blob: 239fae49750b8f29da9c2acd571b1c7bd9782394 [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
Peter Zijlstrae360adb2010-10-14 14:01:34 +080024config HAVE_IRQ_WORK
25 bool
26
27config IRQ_WORK
28 bool
29 depends on HAVE_IRQ_WORK
30
Al Boldiff0cfc62007-07-31 00:39:23 -070031menu "General setup"
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
33config EXPERIMENTAL
34 bool "Prompt for development and/or incomplete code/drivers"
35 ---help---
36 Some of the various things that Linux supports (such as network
37 drivers, file systems, network protocols, etc.) can be in a state
38 of development where the functionality, stability, or the level of
39 testing is not yet high enough for general use. This is usually
40 known as the "alpha-test" phase among developers. If a feature is
41 currently in alpha-test, then the developers usually discourage
42 uninformed widespread use of this feature by the general public to
43 avoid "Why doesn't this work?" type mail messages. However, active
44 testing and use of these systems is welcomed. Just be aware that it
45 may not meet the normal level of reliability or it may fail to work
46 in some special cases. Detailed bug reports from people familiar
47 with the kernel internals are usually welcomed by the developers
48 (before submitting bug reports, please read the documents
49 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
50 <file:Documentation/BUG-HUNTING>, and
51 <file:Documentation/oops-tracing.txt> in the kernel source).
52
53 This option will also make obsoleted drivers available. These are
54 drivers that have been replaced by something else, and/or are
55 scheduled to be removed in a future kernel release.
56
57 Unless you intend to help test and develop a feature or driver that
58 falls into this category, or you have a situation that requires
59 using these features, you should probably say N here, which will
60 cause the configurator to present you with fewer choices. If
61 you say Y here, you will be offered the choice of using features or
62 drivers that are currently considered to be in the alpha-test phase.
63
Linus Torvalds1da177e2005-04-16 15:20:36 -070064config BROKEN
65 bool
Linus Torvalds1da177e2005-04-16 15:20:36 -070066
67config BROKEN_ON_SMP
68 bool
69 depends on BROKEN || !SMP
70 default y
71
72config LOCK_KERNEL
73 bool
Arnd Bergmann6de5bd12010-09-11 18:00:57 +020074 depends on (SMP || PREEMPT) && BKL
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 default y
76
77config INIT_ENV_ARG_LIMIT
78 int
Adrian Bunkdd673bc2006-06-30 01:55:51 -070079 default 32 if !UML
80 default 128 if UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070081 help
Randy Dunlap34ad92c2005-10-30 15:01:46 -080082 Maximum of each of the number of arguments and environment
83 variables passed to init from the kernel command line.
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
Linus Torvalds1da177e2005-04-16 15:20:36 -070085
Roland McGrath84336462009-12-21 16:24:06 -080086config CROSS_COMPILE
87 string "Cross-compiler tool prefix"
88 help
89 Same as running 'make CROSS_COMPILE=prefix-' but stored for
90 default make runs in this kernel build directory. You don't
91 need to set this unless you want the configured kernel build
92 directory to select the cross-compiler automatically.
93
Linus Torvalds1da177e2005-04-16 15:20:36 -070094config LOCALVERSION
95 string "Local version - append to kernel release"
96 help
97 Append an extra string to the end of your kernel version.
98 This will show up when you type uname, for example.
99 The string you set here will be appended after the contents of
100 any files with a filename matching localversion* in your
101 object and source tree, in that order. Your total string can
102 be a maximum of 64 characters.
103
Ryan Andersonaaebf432005-07-31 04:57:49 -0400104config LOCALVERSION_AUTO
105 bool "Automatically append version information to the version string"
106 default y
107 help
108 This will try to automatically determine if the current tree is a
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200109 release tree by looking for git tags that belong to the current
110 top of tree revision.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400111
112 A string of the format -gxxxxxxxx will be added to the localversion
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200113 if a git-based tree is found. The string generated by this will be
Ryan Andersonaaebf432005-07-31 04:57:49 -0400114 appended after any matching localversion* files, and after the value
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200115 set in CONFIG_LOCALVERSION.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400116
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200117 (The actual string used here is the first eight characters produced
118 by running the command:
119
120 $ git rev-parse --verify HEAD
121
122 which is done within the script "scripts/setlocalversion".)
Ryan Andersonaaebf432005-07-31 04:57:49 -0400123
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800124config HAVE_KERNEL_GZIP
125 bool
126
127config HAVE_KERNEL_BZIP2
128 bool
129
130config HAVE_KERNEL_LZMA
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
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800139 depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || 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
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800184config KERNEL_LZO
185 bool "LZO"
186 depends on HAVE_KERNEL_LZO
187 help
188 Its compression ratio is the poorest among the 4. The kernel
Stephan Sperber681b3042010-07-14 11:23:08 +0200189 size is about 10% bigger than gzip; however its speed
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800190 (both compression and decompression) is the fastest.
191
Alain Knaff30d65db2009-01-04 22:46:17 +0100192endchoice
193
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194config SWAP
195 bool "Support for paging of anonymous memory (swap)"
David Howells93614012006-09-30 20:45:40 +0200196 depends on MMU && BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 default y
198 help
199 This option allows you to choose whether you want to have support
Jesper Juhl92c35042006-01-15 02:40:08 +0100200 for so called swap devices or swap files in your kernel that are
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 used to provide more virtual memory than the actual RAM present
202 in your computer. If unsure say Y.
203
204config SYSVIPC
205 bool "System V IPC"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 ---help---
207 Inter Process Communication is a suite of library functions and
208 system calls which let processes (running programs) synchronize and
209 exchange information. It is generally considered to be a good thing,
210 and some programs won't run unless you say Y here. In particular, if
211 you want to run the DOS emulator dosemu under Linux (read the
212 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
213 you'll need to say Y here.
