1 # SPDX-License-Identifier: GPL-2.0-only 1 # SPDX-License-Identifier: GPL-2.0-only
2 config CC_VERSION_TEXT !! 2 config DEFCONFIG_LIST
3 string 3 string
4 default "$(CC_VERSION_TEXT)" !! 4 depends on !UML
5 help !! 5 option defconfig_list
6 This is used in unclear ways: !! 6 default "/lib/modules/$(shell,uname -r)/.config"
7 !! 7 default "/etc/kernel-config"
8 - Re-run Kconfig when the compiler i !! 8 default "/boot/config-$(shell,uname -r)"
9 The 'default' property references !! 9 default "arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG)"
10 CC_VERSION_TEXT so it is recorded <<
11 When the compiler is updated, Kcon <<
12 <<
13 - Ensure full rebuild when the compi <<
14 include/linux/compiler-version.h c <<
15 line so fixdep adds include/config <<
16 auto-generated dependency. When th <<
17 will touch it and then every file <<
18 10
19 config CC_IS_GCC 11 config CC_IS_GCC
20 def_bool $(success,test "$(cc-name)" = !! 12 def_bool $(success,$(CC) --version | head -n 1 | grep -q gcc)
21 13
22 config GCC_VERSION 14 config GCC_VERSION
23 int 15 int
24 default $(cc-version) if CC_IS_GCC !! 16 default $(shell,$(srctree)/scripts/gcc-version.sh $(CC)) if CC_IS_GCC
25 default 0 <<
26 <<
27 config CC_IS_CLANG <<
28 def_bool $(success,test "$(cc-name)" = <<
29 <<
30 config CLANG_VERSION <<
31 int <<
32 default $(cc-version) if CC_IS_CLANG <<
33 default 0 17 default 0
34 18
35 config AS_IS_GNU <<
36 def_bool $(success,test "$(as-name)" = <<
37 <<
38 config AS_IS_LLVM <<
39 def_bool $(success,test "$(as-name)" = <<
40 <<
41 config AS_VERSION <<
42 int <<
43 # Use clang version if this is the int <<
44 default CLANG_VERSION if AS_IS_LLVM <<
45 default $(as-version) <<
46 <<
47 config LD_IS_BFD <<
48 def_bool $(success,test "$(ld-name)" = <<
49 <<
50 config LD_VERSION 19 config LD_VERSION
51 int 20 int
52 default $(ld-version) if LD_IS_BFD !! 21 default $(shell,$(LD) --version | $(srctree)/scripts/ld-version.sh)
53 default 0 <<
54 <<
55 config LD_IS_LLD <<
56 def_bool $(success,test "$(ld-name)" = <<
57 <<
58 config LLD_VERSION <<
59 int <<
60 default $(ld-version) if LD_IS_LLD <<
61 default 0 <<
62 <<
63 config RUSTC_VERSION <<
64 int <<
65 default $(rustc-version) <<
66 help <<
67 It does not depend on `RUST` since t <<
68 in a `depends on`. <<
69 <<
70 config RUST_IS_AVAILABLE <<
71 def_bool $(success,$(srctree)/scripts/ <<
72 help <<
73 This shows whether a suitable Rust t <<
74 <<
75 Please see Documentation/rust/quick- <<
76 to satisfy the build requirements of <<
77 22
78 In particular, the Makefile target ' !! 23 config CC_IS_CLANG
79 why the Rust toolchain is not being !! 24 def_bool $(success,$(CC) --version | head -n 1 | grep -q clang)
80 25
81 config RUSTC_LLVM_VERSION !! 26 config CLANG_VERSION
82 int 27 int
83 default $(rustc-llvm-version) !! 28 default $(shell,$(srctree)/scripts/clang-version.sh $(CC))
84 29
85 config CC_CAN_LINK 30 config CC_CAN_LINK
86 bool !! 31 def_bool $(success,$(srctree)/scripts/cc-can-link.sh $(CC))
87 default $(success,$(srctree)/scripts/c <<
88 default $(success,$(srctree)/scripts/c <<
89 <<
90 config CC_CAN_LINK_STATIC <<
91 bool <<
92 default $(success,$(srctree)/scripts/c <<
93 default $(success,$(srctree)/scripts/c <<
94 <<
95 # Fixed in GCC 14, 13.3, 12.4 and 11.5 <<
96 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id <<
97 config GCC_ASM_GOTO_OUTPUT_BROKEN <<
98 bool <<
99 depends on CC_IS_GCC <<
100 default y if GCC_VERSION < 110500 <<
101 default y if GCC_VERSION >= 120000 && <<
102 default y if GCC_VERSION >= 130000 && <<
103 <<
104 config CC_HAS_ASM_GOTO_OUTPUT <<
105 def_bool y <<
106 depends on !GCC_ASM_GOTO_OUTPUT_BROKEN <<
107 depends on $(success,echo 'int foo(int <<
108 32
109 config CC_HAS_ASM_GOTO_TIED_OUTPUT !! 33 config CC_HAS_ASM_GOTO
110 depends on CC_HAS_ASM_GOTO_OUTPUT !! 34 def_bool $(success,$(srctree)/scripts/gcc-goto.sh $(CC))
111 # Detect buggy gcc and clang, fixed in <<
112 def_bool $(success,echo 'int foo(int * <<
113 35
114 config TOOLS_SUPPORT_RELR 36 config TOOLS_SUPPORT_RELR
115 def_bool $(success,env "CC=$(CC)" "LD= 37 def_bool $(success,env "CC=$(CC)" "LD=$(LD)" "NM=$(NM)" "OBJCOPY=$(OBJCOPY)" $(srctree)/scripts/tools-support-relr.sh)
116 38
117 config CC_HAS_ASM_INLINE 39 config CC_HAS_ASM_INLINE
118 def_bool $(success,echo 'void foo(void 40 def_bool $(success,echo 'void foo(void) { asm inline (""); }' | $(CC) -x c - -c -o /dev/null)
119 41
120 config CC_HAS_NO_PROFILE_FN_ATTR <<
121 def_bool $(success,echo '__attribute__ <<
122 <<
123 config PAHOLE_VERSION <<
124 int <<
125 default $(shell,$(srctree)/scripts/pah <<
126 <<
127 config CONSTRUCTORS 42 config CONSTRUCTORS
128 bool 43 bool
>> 44 depends on !UML
129 45
130 config IRQ_WORK 46 config IRQ_WORK
131 def_bool y if SMP !! 47 bool
132 48
133 config BUILDTIME_TABLE_SORT 49 config BUILDTIME_TABLE_SORT
134 bool 50 bool
135 51
136 config THREAD_INFO_IN_TASK 52 config THREAD_INFO_IN_TASK
137 bool 53 bool
138 help 54 help
139 Select this to move thread_info off 55 Select this to move thread_info off the stack into task_struct. To
140 make this work, an arch will need to 56 make this work, an arch will need to remove all thread_info fields
141 except flags and fix any runtime bug 57 except flags and fix any runtime bugs.
142 58
143 One subtle change that will be neede 59 One subtle change that will be needed is to use try_get_task_stack()
144 and put_task_stack() in save_thread_ 60 and put_task_stack() in save_thread_stack_tsk() and get_wchan().
145 61
146 menu "General setup" 62 menu "General setup"
147 63
148 config BROKEN 64 config BROKEN
149 bool 65 bool
150 66
151 config BROKEN_ON_SMP 67 config BROKEN_ON_SMP
152 bool 68 bool
153 depends on BROKEN || !SMP 69 depends on BROKEN || !SMP
154 default y 70 default y
155 71
156 config INIT_ENV_ARG_LIMIT 72 config INIT_ENV_ARG_LIMIT
157 int 73 int
158 default 32 if !UML 74 default 32 if !UML
159 default 128 if UML 75 default 128 if UML
160 help 76 help
161 Maximum of each of the number of arg 77 Maximum of each of the number of arguments and environment
162 variables passed to init from the ke 78 variables passed to init from the kernel command line.
163 79
164 config COMPILE_TEST 80 config COMPILE_TEST
165 bool "Compile also drivers which will 81 bool "Compile also drivers which will not load"
166 depends on HAS_IOMEM !! 82 depends on !UML
>> 83 default n
167 help 84 help
168 Some drivers can be compiled on a di 85 Some drivers can be compiled on a different platform than they are
169 intended to be run on. Despite they 86 intended to be run on. Despite they cannot be loaded there (or even
170 when they load they cannot be used d 87 when they load they cannot be used due to missing HW support),
171 developers still, opposing to distri 88 developers still, opposing to distributors, might want to build such
172 drivers to compile-test them. 89 drivers to compile-test them.
173 90
174 If you are a developer and want to b 91 If you are a developer and want to build everything available, say Y
175 here. If you are a user/distributor, 92 here. If you are a user/distributor, say N here to exclude useless
176 drivers to be distributed. 93 drivers to be distributed.
177 94
178 config WERROR <<
179 bool "Compile the kernel with warnings <<
180 default COMPILE_TEST <<
181 help <<
182 A kernel build should not cause any <<
183 enables the '-Werror' (for C) and '- <<
184 to enforce that rule by default. Cer <<
185 such as the linker may be upgraded t <<
186 well. <<
187 <<
188 However, if you have a new (or very <<
189 and unusual warnings, or you have so <<
190 you may need to disable this config <<
191 successfully build the kernel. <<
192 <<
193 If in doubt, say Y. <<
194 <<
195 config UAPI_HEADER_TEST 95 config UAPI_HEADER_TEST
196 bool "Compile test UAPI headers" 96 bool "Compile test UAPI headers"
197 depends on HEADERS_INSTALL && CC_CAN_L 97 depends on HEADERS_INSTALL && CC_CAN_LINK
198 help 98 help
199 Compile test headers exported to use 99 Compile test headers exported to user-space to ensure they are
200 self-contained, i.e. compilable as s 100 self-contained, i.e. compilable as standalone units.
201 101
202 If you are a developer or tester and 102 If you are a developer or tester and want to ensure the exported
203 headers are self-contained, say Y he 103 headers are self-contained, say Y here. Otherwise, choose N.
204 104
205 config LOCALVERSION 105 config LOCALVERSION
206 string "Local version - append to kern 106 string "Local version - append to kernel release"
207 help 107 help
208 Append an extra string to the end of 108 Append an extra string to the end of your kernel version.
209 This will show up when you type unam 109 This will show up when you type uname, for example.
210 The string you set here will be appe 110 The string you set here will be appended after the contents of
211 any files with a filename matching l 111 any files with a filename matching localversion* in your
212 object and source tree, in that orde 112 object and source tree, in that order. Your total string can
213 be a maximum of 64 characters. 113 be a maximum of 64 characters.
214 114
215 config LOCALVERSION_AUTO 115 config LOCALVERSION_AUTO
216 bool "Automatically append version inf 116 bool "Automatically append version information to the version string"
217 default y 117 default y
218 depends on !COMPILE_TEST 118 depends on !COMPILE_TEST
219 help 119 help
220 This will try to automatically deter 120 This will try to automatically determine if the current tree is a
221 release tree by looking for git tags 121 release tree by looking for git tags that belong to the current
222 top of tree revision. 122 top of tree revision.
223 123
224 A string of the format -gxxxxxxxx wi 124 A string of the format -gxxxxxxxx will be added to the localversion
225 if a git-based tree is found. The s 125 if a git-based tree is found. The string generated by this will be
226 appended after any matching localver 126 appended after any matching localversion* files, and after the value
227 set in CONFIG_LOCALVERSION. 127 set in CONFIG_LOCALVERSION.
228 128
229 (The actual string used here is the !! 129 (The actual string used here is the first eight characters produced
230 by running the command: 130 by running the command:
231 131
232 $ git rev-parse --verify HEAD 132 $ git rev-parse --verify HEAD
233 133
234 which is done within the script "scr 134 which is done within the script "scripts/setlocalversion".)
235 135
236 config BUILD_SALT 136 config BUILD_SALT
237 string "Build ID Salt" 137 string "Build ID Salt"
238 default "" 138 default ""
239 help 139 help
240 The build ID is used to link binarie 140 The build ID is used to link binaries and their debug info. Setting
241 this option will use the value in th 141 this option will use the value in the calculation of the build id.
242 This is mostly useful for distributi 142 This is mostly useful for distributions which want to ensure the
243 build is unique between builds. It's 143 build is unique between builds. It's safe to leave the default.
244 144
245 config HAVE_KERNEL_GZIP 145 config HAVE_KERNEL_GZIP
246 bool 146 bool
247 147
248 config HAVE_KERNEL_BZIP2 148 config HAVE_KERNEL_BZIP2
249 bool 149 bool
250 150
251 config HAVE_KERNEL_LZMA 151 config HAVE_KERNEL_LZMA
252 bool 152 bool
253 153
254 config HAVE_KERNEL_XZ 154 config HAVE_KERNEL_XZ
255 bool 155 bool
256 156
257 config HAVE_KERNEL_LZO 157 config HAVE_KERNEL_LZO
258 bool 158 bool
259 159
260 config HAVE_KERNEL_LZ4 160 config HAVE_KERNEL_LZ4
261 bool 161 bool
262 162
263 config HAVE_KERNEL_ZSTD <<
264 bool <<
265 <<
266 config HAVE_KERNEL_UNCOMPRESSED 163 config HAVE_KERNEL_UNCOMPRESSED
267 bool 164 bool
268 165
269 choice 166 choice
270 prompt "Kernel compression mode" 167 prompt "Kernel compression mode"
271 default KERNEL_GZIP 168 default KERNEL_GZIP
272 depends on HAVE_KERNEL_GZIP || HAVE_KE !! 169 depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO || HAVE_KERNEL_LZ4 || HAVE_KERNEL_UNCOMPRESSED
273 help 170 help
274 The linux kernel is a kind of self-e 171 The linux kernel is a kind of self-extracting executable.
275 Several compression algorithms are a 172 Several compression algorithms are available, which differ
276 in efficiency, compression and decom 173 in efficiency, compression and decompression speed.
277 Compression speed is only relevant w 174 Compression speed is only relevant when building a kernel.
278 Decompression speed is relevant at e 175 Decompression speed is relevant at each boot.
279 176
280 If you have any problems with bzip2 177 If you have any problems with bzip2 or lzma compressed
281 kernels, mail me (Alain Knaff) <alain 178 kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
282 version of this functionality (bzip2 179 version of this functionality (bzip2 only), for 2.4, was
283 supplied by Christian Ludwig) 180 supplied by Christian Ludwig)
284 181
285 High compression options are mostly 182 High compression options are mostly useful for users, who
286 are low on disk space (embedded syst 183 are low on disk space (embedded systems), but for whom ram
287 size matters less. 184 size matters less.
288 185
289 If in doubt, select 'gzip' 186 If in doubt, select 'gzip'
290 187
291 config KERNEL_GZIP 188 config KERNEL_GZIP
292 bool "Gzip" 189 bool "Gzip"
293 depends on HAVE_KERNEL_GZIP 190 depends on HAVE_KERNEL_GZIP
294 help 191 help
295 The old and tried gzip compression. 192 The old and tried gzip compression. It provides a good balance
296 between compression ratio and decomp 193 between compression ratio and decompression speed.
297 194
298 config KERNEL_BZIP2 195 config KERNEL_BZIP2
299 bool "Bzip2" 196 bool "Bzip2"
300 depends on HAVE_KERNEL_BZIP2 197 depends on HAVE_KERNEL_BZIP2
301 help 198 help
302 Its compression ratio and speed is i 199 Its compression ratio and speed is intermediate.
303 Decompression speed is slowest among 200 Decompression speed is slowest among the choices. The kernel
304 size is about 10% smaller with bzip2 201 size is about 10% smaller with bzip2, in comparison to gzip.
305 Bzip2 uses a large amount of memory. 202 Bzip2 uses a large amount of memory. For modern kernels you
306 will need at least 8MB RAM or more f 203 will need at least 8MB RAM or more for booting.
307 204
308 config KERNEL_LZMA 205 config KERNEL_LZMA
309 bool "LZMA" 206 bool "LZMA"
310 depends on HAVE_KERNEL_LZMA 207 depends on HAVE_KERNEL_LZMA
311 help 208 help
312 This compression algorithm's ratio i 209 This compression algorithm's ratio is best. Decompression speed
313 is between gzip and bzip2. Compress 210 is between gzip and bzip2. Compression is slowest.
314 The kernel size is about 33% smaller 211 The kernel size is about 33% smaller with LZMA in comparison to gzip.
315 212
316 config KERNEL_XZ 213 config KERNEL_XZ
317 bool "XZ" 214 bool "XZ"
318 depends on HAVE_KERNEL_XZ 215 depends on HAVE_KERNEL_XZ
319 help 216 help
320 XZ uses the LZMA2 algorithm and inst 217 XZ uses the LZMA2 algorithm and instruction set specific
321 BCJ filters which can improve compre 218 BCJ filters which can improve compression ratio of executable
322 code. The size of the kernel is abou 219 code. The size of the kernel is about 30% smaller with XZ in
323 comparison to gzip. On architectures 220 comparison to gzip. On architectures for which there is a BCJ
324 filter (i386, x86_64, ARM, ARM64, RI !! 221 filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
325 and SPARC), XZ will create a few per !! 222 will create a few percent smaller kernel than plain LZMA.
326 plain LZMA. <<
327 223
328 The speed is about the same as with 224 The speed is about the same as with LZMA: The decompression
329 speed of XZ is better than that of b 225 speed of XZ is better than that of bzip2 but worse than gzip
330 and LZO. Compression is slow. 226 and LZO. Compression is slow.
331 227
332 config KERNEL_LZO 228 config KERNEL_LZO
333 bool "LZO" 229 bool "LZO"
334 depends on HAVE_KERNEL_LZO 230 depends on HAVE_KERNEL_LZO
335 help 231 help
336 Its compression ratio is the poorest 232 Its compression ratio is the poorest among the choices. The kernel
337 size is about 10% bigger than gzip; 233 size is about 10% bigger than gzip; however its speed
338 (both compression and decompression) 234 (both compression and decompression) is the fastest.
339 235
340 config KERNEL_LZ4 236 config KERNEL_LZ4
341 bool "LZ4" 237 bool "LZ4"
342 depends on HAVE_KERNEL_LZ4 238 depends on HAVE_KERNEL_LZ4
343 help 239 help
344 LZ4 is an LZ77-type compressor with 240 LZ4 is an LZ77-type compressor with a fixed, byte-oriented encoding.
345 A preliminary version of LZ4 de/comp 241 A preliminary version of LZ4 de/compression tool is available at
346 <https://code.google.com/p/lz4/>. 242 <https://code.google.com/p/lz4/>.
