blob: 3f42cd66f0f87a25510dd000aed37de5c0d5cc71 [file] [log] [blame]
Roman Zippel80daa5602008-01-14 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 Oberparleiterb99b87f72009-06-17 16:28:03 -070019config CONSTRUCTORS
20 bool
21 depends on !UML
Peter Oberparleiterb99b87f72009-06-17 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53 drivers that have been replaced by something else, and/or are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 Dunlap34ad92c22005-10-30 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. Dayb0e376502007-05-09 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"
390
Mike Travisc903ff82009-01-15 12:28:29 -0800391menu "RCU Subsystem"
392
393choice
394 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700395 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800396
Mike Travisc903ff82009-01-15 12:28:29 -0800397config TREE_RCU
398 bool "Tree-based hierarchical RCU"
Paul E. McKenney687d7a92010-07-21 06:52:40 -0700399 depends on !PREEMPT && SMP
Mike Travisc903ff82009-01-15 12:28:29 -0800400 help
401 This option selects the RCU implementation that is
402 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700403 thousands of CPUs. It also scales down nicely to
404 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800405
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700406config TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700407 bool "Preemptible tree-based hierarchical RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700408 depends on PREEMPT && SMP
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700409 help
410 This option selects the RCU implementation that is
411 designed for very large SMP systems with hundreds or
412 thousands of CPUs, but for which real-time response
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700413 is also required. It also scales down nicely to
414 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700415
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700416config TINY_RCU
417 bool "UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700418 depends on !PREEMPT && !SMP
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700419 help
420 This option selects the RCU implementation that is
421 designed for UP systems from which real-time response
422 is not required. This option greatly reduces the
423 memory footprint of RCU.
424
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700425config TINY_PREEMPT_RCU
426 bool "Preemptible UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700427 depends on PREEMPT && !SMP
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700428 help
429 This option selects the RCU implementation that is designed
430 for real-time UP systems. This option greatly reduces the
431 memory footprint of RCU.
432
Mike Travisc903ff82009-01-15 12:28:29 -0800433endchoice
434
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700435config PREEMPT_RCU
436 def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
437 help
438 This option enables preemptible-RCU code that is common between
439 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
440
Mike Travisc903ff82009-01-15 12:28:29 -0800441config RCU_TRACE
442 bool "Enable tracing for RCU"
Mike Travisc903ff82009-01-15 12:28:29 -0800443 help
444 This option provides tracing in RCU which presents stats
445 in debugfs for debugging RCU implementation.
446
447 Say Y here if you want to enable RCU tracing
448 Say N if you are unsure.
449
450config RCU_FANOUT
451 int "Tree-based hierarchical RCU fanout value"
452 range 2 64 if 64BIT
453 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700454 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800455 default 64 if 64BIT
456 default 32 if !64BIT
457 help
458 This option controls the fanout of hierarchical implementations
459 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700460 large numbers of CPUs. This value must be at least the fourth
461 root of NR_CPUS, which allows NR_CPUS to be insanely large.
462 The default value of RCU_FANOUT should be used for production
463 systems, but if you are stress-testing the RCU implementation
464 itself, small RCU_FANOUT values allow you to test large-system
465 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800466
467 Select a specific number if testing RCU itself.
468 Take the default if unsure.
469
470config RCU_FANOUT_EXACT
471 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700472 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800473 default n
474 help
475 This option forces use of the exact RCU_FANOUT value specified,
476 regardless of imbalances in the hierarchy. This is useful for
477 testing RCU itself, and might one day be useful on systems with
478 strong NUMA behavior.
479
480 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
481
482 Say N if unsure.
483
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800484config RCU_FAST_NO_HZ
485 bool "Accelerate last non-dyntick-idle CPU's grace periods"
Paul E. McKenneyb807fbf2011-11-03 14:56:12 -0700486 depends on NO_HZ && SMP
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800487 default n
488 help
489 This option causes RCU to attempt to accelerate grace periods
Paul E. McKenneyb807fbf2011-11-03 14:56:12 -0700490 in order to allow CPUs to enter dynticks-idle state more
491 quickly. On the other hand, this option increases the overhead
492 of the dynticks-idle checking, particularly on systems with
493 large numbers of CPUs.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800494
495 Say Y if energy efficiency is critically important, particularly
496 if you have relatively few CPUs.
497
498 Say N if you are unsure.
499
Mike Travisc903ff82009-01-15 12:28:29 -0800500config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700501 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800502 select DEBUG_FS
503 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700504 This option provides tracing for the TREE_RCU and
505 TREE_PREEMPT_RCU implementations, permitting Makefile to
506 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800507
Paul E. McKenney24278d12010-09-27 17:25:23 -0700508config RCU_BOOST
509 bool "Enable RCU priority boosting"
Paul E. McKenney27f4d282011-02-07 12:47:15 -0800510 depends on RT_MUTEXES && PREEMPT_RCU
Paul E. McKenney24278d12010-09-27 17:25:23 -0700511 default n
512 help
513 This option boosts the priority of preempted RCU readers that
514 block the current preemptible RCU grace period for too long.
