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 | |
6e74c6b5 MO |
63 | config RUSTC_VERSION |
64 | int | |
af0121c2 | 65 | default $(rustc-version) |
6e74c6b5 MO |
66 | help |
67 | It does not depend on `RUST` since that one may need to use the version | |
68 | in a `depends on`. | |
69 | ||
2f7ab126 MO |
70 | config RUST_IS_AVAILABLE |
71 | def_bool $(success,$(srctree)/scripts/rust_is_available.sh) | |
72 | help | |
73 | This shows whether a suitable Rust toolchain is available (found). | |
74 | ||
75 | Please see Documentation/rust/quick-start.rst for instructions on how | |
eacf96d2 | 76 | to satisfy the build requirements of Rust support. |
2f7ab126 MO |
77 | |
78 | In particular, the Makefile target 'rustavailable' is useful to check | |
79 | why the Rust toolchain is not being detected. | |
80 | ||
af0121c2 GG |
81 | config RUSTC_LLVM_VERSION |
82 | int | |
83 | default $(rustc-llvm-version) | |
84 | ||
1a927fd3 | 85 | config CC_CAN_LINK |
9371f86e | 86 | bool |
f67695c9 EB |
87 | default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag)) if 64BIT |
88 | default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m32-flag)) | |
b1183b6d | 89 | |
f2f6a8e8 MR |
90 | # Fixed in GCC 14, 13.3, 12.4 and 11.5 |
91 | # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113921 | |
92 | config GCC_ASM_GOTO_OUTPUT_BROKEN | |
93 | bool | |
94 | depends on CC_IS_GCC | |
95 | default y if GCC_VERSION < 110500 | |
96 | default y if GCC_VERSION >= 120000 && GCC_VERSION < 120400 | |
97 | default y if GCC_VERSION >= 130000 && GCC_VERSION < 130300 | |
98 | ||
587f1701 | 99 | config CC_HAS_ASM_GOTO_OUTPUT |
f2f6a8e8 MR |
100 | def_bool y |
101 | depends on !GCC_ASM_GOTO_OUTPUT_BROKEN | |
102 | depends on $(success,echo 'int foo(int x) { asm goto ("": "=r"(x) ::: bar); return x; bar: return 0; }' | $(CC) -x c - -c -o /dev/null) | |
587f1701 | 103 | |
1aa0e8b1 SC |
104 | config CC_HAS_ASM_GOTO_TIED_OUTPUT |
105 | depends on CC_HAS_ASM_GOTO_OUTPUT | |
106 | # Detect buggy gcc and clang, fixed in gcc-11 clang-14. | |
534bd703 | 107 | 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 | 108 | |
5cf896fb | 109 | config TOOLS_SUPPORT_RELR |
2d122942 | 110 | def_bool $(success,env "CC=$(CC)" "LD=$(LD)" "NM=$(NM)" "OBJCOPY=$(OBJCOPY)" $(srctree)/scripts/tools-support-relr.sh) |
5cf896fb | 111 | |
eb111869 RV |
112 | config CC_HAS_ASM_INLINE |
113 | def_bool $(success,echo 'void foo(void) { asm inline (""); }' | $(CC) -x c - -c -o /dev/null) | |
114 | ||
51c2ee6d ND |
115 | config CC_HAS_NO_PROFILE_FN_ATTR |
116 | def_bool $(success,echo '__attribute__((no_profile_instrument_function)) int x();' | $(CC) -x c - -c -o /dev/null -Werror) | |
117 | ||
f06e108a | 118 | config CC_HAS_COUNTED_BY |
5106c650 | 119 | bool |
f06e108a JHF |
120 | # clang needs to be at least 19.1.3 to avoid __bdos miscalculations |
121 | # https://github.com/llvm/llvm-project/pull/110497 | |
122 | # https://github.com/llvm/llvm-project/pull/112636 | |
5106c650 JHF |
123 | default y if CC_IS_CLANG && CLANG_VERSION >= 190103 |
124 | # supported since gcc 15.1.0 | |
125 | # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108896 | |
126 | default y if CC_IS_GCC && GCC_VERSION >= 150100 | |
f06e108a | 127 | |
b688f369 KC |
128 | config CC_HAS_MULTIDIMENSIONAL_NONSTRING |
129 | def_bool $(success,echo 'char tag[][4] __attribute__((__nonstring__)) = { };' | $(CC) $(CLANG_FLAGS) -x c - -c -o /dev/null -Werror) | |
130 | ||
e7607f7d NC |
131 | config LD_CAN_USE_KEEP_IN_OVERLAY |
132 | # ld.lld prior to 21.0.0 did not support KEEP within an overlay description | |
133 | # https://github.com/llvm/llvm-project/pull/130661 | |
134 | def_bool LD_IS_BFD || LLD_VERSION >= 210000 | |
135 | ||
47cb6bf7 XD |
136 | config RUSTC_HAS_COERCE_POINTEE |
137 | def_bool RUSTC_VERSION >= 108400 | |
138 | ||
36174d16 MO |
139 | config RUSTC_HAS_SPAN_FILE |
140 | def_bool RUSTC_VERSION >= 108800 | |
141 | ||
7129ea6e MO |
142 | config RUSTC_HAS_UNNECESSARY_TRANSMUTES |
143 | def_bool RUSTC_VERSION >= 108800 | |
144 | ||
613fe169 NC |
145 | config PAHOLE_VERSION |
146 | int | |
147 | default $(shell,$(srctree)/scripts/pahole-version.sh $(PAHOLE)) | |
148 | ||
b99b87f7 PO |
149 | config CONSTRUCTORS |
150 | bool | |
b99b87f7 | 151 | |
e360adbe | 152 | config IRQ_WORK |
fd0a68a2 | 153 | def_bool y if SMP |
e360adbe | 154 | |
10916706 | 155 | config BUILDTIME_TABLE_SORT |
1dbdc6f1 DD |
156 | bool |
157 | ||
c65eacbe AL |
158 | config THREAD_INFO_IN_TASK |
159 | bool | |
160 | help | |
161 | Select this to move thread_info off the stack into task_struct. To | |
162 | make this work, an arch will need to remove all thread_info fields | |
163 | except flags and fix any runtime bugs. | |
164 | ||
c6c314a6 AL |
165 | One subtle change that will be needed is to use try_get_task_stack() |
166 | and put_task_stack() in save_thread_stack_tsk() and get_wchan(). | |
167 | ||
ff0cfc66 | 168 | menu "General setup" |
1da177e4 | 169 | |
1da177e4 LT |
170 | config BROKEN |
171 | bool | |
1da177e4 LT |
172 | |
173 | config BROKEN_ON_SMP | |
174 | bool | |
175 | depends on BROKEN || !SMP | |
176 | default y | |
177 | ||
1da177e4 LT |
178 | config INIT_ENV_ARG_LIMIT |
179 | int | |
dd673bca AB |
180 | default 32 if !UML |
181 | default 128 if UML | |
1da177e4 | 182 | help |
34ad92c2 RD |
183 | Maximum of each of the number of arguments and environment |
184 | variables passed to init from the kernel command line. | |
1da177e4 | 185 | |
4bb16672 JS |
186 | config COMPILE_TEST |
187 | bool "Compile also drivers which will not load" | |
ea29b20a | 188 | depends on HAS_IOMEM |
4bb16672 JS |
189 | help |
190 | Some drivers can be compiled on a different platform than they are | |
191 | intended to be run on. Despite they cannot be loaded there (or even | |
192 | when they load they cannot be used due to missing HW support), | |
193 | developers still, opposing to distributors, might want to build such | |
194 | drivers to compile-test them. | |
195 | ||
196 | If you are a developer and want to build everything available, say Y | |
197 | here. If you are a user/distributor, say N here to exclude useless | |
198 | drivers to be distributed. | |
199 | ||
3fe617cc LT |
200 | config WERROR |
201 | bool "Compile the kernel with warnings as errors" | |
b339ec9c | 202 | default COMPILE_TEST |
3fe617cc LT |
203 | help |
204 | A kernel build should not cause any compiler warnings, and this | |
2f7ab126 | 205 | enables the '-Werror' (for C) and '-Dwarnings' (for Rust) flags |
e1789d7c XL |
206 | to enforce that rule by default. Certain warnings from other tools |
207 | such as the linker may be upgraded to errors with this option as | |
208 | well. | |
3fe617cc | 209 | |
e1789d7c XL |
210 | However, if you have a new (or very old) compiler or linker with odd |
211 | and unusual warnings, or you have some architecture with problems, | |
3fe617cc LT |
212 | you may need to disable this config option in order to |
213 | successfully build the kernel. | |
214 | ||
215 | If in doubt, say Y. | |
216 | ||
d6fc9fcb MY |
217 | config UAPI_HEADER_TEST |
218 | bool "Compile test UAPI headers" | |
fcbb8461 | 219 | depends on HEADERS_INSTALL && CC_CAN_LINK |
d6fc9fcb MY |
220 | help |
221 | Compile test headers exported to user-space to ensure they are | |
222 | self-contained, i.e. compilable as standalone units. | |
223 | ||
224 | If you are a developer or tester and want to ensure the exported | |
225 | headers are self-contained, say Y here. Otherwise, choose N. | |
226 | ||
1da177e4 LT |
227 | config LOCALVERSION |
228 | string "Local version - append to kernel release" | |
229 | help | |
230 | Append an extra string to the end of your kernel version. | |
231 | This will show up when you type uname, for example. | |
232 | The string you set here will be appended after the contents of | |
233 | any files with a filename matching localversion* in your | |
234 | object and source tree, in that order. Your total string can | |
235 | be a maximum of 64 characters. | |
236 | ||
aaebf433 RA |
237 | config LOCALVERSION_AUTO |
238 | bool "Automatically append version information to the version string" | |
239 | default y | |
ac3339ba | 240 | depends on !COMPILE_TEST |
aaebf433 RA |
241 | help |
242 | This will try to automatically determine if the current tree is a | |
6e5a5420 RD |
243 | release tree by looking for git tags that belong to the current |
244 | top of tree revision. | |
aaebf433 RA |
245 | |
246 | A string of the format -gxxxxxxxx will be added to the localversion | |
6e5a5420 | 247 | if a git-based tree is found. The string generated by this will be |
aaebf433 | 248 | appended after any matching localversion* files, and after the value |
6e5a5420 | 249 | set in CONFIG_LOCALVERSION. |
aaebf433 | 250 | |
0f9c608d | 251 | (The actual string used here is the first 12 characters produced |
6e5a5420 RD |
252 | by running the command: |
253 | ||
254 | $ git rev-parse --verify HEAD | |
255 | ||
256 | which is done within the script "scripts/setlocalversion".) | |
aaebf433 | 257 | |
9afb719e | 258 | config BUILD_SALT |
e8cf4e9c KK |
259 | string "Build ID Salt" |
260 | default "" | |
261 | help | |
262 | The build ID is used to link binaries and their debug info. Setting | |
263 | this option will use the value in the calculation of the build id. | |
264 | This is mostly useful for distributions which want to ensure the | |
265 | build is unique between builds. It's safe to leave the default. | |
9afb719e | 266 | |
2e9f3bdd PA |
267 | config HAVE_KERNEL_GZIP |
268 | bool | |
269 | ||
270 | config HAVE_KERNEL_BZIP2 | |
271 | bool | |
272 | ||
273 | config HAVE_KERNEL_LZMA | |
274 | bool | |
275 | ||
3ebe1243 LC |
276 | config HAVE_KERNEL_XZ |
277 | bool | |
278 | ||
7dd65feb AT |
279 | config HAVE_KERNEL_LZO |
280 | bool | |
281 | ||
e76e1fdf KL |
282 | config HAVE_KERNEL_LZ4 |
283 | bool | |
284 | ||
48f7ddf7 NT |
285 | config HAVE_KERNEL_ZSTD |
286 | bool | |
287 | ||
f16466af VG |
288 | config HAVE_KERNEL_UNCOMPRESSED |
289 | bool | |
290 | ||
30d65dbf | 291 | choice |
2e9f3bdd PA |
292 | prompt "Kernel compression mode" |
293 | default KERNEL_GZIP | |
48f7ddf7 | 294 | 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 | 295 | help |
30d65dbf AK |
296 | The linux kernel is a kind of self-extracting executable. |
297 | Several compression algorithms are available, which differ | |
298 | in efficiency, compression and decompression speed. | |
299 | Compression speed is only relevant when building a kernel. | |
300 | Decompression speed is relevant at each boot. | |
301 | ||
302 | If you have any problems with bzip2 or lzma compressed | |
303 | kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older | |
304 | version of this functionality (bzip2 only), for 2.4, was | |
305 | supplied by Christian Ludwig) | |
306 | ||
307 | High compression options are mostly useful for users, who | |
308 | are low on disk space (embedded systems), but for whom ram | |
309 | size matters less. | |
310 | ||
311 | If in doubt, select 'gzip' | |
312 | ||
313 | config KERNEL_GZIP | |
2e9f3bdd PA |
314 | bool "Gzip" |
315 | depends on HAVE_KERNEL_GZIP | |
316 | help | |
7dd65feb AT |
317 | The old and tried gzip compression. It provides a good balance |
318 | between compression ratio and decompression speed. | |
30d65dbf AK |
319 | |
320 | config KERNEL_BZIP2 | |
321 | bool "Bzip2" | |
2e9f3bdd | 322 | depends on HAVE_KERNEL_BZIP2 |
30d65dbf AK |
323 | help |
324 | Its compression ratio and speed is intermediate. | |
