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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' Giarrussob2670ea2006-10-19 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
Al Boldiff0cfc62007-07-31 00:39:23 -070019menu "General setup"
Linus Torvalds1da177e2005-04-16 15:20:36 -070020
21config EXPERIMENTAL
22 bool "Prompt for development and/or incomplete code/drivers"
23 ---help---
24 Some of the various things that Linux supports (such as network
25 drivers, file systems, network protocols, etc.) can be in a state
26 of development where the functionality, stability, or the level of
27 testing is not yet high enough for general use. This is usually
28 known as the "alpha-test" phase among developers. If a feature is
29 currently in alpha-test, then the developers usually discourage
30 uninformed widespread use of this feature by the general public to
31 avoid "Why doesn't this work?" type mail messages. However, active
32 testing and use of these systems is welcomed. Just be aware that it
33 may not meet the normal level of reliability or it may fail to work
34 in some special cases. Detailed bug reports from people familiar
35 with the kernel internals are usually welcomed by the developers
36 (before submitting bug reports, please read the documents
37 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
38 <file:Documentation/BUG-HUNTING>, and
39 <file:Documentation/oops-tracing.txt> in the kernel source).
40
41 This option will also make obsoleted drivers available. These are
42 drivers that have been replaced by something else, and/or are
43 scheduled to be removed in a future kernel release.
44
45 Unless you intend to help test and develop a feature or driver that
46 falls into this category, or you have a situation that requires
47 using these features, you should probably say N here, which will
48 cause the configurator to present you with fewer choices. If
49 you say Y here, you will be offered the choice of using features or
50 drivers that are currently considered to be in the alpha-test phase.
51
Linus Torvalds1da177e2005-04-16 15:20:36 -070052config BROKEN
53 bool
Linus Torvalds1da177e2005-04-16 15:20:36 -070054
55config BROKEN_ON_SMP
56 bool
57 depends on BROKEN || !SMP
58 default y
59
60config LOCK_KERNEL
61 bool
62 depends on SMP || PREEMPT
63 default y
64
65config INIT_ENV_ARG_LIMIT
66 int
Adrian Bunkdd673bc2006-06-30 01:55:51 -070067 default 32 if !UML
68 default 128 if UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070069 help
Randy Dunlap34ad92c2005-10-30 15:01:46 -080070 Maximum of each of the number of arguments and environment
71 variables passed to init from the kernel command line.
Linus Torvalds1da177e2005-04-16 15:20:36 -070072
Linus Torvalds1da177e2005-04-16 15:20:36 -070073
74config LOCALVERSION
75 string "Local version - append to kernel release"
76 help
77 Append an extra string to the end of your kernel version.
78 This will show up when you type uname, for example.
79 The string you set here will be appended after the contents of
80 any files with a filename matching localversion* in your
81 object and source tree, in that order. Your total string can
82 be a maximum of 64 characters.
83
Ryan Andersonaaebf432005-07-31 04:57:49 -040084config LOCALVERSION_AUTO
85 bool "Automatically append version information to the version string"
86 default y
87 help
88 This will try to automatically determine if the current tree is a
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020089 release tree by looking for git tags that belong to the current
90 top of tree revision.
Ryan Andersonaaebf432005-07-31 04:57:49 -040091
92 A string of the format -gxxxxxxxx will be added to the localversion
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020093 if a git-based tree is found. The string generated by this will be
Ryan Andersonaaebf432005-07-31 04:57:49 -040094 appended after any matching localversion* files, and after the value
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020095 set in CONFIG_LOCALVERSION.
Ryan Andersonaaebf432005-07-31 04:57:49 -040096
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020097 (The actual string used here is the first eight characters produced
98 by running the command:
99
100 $ git rev-parse --verify HEAD
101
102 which is done within the script "scripts/setlocalversion".)
Ryan Andersonaaebf432005-07-31 04:57:49 -0400103
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104config SWAP
105 bool "Support for paging of anonymous memory (swap)"
David Howells93614012006-09-30 20:45:40 +0200106 depends on MMU && BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 default y
108 help
109 This option allows you to choose whether you want to have support
Jesper Juhl92c35042006-01-15 02:40:08 +0100110 for so called swap devices or swap files in your kernel that are
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 used to provide more virtual memory than the actual RAM present
112 in your computer. If unsure say Y.
113
114config SYSVIPC
115 bool "System V IPC"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 ---help---
117 Inter Process Communication is a suite of library functions and
118 system calls which let processes (running programs) synchronize and
119 exchange information. It is generally considered to be a good thing,
120 and some programs won't run unless you say Y here. In particular, if
121 you want to run the DOS emulator dosemu under Linux (read the
122 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
123 you'll need to say Y here.
