xref: /linux/init/Kconfig (revision 2c1ed907520c50326b8f604907a8478b27881a2e)
1# SPDX-License-Identifier: GPL-2.0-only
2config 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
13	  - Ensure full rebuild when the compiler is updated
14	    include/linux/compiler-version.h contains this option in the comment
15	    line so fixdep adds include/config/CC_VERSION_TEXT into the
16	    auto-generated dependency. When the compiler is updated, syncconfig
17	    will touch it and then every file will be rebuilt.
18
19config CC_IS_GCC
20	def_bool $(success,test "$(cc-name)" = GCC)
21
22config GCC_VERSION
23	int
24	default $(cc-version) if CC_IS_GCC
25	default 0
26
27config CC_IS_CLANG
28	def_bool $(success,test "$(cc-name)" = Clang)
29
30config CLANG_VERSION
31	int
32	default $(cc-version) if CC_IS_CLANG
33	default 0
34
35config AS_IS_GNU
36	def_bool $(success,test "$(as-name)" = GNU)
37
38config AS_IS_LLVM
39	def_bool $(success,test "$(as-name)" = LLVM)
40
41config 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
47config LD_IS_BFD
48	def_bool $(success,test "$(ld-name)" = BFD)
49
50config LD_VERSION
51	int
52	default $(ld-version) if LD_IS_BFD
53	default 0
54
55config LD_IS_LLD
56	def_bool $(success,test "$(ld-name)" = LLD)
57
58config LLD_VERSION
59	int
60	default $(ld-version) if LD_IS_LLD
61	default 0
62
63config RUSTC_VERSION
64	int
65	default $(rustc-version)
66	help
67	  It does not depend on `RUST` since that one may need to use the version
68	  in a `depends on`.
69
70config 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
76	  to satisfy the build requirements of Rust support.
77
78	  In particular, the Makefile target 'rustavailable' is useful to check
79	  why the Rust toolchain is not being detected.
80
81config RUSTC_LLVM_VERSION
82	int
83	default $(rustc-llvm-version)
84
85config CC_CAN_LINK
86	bool
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))
89
90config CC_CAN_LINK_STATIC
91	bool
92	default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag) -static) if 64BIT
93	default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m32-flag) -static)
94
95# Fixed in GCC 14, 13.3, 12.4 and 11.5
96# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113921
97config GCC_ASM_GOTO_OUTPUT_BROKEN
98	bool
99	depends on CC_IS_GCC
100	default y if GCC_VERSION < 110500
101	default y if GCC_VERSION >= 120000 && GCC_VERSION < 120400
102	default y if GCC_VERSION >= 130000 && GCC_VERSION < 130300
103
104config CC_HAS_ASM_GOTO_OUTPUT
105	def_bool y
106	depends on !GCC_ASM_GOTO_OUTPUT_BROKEN
107	depends on $(success,echo 'int foo(int x) { asm goto ("": "=r"(x) ::: bar); return x; bar: return 0; }' | $(CC) -x c - -c -o /dev/null)
108
109config CC_HAS_ASM_GOTO_TIED_OUTPUT
110	depends on CC_HAS_ASM_GOTO_OUTPUT
111	# Detect buggy gcc and clang, fixed in gcc-11 clang-14.
112	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)
113
114config TOOLS_SUPPORT_RELR
115	def_bool $(success,env "CC=$(CC)" "LD=$(LD)" "NM=$(NM)" "OBJCOPY=$(OBJCOPY)" $(srctree)/scripts/tools-support-relr.sh)
116
117config CC_HAS_ASM_INLINE
118	def_bool $(success,echo 'void foo(void) { asm inline (""); }' | $(CC) -x c - -c -o /dev/null)
119
120config CC_HAS_NO_PROFILE_FN_ATTR
121	def_bool $(success,echo '__attribute__((no_profile_instrument_function)) int x();' | $(CC) -x c - -c -o /dev/null -Werror)
122
123config CC_HAS_COUNTED_BY
124	# TODO: when gcc 15 is released remove the build test and add
125	# a gcc version check
126	def_bool $(success,echo 'struct flex { int count; int array[] __attribute__((__counted_by__(count))); };' | $(CC) $(CLANG_FLAGS) -x c - -c -o /dev/null -Werror)
127	# clang needs to be at least 19.1.3 to avoid __bdos miscalculations
128	# https://github.com/llvm/llvm-project/pull/110497
129	# https://github.com/llvm/llvm-project/pull/112636
130	depends on !(CC_IS_CLANG && CLANG_VERSION < 190103)
131
132config RUSTC_HAS_COERCE_POINTEE
133	def_bool RUSTC_VERSION >= 108400
134
135config PAHOLE_VERSION
136	int
137	default $(shell,$(srctree)/scripts/pahole-version.sh $(PAHOLE))
138
139config CONSTRUCTORS
140	bool
141
142config IRQ_WORK
143	def_bool y if SMP
144
145config BUILDTIME_TABLE_SORT
146	bool
147
148config THREAD_INFO_IN_TASK
149	bool
150	help
151	  Select this to move thread_info off the stack into task_struct.  To
152	  make this work, an arch will need to remove all thread_info fields
153	  except flags and fix any runtime bugs.
154
155	  One subtle change that will be needed is to use try_get_task_stack()
156	  and put_task_stack() in save_thread_stack_tsk() and get_wchan().
157
158menu "General setup"
159
160config BROKEN
161	bool
162
163config BROKEN_ON_SMP
164	bool
165	depends on BROKEN || !SMP
166	default y
167
168config INIT_ENV_ARG_LIMIT
169	int
170	default 32 if !UML
171	default 128 if UML
172	help
173	  Maximum of each of the number of arguments and environment
174	  variables passed to init from the kernel command line.
175
176config COMPILE_TEST
177	bool "Compile also drivers which will not load"
178	depends on HAS_IOMEM
179	help
180	  Some drivers can be compiled on a different platform than they are
181	  intended to be run on. Despite they cannot be loaded there (or even
182	  when they load they cannot be used due to missing HW support),
183	  developers still, opposing to distributors, might want to build such
184	  drivers to compile-test them.
185
186	  If you are a developer and want to build everything available, say Y
187	  here. If you are a user/distributor, say N here to exclude useless
188	  drivers to be distributed.
189
190config WERROR
191	bool "Compile the kernel with warnings as errors"
192	default COMPILE_TEST
193	help
194	  A kernel build should not cause any compiler warnings, and this
195	  enables the '-Werror' (for C) and '-Dwarnings' (for Rust) flags
196	  to enforce that rule by default. Certain warnings from other tools
197	  such as the linker may be upgraded to errors with this option as
198	  well.
199
200	  However, if you have a new (or very old) compiler or linker with odd
201	  and unusual warnings, or you have some architecture with problems,
202	  you may need to disable this config option in order to
203	  successfully build the kernel.
204
205	  If in doubt, say Y.
206
207config UAPI_HEADER_TEST
208	bool "Compile test UAPI headers"
209	depends on HEADERS_INSTALL && CC_CAN_LINK
210	help
211	  Compile test headers exported to user-space to ensure they are
212	  self-contained, i.e. compilable as standalone units.
213
214	  If you are a developer or tester and want to ensure the exported
215	  headers are self-contained, say Y here. Otherwise, choose N.
216
217config LOCALVERSION
218	string "Local version - append to kernel release"
219	help
220	  Append an extra string to the end of your kernel version.
221	  This will show up when you type uname, for example.
222	  The string you set here will be appended after the contents of
223	  any files with a filename matching localversion* in your
224	  object and source tree, in that order.  Your total string can
225	  be a maximum of 64 characters.
226
227config LOCALVERSION_AUTO
228	bool "Automatically append version information to the version string"
229	default y
230	depends on !COMPILE_TEST
231	help
232	  This will try to automatically determine if the current tree is a
233	  release tree by looking for git tags that belong to the current
234	  top of tree revision.
235
236	  A string of the format -gxxxxxxxx will be added to the localversion
237	  if a git-based tree is found.  The string generated by this will be
238	  appended after any matching localversion* files, and after the value
239	  set in CONFIG_LOCALVERSION.
