blob: 35518243c4bdddf0f93ba5ab2aee4505db1f7e0b [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
22 default y
23
Al Boldiff0cfc62007-07-31 00:39:23 -070024menu "General setup"
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
26config EXPERIMENTAL
27 bool "Prompt for development and/or incomplete code/drivers"
28 ---help---
29 Some of the various things that Linux supports (such as network
30 drivers, file systems, network protocols, etc.) can be in a state
31 of development where the functionality, stability, or the level of
32 testing is not yet high enough for general use. This is usually
33 known as the "alpha-test" phase among developers. If a feature is
34 currently in alpha-test, then the developers usually discourage
35 uninformed widespread use of this feature by the general public to
36 avoid "Why doesn't this work?" type mail messages. However, active
37 testing and use of these systems is welcomed. Just be aware that it
38 may not meet the normal level of reliability or it may fail to work
39 in some special cases. Detailed bug reports from people familiar
40 with the kernel internals are usually welcomed by the developers
41 (before submitting bug reports, please read the documents
42 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
43 <file:Documentation/BUG-HUNTING>, and
44 <file:Documentation/oops-tracing.txt> in the kernel source).
45
46 This option will also make obsoleted drivers available. These are
47 drivers that have been replaced by something else, and/or are
48 scheduled to be removed in a future kernel release.
49
50 Unless you intend to help test and develop a feature or driver that
51 falls into this category, or you have a situation that requires
52 using these features, you should probably say N here, which will
53 cause the configurator to present you with fewer choices. If
54 you say Y here, you will be offered the choice of using features or
55 drivers that are currently considered to be in the alpha-test phase.
56
Linus Torvalds1da177e2005-04-16 15:20:36 -070057config BROKEN
58 bool
Linus Torvalds1da177e2005-04-16 15:20:36 -070059
60config BROKEN_ON_SMP
61 bool
62 depends on BROKEN || !SMP
63 default y
64
65config LOCK_KERNEL
66 bool
67 depends on SMP || PREEMPT
68 default y
69
70config INIT_ENV_ARG_LIMIT
71 int
Adrian Bunkdd673bc2006-06-30 01:55:51 -070072 default 32 if !UML
73 default 128 if UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 help
Randy Dunlap34ad92c2005-10-30 15:01:46 -080075 Maximum of each of the number of arguments and environment
76 variables passed to init from the kernel command line.
Linus Torvalds1da177e2005-04-16 15:20:36 -070077
Linus Torvalds1da177e2005-04-16 15:20:36 -070078
Roland McGrath84336462009-12-21 16:24:06 -080079config CROSS_COMPILE
80 string "Cross-compiler tool prefix"
81 help
82 Same as running 'make CROSS_COMPILE=prefix-' but stored for
83 default make runs in this kernel build directory. You don't
84 need to set this unless you want the configured kernel build
85 directory to select the cross-compiler automatically.
86
Linus Torvalds1da177e2005-04-16 15:20:36 -070087config LOCALVERSION
88 string "Local version - append to kernel release"
89 help
90 Append an extra string to the end of your kernel version.
91 This will show up when you type uname, for example.
92 The string you set here will be appended after the contents of
93 any files with a filename matching localversion* in your
94 object and source tree, in that order. Your total string can
95 be a maximum of 64 characters.
96
Ryan Andersonaaebf432005-07-31 04:57:49 -040097config LOCALVERSION_AUTO
98 bool "Automatically append version information to the version string"
99 default y
100 help
101 This will try to automatically determine if the current tree is a
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200102 release tree by looking for git tags that belong to the current
103 top of tree revision.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400104
105 A string of the format -gxxxxxxxx will be added to the localversion
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200106 if a git-based tree is found. The string generated by this will be
Ryan Andersonaaebf432005-07-31 04:57:49 -0400107 appended after any matching localversion* files, and after the value
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200108 set in CONFIG_LOCALVERSION.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400109
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200110 (The actual string used here is the first eight characters produced
111 by running the command:
112
113 $ git rev-parse --verify HEAD
114
115 which is done within the script "scripts/setlocalversion".)
Ryan Andersonaaebf432005-07-31 04:57:49 -0400116
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800117config HAVE_KERNEL_GZIP
118 bool
119
120config HAVE_KERNEL_BZIP2
121 bool
122
123config HAVE_KERNEL_LZMA
124 bool
125
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800126config HAVE_KERNEL_LZO
127 bool
128
Alain Knaff30d65db2009-01-04 22:46:17 +0100129choice
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800130 prompt "Kernel compression mode"
131 default KERNEL_GZIP
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800132 depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_LZO
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800133 help
Alain Knaff30d65db2009-01-04 22:46:17 +0100134 The linux kernel is a kind of self-extracting executable.
135 Several compression algorithms are available, which differ
136 in efficiency, compression and decompression speed.
137 Compression speed is only relevant when building a kernel.
138 Decompression speed is relevant at each boot.
139
140 If you have any problems with bzip2 or lzma compressed
141 kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
142 version of this functionality (bzip2 only), for 2.4, was
143 supplied by Christian Ludwig)
144
145 High compression options are mostly useful for users, who
146 are low on disk space (embedded systems), but for whom ram
147 size matters less.
148
149 If in doubt, select 'gzip'
150
151config KERNEL_GZIP
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800152 bool "Gzip"
153 depends on HAVE_KERNEL_GZIP
154 help
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800155 The old and tried gzip compression. It provides a good balance
156 between compression ratio and decompression speed.
Alain Knaff30d65db2009-01-04 22:46:17 +0100157
158config KERNEL_BZIP2
159 bool "Bzip2"
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800160 depends on HAVE_KERNEL_BZIP2
Alain Knaff30d65db2009-01-04 22:46:17 +0100161 help
162 Its compression ratio and speed is intermediate.
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800163 Decompression speed is slowest among the three. The kernel
164 size is about 10% smaller with bzip2, in comparison to gzip.
165 Bzip2 uses a large amount of memory. For modern kernels you
166 will need at least 8MB RAM or more for booting.
