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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42 | drivers that have been replaced by something else, and/or are | |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 | |
1da177e4 LT |
104 | config SWAP |
105 | bool "Support for paging of anonymous memory (swap)" | |
9361401e | 106 | depends on MMU && BLOCK |
1da177e4 LT |
107 | default y |
108 | help | |
109 | This option allows you to choose whether you want to have support | |
92c3504e | 110 | for so called swap devices or swap files in your kernel that are |
1da177e4 LT |
111 | used to provide more virtual memory than the actual RAM present |
112 | in your computer. If unsure say Y. | |
113 | ||
114 | config SYSVIPC | |
115 | bool "System V IPC" | |
1da177e4 LT |
116 | ---help--- |
117 | Inter Process Communication is a suite of library functions and | |
118 | system calls which let processes (running programs) synchronize and | |
119 | exchange information. It is generally considered to be a good thing, | |
120 | and some programs won't run unless you say Y here. In particular, if | |
121 | you want to run the DOS emulator dosemu under Linux (read the | |
122 | DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>), | |
123 | you'll need to say Y here. | |
124 | ||
125 | You can find documentation about IPC with "info ipc" and also in | |
126 | section 6.4 of the Linux Programmer's Guide, available from | |
127 | <http://www.tldp.org/guides.html>. | |
128 | ||
a5494dcd EB |
129 | config SYSVIPC_SYSCTL |
130 | bool | |
131 | depends on SYSVIPC | |
132 | depends on SYSCTL | |
133 | default y | |
134 | ||
1da177e4 LT |
135 | config POSIX_MQUEUE |
136 | bool "POSIX Message Queues" | |
137 | depends on NET && EXPERIMENTAL | |
138 | ---help--- | |
139 | POSIX variant of message queues is a part of IPC. In POSIX message | |
140 | queues every message has a priority which decides about succession | |
141 | of receiving it by a process. If you want to compile and run | |
142 | programs written e.g. for Solaris with use of its POSIX message | |
b0e37650 | 143 | queues (functions mq_*) say Y here. |
1da177e4 LT |
144 | |
145 | POSIX message queues are visible as a filesystem called 'mqueue' | |
146 | and can be mounted somewhere if you want to do filesystem | |
147 | operations on message queues. | |
148 | ||
149 | If unsure, say Y. | |
150 | ||
151 | config BSD_PROCESS_ACCT | |
152 | bool "BSD Process Accounting" | |
153 | help | |
154 | If you say Y here, a user level program will be able to instruct the | |
155 | kernel (via a special system call) to write process accounting | |
156 | information to a file: whenever a process exits, information about | |
157 | that process will be appended to the file by the kernel. The | |
158 | information includes things such as creation time, owning user, | |
159 | command name, memory usage, controlling terminal etc. (the complete | |
160 | list is in the struct acct in <file:include/linux/acct.h>). It is | |
161 | up to the user level program to do useful things with this | |
162 | information. This is generally a good idea, so say Y. | |
163 | ||
164 | config BSD_PROCESS_ACCT_V3 | |
165 | bool "BSD Process Accounting version 3 file format" | |
166 | depends on BSD_PROCESS_ACCT | |
167 | default n | |
168 | help | |
169 | If you say Y here, the process accounting information is written | |
170 | in a new file format that also logs the process IDs of each | |
171 | process and it's parent. Note that this file format is incompatible | |
172 | with previous v0/v1/v2 file formats, so you will need updated tools | |
173 | for processing it. A preliminary version of these tools is available | |
37a4c940 | 174 | at <http://www.gnu.org/software/acct/>. |
1da177e4 | 175 | |
c757249a SN |
176 | config TASKSTATS |
177 | bool "Export task/process statistics through netlink (EXPERIMENTAL)" | |
178 | depends on NET | |
179 | default n | |
180 | help | |
181 | Export selected statistics for tasks/processes through the | |
182 | generic netlink interface. Unlike BSD process accounting, the | |
183 | statistics are available during the lifetime of tasks/processes as | |
184 | responses to commands. Like BSD accounting, they are sent to user | |
185 | space on task exit. | |
186 | ||
187 | Say N if unsure. | |
188 | ||
ca74e92b SN |
189 | config TASK_DELAY_ACCT |
190 | bool "Enable per-task delay accounting (EXPERIMENTAL)" | |
6f44993f | 191 | depends on TASKSTATS |
ca74e92b SN |
192 | help |
193 | Collect information on time spent by a task waiting for system | |
194 | resources like cpu, synchronous block I/O completion and swapping | |
195 | in pages. Such statistics can help in setting a task's priorities | |
196 | relative to other tasks for cpu, io, rss limits etc. | |
197 | ||
198 | Say N if unsure. | |
199 | ||
18f705f4 AD |
200 | config TASK_XACCT |
201 | bool "Enable extended accounting over taskstats (EXPERIMENTAL)" | |
202 | depends on TASKSTATS | |
203 | help | |
204 | Collect extended task accounting data and send the data | |
205 | to userland for processing over the taskstats interface. | |
206 | ||
207 | Say N if unsure. | |
