd35cSRandy Dunlap	  Its compression ratio is the poorest among the choices. The kernel
390681b3049SStephan Sperber	  size is about 10% bigger than gzip; however its speed
3917dd65febSAlbin Tonnerre	  (both compression and decompression) is the fastest.
3927dd65febSAlbin Tonnerre
393e76e1fdfSKyungsik Leeconfig KERNEL_LZ4
394e76e1fdfSKyungsik Lee	bool "LZ4"
395e76e1fdfSKyungsik Lee	depends on HAVE_KERNEL_LZ4
396e76e1fdfSKyungsik Lee	help
397e76e1fdfSKyungsik Lee	  LZ4 is an LZ77-type compressor with a fixed, byte-oriented encoding.
398e76e1fdfSKyungsik Lee	  A preliminary version of LZ4 de/compression tool is available at
399e76e1fdfSKyungsik Lee	  <https://code.google.com/p/lz4/>.
400e76e1fdfSKyungsik Lee
401e76e1fdfSKyungsik Lee	  Its compression ratio is worse than LZO. The size of the kernel
402e76e1fdfSKyungsik Lee	  is about 8% bigger than LZO. But the decompression speed is
403e76e1fdfSKyungsik Lee	  faster than LZO.
404e76e1fdfSKyungsik Lee
40548f7ddf7SNick Terrellconfig KERNEL_ZSTD
40648f7ddf7SNick Terrell	bool "ZSTD"
40748f7ddf7SNick Terrell	depends on HAVE_KERNEL_ZSTD
40848f7ddf7SNick Terrell	help
40948f7ddf7SNick Terrell	  ZSTD is a compression algorithm targeting intermediate compression
41048f7ddf7SNick Terrell	  with fast decompression speed. It will compress better than GZIP and
41148f7ddf7SNick Terrell	  decompress around the same speed as LZO, but slower than LZ4. You
41248f7ddf7SNick Terrell	  will need at least 192 KB RAM or more for booting. The zstd command
41348f7ddf7SNick Terrell	  line tool is required for compression.
41448f7ddf7SNick Terrell
415f16466afSVasily Gorbikconfig KERNEL_UNCOMPRESSED
416f16466afSVasily Gorbik	bool "None"
417f16466afSVasily Gorbik	depends on HAVE_KERNEL_UNCOMPRESSED
418f16466afSVasily Gorbik	help
419f16466afSVasily Gorbik	  Produce uncompressed kernel image. This option is usually not what
420f16466afSVasily Gorbik	  you want. It is useful for debugging the kernel in slow simulation
421f16466afSVasily Gorbik	  environments, where decompressing and moving the kernel is awfully
422f16466afSVasily Gorbik	  slow. This option allows early boot code to skip the decompressor
423f16466afSVasily Gorbik	  and jump right at uncompressed kernel image.
424f16466afSVasily Gorbik
42530d65dbfSAlain Knaffendchoice
42630d65dbfSAlain Knaff
427ada4ab7aSChris Downconfig DEFAULT_INIT
428ada4ab7aSChris Down	string "Default init path"
429ada4ab7aSChris Down	default ""
430ada4ab7aSChris Down	help
431ada4ab7aSChris Down	  This option determines the default init for the system if no init=
432ada4ab7aSChris Down	  option is passed on the kernel command line. If the requested path is
433ada4ab7aSChris Down	  not present, we will still then move on to attempting further
434ada4ab7aSChris Down	  locations (e.g. /sbin/init, etc). If this is empty, we will just use
435ada4ab7aSChris Down	  the fallback list when init= is not passed.
436ada4ab7aSChris Down
437bd5dc17bSJosh Triplettconfig DEFAULT_HOSTNAME
438bd5dc17bSJosh Triplett	string "Default hostname"
439bd5dc17bSJosh Triplett	default "(none)"
440bd5dc17bSJosh Triplett	help
441bd5dc17bSJosh Triplett	  This option determines the default system hostname before userspace
442bd5dc17bSJosh Triplett	  calls sethostname(2). The kernel traditionally uses "(none)" here,
443bd5dc17bSJosh Triplett	  but you may wish to use a different default here to make a minimal
444bd5dc17bSJosh Triplett	  system more usable with less configuration.
445bd5dc17bSJosh Triplett
4461da177e4SLinus Torvaldsconfig SYSVIPC
4471da177e4SLinus Torvalds	bool "System V IPC"
448a7f7f624SMasahiro Yamada	help
4491da177e4SLinus Torvalds	  Inter Process Communication is a suite of library functions and
4501da177e4SLinus Torvalds	  system calls which let processes (running programs) synchronize and
4511da177e4SLinus Torvalds	  exchange information. It is generally considered to be a good thing,
4521da177e4SLinus Torvalds	  and some programs won't run unless you say Y here. In particular, if
4531da177e4SLinus Torvalds	  you want to run the DOS emulator dosemu under Linux (read the
4541da177e4SLinus Torvalds	  DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
4551da177e4SLinus Torvalds	  you'll need to say Y here.
4561da177e4SLinus Torvalds
4571da177e4SLinus Torvalds	  You can find documentation about IPC with "info ipc" and also in
4581da177e4SLinus Torvalds	  section 6.4 of the Linux Programmer's Guide, available from
4591da177e4SLinus Torvalds	  <http://www.tldp.org/guides.html>.
4601da177e4SLinus Torvalds
461a5494dcdSEric W. Biedermanconfig SYSVIPC_SYSCTL
462a5494dcdSEric W. Biederman	bool
463a5494dcdSEric W. Biederman	depends on SYSVIPC
464a5494dcdSEric W. Biederman	depends on SYSCTL
465a5494dcdSEric W. Biederman	default y
466a5494dcdSEric W. Biederman
4670cbed0eeSGuo Renconfig SYSVIPC_COMPAT
4680cbed0eeSGuo Ren	def_bool y
4690cbed0eeSGuo Ren	depends on COMPAT && SYSVIPC
4700cbed0eeSGuo Ren
4711da177e4SLinus Torvaldsconfig POSIX_MQUEUE
4721da177e4SLinus Torvalds	bool "POSIX Message Queues"
47319c92399SKees Cook	depends on NET
474a7f7f624SMasahiro Yamada	help
4751da177e4SLinus Torvalds	  POSIX variant of message queues is a part of IPC. In POSIX message
4761da177e4SLinus Torvalds	  queues every message has a priority which decides about succession
4771da177e4SLinus Torvalds	  of receiving it by a process. If you want to compile and run
4781da177e4SLinus Torvalds	  programs written e.g. for Solaris with use of its POSIX message
479b0e37650SRobert P. J. Day	  queues (functions mq_*) say Y here.
4801da177e4SLinus Torvalds
4811da177e4SLinus Torvalds	  POSIX message queues are visible as a filesystem called 'mqueue'
4821da177e4SLinus Torvalds	  and can be mounted somewhere if you want to do filesystem
4831da177e4SLinus Torvalds	  operations on message queues.
4841da177e4SLinus Torvalds
4851da177e4SLinus Torvalds	  If unsure, say Y.
4861da177e4SLinus Torvalds
487bdc8e5f8SSerge E. Hallynconfig POSIX_MQUEUE_SYSCTL
488bdc8e5f8SSerge E. Hallyn	bool
489bdc8e5f8SSerge E. Hallyn	depends on POSIX_MQUEUE
490bdc8e5f8SSerge E. Hallyn	depends on SYSCTL
491bdc8e5f8SSerge E. Hallyn	default y
492bdc8e5f8SSerge E. Hallyn
493c73be61cSDavid Howellsconfig WATCH_QUEUE
494c73be61cSDavid Howells	bool "General notification queue"
495c73be61cSDavid Howells	default n
496c73be61cSDavid Howells	help
497c73be61cSDavid Howells
498c73be61cSDavid Howells	  This is a general notification queue for the kernel to pass events to
499c73be61cSDavid Howells	  userspace by splicing them into pipes.  It can be used in conjunction
500c73be61cSDavid Howells	  with watches for key/keyring change notifications and device
501c73be61cSDavid Howells	  notifications.
502c73be61cSDavid Howells
503c02b872aSMauro Carvalho Chehab	  See Documentation/core-api/watch_queue.rst
504c73be61cSDavid Howells
505226b4ccdSKonstantin Khlebnikovconfig CROSS_MEMORY_ATTACH
506226b4ccdSKonstantin Khlebnikov	bool "Enable process_vm_readv/writev syscalls"
507226b4ccdSKonstantin Khlebnikov	depends on MMU
508226b4ccdSKonstantin Khlebnikov	default y
509226b4ccdSKonstantin Khlebnikov	help
510226b4ccdSKonstantin Khlebnikov	  Enabling this option adds the system calls process_vm_readv and
511226b4ccdSKonstantin Khlebnikov	  process_vm_writev which allow a process with the correct privileges
512a2a368d9SGeert Uytterhoeven	  to directly read from or write to another process' address space.
513226b4ccdSKonstantin Khlebnikov	  See the man page for more details.
514226b4ccdSKonstantin Khlebnikov
5151da177e4SLinus Torvaldsconfig AUDIT
5161da177e4SLinus Torvalds	bool "Auditing support"
517804a6a49SChris Wright	depends on NET
5181da177e4SLinus Torvalds	help
5191da177e4SLinus Torvalds	  Enable auditing infrastructure that can be used with another
5201da177e4SLinus Torvalds	  kernel subsystem, such as SELinux (which requires this for
521cb74ed27SPaul Moore	  logging of avc messages output).  System call auditing is included
522cb74ed27SPaul Moore	  on architectures which support it.
5231da177e4SLinus Torvalds
5247a017721SAKASHI Takahiroconfig HAVE_ARCH_AUDITSYSCALL
5257a017721SAKASHI Takahiro	bool
5267a017721SAKASHI Takahiro
5271da177e4SLinus Torvaldsconfig AUDITSYSCALL
528cb74ed27SPaul Moore	def_bool y
5297a017721SAKASHI Takahiro	depends on AUDIT && HAVE_ARCH_AUDITSYSCALL
53028a3a7ebSEric Paris	select FSNOTIFY
53174c3cbe3SAl Viro
532d9817ebeSThomas Gleixnersource "kernel/irq/Kconfig"
533764e0da1SThomas Gleixnersource "kernel/time/Kconfig"
534b24abcffSDaniel Borkmannsource "kernel/bpf/Kconfig"
53587a4c375SChristoph Hellwigsource "kernel/Kconfig.preempt"
536d9817ebeSThomas Gleixner
537391dc69cSFrederic Weisbeckermenu "CPU/Task time and stats accounting"
538391dc69cSFrederic Weisbecker
539abf917cdSFrederic Weisbeckerconfig VIRT_CPU_ACCOUNTING
540abf917cdSFrederic Weisbecker	bool
541abf917cdSFrederic Weisbecker
542fdf9c356SFrederic Weisbeckerchoice
543fdf9c356SFrederic Weisbecker	prompt "Cputime accounting"
54402382affSNicholas Piggin	default TICK_CPU_ACCOUNTING
545fdf9c356SFrederic Weisbecker
546fdf9c356SFrederic Weisbecker# Kind of a stub config for the pure tick based cputime accounting
547fdf9c356SFrederic Weisbeckerconfig TICK_CPU_ACCOUNTING
548fdf9c356SFrederic Weisbecker	bool "Simple tick based cputime accounting"
549c58b0df1SFrederic Weisbecker	depends on !S390 && !NO_HZ_FULL
550fdf9c356SFrederic Weisbecker	help
551fdf9c356SFrederic Weisbecker	  This is the basic tick based cputime accounting that maintains
552fdf9c356SFrederic Weisbecker	  statistics about user, system and idle time spent on per jiffies
553fdf9c356SFrederic Weisbecker	  granularity.
554fdf9c356SFrederic Weisbecker
555fdf9c356SFrederic Weisbecker	  If unsure, say Y.
556fdf9c356SFrederic Weisbecker
557abf917cdSFrederic Weisbeckerconfig VIRT_CPU_ACCOUNTING_NATIVE
558391dc69cSFrederic Weisbecker	bool "Deterministic task and CPU time accounting"
559c58b0df1SFrederic Weisbecker	depends on HAVE_VIRT_CPU_ACCOUNTING && !NO_HZ_FULL
560abf917cdSFrederic Weisbecker	select VIRT_CPU_ACCOUNTING
561391dc69cSFrederic Weisbecker	help
562391dc69cSFrederic Weisbecker	  Select this option to enable more accurate task and CPU time
563391dc69cSFrederic Weisbecker	  accounting.  This is done by reading a CPU counter on each
564391dc69cSFrederic Weisbecker	  kernel entry and exit and on transitions within the kernel
565391dc69cSFrederic Weisbecker	  between system, softirq and hardirq state, so there is a
566391dc69cSFrederic Weisbecker	  small performance impact.  In the case of s390 or IBM POWER > 5,
567391dc69cSFrederic Weisbecker	  this also enables accounting of stolen time on logically-partitioned
568391dc69cSFrederic Weisbecker	  systems.
569391dc69cSFrederic Weisbecker
570abf917cdSFrederic Weisbeckerconfig VIRT_CPU_ACCOUNTING_GEN
571abf917cdSFrederic Weisbecker	bool "Full dynticks CPU time accounting"
57224a9c541SFrederic Weisbecker	depends on HAVE_CONTEXT_TRACKING_USER
573554b0004SKevin Hilman	depends on HAVE_VIRT_CPU_ACCOUNTING_GEN
574041a1574SArnd Bergmann	depends on GENERIC_CLOCKEVENTS
575abf917cdSFrederic Weisbecker	select VIRT_CPU_ACCOUNTING
57624a9c541SFrederic Weisbecker	select CONTEXT_TRACKING_USER
577abf917cdSFrederic Weisbecker	help
578abf917cdSFrederic Weisbecker	  Select this option to enable task and CPU time accounting on full
579abf917cdSFrederic Weisbecker	  dynticks systems. This accounting is implemented by watching every
580abf917cdSFrederic Weisbecker	  kernel-user boundaries using the context tracking subsystem.
581abf917cdSFrederic Weisbecker	  The accounting is thus performed at the expense of some significant
582abf917cdSFrederic Weisbecker	  overhead.
583abf917cdSFrederic Weisbecker
584abf917cdSFrederic Weisbecker	  For now this is only useful if you are working on the full
585abf917cdSFrederic Weisbecker	  dynticks subsystem development.
586abf917cdSFrederic Weisbecker
587abf917cdSFrederic Weisbecker	  If unsure, say N.
588abf917cdSFrederic Weisbecker
589b58c3584SRik van Rielendchoice
590b58c3584SRik van Riel
591fdf9c356SFrederic Weisbeckerconfig IRQ_TIME_ACCOUNTING
592fdf9c356SFrederic Weisbecker	bool "Fine granularity task level IRQ time accounting"
593b58c3584SRik van Riel	depends on HAVE_IRQ_TIME_ACCOUNTING && !VIRT_CPU_ACCOUNTING_NATIVE
594fdf9c356SFrederic Weisbecker	help
595fdf9c356SFrederic Weisbecker	  Select this option to enable fine granularity task irq time
596fdf9c356SFrederic Weisbecker	  accounting. This is done by reading a timestamp on each
597fdf9c356SFrederic Weisbecker	  transitions between softirq and hardirq state, so there can be a
598fdf9c356SFrederic Weisbecker	  small performance impact.
599fdf9c356SFrederic Weisbecker
600fdf9c356SFrederic Weisbecker	  If in doubt, say N here.
601fdf9c356SFrederic Weisbecker
60211d4afd4SVincent Guittotconfig HAVE_SCHED_AVG_IRQ
60311d4afd4SVincent Guittot	def_bool y
60411d4afd4SVincent Guittot	depends on IRQ_TIME_ACCOUNTING || PARAVIRT_TIME_ACCOUNTING
60511d4afd4SVincent Guittot	depends on SMP
60611d4afd4SVincent Guittot
607d4dbc991SVincent Guittotconfig SCHED_HW_PRESSURE
60898eb401dSValentin Schneider	bool
609fcd7c9c3SValentin Schneider	default y if ARM && ARM_CPU_TOPOLOGY
610fcd7c9c3SValentin Schneider	default y if ARM64
61176504793SThara Gopinath	depends on SMP
61298eb401dSValentin Schneider	depends on CPU_FREQ_THERMAL
61398eb401dSValentin Schneider	help
614d4dbc991SVincent Guittot	  Select this option to enable HW pressure accounting in the
615d4dbc991SVincent Guittot	  scheduler. HW pressure is the value conveyed to the scheduler
61698eb401dSValentin Schneider	  that reflects the reduction in CPU compute capacity resulted from
617d4dbc991SVincent Guittot	  HW throttling. HW throttling occurs when the performance of
618d4dbc991SVincent Guittot	  a CPU is capped due to high operating temperatures as an example.
