blob: 528a0c4111ccb5cac4cfb46414f3cf4191c4417c [file] [log] [blame]
Roman Zippel80daa562008-01-14 04:51:16 +01001config ARCH
2 string
3 option env="ARCH"
4
5config KERNELVERSION
6 string
7 option env="KERNELVERSION"
8
Roman Zippelface4372006-06-08 22:12:45 -07009config DEFCONFIG_LIST
10 string
Paolo 'Blaisorblade' Giarrussob2670eac2006-10-19 23:28:23 -070011 depends on !UML
Roman Zippelface4372006-06-08 22:12:45 -070012 option defconfig_list
13 default "/lib/modules/$UNAME_RELEASE/.config"
14 default "/etc/kernel-config"
15 default "/boot/config-$UNAME_RELEASE"
Sam Ravnborg73531902008-05-25 23:03:18 +020016 default "$ARCH_DEFCONFIG"
Roman Zippelface4372006-06-08 22:12:45 -070017 default "arch/$ARCH/defconfig"
18
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -070019config CONSTRUCTORS
20 bool
21 depends on !UML
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -070022
Peter Zijlstrae360adb2010-10-14 14:01:34 +080023config HAVE_IRQ_WORK
24 bool
25
26config IRQ_WORK
27 bool
28 depends on HAVE_IRQ_WORK
29
Al Boldiff0cfc62007-07-31 00:39:23 -070030menu "General setup"
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
32config EXPERIMENTAL
33 bool "Prompt for development and/or incomplete code/drivers"
34 ---help---
35 Some of the various things that Linux supports (such as network
36 drivers, file systems, network protocols, etc.) can be in a state
37 of development where the functionality, stability, or the level of
38 testing is not yet high enough for general use. This is usually
39 known as the "alpha-test" phase among developers. If a feature is
40 currently in alpha-test, then the developers usually discourage
41 uninformed widespread use of this feature by the general public to
42 avoid "Why doesn't this work?" type mail messages. However, active
43 testing and use of these systems is welcomed. Just be aware that it
44 may not meet the normal level of reliability or it may fail to work
45 in some special cases. Detailed bug reports from people familiar
46 with the kernel internals are usually welcomed by the developers
47 (before submitting bug reports, please read the documents
48 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
49 <file:Documentation/BUG-HUNTING>, and
50 <file:Documentation/oops-tracing.txt> in the kernel source).
51
52 This option will also make obsoleted drivers available. These are
53 drivers that have been replaced by something else, and/or are
54 scheduled to be removed in a future kernel release.
55
56 Unless you intend to help test and develop a feature or driver that
57 falls into this category, or you have a situation that requires
58 using these features, you should probably say N here, which will
59 cause the configurator to present you with fewer choices. If
60 you say Y here, you will be offered the choice of using features or
61 drivers that are currently considered to be in the alpha-test phase.
62
Linus Torvalds1da177e2005-04-16 15:20:36 -070063config BROKEN
64 bool
Linus Torvalds1da177e2005-04-16 15:20:36 -070065
66config BROKEN_ON_SMP
67 bool
68 depends on BROKEN || !SMP
69 default y
70
Linus Torvalds1da177e2005-04-16 15:20:36 -070071config INIT_ENV_ARG_LIMIT
72 int
Adrian Bunkdd673bc2006-06-30 01:55:51 -070073 default 32 if !UML
74 default 128 if UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 help
Randy Dunlap34ad92c2005-10-30 15:01:46 -080076 Maximum of each of the number of arguments and environment
77 variables passed to init from the kernel command line.
Linus Torvalds1da177e2005-04-16 15:20:36 -070078
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
Roland McGrath84336462009-12-21 16:24:06 -080080config CROSS_COMPILE
81 string "Cross-compiler tool prefix"
82 help
83 Same as running 'make CROSS_COMPILE=prefix-' but stored for
84 default make runs in this kernel build directory. You don't
85 need to set this unless you want the configured kernel build
86 directory to select the cross-compiler automatically.
87
Linus Torvalds1da177e2005-04-16 15:20:36 -070088config LOCALVERSION
89 string "Local version - append to kernel release"
90 help
91 Append an extra string to the end of your kernel version.
92 This will show up when you type uname, for example.
93 The string you set here will be appended after the contents of
94 any files with a filename matching localversion* in your
95 object and source tree, in that order. Your total string can
96 be a maximum of 64 characters.
97
Ryan Andersonaaebf432005-07-31 04:57:49 -040098config LOCALVERSION_AUTO
99 bool "Automatically append version information to the version string"
100 default y
101 help
102 This will try to automatically determine if the current tree is a
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200103 release tree by looking for git tags that belong to the current
104 top of tree revision.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400105
106 A string of the format -gxxxxxxxx will be added to the localversion
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200107 if a git-based tree is found. The string generated by this will be
Ryan Andersonaaebf432005-07-31 04:57:49 -0400108 appended after any matching localversion* files, and after the value
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200109 set in CONFIG_LOCALVERSION.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400110
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200111 (The actual string used here is the first eight characters produced
112 by running the command:
113
114 $ git rev-parse --verify HEAD
115
116 which is done within the script "scripts/setlocalversion".)
Ryan Andersonaaebf432005-07-31 04:57:49 -0400117
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800118config HAVE_KERNEL_GZIP
119 bool
120
121config HAVE_KERNEL_BZIP2
122 bool
123
124config HAVE_KERNEL_LZMA
125 bool
126
Lasse Collin3ebe1242011-01-12 17:01:23 -0800127config HAVE_KERNEL_XZ
128 bool
129
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800130config HAVE_KERNEL_LZO
131 bool
132
Alain Knaff30d65db2009-01-04 22:46:17 +0100133choice
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800134 prompt "Kernel compression mode"
135 default KERNEL_GZIP
Lasse Collin3ebe1242011-01-12 17:01:23 -0800136 depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800137 help
Alain Knaff30d65db2009-01-04 22:46:17 +0100138 The linux kernel is a kind of self-extracting executable.
139 Several compression algorithms are available, which differ
140 in efficiency, compression and decompression speed.
141 Compression speed is only relevant when building a kernel.
142 Decompression speed is relevant at each boot.
143
144 If you have any problems with bzip2 or lzma compressed
145 kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
146 version of this functionality (bzip2 only), for 2.4, was
147 supplied by Christian Ludwig)
148
149 High compression options are mostly useful for users, who
150 are low on disk space (embedded systems), but for whom ram
151 size matters less.
152
153 If in doubt, select 'gzip'
154
155config KERNEL_GZIP
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800156 bool "Gzip"
157 depends on HAVE_KERNEL_GZIP
158 help
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800159 The old and tried gzip compression. It provides a good balance
160 between compression ratio and decompression speed.
