xref: /linux/init/Kconfig (revision 98366c20a275e957416e9516db5dcb7195b4e101)
1config DEFCONFIG_LIST
2	string
3	depends on !UML
4	option defconfig_list
5	default "/lib/modules/$UNAME_RELEASE/.config"
6	default "/etc/kernel-config"
7	default "/boot/config-$UNAME_RELEASE"
8	default "arch/$ARCH/defconfig"
9
10menu "General setup"
11
12config EXPERIMENTAL
13	bool "Prompt for development and/or incomplete code/drivers"
14	---help---
15	  Some of the various things that Linux supports (such as network
16	  drivers, file systems, network protocols, etc.) can be in a state
17	  of development where the functionality, stability, or the level of
18	  testing is not yet high enough for general use. This is usually
19	  known as the "alpha-test" phase among developers. If a feature is
20	  currently in alpha-test, then the developers usually discourage
21	  uninformed widespread use of this feature by the general public to
22	  avoid "Why doesn't this work?" type mail messages. However, active
23	  testing and use of these systems is welcomed. Just be aware that it
24	  may not meet the normal level of reliability or it may fail to work
25	  in some special cases. Detailed bug reports from people familiar
26	  with the kernel internals are usually welcomed by the developers
27	  (before submitting bug reports, please read the documents
28	  <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
29	  <file:Documentation/BUG-HUNTING>, and
30	  <file:Documentation/oops-tracing.txt> in the kernel source).
31
32	  This option will also make obsoleted drivers available. These are
33	  drivers that have been replaced by something else, and/or are
34	  scheduled to be removed in a future kernel release.
35
36	  Unless you intend to help test and develop a feature or driver that
37	  falls into this category, or you have a situation that requires
38	  using these features, you should probably say N here, which will
39	  cause the configurator to present you with fewer choices. If
40	  you say Y here, you will be offered the choice of using features or
41	  drivers that are currently considered to be in the alpha-test phase.
42
43config BROKEN
44	bool
45
46config BROKEN_ON_SMP
47	bool
48	depends on BROKEN || !SMP
49	default y
50
51config LOCK_KERNEL
52	bool
53	depends on SMP || PREEMPT
54	default y
55
56config INIT_ENV_ARG_LIMIT
57	int
58	default 32 if !UML
59	default 128 if UML
60	help
61	  Maximum of each of the number of arguments and environment
62	  variables passed to init from the kernel command line.
63
64
65config LOCALVERSION
66	string "Local version - append to kernel release"
67	help
68	  Append an extra string to the end of your kernel version.
69	  This will show up when you type uname, for example.
70	  The string you set here will be appended after the contents of
71	  any files with a filename matching localversion* in your
72	  object and source tree, in that order.  Your total string can
73	  be a maximum of 64 characters.
74
75config LOCALVERSION_AUTO
76	bool "Automatically append version information to the version string"
77	default y
78	help
79	  This will try to automatically determine if the current tree is a
80	  release tree by looking for git tags that belong to the current
81	  top of tree revision.
82
83	  A string of the format -gxxxxxxxx will be added to the localversion
84	  if a git-based tree is found.  The string generated by this will be
85	  appended after any matching localversion* files, and after the value
86	  set in CONFIG_LOCALVERSION.
87
88	  (The actual string used here is the first eight characters produced
89	  by running the command:
90
91	    $ git rev-parse --verify HEAD
92
93	  which is done within the script "scripts/setlocalversion".)
94
95config SWAP
96	bool "Support for paging of anonymous memory (swap)"
97	depends on MMU && BLOCK
98	default y
99	help
100	  This option allows you to choose whether you want to have support
101	  for so called swap devices or swap files in your kernel that are
102	  used to provide more virtual memory than the actual RAM present
103	  in your computer.  If unsure say Y.
104
105config SYSVIPC
106	bool "System V IPC"
107	---help---
108	  Inter Process Communication is a suite of library functions and
109	  system calls which let processes (running programs) synchronize and
110	  exchange information. It is generally considered to be a good thing,
111	  and some programs won't run unless you say Y here. In particular, if
112	  you want to run the DOS emulator dosemu under Linux (read the
113	  DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
114	  you'll need to say Y here.
115
116	  You can find documentation about IPC with "info ipc" and also in
117	  section 6.4 of the Linux Programmer's Guide, available from
118	  <http://www.tldp.org/guides.html>.