240
241	  (The actual string used here is the first 12 characters produced
242	  by running the command:
243
244	    $ git rev-parse --verify HEAD
245
246	  which is done within the script "scripts/setlocalversion".)
247
248config BUILD_SALT
249	string "Build ID Salt"
250	default ""
251	help
252	  The build ID is used to link binaries and their debug info. Setting
253	  this option will use the value in the calculation of the build id.
254	  This is mostly useful for distributions which want to ensure the
255	  build is unique between builds. It's safe to leave the default.
256
257config HAVE_KERNEL_GZIP
258	bool
259
260config HAVE_KERNEL_BZIP2
261	bool
262
263config HAVE_KERNEL_LZMA
264	bool
265
266config HAVE_KERNEL_XZ
267	bool
268
269config HAVE_KERNEL_LZO
270	bool
271
272config HAVE_KERNEL_LZ4
273	bool
274
275config HAVE_KERNEL_ZSTD
276	bool
277
278config HAVE_KERNEL_UNCOMPRESSED
279	bool
280
281choice
282	prompt "Kernel compression mode"
283	default KERNEL_GZIP
284	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
285	help
286	  The linux kernel is a kind of self-extracting executable.
287	  Several compression algorithms are available, which differ
288	  in efficiency, compression and decompression speed.
289	  Compression speed is only relevant when building a kernel.
290	  Decompression speed is relevant at each boot.
291
292	  If you have any problems with bzip2 or lzma compressed
293	  kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
294	  version of this functionality (bzip2 only), for 2.4, was
295	  supplied by Christian Ludwig)
296
297	  High compression options are mostly useful for users, who
298	  are low on disk space (embedded systems), but for whom ram
299	  size matters less.
300
301	  If in doubt, select 'gzip'
302
303config KERNEL_GZIP
304	bool "Gzip"
305	depends on HAVE_KERNEL_GZIP
306	help
307	  The old and tried gzip compression. It provides a good balance
308	  between compression ratio and decompression speed.
309
310config KERNEL_BZIP2
311	bool "Bzip2"
312	depends on HAVE_KERNEL_BZIP2
313	help
314	  Its compression ratio and speed is intermediate.
315	  Decompression speed is slowest among the choices.  The kernel
316	  size is about 10% smaller with bzip2, in comparison to gzip.
317	  Bzip2 uses a large amount of memory. For modern kernels you
318	  will need at least 8MB RAM or more for booting.
319
320config KERNEL_LZMA
321	bool "LZMA"
322	depends on HAVE_KERNEL_LZMA
323	help
324	  This compression algorithm's ratio is best.  Decompression speed
325	  is between gzip and bzip2.  Compression is slowest.
326	  The kernel size is about 33% smaller with LZMA in comparison to gzip.
327
328config KERNEL_XZ
329	bool "XZ"
330	depends on HAVE_KERNEL_XZ
331	help
332	  XZ uses the LZMA2 algorithm and instruction set specific
333	  BCJ filters which can improve compression ratio of executable
334	  code. The size of the kernel is about 30% smaller with XZ in
335	  comparison to gzip. On architectures for which there is a BCJ
336	  filter (i386, x86_64, ARM, ARM64, RISC-V, big endian PowerPC,
337	  and SPARC), XZ will create a few percent smaller kernel than
338	  plain LZMA.
339
340	  The speed is about the same as with LZMA: The decompression
341	  speed of XZ is better than that of bzip2 but worse than gzip
342	  and LZO. Compression is slow.
343
344config KERNEL_LZO
345	bool "LZO"
346	depends on HAVE_KERNEL_LZO
347	help
348	  Its compression ratio is the poorest among the choices. The kernel
349	  size is about 10% bigger than gzip; however its speed
350	  (both compression and decompression) is the fastest.
351
352config KERNEL_LZ4
353	bool "LZ4"
354	depends on HAVE_KERNEL_LZ4
355	help
356	  LZ4 is an LZ77-type compressor with a fixed, byte-oriented encoding.
357	  A preliminary version of LZ4 de/compression tool is available at
358	  <https://code.google.com/p/lz4/>.
359
360	  Its compression ratio is worse than LZO. The size of the kernel
361	  is about 8% bigger than LZO. But the decompression speed is
362	  faster than LZO.
363
364config KERNEL_ZSTD
365	bool "ZSTD"
366	depends on HAVE_KERNEL_ZSTD
367	help
368	  ZSTD is a compression algorithm targeting intermediate compression
369	  with fast decompression speed. It will compress better than GZIP and
370	  decompress around the same speed as LZO, but slower than LZ4. You
371	  will need at least 192 KB RAM or more for booting. The zstd command
372	  line tool is required for compression.
373
374config KERNEL_UNCOMPRESSED
375	bool "None"
376	depends on HAVE_KERNEL_UNCOMPRESSED
377	help
378	  Produce uncompressed kernel image. This option is usually not what
379	  you want. It is useful for debugging the kernel in slow simulation
380	  environments, where decompressing and moving the kernel is awfully
381	  slow. This option allows early boot code to skip the decompressor
382	  and jump right at uncompressed kernel image.
383
384endchoice
385
386config DEFAULT_INIT
387	string "Default init path"
388	default ""
389	help
390	  This option determines the default init for the system if no init=
391	  option is passed on the kernel command line. If the requested path is
392	  not present, we will still then move on to attempting further
393	  locations (e.g. /sbin/init, etc). If this is empty, we will just use
394	  the fallback list when init= is not passed.
395
396config DEFAULT_HOSTNAME
397	string "Default hostname"
398	default "(none)"
399	help
400	  This option determines the default system hostname before userspace
401	  calls sethostname(2). The kernel traditionally uses "(none)" here,
402	  but you may wish to use a different default here to make a minimal
403	  system more usable with less configuration.
404
405config SYSVIPC
406	bool "System V IPC"
407	help
408	  Inter Process Communication is a suite of library functions and
409	  system calls which let processes (running programs) synchronize and
410	  exchange information. It is generally considered to be a good thing,
411	  and some programs won't run unless you say Y here. In particular, if
412	  you want to run the DOS emulator dosemu under Linux (read the
413	  DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
414	  you'll need to say Y here.
415
416	  You can find documentation about IPC with "info ipc" and also in
417	  section 6.4 of the Linux Programmer's Guide, available from
418	  <http://www.tldp.org/guides.html>.
419
420config SYSVIPC_SYSCTL
421	bool
422	depends on SYSVIPC
423	depends on SYSCTL
424	default y
425
426config SYSVIPC_COMPAT
427	def_bool y
428	depends on COMPAT && SYSVIPC
429
430config POSIX_MQUEUE
431	bool "POSIX Message Queues"
432	depends on NET
433	help
434	  POSIX variant of message queues is a part of IPC. In POSIX message
435	  queues every message has a priority which decides about succession
436	  of receiving it by a process. If you want to compile and run
437	  programs written e.g. for Solaris with use of its POSIX message
438	  queues (functions mq_*) say Y here.
439
440	  POSIX message queues are visible as a filesystem called 'mqueue'
441	  and can be mounted somewhere if you want to do filesystem
442	  operations on message queues.
443
444	  If unsure, say Y.
445
446config POSIX_MQUEUE_SYSCTL
447	bool
448	depends on POSIX_MQUEUE
449	depends on SYSCTL
450	default y
451
452config WATCH_QUEUE
453	bool "General notification queue"
454	default n
455	help
456
457	  This is a general notification queue for the kernel to pass events to
458	  userspace by splicing them into pipes.  It can be used in conjunction
459	  with watches for key/keyring change notifications and device
460	  notifications.
461
462	  See Documentation/core-api/watch_queue.rst
463
464config CROSS_MEMORY_ATTACH
465	bool "Enable process_vm_readv/writev syscalls"
466	depends on MMU
467	default y
468	help
469	  Enabling this option adds the system calls process_vm_readv and
470	  process_vm_writev which allow a process with the correct privileges
471	  to directly read from or write to another process' address space.
472	  See the man page for more details.
473
474config USELIB
475	bool "uselib syscall (for libc5 and earlier)"
476	default ALPHA || M68K || SPARC
477	help
478	  This option enables the uselib syscall, a system call used in the
479	  dynamic linker from libc5 and earlier.  glibc does not use this
480	  system call.  If you intend to run programs built on libc5 or
481	  earlier, you may need to enable this syscall.  Current systems
482	  running glibc can safely disable this.