61998eb401dSValentin Schneider
62098eb401dSValentin Schneider	  If selected, the scheduler will be able to balance tasks accordingly,
62198eb401dSValentin Schneider	  i.e. put less load on throttled CPUs than on non/less throttled ones.
62298eb401dSValentin Schneider
62398eb401dSValentin Schneider	  This requires the architecture to implement
624d4dbc991SVincent Guittot	  arch_update_hw_pressure() and arch_scale_thermal_pressure().
62576504793SThara Gopinath
626391dc69cSFrederic Weisbeckerconfig BSD_PROCESS_ACCT
627391dc69cSFrederic Weisbecker	bool "BSD Process Accounting"
6282813893fSIulia Manda	depends on MULTIUSER
629391dc69cSFrederic Weisbecker	help
630391dc69cSFrederic Weisbecker	  If you say Y here, a user level program will be able to instruct the
631391dc69cSFrederic Weisbecker	  kernel (via a special system call) to write process accounting
632391dc69cSFrederic Weisbecker	  information to a file: whenever a process exits, information about
633391dc69cSFrederic Weisbecker	  that process will be appended to the file by the kernel.  The
634391dc69cSFrederic Weisbecker	  information includes things such as creation time, owning user,
635391dc69cSFrederic Weisbecker	  command name, memory usage, controlling terminal etc. (the complete
636391dc69cSFrederic Weisbecker	  list is in the struct acct in <file:include/linux/acct.h>).  It is
637391dc69cSFrederic Weisbecker	  up to the user level program to do useful things with this
638391dc69cSFrederic Weisbecker	  information.  This is generally a good idea, so say Y.
639391dc69cSFrederic Weisbecker
640391dc69cSFrederic Weisbeckerconfig BSD_PROCESS_ACCT_V3
641391dc69cSFrederic Weisbecker	bool "BSD Process Accounting version 3 file format"
642391dc69cSFrederic Weisbecker	depends on BSD_PROCESS_ACCT
643391dc69cSFrederic Weisbecker	default n
644391dc69cSFrederic Weisbecker	help
645391dc69cSFrederic Weisbecker	  If you say Y here, the process accounting information is written
646391dc69cSFrederic Weisbecker	  in a new file format that also logs the process IDs of each
6473903bf94SRandy Dunlap	  process and its parent. Note that this file format is incompatible
648391dc69cSFrederic Weisbecker	  with previous v0/v1/v2 file formats, so you will need updated tools
649391dc69cSFrederic Weisbecker	  for processing it. A preliminary version of these tools is available
650391dc69cSFrederic Weisbecker	  at <http://www.gnu.org/software/acct/>.
651391dc69cSFrederic Weisbecker
652391dc69cSFrederic Weisbeckerconfig TASKSTATS
65319c92399SKees Cook	bool "Export task/process statistics through netlink"
654391dc69cSFrederic Weisbecker	depends on NET
6552813893fSIulia Manda	depends on MULTIUSER
656391dc69cSFrederic Weisbecker	default n
657391dc69cSFrederic Weisbecker	help
658391dc69cSFrederic Weisbecker	  Export selected statistics for tasks/processes through the
659391dc69cSFrederic Weisbecker	  generic netlink interface. Unlike BSD process accounting, the
660391dc69cSFrederic Weisbecker	  statistics are available during the lifetime of tasks/processes as
661391dc69cSFrederic Weisbecker	  responses to commands. Like BSD accounting, they are sent to user
662391dc69cSFrederic Weisbecker	  space on task exit.
663391dc69cSFrederic Weisbecker
664391dc69cSFrederic Weisbecker	  Say N if unsure.
665391dc69cSFrederic Weisbecker
666391dc69cSFrederic Weisbeckerconfig TASK_DELAY_ACCT
66719c92399SKees Cook	bool "Enable per-task delay accounting"
668391dc69cSFrederic Weisbecker	depends on TASKSTATS
669f6db8347SNaveen N. Rao	select SCHED_INFO
670391dc69cSFrederic Weisbecker	help
671391dc69cSFrederic Weisbecker	  Collect information on time spent by a task waiting for system
672391dc69cSFrederic Weisbecker	  resources like cpu, synchronous block I/O completion and swapping
673391dc69cSFrederic Weisbecker	  in pages. Such statistics can help in setting a task's priorities
674391dc69cSFrederic Weisbecker	  relative to other tasks for cpu, io, rss limits etc.
675391dc69cSFrederic Weisbecker
676391dc69cSFrederic Weisbecker	  Say N if unsure.
677391dc69cSFrederic Weisbecker
678391dc69cSFrederic Weisbeckerconfig TASK_XACCT
67919c92399SKees Cook	bool "Enable extended accounting over taskstats"
680391dc69cSFrederic Weisbecker	depends on TASKSTATS
681391dc69cSFrederic Weisbecker	help
682391dc69cSFrederic Weisbecker	  Collect extended task accounting data and send the data
683391dc69cSFrederic Weisbecker	  to userland for processing over the taskstats interface.
684391dc69cSFrederic Weisbecker
685391dc69cSFrederic Weisbecker	  Say N if unsure.
686391dc69cSFrederic Weisbecker
687391dc69cSFrederic Weisbeckerconfig TASK_IO_ACCOUNTING
68819c92399SKees Cook	bool "Enable per-task storage I/O accounting"
689391dc69cSFrederic Weisbecker	depends on TASK_XACCT
690391dc69cSFrederic Weisbecker	help
691391dc69cSFrederic Weisbecker	  Collect information on the number of bytes of storage I/O which this
692391dc69cSFrederic Weisbecker	  task has caused.
693391dc69cSFrederic Weisbecker
694391dc69cSFrederic Weisbecker	  Say N if unsure.
695391dc69cSFrederic Weisbecker
696eb414681SJohannes Weinerconfig PSI
697eb414681SJohannes Weiner	bool "Pressure stall information tracking"
69898dfdd9eSRandy Dunlap	select KERNFS
699eb414681SJohannes Weiner	help
700eb414681SJohannes Weiner	  Collect metrics that indicate how overcommitted the CPU, memory,
701eb414681SJohannes Weiner	  and IO capacity are in the system.
702eb414681SJohannes Weiner
703eb414681SJohannes Weiner	  If you say Y here, the kernel will create /proc/pressure/ with the
704eb414681SJohannes Weiner	  pressure statistics files cpu, memory, and io. These will indicate
705eb414681SJohannes Weiner	  the share of walltime in which some or all tasks in the system are
706eb414681SJohannes Weiner	  delayed due to contention of the respective resource.
707eb414681SJohannes Weiner
7082ce7135aSJohannes Weiner	  In kernels with cgroup support, cgroups (cgroup2 only) will
7092ce7135aSJohannes Weiner	  have cpu.pressure, memory.pressure, and io.pressure files,
7102ce7135aSJohannes Weiner	  which aggregate pressure stalls for the grouped tasks only.
7112ce7135aSJohannes Weiner
712c3123552SMauro Carvalho Chehab	  For more details see Documentation/accounting/psi.rst.
713eb414681SJohannes Weiner
714eb414681SJohannes Weiner	  Say N if unsure.
715eb414681SJohannes Weiner
716e0c27447SJohannes Weinerconfig PSI_DEFAULT_DISABLED
717e0c27447SJohannes Weiner	bool "Require boot parameter to enable pressure stall information tracking"
718e0c27447SJohannes Weiner	default n
719e0c27447SJohannes Weiner	depends on PSI
720e0c27447SJohannes Weiner	help
721e0c27447SJohannes Weiner	  If set, pressure stall information tracking will be disabled
722428a1cb4SBaruch Siach	  per default but can be enabled through passing psi=1 on the
723428a1cb4SBaruch Siach	  kernel commandline during boot.
724e0c27447SJohannes Weiner
7257b2489d3SJohannes Weiner	  This feature adds some code to the task wakeup and sleep
7267b2489d3SJohannes Weiner	  paths of the scheduler. The overhead is too low to affect
7277b2489d3SJohannes Weiner	  common scheduling-intense workloads in practice (such as
7287b2489d3SJohannes Weiner	  webservers, memcache), but it does show up in artificial
7297b2489d3SJohannes Weiner	  scheduler stress tests, such as hackbench.
7307b2489d3SJohannes Weiner
7317b2489d3SJohannes Weiner	  If you are paranoid and not sure what the kernel will be
7327b2489d3SJohannes Weiner	  used for, say Y.
7337b2489d3SJohannes Weiner
7347b2489d3SJohannes Weiner	  Say N if unsure.
7357b2489d3SJohannes Weiner
736391dc69cSFrederic Weisbeckerendmenu # "CPU/Task time and stats accounting"
737391dc69cSFrederic Weisbecker
7385c4991e2SFrederic Weisbeckerconfig CPU_ISOLATION
7395c4991e2SFrederic Weisbecker	bool "CPU isolation"
74097577684SOleg Nesterov	depends on SMP
7412c43838cSFrederic Weisbecker	default y
7425c4991e2SFrederic Weisbecker	help
7435c4991e2SFrederic Weisbecker	  Make sure that CPUs running critical tasks are not disturbed by
7445c4991e2SFrederic Weisbecker	  any source of "noise" such as unbound workqueues, timers, kthreads...
7452c43838cSFrederic Weisbecker	  Unbound jobs get offloaded to housekeeping CPUs. This is driven by
7462c43838cSFrederic Weisbecker	  the "isolcpus=" boot parameter.
7472c43838cSFrederic Weisbecker
7482c43838cSFrederic Weisbecker	  Say Y if unsure.
7495c4991e2SFrederic Weisbecker
7500af92d46SPaul E. McKenneysource "kernel/rcu/Kconfig"
751c903ff83SMike Travis
7521da177e4SLinus Torvaldsconfig IKCONFIG
753f2443ab6SRoss Biro	tristate "Kernel .config support"
754a7f7f624SMasahiro Yamada	help
7551da177e4SLinus Torvalds	  This option enables the complete Linux kernel ".config" file
7561da177e4SLinus Torvalds	  contents to be saved in the kernel. It provides documentation
7571da177e4SLinus Torvalds	  of which kernel options are used in a running kernel or in an
7581da177e4SLinus Torvalds	  on-disk kernel.  This information can be extracted from the kernel
7591da177e4SLinus Torvalds	  image file with the script scripts/extract-ikconfig and used as
7601da177e4SLinus Torvalds	  input to rebuild the current kernel or to build another kernel.
7611da177e4SLinus Torvalds	  It can also be extracted from a running kernel by reading
7621da177e4SLinus Torvalds	  /proc/config.gz if enabled (below).
7631da177e4SLinus Torvalds
7641da177e4SLinus Torvaldsconfig IKCONFIG_PROC
7651da177e4SLinus Torvalds	bool "Enable access to .config through /proc/config.gz"
7661da177e4SLinus Torvalds	depends on IKCONFIG && PROC_FS
767a7f7f624SMasahiro Yamada	help
7681da177e4SLinus Torvalds	  This option enables access to the kernel configuration file
7691da177e4SLinus Torvalds	  through /proc/config.gz.
7701da177e4SLinus Torvalds
771f7b101d3SJoel Fernandes (Google)config IKHEADERS
772f7b101d3SJoel Fernandes (Google)	tristate "Enable kernel headers through /sys/kernel/kheaders.tar.xz"
773f7b101d3SJoel Fernandes (Google)	depends on SYSFS
77443d8ce9dSJoel Fernandes (Google)	help
775f7b101d3SJoel Fernandes (Google)	  This option enables access to the in-kernel headers that are generated during
776f7b101d3SJoel Fernandes (Google)	  the build process. These can be used to build eBPF tracing programs,
777f7b101d3SJoel Fernandes (Google)	  or similar programs.  If you build the headers as a module, a module called
778f7b101d3SJoel Fernandes (Google)	  kheaders.ko is built which can be loaded on-demand to get access to headers.
77943d8ce9dSJoel Fernandes (Google)
780794543a2SAlistair John Strachanconfig LOG_BUF_SHIFT
781794543a2SAlistair John Strachan	int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
7821c4b5ecbSChristoph Hellwig	range 12 25
783f17a32e9SAdrian Bunk	default 17
784361e9dfbSJosh Triplett	depends on PRINTK
785794543a2SAlistair John Strachan	help
78623b2899fSLuis R. Rodriguez	  Select the minimal kernel log buffer size as a power of 2.
78723b2899fSLuis R. Rodriguez	  The final size is affected by LOG_CPU_MAX_BUF_SHIFT config
78823b2899fSLuis R. Rodriguez	  parameter, see below. Any higher size also might be forced
78923b2899fSLuis R. Rodriguez	  by "log_buf_len" boot parameter.
79023b2899fSLuis R. Rodriguez
791f17a32e9SAdrian Bunk	  Examples:
792f17a32e9SAdrian Bunk		     17 => 128 KB
793f17a32e9SAdrian Bunk		     16 => 64 KB
794f17a32e9SAdrian Bunk		     15 => 32 KB
795f17a32e9SAdrian Bunk		     14 => 16 KB
796794543a2SAlistair John Strachan		     13 =>  8 KB
797794543a2SAlistair John Strachan		     12 =>  4 KB
798794543a2SAlistair John Strachan
79923b2899fSLuis R. Rodriguezconfig LOG_CPU_MAX_BUF_SHIFT
80023b2899fSLuis R. Rodriguez	int "CPU kernel log buffer size contribution (13 => 8 KB, 17 => 128KB)"
8012240a31dSGeert Uytterhoeven	depends on SMP
80223b2899fSLuis R. Rodriguez	range 0 21
80323b2899fSLuis R. Rodriguez	default 0 if BASE_SMALL
804320bf431SYoann Congal	default 12
805361e9dfbSJosh Triplett	depends on PRINTK
80623b2899fSLuis R. Rodriguez	help
80723b2899fSLuis R. Rodriguez	  This option allows to increase the default ring buffer size
80823b2899fSLuis R. Rodriguez	  according to the number of CPUs. The value defines the contribution
80923b2899fSLuis R. Rodriguez	  of each CPU as a power of 2. The used space is typically only few
81023b2899fSLuis R. Rodriguez	  lines however it might be much more when problems are reported,
81123b2899fSLuis R. Rodriguez	  e.g. backtraces.
81223b2899fSLuis R. Rodriguez
81323b2899fSLuis R. Rodriguez	  The increased size means that a new buffer has to be allocated and
81423b2899fSLuis R. Rodriguez	  the original static one is unused. It makes sense only on systems
81523b2899fSLuis R. Rodriguez	  with more CPUs. Therefore this value is used only when the sum of
81623b2899fSLuis R. Rodriguez	  contributions is greater than the half of the default kernel ring
81723b2899fSLuis R. Rodriguez	  buffer as defined by LOG_BUF_SHIFT. The default values are set
8180f7636e1SPaul Menzel	  so that more than 16 CPUs are needed to trigger the allocation.
81923b2899fSLuis R. Rodriguez
82023b2899fSLuis R. Rodriguez	  Also this option is ignored when "log_buf_len" kernel parameter is
82123b2899fSLuis R. Rodriguez	  used as it forces an exact (power of two) size of the ring buffer.
82223b2899fSLuis R. Rodriguez
82323b2899fSLuis R. Rodriguez	  The number of possible CPUs is used for this computation ignoring
8245e0d8d59SGeert Uytterhoeven	  hotplugging making the computation optimal for the worst case
8255e0d8d59SGeert Uytterhoeven	  scenario while allowing a simple algorithm to be used from bootup.
82623b2899fSLuis R. Rodriguez
82723b2899fSLuis R. Rodriguez	  Examples shift values and their meaning:
82823b2899fSLuis R. Rodriguez		     17 => 128 KB for each CPU
82923b2899fSLuis R. Rodriguez		     16 =>  64 KB for each CPU
83023b2899fSLuis R. Rodriguez		     15 =>  32 KB for each CPU
83123b2899fSLuis R. Rodriguez		     14 =>  16 KB for each CPU
83223b2899fSLuis R. Rodriguez		     13 =>   8 KB for each CPU
83323b2899fSLuis R. Rodriguez		     12 =>   4 KB for each CPU
83423b2899fSLuis R. Rodriguez
83533701557SChris Downconfig PRINTK_INDEX
83633701557SChris Down	bool "Printk indexing debugfs interface"
83733701557SChris Down	depends on PRINTK && DEBUG_FS
83833701557SChris Down	help
83933701557SChris Down	  Add support for indexing of all printk formats known at compile time
84033701557SChris Down	  at <debugfs>/printk/index/<module>.
84133701557SChris Down
84233701557SChris Down	  This can be used as part of maintaining daemons which monitor
84333701557SChris Down	  /dev/kmsg, as it permits auditing the printk formats present in a
84433701557SChris Down	  kernel, allowing detection of cases where monitored printks are
84533701557SChris Down	  changed or no longer present.