Alain Knaff30d65db2009-01-04 22:46:17 +0100161
162config KERNEL_BZIP2
163 bool "Bzip2"
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800164 depends on HAVE_KERNEL_BZIP2
Alain Knaff30d65db2009-01-04 22:46:17 +0100165 help
166 Its compression ratio and speed is intermediate.
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800167 Decompression speed is slowest among the three. The kernel
168 size is about 10% smaller with bzip2, in comparison to gzip.
169 Bzip2 uses a large amount of memory. For modern kernels you
170 will need at least 8MB RAM or more for booting.
Alain Knaff30d65db2009-01-04 22:46:17 +0100171
172config KERNEL_LZMA
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800173 bool "LZMA"
174 depends on HAVE_KERNEL_LZMA
175 help
176 The most recent compression algorithm.
177 Its ratio is best, decompression speed is between the other
178 two. Compression is slowest. The kernel size is about 33%
179 smaller with LZMA in comparison to gzip.
Alain Knaff30d65db2009-01-04 22:46:17 +0100180
Lasse Collin3ebe1242011-01-12 17:01:23 -0800181config KERNEL_XZ
182 bool "XZ"
183 depends on HAVE_KERNEL_XZ
184 help
185 XZ uses the LZMA2 algorithm and instruction set specific
186 BCJ filters which can improve compression ratio of executable
187 code. The size of the kernel is about 30% smaller with XZ in
188 comparison to gzip. On architectures for which there is a BCJ
189 filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
190 will create a few percent smaller kernel than plain LZMA.
191
192 The speed is about the same as with LZMA: The decompression
193 speed of XZ is better than that of bzip2 but worse than gzip
194 and LZO. Compression is slow.
195
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800196config KERNEL_LZO
197 bool "LZO"
198 depends on HAVE_KERNEL_LZO
199 help
200 Its compression ratio is the poorest among the 4. The kernel
Stephan Sperber681b3042010-07-14 11:23:08 +0200201 size is about 10% bigger than gzip; however its speed
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800202 (both compression and decompression) is the fastest.
203
Alain Knaff30d65db2009-01-04 22:46:17 +0100204endchoice
205
Josh Triplettbd5dc172011-06-15 15:08:28 -0700206config DEFAULT_HOSTNAME
207 string "Default hostname"
208 default "(none)"
209 help
210 This option determines the default system hostname before userspace
211 calls sethostname(2). The kernel traditionally uses "(none)" here,
212 but you may wish to use a different default here to make a minimal
213 system more usable with less configuration.
214
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215config SWAP
216 bool "Support for paging of anonymous memory (swap)"
David Howells93614012006-09-30 20:45:40 +0200217 depends on MMU && BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 default y
219 help
220 This option allows you to choose whether you want to have support
Jesper Juhl92c35042006-01-15 02:40:08 +0100221 for so called swap devices or swap files in your kernel that are
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 used to provide more virtual memory than the actual RAM present
223 in your computer. If unsure say Y.
224
225config SYSVIPC
226 bool "System V IPC"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 ---help---
228 Inter Process Communication is a suite of library functions and
229 system calls which let processes (running programs) synchronize and
230 exchange information. It is generally considered to be a good thing,
231 and some programs won't run unless you say Y here. In particular, if
232 you want to run the DOS emulator dosemu under Linux (read the
233 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
234 you'll need to say Y here.
235
236 You can find documentation about IPC with "info ipc" and also in
237 section 6.4 of the Linux Programmer's Guide, available from
238 <http://www.tldp.org/guides.html>.
239
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800240config SYSVIPC_SYSCTL
241 bool
242 depends on SYSVIPC
243 depends on SYSCTL
244 default y
245
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246config POSIX_MQUEUE
247 bool "POSIX Message Queues"
248 depends on NET && EXPERIMENTAL
249 ---help---
250 POSIX variant of message queues is a part of IPC. In POSIX message
251 queues every message has a priority which decides about succession
252 of receiving it by a process. If you want to compile and run
253 programs written e.g. for Solaris with use of its POSIX message
Robert P. J. Dayb0e37652007-05-09 07:25:13 +0200254 queues (functions mq_*) say Y here.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255
256 POSIX message queues are visible as a filesystem called 'mqueue'
257 and can be mounted somewhere if you want to do filesystem
258 operations on message queues.
259
260 If unsure, say Y.
261
Serge E. Hallynbdc8e5f2009-04-06 19:01:11 -0700262config POSIX_MQUEUE_SYSCTL
263 bool
264 depends on POSIX_MQUEUE
265 depends on SYSCTL
266 default y
267
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268config BSD_PROCESS_ACCT
269 bool "BSD Process Accounting"
270 help
271 If you say Y here, a user level program will be able to instruct the
272 kernel (via a special system call) to write process accounting
273 information to a file: whenever a process exits, information about
274 that process will be appended to the file by the kernel. The
275 information includes things such as creation time, owning user,
276 command name, memory usage, controlling terminal etc. (the complete
277 list is in the struct acct in <file:include/linux/acct.h>). It is
278 up to the user level program to do useful things with this
279 information. This is generally a good idea, so say Y.
280
281config BSD_PROCESS_ACCT_V3
282 bool "BSD Process Accounting version 3 file format"
283 depends on BSD_PROCESS_ACCT
284 default n
285 help
286 If you say Y here, the process accounting information is written
287 in a new file format that also logs the process IDs of each
288 process and it's parent. Note that this file format is incompatible
289 with previous v0/v1/v2 file formats, so you will need updated tools
290 for processing it. A preliminary version of these tools is available
S.Çağlar Onur37a4c942008-06-18 11:45:13 +0300291 at <http://www.gnu.org/software/acct/>.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292
Aneesh Kumar K.V990d6c22011-01-29 18:43:26 +0530293config FHANDLE
294 bool "open by fhandle syscalls"
295 select EXPORTFS
296 help
297 If you say Y here, a user level program will be able to map
298 file names to handle and then later use the handle for
299 different file system operations. This is useful in implementing
300 userspace file servers, which now track files using handles instead
301 of names. The handle would remain the same even if file names
302 get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
303 syscalls.
304
Shailabh Nagarc7572492006-07-14 00:24:40 -0700305config TASKSTATS
306 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
307 depends on NET
308 default n
309 help
310 Export selected statistics for tasks/processes through the
311 generic netlink interface. Unlike BSD process accounting, the
312 statistics are available during the lifetime of tasks/processes as
313 responses to commands. Like BSD accounting, they are sent to user
314 space on task exit.