515 This option also prevents heavy loads from blocking RCU
516 callback invocation for all flavors of RCU.
517
518 Say Y here if you are working with real-time apps or heavy loads
519 Say N here if you are unsure.
520
521config RCU_BOOST_PRIO
522 int "Real-time priority to boost RCU readers to"
523 range 1 99
524 depends on RCU_BOOST
525 default 1
526 help
527 This option specifies the real-time priority to which preempted
528 RCU readers are to be boosted. If you are working with CPU-bound
529 real-time applications, you should specify a priority higher then
530 the highest-priority CPU-bound application.
531
532 Specify the real-time priority, or take the default if unsure.
533
534config RCU_BOOST_DELAY
535 int "Milliseconds to delay boosting after RCU grace-period start"
536 range 0 3000
537 depends on RCU_BOOST
538 default 500
539 help
540 This option specifies the time to wait after the beginning of
541 a given grace period before priority-boosting preempted RCU
542 readers blocking that grace period. Note that any RCU reader
543 blocking an expedited RCU grace period is boosted immediately.
544
545 Accept the default if unsure.
546
Mike Travisc903ff82009-01-15 12:28:29 -0800547endmenu # "RCU Subsystem"
548
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700550 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551 ---help---
552 This option enables the complete Linux kernel ".config" file
553 contents to be saved in the kernel. It provides documentation
554 of which kernel options are used in a running kernel or in an
555 on-disk kernel. This information can be extracted from the kernel
556 image file with the script scripts/extract-ikconfig and used as
557 input to rebuild the current kernel or to build another kernel.
558 It can also be extracted from a running kernel by reading
559 /proc/config.gz if enabled (below).
560
561config IKCONFIG_PROC
562 bool "Enable access to .config through /proc/config.gz"
563 depends on IKCONFIG && PROC_FS
564 ---help---
565 This option enables access to the kernel configuration file
566 through /proc/config.gz.
567
Alistair John Strachan794543a2007-05-08 00:31:15 -0700568config LOG_BUF_SHIFT
569 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
570 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700571 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700572 help
573 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700574 Examples:
575 17 => 128 KB
576 16 => 64 KB
577 15 => 32 KB
578 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700579 13 => 8 KB
580 12 => 4 KB
581
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800582#
583# Architectures with an unreliable sched_clock() should select this:
584#
585config HAVE_UNSTABLE_SCHED_CLOCK
586 bool
587
Li Zefan23964d22009-01-15 13:50:58 -0800588menuconfig CGROUPS
589 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800590 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700591 help
Li Zefan23964d22009-01-15 13:50:58 -0800592 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800593 use with process control subsystems such as Cpusets, CFS, memory
594 controls or device isolation.
595 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800596 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800597 - Documentation/cgroups/ (features for grouping, isolation
598 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700599
600 Say N if unsure.
601
Li Zefan23964d22009-01-15 13:50:58 -0800602if CGROUPS
603
Paul Menage006cb992007-10-18 23:39:43 -0700604config CGROUP_DEBUG
605 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700606 default n
Paul Menage006cb992007-10-18 23:39:43 -0700607 help
608 This option enables a simple cgroup subsystem that
609 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800610 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700611
Li Zefan23964d22009-01-15 13:50:58 -0800612 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700613
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700614config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800615 bool "Freezer cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800616 help
617 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700618 cgroup.
619
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700620config CGROUP_DEVICE
621 bool "Device controller for cgroups"
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700622 help
623 Provides a cgroup implementing whitelists for devices which
624 a process in the cgroup can mknod or open.
625
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626config CPUSETS
627 bool "Cpuset support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700629 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630 allow dynamically partitioning a system into sets of CPUs and
631 Memory Nodes and assigning tasks to run only within those sets.
632 This is primarily useful on large SMP or NUMA systems.
633
634 Say N if unsure.
635
Li Zefan23964d22009-01-15 13:50:58 -0800636config PROC_PID_CPUSET
637 bool "Include legacy /proc/<pid>/cpuset file"
638 depends on CPUSETS
639 default y
640
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100641config CGROUP_CPUACCT
642 bool "Simple CPU accounting cgroup subsystem"
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100643 help
644 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800645 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100646
Pavel Emelianove552b662008-02-07 00:13:49 -0800647config RESOURCE_COUNTERS
648 bool "Resource counters"
649 help
650 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800651 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800652
Balbir Singh00f0b822008-03-04 14:28:39 -0800653config CGROUP_MEM_RES_CTLR
654 bool "Memory Resource Controller for Control Groups"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700655 depends on RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700656 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800657 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700658 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100659 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800660
661 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700662 associated with each page of memory in the system. By this,
663 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
664 usage tracking struct at boot. Total amount of this is printed out
665 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800666
667 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700668 sure you need the memory resource controller. Even when you enable
669 this, you can set "cgroup_disable=memory" at your boot option to
670 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800671 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800672
Balbir Singhcf475ad2008-04-29 01:00:16 -0700673 This config option also selects MM_OWNER config option, which
674 could in turn add some fork/exit overhead.