0a4dd35c | 325 | Decompression speed is slowest among the choices. The kernel |
2e9f3bdd PA |
326 | size is about 10% smaller with bzip2, in comparison to gzip. |
327 | Bzip2 uses a large amount of memory. For modern kernels you | |
328 | will need at least 8MB RAM or more for booting. | |
30d65dbf AK |
329 | |
330 | config KERNEL_LZMA | |
2e9f3bdd PA |
331 | bool "LZMA" |
332 | depends on HAVE_KERNEL_LZMA | |
333 | help | |
0a4dd35c RD |
334 | This compression algorithm's ratio is best. Decompression speed |
335 | is between gzip and bzip2. Compression is slowest. | |
336 | The kernel size is about 33% smaller with LZMA in comparison to gzip. | |
30d65dbf | 337 | |
3ebe1243 LC |
338 | config KERNEL_XZ |
339 | bool "XZ" | |
340 | depends on HAVE_KERNEL_XZ | |
341 | help | |
342 | XZ uses the LZMA2 algorithm and instruction set specific | |
343 | BCJ filters which can improve compression ratio of executable | |
344 | code. The size of the kernel is about 30% smaller with XZ in | |
345 | comparison to gzip. On architectures for which there is a BCJ | |
7472ff8a LC |
346 | filter (i386, x86_64, ARM, ARM64, RISC-V, big endian PowerPC, |
347 | and SPARC), XZ will create a few percent smaller kernel than | |
348 | plain LZMA. | |
3ebe1243 LC |
349 | |
350 | The speed is about the same as with LZMA: The decompression | |
351 | speed of XZ is better than that of bzip2 but worse than gzip | |
352 | and LZO. Compression is slow. | |
353 | ||
7dd65feb AT |
354 | config KERNEL_LZO |
355 | bool "LZO" | |
356 | depends on HAVE_KERNEL_LZO | |
357 | help | |
0a4dd35c | 358 | Its compression ratio is the poorest among the choices. The kernel |
681b3049 | 359 | size is about 10% bigger than gzip; however its speed |
7dd65feb AT |
360 | (both compression and decompression) is the fastest. |
361 | ||
e76e1fdf KL |
362 | config KERNEL_LZ4 |
363 | bool "LZ4" | |
364 | depends on HAVE_KERNEL_LZ4 | |
365 | help | |
366 | LZ4 is an LZ77-type compressor with a fixed, byte-oriented encoding. | |
367 | A preliminary version of LZ4 de/compression tool is available at | |
368 | <https://code.google.com/p/lz4/>. | |
369 | ||
370 | Its compression ratio is worse than LZO. The size of the kernel | |
371 | is about 8% bigger than LZO. But the decompression speed is | |
372 | faster than LZO. | |
373 | ||
48f7ddf7 NT |
374 | config KERNEL_ZSTD |
375 | bool "ZSTD" | |
376 | depends on HAVE_KERNEL_ZSTD | |
377 | help | |
378 | ZSTD is a compression algorithm targeting intermediate compression | |
379 | with fast decompression speed. It will compress better than GZIP and | |
380 | decompress around the same speed as LZO, but slower than LZ4. You | |
381 | will need at least 192 KB RAM or more for booting. The zstd command | |
382 | line tool is required for compression. | |
383 | ||
f16466af VG |
384 | config KERNEL_UNCOMPRESSED |
385 | bool "None" | |
386 | depends on HAVE_KERNEL_UNCOMPRESSED | |
387 | help | |
388 | Produce uncompressed kernel image. This option is usually not what | |
389 | you want. It is useful for debugging the kernel in slow simulation | |
390 | environments, where decompressing and moving the kernel is awfully | |
391 | slow. This option allows early boot code to skip the decompressor | |
392 | and jump right at uncompressed kernel image. | |
393 | ||
30d65dbf AK |
394 | endchoice |
395 | ||
ada4ab7a CD |
396 | config DEFAULT_INIT |
397 | string "Default init path" | |
398 | default "" | |
399 | help | |
400 | This option determines the default init for the system if no init= | |
401 | option is passed on the kernel command line. If the requested path is | |
402 | not present, we will still then move on to attempting further | |
403 | locations (e.g. /sbin/init, etc). If this is empty, we will just use | |
404 | the fallback list when init= is not passed. | |
405 | ||
bd5dc17b JT |
406 | config DEFAULT_HOSTNAME |
407 | string "Default hostname" | |
408 | default "(none)" | |
409 | help | |
410 | This option determines the default system hostname before userspace | |
411 | calls sethostname(2). The kernel traditionally uses "(none)" here, | |
412 | but you may wish to use a different default here to make a minimal | |
413 | system more usable with less configuration. | |
414 | ||
1da177e4 LT |
415 | config SYSVIPC |
416 | bool "System V IPC" | |
a7f7f624 | 417 | help |
1da177e4 LT |
418 | Inter Process Communication is a suite of library functions and |
419 | system calls which let processes (running programs) synchronize and | |
420 | exchange information. It is generally considered to be a good thing, | |
421 | and some programs won't run unless you say Y here. In particular, if | |
422 | you want to run the DOS emulator dosemu under Linux (read the | |
423 | DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>), | |
424 | you'll need to say Y here. | |
425 | ||
426 | You can find documentation about IPC with "info ipc" and also in | |
427 | section 6.4 of the Linux Programmer's Guide, available from | |
428 | <http://www.tldp.org/guides.html>. | |
429 | ||
a5494dcd EB |
430 | config SYSVIPC_SYSCTL |
431 | bool | |
432 | depends on SYSVIPC | |
433 | depends on SYSCTL | |
434 | default y | |
435 | ||
0cbed0ee GR |
436 | config SYSVIPC_COMPAT |
437 | def_bool y | |
438 | depends on COMPAT && SYSVIPC | |
439 | ||
1da177e4 LT |
440 | config POSIX_MQUEUE |
441 | bool "POSIX Message Queues" | |
19c92399 | 442 | depends on NET |
a7f7f624 | 443 | help |
1da177e4 LT |
444 | POSIX variant of message queues is a part of IPC. In POSIX message |
445 | queues every message has a priority which decides about succession | |
446 | of receiving it by a process. If you want to compile and run | |
447 | programs written e.g. for Solaris with use of its POSIX message | |
b0e37650 | 448 | queues (functions mq_*) say Y here. |
1da177e4 LT |
449 | |
450 | POSIX message queues are visible as a filesystem called 'mqueue' | |
451 | and can be mounted somewhere if you want to do filesystem | |
452 | operations on message queues. | |
453 | ||
454 | If unsure, say Y. | |
455 | ||
bdc8e5f8 SH |
456 | config POSIX_MQUEUE_SYSCTL |
457 | bool | |
458 | depends on POSIX_MQUEUE | |
459 | depends on SYSCTL | |
460 | default y | |
461 | ||
c73be61c DH |
462 | config WATCH_QUEUE |
463 | bool "General notification queue" | |
464 | default n | |
465 | help | |
466 | ||
467 | This is a general notification queue for the kernel to pass events to | |
468 | userspace by splicing them into pipes. It can be used in conjunction | |
469 | with watches for key/keyring change notifications and device | |
470 | notifications. | |
471 | ||
c02b872a | 472 | See Documentation/core-api/watch_queue.rst |
c73be61c | 473 | |
226b4ccd KK |
474 | config CROSS_MEMORY_ATTACH |
475 | bool "Enable process_vm_readv/writev syscalls" | |
476 | depends on MMU | |
477 | default y | |
478 | help | |
479 | Enabling this option adds the system calls process_vm_readv and | |
480 | process_vm_writev which allow a process with the correct privileges | |
a2a368d9 | 481 | to directly read from or write to another process' address space. |
226b4ccd KK |
482 | See the man page for more details. |
483 | ||
391dc69c FW |
484 | config AUDIT |
485 | bool "Auditing support" | |
486 | depends on NET | |
487 | help | |
488 | Enable auditing infrastructure that can be used with another | |
489 | kernel subsystem, such as SELinux (which requires this for | |
cb74ed27 PM |
490 | logging of avc messages output). System call auditing is included |
491 | on architectures which support it. | |
391dc69c | 492 | |
7a017721 AT |
493 | config HAVE_ARCH_AUDITSYSCALL |
494 | bool | |
495 | ||
391dc69c | 496 | config AUDITSYSCALL |
cb74ed27 | 497 | def_bool y |
7a017721 | 498 | depends on AUDIT && HAVE_ARCH_AUDITSYSCALL |
391dc69c FW |
499 | select FSNOTIFY |
500 | ||
391dc69c FW |
501 | source "kernel/irq/Kconfig" |
502 | source "kernel/time/Kconfig" | |
b24abcff | 503 | source "kernel/bpf/Kconfig" |
87a4c375 | 504 | source "kernel/Kconfig.preempt" |
391dc69c FW |
505 | |
506 | menu "CPU/Task time and stats accounting" | |
507 | ||
abf917cd FW |
508 | config VIRT_CPU_ACCOUNTING |
509 | bool | |
510 | ||
fdf9c356 FW |
511 | choice |
512 | prompt "Cputime accounting" | |
02382aff | 513 | default TICK_CPU_ACCOUNTING |
fdf9c356 FW |
514 | |
515 | # Kind of a stub config for the pure tick based cputime accounting | |
516 | config TICK_CPU_ACCOUNTING | |
517 | bool "Simple tick based cputime accounting" | |
c58b0df1 | 518 | depends on !S390 && !NO_HZ_FULL |
fdf9c356 FW |
519 | help |
520 | This is the basic tick based cputime accounting that maintains | |
521 | statistics about user, system and idle time spent on per jiffies | |
522 | granularity. | |
523 | ||
524 | If unsure, say Y. | |
525 | ||
abf917cd | 526 | config VIRT_CPU_ACCOUNTING_NATIVE |
b952741c | 527 | bool "Deterministic task and CPU time accounting" |
c58b0df1 | 528 | depends on HAVE_VIRT_CPU_ACCOUNTING && !NO_HZ_FULL |
abf917cd | 529 | select VIRT_CPU_ACCOUNTING |
b952741c FW |
530 | help |
531 | Select this option to enable more accurate task and CPU time | |
532 | accounting. This is done by reading a CPU counter on each | |
533 | kernel entry and exit and on transitions within the kernel | |
534 | between system, softirq and hardirq state, so there is a | |
535 | small performance impact. In the case of s390 or IBM POWER > 5, | |
536 | this also enables accounting of stolen time on logically-partitioned | |
537 | systems. | |
538 | ||
abf917cd FW |
539 | config VIRT_CPU_ACCOUNTING_GEN |
540 | bool "Full dynticks CPU time accounting" | |
24a9c541 | 541 | depends on HAVE_CONTEXT_TRACKING_USER |
554b0004 | 542 | depends on HAVE_VIRT_CPU_ACCOUNTING_GEN |
041a1574 | 543 | depends on GENERIC_CLOCKEVENTS |
abf917cd | 544 | select VIRT_CPU_ACCOUNTING |
24a9c541 | 545 | select CONTEXT_TRACKING_USER |
abf917cd FW |
546 | help |
547 | Select this option to enable task and CPU time accounting on full | |
548 | dynticks systems. This accounting is implemented by watching every | |
549 | kernel-user boundaries using the context tracking subsystem. | |
550 | The accounting is thus performed at the expense of some significant | |
551 | overhead. | |
552 | ||
553 | For now this is only useful if you are working on the full | |
554 | dynticks subsystem development. | |
555 | ||
556 | If unsure, say N. | |
557 | ||
b58c3584 RR |
558 | endchoice |
559 | ||
fdf9c356 FW |
560 | config IRQ_TIME_ACCOUNTING |
561 | bool "Fine granularity task level IRQ time accounting" | |
b58c3584 | 562 | depends on HAVE_IRQ_TIME_ACCOUNTING && !VIRT_CPU_ACCOUNTING_NATIVE |
fdf9c356 FW |
563 | help |
564 | Select this option to enable fine granularity task irq time | |
565 | accounting. This is done by reading a timestamp on each | |
566 | transitions between softirq and hardirq state, so there can be a | |
567 | small performance impact. | |
568 | ||
569 | If in doubt, say N here. | |
570 | ||
11d4afd4 VG |
571 | config HAVE_SCHED_AVG_IRQ |
572 | def_bool y | |
573 | depends on IRQ_TIME_ACCOUNTING || PARAVIRT_TIME_ACCOUNTING | |
574 | depends on SMP | |
575 | ||
d4dbc991 | 576 | config SCHED_HW_PRESSURE |
98eb401d | 577 | bool |
fcd7c9c3 VS |
578 | default y if ARM && ARM_CPU_TOPOLOGY |
579 | default y if ARM64 | |
76504793 | 580 | depends on SMP |
98eb401d VS |
581 | depends on CPU_FREQ_THERMAL |
582 | help | |
d4dbc991 VG |
583 | Select this option to enable HW pressure accounting in the |
584 | scheduler. HW pressure is the value conveyed to the scheduler | |
98eb401d | 585 | that reflects the reduction in CPU compute capacity resulted from |