124
125 You can find documentation about IPC with "info ipc" and also in
126 section 6.4 of the Linux Programmer's Guide, available from
127 <http://www.tldp.org/guides.html>.
128
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800129config SYSVIPC_SYSCTL
130 bool
131 depends on SYSVIPC
132 depends on SYSCTL
133 default y
134
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135config POSIX_MQUEUE
136 bool "POSIX Message Queues"
137 depends on NET && EXPERIMENTAL
138 ---help---
139 POSIX variant of message queues is a part of IPC. In POSIX message
140 queues every message has a priority which decides about succession
141 of receiving it by a process. If you want to compile and run
142 programs written e.g. for Solaris with use of its POSIX message
Robert P. J. Dayb0e37652007-05-09 07:25:13 +0200143 queues (functions mq_*) say Y here.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144
145 POSIX message queues are visible as a filesystem called 'mqueue'
146 and can be mounted somewhere if you want to do filesystem
147 operations on message queues.
148
149 If unsure, say Y.
150
151config BSD_PROCESS_ACCT
152 bool "BSD Process Accounting"
153 help
154 If you say Y here, a user level program will be able to instruct the
155 kernel (via a special system call) to write process accounting
156 information to a file: whenever a process exits, information about
157 that process will be appended to the file by the kernel. The
158 information includes things such as creation time, owning user,
159 command name, memory usage, controlling terminal etc. (the complete
160 list is in the struct acct in <file:include/linux/acct.h>). It is
161 up to the user level program to do useful things with this
162 information. This is generally a good idea, so say Y.
163
164config BSD_PROCESS_ACCT_V3
165 bool "BSD Process Accounting version 3 file format"
166 depends on BSD_PROCESS_ACCT
167 default n
168 help
169 If you say Y here, the process accounting information is written
170 in a new file format that also logs the process IDs of each
171 process and it's parent. Note that this file format is incompatible
172 with previous v0/v1/v2 file formats, so you will need updated tools
173 for processing it. A preliminary version of these tools is available
S.Çağlar Onur37a4c942008-06-18 11:45:13 +0300174 at <http://www.gnu.org/software/acct/>.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175
Shailabh Nagarc7572492006-07-14 00:24:40 -0700176config TASKSTATS
177 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
178 depends on NET
179 default n
180 help
181 Export selected statistics for tasks/processes through the
182 generic netlink interface. Unlike BSD process accounting, the
183 statistics are available during the lifetime of tasks/processes as
184 responses to commands. Like BSD accounting, they are sent to user
185 space on task exit.
186
187 Say N if unsure.
188
Shailabh Nagarca74e922006-07-14 00:24:36 -0700189config TASK_DELAY_ACCT
190 bool "Enable per-task delay accounting (EXPERIMENTAL)"
Shailabh Nagar6f449932006-07-14 00:24:41 -0700191 depends on TASKSTATS
Shailabh Nagarca74e922006-07-14 00:24:36 -0700192 help
193 Collect information on time spent by a task waiting for system
194 resources like cpu, synchronous block I/O completion and swapping
195 in pages. Such statistics can help in setting a task's priorities
196 relative to other tasks for cpu, io, rss limits etc.
197
198 Say N if unsure.
199
Alexey Dobriyan18f705f2007-02-10 01:46:44 -0800200config TASK_XACCT
201 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
202 depends on TASKSTATS
203 help
204 Collect extended task accounting data and send the data
205 to userland for processing over the taskstats interface.
206
207 Say N if unsure.
208
209config TASK_IO_ACCOUNTING
210 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
211 depends on TASK_XACCT
212 help
213 Collect information on the number of bytes of storage I/O which this
214 task has caused.
215
216 Say N if unsure.
217
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218config AUDIT
219 bool "Auditing support"
Chris Wright804a6a42005-05-11 10:52:45 +0100220 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 help
222 Enable auditing infrastructure that can be used with another
223 kernel subsystem, such as SELinux (which requires this for
224 logging of avc messages output). Does not do system-call
225 auditing without CONFIG_AUDITSYSCALL.
226
227config AUDITSYSCALL
228 bool "Enable system-call auditing support"
Yuichi Nakamura1322b9d2007-11-10 19:21:34 +0900229 depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64|| SUPERH)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 default y if SECURITY_SELINUX
231 help
232 Enable low-overhead system-call auditing infrastructure that
233 can be used independently or with another kernel subsystem,
Amy Griffisf368c07d2006-04-07 16:55:56 -0400234 such as SELinux. To use audit's filesystem watch feature, please
235 ensure that INOTIFY is configured.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236
Al Viro74c3cbe2007-07-22 08:04:18 -0400237config AUDIT_TREE
238 def_bool y
239 depends on AUDITSYSCALL && INOTIFY
240
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700242 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243 ---help---
244 This option enables the complete Linux kernel ".config" file
245 contents to be saved in the kernel. It provides documentation
246 of which kernel options are used in a running kernel or in an
247 on-disk kernel. This information can be extracted from the kernel
248 image file with the script scripts/extract-ikconfig and used as
249 input to rebuild the current kernel or to build another kernel.
