blob: a3457926342a5115ae494e53918fc273ca926f47 [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"
16 default "arch/$ARCH/defconfig"
17
Al Boldiff0cfc62007-07-31 00:39:23 -070018menu "General setup"
Linus Torvalds1da177e2005-04-16 15:20:36 -070019
20config EXPERIMENTAL
21 bool "Prompt for development and/or incomplete code/drivers"
22 ---help---
23 Some of the various things that Linux supports (such as network
24 drivers, file systems, network protocols, etc.) can be in a state
25 of development where the functionality, stability, or the level of
26 testing is not yet high enough for general use. This is usually
27 known as the "alpha-test" phase among developers. If a feature is
28 currently in alpha-test, then the developers usually discourage
29 uninformed widespread use of this feature by the general public to
30 avoid "Why doesn't this work?" type mail messages. However, active
31 testing and use of these systems is welcomed. Just be aware that it
32 may not meet the normal level of reliability or it may fail to work
33 in some special cases. Detailed bug reports from people familiar
34 with the kernel internals are usually welcomed by the developers
35 (before submitting bug reports, please read the documents
36 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
37 <file:Documentation/BUG-HUNTING>, and
38 <file:Documentation/oops-tracing.txt> in the kernel source).
39
40 This option will also make obsoleted drivers available. These are
41 drivers that have been replaced by something else, and/or are
42 scheduled to be removed in a future kernel release.
43
44 Unless you intend to help test and develop a feature or driver that
45 falls into this category, or you have a situation that requires
46 using these features, you should probably say N here, which will
47 cause the configurator to present you with fewer choices. If
48 you say Y here, you will be offered the choice of using features or
49 drivers that are currently considered to be in the alpha-test phase.
50
Linus Torvalds1da177e2005-04-16 15:20:36 -070051config BROKEN
52 bool
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
54config BROKEN_ON_SMP
55 bool
56 depends on BROKEN || !SMP
57 default y
58
59config LOCK_KERNEL
60 bool
61 depends on SMP || PREEMPT
62 default y
63
64config INIT_ENV_ARG_LIMIT
65 int
Adrian Bunkdd673bc2006-06-30 01:55:51 -070066 default 32 if !UML
67 default 128 if UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070068 help
Randy Dunlap34ad92c2005-10-30 15:01:46 -080069 Maximum of each of the number of arguments and environment
70 variables passed to init from the kernel command line.
Linus Torvalds1da177e2005-04-16 15:20:36 -070071
Linus Torvalds1da177e2005-04-16 15:20:36 -070072
73config LOCALVERSION
74 string "Local version - append to kernel release"
75 help
76 Append an extra string to the end of your kernel version.
77 This will show up when you type uname, for example.
78 The string you set here will be appended after the contents of
79 any files with a filename matching localversion* in your
80 object and source tree, in that order. Your total string can
81 be a maximum of 64 characters.
82
Ryan Andersonaaebf432005-07-31 04:57:49 -040083config LOCALVERSION_AUTO
84 bool "Automatically append version information to the version string"
85 default y
86 help
87 This will try to automatically determine if the current tree is a
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020088 release tree by looking for git tags that belong to the current
89 top of tree revision.
Ryan Andersonaaebf432005-07-31 04:57:49 -040090
91 A string of the format -gxxxxxxxx will be added to the localversion
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020092 if a git-based tree is found. The string generated by this will be
Ryan Andersonaaebf432005-07-31 04:57:49 -040093 appended after any matching localversion* files, and after the value
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020094 set in CONFIG_LOCALVERSION.
Ryan Andersonaaebf432005-07-31 04:57:49 -040095
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020096 (The actual string used here is the first eight characters produced
97 by running the command:
98
99 $ git rev-parse --verify HEAD
100
101 which is done within the script "scripts/setlocalversion".)
Ryan Andersonaaebf432005-07-31 04:57:49 -0400102
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103config SWAP
104 bool "Support for paging of anonymous memory (swap)"
David Howells93614012006-09-30 20:45:40 +0200105 depends on MMU && BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 default y
107 help
108 This option allows you to choose whether you want to have support
Jesper Juhl92c35042006-01-15 02:40:08 +0100109 for so called swap devices or swap files in your kernel that are
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110 used to provide more virtual memory than the actual RAM present
111 in your computer. If unsure say Y.
