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face4374 RZ |
1 | config DEFCONFIG_LIST |
2 | string | |
b2670eac | 3 | depends on !UML |
face4374 RZ |
4 | option defconfig_list |
5 | default "/lib/modules/$UNAME_RELEASE/.config" | |
6 | default "/etc/kernel-config" | |
7 | default "/boot/config-$UNAME_RELEASE" | |
8 | default "arch/$ARCH/defconfig" | |
9 | ||
ff0cfc66 | 10 | menu "General setup" |
1da177e4 LT |
11 | |
12 | config EXPERIMENTAL | |
13 | bool "Prompt for development and/or incomplete code/drivers" | |
14 | ---help--- | |
15 | Some of the various things that Linux supports (such as network | |
16 | drivers, file systems, network protocols, etc.) can be in a state | |
17 | of development where the functionality, stability, or the level of | |
18 | testing is not yet high enough for general use. This is usually | |
19 | known as the "alpha-test" phase among developers. If a feature is | |
20 | currently in alpha-test, then the developers usually discourage | |
21 | uninformed widespread use of this feature by the general public to | |
22 | avoid "Why doesn't this work?" type mail messages. However, active | |
23 | testing and use of these systems is welcomed. Just be aware that it | |
24 | may not meet the normal level of reliability or it may fail to work | |
25 | in some special cases. Detailed bug reports from people familiar | |
26 | with the kernel internals are usually welcomed by the developers | |
27 | (before submitting bug reports, please read the documents | |
28 | <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>, | |
29 | <file:Documentation/BUG-HUNTING>, and | |
30 | <file:Documentation/oops-tracing.txt> in the kernel source). | |
31 | ||
32 | This option will also make obsoleted drivers available. These are | |
33 | drivers that have been replaced by something else, and/or are | |
34 | scheduled to be removed in a future kernel release. | |
35 | ||
36 | Unless you intend to help test and develop a feature or driver that | |
37 | falls into this category, or you have a situation that requires | |
38 | using these features, you should probably say N here, which will | |
39 | cause the configurator to present you with fewer choices. If | |
40 | you say Y here, you will be offered the choice of using features or | |
41 | drivers that are currently considered to be in the alpha-test phase. | |
42 | ||
1da177e4 LT |
43 | config BROKEN |
44 | bool | |
1da177e4 LT |
45 | |
46 | config BROKEN_ON_SMP | |
47 | bool | |
48 | depends on BROKEN || !SMP | |
49 | default y | |
50 | ||
51 | config LOCK_KERNEL | |
52 | bool | |
53 | depends on SMP || PREEMPT | |
54 | default y | |
55 | ||
56 | config INIT_ENV_ARG_LIMIT | |
57 | int | |
dd673bca AB |
58 | default 32 if !UML |
59 | default 128 if UML | |
1da177e4 | 60 | help |
34ad92c2 RD |
61 | Maximum of each of the number of arguments and environment |
62 | variables passed to init from the kernel command line. | |
1da177e4 | 63 | |
1da177e4 LT |
64 | |
65 | config LOCALVERSION | |
66 | string "Local version - append to kernel release" | |
67 | help | |
68 | Append an extra string to the end of your kernel version. | |
69 | This will show up when you type uname, for example. | |
70 | The string you set here will be appended after the contents of | |
71 | any files with a filename matching localversion* in your | |
72 | object and source tree, in that order. Your total string can | |
73 | be a maximum of 64 characters. | |
74 | ||
aaebf433 RA |
75 | config LOCALVERSION_AUTO |
76 | bool "Automatically append version information to the version string" | |
77 | default y | |
78 | help | |
79 | This will try to automatically determine if the current tree is a | |
6e5a5420 RD |
80 | release tree by looking for git tags that belong to the current |
81 | top of tree revision. | |
aaebf433 RA |
82 | |
83 | A string of the format -gxxxxxxxx will be added to the localversion | |
6e5a5420 | 84 | if a git-based tree is found. The string generated by this will be |
aaebf433 | 85 | appended after any matching localversion* files, and after the value |
6e5a5420 | 86 | set in CONFIG_LOCALVERSION. |
aaebf433 | 87 | |
6e5a5420 RD |
88 | (The actual string used here is the first eight characters produced |
89 | by running the command: | |
90 | ||
91 | $ git rev-parse --verify HEAD | |
92 | ||
