Commit | Line | Data |
---|---|---|
ec8f24b7 | 1 | # SPDX-License-Identifier: GPL-2.0-only |
8b59cd81 MY |
2 | config CC_VERSION_TEXT |
3 | string | |
4 | default "$(CC_VERSION_TEXT)" | |
5 | help | |
6 | This is used in unclear ways: | |
7 | ||
8 | - Re-run Kconfig when the compiler is updated | |
9 | The 'default' property references the environment variable, | |
10 | CC_VERSION_TEXT so it is recorded in include/config/auto.conf.cmd. | |
11 | When the compiler is updated, Kconfig will be invoked. | |
12 | ||
f9c8bc46 | 13 | - Ensure full rebuild when the compiler is updated |
ce6ed1c4 | 14 | include/linux/compiler-version.h contains this option in the comment |
0e0345b7 | 15 | line so fixdep adds include/config/CC_VERSION_TEXT into the |
ce6ed1c4 MY |
16 | auto-generated dependency. When the compiler is updated, syncconfig |
17 | will touch it and then every file will be rebuilt. | |
8b59cd81 | 18 | |
a4353898 | 19 | config CC_IS_GCC |
aec6c60a | 20 | def_bool $(success,test "$(cc-name)" = GCC) |
a4353898 MY |
21 | |
22 | config GCC_VERSION | |
23 | int | |
aec6c60a | 24 | default $(cc-version) if CC_IS_GCC |
a4353898 MY |
25 | default 0 |
26 | ||
469cb737 | 27 | config CC_IS_CLANG |
aec6c60a | 28 | def_bool $(success,test "$(cc-name)" = Clang) |
b744b43f | 29 | |
469cb737 MY |
30 | config CLANG_VERSION |
31 | int | |
aec6c60a MY |
32 | default $(cc-version) if CC_IS_CLANG |
33 | default 0 | |
469cb737 | 34 | |
ba64beb1 MY |
35 | config AS_IS_GNU |
36 | def_bool $(success,test "$(as-name)" = GNU) | |
37 | ||
38 | config AS_IS_LLVM | |
39 | def_bool $(success,test "$(as-name)" = LLVM) | |
40 | ||
41 | config AS_VERSION | |
42 | int | |
43 | # Use clang version if this is the integrated assembler | |
44 | default CLANG_VERSION if AS_IS_LLVM | |
45 | default $(as-version) | |
46 | ||
02aff859 MY |
47 | config LD_IS_BFD |
48 | def_bool $(success,test "$(ld-name)" = BFD) | |
49 | ||
50 | config LD_VERSION | |
51 | int | |
52 | default $(ld-version) if LD_IS_BFD | |
53 | default 0 | |
54 | ||
55 | config LD_IS_LLD | |
56 | def_bool $(success,test "$(ld-name)" = LLD) | |
469cb737 | 57 | |
d5750cd3 NC |
58 | config LLD_VERSION |
59 | int | |
02aff859 MY |
60 | default $(ld-version) if LD_IS_LLD |
61 | default 0 | |
d5750cd3 | 62 | |
2f7ab126 MO |
63 | config RUST_IS_AVAILABLE |
64 | def_bool $(success,$(srctree)/scripts/rust_is_available.sh) | |
65 | help | |
66 | This shows whether a suitable Rust toolchain is available (found). | |
67 | ||
68 | Please see Documentation/rust/quick-start.rst for instructions on how | |
eacf96d2 | 69 | to satisfy the build requirements of Rust support. |
2f7ab126 MO |
70 | |
71 | In particular, the Makefile target 'rustavailable' is useful to check | |
72 | why the Rust toolchain is not being detected. | |
73 | ||
1a927fd3 | 74 | config CC_CAN_LINK |
9371f86e | 75 | bool |
f67695c9 EB |
76 | default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag)) if 64BIT |
77 | default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m32-flag)) | |
b1183b6d MY |
78 | |
79 | config CC_CAN_LINK_STATIC | |
80 | bool | |
f67695c9 EB |
81 | default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag) -static) if 64BIT |
82 | default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m32-flag) -static) | |
1a927fd3 | 83 | |
587f1701 | 84 | config CC_HAS_ASM_GOTO_OUTPUT |
587f1701 ND |
85 | def_bool $(success,echo 'int foo(int x) { asm goto ("": "=r"(x) ::: bar); return x; bar: return 0; }' | $(CC) -x c - -c -o /dev/null) |
86 | ||
1aa0e8b1 SC |
87 | config CC_HAS_ASM_GOTO_TIED_OUTPUT |
88 | depends on CC_HAS_ASM_GOTO_OUTPUT | |
89 | # Detect buggy gcc and clang, fixed in gcc-11 clang-14. | |
534bd703 | 90 | def_bool $(success,echo 'int foo(int *x) { asm goto (".long (%l[bar]) - .": "+m"(*x) ::: bar); return *x; bar: return 0; }' | $CC -x c - -c -o /dev/null) |
1aa0e8b1 | 91 | |
5cf896fb | 92 | config TOOLS_SUPPORT_RELR |
2d122942 | 93 | def_bool $(success,env "CC=$(CC)" "LD=$(LD)" "NM=$(NM)" "OBJCOPY=$(OBJCOPY)" $(srctree)/scripts/tools-support-relr.sh) |
5cf896fb | 94 | |
eb111869 RV |
95 | config CC_HAS_ASM_INLINE |
96 | def_bool $(success,echo 'void foo(void) { asm inline (""); }' | $(CC) -x c - -c -o /dev/null) | |
97 | ||
51c2ee6d ND |
98 | config CC_HAS_NO_PROFILE_FN_ATTR |
99 | def_bool $(success,echo '__attribute__((no_profile_instrument_function)) int x();' | $(CC) -x c - -c -o /dev/null -Werror) | |
100 | ||
613fe169 NC |
101 | config PAHOLE_VERSION |
102 | int | |
103 | default $(shell,$(srctree)/scripts/pahole-version.sh $(PAHOLE)) | |
104 | ||
b99b87f7 PO |
105 | config CONSTRUCTORS |
106 | bool | |
b99b87f7 | 107 | |
e360adbe PZ |
108 | config IRQ_WORK |
109 | bool | |
e360adbe | 110 | |
10916706 | 111 | config BUILDTIME_TABLE_SORT |
1dbdc6f1 DD |
112 | bool |
113 | ||
c65eacbe AL |
114 | config THREAD_INFO_IN_TASK |
115 | bool | |
116 | help | |
117 | Select this to move thread_info off the stack into task_struct. To | |
118 | make this work, an arch will need to remove all thread_info fields | |
119 | except flags and fix any runtime bugs. | |
120 | ||
c6c314a6 AL |
121 | One subtle change that will be needed is to use try_get_task_stack() |
122 | and put_task_stack() in save_thread_stack_tsk() and get_wchan(). | |
123 | ||
ff0cfc66 | 124 | menu "General setup" |
1da177e4 | 125 | |
1da177e4 LT |
126 | config BROKEN |
127 | bool | |
1da177e4 LT |
128 | |
129 | config BROKEN_ON_SMP | |
130 | bool | |
131 | depends on BROKEN || !SMP | |
132 | default y | |
133 | ||
1da177e4 LT |
134 | config INIT_ENV_ARG_LIMIT |
135 | int | |
dd673bca AB |
136 | default 32 if !UML |
137 | default 128 if UML | |
1da177e4 | 138 | help |
34ad92c2 RD |
139 | Maximum of each of the number of arguments and environment |
140 | variables passed to init from the kernel command line. | |
1da177e4 | 141 | |
4bb16672 JS |
142 | config COMPILE_TEST |
143 | bool "Compile also drivers which will not load" | |
ea29b20a | 144 | depends on HAS_IOMEM |
4bb16672 JS |
145 | help |
146 | Some drivers can be compiled on a different platform than they are | |
147 | intended to be run on. Despite they cannot be loaded there (or even | |
148 | when they load they cannot be used due to missing HW support), | |
149 | developers still, opposing to distributors, might want to build such | |
150 | drivers to compile-test them. | |
151 | ||
152 | If you are a developer and want to build everything available, say Y | |
153 | here. If you are a user/distributor, say N here to exclude useless | |
154 | drivers to be distributed. | |
155 | ||
3fe617cc LT |
156 | config WERROR |
157 | bool "Compile the kernel with warnings as errors" | |
b339ec9c | 158 | default COMPILE_TEST |
3fe617cc LT |
159 | help |
160 | A kernel build should not cause any compiler warnings, and this | |
2f7ab126 | 161 | enables the '-Werror' (for C) and '-Dwarnings' (for Rust) flags |
e1789d7c XL |
162 | to enforce that rule by default. Certain warnings from other tools |
163 | such as the linker may be upgraded to errors with this option as | |
164 | well. | |
3fe617cc | 165 | |
e1789d7c XL |
166 | However, if you have a new (or very old) compiler or linker with odd |
167 | and unusual warnings, or you have some architecture with problems, | |
3fe617cc LT |
168 | you may need to disable this config option in order to |
169 | successfully build the kernel. | |
170 | ||
171 | If in doubt, say Y. | |
172 | ||
d6fc9fcb MY |
173 | config UAPI_HEADER_TEST |
174 | bool "Compile test UAPI headers" | |
fcbb8461 | 175 | depends on HEADERS_INSTALL && CC_CAN_LINK |
d6fc9fcb MY |
176 | help |
177 | Compile test headers exported to user-space to ensure they are | |
178 | self-contained, i.e. compilable as standalone units. | |
179 | ||
180 | If you are a developer or tester and want to ensure the exported | |
181 | headers are self-contained, say Y here. Otherwise, choose N. | |
182 | ||
1da177e4 LT |
183 | config LOCALVERSION |
184 | string "Local version - append to kernel release" | |
185 | help | |
186 | Append an extra string to the end of your kernel version. | |
187 | This will show up when you type uname, for example. | |
188 | The string you set here will be appended after the contents of | |
189 | any files with a filename matching localversion* in your | |
190 | object and source tree, in that order. Your total string can | |
191 | be a maximum of 64 characters. | |
192 | ||
aaebf433 RA |
193 | config LOCALVERSION_AUTO |
194 | bool "Automatically append version information to the version string" | |
195 | default y | |
ac3339ba | 196 | depends on !COMPILE_TEST |
aaebf433 RA |
197 | help |
198 | This will try to automatically determine if the current tree is a | |
6e5a5420 RD |
199 | release tree by looking for git tags that belong to the current |
200 | top of tree revision. | |
aaebf433 RA |
201 | |
202 | A string of the format -gxxxxxxxx will be added to the localversion | |
6e5a5420 | 203 | if a git-based tree is found. The string generated by this will be |
aaebf433 | 204 | appended after any matching localversion* files, and after the value |
6e5a5420 | 205 | set in CONFIG_LOCALVERSION. |
aaebf433 | 206 | |
6e5a5420 RD |
207 | (The actual string used here is the first eight characters produced |
208 | by running the command: | |
209 | ||
210 | $ git rev-parse --verify HEAD | |
211 | ||
212 | which is done within the script "scripts/setlocalversion".) | |
aaebf433 | 213 | |
9afb719e | 214 | config BUILD_SALT |
e8cf4e9c KK |
215 | string "Build ID Salt" |
216 | default "" | |
217 | help | |
218 | The build ID is used to link binaries and their debug info. Setting | |
219 | this option will use the value in the calculation of the build id. | |
220 | This is mostly useful for distributions which want to ensure the | |
221 | build is unique between builds. It's safe to leave the default. | |
9afb719e | 222 | |
2e9f3bdd PA |
223 | config HAVE_KERNEL_GZIP |
224 | bool | |
225 | ||
226 | config HAVE_KERNEL_BZIP2 | |
227 | bool | |
228 | ||
229 | config HAVE_KERNEL_LZMA | |
230 | bool | |
231 | ||
3ebe1243 LC |
232 | config HAVE_KERNEL_XZ |
233 | bool | |
234 | ||
7dd65feb AT |
235 | config HAVE_KERNEL_LZO |
236 | bool | |
237 | ||
e76e1fdf KL |
238 | config HAVE_KERNEL_LZ4 |
239 | bool | |
240 | ||
48f7ddf7 NT |
241 | config HAVE_KERNEL_ZSTD |
242 | bool | |
243 | ||
f16466af VG |
244 | config HAVE_KERNEL_UNCOMPRESSED |
245 | bool | |
246 | ||
30d65dbf | 247 | choice |
2e9f3bdd PA |
248 | prompt "Kernel compression mode" |
249 | default KERNEL_GZIP | |
48f7ddf7 | 250 | depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO || HAVE_KERNEL_LZ4 || HAVE_KERNEL_ZSTD || HAVE_KERNEL_UNCOMPRESSED |
2e9f3bdd | 251 | help |
30d65dbf AK |
252 | The linux kernel is a kind of self-extracting executable. |
253 | Several compression algorithms are available, which differ | |
254 | in efficiency, compression and decompression speed. | |
255 | Compression speed is only relevant when building a kernel. | |
256 | Decompression speed is relevant at each boot. | |
257 | ||
258 | If you have any problems with bzip2 or lzma compressed | |
259 | kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older | |
260 | version of this functionality (bzip2 only), for 2.4, was | |
