Thomas Gleixner | ec8f24b | 2019-05-19 13:07:45 +0100 | [diff] [blame] | 1 | # SPDX-License-Identifier: GPL-2.0-only |
Masahiro Yamada | 8b59cd8 | 2020-04-23 23:23:52 +0900 | [diff] [blame] | 2 | config CC_VERSION_TEXT |
| 3 | string |
| 4 | default "$(CC_VERSION_TEXT)" |
| 5 | help |
| 6 | This is used in unclear ways: |
| 7 | |
| 8 | - Re-run Kconfig when the compiler is updated |
| 9 | The 'default' property references the environment variable, |
| 10 | CC_VERSION_TEXT so it is recorded in include/config/auto.conf.cmd. |
| 11 | When the compiler is updated, Kconfig will be invoked. |
| 12 | |
Bhaskar Chowdhury | f9c8bc4 | 2021-02-25 17:22:18 -0800 | [diff] [blame] | 13 | - Ensure full rebuild when the compiler is updated |
Masahiro Yamada | ce6ed1c | 2021-03-04 20:37:08 +0900 | [diff] [blame] | 14 | include/linux/compiler-version.h contains this option in the comment |
Alexey Dobriyan | 0e0345b | 2021-04-15 20:36:07 +0300 | [diff] [blame] | 15 | line so fixdep adds include/config/CC_VERSION_TEXT into the |
Masahiro Yamada | ce6ed1c | 2021-03-04 20:37:08 +0900 | [diff] [blame] | 16 | auto-generated dependency. When the compiler is updated, syncconfig |
| 17 | will touch it and then every file will be rebuilt. |
Masahiro Yamada | 8b59cd8 | 2020-04-23 23:23:52 +0900 | [diff] [blame] | 18 | |
Masahiro Yamada | a435389 | 2018-05-28 18:22:01 +0900 | [diff] [blame] | 19 | config CC_IS_GCC |
Masahiro Yamada | aec6c60 | 2021-01-16 08:35:42 +0900 | [diff] [blame] | 20 | def_bool $(success,test "$(cc-name)" = GCC) |
Masahiro Yamada | a435389 | 2018-05-28 18:22:01 +0900 | [diff] [blame] | 21 | |
| 22 | config GCC_VERSION |
| 23 | int |
Masahiro Yamada | aec6c60 | 2021-01-16 08:35:42 +0900 | [diff] [blame] | 24 | default $(cc-version) if CC_IS_GCC |
Masahiro Yamada | a435389 | 2018-05-28 18:22:01 +0900 | [diff] [blame] | 25 | default 0 |
| 26 | |
Masahiro Yamada | 469cb73 | 2018-05-28 18:22:02 +0900 | [diff] [blame] | 27 | config CC_IS_CLANG |
Masahiro Yamada | aec6c60 | 2021-01-16 08:35:42 +0900 | [diff] [blame] | 28 | def_bool $(success,test "$(cc-name)" = Clang) |
Sami Tolvanen | b744b43 | 2020-04-28 15:14:15 -0700 | [diff] [blame] | 29 | |
Masahiro Yamada | 469cb73 | 2018-05-28 18:22:02 +0900 | [diff] [blame] | 30 | config CLANG_VERSION |
| 31 | int |
Masahiro Yamada | aec6c60 | 2021-01-16 08:35:42 +0900 | [diff] [blame] | 32 | default $(cc-version) if CC_IS_CLANG |
| 33 | default 0 |
Masahiro Yamada | 469cb73 | 2018-05-28 18:22:02 +0900 | [diff] [blame] | 34 | |
Masahiro Yamada | ba64beb | 2021-03-16 01:12:56 +0900 | [diff] [blame] | 35 | config AS_IS_GNU |
| 36 | def_bool $(success,test "$(as-name)" = GNU) |
| 37 | |
| 38 | config AS_IS_LLVM |
| 39 | def_bool $(success,test "$(as-name)" = LLVM) |
| 40 | |
| 41 | config AS_VERSION |
| 42 | int |
| 43 | # Use clang version if this is the integrated assembler |
| 44 | default CLANG_VERSION if AS_IS_LLVM |
| 45 | default $(as-version) |
| 46 | |
Masahiro Yamada | 02aff85 | 2021-02-16 12:10:04 +0900 | [diff] [blame] | 47 | config LD_IS_BFD |
| 48 | def_bool $(success,test "$(ld-name)" = BFD) |
| 49 | |
| 50 | config LD_VERSION |
| 51 | int |
| 52 | default $(ld-version) if LD_IS_BFD |
| 53 | default 0 |
| 54 | |
| 55 | config LD_IS_LLD |
| 56 | def_bool $(success,test "$(ld-name)" = LLD) |
Andy Lutomirski | c65eacb | 2016-09-13 14:29:24 -0700 | [diff] [blame] | 57 | |
Nathan Chancellor | d5750cd | 2020-11-19 13:46:58 -0700 | [diff] [blame] | 58 | config LLD_VERSION |
| 59 | int |
Masahiro Yamada | 02aff85 | 2021-02-16 12:10:04 +0900 | [diff] [blame] | 60 | default $(ld-version) if LD_IS_LLD |
| 61 | default 0 |
Nathan Chancellor | d5750cd | 2020-11-19 13:46:58 -0700 | [diff] [blame] | 62 | |
Miguel Ojeda | 2f7ab12 | 2021-07-03 16:42:57 +0200 | [diff] [blame] | 63 | config RUST_IS_AVAILABLE |
| 64 | def_bool $(success,$(srctree)/scripts/rust_is_available.sh) |
| 65 | help |
| 66 | This shows whether a suitable Rust toolchain is available (found). |
| 67 | |
| 68 | Please see Documentation/rust/quick-start.rst for instructions on how |
Colin Ian King | eacf96d | 2022-10-07 21:43:39 +0100 | [diff] [blame] | 69 | to satisfy the build requirements of Rust support. |
Miguel Ojeda | 2f7ab12 | 2021-07-03 16:42:57 +0200 | [diff] [blame] | 70 | |
| 71 | In particular, the Makefile target 'rustavailable' is useful to check |
| 72 | why the Rust toolchain is not being detected. |
| 73 | |
Masahiro Yamada | 1a927fd | 2019-07-01 09:58:39 +0900 | [diff] [blame] | 74 | config CC_CAN_LINK |
Masahiro Yamada | 9371f86 | 2020-04-29 12:45:13 +0900 | [diff] [blame] | 75 | bool |
Elliot Berman | f67695c9 | 2022-02-01 13:35:42 -0800 | [diff] [blame] | 76 | default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag)) if 64BIT |
| 77 | default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m32-flag)) |
Masahiro Yamada | 1a927fd | 2019-07-01 09:58:39 +0900 | [diff] [blame] | 78 | |
Masahiro Yamada | b1183b6 | 2020-05-09 16:39:15 +0900 | [diff] [blame] | 79 | config CC_CAN_LINK_STATIC |
| 80 | bool |
Elliot Berman | f67695c9 | 2022-02-01 13:35:42 -0800 | [diff] [blame] | 81 | default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag) -static) if 64BIT |
| 82 | default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m32-flag) -static) |
Andy Lutomirski | c65eacb | 2016-09-13 14:29:24 -0700 | [diff] [blame] | 83 | |
Nick Desaulniers | 587f170 | 2020-02-14 14:18:11 -0800 | [diff] [blame] | 84 | config CC_HAS_ASM_GOTO_OUTPUT |
Nick Desaulniers | 587f170 | 2020-02-14 14:18:11 -0800 | [diff] [blame] | 85 | def_bool $(success,echo 'int foo(int x) { asm goto ("": "=r"(x) ::: bar); return x; bar: return 0; }' | $(CC) -x c - -c -o /dev/null) |
| 86 | |
Sean Christopherson | 1aa0e8b | 2022-02-02 00:49:41 +0000 | [diff] [blame] | 87 | config CC_HAS_ASM_GOTO_TIED_OUTPUT |
| 88 | depends on CC_HAS_ASM_GOTO_OUTPUT |
| 89 | # Detect buggy gcc and clang, fixed in gcc-11 clang-14. |
Alexandre Belloni | 534bd70 | 2022-11-15 12:01:58 +0100 | [diff] [blame] | 90 | 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) |
Sean Christopherson | 1aa0e8b | 2022-02-02 00:49:41 +0000 | [diff] [blame] | 91 | |
Linus Torvalds | 68fb3ca | 2024-02-15 11:14:33 -0800 | [diff] [blame] | 92 | config GCC_ASM_GOTO_OUTPUT_WORKAROUND |
| 93 | bool |
| 94 | depends on CC_IS_GCC && CC_HAS_ASM_GOTO_OUTPUT |
| 95 | # Fixed in GCC 14, 13.3, 12.4 and 11.5 |
| 96 | # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113921 |
| 97 | default y if GCC_VERSION < 110500 |
| 98 | default y if GCC_VERSION >= 120000 && GCC_VERSION < 120400 |
| 99 | default y if GCC_VERSION >= 130000 && GCC_VERSION < 130300 |
| 100 | |
Peter Collingbourne | 5cf896fb6 | 2019-07-31 18:18:42 -0700 | [diff] [blame] | 101 | config TOOLS_SUPPORT_RELR |
Will Deacon | 2d12294 | 2019-08-20 10:11:54 +0100 | [diff] [blame] | 102 | def_bool $(success,env "CC=$(CC)" "LD=$(LD)" "NM=$(NM)" "OBJCOPY=$(OBJCOPY)" $(srctree)/scripts/tools-support-relr.sh) |
Peter Collingbourne | 5cf896fb6 | 2019-07-31 18:18:42 -0700 | [diff] [blame] | 103 | |
Rasmus Villemoes | eb11186 | 2019-09-13 00:19:25 +0200 | [diff] [blame] | 104 | config CC_HAS_ASM_INLINE |
| 105 | def_bool $(success,echo 'void foo(void) { asm inline (""); }' | $(CC) -x c - -c -o /dev/null) |
| 106 | |
Nick Desaulniers | 51c2ee6 | 2021-06-21 16:18:22 -0700 | [diff] [blame] | 107 | config CC_HAS_NO_PROFILE_FN_ATTR |
| 108 | def_bool $(success,echo '__attribute__((no_profile_instrument_function)) int x();' | $(CC) -x c - -c -o /dev/null -Werror) |
| 109 | |
Nathan Chancellor | 613fe16 | 2022-02-01 13:56:21 -0700 | [diff] [blame] | 110 | config PAHOLE_VERSION |
| 111 | int |
| 112 | default $(shell,$(srctree)/scripts/pahole-version.sh $(PAHOLE)) |
| 113 | |
Peter Oberparleiter | b99b87f7 | 2009-06-17 16:28:03 -0700 | [diff] [blame] | 114 | config CONSTRUCTORS |
| 115 | bool |
Peter Oberparleiter | b99b87f7 | 2009-06-17 16:28:03 -0700 | [diff] [blame] | 116 | |
Peter Zijlstra | e360adb | 2010-10-14 14:01:34 +0800 | [diff] [blame] | 117 | config IRQ_WORK |
Tejun Heo | fd0a68a | 2024-02-15 19:10:01 -1000 | [diff] [blame] | 118 | def_bool y if SMP |
Peter Zijlstra | e360adb | 2010-10-14 14:01:34 +0800 | [diff] [blame] | 119 | |
Shile Zhang | 1091670 | 2019-12-04 08:46:31 +0800 | [diff] [blame] | 120 | config BUILDTIME_TABLE_SORT |
David Daney | 1dbdc6f | 2012-04-19 14:59:57 -0700 | [diff] [blame] | 121 | bool |
| 122 | |
Andy Lutomirski | c65eacb | 2016-09-13 14:29:24 -0700 | [diff] [blame] | 123 | config THREAD_INFO_IN_TASK |
| 124 | bool |
| 125 | help |
| 126 | Select this to move thread_info off the stack into task_struct. To |
| 127 | make this work, an arch will need to remove all thread_info fields |
| 128 | except flags and fix any runtime bugs. |
| 129 | |
Andy Lutomirski | c6c314a | 2016-09-15 22:45:43 -0700 | [diff] [blame] | 130 | One subtle change that will be needed is to use try_get_task_stack() |
| 131 | and put_task_stack() in save_thread_stack_tsk() and get_wchan(). |
| 132 | |
Al Boldi | ff0cfc6 | 2007-07-31 00:39:23 -0700 | [diff] [blame] | 133 | menu "General setup" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 135 | config BROKEN |
| 136 | bool |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 137 | |
| 138 | config BROKEN_ON_SMP |
| 139 | bool |
| 140 | depends on BROKEN || !SMP |
| 141 | default y |
| 142 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | config INIT_ENV_ARG_LIMIT |
| 144 | int |
Adrian Bunk | dd673bc | 2006-06-30 01:55:51 -0700 | [diff] [blame] | 145 | default 32 if !UML |
| 146 | default 128 if UML |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 147 | help |
Randy Dunlap | 34ad92c2 | 2005-10-30 15:01:46 -0800 | [diff] [blame] | 148 | Maximum of each of the number of arguments and environment |
| 149 | variables passed to init from the kernel command line. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | |
Jiri Slaby | 4bb1667 | 2013-05-22 10:56:24 +0200 | [diff] [blame] | 151 | config COMPILE_TEST |
| 152 | bool "Compile also drivers which will not load" |
Masahiro Yamada | ea29b20 | 2021-03-12 21:07:08 -0800 | [diff] [blame] | 153 | depends on HAS_IOMEM |
Jiri Slaby | 4bb1667 | 2013-05-22 10:56:24 +0200 | [diff] [blame] | 154 | help |
| 155 | Some drivers can be compiled on a different platform than they are |
| 156 | intended to be run on. Despite they cannot be loaded there (or even |
| 157 | when they load they cannot be used due to missing HW support), |
| 158 | developers still, opposing to distributors, might want to build such |
| 159 | drivers to compile-test them. |
| 160 | |
| 161 | If you are a developer and want to build everything available, say Y |
| 162 | here. If you are a user/distributor, say N here to exclude useless |
| 163 | drivers to be distributed. |
| 164 | |
Linus Torvalds | 3fe617c | 2021-09-05 11:24:05 -0700 | [diff] [blame] | 165 | config WERROR |
| 166 | bool "Compile the kernel with warnings as errors" |
Marco Elver | b339ec9 | 2021-09-07 23:12:08 +0200 | [diff] [blame] | 167 | default COMPILE_TEST |
Linus Torvalds | 3fe617c | 2021-09-05 11:24:05 -0700 | [diff] [blame] | 168 | help |
| 169 | A kernel build should not cause any compiler warnings, and this |
Miguel Ojeda | 2f7ab12 | 2021-07-03 16:42:57 +0200 | [diff] [blame] | 170 | enables the '-Werror' (for C) and '-Dwarnings' (for Rust) flags |
Xin Li | e1789d7 | 2022-10-25 00:30:23 -0700 | [diff] [blame] | 171 | to enforce that rule by default. Certain warnings from other tools |
| 172 | such as the linker may be upgraded to errors with this option as |
| 173 | well. |
Linus Torvalds | 3fe617c | 2021-09-05 11:24:05 -0700 | [diff] [blame] | 174 | |
Xin Li | e1789d7 | 2022-10-25 00:30:23 -0700 | [diff] [blame] | 175 | However, if you have a new (or very old) compiler or linker with odd |
| 176 | and unusual warnings, or you have some architecture with problems, |
Linus Torvalds | 3fe617c | 2021-09-05 11:24:05 -0700 | [diff] [blame] | 177 | you may need to disable this config option in order to |
| 178 | successfully build the kernel. |
| 179 | |
| 180 | If in doubt, say Y. |
| 181 | |
Masahiro Yamada | d6fc9fc | 2019-07-01 09:58:40 +0900 | [diff] [blame] | 182 | config UAPI_HEADER_TEST |
| 183 | bool "Compile test UAPI headers" |
Masahiro Yamada | fcbb846 | 2019-11-07 16:14:40 +0900 | [diff] [blame] | 184 | depends on HEADERS_INSTALL && CC_CAN_LINK |
Masahiro Yamada | d6fc9fc | 2019-07-01 09:58:40 +0900 | [diff] [blame] | 185 | help |
| 186 | Compile test headers exported to user-space to ensure they are |
| 187 | self-contained, i.e. compilable as standalone units. |
| 188 | |
| 189 | If you are a developer or tester and want to ensure the exported |
| 190 | headers are self-contained, say Y here. Otherwise, choose N. |
| 191 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 192 | config LOCALVERSION |
| 193 | string "Local version - append to kernel release" |
| 194 | help |
| 195 | Append an extra string to the end of your kernel version. |
| 196 | This will show up when you type uname, for example. |
| 197 | The string you set here will be appended after the contents of |
| 198 | any files with a filename matching localversion* in your |
| 199 | object and source tree, in that order. Your total string can |
| 200 | be a maximum of 64 characters. |
| 201 | |
Ryan Anderson | aaebf43 | 2005-07-31 04:57:49 -0400 | [diff] [blame] | 202 | config LOCALVERSION_AUTO |
| 203 | bool "Automatically append version information to the version string" |
| 204 | default y |
Alexey Dobriyan | ac3339b | 2016-08-02 14:07:21 -0700 | [diff] [blame] | 205 | depends on !COMPILE_TEST |
Ryan Anderson | aaebf43 | 2005-07-31 04:57:49 -0400 | [diff] [blame] | 206 | help |
| 207 | This will try to automatically determine if the current tree is a |
Robert P. J. Day | 6e5a542 | 2007-05-01 23:08:11 +0200 | [diff] [blame] | 208 | release tree by looking for git tags that belong to the current |
| 209 | top of tree revision. |
Ryan Anderson | aaebf43 | 2005-07-31 04:57:49 -0400 | [diff] [blame] | 210 | |
| 211 | A string of the format -gxxxxxxxx will be added to the localversion |
Robert P. J. Day | 6e5a542 | 2007-05-01 23:08:11 +0200 | [diff] [blame] | 212 | if a git-based tree is found. The string generated by this will be |
Ryan Anderson | aaebf43 | 2005-07-31 04:57:49 -0400 | [diff] [blame] | 213 | appended after any matching localversion* files, and after the value |
Robert P. J. Day | 6e5a542 | 2007-05-01 23:08:11 +0200 | [diff] [blame] | 214 | set in CONFIG_LOCALVERSION. |
Ryan Anderson | aaebf43 | 2005-07-31 04:57:49 -0400 | [diff] [blame] | 215 | |
Rasmus Villemoes | 0f9c608 | 2023-01-11 10:38:22 +0100 | [diff] [blame] | 216 | (The actual string used here is the first 12 characters produced |
Robert P. J. Day | 6e5a542 | 2007-05-01 23:08:11 +0200 | [diff] [blame] | 217 | by running the command: |
| 218 | |
| 219 | $ git rev-parse --verify HEAD |
| 220 | |
| 221 | which is done within the script "scripts/setlocalversion".) |
Ryan Anderson | aaebf43 | 2005-07-31 04:57:49 -0400 | [diff] [blame] | 222 | |
Laura Abbott | 9afb719 | 2018-07-05 17:49:37 -0700 | [diff] [blame] | 223 | config BUILD_SALT |
Krzysztof Kozlowski | e8cf4e9 | 2019-12-04 16:52:28 -0800 | [diff] [blame] | 224 | string "Build ID Salt" |
| 225 | default "" |
| 226 | help |
| 227 | The build ID is used to link binaries and their debug info. Setting |
| 228 | this option will use the value in the calculation of the build id. |
| 229 | This is mostly useful for distributions which want to ensure the |
| 230 | build is unique between builds. It's safe to leave the default. |
Laura Abbott | 9afb719 | 2018-07-05 17:49:37 -0700 | [diff] [blame] | 231 | |
H. Peter Anvin | 2e9f3bd | 2009-01-04 15:41:25 -0800 | [diff] [blame] | 232 | config HAVE_KERNEL_GZIP |
| 233 | bool |
| 234 | |
| 235 | config HAVE_KERNEL_BZIP2 |
| 236 | bool |
| 237 | |
| 238 | config HAVE_KERNEL_LZMA |
| 239 | bool |
