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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' 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41 drivers that have been replaced by something else, and/or are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
262 default 17 if S390 || LOCKDEP
263 default 16 if X86_NUMAQ || IA64
264 default 15 if SMP
265 default 14
266 help
267 Select kernel log buffer size as a power of 2.
268 Defaults and Examples:
269 17 => 128 KB for S/390
270 16 => 64 KB for x86 NUMAQ or IA-64
271 15 => 32 KB for SMP
272 14 => 16 KB for uniprocessor
273 13 => 8 KB
274 12 => 4 KB
275
Paul Menageddbcc7e2007-10-18 23:39:30 -0700276config CGROUPS
277 bool "Control Group support"
278 help
279 This option will let you use process cgroup subsystems
280 such as Cpusets
281
282 Say N if unsure.
283
Paul Menage006cb992007-10-18 23:39:43 -0700284config CGROUP_DEBUG
285 bool "Example debug cgroup subsystem"
286 depends on CGROUPS
287 help
288 This option enables a simple cgroup subsystem that
289 exports useful debugging information about the cgroups
290 framework
291
292 Say N if unsure
293
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700294config CGROUP_NS
295 bool "Namespace cgroup subsystem"
296 depends on CGROUPS
297 help
298 Provides a simple namespace cgroup subsystem to
299 provide hierarchical naming of sets of namespaces,
300 for instance virtual servers and checkpoint/restart
301 jobs.
302
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303config CPUSETS
304 bool "Cpuset support"
Paul Menage8793d852007-10-18 23:39:39 -0700305 depends on SMP && CGROUPS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700307 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308 allow dynamically partitioning a system into sets of CPUs and
309 Memory Nodes and assigning tasks to run only within those sets.
310 This is primarily useful on large SMP or NUMA systems.
311
312 Say N if unsure.
313
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100314config GROUP_SCHED
315 bool "Group CPU scheduler"
Ingo Molnarde8d5852007-10-15 17:00:09 +0200316 default y
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +0200317 help
Srivatsa Vaddagirifb615582007-10-15 17:00:12 +0200318 This feature lets CPU scheduler recognize task groups and control CPU
Srivatsa Vaddagiri9b5b7752007-10-15 17:00:09 +0200319 bandwidth allocation to such task groups.
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +0200320
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100321config FAIR_GROUP_SCHED
322 bool "Group scheduling for SCHED_OTHER"
323 depends on GROUP_SCHED
324 default y
Srivatsa Vaddagiri24e377a2007-10-15 17:00:09 +0200325
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100326config RT_GROUP_SCHED
327 bool "Group scheduling for SCHED_RR/FIFO"
328 depends on EXPERIMENTAL
329 depends on GROUP_SCHED
330 default n
331
332choice
333 depends on GROUP_SCHED
334 prompt "Basis for grouping tasks"
335 default USER_SCHED
336
337config USER_SCHED
Srivatsa Vaddagirifb615582007-10-15 17:00:12 +0200338 bool "user id"
339 help
340 This option will choose userid as the basis for grouping
341 tasks, thus providing equal CPU bandwidth to each user.
Srivatsa Vaddagiri24e377a2007-10-15 17:00:09 +0200342
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100343config CGROUP_SCHED
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -0700344 bool "Control groups"
345 depends on CGROUPS
346 help
347 This option allows you to create arbitrary task groups
348 using the "cgroup" pseudo filesystem and control
349 the cpu bandwidth allocated to each such task group.
350 Refer to Documentation/cgroups.txt for more information
351 on "cgroup" pseudo filesystem.
352
Srivatsa Vaddagiri24e377a2007-10-15 17:00:09 +0200353endchoice
354
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100355config CGROUP_CPUACCT
356 bool "Simple CPU accounting cgroup subsystem"
357 depends on CGROUPS
358 help
359 Provides a simple Resource Controller for monitoring the
360 total CPU consumed by the tasks in a cgroup
361
Pavel Emelianove552b662008-02-07 00:13:49 -0800362config RESOURCE_COUNTERS
363 bool "Resource counters"
364 help
365 This option enables controller independent resource accounting
366 infrastructure that works with cgroups
367 depends on CGROUPS
368
Kay Sievers88a22c92006-09-14 11:23:28 +0200369config SYSFS_DEPRECATED
370 bool "Create deprecated sysfs files"
Randy Dunlap9148fe82007-12-31 10:05:34 -0800371 depends on SYSFS
Kay Sievers88a22c92006-09-14 11:23:28 +0200372 default y
373 help
374 This option creates deprecated symlinks such as the
375 "device"-link, the <subsystem>:<name>-link, and the
376 "bus"-link. It may also add deprecated key in the
377 uevent environment.