261 | supplied by Christian Ludwig) | |
262 | ||
263 | High compression options are mostly useful for users, who | |
264 | are low on disk space (embedded systems), but for whom ram | |
265 | size matters less. | |
266 | ||
267 | If in doubt, select 'gzip' | |
268 | ||
269 | config KERNEL_GZIP | |
2e9f3bdd PA |
270 | bool "Gzip" |
271 | depends on HAVE_KERNEL_GZIP | |
272 | help | |
7dd65feb AT |
273 | The old and tried gzip compression. It provides a good balance |
274 | between compression ratio and decompression speed. | |
30d65dbf AK |
275 | |
276 | config KERNEL_BZIP2 | |
277 | bool "Bzip2" | |
2e9f3bdd | 278 | depends on HAVE_KERNEL_BZIP2 |
30d65dbf AK |
279 | help |
280 | Its compression ratio and speed is intermediate. | |
0a4dd35c | 281 | Decompression speed is slowest among the choices. The kernel |
2e9f3bdd PA |
282 | size is about 10% smaller with bzip2, in comparison to gzip. |
283 | Bzip2 uses a large amount of memory. For modern kernels you | |
284 | will need at least 8MB RAM or more for booting. | |
30d65dbf AK |
285 | |
286 | config KERNEL_LZMA | |
2e9f3bdd PA |
287 | bool "LZMA" |
288 | depends on HAVE_KERNEL_LZMA | |
289 | help | |
0a4dd35c RD |
290 | This compression algorithm's ratio is best. Decompression speed |
291 | is between gzip and bzip2. Compression is slowest. | |
292 | The kernel size is about 33% smaller with LZMA in comparison to gzip. | |
30d65dbf | 293 | |
3ebe1243 LC |
294 | config KERNEL_XZ |
295 | bool "XZ" | |
296 | depends on HAVE_KERNEL_XZ | |
297 | help | |
298 | XZ uses the LZMA2 algorithm and instruction set specific | |
299 | BCJ filters which can improve compression ratio of executable | |
300 | code. The size of the kernel is about 30% smaller with XZ in | |
301 | comparison to gzip. On architectures for which there is a BCJ | |
302 | filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ | |
303 | will create a few percent smaller kernel than plain LZMA. | |
304 | ||
305 | The speed is about the same as with LZMA: The decompression | |
306 | speed of XZ is better than that of bzip2 but worse than gzip | |
307 | and LZO. Compression is slow. | |
308 | ||
7dd65feb AT |
309 | config KERNEL_LZO |
310 | bool "LZO" | |
311 | depends on HAVE_KERNEL_LZO | |
312 | help | |
0a4dd35c | 313 | Its compression ratio is the poorest among the choices. The kernel |
681b3049 | 314 | size is about 10% bigger than gzip; however its speed |
7dd65feb AT |
315 | (both compression and decompression) is the fastest. |
316 | ||
e76e1fdf KL |
317 | config KERNEL_LZ4 |
318 | bool "LZ4" | |
319 | depends on HAVE_KERNEL_LZ4 | |
320 | help | |
321 | LZ4 is an LZ77-type compressor with a fixed, byte-oriented encoding. | |
322 | A preliminary version of LZ4 de/compression tool is available at | |
323 | <https://code.google.com/p/lz4/>. | |
324 | ||
325 | Its compression ratio is worse than LZO. The size of the kernel | |
326 | is about 8% bigger than LZO. But the decompression speed is | |
327 | faster than LZO. | |
328 | ||
48f7ddf7 NT |
329 | config KERNEL_ZSTD |
330 | bool "ZSTD" | |
331 | depends on HAVE_KERNEL_ZSTD | |
332 | help | |
333 | ZSTD is a compression algorithm targeting intermediate compression | |
334 | with fast decompression speed. It will compress better than GZIP and | |
335 | decompress around the same speed as LZO, but slower than LZ4. You | |
336 | will need at least 192 KB RAM or more for booting. The zstd command | |
337 | line tool is required for compression. | |
338 | ||
f16466af VG |
339 | config KERNEL_UNCOMPRESSED |
340 | bool "None" | |
341 | depends on HAVE_KERNEL_UNCOMPRESSED | |
342 | help | |
343 | Produce uncompressed kernel image. This option is usually not what | |
344 | you want. It is useful for debugging the kernel in slow simulation | |
345 | environments, where decompressing and moving the kernel is awfully | |
346 | slow. This option allows early boot code to skip the decompressor | |
347 | and jump right at uncompressed kernel image. | |
348 | ||
30d65dbf AK |
349 | endchoice |
350 | ||
ada4ab7a CD |
351 | config DEFAULT_INIT |
352 | string "Default init path" | |
353 | default "" | |
354 | help | |
355 | This option determines the default init for the system if no init= | |
356 | option is passed on the kernel command line. If the requested path is | |
357 | not present, we will still then move on to attempting further | |
358 | locations (e.g. /sbin/init, etc). If this is empty, we will just use | |
359 | the fallback list when init= is not passed. | |
360 | ||
bd5dc17b JT |
361 | config DEFAULT_HOSTNAME |
362 | string "Default hostname" | |
363 | default "(none)" | |
364 | help | |
365 | This option determines the default system hostname before userspace | |
366 | calls sethostname(2). The kernel traditionally uses "(none)" here, | |
367 | but you may wish to use a different default here to make a minimal | |
368 | system more usable with less configuration. | |
369 | ||
1da177e4 LT |
370 | config SYSVIPC |
371 | bool "System V IPC" | |
a7f7f624 | 372 | help |
1da177e4 LT |
373 | Inter Process Communication is a suite of library functions and |
374 | system calls which let processes (running programs) synchronize and | |
375 | exchange information. It is generally considered to be a good thing, | |
376 | and some programs won't run unless you say Y here. In particular, if | |
377 | you want to run the DOS emulator dosemu under Linux (read the | |
378 | DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>), | |
379 | you'll need to say Y here. | |
380 | ||
381 | You can find documentation about IPC with "info ipc" and also in | |
382 | section 6.4 of the Linux Programmer's Guide, available from | |
383 | <http://www.tldp.org/guides.html>. | |
384 | ||
a5494dcd EB |
385 | config SYSVIPC_SYSCTL |
386 | bool | |
387 | depends on SYSVIPC | |
388 | depends on SYSCTL | |
389 | default y | |
390 | ||
0cbed0ee GR |
391 | config SYSVIPC_COMPAT |
392 | def_bool y | |
393 | depends on COMPAT && SYSVIPC | |
394 | ||
1da177e4 LT |
395 | config POSIX_MQUEUE |
396 | bool "POSIX Message Queues" | |
19c92399 | 397 | depends on NET |
a7f7f624 | 398 | help |
1da177e4 LT |
399 | POSIX variant of message queues is a part of IPC. In POSIX message |
400 | queues every message has a priority which decides about succession | |
401 | of receiving it by a process. If you want to compile and run | |
402 | programs written e.g. for Solaris with use of its POSIX message | |
b0e37650 | 403 | queues (functions mq_*) say Y here. |
1da177e4 LT |
404 | |
405 | POSIX message queues are visible as a filesystem called 'mqueue' | |
406 | and can be mounted somewhere if you want to do filesystem | |
407 | operations on message queues. | |
408 | ||
409 | If unsure, say Y. | |
410 | ||
bdc8e5f8 SH |
411 | config POSIX_MQUEUE_SYSCTL |
412 | bool | |
413 | depends on POSIX_MQUEUE | |
414 | depends on SYSCTL | |
415 | default y | |
416 | ||
c73be61c DH |
417 | config WATCH_QUEUE |
418 | bool "General notification queue" | |
419 | default n | |
420 | help | |
421 | ||
422 | This is a general notification queue for the kernel to pass events to | |
423 | userspace by splicing them into pipes. It can be used in conjunction | |
424 | with watches for key/keyring change notifications and device | |
425 | notifications. | |
426 | ||
c02b872a | 427 | See Documentation/core-api/watch_queue.rst |
c73be61c | 428 | |
226b4ccd KK |
429 | config CROSS_MEMORY_ATTACH |
430 | bool "Enable process_vm_readv/writev syscalls" | |
431 | depends on MMU | |
432 | default y | |
433 | help | |
434 | Enabling this option adds the system calls process_vm_readv and | |
435 | process_vm_writev which allow a process with the correct privileges | |
a2a368d9 | 436 | to directly read from or write to another process' address space. |
226b4ccd KK |
437 | See the man page for more details. |
438 | ||
69369a70 | 439 | config USELIB |
7374fa33 KC |
440 | bool "uselib syscall (for libc5 and earlier)" |
441 | default ALPHA || M68K || SPARC | |
69369a70 JT |
442 | help |
443 | This option enables the uselib syscall, a system call used in the | |
444 | dynamic linker from libc5 and earlier. glibc does not use this | |
445 | system call. If you intend to run programs built on libc5 or | |
446 | earlier, you may need to enable this syscall. Current systems | |
447 | running glibc can safely disable this. | |
448 | ||
391dc69c FW |
449 | config AUDIT |
450 | bool "Auditing support" | |
451 | depends on NET | |
452 | help | |
453 | Enable auditing infrastructure that can be used with another | |
454 | kernel subsystem, such as SELinux (which requires this for | |
cb74ed27 PM |
455 | logging of avc messages output). System call auditing is included |
456 | on architectures which support it. | |
391dc69c | 457 | |
7a017721 AT |
458 | config HAVE_ARCH_AUDITSYSCALL |
459 | bool | |
460 | ||
391dc69c | 461 | config AUDITSYSCALL |
cb74ed27 | 462 | def_bool y |
7a017721 | 463 | depends on AUDIT && HAVE_ARCH_AUDITSYSCALL |
391dc69c FW |
464 | select FSNOTIFY |
465 | ||
391dc69c FW |
466 | source "kernel/irq/Kconfig" |
467 | source "kernel/time/Kconfig" | |
b24abcff | 468 | source "kernel/bpf/Kconfig" |
87a4c375 | 469 | source "kernel/Kconfig.preempt" |
391dc69c FW |
470 | |
471 | menu "CPU/Task time and stats accounting" | |
472 | ||
abf917cd FW |
473 | config VIRT_CPU_ACCOUNTING |
474 | bool | |
475 | ||
fdf9c356 FW |
476 | choice |
477 | prompt "Cputime accounting" | |
02382aff | 478 | default TICK_CPU_ACCOUNTING |
fdf9c356 FW |
479 | |
480 | # Kind of a stub config for the pure tick based cputime accounting | |
481 | config TICK_CPU_ACCOUNTING | |
482 | bool "Simple tick based cputime accounting" | |
c58b0df1 | 483 | depends on !S390 && !NO_HZ_FULL |
fdf9c356 FW |
484 | help |
485 | This is the basic tick based cputime accounting that maintains | |
486 | statistics about user, system and idle time spent on per jiffies | |
487 | granularity. | |
488 | ||
489 | If unsure, say Y. | |
490 | ||
abf917cd | 491 | config VIRT_CPU_ACCOUNTING_NATIVE |
b952741c | 492 | bool "Deterministic task and CPU time accounting" |
c58b0df1 | 493 | depends on HAVE_VIRT_CPU_ACCOUNTING && !NO_HZ_FULL |
abf917cd | 494 | select VIRT_CPU_ACCOUNTING |
b952741c FW |
495 | help |
496 | Select this option to enable more accurate task and CPU time | |
497 | accounting. This is done by reading a CPU counter on each | |
498 | kernel entry and exit and on transitions within the kernel | |
499 | between system, softirq and hardirq state, so there is a | |
500 | small performance impact. In the case of s390 or IBM POWER > 5, | |
501 | this also enables accounting of stolen time on logically-partitioned | |
502 | systems. | |
503 | ||
abf917cd FW |
504 | config VIRT_CPU_ACCOUNTING_GEN |
505 | bool "Full dynticks CPU time accounting" | |
24a9c541 | 506 | depends on HAVE_CONTEXT_TRACKING_USER |
554b0004 | 507 | depends on HAVE_VIRT_CPU_ACCOUNTING_GEN |
041a1574 | 508 | depends on GENERIC_CLOCKEVENTS |
abf917cd | 509 | select VIRT_CPU_ACCOUNTING |
24a9c541 | 510 | select CONTEXT_TRACKING_USER |
abf917cd FW |
511 | help |
512 | Select this option to enable task and CPU time accounting on full | |
513 | dynticks systems. This accounting is implemented by watching every | |