| 240 | |
Lasse Collin | 3ebe124 | 2011-01-12 17:01:23 -0800 | [diff] [blame] | 241 | config HAVE_KERNEL_XZ |
| 242 | bool |
| 243 | |
Albin Tonnerre | 7dd65fe | 2010-01-08 14:42:42 -0800 | [diff] [blame] | 244 | config HAVE_KERNEL_LZO |
| 245 | bool |
| 246 | |
Kyungsik Lee | e76e1fd | 2013-07-08 16:01:46 -0700 | [diff] [blame] | 247 | config HAVE_KERNEL_LZ4 |
| 248 | bool |
| 249 | |
Nick Terrell | 48f7ddf | 2020-07-30 12:08:36 -0700 | [diff] [blame] | 250 | config HAVE_KERNEL_ZSTD |
| 251 | bool |
| 252 | |
Vasily Gorbik | f16466a | 2018-06-12 21:26:35 +0200 | [diff] [blame] | 253 | config HAVE_KERNEL_UNCOMPRESSED |
| 254 | bool |
| 255 | |
Alain Knaff | 30d65db | 2009-01-04 22:46:17 +0100 | [diff] [blame] | 256 | choice |
H. Peter Anvin | 2e9f3bd | 2009-01-04 15:41:25 -0800 | [diff] [blame] | 257 | prompt "Kernel compression mode" |
| 258 | default KERNEL_GZIP |
Nick Terrell | 48f7ddf | 2020-07-30 12:08:36 -0700 | [diff] [blame] | 259 | 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 |
H. Peter Anvin | 2e9f3bd | 2009-01-04 15:41:25 -0800 | [diff] [blame] | 260 | help |
Alain Knaff | 30d65db | 2009-01-04 22:46:17 +0100 | [diff] [blame] | 261 | The linux kernel is a kind of self-extracting executable. |
| 262 | Several compression algorithms are available, which differ |
| 263 | in efficiency, compression and decompression speed. |
| 264 | Compression speed is only relevant when building a kernel. |
| 265 | Decompression speed is relevant at each boot. |
| 266 | |
| 267 | If you have any problems with bzip2 or lzma compressed |
| 268 | kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older |
| 269 | version of this functionality (bzip2 only), for 2.4, was |
| 270 | supplied by Christian Ludwig) |
| 271 | |
| 272 | High compression options are mostly useful for users, who |
| 273 | are low on disk space (embedded systems), but for whom ram |
| 274 | size matters less. |
| 275 | |
| 276 | If in doubt, select 'gzip' |
| 277 | |
| 278 | config KERNEL_GZIP |
H. Peter Anvin | 2e9f3bd | 2009-01-04 15:41:25 -0800 | [diff] [blame] | 279 | bool "Gzip" |
| 280 | depends on HAVE_KERNEL_GZIP |
| 281 | help |
Albin Tonnerre | 7dd65fe | 2010-01-08 14:42:42 -0800 | [diff] [blame] | 282 | The old and tried gzip compression. It provides a good balance |
| 283 | between compression ratio and decompression speed. |
Alain Knaff | 30d65db | 2009-01-04 22:46:17 +0100 | [diff] [blame] | 284 | |
| 285 | config KERNEL_BZIP2 |
| 286 | bool "Bzip2" |
H. Peter Anvin | 2e9f3bd | 2009-01-04 15:41:25 -0800 | [diff] [blame] | 287 | depends on HAVE_KERNEL_BZIP2 |
Alain Knaff | 30d65db | 2009-01-04 22:46:17 +0100 | [diff] [blame] | 288 | help |
| 289 | Its compression ratio and speed is intermediate. |
Randy Dunlap | 0a4dd35 | 2012-05-31 16:26:46 -0700 | [diff] [blame] | 290 | Decompression speed is slowest among the choices. The kernel |
H. Peter Anvin | 2e9f3bd | 2009-01-04 15:41:25 -0800 | [diff] [blame] | 291 | size is about 10% smaller with bzip2, in comparison to gzip. |
| 292 | Bzip2 uses a large amount of memory. For modern kernels you |
| 293 | will need at least 8MB RAM or more for booting. |
Alain Knaff | 30d65db | 2009-01-04 22:46:17 +0100 | [diff] [blame] | 294 | |
| 295 | config KERNEL_LZMA |
H. Peter Anvin | 2e9f3bd | 2009-01-04 15:41:25 -0800 | [diff] [blame] | 296 | bool "LZMA" |
| 297 | depends on HAVE_KERNEL_LZMA |
| 298 | help |
Randy Dunlap | 0a4dd35 | 2012-05-31 16:26:46 -0700 | [diff] [blame] | 299 | This compression algorithm's ratio is best. Decompression speed |
| 300 | is between gzip and bzip2. Compression is slowest. |
| 301 | The kernel size is about 33% smaller with LZMA in comparison to gzip. |
Alain Knaff | 30d65db | 2009-01-04 22:46:17 +0100 | [diff] [blame] | 302 | |
Lasse Collin | 3ebe124 | 2011-01-12 17:01:23 -0800 | [diff] [blame] | 303 | config KERNEL_XZ |
| 304 | bool "XZ" |
| 305 | depends on HAVE_KERNEL_XZ |
| 306 | help |
| 307 | XZ uses the LZMA2 algorithm and instruction set specific |
| 308 | BCJ filters which can improve compression ratio of executable |
| 309 | code. The size of the kernel is about 30% smaller with XZ in |
| 310 | comparison to gzip. On architectures for which there is a BCJ |
| 311 | filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ |
| 312 | will create a few percent smaller kernel than plain LZMA. |
| 313 | |
| 314 | The speed is about the same as with LZMA: The decompression |
| 315 | speed of XZ is better than that of bzip2 but worse than gzip |
| 316 | and LZO. Compression is slow. |
| 317 | |
Albin Tonnerre | 7dd65fe | 2010-01-08 14:42:42 -0800 | [diff] [blame] | 318 | config KERNEL_LZO |
| 319 | bool "LZO" |
| 320 | depends on HAVE_KERNEL_LZO |
| 321 | help |
Randy Dunlap | 0a4dd35 | 2012-05-31 16:26:46 -0700 | [diff] [blame] | 322 | Its compression ratio is the poorest among the choices. The kernel |
Stephan Sperber | 681b304 | 2010-07-14 11:23:08 +0200 | [diff] [blame] | 323 | size is about 10% bigger than gzip; however its speed |
Albin Tonnerre | 7dd65fe | 2010-01-08 14:42:42 -0800 | [diff] [blame] | 324 | (both compression and decompression) is the fastest. |
| 325 | |
Kyungsik Lee | e76e1fd | 2013-07-08 16:01:46 -0700 | [diff] [blame] | 326 | config KERNEL_LZ4 |
| 327 | bool "LZ4" |
| 328 | depends on HAVE_KERNEL_LZ4 |
| 329 | help |
| 330 | LZ4 is an LZ77-type compressor with a fixed, byte-oriented encoding. |
| 331 | A preliminary version of LZ4 de/compression tool is available at |
| 332 | <https://code.google.com/p/lz4/>. |
| 333 | |
| 334 | Its compression ratio is worse than LZO. The size of the kernel |
| 335 | is about 8% bigger than LZO. But the decompression speed is |
| 336 | faster than LZO. |
| 337 | |
Nick Terrell | 48f7ddf | 2020-07-30 12:08:36 -0700 | [diff] [blame] | 338 | config KERNEL_ZSTD |
| 339 | bool "ZSTD" |
| 340 | depends on HAVE_KERNEL_ZSTD |
| 341 | help |
| 342 | ZSTD is a compression algorithm targeting intermediate compression |
| 343 | with fast decompression speed. It will compress better than GZIP and |
| 344 | decompress around the same speed as LZO, but slower than LZ4. You |
| 345 | will need at least 192 KB RAM or more for booting. The zstd command |
| 346 | line tool is required for compression. |
| 347 | |
Vasily Gorbik | f16466a | 2018-06-12 21:26:35 +0200 | [diff] [blame] | 348 | config KERNEL_UNCOMPRESSED |
| 349 | bool "None" |
| 350 | depends on HAVE_KERNEL_UNCOMPRESSED |
| 351 | help |
| 352 | Produce uncompressed kernel image. This option is usually not what |
| 353 | you want. It is useful for debugging the kernel in slow simulation |
| 354 | environments, where decompressing and moving the kernel is awfully |
| 355 | slow. This option allows early boot code to skip the decompressor |
| 356 | and jump right at uncompressed kernel image. |
| 357 | |
Alain Knaff | 30d65db | 2009-01-04 22:46:17 +0100 | [diff] [blame] | 358 | endchoice |
| 359 | |
Chris Down | ada4ab7 | 2020-06-04 16:50:53 -0700 | [diff] [blame] | 360 | config DEFAULT_INIT |
| 361 | string "Default init path" |
| 362 | default "" |
| 363 | help |
| 364 | This option determines the default init for the system if no init= |
| 365 | option is passed on the kernel command line. If the requested path is |
| 366 | not present, we will still then move on to attempting further |
| 367 | locations (e.g. /sbin/init, etc). If this is empty, we will just use |
| 368 | the fallback list when init= is not passed. |
| 369 | |
Josh Triplett | bd5dc17 | 2011-06-15 15:08:28 -0700 | [diff] [blame] | 370 | config DEFAULT_HOSTNAME |
| 371 | string "Default hostname" |
| 372 | default "(none)" |
| 373 | help |
| 374 | This option determines the default system hostname before userspace |
| 375 | calls sethostname(2). The kernel traditionally uses "(none)" here, |
| 376 | but you may wish to use a different default here to make a minimal |
| 377 | system more usable with less configuration. |
| 378 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 379 | config SYSVIPC |
| 380 | bool "System V IPC" |
Masahiro Yamada | a7f7f62 | 2020-06-14 01:50:22 +0900 | [diff] [blame] | 381 | help |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 382 | Inter Process Communication is a suite of library functions and |
| 383 | system calls which let processes (running programs) synchronize and |
| 384 | exchange information. It is generally considered to be a good thing, |
| 385 | and some programs won't run unless you say Y here. In particular, if |
| 386 | you want to run the DOS emulator dosemu under Linux (read the |
| 387 | DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>), |
| 388 | you'll need to say Y here. |
| 389 | |
| 390 | You can find documentation about IPC with "info ipc" and also in |
| 391 | section 6.4 of the Linux Programmer's Guide, available from |
| 392 | <http://www.tldp.org/guides.html>. |
| 393 | |
Eric W. Biederman | a5494dc | 2007-02-14 00:34:06 -0800 | [diff] [blame] | 394 | config SYSVIPC_SYSCTL |
| 395 | bool |
| 396 | depends on SYSVIPC |
| 397 | depends on SYSCTL |
| 398 | default y |
| 399 | |
Guo Ren | 0cbed0e | 2022-04-05 15:12:58 +0800 | [diff] [blame] | 400 | config SYSVIPC_COMPAT |
| 401 | def_bool y |
| 402 | depends on COMPAT && SYSVIPC |
| 403 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 404 | config POSIX_MQUEUE |
| 405 | bool "POSIX Message Queues" |
Kees Cook | 19c9239 | 2012-10-02 11:19:29 -0700 | [diff] [blame] | 406 | depends on NET |
Masahiro Yamada | a7f7f62 | 2020-06-14 01:50:22 +0900 | [diff] [blame] | 407 | help |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 408 | POSIX variant of message queues is a part of IPC. In POSIX message |
| 409 | queues every message has a priority which decides about succession |
| 410 | of receiving it by a process. If you want to compile and run |
| 411 | programs written e.g. for Solaris with use of its POSIX message |
Robert P. J. Day | b0e37650 | 2007-05-09 07:25:13 +0200 | [diff] [blame] | 412 | queues (functions mq_*) say Y here. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 413 | |
| 414 | POSIX message queues are visible as a filesystem called 'mqueue' |
| 415 | and can be mounted somewhere if you want to do filesystem |
| 416 | operations on message queues. |
| 417 | |
| 418 | If unsure, say Y. |
| 419 | |
Serge E. Hallyn | bdc8e5f | 2009-04-06 19:01:11 -0700 | [diff] [blame] | 420 | config POSIX_MQUEUE_SYSCTL |
| 421 | bool |
| 422 | depends on POSIX_MQUEUE |
| 423 | depends on SYSCTL |
| 424 | default y |
| 425 | |
David Howells | c73be61 | 2020-01-14 17:07:11 +0000 | [diff] [blame] | 426 | config WATCH_QUEUE |
| 427 | bool "General notification queue" |
| 428 | default n |
| 429 | help |
| 430 | |
| 431 | This is a general notification queue for the kernel to pass events to |
| 432 | userspace by splicing them into pipes. It can be used in conjunction |
| 433 | with watches for key/keyring change notifications and device |
| 434 | notifications. |
| 435 | |
Mauro Carvalho Chehab | c02b872 | 2022-06-26 10:10:56 +0100 | [diff] [blame] | 436 | See Documentation/core-api/watch_queue.rst |
David Howells | c73be61 | 2020-01-14 17:07:11 +0000 | [diff] [blame] | 437 | |
Konstantin Khlebnikov | 226b4cc | 2014-06-04 16:10:50 -0700 | [diff] [blame] | 438 | config CROSS_MEMORY_ATTACH |
| 439 | bool "Enable process_vm_readv/writev syscalls" |
| 440 | depends on MMU |
| 441 | default y |
| 442 | help |
| 443 | Enabling this option adds the system calls process_vm_readv and |
| 444 | process_vm_writev which allow a process with the correct privileges |
Geert Uytterhoeven | a2a368d | 2014-08-12 13:46:11 -0700 | [diff] [blame] | 445 | to directly read from or write to another process' address space. |
Konstantin Khlebnikov | 226b4cc | 2014-06-04 16:10:50 -0700 | [diff] [blame] | 446 | See the man page for more details. |
| 447 | |
Josh Triplett | 69369a7 | 2014-04-03 14:48:27 -0700 | [diff] [blame] | 448 | config USELIB |
Kees Cook | 7374fa3 | 2022-04-29 14:38:01 -0700 | [diff] [blame] | 449 | bool "uselib syscall (for libc5 and earlier)" |
| 450 | default ALPHA || M68K || SPARC |
Josh Triplett | 69369a7 | 2014-04-03 14:48:27 -0700 | [diff] [blame] | 451 | help |
| 452 | This option enables the uselib syscall, a system call used in the |
| 453 | dynamic linker from libc5 and earlier. glibc does not use this |
| 454 | system call. If you intend to run programs built on libc5 or |
| 455 | earlier, you may need to enable this syscall. Current systems |
| 456 | running glibc can safely disable this. |
| 457 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 458 | config AUDIT |
| 459 | bool "Auditing support" |
Chris Wright | 804a6a49 | 2005-05-11 10:52:45 +0100 | [diff] [blame] | 460 | depends on NET |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 461 | help |
| 462 | Enable auditing infrastructure that can be used with another |
| 463 | kernel subsystem, such as SELinux (which requires this for |
Paul Moore | cb74ed2 | 2016-01-13 09:18:55 -0500 | [diff] [blame] | 464 | logging of avc messages output). System call auditing is included |
| 465 | on architectures which support it. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 466 | |
AKASHI Takahiro | 7a01772 | 2014-02-25 18:16:24 +0900 | [diff] [blame] | 467 | config HAVE_ARCH_AUDITSYSCALL |
| 468 | bool |
| 469 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 470 | config AUDITSYSCALL |
Paul Moore | cb74ed2 | 2016-01-13 09:18:55 -0500 | [diff] [blame] | 471 | def_bool y |
AKASHI Takahiro | 7a01772 | 2014-02-25 18:16:24 +0900 | [diff] [blame] | 472 | depends on AUDIT && HAVE_ARCH_AUDITSYSCALL |
Eric Paris | 28a3a7e | 2009-12-17 20:12:05 -0500 | [diff] [blame] | 473 | select FSNOTIFY |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 474 | |
Thomas Gleixner | d9817eb | 2010-09-27 12:45:59 +0000 | [diff] [blame] | 475 | source "kernel/irq/Kconfig" |
Thomas Gleixner | 764e0da | 2012-05-21 23:16:18 +0200 | [diff] [blame] | 476 | source "kernel/time/Kconfig" |
Daniel Borkmann | b24abcf | 2021-05-11 22:35:16 +0200 | [diff] [blame] | 477 | source "kernel/bpf/Kconfig" |
Christoph Hellwig | 87a4c37 | 2018-07-31 13:39:32 +0200 | [diff] [blame] | 478 | source "kernel/Kconfig.preempt" |
Thomas Gleixner | d9817eb | 2010-09-27 12:45:59 +0000 | [diff] [blame] | 479 | |
Frederic Weisbecker | 391dc69 | 2012-09-09 14:22:07 +0200 | [diff] [blame] | 480 | menu "CPU/Task time and stats accounting" |
| 481 | |
Frederic Weisbecker | abf917c | 2012-07-25 07:56:04 +0200 | [diff] [blame] | 482 | config VIRT_CPU_ACCOUNTING |
| 483 | bool |
| 484 | |
Frederic Weisbecker | fdf9c35 | 2012-09-09 14:56:31 +0200 | [diff] [blame] | 485 | choice |
| 486 | prompt "Cputime accounting" |
Nicholas Piggin | 02382af | 2022-09-02 18:53:15 +1000 | [diff] [blame] | 487 | default TICK_CPU_ACCOUNTING |
Frederic Weisbecker | fdf9c35 | 2012-09-09 14:56:31 +0200 | [diff] [blame] | 488 | |
| 489 | # Kind of a stub config for the pure tick based cputime accounting |
| 490 | config TICK_CPU_ACCOUNTING |
| 491 | bool "Simple tick based cputime accounting" |
Frederic Weisbecker | c58b0df | 2013-04-26 15:16:31 +0200 | [diff] [blame] | 492 | depends on !S390 && !NO_HZ_FULL |
Frederic Weisbecker | fdf9c35 | 2012-09-09 14:56:31 +0200 | [diff] [blame] | 493 | help |
| 494 | This is the basic tick based cputime accounting that maintains |
| 495 | statistics about user, system and idle time spent on per jiffies |
| 496 | granularity. |
| 497 | |
| 498 | If unsure, say Y. |
| 499 | |
Frederic Weisbecker | abf917c | 2012-07-25 07:56:04 +0200 | [diff] [blame] | 500 | config VIRT_CPU_ACCOUNTING_NATIVE |
Frederic Weisbecker | 391dc69 | 2012-09-09 14:22:07 +0200 | [diff] [blame] | 501 | bool "Deterministic task and CPU time accounting" |
Frederic Weisbecker | c58b0df | 2013-04-26 15:16:31 +0200 | [diff] [blame] | 502 | depends on HAVE_VIRT_CPU_ACCOUNTING && !NO_HZ_FULL |
