blob: 1e004d0574689c225526290d2a4cc82fe95287b6 [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
David Daney1dbdc6f2012-04-19 14:59:57 -070030config BUILDTIME_EXTABLE_SORT
31 bool
32
Al Boldiff0cfc62007-07-31 00:39:23 -070033menu "General setup"
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
35config EXPERIMENTAL
36 bool "Prompt for development and/or incomplete code/drivers"
37 ---help---
38 Some of the various things that Linux supports (such as network
39 drivers, file systems, network protocols, etc.) can be in a state
40 of development where the functionality, stability, or the level of
41 testing is not yet high enough for general use. This is usually
42 known as the "alpha-test" phase among developers. If a feature is
43 currently in alpha-test, then the developers usually discourage
44 uninformed widespread use of this feature by the general public to
45 avoid "Why doesn't this work?" type mail messages. However, active
46 testing and use of these systems is welcomed. Just be aware that it
47 may not meet the normal level of reliability or it may fail to work
48 in some special cases. Detailed bug reports from people familiar
49 with the kernel internals are usually welcomed by the developers
50 (before submitting bug reports, please read the documents
51 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
52 <file:Documentation/BUG-HUNTING>, and
53 <file:Documentation/oops-tracing.txt> in the kernel source).
54
55 This option will also make obsoleted drivers available. These are
56 drivers that have been replaced by something else, and/or are
57 scheduled to be removed in a future kernel release.
58
59 Unless you intend to help test and develop a feature or driver that
60 falls into this category, or you have a situation that requires
61 using these features, you should probably say N here, which will
62 cause the configurator to present you with fewer choices. If
63 you say Y here, you will be offered the choice of using features or
64 drivers that are currently considered to be in the alpha-test phase.
65
Linus Torvalds1da177e2005-04-16 15:20:36 -070066config BROKEN
67 bool
Linus Torvalds1da177e2005-04-16 15:20:36 -070068
69config BROKEN_ON_SMP
70 bool
71 depends on BROKEN || !SMP
72 default y
73
Linus Torvalds1da177e2005-04-16 15:20:36 -070074config INIT_ENV_ARG_LIMIT
75 int
Adrian Bunkdd673bc2006-06-30 01:55:51 -070076 default 32 if !UML
77 default 128 if UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 help
Randy Dunlap34ad92c2005-10-30 15:01:46 -080079 Maximum of each of the number of arguments and environment
80 variables passed to init from the kernel command line.
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
Linus Torvalds1da177e2005-04-16 15:20:36 -070082
Roland McGrath84336462009-12-21 16:24:06 -080083config CROSS_COMPILE
84 string "Cross-compiler tool prefix"
85 help
86 Same as running 'make CROSS_COMPILE=prefix-' but stored for
87 default make runs in this kernel build directory. You don't
88 need to set this unless you want the configured kernel build
89 directory to select the cross-compiler automatically.
90
Linus Torvalds1da177e2005-04-16 15:20:36 -070091config LOCALVERSION
92 string "Local version - append to kernel release"
93 help
94 Append an extra string to the end of your kernel version.
95 This will show up when you type uname, for example.
96 The string you set here will be appended after the contents of
97 any files with a filename matching localversion* in your
98 object and source tree, in that order. Your total string can
99 be a maximum of 64 characters.
100
Ryan Andersonaaebf432005-07-31 04:57:49 -0400101config LOCALVERSION_AUTO
102 bool "Automatically append version information to the version string"
103 default y
104 help
105 This will try to automatically determine if the current tree is a
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200106 release tree by looking for git tags that belong to the current
107 top of tree revision.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400108
109 A string of the format -gxxxxxxxx will be added to the localversion
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200110 if a git-based tree is found. The string generated by this will be
Ryan Andersonaaebf432005-07-31 04:57:49 -0400111 appended after any matching localversion* files, and after the value
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200112 set in CONFIG_LOCALVERSION.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400113
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200114 (The actual string used here is the first eight characters produced
115 by running the command:
116
117 $ git rev-parse --verify HEAD
118
119 which is done within the script "scripts/setlocalversion".)
Ryan Andersonaaebf432005-07-31 04:57:49 -0400120
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800121config HAVE_KERNEL_GZIP
122 bool
123
124config HAVE_KERNEL_BZIP2
125 bool
126
127config HAVE_KERNEL_LZMA
128 bool
129
Lasse Collin3ebe1242011-01-12 17:01:23 -0800130config HAVE_KERNEL_XZ
131 bool
132
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800133config HAVE_KERNEL_LZO
134 bool
135
Alain Knaff30d65db2009-01-04 22:46:17 +0100136choice
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800137 prompt "Kernel compression mode"
138 default KERNEL_GZIP
Lasse Collin3ebe1242011-01-12 17:01:23 -0800139 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 -0800140 help
Alain Knaff30d65db2009-01-04 22:46:17 +0100141 The linux kernel is a kind of self-extracting executable.
142 Several compression algorithms are available, which differ
143 in efficiency, compression and decompression speed.
144 Compression speed is only relevant when building a kernel.
145 Decompression speed is relevant at each boot.
146
147 If you have any problems with bzip2 or lzma compressed
148 kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
149 version of this functionality (bzip2 only), for 2.4, was
150 supplied by Christian Ludwig)
151
152 High compression options are mostly useful for users, who
153 are low on disk space (embedded systems), but for whom ram
154 size matters less.
155
156 If in doubt, select 'gzip'
157
158config KERNEL_GZIP
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800159 bool "Gzip"
160 depends on HAVE_KERNEL_GZIP
161 help
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800162 The old and tried gzip compression. It provides a good balance
163 between compression ratio and decompression speed.
Alain Knaff30d65db2009-01-04 22:46:17 +0100164
165config KERNEL_BZIP2
166 bool "Bzip2"
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800167 depends on HAVE_KERNEL_BZIP2
Alain Knaff30d65db2009-01-04 22:46:17 +0100168 help
169 Its compression ratio and speed is intermediate.
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800170 Decompression speed is slowest among the three. The kernel
171 size is about 10% smaller with bzip2, in comparison to gzip.
172 Bzip2 uses a large amount of memory. For modern kernels you
173 will need at least 8MB RAM or more for booting.
Alain Knaff30d65db2009-01-04 22:46:17 +0100174
175config KERNEL_LZMA
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800176 bool "LZMA"
177 depends on HAVE_KERNEL_LZMA
178 help
179 The most recent compression algorithm.
180 Its ratio is best, decompression speed is between the other
181 two. Compression is slowest. The kernel size is about 33%
182 smaller with LZMA in comparison to gzip.
Alain Knaff30d65db2009-01-04 22:46:17 +0100183
Lasse Collin3ebe1242011-01-12 17:01:23 -0800184config KERNEL_XZ
185 bool "XZ"
186 depends on HAVE_KERNEL_XZ
187 help
188 XZ uses the LZMA2 algorithm and instruction set specific
189 BCJ filters which can improve compression ratio of executable
190 code. The size of the kernel is about 30% smaller with XZ in
191 comparison to gzip. On architectures for which there is a BCJ
192 filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
193 will create a few percent smaller kernel than plain LZMA.
194
195 The speed is about the same as with LZMA: The decompression
196 speed of XZ is better than that of bzip2 but worse than gzip
197 and LZO. Compression is slow.
198
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800199config KERNEL_LZO
200 bool "LZO"
201 depends on HAVE_KERNEL_LZO
202 help
203 Its compression ratio is the poorest among the 4. The kernel
Stephan Sperber681b3042010-07-14 11:23:08 +0200204 size is about 10% bigger than gzip; however its speed
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800205 (both compression and decompression) is the fastest.