514 | kernel-user boundaries using the context tracking subsystem. | |
515 | The accounting is thus performed at the expense of some significant | |
516 | overhead. | |
517 | ||
518 | For now this is only useful if you are working on the full | |
519 | dynticks subsystem development. | |
520 | ||
521 | If unsure, say N. | |
522 | ||
b58c3584 RR |
523 | endchoice |
524 | ||
fdf9c356 FW |
525 | config IRQ_TIME_ACCOUNTING |
526 | bool "Fine granularity task level IRQ time accounting" | |
b58c3584 | 527 | depends on HAVE_IRQ_TIME_ACCOUNTING && !VIRT_CPU_ACCOUNTING_NATIVE |
fdf9c356 FW |
528 | help |
529 | Select this option to enable fine granularity task irq time | |
530 | accounting. This is done by reading a timestamp on each | |
531 | transitions between softirq and hardirq state, so there can be a | |
532 | small performance impact. | |
533 | ||
534 | If in doubt, say N here. | |
535 | ||
11d4afd4 VG |
536 | config HAVE_SCHED_AVG_IRQ |
537 | def_bool y | |
538 | depends on IRQ_TIME_ACCOUNTING || PARAVIRT_TIME_ACCOUNTING | |
539 | depends on SMP | |
540 | ||
76504793 | 541 | config SCHED_THERMAL_PRESSURE |
98eb401d | 542 | bool |
fcd7c9c3 VS |
543 | default y if ARM && ARM_CPU_TOPOLOGY |
544 | default y if ARM64 | |
76504793 | 545 | depends on SMP |
98eb401d VS |
546 | depends on CPU_FREQ_THERMAL |
547 | help | |
548 | Select this option to enable thermal pressure accounting in the | |
549 | scheduler. Thermal pressure is the value conveyed to the scheduler | |
550 | that reflects the reduction in CPU compute capacity resulted from | |
551 | thermal throttling. Thermal throttling occurs when the performance of | |
552 | a CPU is capped due to high operating temperatures. | |
553 | ||
554 | If selected, the scheduler will be able to balance tasks accordingly, | |
555 | i.e. put less load on throttled CPUs than on non/less throttled ones. | |
556 | ||
557 | This requires the architecture to implement | |
7e97b3dc | 558 | arch_update_thermal_pressure() and arch_scale_thermal_pressure(). |
76504793 | 559 | |
1da177e4 LT |
560 | config BSD_PROCESS_ACCT |
561 | bool "BSD Process Accounting" | |
2813893f | 562 | depends on MULTIUSER |
1da177e4 LT |
563 | help |
564 | If you say Y here, a user level program will be able to instruct the | |
565 | kernel (via a special system call) to write process accounting | |
566 | information to a file: whenever a process exits, information about | |
567 | that process will be appended to the file by the kernel. The | |
568 | information includes things such as creation time, owning user, | |
569 | command name, memory usage, controlling terminal etc. (the complete | |
570 | list is in the struct acct in <file:include/linux/acct.h>). It is | |
571 | up to the user level program to do useful things with this | |
572 | information. This is generally a good idea, so say Y. | |
573 | ||
574 | config BSD_PROCESS_ACCT_V3 | |
575 | bool "BSD Process Accounting version 3 file format" | |
576 | depends on BSD_PROCESS_ACCT | |
577 | default n | |
578 | help | |
579 | If you say Y here, the process accounting information is written | |
580 | in a new file format that also logs the process IDs of each | |
3903bf94 | 581 | process and its parent. Note that this file format is incompatible |
1da177e4 LT |
582 | with previous v0/v1/v2 file formats, so you will need updated tools |
583 | for processing it. A preliminary version of these tools is available | |
37a4c940 | 584 | at <http://www.gnu.org/software/acct/>. |
1da177e4 | 585 | |
c757249a | 586 | config TASKSTATS |
19c92399 | 587 | bool "Export task/process statistics through netlink" |
c757249a | 588 | depends on NET |
2813893f | 589 | depends on MULTIUSER |
c757249a SN |
590 | default n |
591 | help | |
592 | Export selected statistics for tasks/processes through the | |
593 | generic netlink interface. Unlike BSD process accounting, the | |
594 | statistics are available during the lifetime of tasks/processes as | |
595 | responses to commands. Like BSD accounting, they are sent to user | |
596 | space on task exit. | |
597 | ||
598 | Say N if unsure. | |
599 | ||
ca74e92b | 600 | config TASK_DELAY_ACCT |
19c92399 | 601 | bool "Enable per-task delay accounting" |
6f44993f | 602 | depends on TASKSTATS |
f6db8347 | 603 | select SCHED_INFO |
ca74e92b SN |
604 | help |
605 | Collect information on time spent by a task waiting for system | |
606 | resources like cpu, synchronous block I/O completion and swapping | |
607 | in pages. Such statistics can help in setting a task's priorities | |
608 | relative to other tasks for cpu, io, rss limits etc. | |
609 | ||
610 | Say N if unsure. | |
611 | ||
18f705f4 | 612 | config TASK_XACCT |
19c92399 | 613 | bool "Enable extended accounting over taskstats" |
18f705f4 AD |
614 | depends on TASKSTATS |
615 | help | |
616 | Collect extended task accounting data and send the data | |
617 | to userland for processing over the taskstats interface. | |
618 | ||
619 | Say N if unsure. | |
620 | ||
621 | config TASK_IO_ACCOUNTING | |
19c92399 | 622 | bool "Enable per-task storage I/O accounting" |
18f705f4 AD |
623 | depends on TASK_XACCT |
624 | help | |
625 | Collect information on the number of bytes of storage I/O which this | |
626 | task has caused. | |
627 | ||
628 | Say N if unsure. | |
629 | ||
eb414681 JW |
630 | config PSI |
631 | bool "Pressure stall information tracking" | |
632 | help | |
633 | Collect metrics that indicate how overcommitted the CPU, memory, | |
634 | and IO capacity are in the system. | |
635 | ||
636 | If you say Y here, the kernel will create /proc/pressure/ with the | |
637 | pressure statistics files cpu, memory, and io. These will indicate | |
638 | the share of walltime in which some or all tasks in the system are | |
639 | delayed due to contention of the respective resource. | |
640 | ||
2ce7135a JW |
641 | In kernels with cgroup support, cgroups (cgroup2 only) will |
642 | have cpu.pressure, memory.pressure, and io.pressure files, | |
643 | which aggregate pressure stalls for the grouped tasks only. | |
644 | ||
c3123552 | 645 | For more details see Documentation/accounting/psi.rst. |
eb414681 JW |
646 | |
647 | Say N if unsure. | |
648 | ||
e0c27447 JW |
649 | config PSI_DEFAULT_DISABLED |
650 | bool "Require boot parameter to enable pressure stall information tracking" | |
651 | default n | |
652 | depends on PSI | |
653 | help | |
654 | If set, pressure stall information tracking will be disabled | |
428a1cb4 BS |
655 | per default but can be enabled through passing psi=1 on the |
656 | kernel commandline during boot. | |
e0c27447 | 657 | |
7b2489d3 JW |
658 | This feature adds some code to the task wakeup and sleep |
659 | paths of the scheduler. The overhead is too low to affect | |
660 | common scheduling-intense workloads in practice (such as | |
661 | webservers, memcache), but it does show up in artificial | |
662 | scheduler stress tests, such as hackbench. | |
663 | ||
664 | If you are paranoid and not sure what the kernel will be | |
665 | used for, say Y. | |
666 | ||
667 | Say N if unsure. | |
668 | ||
391dc69c | 669 | endmenu # "CPU/Task time and stats accounting" |
d9817ebe | 670 | |
5c4991e2 FW |
671 | config CPU_ISOLATION |
672 | bool "CPU isolation" | |
414a2dc1 | 673 | depends on SMP || COMPILE_TEST |
2c43838c | 674 | default y |
5c4991e2 FW |
675 | help |
676 | Make sure that CPUs running critical tasks are not disturbed by | |
677 | any source of "noise" such as unbound workqueues, timers, kthreads... | |
2c43838c FW |
678 | Unbound jobs get offloaded to housekeeping CPUs. This is driven by |
679 | the "isolcpus=" boot parameter. | |
680 | ||
681 | Say Y if unsure. | |
5c4991e2 | 682 | |
0af92d46 | 683 | source "kernel/rcu/Kconfig" |
c903ff83 | 684 | |
de5b56ba VG |
685 | config BUILD_BIN2C |
686 | bool | |
687 | default n | |
688 | ||
1da177e4 | 689 | config IKCONFIG |
f2443ab6 | 690 | tristate "Kernel .config support" |
a7f7f624 | 691 | help |
1da177e4 LT |
692 | This option enables the complete Linux kernel ".config" file |
693 | contents to be saved in the kernel. It provides documentation | |
694 | of which kernel options are used in a running kernel or in an | |
695 | on-disk kernel. This information can be extracted from the kernel | |
696 | image file with the script scripts/extract-ikconfig and used as | |
697 | input to rebuild the current kernel or to build another kernel. | |
698 | It can also be extracted from a running kernel by reading | |
699 | /proc/config.gz if enabled (below). | |
700 | ||
701 | config IKCONFIG_PROC | |
702 | bool "Enable access to .config through /proc/config.gz" | |
703 | depends on IKCONFIG && PROC_FS | |
a7f7f624 | 704 | help |
1da177e4 LT |
705 | This option enables access to the kernel configuration file |
706 | through /proc/config.gz. | |
707 | ||
f7b101d3 JFG |
708 | config IKHEADERS |
709 | tristate "Enable kernel headers through /sys/kernel/kheaders.tar.xz" | |
710 | depends on SYSFS | |
711 | help | |
712 | This option enables access to the in-kernel headers that are generated during | |
713 | the build process. These can be used to build eBPF tracing programs, | |
714 | or similar programs. If you build the headers as a module, a module called | |
715 | kheaders.ko is built which can be loaded on-demand to get access to headers. | |
43d8ce9d | 716 | |
794543a2 AJS |
717 | config LOG_BUF_SHIFT |
718 | int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" | |
1c4b5ecb | 719 | range 12 25 |
f17a32e9 | 720 | default 17 |
361e9dfb | 721 | depends on PRINTK |
794543a2 | 722 | help |
23b2899f LR |
723 | Select the minimal kernel log buffer size as a power of 2. |
724 | The final size is affected by LOG_CPU_MAX_BUF_SHIFT config | |
725 | parameter, see below. Any higher size also might be forced | |
726 | by "log_buf_len" boot parameter. | |
727 | ||
f17a32e9 | 728 | Examples: |
23b2899f | 729 | 17 => 128 KB |
f17a32e9 | 730 | 16 => 64 KB |
23b2899f LR |
731 | 15 => 32 KB |
732 | 14 => 16 KB | |
794543a2 AJS |
733 | 13 => 8 KB |
734 | 12 => 4 KB | |
735 | ||
23b2899f LR |
736 | config LOG_CPU_MAX_BUF_SHIFT |
737 | int "CPU kernel log buffer size contribution (13 => 8 KB, 17 => 128KB)" | |
2240a31d | 738 | depends on SMP |
23b2899f LR |
739 | range 0 21 |
740 | default 12 if !BASE_SMALL | |
741 | default 0 if BASE_SMALL | |
361e9dfb | 742 | depends on PRINTK |
23b2899f LR |
743 | help |
744 | This option allows to increase the default ring buffer size | |
745 | according to the number of CPUs. The value defines the contribution | |
746 | of each CPU as a power of 2. The used space is typically only few | |
747 | lines however it might be much more when problems are reported, | |
748 | e.g. backtraces. | |
749 | ||
750 | The increased size means that a new buffer has to be allocated and | |
751 | the original static one is unused. It makes sense only on systems | |
752 | with more CPUs. Therefore this value is used only when the sum of | |
753 | contributions is greater than the half of the default kernel ring | |
754 | buffer as defined by LOG_BUF_SHIFT. The default values are set | |
0f7636e1 | 755 | so that more than 16 CPUs are needed to trigger the allocation. |
23b2899f LR |
756 | |
757 | Also this option is ignored when "log_buf_len" kernel parameter is | |
