1 # SPDX-License-Identifier: GPL-2.0-only !! 1 config ARCH
2 config CC_VERSION_TEXT <<
3 string 2 string
4 default "$(CC_VERSION_TEXT)" !! 3 option env="ARCH"
5 help <<
6 This is used in unclear ways: <<
7 <<
8 - Re-run Kconfig when the compiler i <<
9 The 'default' property references <<
10 CC_VERSION_TEXT so it is recorded <<
11 When the compiler is updated, Kcon <<
12 <<
13 - Ensure full rebuild when the compi <<
14 include/linux/compiler-version.h c <<
15 line so fixdep adds include/config <<
16 auto-generated dependency. When th <<
17 will touch it and then every file <<
18 <<
19 config CC_IS_GCC <<
20 def_bool $(success,test "$(cc-name)" = <<
21 <<
22 config GCC_VERSION <<
23 int <<
24 default $(cc-version) if CC_IS_GCC <<
25 default 0 <<
26 <<
27 config CC_IS_CLANG <<
28 def_bool $(success,test "$(cc-name)" = <<
29 <<
30 config CLANG_VERSION <<
31 int <<
32 default $(cc-version) if CC_IS_CLANG <<
33 default 0 <<
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 4
109 config CC_HAS_ASM_GOTO_TIED_OUTPUT !! 5 config KERNELVERSION
110 depends on CC_HAS_ASM_GOTO_OUTPUT !! 6 string
111 # Detect buggy gcc and clang, fixed in !! 7 option env="KERNELVERSION"
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 8
123 config PAHOLE_VERSION !! 9 config DEFCONFIG_LIST
124 int !! 10 string
125 default $(shell,$(srctree)/scripts/pah !! 11 depends on !UML
>> 12 option defconfig_list
>> 13 default "/lib/modules/$UNAME_RELEASE/.config"
>> 14 default "/etc/kernel-config"
>> 15 default "/boot/config-$UNAME_RELEASE"
>> 16 default "$ARCH_DEFCONFIG"
>> 17 default "arch/$ARCH/defconfig"
126 18
127 config CONSTRUCTORS 19 config CONSTRUCTORS
128 bool 20 bool
>> 21 depends on !UML
129 22
130 config IRQ_WORK 23 config IRQ_WORK
131 def_bool y if SMP <<
132 <<
133 config BUILDTIME_TABLE_SORT <<
134 bool 24 bool
135 25
136 config THREAD_INFO_IN_TASK !! 26 config BUILDTIME_EXTABLE_SORT
137 bool 27 bool
138 help <<
139 Select this to move thread_info off <<
140 make this work, an arch will need to <<
141 except flags and fix any runtime bug <<
142 <<
143 One subtle change that will be neede <<
144 and put_task_stack() in save_thread_ <<
145 28
146 menu "General setup" 29 menu "General setup"
147 30
148 config BROKEN 31 config BROKEN
149 bool 32 bool
150 33
151 config BROKEN_ON_SMP 34 config BROKEN_ON_SMP
152 bool 35 bool
153 depends on BROKEN || !SMP 36 depends on BROKEN || !SMP
154 default y 37 default y
155 38
156 config INIT_ENV_ARG_LIMIT 39 config INIT_ENV_ARG_LIMIT
157 int 40 int
158 default 32 if !UML 41 default 32 if !UML
159 default 128 if UML 42 default 128 if UML
160 help 43 help
161 Maximum of each of the number of arg 44 Maximum of each of the number of arguments and environment
162 variables passed to init from the ke 45 variables passed to init from the kernel command line.
163 46
164 config COMPILE_TEST <<
165 bool "Compile also drivers which will <<
166 depends on HAS_IOMEM <<
167 help <<
168 Some drivers can be compiled on a di <<
169 intended to be run on. Despite they <<
170 when they load they cannot be used d <<
171 developers still, opposing to distri <<
172 drivers to compile-test them. <<
173 <<
174 If you are a developer and want to b <<
175 here. If you are a user/distributor, <<
176 drivers to be distributed. <<
177 <<
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 47
202 If you are a developer or tester and !! 48 config CROSS_COMPILE
203 headers are self-contained, say Y he !! 49 string "Cross-compiler tool prefix"
>> 50 help
>> 51 Same as running 'make CROSS_COMPILE=prefix-' but stored for
>> 52 default make runs in this kernel build directory. You don't
>> 53 need to set this unless you want the configured kernel build
>> 54 directory to select the cross-compiler automatically.
204 55
205 config LOCALVERSION 56 config LOCALVERSION
206 string "Local version - append to kern 57 string "Local version - append to kernel release"
207 help 58 help
208 Append an extra string to the end of 59 Append an extra string to the end of your kernel version.
209 This will show up when you type unam 60 This will show up when you type uname, for example.
210 The string you set here will be appe 61 The string you set here will be appended after the contents of
211 any files with a filename matching l 62 any files with a filename matching localversion* in your
212 object and source tree, in that orde 63 object and source tree, in that order. Your total string can
213 be a maximum of 64 characters. 64 be a maximum of 64 characters.
214 65
215 config LOCALVERSION_AUTO 66 config LOCALVERSION_AUTO
216 bool "Automatically append version inf 67 bool "Automatically append version information to the version string"
217 default y 68 default y
218 depends on !COMPILE_TEST <<
219 help 69 help
220 This will try to automatically deter 70 This will try to automatically determine if the current tree is a
221 release tree by looking for git tags 71 release tree by looking for git tags that belong to the current
222 top of tree revision. 72 top of tree revision.
223 73
224 A string of the format -gxxxxxxxx wi 74 A string of the format -gxxxxxxxx will be added to the localversion
225 if a git-based tree is found. The s 75 if a git-based tree is found. The string generated by this will be
226 appended after any matching localver 76 appended after any matching localversion* files, and after the value
227 set in CONFIG_LOCALVERSION. 77 set in CONFIG_LOCALVERSION.
228 78
229 (The actual string used here is the !! 79 (The actual string used here is the first eight characters produced
230 by running the command: 80 by running the command:
231 81
232 $ git rev-parse --verify HEAD 82 $ git rev-parse --verify HEAD
233 83
234 which is done within the script "scr 84 which is done within the script "scripts/setlocalversion".)
235 85
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 86 config HAVE_KERNEL_GZIP
246 bool 87 bool
247 88
248 config HAVE_KERNEL_BZIP2 89 config HAVE_KERNEL_BZIP2
249 bool 90 bool
250 91
251 config HAVE_KERNEL_LZMA 92 config HAVE_KERNEL_LZMA
252 bool 93 bool
253 94
254 config HAVE_KERNEL_XZ 95 config HAVE_KERNEL_XZ
255 bool 96 bool
256 97
257 config HAVE_KERNEL_LZO 98 config HAVE_KERNEL_LZO
258 bool 99 bool
259 100
260 config HAVE_KERNEL_LZ4 <<
261 bool <<
262 <<
263 config HAVE_KERNEL_ZSTD <<
264 bool <<
265 <<
266 config HAVE_KERNEL_UNCOMPRESSED <<
267 bool <<
268 <<
269 choice 101 choice
270 prompt "Kernel compression mode" 102 prompt "Kernel compression mode"
271 default KERNEL_GZIP 103 default KERNEL_GZIP
272 depends on HAVE_KERNEL_GZIP || HAVE_KE !! 104 depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO
273 help 105 help
274 The linux kernel is a kind of self-e 106 The linux kernel is a kind of self-extracting executable.
275 Several compression algorithms are a 107 Several compression algorithms are available, which differ
276 in efficiency, compression and decom 108 in efficiency, compression and decompression speed.
277 Compression speed is only relevant w 109 Compression speed is only relevant when building a kernel.
278 Decompression speed is relevant at e 110 Decompression speed is relevant at each boot.
279 111
280 If you have any problems with bzip2 112 If you have any problems with bzip2 or lzma compressed
281 kernels, mail me (Alain Knaff) <alain 113 kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
282 version of this functionality (bzip2 114 version of this functionality (bzip2 only), for 2.4, was
283 supplied by Christian Ludwig) 115 supplied by Christian Ludwig)
284 116
285 High compression options are mostly 117 High compression options are mostly useful for users, who
286 are low on disk space (embedded syst 118 are low on disk space (embedded systems), but for whom ram
287 size matters less. 119 size matters less.
288 120
289 If in doubt, select 'gzip' 121 If in doubt, select 'gzip'
290 122
291 config KERNEL_GZIP 123 config KERNEL_GZIP
292 bool "Gzip" 124 bool "Gzip"
293 depends on HAVE_KERNEL_GZIP 125 depends on HAVE_KERNEL_GZIP
294 help 126 help
295 The old and tried gzip compression. 127 The old and tried gzip compression. It provides a good balance
296 between compression ratio and decomp 128 between compression ratio and decompression speed.
297 129
298 config KERNEL_BZIP2 130 config KERNEL_BZIP2
299 bool "Bzip2" 131 bool "Bzip2"
300 depends on HAVE_KERNEL_BZIP2 132 depends on HAVE_KERNEL_BZIP2
301 help 133 help
302 Its compression ratio and speed is i 134 Its compression ratio and speed is intermediate.
303 Decompression speed is slowest among 135 Decompression speed is slowest among the choices. The kernel
304 size is about 10% smaller with bzip2 136 size is about 10% smaller with bzip2, in comparison to gzip.
305 Bzip2 uses a large amount of memory. 137 Bzip2 uses a large amount of memory. For modern kernels you
306 will need at least 8MB RAM or more f 138 will need at least 8MB RAM or more for booting.
307 139
308 config KERNEL_LZMA 140 config KERNEL_LZMA
309 bool "LZMA" 141 bool "LZMA"
310 depends on HAVE_KERNEL_LZMA 142 depends on HAVE_KERNEL_LZMA
311 help 143 help
312 This compression algorithm's ratio i 144 This compression algorithm's ratio is best. Decompression speed
313 is between gzip and bzip2. Compress 145 is between gzip and bzip2. Compression is slowest.
314 The kernel size is about 33% smaller 146 The kernel size is about 33% smaller with LZMA in comparison to gzip.
315 147
316 config KERNEL_XZ 148 config KERNEL_XZ
317 bool "XZ" 149 bool "XZ"
318 depends on HAVE_KERNEL_XZ 150 depends on HAVE_KERNEL_XZ
319 help 151 help
320 XZ uses the LZMA2 algorithm and inst 152 XZ uses the LZMA2 algorithm and instruction set specific
321 BCJ filters which can improve compre 153 BCJ filters which can improve compression ratio of executable
322 code. The size of the kernel is abou 154 code. The size of the kernel is about 30% smaller with XZ in
323 comparison to gzip. On architectures 155 comparison to gzip. On architectures for which there is a BCJ
324 filter (i386, x86_64, ARM, ARM64, RI !! 156 filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
325 and SPARC), XZ will create a few per !! 157 will create a few percent smaller kernel than plain LZMA.
326 plain LZMA. <<
327 158
328 The speed is about the same as with 159 The speed is about the same as with LZMA: The decompression
329 speed of XZ is better than that of b 160 speed of XZ is better than that of bzip2 but worse than gzip
330 and LZO. Compression is slow. 161 and LZO. Compression is slow.
331 162
332 config KERNEL_LZO 163 config KERNEL_LZO
333 bool "LZO" 164 bool "LZO"
334 depends on HAVE_KERNEL_LZO 165 depends on HAVE_KERNEL_LZO
335 help 166 help
336 Its compression ratio is the poorest 167 Its compression ratio is the poorest among the choices. The kernel
337 size is about 10% bigger than gzip; 168 size is about 10% bigger than gzip; however its speed
338 (both compression and decompression) 169 (both compression and decompression) is the fastest.
339 170
340 config KERNEL_LZ4 <<
341 bool "LZ4" <<
342 depends on HAVE_KERNEL_LZ4 <<
343 help <<
344 LZ4 is an LZ77-type compressor with <<
345 A preliminary version of LZ4 de/comp <<
346 <https://code.google.com/p/lz4/>. <<
347 <<
348 Its compression ratio is worse than <<
349 is about 8% bigger than LZO. But the <<
350 faster than LZO. <<
351 <<
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 171 endchoice
373 172
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 173 config DEFAULT_HOSTNAME
385 string "Default hostname" 174 string "Default hostname"
386 default "(none)" 175 default "(none)"
387 help 176 help
388 This option determines the default s 177 This option determines the default system hostname before userspace
389 calls sethostname(2). The kernel tra 178 calls sethostname(2). The kernel traditionally uses "(none)" here,
390 but you may wish to use a different 179 but you may wish to use a different default here to make a minimal
391 system more usable with less configu 180 system more usable with less configuration.
392 181
>> 182 config SWAP
>> 183 bool "Support for paging of anonymous memory (swap)"
>> 184 depends on MMU && BLOCK
>> 185 default y
>> 186 help
>> 187 This option allows you to choose whether you want to have support
>> 188 for so called swap devices or swap files in your kernel that are
>> 189 used to provide more virtual memory than the actual RAM present
>> 190 in your computer. If unsure say Y.
>> 191
393 config SYSVIPC 192 config SYSVIPC
394 bool "System V IPC" 193 bool "System V IPC"
395 help !! 194 ---help---
396 Inter Process Communication is a sui 195 Inter Process Communication is a suite of library functions and
397 system calls which let processes (ru 196 system calls which let processes (running programs) synchronize and
398 exchange information. It is generall 197 exchange information. It is generally considered to be a good thing,
399 and some programs won't run unless y 198 and some programs won't run unless you say Y here. In particular, if
400 you want to run the DOS emulator dos 199 you want to run the DOS emulator dosemu under Linux (read the
401 DOSEMU-HOWTO, available from <http:/ 200 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
402 you'll need to say Y here. 201 you'll need to say Y here.
403 202
404 You can find documentation about IPC 203 You can find documentation about IPC with "info ipc" and also in
405 section 6.4 of the Linux Programmer' 204 section 6.4 of the Linux Programmer's Guide, available from
406 <http://www.tldp.org/guides.html>. 205 <http://www.tldp.org/guides.html>.
407 206
408 config SYSVIPC_SYSCTL 207 config SYSVIPC_SYSCTL
409 bool 208 bool
410 depends on SYSVIPC 209 depends on SYSVIPC
411 depends on SYSCTL 210 depends on SYSCTL
412 default y 211 default y
413 212
414 config SYSVIPC_COMPAT <<
415 def_bool y <<
416 depends on COMPAT && SYSVIPC <<
417 <<
418 config POSIX_MQUEUE 213 config POSIX_MQUEUE
419 bool "POSIX Message Queues" 214 bool "POSIX Message Queues"
420 depends on NET 215 depends on NET
421 help !! 216 ---help---
422 POSIX variant of message queues is a 217 POSIX variant of message queues is a part of IPC. In POSIX message
423 queues every message has a priority 218 queues every message has a priority which decides about succession
424 of receiving it by a process. If you 219 of receiving it by a process. If you want to compile and run
425 programs written e.g. for Solaris wi 220 programs written e.g. for Solaris with use of its POSIX message
426 queues (functions mq_*) say Y here. 221 queues (functions mq_*) say Y here.