250 It can also be extracted from a running kernel by reading
251 /proc/config.gz if enabled (below).
252
253config IKCONFIG_PROC
254 bool "Enable access to .config through /proc/config.gz"
255 depends on IKCONFIG && PROC_FS
256 ---help---
257 This option enables access to the kernel configuration file
258 through /proc/config.gz.
259
Alistair John Strachan794543a2007-05-08 00:31:15 -0700260config LOG_BUF_SHIFT
261 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
262 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700263 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700264 help
265 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700266 Examples:
267 17 => 128 KB
268 16 => 64 KB
269 15 => 32 KB
270 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700271 13 => 8 KB
272 12 => 4 KB
273
Paul Menageddbcc7e2007-10-18 23:39:30 -0700274config CGROUPS
275 bool "Control Group support"
276 help
277 This option will let you use process cgroup subsystems
278 such as Cpusets
279
280 Say N if unsure.
281
Paul Menage006cb992007-10-18 23:39:43 -0700282config CGROUP_DEBUG
283 bool "Example debug cgroup subsystem"
284 depends on CGROUPS
Paul Menage418d7d82008-04-29 01:00:05 -0700285 default n
Paul Menage006cb992007-10-18 23:39:43 -0700286 help
287 This option enables a simple cgroup subsystem that
288 exports useful debugging information about the cgroups
289 framework
290
291 Say N if unsure
292
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700293config CGROUP_NS
294 bool "Namespace cgroup subsystem"
295 depends on CGROUPS
296 help
297 Provides a simple namespace cgroup subsystem to
298 provide hierarchical naming of sets of namespaces,
299 for instance virtual servers and checkpoint/restart
300 jobs.
301
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700302config CGROUP_FREEZER
303 bool "control group freezer subsystem"
304 depends on CGROUPS
305 help
306 Provides a way to freeze and unfreeze all tasks in a
307 cgroup.
308
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700309config CGROUP_DEVICE
310 bool "Device controller for cgroups"
311 depends on CGROUPS && EXPERIMENTAL
312 help
313 Provides a cgroup implementing whitelists for devices which
314 a process in the cgroup can mknod or open.
315
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316config CPUSETS
317 bool "Cpuset support"
Paul Menage8793d852007-10-18 23:39:39 -0700318 depends on SMP && CGROUPS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700320 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 allow dynamically partitioning a system into sets of CPUs and
322 Memory Nodes and assigning tasks to run only within those sets.
323 This is primarily useful on large SMP or NUMA systems.
324
325 Say N if unsure.
326
Ingo Molnara5574cf2008-05-05 23:19:50 +0200327#
328# Architectures with an unreliable sched_clock() should select this:
329#
330config HAVE_UNSTABLE_SCHED_CLOCK
331 bool
332
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100333config GROUP_SCHED
334 bool "Group CPU scheduler"
Parag Warudkaraac6abc2008-05-03 20:42:34 -0400335 depends on EXPERIMENTAL
336 default n
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +0200337 help
Srivatsa Vaddagirifb615582007-10-15 17:00:12 +0200338 This feature lets CPU scheduler recognize task groups and control CPU
Srivatsa Vaddagiri9b5b7752007-10-15 17:00:09 +0200339 bandwidth allocation to such task groups.
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +0200340
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100341config FAIR_GROUP_SCHED
342 bool "Group scheduling for SCHED_OTHER"
343 depends on GROUP_SCHED
Parag Warudkaraac6abc2008-05-03 20:42:34 -0400344 default GROUP_SCHED
Srivatsa Vaddagiri24e377a2007-10-15 17:00:09 +0200345
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100346config RT_GROUP_SCHED
347 bool "Group scheduling for SCHED_RR/FIFO"
348 depends on EXPERIMENTAL
349 depends on GROUP_SCHED
350 default n
Viktor Radnaib9b158f2008-04-19 19:45:01 +0200351 help
352 This feature lets you explicitly allocate real CPU bandwidth
353 to users or control groups (depending on the "Basis for grouping tasks"
354 setting below. If enabled, it will also make it impossible to
355 schedule realtime tasks for non-root users until you allocate
356 realtime bandwidth for them.
Adrian Knoth2fe401e2008-11-12 16:23:55 -0800357 See Documentation/scheduler/sched-rt-group.txt for more information.