119
120config SYSVIPC_SYSCTL
121	bool
122	depends on SYSVIPC
123	depends on SYSCTL
124	default y
125
126config POSIX_MQUEUE
127	bool "POSIX Message Queues"
128	depends on NET && EXPERIMENTAL
129	---help---
130	  POSIX variant of message queues is a part of IPC. In POSIX message
131	  queues every message has a priority which decides about succession
132	  of receiving it by a process. If you want to compile and run
133	  programs written e.g. for Solaris with use of its POSIX message
134	  queues (functions mq_*) say Y here.
135
136	  POSIX message queues are visible as a filesystem called 'mqueue'
137	  and can be mounted somewhere if you want to do filesystem
138	  operations on message queues.
139
140	  If unsure, say Y.
141
142config BSD_PROCESS_ACCT
143	bool "BSD Process Accounting"
144	help
145	  If you say Y here, a user level program will be able to instruct the
146	  kernel (via a special system call) to write process accounting
147	  information to a file: whenever a process exits, information about
148	  that process will be appended to the file by the kernel.  The
149	  information includes things such as creation time, owning user,
150	  command name, memory usage, controlling terminal etc. (the complete
151	  list is in the struct acct in <file:include/linux/acct.h>).  It is
152	  up to the user level program to do useful things with this
153	  information.  This is generally a good idea, so say Y.
154
155config BSD_PROCESS_ACCT_V3
156	bool "BSD Process Accounting version 3 file format"
157	depends on BSD_PROCESS_ACCT
158	default n
159	help
160	  If you say Y here, the process accounting information is written
161	  in a new file format that also logs the process IDs of each
162	  process and it's parent. Note that this file format is incompatible
163	  with previous v0/v1/v2 file formats, so you will need updated tools
164	  for processing it. A preliminary version of these tools is available
165	  at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>.
166
167config TASKSTATS
168	bool "Export task/process statistics through netlink (EXPERIMENTAL)"
169	depends on NET
170	default n
171	help
172	  Export selected statistics for tasks/processes through the
173	  generic netlink interface. Unlike BSD process accounting, the
174	  statistics are available during the lifetime of tasks/processes as
175	  responses to commands. Like BSD accounting, they are sent to user
176	  space on task exit.
177
178	  Say N if unsure.
179
180config TASK_DELAY_ACCT
181	bool "Enable per-task delay accounting (EXPERIMENTAL)"
182	depends on TASKSTATS
183	help
184	  Collect information on time spent by a task waiting for system
185	  resources like cpu, synchronous block I/O completion and swapping
186	  in pages. Such statistics can help in setting a task's priorities
187	  relative to other tasks for cpu, io, rss limits etc.
188
189	  Say N if unsure.
190
191config TASK_XACCT
192	bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
193	depends on TASKSTATS
194	help
195	  Collect extended task accounting data and send the data
196	  to userland for processing over the taskstats interface.
197
198	  Say N if unsure.
199
200config TASK_IO_ACCOUNTING
201	bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
202	depends on TASK_XACCT
203	help
204	  Collect information on the number of bytes of storage I/O which this
205	  task has caused.
206
207	  Say N if unsure.
208
209config USER_NS
210	bool "User Namespaces (EXPERIMENTAL)"
211	default n
212	depends on EXPERIMENTAL
213	help
214	  Support user namespaces.  This allows containers, i.e.
215	  vservers, to use user namespaces to provide different
216	  user info for different servers.  If unsure, say N.
217
218config AUDIT
219	bool "Auditing support"
220	depends on NET
221	help
222	  Enable auditing infrastructure that can be used with another
223	  kernel subsystem, such as SELinux (which requires this for
224	  logging of avc messages output).  Does not do system-call
225	  auditing without CONFIG_AUDITSYSCALL.
226
227config AUDITSYSCALL
228	bool "Enable system-call auditing support"
229	depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64)
230	default y if SECURITY_SELINUX
231	help
232	  Enable low-overhead system-call auditing infrastructure that
233	  can be used independently or with another kernel subsystem,
234	  such as SELinux.  To use audit's filesystem watch feature, please
235	  ensure that INOTIFY is configured.
