tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1config 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"
9
10menu "Code maturity level options"
11
12config 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).
31
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33 drivers that have been replaced by something else, and/or are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.
35
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.
42
43config BROKEN
44 bool
45
46config BROKEN_ON_SMP
47 bool
48 depends on BROKEN || !SMP
49 default y
50
51config LOCK_KERNEL
52 bool
53 depends on SMP || PREEMPT
54 default y
55
56config 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.
63
64endmenu
65
66menu "General setup"
67
68config 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.
77
78config 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.
85
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
90
91 Note: This requires Perl, and a git repository, but not necessarily
92 the git or cogito tools to be installed.
93
94config 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.
103
104config 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.
114
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>.
118
119config 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.
127
128config 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/>
139
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.
143
144 If unsure, say Y.
145
146config 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.
158
159config 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/>.
170
171config 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.
181
182 Say N if unsure.
183
184config 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.
192
193 Say N if unsure.
194
195config 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.
202
203config 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.
211
212config 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.
221
222config 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).
233
234config 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.
240
241config 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.
249
250 Say N if unsure.
251
252config RELAY
253 bool "Kernel->user space relay support (formerly relayfs)"
254 help
255 This option enables support for relay interface support in
256 certain file systems (such as debugfs).
257 It is designed to provide an efficient mechanism for tools and
258 facilities to relay large amounts of data from kernel space to
259 user space.
260
261 If unsure, say N.
262
263source "usr/Kconfig"
264
265config CC_OPTIMIZE_FOR_SIZE
266 bool "Optimize for size (Look out for broken compilers!)"
267 default y
268 depends on ARM || H8300 || EXPERIMENTAL
269 help
270 Enabling this option will pass "-Os" instead of "-O2" to gcc
271 resulting in a smaller kernel.
272
273 WARNING: some versions of gcc may generate incorrect code with this
274 option. If problems are observed, a gcc upgrade may be needed.
275
276 If unsure, say N.
277
278config TASK_XACCT
279 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
280 depends on TASKSTATS
281 help
282 Collect extended task accounting data and send the data
283 to userland for processing over the taskstats interface.
284
285 Say N if unsure.
286
287config SYSCTL
288 bool
289
290menuconfig EMBEDDED
291 bool "Configure standard kernel features (for small systems)"
292 help
293 This option allows certain base kernel options and settings
294 to be disabled or tweaked. This is for specialized
295 environments which can tolerate a "non-standard" kernel.
296 Only use this if you really know what you are doing.
297
298config UID16
299 bool "Enable 16-bit UID system calls" if EMBEDDED
300 depends on ARM || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION)
301 default y
302 help
303 This enables the legacy 16-bit UID syscall wrappers.
304
305config SYSCTL_SYSCALL
306 bool "Sysctl syscall support" if EMBEDDED
307 default n
308 select SYSCTL
309 ---help---
310 Enable the deprecated sysctl system call. sys_sysctl uses
311 binary paths that have been found to be a major pain to maintain
312 and use. The interface in /proc/sys is now the primary and what
313 everyone uses.
314
315 Nothing has been using the binary sysctl interface for some
316 time now so nothing should break if you disable sysctl syscall
317 support, and your kernel will get marginally smaller.
318
319 Unless you have an application that uses the sys_sysctl interface
320 you should probably say N here.
321
322config KALLSYMS
323 bool "Load all symbols for debugging/kksymoops" if EMBEDDED
324 default y
325 help
326 Say Y here to let the kernel print out symbolic crash information and
327 symbolic stack backtraces. This increases the size of the kernel
328 somewhat, as all symbols have to be loaded into the kernel image.
329
330config KALLSYMS_ALL
331 bool "Include all symbols in kallsyms"
332 depends on DEBUG_KERNEL && KALLSYMS
333 help
334 Normally kallsyms only contains the symbols of functions, for nicer
335 OOPS messages. Some debuggers can use kallsyms for other
336 symbols too: say Y here to include all symbols, if you need them
337 and you don't care about adding 300k to the size of your kernel.
338
339 Say N.
340
341config KALLSYMS_EXTRA_PASS
342 bool "Do an extra kallsyms pass"
343 depends on KALLSYMS
344 help
345 If kallsyms is not working correctly, the build will fail with
346 inconsistent kallsyms data. If that occurs, log a bug report and
347 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
348 Always say N here unless you find a bug in kallsyms, which must be
349 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
350 you wait for kallsyms to be fixed.
351
352
353config HOTPLUG
354 bool "Support for hot-pluggable devices" if EMBEDDED
355 default y
356 help
357 This option is provided for the case where no hotplug or uevent
358 capabilities is wanted by the kernel. You should only consider
359 disabling this option for embedded systems that do not use modules, a
360 dynamic /dev tree, or dynamic device discovery. Just say Y.
361
362config PRINTK
363 default y
364 bool "Enable support for printk" if EMBEDDED
365 help
366 This option enables normal printk support. Removing it
367 eliminates most of the message strings from the kernel image
368 and makes the kernel more or less silent. As this makes it
369 very difficult to diagnose system problems, saying N here is
370 strongly discouraged.
371
372config BUG
373 bool "BUG() support" if EMBEDDED
374 default y
375 help
376 Disabling this option eliminates support for BUG and WARN, reducing
377 the size of your kernel image and potentially quietly ignoring
378 numerous fatal conditions. You should only consider disabling this
379 option for embedded systems with no facilities for reporting errors.