427 222
428 POSIX message queues are visible as 223 POSIX message queues are visible as a filesystem called 'mqueue'
429 and can be mounted somewhere if you 224 and can be mounted somewhere if you want to do filesystem
430 operations on message queues. 225 operations on message queues.
431 226
432 If unsure, say Y. 227 If unsure, say Y.
433 228
434 config POSIX_MQUEUE_SYSCTL 229 config POSIX_MQUEUE_SYSCTL
435 bool 230 bool
436 depends on POSIX_MQUEUE 231 depends on POSIX_MQUEUE
437 depends on SYSCTL 232 depends on SYSCTL
438 default y 233 default y
439 234
440 config WATCH_QUEUE !! 235 config FHANDLE
441 bool "General notification queue" !! 236 bool "open by fhandle syscalls"
442 default n !! 237 select EXPORTFS
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 <<
453 bool "Enable process_vm_readv/writev s <<
454 depends on MMU <<
455 default y <<
456 help 238 help
457 Enabling this option adds the system !! 239 If you say Y here, a user level program will be able to map
458 process_vm_writev which allow a proc !! 240 file names to handle and then later use the handle for
459 to directly read from or write to an !! 241 different file system operations. This is useful in implementing
460 See the man page for more details. !! 242 userspace file servers, which now track files using handles instead
461 !! 243 of names. The handle would remain the same even if file names
462 config USELIB !! 244 get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
463 bool "uselib syscall (for libc5 and ea !! 245 syscalls.
464 default ALPHA || M68K || SPARC <<
465 help <<
466 This option enables the uselib sysca <<
467 dynamic linker from libc5 and earlie <<
468 system call. If you intend to run p <<
469 earlier, you may need to enable this <<
470 running glibc can safely disable thi <<
471 246
472 config AUDIT 247 config AUDIT
473 bool "Auditing support" 248 bool "Auditing support"
474 depends on NET 249 depends on NET
475 help 250 help
476 Enable auditing infrastructure that 251 Enable auditing infrastructure that can be used with another
477 kernel subsystem, such as SELinux (w 252 kernel subsystem, such as SELinux (which requires this for
478 logging of avc messages output). Sy !! 253 logging of avc messages output). Does not do system-call
479 on architectures which support it. !! 254 auditing without CONFIG_AUDITSYSCALL.
480 <<
481 config HAVE_ARCH_AUDITSYSCALL <<
482 bool <<
483 255
484 config AUDITSYSCALL 256 config AUDITSYSCALL
>> 257 bool "Enable system-call auditing support"
>> 258 depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH || (ARM && AEABI && !OABI_COMPAT))
>> 259 default y if SECURITY_SELINUX
>> 260 help
>> 261 Enable low-overhead system-call auditing infrastructure that
>> 262 can be used independently or with another kernel subsystem,
>> 263 such as SELinux.
>> 264
>> 265 config AUDIT_WATCH
485 def_bool y 266 def_bool y
486 depends on AUDIT && HAVE_ARCH_AUDITSYS !! 267 depends on AUDITSYSCALL
487 select FSNOTIFY 268 select FSNOTIFY
488 269
>> 270 config AUDIT_TREE
>> 271 def_bool y
>> 272 depends on AUDITSYSCALL
>> 273 select FSNOTIFY
>> 274
>> 275 config AUDIT_LOGINUID_IMMUTABLE
>> 276 bool "Make audit loginuid immutable"
>> 277 depends on AUDIT
>> 278 help
>> 279 The config option toggles if a task setting its loginuid requires
>> 280 CAP_SYS_AUDITCONTROL or if that task should require no special permissions
>> 281 but should instead only allow setting its loginuid if it was never
>> 282 previously set. On systems which use systemd or a similar central
>> 283 process to restart login services this should be set to true. On older
>> 284 systems in which an admin would typically have to directly stop and
>> 285 start processes this should be set to false. Setting this to true allows
>> 286 one to drop potentially dangerous capabilites from the login tasks,
>> 287 but may not be backwards compatible with older init systems.
>> 288
489 source "kernel/irq/Kconfig" 289 source "kernel/irq/Kconfig"
490 source "kernel/time/Kconfig" 290 source "kernel/time/Kconfig"
491 source "kernel/bpf/Kconfig" <<
492 source "kernel/Kconfig.preempt" <<
493 291
494 menu "CPU/Task time and stats accounting" 292 menu "CPU/Task time and stats accounting"
495 293
496 config VIRT_CPU_ACCOUNTING 294 config VIRT_CPU_ACCOUNTING
497 bool 295 bool
498 296
499 choice 297 choice
500 prompt "Cputime accounting" 298 prompt "Cputime accounting"
501 default TICK_CPU_ACCOUNTING !! 299 default TICK_CPU_ACCOUNTING if !PPC64
>> 300 default VIRT_CPU_ACCOUNTING_NATIVE if PPC64
502 301
503 # Kind of a stub config for the pure tick base 302 # Kind of a stub config for the pure tick based cputime accounting
504 config TICK_CPU_ACCOUNTING 303 config TICK_CPU_ACCOUNTING
505 bool "Simple tick based cputime accoun 304 bool "Simple tick based cputime accounting"
506 depends on !S390 && !NO_HZ_FULL 305 depends on !S390 && !NO_HZ_FULL
507 help 306 help
508 This is the basic tick based cputime 307 This is the basic tick based cputime accounting that maintains
509 statistics about user, system and id 308 statistics about user, system and idle time spent on per jiffies
510 granularity. 309 granularity.
511 310
512 If unsure, say Y. 311 If unsure, say Y.
513 312
514 config VIRT_CPU_ACCOUNTING_NATIVE 313 config VIRT_CPU_ACCOUNTING_NATIVE
515 bool "Deterministic task and CPU time 314 bool "Deterministic task and CPU time accounting"
516 depends on HAVE_VIRT_CPU_ACCOUNTING && 315 depends on HAVE_VIRT_CPU_ACCOUNTING && !NO_HZ_FULL
517 select VIRT_CPU_ACCOUNTING 316 select VIRT_CPU_ACCOUNTING
518 help 317 help
519 Select this option to enable more ac 318 Select this option to enable more accurate task and CPU time
520 accounting. This is done by reading 319 accounting. This is done by reading a CPU counter on each
521 kernel entry and exit and on transit 320 kernel entry and exit and on transitions within the kernel
522 between system, softirq and hardirq 321 between system, softirq and hardirq state, so there is a
523 small performance impact. In the ca 322 small performance impact. In the case of s390 or IBM POWER > 5,
524 this also enables accounting of stol 323 this also enables accounting of stolen time on logically-partitioned
525 systems. 324 systems.
526 325
527 config VIRT_CPU_ACCOUNTING_GEN 326 config VIRT_CPU_ACCOUNTING_GEN
528 bool "Full dynticks CPU time accountin 327 bool "Full dynticks CPU time accounting"
529 depends on HAVE_CONTEXT_TRACKING_USER !! 328 depends on HAVE_CONTEXT_TRACKING && 64BIT
530 depends on HAVE_VIRT_CPU_ACCOUNTING_GE <<
531 depends on GENERIC_CLOCKEVENTS <<
532 select VIRT_CPU_ACCOUNTING 329 select VIRT_CPU_ACCOUNTING
533 select CONTEXT_TRACKING_USER !! 330 select CONTEXT_TRACKING
534 help 331 help
535 Select this option to enable task an 332 Select this option to enable task and CPU time accounting on full
536 dynticks systems. This accounting is 333 dynticks systems. This accounting is implemented by watching every
537 kernel-user boundaries using the con 334 kernel-user boundaries using the context tracking subsystem.
538 The accounting is thus performed at 335 The accounting is thus performed at the expense of some significant
539 overhead. 336 overhead.
540 337
541 For now this is only useful if you a 338 For now this is only useful if you are working on the full
542 dynticks subsystem development. 339 dynticks subsystem development.
543 340
544 If unsure, say N. 341 If unsure, say N.
545 342
546 endchoice <<
547 <<
548 config IRQ_TIME_ACCOUNTING 343 config IRQ_TIME_ACCOUNTING
549 bool "Fine granularity task level IRQ 344 bool "Fine granularity task level IRQ time accounting"
550 depends on HAVE_IRQ_TIME_ACCOUNTING && !! 345 depends on HAVE_IRQ_TIME_ACCOUNTING && !NO_HZ_FULL
551 help 346 help
552 Select this option to enable fine gr 347 Select this option to enable fine granularity task irq time
553 accounting. This is done by reading 348 accounting. This is done by reading a timestamp on each
554 transitions between softirq and hard 349 transitions between softirq and hardirq state, so there can be a
555 small performance impact. 350 small performance impact.
556 351
557 If in doubt, say N here. 352 If in doubt, say N here.
558 353
559 config HAVE_SCHED_AVG_IRQ !! 354 endchoice
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 <<
582 355
583 config BSD_PROCESS_ACCT 356 config BSD_PROCESS_ACCT
584 bool "BSD Process Accounting" 357 bool "BSD Process Accounting"
585 depends on MULTIUSER <<
586 help 358 help
587 If you say Y here, a user level prog 359 If you say Y here, a user level program will be able to instruct the
588 kernel (via a special system call) t 360 kernel (via a special system call) to write process accounting
589 information to a file: whenever a pr 361 information to a file: whenever a process exits, information about
590 that process will be appended to the 362 that process will be appended to the file by the kernel. The
591 information includes things such as 363 information includes things such as creation time, owning user,
592 command name, memory usage, controll 364 command name, memory usage, controlling terminal etc. (the complete
593 list is in the struct acct in <file: 365 list is in the struct acct in <file:include/linux/acct.h>). It is
594 up to the user level program to do u 366 up to the user level program to do useful things with this
595 information. This is generally a go 367 information. This is generally a good idea, so say Y.
596 368
597 config BSD_PROCESS_ACCT_V3 369 config BSD_PROCESS_ACCT_V3
598 bool "BSD Process Accounting version 3 370 bool "BSD Process Accounting version 3 file format"
599 depends on BSD_PROCESS_ACCT 371 depends on BSD_PROCESS_ACCT
600 default n 372 default n
601 help 373 help
602 If you say Y here, the process accou 374 If you say Y here, the process accounting information is written
603 in a new file format that also logs 375 in a new file format that also logs the process IDs of each
604 process and its parent. Note that th !! 376 process and it's parent. Note that this file format is incompatible
605 with previous v0/v1/v2 file formats, 377 with previous v0/v1/v2 file formats, so you will need updated tools
606 for processing it. A preliminary ver 378 for processing it. A preliminary version of these tools is available
607 at <http://www.gnu.org/software/acct 379 at <http://www.gnu.org/software/acct/>.
608 380
609 config TASKSTATS 381 config TASKSTATS
610 bool "Export task/process statistics t 382 bool "Export task/process statistics through netlink"
611 depends on NET 383 depends on NET
612 depends on MULTIUSER <<
613 default n 384 default n
614 help 385 help
615 Export selected statistics for tasks 386 Export selected statistics for tasks/processes through the
616 generic netlink interface. Unlike BS 387 generic netlink interface. Unlike BSD process accounting, the
617 statistics are available during the 388 statistics are available during the lifetime of tasks/processes as
618 responses to commands. Like BSD acco 389 responses to commands. Like BSD accounting, they are sent to user
619 space on task exit. 390 space on task exit.
620 391
621 Say N if unsure. 392 Say N if unsure.
622 393
623 config TASK_DELAY_ACCT 394 config TASK_DELAY_ACCT
624 bool "Enable per-task delay accounting 395 bool "Enable per-task delay accounting"
625 depends on TASKSTATS 396 depends on TASKSTATS
626 select SCHED_INFO <<
627 help 397 help
628 Collect information on time spent by 398 Collect information on time spent by a task waiting for system
629 resources like cpu, synchronous bloc 399 resources like cpu, synchronous block I/O completion and swapping
630 in pages. Such statistics can help i 400 in pages. Such statistics can help in setting a task's priorities
631 relative to other tasks for cpu, io, 401 relative to other tasks for cpu, io, rss limits etc.
632 402
633 Say N if unsure. 403 Say N if unsure.
634 404
635 config TASK_XACCT 405 config TASK_XACCT
636 bool "Enable extended accounting over 406 bool "Enable extended accounting over taskstats"
637 depends on TASKSTATS 407 depends on TASKSTATS
638 help 408 help
639 Collect extended task accounting dat 409 Collect extended task accounting data and send the data
640 to userland for processing over the 410 to userland for processing over the taskstats interface.
641 411
642 Say N if unsure. 412 Say N if unsure.
643 413
644 config TASK_IO_ACCOUNTING 414 config TASK_IO_ACCOUNTING
645 bool "Enable per-task storage I/O acco 415 bool "Enable per-task storage I/O accounting"
646 depends on TASK_XACCT 416 depends on TASK_XACCT
647 help 417 help
648 Collect information on the number of 418 Collect information on the number of bytes of storage I/O which this
649 task has caused. 419 task has caused.
650 420
651 Say N if unsure. 421 Say N if unsure.
652 422
653 config PSI !! 423 endmenu # "CPU/Task time and stats accounting"
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 <<
668 424
669 For more details see Documentation/a !! 425 menu "RCU Subsystem"
670 426
671 Say N if unsure. !! 427 choice
>> 428 prompt "RCU Implementation"
>> 429 default TREE_RCU
672 430
673 config PSI_DEFAULT_DISABLED !! 431 config TREE_RCU
674 bool "Require boot parameter to enable !! 432 bool "Tree-based hierarchical RCU"
>> 433 depends on !PREEMPT && SMP
>> 434 select IRQ_WORK
>> 435 help
>> 436 This option selects the RCU implementation that is
>> 437 designed for very large SMP system with hundreds or
>> 438 thousands of CPUs. It also scales down nicely to
>> 439 smaller systems.
>> 440
>> 441 config TREE_PREEMPT_RCU
>> 442 bool "Preemptible tree-based hierarchical RCU"
>> 443 depends on PREEMPT
>> 444 help
>> 445 This option selects the RCU implementation that is
>> 446 designed for very large SMP systems with hundreds or
>> 447 thousands of CPUs, but for which real-time response
>> 448 is also required. It also scales down nicely to
>> 449 smaller systems.