214
215 You can find documentation about IPC with "info ipc" and also in
216 section 6.4 of the Linux Programmer's Guide, available from
217 <http://www.tldp.org/guides.html>.
218
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800219config SYSVIPC_SYSCTL
220 bool
221 depends on SYSVIPC
222 depends on SYSCTL
223 default y
224
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225config POSIX_MQUEUE
226 bool "POSIX Message Queues"
227 depends on NET && EXPERIMENTAL
228 ---help---
229 POSIX variant of message queues is a part of IPC. In POSIX message
230 queues every message has a priority which decides about succession
231 of receiving it by a process. If you want to compile and run
232 programs written e.g. for Solaris with use of its POSIX message
Robert P. J. Dayb0e37652007-05-09 07:25:13 +0200233 queues (functions mq_*) say Y here.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234
235 POSIX message queues are visible as a filesystem called 'mqueue'
236 and can be mounted somewhere if you want to do filesystem
237 operations on message queues.
238
239 If unsure, say Y.
240
Serge E. Hallynbdc8e5f2009-04-06 19:01:11 -0700241config POSIX_MQUEUE_SYSCTL
242 bool
243 depends on POSIX_MQUEUE
244 depends on SYSCTL
245 default y
246
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247config BSD_PROCESS_ACCT
248 bool "BSD Process Accounting"
249 help
250 If you say Y here, a user level program will be able to instruct the
251 kernel (via a special system call) to write process accounting
252 information to a file: whenever a process exits, information about
253 that process will be appended to the file by the kernel. The
254 information includes things such as creation time, owning user,
255 command name, memory usage, controlling terminal etc. (the complete
256 list is in the struct acct in <file:include/linux/acct.h>). It is
257 up to the user level program to do useful things with this
258 information. This is generally a good idea, so say Y.
259
260config BSD_PROCESS_ACCT_V3
261 bool "BSD Process Accounting version 3 file format"
262 depends on BSD_PROCESS_ACCT
263 default n
264 help
265 If you say Y here, the process accounting information is written
266 in a new file format that also logs the process IDs of each
267 process and it's parent. Note that this file format is incompatible
268 with previous v0/v1/v2 file formats, so you will need updated tools
269 for processing it. A preliminary version of these tools is available
S.Çağlar Onur37a4c942008-06-18 11:45:13 +0300270 at <http://www.gnu.org/software/acct/>.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271
Shailabh Nagarc7572492006-07-14 00:24:40 -0700272config TASKSTATS
273 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
274 depends on NET
275 default n
276 help
277 Export selected statistics for tasks/processes through the
278 generic netlink interface. Unlike BSD process accounting, the
279 statistics are available during the lifetime of tasks/processes as
280 responses to commands. Like BSD accounting, they are sent to user
281 space on task exit.
282
283 Say N if unsure.
284
Shailabh Nagarca74e922006-07-14 00:24:36 -0700285config TASK_DELAY_ACCT
286 bool "Enable per-task delay accounting (EXPERIMENTAL)"
Shailabh Nagar6f449932006-07-14 00:24:41 -0700287 depends on TASKSTATS
Shailabh Nagarca74e922006-07-14 00:24:36 -0700288 help
289 Collect information on time spent by a task waiting for system
290 resources like cpu, synchronous block I/O completion and swapping
291 in pages. Such statistics can help in setting a task's priorities
292 relative to other tasks for cpu, io, rss limits etc.
293
294 Say N if unsure.
295
Alexey Dobriyan18f705f2007-02-10 01:46:44 -0800296config TASK_XACCT
297 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
298 depends on TASKSTATS
299 help
300 Collect extended task accounting data and send the data
301 to userland for processing over the taskstats interface.
302
303 Say N if unsure.
304
305config TASK_IO_ACCOUNTING
306 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
307 depends on TASK_XACCT
308 help
309 Collect information on the number of bytes of storage I/O which this
310 task has caused.
311
312 Say N if unsure.
313
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314config AUDIT
315 bool "Auditing support"
Chris Wright804a6a492005-05-11 10:52:45 +0100316 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317 help
318 Enable auditing infrastructure that can be used with another
319 kernel subsystem, such as SELinux (which requires this for
320 logging of avc messages output). Does not do system-call
321 auditing without CONFIG_AUDITSYSCALL.
322
323config AUDITSYSCALL
324 bool "Enable system-call auditing support"
Kumar Gala022382a2009-10-16 07:21:37 +0000325 depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326 default y if SECURITY_SELINUX
327 help
328 Enable low-overhead system-call auditing infrastructure that
329 can be used independently or with another kernel subsystem,
Eric Paris67640b62009-12-17 20:12:06 -0500330 such as SELinux.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331
Eric Paris939a67f2009-12-17 20:12:06 -0500332config AUDIT_WATCH
333 def_bool y
334 depends on AUDITSYSCALL
335 select FSNOTIFY
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336
Al Viro74c3cbe2007-07-22 08:04:18 -0400337config AUDIT_TREE
338 def_bool y
Eric Paris63c882a2009-05-21 17:02:01 -0400339 depends on AUDITSYSCALL
Eric Paris28a3a7e2009-12-17 20:12:05 -0500340 select FSNOTIFY
Al Viro74c3cbe2007-07-22 08:04:18 -0400341
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000342source "kernel/irq/Kconfig"
343
Mike Travisc903ff82009-01-15 12:28:29 -0800344menu "RCU Subsystem"
345
346choice
347 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700348 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800349
Mike Travisc903ff82009-01-15 12:28:29 -0800350config TREE_RCU
351 bool "Tree-based hierarchical RCU"
Paul E. McKenney687d7a92010-07-21 06:52:40 -0700352 depends on !PREEMPT && SMP
Mike Travisc903ff82009-01-15 12:28:29 -0800353 help
354 This option selects the RCU implementation that is
355 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700356 thousands of CPUs. It also scales down nicely to
357 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800358
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700359config TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700360 bool "Preemptible tree-based hierarchical RCU"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700361 depends on PREEMPT
362 help
363 This option selects the RCU implementation that is
364 designed for very large SMP systems with hundreds or
365 thousands of CPUs, but for which real-time response
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700366 is also required. It also scales down nicely to
367 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700368
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700369config TINY_RCU
370 bool "UP-only small-memory-footprint RCU"
371 depends on !SMP
372 help
373 This option selects the RCU implementation that is
374 designed for UP systems from which real-time response
375 is not required. This option greatly reduces the
376 memory footprint of RCU.