Frederic Weisbecker | abf917c | 2012-07-25 07:56:04 +0200 | [diff] [blame] | 503 | select VIRT_CPU_ACCOUNTING |
Frederic Weisbecker | 391dc69 | 2012-09-09 14:22:07 +0200 | [diff] [blame] | 504 | help |
| 505 | Select this option to enable more accurate task and CPU time |
| 506 | accounting. This is done by reading a CPU counter on each |
| 507 | kernel entry and exit and on transitions within the kernel |
| 508 | between system, softirq and hardirq state, so there is a |
| 509 | small performance impact. In the case of s390 or IBM POWER > 5, |
| 510 | this also enables accounting of stolen time on logically-partitioned |
| 511 | systems. |
| 512 | |
Frederic Weisbecker | abf917c | 2012-07-25 07:56:04 +0200 | [diff] [blame] | 513 | config VIRT_CPU_ACCOUNTING_GEN |
| 514 | bool "Full dynticks CPU time accounting" |
Frederic Weisbecker | 24a9c541 | 2022-06-08 16:40:24 +0200 | [diff] [blame] | 515 | depends on HAVE_CONTEXT_TRACKING_USER |
Kevin Hilman | 554b000 | 2013-09-16 15:28:21 -0700 | [diff] [blame] | 516 | depends on HAVE_VIRT_CPU_ACCOUNTING_GEN |
Arnd Bergmann | 041a157 | 2019-03-04 21:01:31 +0100 | [diff] [blame] | 517 | depends on GENERIC_CLOCKEVENTS |
Frederic Weisbecker | abf917c | 2012-07-25 07:56:04 +0200 | [diff] [blame] | 518 | select VIRT_CPU_ACCOUNTING |
Frederic Weisbecker | 24a9c541 | 2022-06-08 16:40:24 +0200 | [diff] [blame] | 519 | select CONTEXT_TRACKING_USER |
Frederic Weisbecker | abf917c | 2012-07-25 07:56:04 +0200 | [diff] [blame] | 520 | help |
| 521 | Select this option to enable task and CPU time accounting on full |
| 522 | dynticks systems. This accounting is implemented by watching every |
| 523 | kernel-user boundaries using the context tracking subsystem. |
| 524 | The accounting is thus performed at the expense of some significant |
| 525 | overhead. |
| 526 | |
| 527 | For now this is only useful if you are working on the full |
| 528 | dynticks subsystem development. |
| 529 | |
| 530 | If unsure, say N. |
| 531 | |
Rik van Riel | b58c358 | 2016-07-13 16:50:02 +0200 | [diff] [blame] | 532 | endchoice |
| 533 | |
Frederic Weisbecker | fdf9c35 | 2012-09-09 14:56:31 +0200 | [diff] [blame] | 534 | config IRQ_TIME_ACCOUNTING |
| 535 | bool "Fine granularity task level IRQ time accounting" |
Rik van Riel | b58c358 | 2016-07-13 16:50:02 +0200 | [diff] [blame] | 536 | depends on HAVE_IRQ_TIME_ACCOUNTING && !VIRT_CPU_ACCOUNTING_NATIVE |
Frederic Weisbecker | fdf9c35 | 2012-09-09 14:56:31 +0200 | [diff] [blame] | 537 | help |
| 538 | Select this option to enable fine granularity task irq time |
| 539 | accounting. This is done by reading a timestamp on each |
| 540 | transitions between softirq and hardirq state, so there can be a |
| 541 | small performance impact. |
| 542 | |
| 543 | If in doubt, say N here. |
| 544 | |
Vincent Guittot | 11d4afd | 2018-09-25 11:17:42 +0200 | [diff] [blame] | 545 | config HAVE_SCHED_AVG_IRQ |
| 546 | def_bool y |
| 547 | depends on IRQ_TIME_ACCOUNTING || PARAVIRT_TIME_ACCOUNTING |
| 548 | depends on SMP |
| 549 | |
Vincent Guittot | d4dbc99 | 2024-03-26 10:16:15 +0100 | [diff] [blame] | 550 | config SCHED_HW_PRESSURE |
Valentin Schneider | 98eb401 | 2020-07-12 17:59:16 +0100 | [diff] [blame] | 551 | bool |
Valentin Schneider | fcd7c9c | 2020-07-29 14:57:18 +0100 | [diff] [blame] | 552 | default y if ARM && ARM_CPU_TOPOLOGY |
| 553 | default y if ARM64 |
Thara Gopinath | 7650479 | 2020-02-21 19:52:05 -0500 | [diff] [blame] | 554 | depends on SMP |
Valentin Schneider | 98eb401 | 2020-07-12 17:59:16 +0100 | [diff] [blame] | 555 | depends on CPU_FREQ_THERMAL |
| 556 | help |
Vincent Guittot | d4dbc99 | 2024-03-26 10:16:15 +0100 | [diff] [blame] | 557 | Select this option to enable HW pressure accounting in the |
| 558 | scheduler. HW pressure is the value conveyed to the scheduler |
Valentin Schneider | 98eb401 | 2020-07-12 17:59:16 +0100 | [diff] [blame] | 559 | that reflects the reduction in CPU compute capacity resulted from |
Vincent Guittot | d4dbc99 | 2024-03-26 10:16:15 +0100 | [diff] [blame] | 560 | HW throttling. HW throttling occurs when the performance of |
| 561 | a CPU is capped due to high operating temperatures as an example. |
Valentin Schneider | 98eb401 | 2020-07-12 17:59:16 +0100 | [diff] [blame] | 562 | |
| 563 | If selected, the scheduler will be able to balance tasks accordingly, |
| 564 | i.e. put less load on throttled CPUs than on non/less throttled ones. |
| 565 | |
| 566 | This requires the architecture to implement |
Vincent Guittot | d4dbc99 | 2024-03-26 10:16:15 +0100 | [diff] [blame] | 567 | arch_update_hw_pressure() and arch_scale_thermal_pressure(). |
Thara Gopinath | 7650479 | 2020-02-21 19:52:05 -0500 | [diff] [blame] | 568 | |
Frederic Weisbecker | 391dc69 | 2012-09-09 14:22:07 +0200 | [diff] [blame] | 569 | config BSD_PROCESS_ACCT |
| 570 | bool "BSD Process Accounting" |
Iulia Manda | 2813893 | 2015-04-15 16:16:41 -0700 | [diff] [blame] | 571 | depends on MULTIUSER |
Frederic Weisbecker | 391dc69 | 2012-09-09 14:22:07 +0200 | [diff] [blame] | 572 | help |
| 573 | If you say Y here, a user level program will be able to instruct the |
| 574 | kernel (via a special system call) to write process accounting |
| 575 | information to a file: whenever a process exits, information about |
| 576 | that process will be appended to the file by the kernel. The |
| 577 | information includes things such as creation time, owning user, |
| 578 | command name, memory usage, controlling terminal etc. (the complete |
| 579 | list is in the struct acct in <file:include/linux/acct.h>). It is |
| 580 | up to the user level program to do useful things with this |
| 581 | information. This is generally a good idea, so say Y. |
| 582 | |
| 583 | config BSD_PROCESS_ACCT_V3 |
| 584 | bool "BSD Process Accounting version 3 file format" |
| 585 | depends on BSD_PROCESS_ACCT |
| 586 | default n |
| 587 | help |
| 588 | If you say Y here, the process accounting information is written |
| 589 | in a new file format that also logs the process IDs of each |
Randy Dunlap | 3903bf9 | 2018-08-21 21:58:34 -0700 | [diff] [blame] | 590 | process and its parent. Note that this file format is incompatible |
Frederic Weisbecker | 391dc69 | 2012-09-09 14:22:07 +0200 | [diff] [blame] | 591 | with previous v0/v1/v2 file formats, so you will need updated tools |
| 592 | for processing it. A preliminary version of these tools is available |
| 593 | at <http://www.gnu.org/software/acct/>. |
| 594 | |
| 595 | config TASKSTATS |
Kees Cook | 19c9239 | 2012-10-02 11:19:29 -0700 | [diff] [blame] | 596 | bool "Export task/process statistics through netlink" |
Frederic Weisbecker | 391dc69 | 2012-09-09 14:22:07 +0200 | [diff] [blame] | 597 | depends on NET |
Iulia Manda | 2813893 | 2015-04-15 16:16:41 -0700 | [diff] [blame] | 598 | depends on MULTIUSER |
Frederic Weisbecker | 391dc69 | 2012-09-09 14:22:07 +0200 | [diff] [blame] | 599 | default n |
| 600 | help |
| 601 | Export selected statistics for tasks/processes through the |
| 602 | generic netlink interface. Unlike BSD process accounting, the |
| 603 | statistics are available during the lifetime of tasks/processes as |
| 604 | responses to commands. Like BSD accounting, they are sent to user |
| 605 | space on task exit. |
| 606 | |
| 607 | Say N if unsure. |
| 608 | |
| 609 | config TASK_DELAY_ACCT |
Kees Cook | 19c9239 | 2012-10-02 11:19:29 -0700 | [diff] [blame] | 610 | bool "Enable per-task delay accounting" |
Frederic Weisbecker | 391dc69 | 2012-09-09 14:22:07 +0200 | [diff] [blame] | 611 | depends on TASKSTATS |
Naveen N. Rao | f6db834 | 2015-06-25 23:53:37 +0530 | [diff] [blame] | 612 | select SCHED_INFO |
Frederic Weisbecker | 391dc69 | 2012-09-09 14:22:07 +0200 | [diff] [blame] | 613 | help |
| 614 | Collect information on time spent by a task waiting for system |
| 615 | resources like cpu, synchronous block I/O completion and swapping |
| 616 | in pages. Such statistics can help in setting a task's priorities |
| 617 | relative to other tasks for cpu, io, rss limits etc. |
| 618 | |
| 619 | Say N if unsure. |
| 620 | |
| 621 | config TASK_XACCT |
Kees Cook | 19c9239 | 2012-10-02 11:19:29 -0700 | [diff] [blame] | 622 | bool "Enable extended accounting over taskstats" |
Frederic Weisbecker | 391dc69 | 2012-09-09 14:22:07 +0200 | [diff] [blame] | 623 | depends on TASKSTATS |
| 624 | help |
| 625 | Collect extended task accounting data and send the data |
| 626 | to userland for processing over the taskstats interface. |
| 627 | |
| 628 | Say N if unsure. |
| 629 | |
| 630 | config TASK_IO_ACCOUNTING |
Kees Cook | 19c9239 | 2012-10-02 11:19:29 -0700 | [diff] [blame] | 631 | bool "Enable per-task storage I/O accounting" |
Frederic Weisbecker | 391dc69 | 2012-09-09 14:22:07 +0200 | [diff] [blame] | 632 | depends on TASK_XACCT |
| 633 | help |
| 634 | Collect information on the number of bytes of storage I/O which this |
| 635 | task has caused. |
| 636 | |
| 637 | Say N if unsure. |
| 638 | |
Johannes Weiner | eb41468 | 2018-10-26 15:06:27 -0700 | [diff] [blame] | 639 | config PSI |
| 640 | bool "Pressure stall information tracking" |
Randy Dunlap | 98dfdd9 | 2023-07-30 20:07:40 -0700 | [diff] [blame] | 641 | select KERNFS |
Johannes Weiner | eb41468 | 2018-10-26 15:06:27 -0700 | [diff] [blame] | 642 | help |
| 643 | Collect metrics that indicate how overcommitted the CPU, memory, |
| 644 | and IO capacity are in the system. |
| 645 | |
| 646 | If you say Y here, the kernel will create /proc/pressure/ with the |
| 647 | pressure statistics files cpu, memory, and io. These will indicate |
| 648 | the share of walltime in which some or all tasks in the system are |
| 649 | delayed due to contention of the respective resource. |
| 650 | |
Johannes Weiner | 2ce7135 | 2018-10-26 15:06:31 -0700 | [diff] [blame] | 651 | In kernels with cgroup support, cgroups (cgroup2 only) will |
| 652 | have cpu.pressure, memory.pressure, and io.pressure files, |
| 653 | which aggregate pressure stalls for the grouped tasks only. |
| 654 | |
Mauro Carvalho Chehab | c312355 | 2019-04-17 05:46:08 -0300 | [diff] [blame] | 655 | For more details see Documentation/accounting/psi.rst. |
Johannes Weiner | eb41468 | 2018-10-26 15:06:27 -0700 | [diff] [blame] | 656 | |
| 657 | Say N if unsure. |
| 658 | |
Johannes Weiner | e0c2744 | 2018-11-30 14:09:58 -0800 | [diff] [blame] | 659 | config PSI_DEFAULT_DISABLED |
| 660 | bool "Require boot parameter to enable pressure stall information tracking" |
| 661 | default n |
| 662 | depends on PSI |
| 663 | help |
| 664 | If set, pressure stall information tracking will be disabled |
Baruch Siach | 428a1cb | 2018-12-14 14:17:03 -0800 | [diff] [blame] | 665 | per default but can be enabled through passing psi=1 on the |
| 666 | kernel commandline during boot. |
Johannes Weiner | e0c2744 | 2018-11-30 14:09:58 -0800 | [diff] [blame] | 667 | |
Johannes Weiner | 7b2489d | 2019-02-01 14:21:15 -0800 | [diff] [blame] | 668 | This feature adds some code to the task wakeup and sleep |
| 669 | paths of the scheduler. The overhead is too low to affect |
| 670 | common scheduling-intense workloads in practice (such as |
| 671 | webservers, memcache), but it does show up in artificial |
| 672 | scheduler stress tests, such as hackbench. |
| 673 | |
| 674 | If you are paranoid and not sure what the kernel will be |
| 675 | used for, say Y. |
| 676 | |
| 677 | Say N if unsure. |
| 678 | |
Frederic Weisbecker | 391dc69 | 2012-09-09 14:22:07 +0200 | [diff] [blame] | 679 | endmenu # "CPU/Task time and stats accounting" |
| 680 | |
Frederic Weisbecker | 5c4991e | 2017-10-27 04:42:34 +0200 | [diff] [blame] | 681 | config CPU_ISOLATION |
| 682 | bool "CPU isolation" |
Geert Uytterhoeven | 414a2dc | 2018-01-02 12:13:10 +0100 | [diff] [blame] | 683 | depends on SMP || COMPILE_TEST |
Frederic Weisbecker | 2c43838 | 2017-12-14 19:18:26 +0100 | [diff] [blame] | 684 | default y |
Frederic Weisbecker | 5c4991e | 2017-10-27 04:42:34 +0200 | [diff] [blame] | 685 | help |
| 686 | Make sure that CPUs running critical tasks are not disturbed by |
| 687 | any source of "noise" such as unbound workqueues, timers, kthreads... |
Frederic Weisbecker | 2c43838 | 2017-12-14 19:18:26 +0100 | [diff] [blame] | 688 | Unbound jobs get offloaded to housekeeping CPUs. This is driven by |
| 689 | the "isolcpus=" boot parameter. |
| 690 | |
| 691 | Say Y if unsure. |
Frederic Weisbecker | 5c4991e | 2017-10-27 04:42:34 +0200 | [diff] [blame] | 692 | |
Paul E. McKenney | 0af92d4 | 2017-05-17 08:43:40 -0700 | [diff] [blame] | 693 | source "kernel/rcu/Kconfig" |
Mike Travis | c903ff8 | 2009-01-15 12:28:29 -0800 | [diff] [blame] | 694 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 695 | config IKCONFIG |
Ross Biro | f2443ab | 2006-09-30 23:27:25 -0700 | [diff] [blame] | 696 | tristate "Kernel .config support" |
Masahiro Yamada | a7f7f62 | 2020-06-14 01:50:22 +0900 | [diff] [blame] | 697 | help |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 698 | This option enables the complete Linux kernel ".config" file |
| 699 | contents to be saved in the kernel. It provides documentation |
| 700 | of which kernel options are used in a running kernel or in an |
| 701 | on-disk kernel. This information can be extracted from the kernel |
| 702 | image file with the script scripts/extract-ikconfig and used as |
| 703 | input to rebuild the current kernel or to build another kernel. |
| 704 | It can also be extracted from a running kernel by reading |
| 705 | /proc/config.gz if enabled (below). |
| 706 | |
| 707 | config IKCONFIG_PROC |
| 708 | bool "Enable access to .config through /proc/config.gz" |
| 709 | depends on IKCONFIG && PROC_FS |
Masahiro Yamada | a7f7f62 | 2020-06-14 01:50:22 +0900 | [diff] [blame] | 710 | help |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 711 | This option enables access to the kernel configuration file |
| 712 | through /proc/config.gz. |
| 713 | |
Joel Fernandes (Google) | f7b101d | 2019-05-15 17:35:51 -0400 | [diff] [blame] | 714 | config IKHEADERS |
| 715 | tristate "Enable kernel headers through /sys/kernel/kheaders.tar.xz" |
| 716 | depends on SYSFS |
Joel Fernandes (Google) | 43d8ce9 | 2019-04-26 15:04:29 -0400 | [diff] [blame] | 717 | help |
Joel Fernandes (Google) | f7b101d | 2019-05-15 17:35:51 -0400 | [diff] [blame] | 718 | This option enables access to the in-kernel headers that are generated during |
| 719 | the build process. These can be used to build eBPF tracing programs, |
| 720 | or similar programs. If you build the headers as a module, a module called |
| 721 | kheaders.ko is built which can be loaded on-demand to get access to headers. |
Joel Fernandes (Google) | 43d8ce9 | 2019-04-26 15:04:29 -0400 | [diff] [blame] | 722 | |
Alistair John Strachan | 794543a | 2007-05-08 00:31:15 -0700 | [diff] [blame] | 723 | config LOG_BUF_SHIFT |
| 724 | int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" |
Christoph Hellwig | 1c4b5ec | 2022-02-23 08:47:20 +0100 | [diff] [blame] | 725 | range 12 25 |
Adrian Bunk | f17a32e | 2008-04-29 00:58:58 -0700 | [diff] [blame] | 726 | default 17 |
Josh Triplett | 361e9df | 2014-10-03 16:00:54 -0700 | [diff] [blame] | 727 | depends on PRINTK |
Alistair John Strachan | 794543a | 2007-05-08 00:31:15 -0700 | [diff] [blame] | 728 | help |
Luis R. Rodriguez | 23b2899 | 2014-08-06 16:08:56 -0700 | [diff] [blame] | 729 | Select the minimal kernel log buffer size as a power of 2. |
| 730 | The final size is affected by LOG_CPU_MAX_BUF_SHIFT config |
| 731 | parameter, see below. Any higher size also might be forced |
| 732 | by "log_buf_len" boot parameter. |
| 733 | |
Adrian Bunk | f17a32e | 2008-04-29 00:58:58 -0700 | [diff] [blame] | 734 | Examples: |
Luis R. Rodriguez | 23b2899 | 2014-08-06 16:08:56 -0700 | [diff] [blame] | 735 | 17 => 128 KB |
Adrian Bunk | f17a32e | 2008-04-29 00:58:58 -0700 | [diff] [blame] | 736 | 16 => 64 KB |