315
316 Say N if unsure.
317
Shailabh Nagarca74e922006-07-14 00:24:36 -0700318config TASK_DELAY_ACCT
319 bool "Enable per-task delay accounting (EXPERIMENTAL)"
Shailabh Nagar6f449932006-07-14 00:24:41 -0700320 depends on TASKSTATS
Shailabh Nagarca74e922006-07-14 00:24:36 -0700321 help
322 Collect information on time spent by a task waiting for system
323 resources like cpu, synchronous block I/O completion and swapping
324 in pages. Such statistics can help in setting a task's priorities
325 relative to other tasks for cpu, io, rss limits etc.
326
327 Say N if unsure.
328
Alexey Dobriyan18f705f2007-02-10 01:46:44 -0800329config TASK_XACCT
330 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
331 depends on TASKSTATS
332 help
333 Collect extended task accounting data and send the data
334 to userland for processing over the taskstats interface.
335
336 Say N if unsure.
337
338config TASK_IO_ACCOUNTING
339 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
340 depends on TASK_XACCT
341 help
342 Collect information on the number of bytes of storage I/O which this
343 task has caused.
344
345 Say N if unsure.
346
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347config AUDIT
348 bool "Auditing support"
Chris Wright804a6a492005-05-11 10:52:45 +0100349 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 help
351 Enable auditing infrastructure that can be used with another
352 kernel subsystem, such as SELinux (which requires this for
353 logging of avc messages output). Does not do system-call
354 auditing without CONFIG_AUDITSYSCALL.
355
356config AUDITSYSCALL
357 bool "Enable system-call auditing support"
Nathaniel Husted29ef73b2012-01-03 14:23:09 -0500358 depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH || ARM)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359 default y if SECURITY_SELINUX
360 help
361 Enable low-overhead system-call auditing infrastructure that
362 can be used independently or with another kernel subsystem,
Eric Paris67640b62009-12-17 20:12:06 -0500363 such as SELinux.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364
Eric Paris939a67f2009-12-17 20:12:06 -0500365config AUDIT_WATCH
366 def_bool y
367 depends on AUDITSYSCALL
368 select FSNOTIFY
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369
Al Viro74c3cbe2007-07-22 08:04:18 -0400370config AUDIT_TREE
371 def_bool y
Eric Paris63c882a2009-05-21 17:02:01 -0400372 depends on AUDITSYSCALL
Eric Paris28a3a7e2009-12-17 20:12:05 -0500373 select FSNOTIFY
Al Viro74c3cbe2007-07-22 08:04:18 -0400374
Eric Paris633b4542012-01-03 14:23:08 -0500375config AUDIT_LOGINUID_IMMUTABLE
376 bool "Make audit loginuid immutable"
377 depends on AUDIT
378 help
Linus Torvaldsf429ee32012-01-17 16:06:51 -0800379 The config option toggles if a task setting its loginuid requires
Eric Paris633b4542012-01-03 14:23:08 -0500380 CAP_SYS_AUDITCONTROL or if that task should require no special permissions
381 but should instead only allow setting its loginuid if it was never
382 previously set. On systems which use systemd or a similar central
383 process to restart login services this should be set to true. On older
384 systems in which an admin would typically have to directly stop and
385 start processes this should be set to false. Setting this to true allows
386 one to drop potentially dangerous capabilites from the login tasks,
387 but may not be backwards compatible with older init systems.
388
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000389source "kernel/irq/Kconfig"
Thomas Gleixner764e0da2012-05-21 23:16:18 +0200390source "kernel/time/Kconfig"
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000391
Mike Travisc903ff82009-01-15 12:28:29 -0800392menu "RCU Subsystem"
393
394choice
395 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700396 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800397
Mike Travisc903ff82009-01-15 12:28:29 -0800398config TREE_RCU
399 bool "Tree-based hierarchical RCU"
Paul E. McKenney687d7a92010-07-21 06:52:40 -0700400 depends on !PREEMPT && SMP
Mike Travisc903ff82009-01-15 12:28:29 -0800401 help
402 This option selects the RCU implementation that is
403 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700404 thousands of CPUs. It also scales down nicely to
405 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800406
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700407config TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700408 bool "Preemptible tree-based hierarchical RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700409 depends on PREEMPT && SMP
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700410 help
411 This option selects the RCU implementation that is
412 designed for very large SMP systems with hundreds or
413 thousands of CPUs, but for which real-time response
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700414 is also required. It also scales down nicely to
415 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700416
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700417config TINY_RCU
418 bool "UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700419 depends on !PREEMPT && !SMP
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700420 help
421 This option selects the RCU implementation that is
422 designed for UP systems from which real-time response
423 is not required. This option greatly reduces the
424 memory footprint of RCU.
425
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700426config TINY_PREEMPT_RCU
427 bool "Preemptible UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700428 depends on PREEMPT && !SMP
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700429 help
430 This option selects the RCU implementation that is designed
431 for real-time UP systems. This option greatly reduces the
432 memory footprint of RCU.
433
Mike Travisc903ff82009-01-15 12:28:29 -0800434endchoice
435
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700436config PREEMPT_RCU
437 def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
438 help
439 This option enables preemptible-RCU code that is common between
440 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
441
Mike Travisc903ff82009-01-15 12:28:29 -0800442config RCU_FANOUT
443 int "Tree-based hierarchical RCU fanout value"
444 range 2 64 if 64BIT
445 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700446 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800447 default 64 if 64BIT
448 default 32 if !64BIT
449 help
450 This option controls the fanout of hierarchical implementations
451 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700452 large numbers of CPUs. This value must be at least the fourth
453 root of NR_CPUS, which allows NR_CPUS to be insanely large.
454 The default value of RCU_FANOUT should be used for production
455 systems, but if you are stress-testing the RCU implementation
456 itself, small RCU_FANOUT values allow you to test large-system
457 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800458
459 Select a specific number if testing RCU itself.
460 Take the default if unsure.
461
462config RCU_FANOUT_EXACT
463 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700464 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800465 default n
466 help
467 This option forces use of the exact RCU_FANOUT value specified,
468 regardless of imbalances in the hierarchy. This is useful for
469 testing RCU itself, and might one day be useful on systems with
470 strong NUMA behavior.
471
472 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
473
474 Say N if unsure.
475
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800476config RCU_FAST_NO_HZ
477 bool "Accelerate last non-dyntick-idle CPU's grace periods"
Paul E. McKenneyb807fbf2011-11-03 14:56:12 -0700478 depends on NO_HZ && SMP
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800479 default n
480 help
481 This option causes RCU to attempt to accelerate grace periods
Paul E. McKenneyb807fbf2011-11-03 14:56:12 -0700482 in order to allow CPUs to enter dynticks-idle state more
483 quickly. On the other hand, this option increases the overhead
484 of the dynticks-idle checking, particularly on systems with
485 large numbers of CPUs.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800486
487 Say Y if energy efficiency is critically important, particularly
488 if you have relatively few CPUs.
