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80daa560 RZ |
1 | config ARCH |
2 | string | |
3 | option env="ARCH" | |
4 | ||
5 | config KERNELVERSION | |
6 | string | |
7 | option env="KERNELVERSION" | |
8 | ||
face4374 RZ |
9 | config DEFCONFIG_LIST |
10 | string | |
b2670eac | 11 | depends on !UML |
face4374 RZ |
12 | option defconfig_list |
13 | default "/lib/modules/$UNAME_RELEASE/.config" | |
14 | default "/etc/kernel-config" | |
15 | default "/boot/config-$UNAME_RELEASE" | |
73531905 | 16 | default "$ARCH_DEFCONFIG" |
face4374 RZ |
17 | default "arch/$ARCH/defconfig" |
18 | ||
ff0cfc66 | 19 | menu "General setup" |
1da177e4 LT |
20 | |
21 | config EXPERIMENTAL | |
22 | bool "Prompt for development and/or incomplete code/drivers" | |
23 | ---help--- | |
24 | Some of the various things that Linux supports (such as network | |
25 | drivers, file systems, network protocols, etc.) can be in a state | |
26 | of development where the functionality, stability, or the level of | |
27 | testing is not yet high enough for general use. This is usually | |
28 | known as the "alpha-test" phase among developers. If a feature is | |
29 | currently in alpha-test, then the developers usually discourage | |
30 | uninformed widespread use of this feature by the general public to | |
31 | avoid "Why doesn't this work?" type mail messages. However, active | |
32 | testing and use of these systems is welcomed. Just be aware that it | |
33 | may not meet the normal level of reliability or it may fail to work | |
34 | in some special cases. Detailed bug reports from people familiar | |
35 | with the kernel internals are usually welcomed by the developers | |
36 | (before submitting bug reports, please read the documents | |
37 | <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>, | |
38 | <file:Documentation/BUG-HUNTING>, and | |
39 | <file:Documentation/oops-tracing.txt> in the kernel source). | |
40 | ||
41 | This option will also make obsoleted drivers available. These are | |
42 | drivers that have been replaced by something else, and/or are | |
43 | scheduled to be removed in a future kernel release. | |
44 | ||
45 | Unless you intend to help test and develop a feature or driver that | |
46 | falls into this category, or you have a situation that requires | |
47 | using these features, you should probably say N here, which will | |
48 | cause the configurator to present you with fewer choices. If | |
49 | you say Y here, you will be offered the choice of using features or | |
50 | drivers that are currently considered to be in the alpha-test phase. | |
51 | ||
1da177e4 LT |
52 | config BROKEN |
53 | bool | |
1da177e4 LT |
54 | |
55 | config BROKEN_ON_SMP | |
56 | bool | |
57 | depends on BROKEN || !SMP | |
58 | default y | |
59 | ||
60 | config LOCK_KERNEL | |
61 | bool | |
62 | depends on SMP || PREEMPT | |
63 | default y | |
64 | ||
65 | config INIT_ENV_ARG_LIMIT | |
66 | int | |
dd673bca AB |
67 | default 32 if !UML |
68 | default 128 if UML | |
1da177e4 | 69 | help |
34ad92c2 RD |
70 | Maximum of each of the number of arguments and environment |
71 | variables passed to init from the kernel command line. | |
1da177e4 | 72 | |
1da177e4 LT |
73 | |
74 | config LOCALVERSION | |
75 | string "Local version - append to kernel release" | |
76 | help | |
77 | Append an extra string to the end of your kernel version. | |
78 | This will show up when you type uname, for example. | |
79 | The string you set here will be appended after the contents of | |
80 | any files with a filename matching localversion* in your | |
81 | object and source tree, in that order. Your total string can | |
82 | be a maximum of 64 characters. | |
83 | ||
aaebf433 RA |
84 | config LOCALVERSION_AUTO |
85 | bool "Automatically append version information to the version string" | |
86 | default y | |
87 | help | |
88 | This will try to automatically determine if the current tree is a | |
6e5a5420 RD |
89 | release tree by looking for git tags that belong to the current |
90 | top of tree revision. | |
aaebf433 RA |
91 | |
92 | A string of the format -gxxxxxxxx will be added to the localversion | |
6e5a5420 | 93 | if a git-based tree is found. The string generated by this will be |
aaebf433 | 94 | appended after any matching localversion* files, and after the value |
6e5a5420 | 95 | set in CONFIG_LOCALVERSION. |
aaebf433 | 96 | |
6e5a5420 RD |
97 | (The actual string used here is the first eight characters produced |
98 | by running the command: | |
99 | ||
100 | $ git rev-parse --verify HEAD | |
101 | ||
102 | which is done within the script "scripts/setlocalversion".) | |
aaebf433 | 103 | |
30d65dbf AK |
104 | choice |
105 | prompt "Kernel compression mode" | |
106 | default KERNEL_GZIP | |
107 | help | |
108 | The linux kernel is a kind of self-extracting executable. | |
109 | Several compression algorithms are available, which differ | |
110 | in efficiency, compression and decompression speed. | |
111 | Compression speed is only relevant when building a kernel. | |
112 | Decompression speed is relevant at each boot. | |
113 | ||
114 | If you have any problems with bzip2 or lzma compressed | |
115 | kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older | |
116 | version of this functionality (bzip2 only), for 2.4, was | |
117 | supplied by Christian Ludwig) | |
118 | ||
119 | High compression options are mostly useful for users, who | |
120 | are low on disk space (embedded systems), but for whom ram | |
121 | size matters less. | |
122 | ||
123 | If in doubt, select 'gzip' | |
124 | ||
125 | config KERNEL_GZIP | |
126 | bool "Gzip" | |
127 | help | |
128 | The old and tried gzip compression. Its compression ratio is | |