347 243
348 Its compression ratio is worse than 244 Its compression ratio is worse than LZO. The size of the kernel
349 is about 8% bigger than LZO. But the 245 is about 8% bigger than LZO. But the decompression speed is
350 faster than LZO. 246 faster than LZO.
351 247
352 config KERNEL_ZSTD <<
353 bool "ZSTD" <<
354 depends on HAVE_KERNEL_ZSTD <<
355 help <<
356 ZSTD is a compression algorithm targ <<
357 with fast decompression speed. It wi <<
358 decompress around the same speed as <<
359 will need at least 192 KB RAM or mor <<
360 line tool is required for compressio <<
361 <<
362 config KERNEL_UNCOMPRESSED 248 config KERNEL_UNCOMPRESSED
363 bool "None" 249 bool "None"
364 depends on HAVE_KERNEL_UNCOMPRESSED 250 depends on HAVE_KERNEL_UNCOMPRESSED
365 help 251 help
366 Produce uncompressed kernel image. T 252 Produce uncompressed kernel image. This option is usually not what
367 you want. It is useful for debugging 253 you want. It is useful for debugging the kernel in slow simulation
368 environments, where decompressing an 254 environments, where decompressing and moving the kernel is awfully
369 slow. This option allows early boot 255 slow. This option allows early boot code to skip the decompressor
370 and jump right at uncompressed kerne 256 and jump right at uncompressed kernel image.
371 257
372 endchoice 258 endchoice
373 259
374 config DEFAULT_INIT <<
375 string "Default init path" <<
376 default "" <<
377 help <<
378 This option determines the default i <<
379 option is passed on the kernel comma <<
380 not present, we will still then move <<
381 locations (e.g. /sbin/init, etc). If <<
382 the fallback list when init= is not <<
383 <<
384 config DEFAULT_HOSTNAME 260 config DEFAULT_HOSTNAME
385 string "Default hostname" 261 string "Default hostname"
386 default "(none)" 262 default "(none)"
387 help 263 help
388 This option determines the default s 264 This option determines the default system hostname before userspace
389 calls sethostname(2). The kernel tra 265 calls sethostname(2). The kernel traditionally uses "(none)" here,
390 but you may wish to use a different 266 but you may wish to use a different default here to make a minimal
391 system more usable with less configu 267 system more usable with less configuration.
392 268
>> 269 #
>> 270 # For some reason microblaze and nios2 hard code SWAP=n. Hopefully we can
>> 271 # add proper SWAP support to them, in which case this can be remove.
>> 272 #
>> 273 config ARCH_NO_SWAP
>> 274 bool
>> 275
>> 276 config SWAP
>> 277 bool "Support for paging of anonymous memory (swap)"
>> 278 depends on MMU && BLOCK && !ARCH_NO_SWAP
>> 279 default y
>> 280 help
>> 281 This option allows you to choose whether you want to have support
>> 282 for so called swap devices or swap files in your kernel that are
>> 283 used to provide more virtual memory than the actual RAM present
>> 284 in your computer. If unsure say Y.
>> 285
393 config SYSVIPC 286 config SYSVIPC
394 bool "System V IPC" 287 bool "System V IPC"
395 help !! 288 ---help---
396 Inter Process Communication is a sui 289 Inter Process Communication is a suite of library functions and
397 system calls which let processes (ru 290 system calls which let processes (running programs) synchronize and
398 exchange information. It is generall 291 exchange information. It is generally considered to be a good thing,
399 and some programs won't run unless y 292 and some programs won't run unless you say Y here. In particular, if
400 you want to run the DOS emulator dos 293 you want to run the DOS emulator dosemu under Linux (read the
401 DOSEMU-HOWTO, available from <http:/ 294 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
402 you'll need to say Y here. 295 you'll need to say Y here.
403 296
404 You can find documentation about IPC 297 You can find documentation about IPC with "info ipc" and also in
405 section 6.4 of the Linux Programmer' 298 section 6.4 of the Linux Programmer's Guide, available from
406 <http://www.tldp.org/guides.html>. 299 <http://www.tldp.org/guides.html>.
407 300
408 config SYSVIPC_SYSCTL 301 config SYSVIPC_SYSCTL
409 bool 302 bool
410 depends on SYSVIPC 303 depends on SYSVIPC
411 depends on SYSCTL 304 depends on SYSCTL
412 default y 305 default y
413 306
414 config SYSVIPC_COMPAT <<
415 def_bool y <<
416 depends on COMPAT && SYSVIPC <<
417 <<
418 config POSIX_MQUEUE 307 config POSIX_MQUEUE
419 bool "POSIX Message Queues" 308 bool "POSIX Message Queues"
420 depends on NET 309 depends on NET
421 help !! 310 ---help---
422 POSIX variant of message queues is a 311 POSIX variant of message queues is a part of IPC. In POSIX message
423 queues every message has a priority 312 queues every message has a priority which decides about succession
424 of receiving it by a process. If you 313 of receiving it by a process. If you want to compile and run
425 programs written e.g. for Solaris wi 314 programs written e.g. for Solaris with use of its POSIX message
426 queues (functions mq_*) say Y here. 315 queues (functions mq_*) say Y here.
427 316
428 POSIX message queues are visible as 317 POSIX message queues are visible as a filesystem called 'mqueue'
429 and can be mounted somewhere if you 318 and can be mounted somewhere if you want to do filesystem
430 operations on message queues. 319 operations on message queues.
431 320
432 If unsure, say Y. 321 If unsure, say Y.
433 322
434 config POSIX_MQUEUE_SYSCTL 323 config POSIX_MQUEUE_SYSCTL
435 bool 324 bool
436 depends on POSIX_MQUEUE 325 depends on POSIX_MQUEUE
437 depends on SYSCTL 326 depends on SYSCTL
438 default y 327 default y
439 328
440 config WATCH_QUEUE <<
441 bool "General notification queue" <<
442 default n <<
443 help <<
444 <<
445 This is a general notification queue <<
446 userspace by splicing them into pipe <<
447 with watches for key/keyring change <<
448 notifications. <<
449 <<
450 See Documentation/core-api/watch_que <<
451 <<
452 config CROSS_MEMORY_ATTACH 329 config CROSS_MEMORY_ATTACH
453 bool "Enable process_vm_readv/writev s 330 bool "Enable process_vm_readv/writev syscalls"
454 depends on MMU 331 depends on MMU
455 default y 332 default y
456 help 333 help
457 Enabling this option adds the system 334 Enabling this option adds the system calls process_vm_readv and
458 process_vm_writev which allow a proc 335 process_vm_writev which allow a process with the correct privileges
459 to directly read from or write to an 336 to directly read from or write to another process' address space.
460 See the man page for more details. 337 See the man page for more details.
461 338
462 config USELIB 339 config USELIB
463 bool "uselib syscall (for libc5 and ea !! 340 bool "uselib syscall"
464 default ALPHA || M68K || SPARC !! 341 def_bool ALPHA || M68K || SPARC || X86_32 || IA32_EMULATION
465 help 342 help
466 This option enables the uselib sysca 343 This option enables the uselib syscall, a system call used in the
467 dynamic linker from libc5 and earlie 344 dynamic linker from libc5 and earlier. glibc does not use this
468 system call. If you intend to run p 345 system call. If you intend to run programs built on libc5 or
469 earlier, you may need to enable this 346 earlier, you may need to enable this syscall. Current systems
470 running glibc can safely disable thi 347 running glibc can safely disable this.
471 348
472 config AUDIT 349 config AUDIT
473 bool "Auditing support" 350 bool "Auditing support"
474 depends on NET 351 depends on NET
475 help 352 help
476 Enable auditing infrastructure that 353 Enable auditing infrastructure that can be used with another
477 kernel subsystem, such as SELinux (w 354 kernel subsystem, such as SELinux (which requires this for
478 logging of avc messages output). Sy 355 logging of avc messages output). System call auditing is included
479 on architectures which support it. 356 on architectures which support it.
480 357
481 config HAVE_ARCH_AUDITSYSCALL 358 config HAVE_ARCH_AUDITSYSCALL
482 bool 359 bool
483 360
484 config AUDITSYSCALL 361 config AUDITSYSCALL
485 def_bool y 362 def_bool y
486 depends on AUDIT && HAVE_ARCH_AUDITSYS 363 depends on AUDIT && HAVE_ARCH_AUDITSYSCALL
487 select FSNOTIFY 364 select FSNOTIFY
488 365
489 source "kernel/irq/Kconfig" 366 source "kernel/irq/Kconfig"
490 source "kernel/time/Kconfig" 367 source "kernel/time/Kconfig"
491 source "kernel/bpf/Kconfig" <<
492 source "kernel/Kconfig.preempt" 368 source "kernel/Kconfig.preempt"
493 369
494 menu "CPU/Task time and stats accounting" 370 menu "CPU/Task time and stats accounting"
495 371
496 config VIRT_CPU_ACCOUNTING 372 config VIRT_CPU_ACCOUNTING
497 bool 373 bool
498 374
499 choice 375 choice
500 prompt "Cputime accounting" 376 prompt "Cputime accounting"
501 default TICK_CPU_ACCOUNTING !! 377 default TICK_CPU_ACCOUNTING if !PPC64
>> 378 default VIRT_CPU_ACCOUNTING_NATIVE if PPC64
502 379
503 # Kind of a stub config for the pure tick base 380 # Kind of a stub config for the pure tick based cputime accounting
504 config TICK_CPU_ACCOUNTING 381 config TICK_CPU_ACCOUNTING
505 bool "Simple tick based cputime accoun 382 bool "Simple tick based cputime accounting"
506 depends on !S390 && !NO_HZ_FULL 383 depends on !S390 && !NO_HZ_FULL
507 help 384 help
508 This is the basic tick based cputime 385 This is the basic tick based cputime accounting that maintains
509 statistics about user, system and id 386 statistics about user, system and idle time spent on per jiffies
510 granularity. 387 granularity.
511 388
512 If unsure, say Y. 389 If unsure, say Y.
513 390
514 config VIRT_CPU_ACCOUNTING_NATIVE 391 config VIRT_CPU_ACCOUNTING_NATIVE
515 bool "Deterministic task and CPU time 392 bool "Deterministic task and CPU time accounting"
516 depends on HAVE_VIRT_CPU_ACCOUNTING && 393 depends on HAVE_VIRT_CPU_ACCOUNTING && !NO_HZ_FULL
517 select VIRT_CPU_ACCOUNTING 394 select VIRT_CPU_ACCOUNTING
518 help 395 help
519 Select this option to enable more ac 396 Select this option to enable more accurate task and CPU time
520 accounting. This is done by reading 397 accounting. This is done by reading a CPU counter on each
521 kernel entry and exit and on transit 398 kernel entry and exit and on transitions within the kernel
522 between system, softirq and hardirq 399 between system, softirq and hardirq state, so there is a
523 small performance impact. In the ca 400 small performance impact. In the case of s390 or IBM POWER > 5,
524 this also enables accounting of stol 401 this also enables accounting of stolen time on logically-partitioned
525 systems. 402 systems.
526 403
527 config VIRT_CPU_ACCOUNTING_GEN 404 config VIRT_CPU_ACCOUNTING_GEN
528 bool "Full dynticks CPU time accountin 405 bool "Full dynticks CPU time accounting"
529 depends on HAVE_CONTEXT_TRACKING_USER !! 406 depends on HAVE_CONTEXT_TRACKING
530 depends on HAVE_VIRT_CPU_ACCOUNTING_GE 407 depends on HAVE_VIRT_CPU_ACCOUNTING_GEN
531 depends on GENERIC_CLOCKEVENTS 408 depends on GENERIC_CLOCKEVENTS
532 select VIRT_CPU_ACCOUNTING 409 select VIRT_CPU_ACCOUNTING
533 select CONTEXT_TRACKING_USER !! 410 select CONTEXT_TRACKING
534 help 411 help
535 Select this option to enable task an 412 Select this option to enable task and CPU time accounting on full
536 dynticks systems. This accounting is 413 dynticks systems. This accounting is implemented by watching every
537 kernel-user boundaries using the con 414 kernel-user boundaries using the context tracking subsystem.
538 The accounting is thus performed at 415 The accounting is thus performed at the expense of some significant
539 overhead. 416 overhead.
540 417
541 For now this is only useful if you a 418 For now this is only useful if you are working on the full
542 dynticks subsystem development. 419 dynticks subsystem development.
543 420
544 If unsure, say N. 421 If unsure, say N.
545 422
546 endchoice 423 endchoice
547 424
548 config IRQ_TIME_ACCOUNTING 425 config IRQ_TIME_ACCOUNTING
549 bool "Fine granularity task level IRQ 426 bool "Fine granularity task level IRQ time accounting"
550 depends on HAVE_IRQ_TIME_ACCOUNTING && 427 depends on HAVE_IRQ_TIME_ACCOUNTING && !VIRT_CPU_ACCOUNTING_NATIVE
551 help 428 help
552 Select this option to enable fine gr 429 Select this option to enable fine granularity task irq time
553 accounting. This is done by reading 430 accounting. This is done by reading a timestamp on each
554 transitions between softirq and hard 431 transitions between softirq and hardirq state, so there can be a
555 small performance impact. 432 small performance impact.
556 433
557 If in doubt, say N here. 434 If in doubt, say N here.
558 435
559 config HAVE_SCHED_AVG_IRQ 436 config HAVE_SCHED_AVG_IRQ
560 def_bool y 437 def_bool y
561 depends on IRQ_TIME_ACCOUNTING || PARA 438 depends on IRQ_TIME_ACCOUNTING || PARAVIRT_TIME_ACCOUNTING
562 depends on SMP 439 depends on SMP
563 440
564 config SCHED_HW_PRESSURE !! 441 config SCHED_THERMAL_PRESSURE
565 bool !! 442 bool "Enable periodic averaging of thermal pressure"
566 default y if ARM && ARM_CPU_TOPOLOGY <<
567 default y if ARM64 <<
568 depends on SMP 443 depends on SMP
569 depends on CPU_FREQ_THERMAL <<
570 help <<
571 Select this option to enable HW pres <<
572 scheduler. HW pressure is the value <<
573 that reflects the reduction in CPU c <<
574 HW throttling. HW throttling occurs <<
575 a CPU is capped due to high operatin <<
576 <<
577 If selected, the scheduler will be a <<
578 i.e. put less load on throttled CPUs <<
579 <<
580 This requires the architecture to im <<
581 arch_update_hw_pressure() and arch_s <<
582 444
583 config BSD_PROCESS_ACCT 445 config BSD_PROCESS_ACCT
584 bool "BSD Process Accounting" 446 bool "BSD Process Accounting"
585 depends on MULTIUSER 447 depends on MULTIUSER
586 help 448 help
587 If you say Y here, a user level prog 449 If you say Y here, a user level program will be able to instruct the
588 kernel (via a special system call) t 450 kernel (via a special system call) to write process accounting
589 information to a file: whenever a pr 451 information to a file: whenever a process exits, information about
590 that process will be appended to the 452 that process will be appended to the file by the kernel. The
591 information includes things such as 453 information includes things such as creation time, owning user,
592 command name, memory usage, controll 454 command name, memory usage, controlling terminal etc. (the complete
593 list is in the struct acct in <file: 455 list is in the struct acct in <file:include/linux/acct.h>). It is
594 up to the user level program to do u 456 up to the user level program to do useful things with this
595 information. This is generally a go 457 information. This is generally a good idea, so say Y.
596 458
597 config BSD_PROCESS_ACCT_V3 459 config BSD_PROCESS_ACCT_V3
598 bool "BSD Process Accounting version 3 460 bool "BSD Process Accounting version 3 file format"
599 depends on BSD_PROCESS_ACCT 461 depends on BSD_PROCESS_ACCT
600 default n 462 default n
601 help 463 help
602 If you say Y here, the process accou 464 If you say Y here, the process accounting information is written
603 in a new file format that also logs 465 in a new file format that also logs the process IDs of each
604 process and its parent. Note that th 466 process and its parent. Note that this file format is incompatible
605 with previous v0/v1/v2 file formats, 467 with previous v0/v1/v2 file formats, so you will need updated tools
606 for processing it. A preliminary ver 468 for processing it. A preliminary version of these tools is available
607 at <http://www.gnu.org/software/acct 469 at <http://www.gnu.org/software/acct/>.
608 470
609 config TASKSTATS 471 config TASKSTATS
610 bool "Export task/process statistics t 472 bool "Export task/process statistics through netlink"
611 depends on NET 473 depends on NET
612 depends on MULTIUSER 474 depends on MULTIUSER
613 default n 475 default n
614 help 476 help
615 Export selected statistics for tasks 477 Export selected statistics for tasks/processes through the
616 generic netlink interface. Unlike BS 478 generic netlink interface. Unlike BSD process accounting, the
617 statistics are available during the 479 statistics are available during the lifetime of tasks/processes as
618 responses to commands. Like BSD acco 480 responses to commands. Like BSD accounting, they are sent to user
619 space on task exit. 481 space on task exit.
620 482
621 Say N if unsure. 483 Say N if unsure.
622 484
623 config TASK_DELAY_ACCT 485 config TASK_DELAY_ACCT
624 bool "Enable per-task delay accounting 486 bool "Enable per-task delay accounting"
625 depends on TASKSTATS 487 depends on TASKSTATS
626 select SCHED_INFO 488 select SCHED_INFO
627 help 489 help
628 Collect information on time spent by 490 Collect information on time spent by a task waiting for system
629 resources like cpu, synchronous bloc 491 resources like cpu, synchronous block I/O completion and swapping
630 in pages. Such statistics can help i 492 in pages. Such statistics can help in setting a task's priorities
631 relative to other tasks for cpu, io, 493 relative to other tasks for cpu, io, rss limits etc.
632 494
633 Say N if unsure. 495 Say N if unsure.
634 496
635 config TASK_XACCT 497 config TASK_XACCT
636 bool "Enable extended accounting over 498 bool "Enable extended accounting over taskstats"
637 depends on TASKSTATS 499 depends on TASKSTATS
638 help 500 help
639 Collect extended task accounting dat 501 Collect extended task accounting data and send the data
640 to userland for processing over the 502 to userland for processing over the taskstats interface.
641 503
642 Say N if unsure. 504 Say N if unsure.
643 505
644 config TASK_IO_ACCOUNTING 506 config TASK_IO_ACCOUNTING
645 bool "Enable per-task storage I/O acco 507 bool "Enable per-task storage I/O accounting"
646 depends on TASK_XACCT 508 depends on TASK_XACCT
647 help 509 help
648 Collect information on the number of 510 Collect information on the number of bytes of storage I/O which this
649 task has caused. 511 task has caused.