>> 450
>> 451 Select this option if you are unsure.
>> 452
>> 453 config TINY_RCU
>> 454 bool "UP-only small-memory-footprint RCU"
>> 455 depends on !PREEMPT && !SMP
>> 456 help
>> 457 This option selects the RCU implementation that is
>> 458 designed for UP systems from which real-time response
>> 459 is not required. This option greatly reduces the
>> 460 memory footprint of RCU.
>> 461
>> 462 config TINY_PREEMPT_RCU
>> 463 bool "Preemptible UP-only small-memory-footprint RCU"
>> 464 depends on PREEMPT && !SMP
>> 465 help
>> 466 This option selects the RCU implementation that is designed
>> 467 for real-time UP systems. This option greatly reduces the
>> 468 memory footprint of RCU.
>> 469
>> 470 endchoice
>> 471
>> 472 config PREEMPT_RCU
>> 473 def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
>> 474 help
>> 475 This option enables preemptible-RCU code that is common between
>> 476 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
>> 477
>> 478 config RCU_STALL_COMMON
>> 479 def_bool ( TREE_RCU || TREE_PREEMPT_RCU || RCU_TRACE )
>> 480 help
>> 481 This option enables RCU CPU stall code that is common between
>> 482 the TINY and TREE variants of RCU. The purpose is to allow
>> 483 the tiny variants to disable RCU CPU stall warnings, while
>> 484 making these warnings mandatory for the tree variants.
>> 485
>> 486 config CONTEXT_TRACKING
>> 487 bool
>> 488
>> 489 config RCU_USER_QS
>> 490 bool "Consider userspace as in RCU extended quiescent state"
>> 491 depends on HAVE_CONTEXT_TRACKING && SMP
>> 492 select CONTEXT_TRACKING
>> 493 help
>> 494 This option sets hooks on kernel / userspace boundaries and
>> 495 puts RCU in extended quiescent state when the CPU runs in
>> 496 userspace. It means that when a CPU runs in userspace, it is
>> 497 excluded from the global RCU state machine and thus doesn't
>> 498 try to keep the timer tick on for RCU.
>> 499
>> 500 Unless you want to hack and help the development of the full
>> 501 dynticks mode, you shouldn't enable this option. It also
>> 502 adds unnecessary overhead.
>> 503
>> 504 If unsure say N
>> 505
>> 506 config CONTEXT_TRACKING_FORCE
>> 507 bool "Force context tracking"
>> 508 depends on CONTEXT_TRACKING
>> 509 default CONTEXT_TRACKING
>> 510 help
>> 511 Probe on user/kernel boundaries by default in order to
>> 512 test the features that rely on it such as userspace RCU extended
>> 513 quiescent states.
>> 514 This test is there for debugging until we have a real user like the
>> 515 full dynticks mode.
>> 516
>> 517 config RCU_FANOUT
>> 518 int "Tree-based hierarchical RCU fanout value"
>> 519 range 2 64 if 64BIT
>> 520 range 2 32 if !64BIT
>> 521 depends on TREE_RCU || TREE_PREEMPT_RCU
>> 522 default 64 if 64BIT
>> 523 default 32 if !64BIT
>> 524 help
>> 525 This option controls the fanout of hierarchical implementations
>> 526 of RCU, allowing RCU to work efficiently on machines with
>> 527 large numbers of CPUs. This value must be at least the fourth
>> 528 root of NR_CPUS, which allows NR_CPUS to be insanely large.
>> 529 The default value of RCU_FANOUT should be used for production
>> 530 systems, but if you are stress-testing the RCU implementation
>> 531 itself, small RCU_FANOUT values allow you to test large-system
>> 532 code paths on small(er) systems.
>> 533
>> 534 Select a specific number if testing RCU itself.
>> 535 Take the default if unsure.
>> 536
>> 537 config RCU_FANOUT_LEAF
>> 538 int "Tree-based hierarchical RCU leaf-level fanout value"
>> 539 range 2 RCU_FANOUT if 64BIT
>> 540 range 2 RCU_FANOUT if !64BIT
>> 541 depends on TREE_RCU || TREE_PREEMPT_RCU
>> 542 default 16
>> 543 help
>> 544 This option controls the leaf-level fanout of hierarchical
>> 545 implementations of RCU, and allows trading off cache misses
>> 546 against lock contention. Systems that synchronize their
>> 547 scheduling-clock interrupts for energy-efficiency reasons will
>> 548 want the default because the smaller leaf-level fanout keeps
>> 549 lock contention levels acceptably low. Very large systems
>> 550 (hundreds or thousands of CPUs) will instead want to set this
>> 551 value to the maximum value possible in order to reduce the
>> 552 number of cache misses incurred during RCU's grace-period
>> 553 initialization. These systems tend to run CPU-bound, and thus
>> 554 are not helped by synchronized interrupts, and thus tend to
>> 555 skew them, which reduces lock contention enough that large
>> 556 leaf-level fanouts work well.
>> 557
>> 558 Select a specific number if testing RCU itself.
>> 559
>> 560 Select the maximum permissible value for large systems.
>> 561
>> 562 Take the default if unsure.
>> 563
>> 564 config RCU_FANOUT_EXACT
>> 565 bool "Disable tree-based hierarchical RCU auto-balancing"
>> 566 depends on TREE_RCU || TREE_PREEMPT_RCU
675 default n 567 default n
676 depends on PSI <<
677 help 568 help
678 If set, pressure stall information t !! 569 This option forces use of the exact RCU_FANOUT value specified,
679 per default but can be enabled throu !! 570 regardless of imbalances in the hierarchy. This is useful for
680 kernel commandline during boot. !! 571 testing RCU itself, and might one day be useful on systems with
681 !! 572 strong NUMA behavior.
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 <<
687 573
688 If you are paranoid and not sure wha !! 574 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
689 used for, say Y. <<
690 575
691 Say N if unsure. 576 Say N if unsure.
692 577
693 endmenu # "CPU/Task time and stats accounting" !! 578 config RCU_FAST_NO_HZ
>> 579 bool "Accelerate last non-dyntick-idle CPU's grace periods"
>> 580 depends on NO_HZ_COMMON && SMP
>> 581 default n
>> 582 help
>> 583 This option permits CPUs to enter dynticks-idle state even if
>> 584 they have RCU callbacks queued, and prevents RCU from waking
>> 585 these CPUs up more than roughly once every four jiffies (by
>> 586 default, you can adjust this using the rcutree.rcu_idle_gp_delay
>> 587 parameter), thus improving energy efficiency. On the other
>> 588 hand, this option increases the duration of RCU grace periods,
>> 589 for example, slowing down synchronize_rcu().
>> 590
>> 591 Say Y if energy efficiency is critically important, and you
>> 592 don't care about increased grace-period durations.
>> 593
>> 594 Say N if you are unsure.
>> 595
>> 596 config TREE_RCU_TRACE
>> 597 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
>> 598 select DEBUG_FS
>> 599 help
>> 600 This option provides tracing for the TREE_RCU and
>> 601 TREE_PREEMPT_RCU implementations, permitting Makefile to
>> 602 trivially select kernel/rcutree_trace.c.
>> 603
>> 604 config RCU_BOOST
>> 605 bool "Enable RCU priority boosting"
>> 606 depends on RT_MUTEXES && PREEMPT_RCU
>> 607 default n
>> 608 help
>> 609 This option boosts the priority of preempted RCU readers that
>> 610 block the current preemptible RCU grace period for too long.
>> 611 This option also prevents heavy loads from blocking RCU
>> 612 callback invocation for all flavors of RCU.
>> 613
>> 614 Say Y here if you are working with real-time apps or heavy loads
>> 615 Say N here if you are unsure.
>> 616
>> 617 config RCU_BOOST_PRIO
>> 618 int "Real-time priority to boost RCU readers to"
>> 619 range 1 99
>> 620 depends on RCU_BOOST
>> 621 default 1
>> 622 help
>> 623 This option specifies the real-time priority to which long-term
>> 624 preempted RCU readers are to be boosted. If you are working
>> 625 with a real-time application that has one or more CPU-bound
>> 626 threads running at a real-time priority level, you should set
>> 627 RCU_BOOST_PRIO to a priority higher then the highest-priority
>> 628 real-time CPU-bound thread. The default RCU_BOOST_PRIO value
>> 629 of 1 is appropriate in the common case, which is real-time
>> 630 applications that do not have any CPU-bound threads.
>> 631
>> 632 Some real-time applications might not have a single real-time
>> 633 thread that saturates a given CPU, but instead might have
>> 634 multiple real-time threads that, taken together, fully utilize
>> 635 that CPU. In this case, you should set RCU_BOOST_PRIO to
>> 636 a priority higher than the lowest-priority thread that is
>> 637 conspiring to prevent the CPU from running any non-real-time
>> 638 tasks. For example, if one thread at priority 10 and another
>> 639 thread at priority 5 are between themselves fully consuming
>> 640 the CPU time on a given CPU, then RCU_BOOST_PRIO should be
>> 641 set to priority 6 or higher.
>> 642
>> 643 Specify the real-time priority, or take the default if unsure.
>> 644
>> 645 config RCU_BOOST_DELAY
>> 646 int "Milliseconds to delay boosting after RCU grace-period start"
>> 647 range 0 3000
>> 648 depends on RCU_BOOST
>> 649 default 500
>> 650 help
>> 651 This option specifies the time to wait after the beginning of
>> 652 a given grace period before priority-boosting preempted RCU
>> 653 readers blocking that grace period. Note that any RCU reader
>> 654 blocking an expedited RCU grace period is boosted immediately.
>> 655
>> 656 Accept the default if unsure.
>> 657
>> 658 config RCU_NOCB_CPU
>> 659 bool "Offload RCU callback processing from boot-selected CPUs (EXPERIMENTAL"
>> 660 depends on TREE_RCU || TREE_PREEMPT_RCU
>> 661 default n
>> 662 help
>> 663 Use this option to reduce OS jitter for aggressive HPC or
>> 664 real-time workloads. It can also be used to offload RCU
>> 665 callback invocation to energy-efficient CPUs in battery-powered
>> 666 asymmetric multiprocessors.
>> 667
>> 668 This option offloads callback invocation from the set of
>> 669 CPUs specified at boot time by the rcu_nocbs parameter.
>> 670 For each such CPU, a kthread ("rcuox/N") will be created to
>> 671 invoke callbacks, where the "N" is the CPU being offloaded,
>> 672 and where the "x" is "b" for RCU-bh, "p" for RCU-preempt, and
>> 673 "s" for RCU-sched. Nothing prevents this kthread from running
>> 674 on the specified CPUs, but (1) the kthreads may be preempted
>> 675 between each callback, and (2) affinity or cgroups can be used
>> 676 to force the kthreads to run on whatever set of CPUs is desired.
694 677
695 config CPU_ISOLATION !! 678 Say Y here if you want to help to debug reduced OS jitter.
696 bool "CPU isolation" !! 679 Say N here if you are unsure.
697 depends on SMP || COMPILE_TEST !! 680
698 default y !! 681 choice
>> 682 prompt "Build-forced no-CBs CPUs"
>> 683 default RCU_NOCB_CPU_NONE
699 help 684 help
700 Make sure that CPUs running critical !! 685 This option allows no-CBs CPUs to be specified at build time.
701 any source of "noise" such as unboun !! 686 Additional no-CBs CPUs may be specified by the rcu_nocbs=
702 Unbound jobs get offloaded to housek !! 687 boot parameter.
703 the "isolcpus=" boot parameter. <<
704 688
705 Say Y if unsure. !! 689 config RCU_NOCB_CPU_NONE
>> 690 bool "No build_forced no-CBs CPUs"
>> 691 depends on RCU_NOCB_CPU && !NO_HZ_FULL
>> 692 help
>> 693 This option does not force any of the CPUs to be no-CBs CPUs.
>> 694 Only CPUs designated by the rcu_nocbs= boot parameter will be
>> 695 no-CBs CPUs.
>> 696
>> 697 config RCU_NOCB_CPU_ZERO
>> 698 bool "CPU 0 is a build_forced no-CBs CPU"
>> 699 depends on RCU_NOCB_CPU && !NO_HZ_FULL
>> 700 help
>> 701 This option forces CPU 0 to be a no-CBs CPU. Additional CPUs
>> 702 may be designated as no-CBs CPUs using the rcu_nocbs= boot
>> 703 parameter will be no-CBs CPUs.
>> 704
>> 705 Select this if CPU 0 needs to be a no-CBs CPU for real-time
>> 706 or energy-efficiency reasons.
>> 707
>> 708 config RCU_NOCB_CPU_ALL
>> 709 bool "All CPUs are build_forced no-CBs CPUs"
>> 710 depends on RCU_NOCB_CPU
>> 711 help
>> 712 This option forces all CPUs to be no-CBs CPUs. The rcu_nocbs=
>> 713 boot parameter will be ignored.
>> 714
>> 715 Select this if all CPUs need to be no-CBs CPUs for real-time
>> 716 or energy-efficiency reasons.
706 717
707 source "kernel/rcu/Kconfig" !! 718 endchoice
>> 719
>> 720 endmenu # "RCU Subsystem"
708 721
709 config IKCONFIG 722 config IKCONFIG
710 tristate "Kernel .config support" 723 tristate "Kernel .config support"
711 help !! 724 ---help---
712 This option enables the complete Lin 725 This option enables the complete Linux kernel ".config" file
713 contents to be saved in the kernel. 726 contents to be saved in the kernel. It provides documentation
714 of which kernel options are used in 727 of which kernel options are used in a running kernel or in an
715 on-disk kernel. This information ca 728 on-disk kernel. This information can be extracted from the kernel
716 image file with the script scripts/e 729 image file with the script scripts/extract-ikconfig and used as
717 input to rebuild the current kernel 730 input to rebuild the current kernel or to build another kernel.
718 It can also be extracted from a runn 731 It can also be extracted from a running kernel by reading
719 /proc/config.gz if enabled (below). 732 /proc/config.gz if enabled (below).
720 733
721 config IKCONFIG_PROC 734 config IKCONFIG_PROC
722 bool "Enable access to .config through 735 bool "Enable access to .config through /proc/config.gz"
723 depends on IKCONFIG && PROC_FS 736 depends on IKCONFIG && PROC_FS
724 help !! 737 ---help---
725 This option enables access to the ke 738 This option enables access to the kernel configuration file
726 through /proc/config.gz. 739 through /proc/config.gz.
