| blob | 14d484606fab9b0bbdff72b318d664fc5d7b73b3 |
1 config DEFCONFIG_LIST
2 string
3 depends on !UML
4 option defconfig_list
5 default "/lib/modules/$UNAME_RELEASE/.config"
6 default "/etc/kernel-config"
7 default "/boot/config-$UNAME_RELEASE"
8 default "arch/$ARCH/defconfig"
10 menu "Code maturity level options"
12 config EXPERIMENTAL
13 bool "Prompt for development and/or incomplete code/drivers"
14 ---help---
15 Some of the various things that Linux supports (such as network
16 drivers, file systems, network protocols, etc.) can be in a state
17 of development where the functionality, stability, or the level of
18 testing is not yet high enough for general use. This is usually
19 known as the "alpha-test" phase among developers. If a feature is
20 currently in alpha-test, then the developers usually discourage
21 uninformed widespread use of this feature by the general public to
22 avoid "Why doesn't this work?" type mail messages. However, active
23 testing and use of these systems is welcomed. Just be aware that it
24 may not meet the normal level of reliability or it may fail to work
25 in some special cases. Detailed bug reports from people familiar
26 with the kernel internals are usually welcomed by the developers
27 (before submitting bug reports, please read the documents
28 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
29 <file:Documentation/BUG-HUNTING>, and
30 <file:Documentation/oops-tracing.txt> in the kernel source).
32 This option will also make obsoleted drivers available. These are
33 drivers that have been replaced by something else, and/or are
34 scheduled to be removed in a future kernel release.
36 Unless you intend to help test and develop a feature or driver that
37 falls into this category, or you have a situation that requires
38 using these features, you should probably say N here, which will
39 cause the configurator to present you with fewer choices. If
40 you say Y here, you will be offered the choice of using features or
41 drivers that are currently considered to be in the alpha-test phase.
43 config BROKEN
44 bool
46 config BROKEN_ON_SMP
47 bool
48 depends on BROKEN || !SMP
49 default y
51 config LOCK_KERNEL
52 bool
53 depends on SMP || PREEMPT
54 default y
56 config INIT_ENV_ARG_LIMIT
57 int
58 default 32 if !UML
59 default 128 if UML
60 help
61 Maximum of each of the number of arguments and environment
62 variables passed to init from the kernel command line.
64 endmenu
66 menu "General setup"
68 config LOCALVERSION
69 string "Local version - append to kernel release"
70 help
71 Append an extra string to the end of your kernel version.
72 This will show up when you type uname, for example.
73 The string you set here will be appended after the contents of
74 any files with a filename matching localversion* in your
75 object and source tree, in that order. Your total string can
76 be a maximum of 64 characters.
78 config LOCALVERSION_AUTO
79 bool "Automatically append version information to the version string"
80 default y
81 help
82 This will try to automatically determine if the current tree is a
83 release tree by looking for git tags that
84 belong to the current top of tree revision.
86 A string of the format -gxxxxxxxx will be added to the localversion
87 if a git based tree is found. The string generated by this will be
88 appended after any matching localversion* files, and after the value
89 set in CONFIG_LOCALVERSION
91 Note: This requires Perl, and a git repository, but not necessarily
92 the git or cogito tools to be installed.
94 config SWAP
95 bool "Support for paging of anonymous memory (swap)"
96 depends on MMU && BLOCK
97 default y
98 help
99 This option allows you to choose whether you want to have support
100 for so called swap devices or swap files in your kernel that are
101 used to provide more virtual memory than the actual RAM present
102 in your computer. If unsure say Y.
104 config SYSVIPC
105 bool "System V IPC"
106 ---help---
107 Inter Process Communication is a suite of library functions and
108 system calls which let processes (running programs) synchronize and
109 exchange information. It is generally considered to be a good thing,
110 and some programs won't run unless you say Y here. In particular, if
111 you want to run the DOS emulator dosemu under Linux (read the
112 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
113 you'll need to say Y here.
115 You can find documentation about IPC with "info ipc" and also in
116 section 6.4 of the Linux Programmer's Guide, available from
117 <http://www.tldp.org/guides.html>.
119 config IPC_NS
120 bool "IPC Namespaces"
121 depends on SYSVIPC
122 default n
123 help
124 Support ipc namespaces. This allows containers, i.e. virtual
125 environments, to use ipc namespaces to provide different ipc
126 objects for different servers. If unsure, say N.
128 config POSIX_MQUEUE
129 bool "POSIX Message Queues"
130 depends on NET && EXPERIMENTAL
131 ---help---
132 POSIX variant of message queues is a part of IPC. In POSIX message
133 queues every message has a priority which decides about succession
134 of receiving it by a process. If you want to compile and run
135 programs written e.g. for Solaris with use of its POSIX message
136 queues (functions mq_*) say Y here. To use this feature you will
137 also need mqueue library, available from
138 <http://www.mat.uni.torun.pl/~wrona/posix_ipc/>
140 POSIX message queues are visible as a filesystem called 'mqueue'
141 and can be mounted somewhere if you want to do filesystem
142 operations on message queues.