650 512
651 Say N if unsure. 513 Say N if unsure.
652 514
653 config PSI 515 config PSI
654 bool "Pressure stall information track 516 bool "Pressure stall information tracking"
655 select KERNFS <<
656 help 517 help
657 Collect metrics that indicate how ov 518 Collect metrics that indicate how overcommitted the CPU, memory,
658 and IO capacity are in the system. 519 and IO capacity are in the system.
659 520
660 If you say Y here, the kernel will c 521 If you say Y here, the kernel will create /proc/pressure/ with the
661 pressure statistics files cpu, memor 522 pressure statistics files cpu, memory, and io. These will indicate
662 the share of walltime in which some 523 the share of walltime in which some or all tasks in the system are
663 delayed due to contention of the res 524 delayed due to contention of the respective resource.
664 525
665 In kernels with cgroup support, cgro 526 In kernels with cgroup support, cgroups (cgroup2 only) will
666 have cpu.pressure, memory.pressure, 527 have cpu.pressure, memory.pressure, and io.pressure files,
667 which aggregate pressure stalls for 528 which aggregate pressure stalls for the grouped tasks only.
668 529
669 For more details see Documentation/a 530 For more details see Documentation/accounting/psi.rst.
670 531
671 Say N if unsure. 532 Say N if unsure.
672 533
673 config PSI_DEFAULT_DISABLED 534 config PSI_DEFAULT_DISABLED
674 bool "Require boot parameter to enable 535 bool "Require boot parameter to enable pressure stall information tracking"
675 default n 536 default n
676 depends on PSI 537 depends on PSI
677 help 538 help
678 If set, pressure stall information t 539 If set, pressure stall information tracking will be disabled
679 per default but can be enabled throu 540 per default but can be enabled through passing psi=1 on the
680 kernel commandline during boot. 541 kernel commandline during boot.
681 542
682 This feature adds some code to the t 543 This feature adds some code to the task wakeup and sleep
683 paths of the scheduler. The overhead 544 paths of the scheduler. The overhead is too low to affect
684 common scheduling-intense workloads 545 common scheduling-intense workloads in practice (such as
685 webservers, memcache), but it does s 546 webservers, memcache), but it does show up in artificial
686 scheduler stress tests, such as hack 547 scheduler stress tests, such as hackbench.
687 548
688 If you are paranoid and not sure wha 549 If you are paranoid and not sure what the kernel will be
689 used for, say Y. 550 used for, say Y.
690 551
691 Say N if unsure. 552 Say N if unsure.
692 553
693 endmenu # "CPU/Task time and stats accounting" 554 endmenu # "CPU/Task time and stats accounting"
694 555
695 config CPU_ISOLATION 556 config CPU_ISOLATION
696 bool "CPU isolation" 557 bool "CPU isolation"
697 depends on SMP || COMPILE_TEST 558 depends on SMP || COMPILE_TEST
698 default y 559 default y
699 help 560 help
700 Make sure that CPUs running critical 561 Make sure that CPUs running critical tasks are not disturbed by
701 any source of "noise" such as unboun 562 any source of "noise" such as unbound workqueues, timers, kthreads...
702 Unbound jobs get offloaded to housek 563 Unbound jobs get offloaded to housekeeping CPUs. This is driven by
703 the "isolcpus=" boot parameter. 564 the "isolcpus=" boot parameter.
704 565
705 Say Y if unsure. 566 Say Y if unsure.
706 567
707 source "kernel/rcu/Kconfig" 568 source "kernel/rcu/Kconfig"
708 569
>> 570 config BUILD_BIN2C
>> 571 bool
>> 572 default n
>> 573
709 config IKCONFIG 574 config IKCONFIG
710 tristate "Kernel .config support" 575 tristate "Kernel .config support"
711 help !! 576 ---help---
712 This option enables the complete Lin 577 This option enables the complete Linux kernel ".config" file
713 contents to be saved in the kernel. 578 contents to be saved in the kernel. It provides documentation
714 of which kernel options are used in 579 of which kernel options are used in a running kernel or in an
715 on-disk kernel. This information ca 580 on-disk kernel. This information can be extracted from the kernel
716 image file with the script scripts/e 581 image file with the script scripts/extract-ikconfig and used as
717 input to rebuild the current kernel 582 input to rebuild the current kernel or to build another kernel.
718 It can also be extracted from a runn 583 It can also be extracted from a running kernel by reading
719 /proc/config.gz if enabled (below). 584 /proc/config.gz if enabled (below).
720 585
721 config IKCONFIG_PROC 586 config IKCONFIG_PROC
722 bool "Enable access to .config through 587 bool "Enable access to .config through /proc/config.gz"
723 depends on IKCONFIG && PROC_FS 588 depends on IKCONFIG && PROC_FS
724 help !! 589 ---help---
725 This option enables access to the ke 590 This option enables access to the kernel configuration file
726 through /proc/config.gz. 591 through /proc/config.gz.
727 592
728 config IKHEADERS 593 config IKHEADERS
729 tristate "Enable kernel headers throug 594 tristate "Enable kernel headers through /sys/kernel/kheaders.tar.xz"
730 depends on SYSFS 595 depends on SYSFS
731 help 596 help
732 This option enables access to the in 597 This option enables access to the in-kernel headers that are generated during
733 the build process. These can be used 598 the build process. These can be used to build eBPF tracing programs,
734 or similar programs. If you build t 599 or similar programs. If you build the headers as a module, a module called
735 kheaders.ko is built which can be lo 600 kheaders.ko is built which can be loaded on-demand to get access to headers.
736 601
737 config LOG_BUF_SHIFT 602 config LOG_BUF_SHIFT
738 int "Kernel log buffer size (16 => 64K 603 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
739 range 12 25 604 range 12 25
740 default 17 605 default 17
741 depends on PRINTK 606 depends on PRINTK
742 help 607 help
743 Select the minimal kernel log buffer 608 Select the minimal kernel log buffer size as a power of 2.
744 The final size is affected by LOG_CP 609 The final size is affected by LOG_CPU_MAX_BUF_SHIFT config
745 parameter, see below. Any higher siz 610 parameter, see below. Any higher size also might be forced
746 by "log_buf_len" boot parameter. 611 by "log_buf_len" boot parameter.
747 612
748 Examples: 613 Examples:
749 17 => 128 KB 614 17 => 128 KB
750 16 => 64 KB 615 16 => 64 KB
751 15 => 32 KB 616 15 => 32 KB
752 14 => 16 KB 617 14 => 16 KB
753 13 => 8 KB 618 13 => 8 KB
754 12 => 4 KB 619 12 => 4 KB
755 620
756 config LOG_CPU_MAX_BUF_SHIFT 621 config LOG_CPU_MAX_BUF_SHIFT
757 int "CPU kernel log buffer size contri 622 int "CPU kernel log buffer size contribution (13 => 8 KB, 17 => 128KB)"
758 depends on SMP 623 depends on SMP
759 range 0 21 624 range 0 21
>> 625 default 12 if !BASE_SMALL
760 default 0 if BASE_SMALL 626 default 0 if BASE_SMALL
761 default 12 <<
762 depends on PRINTK 627 depends on PRINTK
763 help 628 help
764 This option allows to increase the d 629 This option allows to increase the default ring buffer size
765 according to the number of CPUs. The 630 according to the number of CPUs. The value defines the contribution
766 of each CPU as a power of 2. The use 631 of each CPU as a power of 2. The used space is typically only few
767 lines however it might be much more 632 lines however it might be much more when problems are reported,
768 e.g. backtraces. 633 e.g. backtraces.
769 634
770 The increased size means that a new 635 The increased size means that a new buffer has to be allocated and
771 the original static one is unused. I 636 the original static one is unused. It makes sense only on systems
772 with more CPUs. Therefore this value 637 with more CPUs. Therefore this value is used only when the sum of
773 contributions is greater than the ha 638 contributions is greater than the half of the default kernel ring
774 buffer as defined by LOG_BUF_SHIFT. 639 buffer as defined by LOG_BUF_SHIFT. The default values are set
775 so that more than 16 CPUs are needed !! 640 so that more than 64 CPUs are needed to trigger the allocation.
776 641
777 Also this option is ignored when "lo 642 Also this option is ignored when "log_buf_len" kernel parameter is
778 used as it forces an exact (power of 643 used as it forces an exact (power of two) size of the ring buffer.
779 644
780 The number of possible CPUs is used 645 The number of possible CPUs is used for this computation ignoring
781 hotplugging making the computation o 646 hotplugging making the computation optimal for the worst case
782 scenario while allowing a simple alg 647 scenario while allowing a simple algorithm to be used from bootup.
783 648
784 Examples shift values and their mean 649 Examples shift values and their meaning:
785 17 => 128 KB for each CPU 650 17 => 128 KB for each CPU
786 16 => 64 KB for each CPU 651 16 => 64 KB for each CPU
787 15 => 32 KB for each CPU 652 15 => 32 KB for each CPU
788 14 => 16 KB for each CPU 653 14 => 16 KB for each CPU
789 13 => 8 KB for each CPU 654 13 => 8 KB for each CPU
790 12 => 4 KB for each CPU 655 12 => 4 KB for each CPU
791 656
792 config PRINTK_INDEX !! 657 config PRINTK_SAFE_LOG_BUF_SHIFT
793 bool "Printk indexing debugfs interfac !! 658 int "Temporary per-CPU printk log buffer size (12 => 4KB, 13 => 8KB)"
794 depends on PRINTK && DEBUG_FS !! 659 range 10 21
795 help !! 660 default 13
796 Add support for indexing of all prin !! 661 depends on PRINTK
797 at <debugfs>/printk/index/<module>. !! 662 help
798 !! 663 Select the size of an alternate printk per-CPU buffer where messages
799 This can be used as part of maintain !! 664 printed from usafe contexts are temporary stored. One example would
800 /dev/kmsg, as it permits auditing th !! 665 be NMI messages, another one - printk recursion. The messages are
801 kernel, allowing detection of cases !! 666 copied to the main log buffer in a safe context to avoid a deadlock.
802 changed or no longer present. !! 667 The value defines the size as a power of 2.
>> 668
>> 669 Those messages are rare and limited. The largest one is when
>> 670 a backtrace is printed. It usually fits into 4KB. Select
>> 671 8KB if you want to be on the safe side.
803 672
804 There is no additional runtime cost !! 673 Examples:
>> 674 17 => 128 KB for each CPU
>> 675 16 => 64 KB for each CPU
>> 676 15 => 32 KB for each CPU
>> 677 14 => 16 KB for each CPU
>> 678 13 => 8 KB for each CPU
>> 679 12 => 4 KB for each CPU
805 680
806 # 681 #
807 # Architectures with an unreliable sched_clock 682 # Architectures with an unreliable sched_clock() should select this:
808 # 683 #
809 config HAVE_UNSTABLE_SCHED_CLOCK 684 config HAVE_UNSTABLE_SCHED_CLOCK
810 bool 685 bool
811 686
812 config GENERIC_SCHED_CLOCK 687 config GENERIC_SCHED_CLOCK
813 bool 688 bool
814 689
815 menu "Scheduler features" 690 menu "Scheduler features"
816 691
817 config UCLAMP_TASK 692 config UCLAMP_TASK
818 bool "Enable utilization clamping for 693 bool "Enable utilization clamping for RT/FAIR tasks"
819 depends on CPU_FREQ_GOV_SCHEDUTIL 694 depends on CPU_FREQ_GOV_SCHEDUTIL
820 help 695 help
821 This feature enables the scheduler t 696 This feature enables the scheduler to track the clamped utilization
822 of each CPU based on RUNNABLE tasks 697 of each CPU based on RUNNABLE tasks scheduled on that CPU.
823 698
824 With this option, the user can speci 699 With this option, the user can specify the min and max CPU
825 utilization allowed for RUNNABLE tas 700 utilization allowed for RUNNABLE tasks. The max utilization defines
826 the maximum frequency a task should 701 the maximum frequency a task should use while the min utilization
827 defines the minimum frequency it sho 702 defines the minimum frequency it should use.
828 703
829 Both min and max utilization clamp v 704 Both min and max utilization clamp values are hints to the scheduler,
830 aiming at improving its frequency se 705 aiming at improving its frequency selection policy, but they do not
831 enforce or grant any specific bandwi 706 enforce or grant any specific bandwidth for tasks.
832 707
833 If in doubt, say N. 708 If in doubt, say N.
834 709
835 config UCLAMP_BUCKETS_COUNT 710 config UCLAMP_BUCKETS_COUNT
836 int "Number of supported utilization c 711 int "Number of supported utilization clamp buckets"
837 range 5 20 712 range 5 20
838 default 5 713 default 5
839 depends on UCLAMP_TASK 714 depends on UCLAMP_TASK
840 help 715 help
841 Defines the number of clamp buckets 716 Defines the number of clamp buckets to use. The range of each bucket
842 will be SCHED_CAPACITY_SCALE/UCLAMP_ 717 will be SCHED_CAPACITY_SCALE/UCLAMP_BUCKETS_COUNT. The higher the
843 number of clamp buckets the finer th 718 number of clamp buckets the finer their granularity and the higher
844 the precision of clamping aggregatio 719 the precision of clamping aggregation and tracking at run-time.
845 720
846 For example, with the minimum config 721 For example, with the minimum configuration value we will have 5
847 clamp buckets tracking 20% utilizati 722 clamp buckets tracking 20% utilization each. A 25% boosted tasks will
848 be refcounted in the [20..39]% bucke 723 be refcounted in the [20..39]% bucket and will set the bucket clamp
849 effective value to 25%. 724 effective value to 25%.
850 If a second 30% boosted task should 725 If a second 30% boosted task should be co-scheduled on the same CPU,
851 that task will be refcounted in the 726 that task will be refcounted in the same bucket of the first task and
852 it will boost the bucket clamp effec 727 it will boost the bucket clamp effective value to 30%.
853 The clamp effective value of a bucke 728 The clamp effective value of a bucket is reset to its nominal value
854 (20% in the example above) when ther 729 (20% in the example above) when there are no more tasks refcounted in
855 that bucket. 730 that bucket.
856 731
857 An additional boost/capping margin c 732 An additional boost/capping margin can be added to some tasks. In the
858 example above the 25% task will be b 733 example above the 25% task will be boosted to 30% until it exits the
859 CPU. If that should be considered no 734 CPU. If that should be considered not acceptable on certain systems,
860 it's always possible to reduce the m 735 it's always possible to reduce the margin by increasing the number of
861 clamp buckets to trade off used memo 736 clamp buckets to trade off used memory for run-time tracking
862 precision. 737 precision.
863 738
864 If in doubt, use the default value. 739 If in doubt, use the default value.
865 740
866 endmenu 741 endmenu
867 742
868 # 743 #
869 # For architectures that want to enable the su 744 # For architectures that want to enable the support for NUMA-affine scheduler
870 # balancing logic: 745 # balancing logic:
871 # 746 #
872 config ARCH_SUPPORTS_NUMA_BALANCING 747 config ARCH_SUPPORTS_NUMA_BALANCING
873 bool 748 bool
874 749
875 # 750 #
876 # For architectures that prefer to flush all T 751 # For architectures that prefer to flush all TLBs after a number of pages
877 # are unmapped instead of sending one IPI per 752 # are unmapped instead of sending one IPI per page to flush. The architecture
878 # must provide guarantees on what happens if a 753 # must provide guarantees on what happens if a clean TLB cache entry is
879 # written after the unmap. Details are in mm/r 754 # written after the unmap. Details are in mm/rmap.c near the check for
880 # should_defer_flush. The architecture should 755 # should_defer_flush. The architecture should also consider if the full flush
881 # and the refill costs are offset by the savin 756 # and the refill costs are offset by the savings of sending fewer IPIs.
882 config ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 757 config ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
883 bool 758 bool
884 759
885 config CC_HAS_INT128 760 config CC_HAS_INT128
886 def_bool !$(cc-option,$(m64-flag) -D__ 761 def_bool !$(cc-option,$(m64-flag) -D__SIZEOF_INT128__=0) && 64BIT
887 762
888 config CC_IMPLICIT_FALLTHROUGH <<
889 string <<
890 default "-Wimplicit-fallthrough=5" if <<
891 default "-Wimplicit-fallthrough" if CC <<
892 <<
893 # Currently, disable gcc-10+ array-bounds glob <<
894 # It's still broken in gcc-13, so no upper bou <<
895 config GCC10_NO_ARRAY_BOUNDS <<
896 def_bool y <<
897 <<
898 config CC_NO_ARRAY_BOUNDS <<
899 bool <<
900 default y if CC_IS_GCC && GCC_VERSION <<
901 <<
902 # Currently, disable -Wstringop-overflow for G <<
903 config GCC_NO_STRINGOP_OVERFLOW <<
904 def_bool y <<
905 <<
906 config CC_NO_STRINGOP_OVERFLOW <<
907 bool <<
908 default y if CC_IS_GCC && GCC_NO_STRIN <<
909 <<
910 config CC_STRINGOP_OVERFLOW <<
911 bool <<
912 default y if CC_IS_GCC && !CC_NO_STRIN <<
913 <<
914 # 763 #
915 # For architectures that know their GCC __int1 764 # For architectures that know their GCC __int128 support is sound
916 # 765 #
917 config ARCH_SUPPORTS_INT128 766 config ARCH_SUPPORTS_INT128
918 bool 767 bool
919 768
920 # For architectures that (ab)use NUMA to repre 769 # For architectures that (ab)use NUMA to represent different memory regions
921 # all cpu-local but of different latencies, su 770 # all cpu-local but of different latencies, such as SuperH.
922 # 771 #
923 config ARCH_WANT_NUMA_VARIABLE_LOCALITY 772 config ARCH_WANT_NUMA_VARIABLE_LOCALITY
924 bool 773 bool
925 774
926 config NUMA_BALANCING 775 config NUMA_BALANCING
927 bool "Memory placement aware NUMA sche 776 bool "Memory placement aware NUMA scheduler"
928 depends on ARCH_SUPPORTS_NUMA_BALANCIN 777 depends on ARCH_SUPPORTS_NUMA_BALANCING
929 depends on !ARCH_WANT_NUMA_VARIABLE_LO 778 depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
930 depends on SMP && NUMA && MIGRATION && !! 779 depends on SMP && NUMA && MIGRATION
931 help 780 help
932 This option adds support for automat 781 This option adds support for automatic NUMA aware memory/task placement.
933 The mechanism is quite primitive and 782 The mechanism is quite primitive and is based on migrating memory when
934 it has references to the node the ta 783 it has references to the node the task is running on.
