xref: /linux/init/Kconfig (revision 6b2d2cec1081a979e0efd6a1e9559e5a01a3c10e)
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33	  drivers that have been replaced by something else, and/or are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 PID_NS
219	bool "PID Namespaces (EXPERIMENTAL)"
220	default n
221	depends on EXPERIMENTAL
222	help
223	  Suport process id namespaces.  This allows having multiple
224	  process with the same pid as long as they are in different
225	  pid namespaces.  This is a building block of containers.
226
227	  Unless you want to work with an experimental feature
228	  say N here.
229
230config AUDIT
231	bool "Auditing support"
232	depends on NET
233	help
234	  Enable auditing infrastructure that can be used with another
235	  kernel subsystem, such as SELinux (which requires this for
236	  logging of avc messages output).  Does not do system-call
237	  auditing without CONFIG_AUDITSYSCALL.
238
239config AUDITSYSCALL
240	bool "Enable system-call auditing support"
241	depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64)
242	default y if SECURITY_SELINUX
243	help
244	  Enable low-overhead system-call auditing infrastructure that
245	  can be used independently or with another kernel subsystem,
246	  such as SELinux.  To use audit's filesystem watch feature, please
247	  ensure that INOTIFY is configured.
248
249config AUDIT_TREE
250	def_bool y
251	depends on AUDITSYSCALL && INOTIFY
252
253config IKCONFIG
254	tristate "Kernel .config support"
255	---help---
256	  This option enables the complete Linux kernel ".config" file
257	  contents to be saved in the kernel. It provides documentation
258	  of which kernel options are used in a running kernel or in an
259	  on-disk kernel.  This information can be extracted from the kernel
260	  image file with the script scripts/extract-ikconfig and used as
261	  input to rebuild the current kernel or to build another kernel.
262	  It can also be extracted from a running kernel by reading
263	  /proc/config.gz if enabled (below).
264
265config IKCONFIG_PROC
266	bool "Enable access to .config through /proc/config.gz"
267	depends on IKCONFIG && PROC_FS
268	---help---
269	  This option enables access to the kernel configuration file
270	  through /proc/config.gz.
271
272config LOG_BUF_SHIFT
273	int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
274	range 12 21
275	default 17 if S390 || LOCKDEP
276	default 16 if X86_NUMAQ || IA64
277	default 15 if SMP
278	default 14
279	help
280	  Select kernel log buffer size as a power of 2.
281	  Defaults and Examples:
282	  	     17 => 128 KB for S/390
283		     16 => 64 KB for x86 NUMAQ or IA-64
284	             15 => 32 KB for SMP
285	             14 => 16 KB for uniprocessor
286		     13 =>  8 KB
287		     12 =>  4 KB
288
289config CGROUPS
290	bool "Control Group support"
291	help
292	  This option will let you use process cgroup subsystems
293	  such as Cpusets
294
295	  Say N if unsure.
296
297config CGROUP_DEBUG
298	bool "Example debug cgroup subsystem"
299	depends on CGROUPS
300	help
301	  This option enables a simple cgroup subsystem that
302	  exports useful debugging information about the cgroups
303	  framework
304
305	  Say N if unsure
306
307config CGROUP_NS
308        bool "Namespace cgroup subsystem"
309        depends on CGROUPS
310        help
311          Provides a simple namespace cgroup subsystem to
312          provide hierarchical naming of sets of namespaces,
313          for instance virtual servers and checkpoint/restart
314          jobs.
315
316config CPUSETS
317	bool "Cpuset support"
318	depends on SMP && CGROUPS
319	help
320	  This option will let you create and manage CPUSETs which
321	  allow dynamically partitioning a system into sets of CPUs and
322	  Memory Nodes and assigning tasks to run only within those sets.
323	  This is primarily useful on large SMP or NUMA systems.
324
325	  Say N if unsure.
326
327config FAIR_GROUP_SCHED
328	bool "Fair group CPU scheduler"
329	default y
330	help
331	  This feature lets CPU scheduler recognize task groups and control CPU
332	  bandwidth allocation to such task groups.
333
334choice
335	depends on FAIR_GROUP_SCHED
336	prompt "Basis for grouping tasks"
337	default FAIR_USER_SCHED
338
339config FAIR_USER_SCHED
340	bool "user id"
341	help
342	  This option will choose userid as the basis for grouping
343	  tasks, thus providing equal CPU bandwidth to each user.
344
345config FAIR_CGROUP_SCHED
346	bool "Control groups"
347 	depends on CGROUPS
348 	help
349	  This option allows you to create arbitrary task groups
350	  using the "cgroup" pseudo filesystem and control
351	  the cpu bandwidth allocated to each such task group.