129 | the poorest among the 3 choices; however its speed (both | |
130 | compression and decompression) is the fastest. | |
131 | ||
132 | config KERNEL_BZIP2 | |
133 | bool "Bzip2" | |
134 | help | |
135 | Its compression ratio and speed is intermediate. | |
136 | Decompression speed is slowest among the 3. | |
137 | The kernel size is about 10 per cent smaller with bzip2, | |
138 | in comparison to gzip. | |
139 | Bzip2 uses a large amount of memory. For modern kernels | |
140 | you will need at least 8MB RAM or more for booting. | |
141 | ||
142 | config KERNEL_LZMA | |
143 | bool "LZMA" | |
144 | help | |
145 | The most recent compression algorithm. | |
146 | Its ratio is best, decompression speed is between the other | |
147 | 2. Compression is slowest. | |
148 | The kernel size is about 33 per cent smaller with lzma, | |
149 | in comparison to gzip. | |
150 | ||
151 | endchoice | |
152 | ||
153 | ||
1da177e4 LT |
154 | config SWAP |
155 | bool "Support for paging of anonymous memory (swap)" | |
9361401e | 156 | depends on MMU && BLOCK |
1da177e4 LT |
157 | default y |
158 | help | |
159 | This option allows you to choose whether you want to have support | |
92c3504e | 160 | for so called swap devices or swap files in your kernel that are |
1da177e4 LT |
161 | used to provide more virtual memory than the actual RAM present |
162 | in your computer. If unsure say Y. | |
163 | ||
164 | config SYSVIPC | |
165 | bool "System V IPC" | |
1da177e4 LT |
166 | ---help--- |
167 | Inter Process Communication is a suite of library functions and | |
168 | system calls which let processes (running programs) synchronize and | |
169 | exchange information. It is generally considered to be a good thing, | |
170 | and some programs won't run unless you say Y here. In particular, if | |
171 | you want to run the DOS emulator dosemu under Linux (read the | |
172 | DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>), | |
173 | you'll need to say Y here. | |
174 | ||
175 | You can find documentation about IPC with "info ipc" and also in | |
176 | section 6.4 of the Linux Programmer's Guide, available from | |
177 | <http://www.tldp.org/guides.html>. | |
178 | ||
a5494dcd EB |
179 | config SYSVIPC_SYSCTL |
180 | bool | |
181 | depends on SYSVIPC | |
182 | depends on SYSCTL | |
183 | default y | |
184 | ||
1da177e4 LT |
185 | config POSIX_MQUEUE |
186 | bool "POSIX Message Queues" | |
187 | depends on NET && EXPERIMENTAL | |
188 | ---help--- | |
189 | POSIX variant of message queues is a part of IPC. In POSIX message | |
190 | queues every message has a priority which decides about succession | |
191 | of receiving it by a process. If you want to compile and run | |
192 | programs written e.g. for Solaris with use of its POSIX message | |
b0e37650 | 193 | queues (functions mq_*) say Y here. |
1da177e4 LT |
194 | |
195 | POSIX message queues are visible as a filesystem called 'mqueue' | |
196 | and can be mounted somewhere if you want to do filesystem | |
197 | operations on message queues. | |
198 | ||
199 | If unsure, say Y. | |
200 | ||
201 | config BSD_PROCESS_ACCT | |
202 | bool "BSD Process Accounting" | |
203 | help | |
204 | If you say Y here, a user level program will be able to instruct the | |
205 | kernel (via a special system call) to write process accounting | |
206 | information to a file: whenever a process exits, information about | |
207 | that process will be appended to the file by the kernel. The | |
208 | information includes things such as creation time, owning user, | |
209 | command name, memory usage, controlling terminal etc. (the complete | |
210 | list is in the struct acct in <file:include/linux/acct.h>). It is | |
211 | up to the user level program to do useful things with this | |
212 | information. This is generally a good idea, so say Y. | |
213 | ||
214 | config BSD_PROCESS_ACCT_V3 | |
215 | bool "BSD Process Accounting version 3 file format" | |
216 | depends on BSD_PROCESS_ACCT | |
217 | default n | |
218 | help | |
219 | If you say Y here, the process accounting information is written | |
220 | in a new file format that also logs the process IDs of each | |
221 | process and it's parent. Note that this file format is incompatible | |
222 | with previous v0/v1/v2 file formats, so you will need updated tools | |
223 | for processing it. A preliminary version of these tools is available | |
37a4c940 | 224 | at <http://www.gnu.org/software/acct/>. |
1da177e4 | 225 | |
c757249a SN |
226 | config TASKSTATS |
227 | bool "Export task/process statistics through netlink (EXPERIMENTAL)" | |
228 | depends on NET | |
229 | default n | |
230 | help | |
231 | Export selected statistics for tasks/processes through the | |
232 | generic netlink interface. Unlike BSD process accounting, the | |
233 | statistics are available during the lifetime of tasks/processes as | |
234 | responses to commands. Like BSD accounting, they are sent to user | |
235 | space on task exit. | |
236 | ||
237 | Say N if unsure. | |
238 | ||
ca74e92b SN |
239 | config TASK_DELAY_ACCT |
240 | bool "Enable per-task delay accounting (EXPERIMENTAL)" | |
6f44993f | 241 | depends on TASKSTATS |
ca74e92b SN |
242 | help |
243 | Collect information on time spent by a task waiting for system | |
244 | resources like cpu, synchronous block I/O completion and swapping | |
245 | in pages. Such statistics can help in setting a task's priorities | |
246 | relative to other tasks for cpu, io, rss limits etc. | |
247 | ||
248 | Say N if unsure. | |
249 | ||
18f705f4 AD |
250 | config TASK_XACCT |
251 | bool "Enable extended accounting over taskstats (EXPERIMENTAL)" | |
252 | depends on TASKSTATS | |
253 | help | |