Alain Knaff30d65db2009-01-04 22:46:17 +0100167
168config KERNEL_LZMA
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800169 bool "LZMA"
170 depends on HAVE_KERNEL_LZMA
171 help
172 The most recent compression algorithm.
173 Its ratio is best, decompression speed is between the other
174 two. Compression is slowest. The kernel size is about 33%
175 smaller with LZMA in comparison to gzip.
Alain Knaff30d65db2009-01-04 22:46:17 +0100176
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800177config KERNEL_LZO
178 bool "LZO"
179 depends on HAVE_KERNEL_LZO
180 help
181 Its compression ratio is the poorest among the 4. The kernel
182 size is about about 10% bigger than gzip; however its speed
183 (both compression and decompression) is the fastest.
184
Alain Knaff30d65db2009-01-04 22:46:17 +0100185endchoice
186
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187config SWAP
188 bool "Support for paging of anonymous memory (swap)"
David Howells93614012006-09-30 20:45:40 +0200189 depends on MMU && BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190 default y
191 help
192 This option allows you to choose whether you want to have support
Jesper Juhl92c35042006-01-15 02:40:08 +0100193 for so called swap devices or swap files in your kernel that are
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 used to provide more virtual memory than the actual RAM present
195 in your computer. If unsure say Y.
196
197config SYSVIPC
198 bool "System V IPC"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 ---help---
200 Inter Process Communication is a suite of library functions and
201 system calls which let processes (running programs) synchronize and
202 exchange information. It is generally considered to be a good thing,
203 and some programs won't run unless you say Y here. In particular, if
204 you want to run the DOS emulator dosemu under Linux (read the
205 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
206 you'll need to say Y here.
207
208 You can find documentation about IPC with "info ipc" and also in
209 section 6.4 of the Linux Programmer's Guide, available from
210 <http://www.tldp.org/guides.html>.
211
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800212config SYSVIPC_SYSCTL
213 bool
214 depends on SYSVIPC
215 depends on SYSCTL
216 default y
217
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218config POSIX_MQUEUE
219 bool "POSIX Message Queues"
220 depends on NET && EXPERIMENTAL
221 ---help---
222 POSIX variant of message queues is a part of IPC. In POSIX message
223 queues every message has a priority which decides about succession
224 of receiving it by a process. If you want to compile and run
225 programs written e.g. for Solaris with use of its POSIX message
Robert P. J. Dayb0e37652007-05-09 07:25:13 +0200226 queues (functions mq_*) say Y here.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227
228 POSIX message queues are visible as a filesystem called 'mqueue'
229 and can be mounted somewhere if you want to do filesystem
230 operations on message queues.
231
232 If unsure, say Y.
233
Serge E. Hallynbdc8e5f2009-04-06 19:01:11 -0700234config POSIX_MQUEUE_SYSCTL
235 bool
236 depends on POSIX_MQUEUE
237 depends on SYSCTL
238 default y
239
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240config BSD_PROCESS_ACCT
241 bool "BSD Process Accounting"
242 help
243 If you say Y here, a user level program will be able to instruct the
244 kernel (via a special system call) to write process accounting
245 information to a file: whenever a process exits, information about
246 that process will be appended to the file by the kernel. The
247 information includes things such as creation time, owning user,
248 command name, memory usage, controlling terminal etc. (the complete
249 list is in the struct acct in <file:include/linux/acct.h>). It is
250 up to the user level program to do useful things with this
251 information. This is generally a good idea, so say Y.
252
253config BSD_PROCESS_ACCT_V3
254 bool "BSD Process Accounting version 3 file format"
255 depends on BSD_PROCESS_ACCT
256 default n
257 help
258 If you say Y here, the process accounting information is written
259 in a new file format that also logs the process IDs of each
260 process and it's parent. Note that this file format is incompatible
261 with previous v0/v1/v2 file formats, so you will need updated tools
262 for processing it. A preliminary version of these tools is available
S.Çağlar Onur37a4c942008-06-18 11:45:13 +0300263 at <http://www.gnu.org/software/acct/>.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264
Shailabh Nagarc7572492006-07-14 00:24:40 -0700265config TASKSTATS
266 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
267 depends on NET
268 default n
269 help
270 Export selected statistics for tasks/processes through the
271 generic netlink interface. Unlike BSD process accounting, the
272 statistics are available during the lifetime of tasks/processes as
273 responses to commands. Like BSD accounting, they are sent to user
274 space on task exit.
275
276 Say N if unsure.
277
Shailabh Nagarca74e922006-07-14 00:24:36 -0700278config TASK_DELAY_ACCT
279 bool "Enable per-task delay accounting (EXPERIMENTAL)"
Shailabh Nagar6f449932006-07-14 00:24:41 -0700280 depends on TASKSTATS
Shailabh Nagarca74e922006-07-14 00:24:36 -0700281 help
282 Collect information on time spent by a task waiting for system
283 resources like cpu, synchronous block I/O completion and swapping
284 in pages. Such statistics can help in setting a task's priorities
285 relative to other tasks for cpu, io, rss limits etc.
286
287 Say N if unsure.
288
Alexey Dobriyan18f705f2007-02-10 01:46:44 -0800289config TASK_XACCT
290 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
291 depends on TASKSTATS
292 help
293 Collect extended task accounting data and send the data
294 to userland for processing over the taskstats interface.
295
296 Say N if unsure.
297
298config TASK_IO_ACCOUNTING
299 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
300 depends on TASK_XACCT
301 help
302 Collect information on the number of bytes of storage I/O which this
303 task has caused.
304
305 Say N if unsure.
306
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307config AUDIT
308 bool "Auditing support"
Chris Wright804a6a492005-05-11 10:52:45 +0100309 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310 help
311 Enable auditing infrastructure that can be used with another
312 kernel subsystem, such as SELinux (which requires this for
313 logging of avc messages output). Does not do system-call
314 auditing without CONFIG_AUDITSYSCALL.
