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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" | |
16 | default "arch/$ARCH/defconfig" | |
17 | ||
ff0cfc66 | 18 | menu "General setup" |
1da177e4 LT |
19 | |
20 | config EXPERIMENTAL | |
21 | bool "Prompt for development and/or incomplete code/drivers" | |
22 | ---help--- | |
23 | Some of the various things that Linux supports (such as network | |
24 | drivers, file systems, network protocols, etc.) can be in a state | |
25 | of development where the functionality, stability, or the level of | |
26 | testing is not yet high enough for general use. This is usually | |
27 | known as the "alpha-test" phase among developers. If a feature is | |
28 | currently in alpha-test, then the developers usually discourage | |
29 | uninformed widespread use of this feature by the general public to | |
30 | avoid "Why doesn't this work?" type mail messages. However, active | |
31 | testing and use of these systems is welcomed. Just be aware that it | |
32 | may not meet the normal level of reliability or it may fail to work | |
33 | in some special cases. Detailed bug reports from people familiar | |
34 | with the kernel internals are usually welcomed by the developers | |
35 | (before submitting bug reports, please read the documents | |
36 | <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>, | |
37 | <file:Documentation/BUG-HUNTING>, and | |
38 | <file:Documentation/oops-tracing.txt> in the kernel source). | |
39 | ||
40 | This option will also make obsoleted drivers available. These are | |
41 | drivers that have been replaced by something else, and/or are | |
42 | scheduled to be removed in a future kernel release. | |
43 | ||
44 | Unless you intend to help test and develop a feature or driver that | |
45 | falls into this category, or you have a situation that requires | |
46 | using these features, you should probably say N here, which will | |
47 | cause the configurator to present you with fewer choices. If | |
48 | you say Y here, you will be offered the choice of using features or | |
49 | drivers that are currently considered to be in the alpha-test phase. | |
50 | ||
1da177e4 LT |
51 | config BROKEN |
52 | bool | |
1da177e4 LT |
53 | |
54 | config BROKEN_ON_SMP | |
55 | bool | |
56 | depends on BROKEN || !SMP | |
57 | default y | |
58 | ||
59 | config LOCK_KERNEL | |
60 | bool | |
61 | depends on SMP || PREEMPT | |
62 | default y | |
63 | ||
64 | config INIT_ENV_ARG_LIMIT | |
65 | int | |
dd673bca AB |
66 | default 32 if !UML |
67 | default 128 if UML | |
1da177e4 | 68 | help |
34ad92c2 RD |
69 | Maximum of each of the number of arguments and environment |
70 | variables passed to init from the kernel command line. | |
1da177e4 | 71 | |
1da177e4 LT |
72 | |
73 | config LOCALVERSION | |
74 | string "Local version - append to kernel release" | |
75 | help | |
76 | Append an extra string to the end of your kernel version. | |
77 | This will show up when you type uname, for example. | |
78 | The string you set here will be appended after the contents of | |
79 | any files with a filename matching localversion* in your | |
80 | object and source tree, in that order. Your total string can | |
81 | be a maximum of 64 characters. | |
82 | ||
aaebf433 RA |
83 | config LOCALVERSION_AUTO |
84 | bool "Automatically append version information to the version string" | |
85 | default y | |
86 | help | |
87 | This will try to automatically determine if the current tree is a | |
6e5a5420 RD |
88 | release tree by looking for git tags that belong to the current |
89 | top of tree revision. | |
aaebf433 RA |
90 | |
91 | A string of the format -gxxxxxxxx will be added to the localversion | |
6e5a5420 | 92 | if a git-based tree is found. The string generated by this will be |
aaebf433 | 93 | appended after any matching localversion* files, and after the value |
6e5a5420 | 94 | set in CONFIG_LOCALVERSION. |
aaebf433 | 95 | |
6e5a5420 RD |
96 | (The actual string used here is the first eight characters produced |
97 | by running the command: | |
98 | ||
99 | $ git rev-parse --verify HEAD | |
100 | ||
101 | which is done within the script "scripts/setlocalversion".) | |
aaebf433 | 102 | |
1da177e4 LT |
103 | config SWAP |
104 | bool "Support for paging of anonymous memory (swap)" | |
9361401e | 105 | depends on MMU && BLOCK |
1da177e4 LT |
106 | default y |
107 | help | |
108 | This option allows you to choose whether you want to have support | |
92c3504e | 109 | for so called swap devices or swap files in your kernel that are |