112
113config SYSVIPC
114 bool "System V IPC"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115 ---help---
116 Inter Process Communication is a suite of library functions and
117 system calls which let processes (running programs) synchronize and
118 exchange information. It is generally considered to be a good thing,
119 and some programs won't run unless you say Y here. In particular, if
120 you want to run the DOS emulator dosemu under Linux (read the
121 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
122 you'll need to say Y here.
123
124 You can find documentation about IPC with "info ipc" and also in
125 section 6.4 of the Linux Programmer's Guide, available from
126 <http://www.tldp.org/guides.html>.
127
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800128config SYSVIPC_SYSCTL
129 bool
130 depends on SYSVIPC
131 depends on SYSCTL
132 default y
133
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134config POSIX_MQUEUE
135 bool "POSIX Message Queues"
136 depends on NET && EXPERIMENTAL
137 ---help---
138 POSIX variant of message queues is a part of IPC. In POSIX message
139 queues every message has a priority which decides about succession
140 of receiving it by a process. If you want to compile and run
141 programs written e.g. for Solaris with use of its POSIX message
Robert P. J. Dayb0e37652007-05-09 07:25:13 +0200142 queues (functions mq_*) say Y here.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143
144 POSIX message queues are visible as a filesystem called 'mqueue'
145 and can be mounted somewhere if you want to do filesystem
146 operations on message queues.
147
148 If unsure, say Y.
149
150config BSD_PROCESS_ACCT
151 bool "BSD Process Accounting"
152 help
153 If you say Y here, a user level program will be able to instruct the
154 kernel (via a special system call) to write process accounting
155 information to a file: whenever a process exits, information about
156 that process will be appended to the file by the kernel. The
157 information includes things such as creation time, owning user,
158 command name, memory usage, controlling terminal etc. (the complete
159 list is in the struct acct in <file:include/linux/acct.h>). It is
160 up to the user level program to do useful things with this
161 information. This is generally a good idea, so say Y.
162
163config BSD_PROCESS_ACCT_V3
164 bool "BSD Process Accounting version 3 file format"
165 depends on BSD_PROCESS_ACCT
166 default n
167 help
168 If you say Y here, the process accounting information is written
169 in a new file format that also logs the process IDs of each
170 process and it's parent. Note that this file format is incompatible
171 with previous v0/v1/v2 file formats, so you will need updated tools
172 for processing it. A preliminary version of these tools is available
173 at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>.
174
Shailabh Nagarc7572492006-07-14 00:24:40 -0700175config TASKSTATS
176 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
177 depends on NET
178 default n
179 help
180 Export selected statistics for tasks/processes through the
181 generic netlink interface. Unlike BSD process accounting, the
182 statistics are available during the lifetime of tasks/processes as
183 responses to commands. Like BSD accounting, they are sent to user
184 space on task exit.
185
186 Say N if unsure.
187
Shailabh Nagarca74e922006-07-14 00:24:36 -0700188config TASK_DELAY_ACCT
189 bool "Enable per-task delay accounting (EXPERIMENTAL)"
Shailabh Nagar6f449932006-07-14 00:24:41 -0700190 depends on TASKSTATS
Shailabh Nagarca74e922006-07-14 00:24:36 -0700191 help
192 Collect information on time spent by a task waiting for system
193 resources like cpu, synchronous block I/O completion and swapping
194 in pages. Such statistics can help in setting a task's priorities
195 relative to other tasks for cpu, io, rss limits etc.
196
197 Say N if unsure.
198
Alexey Dobriyan18f705f2007-02-10 01:46:44 -0800199config TASK_XACCT
200 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
201 depends on TASKSTATS
202 help
203 Collect extended task accounting data and send the data
204 to userland for processing over the taskstats interface.
205
206 Say N if unsure.
207
208config TASK_IO_ACCOUNTING
209 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
210 depends on TASK_XACCT
211 help
212 Collect information on the number of bytes of storage I/O which this
213 task has caused.
214
215 Say N if unsure.
216
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217config AUDIT
218 bool "Auditing support"
Chris Wright804a6a492005-05-11 10:52:45 +0100219 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 help
221 Enable auditing infrastructure that can be used with another
222 kernel subsystem, such as SELinux (which requires this for
223 logging of avc messages output). Does not do system-call
224 auditing without CONFIG_AUDITSYSCALL.