377
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700378config TINY_PREEMPT_RCU
379 bool "Preemptible UP-only small-memory-footprint RCU"
380 depends on !SMP && PREEMPT
381 help
382 This option selects the RCU implementation that is designed
383 for real-time UP systems. This option greatly reduces the
384 memory footprint of RCU.
385
Mike Travisc903ff82009-01-15 12:28:29 -0800386endchoice
387
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700388config PREEMPT_RCU
389 def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
390 help
391 This option enables preemptible-RCU code that is common between
392 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
393
Mike Travisc903ff82009-01-15 12:28:29 -0800394config RCU_TRACE
395 bool "Enable tracing for RCU"
Paul E. McKenney6b3ef482009-08-22 13:56:53 -0700396 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800397 help
398 This option provides tracing in RCU which presents stats
399 in debugfs for debugging RCU implementation.
400
401 Say Y here if you want to enable RCU tracing
402 Say N if you are unsure.
403
404config RCU_FANOUT
405 int "Tree-based hierarchical RCU fanout value"
406 range 2 64 if 64BIT
407 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700408 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800409 default 64 if 64BIT
410 default 32 if !64BIT
411 help
412 This option controls the fanout of hierarchical implementations
413 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700414 large numbers of CPUs. This value must be at least the fourth
415 root of NR_CPUS, which allows NR_CPUS to be insanely large.
416 The default value of RCU_FANOUT should be used for production
417 systems, but if you are stress-testing the RCU implementation
418 itself, small RCU_FANOUT values allow you to test large-system
419 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800420
421 Select a specific number if testing RCU itself.
422 Take the default if unsure.
423
424config RCU_FANOUT_EXACT
425 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700426 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800427 default n
428 help
429 This option forces use of the exact RCU_FANOUT value specified,
430 regardless of imbalances in the hierarchy. This is useful for
431 testing RCU itself, and might one day be useful on systems with
432 strong NUMA behavior.
433
434 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
435
436 Say N if unsure.
437
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800438config RCU_FAST_NO_HZ
439 bool "Accelerate last non-dyntick-idle CPU's grace periods"
440 depends on TREE_RCU && NO_HZ && SMP
441 default n
442 help
443 This option causes RCU to attempt to accelerate grace periods
444 in order to allow the final CPU to enter dynticks-idle state
445 more quickly. On the other hand, this option increases the
446 overhead of the dynticks-idle checking, particularly on systems
447 with large numbers of CPUs.
448
449 Say Y if energy efficiency is critically important, particularly
450 if you have relatively few CPUs.
451
452 Say N if you are unsure.
453
Mike Travisc903ff82009-01-15 12:28:29 -0800454config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700455 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800456 select DEBUG_FS
457 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700458 This option provides tracing for the TREE_RCU and
459 TREE_PREEMPT_RCU implementations, permitting Makefile to
460 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800461
Mike Travisc903ff82009-01-15 12:28:29 -0800462endmenu # "RCU Subsystem"
463
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700465 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466 ---help---
467 This option enables the complete Linux kernel ".config" file
468 contents to be saved in the kernel. It provides documentation
469 of which kernel options are used in a running kernel or in an
470 on-disk kernel. This information can be extracted from the kernel
471 image file with the script scripts/extract-ikconfig and used as
472 input to rebuild the current kernel or to build another kernel.
473 It can also be extracted from a running kernel by reading
474 /proc/config.gz if enabled (below).
475
476config IKCONFIG_PROC
477 bool "Enable access to .config through /proc/config.gz"
478 depends on IKCONFIG && PROC_FS
479 ---help---
480 This option enables access to the kernel configuration file
481 through /proc/config.gz.
482
Alistair John Strachan794543a2007-05-08 00:31:15 -0700483config LOG_BUF_SHIFT
484 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
485 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700486 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700487 help
488 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700489 Examples:
490 17 => 128 KB
491 16 => 64 KB
492 15 => 32 KB
493 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700494 13 => 8 KB
495 12 => 4 KB
496
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800497#
498# Architectures with an unreliable sched_clock() should select this:
499#
500config HAVE_UNSTABLE_SCHED_CLOCK
501 bool
502
Li Zefan23964d22009-01-15 13:50:58 -0800503menuconfig CGROUPS
504 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800505 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700506 help
Li Zefan23964d22009-01-15 13:50:58 -0800507 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800508 use with process control subsystems such as Cpusets, CFS, memory
509 controls or device isolation.
510 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800511 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800512 - Documentation/cgroups/ (features for grouping, isolation
513 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700514
515 Say N if unsure.
516
Li Zefan23964d22009-01-15 13:50:58 -0800517if CGROUPS
518
Paul Menage006cb992007-10-18 23:39:43 -0700519config CGROUP_DEBUG
520 bool "Example debug cgroup subsystem"
521 depends on CGROUPS
Paul Menage418d7d82008-04-29 01:00:05 -0700522 default n
Paul Menage006cb992007-10-18 23:39:43 -0700523 help
524 This option enables a simple cgroup subsystem that
525 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800526 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700527
Li Zefan23964d22009-01-15 13:50:58 -0800528 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700529
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700530config CGROUP_NS
Li Zefan23964d22009-01-15 13:50:58 -0800531 bool "Namespace cgroup subsystem"
532 depends on CGROUPS
533 help
534 Provides a simple namespace cgroup subsystem to
535 provide hierarchical naming of sets of namespaces,
536 for instance virtual servers and checkpoint/restart
537 jobs.