Luis R. Rodriguez | 23b2899 | 2014-08-06 16:08:56 -0700 | [diff] [blame] | 737 | 15 => 32 KB |
| 738 | 14 => 16 KB |
Alistair John Strachan | 794543a | 2007-05-08 00:31:15 -0700 | [diff] [blame] | 739 | 13 => 8 KB |
| 740 | 12 => 4 KB |
| 741 | |
Luis R. Rodriguez | 23b2899 | 2014-08-06 16:08:56 -0700 | [diff] [blame] | 742 | config LOG_CPU_MAX_BUF_SHIFT |
| 743 | int "CPU kernel log buffer size contribution (13 => 8 KB, 17 => 128KB)" |
Geert Uytterhoeven | 2240a31 | 2014-10-13 15:51:11 -0700 | [diff] [blame] | 744 | depends on SMP |
Luis R. Rodriguez | 23b2899 | 2014-08-06 16:08:56 -0700 | [diff] [blame] | 745 | range 0 21 |
Luis R. Rodriguez | 23b2899 | 2014-08-06 16:08:56 -0700 | [diff] [blame] | 746 | default 0 if BASE_SMALL |
Yoann Congal | 320bf43 | 2024-05-05 10:03:41 +0200 | [diff] [blame] | 747 | default 12 |
Josh Triplett | 361e9df | 2014-10-03 16:00:54 -0700 | [diff] [blame] | 748 | depends on PRINTK |
Luis R. Rodriguez | 23b2899 | 2014-08-06 16:08:56 -0700 | [diff] [blame] | 749 | help |
| 750 | This option allows to increase the default ring buffer size |
| 751 | according to the number of CPUs. The value defines the contribution |
| 752 | of each CPU as a power of 2. The used space is typically only few |
| 753 | lines however it might be much more when problems are reported, |
| 754 | e.g. backtraces. |
| 755 | |
| 756 | The increased size means that a new buffer has to be allocated and |
| 757 | the original static one is unused. It makes sense only on systems |
| 758 | with more CPUs. Therefore this value is used only when the sum of |
| 759 | contributions is greater than the half of the default kernel ring |
| 760 | buffer as defined by LOG_BUF_SHIFT. The default values are set |
Paul Menzel | 0f7636e1 | 2020-08-11 11:29:23 +0200 | [diff] [blame] | 761 | so that more than 16 CPUs are needed to trigger the allocation. |
Luis R. Rodriguez | 23b2899 | 2014-08-06 16:08:56 -0700 | [diff] [blame] | 762 | |
| 763 | Also this option is ignored when "log_buf_len" kernel parameter is |
| 764 | used as it forces an exact (power of two) size of the ring buffer. |
| 765 | |
| 766 | The number of possible CPUs is used for this computation ignoring |
Geert Uytterhoeven | 5e0d8d5 | 2016-06-05 10:47:02 +0200 | [diff] [blame] | 767 | hotplugging making the computation optimal for the worst case |
| 768 | scenario while allowing a simple algorithm to be used from bootup. |
Luis R. Rodriguez | 23b2899 | 2014-08-06 16:08:56 -0700 | [diff] [blame] | 769 | |
| 770 | Examples shift values and their meaning: |
| 771 | 17 => 128 KB for each CPU |
| 772 | 16 => 64 KB for each CPU |
| 773 | 15 => 32 KB for each CPU |
| 774 | 14 => 16 KB for each CPU |
| 775 | 13 => 8 KB for each CPU |
| 776 | 12 => 4 KB for each CPU |
| 777 | |
Chris Down | 3370155 | 2021-06-15 17:52:53 +0100 | [diff] [blame] | 778 | config PRINTK_INDEX |
| 779 | bool "Printk indexing debugfs interface" |
| 780 | depends on PRINTK && DEBUG_FS |
| 781 | help |
| 782 | Add support for indexing of all printk formats known at compile time |
| 783 | at <debugfs>/printk/index/<module>. |
| 784 | |
| 785 | This can be used as part of maintaining daemons which monitor |
| 786 | /dev/kmsg, as it permits auditing the printk formats present in a |
| 787 | kernel, allowing detection of cases where monitored printks are |
| 788 | changed or no longer present. |
| 789 | |
| 790 | There is no additional runtime cost to printk with this enabled. |
| 791 | |
KAMEZAWA Hiroyuki | 5cdc38f | 2009-01-07 18:07:30 -0800 | [diff] [blame] | 792 | # |
| 793 | # Architectures with an unreliable sched_clock() should select this: |
| 794 | # |
| 795 | config HAVE_UNSTABLE_SCHED_CLOCK |
| 796 | bool |
| 797 | |
Stephen Boyd | 38ff87f | 2013-06-01 23:39:40 -0700 | [diff] [blame] | 798 | config GENERIC_SCHED_CLOCK |
| 799 | bool |
| 800 | |
Patrick Bellasi | 69842cb | 2019-06-21 09:42:02 +0100 | [diff] [blame] | 801 | menu "Scheduler features" |
| 802 | |
| 803 | config UCLAMP_TASK |
| 804 | bool "Enable utilization clamping for RT/FAIR tasks" |
| 805 | depends on CPU_FREQ_GOV_SCHEDUTIL |
| 806 | help |
| 807 | This feature enables the scheduler to track the clamped utilization |
| 808 | of each CPU based on RUNNABLE tasks scheduled on that CPU. |
| 809 | |
| 810 | With this option, the user can specify the min and max CPU |
| 811 | utilization allowed for RUNNABLE tasks. The max utilization defines |
| 812 | the maximum frequency a task should use while the min utilization |
| 813 | defines the minimum frequency it should use. |
| 814 | |
| 815 | Both min and max utilization clamp values are hints to the scheduler, |
| 816 | aiming at improving its frequency selection policy, but they do not |
| 817 | enforce or grant any specific bandwidth for tasks. |
| 818 | |
| 819 | If in doubt, say N. |
| 820 | |
| 821 | config UCLAMP_BUCKETS_COUNT |
| 822 | int "Number of supported utilization clamp buckets" |
| 823 | range 5 20 |
| 824 | default 5 |
| 825 | depends on UCLAMP_TASK |
| 826 | help |
| 827 | Defines the number of clamp buckets to use. The range of each bucket |
| 828 | will be SCHED_CAPACITY_SCALE/UCLAMP_BUCKETS_COUNT. The higher the |
| 829 | number of clamp buckets the finer their granularity and the higher |
| 830 | the precision of clamping aggregation and tracking at run-time. |
| 831 | |
| 832 | For example, with the minimum configuration value we will have 5 |
| 833 | clamp buckets tracking 20% utilization each. A 25% boosted tasks will |
| 834 | be refcounted in the [20..39]% bucket and will set the bucket clamp |
| 835 | effective value to 25%. |
| 836 | If a second 30% boosted task should be co-scheduled on the same CPU, |
| 837 | that task will be refcounted in the same bucket of the first task and |
| 838 | it will boost the bucket clamp effective value to 30%. |
| 839 | The clamp effective value of a bucket is reset to its nominal value |
| 840 | (20% in the example above) when there are no more tasks refcounted in |
| 841 | that bucket. |
| 842 | |
| 843 | An additional boost/capping margin can be added to some tasks. In the |
| 844 | example above the 25% task will be boosted to 30% until it exits the |
| 845 | CPU. If that should be considered not acceptable on certain systems, |
| 846 | it's always possible to reduce the margin by increasing the number of |
| 847 | clamp buckets to trade off used memory for run-time tracking |
| 848 | precision. |
| 849 | |
| 850 | If in doubt, use the default value. |
| 851 | |
| 852 | endmenu |
| 853 | |
Andrea Arcangeli | be3a728 | 2012-10-04 01:50:47 +0200 | [diff] [blame] | 854 | # |
| 855 | # For architectures that want to enable the support for NUMA-affine scheduler |
| 856 | # balancing logic: |
| 857 | # |
| 858 | config ARCH_SUPPORTS_NUMA_BALANCING |
| 859 | bool |
| 860 | |
Peter Zijlstra | be5e610 | 2013-11-18 18:27:06 +0100 | [diff] [blame] | 861 | # |
Mel Gorman | 72b252a | 2015-09-04 15:47:32 -0700 | [diff] [blame] | 862 | # For architectures that prefer to flush all TLBs after a number of pages |
| 863 | # are unmapped instead of sending one IPI per page to flush. The architecture |
| 864 | # must provide guarantees on what happens if a clean TLB cache entry is |
| 865 | # written after the unmap. Details are in mm/rmap.c near the check for |
| 866 | # should_defer_flush. The architecture should also consider if the full flush |
| 867 | # and the refill costs are offset by the savings of sending fewer IPIs. |
| 868 | config ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH |
| 869 | bool |
| 870 | |
Ard Biesheuvel | c12d336 | 2019-11-08 13:22:27 +0100 | [diff] [blame] | 871 | config CC_HAS_INT128 |
Masahiro Yamada | 3a7c733 | 2020-03-10 19:12:50 +0900 | [diff] [blame] | 872 | def_bool !$(cc-option,$(m64-flag) -D__SIZEOF_INT128__=0) && 64BIT |
Ard Biesheuvel | c12d336 | 2019-11-08 13:22:27 +0100 | [diff] [blame] | 873 | |
Gustavo A. R. Silva | dee2b702 | 2021-11-13 18:57:25 -0600 | [diff] [blame] | 874 | config CC_IMPLICIT_FALLTHROUGH |
| 875 | string |
Gustavo A. R. Silva | 158ea2d | 2021-11-14 20:48:44 -0600 | [diff] [blame] | 876 | default "-Wimplicit-fallthrough=5" if CC_IS_GCC && $(cc-option,-Wimplicit-fallthrough=5) |
Gustavo A. R. Silva | dee2b702 | 2021-11-13 18:57:25 -0600 | [diff] [blame] | 877 | default "-Wimplicit-fallthrough" if CC_IS_CLANG && $(cc-option,-Wunreachable-code-fallthrough) |
| 878 | |
Kees Cook | 3e00f58 | 2024-02-23 09:08:27 -0800 | [diff] [blame] | 879 | # Currently, disable gcc-10+ array-bounds globally. |
Linus Torvalds | 0da6e5f | 2023-04-23 09:56:20 -0700 | [diff] [blame] | 880 | # It's still broken in gcc-13, so no upper bound yet. |
Kees Cook | 3e00f58 | 2024-02-23 09:08:27 -0800 | [diff] [blame] | 881 | config GCC10_NO_ARRAY_BOUNDS |
Linus Torvalds | 5a41237 | 2023-01-09 17:04:49 -0600 | [diff] [blame] | 882 | def_bool y |
| 883 | |
Linus Torvalds | f0be87c | 2022-06-09 10:11:12 -0700 | [diff] [blame] | 884 | config CC_NO_ARRAY_BOUNDS |
| 885 | bool |
Kees Cook | 3e00f58 | 2024-02-23 09:08:27 -0800 | [diff] [blame] | 886 | default y if CC_IS_GCC && GCC_VERSION >= 100000 && GCC10_NO_ARRAY_BOUNDS |
Linus Torvalds | f0be87c | 2022-06-09 10:11:12 -0700 | [diff] [blame] | 887 | |
Linus Torvalds | 0215331 | 2024-02-01 14:57:17 -0800 | [diff] [blame] | 888 | # Currently, disable -Wstringop-overflow for GCC globally. |
| 889 | config GCC_NO_STRINGOP_OVERFLOW |
Gustavo A. R. Silva | a5e0ace0 | 2023-11-30 14:29:34 -0600 | [diff] [blame] | 890 | def_bool y |
| 891 | |
| 892 | config CC_NO_STRINGOP_OVERFLOW |
| 893 | bool |
Linus Torvalds | 0215331 | 2024-02-01 14:57:17 -0800 | [diff] [blame] | 894 | default y if CC_IS_GCC && GCC_NO_STRINGOP_OVERFLOW |
Gustavo A. R. Silva | a5e0ace0 | 2023-11-30 14:29:34 -0600 | [diff] [blame] | 895 | |
| 896 | config CC_STRINGOP_OVERFLOW |
| 897 | bool |
| 898 | default y if CC_IS_GCC && !CC_NO_STRINGOP_OVERFLOW |
| 899 | |
Mel Gorman | 72b252a | 2015-09-04 15:47:32 -0700 | [diff] [blame] | 900 | # |
Peter Zijlstra | be5e610 | 2013-11-18 18:27:06 +0100 | [diff] [blame] | 901 | # For architectures that know their GCC __int128 support is sound |
| 902 | # |
| 903 | config ARCH_SUPPORTS_INT128 |
| 904 | bool |
| 905 | |
Andrea Arcangeli | be3a728 | 2012-10-04 01:50:47 +0200 | [diff] [blame] | 906 | # For architectures that (ab)use NUMA to represent different memory regions |
| 907 | # all cpu-local but of different latencies, such as SuperH. |
| 908 | # |
| 909 | config ARCH_WANT_NUMA_VARIABLE_LOCALITY |
| 910 | bool |
| 911 | |
Andrea Arcangeli | be3a728 | 2012-10-04 01:50:47 +0200 | [diff] [blame] | 912 | config NUMA_BALANCING |
| 913 | bool "Memory placement aware NUMA scheduler" |
Andrea Arcangeli | be3a728 | 2012-10-04 01:50:47 +0200 | [diff] [blame] | 914 | depends on ARCH_SUPPORTS_NUMA_BALANCING |
| 915 | depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY |
Sebastian Andrzej Siewior | 554b0f3 | 2021-11-05 13:35:27 -0700 | [diff] [blame] | 916 | depends on SMP && NUMA && MIGRATION && !PREEMPT_RT |
Andrea Arcangeli | be3a728 | 2012-10-04 01:50:47 +0200 | [diff] [blame] | 917 | help |
| 918 | This option adds support for automatic NUMA aware memory/task placement. |
| 919 | The mechanism is quite primitive and is based on migrating memory when |
Paul Gortmaker | 6d56a41 | 2013-08-13 11:06:50 -0400 | [diff] [blame] | 920 | it has references to the node the task is running on. |
Andrea Arcangeli | be3a728 | 2012-10-04 01:50:47 +0200 | [diff] [blame] | 921 | |
| 922 | This system will be inactive on UMA systems. |
| 923 | |
Aneesh Kumar K.V | 6f7c97e | 2014-12-10 15:43:37 -0800 | [diff] [blame] | 924 | config NUMA_BALANCING_DEFAULT_ENABLED |
| 925 | bool "Automatically enable NUMA aware memory/task placement" |
| 926 | default y |
| 927 | depends on NUMA_BALANCING |
| 928 | help |
| 929 | If set, automatic NUMA balancing will be enabled if running on a NUMA |
| 930 | machine. |
| 931 | |
Suren Baghdasaryan | 21c690a | 2024-03-21 09:36:28 -0700 | [diff] [blame] | 932 | config SLAB_OBJ_EXT |
| 933 | bool |
| 934 | |
Li Zefan | 23964d2 | 2009-01-15 13:50:58 -0800 | [diff] [blame] | 935 | menuconfig CGROUPS |
Christoph Jaeger | 6341e62 | 2014-12-20 15:41:11 -0500 | [diff] [blame] | 936 | bool "Control Group support" |
Tejun Heo | 2bd59d4 | 2014-02-11 11:52:49 -0500 | [diff] [blame] | 937 | select KERNFS |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 938 | help |
Li Zefan | 23964d2 | 2009-01-15 13:50:58 -0800 | [diff] [blame] | 939 | This option adds support for grouping sets of processes together, for |
KAMEZAWA Hiroyuki | 5cdc38f | 2009-01-07 18:07:30 -0800 | [diff] [blame] | 940 | use with process control subsystems such as Cpusets, CFS, memory |
| 941 | controls or device isolation. |
| 942 | See |
Mauro Carvalho Chehab | d6a3b24 | 2019-06-12 14:53:03 -0300 | [diff] [blame] | 943 | - Documentation/scheduler/sched-design-CFS.rst (CFS) |
Mauro Carvalho Chehab | da82c92 | 2019-06-27 13:08:35 -0300 | [diff] [blame] | 944 | - Documentation/admin-guide/cgroup-v1/ (features for grouping, isolation |
Li Zefan | 45ce80f | 2009-01-15 13:50:59 -0800 | [diff] [blame] | 945 | and resource control) |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 946 | |
| 947 | Say N if unsure. |
| 948 | |
Li Zefan | 23964d2 | 2009-01-15 13:50:58 -0800 | [diff] [blame] | 949 | if CGROUPS |
| 950 | |
Johannes Weiner | 3e32cb2 | 2014-12-10 15:42:31 -0800 | [diff] [blame] | 951 | config PAGE_COUNTER |
Krzysztof Kozlowski | e8cf4e9 | 2019-12-04 16:52:28 -0800 | [diff] [blame] | 952 | bool |
Johannes Weiner | 3e32cb2 | 2014-12-10 15:42:31 -0800 | [diff] [blame] | 953 | |
Tejun Heo | 6a010a4 | 2022-07-23 04:28:28 -1000 | [diff] [blame] | 954 | config CGROUP_FAVOR_DYNMODS |
| 955 | bool "Favor dynamic modification latency reduction by default" |
| 956 | help |
| 957 | This option enables the "favordynmods" mount option by default |
| 958 | which reduces the latencies of dynamic cgroup modifications such |
| 959 | as task migrations and controller on/offs at the cost of making |
| 960 | hot path operations such as forks and exits more expensive. |
| 961 | |
| 962 | Say N if unsure. |
| 963 | |
Andrew Morton | c255a45 | 2012-07-31 16:43:02 -0700 | [diff] [blame] | 964 | config MEMCG |
Johannes Weiner | a0166ec | 2015-12-17 17:19:56 -0500 | [diff] [blame] | 965 | bool "Memory controller" |
Johannes Weiner | 3e32cb2 | 2014-12-10 15:42:31 -0800 | [diff] [blame] | 966 | select PAGE_COUNTER |
Tejun Heo | 79bd981 | 2013-11-22 18:20:42 -0500 | [diff] [blame] | 967 | select EVENTFD |
Suren Baghdasaryan | 21c690a | 2024-03-21 09:36:28 -0700 | [diff] [blame] | 968 | select SLAB_OBJ_EXT |
Balbir Singh | 00f0b82 | 2008-03-04 14:28:39 -0800 | [diff] [blame] | 969 | help |
Johannes Weiner | a0166ec | 2015-12-17 17:19:56 -0500 | [diff] [blame] | 970 | Provides control over the memory footprint of tasks in a cgroup. |
Balbir Singh | 00f0b82 | 2008-03-04 14:28:39 -0800 | [diff] [blame] | 971 | |
Kirill Tkhai | 84c07d1 | 2018-08-17 15:47:25 -0700 | [diff] [blame] | 972 | config MEMCG_KMEM |
| 973 | bool |
Vlastimil Babka | c9929f0 | 2023-02-27 17:46:13 +0100 | [diff] [blame] | 974 | depends on MEMCG |
Kirill Tkhai | 84c07d1 | 2018-08-17 15:47:25 -0700 | [diff] [blame] | 975 | default y |
| 976 | |
Johannes Weiner | 6bf024e | 2015-12-17 17:19:57 -0500 | [diff] [blame] | 977 | config BLK_CGROUP |
| 978 | bool "IO controller" |
| 979 | depends on BLOCK |
Aneesh Kumar K.V | 2bc64a2 | 2012-07-31 16:42:12 -0700 | [diff] [blame] | 980 | default n |
Masahiro Yamada | a7f7f62 | 2020-06-14 01:50:22 +0900 | [diff] [blame] | 981 | help |
Johannes Weiner | 6bf024e | 2015-12-17 17:19:57 -0500 | [diff] [blame] | 982 | Generic block IO controller cgroup interface. This is the common |
| 983 | cgroup interface which should be used by various IO controlling |
| 984 | policies. |
Aneesh Kumar K.V | 2bc64a2 | 2012-07-31 16:42:12 -0700 | [diff] [blame] | 985 | |