d4dbc991 VG |
586 | HW throttling. HW throttling occurs when the performance of |
587 | a CPU is capped due to high operating temperatures as an example. | |
98eb401d VS |
588 | |
589 | If selected, the scheduler will be able to balance tasks accordingly, | |
590 | i.e. put less load on throttled CPUs than on non/less throttled ones. | |
591 | ||
592 | This requires the architecture to implement | |
d4dbc991 | 593 | arch_update_hw_pressure() and arch_scale_thermal_pressure(). |
76504793 | 594 | |
1da177e4 LT |
595 | config BSD_PROCESS_ACCT |
596 | bool "BSD Process Accounting" | |
2813893f | 597 | depends on MULTIUSER |
1da177e4 LT |
598 | help |
599 | If you say Y here, a user level program will be able to instruct the | |
600 | kernel (via a special system call) to write process accounting | |
601 | information to a file: whenever a process exits, information about | |
602 | that process will be appended to the file by the kernel. The | |
603 | information includes things such as creation time, owning user, | |
604 | command name, memory usage, controlling terminal etc. (the complete | |
605 | list is in the struct acct in <file:include/linux/acct.h>). It is | |
606 | up to the user level program to do useful things with this | |
607 | information. This is generally a good idea, so say Y. | |
608 | ||
609 | config BSD_PROCESS_ACCT_V3 | |
610 | bool "BSD Process Accounting version 3 file format" | |
611 | depends on BSD_PROCESS_ACCT | |
612 | default n | |
613 | help | |
614 | If you say Y here, the process accounting information is written | |
615 | in a new file format that also logs the process IDs of each | |
3903bf94 | 616 | process and its parent. Note that this file format is incompatible |
1da177e4 LT |
617 | with previous v0/v1/v2 file formats, so you will need updated tools |
618 | for processing it. A preliminary version of these tools is available | |
37a4c940 | 619 | at <http://www.gnu.org/software/acct/>. |
1da177e4 | 620 | |
c757249a | 621 | config TASKSTATS |
19c92399 | 622 | bool "Export task/process statistics through netlink" |
c757249a | 623 | depends on NET |
2813893f | 624 | depends on MULTIUSER |
c757249a SN |
625 | default n |
626 | help | |
627 | Export selected statistics for tasks/processes through the | |
628 | generic netlink interface. Unlike BSD process accounting, the | |
629 | statistics are available during the lifetime of tasks/processes as | |
630 | responses to commands. Like BSD accounting, they are sent to user | |
631 | space on task exit. | |
632 | ||
633 | Say N if unsure. | |
634 | ||
ca74e92b | 635 | config TASK_DELAY_ACCT |
19c92399 | 636 | bool "Enable per-task delay accounting" |
6f44993f | 637 | depends on TASKSTATS |
f6db8347 | 638 | select SCHED_INFO |
ca74e92b SN |
639 | help |
640 | Collect information on time spent by a task waiting for system | |
641 | resources like cpu, synchronous block I/O completion and swapping | |
642 | in pages. Such statistics can help in setting a task's priorities | |
643 | relative to other tasks for cpu, io, rss limits etc. | |
644 | ||
645 | Say N if unsure. | |
646 | ||
18f705f4 | 647 | config TASK_XACCT |
19c92399 | 648 | bool "Enable extended accounting over taskstats" |
18f705f4 AD |
649 | depends on TASKSTATS |
650 | help | |
651 | Collect extended task accounting data and send the data | |
652 | to userland for processing over the taskstats interface. | |
653 | ||
654 | Say N if unsure. | |
655 | ||
656 | config TASK_IO_ACCOUNTING | |
19c92399 | 657 | bool "Enable per-task storage I/O accounting" |
18f705f4 AD |
658 | depends on TASK_XACCT |
659 | help | |
660 | Collect information on the number of bytes of storage I/O which this | |
661 | task has caused. | |
662 | ||
663 | Say N if unsure. | |
664 | ||
eb414681 JW |
665 | config PSI |
666 | bool "Pressure stall information tracking" | |
98dfdd9e | 667 | select KERNFS |
eb414681 JW |
668 | help |
669 | Collect metrics that indicate how overcommitted the CPU, memory, | |
670 | and IO capacity are in the system. | |
671 | ||
672 | If you say Y here, the kernel will create /proc/pressure/ with the | |
673 | pressure statistics files cpu, memory, and io. These will indicate | |
674 | the share of walltime in which some or all tasks in the system are | |
675 | delayed due to contention of the respective resource. | |
676 | ||
2ce7135a JW |
677 | In kernels with cgroup support, cgroups (cgroup2 only) will |
678 | have cpu.pressure, memory.pressure, and io.pressure files, | |
679 | which aggregate pressure stalls for the grouped tasks only. | |
680 | ||
c3123552 | 681 | For more details see Documentation/accounting/psi.rst. |
eb414681 JW |
682 | |
683 | Say N if unsure. | |
684 | ||
e0c27447 JW |
685 | config PSI_DEFAULT_DISABLED |
686 | bool "Require boot parameter to enable pressure stall information tracking" | |
687 | default n | |
688 | depends on PSI | |
689 | help | |
690 | If set, pressure stall information tracking will be disabled | |
428a1cb4 BS |
691 | per default but can be enabled through passing psi=1 on the |
692 | kernel commandline during boot. | |
e0c27447 | 693 | |
7b2489d3 JW |
694 | This feature adds some code to the task wakeup and sleep |
695 | paths of the scheduler. The overhead is too low to affect | |
696 | common scheduling-intense workloads in practice (such as | |
697 | webservers, memcache), but it does show up in artificial | |
698 | scheduler stress tests, such as hackbench. | |
699 | ||
700 | If you are paranoid and not sure what the kernel will be | |
701 | used for, say Y. | |
702 | ||
703 | Say N if unsure. | |
704 | ||
391dc69c | 705 | endmenu # "CPU/Task time and stats accounting" |
d9817ebe | 706 | |
5c4991e2 FW |
707 | config CPU_ISOLATION |
708 | bool "CPU isolation" | |
97577684 | 709 | depends on SMP |
2c43838c | 710 | default y |
5c4991e2 FW |
711 | help |
712 | Make sure that CPUs running critical tasks are not disturbed by | |
713 | any source of "noise" such as unbound workqueues, timers, kthreads... | |
2c43838c FW |
714 | Unbound jobs get offloaded to housekeeping CPUs. This is driven by |
715 | the "isolcpus=" boot parameter. | |
716 | ||
717 | Say Y if unsure. | |
5c4991e2 | 718 | |
0af92d46 | 719 | source "kernel/rcu/Kconfig" |
c903ff83 | 720 | |
1da177e4 | 721 | config IKCONFIG |
f2443ab6 | 722 | tristate "Kernel .config support" |
a7f7f624 | 723 | help |
1da177e4 LT |
724 | This option enables the complete Linux kernel ".config" file |
725 | contents to be saved in the kernel. It provides documentation | |
726 | of which kernel options are used in a running kernel or in an | |
727 | on-disk kernel. This information can be extracted from the kernel | |
728 | image file with the script scripts/extract-ikconfig and used as | |
729 | input to rebuild the current kernel or to build another kernel. | |
730 | It can also be extracted from a running kernel by reading | |
731 | /proc/config.gz if enabled (below). | |
732 | ||
733 | config IKCONFIG_PROC | |
734 | bool "Enable access to .config through /proc/config.gz" | |
735 | depends on IKCONFIG && PROC_FS | |
a7f7f624 | 736 | help |
1da177e4 LT |
737 | This option enables access to the kernel configuration file |
738 | through /proc/config.gz. | |
739 | ||
f7b101d3 JFG |
740 | config IKHEADERS |
741 | tristate "Enable kernel headers through /sys/kernel/kheaders.tar.xz" | |
742 | depends on SYSFS | |
743 | help | |
744 | This option enables access to the in-kernel headers that are generated during | |
745 | the build process. These can be used to build eBPF tracing programs, | |
746 | or similar programs. If you build the headers as a module, a module called | |
747 | kheaders.ko is built which can be loaded on-demand to get access to headers. | |
43d8ce9d | 748 | |
794543a2 AJS |
749 | config LOG_BUF_SHIFT |
750 | int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" | |
1c4b5ecb | 751 | range 12 25 |
f17a32e9 | 752 | default 17 |
361e9dfb | 753 | depends on PRINTK |
794543a2 | 754 | help |
23b2899f LR |
755 | Select the minimal kernel log buffer size as a power of 2. |
756 | The final size is affected by LOG_CPU_MAX_BUF_SHIFT config | |
757 | parameter, see below. Any higher size also might be forced | |
758 | by "log_buf_len" boot parameter. | |
759 | ||
f17a32e9 | 760 | Examples: |
23b2899f | 761 | 17 => 128 KB |
f17a32e9 | 762 | 16 => 64 KB |
23b2899f LR |
763 | 15 => 32 KB |
764 | 14 => 16 KB | |
794543a2 AJS |
765 | 13 => 8 KB |
766 | 12 => 4 KB | |
767 | ||
23b2899f LR |
768 | config LOG_CPU_MAX_BUF_SHIFT |
769 | int "CPU kernel log buffer size contribution (13 => 8 KB, 17 => 128KB)" | |
2240a31d | 770 | depends on SMP |
23b2899f | 771 | range 0 21 |
23b2899f | 772 | default 0 if BASE_SMALL |
320bf431 | 773 | default 12 |
361e9dfb | 774 | depends on PRINTK |
23b2899f LR |
775 | help |
776 | This option allows to increase the default ring buffer size | |
777 | according to the number of CPUs. The value defines the contribution | |
778 | of each CPU as a power of 2. The used space is typically only few | |
779 | lines however it might be much more when problems are reported, | |
780 | e.g. backtraces. | |
781 | ||
782 | The increased size means that a new buffer has to be allocated and | |
783 | the original static one is unused. It makes sense only on systems | |
784 | with more CPUs. Therefore this value is used only when the sum of | |
785 | contributions is greater than the half of the default kernel ring | |
786 | buffer as defined by LOG_BUF_SHIFT. The default values are set | |
0f7636e1 | 787 | so that more than 16 CPUs are needed to trigger the allocation. |
23b2899f LR |
788 | |
789 | Also this option is ignored when "log_buf_len" kernel parameter is | |
790 | used as it forces an exact (power of two) size of the ring buffer. | |
791 | ||
792 | The number of possible CPUs is used for this computation ignoring | |
5e0d8d59 GU |
793 | hotplugging making the computation optimal for the worst case |
794 | scenario while allowing a simple algorithm to be used from bootup. | |
23b2899f LR |
795 | |
796 | Examples shift values and their meaning: | |
797 | 17 => 128 KB for each CPU | |
798 | 16 => 64 KB for each CPU | |
799 | 15 => 32 KB for each CPU | |
800 | 14 => 16 KB for each CPU | |
801 | 13 => 8 KB for each CPU | |
802 | 12 => 4 KB for each CPU | |
803 | ||
33701557 CD |
804 | config PRINTK_INDEX |
805 | bool "Printk indexing debugfs interface" | |
806 | depends on PRINTK && DEBUG_FS | |
807 | help | |
808 | Add support for indexing of all printk formats known at compile time | |
809 | at <debugfs>/printk/index/<module>. | |
810 | ||
811 | This can be used as part of maintaining daemons which monitor | |
812 | /dev/kmsg, as it permits auditing the printk formats present in a | |
813 | kernel, allowing detection of cases where monitored printks are | |
814 | changed or no longer present. | |
815 | ||
816 | There is no additional runtime cost to printk with this enabled. | |
817 | ||
a5574cf6 IM |
818 | # |
819 | # Architectures with an unreliable sched_clock() should select this: | |
820 | # | |
821 | config HAVE_UNSTABLE_SCHED_CLOCK | |
822 | bool | |
823 | ||
38ff87f7 SB |
824 | config GENERIC_SCHED_CLOCK |
825 | bool | |
826 | ||
69842cba PB |
827 | menu "Scheduler features" |
828 | ||
829 | config UCLAMP_TASK | |
830 | bool "Enable utilization clamping for RT/FAIR tasks" | |
831 | depends on CPU_FREQ_GOV_SCHEDUTIL | |
832 | help | |
833 | This feature enables the scheduler to track the clamped utilization | |
834 | of each CPU based on RUNNABLE tasks scheduled on that CPU. | |