84633701557SChris Down
84733701557SChris Down	  There is no additional runtime cost to printk with this enabled.
84833701557SChris Down
8495cdc38f9SKAMEZAWA Hiroyuki#
8505cdc38f9SKAMEZAWA Hiroyuki# Architectures with an unreliable sched_clock() should select this:
8515cdc38f9SKAMEZAWA Hiroyuki#
8525cdc38f9SKAMEZAWA Hiroyukiconfig HAVE_UNSTABLE_SCHED_CLOCK
8535cdc38f9SKAMEZAWA Hiroyuki	bool
8545cdc38f9SKAMEZAWA Hiroyuki
85538ff87f7SStephen Boydconfig GENERIC_SCHED_CLOCK
85638ff87f7SStephen Boyd	bool
85738ff87f7SStephen Boyd
85869842cbaSPatrick Bellasimenu "Scheduler features"
85969842cbaSPatrick Bellasi
86069842cbaSPatrick Bellasiconfig UCLAMP_TASK
86169842cbaSPatrick Bellasi	bool "Enable utilization clamping for RT/FAIR tasks"
86269842cbaSPatrick Bellasi	depends on CPU_FREQ_GOV_SCHEDUTIL
86369842cbaSPatrick Bellasi	help
86469842cbaSPatrick Bellasi	  This feature enables the scheduler to track the clamped utilization
86569842cbaSPatrick Bellasi	  of each CPU based on RUNNABLE tasks scheduled on that CPU.
86669842cbaSPatrick Bellasi
86769842cbaSPatrick Bellasi	  With this option, the user can specify the min and max CPU
86869842cbaSPatrick Bellasi	  utilization allowed for RUNNABLE tasks. The max utilization defines
86969842cbaSPatrick Bellasi	  the maximum frequency a task should use while the min utilization
87069842cbaSPatrick Bellasi	  defines the minimum frequency it should use.
87169842cbaSPatrick Bellasi
87269842cbaSPatrick Bellasi	  Both min and max utilization clamp values are hints to the scheduler,
87369842cbaSPatrick Bellasi	  aiming at improving its frequency selection policy, but they do not
87469842cbaSPatrick Bellasi	  enforce or grant any specific bandwidth for tasks.
87569842cbaSPatrick Bellasi
87669842cbaSPatrick Bellasi	  If in doubt, say N.
87769842cbaSPatrick Bellasi
87869842cbaSPatrick Bellasiconfig UCLAMP_BUCKETS_COUNT
87969842cbaSPatrick Bellasi	int "Number of supported utilization clamp buckets"
88069842cbaSPatrick Bellasi	range 5 20
88169842cbaSPatrick Bellasi	default 5
88269842cbaSPatrick Bellasi	depends on UCLAMP_TASK
88369842cbaSPatrick Bellasi	help
88469842cbaSPatrick Bellasi	  Defines the number of clamp buckets to use. The range of each bucket
88569842cbaSPatrick Bellasi	  will be SCHED_CAPACITY_SCALE/UCLAMP_BUCKETS_COUNT. The higher the
88669842cbaSPatrick Bellasi	  number of clamp buckets the finer their granularity and the higher
88769842cbaSPatrick Bellasi	  the precision of clamping aggregation and tracking at run-time.
88869842cbaSPatrick Bellasi
88969842cbaSPatrick Bellasi	  For example, with the minimum configuration value we will have 5
89069842cbaSPatrick Bellasi	  clamp buckets tracking 20% utilization each. A 25% boosted tasks will
89169842cbaSPatrick Bellasi	  be refcounted in the [20..39]% bucket and will set the bucket clamp
89269842cbaSPatrick Bellasi	  effective value to 25%.
89369842cbaSPatrick Bellasi	  If a second 30% boosted task should be co-scheduled on the same CPU,
89469842cbaSPatrick Bellasi	  that task will be refcounted in the same bucket of the first task and
89569842cbaSPatrick Bellasi	  it will boost the bucket clamp effective value to 30%.
89669842cbaSPatrick Bellasi	  The clamp effective value of a bucket is reset to its nominal value
89769842cbaSPatrick Bellasi	  (20% in the example above) when there are no more tasks refcounted in
89869842cbaSPatrick Bellasi	  that bucket.
89969842cbaSPatrick Bellasi
90069842cbaSPatrick Bellasi	  An additional boost/capping margin can be added to some tasks. In the
90169842cbaSPatrick Bellasi	  example above the 25% task will be boosted to 30% until it exits the
90269842cbaSPatrick Bellasi	  CPU. If that should be considered not acceptable on certain systems,
90369842cbaSPatrick Bellasi	  it's always possible to reduce the margin by increasing the number of
90469842cbaSPatrick Bellasi	  clamp buckets to trade off used memory for run-time tracking
90569842cbaSPatrick Bellasi	  precision.
90669842cbaSPatrick Bellasi
90769842cbaSPatrick Bellasi	  If in doubt, use the default value.
90869842cbaSPatrick Bellasi
90925c411fcSJohn Stultzconfig SCHED_PROXY_EXEC
91025c411fcSJohn Stultz	bool "Proxy Execution"
91125c411fcSJohn Stultz	# Avoid some build failures w/ PREEMPT_RT until it can be fixed
91225c411fcSJohn Stultz	depends on !PREEMPT_RT
91325c411fcSJohn Stultz	# Need to investigate how to inform sched_ext of split contexts
91425c411fcSJohn Stultz	depends on !SCHED_CLASS_EXT
91525c411fcSJohn Stultz	# Not particularly useful until we get to multi-rq proxying
91625c411fcSJohn Stultz	depends on EXPERT
91725c411fcSJohn Stultz	help
91825c411fcSJohn Stultz	  This option enables proxy execution, a mechanism for mutex-owning
91925c411fcSJohn Stultz	  tasks to inherit the scheduling context of higher priority waiters.
92025c411fcSJohn Stultz
92169842cbaSPatrick Bellasiendmenu
92269842cbaSPatrick Bellasi
923be3a7284SAndrea Arcangeli#
924be3a7284SAndrea Arcangeli# For architectures that want to enable the support for NUMA-affine scheduler
925be3a7284SAndrea Arcangeli# balancing logic:
926be3a7284SAndrea Arcangeli#
927be3a7284SAndrea Arcangeliconfig ARCH_SUPPORTS_NUMA_BALANCING
928be3a7284SAndrea Arcangeli	bool
929be3a7284SAndrea Arcangeli
930be5e610cSPeter Zijlstra#
93172b252aeSMel Gorman# For architectures that prefer to flush all TLBs after a number of pages
93272b252aeSMel Gorman# are unmapped instead of sending one IPI per page to flush. The architecture
93372b252aeSMel Gorman# must provide guarantees on what happens if a clean TLB cache entry is
93472b252aeSMel Gorman# written after the unmap. Details are in mm/rmap.c near the check for
93572b252aeSMel Gorman# should_defer_flush. The architecture should also consider if the full flush
93672b252aeSMel Gorman# and the refill costs are offset by the savings of sending fewer IPIs.
93772b252aeSMel Gormanconfig ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
93872b252aeSMel Gorman	bool
93972b252aeSMel Gorman
940c12d3362SArd Biesheuvelconfig CC_HAS_INT128
9413a7c7331SMasahiro Yamada	def_bool !$(cc-option,$(m64-flag) -D__SIZEOF_INT128__=0) && 64BIT
942c12d3362SArd Biesheuvel
943dee2b702SGustavo A. R. Silvaconfig CC_IMPLICIT_FALLTHROUGH
944dee2b702SGustavo A. R. Silva	string
945158ea2d2SGustavo A. R. Silva	default "-Wimplicit-fallthrough=5" if CC_IS_GCC && $(cc-option,-Wimplicit-fallthrough=5)
946dee2b702SGustavo A. R. Silva	default "-Wimplicit-fallthrough" if CC_IS_CLANG && $(cc-option,-Wunreachable-code-fallthrough)
947dee2b702SGustavo A. R. Silva
9483e00f580SKees Cook# Currently, disable gcc-10+ array-bounds globally.
9490da6e5fdSLinus Torvalds# It's still broken in gcc-13, so no upper bound yet.
9503e00f580SKees Cookconfig GCC10_NO_ARRAY_BOUNDS
9515a41237aSLinus Torvalds	def_bool y
9525a41237aSLinus Torvalds
953f0be87c4SLinus Torvaldsconfig CC_NO_ARRAY_BOUNDS
954f0be87c4SLinus Torvalds	bool
9558e5bd4eaSYury Norov	default y if CC_IS_GCC && GCC_VERSION >= 90000 && GCC10_NO_ARRAY_BOUNDS
956f0be87c4SLinus Torvalds
95702153319SLinus Torvalds# Currently, disable -Wstringop-overflow for GCC globally.
95802153319SLinus Torvaldsconfig GCC_NO_STRINGOP_OVERFLOW
959a5e0ace0SGustavo A. R. Silva	def_bool y
960a5e0ace0SGustavo A. R. Silva
961a5e0ace0SGustavo A. R. Silvaconfig CC_NO_STRINGOP_OVERFLOW
962a5e0ace0SGustavo A. R. Silva	bool
96302153319SLinus Torvalds	default y if CC_IS_GCC && GCC_NO_STRINGOP_OVERFLOW
964a5e0ace0SGustavo A. R. Silva
965a5e0ace0SGustavo A. R. Silvaconfig CC_STRINGOP_OVERFLOW
966a5e0ace0SGustavo A. R. Silva	bool
967a5e0ace0SGustavo A. R. Silva	default y if CC_IS_GCC && !CC_NO_STRINGOP_OVERFLOW
968a5e0ace0SGustavo A. R. Silva
96972b252aeSMel Gorman#
970be5e610cSPeter Zijlstra# For architectures that know their GCC __int128 support is sound
971be5e610cSPeter Zijlstra#
972be5e610cSPeter Zijlstraconfig ARCH_SUPPORTS_INT128
973be5e610cSPeter Zijlstra	bool
974be5e610cSPeter Zijlstra
975be3a7284SAndrea Arcangeli# For architectures that (ab)use NUMA to represent different memory regions
976be3a7284SAndrea Arcangeli# all cpu-local but of different latencies, such as SuperH.
977be3a7284SAndrea Arcangeli#
978be3a7284SAndrea Arcangeliconfig ARCH_WANT_NUMA_VARIABLE_LOCALITY
979be3a7284SAndrea Arcangeli	bool
980be3a7284SAndrea Arcangeli
981be3a7284SAndrea Arcangeliconfig NUMA_BALANCING
982be3a7284SAndrea Arcangeli	bool "Memory placement aware NUMA scheduler"
983be3a7284SAndrea Arcangeli	depends on ARCH_SUPPORTS_NUMA_BALANCING
984be3a7284SAndrea Arcangeli	depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
985554b0f3cSSebastian Andrzej Siewior	depends on SMP && NUMA && MIGRATION && !PREEMPT_RT
986be3a7284SAndrea Arcangeli	help
987be3a7284SAndrea Arcangeli	  This option adds support for automatic NUMA aware memory/task placement.
988be3a7284SAndrea Arcangeli	  The mechanism is quite primitive and is based on migrating memory when
9896d56a410SPaul Gortmaker	  it has references to the node the task is running on.
990be3a7284SAndrea Arcangeli
991be3a7284SAndrea Arcangeli	  This system will be inactive on UMA systems.
992be3a7284SAndrea Arcangeli
9936f7c97e8SAneesh Kumar K.Vconfig NUMA_BALANCING_DEFAULT_ENABLED
9946f7c97e8SAneesh Kumar K.V	bool "Automatically enable NUMA aware memory/task placement"
9956f7c97e8SAneesh Kumar K.V	default y
9966f7c97e8SAneesh Kumar K.V	depends on NUMA_BALANCING
9976f7c97e8SAneesh Kumar K.V	help
9986f7c97e8SAneesh Kumar K.V	  If set, automatic NUMA balancing will be enabled if running on a NUMA
9996f7c97e8SAneesh Kumar K.V	  machine.
10006f7c97e8SAneesh Kumar K.V
100121c690a3SSuren Baghdasaryanconfig SLAB_OBJ_EXT
100221c690a3SSuren Baghdasaryan	bool
100321c690a3SSuren Baghdasaryan
100423964d2dSLi Zefanmenuconfig CGROUPS
10056341e62bSChristoph Jaeger	bool "Control Group support"
10062bd59d48STejun Heo	select KERNFS
1007ddbcc7e8SPaul Menage	help
100823964d2dSLi Zefan	  This option adds support for grouping sets of processes together, for
10095cdc38f9SKAMEZAWA Hiroyuki	  use with process control subsystems such as Cpusets, CFS, memory
10105cdc38f9SKAMEZAWA Hiroyuki	  controls or device isolation.
10115cdc38f9SKAMEZAWA Hiroyuki	  See
1012d6a3b247SMauro Carvalho Chehab		- Documentation/scheduler/sched-design-CFS.rst	(CFS)
1013da82c92fSMauro Carvalho Chehab		- Documentation/admin-guide/cgroup-v1/ (features for grouping, isolation
101445ce80fbSLi Zefan					  and resource control)
1015ddbcc7e8SPaul Menage
1016ddbcc7e8SPaul Menage	  Say N if unsure.
1017ddbcc7e8SPaul Menage
101823964d2dSLi Zefanif CGROUPS
101923964d2dSLi Zefan
10203e32cb2eSJohannes Weinerconfig PAGE_COUNTER
10213e32cb2eSJohannes Weiner	bool
10223e32cb2eSJohannes Weiner
10236a010a49STejun Heoconfig CGROUP_FAVOR_DYNMODS
10246a010a49STejun Heo        bool "Favor dynamic modification latency reduction by default"
10256a010a49STejun Heo        help
10266a010a49STejun Heo          This option enables the "favordynmods" mount option by default
10276a010a49STejun Heo          which reduces the latencies of dynamic cgroup modifications such
10286a010a49STejun Heo          as task migrations and controller on/offs at the cost of making
10296a010a49STejun Heo          hot path operations such as forks and exits more expensive.
10306a010a49STejun Heo
10316a010a49STejun Heo          Say N if unsure.
10326a010a49STejun Heo
1033c255a458SAndrew Mortonconfig MEMCG
1034a0166ec4SJohannes Weiner	bool "Memory controller"
10353e32cb2eSJohannes Weiner	select PAGE_COUNTER
103679bd9814STejun Heo	select EVENTFD
103721c690a3SSuren Baghdasaryan	select SLAB_OBJ_EXT
1038fdc5001bSKirill A. Shutemov	select VM_EVENT_COUNTERS
103900f0b825SBalbir Singh	help
1040a0166ec4SJohannes Weiner	  Provides control over the memory footprint of tasks in a cgroup.
104100f0b825SBalbir Singh
104225352d2fSShakeel Buttconfig MEMCG_NMI_UNSAFE
104325352d2fSShakeel Butt	bool
104425352d2fSShakeel Butt	depends on MEMCG
104525352d2fSShakeel Butt	depends on HAVE_NMI
104625352d2fSShakeel Butt	depends on !ARCH_HAS_NMI_SAFE_THIS_CPU_OPS && !ARCH_HAVE_NMI_SAFE_CMPXCHG
104725352d2fSShakeel Butt	default y
104825352d2fSShakeel Butt
1049940b01fcSShakeel Buttconfig MEMCG_NMI_SAFETY_REQUIRES_ATOMIC
1050940b01fcSShakeel Butt	bool
1051940b01fcSShakeel Butt	depends on MEMCG
1052940b01fcSShakeel Butt	depends on HAVE_NMI
1053940b01fcSShakeel Butt	depends on !ARCH_HAS_NMI_SAFE_THIS_CPU_OPS && ARCH_HAVE_NMI_SAFE_CMPXCHG
1054940b01fcSShakeel Butt	default y
1055940b01fcSShakeel Butt
1056e93d4166SRoman Gushchinconfig MEMCG_V1
1057e93d4166SRoman Gushchin	bool "Legacy cgroup v1 memory controller"
1058c9929f0eSVlastimil Babka	depends on MEMCG
1059e93d4166SRoman Gushchin	default n
1060e93d4166SRoman Gushchin	help
1061e93d4166SRoman Gushchin	  Legacy cgroup v1 memory controller which has been deprecated by
1062e93d4166SRoman Gushchin	  cgroup v2 implementation. The v1 is there for legacy applications
1063e93d4166SRoman Gushchin	  which haven't migrated to the new cgroup v2 interface yet. If you
1064e93d4166SRoman Gushchin	  do not have any such application then you are completely fine leaving
1065e93d4166SRoman Gushchin	  this option disabled.