Johannes Weiner | 6bf024e | 2015-12-17 17:19:57 -0500 | [diff] [blame] | 986 | Currently, CFQ IO scheduler uses it to recognize task groups and |
| 987 | control disk bandwidth allocation (proportional time slice allocation) |
| 988 | to such task groups. It is also used by bio throttling logic in |
| 989 | block layer to implement upper limit in IO rates on a device. |
Stephane Eranian | e5d1367 | 2011-02-14 11:20:01 +0200 | [diff] [blame] | 990 | |
Johannes Weiner | 6bf024e | 2015-12-17 17:19:57 -0500 | [diff] [blame] | 991 | This option only enables generic Block IO controller infrastructure. |
| 992 | One needs to also enable actual IO controlling logic/policy. For |
| 993 | enabling proportional weight division of disk bandwidth in CFQ, set |
Krzysztof Kozlowski | 7baf219 | 2020-04-06 20:12:02 -0700 | [diff] [blame] | 994 | CONFIG_BFQ_GROUP_IOSCHED=y; for enabling throttling policy, set |
Johannes Weiner | 6bf024e | 2015-12-17 17:19:57 -0500 | [diff] [blame] | 995 | CONFIG_BLK_DEV_THROTTLING=y. |
| 996 | |
Mauro Carvalho Chehab | da82c92 | 2019-06-27 13:08:35 -0300 | [diff] [blame] | 997 | See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information. |
Johannes Weiner | 6bf024e | 2015-12-17 17:19:57 -0500 | [diff] [blame] | 998 | |
Johannes Weiner | 6bf024e | 2015-12-17 17:19:57 -0500 | [diff] [blame] | 999 | config CGROUP_WRITEBACK |
| 1000 | bool |
| 1001 | depends on MEMCG && BLK_CGROUP |
| 1002 | default y |
Stephane Eranian | e5d1367 | 2011-02-14 11:20:01 +0200 | [diff] [blame] | 1003 | |
Dhaval Giani | 7c94143 | 2010-01-20 13:26:18 +0100 | [diff] [blame] | 1004 | menuconfig CGROUP_SCHED |
Johannes Weiner | a0166ec | 2015-12-17 17:19:56 -0500 | [diff] [blame] | 1005 | bool "CPU controller" |
Dhaval Giani | 7c94143 | 2010-01-20 13:26:18 +0100 | [diff] [blame] | 1006 | default n |
| 1007 | help |
| 1008 | This feature lets CPU scheduler recognize task groups and control CPU |
| 1009 | bandwidth allocation to such task groups. It uses cgroups to group |
| 1010 | tasks. |
| 1011 | |
| 1012 | if CGROUP_SCHED |
| 1013 | config FAIR_GROUP_SCHED |
| 1014 | bool "Group scheduling for SCHED_OTHER" |
| 1015 | depends on CGROUP_SCHED |
| 1016 | default CGROUP_SCHED |
| 1017 | |
Paul Turner | ab84d31 | 2011-07-21 09:43:28 -0700 | [diff] [blame] | 1018 | config CFS_BANDWIDTH |
| 1019 | bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED" |
Paul Turner | ab84d31 | 2011-07-21 09:43:28 -0700 | [diff] [blame] | 1020 | depends on FAIR_GROUP_SCHED |
| 1021 | default n |
| 1022 | help |
| 1023 | This option allows users to define CPU bandwidth rates (limits) for |
| 1024 | tasks running within the fair group scheduler. Groups with no limit |
| 1025 | set are considered to be unconstrained and will run with no |
| 1026 | restriction. |
Mauro Carvalho Chehab | d6a3b24 | 2019-06-12 14:53:03 -0300 | [diff] [blame] | 1027 | See Documentation/scheduler/sched-bwc.rst for more information. |
Paul Turner | ab84d31 | 2011-07-21 09:43:28 -0700 | [diff] [blame] | 1028 | |
Dhaval Giani | 7c94143 | 2010-01-20 13:26:18 +0100 | [diff] [blame] | 1029 | config RT_GROUP_SCHED |
| 1030 | bool "Group scheduling for SCHED_RR/FIFO" |
Dhaval Giani | 7c94143 | 2010-01-20 13:26:18 +0100 | [diff] [blame] | 1031 | depends on CGROUP_SCHED |
| 1032 | default n |
| 1033 | help |
| 1034 | This feature lets you explicitly allocate real CPU bandwidth |
Li Zefan | 32bd7eb | 2010-03-24 13:17:19 +0800 | [diff] [blame] | 1035 | to task groups. If enabled, it will also make it impossible to |
Dhaval Giani | 7c94143 | 2010-01-20 13:26:18 +0100 | [diff] [blame] | 1036 | schedule realtime tasks for non-root users until you allocate |
| 1037 | realtime bandwidth for them. |
Mauro Carvalho Chehab | d6a3b24 | 2019-06-12 14:53:03 -0300 | [diff] [blame] | 1038 | See Documentation/scheduler/sched-rt-group.rst for more information. |
Dhaval Giani | 7c94143 | 2010-01-20 13:26:18 +0100 | [diff] [blame] | 1039 | |
| 1040 | endif #CGROUP_SCHED |
| 1041 | |
Mathieu Desnoyers | af7f588 | 2022-11-22 15:39:09 -0500 | [diff] [blame] | 1042 | config SCHED_MM_CID |
| 1043 | def_bool y |
| 1044 | depends on SMP && RSEQ |
| 1045 | |
Patrick Bellasi | 2480c09 | 2019-08-22 14:28:06 +0100 | [diff] [blame] | 1046 | config UCLAMP_TASK_GROUP |
| 1047 | bool "Utilization clamping per group of tasks" |
| 1048 | depends on CGROUP_SCHED |
| 1049 | depends on UCLAMP_TASK |
| 1050 | default n |
| 1051 | help |
| 1052 | This feature enables the scheduler to track the clamped utilization |
| 1053 | of each CPU based on RUNNABLE tasks currently scheduled on that CPU. |
| 1054 | |
| 1055 | When this option is enabled, the user can specify a min and max |
| 1056 | CPU bandwidth which is allowed for each single task in a group. |
| 1057 | The max bandwidth allows to clamp the maximum frequency a task |
| 1058 | can use, while the min bandwidth allows to define a minimum |
| 1059 | frequency a task will always use. |
| 1060 | |
| 1061 | When task group based utilization clamping is enabled, an eventually |
| 1062 | specified task-specific clamp value is constrained by the cgroup |
| 1063 | specified clamp value. Both minimum and maximum task clamping cannot |
| 1064 | be bigger than the corresponding clamping defined at task group level. |
| 1065 | |
| 1066 | If in doubt, say N. |
| 1067 | |
Johannes Weiner | 6bf024e | 2015-12-17 17:19:57 -0500 | [diff] [blame] | 1068 | config CGROUP_PIDS |
| 1069 | bool "PIDs controller" |
| 1070 | help |
| 1071 | Provides enforcement of process number limits in the scope of a |
| 1072 | cgroup. Any attempt to fork more processes than is allowed in the |
| 1073 | cgroup will fail. PIDs are fundamentally a global resource because it |
| 1074 | is fairly trivial to reach PID exhaustion before you reach even a |
| 1075 | conservative kmemcg limit. As a result, it is possible to grind a |
| 1076 | system to halt without being limited by other cgroup policies. The |
Parav Pandit | 6cc578d | 2016-03-05 11:30:56 +0530 | [diff] [blame] | 1077 | PIDs controller is designed to stop this from happening. |
Johannes Weiner | 6bf024e | 2015-12-17 17:19:57 -0500 | [diff] [blame] | 1078 | |
| 1079 | It should be noted that organisational operations (such as attaching |
Jonathan Neuschäfer | 9807683 | 2019-02-01 14:21:01 -0800 | [diff] [blame] | 1080 | to a cgroup hierarchy) will *not* be blocked by the PIDs controller, |
Johannes Weiner | 6bf024e | 2015-12-17 17:19:57 -0500 | [diff] [blame] | 1081 | since the PIDs limit only affects a process's ability to fork, not to |
| 1082 | attach to a cgroup. |
| 1083 | |
Parav Pandit | 39d3e75 | 2017-01-10 00:02:13 +0000 | [diff] [blame] | 1084 | config CGROUP_RDMA |
| 1085 | bool "RDMA controller" |
| 1086 | help |
| 1087 | Provides enforcement of RDMA resources defined by IB stack. |
| 1088 | It is fairly easy for consumers to exhaust RDMA resources, which |
| 1089 | can result into resource unavailability to other consumers. |
| 1090 | RDMA controller is designed to stop this from happening. |
| 1091 | Attaching processes with active RDMA resources to the cgroup |
| 1092 | hierarchy is allowed even if can cross the hierarchy's limit. |
| 1093 | |
Johannes Weiner | 6bf024e | 2015-12-17 17:19:57 -0500 | [diff] [blame] | 1094 | config CGROUP_FREEZER |
| 1095 | bool "Freezer controller" |
| 1096 | help |
| 1097 | Provides a way to freeze and unfreeze all tasks in a |
| 1098 | cgroup. |
| 1099 | |
Johannes Weiner | 489c2a2 | 2016-01-20 15:02:41 -0800 | [diff] [blame] | 1100 | This option affects the ORIGINAL cgroup interface. The cgroup2 memory |
| 1101 | controller includes important in-kernel memory consumers per default. |
| 1102 | |
| 1103 | If you're using cgroup2, say N. |
| 1104 | |
Johannes Weiner | 6bf024e | 2015-12-17 17:19:57 -0500 | [diff] [blame] | 1105 | config CGROUP_HUGETLB |
| 1106 | bool "HugeTLB controller" |
| 1107 | depends on HUGETLB_PAGE |
| 1108 | select PAGE_COUNTER |
Vivek Goyal | afc24d4 | 2010-04-26 19:27:56 +0200 | [diff] [blame] | 1109 | default n |
Johannes Weiner | 6bf024e | 2015-12-17 17:19:57 -0500 | [diff] [blame] | 1110 | help |
| 1111 | Provides a cgroup controller for HugeTLB pages. |
| 1112 | When you enable this, you can put a per cgroup limit on HugeTLB usage. |
| 1113 | The limit is enforced during page fault. Since HugeTLB doesn't |
| 1114 | support page reclaim, enforcing the limit at page fault time implies |
| 1115 | that, the application will get SIGBUS signal if it tries to access |
| 1116 | HugeTLB pages beyond its limit. This requires the application to know |
| 1117 | beforehand how much HugeTLB pages it would require for its use. The |
| 1118 | control group is tracked in the third page lru pointer. This means |
| 1119 | that we cannot use the controller with huge page less than 3 pages. |
Vivek Goyal | afc24d4 | 2010-04-26 19:27:56 +0200 | [diff] [blame] | 1120 | |
Johannes Weiner | 6bf024e | 2015-12-17 17:19:57 -0500 | [diff] [blame] | 1121 | config CPUSETS |
| 1122 | bool "Cpuset controller" |
Nicolas Pitre | e1d4eee | 2017-06-14 13:19:23 -0400 | [diff] [blame] | 1123 | depends on SMP |
Johannes Weiner | 6bf024e | 2015-12-17 17:19:57 -0500 | [diff] [blame] | 1124 | help |
| 1125 | This option will let you create and manage CPUSETs which |
| 1126 | allow dynamically partitioning a system into sets of CPUs and |
| 1127 | Memory Nodes and assigning tasks to run only within those sets. |
| 1128 | This is primarily useful on large SMP or NUMA systems. |
Vivek Goyal | afc24d4 | 2010-04-26 19:27:56 +0200 | [diff] [blame] | 1129 | |
Johannes Weiner | 6bf024e | 2015-12-17 17:19:57 -0500 | [diff] [blame] | 1130 | Say N if unsure. |
Vivek Goyal | afc24d4 | 2010-04-26 19:27:56 +0200 | [diff] [blame] | 1131 | |
Johannes Weiner | 6bf024e | 2015-12-17 17:19:57 -0500 | [diff] [blame] | 1132 | config PROC_PID_CPUSET |
| 1133 | bool "Include legacy /proc/<pid>/cpuset file" |
| 1134 | depends on CPUSETS |
Tejun Heo | 89e9b9e | 2015-05-22 17:13:36 -0400 | [diff] [blame] | 1135 | default y |
| 1136 | |
Johannes Weiner | 6bf024e | 2015-12-17 17:19:57 -0500 | [diff] [blame] | 1137 | config CGROUP_DEVICE |
| 1138 | bool "Device controller" |
| 1139 | help |
| 1140 | Provides a cgroup controller implementing whitelists for |
| 1141 | devices which a process in the cgroup can mknod or open. |
| 1142 | |
| 1143 | config CGROUP_CPUACCT |
| 1144 | bool "Simple CPU accounting controller" |
| 1145 | help |
| 1146 | Provides a simple controller for monitoring the |
| 1147 | total CPU consumed by the tasks in a cgroup. |
| 1148 | |
| 1149 | config CGROUP_PERF |
| 1150 | bool "Perf controller" |
| 1151 | depends on PERF_EVENTS |
| 1152 | help |
| 1153 | This option extends the perf per-cpu mode to restrict monitoring |
| 1154 | to threads which belong to the cgroup specified and run on the |
Namhyung Kim | 6546b19 | 2020-03-25 21:45:29 +0900 | [diff] [blame] | 1155 | designated cpu. Or this can be used to have cgroup ID in samples |
| 1156 | so that it can monitor performance events among cgroups. |
Johannes Weiner | 6bf024e | 2015-12-17 17:19:57 -0500 | [diff] [blame] | 1157 | |
| 1158 | Say N if unsure. |
| 1159 | |
Daniel Mack | 3007098 | 2016-11-23 16:52:26 +0100 | [diff] [blame] | 1160 | config CGROUP_BPF |
| 1161 | bool "Support for eBPF programs attached to cgroups" |
Andy Lutomirski | 483c493 | 2016-12-16 08:33:45 -0800 | [diff] [blame] | 1162 | depends on BPF_SYSCALL |
| 1163 | select SOCK_CGROUP_DATA |
Daniel Mack | 3007098 | 2016-11-23 16:52:26 +0100 | [diff] [blame] | 1164 | help |
| 1165 | Allow attaching eBPF programs to a cgroup using the bpf(2) |
| 1166 | syscall command BPF_PROG_ATTACH. |
| 1167 | |
| 1168 | In which context these programs are accessed depends on the type |
| 1169 | of attachment. For instance, programs that are attached using |
| 1170 | BPF_CGROUP_INET_INGRESS will be executed on the ingress path of |
| 1171 | inet sockets. |
| 1172 | |
Vipin Sharma | a72232e | 2021-03-29 21:42:04 -0700 | [diff] [blame] | 1173 | config CGROUP_MISC |
| 1174 | bool "Misc resource controller" |
| 1175 | default n |
| 1176 | help |
| 1177 | Provides a controller for miscellaneous resources on a host. |
| 1178 | |
| 1179 | Miscellaneous scalar resources are the resources on the host system |
| 1180 | which cannot be abstracted like the other cgroups. This controller |
| 1181 | tracks and limits the miscellaneous resources used by a process |
| 1182 | attached to a cgroup hierarchy. |
| 1183 | |
| 1184 | For more information, please check misc cgroup section in |
| 1185 | /Documentation/admin-guide/cgroup-v2.rst. |
| 1186 | |
Johannes Weiner | 6bf024e | 2015-12-17 17:19:57 -0500 | [diff] [blame] | 1187 | config CGROUP_DEBUG |
Waiman Long | 23b0be4 | 2017-06-13 17:18:03 -0400 | [diff] [blame] | 1188 | bool "Debug controller" |
Johannes Weiner | 6bf024e | 2015-12-17 17:19:57 -0500 | [diff] [blame] | 1189 | default n |
Waiman Long | 23b0be4 | 2017-06-13 17:18:03 -0400 | [diff] [blame] | 1190 | depends on DEBUG_KERNEL |
Johannes Weiner | 6bf024e | 2015-12-17 17:19:57 -0500 | [diff] [blame] | 1191 | help |
| 1192 | This option enables a simple controller that exports |
Waiman Long | 23b0be4 | 2017-06-13 17:18:03 -0400 | [diff] [blame] | 1193 | debugging information about the cgroups framework. This |
| 1194 | controller is for control cgroup debugging only. Its |
| 1195 | interfaces are not stable. |
Johannes Weiner | 6bf024e | 2015-12-17 17:19:57 -0500 | [diff] [blame] | 1196 | |
| 1197 | Say N. |
| 1198 | |
Arnd Bergmann | 73b3514 | 2017-01-10 13:08:06 +0100 | [diff] [blame] | 1199 | config SOCK_CGROUP_DATA |
| 1200 | bool |
| 1201 | default n |
| 1202 | |
Li Zefan | 23964d2 | 2009-01-15 13:50:58 -0800 | [diff] [blame] | 1203 | endif # CGROUPS |
KAMEZAWA Hiroyuki | c077719 | 2009-01-07 18:07:57 -0800 | [diff] [blame] | 1204 | |
Daniel Lezcano | 8dd2a82 | 2010-10-27 15:34:38 -0700 | [diff] [blame] | 1205 | menuconfig NAMESPACES |
David Rientjes | 6a108a1 | 2011-01-20 14:44:16 -0800 | [diff] [blame] | 1206 | bool "Namespaces support" if EXPERT |
Iulia Manda | 2813893 | 2015-04-15 16:16:41 -0700 | [diff] [blame] | 1207 | depends on MULTIUSER |
David Rientjes | 6a108a1 | 2011-01-20 14:44:16 -0800 | [diff] [blame] | 1208 | default !EXPERT |
Pavel Emelyanov | c5289a6 | 2008-02-08 04:18:19 -0800 | [diff] [blame] | 1209 | help |
| 1210 | Provides the way to make tasks work with different objects using |
| 1211 | the same id. For example same IPC id may refer to different objects |
| 1212 | or same user id or pid may refer to different tasks when used in |
| 1213 | different namespaces. |
| 1214 | |
Daniel Lezcano | 8dd2a82 | 2010-10-27 15:34:38 -0700 | [diff] [blame] | 1215 | if NAMESPACES |
| 1216 | |
Pavel Emelyanov | 58bfdd6d | 2008-02-08 04:18:21 -0800 | [diff] [blame] | 1217 | config UTS_NS |
| 1218 | bool "UTS namespace" |
Daniel Lezcano | 17a6d44 | 2010-10-27 15:34:37 -0700 | [diff] [blame] | 1219 | default y |
Pavel Emelyanov | 58bfdd6d | 2008-02-08 04:18:21 -0800 | [diff] [blame] | 1220 | help |
| 1221 | In this namespace tasks see different info provided with the |
| 1222 | uname() system call |
| 1223 | |
Andrei Vagin | 769071a | 2019-11-12 01:26:52 +0000 | [diff] [blame] | 1224 | config TIME_NS |
| 1225 | bool "TIME namespace" |
Thomas Gleixner | 660fd04 | 2019-11-12 01:27:09 +0000 | [diff] [blame] | 1226 | depends on GENERIC_VDSO_TIME_NS |
Andrei Vagin | 769071a | 2019-11-12 01:26:52 +0000 | [diff] [blame] | 1227 | default y |
| 1228 | help |
| 1229 | In this namespace boottime and monotonic clocks can be set. |
| 1230 | The time will keep going with the same pace. |
| 1231 | |
Pavel Emelyanov | ae5e1b2 | 2008-02-08 04:18:22 -0800 | [diff] [blame] | 1232 | config IPC_NS |
| 1233 | bool "IPC namespace" |
Daniel Lezcano | 8dd2a82 | 2010-10-27 15:34:38 -0700 | [diff] [blame] | 1234 | depends on (SYSVIPC || POSIX_MQUEUE) |
Daniel Lezcano | 17a6d44 | 2010-10-27 15:34:37 -0700 | [diff] [blame] | 1235 | default y |