483
484config 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
490	  logging of avc messages output).  System call auditing is included
491	  on architectures which support it.
492
493config HAVE_ARCH_AUDITSYSCALL
494	bool
495
496config AUDITSYSCALL
497	def_bool y
498	depends on AUDIT && HAVE_ARCH_AUDITSYSCALL
499	select FSNOTIFY
500
501source "kernel/irq/Kconfig"
502source "kernel/time/Kconfig"
503source "kernel/bpf/Kconfig"
504source "kernel/Kconfig.preempt"
505
506menu "CPU/Task time and stats accounting"
507
508config VIRT_CPU_ACCOUNTING
509	bool
510
511choice
512	prompt "Cputime accounting"
513	default TICK_CPU_ACCOUNTING
514
515# Kind of a stub config for the pure tick based cputime accounting
516config TICK_CPU_ACCOUNTING
517	bool "Simple tick based cputime accounting"
518	depends on !S390 && !NO_HZ_FULL
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
526config VIRT_CPU_ACCOUNTING_NATIVE
527	bool "Deterministic task and CPU time accounting"
528	depends on HAVE_VIRT_CPU_ACCOUNTING && !NO_HZ_FULL
529	select VIRT_CPU_ACCOUNTING
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
539config VIRT_CPU_ACCOUNTING_GEN
540	bool "Full dynticks CPU time accounting"
541	depends on HAVE_CONTEXT_TRACKING_USER
542	depends on HAVE_VIRT_CPU_ACCOUNTING_GEN
543	depends on GENERIC_CLOCKEVENTS
544	select VIRT_CPU_ACCOUNTING
545	select CONTEXT_TRACKING_USER
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
558endchoice
559
560config IRQ_TIME_ACCOUNTING
561	bool "Fine granularity task level IRQ time accounting"
562	depends on HAVE_IRQ_TIME_ACCOUNTING && !VIRT_CPU_ACCOUNTING_NATIVE
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
571config HAVE_SCHED_AVG_IRQ
572	def_bool y
573	depends on IRQ_TIME_ACCOUNTING || PARAVIRT_TIME_ACCOUNTING
574	depends on SMP
575
576config SCHED_HW_PRESSURE
577	bool
578	default y if ARM && ARM_CPU_TOPOLOGY
579	default y if ARM64
580	depends on SMP
581	depends on CPU_FREQ_THERMAL
582	help
583	  Select this option to enable HW pressure accounting in the
584	  scheduler. HW pressure is the value conveyed to the scheduler
585	  that reflects the reduction in CPU compute capacity resulted from
586	  HW throttling. HW throttling occurs when the performance of
587	  a CPU is capped due to high operating temperatures as an example.
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
593	  arch_update_hw_pressure() and arch_scale_thermal_pressure().
594
595config BSD_PROCESS_ACCT
596	bool "BSD Process Accounting"
597	depends on MULTIUSER
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
609config 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
616	  process and its parent. Note that this file format is incompatible
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
619	  at <http://www.gnu.org/software/acct/>.
620
621config TASKSTATS
622	bool "Export task/process statistics through netlink"
623	depends on NET
624	depends on MULTIUSER
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
635config TASK_DELAY_ACCT
636	bool "Enable per-task delay accounting"
637	depends on TASKSTATS
638	select SCHED_INFO
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
647config TASK_XACCT
648	bool "Enable extended accounting over taskstats"
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
656config TASK_IO_ACCOUNTING
657	bool "Enable per-task storage I/O accounting"
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
665config PSI
666	bool "Pressure stall information tracking"
667	select KERNFS
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
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
681	  For more details see Documentation/accounting/psi.rst.
682
683	  Say N if unsure.
684
685config 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
691	  per default but can be enabled through passing psi=1 on the
692	  kernel commandline during boot.
693
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
705endmenu # "CPU/Task time and stats accounting"
706
707config CPU_ISOLATION
708	bool "CPU isolation"
709	depends on SMP || COMPILE_TEST
710	default y
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...
714	  Unbound jobs get offloaded to housekeeping CPUs. This is driven by
715	  the "isolcpus=" boot parameter.
716
717	  Say Y if unsure.
718
719source "kernel/rcu/Kconfig"
720
721config IKCONFIG
722	tristate "Kernel .config support"
723	help
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
733config IKCONFIG_PROC
734	bool "Enable access to .config through /proc/config.gz"
735	depends on IKCONFIG && PROC_FS
736	help
737	  This option enables access to the kernel configuration file
738	  through /proc/config.gz.
739
740config 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.
748
749config LOG_BUF_SHIFT
750	int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
751	range 12 25
752	default 17
753	depends on PRINTK
754	help
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
760	  Examples:
761		     17 => 128 KB
762		     16 => 64 KB
763		     15 => 32 KB
764		     14 => 16 KB
765		     13 =>  8 KB
766		     12 =>  4 KB
767
768config LOG_CPU_MAX_BUF_SHIFT
769	int "CPU kernel log buffer size contribution (13 => 8 KB, 17 => 128KB)"
770	depends on SMP
771	range 0 21
772	default 0 if BASE_SMALL
773	default 12
774	depends on PRINTK
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
787	  so that more than 16 CPUs are needed to trigger the allocation.
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
793	  hotplugging making the computation optimal for the worst case
794	  scenario while allowing a simple algorithm to be used from bootup.
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
804config 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
818#
819# Architectures with an unreliable sched_clock() should select this:
820#
821config HAVE_UNSTABLE_SCHED_CLOCK
822	bool
823
824config GENERIC_SCHED_CLOCK
825	bool
826
827menu "Scheduler features"
828
829config 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
847config 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
878endmenu
879
880#
881# For architectures that want to enable the support for NUMA-affine scheduler
882# balancing logic:
883#
884config ARCH_SUPPORTS_NUMA_BALANCING
885	bool
886
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.
894config ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
895	bool
896
897config CC_HAS_INT128
898	def_bool !$(cc-option,$(m64-flag) -D__SIZEOF_INT128__=0) && 64BIT
899
900config CC_IMPLICIT_FALLTHROUGH
901	string
902	default "-Wimplicit-fallthrough=5" if CC_IS_GCC && $(cc-option,-Wimplicit-fallthrough=5)
903	default "-Wimplicit-fallthrough" if CC_IS_CLANG && $(cc-option,-Wunreachable-code-fallthrough)
904
905# Currently, disable gcc-10+ array-bounds globally.
906# It's still broken in gcc-13, so no upper bound yet.
907config GCC10_NO_ARRAY_BOUNDS
908	def_bool y
909
910config CC_NO_ARRAY_BOUNDS
911	bool
912	default y if CC_IS_GCC && GCC_VERSION >= 90000 && GCC10_NO_ARRAY_BOUNDS
913
914# Currently, disable -Wstringop-overflow for GCC globally.
915config GCC_NO_STRINGOP_OVERFLOW
916	def_bool y
917
918config CC_NO_STRINGOP_OVERFLOW
919	bool
920	default y if CC_IS_GCC && GCC_NO_STRINGOP_OVERFLOW
921
922config CC_STRINGOP_OVERFLOW
923	bool
924	default y if CC_IS_GCC && !CC_NO_STRINGOP_OVERFLOW
925
926#
927# For architectures that know their GCC __int128 support is sound
928#
929config ARCH_SUPPORTS_INT128
930	bool
931
932# For architectures that (ab)use NUMA to represent different memory regions
933# all cpu-local but of different latencies, such as SuperH.
934#
935config ARCH_WANT_NUMA_VARIABLE_LOCALITY
936	bool
937
938config NUMA_BALANCING
939	bool "Memory placement aware NUMA scheduler"
940	depends on ARCH_SUPPORTS_NUMA_BALANCING
941	depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
942	depends on SMP && NUMA && MIGRATION && !PREEMPT_RT
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
946	  it has references to the node the task is running on.
947
948	  This system will be inactive on UMA systems.
949
950config 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
958config SLAB_OBJ_EXT
959	bool
960
961menuconfig CGROUPS
962	bool "Control Group support"
963	select KERNFS
964	help
965	  This option adds support for grouping sets of processes together, for
966	  use with process control subsystems such as Cpusets, CFS, memory
967	  controls or device isolation.