675
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800676config CGROUP_MEM_RES_CTLR_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700677 bool "Memory Resource Controller Swap Extension"
678 depends on CGROUP_MEM_RES_CTLR && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800679 help
680 Add swap management feature to memory resource controller. When you
681 enable this, you can limit mem+swap usage per cgroup. In other words,
682 when you disable this, memory resource controller has no cares to
683 usage of swap...a process can exhaust all of the swap. This extension
684 is useful when you want to avoid exhaustion swap but this itself
685 adds more overheads and consumes memory for remembering information.
686 Especially if you use 32bit system or small memory system, please
687 be careful about enabling this. When memory resource controller
688 is disabled by boot option, this will be automatically disabled and
689 there will be no overhead from this. Even when you set this config=y,
WANG Cong00a66d22011-07-25 17:12:12 -0700690 if boot option "swapaccount=0" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700691 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
692 size is 4096bytes, 512k per 1Gbytes of swap.
Michal Hockoa42c3902010-11-24 12:57:08 -0800693config CGROUP_MEM_RES_CTLR_SWAP_ENABLED
694 bool "Memory Resource Controller Swap Extension enabled by default"
695 depends on CGROUP_MEM_RES_CTLR_SWAP
696 default y
697 help
698 Memory Resource Controller Swap Extension comes with its price in
699 a bigger memory consumption. General purpose distribution kernels
Jim Cromie43d547f2010-12-17 14:32:36 -0700700 which want to enable the feature but keep it disabled by default
Michal Hockoa42c3902010-11-24 12:57:08 -0800701 and let the user enable it by swapaccount boot command line
702 parameter should have this option unselected.
703 For those who want to have the feature enabled by default should
704 select this option (if, for some reason, they need to disable it
WANG Cong00a66d22011-07-25 17:12:12 -0700705 then swapaccount=0 does the trick).
Glauber Costae5671df2011-12-11 21:47:01 +0000706config CGROUP_MEM_RES_CTLR_KMEM
707 bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
708 depends on CGROUP_MEM_RES_CTLR && EXPERIMENTAL
709 default n
710 help
711 The Kernel Memory extension for Memory Resource Controller can limit
712 the amount of memory used by kernel objects in the system. Those are
713 fundamentally different from the entities handled by the standard
714 Memory Controller, which are page-based, and can be swapped. Users of
715 the kmem extension can use it to guarantee that no group of processes
716 will ever exhaust kernel resources alone.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800717
Stephane Eraniane5d13672011-02-14 11:20:01 +0200718config CGROUP_PERF
719 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
720 depends on PERF_EVENTS && CGROUPS
721 help
722 This option extends the per-cpu mode to restrict monitoring to
Li Zefan2d0f2522011-03-03 14:26:20 +0800723 threads which belong to the cgroup specified and run on the
Stephane Eraniane5d13672011-02-14 11:20:01 +0200724 designated cpu.
725
726 Say N if unsure.
727
Dhaval Giani7c941432010-01-20 13:26:18 +0100728menuconfig CGROUP_SCHED
729 bool "Group CPU scheduler"
Dhaval Giani7c941432010-01-20 13:26:18 +0100730 default n
731 help
732 This feature lets CPU scheduler recognize task groups and control CPU
733 bandwidth allocation to such task groups. It uses cgroups to group
734 tasks.
735
736if CGROUP_SCHED
737config FAIR_GROUP_SCHED
738 bool "Group scheduling for SCHED_OTHER"
739 depends on CGROUP_SCHED
740 default CGROUP_SCHED
741
Paul Turnerab84d312011-07-21 09:43:28 -0700742config CFS_BANDWIDTH
743 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
744 depends on EXPERIMENTAL
745 depends on FAIR_GROUP_SCHED
746 default n
747 help
748 This option allows users to define CPU bandwidth rates (limits) for
749 tasks running within the fair group scheduler. Groups with no limit
750 set are considered to be unconstrained and will run with no
751 restriction.
752 See tip/Documentation/scheduler/sched-bwc.txt for more information.
753
Dhaval Giani7c941432010-01-20 13:26:18 +0100754config RT_GROUP_SCHED
755 bool "Group scheduling for SCHED_RR/FIFO"
756 depends on EXPERIMENTAL
757 depends on CGROUP_SCHED
758 default n
759 help
760 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +0800761 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +0100762 schedule realtime tasks for non-root users until you allocate
763 realtime bandwidth for them.