727 740
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 741 config LOG_BUF_SHIFT
738 int "Kernel log buffer size (16 => 64K 742 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
739 range 12 25 !! 743 range 12 21
740 default 17 744 default 17
741 depends on PRINTK <<
742 help 745 help
743 Select the minimal kernel log buffer !! 746 Select kernel log buffer size as a power of 2.
744 The final size is affected by LOG_CP <<
745 parameter, see below. Any higher siz <<
746 by "log_buf_len" boot parameter. <<
747 <<
748 Examples: 747 Examples:
749 17 => 128 KB !! 748 17 => 128 KB
750 16 => 64 KB 749 16 => 64 KB
751 15 => 32 KB !! 750 15 => 32 KB
752 14 => 16 KB !! 751 14 => 16 KB
753 13 => 8 KB 752 13 => 8 KB
754 12 => 4 KB 753 12 => 4 KB
755 754
756 config LOG_CPU_MAX_BUF_SHIFT <<
757 int "CPU kernel log buffer size contri <<
758 depends on SMP <<
759 range 0 21 <<
760 default 0 if BASE_SMALL <<
761 default 12 <<
762 depends on PRINTK <<
763 help <<
764 This option allows to increase the d <<
765 according to the number of CPUs. The <<
766 of each CPU as a power of 2. The use <<
767 lines however it might be much more <<
768 e.g. backtraces. <<
769 <<
770 The increased size means that a new <<
771 the original static one is unused. I <<
772 with more CPUs. Therefore this value <<
773 contributions is greater than the ha <<
774 buffer as defined by LOG_BUF_SHIFT. <<
775 so that more than 16 CPUs are needed <<
776 <<
777 Also this option is ignored when "lo <<
778 used as it forces an exact (power of <<
779 <<
780 The number of possible CPUs is used <<
781 hotplugging making the computation o <<
782 scenario while allowing a simple alg <<
783 <<
784 Examples shift values and their mean <<
785 17 => 128 KB for each CPU <<
786 16 => 64 KB for each CPU <<
787 15 => 32 KB for each CPU <<
788 14 => 16 KB for each CPU <<
789 13 => 8 KB for each CPU <<
790 12 => 4 KB for each CPU <<
791 <<
792 config PRINTK_INDEX <<
793 bool "Printk indexing debugfs interfac <<
794 depends on PRINTK && DEBUG_FS <<
795 help <<
796 Add support for indexing of all prin <<
797 at <debugfs>/printk/index/<module>. <<
798 <<
799 This can be used as part of maintain <<
800 /dev/kmsg, as it permits auditing th <<
801 kernel, allowing detection of cases <<
802 changed or no longer present. <<
803 <<
804 There is no additional runtime cost <<
805 <<
806 # 755 #
807 # Architectures with an unreliable sched_clock 756 # Architectures with an unreliable sched_clock() should select this:
808 # 757 #
809 config HAVE_UNSTABLE_SCHED_CLOCK 758 config HAVE_UNSTABLE_SCHED_CLOCK
810 bool 759 bool
811 760
812 config GENERIC_SCHED_CLOCK <<
813 bool <<
814 <<
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 # 761 #
869 # For architectures that want to enable the su 762 # For architectures that want to enable the support for NUMA-affine scheduler
870 # balancing logic: 763 # balancing logic:
871 # 764 #
872 config ARCH_SUPPORTS_NUMA_BALANCING 765 config ARCH_SUPPORTS_NUMA_BALANCING
873 bool 766 bool
874 767
>> 768 # For architectures that (ab)use NUMA to represent different memory regions
>> 769 # all cpu-local but of different latencies, such as SuperH.
875 # 770 #
876 # For architectures that prefer to flush all T !! 771 config ARCH_WANT_NUMA_VARIABLE_LOCALITY
877 # are unmapped instead of sending one IPI per <<
878 # must provide guarantees on what happens if a <<
879 # written after the unmap. Details are in mm/r <<
880 # should_defer_flush. The architecture should <<
881 # and the refill costs are offset by the savin <<
882 config ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH <<
883 bool <<
884 <<
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 772 bool
912 default y if CC_IS_GCC && !CC_NO_STRIN <<
913 773
914 # 774 #
915 # For architectures that know their GCC __int1 !! 775 # For architectures that are willing to define _PAGE_NUMA as _PAGE_PROTNONE
916 # !! 776 config ARCH_WANTS_PROT_NUMA_PROT_NONE
917 config ARCH_SUPPORTS_INT128 <<
918 bool 777 bool
919 778
920 # For architectures that (ab)use NUMA to repre !! 779 config ARCH_USES_NUMA_PROT_NONE
921 # all cpu-local but of different latencies, su <<
922 # <<
923 config ARCH_WANT_NUMA_VARIABLE_LOCALITY <<
924 bool 780 bool
>> 781 default y
>> 782 depends on ARCH_WANTS_PROT_NUMA_PROT_NONE
>> 783 depends on NUMA_BALANCING
>> 784
>> 785 config NUMA_BALANCING_DEFAULT_ENABLED
>> 786 bool "Automatically enable NUMA aware memory/task placement"
>> 787 default y
>> 788 depends on NUMA_BALANCING
>> 789 help
>> 790 If set, autonumic NUMA balancing will be enabled if running on a NUMA
>> 791 machine.
925 792
926 config NUMA_BALANCING 793 config NUMA_BALANCING
927 bool "Memory placement aware NUMA sche 794 bool "Memory placement aware NUMA scheduler"
928 depends on ARCH_SUPPORTS_NUMA_BALANCIN 795 depends on ARCH_SUPPORTS_NUMA_BALANCING
929 depends on !ARCH_WANT_NUMA_VARIABLE_LO 796 depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
930 depends on SMP && NUMA && MIGRATION && !! 797 depends on SMP && NUMA && MIGRATION
931 help 798 help
932 This option adds support for automat 799 This option adds support for automatic NUMA aware memory/task placement.
933 The mechanism is quite primitive and 800 The mechanism is quite primitive and is based on migrating memory when
934 it has references to the node the ta !! 801 it is references to the node the task is running on.
935 802
936 This system will be inactive on UMA 803 This system will be inactive on UMA systems.
937 804
938 config NUMA_BALANCING_DEFAULT_ENABLED <<
939 bool "Automatically enable NUMA aware <<
940 default y <<
941 depends on NUMA_BALANCING <<
942 help <<
943 If set, automatic NUMA balancing wil <<
944 machine. <<
945 <<
946 config SLAB_OBJ_EXT <<
947 bool <<
948 <<
949 menuconfig CGROUPS 805 menuconfig CGROUPS
950 bool "Control Group support" !! 806 boolean "Control Group support"
951 select KERNFS !! 807 depends on EVENTFD
952 help 808 help
953 This option adds support for groupin 809 This option adds support for grouping sets of processes together, for
954 use with process control subsystems 810 use with process control subsystems such as Cpusets, CFS, memory
955 controls or device isolation. 811 controls or device isolation.
956 See 812 See
957 - Documentation/scheduler/sche !! 813 - Documentation/scheduler/sched-design-CFS.txt (CFS)
958 - Documentation/admin-guide/cg !! 814 - Documentation/cgroups/ (features for grouping, isolation
959 and 815 and resource control)
960 816
961 Say N if unsure. 817 Say N if unsure.
962 818
963 if CGROUPS 819 if CGROUPS
964 820
965 config PAGE_COUNTER !! 821 config CGROUP_DEBUG
966 bool !! 822 bool "Example debug cgroup subsystem"
>> 823 default n
>> 824 help
>> 825 This option enables a simple cgroup subsystem that
>> 826 exports useful debugging information about the cgroups
>> 827 framework.
967 828
968 config CGROUP_FAVOR_DYNMODS !! 829 Say N if unsure.
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 <<
975 830
976 Say N if unsure. !! 831 config CGROUP_FREEZER
>> 832 bool "Freezer cgroup subsystem"
>> 833 help
>> 834 Provides a way to freeze and unfreeze all tasks in a
>> 835 cgroup.
977 836
978 config MEMCG !! 837 config CGROUP_DEVICE
979 bool "Memory controller" !! 838 bool "Device controller for cgroups"
980 select PAGE_COUNTER <<
981 select EVENTFD <<
982 select SLAB_OBJ_EXT <<
983 help 839 help
984 Provides control over the memory foo !! 840 Provides a cgroup implementing whitelists for devices which
>> 841 a process in the cgroup can mknod or open.
985 842
986 config MEMCG_V1 !! 843 config CPUSETS
987 bool "Legacy cgroup v1 memory controll !! 844 bool "Cpuset support"
988 depends on MEMCG <<
989 default n <<
990 help 845 help
991 Legacy cgroup v1 memory controller w !! 846 This option will let you create and manage CPUSETs which
992 cgroup v2 implementation. The v1 is !! 847 allow dynamically partitioning a system into sets of CPUs and
993 which haven't migrated to the new cg !! 848 Memory Nodes and assigning tasks to run only within those sets.
994 do not have any such application the !! 849 This is primarily useful on large SMP or NUMA systems.
995 this option disabled. <<
996 <<
997 Please note that feature set of the <<
998 going to shrink due to deprecation p <<
999 controller are highly discouraged. <<
1000 850
1001 Say N if unsure. 851 Say N if unsure.
1002 852
1003 config BLK_CGROUP !! 853 config PROC_PID_CPUSET
1004 bool "IO controller" !! 854 bool "Include legacy /proc/<pid>/cpuset file"
1005 depends on BLOCK !! 855 depends on CPUSETS
1006 default n !! 856 default y
>> 857
>> 858 config CGROUP_CPUACCT
>> 859 bool "Simple CPU accounting cgroup subsystem"
1007 help 860 help
1008 Generic block IO controller cgroup in !! 861 Provides a simple Resource Controller for monitoring the
1009 cgroup interface which should be used !! 862 total CPU consumed by the tasks in a cgroup.
1010 policies. <<
1011 863
1012 Currently, CFQ IO scheduler uses it t !! 864 config RESOURCE_COUNTERS
1013 control disk bandwidth allocation (pr !! 865 bool "Resource counters"
1014 to such task groups. It is also used !! 866 help
1015 block layer to implement upper limit !! 867 This option enables controller independent resource accounting
>> 868 infrastructure that works with cgroups.
1016 869
1017 This option only enables generic Bloc !! 870 config MEMCG
1018 One needs to also enable actual IO co !! 871 bool "Memory Resource Controller for Control Groups"
1019 enabling proportional weight division !! 872 depends on RESOURCE_COUNTERS
1020 CONFIG_BFQ_GROUP_IOSCHED=y; for enabl !! 873 select MM_OWNER
1021 CONFIG_BLK_DEV_THROTTLING=y. !! 874 help
>> 875 Provides a memory resource controller that manages both anonymous
>> 876 memory and page cache. (See Documentation/cgroups/memory.txt)
>> 877
>> 878 Note that setting this option increases fixed memory overhead
>> 879 associated with each page of memory in the system. By this,
>> 880 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
>> 881 usage tracking struct at boot. Total amount of this is printed out
>> 882 at boot.
>> 883
>> 884 Only enable when you're ok with these trade offs and really
>> 885 sure you need the memory resource controller. Even when you enable
>> 886 this, you can set "cgroup_disable=memory" at your boot option to
>> 887 disable memory resource controller and you can avoid overheads.
>> 888 (and lose benefits of memory resource controller)
>> 889
>> 890 This config option also selects MM_OWNER config option, which
>> 891 could in turn add some fork/exit overhead.
>> 892
>> 893 config MEMCG_SWAP
>> 894 bool "Memory Resource Controller Swap Extension"
>> 895 depends on MEMCG && SWAP
>> 896 help
>> 897 Add swap management feature to memory resource controller. When you
>> 898 enable this, you can limit mem+swap usage per cgroup. In other words,
>> 899 when you disable this, memory resource controller has no cares to
>> 900 usage of swap...a process can exhaust all of the swap. This extension
>> 901 is useful when you want to avoid exhaustion swap but this itself
>> 902 adds more overheads and consumes memory for remembering information.
>> 903 Especially if you use 32bit system or small memory system, please
>> 904 be careful about enabling this. When memory resource controller
>> 905 is disabled by boot option, this will be automatically disabled and
>> 906 there will be no overhead from this. Even when you set this config=y,
>> 907 if boot option "swapaccount=0" is set, swap will not be accounted.
>> 908 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
>> 909 size is 4096bytes, 512k per 1Gbytes of swap.
>> 910 config MEMCG_SWAP_ENABLED
>> 911 bool "Memory Resource Controller Swap Extension enabled by default"
>> 912 depends on MEMCG_SWAP
>> 913 default y
>> 914 help
>> 915 Memory Resource Controller Swap Extension comes with its price in
>> 916 a bigger memory consumption. General purpose distribution kernels
>> 917 which want to enable the feature but keep it disabled by default
>> 918 and let the user enable it by swapaccount boot command line
>> 919 parameter should have this option unselected.
>> 920 For those who want to have the feature enabled by default should
>> 921 select this option (if, for some reason, they need to disable it
>> 922 then swapaccount=0 does the trick).
>> 923 config MEMCG_KMEM
>> 924 bool "Memory Resource Controller Kernel Memory accounting"
>> 925 depends on MEMCG
>> 926 depends on SLUB || SLAB
>> 927 help
>> 928 The Kernel Memory extension for Memory Resource Controller can limit
>> 929 the amount of memory used by kernel objects in the system. Those are
>> 930 fundamentally different from the entities handled by the standard
>> 931 Memory Controller, which are page-based, and can be swapped. Users of
>> 932 the kmem extension can use it to guarantee that no group of processes
>> 933 will ever exhaust kernel resources alone.
>> 934
>> 935 config CGROUP_HUGETLB
>> 936 bool "HugeTLB Resource Controller for Control Groups"
>> 937 depends on RESOURCE_COUNTERS && HUGETLB_PAGE
>> 938 default n
>> 939 help
>> 940 Provides a cgroup Resource Controller for HugeTLB pages.
>> 941 When you enable this, you can put a per cgroup limit on HugeTLB usage.
>> 942 The limit is enforced during page fault. Since HugeTLB doesn't
>> 943 support page reclaim, enforcing the limit at page fault time implies
>> 944 that, the application will get SIGBUS signal if it tries to access
>> 945 HugeTLB pages beyond its limit. This requires the application to know
>> 946 beforehand how much HugeTLB pages it would require for its use. The
>> 947 control group is tracked in the third page lru pointer. This means
>> 948 that we cannot use the controller with huge page less than 3 pages.
1022 949
1023 See Documentation/admin-guide/cgroup- !! 950 config CGROUP_PERF
>> 951 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
>> 952 depends on PERF_EVENTS && CGROUPS
>> 953 help
>> 954 This option extends the per-cpu mode to restrict monitoring to
>> 955 threads which belong to the cgroup specified and run on the
>> 956 designated cpu.