93 | which is done within the script "scripts/setlocalversion".) | |
aaebf433 | 94 | |
1da177e4 LT |
95 | config SWAP |
96 | bool "Support for paging of anonymous memory (swap)" | |
9361401e | 97 | depends on MMU && BLOCK |
1da177e4 LT |
98 | default y |
99 | help | |
100 | This option allows you to choose whether you want to have support | |
92c3504e | 101 | for so called swap devices or swap files in your kernel that are |
1da177e4 LT |
102 | used to provide more virtual memory than the actual RAM present |
103 | in your computer. If unsure say Y. | |
104 | ||
105 | config SYSVIPC | |
106 | bool "System V IPC" | |
1da177e4 LT |
107 | ---help--- |
108 | Inter Process Communication is a suite of library functions and | |
109 | system calls which let processes (running programs) synchronize and | |
110 | exchange information. It is generally considered to be a good thing, | |
111 | and some programs won't run unless you say Y here. In particular, if | |
112 | you want to run the DOS emulator dosemu under Linux (read the | |
113 | DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>), | |
114 | you'll need to say Y here. | |
115 | ||
116 | You can find documentation about IPC with "info ipc" and also in | |
117 | section 6.4 of the Linux Programmer's Guide, available from | |
118 | <http://www.tldp.org/guides.html>. | |
119 | ||
a5494dcd EB |
120 | config SYSVIPC_SYSCTL |
121 | bool | |
122 | depends on SYSVIPC | |
123 | depends on SYSCTL | |
124 | default y | |
125 | ||
1da177e4 LT |
126 | config POSIX_MQUEUE |
127 | bool "POSIX Message Queues" | |
128 | depends on NET && EXPERIMENTAL | |
129 | ---help--- | |
130 | POSIX variant of message queues is a part of IPC. In POSIX message | |
131 | queues every message has a priority which decides about succession | |
132 | of receiving it by a process. If you want to compile and run | |
133 | programs written e.g. for Solaris with use of its POSIX message | |
b0e37650 | 134 | queues (functions mq_*) say Y here. |
1da177e4 LT |
135 | |
136 | POSIX message queues are visible as a filesystem called 'mqueue' | |
137 | and can be mounted somewhere if you want to do filesystem | |
138 | operations on message queues. | |
139 | ||
140 | If unsure, say Y. | |
141 | ||
142 | config BSD_PROCESS_ACCT | |
143 | bool "BSD Process Accounting" | |
144 | help | |
145 | If you say Y here, a user level program will be able to instruct the | |
146 | kernel (via a special system call) to write process accounting | |
147 | information to a file: whenever a process exits, information about | |
148 | that process will be appended to the file by the kernel. The | |
149 | information includes things such as creation time, owning user, | |
150 | command name, memory usage, controlling terminal etc. (the complete | |
151 | list is in the struct acct in <file:include/linux/acct.h>). It is | |
152 | up to the user level program to do useful things with this | |
153 | information. This is generally a good idea, so say Y. | |
154 | ||
155 | config BSD_PROCESS_ACCT_V3 | |
156 | bool "BSD Process Accounting version 3 file format" | |
157 | depends on BSD_PROCESS_ACCT | |
158 | default n | |
159 | help | |
160 | If you say Y here, the process accounting information is written | |
161 | in a new file format that also logs the process IDs of each | |
162 | process and it's parent. Note that this file format is incompatible | |
163 | with previous v0/v1/v2 file formats, so you will need updated tools | |
164 | for processing it. A preliminary version of these tools is available | |
165 | at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>. | |
166 | ||
c757249a SN |
167 | config TASKSTATS |
168 | bool "Export task/process statistics through netlink (EXPERIMENTAL)" | |
169 | depends on NET | |
170 | default n | |
171 | help | |
172 | Export selected statistics for tasks/processes through the | |
173 | generic netlink interface. Unlike BSD process accounting, the | |
174 | statistics are available during the lifetime of tasks/processes as | |
175 | responses to commands. Like BSD accounting, they are sent to user | |
176 | space on task exit. | |
177 | ||
178 | Say N if unsure. | |
179 | ||
ca74e92b SN |
180 | config TASK_DELAY_ACCT |
181 | bool "Enable per-task delay accounting (EXPERIMENTAL)" | |
6f44993f | 182 | depends on TASKSTATS |
ca74e92b SN |
183 | help |