764 See Documentation/scheduler/sched-rt-group.txt for more information.
765
766endif #CGROUP_SCHED
767
Vivek Goyalafc24d42010-04-26 19:27:56 +0200768config BLK_CGROUP
769 tristate "Block IO controller"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700770 depends on BLOCK
Vivek Goyalafc24d42010-04-26 19:27:56 +0200771 default n
772 ---help---
773 Generic block IO controller cgroup interface. This is the common
774 cgroup interface which should be used by various IO controlling
775 policies.
776
777 Currently, CFQ IO scheduler uses it to recognize task groups and
778 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -0400779 to such task groups. It is also used by bio throttling logic in
780 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200781
782 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -0400783 One needs to also enable actual IO controlling logic/policy. For
Michael Witten79e2e752011-01-16 21:43:10 +0000784 enabling proportional weight division of disk bandwidth in CFQ, set
785 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
Michael Wittenc5e05912011-01-17 00:08:41 +0000786 CONFIG_BLK_DEV_THROTTLING=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200787
788 See Documentation/cgroups/blkio-controller.txt for more information.
789
790config DEBUG_BLK_CGROUP
791 bool "Enable Block IO controller debugging"
792 depends on BLK_CGROUP
793 default n
794 ---help---
795 Enable some debugging help. Currently it exports additional stat
796 files in a cgroup which can be useful for debugging.
797
Li Zefan23964d22009-01-15 13:50:58 -0800798endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800799
Cyrill Gorcunov067bce12012-01-12 17:20:49 -0800800config CHECKPOINT_RESTORE
801 bool "Checkpoint/restore support" if EXPERT
802 default n
803 help
804 Enables additional kernel features in a sake of checkpoint/restore.
805 In particular it adds auxiliary prctl codes to setup process text,
806 data and heap segment sizes, and a few additional /proc filesystem
807 entries.
808
809 If unsure, say N here.
810
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700811menuconfig NAMESPACES
David Rientjes6a108a12011-01-20 14:44:16 -0800812 bool "Namespaces support" if EXPERT
813 default !EXPERT
Pavel Emelyanovc5289a62008-02-08 04:18:19 -0800814 help
815 Provides the way to make tasks work with different objects using
816 the same id. For example same IPC id may refer to different objects
817 or same user id or pid may refer to different tasks when used in
818 different namespaces.
819
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700820if NAMESPACES
821
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800822config UTS_NS
823 bool "UTS namespace"
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700824 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800825 help
826 In this namespace tasks see different info provided with the
827 uname() system call
828
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800829config IPC_NS
830 bool "IPC namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700831 depends on (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700832 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800833 help
834 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700835 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800836
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800837config USER_NS
838 bool "User namespace (EXPERIMENTAL)"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700839 depends on EXPERIMENTAL
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700840 default y
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800841 help
842 This allows containers, i.e. vservers, to use user namespaces
843 to provide different user info for different servers.
844 If unsure, say N.
845
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800846config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -0700847 bool "PID Namespaces"
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700848 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800849 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +0300850 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +0100851 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800852 pid namespaces. This is a building block of containers.
853
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800854config NET_NS
855 bool "Network namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700856 depends on NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700857 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800858 help
859 Allow user space to create what appear to be multiple instances
860 of the network stack.
861
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700862endif # NAMESPACES
863
Mike Galbraith5091faa2010-11-30 14:18:03 +0100864config SCHED_AUTOGROUP
865 bool "Automatic process group scheduling"
866 select EVENTFD
867 select CGROUPS
868 select CGROUP_SCHED
869 select FAIR_GROUP_SCHED
870 help
871 This option optimizes the scheduler for common desktop workloads by
872 automatically creating and populating task groups. This separation
873 of workloads isolates aggressive CPU burners (like build jobs) from
874 desktop applications. Task group autogeneration is currently based
875 upon task session.
876
Daniel Lezcano7af37be2010-10-27 15:34:41 -0700877config MM_OWNER
878 bool
879
880config SYSFS_DEPRECATED
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +0100881 bool "Enable deprecated sysfs features to support old userspace tools"
Daniel Lezcano7af37be2010-10-27 15:34:41 -0700882 depends on SYSFS
883 default n
884 help
885 This option adds code that switches the layout of the "block" class
886 devices, to not show up in /sys/class/block/, but only in
887 /sys/block/.
888
889 This switch is only active when the sysfs.deprecated=1 boot option is
890 passed or the SYSFS_DEPRECATED_V2 option is set.
891
892 This option allows new kernels to run on old distributions and tools,
893 which might get confused by /sys/class/block/. Since 2007/2008 all
894 major distributions and tools handle this just fine.