378 None of these features or values should be used today, as
379 they export driver core implementation details to userspace
380 or export properties which can't be kept stable across kernel
381 releases.
382
383 If enabled, this option will also move any device structures
David Sterba3dde6ad2007-05-09 07:12:20 +0200384 that belong to a class, back into the /sys/class hierarchy, in
Greg Kroah-Hartman024440d2008-03-03 14:47:13 -0800385 order to support older versions of udev and some userspace
386 programs.
Kay Sievers88a22c92006-09-14 11:23:28 +0200387
Greg Kroah-Hartman024440d2008-03-03 14:47:13 -0800388 If you are using a distro with the most recent userspace
389 packages, it should be safe to say N here.
Kay Sievers88a22c92006-09-14 11:23:28 +0200390
Balbir Singh8cdea7c2008-02-07 00:13:50 -0800391config CGROUP_MEM_CONT
392 bool "Memory controller for cgroups"
393 depends on CGROUPS && RESOURCE_COUNTERS
394 help
395 Provides a memory controller that manages both page cache and
396 RSS memory.
397
Andi Kleen0835ab52008-02-23 15:24:02 -0800398 Note that setting this option increases fixed memory overhead
399 associated with each page of memory in the system by 4/8 bytes
400 and also increases cache misses because struct page on many 64bit
401 systems will not fit into a single cache line anymore.
402
403 Only enable when you're ok with these trade offs and really
404 sure you need the memory controller.
405
Paul Menage8793d852007-10-18 23:39:39 -0700406config PROC_PID_CPUSET
407 bool "Include legacy /proc/<pid>/cpuset file"
408 depends on CPUSETS
409 default y
410
Jens Axboeb86ff9812006-03-23 19:56:55 +0100411config RELAY
412 bool "Kernel->user space relay support (formerly relayfs)"
413 help
414 This option enables support for relay interface support in
415 certain file systems (such as debugfs).
416 It is designed to provide an efficient mechanism for tools and
417 facilities to relay large amounts of data from kernel space to
418 user space.
419
420 If unsure, say N.
421
Pavel Emelyanovc5289a62008-02-08 04:18:19 -0800422config NAMESPACES
423 bool "Namespaces support" if EMBEDDED
424 default !EMBEDDED
425 help
426 Provides the way to make tasks work with different objects using
427 the same id. For example same IPC id may refer to different objects
428 or same user id or pid may refer to different tasks when used in
429 different namespaces.
430
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800431config UTS_NS
432 bool "UTS namespace"
433 depends on NAMESPACES
434 help
435 In this namespace tasks see different info provided with the
436 uname() system call
437
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800438config IPC_NS
439 bool "IPC namespace"
440 depends on NAMESPACES && SYSVIPC
441 help
442 In this namespace tasks work with IPC ids which correspond to
443 different IPC objects in different namespaces
444
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800445config USER_NS
446 bool "User namespace (EXPERIMENTAL)"
447 depends on NAMESPACES && EXPERIMENTAL
448 help
449 This allows containers, i.e. vservers, to use user namespaces
450 to provide different user info for different servers.
451 If unsure, say N.
452
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800453config PID_NS
454 bool "PID Namespaces (EXPERIMENTAL)"
455 default n
456 depends on NAMESPACES && EXPERIMENTAL
457 help
458 Suport process id namespaces. This allows having multiple
459 process with the same pid as long as they are in different
460 pid namespaces. This is a building block of containers.
461
462 Unless you want to work with an experimental feature
463 say N here.