206
Alain Knaff30d65db2009-01-04 22:46:17 +0100207endchoice
208
Josh Triplettbd5dc172011-06-15 15:08:28 -0700209config DEFAULT_HOSTNAME
210 string "Default hostname"
211 default "(none)"
212 help
213 This option determines the default system hostname before userspace
214 calls sethostname(2). The kernel traditionally uses "(none)" here,
215 but you may wish to use a different default here to make a minimal
216 system more usable with less configuration.
217
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218config SWAP
219 bool "Support for paging of anonymous memory (swap)"
David Howells93614012006-09-30 20:45:40 +0200220 depends on MMU && BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 default y
222 help
223 This option allows you to choose whether you want to have support
Jesper Juhl92c35042006-01-15 02:40:08 +0100224 for so called swap devices or swap files in your kernel that are
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 used to provide more virtual memory than the actual RAM present
226 in your computer. If unsure say Y.
227
228config SYSVIPC
229 bool "System V IPC"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 ---help---
231 Inter Process Communication is a suite of library functions and
232 system calls which let processes (running programs) synchronize and
233 exchange information. It is generally considered to be a good thing,
234 and some programs won't run unless you say Y here. In particular, if
235 you want to run the DOS emulator dosemu under Linux (read the
236 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
237 you'll need to say Y here.
238
239 You can find documentation about IPC with "info ipc" and also in
240 section 6.4 of the Linux Programmer's Guide, available from
241 <http://www.tldp.org/guides.html>.
242
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800243config SYSVIPC_SYSCTL
244 bool
245 depends on SYSVIPC
246 depends on SYSCTL
247 default y
248
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249config POSIX_MQUEUE
250 bool "POSIX Message Queues"
251 depends on NET && EXPERIMENTAL
252 ---help---
253 POSIX variant of message queues is a part of IPC. In POSIX message
254 queues every message has a priority which decides about succession
255 of receiving it by a process. If you want to compile and run
256 programs written e.g. for Solaris with use of its POSIX message
Robert P. J. Dayb0e37652007-05-09 07:25:13 +0200257 queues (functions mq_*) say Y here.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258
259 POSIX message queues are visible as a filesystem called 'mqueue'
260 and can be mounted somewhere if you want to do filesystem
261 operations on message queues.
262
263 If unsure, say Y.
264
Serge E. Hallynbdc8e5f2009-04-06 19:01:11 -0700265config POSIX_MQUEUE_SYSCTL
266 bool
267 depends on POSIX_MQUEUE
268 depends on SYSCTL
269 default y
270
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271config BSD_PROCESS_ACCT
272 bool "BSD Process Accounting"
273 help
274 If you say Y here, a user level program will be able to instruct the
275 kernel (via a special system call) to write process accounting
276 information to a file: whenever a process exits, information about
277 that process will be appended to the file by the kernel. The
278 information includes things such as creation time, owning user,
279 command name, memory usage, controlling terminal etc. (the complete
280 list is in the struct acct in <file:include/linux/acct.h>). It is
281 up to the user level program to do useful things with this
282 information. This is generally a good idea, so say Y.
283
284config BSD_PROCESS_ACCT_V3
285 bool "BSD Process Accounting version 3 file format"
286 depends on BSD_PROCESS_ACCT
287 default n
288 help
289 If you say Y here, the process accounting information is written
290 in a new file format that also logs the process IDs of each
291 process and it's parent. Note that this file format is incompatible
292 with previous v0/v1/v2 file formats, so you will need updated tools
293 for processing it. A preliminary version of these tools is available
S.Çağlar Onur37a4c942008-06-18 11:45:13 +0300294 at <http://www.gnu.org/software/acct/>.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295
Aneesh Kumar K.V990d6c22011-01-29 18:43:26 +0530296config FHANDLE
297 bool "open by fhandle syscalls"
298 select EXPORTFS
299 help
300 If you say Y here, a user level program will be able to map
301 file names to handle and then later use the handle for
302 different file system operations. This is useful in implementing
303 userspace file servers, which now track files using handles instead
304 of names. The handle would remain the same even if file names
305 get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
306 syscalls.
307
Shailabh Nagarc7572492006-07-14 00:24:40 -0700308config TASKSTATS
309 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
310 depends on NET
311 default n
312 help
313 Export selected statistics for tasks/processes through the
314 generic netlink interface. Unlike BSD process accounting, the
315 statistics are available during the lifetime of tasks/processes as
316 responses to commands. Like BSD accounting, they are sent to user
317 space on task exit.
318
319 Say N if unsure.
320
Shailabh Nagarca74e922006-07-14 00:24:36 -0700321config TASK_DELAY_ACCT
322 bool "Enable per-task delay accounting (EXPERIMENTAL)"
Shailabh Nagar6f449932006-07-14 00:24:41 -0700323 depends on TASKSTATS
Shailabh Nagarca74e922006-07-14 00:24:36 -0700324 help
325 Collect information on time spent by a task waiting for system
326 resources like cpu, synchronous block I/O completion and swapping
327 in pages. Such statistics can help in setting a task's priorities
328 relative to other tasks for cpu, io, rss limits etc.
329
330 Say N if unsure.
331
Alexey Dobriyan18f705f2007-02-10 01:46:44 -0800332config TASK_XACCT
333 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
334 depends on TASKSTATS
335 help
336 Collect extended task accounting data and send the data
337 to userland for processing over the taskstats interface.
338
339 Say N if unsure.
340
341config TASK_IO_ACCOUNTING
342 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
343 depends on TASK_XACCT
344 help
345 Collect information on the number of bytes of storage I/O which this
346 task has caused.
347
348 Say N if unsure.
349
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350config AUDIT
351 bool "Auditing support"
Chris Wright804a6a492005-05-11 10:52:45 +0100352 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 help
354 Enable auditing infrastructure that can be used with another
355 kernel subsystem, such as SELinux (which requires this for
356 logging of avc messages output). Does not do system-call
357 auditing without CONFIG_AUDITSYSCALL.
358
359config AUDITSYSCALL
360 bool "Enable system-call auditing support"
Nathaniel Husted29ef73b2012-01-03 14:23:09 -0500361 depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH || ARM)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362 default y if SECURITY_SELINUX
363 help
364 Enable low-overhead system-call auditing infrastructure that
365 can be used independently or with another kernel subsystem,
Eric Paris67640b62009-12-17 20:12:06 -0500366 such as SELinux.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367
Eric Paris939a67f2009-12-17 20:12:06 -0500368config AUDIT_WATCH
369 def_bool y
370 depends on AUDITSYSCALL
371 select FSNOTIFY
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372
Al Viro74c3cbe2007-07-22 08:04:18 -0400373config AUDIT_TREE
374 def_bool y
Eric Paris63c882a2009-05-21 17:02:01 -0400375 depends on AUDITSYSCALL
Eric Paris28a3a7e2009-12-17 20:12:05 -0500376 select FSNOTIFY
Al Viro74c3cbe2007-07-22 08:04:18 -0400377
Eric Paris633b4542012-01-03 14:23:08 -0500378config AUDIT_LOGINUID_IMMUTABLE
379 bool "Make audit loginuid immutable"
380 depends on AUDIT
381 help
Linus Torvaldsf429ee32012-01-17 16:06:51 -0800382 The config option toggles if a task setting its loginuid requires
Eric Paris633b4542012-01-03 14:23:08 -0500383 CAP_SYS_AUDITCONTROL or if that task should require no special permissions
384 but should instead only allow setting its loginuid if it was never
385 previously set. On systems which use systemd or a similar central
386 process to restart login services this should be set to true. On older
387 systems in which an admin would typically have to directly stop and
388 start processes this should be set to false. Setting this to true allows
389 one to drop potentially dangerous capabilites from the login tasks,
390 but may not be backwards compatible with older init systems.