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100358
359choice
360 depends on GROUP_SCHED
361 prompt "Basis for grouping tasks"
362 default USER_SCHED
363
364config USER_SCHED
Srivatsa Vaddagirifb615582007-10-15 17:00:12 +0200365 bool "user id"
366 help
367 This option will choose userid as the basis for grouping
368 tasks, thus providing equal CPU bandwidth to each user.
Srivatsa Vaddagiri24e377a2007-10-15 17:00:09 +0200369
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100370config CGROUP_SCHED
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -0700371 bool "Control groups"
372 depends on CGROUPS
373 help
374 This option allows you to create arbitrary task groups
375 using the "cgroup" pseudo filesystem and control
376 the cpu bandwidth allocated to each such task group.
377 Refer to Documentation/cgroups.txt for more information
378 on "cgroup" pseudo filesystem.
379
Srivatsa Vaddagiri24e377a2007-10-15 17:00:09 +0200380endchoice
381
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100382config CGROUP_CPUACCT
383 bool "Simple CPU accounting cgroup subsystem"
384 depends on CGROUPS
385 help
386 Provides a simple Resource Controller for monitoring the
387 total CPU consumed by the tasks in a cgroup
388
Pavel Emelianove552b662008-02-07 00:13:49 -0800389config RESOURCE_COUNTERS
390 bool "Resource counters"
391 help
392 This option enables controller independent resource accounting
393 infrastructure that works with cgroups
394 depends on CGROUPS
395
Balbir Singhcf475ad2008-04-29 01:00:16 -0700396config MM_OWNER
397 bool
398
Balbir Singh00f0b822008-03-04 14:28:39 -0800399config CGROUP_MEM_RES_CTLR
400 bool "Memory Resource Controller for Control Groups"
401 depends on CGROUPS && RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700402 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800403 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700404 Provides a memory resource controller that manages both anonymous
405 memory and page cache. (See Documentation/controllers/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800406
407 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700408 associated with each page of memory in the system. By this,
409 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
410 usage tracking struct at boot. Total amount of this is printed out
411 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800412
413 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700414 sure you need the memory resource controller. Even when you enable
415 this, you can set "cgroup_disable=memory" at your boot option to
416 disable memory resource controller and you can avoid overheads.
417 (and lose benefits of memory resource contoller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800418
Balbir Singhcf475ad2008-04-29 01:00:16 -0700419 This config option also selects MM_OWNER config option, which
420 could in turn add some fork/exit overhead.
421
Kay Sievers88a22c92006-09-14 11:23:28 +0200422config SYSFS_DEPRECATED
Ingo Molnard47846c2008-03-04 14:54:47 +0100423 bool
424
425config SYSFS_DEPRECATED_V2
Kay Sievers88a22c92006-09-14 11:23:28 +0200426 bool "Create deprecated sysfs files"
Randy Dunlap9148fe82007-12-31 10:05:34 -0800427 depends on SYSFS
Kay Sievers88a22c92006-09-14 11:23:28 +0200428 default y
Ingo Molnard47846c2008-03-04 14:54:47 +0100429 select SYSFS_DEPRECATED
Kay Sievers88a22c92006-09-14 11:23:28 +0200430 help
431 This option creates deprecated symlinks such as the
432 "device"-link, the <subsystem>:<name>-link, and the
433 "bus"-link. It may also add deprecated key in the
434 uevent environment.
435 None of these features or values should be used today, as
436 they export driver core implementation details to userspace
437 or export properties which can't be kept stable across kernel
438 releases.
439
440 If enabled, this option will also move any device structures
David Sterba3dde6ad2007-05-09 07:12:20 +0200441 that belong to a class, back into the /sys/class hierarchy, in
Greg Kroah-Hartman024440d2008-03-03 14:47:13 -0800442 order to support older versions of udev and some userspace
443 programs.
Kay Sievers88a22c92006-09-14 11:23:28 +0200444
Greg Kroah-Hartman024440d2008-03-03 14:47:13 -0800445 If you are using a distro with the most recent userspace
446 packages, it should be safe to say N here.
Kay Sievers88a22c92006-09-14 11:23:28 +0200447
Paul Menage8793d852007-10-18 23:39:39 -0700448config PROC_PID_CPUSET
449 bool "Include legacy /proc/<pid>/cpuset file"
450 depends on CPUSETS
451 default y
452
Jens Axboeb86ff982006-03-23 19:56:55 +0100453config RELAY
454 bool "Kernel->user space relay support (formerly relayfs)"
455 help
456 This option enables support for relay interface support in
457 certain file systems (such as debugfs).
458 It is designed to provide an efficient mechanism for tools and
459 facilities to relay large amounts of data from kernel space to
460 user space.