489
490 Say N if you are unsure.
491
Mike Travisc903ff82009-01-15 12:28:29 -0800492config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700493 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800494 select DEBUG_FS
495 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700496 This option provides tracing for the TREE_RCU and
497 TREE_PREEMPT_RCU implementations, permitting Makefile to
498 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800499
Paul E. McKenney24278d12010-09-27 17:25:23 -0700500config RCU_BOOST
501 bool "Enable RCU priority boosting"
Paul E. McKenney27f4d282011-02-07 12:47:15 -0800502 depends on RT_MUTEXES && PREEMPT_RCU
Paul E. McKenney24278d12010-09-27 17:25:23 -0700503 default n
504 help
505 This option boosts the priority of preempted RCU readers that
506 block the current preemptible RCU grace period for too long.
507 This option also prevents heavy loads from blocking RCU
508 callback invocation for all flavors of RCU.
509
510 Say Y here if you are working with real-time apps or heavy loads
511 Say N here if you are unsure.
512
513config RCU_BOOST_PRIO
514 int "Real-time priority to boost RCU readers to"
515 range 1 99
516 depends on RCU_BOOST
517 default 1
518 help
519 This option specifies the real-time priority to which preempted
520 RCU readers are to be boosted. If you are working with CPU-bound
521 real-time applications, you should specify a priority higher then
522 the highest-priority CPU-bound application.
523
524 Specify the real-time priority, or take the default if unsure.
525
526config RCU_BOOST_DELAY
527 int "Milliseconds to delay boosting after RCU grace-period start"
528 range 0 3000
529 depends on RCU_BOOST
530 default 500
531 help
532 This option specifies the time to wait after the beginning of
533 a given grace period before priority-boosting preempted RCU
534 readers blocking that grace period. Note that any RCU reader
535 blocking an expedited RCU grace period is boosted immediately.
536
537 Accept the default if unsure.
538
Mike Travisc903ff82009-01-15 12:28:29 -0800539endmenu # "RCU Subsystem"
540
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700542 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543 ---help---
544 This option enables the complete Linux kernel ".config" file
545 contents to be saved in the kernel. It provides documentation
546 of which kernel options are used in a running kernel or in an
547 on-disk kernel. This information can be extracted from the kernel
548 image file with the script scripts/extract-ikconfig and used as
549 input to rebuild the current kernel or to build another kernel.
550 It can also be extracted from a running kernel by reading
551 /proc/config.gz if enabled (below).
552
553config IKCONFIG_PROC
554 bool "Enable access to .config through /proc/config.gz"
555 depends on IKCONFIG && PROC_FS
556 ---help---
557 This option enables access to the kernel configuration file
558 through /proc/config.gz.
559
Alistair John Strachan794543a2007-05-08 00:31:15 -0700560config LOG_BUF_SHIFT
561 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
562 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700563 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700564 help
565 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700566 Examples:
567 17 => 128 KB
568 16 => 64 KB
569 15 => 32 KB
570 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700571 13 => 8 KB
572 12 => 4 KB
573
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800574#
575# Architectures with an unreliable sched_clock() should select this:
576#
577config HAVE_UNSTABLE_SCHED_CLOCK
578 bool
579
Li Zefan23964d22009-01-15 13:50:58 -0800580menuconfig CGROUPS
581 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800582 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700583 help
Li Zefan23964d22009-01-15 13:50:58 -0800584 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800585 use with process control subsystems such as Cpusets, CFS, memory
586 controls or device isolation.
587 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800588 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800589 - Documentation/cgroups/ (features for grouping, isolation
590 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700591
592 Say N if unsure.
593
Li Zefan23964d22009-01-15 13:50:58 -0800594if CGROUPS
595
Paul Menage006cb992007-10-18 23:39:43 -0700596config CGROUP_DEBUG
597 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700598 default n
Paul Menage006cb992007-10-18 23:39:43 -0700599 help
600 This option enables a simple cgroup subsystem that
601 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800602 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700603
Li Zefan23964d22009-01-15 13:50:58 -0800604 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700605
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700606config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800607 bool "Freezer cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800608 help
609 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700610 cgroup.
611
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700612config CGROUP_DEVICE
613 bool "Device controller for cgroups"
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700614 help
615 Provides a cgroup implementing whitelists for devices which
616 a process in the cgroup can mknod or open.
617
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618config CPUSETS
619 bool "Cpuset support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700621 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622 allow dynamically partitioning a system into sets of CPUs and
623 Memory Nodes and assigning tasks to run only within those sets.
624 This is primarily useful on large SMP or NUMA systems.
625
626 Say N if unsure.
627
Li Zefan23964d22009-01-15 13:50:58 -0800628config PROC_PID_CPUSET
629 bool "Include legacy /proc/<pid>/cpuset file"
630 depends on CPUSETS
631 default y
632
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100633config CGROUP_CPUACCT
634 bool "Simple CPU accounting cgroup subsystem"
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100635 help
636 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800637 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100638
Pavel Emelianove552b662008-02-07 00:13:49 -0800639config RESOURCE_COUNTERS
640 bool "Resource counters"
641 help
642 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800643 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800644
Balbir Singh00f0b822008-03-04 14:28:39 -0800645config CGROUP_MEM_RES_CTLR
646 bool "Memory Resource Controller for Control Groups"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700647 depends on RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700648 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800649 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700650 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100651 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800652
653 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700654 associated with each page of memory in the system. By this,
655 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
656 usage tracking struct at boot. Total amount of this is printed out
657 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800658
659 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700660 sure you need the memory resource controller. Even when you enable
661 this, you can set "cgroup_disable=memory" at your boot option to
662 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800663 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800664
Balbir Singhcf475ad2008-04-29 01:00:16 -0700665 This config option also selects MM_OWNER config option, which
666 could in turn add some fork/exit overhead.
667
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800668config CGROUP_MEM_RES_CTLR_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700669 bool "Memory Resource Controller Swap Extension"
670 depends on CGROUP_MEM_RES_CTLR && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800671 help
672 Add swap management feature to memory resource controller. When you
673 enable this, you can limit mem+swap usage per cgroup. In other words,
674 when you disable this, memory resource controller has no cares to
675 usage of swap...a process can exhaust all of the swap. This extension
676 is useful when you want to avoid exhaustion swap but this itself
677 adds more overheads and consumes memory for remembering information.
678 Especially if you use 32bit system or small memory system, please
679 be careful about enabling this. When memory resource controller
680 is disabled by boot option, this will be automatically disabled and
681 there will be no overhead from this. Even when you set this config=y,
WANG Cong00a66d22011-07-25 17:12:12 -0700682 if boot option "swapaccount=0" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700683 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
684 size is 4096bytes, 512k per 1Gbytes of swap.