254 | Collect extended task accounting data and send the data | |
255 | to userland for processing over the taskstats interface. | |
256 | ||
257 | Say N if unsure. | |
258 | ||
259 | config TASK_IO_ACCOUNTING | |
260 | bool "Enable per-task storage I/O accounting (EXPERIMENTAL)" | |
261 | depends on TASK_XACCT | |
262 | help | |
263 | Collect information on the number of bytes of storage I/O which this | |
264 | task has caused. | |
265 | ||
266 | Say N if unsure. | |
267 | ||
1da177e4 LT |
268 | config AUDIT |
269 | bool "Auditing support" | |
804a6a49 | 270 | depends on NET |
1da177e4 LT |
271 | help |
272 | Enable auditing infrastructure that can be used with another | |
273 | kernel subsystem, such as SELinux (which requires this for | |
274 | logging of avc messages output). Does not do system-call | |
275 | auditing without CONFIG_AUDITSYSCALL. | |
276 | ||
277 | config AUDITSYSCALL | |
278 | bool "Enable system-call auditing support" | |
1322b9de | 279 | depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64|| SUPERH) |
1da177e4 LT |
280 | default y if SECURITY_SELINUX |
281 | help | |
282 | Enable low-overhead system-call auditing infrastructure that | |
283 | can be used independently or with another kernel subsystem, | |
f368c07d AG |
284 | such as SELinux. To use audit's filesystem watch feature, please |
285 | ensure that INOTIFY is configured. | |
1da177e4 | 286 | |
74c3cbe3 AV |
287 | config AUDIT_TREE |
288 | def_bool y | |
289 | depends on AUDITSYSCALL && INOTIFY | |
290 | ||
1da177e4 | 291 | config IKCONFIG |
f2443ab6 | 292 | tristate "Kernel .config support" |
1da177e4 LT |
293 | ---help--- |
294 | This option enables the complete Linux kernel ".config" file | |
295 | contents to be saved in the kernel. It provides documentation | |
296 | of which kernel options are used in a running kernel or in an | |
297 | on-disk kernel. This information can be extracted from the kernel | |
298 | image file with the script scripts/extract-ikconfig and used as | |
299 | input to rebuild the current kernel or to build another kernel. | |
300 | It can also be extracted from a running kernel by reading | |
301 | /proc/config.gz if enabled (below). | |
302 | ||
303 | config IKCONFIG_PROC | |
304 | bool "Enable access to .config through /proc/config.gz" | |
305 | depends on IKCONFIG && PROC_FS | |
306 | ---help--- | |
307 | This option enables access to the kernel configuration file | |
308 | through /proc/config.gz. | |
309 | ||
794543a2 AJS |
310 | config LOG_BUF_SHIFT |
311 | int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" | |
312 | range 12 21 | |
f17a32e9 | 313 | default 17 |
794543a2 AJS |
314 | help |
315 | Select kernel log buffer size as a power of 2. | |
f17a32e9 AB |
316 | Examples: |
317 | 17 => 128 KB | |
318 | 16 => 64 KB | |
319 | 15 => 32 KB | |
320 | 14 => 16 KB | |
794543a2 AJS |
321 | 13 => 8 KB |
322 | 12 => 4 KB | |
323 | ||
ddbcc7e8 PM |
324 | config CGROUPS |
325 | bool "Control Group support" | |
326 | help | |
327 | This option will let you use process cgroup subsystems | |
328 | such as Cpusets | |
329 | ||
330 | Say N if unsure. | |
331 | ||
006cb992 PM |
332 | config CGROUP_DEBUG |
333 | bool "Example debug cgroup subsystem" | |
334 | depends on CGROUPS | |
418d7d87 | 335 | default n |
006cb992 PM |
336 | help |
337 | This option enables a simple cgroup subsystem that | |
338 | exports useful debugging information about the cgroups | |
339 | framework | |
340 | ||
341 | Say N if unsure | |
342 | ||
858d72ea SH |
343 | config CGROUP_NS |
344 | bool "Namespace cgroup subsystem" | |
345 | depends on CGROUPS | |
346 | help | |
347 | Provides a simple namespace cgroup subsystem to | |
348 | provide hierarchical naming of sets of namespaces, | |
349 | for instance virtual servers and checkpoint/restart | |
350 | jobs. | |
351 | ||
dc52ddc0 MH |
352 | config CGROUP_FREEZER |
353 | bool "control group freezer subsystem" | |
354 | depends on CGROUPS | |
355 | help | |
356 | Provides a way to freeze and unfreeze all tasks in a | |
357 | cgroup. | |
358 | ||
08ce5f16 SH |
359 | config CGROUP_DEVICE |
360 | bool "Device controller for cgroups" | |
361 | depends on CGROUPS && EXPERIMENTAL | |
362 | help | |
363 | Provides a cgroup implementing whitelists for devices which | |
364 | a process in the cgroup can mknod or open. | |
365 | ||
1da177e4 LT |
366 | config CPUSETS |
367 | bool "Cpuset support" | |
8793d854 | 368 | depends on SMP && CGROUPS |
1da177e4 | 369 | help |
d9fd8a6d | 370 | This option will let you create and manage CPUSETs which |
1da177e4 LT |
371 | allow dynamically partitioning a system into sets of CPUs and |
372 | Memory Nodes and assigning tasks to run only within those sets. | |
373 | This is primarily useful on large SMP or NUMA systems. | |
374 | ||
375 | Say N if unsure. | |
376 | ||
a5574cf6 IM |
377 | # |
378 | # Architectures with an unreliable sched_clock() should select this: | |
379 | # | |
380 | config HAVE_UNSTABLE_SCHED_CLOCK | |
381 | bool | |
382 | ||
052f1dc7 PZ |
383 | config GROUP_SCHED |
384 | bool "Group CPU scheduler" | |
aac6abca PW |
385 | depends on EXPERIMENTAL |
386 | default n | |
29f59db3 | 387 | help |
fb615581 | 388 | This feature lets CPU scheduler recognize task groups and control CPU |
9b5b7751 | 389 | bandwidth allocation to such task groups. |
29f59db3 | 390 | |
052f1dc7 PZ |
391 | config FAIR_GROUP_SCHED |
392 | bool "Group scheduling for SCHED_OTHER" | |
393 | depends on GROUP_SCHED | |
aac6abca | 394 | default GROUP_SCHED |
052f1dc7 PZ |
395 | |
396 | config RT_GROUP_SCHED | |
397 | bool "Group scheduling for SCHED_RR/FIFO" | |
398 | depends on EXPERIMENTAL | |
399 | depends on GROUP_SCHED | |
400 | default n | |
b9b158fe VR |