236
237config AUDIT_TREE
238	def_bool y
239	depends on AUDITSYSCALL && INOTIFY
240
241config IKCONFIG
242	tristate "Kernel .config support"
243	---help---
244	  This option enables the complete Linux kernel ".config" file
245	  contents to be saved in the kernel. It provides documentation
246	  of which kernel options are used in a running kernel or in an
247	  on-disk kernel.  This information can be extracted from the kernel
248	  image file with the script scripts/extract-ikconfig and used as
249	  input to rebuild the current kernel or to build another kernel.
250	  It can also be extracted from a running kernel by reading
251	  /proc/config.gz if enabled (below).
252
253config IKCONFIG_PROC
254	bool "Enable access to .config through /proc/config.gz"
255	depends on IKCONFIG && PROC_FS
256	---help---
257	  This option enables access to the kernel configuration file
258	  through /proc/config.gz.
259
260config LOG_BUF_SHIFT
261	int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
262	range 12 21
263	default 17 if S390 || LOCKDEP
264	default 16 if X86_NUMAQ || IA64
265	default 15 if SMP
266	default 14
267	help
268	  Select kernel log buffer size as a power of 2.
269	  Defaults and Examples:
270	  	     17 => 128 KB for S/390
271		     16 => 64 KB for x86 NUMAQ or IA-64
272	             15 => 32 KB for SMP
273	             14 => 16 KB for uniprocessor
274		     13 =>  8 KB
275		     12 =>  4 KB
276
277config CGROUPS
278	bool "Control Group support"
279	help
280	  This option will let you use process cgroup subsystems
281	  such as Cpusets
282
283	  Say N if unsure.
284
285config CGROUP_DEBUG
286	bool "Example debug cgroup subsystem"
287	depends on CGROUPS
288	help
289	  This option enables a simple cgroup subsystem that
290	  exports useful debugging information about the cgroups
291	  framework
292
293	  Say N if unsure
294
295config CGROUP_NS
296        bool "Namespace cgroup subsystem"
297        depends on CGROUPS
298        help
299          Provides a simple namespace cgroup subsystem to
300          provide hierarchical naming of sets of namespaces,
301          for instance virtual servers and checkpoint/restart
302          jobs.
303
304config CGROUP_CPUACCT
305	bool "Simple CPU accounting cgroup subsystem"
306	depends on CGROUPS
307	help
308	  Provides a simple Resource Controller for monitoring the
309	  total CPU consumed by the tasks in a cgroup
310
311config CPUSETS
312	bool "Cpuset support"
313	depends on SMP && CGROUPS
314	help
315	  This option will let you create and manage CPUSETs which
316	  allow dynamically partitioning a system into sets of CPUs and
317	  Memory Nodes and assigning tasks to run only within those sets.
318	  This is primarily useful on large SMP or NUMA systems.
319
320	  Say N if unsure.
321
322config FAIR_GROUP_SCHED
323	bool "Fair group CPU scheduler"
324	default y
325	help
326	  This feature lets CPU scheduler recognize task groups and control CPU
327	  bandwidth allocation to such task groups.
328
329choice
330	depends on FAIR_GROUP_SCHED
331	prompt "Basis for grouping tasks"
332	default FAIR_USER_SCHED
333
334config FAIR_USER_SCHED
335	bool "user id"
336	help
337	  This option will choose userid as the basis for grouping
338	  tasks, thus providing equal CPU bandwidth to each user.
339
340config FAIR_CGROUP_SCHED
341	bool "Control groups"
342 	depends on CGROUPS
343 	help
344	  This option allows you to create arbitrary task groups
345	  using the "cgroup" pseudo filesystem and control
346	  the cpu bandwidth allocated to each such task group.
347	  Refer to Documentation/cgroups.txt for more information
348	  on "cgroup" pseudo filesystem.
349
350endchoice
351
352config SYSFS_DEPRECATED
353	bool "Create deprecated sysfs files"
354	default y
355	help
356	  This option creates deprecated symlinks such as the
357	  "device"-link, the <subsystem>:<name>-link, and the
358	  "bus"-link. It may also add deprecated key in the
359	  uevent environment.
360	  None of these features or values should be used today, as
361	  they export driver core implementation details to userspace
362	  or export properties which can't be kept stable across kernel
363	  releases.
364
365	  If enabled, this option will also move any device structures
366	  that belong to a class, back into the /sys/class hierarchy, in
367	  order to support older versions of udev.