225
226config AUDITSYSCALL
227 bool "Enable system-call auditing support"
Yuichi Nakamura1322b9d2007-11-10 19:21:34 +0900228 depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64|| SUPERH)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 default y if SECURITY_SELINUX
230 help
231 Enable low-overhead system-call auditing infrastructure that
232 can be used independently or with another kernel subsystem,
Amy Griffisf368c07d2006-04-07 16:55:56 -0400233 such as SELinux. To use audit's filesystem watch feature, please
234 ensure that INOTIFY is configured.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235
Al Viro74c3cbe2007-07-22 08:04:18 -0400236config AUDIT_TREE
237 def_bool y
238 depends on AUDITSYSCALL && INOTIFY
239
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700241 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242 ---help---
243 This option enables the complete Linux kernel ".config" file
244 contents to be saved in the kernel. It provides documentation
245 of which kernel options are used in a running kernel or in an
246 on-disk kernel. This information can be extracted from the kernel
247 image file with the script scripts/extract-ikconfig and used as
248 input to rebuild the current kernel or to build another kernel.
249 It can also be extracted from a running kernel by reading
250 /proc/config.gz if enabled (below).
251
252config IKCONFIG_PROC
253 bool "Enable access to .config through /proc/config.gz"
254 depends on IKCONFIG && PROC_FS
255 ---help---
256 This option enables access to the kernel configuration file
257 through /proc/config.gz.
258
Alistair John Strachan794543a2007-05-08 00:31:15 -0700259config LOG_BUF_SHIFT
260 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
261 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700262 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700263 help
264 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700265 Examples:
266 17 => 128 KB
267 16 => 64 KB
268 15 => 32 KB
269 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700270 13 => 8 KB
271 12 => 4 KB
272
Paul Menageddbcc7e2007-10-18 23:39:30 -0700273config CGROUPS
274 bool "Control Group support"
275 help
276 This option will let you use process cgroup subsystems
277 such as Cpusets
278
279 Say N if unsure.
280
Paul Menage006cb992007-10-18 23:39:43 -0700281config CGROUP_DEBUG
282 bool "Example debug cgroup subsystem"
283 depends on CGROUPS
Paul Menage418d7d82008-04-29 01:00:05 -0700284 default n
Paul Menage006cb992007-10-18 23:39:43 -0700285 help
286 This option enables a simple cgroup subsystem that
287 exports useful debugging information about the cgroups
288 framework
289
290 Say N if unsure
291
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700292config CGROUP_NS
293 bool "Namespace cgroup subsystem"
294 depends on CGROUPS
295 help
296 Provides a simple namespace cgroup subsystem to
297 provide hierarchical naming of sets of namespaces,
298 for instance virtual servers and checkpoint/restart
299 jobs.
300
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700301config CGROUP_DEVICE
302 bool "Device controller for cgroups"
303 depends on CGROUPS && EXPERIMENTAL
304 help
305 Provides a cgroup implementing whitelists for devices which
306 a process in the cgroup can mknod or open.
307
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308config CPUSETS
309 bool "Cpuset support"
Paul Menage8793d852007-10-18 23:39:39 -0700310 depends on SMP && CGROUPS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700312 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313 allow dynamically partitioning a system into sets of CPUs and
314 Memory Nodes and assigning tasks to run only within those sets.
315 This is primarily useful on large SMP or NUMA systems.
316
317 Say N if unsure.
318
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100319config GROUP_SCHED
320 bool "Group CPU scheduler"
Ingo Molnarde8d5852007-10-15 17:00:09 +0200321 default y
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +0200322 help
Srivatsa Vaddagirifb615582007-10-15 17:00:12 +0200323 This feature lets CPU scheduler recognize task groups and control CPU
Srivatsa Vaddagiri9b5b7752007-10-15 17:00:09 +0200324 bandwidth allocation to such task groups.
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +0200325
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100326config FAIR_GROUP_SCHED
327 bool "Group scheduling for SCHED_OTHER"
328 depends on GROUP_SCHED
329 default y
Srivatsa Vaddagiri24e377a2007-10-15 17:00:09 +0200330
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100331config RT_GROUP_SCHED
332 bool "Group scheduling for SCHED_RR/FIFO"
333 depends on EXPERIMENTAL
334 depends on GROUP_SCHED
335 default n
Viktor Radnaib9b158f2008-04-19 19:45:01 +0200336 help
337 This feature lets you explicitly allocate real CPU bandwidth
338 to users or control groups (depending on the "Basis for grouping tasks"
339 setting below. If enabled, it will also make it impossible to
340 schedule realtime tasks for non-root users until you allocate
341 realtime bandwidth for them.