Michal Hockoa42c3902010-11-24 12:57:08 -0800685config CGROUP_MEM_RES_CTLR_SWAP_ENABLED
686 bool "Memory Resource Controller Swap Extension enabled by default"
687 depends on CGROUP_MEM_RES_CTLR_SWAP
688 default y
689 help
690 Memory Resource Controller Swap Extension comes with its price in
691 a bigger memory consumption. General purpose distribution kernels
Jim Cromie43d547f2010-12-17 14:32:36 -0700692 which want to enable the feature but keep it disabled by default
Michal Hockoa42c3902010-11-24 12:57:08 -0800693 and let the user enable it by swapaccount boot command line
694 parameter should have this option unselected.
695 For those who want to have the feature enabled by default should
696 select this option (if, for some reason, they need to disable it
WANG Cong00a66d22011-07-25 17:12:12 -0700697 then swapaccount=0 does the trick).
Glauber Costae5671df2011-12-11 21:47:01 +0000698config CGROUP_MEM_RES_CTLR_KMEM
699 bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
700 depends on CGROUP_MEM_RES_CTLR && EXPERIMENTAL
701 default n
702 help
703 The Kernel Memory extension for Memory Resource Controller can limit
704 the amount of memory used by kernel objects in the system. Those are
705 fundamentally different from the entities handled by the standard
706 Memory Controller, which are page-based, and can be swapped. Users of
707 the kmem extension can use it to guarantee that no group of processes
708 will ever exhaust kernel resources alone.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800709
Stephane Eraniane5d13672011-02-14 11:20:01 +0200710config CGROUP_PERF
711 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
712 depends on PERF_EVENTS && CGROUPS
713 help
714 This option extends the per-cpu mode to restrict monitoring to
Li Zefan2d0f2522011-03-03 14:26:20 +0800715 threads which belong to the cgroup specified and run on the
Stephane Eraniane5d13672011-02-14 11:20:01 +0200716 designated cpu.
717
718 Say N if unsure.
719
Dhaval Giani7c941432010-01-20 13:26:18 +0100720menuconfig CGROUP_SCHED
721 bool "Group CPU scheduler"
Dhaval Giani7c941432010-01-20 13:26:18 +0100722 default n
723 help
724 This feature lets CPU scheduler recognize task groups and control CPU
725 bandwidth allocation to such task groups. It uses cgroups to group
726 tasks.
727
728if CGROUP_SCHED
729config FAIR_GROUP_SCHED
730 bool "Group scheduling for SCHED_OTHER"
731 depends on CGROUP_SCHED
732 default CGROUP_SCHED
733
Paul Turnerab84d312011-07-21 09:43:28 -0700734config CFS_BANDWIDTH
735 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
736 depends on EXPERIMENTAL
737 depends on FAIR_GROUP_SCHED
738 default n
739 help
740 This option allows users to define CPU bandwidth rates (limits) for
741 tasks running within the fair group scheduler. Groups with no limit
742 set are considered to be unconstrained and will run with no
743 restriction.
744 See tip/Documentation/scheduler/sched-bwc.txt for more information.
745
Dhaval Giani7c941432010-01-20 13:26:18 +0100746config RT_GROUP_SCHED
747 bool "Group scheduling for SCHED_RR/FIFO"
748 depends on EXPERIMENTAL
749 depends on CGROUP_SCHED
750 default n
751 help
752 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +0800753 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +0100754 schedule realtime tasks for non-root users until you allocate
755 realtime bandwidth for them.
756 See Documentation/scheduler/sched-rt-group.txt for more information.
757
758endif #CGROUP_SCHED
759
Vivek Goyalafc24d42010-04-26 19:27:56 +0200760config BLK_CGROUP
761 tristate "Block IO controller"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700762 depends on BLOCK
Vivek Goyalafc24d42010-04-26 19:27:56 +0200763 default n
764 ---help---
765 Generic block IO controller cgroup interface. This is the common
766 cgroup interface which should be used by various IO controlling
767 policies.
768
769 Currently, CFQ IO scheduler uses it to recognize task groups and
770 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -0400771 to such task groups. It is also used by bio throttling logic in
772 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200773
774 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -0400775 One needs to also enable actual IO controlling logic/policy. For
Michael Witten79e2e752011-01-16 21:43:10 +0000776 enabling proportional weight division of disk bandwidth in CFQ, set
777 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
Michael Wittenc5e05912011-01-17 00:08:41 +0000778 CONFIG_BLK_DEV_THROTTLING=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200779
780 See Documentation/cgroups/blkio-controller.txt for more information.
781
782config DEBUG_BLK_CGROUP
783 bool "Enable Block IO controller debugging"
784 depends on BLK_CGROUP
785 default n
786 ---help---
787 Enable some debugging help. Currently it exports additional stat
788 files in a cgroup which can be useful for debugging.
789
Li Zefan23964d22009-01-15 13:50:58 -0800790endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800791
Cyrill Gorcunov067bce12012-01-12 17:20:49 -0800792config CHECKPOINT_RESTORE
793 bool "Checkpoint/restore support" if EXPERT
794 default n
795 help
796 Enables additional kernel features in a sake of checkpoint/restore.
797 In particular it adds auxiliary prctl codes to setup process text,
798 data and heap segment sizes, and a few additional /proc filesystem
799 entries.
800
801 If unsure, say N here.
802
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700803menuconfig NAMESPACES
David Rientjes6a108a12011-01-20 14:44:16 -0800804 bool "Namespaces support" if EXPERT
805 default !EXPERT
Pavel Emelyanovc5289a62008-02-08 04:18:19 -0800806 help
807 Provides the way to make tasks work with different objects using
808 the same id. For example same IPC id may refer to different objects
809 or same user id or pid may refer to different tasks when used in
810 different namespaces.
811
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700812if NAMESPACES
813
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800814config UTS_NS
815 bool "UTS namespace"
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700816 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800817 help
818 In this namespace tasks see different info provided with the
819 uname() system call
820
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800821config IPC_NS
822 bool "IPC namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700823 depends on (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700824 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800825 help
826 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700827 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800828
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800829config USER_NS
830 bool "User namespace (EXPERIMENTAL)"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700831 depends on EXPERIMENTAL
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700832 default y
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800833 help
834 This allows containers, i.e. vservers, to use user namespaces
835 to provide different user info for different servers.
836 If unsure, say N.
837
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800838config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -0700839 bool "PID Namespaces"
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700840 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800841 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +0300842 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +0100843 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800844 pid namespaces. This is a building block of containers.
845
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800846config NET_NS
847 bool "Network namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700848 depends on NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700849 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800850 help
851 Allow user space to create what appear to be multiple instances
852 of the network stack.