1da177e4 LT |
110 | used to provide more virtual memory than the actual RAM present |
111 | in your computer. If unsure say Y. | |
112 | ||
113 | config SYSVIPC | |
114 | bool "System V IPC" | |
1da177e4 LT |
115 | ---help--- |
116 | Inter Process Communication is a suite of library functions and | |
117 | system calls which let processes (running programs) synchronize and | |
118 | exchange information. It is generally considered to be a good thing, | |
119 | and some programs won't run unless you say Y here. In particular, if | |
120 | you want to run the DOS emulator dosemu under Linux (read the | |
121 | DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>), | |
122 | you'll need to say Y here. | |
123 | ||
124 | You can find documentation about IPC with "info ipc" and also in | |
125 | section 6.4 of the Linux Programmer's Guide, available from | |
126 | <http://www.tldp.org/guides.html>. | |
127 | ||
a5494dcd EB |
128 | config SYSVIPC_SYSCTL |
129 | bool | |
130 | depends on SYSVIPC | |
131 | depends on SYSCTL | |
132 | default y | |
133 | ||
1da177e4 LT |
134 | config POSIX_MQUEUE |
135 | bool "POSIX Message Queues" | |
136 | depends on NET && EXPERIMENTAL | |
137 | ---help--- | |
138 | POSIX variant of message queues is a part of IPC. In POSIX message | |
139 | queues every message has a priority which decides about succession | |
140 | of receiving it by a process. If you want to compile and run | |
141 | programs written e.g. for Solaris with use of its POSIX message | |
b0e37650 | 142 | queues (functions mq_*) say Y here. |
1da177e4 LT |
143 | |
144 | POSIX message queues are visible as a filesystem called 'mqueue' | |
145 | and can be mounted somewhere if you want to do filesystem | |
146 | operations on message queues. | |
147 | ||
148 | If unsure, say Y. | |
149 | ||
150 | config BSD_PROCESS_ACCT | |
151 | bool "BSD Process Accounting" | |
152 | help | |
153 | If you say Y here, a user level program will be able to instruct the | |
154 | kernel (via a special system call) to write process accounting | |
155 | information to a file: whenever a process exits, information about | |
156 | that process will be appended to the file by the kernel. The | |
157 | information includes things such as creation time, owning user, | |
158 | command name, memory usage, controlling terminal etc. (the complete | |
159 | list is in the struct acct in <file:include/linux/acct.h>). It is | |
160 | up to the user level program to do useful things with this | |
161 | information. This is generally a good idea, so say Y. | |
162 | ||
163 | config BSD_PROCESS_ACCT_V3 | |
164 | bool "BSD Process Accounting version 3 file format" | |
165 | depends on BSD_PROCESS_ACCT | |
166 | default n | |
167 | help | |
168 | If you say Y here, the process accounting information is written | |
169 | in a new file format that also logs the process IDs of each | |
170 | process and it's parent. Note that this file format is incompatible | |
171 | with previous v0/v1/v2 file formats, so you will need updated tools | |
172 | for processing it. A preliminary version of these tools is available | |
173 | at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>. | |
174 | ||
c757249a SN |
175 | config TASKSTATS |
176 | bool "Export task/process statistics through netlink (EXPERIMENTAL)" | |
177 | depends on NET | |
178 | default n | |
179 | help | |
180 | Export selected statistics for tasks/processes through the | |
181 | generic netlink interface. Unlike BSD process accounting, the | |
182 | statistics are available during the lifetime of tasks/processes as | |
183 | responses to commands. Like BSD accounting, they are sent to user | |
184 | space on task exit. | |
185 | ||
186 | Say N if unsure. | |
187 | ||
ca74e92b SN |
188 | config TASK_DELAY_ACCT |
189 | bool "Enable per-task delay accounting (EXPERIMENTAL)" | |
6f44993f | 190 | depends on TASKSTATS |
ca74e92b SN |
191 | help |
192 | Collect information on time spent by a task waiting for system | |
193 | resources like cpu, synchronous block I/O completion and swapping | |
194 | in pages. Such statistics can help in setting a task's priorities | |
195 | relative to other tasks for cpu, io, rss limits etc. | |
196 | ||
197 | Say N if unsure. | |
198 | ||
18f705f4 AD |
199 | config TASK_XACCT |
200 | bool "Enable extended accounting over taskstats (EXPERIMENTAL)" | |
201 | depends on TASKSTATS | |
202 | help | |
203 | Collect extended task accounting data and send the data | |
204 | to userland for processing over the taskstats interface. | |