935 784
936 This system will be inactive on UMA 785 This system will be inactive on UMA systems.
937 786
938 config NUMA_BALANCING_DEFAULT_ENABLED 787 config NUMA_BALANCING_DEFAULT_ENABLED
939 bool "Automatically enable NUMA aware 788 bool "Automatically enable NUMA aware memory/task placement"
940 default y 789 default y
941 depends on NUMA_BALANCING 790 depends on NUMA_BALANCING
942 help 791 help
943 If set, automatic NUMA balancing wil 792 If set, automatic NUMA balancing will be enabled if running on a NUMA
944 machine. 793 machine.
945 794
946 config SLAB_OBJ_EXT <<
947 bool <<
948 <<
949 menuconfig CGROUPS 795 menuconfig CGROUPS
950 bool "Control Group support" 796 bool "Control Group support"
951 select KERNFS 797 select KERNFS
952 help 798 help
953 This option adds support for groupin 799 This option adds support for grouping sets of processes together, for
954 use with process control subsystems 800 use with process control subsystems such as Cpusets, CFS, memory
955 controls or device isolation. 801 controls or device isolation.
956 See 802 See
957 - Documentation/scheduler/sche 803 - Documentation/scheduler/sched-design-CFS.rst (CFS)
958 - Documentation/admin-guide/cg 804 - Documentation/admin-guide/cgroup-v1/ (features for grouping, isolation
959 and 805 and resource control)
960 806
961 Say N if unsure. 807 Say N if unsure.
962 808
963 if CGROUPS 809 if CGROUPS
964 810
965 config PAGE_COUNTER 811 config PAGE_COUNTER
966 bool 812 bool
967 813
968 config CGROUP_FAVOR_DYNMODS <<
969 bool "Favor dynamic modification laten <<
970 help <<
971 This option enables the "favordynmod <<
972 which reduces the latencies of dynam <<
973 as task migrations and controller on <<
974 hot path operations such as forks an <<
975 <<
976 Say N if unsure. <<
977 <<
978 config MEMCG 814 config MEMCG
979 bool "Memory controller" 815 bool "Memory controller"
980 select PAGE_COUNTER 816 select PAGE_COUNTER
981 select EVENTFD 817 select EVENTFD
982 select SLAB_OBJ_EXT <<
983 help 818 help
984 Provides control over the memory foo 819 Provides control over the memory footprint of tasks in a cgroup.
985 820
986 config MEMCG_V1 !! 821 config MEMCG_SWAP
987 bool "Legacy cgroup v1 memory controll !! 822 bool "Swap controller"
988 depends on MEMCG !! 823 depends on MEMCG && SWAP
989 default n <<
990 help 824 help
991 Legacy cgroup v1 memory controller w !! 825 Provides control over the swap space consumed by tasks in a cgroup.
992 cgroup v2 implementation. The v1 is <<
993 which haven't migrated to the new cg <<
994 do not have any such application the <<
995 this option disabled. <<
996 <<
997 Please note that feature set of the <<
998 going to shrink due to deprecation p <<
999 controller are highly discouraged. <<
1000 826
1001 Say N if unsure. !! 827 config MEMCG_SWAP_ENABLED
>> 828 bool "Swap controller enabled by default"
>> 829 depends on MEMCG_SWAP
>> 830 default y
>> 831 help
>> 832 Memory Resource Controller Swap Extension comes with its price in
>> 833 a bigger memory consumption. General purpose distribution kernels
>> 834 which want to enable the feature but keep it disabled by default
>> 835 and let the user enable it by swapaccount=1 boot command line
>> 836 parameter should have this option unselected.
>> 837 For those who want to have the feature enabled by default should
>> 838 select this option (if, for some reason, they need to disable it
>> 839 then swapaccount=0 does the trick).
>> 840
>> 841 config MEMCG_KMEM
>> 842 bool
>> 843 depends on MEMCG && !SLOB
>> 844 default y
1002 845
1003 config BLK_CGROUP 846 config BLK_CGROUP
1004 bool "IO controller" 847 bool "IO controller"
1005 depends on BLOCK 848 depends on BLOCK
1006 default n 849 default n
1007 help !! 850 ---help---
1008 Generic block IO controller cgroup in 851 Generic block IO controller cgroup interface. This is the common
1009 cgroup interface which should be used 852 cgroup interface which should be used by various IO controlling
1010 policies. 853 policies.
1011 854
1012 Currently, CFQ IO scheduler uses it t 855 Currently, CFQ IO scheduler uses it to recognize task groups and
1013 control disk bandwidth allocation (pr 856 control disk bandwidth allocation (proportional time slice allocation)
1014 to such task groups. It is also used 857 to such task groups. It is also used by bio throttling logic in
1015 block layer to implement upper limit 858 block layer to implement upper limit in IO rates on a device.
1016 859
1017 This option only enables generic Bloc 860 This option only enables generic Block IO controller infrastructure.
1018 One needs to also enable actual IO co 861 One needs to also enable actual IO controlling logic/policy. For
1019 enabling proportional weight division 862 enabling proportional weight division of disk bandwidth in CFQ, set
1020 CONFIG_BFQ_GROUP_IOSCHED=y; for enabl 863 CONFIG_BFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
1021 CONFIG_BLK_DEV_THROTTLING=y. 864 CONFIG_BLK_DEV_THROTTLING=y.
1022 865
1023 See Documentation/admin-guide/cgroup- 866 See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information.
1024 867
1025 config CGROUP_WRITEBACK 868 config CGROUP_WRITEBACK
1026 bool 869 bool
1027 depends on MEMCG && BLK_CGROUP 870 depends on MEMCG && BLK_CGROUP
1028 default y 871 default y
1029 872
1030 menuconfig CGROUP_SCHED 873 menuconfig CGROUP_SCHED
1031 bool "CPU controller" 874 bool "CPU controller"
1032 default n 875 default n
1033 help 876 help
1034 This feature lets CPU scheduler rec 877 This feature lets CPU scheduler recognize task groups and control CPU
1035 bandwidth allocation to such task g 878 bandwidth allocation to such task groups. It uses cgroups to group
1036 tasks. 879 tasks.
1037 880
1038 if CGROUP_SCHED 881 if CGROUP_SCHED
1039 config GROUP_SCHED_WEIGHT <<
1040 def_bool n <<
1041 <<
1042 config FAIR_GROUP_SCHED 882 config FAIR_GROUP_SCHED
1043 bool "Group scheduling for SCHED_OTHE 883 bool "Group scheduling for SCHED_OTHER"
1044 depends on CGROUP_SCHED 884 depends on CGROUP_SCHED
1045 select GROUP_SCHED_WEIGHT <<
1046 default CGROUP_SCHED 885 default CGROUP_SCHED
1047 886
1048 config CFS_BANDWIDTH 887 config CFS_BANDWIDTH
1049 bool "CPU bandwidth provisioning for 888 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
1050 depends on FAIR_GROUP_SCHED 889 depends on FAIR_GROUP_SCHED
1051 default n 890 default n
1052 help 891 help
1053 This option allows users to define 892 This option allows users to define CPU bandwidth rates (limits) for
1054 tasks running within the fair group 893 tasks running within the fair group scheduler. Groups with no limit
1055 set are considered to be unconstrai 894 set are considered to be unconstrained and will run with no
1056 restriction. 895 restriction.
1057 See Documentation/scheduler/sched-b 896 See Documentation/scheduler/sched-bwc.rst for more information.
1058 897
1059 config RT_GROUP_SCHED 898 config RT_GROUP_SCHED
1060 bool "Group scheduling for SCHED_RR/F 899 bool "Group scheduling for SCHED_RR/FIFO"
1061 depends on CGROUP_SCHED 900 depends on CGROUP_SCHED
1062 default n 901 default n
1063 help 902 help
1064 This feature lets you explicitly al 903 This feature lets you explicitly allocate real CPU bandwidth
1065 to task groups. If enabled, it will 904 to task groups. If enabled, it will also make it impossible to
1066 schedule realtime tasks for non-roo 905 schedule realtime tasks for non-root users until you allocate
1067 realtime bandwidth for them. 906 realtime bandwidth for them.
1068 See Documentation/scheduler/sched-r 907 See Documentation/scheduler/sched-rt-group.rst for more information.
1069 908
1070 config EXT_GROUP_SCHED <<
1071 bool <<
1072 depends on SCHED_CLASS_EXT && CGROUP_ <<
1073 select GROUP_SCHED_WEIGHT <<
1074 default y <<
1075 <<
1076 endif #CGROUP_SCHED 909 endif #CGROUP_SCHED
1077 910
1078 config SCHED_MM_CID <<
1079 def_bool y <<
1080 depends on SMP && RSEQ <<
1081 <<
1082 config UCLAMP_TASK_GROUP 911 config UCLAMP_TASK_GROUP
1083 bool "Utilization clamping per group 912 bool "Utilization clamping per group of tasks"
1084 depends on CGROUP_SCHED 913 depends on CGROUP_SCHED
1085 depends on UCLAMP_TASK 914 depends on UCLAMP_TASK
1086 default n 915 default n
1087 help 916 help
1088 This feature enables the scheduler 917 This feature enables the scheduler to track the clamped utilization
1089 of each CPU based on RUNNABLE tasks 918 of each CPU based on RUNNABLE tasks currently scheduled on that CPU.
1090 919
1091 When this option is enabled, the us 920 When this option is enabled, the user can specify a min and max
1092 CPU bandwidth which is allowed for 921 CPU bandwidth which is allowed for each single task in a group.
1093 The max bandwidth allows to clamp t 922 The max bandwidth allows to clamp the maximum frequency a task
1094 can use, while the min bandwidth al 923 can use, while the min bandwidth allows to define a minimum
1095 frequency a task will always use. 924 frequency a task will always use.
1096 925
1097 When task group based utilization c 926 When task group based utilization clamping is enabled, an eventually
1098 specified task-specific clamp value 927 specified task-specific clamp value is constrained by the cgroup
1099 specified clamp value. Both minimum 928 specified clamp value. Both minimum and maximum task clamping cannot
1100 be bigger than the corresponding cl 929 be bigger than the corresponding clamping defined at task group level.
1101 930
1102 If in doubt, say N. 931 If in doubt, say N.
1103 932
1104 config CGROUP_PIDS 933 config CGROUP_PIDS
1105 bool "PIDs controller" 934 bool "PIDs controller"
1106 help 935 help
1107 Provides enforcement of process num 936 Provides enforcement of process number limits in the scope of a
1108 cgroup. Any attempt to fork more pr 937 cgroup. Any attempt to fork more processes than is allowed in the
1109 cgroup will fail. PIDs are fundamen 938 cgroup will fail. PIDs are fundamentally a global resource because it
1110 is fairly trivial to reach PID exha 939 is fairly trivial to reach PID exhaustion before you reach even a
1111 conservative kmemcg limit. As a res 940 conservative kmemcg limit. As a result, it is possible to grind a
1112 system to halt without being limite 941 system to halt without being limited by other cgroup policies. The
1113 PIDs controller is designed to stop 942 PIDs controller is designed to stop this from happening.
1114 943
1115 It should be noted that organisatio 944 It should be noted that organisational operations (such as attaching
1116 to a cgroup hierarchy) will *not* b 945 to a cgroup hierarchy) will *not* be blocked by the PIDs controller,
1117 since the PIDs limit only affects a 946 since the PIDs limit only affects a process's ability to fork, not to
1118 attach to a cgroup. 947 attach to a cgroup.
1119 948
1120 config CGROUP_RDMA 949 config CGROUP_RDMA
1121 bool "RDMA controller" 950 bool "RDMA controller"
1122 help 951 help
1123 Provides enforcement of RDMA resour 952 Provides enforcement of RDMA resources defined by IB stack.
1124 It is fairly easy for consumers to 953 It is fairly easy for consumers to exhaust RDMA resources, which
1125 can result into resource unavailabi 954 can result into resource unavailability to other consumers.
1126 RDMA controller is designed to stop 955 RDMA controller is designed to stop this from happening.
1127 Attaching processes with active RDM 956 Attaching processes with active RDMA resources to the cgroup
1128 hierarchy is allowed even if can cr 957 hierarchy is allowed even if can cross the hierarchy's limit.
1129 958
1130 config CGROUP_FREEZER 959 config CGROUP_FREEZER
1131 bool "Freezer controller" 960 bool "Freezer controller"
1132 help 961 help
1133 Provides a way to freeze and unfree 962 Provides a way to freeze and unfreeze all tasks in a
1134 cgroup. 963 cgroup.
1135 964
1136 This option affects the ORIGINAL cg 965 This option affects the ORIGINAL cgroup interface. The cgroup2 memory
1137 controller includes important in-ke 966 controller includes important in-kernel memory consumers per default.
1138 967
1139 If you're using cgroup2, say N. 968 If you're using cgroup2, say N.
1140 969
1141 config CGROUP_HUGETLB 970 config CGROUP_HUGETLB
1142 bool "HugeTLB controller" 971 bool "HugeTLB controller"
1143 depends on HUGETLB_PAGE 972 depends on HUGETLB_PAGE
1144 select PAGE_COUNTER 973 select PAGE_COUNTER
1145 default n 974 default n
1146 help 975 help
1147 Provides a cgroup controller for Hu 976 Provides a cgroup controller for HugeTLB pages.
1148 When you enable this, you can put a 977 When you enable this, you can put a per cgroup limit on HugeTLB usage.
1149 The limit is enforced during page f 978 The limit is enforced during page fault. Since HugeTLB doesn't
1150 support page reclaim, enforcing the 979 support page reclaim, enforcing the limit at page fault time implies
1151 that, the application will get SIGB 980 that, the application will get SIGBUS signal if it tries to access
1152 HugeTLB pages beyond its limit. Thi 981 HugeTLB pages beyond its limit. This requires the application to know
1153 beforehand how much HugeTLB pages i 982 beforehand how much HugeTLB pages it would require for its use. The
1154 control group is tracked in the thi 983 control group is tracked in the third page lru pointer. This means
1155 that we cannot use the controller w 984 that we cannot use the controller with huge page less than 3 pages.
1156 985
1157 config CPUSETS 986 config CPUSETS
1158 bool "Cpuset controller" 987 bool "Cpuset controller"
1159 depends on SMP 988 depends on SMP
1160 help 989 help
1161 This option will let you create and 990 This option will let you create and manage CPUSETs which
1162 allow dynamically partitioning a sy 991 allow dynamically partitioning a system into sets of CPUs and
1163 Memory Nodes and assigning tasks to 992 Memory Nodes and assigning tasks to run only within those sets.
1164 This is primarily useful on large S 993 This is primarily useful on large SMP or NUMA systems.
1165 994
1166 Say N if unsure. 995 Say N if unsure.
1167 996
1168 config CPUSETS_V1 <<
1169 bool "Legacy cgroup v1 cpusets contro <<
1170 depends on CPUSETS <<
1171 default n <<
1172 help <<
1173 Legacy cgroup v1 cpusets controller <<
1174 cgroup v2 implementation. The v1 is <<
1175 which haven't migrated to the new c <<
1176 do not have any such application th <<
1177 this option disabled. <<
1178 <<
1179 Say N if unsure. <<
1180 <<
1181 config PROC_PID_CPUSET 997 config PROC_PID_CPUSET
1182 bool "Include legacy /proc/<pid>/cpus 998 bool "Include legacy /proc/<pid>/cpuset file"
1183 depends on CPUSETS 999 depends on CPUSETS
1184 default y 1000 default y
1185 1001
1186 config CGROUP_DEVICE 1002 config CGROUP_DEVICE
1187 bool "Device controller" 1003 bool "Device controller"
1188 help 1004 help
1189 Provides a cgroup controller implem 1005 Provides a cgroup controller implementing whitelists for
1190 devices which a process in the cgro 1006 devices which a process in the cgroup can mknod or open.
1191 1007
1192 config CGROUP_CPUACCT 1008 config CGROUP_CPUACCT
1193 bool "Simple CPU accounting controlle 1009 bool "Simple CPU accounting controller"
1194 help 1010 help
1195 Provides a simple controller for mo 1011 Provides a simple controller for monitoring the
1196 total CPU consumed by the tasks in 1012 total CPU consumed by the tasks in a cgroup.
1197 1013
1198 config CGROUP_PERF 1014 config CGROUP_PERF
1199 bool "Perf controller" 1015 bool "Perf controller"
1200 depends on PERF_EVENTS 1016 depends on PERF_EVENTS
1201 help 1017 help
1202 This option extends the perf per-cp 1018 This option extends the perf per-cpu mode to restrict monitoring
1203 to threads which belong to the cgro 1019 to threads which belong to the cgroup specified and run on the
1204 designated cpu. Or this can be use 1020 designated cpu. Or this can be used to have cgroup ID in samples
1205 so that it can monitor performance 1021 so that it can monitor performance events among cgroups.
1206 1022
1207 Say N if unsure. 1023 Say N if unsure.
1208 1024
1209 config CGROUP_BPF 1025 config CGROUP_BPF
1210 bool "Support for eBPF programs attac 1026 bool "Support for eBPF programs attached to cgroups"
1211 depends on BPF_SYSCALL 1027 depends on BPF_SYSCALL
1212 select SOCK_CGROUP_DATA 1028 select SOCK_CGROUP_DATA
1213 help 1029 help
1214 Allow attaching eBPF programs to a 1030 Allow attaching eBPF programs to a cgroup using the bpf(2)
1215 syscall command BPF_PROG_ATTACH. 1031 syscall command BPF_PROG_ATTACH.
1216 1032
1217 In which context these programs are 1033 In which context these programs are accessed depends on the type
1218 of attachment. For instance, progra 1034 of attachment. For instance, programs that are attached using
1219 BPF_CGROUP_INET_INGRESS will be exe 1035 BPF_CGROUP_INET_INGRESS will be executed on the ingress path of
1220 inet sockets. 1036 inet sockets.
1221 1037
1222 config CGROUP_MISC <<
1223 bool "Misc resource controller" <<
1224 default n <<
1225 help <<
1226 Provides a controller for miscellan <<
1227 <<
1228 Miscellaneous scalar resources are <<
1229 which cannot be abstracted like the <<
1230 tracks and limits the miscellaneous <<
1231 attached to a cgroup hierarchy. <<
1232 <<
1233 For more information, please check <<
1234 /Documentation/admin-guide/cgroup-v <<
1235 <<
1236 config CGROUP_DEBUG 1038 config CGROUP_DEBUG
1237 bool "Debug controller" 1039 bool "Debug controller"
1238 default n 1040 default n
1239 depends on DEBUG_KERNEL 1041 depends on DEBUG_KERNEL
1240 help 1042 help
1241 This option enables a simple contro 1043 This option enables a simple controller that exports
1242 debugging information about the cgr 1044 debugging information about the cgroups framework. This
1243 controller is for control cgroup de 1045 controller is for control cgroup debugging only. Its
1244 interfaces are not stable. 1046 interfaces are not stable.