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700538
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700539config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800540 bool "Freezer cgroup subsystem"
541 depends on CGROUPS
542 help
543 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700544 cgroup.
545
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700546config CGROUP_DEVICE
547 bool "Device controller for cgroups"
548 depends on CGROUPS && EXPERIMENTAL
549 help
550 Provides a cgroup implementing whitelists for devices which
551 a process in the cgroup can mknod or open.
552
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553config CPUSETS
554 bool "Cpuset support"
Paul Menagedb7f47c2009-04-02 16:57:55 -0700555 depends on CGROUPS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700557 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558 allow dynamically partitioning a system into sets of CPUs and
559 Memory Nodes and assigning tasks to run only within those sets.
560 This is primarily useful on large SMP or NUMA systems.
561
562 Say N if unsure.
563
Li Zefan23964d22009-01-15 13:50:58 -0800564config PROC_PID_CPUSET
565 bool "Include legacy /proc/<pid>/cpuset file"
566 depends on CPUSETS
567 default y
568
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100569config CGROUP_CPUACCT
570 bool "Simple CPU accounting cgroup subsystem"
571 depends on CGROUPS
572 help
573 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800574 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100575
Pavel Emelianove552b662008-02-07 00:13:49 -0800576config RESOURCE_COUNTERS
577 bool "Resource counters"
578 help
579 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800580 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800581 depends on CGROUPS
582
Balbir Singh00f0b822008-03-04 14:28:39 -0800583config CGROUP_MEM_RES_CTLR
584 bool "Memory Resource Controller for Control Groups"
585 depends on CGROUPS && RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700586 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800587 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700588 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100589 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800590
591 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700592 associated with each page of memory in the system. By this,
593 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
594 usage tracking struct at boot. Total amount of this is printed out
595 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800596
597 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700598 sure you need the memory resource controller. Even when you enable
599 this, you can set "cgroup_disable=memory" at your boot option to
600 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800601 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800602
Balbir Singhcf475ad2008-04-29 01:00:16 -0700603 This config option also selects MM_OWNER config option, which
604 could in turn add some fork/exit overhead.
605
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800606config CGROUP_MEM_RES_CTLR_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700607 bool "Memory Resource Controller Swap Extension"
608 depends on CGROUP_MEM_RES_CTLR && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800609 help
610 Add swap management feature to memory resource controller. When you
611 enable this, you can limit mem+swap usage per cgroup. In other words,
612 when you disable this, memory resource controller has no cares to
613 usage of swap...a process can exhaust all of the swap. This extension
614 is useful when you want to avoid exhaustion swap but this itself
615 adds more overheads and consumes memory for remembering information.
616 Especially if you use 32bit system or small memory system, please
617 be careful about enabling this. When memory resource controller
618 is disabled by boot option, this will be automatically disabled and
619 there will be no overhead from this. Even when you set this config=y,
620 if boot option "noswapaccount" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700621 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
622 size is 4096bytes, 512k per 1Gbytes of swap.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800623
Dhaval Giani7c941432010-01-20 13:26:18 +0100624menuconfig CGROUP_SCHED
625 bool "Group CPU scheduler"
626 depends on EXPERIMENTAL && CGROUPS
627 default n
628 help
629 This feature lets CPU scheduler recognize task groups and control CPU
630 bandwidth allocation to such task groups. It uses cgroups to group
631 tasks.
632
633if CGROUP_SCHED
634config FAIR_GROUP_SCHED
635 bool "Group scheduling for SCHED_OTHER"
636 depends on CGROUP_SCHED
637 default CGROUP_SCHED
638
639config RT_GROUP_SCHED
640 bool "Group scheduling for SCHED_RR/FIFO"
641 depends on EXPERIMENTAL
642 depends on CGROUP_SCHED
643 default n
644 help
645 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +0800646 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +0100647 schedule realtime tasks for non-root users until you allocate
648 realtime bandwidth for them.
649 See Documentation/scheduler/sched-rt-group.txt for more information.
650
651endif #CGROUP_SCHED
652
Vivek Goyalafc24d42010-04-26 19:27:56 +0200653config BLK_CGROUP
654 tristate "Block IO controller"
655 depends on CGROUPS && BLOCK
656 default n
657 ---help---
658 Generic block IO controller cgroup interface. This is the common
659 cgroup interface which should be used by various IO controlling
660 policies.
661
662 Currently, CFQ IO scheduler uses it to recognize task groups and
663 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -0400664 to such task groups. It is also used by bio throttling logic in
665 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200666
667 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -0400668 One needs to also enable actual IO controlling logic/policy. For
669 enabling proportional weight division of disk bandwidth in CFQ seti
670 CONFIG_CFQ_GROUP_IOSCHED=y and for enabling throttling policy set
671 CONFIG_BLK_THROTTLE=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200672
673 See Documentation/cgroups/blkio-controller.txt for more information.
674
675config DEBUG_BLK_CGROUP
676 bool "Enable Block IO controller debugging"
677 depends on BLK_CGROUP
678 default n
679 ---help---
680 Enable some debugging help. Currently it exports additional stat
681 files in a cgroup which can be useful for debugging.