1024 957
1025 config CGROUP_WRITEBACK !! 958 Say N if unsure.
1026 bool <<
1027 depends on MEMCG && BLK_CGROUP <<
1028 default y <<
1029 959
1030 menuconfig CGROUP_SCHED 960 menuconfig CGROUP_SCHED
1031 bool "CPU controller" !! 961 bool "Group CPU scheduler"
1032 default n 962 default n
1033 help 963 help
1034 This feature lets CPU scheduler rec 964 This feature lets CPU scheduler recognize task groups and control CPU
1035 bandwidth allocation to such task g 965 bandwidth allocation to such task groups. It uses cgroups to group
1036 tasks. 966 tasks.
1037 967
1038 if CGROUP_SCHED 968 if CGROUP_SCHED
1039 config GROUP_SCHED_WEIGHT <<
1040 def_bool n <<
1041 <<
1042 config FAIR_GROUP_SCHED 969 config FAIR_GROUP_SCHED
1043 bool "Group scheduling for SCHED_OTHE 970 bool "Group scheduling for SCHED_OTHER"
1044 depends on CGROUP_SCHED 971 depends on CGROUP_SCHED
1045 select GROUP_SCHED_WEIGHT <<
1046 default CGROUP_SCHED 972 default CGROUP_SCHED
1047 973
1048 config CFS_BANDWIDTH 974 config CFS_BANDWIDTH
1049 bool "CPU bandwidth provisioning for 975 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
1050 depends on FAIR_GROUP_SCHED 976 depends on FAIR_GROUP_SCHED
1051 default n 977 default n
1052 help 978 help
1053 This option allows users to define 979 This option allows users to define CPU bandwidth rates (limits) for
1054 tasks running within the fair group 980 tasks running within the fair group scheduler. Groups with no limit
1055 set are considered to be unconstrai 981 set are considered to be unconstrained and will run with no
1056 restriction. 982 restriction.
1057 See Documentation/scheduler/sched-b !! 983 See tip/Documentation/scheduler/sched-bwc.txt for more information.
1058 984
1059 config RT_GROUP_SCHED 985 config RT_GROUP_SCHED
1060 bool "Group scheduling for SCHED_RR/F 986 bool "Group scheduling for SCHED_RR/FIFO"
1061 depends on CGROUP_SCHED 987 depends on CGROUP_SCHED
1062 default n 988 default n
1063 help 989 help
1064 This feature lets you explicitly al 990 This feature lets you explicitly allocate real CPU bandwidth
1065 to task groups. If enabled, it will 991 to task groups. If enabled, it will also make it impossible to
1066 schedule realtime tasks for non-roo 992 schedule realtime tasks for non-root users until you allocate
1067 realtime bandwidth for them. 993 realtime bandwidth for them.
1068 See Documentation/scheduler/sched-r !! 994 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 995
1076 endif #CGROUP_SCHED 996 endif #CGROUP_SCHED
1077 997
1078 config SCHED_MM_CID !! 998 config BLK_CGROUP
1079 def_bool y !! 999 bool "Block IO controller"
1080 depends on SMP && RSEQ !! 1000 depends on BLOCK
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 <<
1105 bool "PIDs controller" <<
1106 help <<
1107 Provides enforcement of process num <<
1108 cgroup. Any attempt to fork more pr <<
1109 cgroup will fail. PIDs are fundamen <<
1110 is fairly trivial to reach PID exha <<
1111 conservative kmemcg limit. As a res <<
1112 system to halt without being limite <<
1113 PIDs controller is designed to stop <<
1114 <<
1115 It should be noted that organisatio <<
1116 to a cgroup hierarchy) will *not* b <<
1117 since the PIDs limit only affects a <<
1118 attach to a cgroup. <<
1119 <<
1120 config CGROUP_RDMA <<
1121 bool "RDMA controller" <<
1122 help <<
1123 Provides enforcement of RDMA resour <<
1124 It is fairly easy for consumers to <<
1125 can result into resource unavailabi <<
1126 RDMA controller is designed to stop <<
1127 Attaching processes with active RDM <<
1128 hierarchy is allowed even if can cr <<
1129 <<
1130 config CGROUP_FREEZER <<
1131 bool "Freezer controller" <<
1132 help <<
1133 Provides a way to freeze and unfree <<
1134 cgroup. <<
1135 <<
1136 This option affects the ORIGINAL cg <<
1137 controller includes important in-ke <<
1138 <<
1139 If you're using cgroup2, say N. <<
1140 <<
1141 config CGROUP_HUGETLB <<
1142 bool "HugeTLB controller" <<
1143 depends on HUGETLB_PAGE <<
1144 select PAGE_COUNTER <<
1145 default n <<
1146 help <<
1147 Provides a cgroup controller for Hu <<
1148 When you enable this, you can put a <<
1149 The limit is enforced during page f <<
1150 support page reclaim, enforcing the <<
1151 that, the application will get SIGB <<
1152 HugeTLB pages beyond its limit. Thi <<
1153 beforehand how much HugeTLB pages i <<
1154 control group is tracked in the thi <<
1155 that we cannot use the controller w <<
1156 <<
1157 config CPUSETS <<
1158 bool "Cpuset controller" <<
1159 depends on SMP <<
1160 help <<
1161 This option will let you create and <<
1162 allow dynamically partitioning a sy <<
1163 Memory Nodes and assigning tasks to <<
1164 This is primarily useful on large S <<
1165 <<
1166 Say N if unsure. <<
1167 <<
1168 config CPUSETS_V1 <<
1169 bool "Legacy cgroup v1 cpusets contro <<
1170 depends on CPUSETS <<
1171 default n 1001 default n
1172 help !! 1002 ---help---
1173 Legacy cgroup v1 cpusets controller !! 1003 Generic block IO controller cgroup interface. This is the common
1174 cgroup v2 implementation. The v1 is !! 1004 cgroup interface which should be used by various IO controlling
1175 which haven't migrated to the new c !! 1005 policies.
1176 do not have any such application th <<
1177 this option disabled. <<
1178 <<
1179 Say N if unsure. <<
1180 <<
1181 config PROC_PID_CPUSET <<
1182 bool "Include legacy /proc/<pid>/cpus <<
1183 depends on CPUSETS <<
1184 default y <<
1185 <<
1186 config CGROUP_DEVICE <<
1187 bool "Device controller" <<
1188 help <<
1189 Provides a cgroup controller implem <<
1190 devices which a process in the cgro <<
1191 <<
1192 config CGROUP_CPUACCT <<
1193 bool "Simple CPU accounting controlle <<
1194 help <<
1195 Provides a simple controller for mo <<
1196 total CPU consumed by the tasks in <<
1197 <<
1198 config CGROUP_PERF <<
1199 bool "Perf controller" <<
1200 depends on PERF_EVENTS <<
1201 help <<
1202 This option extends the perf per-cp <<
1203 to threads which belong to the cgro <<
1204 designated cpu. Or this can be use <<
1205 so that it can monitor performance <<
1206 1006
1207 Say N if unsure. !! 1007 Currently, CFQ IO scheduler uses it to recognize task groups and
>> 1008 control disk bandwidth allocation (proportional time slice allocation)
>> 1009 to such task groups. It is also used by bio throttling logic in
>> 1010 block layer to implement upper limit in IO rates on a device.
1208 1011
1209 config CGROUP_BPF !! 1012 This option only enables generic Block IO controller infrastructure.
1210 bool "Support for eBPF programs attac !! 1013 One needs to also enable actual IO controlling logic/policy. For
1211 depends on BPF_SYSCALL !! 1014 enabling proportional weight division of disk bandwidth in CFQ, set
1212 select SOCK_CGROUP_DATA !! 1015 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
1213 help !! 1016 CONFIG_BLK_DEV_THROTTLING=y.
1214 Allow attaching eBPF programs to a <<
1215 syscall command BPF_PROG_ATTACH. <<
1216 1017
1217 In which context these programs are !! 1018 See Documentation/cgroups/blkio-controller.txt for more information.
1218 of attachment. For instance, progra <<
1219 BPF_CGROUP_INET_INGRESS will be exe <<
1220 inet sockets. <<
1221 1019
1222 config CGROUP_MISC !! 1020 config DEBUG_BLK_CGROUP
1223 bool "Misc resource controller" !! 1021 bool "Enable Block IO controller debugging"
>> 1022 depends on BLK_CGROUP
1224 default n 1023 default n
1225 help !! 1024 ---help---
1226 Provides a controller for miscellan !! 1025 Enable some debugging help. Currently it exports additional stat
>> 1026 files in a cgroup which can be useful for debugging.
1227 1027
1228 Miscellaneous scalar resources are !! 1028 endif # CGROUPS
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 1029
1236 config CGROUP_DEBUG !! 1030 config CHECKPOINT_RESTORE
1237 bool "Debug controller" !! 1031 bool "Checkpoint/restore support" if EXPERT
1238 default n 1032 default n
1239 depends on DEBUG_KERNEL <<
1240 help 1033 help
1241 This option enables a simple contro !! 1034 Enables additional kernel features in a sake of checkpoint/restore.
1242 debugging information about the cgr !! 1035 In particular it adds auxiliary prctl codes to setup process text,
1243 controller is for control cgroup de !! 1036 data and heap segment sizes, and a few additional /proc filesystem
1244 interfaces are not stable. !! 1037 entries.
1245 <<
1246 Say N. <<
1247 <<
1248 config SOCK_CGROUP_DATA <<
1249 bool <<
1250 default n <<
1251 1038
1252 endif # CGROUPS !! 1039 If unsure, say N here.
1253 1040
1254 menuconfig NAMESPACES 1041 menuconfig NAMESPACES
1255 bool "Namespaces support" if EXPERT 1042 bool "Namespaces support" if EXPERT
1256 depends on MULTIUSER <<
1257 default !EXPERT 1043 default !EXPERT
1258 help 1044 help
1259 Provides the way to make tasks work 1045 Provides the way to make tasks work with different objects using
1260 the same id. For example same IPC i 1046 the same id. For example same IPC id may refer to different objects
1261 or same user id or pid may refer to 1047 or same user id or pid may refer to different tasks when used in
1262 different namespaces. 1048 different namespaces.
1263 1049
1264 if NAMESPACES 1050 if NAMESPACES
1265 1051
1266 config UTS_NS 1052 config UTS_NS
1267 bool "UTS namespace" 1053 bool "UTS namespace"
1268 default y 1054 default y
1269 help 1055 help
1270 In this namespace tasks see differe 1056 In this namespace tasks see different info provided with the
1271 uname() system call 1057 uname() system call
1272 1058
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 1059 config IPC_NS
1282 bool "IPC namespace" 1060 bool "IPC namespace"
1283 depends on (SYSVIPC || POSIX_MQUEUE) 1061 depends on (SYSVIPC || POSIX_MQUEUE)
1284 default y 1062 default y
1285 help 1063 help
1286 In this namespace tasks work with I 1064 In this namespace tasks work with IPC ids which correspond to
1287 different IPC objects in different 1065 different IPC objects in different namespaces.
1288 1066
1289 config USER_NS 1067 config USER_NS
1290 bool "User namespace" 1068 bool "User namespace"
>> 1069 depends on UIDGID_CONVERTED
>> 1070 select UIDGID_STRICT_TYPE_CHECKS
>> 1071
1291 default n 1072 default n
1292 help 1073 help
1293 This allows containers, i.e. vserve 1074 This allows containers, i.e. vservers, to use user namespaces
1294 to provide different user info for 1075 to provide different user info for different servers.
1295 1076
1296 When user namespaces are enabled in 1077 When user namespaces are enabled in the kernel it is
1297 recommended that the MEMCG option a !! 1078 recommended that the MEMCG and MEMCG_KMEM options also be
1298 user-space use the memory control g !! 1079 enabled and that user-space use the memory control groups to
1299 of memory a memory unprivileged use !! 1080 limit the amount of memory a memory unprivileged users can
>> 1081 use.
1300 1082
1301 If unsure, say N. 1083 If unsure, say N.
1302 1084
1303 config PID_NS 1085 config PID_NS
1304 bool "PID Namespaces" 1086 bool "PID Namespaces"
1305 default y 1087 default y
1306 help 1088 help
1307 Support process id namespaces. Thi 1089 Support process id namespaces. This allows having multiple
1308 processes with the same pid as long 1090 processes with the same pid as long as they are in different
1309 pid namespaces. This is a building 1091 pid namespaces. This is a building block of containers.
1310 1092
1311 config NET_NS 1093 config NET_NS
1312 bool "Network namespace" 1094 bool "Network namespace"
1313 depends on NET 1095 depends on NET
1314 default y 1096 default y
1315 help 1097 help
1316 Allow user space to create what app 1098 Allow user space to create what appear to be multiple instances
1317 of the network stack. 1099 of the network stack.
1318 1100
1319 endif # NAMESPACES 1101 endif # NAMESPACES
1320 1102
1321 config CHECKPOINT_RESTORE !! 1103 config UIDGID_CONVERTED
1322 bool "Checkpoint/restore support" !! 1104 # True if all of the selected software conmponents are known
1323 depends on PROC_FS !! 1105 # to have uid_t and gid_t converted to kuid_t and kgid_t
1324 select PROC_CHILDREN !! 1106 # where appropriate and are otherwise safe to use with
1325 select KCMP !! 1107 # the user namespace.
>> 1108 bool
>> 1109 default y
>> 1110
>> 1111 # Filesystems
>> 1112 depends on XFS_FS = n
>> 1113
>> 1114 config UIDGID_STRICT_TYPE_CHECKS
>> 1115 bool "Require conversions between uid/gids and their internal representation"
>> 1116 depends on UIDGID_CONVERTED
1326 default n 1117 default n
1327 help 1118 help
1328 Enables additional kernel features !! 1119 While the nececessary conversions are being added to all subsystems this option allows
1329 In particular it adds auxiliary prc !! 1120 the code to continue to build for unconverted subsystems.
1330 data and heap segment sizes, and a <<
1331 entries. <<
1332 1121
1333 If unsure, say N here. !! 1122 Say Y here if you want the strict type checking enabled
1334 1123
1335 config SCHED_AUTOGROUP 1124 config SCHED_AUTOGROUP
1336 bool "Automatic process group schedul 1125 bool "Automatic process group scheduling"
>> 1126 select EVENTFD
1337 select CGROUPS 1127 select CGROUPS
1338 select CGROUP_SCHED 1128 select CGROUP_SCHED
1339 select FAIR_GROUP_SCHED 1129 select FAIR_GROUP_SCHED
1340 help 1130 help
1341 This option optimizes the scheduler 1131 This option optimizes the scheduler for common desktop workloads by
1342 automatically creating and populati 1132 automatically creating and populating task groups. This separation
1343 of workloads isolates aggressive CP 1133 of workloads isolates aggressive CPU burners (like build jobs) from
1344 desktop applications. Task group a 1134 desktop applications. Task group autogeneration is currently based
1345 upon task session. 1135 upon task session.
