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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"
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41 drivers that have been replaced by something else, and/or are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
Cedric Le Goateracce2922007-07-15 23:40:59 -0700217config USER_NS
218 bool "User Namespaces (EXPERIMENTAL)"
219 default n
220 depends on EXPERIMENTAL
221 help
222 Support user namespaces. This allows containers, i.e.
223 vservers, to use user namespaces to provide different
224 user info for different servers. If unsure, say N.
225
Eric W. Biederman57d5f662007-11-14 17:00:13 -0800226config PID_NS
227 bool "PID Namespaces (EXPERIMENTAL)"
228 default n
229 depends on EXPERIMENTAL
230 help
231 Suport process id namespaces. This allows having multiple
232 process with the same pid as long as they are in different
233 pid namespaces. This is a building block of containers.
234
235 Unless you want to work with an experimental feature
236 say N here.
237
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238config AUDIT
239 bool "Auditing support"
Chris Wright804a6a42005-05-11 10:52:45 +0100240 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 help
242 Enable auditing infrastructure that can be used with another
243 kernel subsystem, such as SELinux (which requires this for
244 logging of avc messages output). Does not do system-call
245 auditing without CONFIG_AUDITSYSCALL.
246
247config AUDITSYSCALL
248 bool "Enable system-call auditing support"
Yuichi Nakamura1322b9d2007-11-10 19:21:34 +0900249 depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64|| SUPERH)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 default y if SECURITY_SELINUX
251 help
252 Enable low-overhead system-call auditing infrastructure that
253 can be used independently or with another kernel subsystem,
Amy Griffisf368c07d2006-04-07 16:55:56 -0400254 such as SELinux. To use audit's filesystem watch feature, please
255 ensure that INOTIFY is configured.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256
Al Viro74c3cbe2007-07-22 08:04:18 -0400257config AUDIT_TREE
258 def_bool y
259 depends on AUDITSYSCALL && INOTIFY
260
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700262 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263 ---help---
264 This option enables the complete Linux kernel ".config" file
265 contents to be saved in the kernel. It provides documentation
266 of which kernel options are used in a running kernel or in an
267 on-disk kernel. This information can be extracted from the kernel
268 image file with the script scripts/extract-ikconfig and used as
269 input to rebuild the current kernel or to build another kernel.
270 It can also be extracted from a running kernel by reading
271 /proc/config.gz if enabled (below).
272
273config IKCONFIG_PROC
274 bool "Enable access to .config through /proc/config.gz"
275 depends on IKCONFIG && PROC_FS
276 ---help---
277 This option enables access to the kernel configuration file
278 through /proc/config.gz.
279
Alistair John Strachan794543a2007-05-08 00:31:15 -0700280config LOG_BUF_SHIFT
281 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
282 range 12 21
283 default 17 if S390 || LOCKDEP
284 default 16 if X86_NUMAQ || IA64
285 default 15 if SMP
286 default 14
287 help
288 Select kernel log buffer size as a power of 2.
289 Defaults and Examples:
290 17 => 128 KB for S/390
291 16 => 64 KB for x86 NUMAQ or IA-64
292 15 => 32 KB for SMP
293 14 => 16 KB for uniprocessor
294 13 => 8 KB
295 12 => 4 KB
296
Paul Menageddbcc7e2007-10-18 23:39:30 -0700297config CGROUPS
298 bool "Control Group support"
299 help
300 This option will let you use process cgroup subsystems
301 such as Cpusets
302
303 Say N if unsure.
304
Paul Menage006cb992007-10-18 23:39:43 -0700305config CGROUP_DEBUG
306 bool "Example debug cgroup subsystem"
307 depends on CGROUPS
308 help
309 This option enables a simple cgroup subsystem that
310 exports useful debugging information about the cgroups
311 framework
312
313 Say N if unsure
314
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700315config CGROUP_NS
316 bool "Namespace cgroup subsystem"
317 depends on CGROUPS
318 help
319 Provides a simple namespace cgroup subsystem to
320 provide hierarchical naming of sets of namespaces,
321 for instance virtual servers and checkpoint/restart
322 jobs.