205 | ||
206 | Say N if unsure. | |
207 | ||
208 | config TASK_IO_ACCOUNTING | |
209 | bool "Enable per-task storage I/O accounting (EXPERIMENTAL)" | |
210 | depends on TASK_XACCT | |
211 | help | |
212 | Collect information on the number of bytes of storage I/O which this | |
213 | task has caused. | |
214 | ||
215 | Say N if unsure. | |
216 | ||
acce292c CLG |
217 | config USER_NS |
218 | bool "User Namespaces (EXPERIMENTAL)" | |
219 | default n | |
220 | depends on EXPERIMENTAL | |
221 | help | |
222 | Support user namespaces. This allows containers, i.e. | |
223 | vservers, to use user namespaces to provide different | |
224 | user info for different servers. If unsure, say N. | |
225 | ||
57d5f66b EB |
226 | config PID_NS |
227 | bool "PID Namespaces (EXPERIMENTAL)" | |
228 | default n | |
229 | depends on EXPERIMENTAL | |
230 | help | |
231 | Suport process id namespaces. This allows having multiple | |
232 | process with the same pid as long as they are in different | |
233 | pid namespaces. This is a building block of containers. | |
234 | ||
235 | Unless you want to work with an experimental feature | |
236 | say N here. | |
237 | ||
1da177e4 LT |
238 | config AUDIT |
239 | bool "Auditing support" | |
804a6a49 | 240 | depends on NET |
1da177e4 LT |
241 | help |
242 | Enable auditing infrastructure that can be used with another | |
243 | kernel subsystem, such as SELinux (which requires this for | |
244 | logging of avc messages output). Does not do system-call | |
245 | auditing without CONFIG_AUDITSYSCALL. | |
246 | ||
247 | config AUDITSYSCALL | |
248 | bool "Enable system-call auditing support" | |
1322b9de | 249 | depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64|| SUPERH) |
1da177e4 LT |
250 | default y if SECURITY_SELINUX |
251 | help | |
252 | Enable low-overhead system-call auditing infrastructure that | |
253 | can be used independently or with another kernel subsystem, | |
f368c07d AG |
254 | such as SELinux. To use audit's filesystem watch feature, please |
255 | ensure that INOTIFY is configured. | |
1da177e4 | 256 | |
74c3cbe3 AV |
257 | config AUDIT_TREE |
258 | def_bool y | |
259 | depends on AUDITSYSCALL && INOTIFY | |
260 | ||
1da177e4 | 261 | config IKCONFIG |
f2443ab6 | 262 | tristate "Kernel .config support" |
1da177e4 LT |
263 | ---help--- |
264 | This option enables the complete Linux kernel ".config" file | |
265 | contents to be saved in the kernel. It provides documentation | |
266 | of which kernel options are used in a running kernel or in an | |
267 | on-disk kernel. This information can be extracted from the kernel | |
268 | image file with the script scripts/extract-ikconfig and used as | |
269 | input to rebuild the current kernel or to build another kernel. | |
270 | It can also be extracted from a running kernel by reading | |
271 | /proc/config.gz if enabled (below). | |
272 | ||
273 | config IKCONFIG_PROC | |
274 | bool "Enable access to .config through /proc/config.gz" | |
275 | depends on IKCONFIG && PROC_FS | |
276 | ---help--- | |
277 | This option enables access to the kernel configuration file | |
278 | through /proc/config.gz. | |
279 | ||
794543a2 AJS |
280 | config LOG_BUF_SHIFT |
281 | int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" | |
282 | range 12 21 | |
283 | default 17 if S390 || LOCKDEP | |
284 | default 16 if X86_NUMAQ || IA64 | |
285 | default 15 if SMP | |
286 | default 14 | |
287 | help | |
288 | Select kernel log buffer size as a power of 2. | |
289 | Defaults and Examples: | |
290 | 17 => 128 KB for S/390 | |
291 | 16 => 64 KB for x86 NUMAQ or IA-64 | |
292 | 15 => 32 KB for SMP | |
293 | 14 => 16 KB for uniprocessor | |
294 | 13 => 8 KB | |
295 | 12 => 4 KB | |
296 | ||
ddbcc7e8 PM |
297 | config CGROUPS |
298 | bool "Control Group support" | |
299 | help | |
300 | This option will let you use process cgroup subsystems | |
301 | such as Cpusets | |
302 | ||
303 | Say N if unsure. | |
304 | ||
006cb992 PM |
305 | config CGROUP_DEBUG |
306 | bool "Example debug cgroup subsystem" | |
307 | depends on CGROUPS | |
308 | help | |
309 | This option enables a simple cgroup subsystem that | |
310 | exports useful debugging information about the cgroups | |
311 | framework | |
312 | ||
313 | Say N if unsure | |
314 | ||
858d72ea SH |
315 | config CGROUP_NS |
316 | bool "Namespace cgroup subsystem" | |
317 | depends on CGROUPS | |
318 | help | |
319 | Provides a simple namespace cgroup subsystem to | |
320 | provide hierarchical naming of sets of namespaces, | |