968	  See
969		- Documentation/scheduler/sched-design-CFS.rst	(CFS)
970		- Documentation/admin-guide/cgroup-v1/ (features for grouping, isolation
971					  and resource control)
972
973	  Say N if unsure.
974
975if CGROUPS
976
977config PAGE_COUNTER
978	bool
979
980config 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
990config MEMCG
991	bool "Memory controller"
992	select PAGE_COUNTER
993	select EVENTFD
994	select SLAB_OBJ_EXT
995	help
996	  Provides control over the memory footprint of tasks in a cgroup.
997
998config MEMCG_V1
999	bool "Legacy cgroup v1 memory controller"
1000	depends on MEMCG
1001	default n
1002	help
1003	  Legacy cgroup v1 memory controller which has been deprecated by
1004	  cgroup v2 implementation. The v1 is there for legacy applications
1005	  which haven't migrated to the new cgroup v2 interface yet. If you
1006	  do not have any such application then you are completely fine leaving
1007	  this option disabled.
1008
1009	  Please note that feature set of the legacy memory controller is likely
1010	  going to shrink due to deprecation process. New deployments with v1
1011	  controller are highly discouraged.
1012
1013	  Say N if unsure.
1014
1015config BLK_CGROUP
1016	bool "IO controller"
1017	depends on BLOCK
1018	default n
1019	help
1020	Generic block IO controller cgroup interface. This is the common
1021	cgroup interface which should be used by various IO controlling
1022	policies.
1023
1024	Currently, CFQ IO scheduler uses it to recognize task groups and
1025	control disk bandwidth allocation (proportional time slice allocation)
1026	to such task groups. It is also used by bio throttling logic in
1027	block layer to implement upper limit in IO rates on a device.
1028
1029	This option only enables generic Block IO controller infrastructure.
1030	One needs to also enable actual IO controlling logic/policy. For
1031	enabling proportional weight division of disk bandwidth in CFQ, set
1032	CONFIG_BFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
1033	CONFIG_BLK_DEV_THROTTLING=y.
1034
1035	See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information.
1036
1037config CGROUP_WRITEBACK
1038	bool
1039	depends on MEMCG && BLK_CGROUP
1040	default y
1041
1042menuconfig CGROUP_SCHED
1043	bool "CPU controller"
1044	default n
1045	help
1046	  This feature lets CPU scheduler recognize task groups and control CPU
1047	  bandwidth allocation to such task groups. It uses cgroups to group
1048	  tasks.
1049
1050if CGROUP_SCHED
1051config GROUP_SCHED_WEIGHT
1052	def_bool n
1053
1054config FAIR_GROUP_SCHED
1055	bool "Group scheduling for SCHED_OTHER"
1056	depends on CGROUP_SCHED
1057	select GROUP_SCHED_WEIGHT
1058	default CGROUP_SCHED
1059
1060config CFS_BANDWIDTH
1061	bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
1062	depends on FAIR_GROUP_SCHED
1063	default n
1064	help
1065	  This option allows users to define CPU bandwidth rates (limits) for
1066	  tasks running within the fair group scheduler.  Groups with no limit
1067	  set are considered to be unconstrained and will run with no
1068	  restriction.
1069	  See Documentation/scheduler/sched-bwc.rst for more information.
1070
1071config RT_GROUP_SCHED
1072	bool "Group scheduling for SCHED_RR/FIFO"
1073	depends on CGROUP_SCHED
1074	default n
1075	help
1076	  This feature lets you explicitly allocate real CPU bandwidth
1077	  to task groups. If enabled, it will also make it impossible to
1078	  schedule realtime tasks for non-root users until you allocate
1079	  realtime bandwidth for them.
1080	  See Documentation/scheduler/sched-rt-group.rst for more information.
1081
1082config EXT_GROUP_SCHED
1083	bool
1084	depends on SCHED_CLASS_EXT && CGROUP_SCHED
1085	select GROUP_SCHED_WEIGHT
1086	default y
1087
1088endif #CGROUP_SCHED
1089
1090config SCHED_MM_CID
1091	def_bool y
1092	depends on SMP && RSEQ
1093
1094config UCLAMP_TASK_GROUP
1095	bool "Utilization clamping per group of tasks"
1096	depends on CGROUP_SCHED
1097	depends on UCLAMP_TASK
1098	default n
1099	help
1100	  This feature enables the scheduler to track the clamped utilization
1101	  of each CPU based on RUNNABLE tasks currently scheduled on that CPU.
1102
1103	  When this option is enabled, the user can specify a min and max
1104	  CPU bandwidth which is allowed for each single task in a group.
1105	  The max bandwidth allows to clamp the maximum frequency a task
1106	  can use, while the min bandwidth allows to define a minimum
1107	  frequency a task will always use.
1108
1109	  When task group based utilization clamping is enabled, an eventually
1110	  specified task-specific clamp value is constrained by the cgroup
1111	  specified clamp value. Both minimum and maximum task clamping cannot
1112	  be bigger than the corresponding clamping defined at task group level.
1113
1114	  If in doubt, say N.
1115
1116config CGROUP_PIDS
1117	bool "PIDs controller"
1118	help
1119	  Provides enforcement of process number limits in the scope of a
1120	  cgroup. Any attempt to fork more processes than is allowed in the
1121	  cgroup will fail. PIDs are fundamentally a global resource because it
1122	  is fairly trivial to reach PID exhaustion before you reach even a
1123	  conservative kmemcg limit. As a result, it is possible to grind a
1124	  system to halt without being limited by other cgroup policies. The
1125	  PIDs controller is designed to stop this from happening.
1126
1127	  It should be noted that organisational operations (such as attaching
1128	  to a cgroup hierarchy) will *not* be blocked by the PIDs controller,
1129	  since the PIDs limit only affects a process's ability to fork, not to
1130	  attach to a cgroup.
1131
1132config CGROUP_RDMA
1133	bool "RDMA controller"
1134	help
1135	  Provides enforcement of RDMA resources defined by IB stack.
1136	  It is fairly easy for consumers to exhaust RDMA resources, which
1137	  can result into resource unavailability to other consumers.
1138	  RDMA controller is designed to stop this from happening.
1139	  Attaching processes with active RDMA resources to the cgroup
1140	  hierarchy is allowed even if can cross the hierarchy's limit.
1141
1142config CGROUP_DMEM
1143	bool "Device memory controller (DMEM)"
1144	select PAGE_COUNTER
1145	help
1146	  The DMEM controller allows compatible devices to restrict device
1147	  memory usage based on the cgroup hierarchy.
1148
1149	  As an example, it allows you to restrict VRAM usage for applications
1150	  in the DRM subsystem.
1151
1152config CGROUP_FREEZER
1153	bool "Freezer controller"
1154	help
1155	  Provides a way to freeze and unfreeze all tasks in a
1156	  cgroup.
1157
1158	  This option affects the ORIGINAL cgroup interface. The cgroup2 memory
1159	  controller includes important in-kernel memory consumers per default.
1160
1161	  If you're using cgroup2, say N.
1162
1163config CGROUP_HUGETLB
1164	bool "HugeTLB controller"
1165	depends on HUGETLB_PAGE
1166	select PAGE_COUNTER
1167	default n
1168	help
1169	  Provides a cgroup controller for HugeTLB pages.
1170	  When you enable this, you can put a per cgroup limit on HugeTLB usage.
1171	  The limit is enforced during page fault. Since HugeTLB doesn't
1172	  support page reclaim, enforcing the limit at page fault time implies
1173	  that, the application will get SIGBUS signal if it tries to access
1174	  HugeTLB pages beyond its limit. This requires the application to know
1175	  beforehand how much HugeTLB pages it would require for its use. The
1176	  control group is tracked in the third page lru pointer. This means
1177	  that we cannot use the controller with huge page less than 3 pages.