323
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324config CPUSETS
325 bool "Cpuset support"
Paul Menage8793d852007-10-18 23:39:39 -0700326 depends on SMP && CGROUPS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700328 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329 allow dynamically partitioning a system into sets of CPUs and
330 Memory Nodes and assigning tasks to run only within those sets.
331 This is primarily useful on large SMP or NUMA systems.
332
333 Say N if unsure.
334
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +0200335config FAIR_GROUP_SCHED
Srivatsa Vaddagirifb615582007-10-15 17:00:12 +0200336 bool "Fair group CPU scheduler"
Ingo Molnarde8d5852007-10-15 17:00:09 +0200337 default y
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +0200338 help
Srivatsa Vaddagirifb615582007-10-15 17:00:12 +0200339 This feature lets CPU scheduler recognize task groups and control CPU
Srivatsa Vaddagiri9b5b7752007-10-15 17:00:09 +0200340 bandwidth allocation to such task groups.
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +0200341
Srivatsa Vaddagiri24e377a2007-10-15 17:00:09 +0200342choice
343 depends on FAIR_GROUP_SCHED
344 prompt "Basis for grouping tasks"
345 default FAIR_USER_SCHED
346
Srivatsa Vaddagirifb615582007-10-15 17:00:12 +0200347config FAIR_USER_SCHED
348 bool "user id"
349 help
350 This option will choose userid as the basis for grouping
351 tasks, thus providing equal CPU bandwidth to each user.
Srivatsa Vaddagiri24e377a2007-10-15 17:00:09 +0200352
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -0700353config FAIR_CGROUP_SCHED
354 bool "Control groups"
355 depends on CGROUPS
356 help
357 This option allows you to create arbitrary task groups
358 using the "cgroup" pseudo filesystem and control
359 the cpu bandwidth allocated to each such task group.
360 Refer to Documentation/cgroups.txt for more information
361 on "cgroup" pseudo filesystem.
362
Srivatsa Vaddagiri24e377a2007-10-15 17:00:09 +0200363endchoice
364
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100365config CGROUP_CPUACCT
366 bool "Simple CPU accounting cgroup subsystem"
367 depends on CGROUPS
368 help
369 Provides a simple Resource Controller for monitoring the
370 total CPU consumed by the tasks in a cgroup
371
Pavel Emelianove552b662008-02-07 00:13:49 -0800372config RESOURCE_COUNTERS
373 bool "Resource counters"
374 help
375 This option enables controller independent resource accounting
376 infrastructure that works with cgroups
377 depends on CGROUPS
378
Kay Sievers88a22c92006-09-14 11:23:28 +0200379config SYSFS_DEPRECATED
380 bool "Create deprecated sysfs files"
Randy Dunlap9148fe82007-12-31 10:05:34 -0800381 depends on SYSFS
Kay Sievers88a22c92006-09-14 11:23:28 +0200382 default y
383 help
384 This option creates deprecated symlinks such as the
385 "device"-link, the <subsystem>:<name>-link, and the
386 "bus"-link. It may also add deprecated key in the
387 uevent environment.
388 None of these features or values should be used today, as
389 they export driver core implementation details to userspace
390 or export properties which can't be kept stable across kernel
391 releases.
392
393 If enabled, this option will also move any device structures
David Sterba3dde6ad2007-05-09 07:12:20 +0200394 that belong to a class, back into the /sys/class hierarchy, in
Kay Sievers88a22c92006-09-14 11:23:28 +0200395 order to support older versions of udev.
396
397 If you are using a distro that was released in 2006 or later,
398 it should be safe to say N here.
399
Balbir Singh8cdea7c2008-02-07 00:13:50 -0800400config CGROUP_MEM_CONT
401 bool "Memory controller for cgroups"
402 depends on CGROUPS && RESOURCE_COUNTERS
403 help
404 Provides a memory controller that manages both page cache and
405 RSS memory.
406
Paul Menage8793d852007-10-18 23:39:39 -0700407config PROC_PID_CPUSET
408 bool "Include legacy /proc/<pid>/cpuset file"
409 depends on CPUSETS
410 default y
411
Jens Axboeb86ff982006-03-23 19:56:55 +0100412config RELAY
413 bool "Kernel->user space relay support (formerly relayfs)"
414 help
415 This option enables support for relay interface support in
416 certain file systems (such as debugfs).