208 | ||
209 | config TASK_IO_ACCOUNTING | |
210 | bool "Enable per-task storage I/O accounting (EXPERIMENTAL)" | |
211 | depends on TASK_XACCT | |
212 | help | |
213 | Collect information on the number of bytes of storage I/O which this | |
214 | task has caused. | |
215 | ||
216 | Say N if unsure. | |
217 | ||
1da177e4 LT |
218 | config AUDIT |
219 | bool "Auditing support" | |
804a6a49 | 220 | depends on NET |
1da177e4 LT |
221 | help |
222 | Enable auditing infrastructure that can be used with another | |
223 | kernel subsystem, such as SELinux (which requires this for | |
224 | logging of avc messages output). Does not do system-call | |
225 | auditing without CONFIG_AUDITSYSCALL. | |
226 | ||
227 | config AUDITSYSCALL | |
228 | bool "Enable system-call auditing support" | |
1322b9de | 229 | depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64|| SUPERH) |
1da177e4 LT |
230 | default y if SECURITY_SELINUX |
231 | help | |
232 | Enable low-overhead system-call auditing infrastructure that | |
233 | can be used independently or with another kernel subsystem, | |
f368c07d AG |
234 | such as SELinux. To use audit's filesystem watch feature, please |
235 | ensure that INOTIFY is configured. | |
1da177e4 | 236 | |
74c3cbe3 AV |
237 | config AUDIT_TREE |
238 | def_bool y | |
239 | depends on AUDITSYSCALL && INOTIFY | |
240 | ||
1da177e4 | 241 | config IKCONFIG |
f2443ab6 | 242 | tristate "Kernel .config support" |
1da177e4 LT |
243 | ---help--- |
244 | This option enables the complete Linux kernel ".config" file | |
245 | contents to be saved in the kernel. It provides documentation | |
246 | of which kernel options are used in a running kernel or in an | |
247 | on-disk kernel. This information can be extracted from the kernel | |
248 | image file with the script scripts/extract-ikconfig and used as | |
249 | input to rebuild the current kernel or to build another kernel. | |
250 | It can also be extracted from a running kernel by reading | |
251 | /proc/config.gz if enabled (below). | |
252 | ||
253 | config IKCONFIG_PROC | |
254 | bool "Enable access to .config through /proc/config.gz" | |
255 | depends on IKCONFIG && PROC_FS | |
256 | ---help--- | |
257 | This option enables access to the kernel configuration file | |
258 | through /proc/config.gz. | |
259 | ||
794543a2 AJS |
260 | config LOG_BUF_SHIFT |
261 | int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" | |
262 | range 12 21 | |
f17a32e9 | 263 | default 17 |
794543a2 AJS |
264 | help |
265 | Select kernel log buffer size as a power of 2. | |
f17a32e9 AB |
266 | Examples: |
267 | 17 => 128 KB | |
268 | 16 => 64 KB | |
269 | 15 => 32 KB | |
270 | 14 => 16 KB | |
794543a2 AJS |
271 | 13 => 8 KB |
272 | 12 => 4 KB | |
273 | ||
a5574cf6 IM |
274 | # |
275 | # Architectures with an unreliable sched_clock() should select this: | |
276 | # | |
277 | config HAVE_UNSTABLE_SCHED_CLOCK | |
278 | bool | |
279 | ||
052f1dc7 PZ |
280 | config GROUP_SCHED |
281 | bool "Group CPU scheduler" | |
aac6abca PW |
282 | depends on EXPERIMENTAL |
283 | default n | |
29f59db3 | 284 | help |
fb615581 | 285 | This feature lets CPU scheduler recognize task groups and control CPU |
9b5b7751 | 286 | bandwidth allocation to such task groups. |
5cdc38f9 KH |
287 | In order to create a group from arbitrary set of processes, use |
288 | CONFIG_CGROUPS. (See Control Group support.) | |
29f59db3 | 289 | |
052f1dc7 PZ |
290 | config FAIR_GROUP_SCHED |
291 | bool "Group scheduling for SCHED_OTHER" | |
292 | depends on GROUP_SCHED | |
aac6abca | 293 | default GROUP_SCHED |
052f1dc7 PZ |
294 | |
295 | config RT_GROUP_SCHED | |
296 | bool "Group scheduling for SCHED_RR/FIFO" | |
297 | depends on EXPERIMENTAL | |
298 | depends on GROUP_SCHED | |
299 | default n | |
b9b158fe VR |
300 | help |
301 | This feature lets you explicitly allocate real CPU bandwidth | |
302 | to users or control groups (depending on the "Basis for grouping tasks" | |
303 | setting below. If enabled, it will also make it impossible to | |
304 | schedule realtime tasks for non-root users until you allocate | |
305 | realtime bandwidth for them. | |
2fe401e3 | 306 | See Documentation/scheduler/sched-rt-group.txt for more information. |
052f1dc7 | 307 | |
24e377a8 | 308 | choice |
052f1dc7 | 309 | depends on GROUP_SCHED |
24e377a8 | 310 | prompt "Basis for grouping tasks" |
052f1dc7 | 311 | default USER_SCHED |
24e377a8 | 312 | |
052f1dc7 | 313 | config USER_SCHED |
fb615581 SV |
314 | bool "user id" |
315 | help | |
316 | This option will choose userid as the basis for grouping | |
317 | tasks, thus providing equal CPU bandwidth to each user. | |
24e377a8 | 318 | |
052f1dc7 | 319 | config CGROUP_SCHED |
68318b8e SV |
320 | bool "Control groups" |
321 | depends on CGROUPS | |
322 | help | |
323 | This option allows you to create arbitrary task groups | |
324 | using the "cgroup" pseudo filesystem and control | |
325 | the cpu bandwidth allocated to each such task group. | |
45ce80fb LZ |
326 | Refer to Documentation/cgroups/cgroups.txt for more |
327 | information on "cgroup" pseudo filesystem. | |
68318b8e | 328 | |
24e377a8 SV |
329 | endchoice |
330 | ||
23964d2d LZ |