464
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -0800465config BLK_DEV_INITRD
466 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
467 depends on BROKEN || !FRV
468 help
469 The initial RAM filesystem is a ramfs which is loaded by the
470 boot loader (loadlin or lilo) and that is mounted as root
471 before the normal boot procedure. It is typically used to
472 load modules needed to mount the "real" root file system,
473 etc. See <file:Documentation/initrd.txt> for details.
474
475 If RAM disk support (BLK_DEV_RAM) is also included, this
476 also enables initial RAM disk (initrd) support and adds
477 15 Kbytes (more on some other architectures) to the kernel size.
478
479 If unsure say Y.
480
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800481if BLK_DEV_INITRD
482
Sam Ravnborgdbec4862005-08-10 20:44:50 +0200483source "usr/Kconfig"
484
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800485endif
486
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800487config CC_OPTIMIZE_FOR_SIZE
488 bool "Optimize for size (Look out for broken compilers!)"
489 default y
Paul Mundt32582fa2007-07-25 11:27:05 +0900490 depends on ARM || H8300 || SUPERH || EXPERIMENTAL
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800491 help
492 Enabling this option will pass "-Os" instead of "-O2" to gcc
493 resulting in a smaller kernel.
494
495 WARNING: some versions of gcc may generate incorrect code with this
496 option. If problems are observed, a gcc upgrade may be needed.
497
498 If unsure, say N.
499
Randy Dunlap08470622006-09-30 23:28:13 -0700500config SYSCTL
501 bool
502
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503menuconfig EMBEDDED
504 bool "Configure standard kernel features (for small systems)"
505 help
506 This option allows certain base kernel options and settings
507 to be disabled or tweaked. This is for specialized
508 environments which can tolerate a "non-standard" kernel.
509 Only use this if you really know what you are doing.
510
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700511config UID16
512 bool "Enable 16-bit UID system calls" if EMBEDDED
Mike Frysinger529a73f2007-11-23 14:28:44 +0800513 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 -0700514 default y
515 help
516 This enables the legacy 16-bit UID syscall wrappers.
517
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700518config SYSCTL_SYSCALL
Randy Dunlap08470622006-09-30 23:28:13 -0700519 bool "Sysctl syscall support" if EMBEDDED
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800520 default y
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700521 select SYSCTL
522 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800523 sys_sysctl uses binary paths that have been found challenging
524 to properly maintain and use. The interface in /proc/sys
525 using paths with ascii names is now the primary path to this
526 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700527
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800528 Almost nothing using the binary sysctl interface so if you are
529 trying to save some space it is probably safe to disable this,
530 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700531
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800532 If unsure say Y here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700533
Linus Torvalds1da177e2005-04-16 15:20:36 -0700534config KALLSYMS
Jesper Juhl979c6a12006-12-12 19:25:11 +0100535 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536 default y
537 help
538 Say Y here to let the kernel print out symbolic crash information and
539 symbolic stack backtraces. This increases the size of the kernel
540 somewhat, as all symbols have to be loaded into the kernel image.
541
542config KALLSYMS_ALL
543 bool "Include all symbols in kallsyms"
544 depends on DEBUG_KERNEL && KALLSYMS
545 help
546 Normally kallsyms only contains the symbols of functions, for nicer
547 OOPS messages. Some debuggers can use kallsyms for other
Jesper Juhlf9f97bc2005-07-20 05:43:05 +0200548 symbols too: say Y here to include all symbols, if you need them
549 and you don't care about adding 300k to the size of your kernel.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550
551 Say N.
552
553config KALLSYMS_EXTRA_PASS
554 bool "Do an extra kallsyms pass"
555 depends on KALLSYMS
556 help
557 If kallsyms is not working correctly, the build will fail with
558 inconsistent kallsyms data. If that occurs, log a bug report and
559 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
560 Always say N here unless you find a bug in kallsyms, which must be
561 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
562 you wait for kallsyms to be fixed.
563
Matt Mackalld59745c2005-05-01 08:59:02 -0700564
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -0800565config HOTPLUG
566 bool "Support for hot-pluggable devices" if EMBEDDED
567 default y
568 help
569 This option is provided for the case where no hotplug or uevent
570 capabilities is wanted by the kernel. You should only consider
571 disabling this option for embedded systems that do not use modules, a
572 dynamic /dev tree, or dynamic device discovery. Just say Y.