417 It is designed to provide an efficient mechanism for tools and
418 facilities to relay large amounts of data from kernel space to
419 user space.
420
421 If unsure, say N.
422
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -0800423config BLK_DEV_INITRD
424 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
425 depends on BROKEN || !FRV
426 help
427 The initial RAM filesystem is a ramfs which is loaded by the
428 boot loader (loadlin or lilo) and that is mounted as root
429 before the normal boot procedure. It is typically used to
430 load modules needed to mount the "real" root file system,
431 etc. See <file:Documentation/initrd.txt> for details.
432
433 If RAM disk support (BLK_DEV_RAM) is also included, this
434 also enables initial RAM disk (initrd) support and adds
435 15 Kbytes (more on some other architectures) to the kernel size.
436
437 If unsure say Y.
438
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800439if BLK_DEV_INITRD
440
Sam Ravnborgdbec4862005-08-10 20:44:50 +0200441source "usr/Kconfig"
442
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800443endif
444
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800445config CC_OPTIMIZE_FOR_SIZE
446 bool "Optimize for size (Look out for broken compilers!)"
447 default y
Paul Mundt32582fa2007-07-25 11:27:05 +0900448 depends on ARM || H8300 || SUPERH || EXPERIMENTAL
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800449 help
450 Enabling this option will pass "-Os" instead of "-O2" to gcc
451 resulting in a smaller kernel.
452
453 WARNING: some versions of gcc may generate incorrect code with this
454 option. If problems are observed, a gcc upgrade may be needed.
455
456 If unsure, say N.
457
Randy Dunlap08470622006-09-30 23:28:13 -0700458config SYSCTL
459 bool
460
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461menuconfig EMBEDDED
462 bool "Configure standard kernel features (for small systems)"
463 help
464 This option allows certain base kernel options and settings
465 to be disabled or tweaked. This is for specialized
466 environments which can tolerate a "non-standard" kernel.
467 Only use this if you really know what you are doing.
468
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700469config UID16
470 bool "Enable 16-bit UID system calls" if EMBEDDED
Mike Frysinger529a73f2007-11-23 14:28:44 +0800471 depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION)
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700472 default y
473 help
474 This enables the legacy 16-bit UID syscall wrappers.
475
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700476config SYSCTL_SYSCALL
Randy Dunlap08470622006-09-30 23:28:13 -0700477 bool "Sysctl syscall support" if EMBEDDED
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800478 default y
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700479 select SYSCTL
480 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800481 sys_sysctl uses binary paths that have been found challenging
482 to properly maintain and use. The interface in /proc/sys
483 using paths with ascii names is now the primary path to this
484 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700485
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800486 Almost nothing using the binary sysctl interface so if you are
487 trying to save some space it is probably safe to disable this,
488 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700489
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800490 If unsure say Y here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700491
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492config KALLSYMS
Jesper Juhl979c6a12006-12-12 19:25:11 +0100493 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 default y
495 help
496 Say Y here to let the kernel print out symbolic crash information and
497 symbolic stack backtraces. This increases the size of the kernel
498 somewhat, as all symbols have to be loaded into the kernel image.
499
500config KALLSYMS_ALL
501 bool "Include all symbols in kallsyms"
502 depends on DEBUG_KERNEL && KALLSYMS
503 help
504 Normally kallsyms only contains the symbols of functions, for nicer
505 OOPS messages. Some debuggers can use kallsyms for other
Jesper Juhlf9f97bc2005-07-20 05:43:05 +0200506 symbols too: say Y here to include all symbols, if you need them
507 and you don't care about adding 300k to the size of your kernel.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508
509 Say N.
510
511config KALLSYMS_EXTRA_PASS
512 bool "Do an extra kallsyms pass"
513 depends on KALLSYMS
514 help
515 If kallsyms is not working correctly, the build will fail with
516 inconsistent kallsyms data. If that occurs, log a bug report and
517 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
518 Always say N here unless you find a bug in kallsyms, which must be
519 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
520 you wait for kallsyms to be fixed.