331 | menuconfig CGROUPS |
332 | boolean "Control Group support" | |
5cdc38f9 | 333 | help |
23964d2d | 334 | This option adds support for grouping sets of processes together, for |
5cdc38f9 KH |
335 | use with process control subsystems such as Cpusets, CFS, memory |
336 | controls or device isolation. | |
337 | See | |
5cdc38f9 | 338 | - Documentation/scheduler/sched-design-CFS.txt (CFS) |
45ce80fb LZ |
339 | - Documentation/cgroups/ (features for grouping, isolation |
340 | and resource control) | |
5cdc38f9 KH |
341 | |
342 | Say N if unsure. | |
343 | ||
23964d2d LZ |
344 | if CGROUPS |
345 | ||
5cdc38f9 KH |
346 | config CGROUP_DEBUG |
347 | bool "Example debug cgroup subsystem" | |
348 | depends on CGROUPS | |
349 | default n | |
350 | help | |
351 | This option enables a simple cgroup subsystem that | |
352 | exports useful debugging information about the cgroups | |
23964d2d | 353 | framework. |
5cdc38f9 | 354 | |
23964d2d | 355 | Say N if unsure. |
5cdc38f9 KH |
356 | |
357 | config CGROUP_NS | |
23964d2d LZ |
358 | bool "Namespace cgroup subsystem" |
359 | depends on CGROUPS | |
360 | help | |
361 | Provides a simple namespace cgroup subsystem to | |
362 | provide hierarchical naming of sets of namespaces, | |
363 | for instance virtual servers and checkpoint/restart | |
364 | jobs. | |
5cdc38f9 KH |
365 | |
366 | config CGROUP_FREEZER | |
23964d2d LZ |
367 | bool "Freezer cgroup subsystem" |
368 | depends on CGROUPS | |
369 | help | |
370 | Provides a way to freeze and unfreeze all tasks in a | |
5cdc38f9 KH |
371 | cgroup. |
372 | ||
373 | config CGROUP_DEVICE | |
374 | bool "Device controller for cgroups" | |
375 | depends on CGROUPS && EXPERIMENTAL | |
376 | help | |
377 | Provides a cgroup implementing whitelists for devices which | |
378 | a process in the cgroup can mknod or open. | |
379 | ||
380 | config CPUSETS | |
381 | bool "Cpuset support" | |
382 | depends on SMP && CGROUPS | |
383 | help | |
384 | This option will let you create and manage CPUSETs which | |
385 | allow dynamically partitioning a system into sets of CPUs and | |
386 | Memory Nodes and assigning tasks to run only within those sets. | |
387 | This is primarily useful on large SMP or NUMA systems. | |
388 | ||
389 | Say N if unsure. | |
390 | ||
23964d2d LZ |
391 | config PROC_PID_CPUSET |
392 | bool "Include legacy /proc/<pid>/cpuset file" | |
393 | depends on CPUSETS | |
394 | default y | |
395 | ||
d842de87 SV |
396 | config CGROUP_CPUACCT |
397 | bool "Simple CPU accounting cgroup subsystem" | |
398 | depends on CGROUPS | |
399 | help | |
400 | Provides a simple Resource Controller for monitoring the | |
23964d2d | 401 | total CPU consumed by the tasks in a cgroup. |
d842de87 | 402 | |
e552b661 PE |
403 | config RESOURCE_COUNTERS |
404 | bool "Resource counters" | |
405 | help | |
406 | This option enables controller independent resource accounting | |
23964d2d | 407 | infrastructure that works with cgroups. |
e552b661 PE |
408 | depends on CGROUPS |
409 | ||
00f0b825 BS |
410 | config CGROUP_MEM_RES_CTLR |
411 | bool "Memory Resource Controller for Control Groups" | |
412 | depends on CGROUPS && RESOURCE_COUNTERS | |
cf475ad2 | 413 | select MM_OWNER |
00f0b825 | 414 | help |
84ad6d70 KH |
415 | Provides a memory resource controller that manages both anonymous |
416 | memory and page cache. (See Documentation/controllers/memory.txt) | |
00f0b825 BS |
417 | |
418 | Note that setting this option increases fixed memory overhead | |
84ad6d70 KH |
419 | associated with each page of memory in the system. By this, |
420 | 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory | |
421 | usage tracking struct at boot. Total amount of this is printed out | |
422 | at boot. | |
00f0b825 BS |
423 | |
424 | Only enable when you're ok with these trade offs and really | |
84ad6d70 KH |
425 | sure you need the memory resource controller. Even when you enable |
426 | this, you can set "cgroup_disable=memory" at your boot option to | |
427 | disable memory resource controller and you can avoid overheads. | |
c9d5409f | 428 | (and lose benefits of memory resource controller) |
00f0b825 | 429 | |
cf475ad2 BS |
430 | This config option also selects MM_OWNER config option, which |
431 | could in turn add some fork/exit overhead. | |
432 | ||
c077719b KH |
433 | config CGROUP_MEM_RES_CTLR_SWAP |
434 | bool "Memory Resource Controller Swap Extension(EXPERIMENTAL)" | |
435 | depends on CGROUP_MEM_RES_CTLR && SWAP && EXPERIMENTAL | |
436 | help | |
437 | Add swap management feature to memory resource controller. When you | |
438 | enable this, you can limit mem+swap usage per cgroup. In other words, | |
439 | when you disable this, memory resource controller has no cares to | |
440 | usage of swap...a process can exhaust all of the swap. This extension | |
441 | is useful when you want to avoid exhaustion swap but this itself | |
442 | adds more overheads and consumes memory for remembering information. | |
443 | Especially if you use 32bit system or small memory system, please | |
444 | be careful about enabling this. When memory resource controller | |
445 | is disabled by boot option, this will be automatically disabled and | |