1245 1047
1246 Say N. 1048 Say N.
1247 1049
1248 config SOCK_CGROUP_DATA 1050 config SOCK_CGROUP_DATA
1249 bool 1051 bool
1250 default n 1052 default n
1251 1053
1252 endif # CGROUPS 1054 endif # CGROUPS
1253 1055
1254 menuconfig NAMESPACES 1056 menuconfig NAMESPACES
1255 bool "Namespaces support" if EXPERT 1057 bool "Namespaces support" if EXPERT
1256 depends on MULTIUSER 1058 depends on MULTIUSER
1257 default !EXPERT 1059 default !EXPERT
1258 help 1060 help
1259 Provides the way to make tasks work 1061 Provides the way to make tasks work with different objects using
1260 the same id. For example same IPC i 1062 the same id. For example same IPC id may refer to different objects
1261 or same user id or pid may refer to 1063 or same user id or pid may refer to different tasks when used in
1262 different namespaces. 1064 different namespaces.
1263 1065
1264 if NAMESPACES 1066 if NAMESPACES
1265 1067
1266 config UTS_NS 1068 config UTS_NS
1267 bool "UTS namespace" 1069 bool "UTS namespace"
1268 default y 1070 default y
1269 help 1071 help
1270 In this namespace tasks see differe 1072 In this namespace tasks see different info provided with the
1271 uname() system call 1073 uname() system call
1272 1074
1273 config TIME_NS 1075 config TIME_NS
1274 bool "TIME namespace" 1076 bool "TIME namespace"
1275 depends on GENERIC_VDSO_TIME_NS 1077 depends on GENERIC_VDSO_TIME_NS
1276 default y 1078 default y
1277 help 1079 help
1278 In this namespace boottime and mono 1080 In this namespace boottime and monotonic clocks can be set.
1279 The time will keep going with the s 1081 The time will keep going with the same pace.
1280 1082
1281 config IPC_NS 1083 config IPC_NS
1282 bool "IPC namespace" 1084 bool "IPC namespace"
1283 depends on (SYSVIPC || POSIX_MQUEUE) 1085 depends on (SYSVIPC || POSIX_MQUEUE)
1284 default y 1086 default y
1285 help 1087 help
1286 In this namespace tasks work with I 1088 In this namespace tasks work with IPC ids which correspond to
1287 different IPC objects in different 1089 different IPC objects in different namespaces.
1288 1090
1289 config USER_NS 1091 config USER_NS
1290 bool "User namespace" 1092 bool "User namespace"
1291 default n 1093 default n
1292 help 1094 help
1293 This allows containers, i.e. vserve 1095 This allows containers, i.e. vservers, to use user namespaces
1294 to provide different user info for 1096 to provide different user info for different servers.
1295 1097
1296 When user namespaces are enabled in 1098 When user namespaces are enabled in the kernel it is
1297 recommended that the MEMCG option a 1099 recommended that the MEMCG option also be enabled and that
1298 user-space use the memory control g 1100 user-space use the memory control groups to limit the amount
1299 of memory a memory unprivileged use 1101 of memory a memory unprivileged users can use.
1300 1102
1301 If unsure, say N. 1103 If unsure, say N.
1302 1104
1303 config PID_NS 1105 config PID_NS
1304 bool "PID Namespaces" 1106 bool "PID Namespaces"
1305 default y 1107 default y
1306 help 1108 help
1307 Support process id namespaces. Thi 1109 Support process id namespaces. This allows having multiple
1308 processes with the same pid as long 1110 processes with the same pid as long as they are in different
1309 pid namespaces. This is a building 1111 pid namespaces. This is a building block of containers.
1310 1112
1311 config NET_NS 1113 config NET_NS
1312 bool "Network namespace" 1114 bool "Network namespace"
1313 depends on NET 1115 depends on NET
1314 default y 1116 default y
1315 help 1117 help
1316 Allow user space to create what app 1118 Allow user space to create what appear to be multiple instances
1317 of the network stack. 1119 of the network stack.
1318 1120
1319 endif # NAMESPACES 1121 endif # NAMESPACES
1320 1122
1321 config CHECKPOINT_RESTORE 1123 config CHECKPOINT_RESTORE
1322 bool "Checkpoint/restore support" 1124 bool "Checkpoint/restore support"
1323 depends on PROC_FS <<
1324 select PROC_CHILDREN 1125 select PROC_CHILDREN
1325 select KCMP <<
1326 default n 1126 default n
1327 help 1127 help
1328 Enables additional kernel features 1128 Enables additional kernel features in a sake of checkpoint/restore.
1329 In particular it adds auxiliary prc 1129 In particular it adds auxiliary prctl codes to setup process text,
1330 data and heap segment sizes, and a 1130 data and heap segment sizes, and a few additional /proc filesystem
1331 entries. 1131 entries.
1332 1132
1333 If unsure, say N here. 1133 If unsure, say N here.
1334 1134
1335 config SCHED_AUTOGROUP 1135 config SCHED_AUTOGROUP
1336 bool "Automatic process group schedul 1136 bool "Automatic process group scheduling"
1337 select CGROUPS 1137 select CGROUPS
1338 select CGROUP_SCHED 1138 select CGROUP_SCHED
1339 select FAIR_GROUP_SCHED 1139 select FAIR_GROUP_SCHED
1340 help 1140 help
1341 This option optimizes the scheduler 1141 This option optimizes the scheduler for common desktop workloads by
1342 automatically creating and populati 1142 automatically creating and populating task groups. This separation
1343 of workloads isolates aggressive CP 1143 of workloads isolates aggressive CPU burners (like build jobs) from
1344 desktop applications. Task group a 1144 desktop applications. Task group autogeneration is currently based
1345 upon task session. 1145 upon task session.
1346 1146
>> 1147 config SYSFS_DEPRECATED
>> 1148 bool "Enable deprecated sysfs features to support old userspace tools"
>> 1149 depends on SYSFS
>> 1150 default n
>> 1151 help
>> 1152 This option adds code that switches the layout of the "block" class
>> 1153 devices, to not show up in /sys/class/block/, but only in
>> 1154 /sys/block/.
>> 1155
>> 1156 This switch is only active when the sysfs.deprecated=1 boot option is
>> 1157 passed or the SYSFS_DEPRECATED_V2 option is set.
>> 1158
>> 1159 This option allows new kernels to run on old distributions and tools,
>> 1160 which might get confused by /sys/class/block/. Since 2007/2008 all
>> 1161 major distributions and tools handle this just fine.
>> 1162
>> 1163 Recent distributions and userspace tools after 2009/2010 depend on
>> 1164 the existence of /sys/class/block/, and will not work with this
>> 1165 option enabled.
>> 1166
>> 1167 Only if you are using a new kernel on an old distribution, you might
>> 1168 need to say Y here.
>> 1169
>> 1170 config SYSFS_DEPRECATED_V2
>> 1171 bool "Enable deprecated sysfs features by default"
>> 1172 default n
>> 1173 depends on SYSFS
>> 1174 depends on SYSFS_DEPRECATED
>> 1175 help
>> 1176 Enable deprecated sysfs by default.
>> 1177
>> 1178 See the CONFIG_SYSFS_DEPRECATED option for more details about this
>> 1179 option.
>> 1180
>> 1181 Only if you are using a new kernel on an old distribution, you might
>> 1182 need to say Y here. Even then, odds are you would not need it
>> 1183 enabled, you can always pass the boot option if absolutely necessary.
>> 1184
1347 config RELAY 1185 config RELAY
1348 bool "Kernel->user space relay suppor 1186 bool "Kernel->user space relay support (formerly relayfs)"
1349 select IRQ_WORK 1187 select IRQ_WORK
1350 help 1188 help
1351 This option enables support for rel 1189 This option enables support for relay interface support in
1352 certain file systems (such as debug 1190 certain file systems (such as debugfs).
1353 It is designed to provide an effici 1191 It is designed to provide an efficient mechanism for tools and
1354 facilities to relay large amounts o 1192 facilities to relay large amounts of data from kernel space to
1355 user space. 1193 user space.
1356 1194
1357 If unsure, say N. 1195 If unsure, say N.
1358 1196
1359 config BLK_DEV_INITRD 1197 config BLK_DEV_INITRD
1360 bool "Initial RAM filesystem and RAM 1198 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1361 help 1199 help
1362 The initial RAM filesystem is a ram 1200 The initial RAM filesystem is a ramfs which is loaded by the
1363 boot loader (loadlin or lilo) and t 1201 boot loader (loadlin or lilo) and that is mounted as root
1364 before the normal boot procedure. I 1202 before the normal boot procedure. It is typically used to
1365 load modules needed to mount the "r 1203 load modules needed to mount the "real" root file system,
1366 etc. See <file:Documentation/admin- 1204 etc. See <file:Documentation/admin-guide/initrd.rst> for details.
1367 1205
1368 If RAM disk support (BLK_DEV_RAM) i 1206 If RAM disk support (BLK_DEV_RAM) is also included, this
1369 also enables initial RAM disk (init 1207 also enables initial RAM disk (initrd) support and adds
1370 15 Kbytes (more on some other archi 1208 15 Kbytes (more on some other architectures) to the kernel size.
1371 1209
1372 If unsure say Y. 1210 If unsure say Y.
1373 1211
1374 if BLK_DEV_INITRD 1212 if BLK_DEV_INITRD
1375 1213
1376 source "usr/Kconfig" 1214 source "usr/Kconfig"
1377 1215
1378 endif 1216 endif
1379 1217
1380 config BOOT_CONFIG 1218 config BOOT_CONFIG
1381 bool "Boot config support" 1219 bool "Boot config support"
1382 select BLK_DEV_INITRD if !BOOT_CONFIG !! 1220 select BLK_DEV_INITRD
1383 help 1221 help
1384 Extra boot config allows system adm 1222 Extra boot config allows system admin to pass a config file as
1385 complemental extension of kernel cm 1223 complemental extension of kernel cmdline when booting.
1386 The boot config file must be attach 1224 The boot config file must be attached at the end of initramfs
1387 with checksum, size and magic word. 1225 with checksum, size and magic word.
1388 See <file:Documentation/admin-guide 1226 See <file:Documentation/admin-guide/bootconfig.rst> for details.
1389 1227
1390 If unsure, say Y. 1228 If unsure, say Y.
1391 1229
1392 config BOOT_CONFIG_FORCE <<
1393 bool "Force unconditional bootconfig <<
1394 depends on BOOT_CONFIG <<
1395 default y if BOOT_CONFIG_EMBED <<
1396 help <<
1397 With this Kconfig option set, BOOT_ <<
1398 out even when the "bootconfig" kern <<
1399 In fact, with this Kconfig option s <<
1400 make the kernel ignore the BOOT_CON <<
1401 parameters. <<
1402 <<
1403 If unsure, say N. <<
1404 <<
1405 config BOOT_CONFIG_EMBED <<
1406 bool "Embed bootconfig file in the ke <<
1407 depends on BOOT_CONFIG <<
1408 help <<
1409 Embed a bootconfig file given by BO <<
1410 kernel. Usually, the bootconfig fil <<
1411 image. But if the system doesn't su <<
1412 help you by embedding a bootconfig <<
1413 <<
1414 If unsure, say N. <<
1415 <<
1416 config BOOT_CONFIG_EMBED_FILE <<
1417 string "Embedded bootconfig file path <<
1418 depends on BOOT_CONFIG_EMBED <<
1419 help <<
1420 Specify a bootconfig file which wil <<
1421 This bootconfig will be used if the <<
1422 bootconfig in the initrd. <<
1423 <<
1424 config INITRAMFS_PRESERVE_MTIME <<
1425 bool "Preserve cpio archive mtimes in <<
1426 default y <<
1427 help <<
1428 Each entry in an initramfs cpio arc <<
1429 enabled, extracted cpio items take <<
1430 setting deferred until after creati <<
1431 <<
1432 If unsure, say Y. <<
1433 <<
1434 choice 1230 choice
1435 prompt "Compiler optimization level" 1231 prompt "Compiler optimization level"
1436 default CC_OPTIMIZE_FOR_PERFORMANCE 1232 default CC_OPTIMIZE_FOR_PERFORMANCE
1437 1233
1438 config CC_OPTIMIZE_FOR_PERFORMANCE 1234 config CC_OPTIMIZE_FOR_PERFORMANCE
1439 bool "Optimize for performance (-O2)" 1235 bool "Optimize for performance (-O2)"
1440 help 1236 help
1441 This is the default optimization le 1237 This is the default optimization level for the kernel, building
1442 with the "-O2" compiler flag for be 1238 with the "-O2" compiler flag for best performance and most
1443 helpful compile-time warnings. 1239 helpful compile-time warnings.
1444 1240
>> 1241 config CC_OPTIMIZE_FOR_PERFORMANCE_O3
>> 1242 bool "Optimize more for performance (-O3)"
>> 1243 depends on ARC
>> 1244 help
>> 1245 Choosing this option will pass "-O3" to your compiler to optimize
>> 1246 the kernel yet more for performance.
>> 1247
1445 config CC_OPTIMIZE_FOR_SIZE 1248 config CC_OPTIMIZE_FOR_SIZE
1446 bool "Optimize for size (-Os)" 1249 bool "Optimize for size (-Os)"
1447 help 1250 help
1448 Choosing this option will pass "-Os 1251 Choosing this option will pass "-Os" to your compiler resulting
1449 in a smaller kernel. 1252 in a smaller kernel.
1450 1253
1451 endchoice 1254 endchoice
1452 1255
1453 config HAVE_LD_DEAD_CODE_DATA_ELIMINATION 1256 config HAVE_LD_DEAD_CODE_DATA_ELIMINATION
1454 bool 1257 bool
1455 help 1258 help
1456 This requires that the arch annotat 1259 This requires that the arch annotates or otherwise protects
1457 its external entry points from bein 1260 its external entry points from being discarded. Linker scripts
1458 must also merge .text.*, .data.*, a 1261 must also merge .text.*, .data.*, and .bss.* correctly into
1459 output sections. Care must be taken 1262 output sections. Care must be taken not to pull in unrelated
1460 sections (e.g., '.text.init'). Typi 1263 sections (e.g., '.text.init'). Typically '.' in section names
1461 is used to distinguish them from la 1264 is used to distinguish them from label names / C identifiers.
1462 1265
1463 config LD_DEAD_CODE_DATA_ELIMINATION 1266 config LD_DEAD_CODE_DATA_ELIMINATION
1464 bool "Dead code and data elimination 1267 bool "Dead code and data elimination (EXPERIMENTAL)"
1465 depends on HAVE_LD_DEAD_CODE_DATA_ELI 1268 depends on HAVE_LD_DEAD_CODE_DATA_ELIMINATION
1466 depends on EXPERT 1269 depends on EXPERT
>> 1270 depends on !(FUNCTION_TRACER && CC_IS_GCC && GCC_VERSION < 40800)
1467 depends on $(cc-option,-ffunction-sec 1271 depends on $(cc-option,-ffunction-sections -fdata-sections)
1468 depends on $(ld-option,--gc-sections) 1272 depends on $(ld-option,--gc-sections)
1469 help 1273 help
1470 Enable this if you want to do dead 1274 Enable this if you want to do dead code and data elimination with
1471 the linker by compiling with -ffunc 1275 the linker by compiling with -ffunction-sections -fdata-sections,
1472 and linking with --gc-sections. 1276 and linking with --gc-sections.
1473 1277
1474 This can reduce on disk and in-memo 1278 This can reduce on disk and in-memory size of the kernel
1475 code and static data, particularly 1279 code and static data, particularly for small configs and
1476 on small systems. This has the poss 1280 on small systems. This has the possibility of introducing
1477 silently broken kernel if the requi 1281 silently broken kernel if the required annotations are not
1478 present. This option is not well te 1282 present. This option is not well tested yet, so use at your
1479 own risk. 1283 own risk.
1480 1284
1481 config LD_ORPHAN_WARN <<
1482 def_bool y <<
1483 depends on ARCH_WANT_LD_ORPHAN_WARN <<
1484 depends on $(ld-option,--orphan-handl <<
1485 depends on $(ld-option,--orphan-handl <<
1486 <<
1487 config LD_ORPHAN_WARN_LEVEL <<
1488 string <<
1489 depends on LD_ORPHAN_WARN <<
1490 default "error" if WERROR <<
1491 default "warn" <<
1492 <<
1493 config SYSCTL 1285 config SYSCTL
1494 bool 1286 bool
1495 1287
1496 config HAVE_UID16 1288 config HAVE_UID16
1497 bool 1289 bool
1498 1290
1499 config SYSCTL_EXCEPTION_TRACE 1291 config SYSCTL_EXCEPTION_TRACE
1500 bool 1292 bool
1501 help 1293 help
1502 Enable support for /proc/sys/debug/ 1294 Enable support for /proc/sys/debug/exception-trace.
1503 1295
1504 config SYSCTL_ARCH_UNALIGN_NO_WARN 1296 config SYSCTL_ARCH_UNALIGN_NO_WARN
1505 bool 1297 bool
1506 help 1298 help
1507 Enable support for /proc/sys/kernel 1299 Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
1508 Allows arch to define/use @no_unali 1300 Allows arch to define/use @no_unaligned_warning to possibly warn
1509 about unaligned access emulation go 1301 about unaligned access emulation going on under the hood.
1510 1302
1511 config SYSCTL_ARCH_UNALIGN_ALLOW 1303 config SYSCTL_ARCH_UNALIGN_ALLOW
1512 bool 1304 bool
1513 help 1305 help
1514 Enable support for /proc/sys/kernel 1306 Enable support for /proc/sys/kernel/unaligned-trap
1515 Allows arches to define/use @unalig 1307 Allows arches to define/use @unaligned_enabled to runtime toggle
1516 the unaligned access emulation. 1308 the unaligned access emulation.