835 | ||
836 | With this option, the user can specify the min and max CPU | |
837 | utilization allowed for RUNNABLE tasks. The max utilization defines | |
838 | the maximum frequency a task should use while the min utilization | |
839 | defines the minimum frequency it should use. | |
840 | ||
841 | Both min and max utilization clamp values are hints to the scheduler, | |
842 | aiming at improving its frequency selection policy, but they do not | |
843 | enforce or grant any specific bandwidth for tasks. | |
844 | ||
845 | If in doubt, say N. | |
846 | ||
847 | config UCLAMP_BUCKETS_COUNT | |
848 | int "Number of supported utilization clamp buckets" | |
849 | range 5 20 | |
850 | default 5 | |
851 | depends on UCLAMP_TASK | |
852 | help | |
853 | Defines the number of clamp buckets to use. The range of each bucket | |
854 | will be SCHED_CAPACITY_SCALE/UCLAMP_BUCKETS_COUNT. The higher the | |
855 | number of clamp buckets the finer their granularity and the higher | |
856 | the precision of clamping aggregation and tracking at run-time. | |
857 | ||
858 | For example, with the minimum configuration value we will have 5 | |
859 | clamp buckets tracking 20% utilization each. A 25% boosted tasks will | |
860 | be refcounted in the [20..39]% bucket and will set the bucket clamp | |
861 | effective value to 25%. | |
862 | If a second 30% boosted task should be co-scheduled on the same CPU, | |
863 | that task will be refcounted in the same bucket of the first task and | |
864 | it will boost the bucket clamp effective value to 30%. | |
865 | The clamp effective value of a bucket is reset to its nominal value | |
866 | (20% in the example above) when there are no more tasks refcounted in | |
867 | that bucket. | |
868 | ||
869 | An additional boost/capping margin can be added to some tasks. In the | |
870 | example above the 25% task will be boosted to 30% until it exits the | |
871 | CPU. If that should be considered not acceptable on certain systems, | |
872 | it's always possible to reduce the margin by increasing the number of | |
873 | clamp buckets to trade off used memory for run-time tracking | |
874 | precision. | |
875 | ||
876 | If in doubt, use the default value. | |
877 | ||
878 | endmenu | |
879 | ||
be3a7284 AA |
880 | # |
881 | # For architectures that want to enable the support for NUMA-affine scheduler | |
882 | # balancing logic: | |
883 | # | |
884 | config ARCH_SUPPORTS_NUMA_BALANCING | |
885 | bool | |
886 | ||
72b252ae MG |
887 | # |
888 | # For architectures that prefer to flush all TLBs after a number of pages | |
889 | # are unmapped instead of sending one IPI per page to flush. The architecture | |
890 | # must provide guarantees on what happens if a clean TLB cache entry is | |
891 | # written after the unmap. Details are in mm/rmap.c near the check for | |
892 | # should_defer_flush. The architecture should also consider if the full flush | |
893 | # and the refill costs are offset by the savings of sending fewer IPIs. | |
894 | config ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH | |
895 | bool | |
896 | ||
c12d3362 | 897 | config CC_HAS_INT128 |
3a7c7331 | 898 | def_bool !$(cc-option,$(m64-flag) -D__SIZEOF_INT128__=0) && 64BIT |
c12d3362 | 899 | |
dee2b702 GS |
900 | config CC_IMPLICIT_FALLTHROUGH |
901 | string | |
158ea2d2 | 902 | default "-Wimplicit-fallthrough=5" if CC_IS_GCC && $(cc-option,-Wimplicit-fallthrough=5) |
dee2b702 GS |
903 | default "-Wimplicit-fallthrough" if CC_IS_CLANG && $(cc-option,-Wunreachable-code-fallthrough) |
904 | ||
3e00f580 | 905 | # Currently, disable gcc-10+ array-bounds globally. |
0da6e5fd | 906 | # It's still broken in gcc-13, so no upper bound yet. |
3e00f580 | 907 | config GCC10_NO_ARRAY_BOUNDS |
5a41237a LT |
908 | def_bool y |
909 | ||
f0be87c4 LT |
910 | config CC_NO_ARRAY_BOUNDS |
911 | bool | |
8e5bd4ea | 912 | default y if CC_IS_GCC && GCC_VERSION >= 90000 && GCC10_NO_ARRAY_BOUNDS |
f0be87c4 | 913 | |
02153319 LT |
914 | # Currently, disable -Wstringop-overflow for GCC globally. |
915 | config GCC_NO_STRINGOP_OVERFLOW | |
a5e0ace0 GS |
916 | def_bool y |
917 | ||
918 | config CC_NO_STRINGOP_OVERFLOW | |
919 | bool | |
02153319 | 920 | default y if CC_IS_GCC && GCC_NO_STRINGOP_OVERFLOW |
a5e0ace0 GS |
921 | |
922 | config CC_STRINGOP_OVERFLOW | |
923 | bool | |
924 | default y if CC_IS_GCC && !CC_NO_STRINGOP_OVERFLOW | |
925 | ||
be5e610c PZ |
926 | # |
927 | # For architectures that know their GCC __int128 support is sound | |
928 | # | |
929 | config ARCH_SUPPORTS_INT128 | |
930 | bool | |
931 | ||
be3a7284 AA |
932 | # For architectures that (ab)use NUMA to represent different memory regions |
933 | # all cpu-local but of different latencies, such as SuperH. | |
934 | # | |
935 | config ARCH_WANT_NUMA_VARIABLE_LOCALITY | |
936 | bool | |
937 | ||
be3a7284 AA |
938 | config NUMA_BALANCING |
939 | bool "Memory placement aware NUMA scheduler" | |
be3a7284 AA |
940 | depends on ARCH_SUPPORTS_NUMA_BALANCING |
941 | depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY | |
554b0f3c | 942 | depends on SMP && NUMA && MIGRATION && !PREEMPT_RT |
be3a7284 AA |
943 | help |
944 | This option adds support for automatic NUMA aware memory/task placement. | |
945 | The mechanism is quite primitive and is based on migrating memory when | |
6d56a410 | 946 | it has references to the node the task is running on. |
be3a7284 AA |
947 | |
948 | This system will be inactive on UMA systems. | |
949 | ||
6f7c97e8 AK |
950 | config NUMA_BALANCING_DEFAULT_ENABLED |
951 | bool "Automatically enable NUMA aware memory/task placement" | |
952 | default y | |
953 | depends on NUMA_BALANCING | |
954 | help | |
955 | If set, automatic NUMA balancing will be enabled if running on a NUMA | |
956 | machine. | |
957 | ||
21c690a3 SB |
958 | config SLAB_OBJ_EXT |
959 | bool | |
960 | ||
23964d2d | 961 | menuconfig CGROUPS |
6341e62b | 962 | bool "Control Group support" |
2bd59d48 | 963 | select KERNFS |
5cdc38f9 | 964 | help |
23964d2d | 965 | This option adds support for grouping sets of processes together, for |
5cdc38f9 KH |
966 | use with process control subsystems such as Cpusets, CFS, memory |
967 | controls or device isolation. | |
968 | See | |
d6a3b247 | 969 | - Documentation/scheduler/sched-design-CFS.rst (CFS) |
da82c92f | 970 | - Documentation/admin-guide/cgroup-v1/ (features for grouping, isolation |
45ce80fb | 971 | and resource control) |
5cdc38f9 KH |
972 | |
973 | Say N if unsure. | |
974 | ||
23964d2d LZ |
975 | if CGROUPS |
976 | ||
3e32cb2e | 977 | config PAGE_COUNTER |
e8cf4e9c | 978 | bool |
3e32cb2e | 979 | |
6a010a49 TH |
980 | config CGROUP_FAVOR_DYNMODS |
981 | bool "Favor dynamic modification latency reduction by default" | |
982 | help | |
983 | This option enables the "favordynmods" mount option by default | |
984 | which reduces the latencies of dynamic cgroup modifications such | |
985 | as task migrations and controller on/offs at the cost of making | |
986 | hot path operations such as forks and exits more expensive. | |
987 | ||
988 | Say N if unsure. | |
989 | ||
c255a458 | 990 | config MEMCG |
a0166ec4 | 991 | bool "Memory controller" |
3e32cb2e | 992 | select PAGE_COUNTER |
79bd9814 | 993 | select EVENTFD |
21c690a3 | 994 | select SLAB_OBJ_EXT |
00f0b825 | 995 | help |
a0166ec4 | 996 | Provides control over the memory footprint of tasks in a cgroup. |
00f0b825 | 997 | |
25352d2f SB |
998 | config MEMCG_NMI_UNSAFE |
999 | bool | |
1000 | depends on MEMCG | |
1001 | depends on HAVE_NMI | |
1002 | depends on !ARCH_HAS_NMI_SAFE_THIS_CPU_OPS && !ARCH_HAVE_NMI_SAFE_CMPXCHG | |
1003 | default y | |
1004 | ||
940b01fc SB |
1005 | config MEMCG_NMI_SAFETY_REQUIRES_ATOMIC |
1006 | bool | |
1007 | depends on MEMCG | |
1008 | depends on HAVE_NMI | |
1009 | depends on !ARCH_HAS_NMI_SAFE_THIS_CPU_OPS && ARCH_HAVE_NMI_SAFE_CMPXCHG | |
1010 | default y | |
1011 | ||
e93d4166 RG |
1012 | config MEMCG_V1 |
1013 | bool "Legacy cgroup v1 memory controller" | |
c9929f0e | 1014 | depends on MEMCG |
e93d4166 RG |
1015 | default n |
1016 | help | |
1017 | Legacy cgroup v1 memory controller which has been deprecated by | |
1018 | cgroup v2 implementation. The v1 is there for legacy applications | |
1019 | which haven't migrated to the new cgroup v2 interface yet. If you | |
1020 | do not have any such application then you are completely fine leaving | |
1021 | this option disabled. | |
1022 | ||
1023 | Please note that feature set of the legacy memory controller is likely | |
1024 | going to shrink due to deprecation process. New deployments with v1 | |
1025 | controller are highly discouraged. | |
1026 | ||
fcb4824b | 1027 | Say N if unsure. |
84c07d11 | 1028 | |
6bf024e6 JW |
1029 | config BLK_CGROUP |
1030 | bool "IO controller" | |
1031 | depends on BLOCK | |
2bc64a20 | 1032 | default n |
a7f7f624 | 1033 | help |
6bf024e6 JW |
1034 | Generic block IO controller cgroup interface. This is the common |
1035 | cgroup interface which should be used by various IO controlling | |
1036 | policies. | |
2bc64a20 | 1037 | |
6bf024e6 JW |
1038 | Currently, CFQ IO scheduler uses it to recognize task groups and |
1039 | control disk bandwidth allocation (proportional time slice allocation) | |
1040 | to such task groups. It is also used by bio throttling logic in | |
1041 | block layer to implement upper limit in IO rates on a device. | |
e5d1367f | 1042 | |
6bf024e6 JW |
1043 | This option only enables generic Block IO controller infrastructure. |
1044 | One needs to also enable actual IO controlling logic/policy. For | |
1045 | enabling proportional weight division of disk bandwidth in CFQ, set | |
7baf2199 | 1046 | CONFIG_BFQ_GROUP_IOSCHED=y; for enabling throttling policy, set |
6bf024e6 JW |
1047 | CONFIG_BLK_DEV_THROTTLING=y. |
1048 | ||
da82c92f | 1049 | See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information. |
6bf024e6 | 1050 | |
6bf024e6 JW |
1051 | config CGROUP_WRITEBACK |
1052 | bool | |
1053 | depends on MEMCG && BLK_CGROUP | |
1054 | default y | |
e5d1367f | 1055 | |
7c941438 | 1056 | menuconfig CGROUP_SCHED |
a0166ec4 | 1057 | bool "CPU controller" |
7c941438 DG |
1058 | default n |
1059 | help | |
1060 | This feature lets CPU scheduler recognize task groups and control CPU | |
1061 | bandwidth allocation to such task groups. It uses cgroups to group | |
1062 | tasks. | |
1063 | ||
1064 | if CGROUP_SCHED | |
e179e80c TH |
1065 | config GROUP_SCHED_WEIGHT |
1066 | def_bool n | |
1067 | ||
7c941438 DG |
1068 | config FAIR_GROUP_SCHED |
1069 | bool "Group scheduling for SCHED_OTHER" | |
1070 | depends on CGROUP_SCHED | |
e179e80c | 1071 | select GROUP_SCHED_WEIGHT |
7c941438 DG |
1072 | default CGROUP_SCHED |
1073 | ||
ab84d31e PT |
1074 | config CFS_BANDWIDTH |
1075 | bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED" | |
ab84d31e PT |
1076 | depends on FAIR_GROUP_SCHED |
1077 | default n | |
1078 | help | |
1079 | This option allows users to define CPU bandwidth rates (limits) for | |
1080 | tasks running within the fair group scheduler. Groups with no limit | |
1081 | set are considered to be unconstrained and will run with no | |
1082 | restriction. | |
d6a3b247 | 1083 | See Documentation/scheduler/sched-bwc.rst for more information. |
ab84d31e | 1084 | |
7c941438 DG |
1085 | config RT_GROUP_SCHED |
1086 | bool "Group scheduling for SCHED_RR/FIFO" | |
7c941438 DG |
1087 | depends on CGROUP_SCHED |
1088 | default n | |
1089 | help | |
1090 | This feature lets you explicitly allocate real CPU bandwidth | |