682
Li Zefan23964d22009-01-15 13:50:58 -0800683endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800684
Li Zefan23964d22009-01-15 13:50:58 -0800685config MM_OWNER
686 bool
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800687
Kay Sievers88a22c92006-09-14 11:23:28 +0200688config SYSFS_DEPRECATED
Uwe Kleine-König9e9868a2009-12-03 19:58:00 +0100689 bool "enable deprecated sysfs features to support old userspace tools"
Randy Dunlap9148fe82007-12-31 10:05:34 -0800690 depends on SYSFS
Kay Sieversf6ee6492009-04-16 19:56:37 +0200691 default n
Kay Sievers88a22c92006-09-14 11:23:28 +0200692 help
Andi Kleene52eec12010-09-08 16:54:17 +0200693 This option adds code that switches the layout of the "block" class
694 devices, to not show up in /sys/class/block/, but only in
695 /sys/block/.
Kay Sievers88a22c92006-09-14 11:23:28 +0200696
Andi Kleene52eec12010-09-08 16:54:17 +0200697 This switch is only active when the sysfs.deprecated=1 boot option is
698 passed or the SYSFS_DEPRECATED_V2 option is set.
Kay Sievers88a22c92006-09-14 11:23:28 +0200699
Kay Sievers39aba962010-09-04 22:33:14 -0700700 This option allows new kernels to run on old distributions and tools,
701 which might get confused by /sys/class/block/. Since 2007/2008 all
702 major distributions and tools handle this just fine.
Kay Sieversfce3e802008-11-01 14:03:00 +0100703
Kay Sievers39aba962010-09-04 22:33:14 -0700704 Recent distributions and userspace tools after 2009/2010 depend on
705 the existence of /sys/class/block/, and will not work with this
706 option enabled.
Kay Sieversfce3e802008-11-01 14:03:00 +0100707
Kay Sievers39aba962010-09-04 22:33:14 -0700708 Only if you are using a new kernel on an old distribution, you might
Andi Kleene52eec12010-09-08 16:54:17 +0200709 need to say Y here.
710
711config SYSFS_DEPRECATED_V2
712 bool "enabled deprecated sysfs features by default"
713 default n
714 depends on SYSFS
715 depends on SYSFS_DEPRECATED
716 help
717 Enable deprecated sysfs by default.
718
719 See the CONFIG_SYSFS_DEPRECATED option for more details about this
720 option.
721
722 Only if you are using a new kernel on an old distribution, you might
723 need to say Y here. Even then, odds are you would not need it
724 enabled, you can always pass the boot option if absolutely necessary.
Kay Sievers88a22c92006-09-14 11:23:28 +0200725
Jens Axboeb86ff9812006-03-23 19:56:55 +0100726config RELAY
727 bool "Kernel->user space relay support (formerly relayfs)"
728 help
729 This option enables support for relay interface support in
730 certain file systems (such as debugfs).
731 It is designed to provide an efficient mechanism for tools and
732 facilities to relay large amounts of data from kernel space to
733 user space.
734
735 If unsure, say N.
736
Pavel Emelyanovc5289a62008-02-08 04:18:19 -0800737config NAMESPACES
738 bool "Namespaces support" if EMBEDDED
739 default !EMBEDDED
740 help
741 Provides the way to make tasks work with different objects using
742 the same id. For example same IPC id may refer to different objects
743 or same user id or pid may refer to different tasks when used in
744 different namespaces.
745
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800746config UTS_NS
747 bool "UTS namespace"
748 depends on NAMESPACES
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700749 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800750 help
751 In this namespace tasks see different info provided with the
752 uname() system call
753
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800754config IPC_NS
755 bool "IPC namespace"
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700756 depends on NAMESPACES && (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700757 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800758 help
759 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700760 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800761
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800762config USER_NS
763 bool "User namespace (EXPERIMENTAL)"
764 depends on NAMESPACES && EXPERIMENTAL
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700765 default y
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800766 help
767 This allows containers, i.e. vservers, to use user namespaces
768 to provide different user info for different servers.
769 If unsure, say N.
770
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800771config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -0700772 bool "PID Namespaces"
Daniel Lezcano9bd38c22010-10-27 15:34:37 -0700773 depends on NAMESPACES
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700774 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800775 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +0300776 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +0100777 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800778 pid namespaces. This is a building block of containers.
779
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800780config NET_NS
781 bool "Network namespace"
Daniel Lezcano9bd38c22010-10-27 15:34:37 -0700782 depends on NAMESPACES && NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700783 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800784 help
785 Allow user space to create what appear to be multiple instances
786 of the network stack.
787
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -0800788config BLK_DEV_INITRD
789 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
790 depends on BROKEN || !FRV
791 help
792 The initial RAM filesystem is a ramfs which is loaded by the
793 boot loader (loadlin or lilo) and that is mounted as root
794 before the normal boot procedure. It is typically used to
795 load modules needed to mount the "real" root file system,
796 etc. See <file:Documentation/initrd.txt> for details.
797
798 If RAM disk support (BLK_DEV_RAM) is also included, this
799 also enables initial RAM disk (initrd) support and adds
800 15 Kbytes (more on some other architectures) to the kernel size.
801
802 If unsure say Y.
803
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800804if BLK_DEV_INITRD
805
Sam Ravnborgdbec4862005-08-10 20:44:50 +0200806source "usr/Kconfig"
807
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800808endif
809
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800810config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +0200811 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800812 default y
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800813 help
814 Enabling this option will pass "-Os" instead of "-O2" to gcc
815 resulting in a smaller kernel.
816
jkacur775a7222008-07-16 00:31:16 +0200817 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800818
Randy Dunlap08470622006-09-30 23:28:13 -0700819config SYSCTL
820 bool
821
Randy Dunlapb943c462009-03-10 12:55:46 -0700822config ANON_INODES
823 bool
824
Linus Torvalds1da177e2005-04-16 15:20:36 -0700825menuconfig EMBEDDED
826 bool "Configure standard kernel features (for small systems)"
827 help
828 This option allows certain base kernel options and settings
829 to be disabled or tweaked. This is for specialized
830 environments which can tolerate a "non-standard" kernel.