Pavel Emelyanov | ae5e1b2 | 2008-02-08 04:18:22 -0800 | [diff] [blame] | 1236 | help |
| 1237 | In this namespace tasks work with IPC ids which correspond to |
Serge E. Hallyn | 614b84c | 2009-04-06 19:01:08 -0700 | [diff] [blame] | 1238 | different IPC objects in different namespaces. |
Pavel Emelyanov | ae5e1b2 | 2008-02-08 04:18:22 -0800 | [diff] [blame] | 1239 | |
Pavel Emelyanov | aee16ce | 2008-02-08 04:18:23 -0800 | [diff] [blame] | 1240 | config USER_NS |
Kees Cook | 19c9239 | 2012-10-02 11:19:29 -0700 | [diff] [blame] | 1241 | bool "User namespace" |
Eric W. Biederman | 5673a94 | 2011-11-17 10:23:55 -0800 | [diff] [blame] | 1242 | default n |
Pavel Emelyanov | aee16ce | 2008-02-08 04:18:23 -0800 | [diff] [blame] | 1243 | help |
| 1244 | This allows containers, i.e. vservers, to use user namespaces |
| 1245 | to provide different user info for different servers. |
Eric W. Biederman | e11f0ae | 2013-01-25 16:48:31 -0800 | [diff] [blame] | 1246 | |
| 1247 | When user namespaces are enabled in the kernel it is |
Johannes Weiner | d886f4e | 2016-01-20 15:02:47 -0800 | [diff] [blame] | 1248 | recommended that the MEMCG option also be enabled and that |
| 1249 | user-space use the memory control groups to limit the amount |
| 1250 | of memory a memory unprivileged users can use. |
Eric W. Biederman | e11f0ae | 2013-01-25 16:48:31 -0800 | [diff] [blame] | 1251 | |
Pavel Emelyanov | aee16ce | 2008-02-08 04:18:23 -0800 | [diff] [blame] | 1252 | If unsure, say N. |
| 1253 | |
Pavel Emelyanov | 74bd59b | 2008-02-08 04:18:24 -0800 | [diff] [blame] | 1254 | config PID_NS |
Daniel Lezcano | 9bd38c2 | 2010-10-27 15:34:37 -0700 | [diff] [blame] | 1255 | bool "PID Namespaces" |
Daniel Lezcano | 17a6d44 | 2010-10-27 15:34:37 -0700 | [diff] [blame] | 1256 | default y |
Pavel Emelyanov | 74bd59b | 2008-02-08 04:18:24 -0800 | [diff] [blame] | 1257 | help |
Heikki Orsila | 12d2b8f | 2008-07-06 15:48:02 +0300 | [diff] [blame] | 1258 | Support process id namespaces. This allows having multiple |
Matt LaPlante | 692105b | 2009-01-26 11:12:25 +0100 | [diff] [blame] | 1259 | processes with the same pid as long as they are in different |
Pavel Emelyanov | 74bd59b | 2008-02-08 04:18:24 -0800 | [diff] [blame] | 1260 | pid namespaces. This is a building block of containers. |
| 1261 | |
Matt Helsley | d6eb633 | 2009-01-26 12:25:55 -0800 | [diff] [blame] | 1262 | config NET_NS |
| 1263 | bool "Network namespace" |
Daniel Lezcano | 8dd2a82 | 2010-10-27 15:34:38 -0700 | [diff] [blame] | 1264 | depends on NET |
Daniel Lezcano | 17a6d44 | 2010-10-27 15:34:37 -0700 | [diff] [blame] | 1265 | default y |
Matt Helsley | d6eb633 | 2009-01-26 12:25:55 -0800 | [diff] [blame] | 1266 | help |
| 1267 | Allow user space to create what appear to be multiple instances |
| 1268 | of the network stack. |
| 1269 | |
Daniel Lezcano | 8dd2a82 | 2010-10-27 15:34:38 -0700 | [diff] [blame] | 1270 | endif # NAMESPACES |
| 1271 | |
Adrian Reber | 5cb366b | 2018-08-21 22:01:17 -0700 | [diff] [blame] | 1272 | config CHECKPOINT_RESTORE |
| 1273 | bool "Checkpoint/restore support" |
Ren Zhijie | 30341ec | 2022-09-29 07:00:57 +0000 | [diff] [blame] | 1274 | depends on PROC_FS |
Adrian Reber | 5cb366b | 2018-08-21 22:01:17 -0700 | [diff] [blame] | 1275 | select PROC_CHILDREN |
Chris Wilson | bfe3911 | 2021-02-05 22:00:12 +0000 | [diff] [blame] | 1276 | select KCMP |
Adrian Reber | 5cb366b | 2018-08-21 22:01:17 -0700 | [diff] [blame] | 1277 | default n |
| 1278 | help |
| 1279 | Enables additional kernel features in a sake of checkpoint/restore. |
| 1280 | In particular it adds auxiliary prctl codes to setup process text, |
| 1281 | data and heap segment sizes, and a few additional /proc filesystem |
| 1282 | entries. |
| 1283 | |
| 1284 | If unsure, say N here. |
| 1285 | |
Mike Galbraith | 5091faa | 2010-11-30 14:18:03 +0100 | [diff] [blame] | 1286 | config SCHED_AUTOGROUP |
| 1287 | bool "Automatic process group scheduling" |
Mike Galbraith | 5091faa | 2010-11-30 14:18:03 +0100 | [diff] [blame] | 1288 | select CGROUPS |
| 1289 | select CGROUP_SCHED |
| 1290 | select FAIR_GROUP_SCHED |
| 1291 | help |
| 1292 | This option optimizes the scheduler for common desktop workloads by |
| 1293 | automatically creating and populating task groups. This separation |
| 1294 | of workloads isolates aggressive CPU burners (like build jobs) from |
| 1295 | desktop applications. Task group autogeneration is currently based |
| 1296 | upon task session. |
| 1297 | |
Daniel Lezcano | 7af37be | 2010-10-27 15:34:41 -0700 | [diff] [blame] | 1298 | config RELAY |
| 1299 | bool "Kernel->user space relay support (formerly relayfs)" |
Peter Zijlstra | 26b5679 | 2016-10-11 13:54:33 -0700 | [diff] [blame] | 1300 | select IRQ_WORK |
Daniel Lezcano | 7af37be | 2010-10-27 15:34:41 -0700 | [diff] [blame] | 1301 | help |
| 1302 | This option enables support for relay interface support in |
| 1303 | certain file systems (such as debugfs). |
| 1304 | It is designed to provide an efficient mechanism for tools and |
| 1305 | facilities to relay large amounts of data from kernel space to |
| 1306 | user space. |
| 1307 | |
| 1308 | If unsure, say N. |
| 1309 | |
Dimitri Gorokhovik | f991633 | 2007-03-06 01:42:17 -0800 | [diff] [blame] | 1310 | config BLK_DEV_INITRD |
| 1311 | bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support" |
Dimitri Gorokhovik | f991633 | 2007-03-06 01:42:17 -0800 | [diff] [blame] | 1312 | help |
| 1313 | The initial RAM filesystem is a ramfs which is loaded by the |
| 1314 | boot loader (loadlin or lilo) and that is mounted as root |
| 1315 | before the normal boot procedure. It is typically used to |
| 1316 | load modules needed to mount the "real" root file system, |
Mauro Carvalho Chehab | 8c27ceff3 | 2016-10-18 10:12:27 -0200 | [diff] [blame] | 1317 | etc. See <file:Documentation/admin-guide/initrd.rst> for details. |
Dimitri Gorokhovik | f991633 | 2007-03-06 01:42:17 -0800 | [diff] [blame] | 1318 | |
| 1319 | If RAM disk support (BLK_DEV_RAM) is also included, this |
| 1320 | also enables initial RAM disk (initrd) support and adds |
| 1321 | 15 Kbytes (more on some other architectures) to the kernel size. |
| 1322 | |
| 1323 | If unsure say Y. |
| 1324 | |
Jean-Paul Saman | c33df4e | 2007-02-10 01:44:43 -0800 | [diff] [blame] | 1325 | if BLK_DEV_INITRD |
| 1326 | |
Sam Ravnborg | dbec486 | 2005-08-10 20:44:50 +0200 | [diff] [blame] | 1327 | source "usr/Kconfig" |
| 1328 | |
Jean-Paul Saman | c33df4e | 2007-02-10 01:44:43 -0800 | [diff] [blame] | 1329 | endif |
| 1330 | |
Masami Hiramatsu | 76db5a2 | 2020-01-11 01:03:32 +0900 | [diff] [blame] | 1331 | config BOOT_CONFIG |
| 1332 | bool "Boot config support" |
Masami Hiramatsu | a2a9d67 | 2022-04-06 11:31:19 +0900 | [diff] [blame] | 1333 | select BLK_DEV_INITRD if !BOOT_CONFIG_EMBED |
Masami Hiramatsu | 76db5a2 | 2020-01-11 01:03:32 +0900 | [diff] [blame] | 1334 | help |
| 1335 | Extra boot config allows system admin to pass a config file as |
| 1336 | complemental extension of kernel cmdline when booting. |
Masami Hiramatsu | 0947db0 | 2020-01-20 12:23:00 +0900 | [diff] [blame] | 1337 | The boot config file must be attached at the end of initramfs |
Masami Hiramatsu | 85c46b7 | 2020-02-20 21:18:42 +0900 | [diff] [blame] | 1338 | with checksum, size and magic word. |
Masami Hiramatsu | 0947db0 | 2020-01-20 12:23:00 +0900 | [diff] [blame] | 1339 | See <file:Documentation/admin-guide/bootconfig.rst> for details. |
Masami Hiramatsu | 76db5a2 | 2020-01-11 01:03:32 +0900 | [diff] [blame] | 1340 | |
| 1341 | If unsure, say Y. |
| 1342 | |
Paul E. McKenney | b743852 | 2023-02-22 08:27:48 +0900 | [diff] [blame] | 1343 | config BOOT_CONFIG_FORCE |
| 1344 | bool "Force unconditional bootconfig processing" |
| 1345 | depends on BOOT_CONFIG |
Paul E. McKenney | 6ded8a2 | 2023-02-22 08:27:49 +0900 | [diff] [blame] | 1346 | default y if BOOT_CONFIG_EMBED |
Paul E. McKenney | b743852 | 2023-02-22 08:27:48 +0900 | [diff] [blame] | 1347 | help |
| 1348 | With this Kconfig option set, BOOT_CONFIG processing is carried |
| 1349 | out even when the "bootconfig" kernel-boot parameter is omitted. |
| 1350 | In fact, with this Kconfig option set, there is no way to |
| 1351 | make the kernel ignore the BOOT_CONFIG-supplied kernel-boot |
| 1352 | parameters. |
| 1353 | |
| 1354 | If unsure, say N. |
| 1355 | |
Masami Hiramatsu | a2a9d67 | 2022-04-06 11:31:19 +0900 | [diff] [blame] | 1356 | config BOOT_CONFIG_EMBED |
| 1357 | bool "Embed bootconfig file in the kernel" |
| 1358 | depends on BOOT_CONFIG |
| 1359 | help |
| 1360 | Embed a bootconfig file given by BOOT_CONFIG_EMBED_FILE in the |
| 1361 | kernel. Usually, the bootconfig file is loaded with the initrd |
| 1362 | image. But if the system doesn't support initrd, this option will |
| 1363 | help you by embedding a bootconfig file while building the kernel. |
| 1364 | |
| 1365 | If unsure, say N. |
| 1366 | |
| 1367 | config BOOT_CONFIG_EMBED_FILE |
| 1368 | string "Embedded bootconfig file path" |
| 1369 | depends on BOOT_CONFIG_EMBED |
| 1370 | help |
| 1371 | Specify a bootconfig file which will be embedded to the kernel. |
| 1372 | This bootconfig will be used if there is no initrd or no other |
| 1373 | bootconfig in the initrd. |
| 1374 | |
David Disseldorp | 1274aea1 | 2022-05-09 18:29:19 -0700 | [diff] [blame] | 1375 | config INITRAMFS_PRESERVE_MTIME |
| 1376 | bool "Preserve cpio archive mtimes in initramfs" |
| 1377 | default y |
| 1378 | help |
| 1379 | Each entry in an initramfs cpio archive carries an mtime value. When |
| 1380 | enabled, extracted cpio items take this mtime, with directory mtime |
| 1381 | setting deferred until after creation of any child entries. |
| 1382 | |
| 1383 | If unsure, say Y. |
| 1384 | |
Arnd Bergmann | 877417e | 2016-04-25 17:35:27 +0200 | [diff] [blame] | 1385 | choice |
| 1386 | prompt "Compiler optimization level" |
Ulf Magnusson | 2cc3ce2 | 2017-10-04 01:53:26 +0200 | [diff] [blame] | 1387 | default CC_OPTIMIZE_FOR_PERFORMANCE |
Arnd Bergmann | 877417e | 2016-04-25 17:35:27 +0200 | [diff] [blame] | 1388 | |
| 1389 | config CC_OPTIMIZE_FOR_PERFORMANCE |
Masahiro Yamada | 15f5db6 | 2019-08-21 02:09:40 +0900 | [diff] [blame] | 1390 | bool "Optimize for performance (-O2)" |
Arnd Bergmann | 877417e | 2016-04-25 17:35:27 +0200 | [diff] [blame] | 1391 | help |
| 1392 | This is the default optimization level for the kernel, building |
| 1393 | with the "-O2" compiler flag for best performance and most |
| 1394 | helpful compile-time warnings. |
| 1395 | |
Linus Torvalds | c45b4f1 | 2005-12-14 18:52:21 -0800 | [diff] [blame] | 1396 | config CC_OPTIMIZE_FOR_SIZE |
Masahiro Yamada | 15f5db6 | 2019-08-21 02:09:40 +0900 | [diff] [blame] | 1397 | bool "Optimize for size (-Os)" |
Linus Torvalds | c45b4f1 | 2005-12-14 18:52:21 -0800 | [diff] [blame] | 1398 | help |
Masahiro Yamada | ce3b487 | 2019-08-21 02:09:39 +0900 | [diff] [blame] | 1399 | Choosing this option will pass "-Os" to your compiler resulting |
| 1400 | in a smaller kernel. |
Linus Torvalds | c45b4f1 | 2005-12-14 18:52:21 -0800 | [diff] [blame] | 1401 | |
Arnd Bergmann | 877417e | 2016-04-25 17:35:27 +0200 | [diff] [blame] | 1402 | endchoice |
| 1403 | |
Nicholas Piggin | 5d20ee3 | 2018-05-09 23:00:00 +1000 | [diff] [blame] | 1404 | config HAVE_LD_DEAD_CODE_DATA_ELIMINATION |
| 1405 | bool |
| 1406 | help |
| 1407 | This requires that the arch annotates or otherwise protects |
| 1408 | its external entry points from being discarded. Linker scripts |
| 1409 | must also merge .text.*, .data.*, and .bss.* correctly into |
| 1410 | output sections. Care must be taken not to pull in unrelated |
| 1411 | sections (e.g., '.text.init'). Typically '.' in section names |
| 1412 | is used to distinguish them from label names / C identifiers. |
| 1413 | |
| 1414 | config LD_DEAD_CODE_DATA_ELIMINATION |
| 1415 | bool "Dead code and data elimination (EXPERIMENTAL)" |
| 1416 | depends on HAVE_LD_DEAD_CODE_DATA_ELIMINATION |
| 1417 | depends on EXPERT |
Masahiro Yamada | e85d1d6 | 2018-08-22 22:51:09 +0900 | [diff] [blame] | 1418 | depends on $(cc-option,-ffunction-sections -fdata-sections) |
| 1419 | depends on $(ld-option,--gc-sections) |
Nicholas Piggin | 5d20ee3 | 2018-05-09 23:00:00 +1000 | [diff] [blame] | 1420 | help |
Masahiro Yamada | 8b9d271 | 2018-06-24 01:41:51 +0900 | [diff] [blame] | 1421 | Enable this if you want to do dead code and data elimination with |
| 1422 | the linker by compiling with -ffunction-sections -fdata-sections, |
| 1423 | and linking with --gc-sections. |
Nicholas Piggin | 5d20ee3 | 2018-05-09 23:00:00 +1000 | [diff] [blame] | 1424 | |
| 1425 | This can reduce on disk and in-memory size of the kernel |
| 1426 | code and static data, particularly for small configs and |
| 1427 | on small systems. This has the possibility of introducing |
| 1428 | silently broken kernel if the required annotations are not |
| 1429 | present. This option is not well tested yet, so use at your |
| 1430 | own risk. |
| 1431 | |
Nathan Chancellor | 59612b2 | 2020-11-19 13:46:56 -0700 | [diff] [blame] | 1432 | config LD_ORPHAN_WARN |
| 1433 | def_bool y |
| 1434 | depends on ARCH_WANT_LD_ORPHAN_WARN |
| 1435 | depends on $(ld-option,--orphan-handling=warn) |
Xin Li | e1789d7 | 2022-10-25 00:30:23 -0700 | [diff] [blame] | 1436 | depends on $(ld-option,--orphan-handling=error) |
| 1437 | |
| 1438 | config LD_ORPHAN_WARN_LEVEL |
| 1439 | string |
| 1440 | depends on LD_ORPHAN_WARN |
| 1441 | default "error" if WERROR |
| 1442 | default "warn" |
Nathan Chancellor | 59612b2 | 2020-11-19 13:46:56 -0700 | [diff] [blame] | 1443 | |
Randy Dunlap | 0847062 | 2006-09-30 23:28:13 -0700 | [diff] [blame] | 1444 | config SYSCTL |
| 1445 | bool |
| 1446 | |
Mike Frysinger | 657a520 | 2013-04-30 15:28:45 -0700 | [diff] [blame] | 1447 | config HAVE_UID16 |
| 1448 | bool |
| 1449 | |
| 1450 | config SYSCTL_EXCEPTION_TRACE |
| 1451 | bool |
| 1452 | help |
| 1453 | Enable support for /proc/sys/debug/exception-trace. |
| 1454 | |
| 1455 | config SYSCTL_ARCH_UNALIGN_NO_WARN |
| 1456 | bool |
| 1457 | help |
| 1458 | Enable support for /proc/sys/kernel/ignore-unaligned-usertrap |
| 1459 | Allows arch to define/use @no_unaligned_warning to possibly warn |
| 1460 | about unaligned access emulation going on under the hood. |
| 1461 | |
| 1462 | config SYSCTL_ARCH_UNALIGN_ALLOW |
| 1463 | bool |
| 1464 | help |
| 1465 | Enable support for /proc/sys/kernel/unaligned-trap |
| 1466 | Allows arches to define/use @unaligned_enabled to runtime toggle |
| 1467 | the unaligned access emulation. |
| 1468 | see arch/parisc/kernel/unaligned.c for reference |
| 1469 | |
Mike Frysinger | 657a520 | 2013-04-30 15:28:45 -0700 | [diff] [blame] | 1470 | config HAVE_PCSPKR_PLATFORM |
| 1471 | bool |
| 1472 | |
David Rientjes | 6a108a1 | 2011-01-20 14:44:16 -0800 | [diff] [blame] | 1473 | menuconfig EXPERT |
| 1474 | bool "Configure standard kernel features (expert users)" |
Josh Triplett | f505c55 | 2011-06-05 18:23:58 -0700 | [diff] [blame] | 1475 | # Unhide debug options, to make the on-by-default options visible |
| 1476 | select DEBUG_KERNEL |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1477 | help |
| 1478 | This option allows certain base kernel options and settings |
Krzysztof Kozlowski | e8cf4e9 | 2019-12-04 16:52:28 -0800 | [diff] [blame] | 1479 | to be disabled or tweaked. This is for specialized |
| 1480 | environments which can tolerate a "non-standard" kernel. |
| 1481 | Only use this if you really know what you are doing. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1482 | |
Chuck Ebbert | ae81f9e | 2006-09-16 12:15:53 -0700 | [diff] [blame] | 1483 | config UID16 |
David Rientjes | 6a108a1 | 2011-01-20 14:44:16 -0800 | [diff] [blame] | 1484 | bool "Enable 16-bit UID system calls" if EXPERT |