315
316config AUDITSYSCALL
317 bool "Enable system-call auditing support"
Kumar Gala022382a2009-10-16 07:21:37 +0000318 depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319 default y if SECURITY_SELINUX
320 help
321 Enable low-overhead system-call auditing infrastructure that
322 can be used independently or with another kernel subsystem,
Eric Paris67640b62009-12-17 20:12:06 -0500323 such as SELinux.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324
Eric Paris939a67f2009-12-17 20:12:06 -0500325config AUDIT_WATCH
326 def_bool y
327 depends on AUDITSYSCALL
328 select FSNOTIFY
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329
Al Viro74c3cbe2007-07-22 08:04:18 -0400330config AUDIT_TREE
331 def_bool y
Eric Paris63c882a2009-05-21 17:02:01 -0400332 depends on AUDITSYSCALL
Eric Paris28a3a7e2009-12-17 20:12:05 -0500333 select FSNOTIFY
Al Viro74c3cbe2007-07-22 08:04:18 -0400334
Mike Travisc903ff82009-01-15 12:28:29 -0800335menu "RCU Subsystem"
336
337choice
338 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700339 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800340
Mike Travisc903ff82009-01-15 12:28:29 -0800341config TREE_RCU
342 bool "Tree-based hierarchical RCU"
Paul E. McKenney687d7a92010-07-21 06:52:40 -0700343 depends on !PREEMPT && SMP
Mike Travisc903ff82009-01-15 12:28:29 -0800344 help
345 This option selects the RCU implementation that is
346 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700347 thousands of CPUs. It also scales down nicely to
348 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800349
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700350config TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700351 bool "Preemptible tree-based hierarchical RCU"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700352 depends on PREEMPT
353 help
354 This option selects the RCU implementation that is
355 designed for very large SMP systems with hundreds or
356 thousands of CPUs, but for which real-time response
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700357 is also required. It also scales down nicely to
358 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700359
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700360config TINY_RCU
361 bool "UP-only small-memory-footprint RCU"
362 depends on !SMP
363 help
364 This option selects the RCU implementation that is
365 designed for UP systems from which real-time response
366 is not required. This option greatly reduces the
367 memory footprint of RCU.
368
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700369config TINY_PREEMPT_RCU
370 bool "Preemptible UP-only small-memory-footprint RCU"
371 depends on !SMP && PREEMPT
372 help
373 This option selects the RCU implementation that is designed
374 for real-time UP systems. This option greatly reduces the
375 memory footprint of RCU.
376
Mike Travisc903ff82009-01-15 12:28:29 -0800377endchoice
378
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700379config PREEMPT_RCU
380 def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
381 help
382 This option enables preemptible-RCU code that is common between
383 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
384
Mike Travisc903ff82009-01-15 12:28:29 -0800385config RCU_TRACE
386 bool "Enable tracing for RCU"
Mike Travisc903ff82009-01-15 12:28:29 -0800387 help
388 This option provides tracing in RCU which presents stats
389 in debugfs for debugging RCU implementation.
390
391 Say Y here if you want to enable RCU tracing
392 Say N if you are unsure.
393
394config RCU_FANOUT
395 int "Tree-based hierarchical RCU fanout value"
396 range 2 64 if 64BIT
397 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700398 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800399 default 64 if 64BIT
400 default 32 if !64BIT
401 help
402 This option controls the fanout of hierarchical implementations
403 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700404 large numbers of CPUs. This value must be at least the fourth
405 root of NR_CPUS, which allows NR_CPUS to be insanely large.
406 The default value of RCU_FANOUT should be used for production
407 systems, but if you are stress-testing the RCU implementation
408 itself, small RCU_FANOUT values allow you to test large-system
409 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800410
411 Select a specific number if testing RCU itself.
412 Take the default if unsure.
413
414config RCU_FANOUT_EXACT
415 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700416 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800417 default n
418 help
419 This option forces use of the exact RCU_FANOUT value specified,
420 regardless of imbalances in the hierarchy. This is useful for
421 testing RCU itself, and might one day be useful on systems with
422 strong NUMA behavior.
423
424 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
425
426 Say N if unsure.
427
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800428config RCU_FAST_NO_HZ
429 bool "Accelerate last non-dyntick-idle CPU's grace periods"
430 depends on TREE_RCU && NO_HZ && SMP
431 default n
432 help
433 This option causes RCU to attempt to accelerate grace periods
434 in order to allow the final CPU to enter dynticks-idle state
435 more quickly. On the other hand, this option increases the
436 overhead of the dynticks-idle checking, particularly on systems
437 with large numbers of CPUs.
438
439 Say Y if energy efficiency is critically important, particularly
440 if you have relatively few CPUs.
441
442 Say N if you are unsure.
443
Mike Travisc903ff82009-01-15 12:28:29 -0800444config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700445 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800446 select DEBUG_FS
447 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700448 This option provides tracing for the TREE_RCU and
449 TREE_PREEMPT_RCU implementations, permitting Makefile to
450 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800451
Paul E. McKenney24278d12010-09-27 17:25:23 -0700452config RCU_BOOST
453 bool "Enable RCU priority boosting"
454 depends on RT_MUTEXES && TINY_PREEMPT_RCU
455 default n
456 help
457 This option boosts the priority of preempted RCU readers that
458 block the current preemptible RCU grace period for too long.
459 This option also prevents heavy loads from blocking RCU
460 callback invocation for all flavors of RCU.
461
462 Say Y here if you are working with real-time apps or heavy loads
463 Say N here if you are unsure.
464
465config RCU_BOOST_PRIO
466 int "Real-time priority to boost RCU readers to"
467 range 1 99
468 depends on RCU_BOOST
469 default 1
470 help
471 This option specifies the real-time priority to which preempted
472 RCU readers are to be boosted. If you are working with CPU-bound
473 real-time applications, you should specify a priority higher then
474 the highest-priority CPU-bound application.
475
476 Specify the real-time priority, or take the default if unsure.
477
478config RCU_BOOST_DELAY
479 int "Milliseconds to delay boosting after RCU grace-period start"
480 range 0 3000
481 depends on RCU_BOOST
482 default 500
483 help
484 This option specifies the time to wait after the beginning of
485 a given grace period before priority-boosting preempted RCU
486 readers blocking that grace period. Note that any RCU reader
487 blocking an expedited RCU grace period is boosted immediately.