758 | used as it forces an exact (power of two) size of the ring buffer. | |
759 | ||
760 | The number of possible CPUs is used for this computation ignoring | |
5e0d8d59 GU |
761 | hotplugging making the computation optimal for the worst case |
762 | scenario while allowing a simple algorithm to be used from bootup. | |
23b2899f LR |
763 | |
764 | Examples shift values and their meaning: | |
765 | 17 => 128 KB for each CPU | |
766 | 16 => 64 KB for each CPU | |
767 | 15 => 32 KB for each CPU | |
768 | 14 => 16 KB for each CPU | |
769 | 13 => 8 KB for each CPU | |
770 | 12 => 4 KB for each CPU | |
771 | ||
f92bac3b SS |
772 | config PRINTK_SAFE_LOG_BUF_SHIFT |
773 | int "Temporary per-CPU printk log buffer size (12 => 4KB, 13 => 8KB)" | |
427934b8 PM |
774 | range 10 21 |
775 | default 13 | |
f92bac3b | 776 | depends on PRINTK |
427934b8 | 777 | help |
f92bac3b SS |
778 | Select the size of an alternate printk per-CPU buffer where messages |
779 | printed from usafe contexts are temporary stored. One example would | |
780 | be NMI messages, another one - printk recursion. The messages are | |
781 | copied to the main log buffer in a safe context to avoid a deadlock. | |
782 | The value defines the size as a power of 2. | |
427934b8 | 783 | |
f92bac3b | 784 | Those messages are rare and limited. The largest one is when |
427934b8 PM |
785 | a backtrace is printed. It usually fits into 4KB. Select |
786 | 8KB if you want to be on the safe side. | |
787 | ||
788 | Examples: | |
789 | 17 => 128 KB for each CPU | |
790 | 16 => 64 KB for each CPU | |
791 | 15 => 32 KB for each CPU | |
792 | 14 => 16 KB for each CPU | |
793 | 13 => 8 KB for each CPU | |
794 | 12 => 4 KB for each CPU | |
795 | ||
33701557 CD |
796 | config PRINTK_INDEX |
797 | bool "Printk indexing debugfs interface" | |
798 | depends on PRINTK && DEBUG_FS | |
799 | help | |
800 | Add support for indexing of all printk formats known at compile time | |
801 | at <debugfs>/printk/index/<module>. | |
802 | ||
803 | This can be used as part of maintaining daemons which monitor | |
804 | /dev/kmsg, as it permits auditing the printk formats present in a | |
805 | kernel, allowing detection of cases where monitored printks are | |
806 | changed or no longer present. | |
807 | ||
808 | There is no additional runtime cost to printk with this enabled. | |
809 | ||
a5574cf6 IM |
810 | # |
811 | # Architectures with an unreliable sched_clock() should select this: | |
812 | # | |
813 | config HAVE_UNSTABLE_SCHED_CLOCK | |
814 | bool | |
815 | ||
38ff87f7 SB |
816 | config GENERIC_SCHED_CLOCK |
817 | bool | |
818 | ||
69842cba PB |
819 | menu "Scheduler features" |
820 | ||
821 | config UCLAMP_TASK | |
822 | bool "Enable utilization clamping for RT/FAIR tasks" | |
823 | depends on CPU_FREQ_GOV_SCHEDUTIL | |
824 | help | |
825 | This feature enables the scheduler to track the clamped utilization | |
826 | of each CPU based on RUNNABLE tasks scheduled on that CPU. | |
827 | ||
828 | With this option, the user can specify the min and max CPU | |
829 | utilization allowed for RUNNABLE tasks. The max utilization defines | |
830 | the maximum frequency a task should use while the min utilization | |
831 | defines the minimum frequency it should use. | |
832 | ||
833 | Both min and max utilization clamp values are hints to the scheduler, | |
834 | aiming at improving its frequency selection policy, but they do not | |
835 | enforce or grant any specific bandwidth for tasks. | |
836 | ||
837 | If in doubt, say N. | |
838 | ||
839 | config UCLAMP_BUCKETS_COUNT | |
840 | int "Number of supported utilization clamp buckets" | |
841 | range 5 20 | |
842 | default 5 | |
843 | depends on UCLAMP_TASK | |
844 | help | |
845 | Defines the number of clamp buckets to use. The range of each bucket | |
846 | will be SCHED_CAPACITY_SCALE/UCLAMP_BUCKETS_COUNT. The higher the | |
847 | number of clamp buckets the finer their granularity and the higher | |
848 | the precision of clamping aggregation and tracking at run-time. | |
849 | ||
850 | For example, with the minimum configuration value we will have 5 | |
851 | clamp buckets tracking 20% utilization each. A 25% boosted tasks will | |
852 | be refcounted in the [20..39]% bucket and will set the bucket clamp | |
853 | effective value to 25%. | |
854 | If a second 30% boosted task should be co-scheduled on the same CPU, | |
855 | that task will be refcounted in the same bucket of the first task and | |
856 | it will boost the bucket clamp effective value to 30%. | |
857 | The clamp effective value of a bucket is reset to its nominal value | |
858 | (20% in the example above) when there are no more tasks refcounted in | |
859 | that bucket. | |
860 | ||
861 | An additional boost/capping margin can be added to some tasks. In the | |
862 | example above the 25% task will be boosted to 30% until it exits the | |
863 | CPU. If that should be considered not acceptable on certain systems, | |
864 | it's always possible to reduce the margin by increasing the number of | |
865 | clamp buckets to trade off used memory for run-time tracking | |
866 | precision. | |
867 | ||
868 | If in doubt, use the default value. | |
869 | ||
870 | endmenu | |
871 | ||
be3a7284 AA |
872 | # |
873 | # For architectures that want to enable the support for NUMA-affine scheduler | |
874 | # balancing logic: | |
875 | # | |
876 | config ARCH_SUPPORTS_NUMA_BALANCING | |
877 | bool | |
878 | ||
72b252ae MG |
879 | # |
880 | # For architectures that prefer to flush all TLBs after a number of pages | |
881 | # are unmapped instead of sending one IPI per page to flush. The architecture | |
882 | # must provide guarantees on what happens if a clean TLB cache entry is | |
883 | # written after the unmap. Details are in mm/rmap.c near the check for | |
884 | # should_defer_flush. The architecture should also consider if the full flush | |
885 | # and the refill costs are offset by the savings of sending fewer IPIs. | |
886 | config ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH | |
887 | bool | |
888 | ||
c12d3362 | 889 | config CC_HAS_INT128 |
3a7c7331 | 890 | def_bool !$(cc-option,$(m64-flag) -D__SIZEOF_INT128__=0) && 64BIT |
c12d3362 | 891 | |
dee2b702 GS |
892 | config CC_IMPLICIT_FALLTHROUGH |
893 | string | |
158ea2d2 | 894 | default "-Wimplicit-fallthrough=5" if CC_IS_GCC && $(cc-option,-Wimplicit-fallthrough=5) |
dee2b702 GS |
895 | default "-Wimplicit-fallthrough" if CC_IS_CLANG && $(cc-option,-Wunreachable-code-fallthrough) |
896 | ||
f0be87c4 LT |
897 | # Currently, disable gcc-12 array-bounds globally. |
898 | # We may want to target only particular configurations some day. | |
899 | config GCC12_NO_ARRAY_BOUNDS | |
900 | def_bool y | |
901 | ||
902 | config CC_NO_ARRAY_BOUNDS | |
903 | bool | |
904 | default y if CC_IS_GCC && GCC_VERSION >= 120000 && GCC_VERSION < 130000 && GCC12_NO_ARRAY_BOUNDS | |
905 | ||
be5e610c PZ |
906 | # |
907 | # For architectures that know their GCC __int128 support is sound | |
908 | # | |
909 | config ARCH_SUPPORTS_INT128 | |
910 | bool | |
911 | ||
be3a7284 AA |
912 | # For architectures that (ab)use NUMA to represent different memory regions |
913 | # all cpu-local but of different latencies, such as SuperH. | |
914 | # | |
915 | config ARCH_WANT_NUMA_VARIABLE_LOCALITY | |
916 | bool | |
917 | ||
be3a7284 AA |
918 | config NUMA_BALANCING |
919 | bool "Memory placement aware NUMA scheduler" | |
be3a7284 AA |
920 | depends on ARCH_SUPPORTS_NUMA_BALANCING |
921 | depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY | |
554b0f3c | 922 | depends on SMP && NUMA && MIGRATION && !PREEMPT_RT |
be3a7284 AA |
923 | help |
924 | This option adds support for automatic NUMA aware memory/task placement. | |
925 | The mechanism is quite primitive and is based on migrating memory when | |
6d56a410 | 926 | it has references to the node the task is running on. |
be3a7284 AA |
927 | |
928 | This system will be inactive on UMA systems. | |
929 | ||
6f7c97e8 AK |
930 | config NUMA_BALANCING_DEFAULT_ENABLED |
931 | bool "Automatically enable NUMA aware memory/task placement" | |
932 | default y | |
933 | depends on NUMA_BALANCING | |
934 | help | |
935 | If set, automatic NUMA balancing will be enabled if running on a NUMA | |
936 | machine. | |
937 | ||
23964d2d | 938 | menuconfig CGROUPS |
6341e62b | 939 | bool "Control Group support" |
2bd59d48 | 940 | select KERNFS |
5cdc38f9 | 941 | help |
23964d2d | 942 | This option adds support for grouping sets of processes together, for |
5cdc38f9 KH |
943 | use with process control subsystems such as Cpusets, CFS, memory |
944 | controls or device isolation. | |
945 | See | |
d6a3b247 | 946 | - Documentation/scheduler/sched-design-CFS.rst (CFS) |
da82c92f | 947 | - Documentation/admin-guide/cgroup-v1/ (features for grouping, isolation |
45ce80fb | 948 | and resource control) |
5cdc38f9 KH |
949 | |
950 | Say N if unsure. | |
951 | ||
23964d2d LZ |
952 | if CGROUPS |
953 | ||
3e32cb2e | 954 | config PAGE_COUNTER |
e8cf4e9c | 955 | bool |
3e32cb2e | 956 | |
6a010a49 TH |
957 | config CGROUP_FAVOR_DYNMODS |
958 | bool "Favor dynamic modification latency reduction by default" | |
959 | help | |
960 | This option enables the "favordynmods" mount option by default | |
961 | which reduces the latencies of dynamic cgroup modifications such | |
962 | as task migrations and controller on/offs at the cost of making | |
963 | hot path operations such as forks and exits more expensive. | |
964 | ||
965 | Say N if unsure. | |
966 | ||
c255a458 | 967 | config MEMCG |
a0166ec4 | 968 | bool "Memory controller" |
3e32cb2e | 969 | select PAGE_COUNTER |
79bd9814 | 970 | select EVENTFD |
00f0b825 | 971 | help |
a0166ec4 | 972 | Provides control over the memory footprint of tasks in a cgroup. |
00f0b825 | 973 | |
84c07d11 KT |
974 | config MEMCG_KMEM |
975 | bool | |
976 | depends on MEMCG && !SLOB | |
977 | default y | |
978 | ||
6bf024e6 JW |
979 | config BLK_CGROUP |
980 | bool "IO controller" | |
981 | depends on BLOCK | |
2bc64a20 | 982 | default n |
a7f7f624 | 983 | help |
6bf024e6 JW |
984 | Generic block IO controller cgroup interface. This is the common |
985 | cgroup interface which should be used by various IO controlling | |
986 | policies. | |
2bc64a20 | 987 | |
6bf024e6 JW |
988 | Currently, CFQ IO scheduler uses it to recognize task groups and |
989 | control disk bandwidth allocation (proportional time slice allocation) | |
990 | to such task groups. It is also used by bio throttling logic in | |
991 | block layer to implement upper limit in IO rates on a device. | |
e5d1367f | 992 | |
6bf024e6 JW |
993 | This option only enables generic Block IO controller infrastructure. |
994 | One needs to also enable actual IO controlling logic/policy. For | |
995 | enabling proportional weight division of disk bandwidth in CFQ, set | |
7baf2199 | 996 | CONFIG_BFQ_GROUP_IOSCHED=y; for enabling throttling policy, set |
6bf024e6 JW |
997 | CONFIG_BLK_DEV_THROTTLING=y. |
998 | ||
da82c92f | 999 | See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information. |
6bf024e6 | 1000 | |
6bf024e6 JW |
1001 | config CGROUP_WRITEBACK |
1002 | bool | |
1003 | depends on MEMCG && BLK_CGROUP | |