391
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000392source "kernel/irq/Kconfig"
Thomas Gleixner764e0da2012-05-21 23:16:18 +0200393source "kernel/time/Kconfig"
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000394
Mike Travisc903ff82009-01-15 12:28:29 -0800395menu "RCU Subsystem"
396
397choice
398 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700399 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800400
Mike Travisc903ff82009-01-15 12:28:29 -0800401config TREE_RCU
402 bool "Tree-based hierarchical RCU"
Paul E. McKenney687d7a92010-07-21 06:52:40 -0700403 depends on !PREEMPT && SMP
Mike Travisc903ff82009-01-15 12:28:29 -0800404 help
405 This option selects the RCU implementation that is
406 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700407 thousands of CPUs. It also scales down nicely to
408 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800409
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700410config TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700411 bool "Preemptible tree-based hierarchical RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700412 depends on PREEMPT && SMP
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700413 help
414 This option selects the RCU implementation that is
415 designed for very large SMP systems with hundreds or
416 thousands of CPUs, but for which real-time response
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700417 is also required. It also scales down nicely to
418 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700419
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700420config TINY_RCU
421 bool "UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700422 depends on !PREEMPT && !SMP
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700423 help
424 This option selects the RCU implementation that is
425 designed for UP systems from which real-time response
426 is not required. This option greatly reduces the
427 memory footprint of RCU.
428
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700429config TINY_PREEMPT_RCU
430 bool "Preemptible UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700431 depends on PREEMPT && !SMP
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700432 help
433 This option selects the RCU implementation that is designed
434 for real-time UP systems. This option greatly reduces the
435 memory footprint of RCU.
436
Mike Travisc903ff82009-01-15 12:28:29 -0800437endchoice
438
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700439config PREEMPT_RCU
440 def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
441 help
442 This option enables preemptible-RCU code that is common between
443 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
444
Mike Travisc903ff82009-01-15 12:28:29 -0800445config RCU_FANOUT
446 int "Tree-based hierarchical RCU fanout value"
447 range 2 64 if 64BIT
448 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700449 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800450 default 64 if 64BIT
451 default 32 if !64BIT
452 help
453 This option controls the fanout of hierarchical implementations
454 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700455 large numbers of CPUs. This value must be at least the fourth
456 root of NR_CPUS, which allows NR_CPUS to be insanely large.
457 The default value of RCU_FANOUT should be used for production
458 systems, but if you are stress-testing the RCU implementation
459 itself, small RCU_FANOUT values allow you to test large-system
460 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800461
462 Select a specific number if testing RCU itself.
463 Take the default if unsure.
464
Paul E. McKenney8932a632012-04-19 12:20:14 -0700465config RCU_FANOUT_LEAF
466 int "Tree-based hierarchical RCU leaf-level fanout value"
467 range 2 RCU_FANOUT if 64BIT
468 range 2 RCU_FANOUT if !64BIT
469 depends on TREE_RCU || TREE_PREEMPT_RCU
470 default 16
471 help
472 This option controls the leaf-level fanout of hierarchical
473 implementations of RCU, and allows trading off cache misses
474 against lock contention. Systems that synchronize their
475 scheduling-clock interrupts for energy-efficiency reasons will
476 want the default because the smaller leaf-level fanout keeps
477 lock contention levels acceptably low. Very large systems
478 (hundreds or thousands of CPUs) will instead want to set this
479 value to the maximum value possible in order to reduce the
480 number of cache misses incurred during RCU's grace-period
481 initialization. These systems tend to run CPU-bound, and thus
482 are not helped by synchronized interrupts, and thus tend to
483 skew them, which reduces lock contention enough that large
484 leaf-level fanouts work well.
485
486 Select a specific number if testing RCU itself.
487
488 Select the maximum permissible value for large systems.
489
490 Take the default if unsure.
491
Mike Travisc903ff82009-01-15 12:28:29 -0800492config RCU_FANOUT_EXACT
493 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700494 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800495 default n
496 help
497 This option forces use of the exact RCU_FANOUT value specified,
498 regardless of imbalances in the hierarchy. This is useful for
499 testing RCU itself, and might one day be useful on systems with
500 strong NUMA behavior.
501
502 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
503
504 Say N if unsure.
505
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800506config RCU_FAST_NO_HZ
507 bool "Accelerate last non-dyntick-idle CPU's grace periods"
Paul E. McKenneyb807fbf2011-11-03 14:56:12 -0700508 depends on NO_HZ && SMP
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800509 default n
510 help
511 This option causes RCU to attempt to accelerate grace periods
Paul E. McKenneyb807fbf2011-11-03 14:56:12 -0700512 in order to allow CPUs to enter dynticks-idle state more
513 quickly. On the other hand, this option increases the overhead
514 of the dynticks-idle checking, particularly on systems with
515 large numbers of CPUs.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800516
517 Say Y if energy efficiency is critically important, particularly
518 if you have relatively few CPUs.
519
520 Say N if you are unsure.
521
Mike Travisc903ff82009-01-15 12:28:29 -0800522config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700523 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800524 select DEBUG_FS
525 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700526 This option provides tracing for the TREE_RCU and
527 TREE_PREEMPT_RCU implementations, permitting Makefile to
528 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800529
Paul E. McKenney24278d12010-09-27 17:25:23 -0700530config RCU_BOOST
531 bool "Enable RCU priority boosting"
Paul E. McKenney27f4d282011-02-07 12:47:15 -0800532 depends on RT_MUTEXES && PREEMPT_RCU
Paul E. McKenney24278d12010-09-27 17:25:23 -0700533 default n
534 help
535 This option boosts the priority of preempted RCU readers that
536 block the current preemptible RCU grace period for too long.
537 This option also prevents heavy loads from blocking RCU
538 callback invocation for all flavors of RCU.
539
540 Say Y here if you are working with real-time apps or heavy loads
541 Say N here if you are unsure.
542
543config RCU_BOOST_PRIO
544 int "Real-time priority to boost RCU readers to"
545 range 1 99
546 depends on RCU_BOOST
547 default 1
548 help
Paul E. McKenneyc9336642012-04-18 16:20:18 -0700549 This option specifies the real-time priority to which long-term
550 preempted RCU readers are to be boosted. If you are working
551 with a real-time application that has one or more CPU-bound
552 threads running at a real-time priority level, you should set
553 RCU_BOOST_PRIO to a priority higher then the highest-priority
554 real-time CPU-bound thread. The default RCU_BOOST_PRIO value
555 of 1 is appropriate in the common case, which is real-time
556 applications that do not have any CPU-bound threads.
557
558 Some real-time applications might not have a single real-time
559 thread that saturates a given CPU, but instead might have
560 multiple real-time threads that, taken together, fully utilize
561 that CPU. In this case, you should set RCU_BOOST_PRIO to
562 a priority higher than the lowest-priority thread that is
563 conspiring to prevent the CPU from running any non-real-time
564 tasks. For example, if one thread at priority 10 and another
565 thread at priority 5 are between themselves fully consuming
566 the CPU time on a given CPU, then RCU_BOOST_PRIO should be
567 set to priority 6 or higher.