488
489 Accept the default if unsure.
490
Paul E. McKenney46fdb092010-10-26 02:11:40 -0700491config SRCU_SYNCHRONIZE_DELAY
492 int "Microseconds to delay before waiting for readers"
493 range 0 20
494 default 10
495 help
496 This option controls how long SRCU delays before entering its
497 loop waiting on SRCU readers. The purpose of this loop is
498 to avoid the unconditional context-switch penalty that would
499 otherwise be incurred if there was an active SRCU reader,
500 in a manner similar to adaptive locking schemes. This should
501 be set to be a bit longer than the common-case SRCU read-side
502 critical-section overhead.
503
504 Accept the default if unsure.
505
Mike Travisc903ff82009-01-15 12:28:29 -0800506endmenu # "RCU Subsystem"
507
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700509 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510 ---help---
511 This option enables the complete Linux kernel ".config" file
512 contents to be saved in the kernel. It provides documentation
513 of which kernel options are used in a running kernel or in an
514 on-disk kernel. This information can be extracted from the kernel
515 image file with the script scripts/extract-ikconfig and used as
516 input to rebuild the current kernel or to build another kernel.
517 It can also be extracted from a running kernel by reading
518 /proc/config.gz if enabled (below).
519
520config IKCONFIG_PROC
521 bool "Enable access to .config through /proc/config.gz"
522 depends on IKCONFIG && PROC_FS
523 ---help---
524 This option enables access to the kernel configuration file
525 through /proc/config.gz.
526
Alistair John Strachan794543a2007-05-08 00:31:15 -0700527config LOG_BUF_SHIFT
528 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
529 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700530 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700531 help
532 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700533 Examples:
534 17 => 128 KB
535 16 => 64 KB
536 15 => 32 KB
537 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700538 13 => 8 KB
539 12 => 4 KB
540
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800541#
542# Architectures with an unreliable sched_clock() should select this:
543#
544config HAVE_UNSTABLE_SCHED_CLOCK
545 bool
546
Li Zefan23964d22009-01-15 13:50:58 -0800547menuconfig CGROUPS
548 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800549 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700550 help
Li Zefan23964d22009-01-15 13:50:58 -0800551 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800552 use with process control subsystems such as Cpusets, CFS, memory
553 controls or device isolation.
554 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800555 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800556 - Documentation/cgroups/ (features for grouping, isolation
557 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700558
559 Say N if unsure.
560
Li Zefan23964d22009-01-15 13:50:58 -0800561if CGROUPS
562
Paul Menage006cb992007-10-18 23:39:43 -0700563config CGROUP_DEBUG
564 bool "Example debug cgroup subsystem"
565 depends on CGROUPS
Paul Menage418d7d82008-04-29 01:00:05 -0700566 default n
Paul Menage006cb992007-10-18 23:39:43 -0700567 help
568 This option enables a simple cgroup subsystem that
569 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800570 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700571
Li Zefan23964d22009-01-15 13:50:58 -0800572 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700573
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700574config CGROUP_NS
Li Zefan23964d22009-01-15 13:50:58 -0800575 bool "Namespace cgroup subsystem"
576 depends on CGROUPS
577 help
578 Provides a simple namespace cgroup subsystem to
579 provide hierarchical naming of sets of namespaces,
580 for instance virtual servers and checkpoint/restart
581 jobs.
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700582
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700583config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800584 bool "Freezer cgroup subsystem"
585 depends on CGROUPS
586 help
587 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700588 cgroup.
589
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700590config CGROUP_DEVICE
591 bool "Device controller for cgroups"
592 depends on CGROUPS && EXPERIMENTAL
593 help
594 Provides a cgroup implementing whitelists for devices which
595 a process in the cgroup can mknod or open.
596
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597config CPUSETS
598 bool "Cpuset support"
Paul Menagedb7f47c2009-04-02 16:57:55 -0700599 depends on CGROUPS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700601 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602 allow dynamically partitioning a system into sets of CPUs and
603 Memory Nodes and assigning tasks to run only within those sets.
604 This is primarily useful on large SMP or NUMA systems.
605
606 Say N if unsure.
607
Li Zefan23964d22009-01-15 13:50:58 -0800608config PROC_PID_CPUSET
609 bool "Include legacy /proc/<pid>/cpuset file"
610 depends on CPUSETS
611 default y
612
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100613config CGROUP_CPUACCT
614 bool "Simple CPU accounting cgroup subsystem"
615 depends on CGROUPS
616 help
617 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800618 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100619
Pavel Emelianove552b662008-02-07 00:13:49 -0800620config RESOURCE_COUNTERS
621 bool "Resource counters"
622 help
623 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800624 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800625 depends on CGROUPS
626
Balbir Singh00f0b822008-03-04 14:28:39 -0800627config CGROUP_MEM_RES_CTLR
628 bool "Memory Resource Controller for Control Groups"
629 depends on CGROUPS && RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700630 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800631 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700632 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100633 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800634
635 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700636 associated with each page of memory in the system. By this,
637 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
638 usage tracking struct at boot. Total amount of this is printed out
639 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800640
641 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700642 sure you need the memory resource controller. Even when you enable
643 this, you can set "cgroup_disable=memory" at your boot option to
644 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800645 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800646
Balbir Singhcf475ad2008-04-29 01:00:16 -0700647 This config option also selects MM_OWNER config option, which
648 could in turn add some fork/exit overhead.
649
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800650config CGROUP_MEM_RES_CTLR_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700651 bool "Memory Resource Controller Swap Extension"
652 depends on CGROUP_MEM_RES_CTLR && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800653 help
654 Add swap management feature to memory resource controller. When you
655 enable this, you can limit mem+swap usage per cgroup. In other words,
656 when you disable this, memory resource controller has no cares to
657 usage of swap...a process can exhaust all of the swap. This extension
658 is useful when you want to avoid exhaustion swap but this itself
659 adds more overheads and consumes memory for remembering information.
660 Especially if you use 32bit system or small memory system, please
661 be careful about enabling this. When memory resource controller
662 is disabled by boot option, this will be automatically disabled and
663 there will be no overhead from this. Even when you set this config=y,
664 if boot option "noswapaccount" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700665 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
666 size is 4096bytes, 512k per 1Gbytes of swap.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800667
Dhaval Giani7c941432010-01-20 13:26:18 +0100668menuconfig CGROUP_SCHED
669 bool "Group CPU scheduler"
670 depends on EXPERIMENTAL && CGROUPS
671 default n
672 help
673 This feature lets CPU scheduler recognize task groups and control CPU
674 bandwidth allocation to such task groups. It uses cgroups to group
675 tasks.