1004 | default y | |
e5d1367f | 1005 | |
7c941438 | 1006 | menuconfig CGROUP_SCHED |
a0166ec4 | 1007 | bool "CPU controller" |
7c941438 DG |
1008 | default n |
1009 | help | |
1010 | This feature lets CPU scheduler recognize task groups and control CPU | |
1011 | bandwidth allocation to such task groups. It uses cgroups to group | |
1012 | tasks. | |
1013 | ||
1014 | if CGROUP_SCHED | |
1015 | config FAIR_GROUP_SCHED | |
1016 | bool "Group scheduling for SCHED_OTHER" | |
1017 | depends on CGROUP_SCHED | |
1018 | default CGROUP_SCHED | |
1019 | ||
ab84d31e PT |
1020 | config CFS_BANDWIDTH |
1021 | bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED" | |
ab84d31e PT |
1022 | depends on FAIR_GROUP_SCHED |
1023 | default n | |
1024 | help | |
1025 | This option allows users to define CPU bandwidth rates (limits) for | |
1026 | tasks running within the fair group scheduler. Groups with no limit | |
1027 | set are considered to be unconstrained and will run with no | |
1028 | restriction. | |
d6a3b247 | 1029 | See Documentation/scheduler/sched-bwc.rst for more information. |
ab84d31e | 1030 | |
7c941438 DG |
1031 | config RT_GROUP_SCHED |
1032 | bool "Group scheduling for SCHED_RR/FIFO" | |
7c941438 DG |
1033 | depends on CGROUP_SCHED |
1034 | default n | |
1035 | help | |
1036 | This feature lets you explicitly allocate real CPU bandwidth | |
32bd7eb5 | 1037 | to task groups. If enabled, it will also make it impossible to |
7c941438 DG |
1038 | schedule realtime tasks for non-root users until you allocate |
1039 | realtime bandwidth for them. | |
d6a3b247 | 1040 | See Documentation/scheduler/sched-rt-group.rst for more information. |
7c941438 DG |
1041 | |
1042 | endif #CGROUP_SCHED | |
1043 | ||
2480c093 PB |
1044 | config UCLAMP_TASK_GROUP |
1045 | bool "Utilization clamping per group of tasks" | |
1046 | depends on CGROUP_SCHED | |
1047 | depends on UCLAMP_TASK | |
1048 | default n | |
1049 | help | |
1050 | This feature enables the scheduler to track the clamped utilization | |
1051 | of each CPU based on RUNNABLE tasks currently scheduled on that CPU. | |
1052 | ||
1053 | When this option is enabled, the user can specify a min and max | |
1054 | CPU bandwidth which is allowed for each single task in a group. | |
1055 | The max bandwidth allows to clamp the maximum frequency a task | |
1056 | can use, while the min bandwidth allows to define a minimum | |
1057 | frequency a task will always use. | |
1058 | ||
1059 | When task group based utilization clamping is enabled, an eventually | |
1060 | specified task-specific clamp value is constrained by the cgroup | |
1061 | specified clamp value. Both minimum and maximum task clamping cannot | |
1062 | be bigger than the corresponding clamping defined at task group level. | |
1063 | ||
1064 | If in doubt, say N. | |
1065 | ||
6bf024e6 JW |
1066 | config CGROUP_PIDS |
1067 | bool "PIDs controller" | |
1068 | help | |
1069 | Provides enforcement of process number limits in the scope of a | |
1070 | cgroup. Any attempt to fork more processes than is allowed in the | |
1071 | cgroup will fail. PIDs are fundamentally a global resource because it | |
1072 | is fairly trivial to reach PID exhaustion before you reach even a | |
1073 | conservative kmemcg limit. As a result, it is possible to grind a | |
1074 | system to halt without being limited by other cgroup policies. The | |
6cc578df | 1075 | PIDs controller is designed to stop this from happening. |
6bf024e6 JW |
1076 | |
1077 | It should be noted that organisational operations (such as attaching | |
98076833 | 1078 | to a cgroup hierarchy) will *not* be blocked by the PIDs controller, |
6bf024e6 JW |
1079 | since the PIDs limit only affects a process's ability to fork, not to |
1080 | attach to a cgroup. | |
1081 | ||
39d3e758 PP |
1082 | config CGROUP_RDMA |
1083 | bool "RDMA controller" | |
1084 | help | |
1085 | Provides enforcement of RDMA resources defined by IB stack. | |
1086 | It is fairly easy for consumers to exhaust RDMA resources, which | |
1087 | can result into resource unavailability to other consumers. | |
1088 | RDMA controller is designed to stop this from happening. | |
1089 | Attaching processes with active RDMA resources to the cgroup | |
1090 | hierarchy is allowed even if can cross the hierarchy's limit. | |
1091 | ||
6bf024e6 JW |
1092 | config CGROUP_FREEZER |
1093 | bool "Freezer controller" | |
1094 | help | |
1095 | Provides a way to freeze and unfreeze all tasks in a | |
1096 | cgroup. | |
1097 | ||
489c2a20 JW |
1098 | This option affects the ORIGINAL cgroup interface. The cgroup2 memory |
1099 | controller includes important in-kernel memory consumers per default. | |
1100 | ||
1101 | If you're using cgroup2, say N. | |
1102 | ||
6bf024e6 JW |
1103 | config CGROUP_HUGETLB |
1104 | bool "HugeTLB controller" | |
1105 | depends on HUGETLB_PAGE | |
1106 | select PAGE_COUNTER | |
afc24d49 | 1107 | default n |
6bf024e6 JW |
1108 | help |
1109 | Provides a cgroup controller for HugeTLB pages. | |
1110 | When you enable this, you can put a per cgroup limit on HugeTLB usage. | |
1111 | The limit is enforced during page fault. Since HugeTLB doesn't | |
1112 | support page reclaim, enforcing the limit at page fault time implies | |
1113 | that, the application will get SIGBUS signal if it tries to access | |
1114 | HugeTLB pages beyond its limit. This requires the application to know | |
1115 | beforehand how much HugeTLB pages it would require for its use. The | |
1116 | control group is tracked in the third page lru pointer. This means | |
1117 | that we cannot use the controller with huge page less than 3 pages. | |
afc24d49 | 1118 | |
6bf024e6 JW |
1119 | config CPUSETS |
1120 | bool "Cpuset controller" | |
e1d4eeec | 1121 | depends on SMP |
6bf024e6 JW |
1122 | help |
1123 | This option will let you create and manage CPUSETs which | |
1124 | allow dynamically partitioning a system into sets of CPUs and | |
1125 | Memory Nodes and assigning tasks to run only within those sets. | |
1126 | This is primarily useful on large SMP or NUMA systems. | |
afc24d49 | 1127 | |
6bf024e6 | 1128 | Say N if unsure. |
afc24d49 | 1129 | |
6bf024e6 JW |
1130 | config PROC_PID_CPUSET |
1131 | bool "Include legacy /proc/<pid>/cpuset file" | |
1132 | depends on CPUSETS | |
1133 | default y | |
afc24d49 | 1134 | |
6bf024e6 JW |
1135 | config CGROUP_DEVICE |
1136 | bool "Device controller" | |
1137 | help | |
1138 | Provides a cgroup controller implementing whitelists for | |
1139 | devices which a process in the cgroup can mknod or open. | |
1140 | ||
1141 | config CGROUP_CPUACCT | |
1142 | bool "Simple CPU accounting controller" | |
1143 | help | |
1144 | Provides a simple controller for monitoring the | |
1145 | total CPU consumed by the tasks in a cgroup. | |
1146 | ||
1147 | config CGROUP_PERF | |
1148 | bool "Perf controller" | |
1149 | depends on PERF_EVENTS | |
1150 | help | |
1151 | This option extends the perf per-cpu mode to restrict monitoring | |
1152 | to threads which belong to the cgroup specified and run on the | |
6546b19f NK |
1153 | designated cpu. Or this can be used to have cgroup ID in samples |
1154 | so that it can monitor performance events among cgroups. | |
6bf024e6 JW |
1155 | |
1156 | Say N if unsure. | |
1157 | ||
30070984 DM |
1158 | config CGROUP_BPF |
1159 | bool "Support for eBPF programs attached to cgroups" | |
483c4933 AL |
1160 | depends on BPF_SYSCALL |
1161 | select SOCK_CGROUP_DATA | |
30070984 DM |
1162 | help |
1163 | Allow attaching eBPF programs to a cgroup using the bpf(2) | |
1164 | syscall command BPF_PROG_ATTACH. | |
1165 | ||
1166 | In which context these programs are accessed depends on the type | |
1167 | of attachment. For instance, programs that are attached using | |
1168 | BPF_CGROUP_INET_INGRESS will be executed on the ingress path of | |
1169 | inet sockets. | |
1170 | ||
a72232ea VS |
1171 | config CGROUP_MISC |
1172 | bool "Misc resource controller" | |
1173 | default n | |
1174 | help | |
1175 | Provides a controller for miscellaneous resources on a host. | |
1176 | ||
1177 | Miscellaneous scalar resources are the resources on the host system | |
1178 | which cannot be abstracted like the other cgroups. This controller | |
1179 | tracks and limits the miscellaneous resources used by a process | |
1180 | attached to a cgroup hierarchy. | |
1181 | ||
1182 | For more information, please check misc cgroup section in | |
1183 | /Documentation/admin-guide/cgroup-v2.rst. | |
1184 | ||
6bf024e6 | 1185 | config CGROUP_DEBUG |
23b0be48 | 1186 | bool "Debug controller" |
afc24d49 | 1187 | default n |
23b0be48 | 1188 | depends on DEBUG_KERNEL |
6bf024e6 JW |
1189 | help |
1190 | This option enables a simple controller that exports | |
23b0be48 WL |
1191 | debugging information about the cgroups framework. This |
1192 | controller is for control cgroup debugging only. Its | |
1193 | interfaces are not stable. | |
afc24d49 | 1194 | |
6bf024e6 | 1195 | Say N. |
89e9b9e0 | 1196 | |
73b35147 AB |
1197 | config SOCK_CGROUP_DATA |
1198 | bool | |
1199 | default n | |
1200 | ||
23964d2d | 1201 | endif # CGROUPS |
c077719b | 1202 | |
8dd2a82c | 1203 | menuconfig NAMESPACES |
6a108a14 | 1204 | bool "Namespaces support" if EXPERT |
2813893f | 1205 | depends on MULTIUSER |
6a108a14 | 1206 | default !EXPERT |
c5289a69 PE |
1207 | help |
1208 | Provides the way to make tasks work with different objects using | |
1209 | the same id. For example same IPC id may refer to different objects | |
1210 | or same user id or pid may refer to different tasks when used in | |
1211 | different namespaces. | |
1212 | ||
8dd2a82c DL |
1213 | if NAMESPACES |
1214 | ||
58bfdd6d PE |
1215 | config UTS_NS |
1216 | bool "UTS namespace" | |
17a6d441 | 1217 | default y |
58bfdd6d PE |
1218 | help |
1219 | In this namespace tasks see different info provided with the | |
1220 | uname() system call | |
1221 | ||
769071ac AV |
1222 | config TIME_NS |
1223 | bool "TIME namespace" | |
660fd04f | 1224 | depends on GENERIC_VDSO_TIME_NS |
769071ac AV |
1225 | default y |
1226 | help | |
1227 | In this namespace boottime and monotonic clocks can be set. | |
1228 | The time will keep going with the same pace. | |
1229 | ||
ae5e1b22 PE |
1230 | config IPC_NS |
1231 | bool "IPC namespace" | |
8dd2a82c | 1232 | depends on (SYSVIPC || POSIX_MQUEUE) |
17a6d441 | 1233 | default y |
ae5e1b22 PE |
1234 | help |
1235 | In this namespace tasks work with IPC ids which correspond to | |
614b84cf | 1236 | different IPC objects in different namespaces. |
ae5e1b22 | 1237 | |
aee16ce7 | 1238 | config USER_NS |
19c92399 | 1239 | bool "User namespace" |
5673a94c | 1240 | default n |
aee16ce7 PE |
1241 | help |
1242 | This allows containers, i.e. vservers, to use user namespaces | |
1243 | to provide different user info for different servers. | |
e11f0ae3 EB |
1244 | |
1245 | When user namespaces are enabled in the kernel it is | |
d886f4e4 JW |
1246 | recommended that the MEMCG option also be enabled and that |
1247 | user-space use the memory control groups to limit the amount | |
1248 | of memory a memory unprivileged users can use. | |
e11f0ae3 | 1249 | |
aee16ce7 PE |
1250 | If unsure, say N. |
1251 | ||
74bd59bb | 1252 | config PID_NS |