1178
1179config CPUSETS
1180	bool "Cpuset controller"
1181	depends on SMP
1182	select UNION_FIND
1183	help
1184	  This option will let you create and manage CPUSETs which
1185	  allow dynamically partitioning a system into sets of CPUs and
1186	  Memory Nodes and assigning tasks to run only within those sets.
1187	  This is primarily useful on large SMP or NUMA systems.
1188
1189	  Say N if unsure.
1190
1191config CPUSETS_V1
1192	bool "Legacy cgroup v1 cpusets controller"
1193	depends on CPUSETS
1194	default n
1195	help
1196	  Legacy cgroup v1 cpusets controller which has been deprecated by
1197	  cgroup v2 implementation. The v1 is there for legacy applications
1198	  which haven't migrated to the new cgroup v2 interface yet. If you
1199	  do not have any such application then you are completely fine leaving
1200	  this option disabled.
1201
1202	  Say N if unsure.
1203
1204config PROC_PID_CPUSET
1205	bool "Include legacy /proc/<pid>/cpuset file"
1206	depends on CPUSETS
1207	default y
1208
1209config CGROUP_DEVICE
1210	bool "Device controller"
1211	help
1212	  Provides a cgroup controller implementing whitelists for
1213	  devices which a process in the cgroup can mknod or open.
1214
1215config CGROUP_CPUACCT
1216	bool "Simple CPU accounting controller"
1217	help
1218	  Provides a simple controller for monitoring the
1219	  total CPU consumed by the tasks in a cgroup.
1220
1221config CGROUP_PERF
1222	bool "Perf controller"
1223	depends on PERF_EVENTS
1224	help
1225	  This option extends the perf per-cpu mode to restrict monitoring
1226	  to threads which belong to the cgroup specified and run on the
1227	  designated cpu.  Or this can be used to have cgroup ID in samples
1228	  so that it can monitor performance events among cgroups.
1229
1230	  Say N if unsure.
1231
1232config CGROUP_BPF
1233	bool "Support for eBPF programs attached to cgroups"
1234	depends on BPF_SYSCALL
1235	select SOCK_CGROUP_DATA
1236	help
1237	  Allow attaching eBPF programs to a cgroup using the bpf(2)
1238	  syscall command BPF_PROG_ATTACH.
1239
1240	  In which context these programs are accessed depends on the type
1241	  of attachment. For instance, programs that are attached using
1242	  BPF_CGROUP_INET_INGRESS will be executed on the ingress path of
1243	  inet sockets.
1244
1245config CGROUP_MISC
1246	bool "Misc resource controller"
1247	default n
1248	help
1249	  Provides a controller for miscellaneous resources on a host.
1250
1251	  Miscellaneous scalar resources are the resources on the host system
1252	  which cannot be abstracted like the other cgroups. This controller
1253	  tracks and limits the miscellaneous resources used by a process
1254	  attached to a cgroup hierarchy.
1255
1256	  For more information, please check misc cgroup section in
1257	  /Documentation/admin-guide/cgroup-v2.rst.
1258
1259config CGROUP_DEBUG
1260	bool "Debug controller"
1261	default n
1262	depends on DEBUG_KERNEL
1263	help
1264	  This option enables a simple controller that exports
1265	  debugging information about the cgroups framework. This
1266	  controller is for control cgroup debugging only. Its
1267	  interfaces are not stable.
1268
1269	  Say N.
1270
1271config SOCK_CGROUP_DATA
1272	bool
1273	default n
1274
1275endif # CGROUPS
1276
1277menuconfig NAMESPACES
1278	bool "Namespaces support" if EXPERT
1279	depends on MULTIUSER
1280	default !EXPERT
1281	help
1282	  Provides the way to make tasks work with different objects using
1283	  the same id. For example same IPC id may refer to different objects
1284	  or same user id or pid may refer to different tasks when used in
1285	  different namespaces.
1286
1287if NAMESPACES
1288
1289config UTS_NS
1290	bool "UTS namespace"
1291	default y
1292	help
1293	  In this namespace tasks see different info provided with the
1294	  uname() system call
1295
1296config TIME_NS
1297	bool "TIME namespace"
1298	depends on GENERIC_VDSO_TIME_NS
1299	default y
1300	help
1301	  In this namespace boottime and monotonic clocks can be set.
1302	  The time will keep going with the same pace.
1303
1304config IPC_NS
1305	bool "IPC namespace"
1306	depends on (SYSVIPC || POSIX_MQUEUE)
1307	default y
1308	help
1309	  In this namespace tasks work with IPC ids which correspond to
1310	  different IPC objects in different namespaces.
1311
1312config USER_NS
1313	bool "User namespace"
1314	default n
1315	help
1316	  This allows containers, i.e. vservers, to use user namespaces
1317	  to provide different user info for different servers.
1318
1319	  When user namespaces are enabled in the kernel it is
1320	  recommended that the MEMCG option also be enabled and that
1321	  user-space use the memory control groups to limit the amount
1322	  of memory a memory unprivileged users can use.
1323
1324	  If unsure, say N.
1325
1326config PID_NS
1327	bool "PID Namespaces"
1328	default y
1329	help
1330	  Support process id namespaces.  This allows having multiple
1331	  processes with the same pid as long as they are in different
1332	  pid namespaces.  This is a building block of containers.
1333
1334config NET_NS
1335	bool "Network namespace"
1336	depends on NET
1337	default y
1338	help
1339	  Allow user space to create what appear to be multiple instances
1340	  of the network stack.
1341
1342endif # NAMESPACES
1343
1344config CHECKPOINT_RESTORE
1345	bool "Checkpoint/restore support"
1346	depends on PROC_FS
1347	select PROC_CHILDREN
1348	select KCMP
1349	default n
1350	help
1351	  Enables additional kernel features in a sake of checkpoint/restore.
1352	  In particular it adds auxiliary prctl codes to setup process text,
1353	  data and heap segment sizes, and a few additional /proc filesystem
1354	  entries.
1355
1356	  If unsure, say N here.
1357
1358config SCHED_AUTOGROUP
1359	bool "Automatic process group scheduling"
1360	select CGROUPS
1361	select CGROUP_SCHED
1362	select FAIR_GROUP_SCHED
1363	help
1364	  This option optimizes the scheduler for common desktop workloads by
1365	  automatically creating and populating task groups.  This separation
1366	  of workloads isolates aggressive CPU burners (like build jobs) from
1367	  desktop applications.  Task group autogeneration is currently based
1368	  upon task session.
1369
1370config RELAY
1371	bool "Kernel->user space relay support (formerly relayfs)"
1372	select IRQ_WORK
1373	help
1374	  This option enables support for relay interface support in
1375	  certain file systems (such as debugfs).
1376	  It is designed to provide an efficient mechanism for tools and
1377	  facilities to relay large amounts of data from kernel space to
1378	  user space.
1379
1380	  If unsure, say N.
1381
1382config BLK_DEV_INITRD
1383	bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1384	help
1385	  The initial RAM filesystem is a ramfs which is loaded by the
1386	  boot loader (loadlin or lilo) and that is mounted as root
1387	  before the normal boot procedure. It is typically used to
1388	  load modules needed to mount the "real" root file system,
1389	  etc. See <file:Documentation/admin-guide/initrd.rst> for details.
1390
1391	  If RAM disk support (BLK_DEV_RAM) is also included, this
1392	  also enables initial RAM disk (initrd) support and adds
1393	  15 Kbytes (more on some other architectures) to the kernel size.
1394
1395	  If unsure say Y.
1396
1397if BLK_DEV_INITRD
1398
1399source "usr/Kconfig"
1400
1401endif
1402
1403config BOOT_CONFIG
1404	bool "Boot config support"
1405	select BLK_DEV_INITRD if !BOOT_CONFIG_EMBED
1406	help
1407	  Extra boot config allows system admin to pass a config file as
1408	  complemental extension of kernel cmdline when booting.
1409	  The boot config file must be attached at the end of initramfs
1410	  with checksum, size and magic word.
1411	  See <file:Documentation/admin-guide/bootconfig.rst> for details.
1412
1413	  If unsure, say Y.
1414
1415config BOOT_CONFIG_FORCE
1416	bool "Force unconditional bootconfig processing"
1417	depends on BOOT_CONFIG
1418	default y if BOOT_CONFIG_EMBED
1419	help
1420	  With this Kconfig option set, BOOT_CONFIG processing is carried
1421	  out even when the "bootconfig" kernel-boot parameter is omitted.