Paul E. McKenney24278d12010-09-27 17:25:23 -0700568
569 Specify the real-time priority, or take the default if unsure.
570
571config RCU_BOOST_DELAY
572 int "Milliseconds to delay boosting after RCU grace-period start"
573 range 0 3000
574 depends on RCU_BOOST
575 default 500
576 help
577 This option specifies the time to wait after the beginning of
578 a given grace period before priority-boosting preempted RCU
579 readers blocking that grace period. Note that any RCU reader
580 blocking an expedited RCU grace period is boosted immediately.
581
582 Accept the default if unsure.
583
Mike Travisc903ff82009-01-15 12:28:29 -0800584endmenu # "RCU Subsystem"
585
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700587 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588 ---help---
589 This option enables the complete Linux kernel ".config" file
590 contents to be saved in the kernel. It provides documentation
591 of which kernel options are used in a running kernel or in an
592 on-disk kernel. This information can be extracted from the kernel
593 image file with the script scripts/extract-ikconfig and used as
594 input to rebuild the current kernel or to build another kernel.
595 It can also be extracted from a running kernel by reading
596 /proc/config.gz if enabled (below).
597
598config IKCONFIG_PROC
599 bool "Enable access to .config through /proc/config.gz"
600 depends on IKCONFIG && PROC_FS
601 ---help---
602 This option enables access to the kernel configuration file
603 through /proc/config.gz.
604
Alistair John Strachan794543a2007-05-08 00:31:15 -0700605config LOG_BUF_SHIFT
606 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
607 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700608 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700609 help
610 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700611 Examples:
612 17 => 128 KB
613 16 => 64 KB
614 15 => 32 KB
615 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700616 13 => 8 KB
617 12 => 4 KB
618
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800619#
620# Architectures with an unreliable sched_clock() should select this:
621#
622config HAVE_UNSTABLE_SCHED_CLOCK
623 bool
624
Li Zefan23964d22009-01-15 13:50:58 -0800625menuconfig CGROUPS
626 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800627 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700628 help
Li Zefan23964d22009-01-15 13:50:58 -0800629 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800630 use with process control subsystems such as Cpusets, CFS, memory
631 controls or device isolation.
632 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800633 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800634 - Documentation/cgroups/ (features for grouping, isolation
635 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700636
637 Say N if unsure.
638
Li Zefan23964d22009-01-15 13:50:58 -0800639if CGROUPS
640
Paul Menage006cb992007-10-18 23:39:43 -0700641config CGROUP_DEBUG
642 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700643 default n
Paul Menage006cb992007-10-18 23:39:43 -0700644 help
645 This option enables a simple cgroup subsystem that
646 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800647 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700648
Li Zefan23964d22009-01-15 13:50:58 -0800649 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700650
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700651config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800652 bool "Freezer cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800653 help
654 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700655 cgroup.
656
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700657config CGROUP_DEVICE
658 bool "Device controller for cgroups"
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700659 help
660 Provides a cgroup implementing whitelists for devices which
661 a process in the cgroup can mknod or open.
662
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663config CPUSETS
664 bool "Cpuset support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700666 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667 allow dynamically partitioning a system into sets of CPUs and
668 Memory Nodes and assigning tasks to run only within those sets.
669 This is primarily useful on large SMP or NUMA systems.
670
671 Say N if unsure.
672
Li Zefan23964d22009-01-15 13:50:58 -0800673config PROC_PID_CPUSET
674 bool "Include legacy /proc/<pid>/cpuset file"
675 depends on CPUSETS
676 default y
677
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100678config CGROUP_CPUACCT
679 bool "Simple CPU accounting cgroup subsystem"
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100680 help
681 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800682 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100683
Pavel Emelianove552b662008-02-07 00:13:49 -0800684config RESOURCE_COUNTERS
685 bool "Resource counters"
686 help
687 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800688 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800689
Balbir Singh00f0b822008-03-04 14:28:39 -0800690config CGROUP_MEM_RES_CTLR
691 bool "Memory Resource Controller for Control Groups"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700692 depends on RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700693 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800694 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700695 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100696 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800697
698 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700699 associated with each page of memory in the system. By this,
700 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
701 usage tracking struct at boot. Total amount of this is printed out
702 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800703
704 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700705 sure you need the memory resource controller. Even when you enable
706 this, you can set "cgroup_disable=memory" at your boot option to
707 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800708 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800709
Balbir Singhcf475ad2008-04-29 01:00:16 -0700710 This config option also selects MM_OWNER config option, which
711 could in turn add some fork/exit overhead.
712
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800713config CGROUP_MEM_RES_CTLR_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700714 bool "Memory Resource Controller Swap Extension"
715 depends on CGROUP_MEM_RES_CTLR && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800716 help
717 Add swap management feature to memory resource controller. When you
718 enable this, you can limit mem+swap usage per cgroup. In other words,
719 when you disable this, memory resource controller has no cares to
720 usage of swap...a process can exhaust all of the swap. This extension
721 is useful when you want to avoid exhaustion swap but this itself
722 adds more overheads and consumes memory for remembering information.
723 Especially if you use 32bit system or small memory system, please
724 be careful about enabling this. When memory resource controller
725 is disabled by boot option, this will be automatically disabled and
726 there will be no overhead from this. Even when you set this config=y,
WANG Cong00a66d22011-07-25 17:12:12 -0700727 if boot option "swapaccount=0" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700728 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
729 size is 4096bytes, 512k per 1Gbytes of swap.
Michal Hockoa42c3902010-11-24 12:57:08 -0800730config CGROUP_MEM_RES_CTLR_SWAP_ENABLED
731 bool "Memory Resource Controller Swap Extension enabled by default"
732 depends on CGROUP_MEM_RES_CTLR_SWAP
733 default y
734 help
735 Memory Resource Controller Swap Extension comes with its price in
736 a bigger memory consumption. General purpose distribution kernels
Jim Cromie43d547f2010-12-17 14:32:36 -0700737 which want to enable the feature but keep it disabled by default
Michal Hockoa42c3902010-11-24 12:57:08 -0800738 and let the user enable it by swapaccount boot command line
739 parameter should have this option unselected.
740 For those who want to have the feature enabled by default should
741 select this option (if, for some reason, they need to disable it
WANG Cong00a66d22011-07-25 17:12:12 -0700742 then swapaccount=0 does the trick).
Glauber Costae5671df2011-12-11 21:47:01 +0000743config CGROUP_MEM_RES_CTLR_KMEM
744 bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
745 depends on CGROUP_MEM_RES_CTLR && EXPERIMENTAL
746 default n
747 help
748 The Kernel Memory extension for Memory Resource Controller can limit
749 the amount of memory used by kernel objects in the system. Those are
750 fundamentally different from the entities handled by the standard
751 Memory Controller, which are page-based, and can be swapped. Users of
752 the kmem extension can use it to guarantee that no group of processes
753 will ever exhaust kernel resources alone.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800754
Stephane Eraniane5d13672011-02-14 11:20:01 +0200755config CGROUP_PERF
756 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
757 depends on PERF_EVENTS && CGROUPS
758 help
759 This option extends the per-cpu mode to restrict monitoring to
Li Zefan2d0f2522011-03-03 14:26:20 +0800760 threads which belong to the cgroup specified and run on the
Stephane Eraniane5d13672011-02-14 11:20:01 +0200761 designated cpu.