380 Just say Y.
381
382config ELF_CORE
383 default y
384 bool "Enable ELF core dumps" if EMBEDDED
385 help
386 Enable support for generating core dumps. Disabling saves about 4k.
387
388config BASE_FULL
389 default y
390 bool "Enable full-sized data structures for core" if EMBEDDED
391 help
392 Disabling this option reduces the size of miscellaneous core
393 kernel data structures. This saves memory on small machines,
394 but may reduce performance.
395
396config FUTEX
397 bool "Enable futex support" if EMBEDDED
398 default y
399 select RT_MUTEXES
400 help
401 Disabling this option will cause the kernel to be built without
402 support for "fast userspace mutexes". The resulting kernel may not
403 run glibc-based applications correctly.
404
405config EPOLL
406 bool "Enable eventpoll support" if EMBEDDED
407 default y
408 help
409 Disabling this option will cause the kernel to be built without
410 support for epoll family of system calls.
411
412config SHMEM
413 bool "Use full shmem filesystem" if EMBEDDED
414 default y
415 depends on MMU
416 help
417 The shmem is an internal filesystem used to manage shared memory.
418 It is backed by swap and manages resource limits. It is also exported
419 to userspace as tmpfs if TMPFS is enabled. Disabling this
420 option replaces shmem and tmpfs with the much simpler ramfs code,
421 which may be appropriate on small systems without swap.
422
423config SLAB
424 default y
425 bool "Use full SLAB allocator" if EMBEDDED
426 help
427 Disabling this replaces the advanced SLAB allocator and
428 kmalloc support with the drastically simpler SLOB allocator.
429 SLOB is more space efficient but does not scale well and is
430 more susceptible to fragmentation.
431
432config VM_EVENT_COUNTERS
433 default y
434 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
435 help
436 VM event counters are only needed to for event counts to be
437 shown. They have no function for the kernel itself. This
438 option allows the disabling of the VM event counters.
439 /proc/vmstat will only show page counts.
440
441endmenu # General setup
442
443config RT_MUTEXES
444 boolean
445 select PLIST
446
447config TINY_SHMEM
448 default !SHMEM
449 bool
450
451config BASE_SMALL
452 int
453 default 0 if BASE_FULL
454 default 1 if !BASE_FULL
455
456config SLOB
457 default !SLAB
458 bool
459
460menu "Loadable module support"
461
462config MODULES
463 bool "Enable loadable module support"
464 help
465 Kernel modules are small pieces of compiled code which can
466 be inserted in the running kernel, rather than being
467 permanently built into the kernel. You use the "modprobe"
468 tool to add (and sometimes remove) them. If you say Y here,
469 many parts of the kernel can be built as modules (by
470 answering M instead of Y where indicated): this is most
471 useful for infrequently used options which are not required
472 for booting. For more information, see the man pages for
473 modprobe, lsmod, modinfo, insmod and rmmod.
474
475 If you say Y here, you will need to run "make
476 modules_install" to put the modules under /lib/modules/
477 where modprobe can find them (you may need to be root to do
478 this).
479
480 If unsure, say Y.
481
482config MODULE_UNLOAD
483 bool "Module unloading"
484 depends on MODULES
485 help
486 Without this option you will not be able to unload any
487 modules (note that some modules may not be unloadable
488 anyway), which makes your kernel slightly smaller and
489 simpler. If unsure, say Y.
490
491config MODULE_FORCE_UNLOAD
492 bool "Forced module unloading"
493 depends on MODULE_UNLOAD && EXPERIMENTAL
494 help
495 This option allows you to force a module to unload, even if the
496 kernel believes it is unsafe: the kernel will remove the module
497 without waiting for anyone to stop using it (using the -f option to
498 rmmod). This is mainly for kernel developers and desperate users.
499 If unsure, say N.
500
501config MODVERSIONS
502 bool "Module versioning support"
503 depends on MODULES
504 help
505 Usually, you have to use modules compiled with your kernel.
506 Saying Y here makes it sometimes possible to use modules
507 compiled for different kernels, by adding enough information
508 to the modules to (hopefully) spot any changes which would
509 make them incompatible with the kernel you are running. If
510 unsure, say N.
511
512config MODULE_SRCVERSION_ALL
513 bool "Source checksum for all modules"
514 depends on MODULES
515 help
516 Modules which contain a MODULE_VERSION get an extra "srcversion"
517 field inserted into their modinfo section, which contains a
518 sum of the source files which made it. This helps maintainers
519 see exactly which source was used to build a module (since
520 others sometimes change the module source without updating
521 the version). With this option, such a "srcversion" field
522 will be created for all modules. If unsure, say N.
523
524config KMOD
525 bool "Automatic kernel module loading"
526 depends on MODULES
527 help
528 Normally when you have selected some parts of the kernel to
529 be created as kernel modules, you must load them (using the
530 "modprobe" command) before you can use them. If you say Y
531 here, some parts of the kernel will be able to load modules
532 automatically: when a part of the kernel needs a module, it
533 runs modprobe with the appropriate arguments, thereby
534 loading the module if it is available. If unsure, say Y.
535
536config STOP_MACHINE
537 bool
538 default y
539 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
540 help
541 Need stop_machine() primitive.
542endmenu
543
544menu "Block layer"
545source "block/Kconfig"
546endmenu