676
677if CGROUP_SCHED
678config FAIR_GROUP_SCHED
679 bool "Group scheduling for SCHED_OTHER"
680 depends on CGROUP_SCHED
681 default CGROUP_SCHED
682
683config RT_GROUP_SCHED
684 bool "Group scheduling for SCHED_RR/FIFO"
685 depends on EXPERIMENTAL
686 depends on CGROUP_SCHED
687 default n
688 help
689 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +0800690 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +0100691 schedule realtime tasks for non-root users until you allocate
692 realtime bandwidth for them.
693 See Documentation/scheduler/sched-rt-group.txt for more information.
694
695endif #CGROUP_SCHED
696
Vivek Goyalafc24d42010-04-26 19:27:56 +0200697config BLK_CGROUP
698 tristate "Block IO controller"
699 depends on CGROUPS && BLOCK
700 default n
701 ---help---
702 Generic block IO controller cgroup interface. This is the common
703 cgroup interface which should be used by various IO controlling
704 policies.
705
706 Currently, CFQ IO scheduler uses it to recognize task groups and
707 control disk bandwidth allocation (proportional time slice allocation)
708 to such task groups.
709
710 This option only enables generic Block IO controller infrastructure.
711 One needs to also enable actual IO controlling logic in CFQ for it
712 to take effect. (CONFIG_CFQ_GROUP_IOSCHED=y).
713
714 See Documentation/cgroups/blkio-controller.txt for more information.
715
716config DEBUG_BLK_CGROUP
717 bool "Enable Block IO controller debugging"
718 depends on BLK_CGROUP
719 default n
720 ---help---
721 Enable some debugging help. Currently it exports additional stat
722 files in a cgroup which can be useful for debugging.
723
Li Zefan23964d22009-01-15 13:50:58 -0800724endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800725
Li Zefan23964d22009-01-15 13:50:58 -0800726config MM_OWNER
727 bool
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800728
Kay Sievers88a22c92006-09-14 11:23:28 +0200729config SYSFS_DEPRECATED
Ingo Molnard47846c2008-03-04 14:54:47 +0100730 bool
731
732config SYSFS_DEPRECATED_V2
Uwe Kleine-König9e9868a2009-12-03 19:58:00 +0100733 bool "enable deprecated sysfs features to support old userspace tools"
Randy Dunlap9148fe82007-12-31 10:05:34 -0800734 depends on SYSFS
Kay Sieversf6ee6492009-04-16 19:56:37 +0200735 default n
Ingo Molnard47846c2008-03-04 14:54:47 +0100736 select SYSFS_DEPRECATED
Kay Sievers88a22c92006-09-14 11:23:28 +0200737 help
Kay Sieversfce3e802008-11-01 14:03:00 +0100738 This option switches the layout of sysfs to the deprecated
Kay Sieversf6ee6492009-04-16 19:56:37 +0200739 version. Do not use it on recent distributions.
Kay Sievers88a22c92006-09-14 11:23:28 +0200740
Kay Sieversfce3e802008-11-01 14:03:00 +0100741 The current sysfs layout features a unified device tree at
742 /sys/devices/, which is able to express a hierarchy between
743 class devices. If the deprecated option is set to Y, the
744 unified device tree is split into a bus device tree at
745 /sys/devices/ and several individual class device trees at
746 /sys/class/. The class and bus devices will be connected by
747 "<subsystem>:<name>" and the "device" links. The "block"
748 class devices, will not show up in /sys/class/block/. Some
749 subsystems will suppress the creation of some devices which
750 depend on the unified device tree.
Kay Sievers88a22c92006-09-14 11:23:28 +0200751
Kay Sieversfce3e802008-11-01 14:03:00 +0100752 This option is not a pure compatibility option that can
753 be safely enabled on newer distributions. It will change the
754 layout of sysfs to the non-extensible deprecated version,
755 and disable some features, which can not be exported without
756 confusing older userspace tools. Since 2007/2008 all major
757 distributions do not enable this option, and ship no tools which
758 depend on the deprecated layout or this option.
759
760 If you are using a new kernel on an older distribution, or use
761 older userspace tools, you might need to say Y here. Do not say Y,
762 if the original kernel, that came with your distribution, has
763 this option set to N.
Kay Sievers88a22c92006-09-14 11:23:28 +0200764
Jens Axboeb86ff9812006-03-23 19:56:55 +0100765config RELAY
766 bool "Kernel->user space relay support (formerly relayfs)"
767 help
768 This option enables support for relay interface support in
769 certain file systems (such as debugfs).
770 It is designed to provide an efficient mechanism for tools and
771 facilities to relay large amounts of data from kernel space to
772 user space.
773
774 If unsure, say N.
775
Pavel Emelyanovc5289a62008-02-08 04:18:19 -0800776config NAMESPACES
777 bool "Namespaces support" if EMBEDDED
778 default !EMBEDDED
779 help
780 Provides the way to make tasks work with different objects using
781 the same id. For example same IPC id may refer to different objects
782 or same user id or pid may refer to different tasks when used in
783 different namespaces.
784
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800785config UTS_NS
786 bool "UTS namespace"
787 depends on NAMESPACES
788 help
789 In this namespace tasks see different info provided with the
790 uname() system call
791
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800792config IPC_NS
793 bool "IPC namespace"
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700794 depends on NAMESPACES && (SYSVIPC || POSIX_MQUEUE)
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800795 help
796 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700797 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800798
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800799config USER_NS
800 bool "User namespace (EXPERIMENTAL)"
801 depends on NAMESPACES && EXPERIMENTAL
802 help
803 This allows containers, i.e. vservers, to use user namespaces
804 to provide different user info for different servers.
805 If unsure, say N.
806
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800807config PID_NS
808 bool "PID Namespaces (EXPERIMENTAL)"
809 default n
810 depends on NAMESPACES && EXPERIMENTAL
811 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +0300812 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +0100813 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800814 pid namespaces. This is a building block of containers.
815
816 Unless you want to work with an experimental feature
817 say N here.