342 See Documentation/sched-rt-group.txt for more information.
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100343
344choice
345 depends on GROUP_SCHED
346 prompt "Basis for grouping tasks"
347 default USER_SCHED
348
349config USER_SCHED
Srivatsa Vaddagirifb615582007-10-15 17:00:12 +0200350 bool "user id"
351 help
352 This option will choose userid as the basis for grouping
353 tasks, thus providing equal CPU bandwidth to each user.
Srivatsa Vaddagiri24e377a2007-10-15 17:00:09 +0200354
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100355config CGROUP_SCHED
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -0700356 bool "Control groups"
357 depends on CGROUPS
358 help
359 This option allows you to create arbitrary task groups
360 using the "cgroup" pseudo filesystem and control
361 the cpu bandwidth allocated to each such task group.
362 Refer to Documentation/cgroups.txt for more information
363 on "cgroup" pseudo filesystem.
364
Srivatsa Vaddagiri24e377a2007-10-15 17:00:09 +0200365endchoice
366
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100367config CGROUP_CPUACCT
368 bool "Simple CPU accounting cgroup subsystem"
369 depends on CGROUPS
370 help
371 Provides a simple Resource Controller for monitoring the
372 total CPU consumed by the tasks in a cgroup
373
Pavel Emelianove552b662008-02-07 00:13:49 -0800374config RESOURCE_COUNTERS
375 bool "Resource counters"
376 help
377 This option enables controller independent resource accounting
378 infrastructure that works with cgroups
379 depends on CGROUPS
380
Balbir Singh00f0b822008-03-04 14:28:39 -0800381config CGROUP_MEM_RES_CTLR
382 bool "Memory Resource Controller for Control Groups"
383 depends on CGROUPS && RESOURCE_COUNTERS
384 help
385 Provides a memory resource controller that manages both page cache and
386 RSS memory.
387
388 Note that setting this option increases fixed memory overhead
389 associated with each page of memory in the system by 4/8 bytes
390 and also increases cache misses because struct page on many 64bit
391 systems will not fit into a single cache line anymore.
392
393 Only enable when you're ok with these trade offs and really
394 sure you need the memory resource controller.
395
Kay Sievers88a22c92006-09-14 11:23:28 +0200396config SYSFS_DEPRECATED
Ingo Molnard47846c2008-03-04 14:54:47 +0100397 bool
398
399config SYSFS_DEPRECATED_V2
Kay Sievers88a22c92006-09-14 11:23:28 +0200400 bool "Create deprecated sysfs files"
Randy Dunlap9148fe82007-12-31 10:05:34 -0800401 depends on SYSFS
Kay Sievers88a22c92006-09-14 11:23:28 +0200402 default y
Ingo Molnard47846c2008-03-04 14:54:47 +0100403 select SYSFS_DEPRECATED
Kay Sievers88a22c92006-09-14 11:23:28 +0200404 help
405 This option creates deprecated symlinks such as the
406 "device"-link, the <subsystem>:<name>-link, and the
407 "bus"-link. It may also add deprecated key in the
408 uevent environment.
409 None of these features or values should be used today, as
410 they export driver core implementation details to userspace
411 or export properties which can't be kept stable across kernel
412 releases.
413
414 If enabled, this option will also move any device structures
David Sterba3dde6ad2007-05-09 07:12:20 +0200415 that belong to a class, back into the /sys/class hierarchy, in
Greg Kroah-Hartman024440d2008-03-03 14:47:13 -0800416 order to support older versions of udev and some userspace
417 programs.
Kay Sievers88a22c92006-09-14 11:23:28 +0200418
Greg Kroah-Hartman024440d2008-03-03 14:47:13 -0800419 If you are using a distro with the most recent userspace
420 packages, it should be safe to say N here.