1422	  In fact, with this Kconfig option set, there is no way to
1423	  make the kernel ignore the BOOT_CONFIG-supplied kernel-boot
1424	  parameters.
1425
1426	  If unsure, say N.
1427
1428config BOOT_CONFIG_EMBED
1429	bool "Embed bootconfig file in the kernel"
1430	depends on BOOT_CONFIG
1431	help
1432	  Embed a bootconfig file given by BOOT_CONFIG_EMBED_FILE in the
1433	  kernel. Usually, the bootconfig file is loaded with the initrd
1434	  image. But if the system doesn't support initrd, this option will
1435	  help you by embedding a bootconfig file while building the kernel.
1436
1437	  If unsure, say N.
1438
1439config BOOT_CONFIG_EMBED_FILE
1440	string "Embedded bootconfig file path"
1441	depends on BOOT_CONFIG_EMBED
1442	help
1443	  Specify a bootconfig file which will be embedded to the kernel.
1444	  This bootconfig will be used if there is no initrd or no other
1445	  bootconfig in the initrd.
1446
1447config INITRAMFS_PRESERVE_MTIME
1448	bool "Preserve cpio archive mtimes in initramfs"
1449	default y
1450	help
1451	  Each entry in an initramfs cpio archive carries an mtime value. When
1452	  enabled, extracted cpio items take this mtime, with directory mtime
1453	  setting deferred until after creation of any child entries.
1454
1455	  If unsure, say Y.
1456
1457choice
1458	prompt "Compiler optimization level"
1459	default CC_OPTIMIZE_FOR_PERFORMANCE
1460
1461config CC_OPTIMIZE_FOR_PERFORMANCE
1462	bool "Optimize for performance (-O2)"
1463	help
1464	  This is the default optimization level for the kernel, building
1465	  with the "-O2" compiler flag for best performance and most
1466	  helpful compile-time warnings.
1467
1468config CC_OPTIMIZE_FOR_SIZE
1469	bool "Optimize for size (-Os)"
1470	help
1471	  Choosing this option will pass "-Os" to your compiler resulting
1472	  in a smaller kernel.
1473
1474endchoice
1475
1476config HAVE_LD_DEAD_CODE_DATA_ELIMINATION
1477	bool
1478	help
1479	  This requires that the arch annotates or otherwise protects
1480	  its external entry points from being discarded. Linker scripts
1481	  must also merge .text.*, .data.*, and .bss.* correctly into
1482	  output sections. Care must be taken not to pull in unrelated
1483	  sections (e.g., '.text.init'). Typically '.' in section names
1484	  is used to distinguish them from label names / C identifiers.
1485
1486config LD_DEAD_CODE_DATA_ELIMINATION
1487	bool "Dead code and data elimination (EXPERIMENTAL)"
1488	depends on HAVE_LD_DEAD_CODE_DATA_ELIMINATION
1489	depends on EXPERT
1490	depends on $(cc-option,-ffunction-sections -fdata-sections)
1491	depends on $(ld-option,--gc-sections)
1492	help
1493	  Enable this if you want to do dead code and data elimination with
1494	  the linker by compiling with -ffunction-sections -fdata-sections,
1495	  and linking with --gc-sections.
1496
1497	  This can reduce on disk and in-memory size of the kernel
1498	  code and static data, particularly for small configs and
1499	  on small systems. This has the possibility of introducing
1500	  silently broken kernel if the required annotations are not
1501	  present. This option is not well tested yet, so use at your
1502	  own risk.
1503
1504config LD_ORPHAN_WARN
1505	def_bool y
1506	depends on ARCH_WANT_LD_ORPHAN_WARN
1507	depends on $(ld-option,--orphan-handling=warn)
1508	depends on $(ld-option,--orphan-handling=error)
1509
1510config LD_ORPHAN_WARN_LEVEL
1511        string
1512        depends on LD_ORPHAN_WARN
1513        default "error" if WERROR
1514        default "warn"
1515
1516config SYSCTL
1517	bool
1518
1519config HAVE_UID16
1520	bool
1521
1522config SYSCTL_EXCEPTION_TRACE
1523	bool
1524	help
1525	  Enable support for /proc/sys/debug/exception-trace.
1526
1527config SYSCTL_ARCH_UNALIGN_NO_WARN
1528	bool
1529	help
1530	  Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
1531	  Allows arch to define/use @no_unaligned_warning to possibly warn
1532	  about unaligned access emulation going on under the hood.
1533
1534config SYSCTL_ARCH_UNALIGN_ALLOW
1535	bool
1536	help
1537	  Enable support for /proc/sys/kernel/unaligned-trap
1538	  Allows arches to define/use @unaligned_enabled to runtime toggle
1539	  the unaligned access emulation.
1540	  see arch/parisc/kernel/unaligned.c for reference
1541
1542config HAVE_PCSPKR_PLATFORM
1543	bool
1544
1545menuconfig EXPERT
1546	bool "Configure standard kernel features (expert users)"
1547	# Unhide debug options, to make the on-by-default options visible
1548	select DEBUG_KERNEL
1549	help
1550	  This option allows certain base kernel options and settings
1551	  to be disabled or tweaked. This is for specialized
1552	  environments which can tolerate a "non-standard" kernel.
1553	  Only use this if you really know what you are doing.
1554
1555config UID16
1556	bool "Enable 16-bit UID system calls" if EXPERT
1557	depends on HAVE_UID16 && MULTIUSER
1558	default y
1559	help
1560	  This enables the legacy 16-bit UID syscall wrappers.
1561
1562config MULTIUSER
1563	bool "Multiple users, groups and capabilities support" if EXPERT
1564	default y
1565	help
1566	  This option enables support for non-root users, groups and
1567	  capabilities.
1568
1569	  If you say N here, all processes will run with UID 0, GID 0, and all
1570	  possible capabilities.  Saying N here also compiles out support for
1571	  system calls related to UIDs, GIDs, and capabilities, such as setuid,
1572	  setgid, and capset.
1573
1574	  If unsure, say Y here.
1575
1576config SGETMASK_SYSCALL
1577	bool "sgetmask/ssetmask syscalls support" if EXPERT
1578	default PARISC || M68K || PPC || MIPS || X86 || SPARC || MICROBLAZE || SUPERH
1579	help
1580	  sys_sgetmask and sys_ssetmask are obsolete system calls
1581	  no longer supported in libc but still enabled by default in some
1582	  architectures.
1583
1584	  If unsure, leave the default option here.
1585
1586config SYSFS_SYSCALL
1587	bool "Sysfs syscall support" if EXPERT
1588	default y
1589	help
1590	  sys_sysfs is an obsolete system call no longer supported in libc.
1591	  Note that disabling this option is more secure but might break
1592	  compatibility with some systems.
1593
1594	  If unsure say Y here.
1595
1596config FHANDLE
1597	bool "open by fhandle syscalls" if EXPERT
1598	select EXPORTFS
1599	default y
1600	help
1601	  If you say Y here, a user level program will be able to map
1602	  file names to handle and then later use the handle for
1603	  different file system operations. This is useful in implementing
1604	  userspace file servers, which now track files using handles instead
1605	  of names. The handle would remain the same even if file names
1606	  get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
1607	  syscalls.
1608
1609config POSIX_TIMERS
1610	bool "Posix Clocks & timers" if EXPERT
1611	default y
1612	help
1613	  This includes native support for POSIX timers to the kernel.
1614	  Some embedded systems have no use for them and therefore they
1615	  can be configured out to reduce the size of the kernel image.
1616
1617	  When this option is disabled, the following syscalls won't be
1618	  available: timer_create, timer_gettime: timer_getoverrun,
1619	  timer_settime, timer_delete, clock_adjtime, getitimer,
1620	  setitimer, alarm. Furthermore, the clock_settime, clock_gettime,
1621	  clock_getres and clock_nanosleep syscalls will be limited to
1622	  CLOCK_REALTIME, CLOCK_MONOTONIC and CLOCK_BOOTTIME only.
1623
1624	  If unsure say y.
1625
1626config PRINTK
1627	default y
1628	bool "Enable support for printk" if EXPERT
1629	select IRQ_WORK
1630	help
1631	  This option enables normal printk support. Removing it
1632	  eliminates most of the message strings from the kernel image
1633	  and makes the kernel more or less silent. As this makes it
1634	  very difficult to diagnose system problems, saying N here is
1635	  strongly discouraged.