1066e93d4166SRoman Gushchin
1067e93d4166SRoman Gushchin	  Please note that feature set of the legacy memory controller is likely
1068e93d4166SRoman Gushchin	  going to shrink due to deprecation process. New deployments with v1
1069e93d4166SRoman Gushchin	  controller are highly discouraged.
1070e93d4166SRoman Gushchin
1071fcb4824bSValdis Kletnieks	  Say N if unsure.
107284c07d11SKirill Tkhai
10736bf024e6SJohannes Weinerconfig BLK_CGROUP
10746bf024e6SJohannes Weiner	bool "IO controller"
10756bf024e6SJohannes Weiner	depends on BLOCK
10762bc64a20SAneesh Kumar K.V	default n
1077a7f7f624SMasahiro Yamada	help
10786bf024e6SJohannes Weiner	Generic block IO controller cgroup interface. This is the common
10796bf024e6SJohannes Weiner	cgroup interface which should be used by various IO controlling
10806bf024e6SJohannes Weiner	policies.
10812bc64a20SAneesh Kumar K.V
10826bf024e6SJohannes Weiner	Currently, CFQ IO scheduler uses it to recognize task groups and
10836bf024e6SJohannes Weiner	control disk bandwidth allocation (proportional time slice allocation)
10846bf024e6SJohannes Weiner	to such task groups. It is also used by bio throttling logic in
10856bf024e6SJohannes Weiner	block layer to implement upper limit in IO rates on a device.
1086e5d1367fSStephane Eranian
10876bf024e6SJohannes Weiner	This option only enables generic Block IO controller infrastructure.
10886bf024e6SJohannes Weiner	One needs to also enable actual IO controlling logic/policy. For
10896bf024e6SJohannes Weiner	enabling proportional weight division of disk bandwidth in CFQ, set
10907baf2199SKrzysztof Kozlowski	CONFIG_BFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
10916bf024e6SJohannes Weiner	CONFIG_BLK_DEV_THROTTLING=y.
10926bf024e6SJohannes Weiner
1093da82c92fSMauro Carvalho Chehab	See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information.
10946bf024e6SJohannes Weiner
10956bf024e6SJohannes Weinerconfig CGROUP_WRITEBACK
10966bf024e6SJohannes Weiner	bool
10976bf024e6SJohannes Weiner	depends on MEMCG && BLK_CGROUP
10986bf024e6SJohannes Weiner	default y
1099e5d1367fSStephane Eranian
11007c941438SDhaval Gianimenuconfig CGROUP_SCHED
1101a0166ec4SJohannes Weiner	bool "CPU controller"
11027c941438SDhaval Giani	default n
11037c941438SDhaval Giani	help
11047c941438SDhaval Giani	  This feature lets CPU scheduler recognize task groups and control CPU
11057c941438SDhaval Giani	  bandwidth allocation to such task groups. It uses cgroups to group
11067c941438SDhaval Giani	  tasks.
11077c941438SDhaval Giani
11087c941438SDhaval Gianiif CGROUP_SCHED
1109e179e80cSTejun Heoconfig GROUP_SCHED_WEIGHT
1110e179e80cSTejun Heo	def_bool n
1111e179e80cSTejun Heo
1112ddceadceSTejun Heoconfig GROUP_SCHED_BANDWIDTH
1113ddceadceSTejun Heo        def_bool n
1114ddceadceSTejun Heo
11157c941438SDhaval Gianiconfig FAIR_GROUP_SCHED
11167c941438SDhaval Giani	bool "Group scheduling for SCHED_OTHER"
11177c941438SDhaval Giani	depends on CGROUP_SCHED
1118e179e80cSTejun Heo	select GROUP_SCHED_WEIGHT
11197c941438SDhaval Giani	default CGROUP_SCHED
11207c941438SDhaval Giani
1121ab84d31eSPaul Turnerconfig CFS_BANDWIDTH
1122ab84d31eSPaul Turner	bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
1123ab84d31eSPaul Turner	depends on FAIR_GROUP_SCHED
1124ddceadceSTejun Heo	select GROUP_SCHED_BANDWIDTH
1125ab84d31eSPaul Turner	default n
1126ab84d31eSPaul Turner	help
1127ab84d31eSPaul Turner	  This option allows users to define CPU bandwidth rates (limits) for
1128ab84d31eSPaul Turner	  tasks running within the fair group scheduler.  Groups with no limit
1129ab84d31eSPaul Turner	  set are considered to be unconstrained and will run with no
1130ab84d31eSPaul Turner	  restriction.
1131d6a3b247SMauro Carvalho Chehab	  See Documentation/scheduler/sched-bwc.rst for more information.
1132ab84d31eSPaul Turner
11337c941438SDhaval Gianiconfig RT_GROUP_SCHED
11347c941438SDhaval Giani	bool "Group scheduling for SCHED_RR/FIFO"
11357c941438SDhaval Giani	depends on CGROUP_SCHED
11367c941438SDhaval Giani	default n
11377c941438SDhaval Giani	help
11387c941438SDhaval Giani	  This feature lets you explicitly allocate real CPU bandwidth
113932bd7eb5SLi Zefan	  to task groups. If enabled, it will also make it impossible to
11407c941438SDhaval Giani	  schedule realtime tasks for non-root users until you allocate
11417c941438SDhaval Giani	  realtime bandwidth for them.
1142d6a3b247SMauro Carvalho Chehab	  See Documentation/scheduler/sched-rt-group.rst for more information.
11437c941438SDhaval Giani
1144e34e0131SMichal Koutnýconfig RT_GROUP_SCHED_DEFAULT_DISABLED
1145e34e0131SMichal Koutný	bool "Require boot parameter to enable group scheduling for SCHED_RR/FIFO"
1146e34e0131SMichal Koutný	depends on RT_GROUP_SCHED
1147e34e0131SMichal Koutný	default n
1148e34e0131SMichal Koutný	help
1149e34e0131SMichal Koutný	  When set, the RT group scheduling is disabled by default. The option
1150e34e0131SMichal Koutný	  is in inverted form so that mere RT_GROUP_SCHED enables the group
1151e34e0131SMichal Koutný	  scheduling.
1152e34e0131SMichal Koutný
1153e34e0131SMichal Koutný	  Say N if unsure.
1154e34e0131SMichal Koutný
115581951366STejun Heoconfig EXT_GROUP_SCHED
115681951366STejun Heo	bool
115781951366STejun Heo	depends on SCHED_CLASS_EXT && CGROUP_SCHED
115881951366STejun Heo	select GROUP_SCHED_WEIGHT
1159ddceadceSTejun Heo	select GROUP_SCHED_BANDWIDTH
116081951366STejun Heo	default y
116181951366STejun Heo
11627c941438SDhaval Gianiendif #CGROUP_SCHED
11637c941438SDhaval Giani
1164af7f588dSMathieu Desnoyersconfig SCHED_MM_CID
1165af7f588dSMathieu Desnoyers	def_bool y
1166af7f588dSMathieu Desnoyers	depends on SMP && RSEQ
1167af7f588dSMathieu Desnoyers
11682480c093SPatrick Bellasiconfig UCLAMP_TASK_GROUP
11692480c093SPatrick Bellasi	bool "Utilization clamping per group of tasks"
11702480c093SPatrick Bellasi	depends on CGROUP_SCHED
11712480c093SPatrick Bellasi	depends on UCLAMP_TASK
11722480c093SPatrick Bellasi	default n
11732480c093SPatrick Bellasi	help
11742480c093SPatrick Bellasi	  This feature enables the scheduler to track the clamped utilization
11752480c093SPatrick Bellasi	  of each CPU based on RUNNABLE tasks currently scheduled on that CPU.
11762480c093SPatrick Bellasi
11772480c093SPatrick Bellasi	  When this option is enabled, the user can specify a min and max
11782480c093SPatrick Bellasi	  CPU bandwidth which is allowed for each single task in a group.
11792480c093SPatrick Bellasi	  The max bandwidth allows to clamp the maximum frequency a task
11802480c093SPatrick Bellasi	  can use, while the min bandwidth allows to define a minimum
11812480c093SPatrick Bellasi	  frequency a task will always use.
11822480c093SPatrick Bellasi
11832480c093SPatrick Bellasi	  When task group based utilization clamping is enabled, an eventually
11842480c093SPatrick Bellasi	  specified task-specific clamp value is constrained by the cgroup
11852480c093SPatrick Bellasi	  specified clamp value. Both minimum and maximum task clamping cannot
11862480c093SPatrick Bellasi	  be bigger than the corresponding clamping defined at task group level.
11872480c093SPatrick Bellasi
11882480c093SPatrick Bellasi	  If in doubt, say N.
11892480c093SPatrick Bellasi
11906bf024e6SJohannes Weinerconfig CGROUP_PIDS
11916bf024e6SJohannes Weiner	bool "PIDs controller"
11926bf024e6SJohannes Weiner	help
11936bf024e6SJohannes Weiner	  Provides enforcement of process number limits in the scope of a
11946bf024e6SJohannes Weiner	  cgroup. Any attempt to fork more processes than is allowed in the
11956bf024e6SJohannes Weiner	  cgroup will fail. PIDs are fundamentally a global resource because it
11966bf024e6SJohannes Weiner	  is fairly trivial to reach PID exhaustion before you reach even a
11976bf024e6SJohannes Weiner	  conservative kmemcg limit. As a result, it is possible to grind a
11986bf024e6SJohannes Weiner	  system to halt without being limited by other cgroup policies. The
11996cc578dfSParav Pandit	  PIDs controller is designed to stop this from happening.
12006bf024e6SJohannes Weiner
12016bf024e6SJohannes Weiner	  It should be noted that organisational operations (such as attaching
120298076833SJonathan Neuschäfer	  to a cgroup hierarchy) will *not* be blocked by the PIDs controller,
12036bf024e6SJohannes Weiner	  since the PIDs limit only affects a process's ability to fork, not to
12046bf024e6SJohannes Weiner	  attach to a cgroup.
12056bf024e6SJohannes Weiner
120639d3e758SParav Panditconfig CGROUP_RDMA
120739d3e758SParav Pandit	bool "RDMA controller"
120839d3e758SParav Pandit	help
120939d3e758SParav Pandit	  Provides enforcement of RDMA resources defined by IB stack.
121039d3e758SParav Pandit	  It is fairly easy for consumers to exhaust RDMA resources, which
121139d3e758SParav Pandit	  can result into resource unavailability to other consumers.
121239d3e758SParav Pandit	  RDMA controller is designed to stop this from happening.
121339d3e758SParav Pandit	  Attaching processes with active RDMA resources to the cgroup
121439d3e758SParav Pandit	  hierarchy is allowed even if can cross the hierarchy's limit.
121539d3e758SParav Pandit
1216b168ed45SMaarten Lankhorstconfig CGROUP_DMEM
1217b168ed45SMaarten Lankhorst	bool "Device memory controller (DMEM)"
1218e33b5149SMaxime Ripard	select PAGE_COUNTER
1219b168ed45SMaarten Lankhorst	help
1220b168ed45SMaarten Lankhorst	  The DMEM controller allows compatible devices to restrict device
1221b168ed45SMaarten Lankhorst	  memory usage based on the cgroup hierarchy.
1222b168ed45SMaarten Lankhorst
1223b168ed45SMaarten Lankhorst	  As an example, it allows you to restrict VRAM usage for applications
1224b168ed45SMaarten Lankhorst	  in the DRM subsystem.
1225b168ed45SMaarten Lankhorst
12266bf024e6SJohannes Weinerconfig CGROUP_FREEZER
12276bf024e6SJohannes Weiner	bool "Freezer controller"
12286bf024e6SJohannes Weiner	help
12296bf024e6SJohannes Weiner	  Provides a way to freeze and unfreeze all tasks in a
12306bf024e6SJohannes Weiner	  cgroup.
12316bf024e6SJohannes Weiner
1232489c2a20SJohannes Weiner	  This option affects the ORIGINAL cgroup interface. The cgroup2 memory
1233489c2a20SJohannes Weiner	  controller includes important in-kernel memory consumers per default.
1234489c2a20SJohannes Weiner
1235489c2a20SJohannes Weiner	  If you're using cgroup2, say N.
1236489c2a20SJohannes Weiner
12376bf024e6SJohannes Weinerconfig CGROUP_HUGETLB
12386bf024e6SJohannes Weiner	bool "HugeTLB controller"
12396bf024e6SJohannes Weiner	depends on HUGETLB_PAGE
12406bf024e6SJohannes Weiner	select PAGE_COUNTER
1241afc24d49SVivek Goyal	default n
12426bf024e6SJohannes Weiner	help
12436bf024e6SJohannes Weiner	  Provides a cgroup controller for HugeTLB pages.
12446bf024e6SJohannes Weiner	  When you enable this, you can put a per cgroup limit on HugeTLB usage.
12456bf024e6SJohannes Weiner	  The limit is enforced during page fault. Since HugeTLB doesn't
12466bf024e6SJohannes Weiner	  support page reclaim, enforcing the limit at page fault time implies
12476bf024e6SJohannes Weiner	  that, the application will get SIGBUS signal if it tries to access
12486bf024e6SJohannes Weiner	  HugeTLB pages beyond its limit. This requires the application to know
12496bf024e6SJohannes Weiner	  beforehand how much HugeTLB pages it would require for its use. The
12506bf024e6SJohannes Weiner	  control group is tracked in the third page lru pointer. This means
12516bf024e6SJohannes Weiner	  that we cannot use the controller with huge page less than 3 pages.
1252afc24d49SVivek Goyal
12536bf024e6SJohannes Weinerconfig CPUSETS
12546bf024e6SJohannes Weiner	bool "Cpuset controller"
1255e1d4eeecSNicolas Pitre	depends on SMP
1256bf9850f6SKuan-Wei Chiu	select UNION_FIND
12576bf024e6SJohannes Weiner	help
12586bf024e6SJohannes Weiner	  This option will let you create and manage CPUSETs which
12596bf024e6SJohannes Weiner	  allow dynamically partitioning a system into sets of CPUs and
12606bf024e6SJohannes Weiner	  Memory Nodes and assigning tasks to run only within those sets.
12616bf024e6SJohannes Weiner	  This is primarily useful on large SMP or NUMA systems.
1262afc24d49SVivek Goyal
12636bf024e6SJohannes Weiner	  Say N if unsure.
1264afc24d49SVivek Goyal
12651abab1baSChen Ridongconfig CPUSETS_V1
12661abab1baSChen Ridong	bool "Legacy cgroup v1 cpusets controller"
12671abab1baSChen Ridong	depends on CPUSETS
12681abab1baSChen Ridong	default n
12691abab1baSChen Ridong	help
12701abab1baSChen Ridong	  Legacy cgroup v1 cpusets controller which has been deprecated by
12711abab1baSChen Ridong	  cgroup v2 implementation. The v1 is there for legacy applications
1272dae68fbaSMichal Koutný	  which haven't migrated to the new cgroup v2 interface yet. Legacy
1273dae68fbaSMichal Koutný	  interface includes cpuset filesystem and /proc/<pid>/cpuset. If you
12741abab1baSChen Ridong	  do not have any such application then you are completely fine leaving
12751abab1baSChen Ridong	  this option disabled.
12761abab1baSChen Ridong
12771abab1baSChen Ridong	  Say N if unsure.
12781abab1baSChen Ridong
12796bf024e6SJohannes Weinerconfig PROC_PID_CPUSET
12806bf024e6SJohannes Weiner	bool "Include legacy /proc/<pid>/cpuset file"
1281dae68fbaSMichal Koutný	depends on CPUSETS_V1
128289e9b9e0STejun Heo	default y
128389e9b9e0STejun Heo
12846bf024e6SJohannes Weinerconfig CGROUP_DEVICE
12856bf024e6SJohannes Weiner	bool "Device controller"
12866bf024e6SJohannes Weiner	help
12876bf024e6SJohannes Weiner	  Provides a cgroup controller implementing whitelists for
12886bf024e6SJohannes Weiner	  devices which a process in the cgroup can mknod or open.
12896bf024e6SJohannes Weiner
12906bf024e6SJohannes Weinerconfig CGROUP_CPUACCT
12916bf024e6SJohannes Weiner	bool "Simple CPU accounting controller"
12926bf024e6SJohannes Weiner	help
12936bf024e6SJohannes Weiner	  Provides a simple controller for monitoring the
12946bf024e6SJohannes Weiner	  total CPU consumed by the tasks in a cgroup.
12956bf024e6SJohannes Weiner
12966bf024e6SJohannes Weinerconfig CGROUP_PERF
12976bf024e6SJohannes Weiner	bool "Perf controller"
12986bf024e6SJohannes Weiner	depends on PERF_EVENTS
12996bf024e6SJohannes Weiner	help
13006bf024e6SJohannes Weiner	  This option extends the perf per-cpu mode to restrict monitoring
13016bf024e6SJohannes Weiner	  to threads which belong to the cgroup specified and run on the
13026546b19fSNamhyung Kim	  designated cpu.  Or this can be used to have cgroup ID in samples
13036546b19fSNamhyung Kim	  so that it can monitor performance events among cgroups.