Iulia Manda | 2813893 | 2015-04-15 16:16:41 -0700 | [diff] [blame] | 1485 | depends on HAVE_UID16 && MULTIUSER |
Chuck Ebbert | ae81f9e | 2006-09-16 12:15:53 -0700 | [diff] [blame] | 1486 | default y |
| 1487 | help |
| 1488 | This enables the legacy 16-bit UID syscall wrappers. |
| 1489 | |
Iulia Manda | 2813893 | 2015-04-15 16:16:41 -0700 | [diff] [blame] | 1490 | config MULTIUSER |
| 1491 | bool "Multiple users, groups and capabilities support" if EXPERT |
| 1492 | default y |
| 1493 | help |
| 1494 | This option enables support for non-root users, groups and |
| 1495 | capabilities. |
| 1496 | |
| 1497 | If you say N here, all processes will run with UID 0, GID 0, and all |
| 1498 | possible capabilities. Saying N here also compiles out support for |
| 1499 | system calls related to UIDs, GIDs, and capabilities, such as setuid, |
| 1500 | setgid, and capset. |
| 1501 | |
| 1502 | If unsure, say Y here. |
| 1503 | |
Fabian Frederick | f618776 | 2014-06-04 16:11:12 -0700 | [diff] [blame] | 1504 | config SGETMASK_SYSCALL |
| 1505 | bool "sgetmask/ssetmask syscalls support" if EXPERT |
Masahiro Yamada | cd14b01 | 2024-02-11 21:48:08 +0900 | [diff] [blame] | 1506 | default PARISC || M68K || PPC || MIPS || X86 || SPARC || MICROBLAZE || SUPERH |
Masahiro Yamada | a7f7f62 | 2020-06-14 01:50:22 +0900 | [diff] [blame] | 1507 | help |
Fabian Frederick | f618776 | 2014-06-04 16:11:12 -0700 | [diff] [blame] | 1508 | sys_sgetmask and sys_ssetmask are obsolete system calls |
| 1509 | no longer supported in libc but still enabled by default in some |
| 1510 | architectures. |
| 1511 | |
| 1512 | If unsure, leave the default option here. |
| 1513 | |
Fabian Frederick | 6af9f7b | 2014-04-03 14:48:25 -0700 | [diff] [blame] | 1514 | config SYSFS_SYSCALL |
| 1515 | bool "Sysfs syscall support" if EXPERT |
| 1516 | default y |
Masahiro Yamada | a7f7f62 | 2020-06-14 01:50:22 +0900 | [diff] [blame] | 1517 | help |
Fabian Frederick | 6af9f7b | 2014-04-03 14:48:25 -0700 | [diff] [blame] | 1518 | sys_sysfs is an obsolete system call no longer supported in libc. |
| 1519 | Note that disabling this option is more secure but might break |
| 1520 | compatibility with some systems. |
| 1521 | |
| 1522 | If unsure say Y here. |
| 1523 | |
Randy Dunlap | d1b069f | 2017-11-17 15:31:47 -0800 | [diff] [blame] | 1524 | config FHANDLE |
| 1525 | bool "open by fhandle syscalls" if EXPERT |
| 1526 | select EXPORTFS |
| 1527 | default y |
| 1528 | help |
| 1529 | If you say Y here, a user level program will be able to map |
| 1530 | file names to handle and then later use the handle for |
| 1531 | different file system operations. This is useful in implementing |
| 1532 | userspace file servers, which now track files using handles instead |
| 1533 | of names. The handle would remain the same even if file names |
| 1534 | get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2) |
| 1535 | syscalls. |
| 1536 | |
Nicolas Pitre | baa73d9 | 2016-11-11 00:10:10 -0500 | [diff] [blame] | 1537 | config POSIX_TIMERS |
| 1538 | bool "Posix Clocks & timers" if EXPERT |
| 1539 | default y |
| 1540 | help |
| 1541 | This includes native support for POSIX timers to the kernel. |
| 1542 | Some embedded systems have no use for them and therefore they |
| 1543 | can be configured out to reduce the size of the kernel image. |
| 1544 | |
| 1545 | When this option is disabled, the following syscalls won't be |
| 1546 | available: timer_create, timer_gettime: timer_getoverrun, |
| 1547 | timer_settime, timer_delete, clock_adjtime, getitimer, |
| 1548 | setitimer, alarm. Furthermore, the clock_settime, clock_gettime, |
| 1549 | clock_getres and clock_nanosleep syscalls will be limited to |
| 1550 | CLOCK_REALTIME, CLOCK_MONOTONIC and CLOCK_BOOTTIME only. |
| 1551 | |
| 1552 | If unsure say y. |
| 1553 | |
Matt Mackall | d59745c | 2005-05-01 08:59:02 -0700 | [diff] [blame] | 1554 | config PRINTK |
| 1555 | default y |
David Rientjes | 6a108a1 | 2011-01-20 14:44:16 -0800 | [diff] [blame] | 1556 | bool "Enable support for printk" if EXPERT |
Frederic Weisbecker | 74876a9 | 2012-10-12 18:00:23 +0200 | [diff] [blame] | 1557 | select IRQ_WORK |
Matt Mackall | d59745c | 2005-05-01 08:59:02 -0700 | [diff] [blame] | 1558 | help |
| 1559 | This option enables normal printk support. Removing it |
| 1560 | eliminates most of the message strings from the kernel image |
| 1561 | and makes the kernel more or less silent. As this makes it |
| 1562 | very difficult to diagnose system problems, saying N here is |
| 1563 | strongly discouraged. |
| 1564 | |
Matt Mackall | c8538a7 | 2005-05-01 08:59:01 -0700 | [diff] [blame] | 1565 | config BUG |
David Rientjes | 6a108a1 | 2011-01-20 14:44:16 -0800 | [diff] [blame] | 1566 | bool "BUG() support" if EXPERT |
Matt Mackall | c8538a7 | 2005-05-01 08:59:01 -0700 | [diff] [blame] | 1567 | default y |
| 1568 | help |
Krzysztof Kozlowski | e8cf4e9 | 2019-12-04 16:52:28 -0800 | [diff] [blame] | 1569 | Disabling this option eliminates support for BUG and WARN, reducing |
| 1570 | the size of your kernel image and potentially quietly ignoring |
| 1571 | numerous fatal conditions. You should only consider disabling this |
| 1572 | option for embedded systems with no facilities for reporting errors. |
| 1573 | Just say Y. |
Matt Mackall | c8538a7 | 2005-05-01 08:59:01 -0700 | [diff] [blame] | 1574 | |
Matt Mackall | 708e9a7 | 2006-01-08 01:05:25 -0800 | [diff] [blame] | 1575 | config ELF_CORE |
Alex Kelly | 046d662 | 2012-10-04 17:15:23 -0700 | [diff] [blame] | 1576 | depends on COREDUMP |
Matt Mackall | 708e9a7 | 2006-01-08 01:05:25 -0800 | [diff] [blame] | 1577 | default y |
David Rientjes | 6a108a1 | 2011-01-20 14:44:16 -0800 | [diff] [blame] | 1578 | bool "Enable ELF core dumps" if EXPERT |
Matt Mackall | 708e9a7 | 2006-01-08 01:05:25 -0800 | [diff] [blame] | 1579 | help |
| 1580 | Enable support for generating core dumps. Disabling saves about 4k. |
| 1581 | |
Ralf Baechle | 8761f1a | 2011-06-01 19:05:09 +0100 | [diff] [blame] | 1582 | |
Stas Sergeev | e5e1d3c | 2008-05-07 12:39:56 +0200 | [diff] [blame] | 1583 | config PCSPKR_PLATFORM |
David Rientjes | 6a108a1 | 2011-01-20 14:44:16 -0800 | [diff] [blame] | 1584 | bool "Enable PC-Speaker support" if EXPERT |
Ralf Baechle | 8761f1a | 2011-06-01 19:05:09 +0100 | [diff] [blame] | 1585 | depends on HAVE_PCSPKR_PLATFORM |
Ralf Baechle | 15f304b | 2011-06-01 19:04:59 +0100 | [diff] [blame] | 1586 | select I8253_LOCK |
Stas Sergeev | e5e1d3c | 2008-05-07 12:39:56 +0200 | [diff] [blame] | 1587 | default y |
| 1588 | help |
Krzysztof Kozlowski | e8cf4e9 | 2019-12-04 16:52:28 -0800 | [diff] [blame] | 1589 | This option allows to disable the internal PC-Speaker |
| 1590 | support, saving some memory. |
Stas Sergeev | e5e1d3c | 2008-05-07 12:39:56 +0200 | [diff] [blame] | 1591 | |
Yoann Congal | 2702164 | 2024-05-05 10:03:43 +0200 | [diff] [blame] | 1592 | config BASE_SMALL |
| 1593 | bool "Enable smaller-sized data structures for core" if EXPERT |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1594 | help |
Yoann Congal | 2702164 | 2024-05-05 10:03:43 +0200 | [diff] [blame] | 1595 | Enabling this option reduces the size of miscellaneous core |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1596 | kernel data structures. This saves memory on small machines, |
| 1597 | but may reduce performance. |
| 1598 | |
| 1599 | config FUTEX |
David Rientjes | 6a108a1 | 2011-01-20 14:44:16 -0800 | [diff] [blame] | 1600 | bool "Enable futex support" if EXPERT |
Arnd Bergmann | 3f2beda | 2021-10-26 12:03:47 +0200 | [diff] [blame] | 1601 | depends on !(SPARC32 && SMP) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1602 | default y |
Nicolas Pitre | bc2eecd | 2017-08-01 00:31:32 -0400 | [diff] [blame] | 1603 | imply RT_MUTEXES |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1604 | help |
| 1605 | Disabling this option will cause the kernel to be built without |
| 1606 | support for "fast userspace mutexes". The resulting kernel may not |
| 1607 | run glibc-based applications correctly. |
| 1608 | |
Nicolas Pitre | bc2eecd | 2017-08-01 00:31:32 -0400 | [diff] [blame] | 1609 | config FUTEX_PI |
| 1610 | bool |
| 1611 | depends on FUTEX && RT_MUTEXES |
| 1612 | default y |
| 1613 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1614 | config EPOLL |
David Rientjes | 6a108a1 | 2011-01-20 14:44:16 -0800 | [diff] [blame] | 1615 | bool "Enable eventpoll support" if EXPERT |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1616 | default y |
| 1617 | help |
| 1618 | Disabling this option will cause the kernel to be built without |
| 1619 | support for epoll family of system calls. |
| 1620 | |
Davide Libenzi | fba2afa | 2007-05-10 22:23:13 -0700 | [diff] [blame] | 1621 | config SIGNALFD |
David Rientjes | 6a108a1 | 2011-01-20 14:44:16 -0800 | [diff] [blame] | 1622 | bool "Enable signalfd() system call" if EXPERT |
Davide Libenzi | fba2afa | 2007-05-10 22:23:13 -0700 | [diff] [blame] | 1623 | default y |
| 1624 | help |
| 1625 | Enable the signalfd() system call that allows to receive signals |
| 1626 | on a file descriptor. |
| 1627 | |
| 1628 | If unsure, say Y. |
| 1629 | |
Davide Libenzi | b215e28 | 2007-05-10 22:23:16 -0700 | [diff] [blame] | 1630 | config TIMERFD |
David Rientjes | 6a108a1 | 2011-01-20 14:44:16 -0800 | [diff] [blame] | 1631 | bool "Enable timerfd() system call" if EXPERT |
Davide Libenzi | b215e28 | 2007-05-10 22:23:16 -0700 | [diff] [blame] | 1632 | default y |
| 1633 | help |
| 1634 | Enable the timerfd() system call that allows to receive timer |
| 1635 | events on a file descriptor. |
| 1636 | |
| 1637 | If unsure, say Y. |
| 1638 | |
Davide Libenzi | e1ad746 | 2007-05-10 22:23:19 -0700 | [diff] [blame] | 1639 | config EVENTFD |
David Rientjes | 6a108a1 | 2011-01-20 14:44:16 -0800 | [diff] [blame] | 1640 | bool "Enable eventfd() system call" if EXPERT |
Davide Libenzi | e1ad746 | 2007-05-10 22:23:19 -0700 | [diff] [blame] | 1641 | default y |
| 1642 | help |
| 1643 | Enable the eventfd() system call that allows to receive both |
| 1644 | kernel notification (ie. KAIO) or userspace notifications. |
| 1645 | |
| 1646 | If unsure, say Y. |
| 1647 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1648 | config SHMEM |
David Rientjes | 6a108a1 | 2011-01-20 14:44:16 -0800 | [diff] [blame] | 1649 | bool "Use full shmem filesystem" if EXPERT |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1650 | default y |
| 1651 | depends on MMU |
| 1652 | help |
| 1653 | The shmem is an internal filesystem used to manage shared memory. |
| 1654 | It is backed by swap and manages resource limits. It is also exported |
| 1655 | to userspace as tmpfs if TMPFS is enabled. Disabling this |
| 1656 | option replaces shmem and tmpfs with the much simpler ramfs code, |
| 1657 | which may be appropriate on small systems without swap. |
| 1658 | |
Thomas Petazzoni | ebf3f09 | 2008-10-15 22:05:12 -0700 | [diff] [blame] | 1659 | config AIO |
David Rientjes | 6a108a1 | 2011-01-20 14:44:16 -0800 | [diff] [blame] | 1660 | bool "Enable AIO support" if EXPERT |
Thomas Petazzoni | ebf3f09 | 2008-10-15 22:05:12 -0700 | [diff] [blame] | 1661 | default y |
| 1662 | help |
| 1663 | This option enables POSIX asynchronous I/O which may by used |
Mike Frysinger | 657a520 | 2013-04-30 15:28:45 -0700 | [diff] [blame] | 1664 | by some high performance threaded applications. Disabling |
| 1665 | this option saves about 7k. |
| 1666 | |
Jens Axboe | 2b188cc | 2019-01-07 10:46:33 -0700 | [diff] [blame] | 1667 | config IO_URING |
| 1668 | bool "Enable IO uring support" if EXPERT |
Jens Axboe | 561fb04 | 2019-10-24 07:25:42 -0600 | [diff] [blame] | 1669 | select IO_WQ |
Jens Axboe | 2b188cc | 2019-01-07 10:46:33 -0700 | [diff] [blame] | 1670 | default y |
| 1671 | help |
| 1672 | This option enables support for the io_uring interface, enabling |
| 1673 | applications to submit and complete IO through submission and |
| 1674 | completion rings that are shared between the kernel and application. |
| 1675 | |
Josh Triplett | d3ac21c | 2014-08-17 19:41:09 -0500 | [diff] [blame] | 1676 | config ADVISE_SYSCALLS |
| 1677 | bool "Enable madvise/fadvise syscalls" if EXPERT |
| 1678 | default y |
| 1679 | help |
| 1680 | This option enables the madvise and fadvise syscalls, used by |
| 1681 | applications to advise the kernel about their future memory or file |
| 1682 | usage, improving performance. If building an embedded system where no |
| 1683 | applications use these syscalls, you can disable this option to save |
| 1684 | space. |
| 1685 | |
Mathieu Desnoyers | 5b25b13 | 2015-09-11 13:07:39 -0700 | [diff] [blame] | 1686 | config MEMBARRIER |
| 1687 | bool "Enable membarrier() system call" if EXPERT |
| 1688 | default y |
| 1689 | help |
| 1690 | Enable the membarrier() system call that allows issuing memory |
| 1691 | barriers across all running threads, which can be used to distribute |
| 1692 | the cost of user-space memory barriers asymmetrically by transforming |
| 1693 | pairs of memory barriers into pairs consisting of membarrier() and a |
| 1694 | compiler barrier. |
| 1695 | |
| 1696 | If unsure, say Y. |
| 1697 | |
Randy Dunlap | a751ea3 | 2023-12-07 20:58:19 -0800 | [diff] [blame] | 1698 | config KCMP |
| 1699 | bool "Enable kcmp() system call" if EXPERT |
| 1700 | help |
| 1701 | Enable the kernel resource comparison system call. It provides |
| 1702 | user-space with the ability to compare two processes to see if they |
| 1703 | share a common resource, such as a file descriptor or even virtual |
| 1704 | memory space. |
| 1705 | |
| 1706 | If unsure, say N. |
| 1707 | |
| 1708 | config RSEQ |
| 1709 | bool "Enable rseq() system call" if EXPERT |
| 1710 | default y |
| 1711 | depends on HAVE_RSEQ |
| 1712 | select MEMBARRIER |
| 1713 | help |
| 1714 | Enable the restartable sequences system call. It provides a |
| 1715 | user-space cache for the current CPU number value, which |
| 1716 | speeds up getting the current CPU number from user-space, |
| 1717 | as well as an ABI to speed up user-space operations on |
| 1718 | per-CPU data. |
| 1719 | |
| 1720 | If unsure, say Y. |
| 1721 | |
| 1722 | config DEBUG_RSEQ |
| 1723 | default n |
| 1724 | bool "Enable debugging of rseq() system call" if EXPERT |
| 1725 | depends on RSEQ && DEBUG_KERNEL |
| 1726 | help |
| 1727 | Enable extra debugging checks for the rseq system call. |
| 1728 | |
| 1729 | If unsure, say N. |
| 1730 | |
| 1731 | config CACHESTAT_SYSCALL |
| 1732 | bool "Enable cachestat() system call" if EXPERT |
| 1733 | default y |
| 1734 | help |
| 1735 | Enable the cachestat system call, which queries the page cache |
| 1736 | statistics of a file (number of cached pages, dirty pages, |
| 1737 | pages marked for writeback, (recently) evicted pages). |
| 1738 | |
| 1739 | If unsure say Y here. |
| 1740 | |
| 1741 | config PC104 |
| 1742 | bool "PC/104 support" if EXPERT |
| 1743 | help |
| 1744 | Expose PC/104 form factor device drivers and options available for |
| 1745 | selection and configuration. Enable this option if your target |
| 1746 | machine has a PC/104 bus. |
| 1747 | |
Randy Dunlap | d1b069f | 2017-11-17 15:31:47 -0800 | [diff] [blame] | 1748 | config KALLSYMS |
Krzysztof Kozlowski | e8cf4e9 | 2019-12-04 16:52:28 -0800 | [diff] [blame] | 1749 | bool "Load all symbols for debugging/ksymoops" if EXPERT |
| 1750 | default y |
| 1751 | help |
| 1752 | Say Y here to let the kernel print out symbolic crash information and |
| 1753 | symbolic stack backtraces. This increases the size of the kernel |
| 1754 | somewhat, as all symbols have to be loaded into the kernel image. |
Randy Dunlap | d1b069f | 2017-11-17 15:31:47 -0800 | [diff] [blame] | 1755 | |
Zhen Lei | 30f3bb0 | 2022-11-15 16:33:48 +0800 | [diff] [blame] | 1756 | config KALLSYMS_SELFTEST |
| 1757 | bool "Test the basic functions and performance of kallsyms" |
| 1758 | depends on KALLSYMS |
| 1759 | default n |