461
462 If unsure, say N.
463
Pavel Emelyanovc5289a62008-02-08 04:18:19 -0800464config NAMESPACES
465 bool "Namespaces support" if EMBEDDED
466 default !EMBEDDED
467 help
468 Provides the way to make tasks work with different objects using
469 the same id. For example same IPC id may refer to different objects
470 or same user id or pid may refer to different tasks when used in
471 different namespaces.
472
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800473config UTS_NS
474 bool "UTS namespace"
475 depends on NAMESPACES
476 help
477 In this namespace tasks see different info provided with the
478 uname() system call
479
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800480config IPC_NS
481 bool "IPC namespace"
482 depends on NAMESPACES && SYSVIPC
483 help
484 In this namespace tasks work with IPC ids which correspond to
485 different IPC objects in different namespaces
486
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800487config USER_NS
488 bool "User namespace (EXPERIMENTAL)"
489 depends on NAMESPACES && EXPERIMENTAL
490 help
491 This allows containers, i.e. vservers, to use user namespaces
492 to provide different user info for different servers.
493 If unsure, say N.
494
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800495config PID_NS
496 bool "PID Namespaces (EXPERIMENTAL)"
497 default n
498 depends on NAMESPACES && EXPERIMENTAL
499 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +0300500 Support process id namespaces. This allows having multiple
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800501 process with the same pid as long as they are in different
502 pid namespaces. This is a building block of containers.
503
504 Unless you want to work with an experimental feature
505 say N here.
506
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -0800507config BLK_DEV_INITRD
508 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
509 depends on BROKEN || !FRV
510 help
511 The initial RAM filesystem is a ramfs which is loaded by the
512 boot loader (loadlin or lilo) and that is mounted as root
513 before the normal boot procedure. It is typically used to
514 load modules needed to mount the "real" root file system,
515 etc. See <file:Documentation/initrd.txt> for details.
516
517 If RAM disk support (BLK_DEV_RAM) is also included, this
518 also enables initial RAM disk (initrd) support and adds
519 15 Kbytes (more on some other architectures) to the kernel size.
520
521 If unsure say Y.
522
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800523if BLK_DEV_INITRD
524
Sam Ravnborgdbec4862005-08-10 20:44:50 +0200525source "usr/Kconfig"
526
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800527endif
528
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800529config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +0200530 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800531 default y
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800532 help
533 Enabling this option will pass "-Os" instead of "-O2" to gcc
534 resulting in a smaller kernel.
535
jkacur775a7222008-07-16 00:31:16 +0200536 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800537
Randy Dunlap08470622006-09-30 23:28:13 -0700538config SYSCTL
539 bool
540
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541menuconfig EMBEDDED
542 bool "Configure standard kernel features (for small systems)"
543 help
544 This option allows certain base kernel options and settings
545 to be disabled or tweaked. This is for specialized
546 environments which can tolerate a "non-standard" kernel.
547 Only use this if you really know what you are doing.
548
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700549config UID16
550 bool "Enable 16-bit UID system calls" if EMBEDDED
David S. Miller09337f52008-04-26 03:17:12 -0700551 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 -0700552 default y
553 help
554 This enables the legacy 16-bit UID syscall wrappers.
555
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700556config SYSCTL_SYSCALL
Randy Dunlap08470622006-09-30 23:28:13 -0700557 bool "Sysctl syscall support" if EMBEDDED
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800558 default y
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700559 select SYSCTL
560 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800561 sys_sysctl uses binary paths that have been found challenging
562 to properly maintain and use. The interface in /proc/sys
563 using paths with ascii names is now the primary path to this
564 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700565
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800566 Almost nothing using the binary sysctl interface so if you are
567 trying to save some space it is probably safe to disable this,
568 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700569
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800570 If unsure say Y here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700571
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572config KALLSYMS
Jesper Juhl979c6a12006-12-12 19:25:11 +0100573 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574 default y
575 help
576 Say Y here to let the kernel print out symbolic crash information and
577 symbolic stack backtraces. This increases the size of the kernel
578 somewhat, as all symbols have to be loaded into the kernel image.
579
580config KALLSYMS_ALL
581 bool "Include all symbols in kallsyms"
582 depends on DEBUG_KERNEL && KALLSYMS
583 help
584 Normally kallsyms only contains the symbols of functions, for nicer
585 OOPS messages. Some debuggers can use kallsyms for other
Jesper Juhlf9f97bc2005-07-20 05:43:05 +0200586 symbols too: say Y here to include all symbols, if you need them
587 and you don't care about adding 300k to the size of your kernel.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588
589 Say N.
590
591config KALLSYMS_EXTRA_PASS
592 bool "Do an extra kallsyms pass"
593 depends on KALLSYMS
594 help
595 If kallsyms is not working correctly, the build will fail with
596 inconsistent kallsyms data. If that occurs, log a bug report and
597 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
598 Always say N here unless you find a bug in kallsyms, which must be
599 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
600 you wait for kallsyms to be fixed.