144 If unsure, say Y.
146 config BSD_PROCESS_ACCT
147 bool "BSD Process Accounting"
148 help
149 If you say Y here, a user level program will be able to instruct the
150 kernel (via a special system call) to write process accounting
151 information to a file: whenever a process exits, information about
152 that process will be appended to the file by the kernel. The
153 information includes things such as creation time, owning user,
154 command name, memory usage, controlling terminal etc. (the complete
155 list is in the struct acct in <file:include/linux/acct.h>). It is
156 up to the user level program to do useful things with this
157 information. This is generally a good idea, so say Y.
159 config BSD_PROCESS_ACCT_V3
160 bool "BSD Process Accounting version 3 file format"
161 depends on BSD_PROCESS_ACCT
162 default n
163 help
164 If you say Y here, the process accounting information is written
165 in a new file format that also logs the process IDs of each
166 process and it's parent. Note that this file format is incompatible
167 with previous v0/v1/v2 file formats, so you will need updated tools
168 for processing it. A preliminary version of these tools is available
169 at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>.
171 config TASKSTATS
172 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
173 depends on NET
174 default n
175 help
176 Export selected statistics for tasks/processes through the
177 generic netlink interface. Unlike BSD process accounting, the
178 statistics are available during the lifetime of tasks/processes as
179 responses to commands. Like BSD accounting, they are sent to user
180 space on task exit.
182 Say N if unsure.
184 config TASK_DELAY_ACCT
185 bool "Enable per-task delay accounting (EXPERIMENTAL)"
186 depends on TASKSTATS
187 help
188 Collect information on time spent by a task waiting for system
189 resources like cpu, synchronous block I/O completion and swapping
190 in pages. Such statistics can help in setting a task's priorities
191 relative to other tasks for cpu, io, rss limits etc.
193 Say N if unsure.
195 config UTS_NS
196 bool "UTS Namespaces"
197 default n
198 help
199 Support uts namespaces. This allows containers, i.e.
200 vservers, to use uts namespaces to provide different
201 uts info for different servers. If unsure, say N.
203 config AUDIT
204 bool "Auditing support"
205 depends on NET
206 help
207 Enable auditing infrastructure that can be used with another
208 kernel subsystem, such as SELinux (which requires this for
209 logging of avc messages output). Does not do system-call
210 auditing without CONFIG_AUDITSYSCALL.
212 config AUDITSYSCALL
213 bool "Enable system-call auditing support"
214 depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64)
215 default y if SECURITY_SELINUX
216 help
217 Enable low-overhead system-call auditing infrastructure that
218 can be used independently or with another kernel subsystem,
219 such as SELinux. To use audit's filesystem watch feature, please
220 ensure that INOTIFY is configured.
222 config IKCONFIG
223 tristate "Kernel .config support"
224 ---help---
225 This option enables the complete Linux kernel ".config" file
226 contents to be saved in the kernel. It provides documentation
227 of which kernel options are used in a running kernel or in an
228 on-disk kernel. This information can be extracted from the kernel
229 image file with the script scripts/extract-ikconfig and used as
230 input to rebuild the current kernel or to build another kernel.
231 It can also be extracted from a running kernel by reading
232 /proc/config.gz if enabled (below).
234 config IKCONFIG_PROC
235 bool "Enable access to .config through /proc/config.gz"
236 depends on IKCONFIG && PROC_FS
237 ---help---
238 This option enables access to the kernel configuration file
239 through /proc/config.gz.
241 config CPUSETS
242 bool "Cpuset support"
243 depends on SMP
244 help
245 This option will let you create and manage CPUSETs which
246 allow dynamically partitioning a system into sets of CPUs and
247 Memory Nodes and assigning tasks to run only within those sets.
248 This is primarily useful on large SMP or NUMA systems.
250 Say N if unsure.
252 config SYSFS_DEPRECATED
253 bool "Create deprecated sysfs files"
254 default y
255 help
256 This option creates deprecated symlinks such as the
257 "device"-link, the <subsystem>:<name>-link, and the
258 "bus"-link. It may also add deprecated key in the
259 uevent environment.
260 None of these features or values should be used today, as
261 they export driver core implementation details to userspace
262 or export properties which can't be kept stable across kernel
263 releases.
265 If enabled, this option will also move any device structures
266 that belong to a class, back into the /sys/class heirachy, in
267 order to support older versions of udev.
269 If you are using a distro that was released in 2006 or later,
270 it should be safe to say N here.