521
Matt Mackalld59745c2005-05-01 08:59:02 -0700522
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -0800523config HOTPLUG
524 bool "Support for hot-pluggable devices" if EMBEDDED
525 default y
526 help
527 This option is provided for the case where no hotplug or uevent
528 capabilities is wanted by the kernel. You should only consider
529 disabling this option for embedded systems that do not use modules, a
530 dynamic /dev tree, or dynamic device discovery. Just say Y.
531
Matt Mackalld59745c2005-05-01 08:59:02 -0700532config PRINTK
533 default y
534 bool "Enable support for printk" if EMBEDDED
535 help
536 This option enables normal printk support. Removing it
537 eliminates most of the message strings from the kernel image
538 and makes the kernel more or less silent. As this makes it
539 very difficult to diagnose system problems, saying N here is
540 strongly discouraged.
541
Matt Mackallc8538a72005-05-01 08:59:01 -0700542config BUG
543 bool "BUG() support" if EMBEDDED
544 default y
545 help
546 Disabling this option eliminates support for BUG and WARN, reducing
547 the size of your kernel image and potentially quietly ignoring
548 numerous fatal conditions. You should only consider disabling this
549 option for embedded systems with no facilities for reporting errors.
550 Just say Y.
551
Matt Mackall708e9a72006-01-08 01:05:25 -0800552config ELF_CORE
553 default y
554 bool "Enable ELF core dumps" if EMBEDDED
555 help
556 Enable support for generating core dumps. Disabling saves about 4k.
557
Ingo Molnar32a93232008-02-06 22:39:44 +0100558config COMPAT_BRK
559 bool "Disable heap randomization"
560 default y
561 help
562 Randomizing heap placement makes heap exploits harder, but it
563 also breaks ancient binaries (including anything libc5 based).
564 This option changes the bootup default to heap randomization
565 disabled, and can be overriden runtime by setting
566 /proc/sys/kernel/randomize_va_space to 2.
567
568 On non-ancient distros (post-2000 ones) Y is usually a safe choice.
569
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570config BASE_FULL
571 default y
572 bool "Enable full-sized data structures for core" if EMBEDDED
573 help
574 Disabling this option reduces the size of miscellaneous core
575 kernel data structures. This saves memory on small machines,
576 but may reduce performance.
577
578config FUTEX
579 bool "Enable futex support" if EMBEDDED
580 default y
Ingo Molnar23f78d42006-06-27 02:54:53 -0700581 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582 help
583 Disabling this option will cause the kernel to be built without
584 support for "fast userspace mutexes". The resulting kernel may not
585 run glibc-based applications correctly.
586
Davide Libenzi5dc8bf82007-05-10 22:23:11 -0700587config ANON_INODES
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700588 bool
Davide Libenzi5dc8bf82007-05-10 22:23:11 -0700589
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590config EPOLL
591 bool "Enable eventpoll support" if EMBEDDED
592 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700593 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594 help
595 Disabling this option will cause the kernel to be built without
596 support for epoll family of system calls.
597
Davide Libenzifba2afa2007-05-10 22:23:13 -0700598config SIGNALFD
599 bool "Enable signalfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700600 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -0700601 default y
602 help
603 Enable the signalfd() system call that allows to receive signals
604 on a file descriptor.
605
606 If unsure, say Y.
607
Davide Libenzib215e282007-05-10 22:23:16 -0700608config TIMERFD
609 bool "Enable timerfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700610 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -0700611 default y
612 help
613 Enable the timerfd() system call that allows to receive timer
614 events on a file descriptor.
615
616 If unsure, say Y.
617
Davide Libenzie1ad7462007-05-10 22:23:19 -0700618config EVENTFD
619 bool "Enable eventfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700620 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -0700621 default y
622 help
623 Enable the eventfd() system call that allows to receive both
624 kernel notification (ie. KAIO) or userspace notifications.
625
626 If unsure, say Y.
627
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628config SHMEM
629 bool "Use full shmem filesystem" if EMBEDDED
630 default y
631 depends on MMU
632 help
633 The shmem is an internal filesystem used to manage shared memory.
634 It is backed by swap and manages resource limits. It is also exported
635 to userspace as tmpfs if TMPFS is enabled. Disabling this
636 option replaces shmem and tmpfs with the much simpler ramfs code,
637 which may be appropriate on small systems without swap.