601
Matt Mackalld59745c2005-05-01 08:59:02 -0700602
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -0800603config HOTPLUG
604 bool "Support for hot-pluggable devices" if EMBEDDED
605 default y
606 help
607 This option is provided for the case where no hotplug or uevent
608 capabilities is wanted by the kernel. You should only consider
609 disabling this option for embedded systems that do not use modules, a
610 dynamic /dev tree, or dynamic device discovery. Just say Y.
611
Matt Mackalld59745c2005-05-01 08:59:02 -0700612config PRINTK
613 default y
614 bool "Enable support for printk" if EMBEDDED
615 help
616 This option enables normal printk support. Removing it
617 eliminates most of the message strings from the kernel image
618 and makes the kernel more or less silent. As this makes it
619 very difficult to diagnose system problems, saying N here is
620 strongly discouraged.
621
Matt Mackallc8538a72005-05-01 08:59:01 -0700622config BUG
623 bool "BUG() support" if EMBEDDED
624 default y
625 help
626 Disabling this option eliminates support for BUG and WARN, reducing
627 the size of your kernel image and potentially quietly ignoring
628 numerous fatal conditions. You should only consider disabling this
629 option for embedded systems with no facilities for reporting errors.
630 Just say Y.
631
Matt Mackall708e9a72006-01-08 01:05:25 -0800632config ELF_CORE
633 default y
634 bool "Enable ELF core dumps" if EMBEDDED
635 help
636 Enable support for generating core dumps. Disabling saves about 4k.
637
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +0200638config PCSPKR_PLATFORM
639 bool "Enable PC-Speaker support" if EMBEDDED
640 depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES
641 default y
642 help
643 This option allows to disable the internal PC-Speaker
644 support, saving some memory.
645
Ingo Molnar32a93232008-02-06 22:39:44 +0100646config COMPAT_BRK
647 bool "Disable heap randomization"
648 default y
649 help
650 Randomizing heap placement makes heap exploits harder, but it
651 also breaks ancient binaries (including anything libc5 based).
652 This option changes the bootup default to heap randomization
653 disabled, and can be overriden runtime by setting
654 /proc/sys/kernel/randomize_va_space to 2.
655
Ingo Molnar166124f2008-02-09 23:24:09 +0100656 On non-ancient distros (post-2000 ones) N is usually a safe choice.
Ingo Molnar32a93232008-02-06 22:39:44 +0100657
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658config BASE_FULL
659 default y
660 bool "Enable full-sized data structures for core" if EMBEDDED
661 help
662 Disabling this option reduces the size of miscellaneous core
663 kernel data structures. This saves memory on small machines,
664 but may reduce performance.
665
666config FUTEX
667 bool "Enable futex support" if EMBEDDED
668 default y
Ingo Molnar23f78d42006-06-27 02:54:53 -0700669 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 help
671 Disabling this option will cause the kernel to be built without
672 support for "fast userspace mutexes". The resulting kernel may not
673 run glibc-based applications correctly.
674
Davide Libenzi5dc8bf82007-05-10 22:23:11 -0700675config ANON_INODES
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700676 bool
Davide Libenzi5dc8bf82007-05-10 22:23:11 -0700677
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678config EPOLL
679 bool "Enable eventpoll support" if EMBEDDED
680 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700681 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682 help
683 Disabling this option will cause the kernel to be built without
684 support for epoll family of system calls.
685
Davide Libenzifba2afa2007-05-10 22:23:13 -0700686config SIGNALFD
687 bool "Enable signalfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700688 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -0700689 default y
690 help
691 Enable the signalfd() system call that allows to receive signals
692 on a file descriptor.
693
694 If unsure, say Y.
695
Davide Libenzib215e282007-05-10 22:23:16 -0700696config TIMERFD
697 bool "Enable timerfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700698 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -0700699 default y
700 help
701 Enable the timerfd() system call that allows to receive timer
702 events on a file descriptor.
703
704 If unsure, say Y.
705
Davide Libenzie1ad7462007-05-10 22:23:19 -0700706config EVENTFD
707 bool "Enable eventfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700708 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -0700709 default y
710 help
711 Enable the eventfd() system call that allows to receive both
712 kernel notification (ie. KAIO) or userspace notifications.
713
714 If unsure, say Y.
715
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716config SHMEM
717 bool "Use full shmem filesystem" if EMBEDDED
718 default y
719 depends on MMU
720 help
721 The shmem is an internal filesystem used to manage shared memory.
722 It is backed by swap and manages resource limits. It is also exported
723 to userspace as tmpfs if TMPFS is enabled. Disabling this
724 option replaces shmem and tmpfs with the much simpler ramfs code,
725 which may be appropriate on small systems without swap.