272 config RELAY
273 bool "Kernel->user space relay support (formerly relayfs)"
274 help
275 This option enables support for relay interface support in
276 certain file systems (such as debugfs).
277 It is designed to provide an efficient mechanism for tools and
278 facilities to relay large amounts of data from kernel space to
279 user space.
281 If unsure, say N.
283 source "usr/Kconfig"
285 config CC_OPTIMIZE_FOR_SIZE
286 bool "Optimize for size (Look out for broken compilers!)"
287 default y
288 depends on ARM || H8300 || EXPERIMENTAL
289 help
290 Enabling this option will pass "-Os" instead of "-O2" to gcc
291 resulting in a smaller kernel.
293 WARNING: some versions of gcc may generate incorrect code with this
294 option. If problems are observed, a gcc upgrade may be needed.
296 If unsure, say N.
298 config TASK_XACCT
299 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
300 depends on TASKSTATS
301 help
302 Collect extended task accounting data and send the data
303 to userland for processing over the taskstats interface.
305 Say N if unsure.
307 config SYSCTL
308 bool
310 menuconfig EMBEDDED
311 bool "Configure standard kernel features (for small systems)"
312 help
313 This option allows certain base kernel options and settings
314 to be disabled or tweaked. This is for specialized
315 environments which can tolerate a "non-standard" kernel.
316 Only use this if you really know what you are doing.
318 config UID16
319 bool "Enable 16-bit UID system calls" if EMBEDDED
320 depends on ARM || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION)
321 default y
322 help
323 This enables the legacy 16-bit UID syscall wrappers.
325 config SYSCTL_SYSCALL
326 bool "Sysctl syscall support" if EMBEDDED
327 default y
328 select SYSCTL
329 ---help---
330 sys_sysctl uses binary paths that have been found challenging
331 to properly maintain and use. The interface in /proc/sys
332 using paths with ascii names is now the primary path to this
333 information.
335 Almost nothing using the binary sysctl interface so if you are
336 trying to save some space it is probably safe to disable this,
337 making your kernel marginally smaller.
339 If unsure say Y here.
341 config KALLSYMS
342 bool "Load all symbols for debugging/kksymoops" if EMBEDDED
343 default y
344 help
345 Say Y here to let the kernel print out symbolic crash information and
346 symbolic stack backtraces. This increases the size of the kernel
347 somewhat, as all symbols have to be loaded into the kernel image.
349 config KALLSYMS_ALL
350 bool "Include all symbols in kallsyms"
351 depends on DEBUG_KERNEL && KALLSYMS
352 help
353 Normally kallsyms only contains the symbols of functions, for nicer
354 OOPS messages. Some debuggers can use kallsyms for other
355 symbols too: say Y here to include all symbols, if you need them
356 and you don't care about adding 300k to the size of your kernel.
358 Say N.
360 config KALLSYMS_EXTRA_PASS
361 bool "Do an extra kallsyms pass"
362 depends on KALLSYMS
363 help
364 If kallsyms is not working correctly, the build will fail with
365 inconsistent kallsyms data. If that occurs, log a bug report and
366 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
367 Always say N here unless you find a bug in kallsyms, which must be
368 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
369 you wait for kallsyms to be fixed.
372 config HOTPLUG
373 bool "Support for hot-pluggable devices" if EMBEDDED
374 default y
375 help
376 This option is provided for the case where no hotplug or uevent
377 capabilities is wanted by the kernel. You should only consider
378 disabling this option for embedded systems that do not use modules, a
379 dynamic /dev tree, or dynamic device discovery. Just say Y.
381 config PRINTK
382 default y
383 bool "Enable support for printk" if EMBEDDED
384 help
385 This option enables normal printk support. Removing it
386 eliminates most of the message strings from the kernel image
387 and makes the kernel more or less silent. As this makes it
388 very difficult to diagnose system problems, saying N here is
389 strongly discouraged.
391 config BUG
392 bool "BUG() support" if EMBEDDED
393 default y
394 help
395 Disabling this option eliminates support for BUG and WARN, reducing
396 the size of your kernel image and potentially quietly ignoring
397 numerous fatal conditions. You should only consider disabling this
398 option for embedded systems with no facilities for reporting errors.
399 Just say Y.
401 config ELF_CORE
402 default y
403 bool "Enable ELF core dumps" if EMBEDDED
404 help
405 Enable support for generating core dumps. Disabling saves about 4k.
407 config BASE_FULL
408 default y
409 bool "Enable full-sized data structures for core" if EMBEDDED
410 help
411 Disabling this option reduces the size of miscellaneous core
412 kernel data structures. This saves memory on small machines,
413 but may reduce performance.