762
763 Say N if unsure.
764
Dhaval Giani7c941432010-01-20 13:26:18 +0100765menuconfig CGROUP_SCHED
766 bool "Group CPU scheduler"
Dhaval Giani7c941432010-01-20 13:26:18 +0100767 default n
768 help
769 This feature lets CPU scheduler recognize task groups and control CPU
770 bandwidth allocation to such task groups. It uses cgroups to group
771 tasks.
772
773if CGROUP_SCHED
774config FAIR_GROUP_SCHED
775 bool "Group scheduling for SCHED_OTHER"
776 depends on CGROUP_SCHED
777 default CGROUP_SCHED
778
Paul Turnerab84d312011-07-21 09:43:28 -0700779config CFS_BANDWIDTH
780 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
781 depends on EXPERIMENTAL
782 depends on FAIR_GROUP_SCHED
783 default n
784 help
785 This option allows users to define CPU bandwidth rates (limits) for
786 tasks running within the fair group scheduler. Groups with no limit
787 set are considered to be unconstrained and will run with no
788 restriction.
789 See tip/Documentation/scheduler/sched-bwc.txt for more information.
790
Dhaval Giani7c941432010-01-20 13:26:18 +0100791config RT_GROUP_SCHED
792 bool "Group scheduling for SCHED_RR/FIFO"
793 depends on EXPERIMENTAL
794 depends on CGROUP_SCHED
795 default n
796 help
797 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +0800798 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +0100799 schedule realtime tasks for non-root users until you allocate
800 realtime bandwidth for them.
801 See Documentation/scheduler/sched-rt-group.txt for more information.
802
803endif #CGROUP_SCHED
804
Vivek Goyalafc24d42010-04-26 19:27:56 +0200805config BLK_CGROUP
Tejun Heo32e380a2012-03-05 13:14:54 -0800806 bool "Block IO controller"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700807 depends on BLOCK
Vivek Goyalafc24d42010-04-26 19:27:56 +0200808 default n
809 ---help---
810 Generic block IO controller cgroup interface. This is the common
811 cgroup interface which should be used by various IO controlling
812 policies.
813
814 Currently, CFQ IO scheduler uses it to recognize task groups and
815 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -0400816 to such task groups. It is also used by bio throttling logic in
817 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200818
819 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -0400820 One needs to also enable actual IO controlling logic/policy. For
Michael Witten79e2e752011-01-16 21:43:10 +0000821 enabling proportional weight division of disk bandwidth in CFQ, set
822 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
Michael Wittenc5e05912011-01-17 00:08:41 +0000823 CONFIG_BLK_DEV_THROTTLING=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200824
825 See Documentation/cgroups/blkio-controller.txt for more information.
826
827config DEBUG_BLK_CGROUP
828 bool "Enable Block IO controller debugging"
829 depends on BLK_CGROUP
830 default n
831 ---help---
832 Enable some debugging help. Currently it exports additional stat
833 files in a cgroup which can be useful for debugging.
834
Li Zefan23964d22009-01-15 13:50:58 -0800835endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800836
Cyrill Gorcunov067bce12012-01-12 17:20:49 -0800837config CHECKPOINT_RESTORE
838 bool "Checkpoint/restore support" if EXPERT
839 default n
840 help
841 Enables additional kernel features in a sake of checkpoint/restore.
842 In particular it adds auxiliary prctl codes to setup process text,
843 data and heap segment sizes, and a few additional /proc filesystem
844 entries.
845
846 If unsure, say N here.
847
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700848menuconfig NAMESPACES
David Rientjes6a108a12011-01-20 14:44:16 -0800849 bool "Namespaces support" if EXPERT
850 default !EXPERT
Pavel Emelyanovc5289a62008-02-08 04:18:19 -0800851 help
852 Provides the way to make tasks work with different objects using
853 the same id. For example same IPC id may refer to different objects
854 or same user id or pid may refer to different tasks when used in
855 different namespaces.
856
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700857if NAMESPACES
858
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800859config UTS_NS
860 bool "UTS namespace"
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700861 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800862 help
863 In this namespace tasks see different info provided with the
864 uname() system call
865
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800866config IPC_NS
867 bool "IPC namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700868 depends on (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700869 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800870 help
871 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700872 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800873
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800874config USER_NS
875 bool "User namespace (EXPERIMENTAL)"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700876 depends on EXPERIMENTAL
Eric W. Biedermane1c972b2012-04-21 04:09:01 -0700877 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -0800878 select UIDGID_STRICT_TYPE_CHECKS
Eric W. Biedermane1c972b2012-04-21 04:09:01 -0700879
Eric W. Biederman5673a942011-11-17 10:23:55 -0800880 default n
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800881 help
882 This allows containers, i.e. vservers, to use user namespaces
883 to provide different user info for different servers.
884 If unsure, say N.
885
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800886config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -0700887 bool "PID Namespaces"
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700888 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800889 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +0300890 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +0100891 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800892 pid namespaces. This is a building block of containers.
893
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800894config NET_NS
895 bool "Network namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700896 depends on NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700897 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800898 help
899 Allow user space to create what appear to be multiple instances
900 of the network stack.
901
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700902endif # NAMESPACES
903
Eric W. Biedermane1c972b2012-04-21 04:09:01 -0700904config UIDGID_CONVERTED
905 # True if all of the selected software conmponents are known
906 # to have uid_t and gid_t converted to kuid_t and kgid_t
907 # where appropriate and are otherwise safe to use with
908 # the user namespace.