573
Matt Mackalld59745c2005-05-01 08:59:02 -0700574config PRINTK
575 default y
576 bool "Enable support for printk" if EMBEDDED
577 help
578 This option enables normal printk support. Removing it
579 eliminates most of the message strings from the kernel image
580 and makes the kernel more or less silent. As this makes it
581 very difficult to diagnose system problems, saying N here is
582 strongly discouraged.
583
Matt Mackallc8538a72005-05-01 08:59:01 -0700584config BUG
585 bool "BUG() support" if EMBEDDED
586 default y
587 help
588 Disabling this option eliminates support for BUG and WARN, reducing
589 the size of your kernel image and potentially quietly ignoring
590 numerous fatal conditions. You should only consider disabling this
591 option for embedded systems with no facilities for reporting errors.
592 Just say Y.
593
Matt Mackall708e9a72006-01-08 01:05:25 -0800594config ELF_CORE
595 default y
596 bool "Enable ELF core dumps" if EMBEDDED
597 help
598 Enable support for generating core dumps. Disabling saves about 4k.
599
Ingo Molnar32a93232008-02-06 22:39:44 +0100600config COMPAT_BRK
601 bool "Disable heap randomization"
602 default y
603 help
604 Randomizing heap placement makes heap exploits harder, but it
605 also breaks ancient binaries (including anything libc5 based).
606 This option changes the bootup default to heap randomization
607 disabled, and can be overriden runtime by setting
608 /proc/sys/kernel/randomize_va_space to 2.
609
Ingo Molnar166124f2008-02-09 23:24:09 +0100610 On non-ancient distros (post-2000 ones) N is usually a safe choice.
Ingo Molnar32a93232008-02-06 22:39:44 +0100611
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612config BASE_FULL
613 default y
614 bool "Enable full-sized data structures for core" if EMBEDDED
615 help
616 Disabling this option reduces the size of miscellaneous core
617 kernel data structures. This saves memory on small machines,
618 but may reduce performance.
619
620config FUTEX
621 bool "Enable futex support" if EMBEDDED
622 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -0700623 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624 help
625 Disabling this option will cause the kernel to be built without
626 support for "fast userspace mutexes". The resulting kernel may not
627 run glibc-based applications correctly.
628
Davide Libenzi5dc8bf82007-05-10 22:23:11 -0700629config ANON_INODES
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700630 bool
Davide Libenzi5dc8bf82007-05-10 22:23:11 -0700631
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632config EPOLL
633 bool "Enable eventpoll support" if EMBEDDED
634 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700635 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636 help
637 Disabling this option will cause the kernel to be built without
638 support for epoll family of system calls.
639
Davide Libenzifba2afa2007-05-10 22:23:13 -0700640config SIGNALFD
641 bool "Enable signalfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700642 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -0700643 default y
644 help
645 Enable the signalfd() system call that allows to receive signals
646 on a file descriptor.
647
648 If unsure, say Y.
649
Davide Libenzib215e282007-05-10 22:23:16 -0700650config TIMERFD
651 bool "Enable timerfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700652 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -0700653 default y
654 help
655 Enable the timerfd() system call that allows to receive timer
656 events on a file descriptor.
657
658 If unsure, say Y.
659
Davide Libenzie1ad7462007-05-10 22:23:19 -0700660config EVENTFD
661 bool "Enable eventfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700662 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -0700663 default y
664 help
665 Enable the eventfd() system call that allows to receive both
666 kernel notification (ie. KAIO) or userspace notifications.
667
668 If unsure, say Y.
669
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670config SHMEM
671 bool "Use full shmem filesystem" if EMBEDDED
672 default y
673 depends on MMU
674 help
675 The shmem is an internal filesystem used to manage shared memory.
676 It is backed by swap and manages resource limits. It is also exported
677 to userspace as tmpfs if TMPFS is enabled. Disabling this
678 option replaces shmem and tmpfs with the much simpler ramfs code,
679 which may be appropriate on small systems without swap.