401 | help |
402 | This feature lets you explicitly allocate real CPU bandwidth | |
403 | to users or control groups (depending on the "Basis for grouping tasks" | |
404 | setting below. If enabled, it will also make it impossible to | |
405 | schedule realtime tasks for non-root users until you allocate | |
406 | realtime bandwidth for them. | |
2fe401e3 | 407 | See Documentation/scheduler/sched-rt-group.txt for more information. |
052f1dc7 | 408 | |
24e377a8 | 409 | choice |
052f1dc7 | 410 | depends on GROUP_SCHED |
24e377a8 | 411 | prompt "Basis for grouping tasks" |
052f1dc7 | 412 | default USER_SCHED |
24e377a8 | 413 | |
052f1dc7 | 414 | config USER_SCHED |
fb615581 SV |
415 | bool "user id" |
416 | help | |
417 | This option will choose userid as the basis for grouping | |
418 | tasks, thus providing equal CPU bandwidth to each user. | |
24e377a8 | 419 | |
052f1dc7 | 420 | config CGROUP_SCHED |
68318b8e SV |
421 | bool "Control groups" |
422 | depends on CGROUPS | |
423 | help | |
424 | This option allows you to create arbitrary task groups | |
425 | using the "cgroup" pseudo filesystem and control | |
426 | the cpu bandwidth allocated to each such task group. | |
427 | Refer to Documentation/cgroups.txt for more information | |
428 | on "cgroup" pseudo filesystem. | |
429 | ||
24e377a8 SV |
430 | endchoice |
431 | ||
d842de87 SV |
432 | config CGROUP_CPUACCT |
433 | bool "Simple CPU accounting cgroup subsystem" | |
434 | depends on CGROUPS | |
435 | help | |
436 | Provides a simple Resource Controller for monitoring the | |
437 | total CPU consumed by the tasks in a cgroup | |
438 | ||
e552b661 PE |
439 | config RESOURCE_COUNTERS |
440 | bool "Resource counters" | |
441 | help | |
442 | This option enables controller independent resource accounting | |
443 | infrastructure that works with cgroups | |
444 | depends on CGROUPS | |
445 | ||
cf475ad2 BS |
446 | config MM_OWNER |
447 | bool | |
448 | ||
00f0b825 BS |
449 | config CGROUP_MEM_RES_CTLR |
450 | bool "Memory Resource Controller for Control Groups" | |
451 | depends on CGROUPS && RESOURCE_COUNTERS | |
cf475ad2 | 452 | select MM_OWNER |
00f0b825 | 453 | help |
84ad6d70 KH |
454 | Provides a memory resource controller that manages both anonymous |
455 | memory and page cache. (See Documentation/controllers/memory.txt) | |
00f0b825 BS |
456 | |
457 | Note that setting this option increases fixed memory overhead | |
84ad6d70 KH |
458 | associated with each page of memory in the system. By this, |
459 | 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory | |
460 | usage tracking struct at boot. Total amount of this is printed out | |
461 | at boot. | |
00f0b825 BS |
462 | |
463 | Only enable when you're ok with these trade offs and really | |
84ad6d70 KH |
464 | sure you need the memory resource controller. Even when you enable |
465 | this, you can set "cgroup_disable=memory" at your boot option to | |
466 | disable memory resource controller and you can avoid overheads. | |
467 | (and lose benefits of memory resource contoller) | |
00f0b825 | 468 | |
cf475ad2 BS |
469 | This config option also selects MM_OWNER config option, which |
470 | could in turn add some fork/exit overhead. | |
471 | ||
88a22c98 | 472 | config SYSFS_DEPRECATED |
d47846c5 IM |
473 | bool |
474 | ||
475 | config SYSFS_DEPRECATED_V2 | |
88a22c98 | 476 | bool "Create deprecated sysfs files" |
9148fe87 | 477 | depends on SYSFS |
88a22c98 | 478 | default y |
d47846c5 | 479 | select SYSFS_DEPRECATED |
88a22c98 KS |
480 | help |
481 | This option creates deprecated symlinks such as the | |
482 | "device"-link, the <subsystem>:<name>-link, and the | |
483 | "bus"-link. It may also add deprecated key in the | |
484 | uevent environment. | |
485 | None of these features or values should be used today, as | |
486 | they export driver core implementation details to userspace | |
487 | or export properties which can't be kept stable across kernel | |
488 | releases. | |
489 | ||
490 | If enabled, this option will also move any device structures | |
3dde6ad8 | 491 | that belong to a class, back into the /sys/class hierarchy, in |
024440d2 GKH |
492 | order to support older versions of udev and some userspace |
493 | programs. | |
88a22c98 | 494 | |
024440d2 GKH |
495 | If you are using a distro with the most recent userspace |
496 | packages, it should be safe to say N here. | |
88a22c98 | 497 | |
8793d854 PM |
498 | config PROC_PID_CPUSET |
499 | bool "Include legacy /proc/<pid>/cpuset file" | |
500 | depends on CPUSETS | |
501 | default y | |
502 | ||
b86ff981 JA |
503 | config RELAY |
504 | bool "Kernel->user space relay support (formerly relayfs)" | |
505 | help | |
506 | This option enables support for relay interface support in | |
507 | certain file systems (such as debugfs). | |
508 | It is designed to provide an efficient mechanism for tools and | |
509 | facilities to relay large amounts of data from kernel space to | |
510 | user space. | |
511 | ||
512 | If unsure, say N. | |
513 | ||
c5289a69 PE |
514 | config NAMESPACES |
515 | bool "Namespaces support" if EMBEDDED | |
516 | default !EMBEDDED | |
517 | help | |
518 | Provides the way to make tasks work with different objects using | |
519 | the same id. For example same IPC id may refer to different objects | |
520 | or same user id or pid may refer to different tasks when used in | |
521 | different namespaces. | |
522 | ||
58bfdd6d PE |
523 | config UTS_NS |
524 | bool "UTS namespace" | |
525 | depends on NAMESPACES | |
526 | help | |
527 | In this namespace tasks see different info provided with the | |
528 | uname() system call | |
529 | ||
ae5e1b22 PE |
530 | config IPC_NS |
531 | bool "IPC namespace" | |