9bd38c2c | 1253 | bool "PID Namespaces" |
17a6d441 | 1254 | default y |
74bd59bb | 1255 | help |
12d2b8f9 | 1256 | Support process id namespaces. This allows having multiple |
692105b8 | 1257 | processes with the same pid as long as they are in different |
74bd59bb PE |
1258 | pid namespaces. This is a building block of containers. |
1259 | ||
d6eb633f MH |
1260 | config NET_NS |
1261 | bool "Network namespace" | |
8dd2a82c | 1262 | depends on NET |
17a6d441 | 1263 | default y |
d6eb633f MH |
1264 | help |
1265 | Allow user space to create what appear to be multiple instances | |
1266 | of the network stack. | |
1267 | ||
8dd2a82c DL |
1268 | endif # NAMESPACES |
1269 | ||
5cb366bb AR |
1270 | config CHECKPOINT_RESTORE |
1271 | bool "Checkpoint/restore support" | |
30341ec9 | 1272 | depends on PROC_FS |
5cb366bb | 1273 | select PROC_CHILDREN |
bfe3911a | 1274 | select KCMP |
5cb366bb AR |
1275 | default n |
1276 | help | |
1277 | Enables additional kernel features in a sake of checkpoint/restore. | |
1278 | In particular it adds auxiliary prctl codes to setup process text, | |
1279 | data and heap segment sizes, and a few additional /proc filesystem | |
1280 | entries. | |
1281 | ||
1282 | If unsure, say N here. | |
1283 | ||
5091faa4 MG |
1284 | config SCHED_AUTOGROUP |
1285 | bool "Automatic process group scheduling" | |
5091faa4 MG |
1286 | select CGROUPS |
1287 | select CGROUP_SCHED | |
1288 | select FAIR_GROUP_SCHED | |
1289 | help | |
1290 | This option optimizes the scheduler for common desktop workloads by | |
1291 | automatically creating and populating task groups. This separation | |
1292 | of workloads isolates aggressive CPU burners (like build jobs) from | |
1293 | desktop applications. Task group autogeneration is currently based | |
1294 | upon task session. | |
1295 | ||
7af37bec | 1296 | config SYSFS_DEPRECATED |
5d6a4ea5 | 1297 | bool "Enable deprecated sysfs features to support old userspace tools" |
7af37bec DL |
1298 | depends on SYSFS |
1299 | default n | |
1300 | help | |
1301 | This option adds code that switches the layout of the "block" class | |
1302 | devices, to not show up in /sys/class/block/, but only in | |
1303 | /sys/block/. | |
1304 | ||
1305 | This switch is only active when the sysfs.deprecated=1 boot option is | |
1306 | passed or the SYSFS_DEPRECATED_V2 option is set. | |
1307 | ||
1308 | This option allows new kernels to run on old distributions and tools, | |
1309 | which might get confused by /sys/class/block/. Since 2007/2008 all | |
1310 | major distributions and tools handle this just fine. | |
1311 | ||
1312 | Recent distributions and userspace tools after 2009/2010 depend on | |
1313 | the existence of /sys/class/block/, and will not work with this | |
1314 | option enabled. | |
1315 | ||
1316 | Only if you are using a new kernel on an old distribution, you might | |
1317 | need to say Y here. | |
1318 | ||
1319 | config SYSFS_DEPRECATED_V2 | |
5d6a4ea5 | 1320 | bool "Enable deprecated sysfs features by default" |
7af37bec DL |
1321 | default n |
1322 | depends on SYSFS | |
1323 | depends on SYSFS_DEPRECATED | |
1324 | help | |
1325 | Enable deprecated sysfs by default. | |
1326 | ||
1327 | See the CONFIG_SYSFS_DEPRECATED option for more details about this | |
1328 | option. | |
1329 | ||
1330 | Only if you are using a new kernel on an old distribution, you might | |
1331 | need to say Y here. Even then, odds are you would not need it | |
1332 | enabled, you can always pass the boot option if absolutely necessary. | |
1333 | ||
1334 | config RELAY | |
1335 | bool "Kernel->user space relay support (formerly relayfs)" | |
26b5679e | 1336 | select IRQ_WORK |
7af37bec DL |
1337 | help |
1338 | This option enables support for relay interface support in | |
1339 | certain file systems (such as debugfs). | |
1340 | It is designed to provide an efficient mechanism for tools and | |
1341 | facilities to relay large amounts of data from kernel space to | |
1342 | user space. | |
1343 | ||
1344 | If unsure, say N. | |
1345 | ||
f991633d DG |
1346 | config BLK_DEV_INITRD |
1347 | bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support" | |
f991633d DG |
1348 | help |
1349 | The initial RAM filesystem is a ramfs which is loaded by the | |
1350 | boot loader (loadlin or lilo) and that is mounted as root | |
1351 | before the normal boot procedure. It is typically used to | |
1352 | load modules needed to mount the "real" root file system, | |
8c27ceff | 1353 | etc. See <file:Documentation/admin-guide/initrd.rst> for details. |
f991633d DG |
1354 | |
1355 | If RAM disk support (BLK_DEV_RAM) is also included, this | |
1356 | also enables initial RAM disk (initrd) support and adds | |
1357 | 15 Kbytes (more on some other architectures) to the kernel size. | |
1358 | ||
1359 | If unsure say Y. | |
1360 | ||
c33df4ea JPS |
1361 | if BLK_DEV_INITRD |
1362 | ||
dbec4866 SR |
1363 | source "usr/Kconfig" |
1364 | ||
c33df4ea JPS |
1365 | endif |
1366 | ||
76db5a27 MH |
1367 | config BOOT_CONFIG |
1368 | bool "Boot config support" | |
a2a9d67a | 1369 | select BLK_DEV_INITRD if !BOOT_CONFIG_EMBED |
76db5a27 MH |
1370 | help |
1371 | Extra boot config allows system admin to pass a config file as | |
1372 | complemental extension of kernel cmdline when booting. | |
0947db01 | 1373 | The boot config file must be attached at the end of initramfs |
85c46b78 | 1374 | with checksum, size and magic word. |
0947db01 | 1375 | See <file:Documentation/admin-guide/bootconfig.rst> for details. |
76db5a27 MH |
1376 | |
1377 | If unsure, say Y. | |
1378 | ||
a2a9d67a MH |
1379 | config BOOT_CONFIG_EMBED |
1380 | bool "Embed bootconfig file in the kernel" | |
1381 | depends on BOOT_CONFIG | |
1382 | help | |
1383 | Embed a bootconfig file given by BOOT_CONFIG_EMBED_FILE in the | |
1384 | kernel. Usually, the bootconfig file is loaded with the initrd | |
1385 | image. But if the system doesn't support initrd, this option will | |
1386 | help you by embedding a bootconfig file while building the kernel. | |
1387 | ||
1388 | If unsure, say N. | |
1389 | ||
1390 | config BOOT_CONFIG_EMBED_FILE | |
1391 | string "Embedded bootconfig file path" | |
1392 | depends on BOOT_CONFIG_EMBED | |
1393 | help | |
1394 | Specify a bootconfig file which will be embedded to the kernel. | |
1395 | This bootconfig will be used if there is no initrd or no other | |
1396 | bootconfig in the initrd. | |
1397 | ||
1274aea1 DD |
1398 | config INITRAMFS_PRESERVE_MTIME |
1399 | bool "Preserve cpio archive mtimes in initramfs" | |
1400 | default y | |
1401 | help | |
1402 | Each entry in an initramfs cpio archive carries an mtime value. When | |
1403 | enabled, extracted cpio items take this mtime, with directory mtime | |
1404 | setting deferred until after creation of any child entries. | |
1405 | ||
1406 | If unsure, say Y. | |
76db5a27 | 1407 | |
877417e6 AB |
1408 | choice |
1409 | prompt "Compiler optimization level" | |
2cc3ce24 | 1410 | default CC_OPTIMIZE_FOR_PERFORMANCE |
877417e6 AB |
1411 | |
1412 | config CC_OPTIMIZE_FOR_PERFORMANCE | |
15f5db60 | 1413 | bool "Optimize for performance (-O2)" |
877417e6 AB |
1414 | help |
1415 | This is the default optimization level for the kernel, building | |
1416 | with the "-O2" compiler flag for best performance and most | |
1417 | helpful compile-time warnings. | |
1418 | ||
c45b4f1f | 1419 | config CC_OPTIMIZE_FOR_SIZE |
15f5db60 | 1420 | bool "Optimize for size (-Os)" |
c45b4f1f | 1421 | help |
ce3b487f MY |
1422 | Choosing this option will pass "-Os" to your compiler resulting |
1423 | in a smaller kernel. | |
c45b4f1f | 1424 | |
877417e6 AB |
1425 | endchoice |
1426 | ||
5d20ee31 NP |
1427 | config HAVE_LD_DEAD_CODE_DATA_ELIMINATION |
1428 | bool | |
1429 | help | |
1430 | This requires that the arch annotates or otherwise protects | |
1431 | its external entry points from being discarded. Linker scripts | |
1432 | must also merge .text.*, .data.*, and .bss.* correctly into | |
1433 | output sections. Care must be taken not to pull in unrelated | |
1434 | sections (e.g., '.text.init'). Typically '.' in section names | |
1435 | is used to distinguish them from label names / C identifiers. | |
1436 | ||
1437 | config LD_DEAD_CODE_DATA_ELIMINATION | |
1438 | bool "Dead code and data elimination (EXPERIMENTAL)" | |
1439 | depends on HAVE_LD_DEAD_CODE_DATA_ELIMINATION | |
1440 | depends on EXPERT | |
e85d1d65 MY |
1441 | depends on $(cc-option,-ffunction-sections -fdata-sections) |
1442 | depends on $(ld-option,--gc-sections) | |
5d20ee31 | 1443 | help |
8b9d2712 MY |
1444 | Enable this if you want to do dead code and data elimination with |
1445 | the linker by compiling with -ffunction-sections -fdata-sections, | |
1446 | and linking with --gc-sections. | |
5d20ee31 NP |
1447 | |
1448 | This can reduce on disk and in-memory size of the kernel | |
1449 | code and static data, particularly for small configs and | |
1450 | on small systems. This has the possibility of introducing | |
1451 | silently broken kernel if the required annotations are not | |
1452 | present. This option is not well tested yet, so use at your | |
1453 | own risk. | |
1454 | ||
59612b24 NC |
1455 | config LD_ORPHAN_WARN |
1456 | def_bool y | |
1457 | depends on ARCH_WANT_LD_ORPHAN_WARN | |
1458 | depends on $(ld-option,--orphan-handling=warn) | |
e1789d7c XL |
1459 | depends on $(ld-option,--orphan-handling=error) |
1460 | ||
1461 | config LD_ORPHAN_WARN_LEVEL | |
1462 | string | |
1463 | depends on LD_ORPHAN_WARN | |
1464 | default "error" if WERROR | |
1465 | default "warn" | |
59612b24 | 1466 | |
0847062a RD |
1467 | config SYSCTL |
1468 | bool | |
1469 | ||
657a5209 MF |
1470 | config HAVE_UID16 |
1471 | bool | |
1472 | ||
1473 | config SYSCTL_EXCEPTION_TRACE | |
1474 | bool | |
1475 | help | |
1476 | Enable support for /proc/sys/debug/exception-trace. | |
1477 | ||
1478 | config SYSCTL_ARCH_UNALIGN_NO_WARN | |
1479 | bool | |
1480 | help | |
1481 | Enable support for /proc/sys/kernel/ignore-unaligned-usertrap | |
1482 | Allows arch to define/use @no_unaligned_warning to possibly warn | |
1483 | about unaligned access emulation going on under the hood. | |
1484 | ||
1485 | config SYSCTL_ARCH_UNALIGN_ALLOW | |
1486 | bool | |
1487 | help | |
1488 | Enable support for /proc/sys/kernel/unaligned-trap | |
1489 | Allows arches to define/use @unaligned_enabled to runtime toggle | |
1490 | the unaligned access emulation. | |
1491 | see arch/parisc/kernel/unaligned.c for reference | |
1492 | ||
657a5209 MF |
1493 | config HAVE_PCSPKR_PLATFORM |
1494 | bool | |
1495 | ||
f89b7755 AS |
1496 | # interpreter that classic socket filters depend on |
1497 | config BPF | |
1498 | bool | |
ec8f7f48 | 1499 | select CRYPTO_LIB_SHA1 |
f89b7755 | 1500 | |
6a108a14 DR |
1501 | menuconfig EXPERT |
1502 | bool "Configure standard kernel features (expert users)" | |
f505c553 JT |
1503 | # Unhide debug options, to make the on-by-default options visible |
1504 | select DEBUG_KERNEL | |
1da177e4 LT |
1505 | help |
1506 | This option allows certain base kernel options and settings | |
e8cf4e9c KK |
1507 | to be disabled or tweaked. This is for specialized |
1508 | environments which can tolerate a "non-standard" kernel. | |