1346 1136
>> 1137 config MM_OWNER
>> 1138 bool
>> 1139
>> 1140 config SYSFS_DEPRECATED
>> 1141 bool "Enable deprecated sysfs features to support old userspace tools"
>> 1142 depends on SYSFS
>> 1143 default n
>> 1144 help
>> 1145 This option adds code that switches the layout of the "block" class
>> 1146 devices, to not show up in /sys/class/block/, but only in
>> 1147 /sys/block/.
>> 1148
>> 1149 This switch is only active when the sysfs.deprecated=1 boot option is
>> 1150 passed or the SYSFS_DEPRECATED_V2 option is set.
>> 1151
>> 1152 This option allows new kernels to run on old distributions and tools,
>> 1153 which might get confused by /sys/class/block/. Since 2007/2008 all
>> 1154 major distributions and tools handle this just fine.
>> 1155
>> 1156 Recent distributions and userspace tools after 2009/2010 depend on
>> 1157 the existence of /sys/class/block/, and will not work with this
>> 1158 option enabled.
>> 1159
>> 1160 Only if you are using a new kernel on an old distribution, you might
>> 1161 need to say Y here.
>> 1162
>> 1163 config SYSFS_DEPRECATED_V2
>> 1164 bool "Enable deprecated sysfs features by default"
>> 1165 default n
>> 1166 depends on SYSFS
>> 1167 depends on SYSFS_DEPRECATED
>> 1168 help
>> 1169 Enable deprecated sysfs by default.
>> 1170
>> 1171 See the CONFIG_SYSFS_DEPRECATED option for more details about this
>> 1172 option.
>> 1173
>> 1174 Only if you are using a new kernel on an old distribution, you might
>> 1175 need to say Y here. Even then, odds are you would not need it
>> 1176 enabled, you can always pass the boot option if absolutely necessary.
>> 1177
1347 config RELAY 1178 config RELAY
1348 bool "Kernel->user space relay suppor 1179 bool "Kernel->user space relay support (formerly relayfs)"
1349 select IRQ_WORK <<
1350 help 1180 help
1351 This option enables support for rel 1181 This option enables support for relay interface support in
1352 certain file systems (such as debug 1182 certain file systems (such as debugfs).
1353 It is designed to provide an effici 1183 It is designed to provide an efficient mechanism for tools and
1354 facilities to relay large amounts o 1184 facilities to relay large amounts of data from kernel space to
1355 user space. 1185 user space.
1356 1186
1357 If unsure, say N. 1187 If unsure, say N.
1358 1188
1359 config BLK_DEV_INITRD 1189 config BLK_DEV_INITRD
1360 bool "Initial RAM filesystem and RAM 1190 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
>> 1191 depends on BROKEN || !FRV
1361 help 1192 help
1362 The initial RAM filesystem is a ram 1193 The initial RAM filesystem is a ramfs which is loaded by the
1363 boot loader (loadlin or lilo) and t 1194 boot loader (loadlin or lilo) and that is mounted as root
1364 before the normal boot procedure. I 1195 before the normal boot procedure. It is typically used to
1365 load modules needed to mount the "r 1196 load modules needed to mount the "real" root file system,
1366 etc. See <file:Documentation/admin- !! 1197 etc. See <file:Documentation/initrd.txt> for details.
1367 1198
1368 If RAM disk support (BLK_DEV_RAM) i 1199 If RAM disk support (BLK_DEV_RAM) is also included, this
1369 also enables initial RAM disk (init 1200 also enables initial RAM disk (initrd) support and adds
1370 15 Kbytes (more on some other archi 1201 15 Kbytes (more on some other architectures) to the kernel size.
1371 1202
1372 If unsure say Y. 1203 If unsure say Y.
1373 1204
1374 if BLK_DEV_INITRD 1205 if BLK_DEV_INITRD
1375 1206
1376 source "usr/Kconfig" 1207 source "usr/Kconfig"
1377 1208
1378 endif 1209 endif
1379 1210
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 <<
1435 prompt "Compiler optimization level" <<
1436 default CC_OPTIMIZE_FOR_PERFORMANCE <<
1437 <<
1438 config CC_OPTIMIZE_FOR_PERFORMANCE <<
1439 bool "Optimize for performance (-O2)" <<
1440 help <<
1441 This is the default optimization le <<
1442 with the "-O2" compiler flag for be <<
1443 helpful compile-time warnings. <<
1444 <<
1445 config CC_OPTIMIZE_FOR_SIZE 1211 config CC_OPTIMIZE_FOR_SIZE
1446 bool "Optimize for size (-Os)" !! 1212 bool "Optimize for size"
1447 help 1213 help
1448 Choosing this option will pass "-Os !! 1214 Enabling this option will pass "-Os" instead of "-O2" to gcc
1449 in a smaller kernel. !! 1215 resulting in a smaller kernel.
1450 1216
1451 endchoice !! 1217 If unsure, say N.
1452 1218
1453 config HAVE_LD_DEAD_CODE_DATA_ELIMINATION !! 1219 config SYSCTL
1454 bool 1220 bool
1455 help <<
1456 This requires that the arch annotat <<
1457 its external entry points from bein <<
1458 must also merge .text.*, .data.*, a <<
1459 output sections. Care must be taken <<
1460 sections (e.g., '.text.init'). Typi <<
1461 is used to distinguish them from la <<
1462 <<
1463 config LD_DEAD_CODE_DATA_ELIMINATION <<
1464 bool "Dead code and data elimination <<
1465 depends on HAVE_LD_DEAD_CODE_DATA_ELI <<
1466 depends on EXPERT <<
1467 depends on $(cc-option,-ffunction-sec <<
1468 depends on $(ld-option,--gc-sections) <<
1469 help <<
1470 Enable this if you want to do dead <<
1471 the linker by compiling with -ffunc <<
1472 and linking with --gc-sections. <<
1473 <<
1474 This can reduce on disk and in-memo <<
1475 code and static data, particularly <<
1476 on small systems. This has the poss <<
1477 silently broken kernel if the requi <<
1478 present. This option is not well te <<
1479 own risk. <<
1480 <<
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 1221
1493 config SYSCTL !! 1222 config ANON_INODES
1494 bool 1223 bool
1495 1224
1496 config HAVE_UID16 1225 config HAVE_UID16
1497 bool 1226 bool
1498 1227
1499 config SYSCTL_EXCEPTION_TRACE 1228 config SYSCTL_EXCEPTION_TRACE
1500 bool 1229 bool
1501 help 1230 help
1502 Enable support for /proc/sys/debug/ 1231 Enable support for /proc/sys/debug/exception-trace.
1503 1232
1504 config SYSCTL_ARCH_UNALIGN_NO_WARN 1233 config SYSCTL_ARCH_UNALIGN_NO_WARN
1505 bool 1234 bool
1506 help 1235 help
1507 Enable support for /proc/sys/kernel 1236 Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
1508 Allows arch to define/use @no_unali 1237 Allows arch to define/use @no_unaligned_warning to possibly warn
1509 about unaligned access emulation go 1238 about unaligned access emulation going on under the hood.
1510 1239
1511 config SYSCTL_ARCH_UNALIGN_ALLOW 1240 config SYSCTL_ARCH_UNALIGN_ALLOW
1512 bool 1241 bool
1513 help 1242 help
1514 Enable support for /proc/sys/kernel 1243 Enable support for /proc/sys/kernel/unaligned-trap
1515 Allows arches to define/use @unalig 1244 Allows arches to define/use @unaligned_enabled to runtime toggle
1516 the unaligned access emulation. 1245 the unaligned access emulation.
1517 see arch/parisc/kernel/unaligned.c 1246 see arch/parisc/kernel/unaligned.c for reference
1518 1247
>> 1248 config HOTPLUG
>> 1249 def_bool y
>> 1250
1519 config HAVE_PCSPKR_PLATFORM 1251 config HAVE_PCSPKR_PLATFORM
1520 bool 1252 bool
1521 1253
1522 menuconfig EXPERT 1254 menuconfig EXPERT
1523 bool "Configure standard kernel featu 1255 bool "Configure standard kernel features (expert users)"
1524 # Unhide debug options, to make the o 1256 # Unhide debug options, to make the on-by-default options visible
1525 select DEBUG_KERNEL 1257 select DEBUG_KERNEL
1526 help 1258 help
1527 This option allows certain base ker 1259 This option allows certain base kernel options and settings
1528 to be disabled or tweaked. This is !! 1260 to be disabled or tweaked. This is for specialized
1529 environments which can tolerate a " !! 1261 environments which can tolerate a "non-standard" kernel.
1530 Only use this if you really know wh !! 1262 Only use this if you really know what you are doing.
1531 1263
1532 config UID16 1264 config UID16
1533 bool "Enable 16-bit UID system calls" 1265 bool "Enable 16-bit UID system calls" if EXPERT
1534 depends on HAVE_UID16 && MULTIUSER !! 1266 depends on HAVE_UID16
1535 default y 1267 default y
1536 help 1268 help
1537 This enables the legacy 16-bit UID 1269 This enables the legacy 16-bit UID syscall wrappers.
1538 1270
1539 config MULTIUSER !! 1271 config SYSCTL_SYSCALL
1540 bool "Multiple users, groups and capa !! 1272 bool "Sysctl syscall support" if EXPERT
1541 default y !! 1273 depends on PROC_SYSCTL
1542 help !! 1274 default n
1543 This option enables support for non !! 1275 select SYSCTL
1544 capabilities. !! 1276 ---help---
1545 !! 1277 sys_sysctl uses binary paths that have been found challenging
1546 If you say N here, all processes wi !! 1278 to properly maintain and use. The interface in /proc/sys
1547 possible capabilities. Saying N he !! 1279 using paths with ascii names is now the primary path to this
1548 system calls related to UIDs, GIDs, !! 1280 information.
1549 setgid, and capset. !! 1281
1550 !! 1282 Almost nothing using the binary sysctl interface so if you are
1551 If unsure, say Y here. !! 1283 trying to save some space it is probably safe to disable this,
1552 !! 1284 making your kernel marginally smaller.
1553 config SGETMASK_SYSCALL <<
1554 bool "sgetmask/ssetmask syscalls supp <<
1555 default PARISC || M68K || PPC || MIPS <<
1556 help <<
1557 sys_sgetmask and sys_ssetmask are o <<
1558 no longer supported in libc but sti <<
1559 architectures. <<
1560 <<
1561 If unsure, leave the default option <<
1562 <<
1563 config SYSFS_SYSCALL <<
1564 bool "Sysfs syscall support" if EXPER <<
1565 default y <<
1566 help <<
1567 sys_sysfs is an obsolete system cal <<
1568 Note that disabling this option is <<
1569 compatibility with some systems. <<
1570 1285
1571 If unsure say Y here. !! 1286 If unsure say N here.
1572 1287
1573 config FHANDLE !! 1288 config KALLSYMS
1574 bool "open by fhandle syscalls" if EX !! 1289 bool "Load all symbols for debugging/ksymoops" if EXPERT
1575 select EXPORTFS !! 1290 default y
1576 default y !! 1291 help
1577 help !! 1292 Say Y here to let the kernel print out symbolic crash information and
1578 If you say Y here, a user level pro !! 1293 symbolic stack backtraces. This increases the size of the kernel
1579 file names to handle and then later !! 1294 somewhat, as all symbols have to be loaded into the kernel image.
1580 different file system operations. T <<
1581 userspace file servers, which now t <<
1582 of names. The handle would remain t <<
1583 get renamed. Enables open_by_handle <<
1584 syscalls. <<
1585 1295
1586 config POSIX_TIMERS !! 1296 config KALLSYMS_ALL
1587 bool "Posix Clocks & timers" if EXPER !! 1297 bool "Include all symbols in kallsyms"
1588 default y !! 1298 depends on DEBUG_KERNEL && KALLSYMS
1589 help 1299 help
1590 This includes native support for PO !! 1300 Normally kallsyms only contains the symbols of functions for nicer
1591 Some embedded systems have no use f !! 1301 OOPS messages and backtraces (i.e., symbols from the text and inittext
1592 can be configured out to reduce the !! 1302 sections). This is sufficient for most cases. And only in very rare
1593 !! 1303 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1594 When this option is disabled, the f !! 1304 names of variables from the data sections, etc).
1595 available: timer_create, timer_gett !! 1305
1596 timer_settime, timer_delete, clock_ !! 1306 This option makes sure that all symbols are loaded into the kernel
1597 setitimer, alarm. Furthermore, the !! 1307 image (i.e., symbols from all sections) in cost of increased kernel
1598 clock_getres and clock_nanosleep sy !! 1308 size (depending on the kernel configuration, it may be 300KiB or
1599 CLOCK_REALTIME, CLOCK_MONOTONIC and !! 1309 something like this).
1600 1310
1601 If unsure say y. !! 1311 Say N unless you really need all symbols.
1602 1312
1603 config PRINTK 1313 config PRINTK
1604 default y 1314 default y
1605 bool "Enable support for printk" if E 1315 bool "Enable support for printk" if EXPERT
1606 select IRQ_WORK 1316 select IRQ_WORK
1607 help 1317 help
1608 This option enables normal printk s 1318 This option enables normal printk support. Removing it
1609 eliminates most of the message stri 1319 eliminates most of the message strings from the kernel image
1610 and makes the kernel more or less s 1320 and makes the kernel more or less silent. As this makes it
1611 very difficult to diagnose system p 1321 very difficult to diagnose system problems, saying N here is
1612 strongly discouraged. 1322 strongly discouraged.
1613 1323
1614 config BUG 1324 config BUG
1615 bool "BUG() support" if EXPERT 1325 bool "BUG() support" if EXPERT
1616 default y 1326 default y
1617 help 1327 help
1618 Disabling this option eliminates su !! 1328 Disabling this option eliminates support for BUG and WARN, reducing
1619 the size of your kernel image and p !! 1329 the size of your kernel image and potentially quietly ignoring
1620 numerous fatal conditions. You shou !! 1330 numerous fatal conditions. You should only consider disabling this
1621 option for embedded systems with no !! 1331 option for embedded systems with no facilities for reporting errors.