1517 see arch/parisc/kernel/unaligned.c 1309 see arch/parisc/kernel/unaligned.c for reference
1518 1310
1519 config HAVE_PCSPKR_PLATFORM 1311 config HAVE_PCSPKR_PLATFORM
1520 bool 1312 bool
1521 1313
>> 1314 # interpreter that classic socket filters depend on
>> 1315 config BPF
>> 1316 bool
>> 1317
1522 menuconfig EXPERT 1318 menuconfig EXPERT
1523 bool "Configure standard kernel featu 1319 bool "Configure standard kernel features (expert users)"
1524 # Unhide debug options, to make the o 1320 # Unhide debug options, to make the on-by-default options visible
1525 select DEBUG_KERNEL 1321 select DEBUG_KERNEL
1526 help 1322 help
1527 This option allows certain base ker 1323 This option allows certain base kernel options and settings
1528 to be disabled or tweaked. This is 1324 to be disabled or tweaked. This is for specialized
1529 environments which can tolerate a " 1325 environments which can tolerate a "non-standard" kernel.
1530 Only use this if you really know wh 1326 Only use this if you really know what you are doing.
1531 1327
1532 config UID16 1328 config UID16
1533 bool "Enable 16-bit UID system calls" 1329 bool "Enable 16-bit UID system calls" if EXPERT
1534 depends on HAVE_UID16 && MULTIUSER 1330 depends on HAVE_UID16 && MULTIUSER
1535 default y 1331 default y
1536 help 1332 help
1537 This enables the legacy 16-bit UID 1333 This enables the legacy 16-bit UID syscall wrappers.
1538 1334
1539 config MULTIUSER 1335 config MULTIUSER
1540 bool "Multiple users, groups and capa 1336 bool "Multiple users, groups and capabilities support" if EXPERT
1541 default y 1337 default y
1542 help 1338 help
1543 This option enables support for non 1339 This option enables support for non-root users, groups and
1544 capabilities. 1340 capabilities.
1545 1341
1546 If you say N here, all processes wi 1342 If you say N here, all processes will run with UID 0, GID 0, and all
1547 possible capabilities. Saying N he 1343 possible capabilities. Saying N here also compiles out support for
1548 system calls related to UIDs, GIDs, 1344 system calls related to UIDs, GIDs, and capabilities, such as setuid,
1549 setgid, and capset. 1345 setgid, and capset.
1550 1346
1551 If unsure, say Y here. 1347 If unsure, say Y here.
1552 1348
1553 config SGETMASK_SYSCALL 1349 config SGETMASK_SYSCALL
1554 bool "sgetmask/ssetmask syscalls supp 1350 bool "sgetmask/ssetmask syscalls support" if EXPERT
1555 default PARISC || M68K || PPC || MIPS !! 1351 def_bool PARISC || M68K || PPC || MIPS || X86 || SPARC || MICROBLAZE || SUPERH
1556 help !! 1352 ---help---
1557 sys_sgetmask and sys_ssetmask are o 1353 sys_sgetmask and sys_ssetmask are obsolete system calls
1558 no longer supported in libc but sti 1354 no longer supported in libc but still enabled by default in some
1559 architectures. 1355 architectures.
1560 1356
1561 If unsure, leave the default option 1357 If unsure, leave the default option here.
1562 1358
1563 config SYSFS_SYSCALL 1359 config SYSFS_SYSCALL
1564 bool "Sysfs syscall support" if EXPER 1360 bool "Sysfs syscall support" if EXPERT
1565 default y 1361 default y
1566 help !! 1362 ---help---
1567 sys_sysfs is an obsolete system cal 1363 sys_sysfs is an obsolete system call no longer supported in libc.
1568 Note that disabling this option is 1364 Note that disabling this option is more secure but might break
1569 compatibility with some systems. 1365 compatibility with some systems.
1570 1366
1571 If unsure say Y here. 1367 If unsure say Y here.
1572 1368
1573 config FHANDLE 1369 config FHANDLE
1574 bool "open by fhandle syscalls" if EX 1370 bool "open by fhandle syscalls" if EXPERT
1575 select EXPORTFS 1371 select EXPORTFS
1576 default y 1372 default y
1577 help 1373 help
1578 If you say Y here, a user level pro 1374 If you say Y here, a user level program will be able to map
1579 file names to handle and then later 1375 file names to handle and then later use the handle for
1580 different file system operations. T 1376 different file system operations. This is useful in implementing
1581 userspace file servers, which now t 1377 userspace file servers, which now track files using handles instead
1582 of names. The handle would remain t 1378 of names. The handle would remain the same even if file names
1583 get renamed. Enables open_by_handle 1379 get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
1584 syscalls. 1380 syscalls.
1585 1381
1586 config POSIX_TIMERS 1382 config POSIX_TIMERS
1587 bool "Posix Clocks & timers" if EXPER 1383 bool "Posix Clocks & timers" if EXPERT
1588 default y 1384 default y
1589 help 1385 help
1590 This includes native support for PO 1386 This includes native support for POSIX timers to the kernel.
1591 Some embedded systems have no use f 1387 Some embedded systems have no use for them and therefore they
1592 can be configured out to reduce the 1388 can be configured out to reduce the size of the kernel image.
1593 1389
1594 When this option is disabled, the f 1390 When this option is disabled, the following syscalls won't be
1595 available: timer_create, timer_gett 1391 available: timer_create, timer_gettime: timer_getoverrun,
1596 timer_settime, timer_delete, clock_ 1392 timer_settime, timer_delete, clock_adjtime, getitimer,
1597 setitimer, alarm. Furthermore, the 1393 setitimer, alarm. Furthermore, the clock_settime, clock_gettime,
1598 clock_getres and clock_nanosleep sy 1394 clock_getres and clock_nanosleep syscalls will be limited to
1599 CLOCK_REALTIME, CLOCK_MONOTONIC and 1395 CLOCK_REALTIME, CLOCK_MONOTONIC and CLOCK_BOOTTIME only.
1600 1396
1601 If unsure say y. 1397 If unsure say y.
1602 1398
1603 config PRINTK 1399 config PRINTK
1604 default y 1400 default y
1605 bool "Enable support for printk" if E 1401 bool "Enable support for printk" if EXPERT
1606 select IRQ_WORK 1402 select IRQ_WORK
1607 help 1403 help
1608 This option enables normal printk s 1404 This option enables normal printk support. Removing it
1609 eliminates most of the message stri 1405 eliminates most of the message strings from the kernel image
1610 and makes the kernel more or less s 1406 and makes the kernel more or less silent. As this makes it
1611 very difficult to diagnose system p 1407 very difficult to diagnose system problems, saying N here is
1612 strongly discouraged. 1408 strongly discouraged.
1613 1409
>> 1410 config PRINTK_NMI
>> 1411 def_bool y
>> 1412 depends on PRINTK
>> 1413 depends on HAVE_NMI
>> 1414
1614 config BUG 1415 config BUG
1615 bool "BUG() support" if EXPERT 1416 bool "BUG() support" if EXPERT
1616 default y 1417 default y
1617 help 1418 help
1618 Disabling this option eliminates su 1419 Disabling this option eliminates support for BUG and WARN, reducing
1619 the size of your kernel image and p 1420 the size of your kernel image and potentially quietly ignoring
1620 numerous fatal conditions. You shou 1421 numerous fatal conditions. You should only consider disabling this
1621 option for embedded systems with no 1422 option for embedded systems with no facilities for reporting errors.
1622 Just say Y. 1423 Just say Y.
1623 1424
1624 config ELF_CORE 1425 config ELF_CORE
1625 depends on COREDUMP 1426 depends on COREDUMP
1626 default y 1427 default y
1627 bool "Enable ELF core dumps" if EXPER 1428 bool "Enable ELF core dumps" if EXPERT
1628 help 1429 help
1629 Enable support for generating core 1430 Enable support for generating core dumps. Disabling saves about 4k.
1630 1431
1631 1432
1632 config PCSPKR_PLATFORM 1433 config PCSPKR_PLATFORM
1633 bool "Enable PC-Speaker support" if E 1434 bool "Enable PC-Speaker support" if EXPERT
1634 depends on HAVE_PCSPKR_PLATFORM 1435 depends on HAVE_PCSPKR_PLATFORM
1635 select I8253_LOCK 1436 select I8253_LOCK
1636 default y 1437 default y
1637 help 1438 help
1638 This option allows to disable the i 1439 This option allows to disable the internal PC-Speaker
1639 support, saving some memory. 1440 support, saving some memory.
1640 1441
1641 config BASE_SMALL !! 1442 config BASE_FULL
1642 bool "Enable smaller-sized data struc !! 1443 default y
>> 1444 bool "Enable full-sized data structures for core" if EXPERT
1643 help 1445 help
1644 Enabling this option reduces the si !! 1446 Disabling this option reduces the size of miscellaneous core
1645 kernel data structures. This saves 1447 kernel data structures. This saves memory on small machines,
1646 but may reduce performance. 1448 but may reduce performance.
1647 1449
1648 config FUTEX 1450 config FUTEX
1649 bool "Enable futex support" if EXPERT 1451 bool "Enable futex support" if EXPERT
1650 depends on !(SPARC32 && SMP) <<
1651 default y 1452 default y
1652 imply RT_MUTEXES 1453 imply RT_MUTEXES
1653 help 1454 help
1654 Disabling this option will cause th 1455 Disabling this option will cause the kernel to be built without
1655 support for "fast userspace mutexes 1456 support for "fast userspace mutexes". The resulting kernel may not
1656 run glibc-based applications correc 1457 run glibc-based applications correctly.
1657 1458
1658 config FUTEX_PI 1459 config FUTEX_PI
1659 bool 1460 bool
1660 depends on FUTEX && RT_MUTEXES 1461 depends on FUTEX && RT_MUTEXES
1661 default y 1462 default y
1662 1463
>> 1464 config HAVE_FUTEX_CMPXCHG
>> 1465 bool
>> 1466 depends on FUTEX
>> 1467 help
>> 1468 Architectures should select this if futex_atomic_cmpxchg_inatomic()
>> 1469 is implemented and always working. This removes a couple of runtime
>> 1470 checks.
>> 1471
1663 config EPOLL 1472 config EPOLL
1664 bool "Enable eventpoll support" if EX 1473 bool "Enable eventpoll support" if EXPERT
1665 default y 1474 default y
1666 help 1475 help
1667 Disabling this option will cause th 1476 Disabling this option will cause the kernel to be built without
1668 support for epoll family of system 1477 support for epoll family of system calls.
1669 1478
1670 config SIGNALFD 1479 config SIGNALFD
1671 bool "Enable signalfd() system call" 1480 bool "Enable signalfd() system call" if EXPERT
1672 default y 1481 default y
1673 help 1482 help
1674 Enable the signalfd() system call t 1483 Enable the signalfd() system call that allows to receive signals
1675 on a file descriptor. 1484 on a file descriptor.
1676 1485
1677 If unsure, say Y. 1486 If unsure, say Y.
1678 1487
1679 config TIMERFD 1488 config TIMERFD
1680 bool "Enable timerfd() system call" i 1489 bool "Enable timerfd() system call" if EXPERT
1681 default y 1490 default y
1682 help 1491 help
1683 Enable the timerfd() system call th 1492 Enable the timerfd() system call that allows to receive timer
1684 events on a file descriptor. 1493 events on a file descriptor.
1685 1494
1686 If unsure, say Y. 1495 If unsure, say Y.
1687 1496
1688 config EVENTFD 1497 config EVENTFD
1689 bool "Enable eventfd() system call" i 1498 bool "Enable eventfd() system call" if EXPERT
1690 default y 1499 default y
1691 help 1500 help
1692 Enable the eventfd() system call th 1501 Enable the eventfd() system call that allows to receive both
1693 kernel notification (ie. KAIO) or u 1502 kernel notification (ie. KAIO) or userspace notifications.
1694 1503
1695 If unsure, say Y. 1504 If unsure, say Y.
1696 1505
1697 config SHMEM 1506 config SHMEM
1698 bool "Use full shmem filesystem" if E 1507 bool "Use full shmem filesystem" if EXPERT
1699 default y 1508 default y
1700 depends on MMU 1509 depends on MMU
1701 help 1510 help
1702 The shmem is an internal filesystem 1511 The shmem is an internal filesystem used to manage shared memory.
1703 It is backed by swap and manages re 1512 It is backed by swap and manages resource limits. It is also exported
1704 to userspace as tmpfs if TMPFS is e 1513 to userspace as tmpfs if TMPFS is enabled. Disabling this
1705 option replaces shmem and tmpfs wit 1514 option replaces shmem and tmpfs with the much simpler ramfs code,
1706 which may be appropriate on small s 1515 which may be appropriate on small systems without swap.
1707 1516
1708 config AIO 1517 config AIO
1709 bool "Enable AIO support" if EXPERT 1518 bool "Enable AIO support" if EXPERT
1710 default y 1519 default y
1711 help 1520 help
1712 This option enables POSIX asynchron 1521 This option enables POSIX asynchronous I/O which may by used
1713 by some high performance threaded a 1522 by some high performance threaded applications. Disabling
1714 this option saves about 7k. 1523 this option saves about 7k.
1715 1524
1716 config IO_URING 1525 config IO_URING
1717 bool "Enable IO uring support" if EXP 1526 bool "Enable IO uring support" if EXPERT
1718 select IO_WQ 1527 select IO_WQ
1719 default y 1528 default y
1720 help 1529 help
1721 This option enables support for the 1530 This option enables support for the io_uring interface, enabling
1722 applications to submit and complete 1531 applications to submit and complete IO through submission and
1723 completion rings that are shared be 1532 completion rings that are shared between the kernel and application.
1724 1533
1725 config GCOV_PROFILE_URING <<
1726 bool "Enable GCOV profiling on the io <<
1727 depends on GCOV_KERNEL <<
1728 help <<
1729 Enable GCOV profiling on the io_uri <<
1730 code coverage testing. <<
1731 <<
1732 If unsure, say N. <<
1733 <<
1734 Note that this will have a negative <<
1735 the io_uring subsystem, hence this <<
1736 specific test purposes. <<
1737 <<
1738 config ADVISE_SYSCALLS 1534 config ADVISE_SYSCALLS
1739 bool "Enable madvise/fadvise syscalls 1535 bool "Enable madvise/fadvise syscalls" if EXPERT
1740 default y 1536 default y
1741 help 1537 help
1742 This option enables the madvise and 1538 This option enables the madvise and fadvise syscalls, used by
1743 applications to advise the kernel a 1539 applications to advise the kernel about their future memory or file
1744 usage, improving performance. If bu 1540 usage, improving performance. If building an embedded system where no
1745 applications use these syscalls, yo 1541 applications use these syscalls, you can disable this option to save
1746 space. 1542 space.
1747 1543
>> 1544 config HAVE_ARCH_USERFAULTFD_WP
>> 1545 bool
>> 1546 help
>> 1547 Arch has userfaultfd write protection support
>> 1548
1748 config MEMBARRIER 1549 config MEMBARRIER
1749 bool "Enable membarrier() system call 1550 bool "Enable membarrier() system call" if EXPERT
1750 default y 1551 default y
1751 help 1552 help
1752 Enable the membarrier() system call 1553 Enable the membarrier() system call that allows issuing memory
1753 barriers across all running threads 1554 barriers across all running threads, which can be used to distribute
1754 the cost of user-space memory barri 1555 the cost of user-space memory barriers asymmetrically by transforming
1755 pairs of memory barriers into pairs 1556 pairs of memory barriers into pairs consisting of membarrier() and a
1756 compiler barrier. 1557 compiler barrier.
1757 1558
1758 If unsure, say Y. 1559 If unsure, say Y.
1759 1560
1760 config KCMP <<
1761 bool "Enable kcmp() system call" if E <<
1762 help <<
1763 Enable the kernel resource comparis <<
1764 user-space with the ability to comp <<
1765 share a common resource, such as a <<
1766 memory space. <<
1767 <<
1768 If unsure, say N. <<
1769 <<
1770 config RSEQ <<
1771 bool "Enable rseq() system call" if E <<
1772 default y <<
1773 depends on HAVE_RSEQ <<
1774 select MEMBARRIER <<
1775 help <<
1776 Enable the restartable sequences sy <<
1777 user-space cache for the current CP <<
1778 speeds up getting the current CPU n <<
1779 as well as an ABI to speed up user- <<
1780 per-CPU data. <<
1781 <<
1782 If unsure, say Y. <<
1783 <<
1784 config DEBUG_RSEQ <<
1785 default n <<
1786 bool "Enable debugging of rseq() syst <<
1787 depends on RSEQ && DEBUG_KERNEL <<
1788 help <<
1789 Enable extra debugging checks for t <<
1790 <<
1791 If unsure, say N. <<
1792 <<
1793 config CACHESTAT_SYSCALL <<
1794 bool "Enable cachestat() system call" <<
1795 default y <<
1796 help <<
1797 Enable the cachestat system call, w <<
1798 statistics of a file (number of cac <<
1799 pages marked for writeback, (recent <<
1800 <<
1801 If unsure say Y here. <<
1802 <<
1803 config PC104 <<
1804 bool "PC/104 support" if EXPERT <<
1805 help <<
1806 Expose PC/104 form factor device dr <<
1807 selection and configuration. Enable <<
1808 machine has a PC/104 bus. <<
1809 <<
1810 config KALLSYMS 1561 config KALLSYMS
1811 bool "Load all symbols for debugging/ 1562 bool "Load all symbols for debugging/ksymoops" if EXPERT
1812 default y 1563 default y
1813 help 1564 help
1814 Say Y here to let the kernel print 1565 Say Y here to let the kernel print out symbolic crash information and
1815 symbolic stack backtraces. This inc 1566 symbolic stack backtraces. This increases the size of the kernel
1816 somewhat, as all symbols have to be 1567 somewhat, as all symbols have to be loaded into the kernel image.
1817 1568
1818 config KALLSYMS_SELFTEST <<
1819 bool "Test the basic functions and pe <<
1820 depends on KALLSYMS <<
1821 default n <<
1822 help <<
1823 Test the basic functions and perfor <<
1824 kallsyms_lookup_name. It also calcu <<
1825 kallsyms compression algorithm for <<
1826 <<
1827 Start self-test automatically after <<
1828 "dmesg | grep kallsyms_selftest" to <<
1829 displayed in the last line, indicat <<
1830 <<
1831 config KALLSYMS_ALL 1569 config KALLSYMS_ALL
1832 bool "Include all symbols in kallsyms 1570 bool "Include all symbols in kallsyms"
1833 depends on DEBUG_KERNEL && KALLSYMS 1571 depends on DEBUG_KERNEL && KALLSYMS
1834 help 1572 help
1835 Normally kallsyms only contains the 1573 Normally kallsyms only contains the symbols of functions for nicer
1836 OOPS messages and backtraces (i.e., 1574 OOPS messages and backtraces (i.e., symbols from the text and inittext
1837 sections). This is sufficient for m !! 1575 sections). This is sufficient for most cases. And only in very rare
1838 enable kernel live patching, or oth !! 1576 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1839 when a debugger is used) all symbol !! 1577 names of variables from the data sections, etc).