321 | for instance virtual servers and checkpoint/restart | |
322 | jobs. | |
323 | ||
1da177e4 LT |
324 | config CPUSETS |
325 | bool "Cpuset support" | |
8793d854 | 326 | depends on SMP && CGROUPS |
1da177e4 | 327 | help |
d9fd8a6d | 328 | This option will let you create and manage CPUSETs which |
1da177e4 LT |
329 | allow dynamically partitioning a system into sets of CPUs and |
330 | Memory Nodes and assigning tasks to run only within those sets. | |
331 | This is primarily useful on large SMP or NUMA systems. | |
332 | ||
333 | Say N if unsure. | |
334 | ||
29f59db3 | 335 | config FAIR_GROUP_SCHED |
fb615581 | 336 | bool "Fair group CPU scheduler" |
de8d585a | 337 | default y |
29f59db3 | 338 | help |
fb615581 | 339 | This feature lets CPU scheduler recognize task groups and control CPU |
9b5b7751 | 340 | bandwidth allocation to such task groups. |
29f59db3 | 341 | |
24e377a8 SV |
342 | choice |
343 | depends on FAIR_GROUP_SCHED | |
344 | prompt "Basis for grouping tasks" | |
345 | default FAIR_USER_SCHED | |
346 | ||
fb615581 SV |
347 | config FAIR_USER_SCHED |
348 | bool "user id" | |
349 | help | |
350 | This option will choose userid as the basis for grouping | |
351 | tasks, thus providing equal CPU bandwidth to each user. | |
24e377a8 | 352 | |
68318b8e SV |
353 | config FAIR_CGROUP_SCHED |
354 | bool "Control groups" | |
355 | depends on CGROUPS | |
356 | help | |
357 | This option allows you to create arbitrary task groups | |
358 | using the "cgroup" pseudo filesystem and control | |
359 | the cpu bandwidth allocated to each such task group. | |
360 | Refer to Documentation/cgroups.txt for more information | |
361 | on "cgroup" pseudo filesystem. | |
362 | ||
24e377a8 SV |
363 | endchoice |
364 | ||
d842de87 SV |
365 | config CGROUP_CPUACCT |
366 | bool "Simple CPU accounting cgroup subsystem" | |
367 | depends on CGROUPS | |
368 | help | |
369 | Provides a simple Resource Controller for monitoring the | |
370 | total CPU consumed by the tasks in a cgroup | |
371 | ||
e552b661 PE |
372 | config RESOURCE_COUNTERS |
373 | bool "Resource counters" | |
374 | help | |
375 | This option enables controller independent resource accounting | |
376 | infrastructure that works with cgroups | |
377 | depends on CGROUPS | |
378 | ||
88a22c98 KS |
379 | config SYSFS_DEPRECATED |
380 | bool "Create deprecated sysfs files" | |
9148fe87 | 381 | depends on SYSFS |
88a22c98 KS |
382 | default y |
383 | help | |
384 | This option creates deprecated symlinks such as the | |
385 | "device"-link, the <subsystem>:<name>-link, and the | |
386 | "bus"-link. It may also add deprecated key in the | |
387 | uevent environment. | |
388 | None of these features or values should be used today, as | |
389 | they export driver core implementation details to userspace | |
390 | or export properties which can't be kept stable across kernel | |
391 | releases. | |
392 | ||
393 | If enabled, this option will also move any device structures | |
3dde6ad8 | 394 | that belong to a class, back into the /sys/class hierarchy, in |
88a22c98 KS |
395 | order to support older versions of udev. |
396 | ||
397 | If you are using a distro that was released in 2006 or later, | |
398 | it should be safe to say N here. | |
399 | ||
8cdea7c0 BS |
400 | config CGROUP_MEM_CONT |
401 | bool "Memory controller for cgroups" | |
402 | depends on CGROUPS && RESOURCE_COUNTERS | |
403 | help | |
404 | Provides a memory controller that manages both page cache and | |
405 | RSS memory. | |
406 | ||
8793d854 PM |
407 | config PROC_PID_CPUSET |
408 | bool "Include legacy /proc/<pid>/cpuset file" | |
409 | depends on CPUSETS | |
410 | default y | |
411 | ||
b86ff981 JA |
412 | config RELAY |
413 | bool "Kernel->user space relay support (formerly relayfs)" | |
414 | help | |
415 | This option enables support for relay interface support in | |
416 | certain file systems (such as debugfs). | |
417 | It is designed to provide an efficient mechanism for tools and | |
418 | facilities to relay large amounts of data from kernel space to | |
419 | user space. | |
420 | ||
421 | If unsure, say N. | |
422 | ||
c5289a69 PE |
423 | config NAMESPACES |
424 | bool "Namespaces support" if EMBEDDED | |
425 | default !EMBEDDED | |
426 | help | |
427 | Provides the way to make tasks work with different objects using | |
428 | the same id. For example same IPC id may refer to different objects | |
429 | or same user id or pid may refer to different tasks when used in | |
430 | different namespaces. | |
431 | ||
f991633d DG |