895
896 Recent distributions and userspace tools after 2009/2010 depend on
897 the existence of /sys/class/block/, and will not work with this
898 option enabled.
899
900 Only if you are using a new kernel on an old distribution, you might
901 need to say Y here.
902
903config SYSFS_DEPRECATED_V2
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +0100904 bool "Enable deprecated sysfs features by default"
Daniel Lezcano7af37be2010-10-27 15:34:41 -0700905 default n
906 depends on SYSFS
907 depends on SYSFS_DEPRECATED
908 help
909 Enable deprecated sysfs by default.
910
911 See the CONFIG_SYSFS_DEPRECATED option for more details about this
912 option.
913
914 Only if you are using a new kernel on an old distribution, you might
915 need to say Y here. Even then, odds are you would not need it
916 enabled, you can always pass the boot option if absolutely necessary.
917
918config RELAY
919 bool "Kernel->user space relay support (formerly relayfs)"
920 help
921 This option enables support for relay interface support in
922 certain file systems (such as debugfs).
923 It is designed to provide an efficient mechanism for tools and
924 facilities to relay large amounts of data from kernel space to
925 user space.
926
927 If unsure, say N.
928
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -0800929config BLK_DEV_INITRD
930 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
931 depends on BROKEN || !FRV
932 help
933 The initial RAM filesystem is a ramfs which is loaded by the
934 boot loader (loadlin or lilo) and that is mounted as root
935 before the normal boot procedure. It is typically used to
936 load modules needed to mount the "real" root file system,
937 etc. See <file:Documentation/initrd.txt> for details.
938
939 If RAM disk support (BLK_DEV_RAM) is also included, this
940 also enables initial RAM disk (initrd) support and adds
941 15 Kbytes (more on some other architectures) to the kernel size.
942
943 If unsure say Y.
944
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800945if BLK_DEV_INITRD
946
Sam Ravnborgdbec4862005-08-10 20:44:50 +0200947source "usr/Kconfig"
948
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800949endif
950
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800951config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +0200952 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800953 help
954 Enabling this option will pass "-Os" instead of "-O2" to gcc
955 resulting in a smaller kernel.
956
jkacur775a7222008-07-16 00:31:16 +0200957 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800958
Randy Dunlap08470622006-09-30 23:28:13 -0700959config SYSCTL
960 bool
961
Randy Dunlapb943c462009-03-10 12:55:46 -0700962config ANON_INODES
963 bool
964
David Rientjes6a108a12011-01-20 14:44:16 -0800965menuconfig EXPERT
966 bool "Configure standard kernel features (expert users)"
Josh Triplettf505c552011-06-05 18:23:58 -0700967 # Unhide debug options, to make the on-by-default options visible
968 select DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969 help
970 This option allows certain base kernel options and settings
971 to be disabled or tweaked. This is for specialized
972 environments which can tolerate a "non-standard" kernel.
973 Only use this if you really know what you are doing.
974
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700975config UID16
David Rientjes6a108a12011-01-20 14:44:16 -0800976 bool "Enable 16-bit UID system calls" if EXPERT
David S. Miller09337f52008-04-26 03:17:12 -0700977 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 -0700978 default y
979 help
980 This enables the legacy 16-bit UID syscall wrappers.
981
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700982config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -0800983 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -0800984 depends on PROC_SYSCTL
WANG Congc736de62011-11-02 13:39:25 -0700985 default n
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700986 select SYSCTL
987 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800988 sys_sysctl uses binary paths that have been found challenging
989 to properly maintain and use. The interface in /proc/sys
990 using paths with ascii names is now the primary path to this
991 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700992
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800993 Almost nothing using the binary sysctl interface so if you are
994 trying to save some space it is probably safe to disable this,
995 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700996
WANG Congc736de62011-11-02 13:39:25 -0700997 If unsure say N here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700998
Linus Torvalds1da177e2005-04-16 15:20:36 -0700999config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -08001000 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001001 default y
1002 help
1003 Say Y here to let the kernel print out symbolic crash information and
1004 symbolic stack backtraces. This increases the size of the kernel
1005 somewhat, as all symbols have to be loaded into the kernel image.
1006
1007config KALLSYMS_ALL
1008 bool "Include all symbols in kallsyms"
1009 depends on DEBUG_KERNEL && KALLSYMS
1010 help
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001011 Normally kallsyms only contains the symbols of functions for nicer
1012 OOPS messages and backtraces (i.e., symbols from the text and inittext
1013 sections). This is sufficient for most cases. And only in very rare
1014 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1015 names of variables from the data sections, etc).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001016
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001017 This option makes sure that all symbols are loaded into the kernel
1018 image (i.e., symbols from all sections) in cost of increased kernel
1019 size (depending on the kernel configuration, it may be 300KiB or
1020 something like this).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001021
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001022 Say N unless you really need all symbols.