532 | depends on NAMESPACES && SYSVIPC | |
533 | help | |
534 | In this namespace tasks work with IPC ids which correspond to | |
535 | different IPC objects in different namespaces | |
536 | ||
aee16ce7 PE |
537 | config USER_NS |
538 | bool "User namespace (EXPERIMENTAL)" | |
539 | depends on NAMESPACES && EXPERIMENTAL | |
540 | help | |
541 | This allows containers, i.e. vservers, to use user namespaces | |
542 | to provide different user info for different servers. | |
543 | If unsure, say N. | |
544 | ||
74bd59bb PE |
545 | config PID_NS |
546 | bool "PID Namespaces (EXPERIMENTAL)" | |
547 | default n | |
548 | depends on NAMESPACES && EXPERIMENTAL | |
549 | help | |
12d2b8f9 | 550 | Support process id namespaces. This allows having multiple |
74bd59bb PE |
551 | process with the same pid as long as they are in different |
552 | pid namespaces. This is a building block of containers. | |
553 | ||
554 | Unless you want to work with an experimental feature | |
555 | say N here. | |
556 | ||
f991633d DG |
557 | config BLK_DEV_INITRD |
558 | bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support" | |
559 | depends on BROKEN || !FRV | |
560 | help | |
561 | The initial RAM filesystem is a ramfs which is loaded by the | |
562 | boot loader (loadlin or lilo) and that is mounted as root | |
563 | before the normal boot procedure. It is typically used to | |
564 | load modules needed to mount the "real" root file system, | |
565 | etc. See <file:Documentation/initrd.txt> for details. | |
566 | ||
567 | If RAM disk support (BLK_DEV_RAM) is also included, this | |
568 | also enables initial RAM disk (initrd) support and adds | |
569 | 15 Kbytes (more on some other architectures) to the kernel size. | |
570 | ||
571 | If unsure say Y. | |
572 | ||
c33df4ea JPS |
573 | if BLK_DEV_INITRD |
574 | ||
dbec4866 SR |
575 | source "usr/Kconfig" |
576 | ||
c33df4ea JPS |
577 | endif |
578 | ||
c45b4f1f | 579 | config CC_OPTIMIZE_FOR_SIZE |
96fffeb4 | 580 | bool "Optimize for size" |
c45b4f1f | 581 | default y |
c45b4f1f LT |
582 | help |
583 | Enabling this option will pass "-Os" instead of "-O2" to gcc | |
584 | resulting in a smaller kernel. | |
585 | ||
775a7229 | 586 | If unsure, say Y. |
c45b4f1f | 587 | |
0847062a RD |
588 | config SYSCTL |
589 | bool | |
590 | ||
1da177e4 LT |
591 | menuconfig EMBEDDED |
592 | bool "Configure standard kernel features (for small systems)" | |
593 | help | |
594 | This option allows certain base kernel options and settings | |
595 | to be disabled or tweaked. This is for specialized | |
596 | environments which can tolerate a "non-standard" kernel. | |
597 | Only use this if you really know what you are doing. | |
598 | ||
ae81f9e3 CE |
599 | config UID16 |
600 | bool "Enable 16-bit UID system calls" if EMBEDDED | |
09337f50 | 601 | depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION) |
ae81f9e3 CE |
602 | default y |
603 | help | |
604 | This enables the legacy 16-bit UID syscall wrappers. | |
605 | ||
b89a8171 | 606 | config SYSCTL_SYSCALL |
0847062a | 607 | bool "Sysctl syscall support" if EMBEDDED |
13bb7e37 | 608 | default y |
b89a8171 | 609 | select SYSCTL |
ae81f9e3 | 610 | ---help--- |
13bb7e37 EB |
611 | sys_sysctl uses binary paths that have been found challenging |
612 | to properly maintain and use. The interface in /proc/sys | |
613 | using paths with ascii names is now the primary path to this | |
614 | information. | |
b89a8171 | 615 | |
13bb7e37 EB |
616 | Almost nothing using the binary sysctl interface so if you are |
617 | trying to save some space it is probably safe to disable this, | |
618 | making your kernel marginally smaller. | |
b89a8171 | 619 | |
13bb7e37 | 620 | If unsure say Y here. |
ae81f9e3 | 621 | |
1da177e4 | 622 | config KALLSYMS |
979c6a1e | 623 | bool "Load all symbols for debugging/ksymoops" if EMBEDDED |
1da177e4 LT |
624 | default y |
625 | help | |
626 | Say Y here to let the kernel print out symbolic crash information and | |
627 | symbolic stack backtraces. This increases the size of the kernel | |
628 | somewhat, as all symbols have to be loaded into the kernel image. | |
629 | ||
630 | config KALLSYMS_ALL | |
631 | bool "Include all symbols in kallsyms" | |
632 | depends on DEBUG_KERNEL && KALLSYMS | |
633 | help | |
634 | Normally kallsyms only contains the symbols of functions, for nicer | |
635 | OOPS messages. Some debuggers can use kallsyms for other | |
f9f97bc0 JJ |
636 | symbols too: say Y here to include all symbols, if you need them |
637 | and you don't care about adding 300k to the size of your kernel. | |
1da177e4 LT |
638 | |
639 | Say N. | |
640 | ||
9bb48247 JB |
641 | config KALLSYMS_STRIP_GENERATED |
642 | bool "Strip machine generated symbols from kallsyms" | |
643 | depends on KALLSYMS_ALL | |
644 | default y | |
645 | help | |
646 | Say N if you want kallsyms to retain even machine generated symbols. | |
647 | ||
1da177e4 LT |
648 | config KALLSYMS_EXTRA_PASS |
649 | bool "Do an extra kallsyms pass" | |
650 | depends on KALLSYMS | |
651 | help | |
652 | If kallsyms is not working correctly, the build will fail with | |
653 | inconsistent kallsyms data. If that occurs, log a bug report and | |
654 | turn on KALLSYMS_EXTRA_PASS which should result in a stable build. | |
655 | Always say N here unless you find a bug in kallsyms, which must be | |
656 | reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while | |
657 | you wait for kallsyms to be fixed. | |
658 | ||
d59745ce | 659 | |
712f47ce GKH |
660 | config HOTPLUG |
661 | bool "Support for hot-pluggable devices" if EMBEDDED | |
662 | default y | |
663 | help | |
664 | This option is provided for the case where no hotplug or uevent | |