32bd7eb5 | 1091 | to task groups. If enabled, it will also make it impossible to |
7c941438 DG |
1092 | schedule realtime tasks for non-root users until you allocate |
1093 | realtime bandwidth for them. | |
d6a3b247 | 1094 | See Documentation/scheduler/sched-rt-group.rst for more information. |
7c941438 | 1095 | |
e34e0131 MK |
1096 | config RT_GROUP_SCHED_DEFAULT_DISABLED |
1097 | bool "Require boot parameter to enable group scheduling for SCHED_RR/FIFO" | |
1098 | depends on RT_GROUP_SCHED | |
1099 | default n | |
1100 | help | |
1101 | When set, the RT group scheduling is disabled by default. The option | |
1102 | is in inverted form so that mere RT_GROUP_SCHED enables the group | |
1103 | scheduling. | |
1104 | ||
1105 | Say N if unsure. | |
1106 | ||
81951366 TH |
1107 | config EXT_GROUP_SCHED |
1108 | bool | |
1109 | depends on SCHED_CLASS_EXT && CGROUP_SCHED | |
1110 | select GROUP_SCHED_WEIGHT | |
1111 | default y | |
1112 | ||
7c941438 DG |
1113 | endif #CGROUP_SCHED |
1114 | ||
af7f588d MD |
1115 | config SCHED_MM_CID |
1116 | def_bool y | |
1117 | depends on SMP && RSEQ | |
1118 | ||
2480c093 PB |
1119 | config UCLAMP_TASK_GROUP |
1120 | bool "Utilization clamping per group of tasks" | |
1121 | depends on CGROUP_SCHED | |
1122 | depends on UCLAMP_TASK | |
1123 | default n | |
1124 | help | |
1125 | This feature enables the scheduler to track the clamped utilization | |
1126 | of each CPU based on RUNNABLE tasks currently scheduled on that CPU. | |
1127 | ||
1128 | When this option is enabled, the user can specify a min and max | |
1129 | CPU bandwidth which is allowed for each single task in a group. | |
1130 | The max bandwidth allows to clamp the maximum frequency a task | |
1131 | can use, while the min bandwidth allows to define a minimum | |
1132 | frequency a task will always use. | |
1133 | ||
1134 | When task group based utilization clamping is enabled, an eventually | |
1135 | specified task-specific clamp value is constrained by the cgroup | |
1136 | specified clamp value. Both minimum and maximum task clamping cannot | |
1137 | be bigger than the corresponding clamping defined at task group level. | |
1138 | ||
1139 | If in doubt, say N. | |
1140 | ||
6bf024e6 JW |
1141 | config CGROUP_PIDS |
1142 | bool "PIDs controller" | |
1143 | help | |
1144 | Provides enforcement of process number limits in the scope of a | |
1145 | cgroup. Any attempt to fork more processes than is allowed in the | |
1146 | cgroup will fail. PIDs are fundamentally a global resource because it | |
1147 | is fairly trivial to reach PID exhaustion before you reach even a | |
1148 | conservative kmemcg limit. As a result, it is possible to grind a | |
1149 | system to halt without being limited by other cgroup policies. The | |
6cc578df | 1150 | PIDs controller is designed to stop this from happening. |
6bf024e6 JW |
1151 | |
1152 | It should be noted that organisational operations (such as attaching | |
98076833 | 1153 | to a cgroup hierarchy) will *not* be blocked by the PIDs controller, |
6bf024e6 JW |
1154 | since the PIDs limit only affects a process's ability to fork, not to |
1155 | attach to a cgroup. | |
1156 | ||
39d3e758 PP |
1157 | config CGROUP_RDMA |
1158 | bool "RDMA controller" | |
1159 | help | |
1160 | Provides enforcement of RDMA resources defined by IB stack. | |
1161 | It is fairly easy for consumers to exhaust RDMA resources, which | |
1162 | can result into resource unavailability to other consumers. | |
1163 | RDMA controller is designed to stop this from happening. | |
1164 | Attaching processes with active RDMA resources to the cgroup | |
1165 | hierarchy is allowed even if can cross the hierarchy's limit. | |
1166 | ||
b168ed45 ML |
1167 | config CGROUP_DMEM |
1168 | bool "Device memory controller (DMEM)" | |
e33b5149 | 1169 | select PAGE_COUNTER |
b168ed45 ML |
1170 | help |
1171 | The DMEM controller allows compatible devices to restrict device | |
1172 | memory usage based on the cgroup hierarchy. | |
1173 | ||
1174 | As an example, it allows you to restrict VRAM usage for applications | |
1175 | in the DRM subsystem. | |
1176 | ||
6bf024e6 JW |
1177 | config CGROUP_FREEZER |
1178 | bool "Freezer controller" | |
1179 | help | |
1180 | Provides a way to freeze and unfreeze all tasks in a | |
1181 | cgroup. | |
1182 | ||
489c2a20 JW |
1183 | This option affects the ORIGINAL cgroup interface. The cgroup2 memory |
1184 | controller includes important in-kernel memory consumers per default. | |
1185 | ||
1186 | If you're using cgroup2, say N. | |
1187 | ||
6bf024e6 JW |
1188 | config CGROUP_HUGETLB |
1189 | bool "HugeTLB controller" | |
1190 | depends on HUGETLB_PAGE | |
1191 | select PAGE_COUNTER | |
afc24d49 | 1192 | default n |
6bf024e6 JW |
1193 | help |
1194 | Provides a cgroup controller for HugeTLB pages. | |
1195 | When you enable this, you can put a per cgroup limit on HugeTLB usage. | |
1196 | The limit is enforced during page fault. Since HugeTLB doesn't | |
1197 | support page reclaim, enforcing the limit at page fault time implies | |
1198 | that, the application will get SIGBUS signal if it tries to access | |
1199 | HugeTLB pages beyond its limit. This requires the application to know | |
1200 | beforehand how much HugeTLB pages it would require for its use. The | |
1201 | control group is tracked in the third page lru pointer. This means | |
1202 | that we cannot use the controller with huge page less than 3 pages. | |
afc24d49 | 1203 | |
6bf024e6 JW |
1204 | config CPUSETS |
1205 | bool "Cpuset controller" | |
e1d4eeec | 1206 | depends on SMP |
bf9850f6 | 1207 | select UNION_FIND |
6bf024e6 JW |
1208 | help |
1209 | This option will let you create and manage CPUSETs which | |
1210 | allow dynamically partitioning a system into sets of CPUs and | |
1211 | Memory Nodes and assigning tasks to run only within those sets. | |
1212 | This is primarily useful on large SMP or NUMA systems. | |
afc24d49 | 1213 | |
6bf024e6 | 1214 | Say N if unsure. |
afc24d49 | 1215 | |
1abab1ba CR |
1216 | config CPUSETS_V1 |
1217 | bool "Legacy cgroup v1 cpusets controller" | |
1218 | depends on CPUSETS | |
1219 | default n | |
1220 | help | |
1221 | Legacy cgroup v1 cpusets controller which has been deprecated by | |
1222 | cgroup v2 implementation. The v1 is there for legacy applications | |
dae68fba MK |
1223 | which haven't migrated to the new cgroup v2 interface yet. Legacy |
1224 | interface includes cpuset filesystem and /proc/<pid>/cpuset. If you | |
1abab1ba CR |
1225 | do not have any such application then you are completely fine leaving |
1226 | this option disabled. | |
1227 | ||
1228 | Say N if unsure. | |
1229 | ||
6bf024e6 JW |
1230 | config PROC_PID_CPUSET |
1231 | bool "Include legacy /proc/<pid>/cpuset file" | |
dae68fba | 1232 | depends on CPUSETS_V1 |
6bf024e6 | 1233 | default y |
afc24d49 | 1234 | |
6bf024e6 JW |
1235 | config CGROUP_DEVICE |
1236 | bool "Device controller" | |
1237 | help | |
1238 | Provides a cgroup controller implementing whitelists for | |
1239 | devices which a process in the cgroup can mknod or open. | |
1240 | ||
1241 | config CGROUP_CPUACCT | |
1242 | bool "Simple CPU accounting controller" | |
1243 | help | |
1244 | Provides a simple controller for monitoring the | |
1245 | total CPU consumed by the tasks in a cgroup. | |
1246 | ||
1247 | config CGROUP_PERF | |
1248 | bool "Perf controller" | |
1249 | depends on PERF_EVENTS | |
1250 | help | |
1251 | This option extends the perf per-cpu mode to restrict monitoring | |
1252 | to threads which belong to the cgroup specified and run on the | |
6546b19f NK |
1253 | designated cpu. Or this can be used to have cgroup ID in samples |
1254 | so that it can monitor performance events among cgroups. | |
6bf024e6 JW |
1255 | |
1256 | Say N if unsure. | |
1257 | ||
30070984 DM |
1258 | config CGROUP_BPF |
1259 | bool "Support for eBPF programs attached to cgroups" | |
483c4933 AL |
1260 | depends on BPF_SYSCALL |
1261 | select SOCK_CGROUP_DATA | |
30070984 DM |
1262 | help |
1263 | Allow attaching eBPF programs to a cgroup using the bpf(2) | |
1264 | syscall command BPF_PROG_ATTACH. | |
1265 | ||
1266 | In which context these programs are accessed depends on the type | |
1267 | of attachment. For instance, programs that are attached using | |
1268 | BPF_CGROUP_INET_INGRESS will be executed on the ingress path of | |
1269 | inet sockets. | |
1270 | ||
a72232ea VS |
1271 | config CGROUP_MISC |
1272 | bool "Misc resource controller" | |
1273 | default n | |
1274 | help | |
1275 | Provides a controller for miscellaneous resources on a host. | |
1276 | ||
1277 | Miscellaneous scalar resources are the resources on the host system | |
1278 | which cannot be abstracted like the other cgroups. This controller | |
1279 | tracks and limits the miscellaneous resources used by a process | |
1280 | attached to a cgroup hierarchy. | |
1281 | ||
1282 | For more information, please check misc cgroup section in | |
1283 | /Documentation/admin-guide/cgroup-v2.rst. | |
1284 | ||
6bf024e6 | 1285 | config CGROUP_DEBUG |
23b0be48 | 1286 | bool "Debug controller" |
afc24d49 | 1287 | default n |
23b0be48 | 1288 | depends on DEBUG_KERNEL |
6bf024e6 JW |
1289 | help |
1290 | This option enables a simple controller that exports | |
23b0be48 WL |
1291 | debugging information about the cgroups framework. This |
1292 | controller is for control cgroup debugging only. Its | |
1293 | interfaces are not stable. | |
afc24d49 | 1294 | |
6bf024e6 | 1295 | Say N. |
89e9b9e0 | 1296 | |
73b35147 AB |
1297 | config SOCK_CGROUP_DATA |
1298 | bool | |
1299 | default n | |
1300 | ||
23964d2d | 1301 | endif # CGROUPS |
c077719b | 1302 | |
8dd2a82c | 1303 | menuconfig NAMESPACES |
6a108a14 | 1304 | bool "Namespaces support" if EXPERT |
2813893f | 1305 | depends on MULTIUSER |
6a108a14 | 1306 | default !EXPERT |
c5289a69 PE |
1307 | help |
1308 | Provides the way to make tasks work with different objects using | |
1309 | the same id. For example same IPC id may refer to different objects | |
1310 | or same user id or pid may refer to different tasks when used in | |
1311 | different namespaces. | |
1312 | ||
8dd2a82c DL |
1313 | if NAMESPACES |
1314 | ||
58bfdd6d PE |
1315 | config UTS_NS |
1316 | bool "UTS namespace" | |
17a6d441 | 1317 | default y |
58bfdd6d PE |
1318 | help |
1319 | In this namespace tasks see different info provided with the | |
1320 | uname() system call | |
1321 | ||
769071ac AV |
1322 | config TIME_NS |
1323 | bool "TIME namespace" | |
660fd04f | 1324 | depends on GENERIC_VDSO_TIME_NS |
769071ac AV |
1325 | default y |
1326 | help | |
1327 | In this namespace boottime and monotonic clocks can be set. | |
1328 | The time will keep going with the same pace. | |
1329 | ||
ae5e1b22 PE |
1330 | config IPC_NS |
1331 | bool "IPC namespace" | |
8dd2a82c | 1332 | depends on (SYSVIPC || POSIX_MQUEUE) |
17a6d441 | 1333 | default y |
ae5e1b22 PE |
1334 | help |
1335 | In this namespace tasks work with IPC ids which correspond to | |
614b84cf | 1336 | different IPC objects in different namespaces. |
ae5e1b22 | 1337 | |
aee16ce7 | 1338 | config USER_NS |
19c92399 | 1339 | bool "User namespace" |
5673a94c | 1340 | default n |
aee16ce7 PE |
1341 | help |
1342 | This allows containers, i.e. vservers, to use user namespaces | |
1343 | to provide different user info for different servers. | |
e11f0ae3 EB |
1344 | |
1345 | When user namespaces are enabled in the kernel it is | |
d886f4e4 JW |
1346 | recommended that the MEMCG option also be enabled and that |