909 bool
910 default y
911
912 # List of kernel pieces that need user namespace work
913 # Features
Eric W. Biedermane1c972b2012-04-21 04:09:01 -0700914 depends on SYSVIPC = n
915 depends on IMA = n
916 depends on EVM = n
917 depends on KEYS = n
918 depends on AUDIT = n
919 depends on AUDITSYSCALL = n
920 depends on TASKSTATS = n
921 depends on TRACING = n
922 depends on FS_POSIX_ACL = n
923 depends on QUOTA = n
924 depends on QUOTACTL = n
925 depends on DEBUG_CREDENTIALS = n
926 depends on BSD_PROCESS_ACCT = n
927 depends on DRM = n
928 depends on PROC_EVENTS = n
929
930 # Networking
931 depends on NET = n
932 depends on NET_9P = n
933 depends on IPX = n
934 depends on PHONET = n
935 depends on NET_CLS_FLOW = n
936 depends on NETFILTER_XT_MATCH_OWNER = n
937 depends on NETFILTER_XT_MATCH_RECENT = n
938 depends on NETFILTER_XT_TARGET_LOG = n
939 depends on NETFILTER_NETLINK_LOG = n
940 depends on INET = n
941 depends on IPV6 = n
942 depends on IP_SCTP = n
943 depends on AF_RXRPC = n
944 depends on LLC2 = n
945 depends on NET_KEY = n
946 depends on INET_DIAG = n
947 depends on DNS_RESOLVER = n
948 depends on AX25 = n
949 depends on ATALK = n
950
951 # Filesystems
952 depends on USB_DEVICEFS = n
953 depends on USB_GADGETFS = n
954 depends on USB_FUNCTIONFS = n
955 depends on DEVTMPFS = n
956 depends on XENFS = n
957
958 depends on 9P_FS = n
959 depends on ADFS_FS = n
960 depends on AFFS_FS = n
961 depends on AFS_FS = n
962 depends on AUTOFS4_FS = n
963 depends on BEFS_FS = n
964 depends on BFS_FS = n
965 depends on BTRFS_FS = n
966 depends on CEPH_FS = n
967 depends on CIFS = n
968 depends on CODA_FS = n
969 depends on CONFIGFS_FS = n
970 depends on CRAMFS = n
971 depends on DEBUG_FS = n
972 depends on ECRYPT_FS = n
973 depends on EFS_FS = n
974 depends on EXOFS_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -0700975 depends on FAT_FS = n
976 depends on FUSE_FS = n
977 depends on GFS2_FS = n
978 depends on HFS_FS = n
979 depends on HFSPLUS_FS = n
980 depends on HPFS_FS = n
981 depends on HUGETLBFS = n
982 depends on ISO9660_FS = n
983 depends on JFFS2_FS = n
984 depends on JFS_FS = n
985 depends on LOGFS = n
986 depends on MINIX_FS = n
987 depends on NCP_FS = n
988 depends on NFSD = n
989 depends on NFS_FS = n
990 depends on NILFS2_FS = n
991 depends on NTFS_FS = n
992 depends on OCFS2_FS = n
993 depends on OMFS_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -0700994 depends on QNX4FS_FS = n
995 depends on QNX6FS_FS = n
996 depends on REISERFS_FS = n
997 depends on SQUASHFS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -0700998 depends on SYSV_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -0700999 depends on UBIFS_FS = n
1000 depends on UDF_FS = n
1001 depends on UFS_FS = n
1002 depends on VXFS_FS = n
1003 depends on XFS_FS = n
1004
1005 depends on !UML || HOSTFS = n
1006
1007 # The rare drivers that won't build
1008 depends on AIRO = n
1009 depends on AIRO_CS = n
1010 depends on TUN = n
1011 depends on INFINIBAND_QIB = n
1012 depends on BLK_DEV_LOOP = n
1013 depends on ANDROID_BINDER_IPC = n
1014
1015 # Security modules
1016 depends on SECURITY_TOMOYO = n
1017 depends on SECURITY_APPARMOR = n
1018
Eric W. Biederman5673a942011-11-17 10:23:55 -08001019config UIDGID_STRICT_TYPE_CHECKS
1020 bool "Require conversions between uid/gids and their internal representation"
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001021 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -08001022 default n
1023 help
1024 While the nececessary conversions are being added to all subsystems this option allows
1025 the code to continue to build for unconverted subsystems.
1026
1027 Say Y here if you want the strict type checking enabled
1028
Mike Galbraith5091faa2010-11-30 14:18:03 +01001029config SCHED_AUTOGROUP
1030 bool "Automatic process group scheduling"
1031 select EVENTFD
1032 select CGROUPS
1033 select CGROUP_SCHED
1034 select FAIR_GROUP_SCHED
1035 help
1036 This option optimizes the scheduler for common desktop workloads by
1037 automatically creating and populating task groups. This separation
1038 of workloads isolates aggressive CPU burners (like build jobs) from
1039 desktop applications. Task group autogeneration is currently based
1040 upon task session.
1041
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001042config MM_OWNER
1043 bool
1044
1045config SYSFS_DEPRECATED
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001046 bool "Enable deprecated sysfs features to support old userspace tools"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001047 depends on SYSFS
1048 default n
1049 help
1050 This option adds code that switches the layout of the "block" class
1051 devices, to not show up in /sys/class/block/, but only in
1052 /sys/block/.
1053
1054 This switch is only active when the sysfs.deprecated=1 boot option is
1055 passed or the SYSFS_DEPRECATED_V2 option is set.
1056
1057 This option allows new kernels to run on old distributions and tools,
1058 which might get confused by /sys/class/block/. Since 2007/2008 all
1059 major distributions and tools handle this just fine.
1060
1061 Recent distributions and userspace tools after 2009/2010 depend on
1062 the existence of /sys/class/block/, and will not work with this
1063 option enabled.
1064
1065 Only if you are using a new kernel on an old distribution, you might
1066 need to say Y here.
1067
1068config SYSFS_DEPRECATED_V2
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001069 bool "Enable deprecated sysfs features by default"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001070 default n
1071 depends on SYSFS
1072 depends on SYSFS_DEPRECATED
1073 help
1074 Enable deprecated sysfs by default.
1075
1076 See the CONFIG_SYSFS_DEPRECATED option for more details about this
1077 option.
1078
1079 Only if you are using a new kernel on an old distribution, you might
1080 need to say Y here. Even then, odds are you would not need it
1081 enabled, you can always pass the boot option if absolutely necessary.
1082
1083config RELAY
1084 bool "Kernel->user space relay support (formerly relayfs)"
1085 help
1086 This option enables support for relay interface support in
1087 certain file systems (such as debugfs).
1088 It is designed to provide an efficient mechanism for tools and
1089 facilities to relay large amounts of data from kernel space to
1090 user space.
1091
1092 If unsure, say N.
1093
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -08001094config BLK_DEV_INITRD
1095 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1096 depends on BROKEN || !FRV
1097 help
1098 The initial RAM filesystem is a ramfs which is loaded by the
1099 boot loader (loadlin or lilo) and that is mounted as root
1100 before the normal boot procedure. It is typically used to
1101 load modules needed to mount the "real" root file system,
1102 etc. See <file:Documentation/initrd.txt> for details.
1103
1104 If RAM disk support (BLK_DEV_RAM) is also included, this
1105 also enables initial RAM disk (initrd) support and adds
1106 15 Kbytes (more on some other architectures) to the kernel size.
1107
1108 If unsure say Y.
1109
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001110if BLK_DEV_INITRD
1111
Sam Ravnborgdbec4862005-08-10 20:44:50 +02001112source "usr/Kconfig"
1113
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001114endif
1115
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001116config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +02001117 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001118 help
1119 Enabling this option will pass "-Os" instead of "-O2" to gcc
1120 resulting in a smaller kernel.
1121
jkacur775a7222008-07-16 00:31:16 +02001122 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001123
Randy Dunlap08470622006-09-30 23:28:13 -07001124config SYSCTL
1125 bool
1126
Randy Dunlapb943c462009-03-10 12:55:46 -07001127config ANON_INODES
1128 bool
1129
David Rientjes6a108a12011-01-20 14:44:16 -08001130menuconfig EXPERT
1131 bool "Configure standard kernel features (expert users)"
Josh Triplettf505c552011-06-05 18:23:58 -07001132 # Unhide debug options, to make the on-by-default options visible
1133 select DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -07001134 help
1135 This option allows certain base kernel options and settings
1136 to be disabled or tweaked. This is for specialized
1137 environments which can tolerate a "non-standard" kernel.
1138 Only use this if you really know what you are doing.
1139
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001140config UID16
David Rientjes6a108a12011-01-20 14:44:16 -08001141 bool "Enable 16-bit UID system calls" if EXPERT
David S. Miller09337f52008-04-26 03:17:12 -07001142 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 -07001143 default y
1144 help
1145 This enables the legacy 16-bit UID syscall wrappers.
1146
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001147config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -08001148 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -08001149 depends on PROC_SYSCTL
WANG Congc736de62011-11-02 13:39:25 -07001150 default n
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001151 select SYSCTL
1152 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001153 sys_sysctl uses binary paths that have been found challenging
1154 to properly maintain and use. The interface in /proc/sys
1155 using paths with ascii names is now the primary path to this
1156 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001157
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001158 Almost nothing using the binary sysctl interface so if you are
1159 trying to save some space it is probably safe to disable this,
1160 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001161
WANG Congc736de62011-11-02 13:39:25 -07001162 If unsure say N here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001163
Linus Torvalds1da177e2005-04-16 15:20:36 -07001164config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -08001165 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001166 default y
1167 help
1168 Say Y here to let the kernel print out symbolic crash information and
1169 symbolic stack backtraces. This increases the size of the kernel
1170 somewhat, as all symbols have to be loaded into the kernel image.