Matt Mackalld59745c2005-05-01 08:59:02 -07001023
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001024config HOTPLUG
David Rientjes6a108a12011-01-20 14:44:16 -08001025 bool "Support for hot-pluggable devices" if EXPERT
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001026 default y
1027 help
1028 This option is provided for the case where no hotplug or uevent
1029 capabilities is wanted by the kernel. You should only consider
1030 disabling this option for embedded systems that do not use modules, a
1031 dynamic /dev tree, or dynamic device discovery. Just say Y.
1032
Matt Mackalld59745c2005-05-01 08:59:02 -07001033config PRINTK
1034 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001035 bool "Enable support for printk" if EXPERT
Matt Mackalld59745c2005-05-01 08:59:02 -07001036 help
1037 This option enables normal printk support. Removing it
1038 eliminates most of the message strings from the kernel image
1039 and makes the kernel more or less silent. As this makes it
1040 very difficult to diagnose system problems, saying N here is
1041 strongly discouraged.
1042
Matt Mackallc8538a72005-05-01 08:59:01 -07001043config BUG
David Rientjes6a108a12011-01-20 14:44:16 -08001044 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -07001045 default y
1046 help
1047 Disabling this option eliminates support for BUG and WARN, reducing
1048 the size of your kernel image and potentially quietly ignoring
1049 numerous fatal conditions. You should only consider disabling this
1050 option for embedded systems with no facilities for reporting errors.
1051 Just say Y.
1052
Matt Mackall708e9a72006-01-08 01:05:25 -08001053config ELF_CORE
1054 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001055 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001056 help
1057 Enable support for generating core dumps. Disabling saves about 4k.
1058
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001059
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001060config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001061 bool "Enable PC-Speaker support" if EXPERT
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001062 depends on HAVE_PCSPKR_PLATFORM
Ralf Baechle15f304b2011-06-01 19:04:59 +01001063 select I8253_LOCK
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001064 default y
1065 help
1066 This option allows to disable the internal PC-Speaker
1067 support, saving some memory.
1068
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001069config HAVE_PCSPKR_PLATFORM
1070 bool
1071
Linus Torvalds1da177e2005-04-16 15:20:36 -07001072config BASE_FULL
1073 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001074 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001075 help
1076 Disabling this option reduces the size of miscellaneous core
1077 kernel data structures. This saves memory on small machines,
1078 but may reduce performance.
1079
1080config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001081 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001082 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001083 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001084 help
1085 Disabling this option will cause the kernel to be built without
1086 support for "fast userspace mutexes". The resulting kernel may not
1087 run glibc-based applications correctly.
1088
1089config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001090 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001091 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001092 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001093 help
1094 Disabling this option will cause the kernel to be built without
1095 support for epoll family of system calls.
1096
Davide Libenzifba2afa2007-05-10 22:23:13 -07001097config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001098 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001099 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001100 default y
1101 help
1102 Enable the signalfd() system call that allows to receive signals
1103 on a file descriptor.
1104
1105 If unsure, say Y.
1106
Davide Libenzib215e282007-05-10 22:23:16 -07001107config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001108 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001109 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001110 default y
1111 help
1112 Enable the timerfd() system call that allows to receive timer
1113 events on a file descriptor.
1114
1115 If unsure, say Y.
1116
Davide Libenzie1ad7462007-05-10 22:23:19 -07001117config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001118 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001119 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001120 default y
1121 help
1122 Enable the eventfd() system call that allows to receive both
1123 kernel notification (ie. KAIO) or userspace notifications.
1124
1125 If unsure, say Y.
1126
Linus Torvalds1da177e2005-04-16 15:20:36 -07001127config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001128 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001129 default y
1130 depends on MMU
1131 help
1132 The shmem is an internal filesystem used to manage shared memory.
1133 It is backed by swap and manages resource limits. It is also exported
1134 to userspace as tmpfs if TMPFS is enabled. Disabling this
1135 option replaces shmem and tmpfs with the much simpler ramfs code,
1136 which may be appropriate on small systems without swap.
1137
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001138config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001139 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001140 default y
1141 help
1142 This option enables POSIX asynchronous I/O which may by used
1143 by some high performance threaded applications. Disabling
1144 this option saves about 7k.
1145
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001146config EMBEDDED
1147 bool "Embedded system"
1148 select EXPERT
1149 help
1150 This option should be enabled if compiling the kernel for
1151 an embedded system so certain expert options are available
1152 for configuration.
1153
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001154config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001155 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001156 help
1157 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001158
Peter Zijlstra906010b2009-09-21 16:08:49 +02001159config PERF_USE_VMALLOC
1160 bool
1161 help
1162 See tools/perf/design.txt for details
1163
Ingo Molnar57c0c152009-09-21 12:20:38 +02001164menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001165
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001166config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001167 bool "Kernel performance events and counters"
1168 default y if (PROFILING || PERF_COUNTERS)
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001169 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001170 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001171 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001172 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001173 Enable kernel support for various performance events provided
1174 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001175
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001176 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001177 use of generic tracepoints.