Kay Sievers88a22c92006-09-14 11:23:28 +0200421
Paul Menage8793d852007-10-18 23:39:39 -0700422config PROC_PID_CPUSET
423 bool "Include legacy /proc/<pid>/cpuset file"
424 depends on CPUSETS
425 default y
426
Jens Axboeb86ff9812006-03-23 19:56:55 +0100427config RELAY
428 bool "Kernel->user space relay support (formerly relayfs)"
429 help
430 This option enables support for relay interface support in
431 certain file systems (such as debugfs).
432 It is designed to provide an efficient mechanism for tools and
433 facilities to relay large amounts of data from kernel space to
434 user space.
435
436 If unsure, say N.
437
Pavel Emelyanovc5289a62008-02-08 04:18:19 -0800438config NAMESPACES
439 bool "Namespaces support" if EMBEDDED
440 default !EMBEDDED
441 help
442 Provides the way to make tasks work with different objects using
443 the same id. For example same IPC id may refer to different objects
444 or same user id or pid may refer to different tasks when used in
445 different namespaces.
446
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800447config UTS_NS
448 bool "UTS namespace"
449 depends on NAMESPACES
450 help
451 In this namespace tasks see different info provided with the
452 uname() system call
453
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800454config IPC_NS
455 bool "IPC namespace"
456 depends on NAMESPACES && SYSVIPC
457 help
458 In this namespace tasks work with IPC ids which correspond to
459 different IPC objects in different namespaces
460
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800461config USER_NS
462 bool "User namespace (EXPERIMENTAL)"
463 depends on NAMESPACES && EXPERIMENTAL
464 help
465 This allows containers, i.e. vservers, to use user namespaces
466 to provide different user info for different servers.
467 If unsure, say N.
468
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800469config PID_NS
470 bool "PID Namespaces (EXPERIMENTAL)"
471 default n
472 depends on NAMESPACES && EXPERIMENTAL
473 help
474 Suport process id namespaces. This allows having multiple
475 process with the same pid as long as they are in different
476 pid namespaces. This is a building block of containers.
477
478 Unless you want to work with an experimental feature
479 say N here.
480
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -0800481config BLK_DEV_INITRD
482 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
483 depends on BROKEN || !FRV
484 help
485 The initial RAM filesystem is a ramfs which is loaded by the
486 boot loader (loadlin or lilo) and that is mounted as root
487 before the normal boot procedure. It is typically used to
488 load modules needed to mount the "real" root file system,
489 etc. See <file:Documentation/initrd.txt> for details.
490
491 If RAM disk support (BLK_DEV_RAM) is also included, this
492 also enables initial RAM disk (initrd) support and adds
493 15 Kbytes (more on some other architectures) to the kernel size.
494
495 If unsure say Y.
496
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800497if BLK_DEV_INITRD
498
Sam Ravnborgdbec4862005-08-10 20:44:50 +0200499source "usr/Kconfig"
500
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800501endif
502
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800503config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +0200504 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800505 default y
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800506 help
507 Enabling this option will pass "-Os" instead of "-O2" to gcc
508 resulting in a smaller kernel.
509
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800510 If unsure, say N.
511
Randy Dunlap08470622006-09-30 23:28:13 -0700512config SYSCTL
513 bool
514
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515menuconfig EMBEDDED
516 bool "Configure standard kernel features (for small systems)"
517 help
518 This option allows certain base kernel options and settings
519 to be disabled or tweaked. This is for specialized
520 environments which can tolerate a "non-standard" kernel.
521 Only use this if you really know what you are doing.
522
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700523config UID16
524 bool "Enable 16-bit UID system calls" if EMBEDDED
David S. Miller09337f52008-04-26 03:17:12 -0700525 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 -0700526 default y
527 help
528 This enables the legacy 16-bit UID syscall wrappers.
529
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700530config SYSCTL_SYSCALL
Randy Dunlap08470622006-09-30 23:28:13 -0700531 bool "Sysctl syscall support" if EMBEDDED
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800532 default y
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700533 select SYSCTL
534 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800535 sys_sysctl uses binary paths that have been found challenging
536 to properly maintain and use. The interface in /proc/sys
537 using paths with ascii names is now the primary path to this
538 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700539
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800540 Almost nothing using the binary sysctl interface so if you are
541 trying to save some space it is probably safe to disable this,
542 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700543
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800544 If unsure say Y here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700545
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546config KALLSYMS
Jesper Juhl979c6a12006-12-12 19:25:11 +0100547 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548 default y
549 help
550 Say Y here to let the kernel print out symbolic crash information and
551 symbolic stack backtraces. This increases the size of the kernel
552 somewhat, as all symbols have to be loaded into the kernel image.