853
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700854endif # NAMESPACES
855
Mike Galbraith5091faa2010-11-30 14:18:03 +0100856config SCHED_AUTOGROUP
857 bool "Automatic process group scheduling"
858 select EVENTFD
859 select CGROUPS
860 select CGROUP_SCHED
861 select FAIR_GROUP_SCHED
862 help
863 This option optimizes the scheduler for common desktop workloads by
864 automatically creating and populating task groups. This separation
865 of workloads isolates aggressive CPU burners (like build jobs) from
866 desktop applications. Task group autogeneration is currently based
867 upon task session.
868
Daniel Lezcano7af37be2010-10-27 15:34:41 -0700869config MM_OWNER
870 bool
871
872config SYSFS_DEPRECATED
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +0100873 bool "Enable deprecated sysfs features to support old userspace tools"
Daniel Lezcano7af37be2010-10-27 15:34:41 -0700874 depends on SYSFS
875 default n
876 help
877 This option adds code that switches the layout of the "block" class
878 devices, to not show up in /sys/class/block/, but only in
879 /sys/block/.
880
881 This switch is only active when the sysfs.deprecated=1 boot option is
882 passed or the SYSFS_DEPRECATED_V2 option is set.
883
884 This option allows new kernels to run on old distributions and tools,
885 which might get confused by /sys/class/block/. Since 2007/2008 all
886 major distributions and tools handle this just fine.
887
888 Recent distributions and userspace tools after 2009/2010 depend on
889 the existence of /sys/class/block/, and will not work with this
890 option enabled.
891
892 Only if you are using a new kernel on an old distribution, you might
893 need to say Y here.
894
895config SYSFS_DEPRECATED_V2
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +0100896 bool "Enable deprecated sysfs features by default"
Daniel Lezcano7af37be2010-10-27 15:34:41 -0700897 default n
898 depends on SYSFS
899 depends on SYSFS_DEPRECATED
900 help
901 Enable deprecated sysfs by default.
902
903 See the CONFIG_SYSFS_DEPRECATED option for more details about this
904 option.
905
906 Only if you are using a new kernel on an old distribution, you might
907 need to say Y here. Even then, odds are you would not need it
908 enabled, you can always pass the boot option if absolutely necessary.
909
910config RELAY
911 bool "Kernel->user space relay support (formerly relayfs)"
912 help
913 This option enables support for relay interface support in
914 certain file systems (such as debugfs).
915 It is designed to provide an efficient mechanism for tools and
916 facilities to relay large amounts of data from kernel space to
917 user space.
918
919 If unsure, say N.
920
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -0800921config BLK_DEV_INITRD
922 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
923 depends on BROKEN || !FRV
924 help
925 The initial RAM filesystem is a ramfs which is loaded by the
926 boot loader (loadlin or lilo) and that is mounted as root
927 before the normal boot procedure. It is typically used to
928 load modules needed to mount the "real" root file system,
929 etc. See <file:Documentation/initrd.txt> for details.
930
931 If RAM disk support (BLK_DEV_RAM) is also included, this
932 also enables initial RAM disk (initrd) support and adds
933 15 Kbytes (more on some other architectures) to the kernel size.
934
935 If unsure say Y.
936
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800937if BLK_DEV_INITRD
938
Sam Ravnborgdbec4862005-08-10 20:44:50 +0200939source "usr/Kconfig"
940
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800941endif
942
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800943config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +0200944 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800945 help
946 Enabling this option will pass "-Os" instead of "-O2" to gcc
947 resulting in a smaller kernel.
948
jkacur775a7222008-07-16 00:31:16 +0200949 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800950
Randy Dunlap08470622006-09-30 23:28:13 -0700951config SYSCTL
952 bool
953
Randy Dunlapb943c462009-03-10 12:55:46 -0700954config ANON_INODES
955 bool
956
David Rientjes6a108a12011-01-20 14:44:16 -0800957menuconfig EXPERT
958 bool "Configure standard kernel features (expert users)"
Josh Triplettf505c552011-06-05 18:23:58 -0700959 # Unhide debug options, to make the on-by-default options visible
960 select DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961 help
962 This option allows certain base kernel options and settings
963 to be disabled or tweaked. This is for specialized
964 environments which can tolerate a "non-standard" kernel.
965 Only use this if you really know what you are doing.
966
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700967config UID16
David Rientjes6a108a12011-01-20 14:44:16 -0800968 bool "Enable 16-bit UID system calls" if EXPERT
David S. Miller09337f52008-04-26 03:17:12 -0700969 depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION)
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700970 default y
971 help
972 This enables the legacy 16-bit UID syscall wrappers.
973
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700974config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -0800975 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -0800976 depends on PROC_SYSCTL
WANG Congc736de62011-11-02 13:39:25 -0700977 default n
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700978 select SYSCTL
979 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800980 sys_sysctl uses binary paths that have been found challenging
981 to properly maintain and use. The interface in /proc/sys
982 using paths with ascii names is now the primary path to this
983 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700984
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800985 Almost nothing using the binary sysctl interface so if you are
986 trying to save some space it is probably safe to disable this,
987 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700988
WANG Congc736de62011-11-02 13:39:25 -0700989 If unsure say N here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700990
Linus Torvalds1da177e2005-04-16 15:20:36 -0700991config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -0800992 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700993 default y
994 help
995 Say Y here to let the kernel print out symbolic crash information and
996 symbolic stack backtraces. This increases the size of the kernel
997 somewhat, as all symbols have to be loaded into the kernel image.
998
999config KALLSYMS_ALL
1000 bool "Include all symbols in kallsyms"
1001 depends on DEBUG_KERNEL && KALLSYMS
1002 help
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001003 Normally kallsyms only contains the symbols of functions for nicer
1004 OOPS messages and backtraces (i.e., symbols from the text and inittext
1005 sections). This is sufficient for most cases. And only in very rare
1006 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1007 names of variables from the data sections, etc).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001008
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001009 This option makes sure that all symbols are loaded into the kernel
1010 image (i.e., symbols from all sections) in cost of increased kernel
1011 size (depending on the kernel configuration, it may be 300KiB or
1012 something like this).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001013
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001014 Say N unless you really need all symbols.
Matt Mackalld59745c2005-05-01 08:59:02 -07001015
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001016config HOTPLUG
David Rientjes6a108a12011-01-20 14:44:16 -08001017 bool "Support for hot-pluggable devices" if EXPERT
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001018 default y
1019 help
1020 This option is provided for the case where no hotplug or uevent
1021 capabilities is wanted by the kernel. You should only consider
1022 disabling this option for embedded systems that do not use modules, a
1023 dynamic /dev tree, or dynamic device discovery. Just say Y.
1024
Matt Mackalld59745c2005-05-01 08:59:02 -07001025config PRINTK
1026 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001027 bool "Enable support for printk" if EXPERT
Matt Mackalld59745c2005-05-01 08:59:02 -07001028 help
1029 This option enables normal printk support. Removing it
1030 eliminates most of the message strings from the kernel image
1031 and makes the kernel more or less silent. As this makes it
1032 very difficult to diagnose system problems, saying N here is
1033 strongly discouraged.