432 | config BLK_DEV_INITRD |
433 | bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support" | |
434 | depends on BROKEN || !FRV | |
435 | help | |
436 | The initial RAM filesystem is a ramfs which is loaded by the | |
437 | boot loader (loadlin or lilo) and that is mounted as root | |
438 | before the normal boot procedure. It is typically used to | |
439 | load modules needed to mount the "real" root file system, | |
440 | etc. See <file:Documentation/initrd.txt> for details. | |
441 | ||
442 | If RAM disk support (BLK_DEV_RAM) is also included, this | |
443 | also enables initial RAM disk (initrd) support and adds | |
444 | 15 Kbytes (more on some other architectures) to the kernel size. | |
445 | ||
446 | If unsure say Y. | |
447 | ||
c33df4ea JPS |
448 | if BLK_DEV_INITRD |
449 | ||
dbec4866 SR |
450 | source "usr/Kconfig" |
451 | ||
c33df4ea JPS |
452 | endif |
453 | ||
c45b4f1f LT |
454 | config CC_OPTIMIZE_FOR_SIZE |
455 | bool "Optimize for size (Look out for broken compilers!)" | |
456 | default y | |
32582fa4 | 457 | depends on ARM || H8300 || SUPERH || EXPERIMENTAL |
c45b4f1f LT |
458 | help |
459 | Enabling this option will pass "-Os" instead of "-O2" to gcc | |
460 | resulting in a smaller kernel. | |
461 | ||
462 | WARNING: some versions of gcc may generate incorrect code with this | |
463 | option. If problems are observed, a gcc upgrade may be needed. | |
464 | ||
465 | If unsure, say N. | |
466 | ||
0847062a RD |
467 | config SYSCTL |
468 | bool | |
469 | ||
1da177e4 LT |
470 | menuconfig EMBEDDED |
471 | bool "Configure standard kernel features (for small systems)" | |
472 | help | |
473 | This option allows certain base kernel options and settings | |
474 | to be disabled or tweaked. This is for specialized | |
475 | environments which can tolerate a "non-standard" kernel. | |
476 | Only use this if you really know what you are doing. | |
477 | ||
ae81f9e3 CE |
478 | config UID16 |
479 | bool "Enable 16-bit UID system calls" if EMBEDDED | |
529a73fb | 480 | depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION) |
ae81f9e3 CE |
481 | default y |
482 | help | |
483 | This enables the legacy 16-bit UID syscall wrappers. | |
484 | ||
b89a8171 | 485 | config SYSCTL_SYSCALL |
0847062a | 486 | bool "Sysctl syscall support" if EMBEDDED |
13bb7e37 | 487 | default y |
b89a8171 | 488 | select SYSCTL |
ae81f9e3 | 489 | ---help--- |
13bb7e37 EB |
490 | sys_sysctl uses binary paths that have been found challenging |
491 | to properly maintain and use. The interface in /proc/sys | |
492 | using paths with ascii names is now the primary path to this | |
493 | information. | |
b89a8171 | 494 | |
13bb7e37 EB |
495 | Almost nothing using the binary sysctl interface so if you are |
496 | trying to save some space it is probably safe to disable this, | |
497 | making your kernel marginally smaller. | |
b89a8171 | 498 | |
13bb7e37 | 499 | If unsure say Y here. |
ae81f9e3 | 500 | |
1da177e4 | 501 | config KALLSYMS |
979c6a1e | 502 | bool "Load all symbols for debugging/ksymoops" if EMBEDDED |
1da177e4 LT |
503 | default y |
504 | help | |
505 | Say Y here to let the kernel print out symbolic crash information and | |
506 | symbolic stack backtraces. This increases the size of the kernel | |
507 | somewhat, as all symbols have to be loaded into the kernel image. | |
508 | ||
509 | config KALLSYMS_ALL | |
510 | bool "Include all symbols in kallsyms" | |
511 | depends on DEBUG_KERNEL && KALLSYMS | |
512 | help | |
513 | Normally kallsyms only contains the symbols of functions, for nicer | |
514 | OOPS messages. Some debuggers can use kallsyms for other | |
f9f97bc0 JJ |
515 | symbols too: say Y here to include all symbols, if you need them |
516 | and you don't care about adding 300k to the size of your kernel. | |
1da177e4 LT |
517 | |
518 | Say N. | |
519 | ||
520 | config KALLSYMS_EXTRA_PASS | |
521 | bool "Do an extra kallsyms pass" | |
522 | depends on KALLSYMS | |
523 | help | |
524 | If kallsyms is not working correctly, the build will fail with | |
525 | inconsistent kallsyms data. If that occurs, log a bug report and | |
526 | turn on KALLSYMS_EXTRA_PASS which should result in a stable build. | |
527 | Always say N here unless you find a bug in kallsyms, which must be | |
528 | reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while | |
529 | you wait for kallsyms to be fixed. | |
530 | ||
d59745ce | 531 | |
712f47ce GKH |
532 | config HOTPLUG |
533 | bool "Support for hot-pluggable devices" if EMBEDDED | |
534 | default y | |
535 | help | |