831 Only use this if you really know what you are doing.
832
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700833config UID16
834 bool "Enable 16-bit UID system calls" if EMBEDDED
David S. Miller09337f52008-04-26 03:17:12 -0700835 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 -0700836 default y
837 help
838 This enables the legacy 16-bit UID syscall wrappers.
839
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700840config SYSCTL_SYSCALL
Randy Dunlap08470622006-09-30 23:28:13 -0700841 bool "Sysctl syscall support" if EMBEDDED
Eric W. Biederman26a70342009-11-05 05:26:41 -0800842 depends on PROC_SYSCTL
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800843 default y
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700844 select SYSCTL
845 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800846 sys_sysctl uses binary paths that have been found challenging
847 to properly maintain and use. The interface in /proc/sys
848 using paths with ascii names is now the primary path to this
849 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700850
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800851 Almost nothing using the binary sysctl interface so if you are
852 trying to save some space it is probably safe to disable this,
853 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700854
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800855 If unsure say Y here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700856
Linus Torvalds1da177e2005-04-16 15:20:36 -0700857config KALLSYMS
Jesper Juhl979c6a12006-12-12 19:25:11 +0100858 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
Linus Torvalds1da177e2005-04-16 15:20:36 -0700859 default y
860 help
861 Say Y here to let the kernel print out symbolic crash information and
862 symbolic stack backtraces. This increases the size of the kernel
863 somewhat, as all symbols have to be loaded into the kernel image.
864
865config KALLSYMS_ALL
866 bool "Include all symbols in kallsyms"
867 depends on DEBUG_KERNEL && KALLSYMS
868 help
869 Normally kallsyms only contains the symbols of functions, for nicer
870 OOPS messages. Some debuggers can use kallsyms for other
Jesper Juhlf9f97bc2005-07-20 05:43:05 +0200871 symbols too: say Y here to include all symbols, if you need them
872 and you don't care about adding 300k to the size of your kernel.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700873
874 Say N.
875
876config KALLSYMS_EXTRA_PASS
877 bool "Do an extra kallsyms pass"
878 depends on KALLSYMS
879 help
880 If kallsyms is not working correctly, the build will fail with
881 inconsistent kallsyms data. If that occurs, log a bug report and
882 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
883 Always say N here unless you find a bug in kallsyms, which must be
884 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
885 you wait for kallsyms to be fixed.
886
Matt Mackalld59745c2005-05-01 08:59:02 -0700887
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -0800888config HOTPLUG
889 bool "Support for hot-pluggable devices" if EMBEDDED
890 default y
891 help
892 This option is provided for the case where no hotplug or uevent
893 capabilities is wanted by the kernel. You should only consider
894 disabling this option for embedded systems that do not use modules, a
895 dynamic /dev tree, or dynamic device discovery. Just say Y.
896
Matt Mackalld59745c2005-05-01 08:59:02 -0700897config PRINTK
898 default y
899 bool "Enable support for printk" if EMBEDDED
900 help
901 This option enables normal printk support. Removing it
902 eliminates most of the message strings from the kernel image
903 and makes the kernel more or less silent. As this makes it
904 very difficult to diagnose system problems, saying N here is
905 strongly discouraged.
906
Matt Mackallc8538a72005-05-01 08:59:01 -0700907config BUG
908 bool "BUG() support" if EMBEDDED
909 default y
910 help
911 Disabling this option eliminates support for BUG and WARN, reducing
912 the size of your kernel image and potentially quietly ignoring
913 numerous fatal conditions. You should only consider disabling this
914 option for embedded systems with no facilities for reporting errors.
915 Just say Y.
916
Matt Mackall708e9a72006-01-08 01:05:25 -0800917config ELF_CORE
918 default y
919 bool "Enable ELF core dumps" if EMBEDDED
920 help
921 Enable support for generating core dumps. Disabling saves about 4k.
922
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +0200923config PCSPKR_PLATFORM
924 bool "Enable PC-Speaker support" if EMBEDDED
925 depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES
926 default y
927 help
928 This option allows to disable the internal PC-Speaker
929 support, saving some memory.
930
Linus Torvalds1da177e2005-04-16 15:20:36 -0700931config BASE_FULL
932 default y
933 bool "Enable full-sized data structures for core" if EMBEDDED
934 help
935 Disabling this option reduces the size of miscellaneous core
936 kernel data structures. This saves memory on small machines,
937 but may reduce performance.
938
939config FUTEX
940 bool "Enable futex support" if EMBEDDED
941 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -0700942 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700943 help
944 Disabling this option will cause the kernel to be built without
945 support for "fast userspace mutexes". The resulting kernel may not
946 run glibc-based applications correctly.
947
948config EPOLL
949 bool "Enable eventpoll support" if EMBEDDED
950 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700951 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700952 help
953 Disabling this option will cause the kernel to be built without
954 support for epoll family of system calls.
955
Davide Libenzifba2afa2007-05-10 22:23:13 -0700956config SIGNALFD
957 bool "Enable signalfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700958 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -0700959 default y
960 help
961 Enable the signalfd() system call that allows to receive signals
962 on a file descriptor.
963
964 If unsure, say Y.
965
Davide Libenzib215e282007-05-10 22:23:16 -0700966config TIMERFD
967 bool "Enable timerfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700968 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -0700969 default y
970 help
971 Enable the timerfd() system call that allows to receive timer
972 events on a file descriptor.