818
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800819config NET_NS
820 bool "Network namespace"
821 default n
822 depends on NAMESPACES && EXPERIMENTAL && NET
823 help
824 Allow user space to create what appear to be multiple instances
825 of the network stack.
826
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -0800827config BLK_DEV_INITRD
828 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
829 depends on BROKEN || !FRV
830 help
831 The initial RAM filesystem is a ramfs which is loaded by the
832 boot loader (loadlin or lilo) and that is mounted as root
833 before the normal boot procedure. It is typically used to
834 load modules needed to mount the "real" root file system,
835 etc. See <file:Documentation/initrd.txt> for details.
836
837 If RAM disk support (BLK_DEV_RAM) is also included, this
838 also enables initial RAM disk (initrd) support and adds
839 15 Kbytes (more on some other architectures) to the kernel size.
840
841 If unsure say Y.
842
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800843if BLK_DEV_INITRD
844
Sam Ravnborgdbec4862005-08-10 20:44:50 +0200845source "usr/Kconfig"
846
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800847endif
848
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800849config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +0200850 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800851 default y
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800852 help
853 Enabling this option will pass "-Os" instead of "-O2" to gcc
854 resulting in a smaller kernel.
855
jkacur775a7222008-07-16 00:31:16 +0200856 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800857
Randy Dunlap08470622006-09-30 23:28:13 -0700858config SYSCTL
859 bool
860
Randy Dunlapb943c462009-03-10 12:55:46 -0700861config ANON_INODES
862 bool
863
Linus Torvalds1da177e2005-04-16 15:20:36 -0700864menuconfig EMBEDDED
865 bool "Configure standard kernel features (for small systems)"
866 help
867 This option allows certain base kernel options and settings
868 to be disabled or tweaked. This is for specialized
869 environments which can tolerate a "non-standard" kernel.
870 Only use this if you really know what you are doing.
871
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700872config UID16
873 bool "Enable 16-bit UID system calls" if EMBEDDED
David S. Miller09337f52008-04-26 03:17:12 -0700874 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 -0700875 default y
876 help
877 This enables the legacy 16-bit UID syscall wrappers.
878
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700879config SYSCTL_SYSCALL
Randy Dunlap08470622006-09-30 23:28:13 -0700880 bool "Sysctl syscall support" if EMBEDDED
Eric W. Biederman26a70342009-11-05 05:26:41 -0800881 depends on PROC_SYSCTL
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800882 default y
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700883 select SYSCTL
884 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800885 sys_sysctl uses binary paths that have been found challenging
886 to properly maintain and use. The interface in /proc/sys
887 using paths with ascii names is now the primary path to this
888 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700889
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800890 Almost nothing using the binary sysctl interface so if you are
891 trying to save some space it is probably safe to disable this,
892 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700893
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800894 If unsure say Y here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700895
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896config KALLSYMS
Jesper Juhl979c6a12006-12-12 19:25:11 +0100897 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898 default y
899 help
900 Say Y here to let the kernel print out symbolic crash information and
901 symbolic stack backtraces. This increases the size of the kernel
902 somewhat, as all symbols have to be loaded into the kernel image.
903
904config KALLSYMS_ALL
905 bool "Include all symbols in kallsyms"
906 depends on DEBUG_KERNEL && KALLSYMS
907 help
908 Normally kallsyms only contains the symbols of functions, for nicer
909 OOPS messages. Some debuggers can use kallsyms for other
Jesper Juhlf9f97bc2005-07-20 05:43:05 +0200910 symbols too: say Y here to include all symbols, if you need them
911 and you don't care about adding 300k to the size of your kernel.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700912
913 Say N.
914
915config KALLSYMS_EXTRA_PASS
916 bool "Do an extra kallsyms pass"
917 depends on KALLSYMS
918 help
919 If kallsyms is not working correctly, the build will fail with
920 inconsistent kallsyms data. If that occurs, log a bug report and
921 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
922 Always say N here unless you find a bug in kallsyms, which must be
923 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
924 you wait for kallsyms to be fixed.
925
Matt Mackalld59745c2005-05-01 08:59:02 -0700926
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -0800927config HOTPLUG
928 bool "Support for hot-pluggable devices" if EMBEDDED
929 default y
930 help
931 This option is provided for the case where no hotplug or uevent
932 capabilities is wanted by the kernel. You should only consider
933 disabling this option for embedded systems that do not use modules, a
934 dynamic /dev tree, or dynamic device discovery. Just say Y.
935
Matt Mackalld59745c2005-05-01 08:59:02 -0700936config PRINTK
937 default y
938 bool "Enable support for printk" if EMBEDDED
939 help
940 This option enables normal printk support. Removing it
941 eliminates most of the message strings from the kernel image
942 and makes the kernel more or less silent. As this makes it
943 very difficult to diagnose system problems, saying N here is
944 strongly discouraged.
945
Matt Mackallc8538a72005-05-01 08:59:01 -0700946config BUG
947 bool "BUG() support" if EMBEDDED
948 default y
949 help
950 Disabling this option eliminates support for BUG and WARN, reducing
951 the size of your kernel image and potentially quietly ignoring
952 numerous fatal conditions. You should only consider disabling this
953 option for embedded systems with no facilities for reporting errors.
954 Just say Y.
955
Matt Mackall708e9a72006-01-08 01:05:25 -0800956config ELF_CORE
957 default y
958 bool "Enable ELF core dumps" if EMBEDDED
959 help
960 Enable support for generating core dumps. Disabling saves about 4k.
961
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +0200962config PCSPKR_PLATFORM
963 bool "Enable PC-Speaker support" if EMBEDDED
964 depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES
965 default y
966 help
967 This option allows to disable the internal PC-Speaker
968 support, saving some memory.
969
Linus Torvalds1da177e2005-04-16 15:20:36 -0700970config BASE_FULL
971 default y
972 bool "Enable full-sized data structures for core" if EMBEDDED
973 help
974 Disabling this option reduces the size of miscellaneous core
975 kernel data structures. This saves memory on small machines,
976 but may reduce performance.
977
978config FUTEX
979 bool "Enable futex support" if EMBEDDED
980 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -0700981 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700982 help
983 Disabling this option will cause the kernel to be built without
984 support for "fast userspace mutexes". The resulting kernel may not
985 run glibc-based applications correctly.