638
Christoph Lameterf8891e52006-06-30 01:55:45 -0700639config VM_EVENT_COUNTERS
640 default y
641 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
642 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -0800643 VM event counters are needed for event counts to be shown.
644 This option allows the disabling of the VM event counters
645 on EMBEDDED systems. /proc/vmstat will only show page counts
646 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -0700647
Christoph Lameter41ecc552007-05-09 02:32:44 -0700648config SLUB_DEBUG
649 default y
650 bool "Enable SLUB debugging support" if EMBEDDED
Christoph Lameterd4751a22007-05-10 03:15:40 -0700651 depends on SLUB
Christoph Lameter41ecc552007-05-09 02:32:44 -0700652 help
653 SLUB has extensive debug support features. Disabling these can
654 result in significant savings in code size. This also disables
655 SLUB sysfs support. /sys/slab will not exist and there will be
656 no support for cache validation etc.
657
Christoph Lameter81819f02007-05-06 14:49:36 -0700658choice
659 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -0700660 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -0700661 help
662 This option allows to select a slab allocator.
663
664config SLAB
665 bool "SLAB"
666 help
667 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -0700668 well in all environments. It organizes cache hot objects in
Christoph Lameter81819f02007-05-06 14:49:36 -0700669 per cpu and per node queues. SLAB is the default choice for
Christoph Lameter34013882007-05-09 02:32:47 -0700670 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -0700671
672config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -0700673 bool "SLUB (Unqueued Allocator)"
674 help
675 SLUB is a slab allocator that minimizes cache line usage
676 instead of managing queues of cached objects (SLAB approach).
677 Per cpu caching is realized using slabs of objects instead
678 of queues of objects. SLUB can use memory efficiently
Christoph Lameter34013882007-05-09 02:32:47 -0700679 and has enhanced diagnostics.
Christoph Lameter81819f02007-05-06 14:49:36 -0700680
681config SLOB
Paul Mundt84a01c22007-07-15 23:38:24 -0700682 depends on EMBEDDED
Christoph Lameter81819f02007-05-06 14:49:36 -0700683 bool "SLOB (Simple Allocator)"
684 help
Matt Mackall37291452008-02-04 22:29:38 -0800685 SLOB replaces the stock allocator with a drastically simpler
686 allocator. SLOB is generally more space efficient but
687 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -0700688
689endchoice
690
Mathieu Desnoyers125e5642008-02-02 15:10:36 -0500691config PROFILING
692 bool "Profiling support (EXPERIMENTAL)"
693 help
694 Say Y here to enable the extended profiling support mechanisms used
695 by profilers such as OProfile.
696
697config MARKERS
698 bool "Activate markers"
699 help
700 Place an empty function call at each marker site. Can be
701 dynamically changed for a probe function.
702
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -0500703source "arch/Kconfig"
704
Matt Mackall1e883282008-02-04 22:29:07 -0800705config PROC_PAGE_MONITOR
706 default y
707 depends on PROC_FS && MMU
708 bool "Enable /proc page monitoring" if EMBEDDED
709 help
710 Various /proc files exist to monitor process memory utilization:
711 /proc/pid/smaps, /proc/pid/clear_refs, /proc/pid/pagemap,
712 /proc/kpagecount, and /proc/kpageflags. Disabling these
713 interfaces will reduce the size of the kernel by approximately 4kb.
714
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715endmenu # General setup
716
Linus Torvalds158a9622008-01-02 13:04:48 -0800717config SLABINFO
718 bool
719 depends on PROC_FS
720 depends on SLAB || SLUB
721 default y
722
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700723config RT_MUTEXES
724 boolean
725 select PLIST
726
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727config TINY_SHMEM
728 default !SHMEM
729 bool
730
731config BASE_SMALL
732 int
733 default 0 if BASE_FULL
734 default 1 if !BASE_FULL
735
Jan Engelhardt66da5732007-07-15 23:39:29 -0700736menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737 bool "Enable loadable module support"
738 help
739 Kernel modules are small pieces of compiled code which can
740 be inserted in the running kernel, rather than being
741 permanently built into the kernel. You use the "modprobe"
742 tool to add (and sometimes remove) them. If you say Y here,
743 many parts of the kernel can be built as modules (by
744 answering M instead of Y where indicated): this is most
745 useful for infrequently used options which are not required
746 for booting. For more information, see the man pages for
747 modprobe, lsmod, modinfo, insmod and rmmod.