553
554config KALLSYMS_ALL
555 bool "Include all symbols in kallsyms"
556 depends on DEBUG_KERNEL && KALLSYMS
557 help
558 Normally kallsyms only contains the symbols of functions, for nicer
559 OOPS messages. Some debuggers can use kallsyms for other
Jesper Juhlf9f97bc2005-07-20 05:43:05 +0200560 symbols too: say Y here to include all symbols, if you need them
561 and you don't care about adding 300k to the size of your kernel.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562
563 Say N.
564
565config KALLSYMS_EXTRA_PASS
566 bool "Do an extra kallsyms pass"
567 depends on KALLSYMS
568 help
569 If kallsyms is not working correctly, the build will fail with
570 inconsistent kallsyms data. If that occurs, log a bug report and
571 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
572 Always say N here unless you find a bug in kallsyms, which must be
573 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
574 you wait for kallsyms to be fixed.
575
Matt Mackalld59745c2005-05-01 08:59:02 -0700576
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -0800577config HOTPLUG
578 bool "Support for hot-pluggable devices" if EMBEDDED
579 default y
580 help
581 This option is provided for the case where no hotplug or uevent
582 capabilities is wanted by the kernel. You should only consider
583 disabling this option for embedded systems that do not use modules, a
584 dynamic /dev tree, or dynamic device discovery. Just say Y.
585
Matt Mackalld59745c2005-05-01 08:59:02 -0700586config PRINTK
587 default y
588 bool "Enable support for printk" if EMBEDDED
589 help
590 This option enables normal printk support. Removing it
591 eliminates most of the message strings from the kernel image
592 and makes the kernel more or less silent. As this makes it
593 very difficult to diagnose system problems, saying N here is
594 strongly discouraged.
595
Matt Mackallc8538a72005-05-01 08:59:01 -0700596config BUG
597 bool "BUG() support" if EMBEDDED
598 default y
599 help
600 Disabling this option eliminates support for BUG and WARN, reducing
601 the size of your kernel image and potentially quietly ignoring
602 numerous fatal conditions. You should only consider disabling this
603 option for embedded systems with no facilities for reporting errors.
604 Just say Y.
605
Matt Mackall708e9a72006-01-08 01:05:25 -0800606config ELF_CORE
607 default y
608 bool "Enable ELF core dumps" if EMBEDDED
609 help
610 Enable support for generating core dumps. Disabling saves about 4k.
611
Ingo Molnar32a93232008-02-06 22:39:44 +0100612config COMPAT_BRK
613 bool "Disable heap randomization"
614 default y
615 help
616 Randomizing heap placement makes heap exploits harder, but it
617 also breaks ancient binaries (including anything libc5 based).
618 This option changes the bootup default to heap randomization
619 disabled, and can be overriden runtime by setting
620 /proc/sys/kernel/randomize_va_space to 2.
621
Ingo Molnar166124f2008-02-09 23:24:09 +0100622 On non-ancient distros (post-2000 ones) N is usually a safe choice.
Ingo Molnar32a93232008-02-06 22:39:44 +0100623
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624config BASE_FULL
625 default y
626 bool "Enable full-sized data structures for core" if EMBEDDED
627 help
628 Disabling this option reduces the size of miscellaneous core
629 kernel data structures. This saves memory on small machines,
630 but may reduce performance.
631
632config FUTEX
633 bool "Enable futex support" if EMBEDDED
634 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -0700635 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636 help
637 Disabling this option will cause the kernel to be built without
638 support for "fast userspace mutexes". The resulting kernel may not
639 run glibc-based applications correctly.
640
Davide Libenzi5dc8bf82007-05-10 22:23:11 -0700641config ANON_INODES
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700642 bool
Davide Libenzi5dc8bf82007-05-10 22:23:11 -0700643
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644config EPOLL
645 bool "Enable eventpoll support" if EMBEDDED
646 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700647 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648 help
649 Disabling this option will cause the kernel to be built without
650 support for epoll family of system calls.
651
Davide Libenzifba2afa2007-05-10 22:23:13 -0700652config SIGNALFD
653 bool "Enable signalfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700654 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -0700655 default y
656 help
657 Enable the signalfd() system call that allows to receive signals
658 on a file descriptor.