13046bf024e6SJohannes Weiner
13056bf024e6SJohannes Weiner	  Say N if unsure.
13066bf024e6SJohannes Weiner
130730070984SDaniel Mackconfig CGROUP_BPF
130830070984SDaniel Mack	bool "Support for eBPF programs attached to cgroups"
1309483c4933SAndy Lutomirski	depends on BPF_SYSCALL
1310483c4933SAndy Lutomirski	select SOCK_CGROUP_DATA
131130070984SDaniel Mack	help
131230070984SDaniel Mack	  Allow attaching eBPF programs to a cgroup using the bpf(2)
131330070984SDaniel Mack	  syscall command BPF_PROG_ATTACH.
131430070984SDaniel Mack
131530070984SDaniel Mack	  In which context these programs are accessed depends on the type
131630070984SDaniel Mack	  of attachment. For instance, programs that are attached using
131730070984SDaniel Mack	  BPF_CGROUP_INET_INGRESS will be executed on the ingress path of
131830070984SDaniel Mack	  inet sockets.
131930070984SDaniel Mack
1320a72232eaSVipin Sharmaconfig CGROUP_MISC
1321a72232eaSVipin Sharma	bool "Misc resource controller"
1322a72232eaSVipin Sharma	default n
1323a72232eaSVipin Sharma	help
1324a72232eaSVipin Sharma	  Provides a controller for miscellaneous resources on a host.
1325a72232eaSVipin Sharma
1326a72232eaSVipin Sharma	  Miscellaneous scalar resources are the resources on the host system
1327a72232eaSVipin Sharma	  which cannot be abstracted like the other cgroups. This controller
1328a72232eaSVipin Sharma	  tracks and limits the miscellaneous resources used by a process
1329a72232eaSVipin Sharma	  attached to a cgroup hierarchy.
1330a72232eaSVipin Sharma
1331a72232eaSVipin Sharma	  For more information, please check misc cgroup section in
1332a72232eaSVipin Sharma	  /Documentation/admin-guide/cgroup-v2.rst.
1333a72232eaSVipin Sharma
13346bf024e6SJohannes Weinerconfig CGROUP_DEBUG
133523b0be48SWaiman Long	bool "Debug controller"
13366bf024e6SJohannes Weiner	default n
133723b0be48SWaiman Long	depends on DEBUG_KERNEL
13386bf024e6SJohannes Weiner	help
13396bf024e6SJohannes Weiner	  This option enables a simple controller that exports
134023b0be48SWaiman Long	  debugging information about the cgroups framework. This
134123b0be48SWaiman Long	  controller is for control cgroup debugging only. Its
134223b0be48SWaiman Long	  interfaces are not stable.
13436bf024e6SJohannes Weiner
13446bf024e6SJohannes Weiner	  Say N.
13456bf024e6SJohannes Weiner
134673b35147SArnd Bergmannconfig SOCK_CGROUP_DATA
134773b35147SArnd Bergmann	bool
134873b35147SArnd Bergmann	default n
134973b35147SArnd Bergmann
135023964d2dSLi Zefanendif # CGROUPS
1351c077719bSKAMEZAWA Hiroyuki
13528dd2a82cSDaniel Lezcanomenuconfig NAMESPACES
13536a108a14SDavid Rientjes	bool "Namespaces support" if EXPERT
13542813893fSIulia Manda	depends on MULTIUSER
13556a108a14SDavid Rientjes	default !EXPERT
1356c5289a69SPavel Emelyanov	help
1357c5289a69SPavel Emelyanov	  Provides the way to make tasks work with different objects using
1358c5289a69SPavel Emelyanov	  the same id. For example same IPC id may refer to different objects
1359c5289a69SPavel Emelyanov	  or same user id or pid may refer to different tasks when used in
1360c5289a69SPavel Emelyanov	  different namespaces.
1361c5289a69SPavel Emelyanov
13628dd2a82cSDaniel Lezcanoif NAMESPACES
13638dd2a82cSDaniel Lezcano
136458bfdd6dSPavel Emelyanovconfig UTS_NS
136558bfdd6dSPavel Emelyanov	bool "UTS namespace"
136617a6d441SDaniel Lezcano	default y
136758bfdd6dSPavel Emelyanov	help
136858bfdd6dSPavel Emelyanov	  In this namespace tasks see different info provided with the
136958bfdd6dSPavel Emelyanov	  uname() system call
137058bfdd6dSPavel Emelyanov
1371769071acSAndrei Vaginconfig TIME_NS
1372769071acSAndrei Vagin	bool "TIME namespace"
1373bad53ae2SThomas Weißschuh	depends on GENERIC_GETTIMEOFDAY
1374769071acSAndrei Vagin	default y
1375769071acSAndrei Vagin	help
1376769071acSAndrei Vagin	  In this namespace boottime and monotonic clocks can be set.
1377769071acSAndrei Vagin	  The time will keep going with the same pace.
1378769071acSAndrei Vagin
1379ae5e1b22SPavel Emelyanovconfig IPC_NS
1380ae5e1b22SPavel Emelyanov	bool "IPC namespace"
13818dd2a82cSDaniel Lezcano	depends on (SYSVIPC || POSIX_MQUEUE)
138217a6d441SDaniel Lezcano	default y
1383ae5e1b22SPavel Emelyanov	help
1384ae5e1b22SPavel Emelyanov	  In this namespace tasks work with IPC ids which correspond to
1385614b84cfSSerge E. Hallyn	  different IPC objects in different namespaces.
1386ae5e1b22SPavel Emelyanov
1387aee16ce7SPavel Emelyanovconfig USER_NS
138819c92399SKees Cook	bool "User namespace"
13895673a94cSEric W. Biederman	default n
1390aee16ce7SPavel Emelyanov	help
1391aee16ce7SPavel Emelyanov	  This allows containers, i.e. vservers, to use user namespaces
1392aee16ce7SPavel Emelyanov	  to provide different user info for different servers.
1393e11f0ae3SEric W. Biederman
1394e11f0ae3SEric W. Biederman	  When user namespaces are enabled in the kernel it is
1395d886f4e4SJohannes Weiner	  recommended that the MEMCG option also be enabled and that
1396d886f4e4SJohannes Weiner	  user-space use the memory control groups to limit the amount
1397d886f4e4SJohannes Weiner	  of memory a memory unprivileged users can use.
1398e11f0ae3SEric W. Biederman
1399aee16ce7SPavel Emelyanov	  If unsure, say N.
1400aee16ce7SPavel Emelyanov
140174bd59bbSPavel Emelyanovconfig PID_NS
14029bd38c2cSDaniel Lezcano	bool "PID Namespaces"
140317a6d441SDaniel Lezcano	default y
140474bd59bbSPavel Emelyanov	help
140512d2b8f9SHeikki Orsila	  Support process id namespaces.  This allows having multiple
1406692105b8SMatt LaPlante	  processes with the same pid as long as they are in different
140774bd59bbSPavel Emelyanov	  pid namespaces.  This is a building block of containers.
140874bd59bbSPavel Emelyanov
1409d6eb633fSMatt Helsleyconfig NET_NS
1410d6eb633fSMatt Helsley	bool "Network namespace"
14118dd2a82cSDaniel Lezcano	depends on NET
141217a6d441SDaniel Lezcano	default y
1413d6eb633fSMatt Helsley	help
1414d6eb633fSMatt Helsley	  Allow user space to create what appear to be multiple instances
1415d6eb633fSMatt Helsley	  of the network stack.
1416d6eb633fSMatt Helsley
14178dd2a82cSDaniel Lezcanoendif # NAMESPACES
14188dd2a82cSDaniel Lezcano
14195cb366bbSAdrian Reberconfig CHECKPOINT_RESTORE
14205cb366bbSAdrian Reber	bool "Checkpoint/restore support"
142130341ec9SRen Zhijie	depends on PROC_FS
14225cb366bbSAdrian Reber	select PROC_CHILDREN
1423bfe3911aSChris Wilson	select KCMP
14245cb366bbSAdrian Reber	default n
14255cb366bbSAdrian Reber	help
14265cb366bbSAdrian Reber	  Enables additional kernel features in a sake of checkpoint/restore.
14275cb366bbSAdrian Reber	  In particular it adds auxiliary prctl codes to setup process text,
14285cb366bbSAdrian Reber	  data and heap segment sizes, and a few additional /proc filesystem
14295cb366bbSAdrian Reber	  entries.
14305cb366bbSAdrian Reber
14315cb366bbSAdrian Reber	  If unsure, say N here.
14325cb366bbSAdrian Reber
14335091faa4SMike Galbraithconfig SCHED_AUTOGROUP
14345091faa4SMike Galbraith	bool "Automatic process group scheduling"
14355091faa4SMike Galbraith	select CGROUPS
14365091faa4SMike Galbraith	select CGROUP_SCHED
14375091faa4SMike Galbraith	select FAIR_GROUP_SCHED
14385091faa4SMike Galbraith	help
14395091faa4SMike Galbraith	  This option optimizes the scheduler for common desktop workloads by
14405091faa4SMike Galbraith	  automatically creating and populating task groups.  This separation
14415091faa4SMike Galbraith	  of workloads isolates aggressive CPU burners (like build jobs) from
14425091faa4SMike Galbraith	  desktop applications.  Task group autogeneration is currently based
14435091faa4SMike Galbraith	  upon task session.
14445091faa4SMike Galbraith
14457af37becSDaniel Lezcanoconfig RELAY
14467af37becSDaniel Lezcano	bool "Kernel->user space relay support (formerly relayfs)"
144726b5679eSPeter Zijlstra	select IRQ_WORK
14487af37becSDaniel Lezcano	help
14497af37becSDaniel Lezcano	  This option enables support for relay interface support in
14507af37becSDaniel Lezcano	  certain file systems (such as debugfs).
14517af37becSDaniel Lezcano	  It is designed to provide an efficient mechanism for tools and
14527af37becSDaniel Lezcano	  facilities to relay large amounts of data from kernel space to
14537af37becSDaniel Lezcano	  user space.
14547af37becSDaniel Lezcano
14557af37becSDaniel Lezcano	  If unsure, say N.
14567af37becSDaniel Lezcano
1457f991633dSDimitri Gorokhovikconfig BLK_DEV_INITRD
1458f991633dSDimitri Gorokhovik	bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1459f991633dSDimitri Gorokhovik	help
1460f991633dSDimitri Gorokhovik	  The initial RAM filesystem is a ramfs which is loaded by the
1461f991633dSDimitri Gorokhovik	  boot loader (loadlin or lilo) and that is mounted as root
1462f991633dSDimitri Gorokhovik	  before the normal boot procedure. It is typically used to
1463f991633dSDimitri Gorokhovik	  load modules needed to mount the "real" root file system,
14648c27ceffSMauro Carvalho Chehab	  etc. See <file:Documentation/admin-guide/initrd.rst> for details.
1465f991633dSDimitri Gorokhovik
1466f991633dSDimitri Gorokhovik	  If RAM disk support (BLK_DEV_RAM) is also included, this
1467f991633dSDimitri Gorokhovik	  also enables initial RAM disk (initrd) support and adds
1468f991633dSDimitri Gorokhovik	  15 Kbytes (more on some other architectures) to the kernel size.
1469f991633dSDimitri Gorokhovik
1470f991633dSDimitri Gorokhovik	  If unsure say Y.
1471f991633dSDimitri Gorokhovik
1472c33df4eaSJean-Paul Samanif BLK_DEV_INITRD
1473c33df4eaSJean-Paul Saman
1474dbec4866SSam Ravnborgsource "usr/Kconfig"
1475dbec4866SSam Ravnborg
1476c33df4eaSJean-Paul Samanendif
1477c33df4eaSJean-Paul Saman
147876db5a27SMasami Hiramatsuconfig BOOT_CONFIG
147976db5a27SMasami Hiramatsu	bool "Boot config support"
1480a2a9d67aSMasami Hiramatsu	select BLK_DEV_INITRD if !BOOT_CONFIG_EMBED
148176db5a27SMasami Hiramatsu	help
148276db5a27SMasami Hiramatsu	  Extra boot config allows system admin to pass a config file as
148376db5a27SMasami Hiramatsu	  complemental extension of kernel cmdline when booting.
14840947db01SMasami Hiramatsu	  The boot config file must be attached at the end of initramfs
148585c46b78SMasami Hiramatsu	  with checksum, size and magic word.
14860947db01SMasami Hiramatsu	  See <file:Documentation/admin-guide/bootconfig.rst> for details.
148776db5a27SMasami Hiramatsu
148876db5a27SMasami Hiramatsu	  If unsure, say Y.
148976db5a27SMasami Hiramatsu
1490b743852cSPaul E. McKenneyconfig BOOT_CONFIG_FORCE
1491b743852cSPaul E. McKenney	bool "Force unconditional bootconfig processing"
1492b743852cSPaul E. McKenney	depends on BOOT_CONFIG
14936ded8a28SPaul E. McKenney	default y if BOOT_CONFIG_EMBED
1494b743852cSPaul E. McKenney	help
1495b743852cSPaul E. McKenney	  With this Kconfig option set, BOOT_CONFIG processing is carried
1496b743852cSPaul E. McKenney	  out even when the "bootconfig" kernel-boot parameter is omitted.
1497b743852cSPaul E. McKenney	  In fact, with this Kconfig option set, there is no way to
1498b743852cSPaul E. McKenney	  make the kernel ignore the BOOT_CONFIG-supplied kernel-boot
1499b743852cSPaul E. McKenney	  parameters.
1500b743852cSPaul E. McKenney
1501b743852cSPaul E. McKenney	  If unsure, say N.
1502b743852cSPaul E. McKenney
1503a2a9d67aSMasami Hiramatsuconfig BOOT_CONFIG_EMBED
1504a2a9d67aSMasami Hiramatsu	bool "Embed bootconfig file in the kernel"
1505a2a9d67aSMasami Hiramatsu	depends on BOOT_CONFIG
1506a2a9d67aSMasami Hiramatsu	help
1507a2a9d67aSMasami Hiramatsu	  Embed a bootconfig file given by BOOT_CONFIG_EMBED_FILE in the
1508a2a9d67aSMasami Hiramatsu	  kernel. Usually, the bootconfig file is loaded with the initrd
1509a2a9d67aSMasami Hiramatsu	  image. But if the system doesn't support initrd, this option will
1510a2a9d67aSMasami Hiramatsu	  help you by embedding a bootconfig file while building the kernel.
1511a2a9d67aSMasami Hiramatsu
1512a2a9d67aSMasami Hiramatsu	  If unsure, say N.
1513a2a9d67aSMasami Hiramatsu
1514a2a9d67aSMasami Hiramatsuconfig BOOT_CONFIG_EMBED_FILE
1515a2a9d67aSMasami Hiramatsu	string "Embedded bootconfig file path"
1516a2a9d67aSMasami Hiramatsu	depends on BOOT_CONFIG_EMBED
1517a2a9d67aSMasami Hiramatsu	help
1518a2a9d67aSMasami Hiramatsu	  Specify a bootconfig file which will be embedded to the kernel.
1519a2a9d67aSMasami Hiramatsu	  This bootconfig will be used if there is no initrd or no other
1520a2a9d67aSMasami Hiramatsu	  bootconfig in the initrd.
1521a2a9d67aSMasami Hiramatsu
1522032a7302SDouglas Andersonconfig CMDLINE_LOG_WRAP_IDEAL_LEN
1523032a7302SDouglas Anderson	int "Length to try to wrap the cmdline when logged at boot"
1524032a7302SDouglas Anderson	default 1021
1525032a7302SDouglas Anderson	range 0 1021
1526032a7302SDouglas Anderson	help
1527032a7302SDouglas Anderson	  At boot time, the kernel command line is logged to the console.
1528032a7302SDouglas Anderson	  The log message will start with the prefix "Kernel command line: ".
1529032a7302SDouglas Anderson	  The log message will attempt to be wrapped (split into multiple log
1530032a7302SDouglas Anderson	  messages) at spaces based on CMDLINE_LOG_WRAP_IDEAL_LEN characters.
1531032a7302SDouglas Anderson	  If wrapping happens, each log message will start with the prefix and
1532032a7302SDouglas Anderson	  all but the last message will end with " \". Messages may exceed the
1533032a7302SDouglas Anderson	  ideal length if a place to wrap isn't found before the specified
1534032a7302SDouglas Anderson	  number of characters.
1535032a7302SDouglas Anderson
1536032a7302SDouglas Anderson	  A value of 0 disables wrapping, though be warned that the maximum
1537032a7302SDouglas Anderson	  length of a log message (1021 characters) may cause the cmdline to
1538032a7302SDouglas Anderson	  be truncated.