1034
Matt Mackallc8538a72005-05-01 08:59:01 -07001035config BUG
David Rientjes6a108a12011-01-20 14:44:16 -08001036 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -07001037 default y
1038 help
1039 Disabling this option eliminates support for BUG and WARN, reducing
1040 the size of your kernel image and potentially quietly ignoring
1041 numerous fatal conditions. You should only consider disabling this
1042 option for embedded systems with no facilities for reporting errors.
1043 Just say Y.
1044
Matt Mackall708e9a72006-01-08 01:05:25 -08001045config ELF_CORE
1046 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001047 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001048 help
1049 Enable support for generating core dumps. Disabling saves about 4k.
1050
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001051
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001052config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001053 bool "Enable PC-Speaker support" if EXPERT
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001054 depends on HAVE_PCSPKR_PLATFORM
Ralf Baechle15f304b2011-06-01 19:04:59 +01001055 select I8253_LOCK
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001056 default y
1057 help
1058 This option allows to disable the internal PC-Speaker
1059 support, saving some memory.
1060
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001061config HAVE_PCSPKR_PLATFORM
1062 bool
1063
Linus Torvalds1da177e2005-04-16 15:20:36 -07001064config BASE_FULL
1065 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001066 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001067 help
1068 Disabling this option reduces the size of miscellaneous core
1069 kernel data structures. This saves memory on small machines,
1070 but may reduce performance.
1071
1072config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001073 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001074 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001075 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001076 help
1077 Disabling this option will cause the kernel to be built without
1078 support for "fast userspace mutexes". The resulting kernel may not
1079 run glibc-based applications correctly.
1080
1081config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001082 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001083 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001084 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001085 help
1086 Disabling this option will cause the kernel to be built without
1087 support for epoll family of system calls.
1088
Davide Libenzifba2afa2007-05-10 22:23:13 -07001089config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001090 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001091 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001092 default y
1093 help
1094 Enable the signalfd() system call that allows to receive signals
1095 on a file descriptor.
1096
1097 If unsure, say Y.
1098
Davide Libenzib215e282007-05-10 22:23:16 -07001099config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001100 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001101 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001102 default y
1103 help
1104 Enable the timerfd() system call that allows to receive timer
1105 events on a file descriptor.
1106
1107 If unsure, say Y.
1108
Davide Libenzie1ad7462007-05-10 22:23:19 -07001109config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001110 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001111 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001112 default y
1113 help
1114 Enable the eventfd() system call that allows to receive both
1115 kernel notification (ie. KAIO) or userspace notifications.
1116
1117 If unsure, say Y.
1118
Linus Torvalds1da177e2005-04-16 15:20:36 -07001119config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001120 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001121 default y
1122 depends on MMU
1123 help
1124 The shmem is an internal filesystem used to manage shared memory.
1125 It is backed by swap and manages resource limits. It is also exported
1126 to userspace as tmpfs if TMPFS is enabled. Disabling this
1127 option replaces shmem and tmpfs with the much simpler ramfs code,
1128 which may be appropriate on small systems without swap.
1129
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001130config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001131 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001132 default y
1133 help
1134 This option enables POSIX asynchronous I/O which may by used
1135 by some high performance threaded applications. Disabling
1136 this option saves about 7k.
1137
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001138config EMBEDDED
1139 bool "Embedded system"
1140 select EXPERT
1141 help
1142 This option should be enabled if compiling the kernel for
1143 an embedded system so certain expert options are available
1144 for configuration.
1145
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001146config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001147 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001148 help
1149 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001150
Peter Zijlstra906010b2009-09-21 16:08:49 +02001151config PERF_USE_VMALLOC
1152 bool
1153 help
1154 See tools/perf/design.txt for details
1155
Ingo Molnar57c0c152009-09-21 12:20:38 +02001156menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001157
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001158config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001159 bool "Kernel performance events and counters"
1160 default y if (PROFILING || PERF_COUNTERS)
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001161 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001162 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001163 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001164 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001165 Enable kernel support for various performance events provided
1166 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001167
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001168 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001169 use of generic tracepoints.
1170
1171 Most modern CPUs support performance events via performance
1172 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001173 types of hw events: such as instructions executed, cachemisses
1174 suffered, or branches mis-predicted - without slowing down the
1175 kernel or applications. These registers can also trigger interrupts
1176 when a threshold number of events have passed - and can thus be
1177 used to profile the code that runs on that CPU.
1178
Ingo Molnar57c0c152009-09-21 12:20:38 +02001179 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001180 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001181 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001182 provides per task and per CPU counters, and it provides event
1183 capabilities on top of those.
1184
1185 Say Y if unsure.
1186
Ingo Molnar57c0c152009-09-21 12:20:38 +02001187config PERF_COUNTERS
1188 bool "Kernel performance counters (old config option)"
1189 depends on HAVE_PERF_EVENTS
1190 help
1191 This config has been obsoleted by the PERF_EVENTS
1192 config option - please see that one for details.
1193
1194 It has no effect on the kernel whether you enable
1195 it or not, it is a compatibility placeholder.
1196
1197 Say N if unsure.
1198
Peter Zijlstra906010b2009-09-21 16:08:49 +02001199config DEBUG_PERF_USE_VMALLOC
1200 default n
1201 bool "Debug: use vmalloc to back perf mmap() buffers"
1202 depends on PERF_EVENTS && DEBUG_KERNEL
1203 select PERF_USE_VMALLOC
1204 help
1205 Use vmalloc memory to back perf mmap() buffers.
1206
1207 Mostly useful for debugging the vmalloc code on platforms
1208 that don't require it.
1209
1210 Say N if unsure.
1211
Thomas Gleixner0793a612008-12-04 20:12:29 +01001212endmenu
1213
Christoph Lameterf8891e52006-06-30 01:55:45 -07001214config VM_EVENT_COUNTERS
1215 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001216 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001217 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001218 VM event counters are needed for event counts to be shown.
1219 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001220 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001221 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001222
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001223config PCI_QUIRKS
1224 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001225 bool "Enable PCI quirk workarounds" if EXPERT
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001226 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001227 help
1228 This enables workarounds for various PCI chipset
1229 bugs/quirks. Disable this only if your target machine is
1230 unaffected by PCI quirks.
1231
Christoph Lameter41ecc552007-05-09 02:32:44 -07001232config SLUB_DEBUG
1233 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001234 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001235 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001236 help
1237 SLUB has extensive debug support features. Disabling these can
1238 result in significant savings in code size. This also disables
1239 SLUB sysfs support. /sys/slab will not exist and there will be
1240 no support for cache validation etc.