659
660 If unsure, say Y.
661
Davide Libenzib215e282007-05-10 22:23:16 -0700662config TIMERFD
663 bool "Enable timerfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700664 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -0700665 default y
666 help
667 Enable the timerfd() system call that allows to receive timer
668 events on a file descriptor.
669
670 If unsure, say Y.
671
Davide Libenzie1ad7462007-05-10 22:23:19 -0700672config EVENTFD
673 bool "Enable eventfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700674 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -0700675 default y
676 help
677 Enable the eventfd() system call that allows to receive both
678 kernel notification (ie. KAIO) or userspace notifications.
679
680 If unsure, say Y.
681
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682config SHMEM
683 bool "Use full shmem filesystem" if EMBEDDED
684 default y
685 depends on MMU
686 help
687 The shmem is an internal filesystem used to manage shared memory.
688 It is backed by swap and manages resource limits. It is also exported
689 to userspace as tmpfs if TMPFS is enabled. Disabling this
690 option replaces shmem and tmpfs with the much simpler ramfs code,
691 which may be appropriate on small systems without swap.
692
Christoph Lameterf8891e52006-06-30 01:55:45 -0700693config VM_EVENT_COUNTERS
694 default y
695 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
696 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -0800697 VM event counters are needed for event counts to be shown.
698 This option allows the disabling of the VM event counters
699 on EMBEDDED systems. /proc/vmstat will only show page counts
700 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -0700701
Christoph Lameter41ecc552007-05-09 02:32:44 -0700702config SLUB_DEBUG
703 default y
704 bool "Enable SLUB debugging support" if EMBEDDED
Christoph Lameterd4751a22007-05-10 03:15:40 -0700705 depends on SLUB
Christoph Lameter41ecc552007-05-09 02:32:44 -0700706 help
707 SLUB has extensive debug support features. Disabling these can
708 result in significant savings in code size. This also disables
709 SLUB sysfs support. /sys/slab will not exist and there will be
710 no support for cache validation etc.
711
Christoph Lameter81819f02007-05-06 14:49:36 -0700712choice
713 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -0700714 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -0700715 help
716 This option allows to select a slab allocator.
717
718config SLAB
719 bool "SLAB"
720 help
721 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -0700722 well in all environments. It organizes cache hot objects in
Christoph Lameter81819f02007-05-06 14:49:36 -0700723 per cpu and per node queues. SLAB is the default choice for
Christoph Lameter34013882007-05-09 02:32:47 -0700724 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -0700725
726config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -0700727 bool "SLUB (Unqueued Allocator)"
728 help
729 SLUB is a slab allocator that minimizes cache line usage
730 instead of managing queues of cached objects (SLAB approach).
731 Per cpu caching is realized using slabs of objects instead
732 of queues of objects. SLUB can use memory efficiently
Christoph Lameter34013882007-05-09 02:32:47 -0700733 and has enhanced diagnostics.
Christoph Lameter81819f02007-05-06 14:49:36 -0700734
735config SLOB
Paul Mundt84a01c22007-07-15 23:38:24 -0700736 depends on EMBEDDED
Christoph Lameter81819f02007-05-06 14:49:36 -0700737 bool "SLOB (Simple Allocator)"
738 help
Matt Mackall37291452008-02-04 22:29:38 -0800739 SLOB replaces the stock allocator with a drastically simpler
740 allocator. SLOB is generally more space efficient but
741 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -0700742
743endchoice
744
Mathieu Desnoyers125e5642008-02-02 15:10:36 -0500745config PROFILING
746 bool "Profiling support (EXPERIMENTAL)"
747 help
748 Say Y here to enable the extended profiling support mechanisms used
749 by profilers such as OProfile.
750
751config MARKERS
752 bool "Activate markers"
753 help
754 Place an empty function call at each marker site. Can be
755 dynamically changed for a probe function.
756
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -0500757source "arch/Kconfig"
758
Matt Mackall1e883282008-02-04 22:29:07 -0800759config PROC_PAGE_MONITOR
760 default y
761 depends on PROC_FS && MMU
762 bool "Enable /proc page monitoring" if EMBEDDED
763 help
764 Various /proc files exist to monitor process memory utilization:
765 /proc/pid/smaps, /proc/pid/clear_refs, /proc/pid/pagemap,
766 /proc/kpagecount, and /proc/kpageflags. Disabling these
767 interfaces will reduce the size of the kernel by approximately 4kb.