536 | This option is provided for the case where no hotplug or uevent | |
537 | capabilities is wanted by the kernel. You should only consider | |
538 | disabling this option for embedded systems that do not use modules, a | |
539 | dynamic /dev tree, or dynamic device discovery. Just say Y. | |
540 | ||
d59745ce MM |
541 | config PRINTK |
542 | default y | |
543 | bool "Enable support for printk" if EMBEDDED | |
544 | help | |
545 | This option enables normal printk support. Removing it | |
546 | eliminates most of the message strings from the kernel image | |
547 | and makes the kernel more or less silent. As this makes it | |
548 | very difficult to diagnose system problems, saying N here is | |
549 | strongly discouraged. | |
550 | ||
c8538a7a MM |
551 | config BUG |
552 | bool "BUG() support" if EMBEDDED | |
553 | default y | |
554 | help | |
555 | Disabling this option eliminates support for BUG and WARN, reducing | |
556 | the size of your kernel image and potentially quietly ignoring | |
557 | numerous fatal conditions. You should only consider disabling this | |
558 | option for embedded systems with no facilities for reporting errors. | |
559 | Just say Y. | |
560 | ||
708e9a79 MM |
561 | config ELF_CORE |
562 | default y | |
563 | bool "Enable ELF core dumps" if EMBEDDED | |
564 | help | |
565 | Enable support for generating core dumps. Disabling saves about 4k. | |
566 | ||
32a93233 IM |
567 | config COMPAT_BRK |
568 | bool "Disable heap randomization" | |
569 | default y | |
570 | help | |
571 | Randomizing heap placement makes heap exploits harder, but it | |
572 | also breaks ancient binaries (including anything libc5 based). | |
573 | This option changes the bootup default to heap randomization | |
574 | disabled, and can be overriden runtime by setting | |
575 | /proc/sys/kernel/randomize_va_space to 2. | |
576 | ||
577 | On non-ancient distros (post-2000 ones) Y is usually a safe choice. | |
578 | ||
1da177e4 LT |
579 | config BASE_FULL |
580 | default y | |
581 | bool "Enable full-sized data structures for core" if EMBEDDED | |
582 | help | |
583 | Disabling this option reduces the size of miscellaneous core | |
584 | kernel data structures. This saves memory on small machines, | |
585 | but may reduce performance. | |
586 | ||
587 | config FUTEX | |
588 | bool "Enable futex support" if EMBEDDED | |
589 | default y | |
23f78d4a | 590 | select RT_MUTEXES |
1da177e4 LT |
591 | help |
592 | Disabling this option will cause the kernel to be built without | |
593 | support for "fast userspace mutexes". The resulting kernel may not | |
594 | run glibc-based applications correctly. | |
595 | ||
5dc8bf81 | 596 | config ANON_INODES |
448e3cee | 597 | bool |
5dc8bf81 | 598 | |
1da177e4 LT |
599 | config EPOLL |
600 | bool "Enable eventpoll support" if EMBEDDED | |
601 | default y | |
448e3cee | 602 | select ANON_INODES |
1da177e4 LT |
603 | help |
604 | Disabling this option will cause the kernel to be built without | |
605 | support for epoll family of system calls. | |
606 | ||
fba2afaa DL |
607 | config SIGNALFD |
608 | bool "Enable signalfd() system call" if EMBEDDED | |
448e3cee | 609 | select ANON_INODES |
fba2afaa DL |
610 | default y |
611 | help | |
612 | Enable the signalfd() system call that allows to receive signals | |
613 | on a file descriptor. | |
614 | ||
615 | If unsure, say Y. | |
616 | ||
b215e283 DL |
617 | config TIMERFD |
618 | bool "Enable timerfd() system call" if EMBEDDED | |
448e3cee | 619 | select ANON_INODES |
b215e283 DL |
620 | default y |
621 | help | |
622 | Enable the timerfd() system call that allows to receive timer | |
623 | events on a file descriptor. | |
624 | ||
625 | If unsure, say Y. | |
626 | ||
e1ad7468 DL |
627 | config EVENTFD |
628 | bool "Enable eventfd() system call" if EMBEDDED | |
448e3cee | 629 | select ANON_INODES |
e1ad7468 DL |
630 | default y |
631 | help | |
632 | Enable the eventfd() system call that allows to receive both | |
633 | kernel notification (ie. KAIO) or userspace notifications. | |
634 | ||
635 | If unsure, say Y. | |
636 | ||
1da177e4 LT |
637 | config SHMEM |
638 | bool "Use full shmem filesystem" if EMBEDDED | |
639 | default y | |
640 | depends on MMU | |
641 | help | |
642 | The shmem is an internal filesystem used to manage shared memory. | |
643 | It is backed by swap and manages resource limits. It is also exported | |
644 | to userspace as tmpfs if TMPFS is enabled. Disabling this | |
645 | option replaces shmem and tmpfs with the much simpler ramfs code, | |