| 1760 | help |
| 1761 | Test the basic functions and performance of some interfaces, such as |
| 1762 | kallsyms_lookup_name. It also calculates the compression rate of the |
| 1763 | kallsyms compression algorithm for the current symbol set. |
| 1764 | |
| 1765 | Start self-test automatically after system startup. Suggest executing |
| 1766 | "dmesg | grep kallsyms_selftest" to collect test results. "finish" is |
| 1767 | displayed in the last line, indicating that the test is complete. |
| 1768 | |
Randy Dunlap | d1b069f | 2017-11-17 15:31:47 -0800 | [diff] [blame] | 1769 | config KALLSYMS_ALL |
| 1770 | bool "Include all symbols in kallsyms" |
| 1771 | depends on DEBUG_KERNEL && KALLSYMS |
| 1772 | help |
Krzysztof Kozlowski | e8cf4e9 | 2019-12-04 16:52:28 -0800 | [diff] [blame] | 1773 | Normally kallsyms only contains the symbols of functions for nicer |
| 1774 | OOPS messages and backtraces (i.e., symbols from the text and inittext |
Baruch Siach | bdf0fe3 | 2022-07-07 07:43:29 +0300 | [diff] [blame] | 1775 | sections). This is sufficient for most cases. And only if you want to |
| 1776 | enable kernel live patching, or other less common use cases (e.g., |
| 1777 | when a debugger is used) all symbols are required (i.e., names of |
| 1778 | variables from the data sections, etc). |
Randy Dunlap | d1b069f | 2017-11-17 15:31:47 -0800 | [diff] [blame] | 1779 | |
Krzysztof Kozlowski | e8cf4e9 | 2019-12-04 16:52:28 -0800 | [diff] [blame] | 1780 | This option makes sure that all symbols are loaded into the kernel |
| 1781 | image (i.e., symbols from all sections) in cost of increased kernel |
| 1782 | size (depending on the kernel configuration, it may be 300KiB or |
| 1783 | something like this). |
Randy Dunlap | d1b069f | 2017-11-17 15:31:47 -0800 | [diff] [blame] | 1784 | |
Baruch Siach | bdf0fe3 | 2022-07-07 07:43:29 +0300 | [diff] [blame] | 1785 | Say N unless you really need all symbols, or kernel live patching. |
Randy Dunlap | d1b069f | 2017-11-17 15:31:47 -0800 | [diff] [blame] | 1786 | |
| 1787 | config KALLSYMS_ABSOLUTE_PERCPU |
| 1788 | bool |
| 1789 | depends on KALLSYMS |
| 1790 | default X86_64 && SMP |
| 1791 | |
| 1792 | config KALLSYMS_BASE_RELATIVE |
| 1793 | bool |
| 1794 | depends on KALLSYMS |
Ard Biesheuvel | cf8e865 | 2022-10-20 15:54:33 +0200 | [diff] [blame] | 1795 | default y |
Randy Dunlap | d1b069f | 2017-11-17 15:31:47 -0800 | [diff] [blame] | 1796 | help |
| 1797 | Instead of emitting them as absolute values in the native word size, |
| 1798 | emit the symbol references in the kallsyms table as 32-bit entries, |
| 1799 | each containing a relative value in the range [base, base + U32_MAX] |
| 1800 | or, when KALLSYMS_ABSOLUTE_PERCPU is in effect, each containing either |
| 1801 | an absolute value in the range [0, S32_MAX] or a relative value in the |
| 1802 | range [base, base + S32_MAX], where base is the lowest relative symbol |
| 1803 | address encountered in the image. |
| 1804 | |
| 1805 | On 64-bit builds, this reduces the size of the address table by 50%, |
| 1806 | but more importantly, it results in entries whose values are build |
| 1807 | time constants, and no relocation pass is required at runtime to fix |
| 1808 | up the entries based on the runtime load address of the kernel. |
| 1809 | |
| 1810 | # end of the "standard kernel features (expert users)" menu |
| 1811 | |
Mathieu Desnoyers | 3ccfebe | 2018-01-29 15:20:11 -0500 | [diff] [blame] | 1812 | config ARCH_HAS_MEMBARRIER_CALLBACKS |
| 1813 | bool |
| 1814 | |
Mathieu Desnoyers | 70216e1 | 2018-01-29 15:20:17 -0500 | [diff] [blame] | 1815 | config ARCH_HAS_MEMBARRIER_SYNC_CORE |
| 1816 | bool |
| 1817 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1818 | config HAVE_PERF_EVENTS |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1819 | bool |
Mike Frysinger | 018df72 | 2009-06-12 13:17:43 -0400 | [diff] [blame] | 1820 | help |
| 1821 | See tools/perf/design.txt for details. |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1822 | |
Sean Christopherson | 2aef6f3 | 2021-11-11 02:07:29 +0000 | [diff] [blame] | 1823 | config GUEST_PERF_EVENTS |
| 1824 | bool |
| 1825 | depends on HAVE_PERF_EVENTS |
| 1826 | |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 1827 | config PERF_USE_VMALLOC |
| 1828 | bool |
| 1829 | help |
| 1830 | See tools/perf/design.txt for details |
| 1831 | |
Ingo Molnar | 57c0c15 | 2009-09-21 12:20:38 +0200 | [diff] [blame] | 1832 | menu "Kernel Performance Events And Counters" |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1833 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1834 | config PERF_EVENTS |
Ingo Molnar | 57c0c15 | 2009-09-21 12:20:38 +0200 | [diff] [blame] | 1835 | bool "Kernel performance events and counters" |
Robert Richter | 392d65a | 2012-04-05 18:24:44 +0200 | [diff] [blame] | 1836 | default y if PROFILING |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1837 | depends on HAVE_PERF_EVENTS |
Peter Zijlstra | e360adb | 2010-10-14 14:01:34 +0800 | [diff] [blame] | 1838 | select IRQ_WORK |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1839 | help |
Ingo Molnar | 57c0c15 | 2009-09-21 12:20:38 +0200 | [diff] [blame] | 1840 | Enable kernel support for various performance events provided |
| 1841 | by software and hardware. |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1842 | |
Thadeu Lima de Souza Cascardo | dd77038 | 2009-10-30 19:32:25 -0200 | [diff] [blame] | 1843 | Software events are supported either built-in or via the |
Ingo Molnar | 57c0c15 | 2009-09-21 12:20:38 +0200 | [diff] [blame] | 1844 | use of generic tracepoints. |
| 1845 | |
| 1846 | Most modern CPUs support performance events via performance |
| 1847 | counter registers. These registers count the number of certain |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1848 | types of hw events: such as instructions executed, cachemisses |
| 1849 | suffered, or branches mis-predicted - without slowing down the |
| 1850 | kernel or applications. These registers can also trigger interrupts |
| 1851 | when a threshold number of events have passed - and can thus be |
| 1852 | used to profile the code that runs on that CPU. |
| 1853 | |
Ingo Molnar | 57c0c15 | 2009-09-21 12:20:38 +0200 | [diff] [blame] | 1854 | The Linux Performance Event subsystem provides an abstraction of |
Thadeu Lima de Souza Cascardo | dd77038 | 2009-10-30 19:32:25 -0200 | [diff] [blame] | 1855 | these software and hardware event capabilities, available via a |
Ingo Molnar | 57c0c15 | 2009-09-21 12:20:38 +0200 | [diff] [blame] | 1856 | system call and used by the "perf" utility in tools/perf/. It |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1857 | provides per task and per CPU counters, and it provides event |
| 1858 | capabilities on top of those. |
| 1859 | |
| 1860 | Say Y if unsure. |
| 1861 | |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 1862 | config DEBUG_PERF_USE_VMALLOC |
| 1863 | default n |
| 1864 | bool "Debug: use vmalloc to back perf mmap() buffers" |
Michael Ellerman | cb307113 | 2015-05-04 16:26:39 +1000 | [diff] [blame] | 1865 | depends on PERF_EVENTS && DEBUG_KERNEL && !PPC |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 1866 | select PERF_USE_VMALLOC |
| 1867 | help |
Krzysztof Kozlowski | e8cf4e9 | 2019-12-04 16:52:28 -0800 | [diff] [blame] | 1868 | Use vmalloc memory to back perf mmap() buffers. |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 1869 | |
Krzysztof Kozlowski | e8cf4e9 | 2019-12-04 16:52:28 -0800 | [diff] [blame] | 1870 | Mostly useful for debugging the vmalloc code on platforms |
| 1871 | that don't require it. |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 1872 | |
Krzysztof Kozlowski | e8cf4e9 | 2019-12-04 16:52:28 -0800 | [diff] [blame] | 1873 | Say N if unsure. |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 1874 | |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1875 | endmenu |
| 1876 | |
David Howells | 091f6e2 | 2015-07-20 21:16:28 +0100 | [diff] [blame] | 1877 | config SYSTEM_DATA_VERIFICATION |
| 1878 | def_bool n |
| 1879 | select SYSTEM_TRUSTED_KEYRING |
| 1880 | select KEYS |
| 1881 | select CRYPTO |
David Howells | d43de6c | 2016-03-03 21:49:27 +0000 | [diff] [blame] | 1882 | select CRYPTO_RSA |
David Howells | 091f6e2 | 2015-07-20 21:16:28 +0100 | [diff] [blame] | 1883 | select ASYMMETRIC_KEY_TYPE |
| 1884 | select ASYMMETRIC_PUBLIC_KEY_SUBTYPE |
David Howells | 091f6e2 | 2015-07-20 21:16:28 +0100 | [diff] [blame] | 1885 | select ASN1 |
| 1886 | select OID_REGISTRY |
| 1887 | select X509_CERTIFICATE_PARSER |
| 1888 | select PKCS7_MESSAGE_PARSER |
Peter Foley | 82c04ff | 2014-04-18 15:07:11 -0700 | [diff] [blame] | 1889 | help |
David Howells | 091f6e2 | 2015-07-20 21:16:28 +0100 | [diff] [blame] | 1890 | Provide PKCS#7 message verification using the contents of the system |
| 1891 | trusted keyring to provide public keys. This then can be used for |
| 1892 | module verification, kexec image verification and firmware blob |
| 1893 | verification. |
Peter Foley | 82c04ff | 2014-04-18 15:07:11 -0700 | [diff] [blame] | 1894 | |
Mathieu Desnoyers | 125e564 | 2008-02-02 15:10:36 -0500 | [diff] [blame] | 1895 | config PROFILING |
Robert Richter | b309a29 | 2010-02-26 15:01:23 +0100 | [diff] [blame] | 1896 | bool "Profiling support" |
Mathieu Desnoyers | 125e564 | 2008-02-02 15:10:36 -0500 | [diff] [blame] | 1897 | help |
| 1898 | Say Y here to enable the extended profiling support mechanisms used |
Viresh Kumar | f840826 | 2021-01-14 17:05:30 +0530 | [diff] [blame] | 1899 | by profilers. |
Mathieu Desnoyers | 125e564 | 2008-02-02 15:10:36 -0500 | [diff] [blame] | 1900 | |
Miguel Ojeda | 2f7ab12 | 2021-07-03 16:42:57 +0200 | [diff] [blame] | 1901 | config RUST |
| 1902 | bool "Rust support" |
| 1903 | depends on HAVE_RUST |
| 1904 | depends on RUST_IS_AVAILABLE |
Conor Dooley | 8933cf4 | 2024-04-04 15:17:02 +0100 | [diff] [blame] | 1905 | depends on !CFI_CLANG |
Miguel Ojeda | 2f7ab12 | 2021-07-03 16:42:57 +0200 | [diff] [blame] | 1906 | depends on !MODVERSIONS |
| 1907 | depends on !GCC_PLUGINS |
| 1908 | depends on !RANDSTRUCT |
Martin Rodriguez Reboredo | c117797 | 2023-01-11 12:20:50 -0300 | [diff] [blame] | 1909 | depends on !DEBUG_INFO_BTF || PAHOLE_HAS_LANG_EXCLUDE |
Miguel Ojeda | 2f7ab12 | 2021-07-03 16:42:57 +0200 | [diff] [blame] | 1910 | help |
| 1911 | Enables Rust support in the kernel. |
| 1912 | |
| 1913 | This allows other Rust-related options, like drivers written in Rust, |
| 1914 | to be selected. |
| 1915 | |
| 1916 | It is also required to be able to load external kernel modules |
| 1917 | written in Rust. |
| 1918 | |
| 1919 | See Documentation/rust/ for more information. |
| 1920 | |
| 1921 | If unsure, say N. |
| 1922 | |
| 1923 | config RUSTC_VERSION_TEXT |
| 1924 | string |
| 1925 | depends on RUST |
| 1926 | default $(shell,command -v $(RUSTC) >/dev/null 2>&1 && $(RUSTC) --version || echo n) |
| 1927 | |
| 1928 | config BINDGEN_VERSION_TEXT |
| 1929 | string |
| 1930 | depends on RUST |
| 1931 | default $(shell,command -v $(BINDGEN) >/dev/null 2>&1 && $(BINDGEN) --version || echo n) |
| 1932 | |
Ingo Molnar | 5f87f11 | 2008-07-23 14:15:22 +0200 | [diff] [blame] | 1933 | # |
| 1934 | # Place an empty function call at each tracepoint site. Can be |
| 1935 | # dynamically changed for a probe function. |
| 1936 | # |
Mathieu Desnoyers | 97e1c18 | 2008-07-18 12:16:16 -0400 | [diff] [blame] | 1937 | config TRACEPOINTS |
Ingo Molnar | 5f87f11 | 2008-07-23 14:15:22 +0200 | [diff] [blame] | 1938 | bool |
Mathieu Desnoyers | 97e1c18 | 2008-07-18 12:16:16 -0400 | [diff] [blame] | 1939 | |
Eric DeVolder | 89cde45 | 2023-07-12 12:15:32 -0400 | [diff] [blame] | 1940 | source "kernel/Kconfig.kexec" |
| 1941 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1942 | endmenu # General setup |
| 1943 | |
Christoph Hellwig | 1572497 | 2018-07-31 13:39:30 +0200 | [diff] [blame] | 1944 | source "arch/Kconfig" |
| 1945 | |
Chuck Ebbert | ae81f9e | 2006-09-16 12:15:53 -0700 | [diff] [blame] | 1946 | config RT_MUTEXES |
Christoph Jaeger | 6341e62 | 2014-12-20 15:41:11 -0500 | [diff] [blame] | 1947 | bool |
Sebastian Andrzej Siewior | 1c6f9ec | 2022-02-08 18:21:10 +0100 | [diff] [blame] | 1948 | default y if PREEMPT_RT |
Chuck Ebbert | ae81f9e | 2006-09-16 12:15:53 -0700 | [diff] [blame] | 1949 | |
Thiago Jung Bauermann | c8424e7 | 2019-07-04 15:57:34 -0300 | [diff] [blame] | 1950 | config MODULE_SIG_FORMAT |
| 1951 | def_bool n |
| 1952 | select SYSTEM_DATA_VERIFICATION |
| 1953 | |
Christophe Leroy | 73b4fc9 | 2022-07-12 07:52:33 +0200 | [diff] [blame] | 1954 | source "kernel/module/Kconfig" |
Peter Zijlstra | 6c9692e2 | 2015-05-27 11:09:37 +0930 | [diff] [blame] | 1955 | |
Rusty Russell | 98a79d6 | 2008-12-13 21:19:41 +1030 | [diff] [blame] | 1956 | config INIT_ALL_POSSIBLE |
| 1957 | bool |
| 1958 | help |
Rusty Russell | 5f054e3 | 2012-03-29 15:38:31 +1030 | [diff] [blame] | 1959 | Back when each arch used to define their own cpu_online_mask and |
| 1960 | cpu_possible_mask, some of them chose to initialize cpu_possible_mask |
Rusty Russell | 98a79d6 | 2008-12-13 21:19:41 +1030 | [diff] [blame] | 1961 | with all 1s, and others with all 0s. When they were centralised, |
| 1962 | it was better to provide this option than to break all the archs |
Matt LaPlante | 692105b | 2009-01-26 11:12:25 +0100 | [diff] [blame] | 1963 | and have several arch maintainers pursuing me down dark alleys. |
Rusty Russell | 98a79d6 | 2008-12-13 21:19:41 +1030 | [diff] [blame] | 1964 | |
Jens Axboe | 3a65dfe | 2005-11-04 08:43:35 +0100 | [diff] [blame] | 1965 | source "block/Kconfig" |
Avi Kivity | e98c320 | 2007-10-16 23:27:31 -0700 | [diff] [blame] | 1966 | |
| 1967 | config PREEMPT_NOTIFIERS |
| 1968 | bool |
Paul E. McKenney | e260be6 | 2008-01-25 21:08:24 +0100 | [diff] [blame] | 1969 | |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 1970 | config PADATA |
| 1971 | depends on SMP |
| 1972 | bool |
| 1973 | |
David Howells | 4520c6a | 2012-09-21 23:31:13 +0100 | [diff] [blame] | 1974 | config ASN1 |
| 1975 | tristate |
| 1976 | help |
| 1977 | Build a simple ASN.1 grammar compiler that produces a bytecode output |
| 1978 | that can be interpreted by the ASN.1 stream decoder and used to |
| 1979 | inform it as to what tags are to be expected in a stream and what |
| 1980 | functions to call on what tags. |
| 1981 | |
Thomas Gleixner | 6beb000 | 2009-11-09 15:21:34 +0000 | [diff] [blame] | 1982 | source "kernel/Kconfig.locks" |
Mathieu Desnoyers | e61938a | 2018-01-29 15:20:15 -0500 | [diff] [blame] | 1983 | |
Daniel Borkmann | 0ebeea8 | 2020-05-15 12:11:16 +0200 | [diff] [blame] | 1984 | config ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE |
| 1985 | bool |
| 1986 | |
Andrea Parri | 4ff4c74 | 2024-01-31 15:49:35 +0100 | [diff] [blame] | 1987 | config ARCH_HAS_PREPARE_SYNC_CORE_CMD |
| 1988 | bool |
| 1989 | |
Mathieu Desnoyers | e61938a | 2018-01-29 15:20:15 -0500 | [diff] [blame] | 1990 | config ARCH_HAS_SYNC_CORE_BEFORE_USERMODE |
| 1991 | bool |
Dominik Brodowski | 1bd21c6 | 2018-04-05 11:53:01 +0200 | [diff] [blame] | 1992 | |
| 1993 | # It may be useful for an architecture to override the definitions of the |
Dominik Brodowski | 7303e30 | 2018-04-05 11:53:03 +0200 | [diff] [blame] | 1994 | # SYSCALL_DEFINE() and __SYSCALL_DEFINEx() macros in <linux/syscalls.h> |
| 1995 | # and the COMPAT_ variants in <linux/compat.h>, in particular to use a |
| 1996 | # different calling convention for syscalls. They can also override the |
| 1997 | # macros for not-implemented syscalls in kernel/sys_ni.c and |
| 1998 | # kernel/time/posix-stubs.c. All these overrides need to be available in |
| 1999 | # <asm/syscall_wrapper.h>. |
Dominik Brodowski | 1bd21c6 | 2018-04-05 11:53:01 +0200 | [diff] [blame] | 2000 | config ARCH_HAS_SYSCALL_WRAPPER |
| 2001 | def_bool n |