768
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769endmenu # General setup
770
Linus Torvalds158a9622008-01-02 13:04:48 -0800771config SLABINFO
772 bool
773 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +0300774 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -0800775 default y
776
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700777config RT_MUTEXES
778 boolean
779 select PLIST
780
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781config TINY_SHMEM
782 default !SHMEM
783 bool
784
785config BASE_SMALL
786 int
787 default 0 if BASE_FULL
788 default 1 if !BASE_FULL
789
Jan Engelhardt66da5732007-07-15 23:39:29 -0700790menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791 bool "Enable loadable module support"
792 help
793 Kernel modules are small pieces of compiled code which can
794 be inserted in the running kernel, rather than being
795 permanently built into the kernel. You use the "modprobe"
796 tool to add (and sometimes remove) them. If you say Y here,
797 many parts of the kernel can be built as modules (by
798 answering M instead of Y where indicated): this is most
799 useful for infrequently used options which are not required
800 for booting. For more information, see the man pages for
801 modprobe, lsmod, modinfo, insmod and rmmod.
802
803 If you say Y here, you will need to run "make
804 modules_install" to put the modules under /lib/modules/
805 where modprobe can find them (you may need to be root to do
806 this).
807
808 If unsure, say Y.
809
810config MODULE_UNLOAD
811 bool "Module unloading"
812 depends on MODULES
813 help
814 Without this option you will not be able to unload any
815 modules (note that some modules may not be unloadable
816 anyway), which makes your kernel slightly smaller and
817 simpler. If unsure, say Y.
818
819config MODULE_FORCE_UNLOAD
820 bool "Forced module unloading"
821 depends on MODULE_UNLOAD && EXPERIMENTAL
822 help
823 This option allows you to force a module to unload, even if the
824 kernel believes it is unsafe: the kernel will remove the module
825 without waiting for anyone to stop using it (using the -f option to
826 rmmod). This is mainly for kernel developers and desperate users.
827 If unsure, say N.
828
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +0100830 bool "Module versioning support"
831 depends on MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700832 help
833 Usually, you have to use modules compiled with your kernel.
834 Saying Y here makes it sometimes possible to use modules
835 compiled for different kernels, by adding enough information
836 to the modules to (hopefully) spot any changes which would
837 make them incompatible with the kernel you are running. If
838 unsure, say N.
839
840config MODULE_SRCVERSION_ALL
841 bool "Source checksum for all modules"
842 depends on MODULES
843 help
844 Modules which contain a MODULE_VERSION get an extra "srcversion"
845 field inserted into their modinfo section, which contains a
846 sum of the source files which made it. This helps maintainers
847 see exactly which source was used to build a module (since
848 others sometimes change the module source without updating
849 the version). With this option, such a "srcversion" field
850 will be created for all modules. If unsure, say N.
851
852config KMOD
853 bool "Automatic kernel module loading"
854 depends on MODULES
855 help
856 Normally when you have selected some parts of the kernel to
857 be created as kernel modules, you must load them (using the
858 "modprobe" command) before you can use them. If you say Y
859 here, some parts of the kernel will be able to load modules
860 automatically: when a part of the kernel needs a module, it
861 runs modprobe with the appropriate arguments, thereby
862 loading the module if it is available. If unsure, say Y.
863
864config STOP_MACHINE
865 bool
866 default y
867 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
868 help
869 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +0100870
Jens Axboe3a65dfe2005-11-04 08:43:35 +0100871source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -0700872
873config PREEMPT_NOTIFIERS
874 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +0100875
Paul E. McKenneye260be62008-01-25 21:08:24 +0100876config CLASSIC_RCU
Paul E. McKenney21bbb392008-03-10 11:43:57 -0700877 def_bool !PREEMPT_RCU
Paul E. McKenneye260be62008-01-25 21:08:24 +0100878 help
879 This option selects the classic RCU implementation that is
880 designed for best read-side performance on non-realtime
Paul E. McKenney21bbb392008-03-10 11:43:57 -0700881 systems. Classic RCU is the default. Note that the
882 PREEMPT_RCU symbol is used to select/deselect this option.