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