680
Christoph Lameterf8891e52006-06-30 01:55:45 -0700681config VM_EVENT_COUNTERS
682 default y
683 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
684 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -0800685 VM event counters are needed for event counts to be shown.
686 This option allows the disabling of the VM event counters
687 on EMBEDDED systems. /proc/vmstat will only show page counts
688 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -0700689
Christoph Lameter41ecc552007-05-09 02:32:44 -0700690config SLUB_DEBUG
691 default y
692 bool "Enable SLUB debugging support" if EMBEDDED
Christoph Lameterd4751a22007-05-10 03:15:40 -0700693 depends on SLUB
Christoph Lameter41ecc552007-05-09 02:32:44 -0700694 help
695 SLUB has extensive debug support features. Disabling these can
696 result in significant savings in code size. This also disables
697 SLUB sysfs support. /sys/slab will not exist and there will be
698 no support for cache validation etc.
699
Christoph Lameter81819f02007-05-06 14:49:36 -0700700choice
701 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -0700702 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -0700703 help
704 This option allows to select a slab allocator.
705
706config SLAB
707 bool "SLAB"
708 help
709 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -0700710 well in all environments. It organizes cache hot objects in
Christoph Lameter81819f02007-05-06 14:49:36 -0700711 per cpu and per node queues. SLAB is the default choice for
Christoph Lameter34013882007-05-09 02:32:47 -0700712 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -0700713
714config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -0700715 bool "SLUB (Unqueued Allocator)"
716 help
717 SLUB is a slab allocator that minimizes cache line usage
718 instead of managing queues of cached objects (SLAB approach).
719 Per cpu caching is realized using slabs of objects instead
720 of queues of objects. SLUB can use memory efficiently
Christoph Lameter34013882007-05-09 02:32:47 -0700721 and has enhanced diagnostics.
Christoph Lameter81819f02007-05-06 14:49:36 -0700722
723config SLOB
Paul Mundt84a01c22007-07-15 23:38:24 -0700724 depends on EMBEDDED
Christoph Lameter81819f02007-05-06 14:49:36 -0700725 bool "SLOB (Simple Allocator)"
726 help
Matt Mackall37291452008-02-04 22:29:38 -0800727 SLOB replaces the stock allocator with a drastically simpler
728 allocator. SLOB is generally more space efficient but
729 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -0700730
731endchoice
732
Mathieu Desnoyers125e5642008-02-02 15:10:36 -0500733config PROFILING
734 bool "Profiling support (EXPERIMENTAL)"
735 help
736 Say Y here to enable the extended profiling support mechanisms used
737 by profilers such as OProfile.
738
739config MARKERS
740 bool "Activate markers"
741 help
742 Place an empty function call at each marker site. Can be
743 dynamically changed for a probe function.
744
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -0500745source "arch/Kconfig"
746
Matt Mackall1e883282008-02-04 22:29:07 -0800747config PROC_PAGE_MONITOR
748 default y
749 depends on PROC_FS && MMU
750 bool "Enable /proc page monitoring" if EMBEDDED
751 help
752 Various /proc files exist to monitor process memory utilization:
753 /proc/pid/smaps, /proc/pid/clear_refs, /proc/pid/pagemap,
754 /proc/kpagecount, and /proc/kpageflags. Disabling these
755 interfaces will reduce the size of the kernel by approximately 4kb.
756
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757endmenu # General setup
758
Linus Torvalds158a9622008-01-02 13:04:48 -0800759config SLABINFO
760 bool
761 depends on PROC_FS
762 depends on SLAB || SLUB
763 default y
764
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700765config RT_MUTEXES
766 boolean
767 select PLIST
768
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769config TINY_SHMEM
770 default !SHMEM
771 bool
772
773config BASE_SMALL
774 int
775 default 0 if BASE_FULL
776 default 1 if !BASE_FULL
777
Jan Engelhardt66da5732007-07-15 23:39:29 -0700778menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779 bool "Enable loadable module support"
780 help
781 Kernel modules are small pieces of compiled code which can
782 be inserted in the running kernel, rather than being
783 permanently built into the kernel. You use the "modprobe"
784 tool to add (and sometimes remove) them. If you say Y here,
785 many parts of the kernel can be built as modules (by
786 answering M instead of Y where indicated): this is most
787 useful for infrequently used options which are not required
788 for booting. For more information, see the man pages for
789 modprobe, lsmod, modinfo, insmod and rmmod.