646 | which may be appropriate on small systems without swap. | |
647 | ||
f8891e5e CL |
648 | config VM_EVENT_COUNTERS |
649 | default y | |
650 | bool "Enable VM event counters for /proc/vmstat" if EMBEDDED | |
651 | help | |
2aea4fb6 PJ |
652 | VM event counters are needed for event counts to be shown. |
653 | This option allows the disabling of the VM event counters | |
654 | on EMBEDDED systems. /proc/vmstat will only show page counts | |
655 | if VM event counters are disabled. | |
f8891e5e | 656 | |
41ecc55b CL |
657 | config SLUB_DEBUG |
658 | default y | |
659 | bool "Enable SLUB debugging support" if EMBEDDED | |
d4751a27 | 660 | depends on SLUB |
41ecc55b CL |
661 | help |
662 | SLUB has extensive debug support features. Disabling these can | |
663 | result in significant savings in code size. This also disables | |
664 | SLUB sysfs support. /sys/slab will not exist and there will be | |
665 | no support for cache validation etc. | |
666 | ||
81819f0f CL |
667 | choice |
668 | prompt "Choose SLAB allocator" | |
a0acd820 | 669 | default SLUB |
81819f0f CL |
670 | help |
671 | This option allows to select a slab allocator. | |
672 | ||
673 | config SLAB | |
674 | bool "SLAB" | |
675 | help | |
676 | The regular slab allocator that is established and known to work | |
34013886 | 677 | well in all environments. It organizes cache hot objects in |
81819f0f | 678 | per cpu and per node queues. SLAB is the default choice for |
34013886 | 679 | a slab allocator. |
81819f0f CL |
680 | |
681 | config SLUB | |
81819f0f CL |
682 | bool "SLUB (Unqueued Allocator)" |
683 | help | |
684 | SLUB is a slab allocator that minimizes cache line usage | |
685 | instead of managing queues of cached objects (SLAB approach). | |
686 | Per cpu caching is realized using slabs of objects instead | |
687 | of queues of objects. SLUB can use memory efficiently | |
34013886 | 688 | and has enhanced diagnostics. |
81819f0f CL |
689 | |
690 | config SLOB | |
84a01c2f | 691 | depends on EMBEDDED |
81819f0f CL |
692 | bool "SLOB (Simple Allocator)" |
693 | help | |
37291458 MM |
694 | SLOB replaces the stock allocator with a drastically simpler |
695 | allocator. SLOB is generally more space efficient but | |
696 | does not perform as well on large systems. | |
81819f0f CL |
697 | |
698 | endchoice | |
699 | ||
125e5645 MD |
700 | config PROFILING |
701 | bool "Profiling support (EXPERIMENTAL)" | |
702 | help | |
703 | Say Y here to enable the extended profiling support mechanisms used | |
704 | by profilers such as OProfile. | |
705 | ||
706 | config MARKERS | |
707 | bool "Activate markers" | |
708 | help | |
709 | Place an empty function call at each marker site. Can be | |
710 | dynamically changed for a probe function. | |
711 | ||
fb32e03f MD |
712 | source "arch/Kconfig" |
713 | ||
1e883281 MM |
714 | config PROC_PAGE_MONITOR |
715 | default y | |
716 | depends on PROC_FS && MMU | |
717 | bool "Enable /proc page monitoring" if EMBEDDED | |
718 | help | |
719 | Various /proc files exist to monitor process memory utilization: | |
720 | /proc/pid/smaps, /proc/pid/clear_refs, /proc/pid/pagemap, | |
721 | /proc/kpagecount, and /proc/kpageflags. Disabling these | |
722 | interfaces will reduce the size of the kernel by approximately 4kb. | |
723 | ||
1da177e4 LT |
724 | endmenu # General setup |
725 | ||
158a9624 LT |
726 | config SLABINFO |
727 | bool | |
728 | depends on PROC_FS | |
729 | depends on SLAB || SLUB | |
730 | default y | |
731 | ||
ae81f9e3 CE |
732 | config RT_MUTEXES |
733 | boolean | |
734 | select PLIST | |
735 | ||
1da177e4 LT |
736 | config TINY_SHMEM |
737 | default !SHMEM | |
738 | bool | |
739 | ||
740 | config BASE_SMALL | |
741 | int | |
742 | default 0 if BASE_FULL | |
743 | default 1 if !BASE_FULL | |
744 | ||
66da5733 | 745 | menuconfig MODULES |
1da177e4 LT |
746 | bool "Enable loadable module support" |
747 | help | |
748 | Kernel modules are small pieces of compiled code which can | |
749 | be inserted in the running kernel, rather than being | |
750 | permanently built into the kernel. You use the "modprobe" | |
751 | tool to add (and sometimes remove) them. If you say Y here, | |
752 | many parts of the kernel can be built as modules (by | |
753 | answering M instead of Y where indicated): this is most | |
754 | useful for infrequently used options which are not required | |
755 | for booting. For more information, see the man pages for | |
756 | modprobe, lsmod, modinfo, insmod and rmmod. | |
757 | ||
758 | If you say Y here, you will need to run "make | |