1171
1172config KALLSYMS_ALL
1173 bool "Include all symbols in kallsyms"
1174 depends on DEBUG_KERNEL && KALLSYMS
1175 help
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001176 Normally kallsyms only contains the symbols of functions for nicer
1177 OOPS messages and backtraces (i.e., symbols from the text and inittext
1178 sections). This is sufficient for most cases. And only in very rare
1179 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1180 names of variables from the data sections, etc).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001181
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001182 This option makes sure that all symbols are loaded into the kernel
1183 image (i.e., symbols from all sections) in cost of increased kernel
1184 size (depending on the kernel configuration, it may be 300KiB or
1185 something like this).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001186
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001187 Say N unless you really need all symbols.
Matt Mackalld59745c2005-05-01 08:59:02 -07001188
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001189config HOTPLUG
David Rientjes6a108a12011-01-20 14:44:16 -08001190 bool "Support for hot-pluggable devices" if EXPERT
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001191 default y
1192 help
1193 This option is provided for the case where no hotplug or uevent
1194 capabilities is wanted by the kernel. You should only consider
1195 disabling this option for embedded systems that do not use modules, a
1196 dynamic /dev tree, or dynamic device discovery. Just say Y.
1197
Matt Mackalld59745c2005-05-01 08:59:02 -07001198config PRINTK
1199 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001200 bool "Enable support for printk" if EXPERT
Matt Mackalld59745c2005-05-01 08:59:02 -07001201 help
1202 This option enables normal printk support. Removing it
1203 eliminates most of the message strings from the kernel image
1204 and makes the kernel more or less silent. As this makes it
1205 very difficult to diagnose system problems, saying N here is
1206 strongly discouraged.
1207
Matt Mackallc8538a72005-05-01 08:59:01 -07001208config BUG
David Rientjes6a108a12011-01-20 14:44:16 -08001209 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -07001210 default y
1211 help
1212 Disabling this option eliminates support for BUG and WARN, reducing
1213 the size of your kernel image and potentially quietly ignoring
1214 numerous fatal conditions. You should only consider disabling this
1215 option for embedded systems with no facilities for reporting errors.
1216 Just say Y.
1217
Matt Mackall708e9a72006-01-08 01:05:25 -08001218config ELF_CORE
1219 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001220 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001221 help
1222 Enable support for generating core dumps. Disabling saves about 4k.
1223
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001224
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001225config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001226 bool "Enable PC-Speaker support" if EXPERT
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001227 depends on HAVE_PCSPKR_PLATFORM
Ralf Baechle15f304b2011-06-01 19:04:59 +01001228 select I8253_LOCK
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001229 default y
1230 help
1231 This option allows to disable the internal PC-Speaker
1232 support, saving some memory.
1233
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001234config HAVE_PCSPKR_PLATFORM
1235 bool
1236
Linus Torvalds1da177e2005-04-16 15:20:36 -07001237config BASE_FULL
1238 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001239 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001240 help
1241 Disabling this option reduces the size of miscellaneous core
1242 kernel data structures. This saves memory on small machines,
1243 but may reduce performance.
1244
1245config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001246 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001247 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001248 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001249 help
1250 Disabling this option will cause the kernel to be built without
1251 support for "fast userspace mutexes". The resulting kernel may not
1252 run glibc-based applications correctly.
1253
1254config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001255 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001256 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001257 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001258 help
1259 Disabling this option will cause the kernel to be built without
1260 support for epoll family of system calls.
1261
Davide Libenzifba2afa2007-05-10 22:23:13 -07001262config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001263 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001264 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001265 default y
1266 help
1267 Enable the signalfd() system call that allows to receive signals
1268 on a file descriptor.
1269
1270 If unsure, say Y.
1271
Davide Libenzib215e282007-05-10 22:23:16 -07001272config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001273 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001274 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001275 default y
1276 help
1277 Enable the timerfd() system call that allows to receive timer
1278 events on a file descriptor.
1279
1280 If unsure, say Y.
1281
Davide Libenzie1ad7462007-05-10 22:23:19 -07001282config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001283 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001284 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001285 default y
1286 help
1287 Enable the eventfd() system call that allows to receive both
1288 kernel notification (ie. KAIO) or userspace notifications.
1289
1290 If unsure, say Y.
1291
Linus Torvalds1da177e2005-04-16 15:20:36 -07001292config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001293 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001294 default y
1295 depends on MMU
1296 help
1297 The shmem is an internal filesystem used to manage shared memory.
1298 It is backed by swap and manages resource limits. It is also exported
1299 to userspace as tmpfs if TMPFS is enabled. Disabling this
1300 option replaces shmem and tmpfs with the much simpler ramfs code,
1301 which may be appropriate on small systems without swap.
1302
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001303config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001304 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001305 default y
1306 help
1307 This option enables POSIX asynchronous I/O which may by used
1308 by some high performance threaded applications. Disabling
1309 this option saves about 7k.
1310
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001311config EMBEDDED
1312 bool "Embedded system"
1313 select EXPERT
1314 help
1315 This option should be enabled if compiling the kernel for
1316 an embedded system so certain expert options are available
1317 for configuration.
1318
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001319config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001320 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001321 help
1322 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001323
Peter Zijlstra906010b2009-09-21 16:08:49 +02001324config PERF_USE_VMALLOC
1325 bool
1326 help
1327 See tools/perf/design.txt for details
1328
Ingo Molnar57c0c152009-09-21 12:20:38 +02001329menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001330
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001331config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001332 bool "Kernel performance events and counters"
Robert Richter392d65a2012-04-05 18:24:44 +02001333 default y if PROFILING
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001334 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001335 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001336 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001337 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001338 Enable kernel support for various performance events provided
1339 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001340
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001341 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001342 use of generic tracepoints.
1343
1344 Most modern CPUs support performance events via performance
1345 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001346 types of hw events: such as instructions executed, cachemisses
1347 suffered, or branches mis-predicted - without slowing down the
1348 kernel or applications. These registers can also trigger interrupts
1349 when a threshold number of events have passed - and can thus be
1350 used to profile the code that runs on that CPU.
1351
Ingo Molnar57c0c152009-09-21 12:20:38 +02001352 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001353 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001354 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001355 provides per task and per CPU counters, and it provides event
1356 capabilities on top of those.
1357
1358 Say Y if unsure.
1359
Peter Zijlstra906010b2009-09-21 16:08:49 +02001360config DEBUG_PERF_USE_VMALLOC
1361 default n
1362 bool "Debug: use vmalloc to back perf mmap() buffers"
1363 depends on PERF_EVENTS && DEBUG_KERNEL
1364 select PERF_USE_VMALLOC
1365 help
1366 Use vmalloc memory to back perf mmap() buffers.
1367
1368 Mostly useful for debugging the vmalloc code on platforms
1369 that don't require it.
1370
1371 Say N if unsure.
1372
Thomas Gleixner0793a612008-12-04 20:12:29 +01001373endmenu
1374
Christoph Lameterf8891e52006-06-30 01:55:45 -07001375config VM_EVENT_COUNTERS
1376 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001377 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001378 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001379 VM event counters are needed for event counts to be shown.