665 | capabilities is wanted by the kernel. You should only consider | |
666 | disabling this option for embedded systems that do not use modules, a | |
667 | dynamic /dev tree, or dynamic device discovery. Just say Y. | |
668 | ||
d59745ce MM |
669 | config PRINTK |
670 | default y | |
671 | bool "Enable support for printk" if EMBEDDED | |
672 | help | |
673 | This option enables normal printk support. Removing it | |
674 | eliminates most of the message strings from the kernel image | |
675 | and makes the kernel more or less silent. As this makes it | |
676 | very difficult to diagnose system problems, saying N here is | |
677 | strongly discouraged. | |
678 | ||
c8538a7a MM |
679 | config BUG |
680 | bool "BUG() support" if EMBEDDED | |
681 | default y | |
682 | help | |
683 | Disabling this option eliminates support for BUG and WARN, reducing | |
684 | the size of your kernel image and potentially quietly ignoring | |
685 | numerous fatal conditions. You should only consider disabling this | |
686 | option for embedded systems with no facilities for reporting errors. | |
687 | Just say Y. | |
688 | ||
708e9a79 MM |
689 | config ELF_CORE |
690 | default y | |
691 | bool "Enable ELF core dumps" if EMBEDDED | |
692 | help | |
693 | Enable support for generating core dumps. Disabling saves about 4k. | |
694 | ||
e5e1d3cb SS |
695 | config PCSPKR_PLATFORM |
696 | bool "Enable PC-Speaker support" if EMBEDDED | |
697 | depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES | |
698 | default y | |
699 | help | |
700 | This option allows to disable the internal PC-Speaker | |
701 | support, saving some memory. | |
702 | ||
32a93233 IM |
703 | config COMPAT_BRK |
704 | bool "Disable heap randomization" | |
705 | default y | |
706 | help | |
707 | Randomizing heap placement makes heap exploits harder, but it | |
708 | also breaks ancient binaries (including anything libc5 based). | |
709 | This option changes the bootup default to heap randomization | |
710 | disabled, and can be overriden runtime by setting | |
711 | /proc/sys/kernel/randomize_va_space to 2. | |
712 | ||
166124fd | 713 | On non-ancient distros (post-2000 ones) N is usually a safe choice. |
32a93233 | 714 | |
1da177e4 LT |
715 | config BASE_FULL |
716 | default y | |
717 | bool "Enable full-sized data structures for core" if EMBEDDED | |
718 | help | |
719 | Disabling this option reduces the size of miscellaneous core | |
720 | kernel data structures. This saves memory on small machines, | |
721 | but may reduce performance. | |
722 | ||
723 | config FUTEX | |
724 | bool "Enable futex support" if EMBEDDED | |
725 | default y | |
23f78d4a | 726 | select RT_MUTEXES |
1da177e4 LT |
727 | help |
728 | Disabling this option will cause the kernel to be built without | |
729 | support for "fast userspace mutexes". The resulting kernel may not | |
730 | run glibc-based applications correctly. | |
731 | ||
5dc8bf81 | 732 | config ANON_INODES |
448e3cee | 733 | bool |
5dc8bf81 | 734 | |
1da177e4 LT |
735 | config EPOLL |
736 | bool "Enable eventpoll support" if EMBEDDED | |
737 | default y | |
448e3cee | 738 | select ANON_INODES |
1da177e4 LT |
739 | help |
740 | Disabling this option will cause the kernel to be built without | |
741 | support for epoll family of system calls. | |
742 | ||
fba2afaa DL |
743 | config SIGNALFD |
744 | bool "Enable signalfd() system call" if EMBEDDED | |
448e3cee | 745 | select ANON_INODES |
fba2afaa DL |
746 | default y |
747 | help | |
748 | Enable the signalfd() system call that allows to receive signals | |
749 | on a file descriptor. | |
750 | ||
751 | If unsure, say Y. | |
752 | ||
b215e283 DL |
753 | config TIMERFD |
754 | bool "Enable timerfd() system call" if EMBEDDED | |
448e3cee | 755 | select ANON_INODES |
b215e283 DL |
756 | default y |
757 | help | |
758 | Enable the timerfd() system call that allows to receive timer | |
759 | events on a file descriptor. | |
760 | ||
761 | If unsure, say Y. | |
762 | ||
e1ad7468 DL |
763 | config EVENTFD |
764 | bool "Enable eventfd() system call" if EMBEDDED | |
448e3cee | 765 | select ANON_INODES |
e1ad7468 DL |
766 | default y |
767 | help | |
768 | Enable the eventfd() system call that allows to receive both | |
769 | kernel notification (ie. KAIO) or userspace notifications. | |
770 | ||
771 | If unsure, say Y. | |
772 | ||
1da177e4 LT |
773 | config SHMEM |
774 | bool "Use full shmem filesystem" if EMBEDDED | |
775 | default y | |
776 | depends on MMU | |
777 | help | |
778 | The shmem is an internal filesystem used to manage shared memory. | |
779 | It is backed by swap and manages resource limits. It is also exported | |
780 | to userspace as tmpfs if TMPFS is enabled. Disabling this | |
781 | option replaces shmem and tmpfs with the much simpler ramfs code, | |
782 | which may be appropriate on small systems without swap. | |
783 | ||
ebf3f09c TP |
784 | config AIO |
785 | bool "Enable AIO support" if EMBEDDED | |
786 | default y | |
787 | help | |
788 | This option enables POSIX asynchronous I/O which may by used | |
789 | by some high performance threaded applications. Disabling | |
790 | this option saves about 7k. | |
791 | ||
f8891e5e CL |
792 | config VM_EVENT_COUNTERS |
793 | default y | |
794 | bool "Enable VM event counters for /proc/vmstat" if EMBEDDED | |
795 | help | |
2aea4fb6 PJ |
796 | VM event counters are needed for event counts to be shown. |
797 | This option allows the disabling of the VM event counters | |
798 | on EMBEDDED systems. /proc/vmstat will only show page counts | |
799 | if VM event counters are disabled. | |
f8891e5e | 800 | |
3d137310 TP |
801 | config PCI_QUIRKS |
802 | default y | |
61cfc7e4 GU |
803 | bool "Enable PCI quirk workarounds" if EMBEDDED |