748
749 If you say Y here, you will need to run "make
750 modules_install" to put the modules under /lib/modules/
751 where modprobe can find them (you may need to be root to do
752 this).
753
754 If unsure, say Y.
755
756config MODULE_UNLOAD
757 bool "Module unloading"
758 depends on MODULES
759 help
760 Without this option you will not be able to unload any
761 modules (note that some modules may not be unloadable
762 anyway), which makes your kernel slightly smaller and
763 simpler. If unsure, say Y.
764
765config MODULE_FORCE_UNLOAD
766 bool "Forced module unloading"
767 depends on MODULE_UNLOAD && EXPERIMENTAL
768 help
769 This option allows you to force a module to unload, even if the
770 kernel believes it is unsafe: the kernel will remove the module
771 without waiting for anyone to stop using it (using the -f option to
772 rmmod). This is mainly for kernel developers and desperate users.
773 If unsure, say N.
774
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +0100776 bool "Module versioning support"
777 depends on MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778 help
779 Usually, you have to use modules compiled with your kernel.
780 Saying Y here makes it sometimes possible to use modules
781 compiled for different kernels, by adding enough information
782 to the modules to (hopefully) spot any changes which would
783 make them incompatible with the kernel you are running. If
784 unsure, say N.
785
786config MODULE_SRCVERSION_ALL
787 bool "Source checksum for all modules"
788 depends on MODULES
789 help
790 Modules which contain a MODULE_VERSION get an extra "srcversion"
791 field inserted into their modinfo section, which contains a
792 sum of the source files which made it. This helps maintainers
793 see exactly which source was used to build a module (since
794 others sometimes change the module source without updating
795 the version). With this option, such a "srcversion" field
796 will be created for all modules. If unsure, say N.
797
798config KMOD
799 bool "Automatic kernel module loading"
800 depends on MODULES
801 help
802 Normally when you have selected some parts of the kernel to
803 be created as kernel modules, you must load them (using the
804 "modprobe" command) before you can use them. If you say Y
805 here, some parts of the kernel will be able to load modules
806 automatically: when a part of the kernel needs a module, it
807 runs modprobe with the appropriate arguments, thereby
808 loading the module if it is available. If unsure, say Y.
809
810config STOP_MACHINE
811 bool
812 default y
813 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
814 help
815 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +0100816
Jens Axboe3a65dfe2005-11-04 08:43:35 +0100817source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -0700818
819config PREEMPT_NOTIFIERS
820 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +0100821
822choice
823 prompt "RCU implementation type:"
824 default CLASSIC_RCU
Paul E. McKenney09503102008-01-31 22:45:22 +0100825 help
826 This allows you to choose either the classic RCU implementation
827 that is designed for best read-side performance on non-realtime
828 systems, or the preemptible RCU implementation for best latency
829 on realtime systems. Note that some kernel preemption modes
830 will restrict your choice.
831
832 Select the default if you are unsure.
Paul E. McKenneye260be62008-01-25 21:08:24 +0100833
834config CLASSIC_RCU
835 bool "Classic RCU"
836 help
837 This option selects the classic RCU implementation that is
838 designed for best read-side performance on non-realtime
839 systems.
840
841 Say Y if you are unsure.
842
843config PREEMPT_RCU
844 bool "Preemptible RCU"
845 depends on PREEMPT
846 help
847 This option reduces the latency of the kernel by making certain
848 RCU sections preemptible. Normally RCU code is non-preemptible, if
849 this option is selected then read-only RCU sections become
850 preemptible. This helps latency, but may expose bugs due to
851 now-naive assumptions about each RCU read-side critical section
852 remaining on a given CPU through its execution.
853
854 Say N if you are unsure.
855
856endchoice