1347 | user-space use the memory control groups to limit the amount | |
1348 | of memory a memory unprivileged users can use. | |
e11f0ae3 | 1349 | |
aee16ce7 PE |
1350 | If unsure, say N. |
1351 | ||
74bd59bb | 1352 | config PID_NS |
9bd38c2c | 1353 | bool "PID Namespaces" |
17a6d441 | 1354 | default y |
74bd59bb | 1355 | help |
12d2b8f9 | 1356 | Support process id namespaces. This allows having multiple |
692105b8 | 1357 | processes with the same pid as long as they are in different |
74bd59bb PE |
1358 | pid namespaces. This is a building block of containers. |
1359 | ||
d6eb633f MH |
1360 | config NET_NS |
1361 | bool "Network namespace" | |
8dd2a82c | 1362 | depends on NET |
17a6d441 | 1363 | default y |
d6eb633f MH |
1364 | help |
1365 | Allow user space to create what appear to be multiple instances | |
1366 | of the network stack. | |
1367 | ||
8dd2a82c DL |
1368 | endif # NAMESPACES |
1369 | ||
5cb366bb AR |
1370 | config CHECKPOINT_RESTORE |
1371 | bool "Checkpoint/restore support" | |
30341ec9 | 1372 | depends on PROC_FS |
5cb366bb | 1373 | select PROC_CHILDREN |
bfe3911a | 1374 | select KCMP |
5cb366bb AR |
1375 | default n |
1376 | help | |
1377 | Enables additional kernel features in a sake of checkpoint/restore. | |
1378 | In particular it adds auxiliary prctl codes to setup process text, | |
1379 | data and heap segment sizes, and a few additional /proc filesystem | |
1380 | entries. | |
1381 | ||
1382 | If unsure, say N here. | |
1383 | ||
5091faa4 MG |
1384 | config SCHED_AUTOGROUP |
1385 | bool "Automatic process group scheduling" | |
5091faa4 MG |
1386 | select CGROUPS |
1387 | select CGROUP_SCHED | |
1388 | select FAIR_GROUP_SCHED | |
1389 | help | |
1390 | This option optimizes the scheduler for common desktop workloads by | |
1391 | automatically creating and populating task groups. This separation | |
1392 | of workloads isolates aggressive CPU burners (like build jobs) from | |
1393 | desktop applications. Task group autogeneration is currently based | |
1394 | upon task session. | |
1395 | ||
7af37bec DL |
1396 | config RELAY |
1397 | bool "Kernel->user space relay support (formerly relayfs)" | |
26b5679e | 1398 | select IRQ_WORK |
7af37bec DL |
1399 | help |
1400 | This option enables support for relay interface support in | |
1401 | certain file systems (such as debugfs). | |
1402 | It is designed to provide an efficient mechanism for tools and | |
1403 | facilities to relay large amounts of data from kernel space to | |
1404 | user space. | |
1405 | ||
1406 | If unsure, say N. | |
1407 | ||
f991633d DG |
1408 | config BLK_DEV_INITRD |
1409 | bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support" | |
f991633d DG |
1410 | help |
1411 | The initial RAM filesystem is a ramfs which is loaded by the | |
1412 | boot loader (loadlin or lilo) and that is mounted as root | |
1413 | before the normal boot procedure. It is typically used to | |
1414 | load modules needed to mount the "real" root file system, | |
8c27ceff | 1415 | etc. See <file:Documentation/admin-guide/initrd.rst> for details. |
f991633d DG |
1416 | |
1417 | If RAM disk support (BLK_DEV_RAM) is also included, this | |
1418 | also enables initial RAM disk (initrd) support and adds | |
1419 | 15 Kbytes (more on some other architectures) to the kernel size. | |
1420 | ||
1421 | If unsure say Y. | |
1422 | ||
c33df4ea JPS |
1423 | if BLK_DEV_INITRD |
1424 | ||
dbec4866 SR |
1425 | source "usr/Kconfig" |
1426 | ||
c33df4ea JPS |
1427 | endif |
1428 | ||
76db5a27 MH |
1429 | config BOOT_CONFIG |
1430 | bool "Boot config support" | |
a2a9d67a | 1431 | select BLK_DEV_INITRD if !BOOT_CONFIG_EMBED |
76db5a27 MH |
1432 | help |
1433 | Extra boot config allows system admin to pass a config file as | |
1434 | complemental extension of kernel cmdline when booting. | |
0947db01 | 1435 | The boot config file must be attached at the end of initramfs |
85c46b78 | 1436 | with checksum, size and magic word. |
0947db01 | 1437 | See <file:Documentation/admin-guide/bootconfig.rst> for details. |
76db5a27 MH |
1438 | |
1439 | If unsure, say Y. | |
1440 | ||
b743852c PM |
1441 | config BOOT_CONFIG_FORCE |
1442 | bool "Force unconditional bootconfig processing" | |
1443 | depends on BOOT_CONFIG | |
6ded8a28 | 1444 | default y if BOOT_CONFIG_EMBED |
b743852c PM |
1445 | help |
1446 | With this Kconfig option set, BOOT_CONFIG processing is carried | |
1447 | out even when the "bootconfig" kernel-boot parameter is omitted. | |
1448 | In fact, with this Kconfig option set, there is no way to | |
1449 | make the kernel ignore the BOOT_CONFIG-supplied kernel-boot | |
1450 | parameters. | |
1451 | ||
1452 | If unsure, say N. | |
1453 | ||
a2a9d67a MH |
1454 | config BOOT_CONFIG_EMBED |
1455 | bool "Embed bootconfig file in the kernel" | |
1456 | depends on BOOT_CONFIG | |
1457 | help | |
1458 | Embed a bootconfig file given by BOOT_CONFIG_EMBED_FILE in the | |
1459 | kernel. Usually, the bootconfig file is loaded with the initrd | |
1460 | image. But if the system doesn't support initrd, this option will | |
1461 | help you by embedding a bootconfig file while building the kernel. | |
1462 | ||
1463 | If unsure, say N. | |
1464 | ||
1465 | config BOOT_CONFIG_EMBED_FILE | |
1466 | string "Embedded bootconfig file path" | |
1467 | depends on BOOT_CONFIG_EMBED | |
1468 | help | |
1469 | Specify a bootconfig file which will be embedded to the kernel. | |
1470 | This bootconfig will be used if there is no initrd or no other | |
1471 | bootconfig in the initrd. | |
1472 | ||
1274aea1 DD |
1473 | config INITRAMFS_PRESERVE_MTIME |
1474 | bool "Preserve cpio archive mtimes in initramfs" | |
1475 | default y | |
1476 | help | |
1477 | Each entry in an initramfs cpio archive carries an mtime value. When | |
1478 | enabled, extracted cpio items take this mtime, with directory mtime | |
1479 | setting deferred until after creation of any child entries. | |
1480 | ||
1481 | If unsure, say Y. | |
76db5a27 | 1482 | |
83c0b272 DD |
1483 | config INITRAMFS_TEST |
1484 | bool "Test initramfs cpio archive extraction" if !KUNIT_ALL_TESTS | |
1485 | depends on BLK_DEV_INITRD && KUNIT=y | |
1486 | default KUNIT_ALL_TESTS | |
1487 | help | |
1488 | Build KUnit tests for initramfs. See Documentation/dev-tools/kunit | |
1489 | ||
877417e6 AB |
1490 | choice |
1491 | prompt "Compiler optimization level" | |
2cc3ce24 | 1492 | default CC_OPTIMIZE_FOR_PERFORMANCE |
877417e6 AB |
1493 | |
1494 | config CC_OPTIMIZE_FOR_PERFORMANCE | |
15f5db60 | 1495 | bool "Optimize for performance (-O2)" |
877417e6 AB |
1496 | help |
1497 | This is the default optimization level for the kernel, building | |
1498 | with the "-O2" compiler flag for best performance and most | |
1499 | helpful compile-time warnings. | |
1500 | ||
c45b4f1f | 1501 | config CC_OPTIMIZE_FOR_SIZE |
15f5db60 | 1502 | bool "Optimize for size (-Os)" |
c45b4f1f | 1503 | help |
ce3b487f MY |
1504 | Choosing this option will pass "-Os" to your compiler resulting |
1505 | in a smaller kernel. | |
c45b4f1f | 1506 | |
877417e6 AB |
1507 | endchoice |
1508 | ||
5d20ee31 NP |
1509 | config HAVE_LD_DEAD_CODE_DATA_ELIMINATION |
1510 | bool | |
1511 | help | |
1512 | This requires that the arch annotates or otherwise protects | |
1513 | its external entry points from being discarded. Linker scripts | |
1514 | must also merge .text.*, .data.*, and .bss.* correctly into | |
1515 | output sections. Care must be taken not to pull in unrelated | |
1516 | sections (e.g., '.text.init'). Typically '.' in section names | |
1517 | is used to distinguish them from label names / C identifiers. | |
1518 | ||
1519 | config LD_DEAD_CODE_DATA_ELIMINATION | |
1520 | bool "Dead code and data elimination (EXPERIMENTAL)" | |
1521 | depends on HAVE_LD_DEAD_CODE_DATA_ELIMINATION | |
1522 | depends on EXPERT | |
e85d1d65 MY |
1523 | depends on $(cc-option,-ffunction-sections -fdata-sections) |
1524 | depends on $(ld-option,--gc-sections) | |
5d20ee31 | 1525 | help |
8b9d2712 MY |
1526 | Enable this if you want to do dead code and data elimination with |
1527 | the linker by compiling with -ffunction-sections -fdata-sections, | |
1528 | and linking with --gc-sections. | |
5d20ee31 NP |
1529 | |
1530 | This can reduce on disk and in-memory size of the kernel | |
1531 | code and static data, particularly for small configs and | |
1532 | on small systems. This has the possibility of introducing | |
1533 | silently broken kernel if the required annotations are not | |
1534 | present. This option is not well tested yet, so use at your | |
1535 | own risk. | |
1536 | ||
59612b24 NC |
1537 | config LD_ORPHAN_WARN |
1538 | def_bool y | |
1539 | depends on ARCH_WANT_LD_ORPHAN_WARN | |
1540 | depends on $(ld-option,--orphan-handling=warn) | |
e1789d7c XL |
1541 | depends on $(ld-option,--orphan-handling=error) |
1542 | ||
1543 | config LD_ORPHAN_WARN_LEVEL | |
1544 | string | |
1545 | depends on LD_ORPHAN_WARN | |
1546 | default "error" if WERROR | |
1547 | default "warn" | |
59612b24 | 1548 | |
0847062a RD |
1549 | config SYSCTL |
1550 | bool | |
1551 | ||
657a5209 MF |
1552 | config HAVE_UID16 |
1553 | bool | |
1554 | ||
1555 | config SYSCTL_EXCEPTION_TRACE | |
1556 | bool | |
1557 | help | |
1558 | Enable support for /proc/sys/debug/exception-trace. | |
1559 | ||
1560 | config SYSCTL_ARCH_UNALIGN_NO_WARN | |
1561 | bool | |
1562 | help | |
1563 | Enable support for /proc/sys/kernel/ignore-unaligned-usertrap | |
1564 | Allows arch to define/use @no_unaligned_warning to possibly warn | |
1565 | about unaligned access emulation going on under the hood. | |
1566 | ||
1567 | config SYSCTL_ARCH_UNALIGN_ALLOW | |
1568 | bool | |
1569 | help | |
1570 | Enable support for /proc/sys/kernel/unaligned-trap | |
1571 | Allows arches to define/use @unaligned_enabled to runtime toggle | |
1572 | the unaligned access emulation. | |
1573 | see arch/parisc/kernel/unaligned.c for reference | |
1574 | ||
c443279a CB |
1575 | config SYSFS_SYSCALL |
1576 | bool "Sysfs syscall support" | |
1577 | default n | |
1578 | help | |
1579 | sys_sysfs is an obsolete system call no longer supported in libc. | |
1580 | Note that disabling this option is more secure but might break | |
1581 | compatibility with some systems. | |
1582 | ||
1583 | If unsure say N here. | |
1584 | ||
657a5209 MF |
1585 | config HAVE_PCSPKR_PLATFORM |
1586 | bool | |
1587 | ||
6a108a14 DR |
1588 | menuconfig EXPERT |
1589 | bool "Configure standard kernel features (expert users)" | |
f505c553 JT |
1590 | # Unhide debug options, to make the on-by-default options visible |
1591 | select DEBUG_KERNEL | |
1da177e4 LT |
1592 | help |
1593 | This option allows certain base kernel options and settings | |
e8cf4e9c KK |
1594 | to be disabled or tweaked. This is for specialized |
1595 | environments which can tolerate a "non-standard" kernel. | |
1596 | Only use this if you really know what you are doing. | |
1da177e4 | 1597 | |
ae81f9e3 | 1598 | config UID16 |
6a108a14 | 1599 | bool "Enable 16-bit UID system calls" if EXPERT |
2813893f | 1600 | depends on HAVE_UID16 && MULTIUSER |
ae81f9e3 CE |
1601 | default y |
1602 | help | |
1603 | This enables the legacy 16-bit UID syscall wrappers. | |
1604 | ||
2813893f IM |
1605 | config MULTIUSER |
1606 | bool "Multiple users, groups and capabilities support" if EXPERT | |
1607 | default y | |
1608 | help | |
1609 | This option enables support for non-root users, groups and | |
1610 | capabilities. | |
1611 | ||
1612 | If you say N here, all processes will run with UID 0, GID 0, and all | |