1840 variables from the data sections, e <<
1841 1578
1842 This option makes sure that all sym 1579 This option makes sure that all symbols are loaded into the kernel
1843 image (i.e., symbols from all secti 1580 image (i.e., symbols from all sections) in cost of increased kernel
1844 size (depending on the kernel confi 1581 size (depending on the kernel configuration, it may be 300KiB or
1845 something like this). 1582 something like this).
1846 1583
1847 Say N unless you really need all sy !! 1584 Say N unless you really need all symbols.
1848 1585
1849 config KALLSYMS_ABSOLUTE_PERCPU 1586 config KALLSYMS_ABSOLUTE_PERCPU
1850 bool 1587 bool
1851 depends on KALLSYMS 1588 depends on KALLSYMS
1852 default X86_64 && SMP 1589 default X86_64 && SMP
1853 1590
>> 1591 config KALLSYMS_BASE_RELATIVE
>> 1592 bool
>> 1593 depends on KALLSYMS
>> 1594 default !IA64
>> 1595 help
>> 1596 Instead of emitting them as absolute values in the native word size,
>> 1597 emit the symbol references in the kallsyms table as 32-bit entries,
>> 1598 each containing a relative value in the range [base, base + U32_MAX]
>> 1599 or, when KALLSYMS_ABSOLUTE_PERCPU is in effect, each containing either
>> 1600 an absolute value in the range [0, S32_MAX] or a relative value in the
>> 1601 range [base, base + S32_MAX], where base is the lowest relative symbol
>> 1602 address encountered in the image.
>> 1603
>> 1604 On 64-bit builds, this reduces the size of the address table by 50%,
>> 1605 but more importantly, it results in entries whose values are build
>> 1606 time constants, and no relocation pass is required at runtime to fix
>> 1607 up the entries based on the runtime load address of the kernel.
>> 1608
1854 # end of the "standard kernel features (exper 1609 # end of the "standard kernel features (expert users)" menu
1855 1610
>> 1611 # syscall, maps, verifier
>> 1612
>> 1613 config BPF_LSM
>> 1614 bool "LSM Instrumentation with BPF"
>> 1615 depends on BPF_EVENTS
>> 1616 depends on BPF_SYSCALL
>> 1617 depends on SECURITY
>> 1618 depends on BPF_JIT
>> 1619 help
>> 1620 Enables instrumentation of the security hooks with eBPF programs for
>> 1621 implementing dynamic MAC and Audit Policies.
>> 1622
>> 1623 If you are unsure how to answer this question, answer N.
>> 1624
>> 1625 config BPF_SYSCALL
>> 1626 bool "Enable bpf() system call"
>> 1627 select BPF
>> 1628 select IRQ_WORK
>> 1629 default n
>> 1630 help
>> 1631 Enable the bpf() system call that allows to manipulate eBPF
>> 1632 programs and maps via file descriptors.
>> 1633
>> 1634 config ARCH_WANT_DEFAULT_BPF_JIT
>> 1635 bool
>> 1636
>> 1637 config BPF_JIT_ALWAYS_ON
>> 1638 bool "Permanently enable BPF JIT and remove BPF interpreter"
>> 1639 depends on BPF_SYSCALL && HAVE_EBPF_JIT && BPF_JIT
>> 1640 help
>> 1641 Enables BPF JIT and removes BPF interpreter to avoid
>> 1642 speculative execution of BPF instructions by the interpreter
>> 1643
>> 1644 config BPF_JIT_DEFAULT_ON
>> 1645 def_bool ARCH_WANT_DEFAULT_BPF_JIT || BPF_JIT_ALWAYS_ON
>> 1646 depends on HAVE_EBPF_JIT && BPF_JIT
>> 1647
>> 1648 config USERFAULTFD
>> 1649 bool "Enable userfaultfd() system call"
>> 1650 depends on MMU
>> 1651 help
>> 1652 Enable the userfaultfd() system call that allows to intercept and
>> 1653 handle page faults in userland.
>> 1654
1856 config ARCH_HAS_MEMBARRIER_CALLBACKS 1655 config ARCH_HAS_MEMBARRIER_CALLBACKS
1857 bool 1656 bool
1858 1657
1859 config ARCH_HAS_MEMBARRIER_SYNC_CORE 1658 config ARCH_HAS_MEMBARRIER_SYNC_CORE
1860 bool 1659 bool
1861 1660
>> 1661 config RSEQ
>> 1662 bool "Enable rseq() system call" if EXPERT
>> 1663 default y
>> 1664 depends on HAVE_RSEQ
>> 1665 select MEMBARRIER
>> 1666 help
>> 1667 Enable the restartable sequences system call. It provides a
>> 1668 user-space cache for the current CPU number value, which
>> 1669 speeds up getting the current CPU number from user-space,
>> 1670 as well as an ABI to speed up user-space operations on
>> 1671 per-CPU data.
>> 1672
>> 1673 If unsure, say Y.
>> 1674
>> 1675 config DEBUG_RSEQ
>> 1676 default n
>> 1677 bool "Enabled debugging of rseq() system call" if EXPERT
>> 1678 depends on RSEQ && DEBUG_KERNEL
>> 1679 help
>> 1680 Enable extra debugging checks for the rseq system call.
>> 1681
>> 1682 If unsure, say N.
>> 1683
>> 1684 config EMBEDDED
>> 1685 bool "Embedded system"
>> 1686 option allnoconfig_y
>> 1687 select EXPERT
>> 1688 help
>> 1689 This option should be enabled if compiling the kernel for
>> 1690 an embedded system so certain expert options are available
>> 1691 for configuration.
>> 1692
1862 config HAVE_PERF_EVENTS 1693 config HAVE_PERF_EVENTS
1863 bool 1694 bool
1864 help 1695 help
1865 See tools/perf/design.txt for detai 1696 See tools/perf/design.txt for details.
1866 1697
1867 config GUEST_PERF_EVENTS <<
1868 bool <<
1869 depends on HAVE_PERF_EVENTS <<
1870 <<
1871 config PERF_USE_VMALLOC 1698 config PERF_USE_VMALLOC
1872 bool 1699 bool
1873 help 1700 help
1874 See tools/perf/design.txt for detai 1701 See tools/perf/design.txt for details
1875 1702
>> 1703 config PC104
>> 1704 bool "PC/104 support" if EXPERT
>> 1705 help
>> 1706 Expose PC/104 form factor device drivers and options available for
>> 1707 selection and configuration. Enable this option if your target
>> 1708 machine has a PC/104 bus.
>> 1709
1876 menu "Kernel Performance Events And Counters" 1710 menu "Kernel Performance Events And Counters"
1877 1711
1878 config PERF_EVENTS 1712 config PERF_EVENTS
1879 bool "Kernel performance events and c 1713 bool "Kernel performance events and counters"
1880 default y if PROFILING 1714 default y if PROFILING
1881 depends on HAVE_PERF_EVENTS 1715 depends on HAVE_PERF_EVENTS
1882 select IRQ_WORK 1716 select IRQ_WORK
>> 1717 select SRCU
1883 help 1718 help
1884 Enable kernel support for various p 1719 Enable kernel support for various performance events provided
1885 by software and hardware. 1720 by software and hardware.
1886 1721
1887 Software events are supported eithe 1722 Software events are supported either built-in or via the
1888 use of generic tracepoints. 1723 use of generic tracepoints.
1889 1724
1890 Most modern CPUs support performanc 1725 Most modern CPUs support performance events via performance
1891 counter registers. These registers 1726 counter registers. These registers count the number of certain
1892 types of hw events: such as instruc 1727 types of hw events: such as instructions executed, cachemisses
1893 suffered, or branches mis-predicted 1728 suffered, or branches mis-predicted - without slowing down the
1894 kernel or applications. These regis 1729 kernel or applications. These registers can also trigger interrupts
1895 when a threshold number of events h 1730 when a threshold number of events have passed - and can thus be
1896 used to profile the code that runs 1731 used to profile the code that runs on that CPU.
1897 1732
1898 The Linux Performance Event subsyst 1733 The Linux Performance Event subsystem provides an abstraction of
1899 these software and hardware event c 1734 these software and hardware event capabilities, available via a
1900 system call and used by the "perf" 1735 system call and used by the "perf" utility in tools/perf/. It
1901 provides per task and per CPU count 1736 provides per task and per CPU counters, and it provides event
1902 capabilities on top of those. 1737 capabilities on top of those.
1903 1738
1904 Say Y if unsure. 1739 Say Y if unsure.
1905 1740
1906 config DEBUG_PERF_USE_VMALLOC 1741 config DEBUG_PERF_USE_VMALLOC
1907 default n 1742 default n
1908 bool "Debug: use vmalloc to back perf 1743 bool "Debug: use vmalloc to back perf mmap() buffers"
1909 depends on PERF_EVENTS && DEBUG_KERNE 1744 depends on PERF_EVENTS && DEBUG_KERNEL && !PPC
1910 select PERF_USE_VMALLOC 1745 select PERF_USE_VMALLOC
1911 help 1746 help
1912 Use vmalloc memory to back perf mma 1747 Use vmalloc memory to back perf mmap() buffers.
1913 1748
1914 Mostly useful for debugging the vma 1749 Mostly useful for debugging the vmalloc code on platforms
1915 that don't require it. 1750 that don't require it.
1916 1751
1917 Say N if unsure. 1752 Say N if unsure.
1918 1753
1919 endmenu 1754 endmenu
1920 1755
>> 1756 config VM_EVENT_COUNTERS
>> 1757 default y
>> 1758 bool "Enable VM event counters for /proc/vmstat" if EXPERT
>> 1759 help
>> 1760 VM event counters are needed for event counts to be shown.
>> 1761 This option allows the disabling of the VM event counters
>> 1762 on EXPERT systems. /proc/vmstat will only show page counts
>> 1763 if VM event counters are disabled.
>> 1764
>> 1765 config SLUB_DEBUG
>> 1766 default y
>> 1767 bool "Enable SLUB debugging support" if EXPERT
>> 1768 depends on SLUB && SYSFS
>> 1769 help
>> 1770 SLUB has extensive debug support features. Disabling these can
>> 1771 result in significant savings in code size. This also disables
>> 1772 SLUB sysfs support. /sys/slab will not exist and there will be
>> 1773 no support for cache validation etc.
>> 1774
>> 1775 config SLUB_MEMCG_SYSFS_ON
>> 1776 default n
>> 1777 bool "Enable memcg SLUB sysfs support by default" if EXPERT
>> 1778 depends on SLUB && SYSFS && MEMCG
>> 1779 help
>> 1780 SLUB creates a directory under /sys/kernel/slab for each
>> 1781 allocation cache to host info and debug files. If memory
>> 1782 cgroup is enabled, each cache can have per memory cgroup
>> 1783 caches. SLUB can create the same sysfs directories for these
>> 1784 caches under /sys/kernel/slab/CACHE/cgroup but it can lead
>> 1785 to a very high number of debug files being created. This is
>> 1786 controlled by slub_memcg_sysfs boot parameter and this
>> 1787 config option determines the parameter's default value.
>> 1788
>> 1789 config COMPAT_BRK
>> 1790 bool "Disable heap randomization"
>> 1791 default y
>> 1792 help
>> 1793 Randomizing heap placement makes heap exploits harder, but it
>> 1794 also breaks ancient binaries (including anything libc5 based).
>> 1795 This option changes the bootup default to heap randomization
>> 1796 disabled, and can be overridden at runtime by setting
>> 1797 /proc/sys/kernel/randomize_va_space to 2.
>> 1798
>> 1799 On non-ancient distros (post-2000 ones) N is usually a safe choice.
>> 1800
>> 1801 choice
>> 1802 prompt "Choose SLAB allocator"
>> 1803 default SLUB
>> 1804 help
>> 1805 This option allows to select a slab allocator.
>> 1806
>> 1807 config SLAB
>> 1808 bool "SLAB"
>> 1809 select HAVE_HARDENED_USERCOPY_ALLOCATOR
>> 1810 help
>> 1811 The regular slab allocator that is established and known to work
>> 1812 well in all environments. It organizes cache hot objects in
>> 1813 per cpu and per node queues.
>> 1814
>> 1815 config SLUB
>> 1816 bool "SLUB (Unqueued Allocator)"
>> 1817 select HAVE_HARDENED_USERCOPY_ALLOCATOR
>> 1818 help
>> 1819 SLUB is a slab allocator that minimizes cache line usage
>> 1820 instead of managing queues of cached objects (SLAB approach).
>> 1821 Per cpu caching is realized using slabs of objects instead
>> 1822 of queues of objects. SLUB can use memory efficiently
>> 1823 and has enhanced diagnostics. SLUB is the default choice for
>> 1824 a slab allocator.
>> 1825
>> 1826 config SLOB
>> 1827 depends on EXPERT
>> 1828 bool "SLOB (Simple Allocator)"
>> 1829 help
>> 1830 SLOB replaces the stock allocator with a drastically simpler
>> 1831 allocator. SLOB is generally more space efficient but
>> 1832 does not perform as well on large systems.
>> 1833
>> 1834 endchoice
>> 1835
>> 1836 config SLAB_MERGE_DEFAULT
>> 1837 bool "Allow slab caches to be merged"
>> 1838 default y
>> 1839 help
>> 1840 For reduced kernel memory fragmentation, slab caches can be
>> 1841 merged when they share the same size and other characteristics.
>> 1842 This carries a risk of kernel heap overflows being able to
>> 1843 overwrite objects from merged caches (and more easily control
>> 1844 cache layout), which makes such heap attacks easier to exploit
>> 1845 by attackers. By keeping caches unmerged, these kinds of exploits
>> 1846 can usually only damage objects in the same cache. To disable
>> 1847 merging at runtime, "slab_nomerge" can be passed on the kernel
>> 1848 command line.
>> 1849
>> 1850 config SLAB_FREELIST_RANDOM
>> 1851 default n
>> 1852 depends on SLAB || SLUB
>> 1853 bool "SLAB freelist randomization"
>> 1854 help
>> 1855 Randomizes the freelist order used on creating new pages. This
>> 1856 security feature reduces the predictability of the kernel slab
>> 1857 allocator against heap overflows.
>> 1858
>> 1859 config SLAB_FREELIST_HARDENED
>> 1860 bool "Harden slab freelist metadata"
>> 1861 depends on SLUB
>> 1862 help
>> 1863 Many kernel heap attacks try to target slab cache metadata and
>> 1864 other infrastructure. This options makes minor performance
>> 1865 sacrifices to harden the kernel slab allocator against common
>> 1866 freelist exploit methods.
>> 1867
>> 1868 config SHUFFLE_PAGE_ALLOCATOR
>> 1869 bool "Page allocator randomization"
>> 1870 default SLAB_FREELIST_RANDOM && ACPI_NUMA
>> 1871 help
>> 1872 Randomization of the page allocator improves the average
>> 1873 utilization of a direct-mapped memory-side-cache. See section
>> 1874 5.2.27 Heterogeneous Memory Attribute Table (HMAT) in the ACPI
>> 1875 6.2a specification for an example of how a platform advertises
>> 1876 the presence of a memory-side-cache. There are also incidental
>> 1877 security benefits as it reduces the predictability of page
>> 1878 allocations to compliment SLAB_FREELIST_RANDOM, but the
>> 1879 default granularity of shuffling on the "MAX_ORDER - 1" i.e,
>> 1880 10th order of pages is selected based on cache utilization
>> 1881 benefits on x86.
>> 1882
>> 1883 While the randomization improves cache utilization it may
>> 1884 negatively impact workloads on platforms without a cache. For
>> 1885 this reason, by default, the randomization is enabled only
>> 1886 after runtime detection of a direct-mapped memory-side-cache.
>> 1887 Otherwise, the randomization may be force enabled with the
>> 1888 'page_alloc.shuffle' kernel command line parameter.
>> 1889
>> 1890 Say Y if unsure.
>> 1891
>> 1892 config SLUB_CPU_PARTIAL
>> 1893 default y
>> 1894 depends on SLUB && SMP
>> 1895 bool "SLUB per cpu partial cache"
>> 1896 help
>> 1897 Per cpu partial caches accelerate objects allocation and freeing
>> 1898 that is local to a processor at the price of more indeterminism
>> 1899 in the latency of the free. On overflow these caches will be cleared
>> 1900 which requires the taking of locks that may cause latency spikes.
>> 1901 Typically one would choose no for a realtime system.
>> 1902
>> 1903 config MMAP_ALLOW_UNINITIALIZED
>> 1904 bool "Allow mmapped anonymous memory to be uninitialized"
>> 1905 depends on EXPERT && !MMU
>> 1906 default n
>> 1907 help
>> 1908 Normally, and according to the Linux spec, anonymous memory obtained
>> 1909 from mmap() has its contents cleared before it is passed to
>> 1910 userspace. Enabling this config option allows you to request that
>> 1911 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
>> 1912 providing a huge performance boost. If this option is not enabled,
>> 1913 then the flag will be ignored.
>> 1914
>> 1915 This is taken advantage of by uClibc's malloc(), and also by
>> 1916 ELF-FDPIC binfmt's brk and stack allocator.
>> 1917
>> 1918 Because of the obvious security issues, this option should only be
>> 1919 enabled on embedded devices where you control what is run in
>> 1920 userspace. Since that isn't generally a problem on no-MMU systems,
>> 1921 it is normally safe to say Y here.
>> 1922
>> 1923 See Documentation/nommu-mmap.txt for more information.
>> 1924
1921 config SYSTEM_DATA_VERIFICATION 1925 config SYSTEM_DATA_VERIFICATION
1922 def_bool n 1926 def_bool n
1923 select SYSTEM_TRUSTED_KEYRING 1927 select SYSTEM_TRUSTED_KEYRING
1924 select KEYS 1928 select KEYS
1925 select CRYPTO 1929 select CRYPTO
1926 select CRYPTO_RSA 1930 select CRYPTO_RSA
1927 select ASYMMETRIC_KEY_TYPE 1931 select ASYMMETRIC_KEY_TYPE
1928 select ASYMMETRIC_PUBLIC_KEY_SUBTYPE 1932 select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
1929 select ASN1 1933 select ASN1
1930 select OID_REGISTRY 1934 select OID_REGISTRY
1931 select X509_CERTIFICATE_PARSER 1935 select X509_CERTIFICATE_PARSER
1932 select PKCS7_MESSAGE_PARSER 1936 select PKCS7_MESSAGE_PARSER
1933 help 1937 help
1934 Provide PKCS#7 message verification 1938 Provide PKCS#7 message verification using the contents of the system
1935 trusted keyring to provide public k 1939 trusted keyring to provide public keys. This then can be used for
1936 module verification, kexec image ve 1940 module verification, kexec image verification and firmware blob
1937 verification. 1941 verification.