1241
Randy Dunlapb943c462009-03-10 12:55:46 -07001242config COMPAT_BRK
1243 bool "Disable heap randomization"
1244 default y
1245 help
1246 Randomizing heap placement makes heap exploits harder, but it
1247 also breaks ancient binaries (including anything libc5 based).
1248 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001249 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001250 /proc/sys/kernel/randomize_va_space to 2.
1251
1252 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1253
Christoph Lameter81819f02007-05-06 14:49:36 -07001254choice
1255 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001256 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001257 help
1258 This option allows to select a slab allocator.
1259
1260config SLAB
1261 bool "SLAB"
1262 help
1263 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001264 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001265 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001266
1267config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001268 bool "SLUB (Unqueued Allocator)"
1269 help
1270 SLUB is a slab allocator that minimizes cache line usage
1271 instead of managing queues of cached objects (SLAB approach).
1272 Per cpu caching is realized using slabs of objects instead
1273 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001274 and has enhanced diagnostics. SLUB is the default choice for
1275 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001276
1277config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001278 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001279 bool "SLOB (Simple Allocator)"
1280 help
Matt Mackall37291452008-02-04 22:29:38 -08001281 SLOB replaces the stock allocator with a drastically simpler
1282 allocator. SLOB is generally more space efficient but
1283 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001284
1285endchoice
1286
Jie Zhangea637632009-12-14 18:00:02 -08001287config MMAP_ALLOW_UNINITIALIZED
1288 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001289 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001290 default n
1291 help
1292 Normally, and according to the Linux spec, anonymous memory obtained
1293 from mmap() has it's contents cleared before it is passed to
1294 userspace. Enabling this config option allows you to request that
1295 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1296 providing a huge performance boost. If this option is not enabled,
1297 then the flag will be ignored.
1298
1299 This is taken advantage of by uClibc's malloc(), and also by
1300 ELF-FDPIC binfmt's brk and stack allocator.
1301
1302 Because of the obvious security issues, this option should only be
1303 enabled on embedded devices where you control what is run in
1304 userspace. Since that isn't generally a problem on no-MMU systems,
1305 it is normally safe to say Y here.
1306
1307 See Documentation/nommu-mmap.txt for more information.
1308
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001309config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001310 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001311 help
1312 Say Y here to enable the extended profiling support mechanisms used
1313 by profilers such as OProfile.
1314
Ingo Molnar5f87f112008-07-23 14:15:22 +02001315#
1316# Place an empty function call at each tracepoint site. Can be
1317# dynamically changed for a probe function.
1318#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001319config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001320 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001321
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001322source "arch/Kconfig"
1323
Linus Torvalds1da177e2005-04-16 15:20:36 -07001324endmenu # General setup
1325
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001326config HAVE_GENERIC_DMA_COHERENT
1327 bool
1328 default n
1329
Linus Torvalds158a9622008-01-02 13:04:48 -08001330config SLABINFO
1331 bool
1332 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001333 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001334 default y
1335
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001336config RT_MUTEXES
1337 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001338
Linus Torvalds1da177e2005-04-16 15:20:36 -07001339config BASE_SMALL
1340 int
1341 default 0 if BASE_FULL
1342 default 1 if !BASE_FULL
1343
Jan Engelhardt66da5732007-07-15 23:39:29 -07001344menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001345 bool "Enable loadable module support"
1346 help
1347 Kernel modules are small pieces of compiled code which can
1348 be inserted in the running kernel, rather than being
1349 permanently built into the kernel. You use the "modprobe"
1350 tool to add (and sometimes remove) them. If you say Y here,
1351 many parts of the kernel can be built as modules (by
1352 answering M instead of Y where indicated): this is most
1353 useful for infrequently used options which are not required
1354 for booting. For more information, see the man pages for
1355 modprobe, lsmod, modinfo, insmod and rmmod.
1356
1357 If you say Y here, you will need to run "make
1358 modules_install" to put the modules under /lib/modules/
1359 where modprobe can find them (you may need to be root to do
1360 this).
1361
1362 If unsure, say Y.
1363
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001364if MODULES
1365
Linus Torvalds826e4502008-05-04 17:04:16 -07001366config MODULE_FORCE_LOAD
1367 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001368 default n
1369 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001370 Allow loading of modules without version information (ie. modprobe
1371 --force). Forced module loading sets the 'F' (forced) taint flag and
1372 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001373
Linus Torvalds1da177e2005-04-16 15:20:36 -07001374config MODULE_UNLOAD
1375 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001376 help
1377 Without this option you will not be able to unload any
1378 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001379 anyway), which makes your kernel smaller, faster
1380 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001381
1382config MODULE_FORCE_UNLOAD
1383 bool "Forced module unloading"
1384 depends on MODULE_UNLOAD && EXPERIMENTAL
1385 help
1386 This option allows you to force a module to unload, even if the
1387 kernel believes it is unsafe: the kernel will remove the module
1388 without waiting for anyone to stop using it (using the -f option to
1389 rmmod). This is mainly for kernel developers and desperate users.
1390 If unsure, say N.
1391
Linus Torvalds1da177e2005-04-16 15:20:36 -07001392config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001393 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001394 help
1395 Usually, you have to use modules compiled with your kernel.
1396 Saying Y here makes it sometimes possible to use modules
1397 compiled for different kernels, by adding enough information
1398 to the modules to (hopefully) spot any changes which would
1399 make them incompatible with the kernel you are running. If
1400 unsure, say N.
1401
1402config MODULE_SRCVERSION_ALL
1403 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001404 help
1405 Modules which contain a MODULE_VERSION get an extra "srcversion"
1406 field inserted into their modinfo section, which contains a
1407 sum of the source files which made it. This helps maintainers
1408 see exactly which source was used to build a module (since
1409 others sometimes change the module source without updating
1410 the version). With this option, such a "srcversion" field
1411 will be created for all modules. If unsure, say N.
1412
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001413endif # MODULES
1414
Rusty Russell98a79d62008-12-13 21:19:41 +10301415config INIT_ALL_POSSIBLE
1416 bool
1417 help
Rusty Russell5f054e32012-03-29 15:38:31 +10301418 Back when each arch used to define their own cpu_online_mask and
1419 cpu_possible_mask, some of them chose to initialize cpu_possible_mask
Rusty Russell98a79d62008-12-13 21:19:41 +10301420 with all 1s, and others with all 0s. When they were centralised,
1421 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001422 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301423
Linus Torvalds1da177e2005-04-16 15:20:36 -07001424config STOP_MACHINE
1425 bool
1426 default y
1427 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1428 help
1429 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001430
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001431source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001432
1433config PREEMPT_NOTIFIERS
1434 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001435
Steffen Klassert16295be2010-01-06 19:47:10 +11001436config PADATA
1437 depends on SMP
1438 bool
1439
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001440source "kernel/Kconfig.locks"