1622 Just say Y. !! 1332 Just say Y.
1623 1333
1624 config ELF_CORE 1334 config ELF_CORE
1625 depends on COREDUMP 1335 depends on COREDUMP
1626 default y 1336 default y
1627 bool "Enable ELF core dumps" if EXPER 1337 bool "Enable ELF core dumps" if EXPERT
1628 help 1338 help
1629 Enable support for generating core 1339 Enable support for generating core dumps. Disabling saves about 4k.
1630 1340
1631 1341
1632 config PCSPKR_PLATFORM 1342 config PCSPKR_PLATFORM
1633 bool "Enable PC-Speaker support" if E 1343 bool "Enable PC-Speaker support" if EXPERT
1634 depends on HAVE_PCSPKR_PLATFORM 1344 depends on HAVE_PCSPKR_PLATFORM
1635 select I8253_LOCK 1345 select I8253_LOCK
1636 default y 1346 default y
1637 help 1347 help
1638 This option allows to disable the i !! 1348 This option allows to disable the internal PC-Speaker
1639 support, saving some memory. !! 1349 support, saving some memory.
1640 1350
1641 config BASE_SMALL !! 1351 config BASE_FULL
1642 bool "Enable smaller-sized data struc !! 1352 default y
>> 1353 bool "Enable full-sized data structures for core" if EXPERT
1643 help 1354 help
1644 Enabling this option reduces the si !! 1355 Disabling this option reduces the size of miscellaneous core
1645 kernel data structures. This saves 1356 kernel data structures. This saves memory on small machines,
1646 but may reduce performance. 1357 but may reduce performance.
1647 1358
1648 config FUTEX 1359 config FUTEX
1649 bool "Enable futex support" if EXPERT 1360 bool "Enable futex support" if EXPERT
1650 depends on !(SPARC32 && SMP) <<
1651 default y 1361 default y
1652 imply RT_MUTEXES !! 1362 select RT_MUTEXES
1653 help 1363 help
1654 Disabling this option will cause th 1364 Disabling this option will cause the kernel to be built without
1655 support for "fast userspace mutexes 1365 support for "fast userspace mutexes". The resulting kernel may not
1656 run glibc-based applications correc 1366 run glibc-based applications correctly.
1657 1367
1658 config FUTEX_PI !! 1368 config HAVE_FUTEX_CMPXCHG
1659 bool 1369 bool
1660 depends on FUTEX && RT_MUTEXES !! 1370 depends on FUTEX
1661 default y !! 1371 help
>> 1372 Architectures should select this if futex_atomic_cmpxchg_inatomic()
>> 1373 is implemented and always working. This removes a couple of runtime
>> 1374 checks.
1662 1375
1663 config EPOLL 1376 config EPOLL
1664 bool "Enable eventpoll support" if EX 1377 bool "Enable eventpoll support" if EXPERT
1665 default y 1378 default y
>> 1379 select ANON_INODES
1666 help 1380 help
1667 Disabling this option will cause th 1381 Disabling this option will cause the kernel to be built without
1668 support for epoll family of system 1382 support for epoll family of system calls.
1669 1383
1670 config SIGNALFD 1384 config SIGNALFD
1671 bool "Enable signalfd() system call" 1385 bool "Enable signalfd() system call" if EXPERT
>> 1386 select ANON_INODES
1672 default y 1387 default y
1673 help 1388 help
1674 Enable the signalfd() system call t 1389 Enable the signalfd() system call that allows to receive signals
1675 on a file descriptor. 1390 on a file descriptor.
1676 1391
1677 If unsure, say Y. 1392 If unsure, say Y.
1678 1393
1679 config TIMERFD 1394 config TIMERFD
1680 bool "Enable timerfd() system call" i 1395 bool "Enable timerfd() system call" if EXPERT
>> 1396 select ANON_INODES
1681 default y 1397 default y
1682 help 1398 help
1683 Enable the timerfd() system call th 1399 Enable the timerfd() system call that allows to receive timer
1684 events on a file descriptor. 1400 events on a file descriptor.
1685 1401
1686 If unsure, say Y. 1402 If unsure, say Y.
1687 1403
1688 config EVENTFD 1404 config EVENTFD
1689 bool "Enable eventfd() system call" i 1405 bool "Enable eventfd() system call" if EXPERT
>> 1406 select ANON_INODES
1690 default y 1407 default y
1691 help 1408 help
1692 Enable the eventfd() system call th 1409 Enable the eventfd() system call that allows to receive both
1693 kernel notification (ie. KAIO) or u 1410 kernel notification (ie. KAIO) or userspace notifications.
1694 1411
1695 If unsure, say Y. 1412 If unsure, say Y.
1696 1413
1697 config SHMEM 1414 config SHMEM
1698 bool "Use full shmem filesystem" if E 1415 bool "Use full shmem filesystem" if EXPERT
1699 default y 1416 default y
1700 depends on MMU 1417 depends on MMU
1701 help 1418 help
1702 The shmem is an internal filesystem 1419 The shmem is an internal filesystem used to manage shared memory.
1703 It is backed by swap and manages re 1420 It is backed by swap and manages resource limits. It is also exported
1704 to userspace as tmpfs if TMPFS is e 1421 to userspace as tmpfs if TMPFS is enabled. Disabling this
1705 option replaces shmem and tmpfs wit 1422 option replaces shmem and tmpfs with the much simpler ramfs code,
1706 which may be appropriate on small s 1423 which may be appropriate on small systems without swap.
1707 1424
1708 config AIO 1425 config AIO
1709 bool "Enable AIO support" if EXPERT 1426 bool "Enable AIO support" if EXPERT
1710 default y 1427 default y
1711 help 1428 help
1712 This option enables POSIX asynchron 1429 This option enables POSIX asynchronous I/O which may by used
1713 by some high performance threaded a 1430 by some high performance threaded applications. Disabling
1714 this option saves about 7k. 1431 this option saves about 7k.
1715 1432
1716 config IO_URING !! 1433 config PCI_QUIRKS
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 <<
1739 bool "Enable madvise/fadvise syscalls <<
1740 default y <<
1741 help <<
1742 This option enables the madvise and <<
1743 applications to advise the kernel a <<
1744 usage, improving performance. If bu <<
1745 applications use these syscalls, yo <<
1746 space. <<
1747 <<
1748 config MEMBARRIER <<
1749 bool "Enable membarrier() system call <<
1750 default y <<
1751 help <<
1752 Enable the membarrier() system call <<
1753 barriers across all running threads <<
1754 the cost of user-space memory barri <<
1755 pairs of memory barriers into pairs <<
1756 compiler barrier. <<
1757 <<
1758 If unsure, say Y. <<
1759 <<
1760 config KCMP <<
1761 bool "Enable kcmp() system call" if E <<
1762 help <<
1763 Enable the kernel resource comparis <<
1764 user-space with the ability to comp <<
1765 share a common resource, such as a <<
1766 memory space. <<
1767 <<
1768 If unsure, say N. <<
1769 <<
1770 config RSEQ <<
1771 bool "Enable rseq() system call" if E <<
1772 default y <<
1773 depends on HAVE_RSEQ <<
1774 select MEMBARRIER <<
1775 help <<
1776 Enable the restartable sequences sy <<
1777 user-space cache for the current CP <<
1778 speeds up getting the current CPU n <<
1779 as well as an ABI to speed up user- <<
1780 per-CPU data. <<
1781 <<
1782 If unsure, say Y. <<
1783 <<
1784 config DEBUG_RSEQ <<
1785 default n <<
1786 bool "Enable debugging of rseq() syst <<
1787 depends on RSEQ && DEBUG_KERNEL <<
1788 help <<
1789 Enable extra debugging checks for t <<
1790 <<
1791 If unsure, say N. <<
1792 <<
1793 config CACHESTAT_SYSCALL <<
1794 bool "Enable cachestat() system call" <<
1795 default y <<
1796 help <<
1797 Enable the cachestat system call, w <<
1798 statistics of a file (number of cac <<
1799 pages marked for writeback, (recent <<
1800 <<
1801 If unsure say Y here. <<
1802 <<
1803 config PC104 <<
1804 bool "PC/104 support" if EXPERT <<
1805 help <<
1806 Expose PC/104 form factor device dr <<
1807 selection and configuration. Enable <<
1808 machine has a PC/104 bus. <<
1809 <<
1810 config KALLSYMS <<
1811 bool "Load all symbols for debugging/ <<
1812 default y 1434 default y
>> 1435 bool "Enable PCI quirk workarounds" if EXPERT
>> 1436 depends on PCI
1813 help 1437 help
1814 Say Y here to let the kernel print !! 1438 This enables workarounds for various PCI chipset
1815 symbolic stack backtraces. This inc !! 1439 bugs/quirks. Disable this only if your target machine is
1816 somewhat, as all symbols have to be !! 1440 unaffected by PCI quirks.
1817 !! 1441
1818 config KALLSYMS_SELFTEST !! 1442 config EMBEDDED
1819 bool "Test the basic functions and pe !! 1443 bool "Embedded system"
1820 depends on KALLSYMS !! 1444 select EXPERT
1821 default n !! 1445 help
1822 help !! 1446 This option should be enabled if compiling the kernel for
1823 Test the basic functions and perfor !! 1447 an embedded system so certain expert options are available
1824 kallsyms_lookup_name. It also calcu !! 1448 for configuration.
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 1449
1862 config HAVE_PERF_EVENTS 1450 config HAVE_PERF_EVENTS
1863 bool 1451 bool
1864 help 1452 help
1865 See tools/perf/design.txt for detai 1453 See tools/perf/design.txt for details.
1866 1454
1867 config GUEST_PERF_EVENTS <<
1868 bool <<
1869 depends on HAVE_PERF_EVENTS <<
1870 <<
1871 config PERF_USE_VMALLOC 1455 config PERF_USE_VMALLOC
1872 bool 1456 bool
1873 help 1457 help
1874 See tools/perf/design.txt for detai 1458 See tools/perf/design.txt for details
1875 1459
1876 menu "Kernel Performance Events And Counters" 1460 menu "Kernel Performance Events And Counters"
1877 1461
1878 config PERF_EVENTS 1462 config PERF_EVENTS
1879 bool "Kernel performance events and c 1463 bool "Kernel performance events and counters"
1880 default y if PROFILING 1464 default y if PROFILING
1881 depends on HAVE_PERF_EVENTS 1465 depends on HAVE_PERF_EVENTS
>> 1466 select ANON_INODES
1882 select IRQ_WORK 1467 select IRQ_WORK
1883 help 1468 help
1884 Enable kernel support for various p 1469 Enable kernel support for various performance events provided
1885 by software and hardware. 1470 by software and hardware.
1886 1471
1887 Software events are supported eithe 1472 Software events are supported either built-in or via the
1888 use of generic tracepoints. 1473 use of generic tracepoints.
1889 1474
1890 Most modern CPUs support performanc 1475 Most modern CPUs support performance events via performance
1891 counter registers. These registers 1476 counter registers. These registers count the number of certain
1892 types of hw events: such as instruc 1477 types of hw events: such as instructions executed, cachemisses
1893 suffered, or branches mis-predicted 1478 suffered, or branches mis-predicted - without slowing down the
1894 kernel or applications. These regis 1479 kernel or applications. These registers can also trigger interrupts
1895 when a threshold number of events h 1480 when a threshold number of events have passed - and can thus be
1896 used to profile the code that runs 1481 used to profile the code that runs on that CPU.
1897 1482
1898 The Linux Performance Event subsyst 1483 The Linux Performance Event subsystem provides an abstraction of
1899 these software and hardware event c 1484 these software and hardware event capabilities, available via a
1900 system call and used by the "perf" 1485 system call and used by the "perf" utility in tools/perf/. It
1901 provides per task and per CPU count 1486 provides per task and per CPU counters, and it provides event
1902 capabilities on top of those. 1487 capabilities on top of those.
1903 1488
1904 Say Y if unsure. 1489 Say Y if unsure.
1905 1490
1906 config DEBUG_PERF_USE_VMALLOC 1491 config DEBUG_PERF_USE_VMALLOC
1907 default n 1492 default n
1908 bool "Debug: use vmalloc to back perf 1493 bool "Debug: use vmalloc to back perf mmap() buffers"
1909 depends on PERF_EVENTS && DEBUG_KERNE !! 1494 depends on PERF_EVENTS && DEBUG_KERNEL
1910 select PERF_USE_VMALLOC 1495 select PERF_USE_VMALLOC
1911 help 1496 help
1912 Use vmalloc memory to back perf mma !! 1497 Use vmalloc memory to back perf mmap() buffers.
1913 1498
1914 Mostly useful for debugging the vma !! 1499 Mostly useful for debugging the vmalloc code on platforms
1915 that don't require it. !! 1500 that don't require it.
1916 1501
1917 Say N if unsure. !! 1502 Say N if unsure.
1918 1503
1919 endmenu 1504 endmenu
1920 1505
1921 config SYSTEM_DATA_VERIFICATION !! 1506 config VM_EVENT_COUNTERS
1922 def_bool n !! 1507 default y
1923 select SYSTEM_TRUSTED_KEYRING !! 1508 bool "Enable VM event counters for /proc/vmstat" if EXPERT
1924 select KEYS <<
1925 select CRYPTO <<
1926 select CRYPTO_RSA <<
1927 select ASYMMETRIC_KEY_TYPE <<
1928 select ASYMMETRIC_PUBLIC_KEY_SUBTYPE <<
1929 select ASN1 <<
1930 select OID_REGISTRY <<
1931 select X509_CERTIFICATE_PARSER <<
1932 select PKCS7_MESSAGE_PARSER <<
1933 help 1509 help
1934 Provide PKCS#7 message verification !! 1510 VM event counters are needed for event counts to be shown.
1935 trusted keyring to provide public k !! 1511 This option allows the disabling of the VM event counters
1936 module verification, kexec image ve !! 1512 on EXPERT systems. /proc/vmstat will only show page counts
1937 verification. !! 1513 if VM event counters are disabled.
1938 1514
1939 config PROFILING !! 1515 config SLUB_DEBUG
1940 bool "Profiling support" !! 1516 default y
>> 1517 bool "Enable SLUB debugging support" if EXPERT
>> 1518 depends on SLUB && SYSFS
1941 help 1519 help
1942 Say Y here to enable the extended p !! 1520 SLUB has extensive debug support features. Disabling these can
1943 by profilers. !! 1521 result in significant savings in code size. This also disables
>> 1522 SLUB sysfs support. /sys/slab will not exist and there will be
>> 1523 no support for cache validation etc.
1944 1524
1945 config RUST !! 1525 config COMPAT_BRK
1946 bool "Rust support" !! 1526 bool "Disable heap randomization"
1947 depends on HAVE_RUST !! 1527 default y
1948 depends on RUST_IS_AVAILABLE !! 1528 help
1949 depends on !MODVERSIONS !! 1529 Randomizing heap placement makes heap exploits harder, but it
1950 depends on !GCC_PLUGIN_RANDSTRUCT !! 1530 also breaks ancient binaries (including anything libc5 based).