973
974 If unsure, say Y.
975
Davide Libenzie1ad7462007-05-10 22:23:19 -0700976config EVENTFD
977 bool "Enable eventfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700978 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -0700979 default y
980 help
981 Enable the eventfd() system call that allows to receive both
982 kernel notification (ie. KAIO) or userspace notifications.
983
984 If unsure, say Y.
985
Linus Torvalds1da177e2005-04-16 15:20:36 -0700986config SHMEM
987 bool "Use full shmem filesystem" if EMBEDDED
988 default y
989 depends on MMU
990 help
991 The shmem is an internal filesystem used to manage shared memory.
992 It is backed by swap and manages resource limits. It is also exported
993 to userspace as tmpfs if TMPFS is enabled. Disabling this
994 option replaces shmem and tmpfs with the much simpler ramfs code,
995 which may be appropriate on small systems without swap.
996
Thomas Petazzoniebf3f092008-10-15 22:05:12 -0700997config AIO
998 bool "Enable AIO support" if EMBEDDED
999 default y
1000 help
1001 This option enables POSIX asynchronous I/O which may by used
1002 by some high performance threaded applications. Disabling
1003 this option saves about 7k.
1004
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001005config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001006 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001007 help
1008 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001009
Peter Zijlstra906010b2009-09-21 16:08:49 +02001010config PERF_USE_VMALLOC
1011 bool
1012 help
1013 See tools/perf/design.txt for details
1014
Ingo Molnar57c0c152009-09-21 12:20:38 +02001015menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001016
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001017config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001018 bool "Kernel performance events and counters"
1019 default y if (PROFILING || PERF_COUNTERS)
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001020 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001021 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001022 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001023 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001024 Enable kernel support for various performance events provided
1025 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001026
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001027 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001028 use of generic tracepoints.
1029
1030 Most modern CPUs support performance events via performance
1031 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001032 types of hw events: such as instructions executed, cachemisses
1033 suffered, or branches mis-predicted - without slowing down the
1034 kernel or applications. These registers can also trigger interrupts
1035 when a threshold number of events have passed - and can thus be
1036 used to profile the code that runs on that CPU.
1037
Ingo Molnar57c0c152009-09-21 12:20:38 +02001038 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001039 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001040 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001041 provides per task and per CPU counters, and it provides event
1042 capabilities on top of those.
1043
1044 Say Y if unsure.
1045
Ingo Molnar57c0c152009-09-21 12:20:38 +02001046config PERF_COUNTERS
1047 bool "Kernel performance counters (old config option)"
1048 depends on HAVE_PERF_EVENTS
1049 help
1050 This config has been obsoleted by the PERF_EVENTS
1051 config option - please see that one for details.
1052
1053 It has no effect on the kernel whether you enable
1054 it or not, it is a compatibility placeholder.
1055
1056 Say N if unsure.
1057
Peter Zijlstra906010b2009-09-21 16:08:49 +02001058config DEBUG_PERF_USE_VMALLOC
1059 default n
1060 bool "Debug: use vmalloc to back perf mmap() buffers"
1061 depends on PERF_EVENTS && DEBUG_KERNEL
1062 select PERF_USE_VMALLOC
1063 help
1064 Use vmalloc memory to back perf mmap() buffers.
1065
1066 Mostly useful for debugging the vmalloc code on platforms
1067 that don't require it.
1068
1069 Say N if unsure.
1070
Thomas Gleixner0793a612008-12-04 20:12:29 +01001071endmenu
1072
Christoph Lameterf8891e52006-06-30 01:55:45 -07001073config VM_EVENT_COUNTERS
1074 default y
1075 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
1076 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001077 VM event counters are needed for event counts to be shown.
1078 This option allows the disabling of the VM event counters
1079 on EMBEDDED systems. /proc/vmstat will only show page counts
1080 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001081
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001082config PCI_QUIRKS
1083 default y
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001084 bool "Enable PCI quirk workarounds" if EMBEDDED
1085 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001086 help
1087 This enables workarounds for various PCI chipset
1088 bugs/quirks. Disable this only if your target machine is
1089 unaffected by PCI quirks.
1090
Christoph Lameter41ecc552007-05-09 02:32:44 -07001091config SLUB_DEBUG
1092 default y
1093 bool "Enable SLUB debugging support" if EMBEDDED
Christoph Lameterf6acb632008-04-29 16:16:06 -07001094 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001095 help
1096 SLUB has extensive debug support features. Disabling these can
1097 result in significant savings in code size. This also disables
1098 SLUB sysfs support. /sys/slab will not exist and there will be
1099 no support for cache validation etc.
1100
Randy Dunlapb943c462009-03-10 12:55:46 -07001101config COMPAT_BRK
1102 bool "Disable heap randomization"
1103 default y
1104 help
1105 Randomizing heap placement makes heap exploits harder, but it
1106 also breaks ancient binaries (including anything libc5 based).
1107 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001108 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001109 /proc/sys/kernel/randomize_va_space to 2.
1110
1111 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1112
Christoph Lameter81819f02007-05-06 14:49:36 -07001113choice
1114 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001115 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001116 help
1117 This option allows to select a slab allocator.
1118
1119config SLAB
1120 bool "SLAB"
1121 help
1122 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001123 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001124 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001125
1126config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001127 bool "SLUB (Unqueued Allocator)"
1128 help
1129 SLUB is a slab allocator that minimizes cache line usage
1130 instead of managing queues of cached objects (SLAB approach).