446 | there will be no overhead from this. Even when you set this config=y, | |
447 | if boot option "noswapaccount" is set, swap will not be accounted. | |
448 | ||
23964d2d | 449 | endif # CGROUPS |
c077719b | 450 | |
23964d2d LZ |
451 | config MM_OWNER |
452 | bool | |
5cdc38f9 | 453 | |
88a22c98 | 454 | config SYSFS_DEPRECATED |
d47846c5 IM |
455 | bool |
456 | ||
457 | config SYSFS_DEPRECATED_V2 | |
fce3e804 | 458 | bool "Create deprecated sysfs layout for older userspace tools" |
9148fe87 | 459 | depends on SYSFS |
88a22c98 | 460 | default y |
d47846c5 | 461 | select SYSFS_DEPRECATED |
88a22c98 | 462 | help |
fce3e804 KS |
463 | This option switches the layout of sysfs to the deprecated |
464 | version. | |
465 | ||
466 | The current sysfs layout features a unified device tree at | |
467 | /sys/devices/, which is able to express a hierarchy between | |
468 | class devices. If the deprecated option is set to Y, the | |
469 | unified device tree is split into a bus device tree at | |
470 | /sys/devices/ and several individual class device trees at | |
471 | /sys/class/. The class and bus devices will be connected by | |
472 | "<subsystem>:<name>" and the "device" links. The "block" | |
473 | class devices, will not show up in /sys/class/block/. Some | |
474 | subsystems will suppress the creation of some devices which | |
475 | depend on the unified device tree. | |
476 | ||
477 | This option is not a pure compatibility option that can | |
478 | be safely enabled on newer distributions. It will change the | |
479 | layout of sysfs to the non-extensible deprecated version, | |
480 | and disable some features, which can not be exported without | |
481 | confusing older userspace tools. Since 2007/2008 all major | |
482 | distributions do not enable this option, and ship no tools which | |
483 | depend on the deprecated layout or this option. | |
484 | ||
485 | If you are using a new kernel on an older distribution, or use | |
486 | older userspace tools, you might need to say Y here. Do not say Y, | |
487 | if the original kernel, that came with your distribution, has | |
488 | this option set to N. | |
88a22c98 | 489 | |
b86ff981 JA |
490 | config RELAY |
491 | bool "Kernel->user space relay support (formerly relayfs)" | |
492 | help | |
493 | This option enables support for relay interface support in | |
494 | certain file systems (such as debugfs). | |
495 | It is designed to provide an efficient mechanism for tools and | |
496 | facilities to relay large amounts of data from kernel space to | |
497 | user space. | |
498 | ||
499 | If unsure, say N. | |
500 | ||
c5289a69 PE |
501 | config NAMESPACES |
502 | bool "Namespaces support" if EMBEDDED | |
503 | default !EMBEDDED | |
504 | help | |
505 | Provides the way to make tasks work with different objects using | |
506 | the same id. For example same IPC id may refer to different objects | |
507 | or same user id or pid may refer to different tasks when used in | |
508 | different namespaces. | |
509 | ||
58bfdd6d PE |
510 | config UTS_NS |
511 | bool "UTS namespace" | |
512 | depends on NAMESPACES | |
513 | help | |
514 | In this namespace tasks see different info provided with the | |
515 | uname() system call | |
516 | ||
ae5e1b22 PE |
517 | config IPC_NS |
518 | bool "IPC namespace" | |
519 | depends on NAMESPACES && SYSVIPC | |
520 | help | |
521 | In this namespace tasks work with IPC ids which correspond to | |
522 | different IPC objects in different namespaces | |
523 | ||
aee16ce7 PE |
524 | config USER_NS |
525 | bool "User namespace (EXPERIMENTAL)" | |
526 | depends on NAMESPACES && EXPERIMENTAL | |
527 | help | |
528 | This allows containers, i.e. vservers, to use user namespaces | |
529 | to provide different user info for different servers. | |
530 | If unsure, say N. | |
531 | ||
74bd59bb PE |
532 | config PID_NS |
533 | bool "PID Namespaces (EXPERIMENTAL)" | |
534 | default n | |
535 | depends on NAMESPACES && EXPERIMENTAL | |
536 | help | |
12d2b8f9 | 537 | Support process id namespaces. This allows having multiple |
74bd59bb PE |
538 | process with the same pid as long as they are in different |
539 | pid namespaces. This is a building block of containers. | |
540 | ||
541 | Unless you want to work with an experimental feature | |
542 | say N here. | |
543 | ||
f991633d DG |
544 | config BLK_DEV_INITRD |
545 | bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support" | |
546 | depends on BROKEN || !FRV | |
547 | help | |
548 | The initial RAM filesystem is a ramfs which is loaded by the | |
549 | boot loader (loadlin or lilo) and that is mounted as root | |
550 | before the normal boot procedure. It is typically used to | |
551 | load modules needed to mount the "real" root file system, | |
552 | etc. See <file:Documentation/initrd.txt> for details. | |
553 | ||
554 | If RAM disk support (BLK_DEV_RAM) is also included, this | |
555 | also enables initial RAM disk (initrd) support and adds | |
556 | 15 Kbytes (more on some other architectures) to the kernel size. | |
557 | ||
558 | If unsure say Y. | |
559 | ||
c33df4ea JPS |
560 | if BLK_DEV_INITRD |
561 | ||