790
791 If you say Y here, you will need to run "make
792 modules_install" to put the modules under /lib/modules/
793 where modprobe can find them (you may need to be root to do
794 this).
795
796 If unsure, say Y.
797
798config MODULE_UNLOAD
799 bool "Module unloading"
800 depends on MODULES
801 help
802 Without this option you will not be able to unload any
803 modules (note that some modules may not be unloadable
804 anyway), which makes your kernel slightly smaller and
805 simpler. If unsure, say Y.
806
807config MODULE_FORCE_UNLOAD
808 bool "Forced module unloading"
809 depends on MODULE_UNLOAD && EXPERIMENTAL
810 help
811 This option allows you to force a module to unload, even if the
812 kernel believes it is unsafe: the kernel will remove the module
813 without waiting for anyone to stop using it (using the -f option to
814 rmmod). This is mainly for kernel developers and desperate users.
815 If unsure, say N.
816
Linus Torvalds1da177e2005-04-16 15:20:36 -0700817config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +0100818 bool "Module versioning support"
819 depends on MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700820 help
821 Usually, you have to use modules compiled with your kernel.
822 Saying Y here makes it sometimes possible to use modules
823 compiled for different kernels, by adding enough information
824 to the modules to (hopefully) spot any changes which would
825 make them incompatible with the kernel you are running. If
826 unsure, say N.
827
828config MODULE_SRCVERSION_ALL
829 bool "Source checksum for all modules"
830 depends on MODULES
831 help
832 Modules which contain a MODULE_VERSION get an extra "srcversion"
833 field inserted into their modinfo section, which contains a
834 sum of the source files which made it. This helps maintainers
835 see exactly which source was used to build a module (since
836 others sometimes change the module source without updating
837 the version). With this option, such a "srcversion" field
838 will be created for all modules. If unsure, say N.
839
840config KMOD
841 bool "Automatic kernel module loading"
842 depends on MODULES
843 help
844 Normally when you have selected some parts of the kernel to
845 be created as kernel modules, you must load them (using the
846 "modprobe" command) before you can use them. If you say Y
847 here, some parts of the kernel will be able to load modules
848 automatically: when a part of the kernel needs a module, it
849 runs modprobe with the appropriate arguments, thereby
850 loading the module if it is available. If unsure, say Y.
851
852config STOP_MACHINE
853 bool
854 default y
855 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
856 help
857 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +0100858
Jens Axboe3a65dfe2005-11-04 08:43:35 +0100859source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -0700860
861config PREEMPT_NOTIFIERS
862 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +0100863
864choice
865 prompt "RCU implementation type:"
866 default CLASSIC_RCU
Paul E. McKenney09503102008-01-31 22:45:22 +0100867 help
868 This allows you to choose either the classic RCU implementation
869 that is designed for best read-side performance on non-realtime
870 systems, or the preemptible RCU implementation for best latency
871 on realtime systems. Note that some kernel preemption modes
872 will restrict your choice.
873
874 Select the default if you are unsure.
Paul E. McKenneye260be62008-01-25 21:08:24 +0100875
876config CLASSIC_RCU
877 bool "Classic RCU"
878 help
879 This option selects the classic RCU implementation that is
880 designed for best read-side performance on non-realtime
881 systems.
882
883 Say Y if you are unsure.
884
885config PREEMPT_RCU
886 bool "Preemptible RCU"
887 depends on PREEMPT
888 help
889 This option reduces the latency of the kernel by making certain
890 RCU sections preemptible. Normally RCU code is non-preemptible, if
891 this option is selected then read-only RCU sections become
892 preemptible. This helps latency, but may expose bugs due to
893 now-naive assumptions about each RCU read-side critical section
894 remaining on a given CPU through its execution.
895
896 Say N if you are unsure.
897
898endchoice