759 | modules_install" to put the modules under /lib/modules/ | |
760 | where modprobe can find them (you may need to be root to do | |
761 | this). | |
762 | ||
763 | If unsure, say Y. | |
764 | ||
765 | config MODULE_UNLOAD | |
766 | bool "Module unloading" | |
767 | depends on MODULES | |
768 | help | |
769 | Without this option you will not be able to unload any | |
770 | modules (note that some modules may not be unloadable | |
771 | anyway), which makes your kernel slightly smaller and | |
772 | simpler. If unsure, say Y. | |
773 | ||
774 | config MODULE_FORCE_UNLOAD | |
775 | bool "Forced module unloading" | |
776 | depends on MODULE_UNLOAD && EXPERIMENTAL | |
777 | help | |
778 | This option allows you to force a module to unload, even if the | |
779 | kernel believes it is unsafe: the kernel will remove the module | |
780 | without waiting for anyone to stop using it (using the -f option to | |
781 | rmmod). This is mainly for kernel developers and desperate users. | |
782 | If unsure, say N. | |
783 | ||
1da177e4 | 784 | config MODVERSIONS |
0d541643 SR |
785 | bool "Module versioning support" |
786 | depends on MODULES | |
1da177e4 LT |
787 | help |
788 | Usually, you have to use modules compiled with your kernel. | |
789 | Saying Y here makes it sometimes possible to use modules | |
790 | compiled for different kernels, by adding enough information | |
791 | to the modules to (hopefully) spot any changes which would | |
792 | make them incompatible with the kernel you are running. If | |
793 | unsure, say N. | |
794 | ||
795 | config MODULE_SRCVERSION_ALL | |
796 | bool "Source checksum for all modules" | |
797 | depends on MODULES | |
798 | help | |
799 | Modules which contain a MODULE_VERSION get an extra "srcversion" | |
800 | field inserted into their modinfo section, which contains a | |
801 | sum of the source files which made it. This helps maintainers | |
802 | see exactly which source was used to build a module (since | |
803 | others sometimes change the module source without updating | |
804 | the version). With this option, such a "srcversion" field | |
805 | will be created for all modules. If unsure, say N. | |
806 | ||
807 | config KMOD | |
808 | bool "Automatic kernel module loading" | |
809 | depends on MODULES | |
810 | help | |
811 | Normally when you have selected some parts of the kernel to | |
812 | be created as kernel modules, you must load them (using the | |
813 | "modprobe" command) before you can use them. If you say Y | |
814 | here, some parts of the kernel will be able to load modules | |
815 | automatically: when a part of the kernel needs a module, it | |
816 | runs modprobe with the appropriate arguments, thereby | |
817 | loading the module if it is available. If unsure, say Y. | |
818 | ||
819 | config STOP_MACHINE | |
820 | bool | |
821 | default y | |
822 | depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU | |
823 | help | |
824 | Need stop_machine() primitive. | |
3a65dfe8 | 825 | |
3a65dfe8 | 826 | source "block/Kconfig" |
e98c3202 AK |
827 | |
828 | config PREEMPT_NOTIFIERS | |
829 | bool | |
e260be67 PM |
830 | |
831 | choice | |
832 | prompt "RCU implementation type:" | |
833 | default CLASSIC_RCU | |
09503105 PM |
834 | help |
835 | This allows you to choose either the classic RCU implementation | |
836 | that is designed for best read-side performance on non-realtime | |
837 | systems, or the preemptible RCU implementation for best latency | |
838 | on realtime systems. Note that some kernel preemption modes | |
839 | will restrict your choice. | |
840 | ||
841 | Select the default if you are unsure. | |
e260be67 PM |
842 | |
843 | config CLASSIC_RCU | |
844 | bool "Classic RCU" | |
845 | help | |
846 | This option selects the classic RCU implementation that is | |
847 | designed for best read-side performance on non-realtime | |
848 | systems. | |
849 | ||
850 | Say Y if you are unsure. | |
851 | ||
852 | config PREEMPT_RCU | |
853 | bool "Preemptible RCU" | |
854 | depends on PREEMPT | |
855 | help | |
856 | This option reduces the latency of the kernel by making certain | |
857 | RCU sections preemptible. Normally RCU code is non-preemptible, if | |
858 | this option is selected then read-only RCU sections become | |
859 | preemptible. This helps latency, but may expose bugs due to | |
860 | now-naive assumptions about each RCU read-side critical section | |
861 | remaining on a given CPU through its execution. | |
862 | ||
863 | Say N if you are unsure. | |
864 | ||
865 | endchoice |