1539032a7302SDouglas Anderson
15401274aea1SDavid Disseldorpconfig INITRAMFS_PRESERVE_MTIME
15411274aea1SDavid Disseldorp	bool "Preserve cpio archive mtimes in initramfs"
154274792608SGeert Uytterhoeven	depends on BLK_DEV_INITRD
15431274aea1SDavid Disseldorp	default y
15441274aea1SDavid Disseldorp	help
15451274aea1SDavid Disseldorp	  Each entry in an initramfs cpio archive carries an mtime value. When
15461274aea1SDavid Disseldorp	  enabled, extracted cpio items take this mtime, with directory mtime
15471274aea1SDavid Disseldorp	  setting deferred until after creation of any child entries.
15481274aea1SDavid Disseldorp
15491274aea1SDavid Disseldorp	  If unsure, say Y.
15501274aea1SDavid Disseldorp
155183c0b272SDavid Disseldorpconfig INITRAMFS_TEST
155283c0b272SDavid Disseldorp	bool "Test initramfs cpio archive extraction" if !KUNIT_ALL_TESTS
155383c0b272SDavid Disseldorp	depends on BLK_DEV_INITRD && KUNIT=y
155483c0b272SDavid Disseldorp	default KUNIT_ALL_TESTS
155583c0b272SDavid Disseldorp	help
155683c0b272SDavid Disseldorp	  Build KUnit tests for initramfs. See Documentation/dev-tools/kunit
155783c0b272SDavid Disseldorp
1558877417e6SArnd Bergmannchoice
1559877417e6SArnd Bergmann	prompt "Compiler optimization level"
15602cc3ce24SUlf Magnusson	default CC_OPTIMIZE_FOR_PERFORMANCE
1561877417e6SArnd Bergmann
1562877417e6SArnd Bergmannconfig CC_OPTIMIZE_FOR_PERFORMANCE
156315f5db60SMasahiro Yamada	bool "Optimize for performance (-O2)"
1564877417e6SArnd Bergmann	help
1565877417e6SArnd Bergmann	  This is the default optimization level for the kernel, building
1566877417e6SArnd Bergmann	  with the "-O2" compiler flag for best performance and most
1567877417e6SArnd Bergmann	  helpful compile-time warnings.
1568877417e6SArnd Bergmann
1569c45b4f1fSLinus Torvaldsconfig CC_OPTIMIZE_FOR_SIZE
157015f5db60SMasahiro Yamada	bool "Optimize for size (-Os)"
1571c45b4f1fSLinus Torvalds	help
1572ce3b487fSMasahiro Yamada	  Choosing this option will pass "-Os" to your compiler resulting
1573ce3b487fSMasahiro Yamada	  in a smaller kernel.
1574c45b4f1fSLinus Torvalds
1575877417e6SArnd Bergmannendchoice
1576877417e6SArnd Bergmann
15775d20ee31SNicholas Pigginconfig HAVE_LD_DEAD_CODE_DATA_ELIMINATION
15785d20ee31SNicholas Piggin	bool
15795d20ee31SNicholas Piggin	help
15805d20ee31SNicholas Piggin	  This requires that the arch annotates or otherwise protects
15815d20ee31SNicholas Piggin	  its external entry points from being discarded. Linker scripts
15825d20ee31SNicholas Piggin	  must also merge .text.*, .data.*, and .bss.* correctly into
15835d20ee31SNicholas Piggin	  output sections. Care must be taken not to pull in unrelated
15845d20ee31SNicholas Piggin	  sections (e.g., '.text.init'). Typically '.' in section names
15855d20ee31SNicholas Piggin	  is used to distinguish them from label names / C identifiers.
15865d20ee31SNicholas Piggin
15875d20ee31SNicholas Pigginconfig LD_DEAD_CODE_DATA_ELIMINATION
15885d20ee31SNicholas Piggin	bool "Dead code and data elimination (EXPERIMENTAL)"
15895d20ee31SNicholas Piggin	depends on HAVE_LD_DEAD_CODE_DATA_ELIMINATION
15905d20ee31SNicholas Piggin	depends on EXPERT
1591e85d1d65SMasahiro Yamada	depends on $(cc-option,-ffunction-sections -fdata-sections)
1592e85d1d65SMasahiro Yamada	depends on $(ld-option,--gc-sections)
15935d20ee31SNicholas Piggin	help
15948b9d2712SMasahiro Yamada	  Enable this if you want to do dead code and data elimination with
15958b9d2712SMasahiro Yamada	  the linker by compiling with -ffunction-sections -fdata-sections,
15968b9d2712SMasahiro Yamada	  and linking with --gc-sections.
15975d20ee31SNicholas Piggin
15985d20ee31SNicholas Piggin	  This can reduce on disk and in-memory size of the kernel
15995d20ee31SNicholas Piggin	  code and static data, particularly for small configs and
16005d20ee31SNicholas Piggin	  on small systems. This has the possibility of introducing
16015d20ee31SNicholas Piggin	  silently broken kernel if the required annotations are not
16025d20ee31SNicholas Piggin	  present. This option is not well tested yet, so use at your
16035d20ee31SNicholas Piggin	  own risk.
16045d20ee31SNicholas Piggin
160559612b24SNathan Chancellorconfig LD_ORPHAN_WARN
160659612b24SNathan Chancellor	def_bool y
160759612b24SNathan Chancellor	depends on ARCH_WANT_LD_ORPHAN_WARN
160859612b24SNathan Chancellor	depends on $(ld-option,--orphan-handling=warn)
1609e1789d7cSXin Li	depends on $(ld-option,--orphan-handling=error)
1610e1789d7cSXin Li
1611e1789d7cSXin Liconfig LD_ORPHAN_WARN_LEVEL
1612e1789d7cSXin Li        string
1613e1789d7cSXin Li        depends on LD_ORPHAN_WARN
1614e1789d7cSXin Li        default "error" if WERROR
1615e1789d7cSXin Li        default "warn"
161659612b24SNathan Chancellor
16170847062aSRandy Dunlapconfig SYSCTL
16180847062aSRandy Dunlap	bool
16190847062aSRandy Dunlap
1620657a5209SMike Frysingerconfig HAVE_UID16
1621657a5209SMike Frysinger	bool
1622657a5209SMike Frysinger
1623657a5209SMike Frysingerconfig SYSCTL_EXCEPTION_TRACE
1624657a5209SMike Frysinger	bool
1625657a5209SMike Frysinger	help
1626657a5209SMike Frysinger	  Enable support for /proc/sys/debug/exception-trace.
1627657a5209SMike Frysinger
1628657a5209SMike Frysingerconfig SYSCTL_ARCH_UNALIGN_NO_WARN
1629657a5209SMike Frysinger	bool
1630657a5209SMike Frysinger	help
1631657a5209SMike Frysinger	  Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
1632657a5209SMike Frysinger	  Allows arch to define/use @no_unaligned_warning to possibly warn
1633657a5209SMike Frysinger	  about unaligned access emulation going on under the hood.
1634657a5209SMike Frysinger
1635657a5209SMike Frysingerconfig SYSCTL_ARCH_UNALIGN_ALLOW
1636657a5209SMike Frysinger	bool
1637657a5209SMike Frysinger	help
1638657a5209SMike Frysinger	  Enable support for /proc/sys/kernel/unaligned-trap
1639657a5209SMike Frysinger	  Allows arches to define/use @unaligned_enabled to runtime toggle
1640657a5209SMike Frysinger	  the unaligned access emulation.
1641657a5209SMike Frysinger	  see arch/parisc/kernel/unaligned.c for reference
1642657a5209SMike Frysinger
1643c443279aSChristian Braunerconfig SYSFS_SYSCALL
1644c443279aSChristian Brauner	bool "Sysfs syscall support"
1645c443279aSChristian Brauner	default n
1646c443279aSChristian Brauner	help
1647c443279aSChristian Brauner	  sys_sysfs is an obsolete system call no longer supported in libc.
1648c443279aSChristian Brauner	  Note that disabling this option is more secure but might break
1649c443279aSChristian Brauner	  compatibility with some systems.
1650c443279aSChristian Brauner
1651c443279aSChristian Brauner	  If unsure say N here.
1652c443279aSChristian Brauner
1653657a5209SMike Frysingerconfig HAVE_PCSPKR_PLATFORM
1654657a5209SMike Frysinger	bool
1655657a5209SMike Frysinger
16566a108a14SDavid Rientjesmenuconfig EXPERT
16576a108a14SDavid Rientjes	bool "Configure standard kernel features (expert users)"
1658f505c553SJosh Triplett	# Unhide debug options, to make the on-by-default options visible
1659f505c553SJosh Triplett	select DEBUG_KERNEL
16601da177e4SLinus Torvalds	help
16611da177e4SLinus Torvalds	  This option allows certain base kernel options and settings
16621da177e4SLinus Torvalds	  to be disabled or tweaked. This is for specialized
16631da177e4SLinus Torvalds	  environments which can tolerate a "non-standard" kernel.
16641da177e4SLinus Torvalds	  Only use this if you really know what you are doing.
16651da177e4SLinus Torvalds
1666ae81f9e3SChuck Ebbertconfig UID16
16676a108a14SDavid Rientjes	bool "Enable 16-bit UID system calls" if EXPERT
16682813893fSIulia Manda	depends on HAVE_UID16 && MULTIUSER
1669ae81f9e3SChuck Ebbert	default y
1670ae81f9e3SChuck Ebbert	help
1671ae81f9e3SChuck Ebbert	  This enables the legacy 16-bit UID syscall wrappers.
1672ae81f9e3SChuck Ebbert
16732813893fSIulia Mandaconfig MULTIUSER
16742813893fSIulia Manda	bool "Multiple users, groups and capabilities support" if EXPERT
16752813893fSIulia Manda	default y
16762813893fSIulia Manda	help
16772813893fSIulia Manda	  This option enables support for non-root users, groups and
16782813893fSIulia Manda	  capabilities.
16792813893fSIulia Manda
16802813893fSIulia Manda	  If you say N here, all processes will run with UID 0, GID 0, and all
16812813893fSIulia Manda	  possible capabilities.  Saying N here also compiles out support for
16822813893fSIulia Manda	  system calls related to UIDs, GIDs, and capabilities, such as setuid,
16832813893fSIulia Manda	  setgid, and capset.
16842813893fSIulia Manda
16852813893fSIulia Manda	  If unsure, say Y here.
16862813893fSIulia Manda
1687f6187769SFabian Frederickconfig SGETMASK_SYSCALL
1688f6187769SFabian Frederick	bool "sgetmask/ssetmask syscalls support" if EXPERT
1689cd14b018SMasahiro Yamada	default PARISC || M68K || PPC || MIPS || X86 || SPARC || MICROBLAZE || SUPERH
1690a7f7f624SMasahiro Yamada	help
1691f6187769SFabian Frederick	  sys_sgetmask and sys_ssetmask are obsolete system calls
1692f6187769SFabian Frederick	  no longer supported in libc but still enabled by default in some
1693f6187769SFabian Frederick	  architectures.
1694f6187769SFabian Frederick
1695f6187769SFabian Frederick	  If unsure, leave the default option here.
1696f6187769SFabian Frederick
1697d1b069f5SRandy Dunlapconfig FHANDLE
1698d1b069f5SRandy Dunlap	bool "open by fhandle syscalls" if EXPERT
1699d1b069f5SRandy Dunlap	select EXPORTFS
1700d1b069f5SRandy Dunlap	default y
1701d1b069f5SRandy Dunlap	help
1702d1b069f5SRandy Dunlap	  If you say Y here, a user level program will be able to map
1703d1b069f5SRandy Dunlap	  file names to handle and then later use the handle for
1704d1b069f5SRandy Dunlap	  different file system operations. This is useful in implementing
1705d1b069f5SRandy Dunlap	  userspace file servers, which now track files using handles instead
1706d1b069f5SRandy Dunlap	  of names. The handle would remain the same even if file names
1707d1b069f5SRandy Dunlap	  get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
1708d1b069f5SRandy Dunlap	  syscalls.
1709d1b069f5SRandy Dunlap
1710baa73d9eSNicolas Pitreconfig POSIX_TIMERS
1711baa73d9eSNicolas Pitre	bool "Posix Clocks & timers" if EXPERT
1712baa73d9eSNicolas Pitre	default y
1713baa73d9eSNicolas Pitre	help
1714baa73d9eSNicolas Pitre	  This includes native support for POSIX timers to the kernel.
1715baa73d9eSNicolas Pitre	  Some embedded systems have no use for them and therefore they
1716baa73d9eSNicolas Pitre	  can be configured out to reduce the size of the kernel image.
1717baa73d9eSNicolas Pitre
1718baa73d9eSNicolas Pitre	  When this option is disabled, the following syscalls won't be
1719baa73d9eSNicolas Pitre	  available: timer_create, timer_gettime: timer_getoverrun,
1720baa73d9eSNicolas Pitre	  timer_settime, timer_delete, clock_adjtime, getitimer,
1721baa73d9eSNicolas Pitre	  setitimer, alarm. Furthermore, the clock_settime, clock_gettime,
1722baa73d9eSNicolas Pitre	  clock_getres and clock_nanosleep syscalls will be limited to
1723baa73d9eSNicolas Pitre	  CLOCK_REALTIME, CLOCK_MONOTONIC and CLOCK_BOOTTIME only.
1724baa73d9eSNicolas Pitre
1725baa73d9eSNicolas Pitre	  If unsure say y.
1726baa73d9eSNicolas Pitre
1727d59745ceSMatt Mackallconfig PRINTK
1728d59745ceSMatt Mackall	default y
17296a108a14SDavid Rientjes	bool "Enable support for printk" if EXPERT
173074876a98SFrederic Weisbecker	select IRQ_WORK
1731d59745ceSMatt Mackall	help
1732d59745ceSMatt Mackall	  This option enables normal printk support. Removing it
1733d59745ceSMatt Mackall	  eliminates most of the message strings from the kernel image
1734d59745ceSMatt Mackall	  and makes the kernel more or less silent. As this makes it
1735d59745ceSMatt Mackall	  very difficult to diagnose system problems, saying N here is
1736d59745ceSMatt Mackall	  strongly discouraged.
1737d59745ceSMatt Mackall
17385ea2bcdfSThomas Weißschuhconfig PRINTK_RINGBUFFER_KUNIT_TEST
17395ea2bcdfSThomas Weißschuh	tristate "KUnit Test for the printk ringbuffer" if !KUNIT_ALL_TESTS
17405ea2bcdfSThomas Weißschuh	depends on PRINTK && KUNIT
17415ea2bcdfSThomas Weißschuh	default KUNIT_ALL_TESTS
17425ea2bcdfSThomas Weißschuh	help
17435ea2bcdfSThomas Weißschuh	  This builds the printk ringbuffer KUnit test suite.
17445ea2bcdfSThomas Weißschuh
17455ea2bcdfSThomas Weißschuh	  For more information on KUnit and unit tests in general, please refer
17465ea2bcdfSThomas Weißschuh	  to the KUnit documentation.
17475ea2bcdfSThomas Weißschuh
17485ea2bcdfSThomas Weißschuh	  If unsure, say N.
17495ea2bcdfSThomas Weißschuh
1750c8538a7aSMatt Mackallconfig BUG
17516a108a14SDavid Rientjes	bool "BUG() support" if EXPERT
1752c8538a7aSMatt Mackall	default y
1753c8538a7aSMatt Mackall	help
1754c8538a7aSMatt Mackall	  Disabling this option eliminates support for BUG and WARN, reducing
1755c8538a7aSMatt Mackall	  the size of your kernel image and potentially quietly ignoring
1756c8538a7aSMatt Mackall	  numerous fatal conditions. You should only consider disabling this
1757c8538a7aSMatt Mackall	  option for embedded systems with no facilities for reporting errors.
1758c8538a7aSMatt Mackall	  Just say Y.
1759c8538a7aSMatt Mackall
1760708e9a79SMatt Mackallconfig ELF_CORE
1761046d662fSAlex Kelly	depends on COREDUMP
1762708e9a79SMatt Mackall	default y
17636a108a14SDavid Rientjes	bool "Enable ELF core dumps" if EXPERT
1764708e9a79SMatt Mackall	help
1765708e9a79SMatt Mackall	  Enable support for generating core dumps. Disabling saves about 4k.
1766708e9a79SMatt Mackall
17678761f1abSRalf Baechle
1768e5e1d3cbSStas Sergeevconfig PCSPKR_PLATFORM
17696a108a14SDavid Rientjes	bool "Enable PC-Speaker support" if EXPERT
17708761f1abSRalf Baechle	depends on HAVE_PCSPKR_PLATFORM
177115f304b6SRalf Baechle	select I8253_LOCK
1772e5e1d3cbSStas Sergeev	default y
1773e5e1d3cbSStas Sergeev	help
1774e5e1d3cbSStas Sergeev	  This option allows to disable the internal PC-Speaker
1775e5e1d3cbSStas Sergeev	  support, saving some memory.