1951 depends on !RANDSTRUCT !! 1531 This option changes the bootup default to heap randomization
1952 depends on !DEBUG_INFO_BTF || PAHOLE_ !! 1532 disabled, and can be overridden at runtime by setting
1953 depends on !CFI_CLANG || HAVE_CFI_ICA !! 1533 /proc/sys/kernel/randomize_va_space to 2.
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 1534
1961 This allows other Rust-related opti !! 1535 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1962 to be selected. <<
1963 1536
1964 It is also required to be able to l !! 1537 choice
1965 written in Rust. !! 1538 prompt "Choose SLAB allocator"
>> 1539 default SLUB
>> 1540 help
>> 1541 This option allows to select a slab allocator.
1966 1542
1967 See Documentation/rust/ for more in !! 1543 config SLAB
>> 1544 bool "SLAB"
>> 1545 help
>> 1546 The regular slab allocator that is established and known to work
>> 1547 well in all environments. It organizes cache hot objects in
>> 1548 per cpu and per node queues.
1968 1549
1969 If unsure, say N. !! 1550 config SLUB
>> 1551 bool "SLUB (Unqueued Allocator)"
>> 1552 help
>> 1553 SLUB is a slab allocator that minimizes cache line usage
>> 1554 instead of managing queues of cached objects (SLAB approach).
>> 1555 Per cpu caching is realized using slabs of objects instead
>> 1556 of queues of objects. SLUB can use memory efficiently
>> 1557 and has enhanced diagnostics. SLUB is the default choice for
>> 1558 a slab allocator.
1970 1559
1971 config RUSTC_VERSION_TEXT !! 1560 config SLOB
1972 string !! 1561 depends on EXPERT
1973 depends on RUST !! 1562 bool "SLOB (Simple Allocator)"
1974 default "$(RUSTC_VERSION_TEXT)" <<
1975 help 1563 help
1976 See `CC_VERSION_TEXT`. !! 1564 SLOB replaces the stock allocator with a drastically simpler
>> 1565 allocator. SLOB is generally more space efficient but
>> 1566 does not perform as well on large systems.
1977 1567
1978 config BINDGEN_VERSION_TEXT !! 1568 endchoice
1979 string !! 1569
1980 depends on RUST !! 1570 config MMAP_ALLOW_UNINITIALIZED
1981 # The dummy parameter `workaround-for !! 1571 bool "Allow mmapped anonymous memory to be uninitialized"
1982 # (https://github.com/rust-lang/rust- !! 1572 depends on EXPERT && !MMU
1983 # the minimum version is upgraded pas !! 1573 default n
1984 default "$(shell,$(BINDGEN) --version !! 1574 help
>> 1575 Normally, and according to the Linux spec, anonymous memory obtained
>> 1576 from mmap() has it's contents cleared before it is passed to
>> 1577 userspace. Enabling this config option allows you to request that
>> 1578 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
>> 1579 providing a huge performance boost. If this option is not enabled,
>> 1580 then the flag will be ignored.
>> 1581
>> 1582 This is taken advantage of by uClibc's malloc(), and also by
>> 1583 ELF-FDPIC binfmt's brk and stack allocator.
>> 1584
>> 1585 Because of the obvious security issues, this option should only be
>> 1586 enabled on embedded devices where you control what is run in
>> 1587 userspace. Since that isn't generally a problem on no-MMU systems,
>> 1588 it is normally safe to say Y here.
>> 1589
>> 1590 See Documentation/nommu-mmap.txt for more information.
>> 1591
>> 1592 config PROFILING
>> 1593 bool "Profiling support"
>> 1594 help
>> 1595 Say Y here to enable the extended profiling support mechanisms used
>> 1596 by profilers such as OProfile.
1985 1597
1986 # 1598 #
1987 # Place an empty function call at each tracep 1599 # Place an empty function call at each tracepoint site. Can be
1988 # dynamically changed for a probe function. 1600 # dynamically changed for a probe function.
1989 # 1601 #
1990 config TRACEPOINTS 1602 config TRACEPOINTS
1991 bool 1603 bool
1992 1604
1993 source "kernel/Kconfig.kexec" !! 1605 source "arch/Kconfig"
1994 1606
1995 endmenu # General setup 1607 endmenu # General setup
1996 1608
1997 source "arch/Kconfig" !! 1609 config HAVE_GENERIC_DMA_COHERENT
>> 1610 bool
>> 1611 default n
1998 1612
1999 config RT_MUTEXES !! 1613 config SLABINFO
2000 bool 1614 bool
2001 default y if PREEMPT_RT !! 1615 depends on PROC_FS
>> 1616 depends on SLAB || SLUB_DEBUG
>> 1617 default y
>> 1618
>> 1619 config RT_MUTEXES
>> 1620 boolean
>> 1621
>> 1622 config BASE_SMALL
>> 1623 int
>> 1624 default 0 if BASE_FULL
>> 1625 default 1 if !BASE_FULL
>> 1626
>> 1627 menuconfig MODULES
>> 1628 bool "Enable loadable module support"
>> 1629 help
>> 1630 Kernel modules are small pieces of compiled code which can
>> 1631 be inserted in the running kernel, rather than being
>> 1632 permanently built into the kernel. You use the "modprobe"
>> 1633 tool to add (and sometimes remove) them. If you say Y here,
>> 1634 many parts of the kernel can be built as modules (by
>> 1635 answering M instead of Y where indicated): this is most
>> 1636 useful for infrequently used options which are not required
>> 1637 for booting. For more information, see the man pages for
>> 1638 modprobe, lsmod, modinfo, insmod and rmmod.
>> 1639
>> 1640 If you say Y here, you will need to run "make
>> 1641 modules_install" to put the modules under /lib/modules/
>> 1642 where modprobe can find them (you may need to be root to do
>> 1643 this).
2002 1644
2003 config MODULE_SIG_FORMAT !! 1645 If unsure, say Y.
2004 def_bool n <<
2005 select SYSTEM_DATA_VERIFICATION <<
2006 1646
2007 source "kernel/module/Kconfig" !! 1647 if MODULES
>> 1648
>> 1649 config MODULE_FORCE_LOAD
>> 1650 bool "Forced module loading"
>> 1651 default n
>> 1652 help
>> 1653 Allow loading of modules without version information (ie. modprobe
>> 1654 --force). Forced module loading sets the 'F' (forced) taint flag and
>> 1655 is usually a really bad idea.
>> 1656
>> 1657 config MODULE_UNLOAD
>> 1658 bool "Module unloading"
>> 1659 help
>> 1660 Without this option you will not be able to unload any
>> 1661 modules (note that some modules may not be unloadable
>> 1662 anyway), which makes your kernel smaller, faster
>> 1663 and simpler. If unsure, say Y.
>> 1664
>> 1665 config MODULE_FORCE_UNLOAD
>> 1666 bool "Forced module unloading"
>> 1667 depends on MODULE_UNLOAD
>> 1668 help
>> 1669 This option allows you to force a module to unload, even if the
>> 1670 kernel believes it is unsafe: the kernel will remove the module
>> 1671 without waiting for anyone to stop using it (using the -f option to
>> 1672 rmmod). This is mainly for kernel developers and desperate users.
>> 1673 If unsure, say N.
>> 1674
>> 1675 config MODVERSIONS
>> 1676 bool "Module versioning support"
>> 1677 help
>> 1678 Usually, you have to use modules compiled with your kernel.
>> 1679 Saying Y here makes it sometimes possible to use modules
>> 1680 compiled for different kernels, by adding enough information
>> 1681 to the modules to (hopefully) spot any changes which would
>> 1682 make them incompatible with the kernel you are running. If
>> 1683 unsure, say N.
>> 1684
>> 1685 config MODULE_SRCVERSION_ALL
>> 1686 bool "Source checksum for all modules"
>> 1687 help
>> 1688 Modules which contain a MODULE_VERSION get an extra "srcversion"
>> 1689 field inserted into their modinfo section, which contains a
>> 1690 sum of the source files which made it. This helps maintainers
>> 1691 see exactly which source was used to build a module (since
>> 1692 others sometimes change the module source without updating
>> 1693 the version). With this option, such a "srcversion" field
>> 1694 will be created for all modules. If unsure, say N.
>> 1695
>> 1696 config MODULE_SIG
>> 1697 bool "Module signature verification"
>> 1698 depends on MODULES
>> 1699 select KEYS
>> 1700 select CRYPTO
>> 1701 select ASYMMETRIC_KEY_TYPE
>> 1702 select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
>> 1703 select PUBLIC_KEY_ALGO_RSA
>> 1704 select ASN1
>> 1705 select OID_REGISTRY
>> 1706 select X509_CERTIFICATE_PARSER
>> 1707 help
>> 1708 Check modules for valid signatures upon load: the signature
>> 1709 is simply appended to the module. For more information see
>> 1710 Documentation/module-signing.txt.
>> 1711
>> 1712 !!!WARNING!!! If you enable this option, you MUST make sure that the
>> 1713 module DOES NOT get stripped after being signed. This includes the
>> 1714 debuginfo strip done by some packagers (such as rpmbuild) and
>> 1715 inclusion into an initramfs that wants the module size reduced.
>> 1716
>> 1717 config MODULE_SIG_FORCE
>> 1718 bool "Require modules to be validly signed"
>> 1719 depends on MODULE_SIG
>> 1720 help
>> 1721 Reject unsigned modules or signed modules for which we don't have a
>> 1722 key. Without this, such modules will simply taint the kernel.
>> 1723
>> 1724 config MODULE_SIG_ALL
>> 1725 bool "Automatically sign all modules"
>> 1726 default y
>> 1727 depends on MODULE_SIG
>> 1728 help
>> 1729 Sign all modules during make modules_install. Without this option,
>> 1730 modules must be signed manually, using the scripts/sign-file tool.
>> 1731
>> 1732 comment "Do not forget to sign required modules with scripts/sign-file"
>> 1733 depends on MODULE_SIG_FORCE && !MODULE_SIG_ALL
>> 1734
>> 1735 choice
>> 1736 prompt "Which hash algorithm should modules be signed with?"
>> 1737 depends on MODULE_SIG
>> 1738 help
>> 1739 This determines which sort of hashing algorithm will be used during
>> 1740 signature generation. This algorithm _must_ be built into the kernel
>> 1741 directly so that signature verification can take place. It is not
>> 1742 possible to load a signed module containing the algorithm to check
>> 1743 the signature on that module.
>> 1744
>> 1745 config MODULE_SIG_SHA1
>> 1746 bool "Sign modules with SHA-1"
>> 1747 select CRYPTO_SHA1
>> 1748
>> 1749 config MODULE_SIG_SHA224
>> 1750 bool "Sign modules with SHA-224"
>> 1751 select CRYPTO_SHA256
>> 1752
>> 1753 config MODULE_SIG_SHA256
>> 1754 bool "Sign modules with SHA-256"
>> 1755 select CRYPTO_SHA256
>> 1756
>> 1757 config MODULE_SIG_SHA384
>> 1758 bool "Sign modules with SHA-384"
>> 1759 select CRYPTO_SHA512
>> 1760
>> 1761 config MODULE_SIG_SHA512
>> 1762 bool "Sign modules with SHA-512"
>> 1763 select CRYPTO_SHA512
>> 1764
>> 1765 endchoice
>> 1766
>> 1767 config MODULE_SIG_HASH
>> 1768 string
>> 1769 depends on MODULE_SIG
>> 1770 default "sha1" if MODULE_SIG_SHA1
>> 1771 default "sha224" if MODULE_SIG_SHA224
>> 1772 default "sha256" if MODULE_SIG_SHA256
>> 1773 default "sha384" if MODULE_SIG_SHA384
>> 1774 default "sha512" if MODULE_SIG_SHA512
>> 1775
>> 1776 endif # MODULES
2008 1777
2009 config INIT_ALL_POSSIBLE 1778 config INIT_ALL_POSSIBLE
2010 bool 1779 bool
2011 help 1780 help
2012 Back when each arch used to define 1781 Back when each arch used to define their own cpu_online_mask and
2013 cpu_possible_mask, some of them cho 1782 cpu_possible_mask, some of them chose to initialize cpu_possible_mask
2014 with all 1s, and others with all 0s 1783 with all 1s, and others with all 0s. When they were centralised,
2015 it was better to provide this optio 1784 it was better to provide this option than to break all the archs
2016 and have several arch maintainers p 1785 and have several arch maintainers pursuing me down dark alleys.
2017 1786
>> 1787 config STOP_MACHINE
>> 1788 bool
>> 1789 default y
>> 1790 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
>> 1791 help
>> 1792 Need stop_machine() primitive.
>> 1793
2018 source "block/Kconfig" 1794 source "block/Kconfig"
2019 1795
2020 config PREEMPT_NOTIFIERS 1796 config PREEMPT_NOTIFIERS
2021 bool 1797 bool
2022 1798
2023 config PADATA 1799 config PADATA
2024 depends on SMP 1800 depends on SMP
2025 bool 1801 bool
2026 1802
>> 1803 # Can be selected by architectures with broken toolchains
>> 1804 # that get confused by correct const<->read_only section
>> 1805 # mappings
>> 1806 config BROKEN_RODATA
>> 1807 bool
>> 1808
2027 config ASN1 1809 config ASN1
2028 tristate 1810 tristate
2029 help 1811 help
2030 Build a simple ASN.1 grammar compil 1812 Build a simple ASN.1 grammar compiler that produces a bytecode output
2031 that can be interpreted by the ASN. 1813 that can be interpreted by the ASN.1 stream decoder and used to
2032 inform it as to what tags are to be 1814 inform it as to what tags are to be expected in a stream and what
2033 functions to call on what tags. 1815 functions to call on what tags.
2034 1816
2035 source "kernel/Kconfig.locks" 1817 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 <<
2043 config ARCH_HAS_SYNC_CORE_BEFORE_USERMODE <<
2044 bool <<
2045 <<
2046 # It may be useful for an architecture to ove <<
2047 # SYSCALL_DEFINE() and __SYSCALL_DEFINEx() ma <<
2048 # and the COMPAT_ variants in <linux/compat.h <<
2049 # different calling convention for syscalls. <<
2050 # macros for not-implemented syscalls in kern <<
2051 # kernel/time/posix-stubs.c. All these overri <<
2052 # <asm/syscall_wrapper.h>. <<
2053 config ARCH_HAS_SYSCALL_WRAPPER <<
2054 def_bool n <<
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