dbec4866 SR |
562 | source "usr/Kconfig" |
563 | ||
c33df4ea JPS |
564 | endif |
565 | ||
c45b4f1f | 566 | config CC_OPTIMIZE_FOR_SIZE |
96fffeb4 | 567 | bool "Optimize for size" |
c45b4f1f | 568 | default y |
c45b4f1f LT |
569 | help |
570 | Enabling this option will pass "-Os" instead of "-O2" to gcc | |
571 | resulting in a smaller kernel. | |
572 | ||
775a7229 | 573 | If unsure, say Y. |
c45b4f1f | 574 | |
0847062a RD |
575 | config SYSCTL |
576 | bool | |
577 | ||
1da177e4 LT |
578 | menuconfig EMBEDDED |
579 | bool "Configure standard kernel features (for small systems)" | |
580 | help | |
581 | This option allows certain base kernel options and settings | |
582 | to be disabled or tweaked. This is for specialized | |
583 | environments which can tolerate a "non-standard" kernel. | |
584 | Only use this if you really know what you are doing. | |
585 | ||
ae81f9e3 CE |
586 | config UID16 |
587 | bool "Enable 16-bit UID system calls" if EMBEDDED | |
09337f50 | 588 | depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION) |
ae81f9e3 CE |
589 | default y |
590 | help | |
591 | This enables the legacy 16-bit UID syscall wrappers. | |
592 | ||
b89a8171 | 593 | config SYSCTL_SYSCALL |
0847062a | 594 | bool "Sysctl syscall support" if EMBEDDED |
13bb7e37 | 595 | default y |
b89a8171 | 596 | select SYSCTL |
ae81f9e3 | 597 | ---help--- |
13bb7e37 EB |
598 | sys_sysctl uses binary paths that have been found challenging |
599 | to properly maintain and use. The interface in /proc/sys | |
600 | using paths with ascii names is now the primary path to this | |
601 | information. | |
b89a8171 | 602 | |
13bb7e37 EB |
603 | Almost nothing using the binary sysctl interface so if you are |
604 | trying to save some space it is probably safe to disable this, | |
605 | making your kernel marginally smaller. | |
b89a8171 | 606 | |
13bb7e37 | 607 | If unsure say Y here. |
ae81f9e3 | 608 | |
1da177e4 | 609 | config KALLSYMS |
979c6a1e | 610 | bool "Load all symbols for debugging/ksymoops" if EMBEDDED |
1da177e4 LT |
611 | default y |
612 | help | |
613 | Say Y here to let the kernel print out symbolic crash information and | |
614 | symbolic stack backtraces. This increases the size of the kernel | |
615 | somewhat, as all symbols have to be loaded into the kernel image. | |
616 | ||
617 | config KALLSYMS_ALL | |
618 | bool "Include all symbols in kallsyms" | |
619 | depends on DEBUG_KERNEL && KALLSYMS | |
620 | help | |
621 | Normally kallsyms only contains the symbols of functions, for nicer | |
622 | OOPS messages. Some debuggers can use kallsyms for other | |
f9f97bc0 JJ |
623 | symbols too: say Y here to include all symbols, if you need them |
624 | and you don't care about adding 300k to the size of your kernel. | |
1da177e4 LT |
625 | |
626 | Say N. | |
627 | ||
9bb48247 JB |
628 | config KALLSYMS_STRIP_GENERATED |
629 | bool "Strip machine generated symbols from kallsyms" | |
630 | depends on KALLSYMS_ALL | |
631 | default y | |
632 | help | |
633 | Say N if you want kallsyms to retain even machine generated symbols. | |
634 | ||
1da177e4 LT |
635 | config KALLSYMS_EXTRA_PASS |
636 | bool "Do an extra kallsyms pass" | |
637 | depends on KALLSYMS | |
638 | help | |
639 | If kallsyms is not working correctly, the build will fail with | |
640 | inconsistent kallsyms data. If that occurs, log a bug report and | |
641 | turn on KALLSYMS_EXTRA_PASS which should result in a stable build. | |
642 | Always say N here unless you find a bug in kallsyms, which must be | |
643 | reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while | |
644 | you wait for kallsyms to be fixed. | |
645 | ||
d59745ce | 646 | |
712f47ce GKH |
647 | config HOTPLUG |
648 | bool "Support for hot-pluggable devices" if EMBEDDED | |
649 | default y | |
650 | help | |
651 | This option is provided for the case where no hotplug or uevent | |
652 | capabilities is wanted by the kernel. You should only consider | |
653 | disabling this option for embedded systems that do not use modules, a | |
654 | dynamic /dev tree, or dynamic device discovery. Just say Y. | |
655 | ||
d59745ce MM |
656 | config PRINTK |
657 | default y | |
658 | bool "Enable support for printk" if EMBEDDED | |
659 | help | |
660 | This option enables normal printk support. Removing it | |
661 | eliminates most of the message strings from the kernel image | |
662 | and makes the kernel more or less silent. As this makes it | |
663 | very difficult to diagnose system problems, saying N here is | |
664 | strongly discouraged. | |
665 | ||
c8538a7a MM |
666 | config BUG |
667 | bool "BUG() support" if EMBEDDED | |
668 | default y | |
669 | help | |
670 | Disabling this option eliminates support for BUG and WARN, reducing | |
671 | the size of your kernel image and potentially quietly ignoring | |
672 | numerous fatal conditions. You should only consider disabling this | |
673 | option for embedded systems with no facilities for reporting errors. | |
674 | Just say Y. | |
675 | ||
708e9a79 MM |
676 | config ELF_CORE |
677 | default y | |
678 | bool "Enable ELF core dumps" if EMBEDDED | |
679 | help | |
680 | Enable support for generating core dumps. Disabling saves about 4k. | |