1636
1637config BUG
1638	bool "BUG() support" if EXPERT
1639	default y
1640	help
1641	  Disabling this option eliminates support for BUG and WARN, reducing
1642	  the size of your kernel image and potentially quietly ignoring
1643	  numerous fatal conditions. You should only consider disabling this
1644	  option for embedded systems with no facilities for reporting errors.
1645	  Just say Y.
1646
1647config ELF_CORE
1648	depends on COREDUMP
1649	default y
1650	bool "Enable ELF core dumps" if EXPERT
1651	help
1652	  Enable support for generating core dumps. Disabling saves about 4k.
1653
1654
1655config PCSPKR_PLATFORM
1656	bool "Enable PC-Speaker support" if EXPERT
1657	depends on HAVE_PCSPKR_PLATFORM
1658	select I8253_LOCK
1659	default y
1660	help
1661	  This option allows to disable the internal PC-Speaker
1662	  support, saving some memory.
1663
1664config BASE_SMALL
1665	bool "Enable smaller-sized data structures for core" if EXPERT
1666	help
1667	  Enabling this option reduces the size of miscellaneous core
1668	  kernel data structures. This saves memory on small machines,
1669	  but may reduce performance.
1670
1671config FUTEX
1672	bool "Enable futex support" if EXPERT
1673	depends on !(SPARC32 && SMP)
1674	default y
1675	imply RT_MUTEXES
1676	help
1677	  Disabling this option will cause the kernel to be built without
1678	  support for "fast userspace mutexes".  The resulting kernel may not
1679	  run glibc-based applications correctly.
1680
1681config FUTEX_PI
1682	bool
1683	depends on FUTEX && RT_MUTEXES
1684	default y
1685
1686config EPOLL
1687	bool "Enable eventpoll support" if EXPERT
1688	default y
1689	help
1690	  Disabling this option will cause the kernel to be built without
1691	  support for epoll family of system calls.
1692
1693config SIGNALFD
1694	bool "Enable signalfd() system call" if EXPERT
1695	default y
1696	help
1697	  Enable the signalfd() system call that allows to receive signals
1698	  on a file descriptor.
1699
1700	  If unsure, say Y.
1701
1702config TIMERFD
1703	bool "Enable timerfd() system call" if EXPERT
1704	default y
1705	help
1706	  Enable the timerfd() system call that allows to receive timer
1707	  events on a file descriptor.
1708
1709	  If unsure, say Y.
1710
1711config EVENTFD
1712	bool "Enable eventfd() system call" if EXPERT
1713	default y
1714	help
1715	  Enable the eventfd() system call that allows to receive both
1716	  kernel notification (ie. KAIO) or userspace notifications.
1717
1718	  If unsure, say Y.
1719
1720config SHMEM
1721	bool "Use full shmem filesystem" if EXPERT
1722	default y
1723	depends on MMU
1724	help
1725	  The shmem is an internal filesystem used to manage shared memory.
1726	  It is backed by swap and manages resource limits. It is also exported
1727	  to userspace as tmpfs if TMPFS is enabled. Disabling this
1728	  option replaces shmem and tmpfs with the much simpler ramfs code,
1729	  which may be appropriate on small systems without swap.
1730
1731config AIO
1732	bool "Enable AIO support" if EXPERT
1733	default y
1734	help
1735	  This option enables POSIX asynchronous I/O which may by used
1736	  by some high performance threaded applications. Disabling
1737	  this option saves about 7k.
1738
1739config IO_URING
1740	bool "Enable IO uring support" if EXPERT
1741	select IO_WQ
1742	default y
1743	help
1744	  This option enables support for the io_uring interface, enabling
1745	  applications to submit and complete IO through submission and
1746	  completion rings that are shared between the kernel and application.
1747
1748config GCOV_PROFILE_URING
1749	bool "Enable GCOV profiling on the io_uring subsystem"
1750	depends on GCOV_KERNEL
1751	help
1752	  Enable GCOV profiling on the io_uring subsystem, to facilitate
1753	  code coverage testing.
1754
1755	  If unsure, say N.
1756
1757	  Note that this will have a negative impact on the performance of
1758	  the io_uring subsystem, hence this should only be enabled for
1759	  specific test purposes.
1760
1761config ADVISE_SYSCALLS
1762	bool "Enable madvise/fadvise syscalls" if EXPERT
1763	default y
1764	help
1765	  This option enables the madvise and fadvise syscalls, used by
1766	  applications to advise the kernel about their future memory or file
1767	  usage, improving performance. If building an embedded system where no
1768	  applications use these syscalls, you can disable this option to save
1769	  space.
1770
1771config MEMBARRIER
1772	bool "Enable membarrier() system call" if EXPERT
1773	default y
1774	help
1775	  Enable the membarrier() system call that allows issuing memory
1776	  barriers across all running threads, which can be used to distribute
1777	  the cost of user-space memory barriers asymmetrically by transforming
1778	  pairs of memory barriers into pairs consisting of membarrier() and a
1779	  compiler barrier.
1780
1781	  If unsure, say Y.
1782
1783config KCMP
1784	bool "Enable kcmp() system call" if EXPERT
1785	help
1786	  Enable the kernel resource comparison system call. It provides
1787	  user-space with the ability to compare two processes to see if they
1788	  share a common resource, such as a file descriptor or even virtual
1789	  memory space.
1790
1791	  If unsure, say N.
1792
1793config RSEQ
1794	bool "Enable rseq() system call" if EXPERT
1795	default y
1796	depends on HAVE_RSEQ
1797	select MEMBARRIER
1798	help
1799	  Enable the restartable sequences system call. It provides a
1800	  user-space cache for the current CPU number value, which
1801	  speeds up getting the current CPU number from user-space,
1802	  as well as an ABI to speed up user-space operations on
1803	  per-CPU data.
1804
1805	  If unsure, say Y.
1806
1807config DEBUG_RSEQ
1808	default n
1809	bool "Enable debugging of rseq() system call" if EXPERT
1810	depends on RSEQ && DEBUG_KERNEL
1811	help
1812	  Enable extra debugging checks for the rseq system call.
1813
1814	  If unsure, say N.
1815
1816config CACHESTAT_SYSCALL
1817	bool "Enable cachestat() system call" if EXPERT
1818	default y
1819	help
1820	  Enable the cachestat system call, which queries the page cache
1821	  statistics of a file (number of cached pages, dirty pages,
1822	  pages marked for writeback, (recently) evicted pages).
1823
1824	  If unsure say Y here.
1825
1826config PC104
1827	bool "PC/104 support" if EXPERT
1828	help
1829	  Expose PC/104 form factor device drivers and options available for
1830	  selection and configuration. Enable this option if your target
1831	  machine has a PC/104 bus.
1832
1833config KALLSYMS
1834	bool "Load all symbols for debugging/ksymoops" if EXPERT
1835	default y
1836	help
1837	  Say Y here to let the kernel print out symbolic crash information and
1838	  symbolic stack backtraces. This increases the size of the kernel
1839	  somewhat, as all symbols have to be loaded into the kernel image.
1840
1841config KALLSYMS_SELFTEST
1842	bool "Test the basic functions and performance of kallsyms"
1843	depends on KALLSYMS
1844	default n
1845	help
1846	  Test the basic functions and performance of some interfaces, such as
1847	  kallsyms_lookup_name. It also calculates the compression rate of the
1848	  kallsyms compression algorithm for the current symbol set.
1849
1850	  Start self-test automatically after system startup. Suggest executing
1851	  "dmesg | grep kallsyms_selftest" to collect test results. "finish" is
1852	  displayed in the last line, indicating that the test is complete.
1853
1854config KALLSYMS_ALL
1855	bool "Include all symbols in kallsyms"
1856	depends on DEBUG_KERNEL && KALLSYMS
1857	help
1858	  Normally kallsyms only contains the symbols of functions for nicer
1859	  OOPS messages and backtraces (i.e., symbols from the text and inittext
1860	  sections). This is sufficient for most cases. And only if you want to
1861	  enable kernel live patching, or other less common use cases (e.g.,
1862	  when a debugger is used) all symbols are required (i.e., names of
1863	  variables from the data sections, etc).