1509 | Only use this if you really know what you are doing. | |
1da177e4 | 1510 | |
ae81f9e3 | 1511 | config UID16 |
6a108a14 | 1512 | bool "Enable 16-bit UID system calls" if EXPERT |
2813893f | 1513 | depends on HAVE_UID16 && MULTIUSER |
ae81f9e3 CE |
1514 | default y |
1515 | help | |
1516 | This enables the legacy 16-bit UID syscall wrappers. | |
1517 | ||
2813893f IM |
1518 | config MULTIUSER |
1519 | bool "Multiple users, groups and capabilities support" if EXPERT | |
1520 | default y | |
1521 | help | |
1522 | This option enables support for non-root users, groups and | |
1523 | capabilities. | |
1524 | ||
1525 | If you say N here, all processes will run with UID 0, GID 0, and all | |
1526 | possible capabilities. Saying N here also compiles out support for | |
1527 | system calls related to UIDs, GIDs, and capabilities, such as setuid, | |
1528 | setgid, and capset. | |
1529 | ||
1530 | If unsure, say Y here. | |
1531 | ||
f6187769 FF |
1532 | config SGETMASK_SYSCALL |
1533 | bool "sgetmask/ssetmask syscalls support" if EXPERT | |
a687a533 | 1534 | def_bool PARISC || M68K || PPC || MIPS || X86 || SPARC || MICROBLAZE || SUPERH |
a7f7f624 | 1535 | help |
f6187769 FF |
1536 | sys_sgetmask and sys_ssetmask are obsolete system calls |
1537 | no longer supported in libc but still enabled by default in some | |
1538 | architectures. | |
1539 | ||
1540 | If unsure, leave the default option here. | |
1541 | ||
6af9f7bf FF |
1542 | config SYSFS_SYSCALL |
1543 | bool "Sysfs syscall support" if EXPERT | |
1544 | default y | |
a7f7f624 | 1545 | help |
6af9f7bf FF |
1546 | sys_sysfs is an obsolete system call no longer supported in libc. |
1547 | Note that disabling this option is more secure but might break | |
1548 | compatibility with some systems. | |
1549 | ||
1550 | If unsure say Y here. | |
1551 | ||
d1b069f5 RD |
1552 | config FHANDLE |
1553 | bool "open by fhandle syscalls" if EXPERT | |
1554 | select EXPORTFS | |
1555 | default y | |
1556 | help | |
1557 | If you say Y here, a user level program will be able to map | |
1558 | file names to handle and then later use the handle for | |
1559 | different file system operations. This is useful in implementing | |
1560 | userspace file servers, which now track files using handles instead | |
1561 | of names. The handle would remain the same even if file names | |
1562 | get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2) | |
1563 | syscalls. | |
1564 | ||
baa73d9e NP |
1565 | config POSIX_TIMERS |
1566 | bool "Posix Clocks & timers" if EXPERT | |
1567 | default y | |
1568 | help | |
1569 | This includes native support for POSIX timers to the kernel. | |
1570 | Some embedded systems have no use for them and therefore they | |
1571 | can be configured out to reduce the size of the kernel image. | |
1572 | ||
1573 | When this option is disabled, the following syscalls won't be | |
1574 | available: timer_create, timer_gettime: timer_getoverrun, | |
1575 | timer_settime, timer_delete, clock_adjtime, getitimer, | |
1576 | setitimer, alarm. Furthermore, the clock_settime, clock_gettime, | |
1577 | clock_getres and clock_nanosleep syscalls will be limited to | |
1578 | CLOCK_REALTIME, CLOCK_MONOTONIC and CLOCK_BOOTTIME only. | |
1579 | ||
1580 | If unsure say y. | |
1581 | ||
d59745ce MM |
1582 | config PRINTK |
1583 | default y | |
6a108a14 | 1584 | bool "Enable support for printk" if EXPERT |
74876a98 | 1585 | select IRQ_WORK |
d59745ce MM |
1586 | help |
1587 | This option enables normal printk support. Removing it | |
1588 | eliminates most of the message strings from the kernel image | |
1589 | and makes the kernel more or less silent. As this makes it | |
1590 | very difficult to diagnose system problems, saying N here is | |
1591 | strongly discouraged. | |
1592 | ||
c8538a7a | 1593 | config BUG |
6a108a14 | 1594 | bool "BUG() support" if EXPERT |
c8538a7a MM |
1595 | default y |
1596 | help | |
e8cf4e9c KK |
1597 | Disabling this option eliminates support for BUG and WARN, reducing |
1598 | the size of your kernel image and potentially quietly ignoring | |
1599 | numerous fatal conditions. You should only consider disabling this | |
1600 | option for embedded systems with no facilities for reporting errors. | |
1601 | Just say Y. | |
c8538a7a | 1602 | |
708e9a79 | 1603 | config ELF_CORE |
046d662f | 1604 | depends on COREDUMP |
708e9a79 | 1605 | default y |
6a108a14 | 1606 | bool "Enable ELF core dumps" if EXPERT |
708e9a79 MM |
1607 | help |
1608 | Enable support for generating core dumps. Disabling saves about 4k. | |
1609 | ||
8761f1ab | 1610 | |
e5e1d3cb | 1611 | config PCSPKR_PLATFORM |
6a108a14 | 1612 | bool "Enable PC-Speaker support" if EXPERT |
8761f1ab | 1613 | depends on HAVE_PCSPKR_PLATFORM |
15f304b6 | 1614 | select I8253_LOCK |
e5e1d3cb SS |
1615 | default y |
1616 | help | |
e8cf4e9c KK |
1617 | This option allows to disable the internal PC-Speaker |
1618 | support, saving some memory. | |
e5e1d3cb | 1619 | |
1da177e4 LT |
1620 | config BASE_FULL |
1621 | default y | |
6a108a14 | 1622 | bool "Enable full-sized data structures for core" if EXPERT |
1da177e4 LT |
1623 | help |
1624 | Disabling this option reduces the size of miscellaneous core | |
1625 | kernel data structures. This saves memory on small machines, | |
1626 | but may reduce performance. | |
1627 | ||
1628 | config FUTEX | |
6a108a14 | 1629 | bool "Enable futex support" if EXPERT |
3f2bedab | 1630 | depends on !(SPARC32 && SMP) |
1da177e4 | 1631 | default y |
bc2eecd7 | 1632 | imply RT_MUTEXES |
1da177e4 LT |
1633 | help |
1634 | Disabling this option will cause the kernel to be built without | |
1635 | support for "fast userspace mutexes". The resulting kernel may not | |
1636 | run glibc-based applications correctly. | |
1637 | ||
bc2eecd7 NP |
1638 | config FUTEX_PI |
1639 | bool | |
1640 | depends on FUTEX && RT_MUTEXES | |
1641 | default y | |
1642 | ||
1da177e4 | 1643 | config EPOLL |
6a108a14 | 1644 | bool "Enable eventpoll support" if EXPERT |
1da177e4 LT |
1645 | default y |
1646 | help | |
1647 | Disabling this option will cause the kernel to be built without | |
1648 | support for epoll family of system calls. | |
1649 | ||
fba2afaa | 1650 | config SIGNALFD |
6a108a14 | 1651 | bool "Enable signalfd() system call" if EXPERT |
fba2afaa DL |
1652 | default y |
1653 | help | |
1654 | Enable the signalfd() system call that allows to receive signals | |
1655 | on a file descriptor. | |
1656 | ||
1657 | If unsure, say Y. | |
1658 | ||
b215e283 | 1659 | config TIMERFD |
6a108a14 | 1660 | bool "Enable timerfd() system call" if EXPERT |
b215e283 DL |
1661 | default y |
1662 | help | |
1663 | Enable the timerfd() system call that allows to receive timer | |
1664 | events on a file descriptor. | |
1665 | ||
1666 | If unsure, say Y. | |
1667 | ||
e1ad7468 | 1668 | config EVENTFD |
6a108a14 | 1669 | bool "Enable eventfd() system call" if EXPERT |
e1ad7468 DL |
1670 | default y |
1671 | help | |
1672 | Enable the eventfd() system call that allows to receive both | |
1673 | kernel notification (ie. KAIO) or userspace notifications. | |
1674 | ||
1675 | If unsure, say Y. | |
1676 | ||
1da177e4 | 1677 | config SHMEM |
6a108a14 | 1678 | bool "Use full shmem filesystem" if EXPERT |
1da177e4 LT |
1679 | default y |
1680 | depends on MMU | |
1681 | help | |
1682 | The shmem is an internal filesystem used to manage shared memory. | |
1683 | It is backed by swap and manages resource limits. It is also exported | |
1684 | to userspace as tmpfs if TMPFS is enabled. Disabling this | |
1685 | option replaces shmem and tmpfs with the much simpler ramfs code, | |
1686 | which may be appropriate on small systems without swap. | |
1687 | ||
ebf3f09c | 1688 | config AIO |
6a108a14 | 1689 | bool "Enable AIO support" if EXPERT |
ebf3f09c TP |
1690 | default y |
1691 | help | |
1692 | This option enables POSIX asynchronous I/O which may by used | |
657a5209 MF |
1693 | by some high performance threaded applications. Disabling |
1694 | this option saves about 7k. | |
1695 | ||
2b188cc1 JA |
1696 | config IO_URING |
1697 | bool "Enable IO uring support" if EXPERT | |
561fb04a | 1698 | select IO_WQ |
2b188cc1 JA |
1699 | default y |
1700 | help | |
1701 | This option enables support for the io_uring interface, enabling | |
1702 | applications to submit and complete IO through submission and | |
1703 | completion rings that are shared between the kernel and application. | |
1704 | ||
d3ac21ca JT |
1705 | config ADVISE_SYSCALLS |
1706 | bool "Enable madvise/fadvise syscalls" if EXPERT | |
1707 | default y | |
1708 | help | |
1709 | This option enables the madvise and fadvise syscalls, used by | |
1710 | applications to advise the kernel about their future memory or file | |
1711 | usage, improving performance. If building an embedded system where no | |
1712 | applications use these syscalls, you can disable this option to save | |
1713 | space. | |
1714 | ||
5b25b13a MD |
1715 | config MEMBARRIER |
1716 | bool "Enable membarrier() system call" if EXPERT | |
1717 | default y | |
1718 | help | |
1719 | Enable the membarrier() system call that allows issuing memory | |
1720 | barriers across all running threads, which can be used to distribute | |
1721 | the cost of user-space memory barriers asymmetrically by transforming | |
1722 | pairs of memory barriers into pairs consisting of membarrier() and a | |
1723 | compiler barrier. | |
1724 | ||
1725 | If unsure, say Y. | |
1726 | ||
d1b069f5 | 1727 | config KALLSYMS |
e8cf4e9c KK |
1728 | bool "Load all symbols for debugging/ksymoops" if EXPERT |
1729 | default y | |
1730 | help | |
1731 | Say Y here to let the kernel print out symbolic crash information and | |
1732 | symbolic stack backtraces. This increases the size of the kernel | |
1733 | somewhat, as all symbols have to be loaded into the kernel image. | |
d1b069f5 | 1734 | |
30f3bb09 ZL |
1735 | config KALLSYMS_SELFTEST |
1736 | bool "Test the basic functions and performance of kallsyms" | |
1737 | depends on KALLSYMS | |
1738 | default n | |
1739 | help | |
1740 | Test the basic functions and performance of some interfaces, such as | |
1741 | kallsyms_lookup_name. It also calculates the compression rate of the | |
1742 | kallsyms compression algorithm for the current symbol set. | |
1743 | ||
1744 | Start self-test automatically after system startup. Suggest executing | |
1745 | "dmesg | grep kallsyms_selftest" to collect test results. "finish" is | |
1746 | displayed in the last line, indicating that the test is complete. | |
1747 | ||
d1b069f5 RD |
1748 | config KALLSYMS_ALL |
1749 | bool "Include all symbols in kallsyms" | |
1750 | depends on DEBUG_KERNEL && KALLSYMS | |
1751 | help | |
e8cf4e9c KK |
1752 | Normally kallsyms only contains the symbols of functions for nicer |
1753 | OOPS messages and backtraces (i.e., symbols from the text and inittext | |
bdf0fe33 BS |
1754 | sections). This is sufficient for most cases. And only if you want to |
1755 | enable kernel live patching, or other less common use cases (e.g., | |
1756 | when a debugger is used) all symbols are required (i.e., names of | |
1757 | variables from the data sections, etc). | |
d1b069f5 | 1758 | |
e8cf4e9c KK |