1178
1179 Most modern CPUs support performance events via performance
1180 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001181 types of hw events: such as instructions executed, cachemisses
1182 suffered, or branches mis-predicted - without slowing down the
1183 kernel or applications. These registers can also trigger interrupts
1184 when a threshold number of events have passed - and can thus be
1185 used to profile the code that runs on that CPU.
1186
Ingo Molnar57c0c152009-09-21 12:20:38 +02001187 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001188 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001189 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001190 provides per task and per CPU counters, and it provides event
1191 capabilities on top of those.
1192
1193 Say Y if unsure.
1194
Ingo Molnar57c0c152009-09-21 12:20:38 +02001195config PERF_COUNTERS
1196 bool "Kernel performance counters (old config option)"
1197 depends on HAVE_PERF_EVENTS
1198 help
1199 This config has been obsoleted by the PERF_EVENTS
1200 config option - please see that one for details.
1201
1202 It has no effect on the kernel whether you enable
1203 it or not, it is a compatibility placeholder.
1204
1205 Say N if unsure.
1206
Peter Zijlstra906010b2009-09-21 16:08:49 +02001207config DEBUG_PERF_USE_VMALLOC
1208 default n
1209 bool "Debug: use vmalloc to back perf mmap() buffers"
1210 depends on PERF_EVENTS && DEBUG_KERNEL
1211 select PERF_USE_VMALLOC
1212 help
1213 Use vmalloc memory to back perf mmap() buffers.
1214
1215 Mostly useful for debugging the vmalloc code on platforms
1216 that don't require it.
1217
1218 Say N if unsure.
1219
Thomas Gleixner0793a612008-12-04 20:12:29 +01001220endmenu
1221
Christoph Lameterf8891e52006-06-30 01:55:45 -07001222config VM_EVENT_COUNTERS
1223 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001224 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001225 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001226 VM event counters are needed for event counts to be shown.
1227 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001228 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001229 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001230
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001231config PCI_QUIRKS
1232 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001233 bool "Enable PCI quirk workarounds" if EXPERT
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001234 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001235 help
1236 This enables workarounds for various PCI chipset
1237 bugs/quirks. Disable this only if your target machine is
1238 unaffected by PCI quirks.
1239
Christoph Lameter41ecc552007-05-09 02:32:44 -07001240config SLUB_DEBUG
1241 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001242 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001243 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001244 help
1245 SLUB has extensive debug support features. Disabling these can
1246 result in significant savings in code size. This also disables
1247 SLUB sysfs support. /sys/slab will not exist and there will be
1248 no support for cache validation etc.
1249
Randy Dunlapb943c462009-03-10 12:55:46 -07001250config COMPAT_BRK
1251 bool "Disable heap randomization"
1252 default y
1253 help
1254 Randomizing heap placement makes heap exploits harder, but it
1255 also breaks ancient binaries (including anything libc5 based).
1256 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001257 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001258 /proc/sys/kernel/randomize_va_space to 2.
1259
1260 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1261
Christoph Lameter81819f02007-05-06 14:49:36 -07001262choice
1263 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001264 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001265 help
1266 This option allows to select a slab allocator.
1267
1268config SLAB
1269 bool "SLAB"
1270 help
1271 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001272 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001273 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001274
1275config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001276 bool "SLUB (Unqueued Allocator)"
1277 help
1278 SLUB is a slab allocator that minimizes cache line usage
1279 instead of managing queues of cached objects (SLAB approach).
1280 Per cpu caching is realized using slabs of objects instead
1281 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001282 and has enhanced diagnostics. SLUB is the default choice for
1283 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001284
1285config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001286 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001287 bool "SLOB (Simple Allocator)"
1288 help
Matt Mackall37291452008-02-04 22:29:38 -08001289 SLOB replaces the stock allocator with a drastically simpler
1290 allocator. SLOB is generally more space efficient but
1291 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001292
1293endchoice
1294
Jie Zhangea637632009-12-14 18:00:02 -08001295config MMAP_ALLOW_UNINITIALIZED
1296 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001297 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001298 default n
1299 help
1300 Normally, and according to the Linux spec, anonymous memory obtained
1301 from mmap() has it's contents cleared before it is passed to
1302 userspace. Enabling this config option allows you to request that
1303 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1304 providing a huge performance boost. If this option is not enabled,
1305 then the flag will be ignored.
1306
1307 This is taken advantage of by uClibc's malloc(), and also by
1308 ELF-FDPIC binfmt's brk and stack allocator.
1309
1310 Because of the obvious security issues, this option should only be
1311 enabled on embedded devices where you control what is run in
1312 userspace. Since that isn't generally a problem on no-MMU systems,
1313 it is normally safe to say Y here.