352	  Refer to Documentation/cgroups.txt for more information
353	  on "cgroup" pseudo filesystem.
354
355endchoice
356
357config CGROUP_CPUACCT
358	bool "Simple CPU accounting cgroup subsystem"
359	depends on CGROUPS
360	help
361	  Provides a simple Resource Controller for monitoring the
362	  total CPU consumed by the tasks in a cgroup
363
364config SYSFS_DEPRECATED
365	bool "Create deprecated sysfs files"
366	default y
367	help
368	  This option creates deprecated symlinks such as the
369	  "device"-link, the <subsystem>:<name>-link, and the
370	  "bus"-link. It may also add deprecated key in the
371	  uevent environment.
372	  None of these features or values should be used today, as
373	  they export driver core implementation details to userspace
374	  or export properties which can't be kept stable across kernel
375	  releases.
376
377	  If enabled, this option will also move any device structures
378	  that belong to a class, back into the /sys/class hierarchy, in
379	  order to support older versions of udev.
380
381	  If you are using a distro that was released in 2006 or later,
382	  it should be safe to say N here.
383
384config PROC_PID_CPUSET
385	bool "Include legacy /proc/<pid>/cpuset file"
386	depends on CPUSETS
387	default y
388
389config RELAY
390	bool "Kernel->user space relay support (formerly relayfs)"
391	help
392	  This option enables support for relay interface support in
393	  certain file systems (such as debugfs).
394	  It is designed to provide an efficient mechanism for tools and
395	  facilities to relay large amounts of data from kernel space to
396	  user space.
397
398	  If unsure, say N.
399
400config BLK_DEV_INITRD
401	bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
402	depends on BROKEN || !FRV
403	help
404	  The initial RAM filesystem is a ramfs which is loaded by the
405	  boot loader (loadlin or lilo) and that is mounted as root
406	  before the normal boot procedure. It is typically used to
407	  load modules needed to mount the "real" root file system,
408	  etc. See <file:Documentation/initrd.txt> for details.
409
410	  If RAM disk support (BLK_DEV_RAM) is also included, this
411	  also enables initial RAM disk (initrd) support and adds
412	  15 Kbytes (more on some other architectures) to the kernel size.
413
414	  If unsure say Y.
415
416if BLK_DEV_INITRD
417
418source "usr/Kconfig"
419
420endif
421
422config CC_OPTIMIZE_FOR_SIZE
423	bool "Optimize for size (Look out for broken compilers!)"
424	default y
425	depends on ARM || H8300 || SUPERH || EXPERIMENTAL
426	help
427	  Enabling this option will pass "-Os" instead of "-O2" to gcc
428	  resulting in a smaller kernel.
429
430	  WARNING: some versions of gcc may generate incorrect code with this
431	  option.  If problems are observed, a gcc upgrade may be needed.
432
433	  If unsure, say N.
434
435config SYSCTL
436	bool
437
438menuconfig EMBEDDED
439	bool "Configure standard kernel features (for small systems)"
440	help
441	  This option allows certain base kernel options and settings
442          to be disabled or tweaked. This is for specialized
443          environments which can tolerate a "non-standard" kernel.
444          Only use this if you really know what you are doing.
445
446config UID16
447	bool "Enable 16-bit UID system calls" if EMBEDDED
448	depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION)
449	default y
450	help
451	  This enables the legacy 16-bit UID syscall wrappers.
452
453config SYSCTL_SYSCALL
454	bool "Sysctl syscall support" if EMBEDDED
455	default y
456	select SYSCTL
457	---help---
458	  sys_sysctl uses binary paths that have been found challenging
459	  to properly maintain and use.  The interface in /proc/sys
460	  using paths with ascii names is now the primary path to this
461	  information.
462
463	  Almost nothing using the binary sysctl interface so if you are
464	  trying to save some space it is probably safe to disable this,
465	  making your kernel marginally smaller.
466
467	  If unsure say Y here.
468
469config KALLSYMS
470	 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
471	 default y
472	 help
473	   Say Y here to let the kernel print out symbolic crash information and
474	   symbolic stack backtraces. This increases the size of the kernel
475	   somewhat, as all symbols have to be loaded into the kernel image.
476
477config KALLSYMS_ALL
478	bool "Include all symbols in kallsyms"
479	depends on DEBUG_KERNEL && KALLSYMS
480	help
481	   Normally kallsyms only contains the symbols of functions, for nicer
482	   OOPS messages.  Some debuggers can use kallsyms for other
483	   symbols too: say Y here to include all symbols, if you need them
484	   and you don't care about adding 300k to the size of your kernel.