1759 | This option makes sure that all symbols are loaded into the kernel |
1760 | image (i.e., symbols from all sections) in cost of increased kernel | |
1761 | size (depending on the kernel configuration, it may be 300KiB or | |
1762 | something like this). | |
d1b069f5 | 1763 | |
bdf0fe33 | 1764 | Say N unless you really need all symbols, or kernel live patching. |
d1b069f5 RD |
1765 | |
1766 | config KALLSYMS_ABSOLUTE_PERCPU | |
1767 | bool | |
1768 | depends on KALLSYMS | |
1769 | default X86_64 && SMP | |
1770 | ||
1771 | config KALLSYMS_BASE_RELATIVE | |
1772 | bool | |
1773 | depends on KALLSYMS | |
a687a533 | 1774 | default !IA64 |
d1b069f5 RD |
1775 | help |
1776 | Instead of emitting them as absolute values in the native word size, | |
1777 | emit the symbol references in the kallsyms table as 32-bit entries, | |
1778 | each containing a relative value in the range [base, base + U32_MAX] | |
1779 | or, when KALLSYMS_ABSOLUTE_PERCPU is in effect, each containing either | |
1780 | an absolute value in the range [0, S32_MAX] or a relative value in the | |
1781 | range [base, base + S32_MAX], where base is the lowest relative symbol | |
1782 | address encountered in the image. | |
1783 | ||
1784 | On 64-bit builds, this reduces the size of the address table by 50%, | |
1785 | but more importantly, it results in entries whose values are build | |
1786 | time constants, and no relocation pass is required at runtime to fix | |
1787 | up the entries based on the runtime load address of the kernel. | |
1788 | ||
1789 | # end of the "standard kernel features (expert users)" menu | |
1790 | ||
1791 | # syscall, maps, verifier | |
fc611f47 | 1792 | |
3ccfebed MD |
1793 | config ARCH_HAS_MEMBARRIER_CALLBACKS |
1794 | bool | |
1795 | ||
70216e18 MD |
1796 | config ARCH_HAS_MEMBARRIER_SYNC_CORE |
1797 | bool | |
1798 | ||
bfe3911a CW |
1799 | config KCMP |
1800 | bool "Enable kcmp() system call" if EXPERT | |
1801 | help | |
1802 | Enable the kernel resource comparison system call. It provides | |
1803 | user-space with the ability to compare two processes to see if they | |
1804 | share a common resource, such as a file descriptor or even virtual | |
1805 | memory space. | |
1806 | ||
1807 | If unsure, say N. | |
1808 | ||
d7822b1e MD |
1809 | config RSEQ |
1810 | bool "Enable rseq() system call" if EXPERT | |
1811 | default y | |
1812 | depends on HAVE_RSEQ | |
1813 | select MEMBARRIER | |
1814 | help | |
1815 | Enable the restartable sequences system call. It provides a | |
1816 | user-space cache for the current CPU number value, which | |
1817 | speeds up getting the current CPU number from user-space, | |
1818 | as well as an ABI to speed up user-space operations on | |
1819 | per-CPU data. | |
1820 | ||
1821 | If unsure, say Y. | |
1822 | ||
1823 | config DEBUG_RSEQ | |
1824 | default n | |
1825 | bool "Enabled debugging of rseq() system call" if EXPERT | |
1826 | depends on RSEQ && DEBUG_KERNEL | |
1827 | help | |
1828 | Enable extra debugging checks for the rseq system call. | |
1829 | ||
1830 | If unsure, say N. | |
1831 | ||
6befe5f6 RD |
1832 | config EMBEDDED |
1833 | bool "Embedded system" | |
1834 | select EXPERT | |
1835 | help | |
1836 | This option should be enabled if compiling the kernel for | |
1837 | an embedded system so certain expert options are available | |
1838 | for configuration. | |
1839 | ||
cdd6c482 | 1840 | config HAVE_PERF_EVENTS |
0793a61d | 1841 | bool |
018df72d MF |
1842 | help |
1843 | See tools/perf/design.txt for details. | |
0793a61d | 1844 | |
2aef6f30 SC |
1845 | config GUEST_PERF_EVENTS |
1846 | bool | |
1847 | depends on HAVE_PERF_EVENTS | |
1848 | ||
906010b2 PZ |
1849 | config PERF_USE_VMALLOC |
1850 | bool | |
1851 | help | |
1852 | See tools/perf/design.txt for details | |
1853 | ||
ad90a3de | 1854 | config PC104 |
424529fb | 1855 | bool "PC/104 support" if EXPERT |
ad90a3de WBG |
1856 | help |
1857 | Expose PC/104 form factor device drivers and options available for | |
1858 | selection and configuration. Enable this option if your target | |
1859 | machine has a PC/104 bus. | |
1860 | ||
57c0c15b | 1861 | menu "Kernel Performance Events And Counters" |
0793a61d | 1862 | |
cdd6c482 | 1863 | config PERF_EVENTS |
57c0c15b | 1864 | bool "Kernel performance events and counters" |
392d65a9 | 1865 | default y if PROFILING |
cdd6c482 | 1866 | depends on HAVE_PERF_EVENTS |
e360adbe | 1867 | select IRQ_WORK |
83fe27ea | 1868 | select SRCU |
0793a61d | 1869 | help |
57c0c15b IM |
1870 | Enable kernel support for various performance events provided |
1871 | by software and hardware. | |
0793a61d | 1872 | |
dd77038d | 1873 | Software events are supported either built-in or via the |
57c0c15b | 1874 | use of generic tracepoints. |
0793a61d | 1875 | |
57c0c15b IM |
1876 | Most modern CPUs support performance events via performance |
1877 | counter registers. These registers count the number of certain | |
0793a61d TG |
1878 | types of hw events: such as instructions executed, cachemisses |
1879 | suffered, or branches mis-predicted - without slowing down the | |
1880 | kernel or applications. These registers can also trigger interrupts | |
1881 | when a threshold number of events have passed - and can thus be | |
1882 | used to profile the code that runs on that CPU. | |
1883 | ||
57c0c15b | 1884 | The Linux Performance Event subsystem provides an abstraction of |
dd77038d | 1885 | these software and hardware event capabilities, available via a |
57c0c15b | 1886 | system call and used by the "perf" utility in tools/perf/. It |
0793a61d TG |
1887 | provides per task and per CPU counters, and it provides event |
1888 | capabilities on top of those. | |
1889 | ||
1890 | Say Y if unsure. | |
1891 | ||
906010b2 PZ |
1892 | config DEBUG_PERF_USE_VMALLOC |
1893 | default n | |
1894 | bool "Debug: use vmalloc to back perf mmap() buffers" | |
cb307113 | 1895 | depends on PERF_EVENTS && DEBUG_KERNEL && !PPC |
906010b2 PZ |
1896 | select PERF_USE_VMALLOC |
1897 | help | |
e8cf4e9c | 1898 | Use vmalloc memory to back perf mmap() buffers. |
906010b2 | 1899 | |
e8cf4e9c KK |
1900 | Mostly useful for debugging the vmalloc code on platforms |
1901 | that don't require it. | |
906010b2 | 1902 | |
e8cf4e9c | 1903 | Say N if unsure. |
906010b2 | 1904 | |
0793a61d TG |
1905 | endmenu |
1906 | ||
091f6e26 DH |
1907 | config SYSTEM_DATA_VERIFICATION |
1908 | def_bool n | |
1909 | select SYSTEM_TRUSTED_KEYRING | |
1910 | select KEYS | |
1911 | select CRYPTO | |
d43de6c7 | 1912 | select CRYPTO_RSA |
091f6e26 DH |
1913 | select ASYMMETRIC_KEY_TYPE |
1914 | select ASYMMETRIC_PUBLIC_KEY_SUBTYPE | |
091f6e26 DH |
1915 | select ASN1 |
1916 | select OID_REGISTRY | |
1917 | select X509_CERTIFICATE_PARSER | |
1918 | select PKCS7_MESSAGE_PARSER | |
82c04ff8 | 1919 | help |
091f6e26 DH |
1920 | Provide PKCS#7 message verification using the contents of the system |
1921 | trusted keyring to provide public keys. This then can be used for | |
1922 | module verification, kexec image verification and firmware blob | |
1923 | verification. | |
82c04ff8 | 1924 | |
125e5645 | 1925 | config PROFILING |
b309a294 | 1926 | bool "Profiling support" |
125e5645 MD |
1927 | help |
1928 | Say Y here to enable the extended profiling support mechanisms used | |
f8408264 | 1929 | by profilers. |
125e5645 | 1930 | |
2f7ab126 MO |
1931 | config RUST |
1932 | bool "Rust support" | |
1933 | depends on HAVE_RUST | |
1934 | depends on RUST_IS_AVAILABLE | |
1935 | depends on !MODVERSIONS | |
1936 | depends on !GCC_PLUGINS | |
1937 | depends on !RANDSTRUCT | |
1938 | depends on !DEBUG_INFO_BTF | |
1939 | select CONSTRUCTORS | |
1940 | help | |
1941 | Enables Rust support in the kernel. | |
1942 | ||
1943 | This allows other Rust-related options, like drivers written in Rust, | |
1944 | to be selected. | |
1945 | ||
1946 | It is also required to be able to load external kernel modules | |
1947 | written in Rust. | |
1948 | ||
1949 | See Documentation/rust/ for more information. | |
1950 | ||
1951 | If unsure, say N. | |
1952 | ||
1953 | config RUSTC_VERSION_TEXT | |
1954 | string | |
1955 | depends on RUST | |
1956 | default $(shell,command -v $(RUSTC) >/dev/null 2>&1 && $(RUSTC) --version || echo n) | |
1957 | ||
1958 | config BINDGEN_VERSION_TEXT | |
1959 | string | |
1960 | depends on RUST | |
1961 | default $(shell,command -v $(BINDGEN) >/dev/null 2>&1 && $(BINDGEN) --version || echo n) | |
1962 | ||
5f87f112 IM |
1963 | # |
1964 | # Place an empty function call at each tracepoint site. Can be | |
1965 | # dynamically changed for a probe function. | |
1966 | # | |
97e1c18e | 1967 | config TRACEPOINTS |
5f87f112 | 1968 | bool |
97e1c18e | 1969 | |
1da177e4 LT |
1970 | endmenu # General setup |
1971 | ||
1572497c CH |
1972 | source "arch/Kconfig" |
1973 | ||
ae81f9e3 | 1974 | config RT_MUTEXES |
6341e62b | 1975 | bool |
1c6f9ec0 | 1976 | default y if PREEMPT_RT |
ae81f9e3 | 1977 | |
1da177e4 LT |
1978 | config BASE_SMALL |
1979 | int | |
1980 | default 0 if BASE_FULL | |
1981 | default 1 if !BASE_FULL | |
1982 | ||
c8424e77 TJB |
1983 | config MODULE_SIG_FORMAT |
1984 | def_bool n | |
1985 | select SYSTEM_DATA_VERIFICATION | |
1986 | ||
73b4fc92 | 1987 | source "kernel/module/Kconfig" |
6c9692e2 | 1988 | |
98a79d6a RR |
1989 | config INIT_ALL_POSSIBLE |
1990 | bool | |
1991 | help | |
5f054e31 RR |
1992 | Back when each arch used to define their own cpu_online_mask and |
1993 | cpu_possible_mask, some of them chose to initialize cpu_possible_mask | |
98a79d6a RR |
1994 | with all 1s, and others with all 0s. When they were centralised, |
1995 | it was better to provide this option than to break all the archs | |
692105b8 | 1996 | and have several arch maintainers pursuing me down dark alleys. |
98a79d6a | 1997 | |
3a65dfe8 | 1998 | source "block/Kconfig" |
e98c3202 AK |
1999 | |
2000 | config PREEMPT_NOTIFIERS | |
2001 | bool | |
e260be67 | 2002 | |
16295bec SK |
2003 | config PADATA |
2004 | depends on SMP | |
2005 | bool | |
2006 | ||
4520c6a4 DH |
2007 | config ASN1 |
2008 | tristate | |
2009 | help | |
2010 | Build a simple ASN.1 grammar compiler that produces a bytecode output | |
2011 | that can be interpreted by the ASN.1 stream decoder and used to | |
2012 | inform it as to what tags are to be expected in a stream and what | |
2013 | functions to call on what tags. | |
2014 | ||
6beb0009 | 2015 | source "kernel/Kconfig.locks" |
e61938a9 | 2016 | |
0ebeea8c DB |
2017 | config ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE |
2018 | bool | |
2019 | ||
e61938a9 MD |
2020 | config ARCH_HAS_SYNC_CORE_BEFORE_USERMODE |
2021 | bool | |
1bd21c6c DB |
2022 | |
2023 | # It may be useful for an architecture to override the definitions of the | |
7303e30e DB |
2024 | # SYSCALL_DEFINE() and __SYSCALL_DEFINEx() macros in <linux/syscalls.h> |
2025 | # and the COMPAT_ variants in <linux/compat.h>, in particular to use a | |
2026 | # different calling convention for syscalls. They can also override the | |
2027 | # macros for not-implemented syscalls in kernel/sys_ni.c and | |
2028 | # kernel/time/posix-stubs.c. All these overrides need to be available in | |
2029 | # <asm/syscall_wrapper.h>. | |
1bd21c6c DB |
2030 | config ARCH_HAS_SYSCALL_WRAPPER |
2031 | def_bool n |