1380 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001381 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001382 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001383
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001384config PCI_QUIRKS
1385 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001386 bool "Enable PCI quirk workarounds" if EXPERT
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001387 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001388 help
1389 This enables workarounds for various PCI chipset
1390 bugs/quirks. Disable this only if your target machine is
1391 unaffected by PCI quirks.
1392
Christoph Lameter41ecc552007-05-09 02:32:44 -07001393config SLUB_DEBUG
1394 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001395 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001396 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001397 help
1398 SLUB has extensive debug support features. Disabling these can
1399 result in significant savings in code size. This also disables
1400 SLUB sysfs support. /sys/slab will not exist and there will be
1401 no support for cache validation etc.
1402
Randy Dunlapb943c462009-03-10 12:55:46 -07001403config COMPAT_BRK
1404 bool "Disable heap randomization"
1405 default y
1406 help
1407 Randomizing heap placement makes heap exploits harder, but it
1408 also breaks ancient binaries (including anything libc5 based).
1409 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001410 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001411 /proc/sys/kernel/randomize_va_space to 2.
1412
1413 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1414
Christoph Lameter81819f02007-05-06 14:49:36 -07001415choice
1416 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001417 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001418 help
1419 This option allows to select a slab allocator.
1420
1421config SLAB
1422 bool "SLAB"
1423 help
1424 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001425 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001426 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001427
1428config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001429 bool "SLUB (Unqueued Allocator)"
1430 help
1431 SLUB is a slab allocator that minimizes cache line usage
1432 instead of managing queues of cached objects (SLAB approach).
1433 Per cpu caching is realized using slabs of objects instead
1434 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001435 and has enhanced diagnostics. SLUB is the default choice for
1436 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001437
1438config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001439 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001440 bool "SLOB (Simple Allocator)"
1441 help
Matt Mackall37291452008-02-04 22:29:38 -08001442 SLOB replaces the stock allocator with a drastically simpler
1443 allocator. SLOB is generally more space efficient but
1444 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001445
1446endchoice
1447
Jie Zhangea637632009-12-14 18:00:02 -08001448config MMAP_ALLOW_UNINITIALIZED
1449 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001450 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001451 default n
1452 help
1453 Normally, and according to the Linux spec, anonymous memory obtained
1454 from mmap() has it's contents cleared before it is passed to
1455 userspace. Enabling this config option allows you to request that
1456 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1457 providing a huge performance boost. If this option is not enabled,
1458 then the flag will be ignored.
1459
1460 This is taken advantage of by uClibc's malloc(), and also by
1461 ELF-FDPIC binfmt's brk and stack allocator.
1462
1463 Because of the obvious security issues, this option should only be
1464 enabled on embedded devices where you control what is run in
1465 userspace. Since that isn't generally a problem on no-MMU systems,
1466 it is normally safe to say Y here.
1467
1468 See Documentation/nommu-mmap.txt for more information.
1469
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001470config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001471 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001472 help
1473 Say Y here to enable the extended profiling support mechanisms used
1474 by profilers such as OProfile.
1475
Ingo Molnar5f87f112008-07-23 14:15:22 +02001476#
1477# Place an empty function call at each tracepoint site. Can be
1478# dynamically changed for a probe function.
1479#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001480config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001481 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001482
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001483source "arch/Kconfig"
1484
Linus Torvalds1da177e2005-04-16 15:20:36 -07001485endmenu # General setup
1486
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001487config HAVE_GENERIC_DMA_COHERENT
1488 bool
1489 default n
1490
Linus Torvalds158a9622008-01-02 13:04:48 -08001491config SLABINFO
1492 bool
1493 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001494 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001495 default y
1496
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001497config RT_MUTEXES
1498 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001499
Linus Torvalds1da177e2005-04-16 15:20:36 -07001500config BASE_SMALL
1501 int
1502 default 0 if BASE_FULL
1503 default 1 if !BASE_FULL
1504
Jan Engelhardt66da5732007-07-15 23:39:29 -07001505menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001506 bool "Enable loadable module support"
1507 help
1508 Kernel modules are small pieces of compiled code which can
1509 be inserted in the running kernel, rather than being
1510 permanently built into the kernel. You use the "modprobe"
1511 tool to add (and sometimes remove) them. If you say Y here,
1512 many parts of the kernel can be built as modules (by
1513 answering M instead of Y where indicated): this is most
1514 useful for infrequently used options which are not required
1515 for booting. For more information, see the man pages for
1516 modprobe, lsmod, modinfo, insmod and rmmod.
1517
1518 If you say Y here, you will need to run "make
1519 modules_install" to put the modules under /lib/modules/
1520 where modprobe can find them (you may need to be root to do
1521 this).
1522
1523 If unsure, say Y.
1524
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001525if MODULES
1526
Linus Torvalds826e4502008-05-04 17:04:16 -07001527config MODULE_FORCE_LOAD
1528 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001529 default n
1530 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001531 Allow loading of modules without version information (ie. modprobe
1532 --force). Forced module loading sets the 'F' (forced) taint flag and
1533 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001534
Linus Torvalds1da177e2005-04-16 15:20:36 -07001535config MODULE_UNLOAD
1536 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001537 help
1538 Without this option you will not be able to unload any
1539 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001540 anyway), which makes your kernel smaller, faster
1541 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001542
1543config MODULE_FORCE_UNLOAD
1544 bool "Forced module unloading"
1545 depends on MODULE_UNLOAD && EXPERIMENTAL
1546 help
1547 This option allows you to force a module to unload, even if the
1548 kernel believes it is unsafe: the kernel will remove the module
1549 without waiting for anyone to stop using it (using the -f option to
1550 rmmod). This is mainly for kernel developers and desperate users.
1551 If unsure, say N.
1552
Linus Torvalds1da177e2005-04-16 15:20:36 -07001553config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001554 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001555 help
1556 Usually, you have to use modules compiled with your kernel.
1557 Saying Y here makes it sometimes possible to use modules
1558 compiled for different kernels, by adding enough information
1559 to the modules to (hopefully) spot any changes which would
1560 make them incompatible with the kernel you are running. If
1561 unsure, say N.
1562
1563config MODULE_SRCVERSION_ALL
1564 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001565 help
1566 Modules which contain a MODULE_VERSION get an extra "srcversion"
1567 field inserted into their modinfo section, which contains a
1568 sum of the source files which made it. This helps maintainers
1569 see exactly which source was used to build a module (since
1570 others sometimes change the module source without updating
1571 the version). With this option, such a "srcversion" field
1572 will be created for all modules. If unsure, say N.
1573
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001574endif # MODULES
1575
Rusty Russell98a79d62008-12-13 21:19:41 +10301576config INIT_ALL_POSSIBLE
1577 bool
1578 help
Rusty Russell5f054e32012-03-29 15:38:31 +10301579 Back when each arch used to define their own cpu_online_mask and
1580 cpu_possible_mask, some of them chose to initialize cpu_possible_mask
Rusty Russell98a79d62008-12-13 21:19:41 +10301581 with all 1s, and others with all 0s. When they were centralised,
1582 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001583 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301584
Linus Torvalds1da177e2005-04-16 15:20:36 -07001585config STOP_MACHINE
1586 bool
1587 default y
1588 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1589 help
1590 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001591
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001592source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001593
1594config PREEMPT_NOTIFIERS
1595 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001596
Steffen Klassert16295be2010-01-06 19:47:10 +11001597config PADATA
1598 depends on SMP
1599 bool
1600
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001601source "kernel/Kconfig.locks"