485
486	   Say N.
487
488config KALLSYMS_EXTRA_PASS
489	bool "Do an extra kallsyms pass"
490	depends on KALLSYMS
491	help
492	   If kallsyms is not working correctly, the build will fail with
493	   inconsistent kallsyms data.  If that occurs, log a bug report and
494	   turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
495	   Always say N here unless you find a bug in kallsyms, which must be
496	   reported.  KALLSYMS_EXTRA_PASS is only a temporary workaround while
497	   you wait for kallsyms to be fixed.
498
499
500config HOTPLUG
501	bool "Support for hot-pluggable devices" if EMBEDDED
502	default y
503	help
504	  This option is provided for the case where no hotplug or uevent
505	  capabilities is wanted by the kernel.  You should only consider
506	  disabling this option for embedded systems that do not use modules, a
507	  dynamic /dev tree, or dynamic device discovery.  Just say Y.
508
509config PRINTK
510	default y
511	bool "Enable support for printk" if EMBEDDED
512	help
513	  This option enables normal printk support. Removing it
514	  eliminates most of the message strings from the kernel image
515	  and makes the kernel more or less silent. As this makes it
516	  very difficult to diagnose system problems, saying N here is
517	  strongly discouraged.
518
519config BUG
520	bool "BUG() support" if EMBEDDED
521	default y
522	help
523          Disabling this option eliminates support for BUG and WARN, reducing
524          the size of your kernel image and potentially quietly ignoring
525          numerous fatal conditions. You should only consider disabling this
526          option for embedded systems with no facilities for reporting errors.
527          Just say Y.
528
529config ELF_CORE
530	default y
531	bool "Enable ELF core dumps" if EMBEDDED
532	help
533	  Enable support for generating core dumps. Disabling saves about 4k.
534
535config BASE_FULL
536	default y
537	bool "Enable full-sized data structures for core" if EMBEDDED
538	help
539	  Disabling this option reduces the size of miscellaneous core
540	  kernel data structures. This saves memory on small machines,
541	  but may reduce performance.
542
543config FUTEX
544	bool "Enable futex support" if EMBEDDED
545	default y
546	select RT_MUTEXES
547	help
548	  Disabling this option will cause the kernel to be built without
549	  support for "fast userspace mutexes".  The resulting kernel may not
550	  run glibc-based applications correctly.
551
552config ANON_INODES
553	bool
554
555config EPOLL
556	bool "Enable eventpoll support" if EMBEDDED
557	default y
558	select ANON_INODES
559	help
560	  Disabling this option will cause the kernel to be built without
561	  support for epoll family of system calls.
562
563config SIGNALFD
564	bool "Enable signalfd() system call" if EMBEDDED
565	select ANON_INODES
566	default y
567	help
568	  Enable the signalfd() system call that allows to receive signals
569	  on a file descriptor.
570
571	  If unsure, say Y.
572
573config TIMERFD
574	bool "Enable timerfd() system call" if EMBEDDED
575	select ANON_INODES
576	depends on BROKEN
577	default y
578	help
579	  Enable the timerfd() system call that allows to receive timer
580	  events on a file descriptor.
581
582	  If unsure, say Y.
583
584config EVENTFD
585	bool "Enable eventfd() system call" if EMBEDDED
586	select ANON_INODES
587	default y
588	help
589	  Enable the eventfd() system call that allows to receive both
590	  kernel notification (ie. KAIO) or userspace notifications.
591
592	  If unsure, say Y.
593
594config SHMEM
595	bool "Use full shmem filesystem" if EMBEDDED
596	default y
597	depends on MMU
598	help
599	  The shmem is an internal filesystem used to manage shared memory.
600	  It is backed by swap and manages resource limits. It is also exported
601	  to userspace as tmpfs if TMPFS is enabled. Disabling this
602	  option replaces shmem and tmpfs with the much simpler ramfs code,
603	  which may be appropriate on small systems without swap.
604
605config VM_EVENT_COUNTERS
606	default y
607	bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
608	help
609	  VM event counters are needed for event counts to be shown.
610	  This option allows the disabling of the VM event counters
611	  on EMBEDDED systems.  /proc/vmstat will only show page counts
612	  if VM event counters are disabled.
613
614config SLUB_DEBUG
615	default y
616	bool "Enable SLUB debugging support" if EMBEDDED
617	depends on SLUB
618	help
619	  SLUB has extensive debug support features. Disabling these can
620	  result in significant savings in code size. This also disables
621	  SLUB sysfs support. /sys/slab will not exist and there will be
622	  no support for cache validation etc.