804 | depends on PCI | |
3d137310 TP |
805 | help |
806 | This enables workarounds for various PCI chipset | |
807 | bugs/quirks. Disable this only if your target machine is | |
808 | unaffected by PCI quirks. | |
809 | ||
41ecc55b CL |
810 | config SLUB_DEBUG |
811 | default y | |
812 | bool "Enable SLUB debugging support" if EMBEDDED | |
f6acb635 | 813 | depends on SLUB && SYSFS |
41ecc55b CL |
814 | help |
815 | SLUB has extensive debug support features. Disabling these can | |
816 | result in significant savings in code size. This also disables | |
817 | SLUB sysfs support. /sys/slab will not exist and there will be | |
818 | no support for cache validation etc. | |
819 | ||
81819f0f CL |
820 | choice |
821 | prompt "Choose SLAB allocator" | |
a0acd820 | 822 | default SLUB |
81819f0f CL |
823 | help |
824 | This option allows to select a slab allocator. | |
825 | ||
826 | config SLAB | |
827 | bool "SLAB" | |
828 | help | |
829 | The regular slab allocator that is established and known to work | |
34013886 | 830 | well in all environments. It organizes cache hot objects in |
02f56210 | 831 | per cpu and per node queues. |
81819f0f CL |
832 | |
833 | config SLUB | |
81819f0f CL |
834 | bool "SLUB (Unqueued Allocator)" |
835 | help | |
836 | SLUB is a slab allocator that minimizes cache line usage | |
837 | instead of managing queues of cached objects (SLAB approach). | |
838 | Per cpu caching is realized using slabs of objects instead | |
839 | of queues of objects. SLUB can use memory efficiently | |
02f56210 SA |
840 | and has enhanced diagnostics. SLUB is the default choice for |
841 | a slab allocator. | |
81819f0f CL |
842 | |
843 | config SLOB | |
84a01c2f | 844 | depends on EMBEDDED |
81819f0f CL |
845 | bool "SLOB (Simple Allocator)" |
846 | help | |
37291458 MM |
847 | SLOB replaces the stock allocator with a drastically simpler |
848 | allocator. SLOB is generally more space efficient but | |
849 | does not perform as well on large systems. | |
81819f0f CL |
850 | |
851 | endchoice | |
852 | ||
125e5645 MD |
853 | config PROFILING |
854 | bool "Profiling support (EXPERIMENTAL)" | |
855 | help | |
856 | Say Y here to enable the extended profiling support mechanisms used | |
857 | by profilers such as OProfile. | |
858 | ||
5f87f112 IM |
859 | # |
860 | # Place an empty function call at each tracepoint site. Can be | |
861 | # dynamically changed for a probe function. | |
862 | # | |
97e1c18e | 863 | config TRACEPOINTS |
5f87f112 | 864 | bool |
97e1c18e | 865 | |
125e5645 MD |
866 | config MARKERS |
867 | bool "Activate markers" | |
c1df1bd2 | 868 | depends on TRACEPOINTS |
125e5645 MD |
869 | help |
870 | Place an empty function call at each marker site. Can be | |
871 | dynamically changed for a probe function. | |
872 | ||
fb32e03f MD |
873 | source "arch/Kconfig" |
874 | ||
1da177e4 LT |
875 | endmenu # General setup |
876 | ||
ee7e5516 DES |
877 | config HAVE_GENERIC_DMA_COHERENT |
878 | bool | |
879 | default n | |
880 | ||
158a9624 LT |
881 | config SLABINFO |
882 | bool | |
883 | depends on PROC_FS | |
0f389ec6 | 884 | depends on SLAB || SLUB_DEBUG |
158a9624 LT |
885 | default y |
886 | ||
ae81f9e3 CE |
887 | config RT_MUTEXES |
888 | boolean | |
889 | select PLIST | |
890 | ||
1da177e4 LT |
891 | config TINY_SHMEM |
892 | default !SHMEM | |
893 | bool | |
894 | ||
895 | config BASE_SMALL | |
896 | int | |
897 | default 0 if BASE_FULL | |
898 | default 1 if !BASE_FULL | |
899 | ||
66da5733 | 900 | menuconfig MODULES |
1da177e4 LT |
901 | bool "Enable loadable module support" |
902 | help | |
903 | Kernel modules are small pieces of compiled code which can | |
904 | be inserted in the running kernel, rather than being | |
905 | permanently built into the kernel. You use the "modprobe" | |
906 | tool to add (and sometimes remove) them. If you say Y here, | |
907 | many parts of the kernel can be built as modules (by | |
908 | answering M instead of Y where indicated): this is most | |
909 | useful for infrequently used options which are not required | |
910 | for booting. For more information, see the man pages for | |
911 | modprobe, lsmod, modinfo, insmod and rmmod. | |
912 | ||
913 | If you say Y here, you will need to run "make | |
914 | modules_install" to put the modules under /lib/modules/ | |
915 | where modprobe can find them (you may need to be root to do | |
916 | this). | |
917 | ||
918 | If unsure, say Y. | |
919 | ||
0b0de144 RD |
920 | if MODULES |
921 | ||
826e4506 LT |
922 | config MODULE_FORCE_LOAD |
923 | bool "Forced module loading" | |
826e4506 LT |
924 | default n |
925 | help | |
91e37a79 RR |
926 | Allow loading of modules without version information (ie. modprobe |
927 | --force). Forced module loading sets the 'F' (forced) taint flag and | |
928 | is usually a really bad idea. | |
826e4506 | 929 | |
1da177e4 LT |
930 | config MODULE_UNLOAD |
931 | bool "Module unloading" | |
1da177e4 LT |
932 | help |
933 | Without this option you will not be able to unload any | |
934 | modules (note that some modules may not be unloadable | |
f7f5b675 DV |
935 | anyway), which makes your kernel smaller, faster |
936 | and simpler. If unsure, say Y. | |
1da177e4 LT |
937 | |
938 | config MODULE_FORCE_UNLOAD | |
939 | bool "Forced module unloading" | |
940 | depends on MODULE_UNLOAD && EXPERIMENTAL | |
941 | help | |
942 | This option allows you to force a module to unload, even if the | |
943 | kernel believes it is unsafe: the kernel will remove the module | |
944 | without waiting for anyone to stop using it (using the -f option to | |
945 | rmmod). This is mainly for kernel developers and desperate users. | |
946 | If unsure, say N. | |
947 | ||