681 | ||
e5e1d3cb SS |
682 | config PCSPKR_PLATFORM |
683 | bool "Enable PC-Speaker support" if EMBEDDED | |
684 | depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES | |
685 | default y | |
686 | help | |
687 | This option allows to disable the internal PC-Speaker | |
688 | support, saving some memory. | |
689 | ||
32a93233 IM |
690 | config COMPAT_BRK |
691 | bool "Disable heap randomization" | |
692 | default y | |
693 | help | |
694 | Randomizing heap placement makes heap exploits harder, but it | |
695 | also breaks ancient binaries (including anything libc5 based). | |
696 | This option changes the bootup default to heap randomization | |
697 | disabled, and can be overriden runtime by setting | |
698 | /proc/sys/kernel/randomize_va_space to 2. | |
699 | ||
166124fd | 700 | On non-ancient distros (post-2000 ones) N is usually a safe choice. |
32a93233 | 701 | |
1da177e4 LT |
702 | config BASE_FULL |
703 | default y | |
704 | bool "Enable full-sized data structures for core" if EMBEDDED | |
705 | help | |
706 | Disabling this option reduces the size of miscellaneous core | |
707 | kernel data structures. This saves memory on small machines, | |
708 | but may reduce performance. | |
709 | ||
710 | config FUTEX | |
711 | bool "Enable futex support" if EMBEDDED | |
712 | default y | |
23f78d4a | 713 | select RT_MUTEXES |
1da177e4 LT |
714 | help |
715 | Disabling this option will cause the kernel to be built without | |
716 | support for "fast userspace mutexes". The resulting kernel may not | |
717 | run glibc-based applications correctly. | |
718 | ||
5dc8bf81 | 719 | config ANON_INODES |
448e3cee | 720 | bool |
5dc8bf81 | 721 | |
1da177e4 LT |
722 | config EPOLL |
723 | bool "Enable eventpoll support" if EMBEDDED | |
724 | default y | |
448e3cee | 725 | select ANON_INODES |
1da177e4 LT |
726 | help |
727 | Disabling this option will cause the kernel to be built without | |
728 | support for epoll family of system calls. | |
729 | ||
fba2afaa DL |
730 | config SIGNALFD |
731 | bool "Enable signalfd() system call" if EMBEDDED | |
448e3cee | 732 | select ANON_INODES |
fba2afaa DL |
733 | default y |
734 | help | |
735 | Enable the signalfd() system call that allows to receive signals | |
736 | on a file descriptor. | |
737 | ||
738 | If unsure, say Y. | |
739 | ||
b215e283 DL |
740 | config TIMERFD |
741 | bool "Enable timerfd() system call" if EMBEDDED | |
448e3cee | 742 | select ANON_INODES |
b215e283 DL |
743 | default y |
744 | help | |
745 | Enable the timerfd() system call that allows to receive timer | |
746 | events on a file descriptor. | |
747 | ||
748 | If unsure, say Y. | |
749 | ||
e1ad7468 DL |
750 | config EVENTFD |
751 | bool "Enable eventfd() system call" if EMBEDDED | |
448e3cee | 752 | select ANON_INODES |
e1ad7468 DL |
753 | default y |
754 | help | |
755 | Enable the eventfd() system call that allows to receive both | |
756 | kernel notification (ie. KAIO) or userspace notifications. | |
757 | ||
758 | If unsure, say Y. | |
759 | ||
1da177e4 LT |
760 | config SHMEM |
761 | bool "Use full shmem filesystem" if EMBEDDED | |
762 | default y | |
763 | depends on MMU | |
764 | help | |
765 | The shmem is an internal filesystem used to manage shared memory. | |
766 | It is backed by swap and manages resource limits. It is also exported | |
767 | to userspace as tmpfs if TMPFS is enabled. Disabling this | |
768 | option replaces shmem and tmpfs with the much simpler ramfs code, | |
769 | which may be appropriate on small systems without swap. | |
770 | ||
ebf3f09c TP |
771 | config AIO |
772 | bool "Enable AIO support" if EMBEDDED | |
773 | default y | |
774 | help | |
775 | This option enables POSIX asynchronous I/O which may by used | |
776 | by some high performance threaded applications. Disabling | |
777 | this option saves about 7k. | |
778 | ||
f8891e5e CL |
779 | config VM_EVENT_COUNTERS |
780 | default y | |
781 | bool "Enable VM event counters for /proc/vmstat" if EMBEDDED | |
782 | help | |
2aea4fb6 PJ |
783 | VM event counters are needed for event counts to be shown. |
784 | This option allows the disabling of the VM event counters | |
785 | on EMBEDDED systems. /proc/vmstat will only show page counts | |
786 | if VM event counters are disabled. | |
f8891e5e | 787 | |
3d137310 TP |
788 | config PCI_QUIRKS |
789 | default y | |
61cfc7e4 GU |
790 | bool "Enable PCI quirk workarounds" if EMBEDDED |
791 | depends on PCI | |
3d137310 TP |
792 | help |
793 | This enables workarounds for various PCI chipset | |
794 | bugs/quirks. Disable this only if your target machine is | |
795 | unaffected by PCI quirks. | |
796 | ||
41ecc55b CL |
797 | config SLUB_DEBUG |
798 | default y | |
799 | bool "Enable SLUB debugging support" if EMBEDDED | |
f6acb635 | 800 | depends on SLUB && SYSFS |
41ecc55b CL |
801 | help |
802 | SLUB has extensive debug support features. Disabling these can | |
803 | result in significant savings in code size. This also disables | |
804 | SLUB sysfs support. /sys/slab will not exist and there will be | |
805 | no support for cache validation etc. | |
806 | ||
81819f0f CL |
807 | choice |