1776e5e1d3cbSStas Sergeev
177727021649SYoann Congalconfig BASE_SMALL
177827021649SYoann Congal	bool "Enable smaller-sized data structures for core" if EXPERT
17791da177e4SLinus Torvalds	help
178027021649SYoann Congal	  Enabling this option reduces the size of miscellaneous core
17811da177e4SLinus Torvalds	  kernel data structures. This saves memory on small machines,
17821da177e4SLinus Torvalds	  but may reduce performance.
17831da177e4SLinus Torvalds
17841da177e4SLinus Torvaldsconfig FUTEX
17856a108a14SDavid Rientjes	bool "Enable futex support" if EXPERT
17863f2bedabSArnd Bergmann	depends on !(SPARC32 && SMP)
17871da177e4SLinus Torvalds	default y
1788bc2eecd7SNicolas Pitre	imply RT_MUTEXES
17891da177e4SLinus Torvalds	help
17901da177e4SLinus Torvalds	  Disabling this option will cause the kernel to be built without
17911da177e4SLinus Torvalds	  support for "fast userspace mutexes".  The resulting kernel may not
17921da177e4SLinus Torvalds	  run glibc-based applications correctly.
17931da177e4SLinus Torvalds
1794bc2eecd7SNicolas Pitreconfig FUTEX_PI
1795bc2eecd7SNicolas Pitre	bool
1796bc2eecd7SNicolas Pitre	depends on FUTEX && RT_MUTEXES
1797bc2eecd7SNicolas Pitre	default y
1798bc2eecd7SNicolas Pitre
179980367ad0SSebastian Andrzej Siewiorconfig FUTEX_PRIVATE_HASH
180080367ad0SSebastian Andrzej Siewior	bool
180180367ad0SSebastian Andrzej Siewior	depends on FUTEX && !BASE_SMALL && MMU
180280367ad0SSebastian Andrzej Siewior	default y
180380367ad0SSebastian Andrzej Siewior
1804c042c505SPeter Zijlstraconfig FUTEX_MPOL
1805c042c505SPeter Zijlstra	bool
1806c042c505SPeter Zijlstra	depends on FUTEX && NUMA
1807c042c505SPeter Zijlstra	default y
1808c042c505SPeter Zijlstra
18091da177e4SLinus Torvaldsconfig EPOLL
18106a108a14SDavid Rientjes	bool "Enable eventpoll support" if EXPERT
18111da177e4SLinus Torvalds	default y
18121da177e4SLinus Torvalds	help
18131da177e4SLinus Torvalds	  Disabling this option will cause the kernel to be built without
18141da177e4SLinus Torvalds	  support for epoll family of system calls.
18151da177e4SLinus Torvalds
1816fba2afaaSDavide Libenziconfig SIGNALFD
18176a108a14SDavid Rientjes	bool "Enable signalfd() system call" if EXPERT
1818fba2afaaSDavide Libenzi	default y
1819fba2afaaSDavide Libenzi	help
1820fba2afaaSDavide Libenzi	  Enable the signalfd() system call that allows to receive signals
1821fba2afaaSDavide Libenzi	  on a file descriptor.
1822fba2afaaSDavide Libenzi
1823fba2afaaSDavide Libenzi	  If unsure, say Y.
1824fba2afaaSDavide Libenzi
1825b215e283SDavide Libenziconfig TIMERFD
18266a108a14SDavid Rientjes	bool "Enable timerfd() system call" if EXPERT
1827b215e283SDavide Libenzi	default y
1828b215e283SDavide Libenzi	help
1829b215e283SDavide Libenzi	  Enable the timerfd() system call that allows to receive timer
1830b215e283SDavide Libenzi	  events on a file descriptor.
1831b215e283SDavide Libenzi
1832b215e283SDavide Libenzi	  If unsure, say Y.
1833b215e283SDavide Libenzi
1834e1ad7468SDavide Libenziconfig EVENTFD
18356a108a14SDavid Rientjes	bool "Enable eventfd() system call" if EXPERT
1836e1ad7468SDavide Libenzi	default y
1837e1ad7468SDavide Libenzi	help
1838e1ad7468SDavide Libenzi	  Enable the eventfd() system call that allows to receive both
1839e1ad7468SDavide Libenzi	  kernel notification (ie. KAIO) or userspace notifications.
1840e1ad7468SDavide Libenzi
1841e1ad7468SDavide Libenzi	  If unsure, say Y.
1842e1ad7468SDavide Libenzi
18431da177e4SLinus Torvaldsconfig SHMEM
18446a108a14SDavid Rientjes	bool "Use full shmem filesystem" if EXPERT
18451da177e4SLinus Torvalds	default y
18461da177e4SLinus Torvalds	depends on MMU
18471da177e4SLinus Torvalds	help
18481da177e4SLinus Torvalds	  The shmem is an internal filesystem used to manage shared memory.
18491da177e4SLinus Torvalds	  It is backed by swap and manages resource limits. It is also exported
18501da177e4SLinus Torvalds	  to userspace as tmpfs if TMPFS is enabled. Disabling this
18511da177e4SLinus Torvalds	  option replaces shmem and tmpfs with the much simpler ramfs code,
18521da177e4SLinus Torvalds	  which may be appropriate on small systems without swap.
18531da177e4SLinus Torvalds
1854ebf3f09cSThomas Petazzoniconfig AIO
18556a108a14SDavid Rientjes	bool "Enable AIO support" if EXPERT
1856ebf3f09cSThomas Petazzoni	default y
1857ebf3f09cSThomas Petazzoni	help
1858ebf3f09cSThomas Petazzoni	  This option enables POSIX asynchronous I/O which may by used
1859ebf3f09cSThomas Petazzoni	  by some high performance threaded applications. Disabling
1860ebf3f09cSThomas Petazzoni	  this option saves about 7k.
1861ebf3f09cSThomas Petazzoni
18622b188cc1SJens Axboeconfig IO_URING
18632b188cc1SJens Axboe	bool "Enable IO uring support" if EXPERT
1864561fb04aSJens Axboe	select IO_WQ
18652b188cc1SJens Axboe	default y
18662b188cc1SJens Axboe	help
18672b188cc1SJens Axboe	  This option enables support for the io_uring interface, enabling
18682b188cc1SJens Axboe	  applications to submit and complete IO through submission and
18692b188cc1SJens Axboe	  completion rings that are shared between the kernel and application.
18702b188cc1SJens Axboe
18711802656eSJens Axboeconfig GCOV_PROFILE_URING
18721802656eSJens Axboe	bool "Enable GCOV profiling on the io_uring subsystem"
1873d1fbe1ebSRandy Dunlap	depends on IO_URING && GCOV_KERNEL
18741802656eSJens Axboe	help
18751802656eSJens Axboe	  Enable GCOV profiling on the io_uring subsystem, to facilitate
18761802656eSJens Axboe	  code coverage testing.
18771802656eSJens Axboe
18781802656eSJens Axboe	  If unsure, say N.
18791802656eSJens Axboe
18801802656eSJens Axboe	  Note that this will have a negative impact on the performance of
18811802656eSJens Axboe	  the io_uring subsystem, hence this should only be enabled for
18821802656eSJens Axboe	  specific test purposes.
18831802656eSJens Axboe
18843a0ae385SPavel Begunkovconfig IO_URING_MOCK_FILE
18853a0ae385SPavel Begunkov	tristate "Enable io_uring mock files (Experimental)" if EXPERT
18863a0ae385SPavel Begunkov	default n
18873a0ae385SPavel Begunkov	depends on IO_URING
18883a0ae385SPavel Begunkov	help
18893a0ae385SPavel Begunkov	  Enable mock files for io_uring subststem testing. The ABI might
18903a0ae385SPavel Begunkov	  still change, so it's still experimental and should only be enabled
18913a0ae385SPavel Begunkov	  for specific test purposes.
18923a0ae385SPavel Begunkov
18933a0ae385SPavel Begunkov	  If unsure, say N.
18943a0ae385SPavel Begunkov
1895d3ac21caSJosh Triplettconfig ADVISE_SYSCALLS
1896d3ac21caSJosh Triplett	bool "Enable madvise/fadvise syscalls" if EXPERT
1897d3ac21caSJosh Triplett	default y
1898d3ac21caSJosh Triplett	help
1899d3ac21caSJosh Triplett	  This option enables the madvise and fadvise syscalls, used by
1900d3ac21caSJosh Triplett	  applications to advise the kernel about their future memory or file
1901d3ac21caSJosh Triplett	  usage, improving performance. If building an embedded system where no
1902d3ac21caSJosh Triplett	  applications use these syscalls, you can disable this option to save
1903d3ac21caSJosh Triplett	  space.
1904d3ac21caSJosh Triplett
19055b25b13aSMathieu Desnoyersconfig MEMBARRIER
19065b25b13aSMathieu Desnoyers	bool "Enable membarrier() system call" if EXPERT
19075b25b13aSMathieu Desnoyers	default y
19085b25b13aSMathieu Desnoyers	help
19095b25b13aSMathieu Desnoyers	  Enable the membarrier() system call that allows issuing memory
19105b25b13aSMathieu Desnoyers	  barriers across all running threads, which can be used to distribute
19115b25b13aSMathieu Desnoyers	  the cost of user-space memory barriers asymmetrically by transforming
19125b25b13aSMathieu Desnoyers	  pairs of memory barriers into pairs consisting of membarrier() and a
19135b25b13aSMathieu Desnoyers	  compiler barrier.
19145b25b13aSMathieu Desnoyers
19155b25b13aSMathieu Desnoyers	  If unsure, say Y.
19165b25b13aSMathieu Desnoyers
1917a751ea34SRandy Dunlapconfig KCMP
1918a751ea34SRandy Dunlap	bool "Enable kcmp() system call" if EXPERT
1919a751ea34SRandy Dunlap	help
1920a751ea34SRandy Dunlap	  Enable the kernel resource comparison system call. It provides
1921a751ea34SRandy Dunlap	  user-space with the ability to compare two processes to see if they
1922a751ea34SRandy Dunlap	  share a common resource, such as a file descriptor or even virtual
1923a751ea34SRandy Dunlap	  memory space.
1924a751ea34SRandy Dunlap
1925a751ea34SRandy Dunlap	  If unsure, say N.
1926a751ea34SRandy Dunlap
1927a751ea34SRandy Dunlapconfig RSEQ
1928a751ea34SRandy Dunlap	bool "Enable rseq() system call" if EXPERT
1929a751ea34SRandy Dunlap	default y
1930a751ea34SRandy Dunlap	depends on HAVE_RSEQ
1931a751ea34SRandy Dunlap	select MEMBARRIER
1932a751ea34SRandy Dunlap	help
1933a751ea34SRandy Dunlap	  Enable the restartable sequences system call. It provides a
1934a751ea34SRandy Dunlap	  user-space cache for the current CPU number value, which
1935a751ea34SRandy Dunlap	  speeds up getting the current CPU number from user-space,
1936a751ea34SRandy Dunlap	  as well as an ABI to speed up user-space operations on
1937a751ea34SRandy Dunlap	  per-CPU data.
1938a751ea34SRandy Dunlap
1939a751ea34SRandy Dunlap	  If unsure, say Y.
1940a751ea34SRandy Dunlap
194154129104SThomas Gleixnerconfig RSEQ_STATS
194254129104SThomas Gleixner	default n
194354129104SThomas Gleixner	bool "Enable lightweight statistics of restartable sequences" if EXPERT
194454129104SThomas Gleixner	depends on RSEQ && DEBUG_FS
194554129104SThomas Gleixner	help
194654129104SThomas Gleixner	  Enable lightweight counters which expose information about the
194754129104SThomas Gleixner	  frequency of RSEQ operations via debugfs. Mostly interesting for
194854129104SThomas Gleixner	  kernel debugging or performance analysis. While lightweight it's
194954129104SThomas Gleixner	  still adding code into the user/kernel mode transitions.
195054129104SThomas Gleixner
195154129104SThomas Gleixner	  If unsure, say N.
195254129104SThomas Gleixner
19539c37cb6eSThomas Gleixnerconfig RSEQ_DEBUG_DEFAULT_ENABLE
19549c37cb6eSThomas Gleixner	default n
19559c37cb6eSThomas Gleixner	bool "Enable restartable sequences debug mode by default" if EXPERT
19569c37cb6eSThomas Gleixner	depends on RSEQ
19579c37cb6eSThomas Gleixner	help
19589c37cb6eSThomas Gleixner	  This enables the static branch for debug mode of restartable
19599c37cb6eSThomas Gleixner	  sequences.
19609c37cb6eSThomas Gleixner
19619c37cb6eSThomas Gleixner	  This also can be controlled on the kernel command line via the
19629c37cb6eSThomas Gleixner	  command line parameter "rseq_debug=0/1" and through debugfs.
19639c37cb6eSThomas Gleixner
19649c37cb6eSThomas Gleixner	  If unsure, say N.
19659c37cb6eSThomas Gleixner
1966a751ea34SRandy Dunlapconfig DEBUG_RSEQ
1967a751ea34SRandy Dunlap	default n
1968a751ea34SRandy Dunlap	bool "Enable debugging of rseq() system call" if EXPERT
19693db6b38dSThomas Gleixner	depends on RSEQ && DEBUG_KERNEL && !GENERIC_ENTRY
19709c37cb6eSThomas Gleixner	select RSEQ_DEBUG_DEFAULT_ENABLE
1971a751ea34SRandy Dunlap	help
1972a751ea34SRandy Dunlap	  Enable extra debugging checks for the rseq system call.
1973a751ea34SRandy Dunlap
1974a751ea34SRandy Dunlap	  If unsure, say N.
1975a751ea34SRandy Dunlap
1976a751ea34SRandy Dunlapconfig CACHESTAT_SYSCALL
1977a751ea34SRandy Dunlap	bool "Enable cachestat() system call" if EXPERT
1978a751ea34SRandy Dunlap	default y
1979a751ea34SRandy Dunlap	help
1980a751ea34SRandy Dunlap	  Enable the cachestat system call, which queries the page cache
1981a751ea34SRandy Dunlap	  statistics of a file (number of cached pages, dirty pages,
1982a751ea34SRandy Dunlap	  pages marked for writeback, (recently) evicted pages).
1983a751ea34SRandy Dunlap
1984a751ea34SRandy Dunlap	  If unsure say Y here.
1985a751ea34SRandy Dunlap
1986d1b069f5SRandy Dunlapconfig KALLSYMS
1987d1b069f5SRandy Dunlap	bool "Load all symbols for debugging/ksymoops" if EXPERT
1988d1b069f5SRandy Dunlap	default y
1989d1b069f5SRandy Dunlap	help
1990d1b069f5SRandy Dunlap	  Say Y here to let the kernel print out symbolic crash information and
1991d1b069f5SRandy Dunlap	  symbolic stack backtraces. This increases the size of the kernel
1992d1b069f5SRandy Dunlap	  somewhat, as all symbols have to be loaded into the kernel image.
1993d1b069f5SRandy Dunlap
199430f3bb09SZhen Leiconfig KALLSYMS_SELFTEST
199530f3bb09SZhen Lei	bool "Test the basic functions and performance of kallsyms"
199630f3bb09SZhen Lei	depends on KALLSYMS
199730f3bb09SZhen Lei	default n
199830f3bb09SZhen Lei	help
199930f3bb09SZhen Lei	  Test the basic functions and performance of some interfaces, such as
200030f3bb09SZhen Lei	  kallsyms_lookup_name. It also calculates the compression rate of the
200130f3bb09SZhen Lei	  kallsyms compression algorithm for the current symbol set.
200230f3bb09SZhen Lei
200330f3bb09SZhen Lei	  Start self-test automatically after system startup. Suggest executing
200430f3bb09SZhen Lei	  "dmesg | grep kallsyms_selftest" to collect test results. "finish" is
200530f3bb09SZhen Lei	  displayed in the last line, indicating that the test is complete.
200630f3bb09SZhen Lei
2007d1b069f5SRandy Dunlapconfig KALLSYMS_ALL
2008d1b069f5SRandy Dunlap	bool "Include all symbols in kallsyms"
2009d1b069f5SRandy Dunlap	depends on DEBUG_KERNEL && KALLSYMS
2010d1b069f5SRandy Dunlap	help
2011d1b069f5SRandy Dunlap	  Normally kallsyms only contains the symbols of functions for nicer
2012d1b069f5SRandy Dunlap	  OOPS messages and backtraces (i.e., symbols from the text and inittext
2013bdf0fe33SBaruch Siach	  sections). This is sufficient for most cases. And only if you want to
2014bdf0fe33SBaruch Siach	  enable kernel live patching, or other less common use cases (e.g.,
2015bdf0fe33SBaruch Siach	  when a debugger is used) all symbols are required (i.e., names of
2016bdf0fe33SBaruch Siach	  variables from the data sections, etc).