415 config FUTEX
416 bool "Enable futex support" if EMBEDDED
417 default y
418 select RT_MUTEXES
419 help
420 Disabling this option will cause the kernel to be built without
421 support for "fast userspace mutexes". The resulting kernel may not
422 run glibc-based applications correctly.
424 config EPOLL
425 bool "Enable eventpoll support" if EMBEDDED
426 default y
427 help
428 Disabling this option will cause the kernel to be built without
429 support for epoll family of system calls.
431 config SHMEM
432 bool "Use full shmem filesystem" if EMBEDDED
433 default y
434 depends on MMU
435 help
436 The shmem is an internal filesystem used to manage shared memory.
437 It is backed by swap and manages resource limits. It is also exported
438 to userspace as tmpfs if TMPFS is enabled. Disabling this
439 option replaces shmem and tmpfs with the much simpler ramfs code,
440 which may be appropriate on small systems without swap.
442 config SLAB
443 default y
444 bool "Use full SLAB allocator" if EMBEDDED
445 help
446 Disabling this replaces the advanced SLAB allocator and
447 kmalloc support with the drastically simpler SLOB allocator.
448 SLOB is more space efficient but does not scale well and is
449 more susceptible to fragmentation.
451 config VM_EVENT_COUNTERS
452 default y
453 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
454 help
455 VM event counters are only needed to for event counts to be
456 shown. They have no function for the kernel itself. This
457 option allows the disabling of the VM event counters.
458 /proc/vmstat will only show page counts.
460 endmenu # General setup
462 config RT_MUTEXES
463 boolean
464 select PLIST
466 config TINY_SHMEM
467 default !SHMEM
468 bool
470 config BASE_SMALL
471 int
472 default 0 if BASE_FULL
473 default 1 if !BASE_FULL
475 config SLOB
476 default !SLAB
477 bool
479 menu "Loadable module support"
481 config MODULES
482 bool "Enable loadable module support"
483 help
484 Kernel modules are small pieces of compiled code which can
485 be inserted in the running kernel, rather than being
486 permanently built into the kernel. You use the "modprobe"
487 tool to add (and sometimes remove) them. If you say Y here,
488 many parts of the kernel can be built as modules (by
489 answering M instead of Y where indicated): this is most
490 useful for infrequently used options which are not required
491 for booting. For more information, see the man pages for
492 modprobe, lsmod, modinfo, insmod and rmmod.
494 If you say Y here, you will need to run "make
495 modules_install" to put the modules under /lib/modules/
496 where modprobe can find them (you may need to be root to do
497 this).
499 If unsure, say Y.
501 config MODULE_UNLOAD
502 bool "Module unloading"
503 depends on MODULES
504 help
505 Without this option you will not be able to unload any
506 modules (note that some modules may not be unloadable
507 anyway), which makes your kernel slightly smaller and
508 simpler. If unsure, say Y.
510 config MODULE_FORCE_UNLOAD
511 bool "Forced module unloading"
512 depends on MODULE_UNLOAD && EXPERIMENTAL
513 help
514 This option allows you to force a module to unload, even if the
515 kernel believes it is unsafe: the kernel will remove the module
516 without waiting for anyone to stop using it (using the -f option to
517 rmmod). This is mainly for kernel developers and desperate users.
518 If unsure, say N.
520 config MODVERSIONS
521 bool "Module versioning support"
522 depends on MODULES
523 help
524 Usually, you have to use modules compiled with your kernel.
525 Saying Y here makes it sometimes possible to use modules
526 compiled for different kernels, by adding enough information
527 to the modules to (hopefully) spot any changes which would
528 make them incompatible with the kernel you are running. If
529 unsure, say N.
531 config MODULE_SRCVERSION_ALL
532 bool "Source checksum for all modules"
533 depends on MODULES
534 help
535 Modules which contain a MODULE_VERSION get an extra "srcversion"
536 field inserted into their modinfo section, which contains a
537 sum of the source files which made it. This helps maintainers
538 see exactly which source was used to build a module (since
539 others sometimes change the module source without updating
540 the version). With this option, such a "srcversion" field
541 will be created for all modules. If unsure, say N.
543 config KMOD
544 bool "Automatic kernel module loading"
545 depends on MODULES
546 help
547 Normally when you have selected some parts of the kernel to
548 be created as kernel modules, you must load them (using the
549 "modprobe" command) before you can use them. If you say Y
550 here, some parts of the kernel will be able to load modules
551 automatically: when a part of the kernel needs a module, it
552 runs modprobe with the appropriate arguments, thereby
553 loading the module if it is available. If unsure, say Y.
555 config STOP_MACHINE
556 bool
557 default y
558 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
559 help
560 Need stop_machine() primitive.
561 endmenu
563 menu "Block layer"
564 source "block/Kconfig"
565 endmenu