368
369	  If you are using a distro that was released in 2006 or later,
370	  it should be safe to say N here.
371
372config PROC_PID_CPUSET
373	bool "Include legacy /proc/<pid>/cpuset file"
374	depends on CPUSETS
375	default y
376
377config RELAY
378	bool "Kernel->user space relay support (formerly relayfs)"
379	help
380	  This option enables support for relay interface support in
381	  certain file systems (such as debugfs).
382	  It is designed to provide an efficient mechanism for tools and
383	  facilities to relay large amounts of data from kernel space to
384	  user space.
385
386	  If unsure, say N.
387
388config BLK_DEV_INITRD
389	bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
390	depends on BROKEN || !FRV
391	help
392	  The initial RAM filesystem is a ramfs which is loaded by the
393	  boot loader (loadlin or lilo) and that is mounted as root
394	  before the normal boot procedure. It is typically used to
395	  load modules needed to mount the "real" root file system,
396	  etc. See <file:Documentation/initrd.txt> for details.
397
398	  If RAM disk support (BLK_DEV_RAM) is also included, this
399	  also enables initial RAM disk (initrd) support and adds
400	  15 Kbytes (more on some other architectures) to the kernel size.
401
402	  If unsure say Y.
403
404if BLK_DEV_INITRD
405
406source "usr/Kconfig"
407
408endif
409
410config CC_OPTIMIZE_FOR_SIZE
411	bool "Optimize for size (Look out for broken compilers!)"
412	default y
413	depends on ARM || H8300 || SUPERH || EXPERIMENTAL
414	help
415	  Enabling this option will pass "-Os" instead of "-O2" to gcc
416	  resulting in a smaller kernel.
417
418	  WARNING: some versions of gcc may generate incorrect code with this
419	  option.  If problems are observed, a gcc upgrade may be needed.
420
421	  If unsure, say N.
422
423config SYSCTL
424	bool
425
426menuconfig EMBEDDED
427	bool "Configure standard kernel features (for small systems)"
428	help
429	  This option allows certain base kernel options and settings
430          to be disabled or tweaked. This is for specialized
431          environments which can tolerate a "non-standard" kernel.
432          Only use this if you really know what you are doing.
433
434config UID16
435	bool "Enable 16-bit UID system calls" if EMBEDDED
436	depends on ARM || BFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION)
437	default y
438	help
439	  This enables the legacy 16-bit UID syscall wrappers.
440
441config SYSCTL_SYSCALL
442	bool "Sysctl syscall support" if EMBEDDED
443	default y
444	select SYSCTL
445	---help---
446	  sys_sysctl uses binary paths that have been found challenging
447	  to properly maintain and use.  The interface in /proc/sys
448	  using paths with ascii names is now the primary path to this
449	  information.
450
451	  Almost nothing using the binary sysctl interface so if you are
452	  trying to save some space it is probably safe to disable this,
453	  making your kernel marginally smaller.
454
455	  If unsure say Y here.
456
457config KALLSYMS
458	 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
459	 default y
460	 help
461	   Say Y here to let the kernel print out symbolic crash information and
462	   symbolic stack backtraces. This increases the size of the kernel
463	   somewhat, as all symbols have to be loaded into the kernel image.
464
465config KALLSYMS_ALL
466	bool "Include all symbols in kallsyms"
467	depends on DEBUG_KERNEL && KALLSYMS
468	help
469	   Normally kallsyms only contains the symbols of functions, for nicer
470	   OOPS messages.  Some debuggers can use kallsyms for other
471	   symbols too: say Y here to include all symbols, if you need them
472	   and you don't care about adding 300k to the size of your kernel.
473
474	   Say N.
475
476config KALLSYMS_EXTRA_PASS
477	bool "Do an extra kallsyms pass"
478	depends on KALLSYMS
479	help
480	   If kallsyms is not working correctly, the build will fail with
481	   inconsistent kallsyms data.  If that occurs, log a bug report and
482	   turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
483	   Always say N here unless you find a bug in kallsyms, which must be
484	   reported.  KALLSYMS_EXTRA_PASS is only a temporary workaround while
485	   you wait for kallsyms to be fixed.