1613 | possible capabilities. Saying N here also compiles out support for | |
1614 | system calls related to UIDs, GIDs, and capabilities, such as setuid, | |
1615 | setgid, and capset. | |
1616 | ||
1617 | If unsure, say Y here. | |
1618 | ||
f6187769 FF |
1619 | config SGETMASK_SYSCALL |
1620 | bool "sgetmask/ssetmask syscalls support" if EXPERT | |
cd14b018 | 1621 | default PARISC || M68K || PPC || MIPS || X86 || SPARC || MICROBLAZE || SUPERH |
a7f7f624 | 1622 | help |
f6187769 FF |
1623 | sys_sgetmask and sys_ssetmask are obsolete system calls |
1624 | no longer supported in libc but still enabled by default in some | |
1625 | architectures. | |
1626 | ||
1627 | If unsure, leave the default option here. | |
1628 | ||
d1b069f5 RD |
1629 | config FHANDLE |
1630 | bool "open by fhandle syscalls" if EXPERT | |
1631 | select EXPORTFS | |
1632 | default y | |
1633 | help | |
1634 | If you say Y here, a user level program will be able to map | |
1635 | file names to handle and then later use the handle for | |
1636 | different file system operations. This is useful in implementing | |
1637 | userspace file servers, which now track files using handles instead | |
1638 | of names. The handle would remain the same even if file names | |
1639 | get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2) | |
1640 | syscalls. | |
1641 | ||
baa73d9e NP |
1642 | config POSIX_TIMERS |
1643 | bool "Posix Clocks & timers" if EXPERT | |
1644 | default y | |
1645 | help | |
1646 | This includes native support for POSIX timers to the kernel. | |
1647 | Some embedded systems have no use for them and therefore they | |
1648 | can be configured out to reduce the size of the kernel image. | |
1649 | ||
1650 | When this option is disabled, the following syscalls won't be | |
1651 | available: timer_create, timer_gettime: timer_getoverrun, | |
1652 | timer_settime, timer_delete, clock_adjtime, getitimer, | |
1653 | setitimer, alarm. Furthermore, the clock_settime, clock_gettime, | |
1654 | clock_getres and clock_nanosleep syscalls will be limited to | |
1655 | CLOCK_REALTIME, CLOCK_MONOTONIC and CLOCK_BOOTTIME only. | |
1656 | ||
1657 | If unsure say y. | |
1658 | ||
d59745ce MM |
1659 | config PRINTK |
1660 | default y | |
6a108a14 | 1661 | bool "Enable support for printk" if EXPERT |
74876a98 | 1662 | select IRQ_WORK |
d59745ce MM |
1663 | help |
1664 | This option enables normal printk support. Removing it | |
1665 | eliminates most of the message strings from the kernel image | |
1666 | and makes the kernel more or less silent. As this makes it | |
1667 | very difficult to diagnose system problems, saying N here is | |
1668 | strongly discouraged. | |
1669 | ||
c8538a7a | 1670 | config BUG |
6a108a14 | 1671 | bool "BUG() support" if EXPERT |
c8538a7a MM |
1672 | default y |
1673 | help | |
e8cf4e9c KK |
1674 | Disabling this option eliminates support for BUG and WARN, reducing |
1675 | the size of your kernel image and potentially quietly ignoring | |
1676 | numerous fatal conditions. You should only consider disabling this | |
1677 | option for embedded systems with no facilities for reporting errors. | |
1678 | Just say Y. | |
c8538a7a | 1679 | |
708e9a79 | 1680 | config ELF_CORE |
046d662f | 1681 | depends on COREDUMP |
708e9a79 | 1682 | default y |
6a108a14 | 1683 | bool "Enable ELF core dumps" if EXPERT |
708e9a79 MM |
1684 | help |
1685 | Enable support for generating core dumps. Disabling saves about 4k. | |
1686 | ||
8761f1ab | 1687 | |
e5e1d3cb | 1688 | config PCSPKR_PLATFORM |
6a108a14 | 1689 | bool "Enable PC-Speaker support" if EXPERT |
8761f1ab | 1690 | depends on HAVE_PCSPKR_PLATFORM |
15f304b6 | 1691 | select I8253_LOCK |
e5e1d3cb SS |
1692 | default y |
1693 | help | |
e8cf4e9c KK |
1694 | This option allows to disable the internal PC-Speaker |
1695 | support, saving some memory. | |
e5e1d3cb | 1696 | |
27021649 YC |
1697 | config BASE_SMALL |
1698 | bool "Enable smaller-sized data structures for core" if EXPERT | |
1da177e4 | 1699 | help |
27021649 | 1700 | Enabling this option reduces the size of miscellaneous core |
1da177e4 LT |
1701 | kernel data structures. This saves memory on small machines, |
1702 | but may reduce performance. | |
1703 | ||
1704 | config FUTEX | |
6a108a14 | 1705 | bool "Enable futex support" if EXPERT |
3f2bedab | 1706 | depends on !(SPARC32 && SMP) |
1da177e4 | 1707 | default y |
bc2eecd7 | 1708 | imply RT_MUTEXES |
1da177e4 LT |
1709 | help |
1710 | Disabling this option will cause the kernel to be built without | |
1711 | support for "fast userspace mutexes". The resulting kernel may not | |
1712 | run glibc-based applications correctly. | |
1713 | ||
bc2eecd7 NP |
1714 | config FUTEX_PI |
1715 | bool | |
1716 | depends on FUTEX && RT_MUTEXES | |
1717 | default y | |
1718 | ||
80367ad0 SAS |
1719 | config FUTEX_PRIVATE_HASH |
1720 | bool | |
1721 | depends on FUTEX && !BASE_SMALL && MMU | |
1722 | default y | |
1723 | ||
c042c505 PZ |
1724 | config FUTEX_MPOL |
1725 | bool | |
1726 | depends on FUTEX && NUMA | |
1727 | default y | |
1728 | ||
1da177e4 | 1729 | config EPOLL |
6a108a14 | 1730 | bool "Enable eventpoll support" if EXPERT |
1da177e4 LT |
1731 | default y |
1732 | help | |
1733 | Disabling this option will cause the kernel to be built without | |
1734 | support for epoll family of system calls. | |
1735 | ||
fba2afaa | 1736 | config SIGNALFD |
6a108a14 | 1737 | bool "Enable signalfd() system call" if EXPERT |
fba2afaa DL |
1738 | default y |
1739 | help | |
1740 | Enable the signalfd() system call that allows to receive signals | |
1741 | on a file descriptor. | |
1742 | ||
1743 | If unsure, say Y. | |
1744 | ||
b215e283 | 1745 | config TIMERFD |
6a108a14 | 1746 | bool "Enable timerfd() system call" if EXPERT |
b215e283 DL |
1747 | default y |
1748 | help | |
1749 | Enable the timerfd() system call that allows to receive timer | |
1750 | events on a file descriptor. | |
1751 | ||
1752 | If unsure, say Y. | |
1753 | ||
e1ad7468 | 1754 | config EVENTFD |
6a108a14 | 1755 | bool "Enable eventfd() system call" if EXPERT |
e1ad7468 DL |
1756 | default y |
1757 | help | |
1758 | Enable the eventfd() system call that allows to receive both | |
1759 | kernel notification (ie. KAIO) or userspace notifications. | |
1760 | ||
1761 | If unsure, say Y. | |
1762 | ||
1da177e4 | 1763 | config SHMEM |
6a108a14 | 1764 | bool "Use full shmem filesystem" if EXPERT |
1da177e4 LT |
1765 | default y |
1766 | depends on MMU | |
1767 | help | |
1768 | The shmem is an internal filesystem used to manage shared memory. | |
1769 | It is backed by swap and manages resource limits. It is also exported | |
1770 | to userspace as tmpfs if TMPFS is enabled. Disabling this | |
1771 | option replaces shmem and tmpfs with the much simpler ramfs code, | |
1772 | which may be appropriate on small systems without swap. | |
1773 | ||
ebf3f09c | 1774 | config AIO |
6a108a14 | 1775 | bool "Enable AIO support" if EXPERT |
ebf3f09c TP |
1776 | default y |
1777 | help | |
1778 | This option enables POSIX asynchronous I/O which may by used | |
657a5209 MF |
1779 | by some high performance threaded applications. Disabling |
1780 | this option saves about 7k. | |
1781 | ||
2b188cc1 JA |
1782 | config IO_URING |
1783 | bool "Enable IO uring support" if EXPERT | |
561fb04a | 1784 | select IO_WQ |
2b188cc1 JA |
1785 | default y |
1786 | help | |
1787 | This option enables support for the io_uring interface, enabling | |
1788 | applications to submit and complete IO through submission and | |
1789 | completion rings that are shared between the kernel and application. | |
1790 | ||
1802656e JA |
1791 | config GCOV_PROFILE_URING |
1792 | bool "Enable GCOV profiling on the io_uring subsystem" | |
1793 | depends on GCOV_KERNEL | |
1794 | help | |
1795 | Enable GCOV profiling on the io_uring subsystem, to facilitate | |
1796 | code coverage testing. | |
1797 | ||
1798 | If unsure, say N. | |
1799 | ||
1800 | Note that this will have a negative impact on the performance of | |
1801 | the io_uring subsystem, hence this should only be enabled for | |
1802 | specific test purposes. | |
1803 | ||
d3ac21ca JT |
1804 | config ADVISE_SYSCALLS |
1805 | bool "Enable madvise/fadvise syscalls" if EXPERT | |
1806 | default y | |
1807 | help | |
1808 | This option enables the madvise and fadvise syscalls, used by | |
1809 | applications to advise the kernel about their future memory or file | |
1810 | usage, improving performance. If building an embedded system where no | |
1811 | applications use these syscalls, you can disable this option to save | |
1812 | space. | |
1813 | ||
5b25b13a MD |
1814 | config MEMBARRIER |
1815 | bool "Enable membarrier() system call" if EXPERT | |
1816 | default y | |
1817 | help | |
1818 | Enable the membarrier() system call that allows issuing memory | |
1819 | barriers across all running threads, which can be used to distribute | |
1820 | the cost of user-space memory barriers asymmetrically by transforming | |
1821 | pairs of memory barriers into pairs consisting of membarrier() and a | |
1822 | compiler barrier. | |
1823 | ||
1824 | If unsure, say Y. | |
1825 | ||
a751ea34 RD |
1826 | config KCMP |
1827 | bool "Enable kcmp() system call" if EXPERT | |
1828 | help | |
1829 | Enable the kernel resource comparison system call. It provides | |
1830 | user-space with the ability to compare two processes to see if they | |
1831 | share a common resource, such as a file descriptor or even virtual | |
1832 | memory space. | |
1833 | ||
1834 | If unsure, say N. | |
1835 | ||
1836 | config RSEQ | |
1837 | bool "Enable rseq() system call" if EXPERT | |
1838 | default y | |
1839 | depends on HAVE_RSEQ | |
1840 | select MEMBARRIER | |
1841 | help | |
1842 | Enable the restartable sequences system call. It provides a | |
1843 | user-space cache for the current CPU number value, which | |
1844 | speeds up getting the current CPU number from user-space, | |
1845 | as well as an ABI to speed up user-space operations on | |
1846 | per-CPU data. | |
1847 | ||
1848 | If unsure, say Y. | |
1849 | ||
1850 | config DEBUG_RSEQ | |
1851 | default n | |
1852 | bool "Enable debugging of rseq() system call" if EXPERT | |
1853 | depends on RSEQ && DEBUG_KERNEL | |
1854 | help | |
1855 | Enable extra debugging checks for the rseq system call. | |
1856 | ||
1857 | If unsure, say N. | |
1858 | ||
1859 | config CACHESTAT_SYSCALL | |
1860 | bool "Enable cachestat() system call" if EXPERT | |
1861 | default y | |
1862 | help | |
1863 | Enable the cachestat system call, which queries the page cache | |
1864 | statistics of a file (number of cached pages, dirty pages, | |
1865 | pages marked for writeback, (recently) evicted pages). | |
1866 | ||
1867 | If unsure say Y here. | |
1868 | ||
1869 | config PC104 | |
1870 | bool "PC/104 support" if EXPERT | |
1871 | help | |
1872 | Expose PC/104 form factor device drivers and options available for | |
1873 | selection and configuration. Enable this option if your target | |
1874 | machine has a PC/104 bus. | |
1875 | ||
d1b069f5 | 1876 | config KALLSYMS |
e8cf4e9c KK |
1877 | bool "Load all symbols for debugging/ksymoops" if EXPERT |
1878 | default y | |
1879 | help | |
1880 | Say Y here to let the kernel print out symbolic crash information and | |
1881 | symbolic stack backtraces. This increases the size of the kernel | |
1882 | somewhat, as all symbols have to be loaded into the kernel image. | |
d1b069f5 | 1883 | |
30f3bb09 ZL |
1884 | config KALLSYMS_SELFTEST |
1885 | bool "Test the basic functions and performance of kallsyms" | |