986
987config EPOLL
988 bool "Enable eventpoll support" if EMBEDDED
989 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700990 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700991 help
992 Disabling this option will cause the kernel to be built without
993 support for epoll family of system calls.
994
Davide Libenzifba2afa2007-05-10 22:23:13 -0700995config SIGNALFD
996 bool "Enable signalfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700997 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -0700998 default y
999 help
1000 Enable the signalfd() system call that allows to receive signals
1001 on a file descriptor.
1002
1003 If unsure, say Y.
1004
Davide Libenzib215e282007-05-10 22:23:16 -07001005config TIMERFD
1006 bool "Enable timerfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001007 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001008 default y
1009 help
1010 Enable the timerfd() system call that allows to receive timer
1011 events on a file descriptor.
1012
1013 If unsure, say Y.
1014
Davide Libenzie1ad7462007-05-10 22:23:19 -07001015config EVENTFD
1016 bool "Enable eventfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001017 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001018 default y
1019 help
1020 Enable the eventfd() system call that allows to receive both
1021 kernel notification (ie. KAIO) or userspace notifications.
1022
1023 If unsure, say Y.
1024
Linus Torvalds1da177e2005-04-16 15:20:36 -07001025config SHMEM
1026 bool "Use full shmem filesystem" if EMBEDDED
1027 default y
1028 depends on MMU
1029 help
1030 The shmem is an internal filesystem used to manage shared memory.
1031 It is backed by swap and manages resource limits. It is also exported
1032 to userspace as tmpfs if TMPFS is enabled. Disabling this
1033 option replaces shmem and tmpfs with the much simpler ramfs code,
1034 which may be appropriate on small systems without swap.
1035
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001036config AIO
1037 bool "Enable AIO support" if EMBEDDED
1038 default y
1039 help
1040 This option enables POSIX asynchronous I/O which may by used
1041 by some high performance threaded applications. Disabling
1042 this option saves about 7k.
1043
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001044config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001045 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001046 help
1047 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001048
Peter Zijlstra906010b2009-09-21 16:08:49 +02001049config PERF_USE_VMALLOC
1050 bool
1051 help
1052 See tools/perf/design.txt for details
1053
Ingo Molnar57c0c152009-09-21 12:20:38 +02001054menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001055
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001056config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001057 bool "Kernel performance events and counters"
1058 default y if (PROFILING || PERF_COUNTERS)
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001059 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001060 select ANON_INODES
Thomas Gleixner0793a612008-12-04 20:12:29 +01001061 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001062 Enable kernel support for various performance events provided
1063 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001064
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001065 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001066 use of generic tracepoints.
1067
1068 Most modern CPUs support performance events via performance
1069 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001070 types of hw events: such as instructions executed, cachemisses
1071 suffered, or branches mis-predicted - without slowing down the
1072 kernel or applications. These registers can also trigger interrupts
1073 when a threshold number of events have passed - and can thus be
1074 used to profile the code that runs on that CPU.
1075
Ingo Molnar57c0c152009-09-21 12:20:38 +02001076 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001077 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001078 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001079 provides per task and per CPU counters, and it provides event
1080 capabilities on top of those.
1081
1082 Say Y if unsure.
1083
Ingo Molnar57c0c152009-09-21 12:20:38 +02001084config PERF_COUNTERS
1085 bool "Kernel performance counters (old config option)"
1086 depends on HAVE_PERF_EVENTS
1087 help
1088 This config has been obsoleted by the PERF_EVENTS
1089 config option - please see that one for details.
1090
1091 It has no effect on the kernel whether you enable
1092 it or not, it is a compatibility placeholder.
1093
1094 Say N if unsure.
1095
Peter Zijlstra906010b2009-09-21 16:08:49 +02001096config DEBUG_PERF_USE_VMALLOC
1097 default n
1098 bool "Debug: use vmalloc to back perf mmap() buffers"
1099 depends on PERF_EVENTS && DEBUG_KERNEL
1100 select PERF_USE_VMALLOC
1101 help
1102 Use vmalloc memory to back perf mmap() buffers.
1103
1104 Mostly useful for debugging the vmalloc code on platforms
1105 that don't require it.
1106
1107 Say N if unsure.
1108
Thomas Gleixner0793a612008-12-04 20:12:29 +01001109endmenu
1110
Christoph Lameterf8891e52006-06-30 01:55:45 -07001111config VM_EVENT_COUNTERS
1112 default y
1113 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
1114 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001115 VM event counters are needed for event counts to be shown.
1116 This option allows the disabling of the VM event counters
1117 on EMBEDDED systems. /proc/vmstat will only show page counts
1118 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001119
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001120config PCI_QUIRKS
1121 default y
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001122 bool "Enable PCI quirk workarounds" if EMBEDDED
1123 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001124 help
1125 This enables workarounds for various PCI chipset
1126 bugs/quirks. Disable this only if your target machine is
1127 unaffected by PCI quirks.
1128
Christoph Lameter41ecc552007-05-09 02:32:44 -07001129config SLUB_DEBUG
1130 default y
1131 bool "Enable SLUB debugging support" if EMBEDDED
Christoph Lameterf6acb632008-04-29 16:16:06 -07001132 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001133 help
1134 SLUB has extensive debug support features. Disabling these can
1135 result in significant savings in code size. This also disables
1136 SLUB sysfs support. /sys/slab will not exist and there will be
1137 no support for cache validation etc.
1138
Randy Dunlapb943c462009-03-10 12:55:46 -07001139config COMPAT_BRK
1140 bool "Disable heap randomization"
1141 default y
1142 help
1143 Randomizing heap placement makes heap exploits harder, but it
1144 also breaks ancient binaries (including anything libc5 based).
1145 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001146 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001147 /proc/sys/kernel/randomize_va_space to 2.
1148
1149 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1150
Christoph Lameter81819f02007-05-06 14:49:36 -07001151choice
1152 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001153 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001154 help
1155 This option allows to select a slab allocator.
1156
1157config SLAB
1158 bool "SLAB"
1159 help
1160 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001161 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001162 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001163
1164config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001165 bool "SLUB (Unqueued Allocator)"
1166 help
1167 SLUB is a slab allocator that minimizes cache line usage
1168 instead of managing queues of cached objects (SLAB approach).