486
487
488config HOTPLUG
489	bool "Support for hot-pluggable devices" if EMBEDDED
490	default y
491	help
492	  This option is provided for the case where no hotplug or uevent
493	  capabilities is wanted by the kernel.  You should only consider
494	  disabling this option for embedded systems that do not use modules, a
495	  dynamic /dev tree, or dynamic device discovery.  Just say Y.
496
497config PRINTK
498	default y
499	bool "Enable support for printk" if EMBEDDED
500	help
501	  This option enables normal printk support. Removing it
502	  eliminates most of the message strings from the kernel image
503	  and makes the kernel more or less silent. As this makes it
504	  very difficult to diagnose system problems, saying N here is
505	  strongly discouraged.
506
507config BUG
508	bool "BUG() support" if EMBEDDED
509	default y
510	help
511          Disabling this option eliminates support for BUG and WARN, reducing
512          the size of your kernel image and potentially quietly ignoring
513          numerous fatal conditions. You should only consider disabling this
514          option for embedded systems with no facilities for reporting errors.
515          Just say Y.
516
517config ELF_CORE
518	default y
519	bool "Enable ELF core dumps" if EMBEDDED
520	help
521	  Enable support for generating core dumps. Disabling saves about 4k.
522
523config BASE_FULL
524	default y
525	bool "Enable full-sized data structures for core" if EMBEDDED
526	help
527	  Disabling this option reduces the size of miscellaneous core
528	  kernel data structures. This saves memory on small machines,
529	  but may reduce performance.
530
531config FUTEX
532	bool "Enable futex support" if EMBEDDED
533	default y
534	select RT_MUTEXES
535	help
536	  Disabling this option will cause the kernel to be built without
537	  support for "fast userspace mutexes".  The resulting kernel may not
538	  run glibc-based applications correctly.
539
540config ANON_INODES
541	bool
542
543config EPOLL
544	bool "Enable eventpoll support" if EMBEDDED
545	default y
546	select ANON_INODES
547	help
548	  Disabling this option will cause the kernel to be built without
549	  support for epoll family of system calls.
550
551config SIGNALFD
552	bool "Enable signalfd() system call" if EMBEDDED
553	select ANON_INODES
554	default y
555	help
556	  Enable the signalfd() system call that allows to receive signals
557	  on a file descriptor.
558
559	  If unsure, say Y.
560
561config TIMERFD
562	bool "Enable timerfd() system call" if EMBEDDED
563	select ANON_INODES
564	depends on BROKEN
565	default y
566	help
567	  Enable the timerfd() system call that allows to receive timer
568	  events on a file descriptor.
569
570	  If unsure, say Y.
571
572config EVENTFD
573	bool "Enable eventfd() system call" if EMBEDDED
574	select ANON_INODES
575	default y
576	help
577	  Enable the eventfd() system call that allows to receive both
578	  kernel notification (ie. KAIO) or userspace notifications.
579
580	  If unsure, say Y.
581
582config SHMEM
583	bool "Use full shmem filesystem" if EMBEDDED
584	default y
585	depends on MMU
586	help
587	  The shmem is an internal filesystem used to manage shared memory.
588	  It is backed by swap and manages resource limits. It is also exported
589	  to userspace as tmpfs if TMPFS is enabled. Disabling this
590	  option replaces shmem and tmpfs with the much simpler ramfs code,
591	  which may be appropriate on small systems without swap.
592
593config VM_EVENT_COUNTERS
594	default y
595	bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
596	help
597	  VM event counters are needed for event counts to be shown.
598	  This option allows the disabling of the VM event counters
599	  on EMBEDDED systems.  /proc/vmstat will only show page counts
600	  if VM event counters are disabled.
601
602config SLUB_DEBUG
603	default y
604	bool "Enable SLUB debugging support" if EMBEDDED
605	depends on SLUB
606	help
607	  SLUB has extensive debug support features. Disabling these can
608	  result in significant savings in code size. This also disables
609	  SLUB sysfs support. /sys/slab will not exist and there will be
610	  no support for cache validation etc.
611
612choice
613	prompt "Choose SLAB allocator"
614	default SLUB
615	help
616	   This option allows to select a slab allocator.
617
618config SLAB
619	bool "SLAB"
620	help
621	  The regular slab allocator that is established and known to work
622	  well in all environments. It organizes cache hot objects in
623	  per cpu and per node queues. SLAB is the default choice for
624	  a slab allocator.