726
Thomas Petazzoniebf3f092008-10-15 22:05:12 -0700727config AIO
728 bool "Enable AIO support" if EMBEDDED
729 default y
730 help
731 This option enables POSIX asynchronous I/O which may by used
732 by some high performance threaded applications. Disabling
733 this option saves about 7k.
734
Thomas Gleixner0793a612008-12-04 20:12:29 +0100735config HAVE_PERF_COUNTERS
736 bool
737
738menu "Performance Counters"
739
740config PERF_COUNTERS
741 bool "Kernel Performance Counters"
742 depends on HAVE_PERF_COUNTERS
743 default y
Ingo Molnar4c59e462008-12-08 19:38:33 +0100744 select ANON_INODES
Thomas Gleixner0793a612008-12-04 20:12:29 +0100745 help
746 Enable kernel support for performance counter hardware.
747
748 Performance counters are special hardware registers available
749 on most modern CPUs. These registers count the number of certain
750 types of hw events: such as instructions executed, cachemisses
751 suffered, or branches mis-predicted - without slowing down the
752 kernel or applications. These registers can also trigger interrupts
753 when a threshold number of events have passed - and can thus be
754 used to profile the code that runs on that CPU.
755
756 The Linux Performance Counter subsystem provides an abstraction of
757 these hardware capabilities, available via a system call. It
758 provides per task and per CPU counters, and it provides event
759 capabilities on top of those.
760
761 Say Y if unsure.
762
763endmenu
764
Christoph Lameterf8891e52006-06-30 01:55:45 -0700765config VM_EVENT_COUNTERS
766 default y
767 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
768 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -0800769 VM event counters are needed for event counts to be shown.
770 This option allows the disabling of the VM event counters
771 on EMBEDDED systems. /proc/vmstat will only show page counts
772 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -0700773
Thomas Petazzoni3d137312008-08-19 10:28:24 +0200774config PCI_QUIRKS
775 default y
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +0200776 bool "Enable PCI quirk workarounds" if EMBEDDED
777 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +0200778 help
779 This enables workarounds for various PCI chipset
780 bugs/quirks. Disable this only if your target machine is
781 unaffected by PCI quirks.
782
Christoph Lameter41ecc552007-05-09 02:32:44 -0700783config SLUB_DEBUG
784 default y
785 bool "Enable SLUB debugging support" if EMBEDDED
Christoph Lameterf6acb632008-04-29 16:16:06 -0700786 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -0700787 help
788 SLUB has extensive debug support features. Disabling these can
789 result in significant savings in code size. This also disables
790 SLUB sysfs support. /sys/slab will not exist and there will be
791 no support for cache validation etc.
792
Christoph Lameter81819f02007-05-06 14:49:36 -0700793choice
794 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -0700795 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -0700796 help
797 This option allows to select a slab allocator.
798
799config SLAB
800 bool "SLAB"
801 help
802 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -0700803 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +0000804 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -0700805
806config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -0700807 bool "SLUB (Unqueued Allocator)"
808 help
809 SLUB is a slab allocator that minimizes cache line usage
810 instead of managing queues of cached objects (SLAB approach).
811 Per cpu caching is realized using slabs of objects instead
812 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +0000813 and has enhanced diagnostics. SLUB is the default choice for
814 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -0700815
816config SLOB
Paul Mundt84a01c22007-07-15 23:38:24 -0700817 depends on EMBEDDED
Christoph Lameter81819f02007-05-06 14:49:36 -0700818 bool "SLOB (Simple Allocator)"
819 help
Matt Mackall37291452008-02-04 22:29:38 -0800820 SLOB replaces the stock allocator with a drastically simpler
821 allocator. SLOB is generally more space efficient but
822 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -0700823
824endchoice
825
Mathieu Desnoyers125e5642008-02-02 15:10:36 -0500826config PROFILING
827 bool "Profiling support (EXPERIMENTAL)"
828 help
829 Say Y here to enable the extended profiling support mechanisms used
830 by profilers such as OProfile.
831
Ingo Molnar5f87f112008-07-23 14:15:22 +0200832#
833# Place an empty function call at each tracepoint site. Can be
834# dynamically changed for a probe function.
835#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -0400836config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +0200837 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -0400838
Mathieu Desnoyers125e5642008-02-02 15:10:36 -0500839config MARKERS
840 bool "Activate markers"
841 help
842 Place an empty function call at each marker site. Can be
843 dynamically changed for a probe function.