1886 | depends on KALLSYMS | |
1887 | default n | |
1888 | help | |
1889 | Test the basic functions and performance of some interfaces, such as | |
1890 | kallsyms_lookup_name. It also calculates the compression rate of the | |
1891 | kallsyms compression algorithm for the current symbol set. | |
1892 | ||
1893 | Start self-test automatically after system startup. Suggest executing | |
1894 | "dmesg | grep kallsyms_selftest" to collect test results. "finish" is | |
1895 | displayed in the last line, indicating that the test is complete. | |
1896 | ||
d1b069f5 RD |
1897 | config KALLSYMS_ALL |
1898 | bool "Include all symbols in kallsyms" | |
1899 | depends on DEBUG_KERNEL && KALLSYMS | |
1900 | help | |
e8cf4e9c KK |
1901 | Normally kallsyms only contains the symbols of functions for nicer |
1902 | OOPS messages and backtraces (i.e., symbols from the text and inittext | |
bdf0fe33 BS |
1903 | sections). This is sufficient for most cases. And only if you want to |
1904 | enable kernel live patching, or other less common use cases (e.g., | |
1905 | when a debugger is used) all symbols are required (i.e., names of | |
1906 | variables from the data sections, etc). | |
d1b069f5 | 1907 | |
e8cf4e9c KK |
1908 | This option makes sure that all symbols are loaded into the kernel |
1909 | image (i.e., symbols from all sections) in cost of increased kernel | |
1910 | size (depending on the kernel configuration, it may be 300KiB or | |
1911 | something like this). | |
d1b069f5 | 1912 | |
bdf0fe33 | 1913 | Say N unless you really need all symbols, or kernel live patching. |
d1b069f5 | 1914 | |
d1b069f5 RD |
1915 | # end of the "standard kernel features (expert users)" menu |
1916 | ||
3ccfebed MD |
1917 | config ARCH_HAS_MEMBARRIER_CALLBACKS |
1918 | bool | |
1919 | ||
70216e18 MD |
1920 | config ARCH_HAS_MEMBARRIER_SYNC_CORE |
1921 | bool | |
1922 | ||
5796d396 JX |
1923 | config ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS |
1924 | bool | |
1925 | help | |
1926 | Control MSEAL_SYSTEM_MAPPINGS access based on architecture. | |
1927 | ||
1928 | A 64-bit kernel is required for the memory sealing feature. | |
1929 | No specific hardware features from the CPU are needed. | |
1930 | ||
1931 | To enable this feature, the architecture needs to update their | |
1932 | special mappings calls to include the sealing flag and confirm | |
1933 | that it doesn't unmap/remap system mappings during the life | |
1934 | time of the process. The existence of this flag for an architecture | |
1935 | implies that it does not require the remapping of the system | |
1936 | mappings during process lifetime, so sealing these mappings is safe | |
1937 | from a kernel perspective. | |
1938 | ||
1939 | After the architecture enables this, a distribution can set | |
1940 | CONFIG_MSEAL_SYSTEM_MAPPING to manage access to the feature. | |
1941 | ||
1942 | For complete descriptions of memory sealing, please see | |
1943 | Documentation/userspace-api/mseal.rst | |
1944 | ||
cdd6c482 | 1945 | config HAVE_PERF_EVENTS |
0793a61d | 1946 | bool |
018df72d MF |
1947 | help |
1948 | See tools/perf/design.txt for details. | |
0793a61d | 1949 | |
2aef6f30 SC |
1950 | config GUEST_PERF_EVENTS |
1951 | bool | |
1952 | depends on HAVE_PERF_EVENTS | |
1953 | ||
906010b2 PZ |
1954 | config PERF_USE_VMALLOC |
1955 | bool | |
1956 | help | |
1957 | See tools/perf/design.txt for details | |
1958 | ||
57c0c15b | 1959 | menu "Kernel Performance Events And Counters" |
0793a61d | 1960 | |
cdd6c482 | 1961 | config PERF_EVENTS |
57c0c15b | 1962 | bool "Kernel performance events and counters" |
392d65a9 | 1963 | default y if PROFILING |
cdd6c482 | 1964 | depends on HAVE_PERF_EVENTS |
e360adbe | 1965 | select IRQ_WORK |
0793a61d | 1966 | help |
57c0c15b IM |
1967 | Enable kernel support for various performance events provided |
1968 | by software and hardware. | |
0793a61d | 1969 | |
dd77038d | 1970 | Software events are supported either built-in or via the |
57c0c15b | 1971 | use of generic tracepoints. |
0793a61d | 1972 | |
57c0c15b IM |
1973 | Most modern CPUs support performance events via performance |
1974 | counter registers. These registers count the number of certain | |
0793a61d TG |
1975 | types of hw events: such as instructions executed, cachemisses |
1976 | suffered, or branches mis-predicted - without slowing down the | |
1977 | kernel or applications. These registers can also trigger interrupts | |
1978 | when a threshold number of events have passed - and can thus be | |
1979 | used to profile the code that runs on that CPU. | |
1980 | ||
57c0c15b | 1981 | The Linux Performance Event subsystem provides an abstraction of |
dd77038d | 1982 | these software and hardware event capabilities, available via a |
57c0c15b | 1983 | system call and used by the "perf" utility in tools/perf/. It |
0793a61d TG |
1984 | provides per task and per CPU counters, and it provides event |
1985 | capabilities on top of those. | |
1986 | ||
1987 | Say Y if unsure. | |
1988 | ||
906010b2 PZ |
1989 | config DEBUG_PERF_USE_VMALLOC |
1990 | default n | |
1991 | bool "Debug: use vmalloc to back perf mmap() buffers" | |
cb307113 | 1992 | depends on PERF_EVENTS && DEBUG_KERNEL && !PPC |
906010b2 PZ |
1993 | select PERF_USE_VMALLOC |
1994 | help | |
e8cf4e9c | 1995 | Use vmalloc memory to back perf mmap() buffers. |
906010b2 | 1996 | |
e8cf4e9c KK |
1997 | Mostly useful for debugging the vmalloc code on platforms |
1998 | that don't require it. | |
906010b2 | 1999 | |
e8cf4e9c | 2000 | Say N if unsure. |
906010b2 | 2001 | |
0793a61d TG |
2002 | endmenu |
2003 | ||
091f6e26 DH |
2004 | config SYSTEM_DATA_VERIFICATION |
2005 | def_bool n | |
2006 | select SYSTEM_TRUSTED_KEYRING | |
2007 | select KEYS | |
2008 | select CRYPTO | |
d43de6c7 | 2009 | select CRYPTO_RSA |
091f6e26 DH |
2010 | select ASYMMETRIC_KEY_TYPE |
2011 | select ASYMMETRIC_PUBLIC_KEY_SUBTYPE | |
091f6e26 DH |
2012 | select ASN1 |
2013 | select OID_REGISTRY | |
2014 | select X509_CERTIFICATE_PARSER | |
2015 | select PKCS7_MESSAGE_PARSER | |
82c04ff8 | 2016 | help |
091f6e26 DH |
2017 | Provide PKCS#7 message verification using the contents of the system |
2018 | trusted keyring to provide public keys. This then can be used for | |
2019 | module verification, kexec image verification and firmware blob | |
2020 | verification. | |
82c04ff8 | 2021 | |
125e5645 | 2022 | config PROFILING |
b309a294 | 2023 | bool "Profiling support" |
125e5645 MD |
2024 | help |
2025 | Say Y here to enable the extended profiling support mechanisms used | |
f8408264 | 2026 | by profilers. |
125e5645 | 2027 | |
2f7ab126 MO |
2028 | config RUST |
2029 | bool "Rust support" | |
2030 | depends on HAVE_RUST | |
2031 | depends on RUST_IS_AVAILABLE | |
ac61506b ST |
2032 | select EXTENDED_MODVERSIONS if MODVERSIONS |
2033 | depends on !MODVERSIONS || GENDWARFKSYMS | |
f1385dc6 | 2034 | depends on !GCC_PLUGIN_RANDSTRUCT |
2f7ab126 | 2035 | depends on !RANDSTRUCT |
5daa0c35 | 2036 | depends on !DEBUG_INFO_BTF || (PAHOLE_HAS_LANG_EXCLUDE && !LTO) |
8b8ca9c2 | 2037 | depends on !CFI_CLANG || HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC |
ca627e63 | 2038 | select CFI_ICALL_NORMALIZE_INTEGERS if CFI_CLANG |
af6017b6 | 2039 | depends on !CALL_PADDING || RUSTC_VERSION >= 108100 |
f64e2f3a | 2040 | depends on !KASAN_SW_TAGS |
93e34a0b | 2041 | depends on !(MITIGATION_RETHUNK && KASAN) || RUSTC_VERSION >= 108300 |
2f7ab126 MO |
2042 | help |
2043 | Enables Rust support in the kernel. | |
2044 | ||
2045 | This allows other Rust-related options, like drivers written in Rust, | |
2046 | to be selected. | |
2047 | ||
2048 | It is also required to be able to load external kernel modules | |
2049 | written in Rust. | |
2050 | ||
2051 | See Documentation/rust/ for more information. | |
2052 | ||
2053 | If unsure, say N. | |
2054 | ||
2055 | config RUSTC_VERSION_TEXT | |
2056 | string | |
2057 | depends on RUST | |
5134a335 MO |
2058 | default "$(RUSTC_VERSION_TEXT)" |
2059 | help | |
2060 | See `CC_VERSION_TEXT`. | |
2f7ab126 MO |
2061 | |
2062 | config BINDGEN_VERSION_TEXT | |
2063 | string | |
2064 | depends on RUST | |
9e98db17 | 2065 | # The dummy parameter `workaround-for-0.69.0` is required to support 0.69.0 |
c23d1f7e MO |
2066 | # (https://github.com/rust-lang/rust-bindgen/pull/2678) and 0.71.0 |
2067 | # (https://github.com/rust-lang/rust-bindgen/pull/3040). It can be removed | |
2068 | # when the minimum version is upgraded past the latter (0.69.1 and 0.71.1 | |
2069 | # both fixed the issue). | |
aacf93e8 | 2070 | default "$(shell,$(BINDGEN) --version workaround-for-0.69.0 2>/dev/null)" |
2f7ab126 | 2071 | |
5f87f112 IM |
2072 | # |
2073 | # Place an empty function call at each tracepoint site. Can be | |
2074 | # dynamically changed for a probe function. | |
2075 | # | |
97e1c18e | 2076 | config TRACEPOINTS |
5f87f112 | 2077 | bool |
a363d27c | 2078 | select TASKS_TRACE_RCU |
97e1c18e | 2079 | |
89cde455 ED |
2080 | source "kernel/Kconfig.kexec" |
2081 | ||
1da177e4 LT |
2082 | endmenu # General setup |
2083 | ||
1572497c CH |
2084 | source "arch/Kconfig" |
2085 | ||
ae81f9e3 | 2086 | config RT_MUTEXES |
6341e62b | 2087 | bool |
1c6f9ec0 | 2088 | default y if PREEMPT_RT |
ae81f9e3 | 2089 | |
c8424e77 TJB |
2090 | config MODULE_SIG_FORMAT |
2091 | def_bool n | |
2092 | select SYSTEM_DATA_VERIFICATION | |
2093 | ||
73b4fc92 | 2094 | source "kernel/module/Kconfig" |
6c9692e2 | 2095 | |
98a79d6a RR |
2096 | config INIT_ALL_POSSIBLE |
2097 | bool | |
2098 | help | |
5f054e31 RR |
2099 | Back when each arch used to define their own cpu_online_mask and |
2100 | cpu_possible_mask, some of them chose to initialize cpu_possible_mask | |
98a79d6a RR |
2101 | with all 1s, and others with all 0s. When they were centralised, |
2102 | it was better to provide this option than to break all the archs | |
692105b8 | 2103 | and have several arch maintainers pursuing me down dark alleys. |
98a79d6a | 2104 | |
3a65dfe8 | 2105 | source "block/Kconfig" |
e98c3202 AK |
2106 | |
2107 | config PREEMPT_NOTIFIERS | |
2108 | bool | |
e260be67 | 2109 | |
16295bec SK |
2110 | config PADATA |
2111 | depends on SMP | |
2112 | bool | |
2113 | ||
4520c6a4 DH |
2114 | config ASN1 |
2115 | tristate | |
2116 | help | |
2117 | Build a simple ASN.1 grammar compiler that produces a bytecode output | |
2118 | that can be interpreted by the ASN.1 stream decoder and used to | |
2119 | inform it as to what tags are to be expected in a stream and what | |
2120 | functions to call on what tags. | |
2121 | ||
6beb0009 | 2122 | source "kernel/Kconfig.locks" |
e61938a9 | 2123 | |
0ebeea8c DB |
2124 | config ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE |
2125 | bool | |
2126 | ||
4ff4c745 AP |
2127 | config ARCH_HAS_PREPARE_SYNC_CORE_CMD |
2128 | bool | |
2129 | ||
e61938a9 MD |
2130 | config ARCH_HAS_SYNC_CORE_BEFORE_USERMODE |
2131 | bool | |
1bd21c6c DB |
2132 | |
2133 | # It may be useful for an architecture to override the definitions of the | |
7303e30e DB |
2134 | # SYSCALL_DEFINE() and __SYSCALL_DEFINEx() macros in <linux/syscalls.h> |
2135 | # and the COMPAT_ variants in <linux/compat.h>, in particular to use a | |
2136 | # different calling convention for syscalls. They can also override the | |
2137 | # macros for not-implemented syscalls in kernel/sys_ni.c and | |
2138 | # kernel/time/posix-stubs.c. All these overrides need to be available in | |
2139 | # <asm/syscall_wrapper.h>. | |
1bd21c6c DB |
2140 | config ARCH_HAS_SYSCALL_WRAPPER |
2141 | def_bool n |