808 | prompt "Choose SLAB allocator" | |
a0acd820 | 809 | default SLUB |
81819f0f CL |
810 | help |
811 | This option allows to select a slab allocator. | |
812 | ||
813 | config SLAB | |
814 | bool "SLAB" | |
815 | help | |
816 | The regular slab allocator that is established and known to work | |
34013886 | 817 | well in all environments. It organizes cache hot objects in |
02f56210 | 818 | per cpu and per node queues. |
81819f0f CL |
819 | |
820 | config SLUB | |
81819f0f CL |
821 | bool "SLUB (Unqueued Allocator)" |
822 | help | |
823 | SLUB is a slab allocator that minimizes cache line usage | |
824 | instead of managing queues of cached objects (SLAB approach). | |
825 | Per cpu caching is realized using slabs of objects instead | |
826 | of queues of objects. SLUB can use memory efficiently | |
02f56210 SA |
827 | and has enhanced diagnostics. SLUB is the default choice for |
828 | a slab allocator. | |
81819f0f CL |
829 | |
830 | config SLOB | |
84a01c2f | 831 | depends on EMBEDDED |
81819f0f CL |
832 | bool "SLOB (Simple Allocator)" |
833 | help | |
37291458 MM |
834 | SLOB replaces the stock allocator with a drastically simpler |
835 | allocator. SLOB is generally more space efficient but | |
836 | does not perform as well on large systems. | |
81819f0f CL |
837 | |
838 | endchoice | |
839 | ||
125e5645 MD |
840 | config PROFILING |
841 | bool "Profiling support (EXPERIMENTAL)" | |
842 | help | |
843 | Say Y here to enable the extended profiling support mechanisms used | |
844 | by profilers such as OProfile. | |
845 | ||
5f87f112 IM |
846 | # |
847 | # Place an empty function call at each tracepoint site. Can be | |
848 | # dynamically changed for a probe function. | |
849 | # | |
97e1c18e | 850 | config TRACEPOINTS |
5f87f112 | 851 | bool |
97e1c18e | 852 | |
125e5645 MD |
853 | config MARKERS |
854 | bool "Activate markers" | |
c1df1bd2 | 855 | depends on TRACEPOINTS |
125e5645 MD |
856 | help |
857 | Place an empty function call at each marker site. Can be | |
858 | dynamically changed for a probe function. | |
859 | ||
fb32e03f MD |
860 | source "arch/Kconfig" |
861 | ||
1da177e4 LT |
862 | endmenu # General setup |
863 | ||
ee7e5516 DB |
864 | config HAVE_GENERIC_DMA_COHERENT |
865 | bool | |
866 | default n | |
867 | ||
158a9624 LT |
868 | config SLABINFO |
869 | bool | |
870 | depends on PROC_FS | |
0f389ec6 | 871 | depends on SLAB || SLUB_DEBUG |
158a9624 LT |
872 | default y |
873 | ||
ae81f9e3 CE |
874 | config RT_MUTEXES |
875 | boolean | |
876 | select PLIST | |
877 | ||
1da177e4 LT |
878 | config BASE_SMALL |
879 | int | |
880 | default 0 if BASE_FULL | |
881 | default 1 if !BASE_FULL | |
882 | ||
66da5733 | 883 | menuconfig MODULES |
1da177e4 LT |
884 | bool "Enable loadable module support" |
885 | help | |
886 | Kernel modules are small pieces of compiled code which can | |
887 | be inserted in the running kernel, rather than being | |
888 | permanently built into the kernel. You use the "modprobe" | |
889 | tool to add (and sometimes remove) them. If you say Y here, | |
890 | many parts of the kernel can be built as modules (by | |
891 | answering M instead of Y where indicated): this is most | |
892 | useful for infrequently used options which are not required | |
893 | for booting. For more information, see the man pages for | |
894 | modprobe, lsmod, modinfo, insmod and rmmod. | |
895 | ||
896 | If you say Y here, you will need to run "make | |
897 | modules_install" to put the modules under /lib/modules/ | |
898 | where modprobe can find them (you may need to be root to do | |
899 | this). | |
900 | ||
901 | If unsure, say Y. | |
902 | ||
0b0de144 RD |
903 | if MODULES |
904 | ||
826e4506 LT |
905 | config MODULE_FORCE_LOAD |
906 | bool "Forced module loading" | |
826e4506 LT |
907 | default n |
908 | help | |
91e37a79 RR |
909 | Allow loading of modules without version information (ie. modprobe |
910 | --force). Forced module loading sets the 'F' (forced) taint flag and | |
911 | is usually a really bad idea. | |
826e4506 | 912 | |
1da177e4 LT |
913 | config MODULE_UNLOAD |
914 | bool "Module unloading" | |
1da177e4 LT |
915 | help |
916 | Without this option you will not be able to unload any | |
917 | modules (note that some modules may not be unloadable | |
f7f5b675 DV |
918 | anyway), which makes your kernel smaller, faster |
919 | and simpler. If unsure, say Y. | |
1da177e4 LT |
920 | |
921 | config MODULE_FORCE_UNLOAD | |
922 | bool "Forced module unloading" | |
923 | depends on MODULE_UNLOAD && EXPERIMENTAL | |
924 | help | |
925 | This option allows you to force a module to unload, even if the | |
926 | kernel believes it is unsafe: the kernel will remove the module | |
927 | without waiting for anyone to stop using it (using the -f option to | |
928 | rmmod). This is mainly for kernel developers and desperate users. | |
929 | If unsure, say N. | |
930 | ||
1da177e4 | 931 | config MODVERSIONS |
0d541643 | 932 | bool "Module versioning support" |
1da177e4 LT |
933 | help |
934 | Usually, you have to use modules compiled with your kernel. | |
935 | Saying Y here makes it sometimes possible to use modules | |
936 | compiled for different kernels, by adding enough information | |