1314
1315 See Documentation/nommu-mmap.txt for more information.
1316
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001317config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001318 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001319 help
1320 Say Y here to enable the extended profiling support mechanisms used
1321 by profilers such as OProfile.
1322
Ingo Molnar5f87f112008-07-23 14:15:22 +02001323#
1324# Place an empty function call at each tracepoint site. Can be
1325# dynamically changed for a probe function.
1326#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001327config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001328 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001329
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001330source "arch/Kconfig"
1331
Linus Torvalds1da177e2005-04-16 15:20:36 -07001332endmenu # General setup
1333
Dmitry Baryshkovee7e55162008-06-29 14:18:46 +04001334config HAVE_GENERIC_DMA_COHERENT
1335 bool
1336 default n
1337
Linus Torvalds158a9622008-01-02 13:04:48 -08001338config SLABINFO
1339 bool
1340 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001341 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001342 default y
1343
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001344config RT_MUTEXES
1345 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001346
Linus Torvalds1da177e2005-04-16 15:20:36 -07001347config BASE_SMALL
1348 int
1349 default 0 if BASE_FULL
1350 default 1 if !BASE_FULL
1351
Jan Engelhardt66da5732007-07-15 23:39:29 -07001352menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001353 bool "Enable loadable module support"
1354 help
1355 Kernel modules are small pieces of compiled code which can
1356 be inserted in the running kernel, rather than being
1357 permanently built into the kernel. You use the "modprobe"
1358 tool to add (and sometimes remove) them. If you say Y here,
1359 many parts of the kernel can be built as modules (by
1360 answering M instead of Y where indicated): this is most
1361 useful for infrequently used options which are not required
1362 for booting. For more information, see the man pages for
1363 modprobe, lsmod, modinfo, insmod and rmmod.
1364
1365 If you say Y here, you will need to run "make
1366 modules_install" to put the modules under /lib/modules/
1367 where modprobe can find them (you may need to be root to do
1368 this).
1369
1370 If unsure, say Y.
1371
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001372if MODULES
1373
Linus Torvalds826e4502008-05-04 17:04:16 -07001374config MODULE_FORCE_LOAD
1375 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001376 default n
1377 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001378 Allow loading of modules without version information (ie. modprobe
1379 --force). Forced module loading sets the 'F' (forced) taint flag and
1380 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001381
Linus Torvalds1da177e2005-04-16 15:20:36 -07001382config MODULE_UNLOAD
1383 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001384 help
1385 Without this option you will not be able to unload any
1386 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001387 anyway), which makes your kernel smaller, faster
1388 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001389
1390config MODULE_FORCE_UNLOAD
1391 bool "Forced module unloading"
1392 depends on MODULE_UNLOAD && EXPERIMENTAL
1393 help
1394 This option allows you to force a module to unload, even if the
1395 kernel believes it is unsafe: the kernel will remove the module
1396 without waiting for anyone to stop using it (using the -f option to
1397 rmmod). This is mainly for kernel developers and desperate users.
1398 If unsure, say N.
1399
Linus Torvalds1da177e2005-04-16 15:20:36 -07001400config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001401 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001402 help
1403 Usually, you have to use modules compiled with your kernel.
1404 Saying Y here makes it sometimes possible to use modules
1405 compiled for different kernels, by adding enough information
1406 to the modules to (hopefully) spot any changes which would
1407 make them incompatible with the kernel you are running. If
1408 unsure, say N.
1409
1410config MODULE_SRCVERSION_ALL
1411 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001412 help
1413 Modules which contain a MODULE_VERSION get an extra "srcversion"
1414 field inserted into their modinfo section, which contains a
1415 sum of the source files which made it. This helps maintainers
1416 see exactly which source was used to build a module (since
1417 others sometimes change the module source without updating
1418 the version). With this option, such a "srcversion" field
1419 will be created for all modules. If unsure, say N.
1420
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001421endif # MODULES
1422
Rusty Russell98a79d62008-12-13 21:19:41 +10301423config INIT_ALL_POSSIBLE
1424 bool
1425 help
1426 Back when each arch used to define their own cpu_online_map and
1427 cpu_possible_map, some of them chose to initialize cpu_possible_map
1428 with all 1s, and others with all 0s. When they were centralised,
1429 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001430 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301431
Linus Torvalds1da177e2005-04-16 15:20:36 -07001432config STOP_MACHINE
1433 bool
1434 default y
1435 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1436 help
1437 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001438
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001439source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001440
1441config PREEMPT_NOTIFIERS
1442 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001443
Steffen Klassert16295be2010-01-06 19:47:10 +11001444config PADATA
1445 depends on SMP
1446 bool
1447
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001448source "kernel/Kconfig.locks"