623
624choice
625	prompt "Choose SLAB allocator"
626	default SLUB
627	help
628	   This option allows to select a slab allocator.
629
630config SLAB
631	bool "SLAB"
632	help
633	  The regular slab allocator that is established and known to work
634	  well in all environments. It organizes cache hot objects in
635	  per cpu and per node queues. SLAB is the default choice for
636	  a slab allocator.
637
638config SLUB
639	bool "SLUB (Unqueued Allocator)"
640	help
641	   SLUB is a slab allocator that minimizes cache line usage
642	   instead of managing queues of cached objects (SLAB approach).
643	   Per cpu caching is realized using slabs of objects instead
644	   of queues of objects. SLUB can use memory efficiently
645	   and has enhanced diagnostics.
646
647config SLOB
648	depends on EMBEDDED
649	bool "SLOB (Simple Allocator)"
650	help
651	   SLOB replaces the SLAB allocator with a drastically simpler
652	   allocator.  SLOB is more space efficient than SLAB but does not
653	   scale well (single lock for all operations) and is also highly
654	   susceptible to fragmentation. SLUB can accomplish a higher object
655	   density. It is usually better to use SLUB instead of SLOB.
656
657endchoice
658
659endmenu		# General setup
660
661config SLABINFO
662	bool
663	depends on PROC_FS
664	depends on SLAB || SLUB
665	default y
666
667config RT_MUTEXES
668	boolean
669	select PLIST
670
671config TINY_SHMEM
672	default !SHMEM
673	bool
674
675config BASE_SMALL
676	int
677	default 0 if BASE_FULL
678	default 1 if !BASE_FULL
679
680menuconfig MODULES
681	bool "Enable loadable module support"
682	help
683	  Kernel modules are small pieces of compiled code which can
684	  be inserted in the running kernel, rather than being
685	  permanently built into the kernel.  You use the "modprobe"
686	  tool to add (and sometimes remove) them.  If you say Y here,
687	  many parts of the kernel can be built as modules (by
688	  answering M instead of Y where indicated): this is most
689	  useful for infrequently used options which are not required
690	  for booting.  For more information, see the man pages for
691	  modprobe, lsmod, modinfo, insmod and rmmod.
692
693	  If you say Y here, you will need to run "make
694	  modules_install" to put the modules under /lib/modules/
695	  where modprobe can find them (you may need to be root to do
696	  this).
697
698	  If unsure, say Y.
699
700config MODULE_UNLOAD
701	bool "Module unloading"
702	depends on MODULES
703	help
704	  Without this option you will not be able to unload any
705	  modules (note that some modules may not be unloadable
706	  anyway), which makes your kernel slightly smaller and
707	  simpler.  If unsure, say Y.
708
709config MODULE_FORCE_UNLOAD
710	bool "Forced module unloading"
711	depends on MODULE_UNLOAD && EXPERIMENTAL
712	help
713	  This option allows you to force a module to unload, even if the
714	  kernel believes it is unsafe: the kernel will remove the module
715	  without waiting for anyone to stop using it (using the -f option to
716	  rmmod).  This is mainly for kernel developers and desperate users.
717	  If unsure, say N.
718
719config MODVERSIONS
720	bool "Module versioning support"
721	depends on MODULES
722	help
723	  Usually, you have to use modules compiled with your kernel.
724	  Saying Y here makes it sometimes possible to use modules
725	  compiled for different kernels, by adding enough information
726	  to the modules to (hopefully) spot any changes which would
727	  make them incompatible with the kernel you are running.  If
728	  unsure, say N.
729
730config MODULE_SRCVERSION_ALL
731	bool "Source checksum for all modules"
732	depends on MODULES
733	help
734	  Modules which contain a MODULE_VERSION get an extra "srcversion"
735	  field inserted into their modinfo section, which contains a
736    	  sum of the source files which made it.  This helps maintainers
737	  see exactly which source was used to build a module (since
738	  others sometimes change the module source without updating
739	  the version).  With this option, such a "srcversion" field
740	  will be created for all modules.  If unsure, say N.
741
742config KMOD
743	bool "Automatic kernel module loading"
744	depends on MODULES
745	help
746	  Normally when you have selected some parts of the kernel to
747	  be created as kernel modules, you must load them (using the
748	  "modprobe" command) before you can use them. If you say Y
749	  here, some parts of the kernel will be able to load modules
750	  automatically: when a part of the kernel needs a module, it
751	  runs modprobe with the appropriate arguments, thereby
752	  loading the module if it is available.  If unsure, say Y.
753
754config STOP_MACHINE
755	bool
756	default y
757	depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
758	help
759	  Need stop_machine() primitive.
760
761source "block/Kconfig"
762
763config PREEMPT_NOTIFIERS
764	bool
765