1da177e4 | 948 | config MODVERSIONS |
0d541643 | 949 | bool "Module versioning support" |
1da177e4 LT |
950 | help |
951 | Usually, you have to use modules compiled with your kernel. | |
952 | Saying Y here makes it sometimes possible to use modules | |
953 | compiled for different kernels, by adding enough information | |
954 | to the modules to (hopefully) spot any changes which would | |
955 | make them incompatible with the kernel you are running. If | |
956 | unsure, say N. | |
957 | ||
958 | config MODULE_SRCVERSION_ALL | |
959 | bool "Source checksum for all modules" | |
1da177e4 LT |
960 | help |
961 | Modules which contain a MODULE_VERSION get an extra "srcversion" | |
962 | field inserted into their modinfo section, which contains a | |
963 | sum of the source files which made it. This helps maintainers | |
964 | see exactly which source was used to build a module (since | |
965 | others sometimes change the module source without updating | |
966 | the version). With this option, such a "srcversion" field | |
967 | will be created for all modules. If unsure, say N. | |
968 | ||
969 | config KMOD | |
baabaae9 | 970 | def_bool y |
1da177e4 | 971 | help |
baabaae9 JB |
972 | This is being removed soon. These days, CONFIG_MODULES |
973 | implies CONFIG_KMOD, so use that instead. | |
1da177e4 | 974 | |
0b0de144 RD |
975 | endif # MODULES |
976 | ||
98a79d6a RR |
977 | config INIT_ALL_POSSIBLE |
978 | bool | |
979 | help | |
980 | Back when each arch used to define their own cpu_online_map and | |
981 | cpu_possible_map, some of them chose to initialize cpu_possible_map | |
982 | with all 1s, and others with all 0s. When they were centralised, | |
983 | it was better to provide this option than to break all the archs | |
984 | and have several arch maintainers persuing me down dark alleys. | |
985 | ||
1da177e4 LT |
986 | config STOP_MACHINE |
987 | bool | |
988 | default y | |
989 | depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU | |
990 | help | |
991 | Need stop_machine() primitive. | |
3a65dfe8 | 992 | |
3a65dfe8 | 993 | source "block/Kconfig" |
e98c3202 AK |
994 | |
995 | config PREEMPT_NOTIFIERS | |
996 | bool | |
e260be67 | 997 | |
12d79baf IM |
998 | choice |
999 | prompt "RCU Implementation" | |
1000 | default CLASSIC_RCU | |
1001 | ||
e260be67 | 1002 | config CLASSIC_RCU |
12d79baf | 1003 | bool "Classic RCU" |
e260be67 PM |
1004 | help |
1005 | This option selects the classic RCU implementation that is | |
1006 | designed for best read-side performance on non-realtime | |
12d79baf IM |
1007 | systems. |
1008 | ||
1009 | Select this option if you are unsure. | |
1010 | ||
1011 | config TREE_RCU | |
1012 | bool "Tree-based hierarchical RCU" | |
1013 | help | |
1014 | This option selects the RCU implementation that is | |
1015 | designed for very large SMP system with hundreds or | |
1016 | thousands of CPUs. | |
1017 | ||
1018 | config PREEMPT_RCU | |
1019 | bool "Preemptible RCU" | |
1020 | depends on PREEMPT | |
1021 | help | |
1022 | This option reduces the latency of the kernel by making certain | |
1023 | RCU sections preemptible. Normally RCU code is non-preemptible, if | |
1024 | this option is selected then read-only RCU sections become | |
1025 | preemptible. This helps latency, but may expose bugs due to | |
1026 | now-naive assumptions about each RCU read-side critical section | |
1027 | remaining on a given CPU through its execution. | |
1028 | ||
1029 | endchoice | |
1030 | ||
1031 | config RCU_TRACE | |
1032 | bool "Enable tracing for RCU" | |
1033 | depends on TREE_RCU || PREEMPT_RCU | |
1034 | help | |
1035 | This option provides tracing in RCU which presents stats | |
1036 | in debugfs for debugging RCU implementation. | |
1037 | ||
1038 | Say Y here if you want to enable RCU tracing | |
1039 | Say N if you are unsure. | |
1040 | ||
1041 | config RCU_FANOUT | |
1042 | int "Tree-based hierarchical RCU fanout value" | |
1043 | range 2 64 if 64BIT | |
1044 | range 2 32 if !64BIT | |
1045 | depends on TREE_RCU | |
1046 | default 64 if 64BIT | |
1047 | default 32 if !64BIT | |
1048 | help | |
1049 | This option controls the fanout of hierarchical implementations | |
1050 | of RCU, allowing RCU to work efficiently on machines with | |
1051 | large numbers of CPUs. This value must be at least the cube | |
1052 | root of NR_CPUS, which allows NR_CPUS up to 32,768 for 32-bit | |
1053 | systems and up to 262,144 for 64-bit systems. | |
1054 | ||
1055 | Select a specific number if testing RCU itself. | |
1056 | Take the default if unsure. | |
1057 | ||
1058 | config RCU_FANOUT_EXACT | |
1059 | bool "Disable tree-based hierarchical RCU auto-balancing" | |
1060 | depends on TREE_RCU | |
1061 | default n | |
1062 | help | |
1063 | This option forces use of the exact RCU_FANOUT value specified, | |
1064 | regardless of imbalances in the hierarchy. This is useful for | |
1065 | testing RCU itself, and might one day be useful on systems with | |
1066 | strong NUMA behavior. | |
1067 | ||
1068 | Without RCU_FANOUT_EXACT, the code will balance the hierarchy. | |
1069 | ||
1070 | Say N if unsure. | |
1071 | ||
64db4cff PM |
1072 | config TREE_RCU_TRACE |
1073 | def_bool RCU_TRACE && TREE_RCU | |
1074 | select DEBUG_FS | |
e260be67 | 1075 | help |
64db4cff PM |
1076 | This option provides tracing for the TREE_RCU implementation, |
1077 | permitting Makefile to trivially select kernel/rcutree_trace.c. | |
1078 | ||
1079 | config PREEMPT_RCU_TRACE | |
1080 | def_bool RCU_TRACE && PREEMPT_RCU | |
1081 | select DEBUG_FS | |
1082 | help | |
1083 | This option provides tracing for the PREEMPT_RCU implementation, | |
1084 | permitting Makefile to trivially select kernel/rcupreempt_trace.c. |