1938 1942
1939 config PROFILING 1943 config PROFILING
1940 bool "Profiling support" 1944 bool "Profiling support"
1941 help 1945 help
1942 Say Y here to enable the extended p 1946 Say Y here to enable the extended profiling support mechanisms used
1943 by profilers. !! 1947 by profilers such as OProfile.
1944 <<
1945 config RUST <<
1946 bool "Rust support" <<
1947 depends on HAVE_RUST <<
1948 depends on RUST_IS_AVAILABLE <<
1949 depends on !MODVERSIONS <<
1950 depends on !GCC_PLUGIN_RANDSTRUCT <<
1951 depends on !RANDSTRUCT <<
1952 depends on !DEBUG_INFO_BTF || PAHOLE_ <<
1953 depends on !CFI_CLANG || HAVE_CFI_ICA <<
1954 select CFI_ICALL_NORMALIZE_INTEGERS i <<
1955 depends on !CALL_PADDING || RUSTC_VER <<
1956 depends on !KASAN_SW_TAGS <<
1957 depends on !(MITIGATION_RETHUNK && KA <<
1958 help <<
1959 Enables Rust support in the kernel. <<
1960 <<
1961 This allows other Rust-related opti <<
1962 to be selected. <<
1963 <<
1964 It is also required to be able to l <<
1965 written in Rust. <<
1966 <<
1967 See Documentation/rust/ for more in <<
1968 <<
1969 If unsure, say N. <<
1970 <<
1971 config RUSTC_VERSION_TEXT <<
1972 string <<
1973 depends on RUST <<
1974 default "$(RUSTC_VERSION_TEXT)" <<
1975 help <<
1976 See `CC_VERSION_TEXT`. <<
1977 <<
1978 config BINDGEN_VERSION_TEXT <<
1979 string <<
1980 depends on RUST <<
1981 # The dummy parameter `workaround-for <<
1982 # (https://github.com/rust-lang/rust- <<
1983 # the minimum version is upgraded pas <<
1984 default "$(shell,$(BINDGEN) --version <<
1985 1948
1986 # 1949 #
1987 # Place an empty function call at each tracep 1950 # Place an empty function call at each tracepoint site. Can be
1988 # dynamically changed for a probe function. 1951 # dynamically changed for a probe function.
1989 # 1952 #
1990 config TRACEPOINTS 1953 config TRACEPOINTS
1991 bool 1954 bool
1992 1955
1993 source "kernel/Kconfig.kexec" <<
1994 <<
1995 endmenu # General setup 1956 endmenu # General setup
1996 1957
1997 source "arch/Kconfig" 1958 source "arch/Kconfig"
1998 1959
1999 config RT_MUTEXES 1960 config RT_MUTEXES
2000 bool 1961 bool
2001 default y if PREEMPT_RT !! 1962
>> 1963 config BASE_SMALL
>> 1964 int
>> 1965 default 0 if BASE_FULL
>> 1966 default 1 if !BASE_FULL
2002 1967
2003 config MODULE_SIG_FORMAT 1968 config MODULE_SIG_FORMAT
2004 def_bool n 1969 def_bool n
2005 select SYSTEM_DATA_VERIFICATION 1970 select SYSTEM_DATA_VERIFICATION
2006 1971
2007 source "kernel/module/Kconfig" !! 1972 menuconfig MODULES
>> 1973 bool "Enable loadable module support"
>> 1974 option modules
>> 1975 help
>> 1976 Kernel modules are small pieces of compiled code which can
>> 1977 be inserted in the running kernel, rather than being
>> 1978 permanently built into the kernel. You use the "modprobe"
>> 1979 tool to add (and sometimes remove) them. If you say Y here,
>> 1980 many parts of the kernel can be built as modules (by
>> 1981 answering M instead of Y where indicated): this is most
>> 1982 useful for infrequently used options which are not required
>> 1983 for booting. For more information, see the man pages for
>> 1984 modprobe, lsmod, modinfo, insmod and rmmod.
>> 1985
>> 1986 If you say Y here, you will need to run "make
>> 1987 modules_install" to put the modules under /lib/modules/
>> 1988 where modprobe can find them (you may need to be root to do
>> 1989 this).
>> 1990
>> 1991 If unsure, say Y.
>> 1992
>> 1993 if MODULES
>> 1994
>> 1995 config MODULE_FORCE_LOAD
>> 1996 bool "Forced module loading"
>> 1997 default n
>> 1998 help
>> 1999 Allow loading of modules without version information (ie. modprobe
>> 2000 --force). Forced module loading sets the 'F' (forced) taint flag and
>> 2001 is usually a really bad idea.
>> 2002
>> 2003 config MODULE_UNLOAD
>> 2004 bool "Module unloading"
>> 2005 help
>> 2006 Without this option you will not be able to unload any
>> 2007 modules (note that some modules may not be unloadable
>> 2008 anyway), which makes your kernel smaller, faster
>> 2009 and simpler. If unsure, say Y.
>> 2010
>> 2011 config MODULE_FORCE_UNLOAD
>> 2012 bool "Forced module unloading"
>> 2013 depends on MODULE_UNLOAD
>> 2014 help
>> 2015 This option allows you to force a module to unload, even if the
>> 2016 kernel believes it is unsafe: the kernel will remove the module
>> 2017 without waiting for anyone to stop using it (using the -f option to
>> 2018 rmmod). This is mainly for kernel developers and desperate users.
>> 2019 If unsure, say N.
>> 2020
>> 2021 config MODVERSIONS
>> 2022 bool "Module versioning support"
>> 2023 help
>> 2024 Usually, you have to use modules compiled with your kernel.
>> 2025 Saying Y here makes it sometimes possible to use modules
>> 2026 compiled for different kernels, by adding enough information
>> 2027 to the modules to (hopefully) spot any changes which would
>> 2028 make them incompatible with the kernel you are running. If
>> 2029 unsure, say N.
>> 2030
>> 2031 config ASM_MODVERSIONS
>> 2032 bool
>> 2033 default HAVE_ASM_MODVERSIONS && MODVERSIONS
>> 2034 help
>> 2035 This enables module versioning for exported symbols also from
>> 2036 assembly. This can be enabled only when the target architecture
>> 2037 supports it.
>> 2038
>> 2039 config MODULE_REL_CRCS
>> 2040 bool
>> 2041 depends on MODVERSIONS
>> 2042
>> 2043 config MODULE_SRCVERSION_ALL
>> 2044 bool "Source checksum for all modules"
>> 2045 help
>> 2046 Modules which contain a MODULE_VERSION get an extra "srcversion"
>> 2047 field inserted into their modinfo section, which contains a
>> 2048 sum of the source files which made it. This helps maintainers
>> 2049 see exactly which source was used to build a module (since
>> 2050 others sometimes change the module source without updating
>> 2051 the version). With this option, such a "srcversion" field
>> 2052 will be created for all modules. If unsure, say N.
>> 2053
>> 2054 config MODULE_SIG
>> 2055 bool "Module signature verification"
>> 2056 select MODULE_SIG_FORMAT
>> 2057 help
>> 2058 Check modules for valid signatures upon load: the signature
>> 2059 is simply appended to the module. For more information see
>> 2060 <file:Documentation/admin-guide/module-signing.rst>.
>> 2061
>> 2062 Note that this option adds the OpenSSL development packages as a
>> 2063 kernel build dependency so that the signing tool can use its crypto
>> 2064 library.
>> 2065
>> 2066 You should enable this option if you wish to use either
>> 2067 CONFIG_SECURITY_LOCKDOWN_LSM or lockdown functionality imposed via
>> 2068 another LSM - otherwise unsigned modules will be loadable regardless
>> 2069 of the lockdown policy.
>> 2070
>> 2071 !!!WARNING!!! If you enable this option, you MUST make sure that the
>> 2072 module DOES NOT get stripped after being signed. This includes the
>> 2073 debuginfo strip done by some packagers (such as rpmbuild) and
>> 2074 inclusion into an initramfs that wants the module size reduced.
>> 2075
>> 2076 config MODULE_SIG_FORCE
>> 2077 bool "Require modules to be validly signed"
>> 2078 depends on MODULE_SIG
>> 2079 help
>> 2080 Reject unsigned modules or signed modules for which we don't have a
>> 2081 key. Without this, such modules will simply taint the kernel.
>> 2082
>> 2083 config MODULE_SIG_ALL
>> 2084 bool "Automatically sign all modules"
>> 2085 default y
>> 2086 depends on MODULE_SIG
>> 2087 help
>> 2088 Sign all modules during make modules_install. Without this option,
>> 2089 modules must be signed manually, using the scripts/sign-file tool.
>> 2090
>> 2091 comment "Do not forget to sign required modules with scripts/sign-file"
>> 2092 depends on MODULE_SIG_FORCE && !MODULE_SIG_ALL
>> 2093
>> 2094 choice
>> 2095 prompt "Which hash algorithm should modules be signed with?"
>> 2096 depends on MODULE_SIG
>> 2097 help
>> 2098 This determines which sort of hashing algorithm will be used during
>> 2099 signature generation. This algorithm _must_ be built into the kernel
>> 2100 directly so that signature verification can take place. It is not
>> 2101 possible to load a signed module containing the algorithm to check
>> 2102 the signature on that module.
>> 2103
>> 2104 config MODULE_SIG_SHA1
>> 2105 bool "Sign modules with SHA-1"
>> 2106 select CRYPTO_SHA1
>> 2107
>> 2108 config MODULE_SIG_SHA224
>> 2109 bool "Sign modules with SHA-224"
>> 2110 select CRYPTO_SHA256
>> 2111
>> 2112 config MODULE_SIG_SHA256
>> 2113 bool "Sign modules with SHA-256"
>> 2114 select CRYPTO_SHA256
>> 2115
>> 2116 config MODULE_SIG_SHA384
>> 2117 bool "Sign modules with SHA-384"
>> 2118 select CRYPTO_SHA512
>> 2119
>> 2120 config MODULE_SIG_SHA512
>> 2121 bool "Sign modules with SHA-512"
>> 2122 select CRYPTO_SHA512
>> 2123
>> 2124 endchoice
>> 2125
>> 2126 config MODULE_SIG_HASH
>> 2127 string
>> 2128 depends on MODULE_SIG
>> 2129 default "sha1" if MODULE_SIG_SHA1
>> 2130 default "sha224" if MODULE_SIG_SHA224
>> 2131 default "sha256" if MODULE_SIG_SHA256
>> 2132 default "sha384" if MODULE_SIG_SHA384
>> 2133 default "sha512" if MODULE_SIG_SHA512
>> 2134
>> 2135 config MODULE_COMPRESS
>> 2136 bool "Compress modules on installation"
>> 2137 help
>> 2138
>> 2139 Compresses kernel modules when 'make modules_install' is run; gzip or
>> 2140 xz depending on "Compression algorithm" below.
>> 2141
>> 2142 module-init-tools MAY support gzip, and kmod MAY support gzip and xz.
>> 2143
>> 2144 Out-of-tree kernel modules installed using Kbuild will also be
>> 2145 compressed upon installation.
>> 2146
>> 2147 Note: for modules inside an initrd or initramfs, it's more efficient
>> 2148 to compress the whole initrd or initramfs instead.
>> 2149
>> 2150 Note: This is fully compatible with signed modules.
>> 2151
>> 2152 If in doubt, say N.
>> 2153
>> 2154 choice
>> 2155 prompt "Compression algorithm"
>> 2156 depends on MODULE_COMPRESS
>> 2157 default MODULE_COMPRESS_GZIP
>> 2158 help
>> 2159 This determines which sort of compression will be used during
>> 2160 'make modules_install'.
>> 2161
>> 2162 GZIP (default) and XZ are supported.
>> 2163
>> 2164 config MODULE_COMPRESS_GZIP
>> 2165 bool "GZIP"
>> 2166
>> 2167 config MODULE_COMPRESS_XZ
>> 2168 bool "XZ"
>> 2169
>> 2170 endchoice
>> 2171
>> 2172 config MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
>> 2173 bool "Allow loading of modules with missing namespace imports"
>> 2174 help
>> 2175 Symbols exported with EXPORT_SYMBOL_NS*() are considered exported in
>> 2176 a namespace. A module that makes use of a symbol exported with such a
>> 2177 namespace is required to import the namespace via MODULE_IMPORT_NS().
>> 2178 There is no technical reason to enforce correct namespace imports,
>> 2179 but it creates consistency between symbols defining namespaces and
>> 2180 users importing namespaces they make use of. This option relaxes this
>> 2181 requirement and lifts the enforcement when loading a module.
>> 2182
>> 2183 If unsure, say N.
>> 2184
>> 2185 config UNUSED_SYMBOLS
>> 2186 bool "Enable unused/obsolete exported symbols"
>> 2187 default y if X86
>> 2188 help
>> 2189 Unused but exported symbols make the kernel needlessly bigger. For
>> 2190 that reason most of these unused exports will soon be removed. This
>> 2191 option is provided temporarily to provide a transition period in case
>> 2192 some external kernel module needs one of these symbols anyway. If you
>> 2193 encounter such a case in your module, consider if you are actually
>> 2194 using the right API. (rationale: since nobody in the kernel is using
>> 2195 this in a module, there is a pretty good chance it's actually the
>> 2196 wrong interface to use). If you really need the symbol, please send a
>> 2197 mail to the linux kernel mailing list mentioning the symbol and why
>> 2198 you really need it, and what the merge plan to the mainline kernel for
>> 2199 your module is.
>> 2200
>> 2201 config TRIM_UNUSED_KSYMS
>> 2202 bool "Trim unused exported kernel symbols"
>> 2203 depends on !UNUSED_SYMBOLS
>> 2204 help
>> 2205 The kernel and some modules make many symbols available for
>> 2206 other modules to use via EXPORT_SYMBOL() and variants. Depending
>> 2207 on the set of modules being selected in your kernel configuration,
>> 2208 many of those exported symbols might never be used.
>> 2209
>> 2210 This option allows for unused exported symbols to be dropped from
>> 2211 the build. In turn, this provides the compiler more opportunities
>> 2212 (especially when using LTO) for optimizing the code and reducing
>> 2213 binary size. This might have some security advantages as well.
>> 2214
>> 2215 If unsure, or if you need to build out-of-tree modules, say N.
>> 2216
>> 2217 config UNUSED_KSYMS_WHITELIST
>> 2218 string "Whitelist of symbols to keep in ksymtab"
>> 2219 depends on TRIM_UNUSED_KSYMS
>> 2220 help
>> 2221 By default, all unused exported symbols will be un-exported from the
>> 2222 build when TRIM_UNUSED_KSYMS is selected.
>> 2223
>> 2224 UNUSED_KSYMS_WHITELIST allows to whitelist symbols that must be kept
>> 2225 exported at all times, even in absence of in-tree users. The value to
>> 2226 set here is the path to a text file containing the list of symbols,
>> 2227 one per line. The path can be absolute, or relative to the kernel
>> 2228 source tree.
>> 2229
>> 2230 endif # MODULES
>> 2231
>> 2232 config MODULES_TREE_LOOKUP
>> 2233 def_bool y
>> 2234 depends on PERF_EVENTS || TRACING
2008 2235
2009 config INIT_ALL_POSSIBLE 2236 config INIT_ALL_POSSIBLE
2010 bool 2237 bool
2011 help 2238 help
2012 Back when each arch used to define 2239 Back when each arch used to define their own cpu_online_mask and
2013 cpu_possible_mask, some of them cho 2240 cpu_possible_mask, some of them chose to initialize cpu_possible_mask
2014 with all 1s, and others with all 0s 2241 with all 1s, and others with all 0s. When they were centralised,
2015 it was better to provide this optio 2242 it was better to provide this option than to break all the archs
2016 and have several arch maintainers p 2243 and have several arch maintainers pursuing me down dark alleys.
2017 2244
2018 source "block/Kconfig" 2245 source "block/Kconfig"
2019 2246
2020 config PREEMPT_NOTIFIERS 2247 config PREEMPT_NOTIFIERS
2021 bool 2248 bool
2022 2249
2023 config PADATA 2250 config PADATA
2024 depends on SMP 2251 depends on SMP
2025 bool 2252 bool
2026 2253
2027 config ASN1 2254 config ASN1
2028 tristate 2255 tristate
2029 help 2256 help
2030 Build a simple ASN.1 grammar compil 2257 Build a simple ASN.1 grammar compiler that produces a bytecode output
2031 that can be interpreted by the ASN. 2258 that can be interpreted by the ASN.1 stream decoder and used to
2032 inform it as to what tags are to be 2259 inform it as to what tags are to be expected in a stream and what
2033 functions to call on what tags. 2260 functions to call on what tags.
2034 2261
2035 source "kernel/Kconfig.locks" 2262 source "kernel/Kconfig.locks"
2036 2263
2037 config ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 2264 config ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
2038 bool <<
2039 <<
2040 config ARCH_HAS_PREPARE_SYNC_CORE_CMD <<
2041 bool 2265 bool
2042 2266
2043 config ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 2267 config ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
2044 bool 2268 bool
2045 2269
2046 # It may be useful for an architecture to ove 2270 # It may be useful for an architecture to override the definitions of the
2047 # SYSCALL_DEFINE() and __SYSCALL_DEFINEx() ma 2271 # SYSCALL_DEFINE() and __SYSCALL_DEFINEx() macros in <linux/syscalls.h>
2048 # and the COMPAT_ variants in <linux/compat.h 2272 # and the COMPAT_ variants in <linux/compat.h>, in particular to use a
2049 # different calling convention for syscalls. 2273 # different calling convention for syscalls. They can also override the
2050 # macros for not-implemented syscalls in kern 2274 # macros for not-implemented syscalls in kernel/sys_ni.c and
2051 # kernel/time/posix-stubs.c. All these overri 2275 # kernel/time/posix-stubs.c. All these overrides need to be available in
2052 # <asm/syscall_wrapper.h>. 2276 # <asm/syscall_wrapper.h>.
2053 config ARCH_HAS_SYSCALL_WRAPPER 2277 config ARCH_HAS_SYSCALL_WRAPPER
2054 def_bool n 2278 def_bool n
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