844
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -0500845source "arch/Kconfig"
846
Linus Torvalds1da177e2005-04-16 15:20:36 -0700847endmenu # General setup
848
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +0400849config HAVE_GENERIC_DMA_COHERENT
850 bool
851 default n
852
Linus Torvalds158a9622008-01-02 13:04:48 -0800853config SLABINFO
854 bool
855 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +0300856 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -0800857 default y
858
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700859config RT_MUTEXES
860 boolean
861 select PLIST
862
Linus Torvalds1da177e2005-04-16 15:20:36 -0700863config TINY_SHMEM
864 default !SHMEM
865 bool
866
867config BASE_SMALL
868 int
869 default 0 if BASE_FULL
870 default 1 if !BASE_FULL
871
Jan Engelhardt66da5732007-07-15 23:39:29 -0700872menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700873 bool "Enable loadable module support"
874 help
875 Kernel modules are small pieces of compiled code which can
876 be inserted in the running kernel, rather than being
877 permanently built into the kernel. You use the "modprobe"
878 tool to add (and sometimes remove) them. If you say Y here,
879 many parts of the kernel can be built as modules (by
880 answering M instead of Y where indicated): this is most
881 useful for infrequently used options which are not required
882 for booting. For more information, see the man pages for
883 modprobe, lsmod, modinfo, insmod and rmmod.
884
885 If you say Y here, you will need to run "make
886 modules_install" to put the modules under /lib/modules/
887 where modprobe can find them (you may need to be root to do
888 this).
889
890 If unsure, say Y.
891
Robert P. J. Day0b0de142008-08-04 13:31:32 -0400892if MODULES
893
Linus Torvalds826e4502008-05-04 17:04:16 -0700894config MODULE_FORCE_LOAD
895 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -0700896 default n
897 help
Rusty Russell91e37a72008-05-09 16:25:28 +1000898 Allow loading of modules without version information (ie. modprobe
899 --force). Forced module loading sets the 'F' (forced) taint flag and
900 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -0700901
Linus Torvalds1da177e2005-04-16 15:20:36 -0700902config MODULE_UNLOAD
903 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700904 help
905 Without this option you will not be able to unload any
906 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -0500907 anyway), which makes your kernel smaller, faster
908 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700909
910config MODULE_FORCE_UNLOAD
911 bool "Forced module unloading"
912 depends on MODULE_UNLOAD && EXPERIMENTAL
913 help
914 This option allows you to force a module to unload, even if the
915 kernel believes it is unsafe: the kernel will remove the module
916 without waiting for anyone to stop using it (using the -f option to
917 rmmod). This is mainly for kernel developers and desperate users.
918 If unsure, say N.
919
Linus Torvalds1da177e2005-04-16 15:20:36 -0700920config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +0100921 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700922 help
923 Usually, you have to use modules compiled with your kernel.
924 Saying Y here makes it sometimes possible to use modules
925 compiled for different kernels, by adding enough information
926 to the modules to (hopefully) spot any changes which would
927 make them incompatible with the kernel you are running. If
928 unsure, say N.
929
930config MODULE_SRCVERSION_ALL
931 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700932 help
933 Modules which contain a MODULE_VERSION get an extra "srcversion"
934 field inserted into their modinfo section, which contains a
935 sum of the source files which made it. This helps maintainers
936 see exactly which source was used to build a module (since
937 others sometimes change the module source without updating
938 the version). With this option, such a "srcversion" field
939 will be created for all modules. If unsure, say N.
940
941config KMOD
Johannes Bergbaabaae2008-07-08 19:00:16 +0200942 def_bool y
Linus Torvalds1da177e2005-04-16 15:20:36 -0700943 help
Johannes Bergbaabaae2008-07-08 19:00:16 +0200944 This is being removed soon. These days, CONFIG_MODULES
945 implies CONFIG_KMOD, so use that instead.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700946
Robert P. J. Day0b0de142008-08-04 13:31:32 -0400947endif # MODULES
948
Linus Torvalds1da177e2005-04-16 15:20:36 -0700949config STOP_MACHINE
950 bool
951 default y
952 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
953 help
954 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +0100955
Jens Axboe3a65dfe2005-11-04 08:43:35 +0100956source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -0700957
958config PREEMPT_NOTIFIERS
959 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +0100960
Paul E. McKenneye260be62008-01-25 21:08:24 +0100961config CLASSIC_RCU
Paul E. McKenney21bbb392008-03-10 11:43:57 -0700962 def_bool !PREEMPT_RCU
Paul E. McKenneye260be62008-01-25 21:08:24 +0100963 help
964 This option selects the classic RCU implementation that is
965 designed for best read-side performance on non-realtime
Paul E. McKenney21bbb392008-03-10 11:43:57 -0700966 systems. Classic RCU is the default. Note that the
967 PREEMPT_RCU symbol is used to select/deselect this option.