1131 Per cpu caching is realized using slabs of objects instead
1132 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001133 and has enhanced diagnostics. SLUB is the default choice for
1134 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001135
1136config SLOB
Paul Mundt84a01c22007-07-15 23:38:24 -07001137 depends on EMBEDDED
Christoph Lameter81819f02007-05-06 14:49:36 -07001138 bool "SLOB (Simple Allocator)"
1139 help
Matt Mackall37291452008-02-04 22:29:38 -08001140 SLOB replaces the stock allocator with a drastically simpler
1141 allocator. SLOB is generally more space efficient but
1142 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001143
1144endchoice
1145
Jie Zhangea637632009-12-14 18:00:02 -08001146config MMAP_ALLOW_UNINITIALIZED
1147 bool "Allow mmapped anonymous memory to be uninitialized"
1148 depends on EMBEDDED && !MMU
1149 default n
1150 help
1151 Normally, and according to the Linux spec, anonymous memory obtained
1152 from mmap() has it's contents cleared before it is passed to
1153 userspace. Enabling this config option allows you to request that
1154 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1155 providing a huge performance boost. If this option is not enabled,
1156 then the flag will be ignored.
1157
1158 This is taken advantage of by uClibc's malloc(), and also by
1159 ELF-FDPIC binfmt's brk and stack allocator.
1160
1161 Because of the obvious security issues, this option should only be
1162 enabled on embedded devices where you control what is run in
1163 userspace. Since that isn't generally a problem on no-MMU systems,
1164 it is normally safe to say Y here.
1165
1166 See Documentation/nommu-mmap.txt for more information.
1167
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001168config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001169 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001170 help
1171 Say Y here to enable the extended profiling support mechanisms used
1172 by profilers such as OProfile.
1173
Ingo Molnar5f87f112008-07-23 14:15:22 +02001174#
1175# Place an empty function call at each tracepoint site. Can be
1176# dynamically changed for a probe function.
1177#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001178config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001179 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001180
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001181source "arch/Kconfig"
1182
Linus Torvalds1da177e2005-04-16 15:20:36 -07001183endmenu # General setup
1184
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001185config HAVE_GENERIC_DMA_COHERENT
1186 bool
1187 default n
1188
Linus Torvalds158a9622008-01-02 13:04:48 -08001189config SLABINFO
1190 bool
1191 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001192 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001193 default y
1194
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001195config RT_MUTEXES
1196 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001197
Linus Torvalds1da177e2005-04-16 15:20:36 -07001198config BASE_SMALL
1199 int
1200 default 0 if BASE_FULL
1201 default 1 if !BASE_FULL
1202
Jan Engelhardt66da5732007-07-15 23:39:29 -07001203menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001204 bool "Enable loadable module support"
1205 help
1206 Kernel modules are small pieces of compiled code which can
1207 be inserted in the running kernel, rather than being
1208 permanently built into the kernel. You use the "modprobe"
1209 tool to add (and sometimes remove) them. If you say Y here,
1210 many parts of the kernel can be built as modules (by
1211 answering M instead of Y where indicated): this is most
1212 useful for infrequently used options which are not required
1213 for booting. For more information, see the man pages for
1214 modprobe, lsmod, modinfo, insmod and rmmod.
1215
1216 If you say Y here, you will need to run "make
1217 modules_install" to put the modules under /lib/modules/
1218 where modprobe can find them (you may need to be root to do
1219 this).
1220
1221 If unsure, say Y.
1222
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001223if MODULES
1224
Linus Torvalds826e4502008-05-04 17:04:16 -07001225config MODULE_FORCE_LOAD
1226 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001227 default n
1228 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001229 Allow loading of modules without version information (ie. modprobe
1230 --force). Forced module loading sets the 'F' (forced) taint flag and
1231 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001232
Linus Torvalds1da177e2005-04-16 15:20:36 -07001233config MODULE_UNLOAD
1234 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001235 help
1236 Without this option you will not be able to unload any
1237 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001238 anyway), which makes your kernel smaller, faster
1239 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001240
1241config MODULE_FORCE_UNLOAD
1242 bool "Forced module unloading"
1243 depends on MODULE_UNLOAD && EXPERIMENTAL
1244 help
1245 This option allows you to force a module to unload, even if the
1246 kernel believes it is unsafe: the kernel will remove the module
1247 without waiting for anyone to stop using it (using the -f option to
1248 rmmod). This is mainly for kernel developers and desperate users.
1249 If unsure, say N.
1250
Linus Torvalds1da177e2005-04-16 15:20:36 -07001251config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001252 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001253 help
1254 Usually, you have to use modules compiled with your kernel.
1255 Saying Y here makes it sometimes possible to use modules
1256 compiled for different kernels, by adding enough information
1257 to the modules to (hopefully) spot any changes which would
1258 make them incompatible with the kernel you are running. If
1259 unsure, say N.
1260
1261config MODULE_SRCVERSION_ALL
1262 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001263 help
1264 Modules which contain a MODULE_VERSION get an extra "srcversion"
1265 field inserted into their modinfo section, which contains a
1266 sum of the source files which made it. This helps maintainers
1267 see exactly which source was used to build a module (since
1268 others sometimes change the module source without updating
1269 the version). With this option, such a "srcversion" field
1270 will be created for all modules. If unsure, say N.
1271
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001272endif # MODULES
1273
Rusty Russell98a79d62008-12-13 21:19:41 +10301274config INIT_ALL_POSSIBLE
1275 bool
1276 help
1277 Back when each arch used to define their own cpu_online_map and
1278 cpu_possible_map, some of them chose to initialize cpu_possible_map
1279 with all 1s, and others with all 0s. When they were centralised,
1280 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001281 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301282
Linus Torvalds1da177e2005-04-16 15:20:36 -07001283config STOP_MACHINE
1284 bool
1285 default y
1286 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1287 help
1288 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001289
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001290source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001291
1292config PREEMPT_NOTIFIERS
1293 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001294
Steffen Klassert16295be2010-01-06 19:47:10 +11001295config PADATA
1296 depends on SMP
1297 bool
1298
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001299source "kernel/Kconfig.locks"