937 | to the modules to (hopefully) spot any changes which would | |
938 | make them incompatible with the kernel you are running. If | |
939 | unsure, say N. | |
940 | ||
941 | config MODULE_SRCVERSION_ALL | |
942 | bool "Source checksum for all modules" | |
1da177e4 LT |
943 | help |
944 | Modules which contain a MODULE_VERSION get an extra "srcversion" | |
945 | field inserted into their modinfo section, which contains a | |
946 | sum of the source files which made it. This helps maintainers | |
947 | see exactly which source was used to build a module (since | |
948 | others sometimes change the module source without updating | |
949 | the version). With this option, such a "srcversion" field | |
950 | will be created for all modules. If unsure, say N. | |
951 | ||
0b0de144 RD |
952 | endif # MODULES |
953 | ||
98a79d6a RR |
954 | config INIT_ALL_POSSIBLE |
955 | bool | |
956 | help | |
957 | Back when each arch used to define their own cpu_online_map and | |
958 | cpu_possible_map, some of them chose to initialize cpu_possible_map | |
959 | with all 1s, and others with all 0s. When they were centralised, | |
960 | it was better to provide this option than to break all the archs | |
961 | and have several arch maintainers persuing me down dark alleys. | |
962 | ||
1da177e4 LT |
963 | config STOP_MACHINE |
964 | bool | |
965 | default y | |
966 | depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU | |
967 | help | |
968 | Need stop_machine() primitive. | |
3a65dfe8 | 969 | |
3a65dfe8 | 970 | source "block/Kconfig" |
e98c3202 AK |
971 | |
972 | config PREEMPT_NOTIFIERS | |
973 | bool | |
e260be67 | 974 | |
12d79baf IM |
975 | choice |
976 | prompt "RCU Implementation" | |
977 | default CLASSIC_RCU | |
978 | ||
e260be67 | 979 | config CLASSIC_RCU |
12d79baf | 980 | bool "Classic RCU" |
e260be67 PM |
981 | help |
982 | This option selects the classic RCU implementation that is | |
983 | designed for best read-side performance on non-realtime | |
12d79baf IM |
984 | systems. |
985 | ||
986 | Select this option if you are unsure. | |
987 | ||
988 | config TREE_RCU | |
989 | bool "Tree-based hierarchical RCU" | |
990 | help | |
991 | This option selects the RCU implementation that is | |
992 | designed for very large SMP system with hundreds or | |
993 | thousands of CPUs. | |
994 | ||
995 | config PREEMPT_RCU | |
996 | bool "Preemptible RCU" | |
997 | depends on PREEMPT | |
998 | help | |
999 | This option reduces the latency of the kernel by making certain | |
1000 | RCU sections preemptible. Normally RCU code is non-preemptible, if | |
1001 | this option is selected then read-only RCU sections become | |
1002 | preemptible. This helps latency, but may expose bugs due to | |
1003 | now-naive assumptions about each RCU read-side critical section | |
1004 | remaining on a given CPU through its execution. | |
1005 | ||
1006 | endchoice | |
1007 | ||
1008 | config RCU_TRACE | |
1009 | bool "Enable tracing for RCU" | |
1010 | depends on TREE_RCU || PREEMPT_RCU | |
1011 | help | |
1012 | This option provides tracing in RCU which presents stats | |
1013 | in debugfs for debugging RCU implementation. | |
1014 | ||
1015 | Say Y here if you want to enable RCU tracing | |
1016 | Say N if you are unsure. | |
1017 | ||
1018 | config RCU_FANOUT | |
1019 | int "Tree-based hierarchical RCU fanout value" | |
1020 | range 2 64 if 64BIT | |
1021 | range 2 32 if !64BIT | |
1022 | depends on TREE_RCU | |
1023 | default 64 if 64BIT | |
1024 | default 32 if !64BIT | |
1025 | help | |
1026 | This option controls the fanout of hierarchical implementations | |
1027 | of RCU, allowing RCU to work efficiently on machines with | |
1028 | large numbers of CPUs. This value must be at least the cube | |
1029 | root of NR_CPUS, which allows NR_CPUS up to 32,768 for 32-bit | |
1030 | systems and up to 262,144 for 64-bit systems. | |
1031 | ||
1032 | Select a specific number if testing RCU itself. | |
1033 | Take the default if unsure. | |
1034 | ||
1035 | config RCU_FANOUT_EXACT | |
1036 | bool "Disable tree-based hierarchical RCU auto-balancing" | |
1037 | depends on TREE_RCU | |
1038 | default n | |
1039 | help | |
1040 | This option forces use of the exact RCU_FANOUT value specified, | |
1041 | regardless of imbalances in the hierarchy. This is useful for | |
1042 | testing RCU itself, and might one day be useful on systems with | |
1043 | strong NUMA behavior. | |
1044 | ||
1045 | Without RCU_FANOUT_EXACT, the code will balance the hierarchy. | |
1046 | ||
1047 | Say N if unsure. | |
1048 | ||
64db4cff PM |
1049 | config TREE_RCU_TRACE |
1050 | def_bool RCU_TRACE && TREE_RCU | |
1051 | select DEBUG_FS | |
e260be67 | 1052 | help |
64db4cff PM |
1053 | This option provides tracing for the TREE_RCU implementation, |
1054 | permitting Makefile to trivially select kernel/rcutree_trace.c. | |
1055 | ||
1056 | config PREEMPT_RCU_TRACE | |
1057 | def_bool RCU_TRACE && PREEMPT_RCU | |
1058 | select DEBUG_FS | |
1059 | help | |
1060 | This option provides tracing for the PREEMPT_RCU implementation, | |
1061 | permitting Makefile to trivially select kernel/rcupreempt_trace.c. |