2017d1b069f5SRandy Dunlap
2018d1b069f5SRandy Dunlap	  This option makes sure that all symbols are loaded into the kernel
2019d1b069f5SRandy Dunlap	  image (i.e., symbols from all sections) in cost of increased kernel
2020d1b069f5SRandy Dunlap	  size (depending on the kernel configuration, it may be 300KiB or
2021d1b069f5SRandy Dunlap	  something like this).
2022d1b069f5SRandy Dunlap
2023bdf0fe33SBaruch Siach	  Say N unless you really need all symbols, or kernel live patching.
2024d1b069f5SRandy Dunlap
2025d1b069f5SRandy Dunlap# end of the "standard kernel features (expert users)" menu
2026d1b069f5SRandy Dunlap
20273ccfebedSMathieu Desnoyersconfig ARCH_HAS_MEMBARRIER_CALLBACKS
20283ccfebedSMathieu Desnoyers	bool
20293ccfebedSMathieu Desnoyers
203070216e18SMathieu Desnoyersconfig ARCH_HAS_MEMBARRIER_SYNC_CORE
203170216e18SMathieu Desnoyers	bool
203270216e18SMathieu Desnoyers
20335796d396SJeff Xuconfig ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS
20345796d396SJeff Xu	bool
20355796d396SJeff Xu	help
20365796d396SJeff Xu	  Control MSEAL_SYSTEM_MAPPINGS access based on architecture.
20375796d396SJeff Xu
20385796d396SJeff Xu	  A 64-bit kernel is required for the memory sealing feature.
20395796d396SJeff Xu	  No specific hardware features from the CPU are needed.
20405796d396SJeff Xu
20415796d396SJeff Xu	  To enable this feature, the architecture needs to update their
20425796d396SJeff Xu	  special mappings calls to include the sealing flag and confirm
20435796d396SJeff Xu	  that it doesn't unmap/remap system mappings during the life
20445796d396SJeff Xu	  time of the process. The existence of this flag for an architecture
20455796d396SJeff Xu	  implies that it does not require the remapping of the system
20465796d396SJeff Xu	  mappings during process lifetime, so sealing these mappings is safe
20475796d396SJeff Xu	  from a kernel perspective.
20485796d396SJeff Xu
20495796d396SJeff Xu	  After the architecture enables this, a distribution can set
20505796d396SJeff Xu	  CONFIG_MSEAL_SYSTEM_MAPPING to manage access to the feature.
20515796d396SJeff Xu
20525796d396SJeff Xu	  For complete descriptions of memory sealing, please see
20535796d396SJeff Xu	  Documentation/userspace-api/mseal.rst
20545796d396SJeff Xu
2055cdd6c482SIngo Molnarconfig HAVE_PERF_EVENTS
20560793a61dSThomas Gleixner	bool
2057018df72dSMike Frysinger	help
2058018df72dSMike Frysinger	  See tools/perf/design.txt for details.
20590793a61dSThomas Gleixner
20602aef6f30SSean Christophersonconfig GUEST_PERF_EVENTS
20612aef6f30SSean Christopherson	bool
20622aef6f30SSean Christopherson	depends on HAVE_PERF_EVENTS
20632aef6f30SSean Christopherson
2064906010b2SPeter Zijlstraconfig PERF_USE_VMALLOC
2065906010b2SPeter Zijlstra	bool
2066906010b2SPeter Zijlstra	help
2067906010b2SPeter Zijlstra	  See tools/perf/design.txt for details
2068906010b2SPeter Zijlstra
206957c0c15bSIngo Molnarmenu "Kernel Performance Events And Counters"
20700793a61dSThomas Gleixner
2071cdd6c482SIngo Molnarconfig PERF_EVENTS
207257c0c15bSIngo Molnar	bool "Kernel performance events and counters"
2073392d65a9SRobert Richter	default y if PROFILING
2074cdd6c482SIngo Molnar	depends on HAVE_PERF_EVENTS
2075e360adbeSPeter Zijlstra	select IRQ_WORK
20760793a61dSThomas Gleixner	help
207757c0c15bSIngo Molnar	  Enable kernel support for various performance events provided
207857c0c15bSIngo Molnar	  by software and hardware.
20790793a61dSThomas Gleixner
2080dd77038dSThadeu Lima de Souza Cascardo	  Software events are supported either built-in or via the
208157c0c15bSIngo Molnar	  use of generic tracepoints.
208257c0c15bSIngo Molnar
208357c0c15bSIngo Molnar	  Most modern CPUs support performance events via performance
208457c0c15bSIngo Molnar	  counter registers. These registers count the number of certain
20850793a61dSThomas Gleixner	  types of hw events: such as instructions executed, cachemisses
20860793a61dSThomas Gleixner	  suffered, or branches mis-predicted - without slowing down the
20870793a61dSThomas Gleixner	  kernel or applications. These registers can also trigger interrupts
20880793a61dSThomas Gleixner	  when a threshold number of events have passed - and can thus be
20890793a61dSThomas Gleixner	  used to profile the code that runs on that CPU.
20900793a61dSThomas Gleixner
209157c0c15bSIngo Molnar	  The Linux Performance Event subsystem provides an abstraction of
2092dd77038dSThadeu Lima de Souza Cascardo	  these software and hardware event capabilities, available via a
209357c0c15bSIngo Molnar	  system call and used by the "perf" utility in tools/perf/. It
20940793a61dSThomas Gleixner	  provides per task and per CPU counters, and it provides event
20950793a61dSThomas Gleixner	  capabilities on top of those.
20960793a61dSThomas Gleixner
20970793a61dSThomas Gleixner	  Say Y if unsure.
20980793a61dSThomas Gleixner
2099906010b2SPeter Zijlstraconfig DEBUG_PERF_USE_VMALLOC
2100906010b2SPeter Zijlstra	default n
2101906010b2SPeter Zijlstra	bool "Debug: use vmalloc to back perf mmap() buffers"
2102cb307113SMichael Ellerman	depends on PERF_EVENTS && DEBUG_KERNEL && !PPC
2103906010b2SPeter Zijlstra	select PERF_USE_VMALLOC
2104906010b2SPeter Zijlstra	help
2105906010b2SPeter Zijlstra	  Use vmalloc memory to back perf mmap() buffers.
2106906010b2SPeter Zijlstra
2107906010b2SPeter Zijlstra	  Mostly useful for debugging the vmalloc code on platforms
2108906010b2SPeter Zijlstra	  that don't require it.
2109906010b2SPeter Zijlstra
2110906010b2SPeter Zijlstra	  Say N if unsure.
2111906010b2SPeter Zijlstra
21120793a61dSThomas Gleixnerendmenu
21130793a61dSThomas Gleixner
2114091f6e26SDavid Howellsconfig SYSTEM_DATA_VERIFICATION
2115091f6e26SDavid Howells	def_bool n
2116091f6e26SDavid Howells	select SYSTEM_TRUSTED_KEYRING
2117091f6e26SDavid Howells	select KEYS
2118091f6e26SDavid Howells	select CRYPTO
2119d43de6c7SDavid Howells	select CRYPTO_RSA
2120091f6e26SDavid Howells	select ASYMMETRIC_KEY_TYPE
2121091f6e26SDavid Howells	select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
2122091f6e26SDavid Howells	select ASN1
2123091f6e26SDavid Howells	select OID_REGISTRY
2124091f6e26SDavid Howells	select X509_CERTIFICATE_PARSER
2125091f6e26SDavid Howells	select PKCS7_MESSAGE_PARSER
212682c04ff8SPeter Foley	help
2127091f6e26SDavid Howells	  Provide PKCS#7 message verification using the contents of the system
2128091f6e26SDavid Howells	  trusted keyring to provide public keys.  This then can be used for
2129091f6e26SDavid Howells	  module verification, kexec image verification and firmware blob
2130091f6e26SDavid Howells	  verification.
213182c04ff8SPeter Foley
2132125e5645SMathieu Desnoyersconfig PROFILING
2133b309a294SRobert Richter	bool "Profiling support"
2134125e5645SMathieu Desnoyers	help
2135125e5645SMathieu Desnoyers	  Say Y here to enable the extended profiling support mechanisms used
2136f8408264SViresh Kumar	  by profilers.
2137125e5645SMathieu Desnoyers
21382f7ab126SMiguel Ojedaconfig RUST
21392f7ab126SMiguel Ojeda	bool "Rust support"
21402f7ab126SMiguel Ojeda	depends on HAVE_RUST
21412f7ab126SMiguel Ojeda	depends on RUST_IS_AVAILABLE
2142ac61506bSSami Tolvanen	select EXTENDED_MODVERSIONS if MODVERSIONS
2143ac61506bSSami Tolvanen	depends on !MODVERSIONS || GENDWARFKSYMS
2144f1385dc6SNeal Gompa	depends on !GCC_PLUGIN_RANDSTRUCT
21452f7ab126SMiguel Ojeda	depends on !RANDSTRUCT
21465daa0c35SMatthew Maurer	depends on !DEBUG_INFO_BTF || (PAHOLE_HAS_LANG_EXCLUDE && !LTO)
214723ef9d43SKees Cook	depends on !CFI || HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC
214823ef9d43SKees Cook	select CFI_ICALL_NORMALIZE_INTEGERS if CFI
2149af6017b6SMiguel Ojeda	depends on !CALL_PADDING || RUSTC_VERSION >= 108100
2150f64e2f3aSMatthew Maurer	depends on !KASAN_SW_TAGS
215193e34a0bSAlice Ryhl	depends on !(MITIGATION_RETHUNK && KASAN) || RUSTC_VERSION >= 108300
21522f7ab126SMiguel Ojeda	help
21532f7ab126SMiguel Ojeda	  Enables Rust support in the kernel.
21542f7ab126SMiguel Ojeda
21552f7ab126SMiguel Ojeda	  This allows other Rust-related options, like drivers written in Rust,
21562f7ab126SMiguel Ojeda	  to be selected.
21572f7ab126SMiguel Ojeda
21582f7ab126SMiguel Ojeda	  It is also required to be able to load external kernel modules
21592f7ab126SMiguel Ojeda	  written in Rust.
21602f7ab126SMiguel Ojeda
21612f7ab126SMiguel Ojeda	  See Documentation/rust/ for more information.
21622f7ab126SMiguel Ojeda
21632f7ab126SMiguel Ojeda	  If unsure, say N.
21642f7ab126SMiguel Ojeda
21652f7ab126SMiguel Ojedaconfig RUSTC_VERSION_TEXT
21662f7ab126SMiguel Ojeda	string
21672f7ab126SMiguel Ojeda	depends on RUST
21685134a335SMiguel Ojeda	default "$(RUSTC_VERSION_TEXT)"
21695134a335SMiguel Ojeda	help
21705134a335SMiguel Ojeda	  See `CC_VERSION_TEXT`.
21712f7ab126SMiguel Ojeda
21722f7ab126SMiguel Ojedaconfig BINDGEN_VERSION_TEXT
21732f7ab126SMiguel Ojeda	string
21742f7ab126SMiguel Ojeda	depends on RUST
21759e98db17SMiguel Ojeda	# The dummy parameter `workaround-for-0.69.0` is required to support 0.69.0
2176c23d1f7eSMiguel Ojeda	# (https://github.com/rust-lang/rust-bindgen/pull/2678) and 0.71.0
2177c23d1f7eSMiguel Ojeda	# (https://github.com/rust-lang/rust-bindgen/pull/3040). It can be removed
2178c23d1f7eSMiguel Ojeda	# when the minimum version is upgraded past the latter (0.69.1 and 0.71.1
2179c23d1f7eSMiguel Ojeda	# both fixed the issue).
2180aacf93e8SMasahiro Yamada	default "$(shell,$(BINDGEN) --version workaround-for-0.69.0 2>/dev/null)"
21812f7ab126SMiguel Ojeda
21825f87f112SIngo Molnar#
21835f87f112SIngo Molnar# Place an empty function call at each tracepoint site. Can be
21845f87f112SIngo Molnar# dynamically changed for a probe function.
21855f87f112SIngo Molnar#
218697e1c18eSMathieu Desnoyersconfig TRACEPOINTS
21875f87f112SIngo Molnar	bool
2188a363d27cSMathieu Desnoyers	select TASKS_TRACE_RCU
218997e1c18eSMathieu Desnoyers
219089cde455SEric DeVoldersource "kernel/Kconfig.kexec"
219189cde455SEric DeVolder
2192*48a1b232SPasha Tatashinsource "kernel/liveupdate/Kconfig"
2193*48a1b232SPasha Tatashin
21941da177e4SLinus Torvaldsendmenu		# General setup
21951da177e4SLinus Torvalds
21961572497cSChristoph Hellwigsource "arch/Kconfig"
21971572497cSChristoph Hellwig
2198ae81f9e3SChuck Ebbertconfig RT_MUTEXES
21996341e62bSChristoph Jaeger	bool
22001c6f9ec0SSebastian Andrzej Siewior	default y if PREEMPT_RT
2201ae81f9e3SChuck Ebbert
2202c8424e77SThiago Jung Bauermannconfig MODULE_SIG_FORMAT
2203c8424e77SThiago Jung Bauermann	def_bool n
2204c8424e77SThiago Jung Bauermann	select SYSTEM_DATA_VERIFICATION
2205c8424e77SThiago Jung Bauermann
220673b4fc92SChristophe Leroysource "kernel/module/Kconfig"
22076c9692e2SPeter Zijlstra
220898a79d6aSRusty Russellconfig INIT_ALL_POSSIBLE
220998a79d6aSRusty Russell	bool
221098a79d6aSRusty Russell	help
22115f054e31SRusty Russell	  Back when each arch used to define their own cpu_online_mask and
22125f054e31SRusty Russell	  cpu_possible_mask, some of them chose to initialize cpu_possible_mask
221398a79d6aSRusty Russell	  with all 1s, and others with all 0s.  When they were centralised,
221498a79d6aSRusty Russell	  it was better to provide this option than to break all the archs
2215692105b8SMatt LaPlante	  and have several arch maintainers pursuing me down dark alleys.
221698a79d6aSRusty Russell
22173a65dfe8SJens Axboesource "block/Kconfig"
2218e98c3202SAvi Kivity
2219e98c3202SAvi Kivityconfig PREEMPT_NOTIFIERS
2220e98c3202SAvi Kivity	bool
2221e260be67SPaul E. McKenney
222216295becSSteffen Klassertconfig PADATA
222316295becSSteffen Klassert	depends on SMP
222416295becSSteffen Klassert	bool
222516295becSSteffen Klassert
22264520c6a4SDavid Howellsconfig ASN1
22274520c6a4SDavid Howells	tristate
22284520c6a4SDavid Howells	help
22294520c6a4SDavid Howells	  Build a simple ASN.1 grammar compiler that produces a bytecode output
22304520c6a4SDavid Howells	  that can be interpreted by the ASN.1 stream decoder and used to
22314520c6a4SDavid Howells	  inform it as to what tags are to be expected in a stream and what
22324520c6a4SDavid Howells	  functions to call on what tags.
22334520c6a4SDavid Howells
22346beb0009SThomas Gleixnersource "kernel/Kconfig.locks"
2235e61938a9SMathieu Desnoyers
22360ebeea8cSDaniel Borkmannconfig ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
22370ebeea8cSDaniel Borkmann	bool
22380ebeea8cSDaniel Borkmann
22394ff4c745SAndrea Parriconfig ARCH_HAS_PREPARE_SYNC_CORE_CMD
22404ff4c745SAndrea Parri	bool
22414ff4c745SAndrea Parri
2242e61938a9SMathieu Desnoyersconfig ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
2243e61938a9SMathieu Desnoyers	bool
22441bd21c6cSDominik Brodowski
22451bd21c6cSDominik Brodowski# It may be useful for an architecture to override the definitions of the
22467303e30eSDominik Brodowski# SYSCALL_DEFINE() and __SYSCALL_DEFINEx() macros in <linux/syscalls.h>
22477303e30eSDominik Brodowski# and the COMPAT_ variants in <linux/compat.h>, in particular to use a
22487303e30eSDominik Brodowski# different calling convention for syscalls. They can also override the
22497303e30eSDominik Brodowski# macros for not-implemented syscalls in kernel/sys_ni.c and
22507303e30eSDominik Brodowski# kernel/time/posix-stubs.c. All these overrides need to be available in
22517303e30eSDominik Brodowski# <asm/syscall_wrapper.h>.
22521bd21c6cSDominik Brodowskiconfig ARCH_HAS_SYSCALL_WRAPPER
22531bd21c6cSDominik Brodowski	def_bool n
2254