1864
1865	  This option makes sure that all symbols are loaded into the kernel
1866	  image (i.e., symbols from all sections) in cost of increased kernel
1867	  size (depending on the kernel configuration, it may be 300KiB or
1868	  something like this).
1869
1870	  Say N unless you really need all symbols, or kernel live patching.
1871
1872config KALLSYMS_ABSOLUTE_PERCPU
1873	bool
1874	depends on KALLSYMS
1875	default X86_64 && SMP
1876
1877# end of the "standard kernel features (expert users)" menu
1878
1879config ARCH_HAS_MEMBARRIER_CALLBACKS
1880	bool
1881
1882config ARCH_HAS_MEMBARRIER_SYNC_CORE
1883	bool
1884
1885config HAVE_PERF_EVENTS
1886	bool
1887	help
1888	  See tools/perf/design.txt for details.
1889
1890config GUEST_PERF_EVENTS
1891	bool
1892	depends on HAVE_PERF_EVENTS
1893
1894config PERF_USE_VMALLOC
1895	bool
1896	help
1897	  See tools/perf/design.txt for details
1898
1899menu "Kernel Performance Events And Counters"
1900
1901config PERF_EVENTS
1902	bool "Kernel performance events and counters"
1903	default y if PROFILING
1904	depends on HAVE_PERF_EVENTS
1905	select IRQ_WORK
1906	help
1907	  Enable kernel support for various performance events provided
1908	  by software and hardware.
1909
1910	  Software events are supported either built-in or via the
1911	  use of generic tracepoints.
1912
1913	  Most modern CPUs support performance events via performance
1914	  counter registers. These registers count the number of certain
1915	  types of hw events: such as instructions executed, cachemisses
1916	  suffered, or branches mis-predicted - without slowing down the
1917	  kernel or applications. These registers can also trigger interrupts
1918	  when a threshold number of events have passed - and can thus be
1919	  used to profile the code that runs on that CPU.
1920
1921	  The Linux Performance Event subsystem provides an abstraction of
1922	  these software and hardware event capabilities, available via a
1923	  system call and used by the "perf" utility in tools/perf/. It
1924	  provides per task and per CPU counters, and it provides event
1925	  capabilities on top of those.
1926
1927	  Say Y if unsure.
1928
1929config DEBUG_PERF_USE_VMALLOC
1930	default n
1931	bool "Debug: use vmalloc to back perf mmap() buffers"
1932	depends on PERF_EVENTS && DEBUG_KERNEL && !PPC
1933	select PERF_USE_VMALLOC
1934	help
1935	  Use vmalloc memory to back perf mmap() buffers.
1936
1937	  Mostly useful for debugging the vmalloc code on platforms
1938	  that don't require it.
1939
1940	  Say N if unsure.
1941
1942endmenu
1943
1944config SYSTEM_DATA_VERIFICATION
1945	def_bool n
1946	select SYSTEM_TRUSTED_KEYRING
1947	select KEYS
1948	select CRYPTO
1949	select CRYPTO_RSA
1950	select ASYMMETRIC_KEY_TYPE
1951	select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
1952	select ASN1
1953	select OID_REGISTRY
1954	select X509_CERTIFICATE_PARSER
1955	select PKCS7_MESSAGE_PARSER
1956	help
1957	  Provide PKCS#7 message verification using the contents of the system
1958	  trusted keyring to provide public keys.  This then can be used for
1959	  module verification, kexec image verification and firmware blob
1960	  verification.
1961
1962config PROFILING
1963	bool "Profiling support"
1964	help
1965	  Say Y here to enable the extended profiling support mechanisms used
1966	  by profilers.
1967
1968config RUST
1969	bool "Rust support"
1970	depends on HAVE_RUST
1971	depends on RUST_IS_AVAILABLE
1972	select EXTENDED_MODVERSIONS if MODVERSIONS
1973	depends on !MODVERSIONS || GENDWARFKSYMS
1974	depends on !GCC_PLUGIN_RANDSTRUCT
1975	depends on !RANDSTRUCT
1976	depends on !DEBUG_INFO_BTF || PAHOLE_HAS_LANG_EXCLUDE
1977	depends on !CFI_CLANG || HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC
1978	select CFI_ICALL_NORMALIZE_INTEGERS if CFI_CLANG
1979	depends on !CALL_PADDING || RUSTC_VERSION >= 108100
1980	depends on !KASAN_SW_TAGS
1981	depends on !(MITIGATION_RETHUNK && KASAN) || RUSTC_VERSION >= 108300
1982	help
1983	  Enables Rust support in the kernel.
1984
1985	  This allows other Rust-related options, like drivers written in Rust,
1986	  to be selected.
1987
1988	  It is also required to be able to load external kernel modules
1989	  written in Rust.
1990
1991	  See Documentation/rust/ for more information.
1992
1993	  If unsure, say N.
1994
1995config RUSTC_VERSION_TEXT
1996	string
1997	depends on RUST
1998	default "$(RUSTC_VERSION_TEXT)"
1999	help
2000	  See `CC_VERSION_TEXT`.
2001
2002config BINDGEN_VERSION_TEXT
2003	string
2004	depends on RUST
2005	# The dummy parameter `workaround-for-0.69.0` is required to support 0.69.0
2006	# (https://github.com/rust-lang/rust-bindgen/pull/2678) and 0.71.0
2007	# (https://github.com/rust-lang/rust-bindgen/pull/3040). It can be removed
2008	# when the minimum version is upgraded past the latter (0.69.1 and 0.71.1
2009	# both fixed the issue).
2010	default "$(shell,$(BINDGEN) --version workaround-for-0.69.0 2>/dev/null)"
2011
2012#
2013# Place an empty function call at each tracepoint site. Can be
2014# dynamically changed for a probe function.
2015#
2016config TRACEPOINTS
2017	bool
2018	select TASKS_TRACE_RCU
2019
2020source "kernel/Kconfig.kexec"
2021
2022endmenu		# General setup
2023
2024source "arch/Kconfig"
2025
2026config RT_MUTEXES
2027	bool
2028	default y if PREEMPT_RT
2029
2030config MODULE_SIG_FORMAT
2031	def_bool n
2032	select SYSTEM_DATA_VERIFICATION
2033
2034source "kernel/module/Kconfig"
2035
2036config INIT_ALL_POSSIBLE
2037	bool
2038	help
2039	  Back when each arch used to define their own cpu_online_mask and
2040	  cpu_possible_mask, some of them chose to initialize cpu_possible_mask
2041	  with all 1s, and others with all 0s.  When they were centralised,
2042	  it was better to provide this option than to break all the archs
2043	  and have several arch maintainers pursuing me down dark alleys.
2044
2045source "block/Kconfig"
2046
2047config PREEMPT_NOTIFIERS
2048	bool
2049
2050config PADATA
2051	depends on SMP
2052	bool
2053
2054config ASN1
2055	tristate
2056	help
2057	  Build a simple ASN.1 grammar compiler that produces a bytecode output
2058	  that can be interpreted by the ASN.1 stream decoder and used to
2059	  inform it as to what tags are to be expected in a stream and what
2060	  functions to call on what tags.
2061
2062source "kernel/Kconfig.locks"
2063
2064config ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
2065	bool
2066
2067config ARCH_HAS_PREPARE_SYNC_CORE_CMD
2068	bool
2069
2070config ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
2071	bool
2072
2073# It may be useful for an architecture to override the definitions of the
2074# SYSCALL_DEFINE() and __SYSCALL_DEFINEx() macros in <linux/syscalls.h>
2075# and the COMPAT_ variants in <linux/compat.h>, in particular to use a
2076# different calling convention for syscalls. They can also override the
2077# macros for not-implemented syscalls in kernel/sys_ni.c and
2078# kernel/time/posix-stubs.c. All these overrides need to be available in
2079# <asm/syscall_wrapper.h>.
2080config ARCH_HAS_SYSCALL_WRAPPER
2081	def_bool n
2082