1169 Per cpu caching is realized using slabs of objects instead
1170 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001171 and has enhanced diagnostics. SLUB is the default choice for
1172 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001173
1174config SLOB
Paul Mundt84a01c22007-07-15 23:38:24 -07001175 depends on EMBEDDED
Christoph Lameter81819f02007-05-06 14:49:36 -07001176 bool "SLOB (Simple Allocator)"
1177 help
Matt Mackall37291452008-02-04 22:29:38 -08001178 SLOB replaces the stock allocator with a drastically simpler
1179 allocator. SLOB is generally more space efficient but
1180 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001181
1182endchoice
1183
Jie Zhangea637632009-12-14 18:00:02 -08001184config MMAP_ALLOW_UNINITIALIZED
1185 bool "Allow mmapped anonymous memory to be uninitialized"
1186 depends on EMBEDDED && !MMU
1187 default n
1188 help
1189 Normally, and according to the Linux spec, anonymous memory obtained
1190 from mmap() has it's contents cleared before it is passed to
1191 userspace. Enabling this config option allows you to request that
1192 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1193 providing a huge performance boost. If this option is not enabled,
1194 then the flag will be ignored.
1195
1196 This is taken advantage of by uClibc's malloc(), and also by
1197 ELF-FDPIC binfmt's brk and stack allocator.
1198
1199 Because of the obvious security issues, this option should only be
1200 enabled on embedded devices where you control what is run in
1201 userspace. Since that isn't generally a problem on no-MMU systems,
1202 it is normally safe to say Y here.
1203
1204 See Documentation/nommu-mmap.txt for more information.
1205
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001206config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001207 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001208 help
1209 Say Y here to enable the extended profiling support mechanisms used
1210 by profilers such as OProfile.
1211
Ingo Molnar5f87f112008-07-23 14:15:22 +02001212#
1213# Place an empty function call at each tracepoint site. Can be
1214# dynamically changed for a probe function.
1215#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001216config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001217 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001218
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001219source "arch/Kconfig"
1220
Linus Torvalds1da177e2005-04-16 15:20:36 -07001221endmenu # General setup
1222
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001223config HAVE_GENERIC_DMA_COHERENT
1224 bool
1225 default n
1226
Linus Torvalds158a9622008-01-02 13:04:48 -08001227config SLABINFO
1228 bool
1229 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001230 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001231 default y
1232
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001233config RT_MUTEXES
1234 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001235
Linus Torvalds1da177e2005-04-16 15:20:36 -07001236config BASE_SMALL
1237 int
1238 default 0 if BASE_FULL
1239 default 1 if !BASE_FULL
1240
Jan Engelhardt66da5732007-07-15 23:39:29 -07001241menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001242 bool "Enable loadable module support"
1243 help
1244 Kernel modules are small pieces of compiled code which can
1245 be inserted in the running kernel, rather than being
1246 permanently built into the kernel. You use the "modprobe"
1247 tool to add (and sometimes remove) them. If you say Y here,
1248 many parts of the kernel can be built as modules (by
1249 answering M instead of Y where indicated): this is most
1250 useful for infrequently used options which are not required
1251 for booting. For more information, see the man pages for
1252 modprobe, lsmod, modinfo, insmod and rmmod.
1253
1254 If you say Y here, you will need to run "make
1255 modules_install" to put the modules under /lib/modules/
1256 where modprobe can find them (you may need to be root to do
1257 this).
1258
1259 If unsure, say Y.
1260
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001261if MODULES
1262
Linus Torvalds826e4502008-05-04 17:04:16 -07001263config MODULE_FORCE_LOAD
1264 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001265 default n
1266 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001267 Allow loading of modules without version information (ie. modprobe
1268 --force). Forced module loading sets the 'F' (forced) taint flag and
1269 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001270
Linus Torvalds1da177e2005-04-16 15:20:36 -07001271config MODULE_UNLOAD
1272 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001273 help
1274 Without this option you will not be able to unload any
1275 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001276 anyway), which makes your kernel smaller, faster
1277 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001278
1279config MODULE_FORCE_UNLOAD
1280 bool "Forced module unloading"
1281 depends on MODULE_UNLOAD && EXPERIMENTAL
1282 help
1283 This option allows you to force a module to unload, even if the
1284 kernel believes it is unsafe: the kernel will remove the module
1285 without waiting for anyone to stop using it (using the -f option to
1286 rmmod). This is mainly for kernel developers and desperate users.
1287 If unsure, say N.
1288
Linus Torvalds1da177e2005-04-16 15:20:36 -07001289config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001290 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001291 help
1292 Usually, you have to use modules compiled with your kernel.
1293 Saying Y here makes it sometimes possible to use modules
1294 compiled for different kernels, by adding enough information
1295 to the modules to (hopefully) spot any changes which would
1296 make them incompatible with the kernel you are running. If
1297 unsure, say N.
1298
1299config MODULE_SRCVERSION_ALL
1300 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001301 help
1302 Modules which contain a MODULE_VERSION get an extra "srcversion"
1303 field inserted into their modinfo section, which contains a
1304 sum of the source files which made it. This helps maintainers
1305 see exactly which source was used to build a module (since
1306 others sometimes change the module source without updating
1307 the version). With this option, such a "srcversion" field
1308 will be created for all modules. If unsure, say N.
1309
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001310endif # MODULES
1311
Rusty Russell98a79d62008-12-13 21:19:41 +10301312config INIT_ALL_POSSIBLE
1313 bool
1314 help
1315 Back when each arch used to define their own cpu_online_map and
1316 cpu_possible_map, some of them chose to initialize cpu_possible_map
1317 with all 1s, and others with all 0s. When they were centralised,
1318 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001319 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301320
Linus Torvalds1da177e2005-04-16 15:20:36 -07001321config STOP_MACHINE
1322 bool
1323 default y
1324 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1325 help
1326 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001327
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001328source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001329
1330config PREEMPT_NOTIFIERS
1331 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001332
Steffen Klassert16295be2010-01-06 19:47:10 +11001333config PADATA
1334 depends on SMP
1335 bool
1336
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001337source "kernel/Kconfig.locks"