625
626config SLUB
627	bool "SLUB (Unqueued Allocator)"
628	help
629	   SLUB is a slab allocator that minimizes cache line usage
630	   instead of managing queues of cached objects (SLAB approach).
631	   Per cpu caching is realized using slabs of objects instead
632	   of queues of objects. SLUB can use memory efficiently
633	   and has enhanced diagnostics.
634
635config SLOB
636	depends on EMBEDDED
637	bool "SLOB (Simple Allocator)"
638	help
639	   SLOB replaces the SLAB allocator with a drastically simpler
640	   allocator.  SLOB is more space efficient than SLAB but does not
641	   scale well (single lock for all operations) and is also highly
642	   susceptible to fragmentation. SLUB can accomplish a higher object
643	   density. It is usually better to use SLUB instead of SLOB.
644
645endchoice
646
647endmenu		# General setup
648
649config RT_MUTEXES
650	boolean
651	select PLIST
652
653config TINY_SHMEM
654	default !SHMEM
655	bool
656
657config BASE_SMALL
658	int
659	default 0 if BASE_FULL
660	default 1 if !BASE_FULL
661
662menuconfig MODULES
663	bool "Enable loadable module support"
664	help
665	  Kernel modules are small pieces of compiled code which can
666	  be inserted in the running kernel, rather than being
667	  permanently built into the kernel.  You use the "modprobe"
668	  tool to add (and sometimes remove) them.  If you say Y here,
669	  many parts of the kernel can be built as modules (by
670	  answering M instead of Y where indicated): this is most
671	  useful for infrequently used options which are not required
672	  for booting.  For more information, see the man pages for
673	  modprobe, lsmod, modinfo, insmod and rmmod.
674
675	  If you say Y here, you will need to run "make
676	  modules_install" to put the modules under /lib/modules/
677	  where modprobe can find them (you may need to be root to do
678	  this).
679
680	  If unsure, say Y.
681
682config MODULE_UNLOAD
683	bool "Module unloading"
684	depends on MODULES
685	help
686	  Without this option you will not be able to unload any
687	  modules (note that some modules may not be unloadable
688	  anyway), which makes your kernel slightly smaller and
689	  simpler.  If unsure, say Y.
690
691config MODULE_FORCE_UNLOAD
692	bool "Forced module unloading"
693	depends on MODULE_UNLOAD && EXPERIMENTAL
694	help
695	  This option allows you to force a module to unload, even if the
696	  kernel believes it is unsafe: the kernel will remove the module
697	  without waiting for anyone to stop using it (using the -f option to
698	  rmmod).  This is mainly for kernel developers and desperate users.
699	  If unsure, say N.
700
701config MODVERSIONS
702	bool "Module versioning support"
703	depends on MODULES
704	help
705	  Usually, you have to use modules compiled with your kernel.
706	  Saying Y here makes it sometimes possible to use modules
707	  compiled for different kernels, by adding enough information
708	  to the modules to (hopefully) spot any changes which would
709	  make them incompatible with the kernel you are running.  If
710	  unsure, say N.
711
712config MODULE_SRCVERSION_ALL
713	bool "Source checksum for all modules"
714	depends on MODULES
715	help
716	  Modules which contain a MODULE_VERSION get an extra "srcversion"
717	  field inserted into their modinfo section, which contains a
718    	  sum of the source files which made it.  This helps maintainers
719	  see exactly which source was used to build a module (since
720	  others sometimes change the module source without updating
721	  the version).  With this option, such a "srcversion" field
722	  will be created for all modules.  If unsure, say N.
723
724config KMOD
725	bool "Automatic kernel module loading"
726	depends on MODULES
727	help
728	  Normally when you have selected some parts of the kernel to
729	  be created as kernel modules, you must load them (using the
730	  "modprobe" command) before you can use them. If you say Y
731	  here, some parts of the kernel will be able to load modules
732	  automatically: when a part of the kernel needs a module, it
733	  runs modprobe with the appropriate arguments, thereby
734	  loading the module if it is available.  If unsure, say Y.
735
736config STOP_MACHINE
737	bool
738	default y
739	depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
740	help
741	  Need stop_machine() primitive.
742
743source "block/Kconfig"
744
745config PREEMPT_NOTIFIERS
746	bool
747