184 | Collect information on time spent by a task waiting for system | |
185 | resources like cpu, synchronous block I/O completion and swapping | |
186 | in pages. Such statistics can help in setting a task's priorities | |
187 | relative to other tasks for cpu, io, rss limits etc. | |
188 | ||
189 | Say N if unsure. | |
190 | ||
18f705f4 AD |
191 | config TASK_XACCT |
192 | bool "Enable extended accounting over taskstats (EXPERIMENTAL)" | |
193 | depends on TASKSTATS | |
194 | help | |
195 | Collect extended task accounting data and send the data | |
196 | to userland for processing over the taskstats interface. | |
197 | ||
198 | Say N if unsure. | |
199 | ||
200 | config TASK_IO_ACCOUNTING | |
201 | bool "Enable per-task storage I/O accounting (EXPERIMENTAL)" | |
202 | depends on TASK_XACCT | |
203 | help | |
204 | Collect information on the number of bytes of storage I/O which this | |
205 | task has caused. | |
206 | ||
207 | Say N if unsure. | |
208 | ||
acce292c CLG |
209 | config USER_NS |
210 | bool "User Namespaces (EXPERIMENTAL)" | |
211 | default n | |
212 | depends on EXPERIMENTAL | |
213 | help | |
214 | Support user namespaces. This allows containers, i.e. | |
215 | vservers, to use user namespaces to provide different | |
216 | user info for different servers. If unsure, say N. | |
217 | ||
57d5f66b EB |
218 | config PID_NS |
219 | bool "PID Namespaces (EXPERIMENTAL)" | |
220 | default n | |
221 | depends on EXPERIMENTAL | |
222 | help | |
223 | Suport process id namespaces. This allows having multiple | |
224 | process with the same pid as long as they are in different | |
225 | pid namespaces. This is a building block of containers. | |
226 | ||
227 | Unless you want to work with an experimental feature | |
228 | say N here. | |
229 | ||
1da177e4 LT |
230 | config AUDIT |
231 | bool "Auditing support" | |
804a6a49 | 232 | depends on NET |
1da177e4 LT |
233 | help |
234 | Enable auditing infrastructure that can be used with another | |
235 | kernel subsystem, such as SELinux (which requires this for | |
236 | logging of avc messages output). Does not do system-call | |
237 | auditing without CONFIG_AUDITSYSCALL. | |
238 | ||
239 | config AUDITSYSCALL | |
240 | bool "Enable system-call auditing support" | |
347a8dc3 | 241 | depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64) |
1da177e4 LT |
242 | default y if SECURITY_SELINUX |
243 | help | |
244 | Enable low-overhead system-call auditing infrastructure that | |
245 | can be used independently or with another kernel subsystem, | |
f368c07d AG |
246 | such as SELinux. To use audit's filesystem watch feature, please |
247 | ensure that INOTIFY is configured. | |
1da177e4 | 248 | |
74c3cbe3 AV |
249 | config AUDIT_TREE |
250 | def_bool y | |
251 | depends on AUDITSYSCALL && INOTIFY | |
252 | ||
1da177e4 | 253 | config IKCONFIG |
f2443ab6 | 254 | tristate "Kernel .config support" |
1da177e4 LT |
255 | ---help--- |
256 | This option enables the complete Linux kernel ".config" file | |
257 | contents to be saved in the kernel. It provides documentation | |
258 | of which kernel options are used in a running kernel or in an | |
259 | on-disk kernel. This information can be extracted from the kernel | |
260 | image file with the script scripts/extract-ikconfig and used as | |
261 | input to rebuild the current kernel or to build another kernel. | |
262 | It can also be extracted from a running kernel by reading | |
263 | /proc/config.gz if enabled (below). | |
264 | ||
265 | config IKCONFIG_PROC | |
266 | bool "Enable access to .config through /proc/config.gz" | |
267 | depends on IKCONFIG && PROC_FS | |
268 | ---help--- | |
269 | This option enables access to the kernel configuration file | |
270 | through /proc/config.gz. | |
271 | ||
794543a2 AJS |
272 | config LOG_BUF_SHIFT |
273 | int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" | |
274 | range 12 21 | |
275 | default 17 if S390 || LOCKDEP | |
276 | default 16 if X86_NUMAQ || IA64 | |
277 | default 15 if SMP | |
278 | default 14 | |
279 | help | |
280 | Select kernel log buffer size as a power of 2. | |
281 | Defaults and Examples: | |
282 | 17 => 128 KB for S/390 | |
283 | 16 => 64 KB for x86 NUMAQ or IA-64 | |
284 | 15 => 32 KB for SMP | |
285 | 14 => 16 KB for uniprocessor | |
286 | 13 => 8 KB | |
287 | 12 => 4 KB | |
288 | ||
ddbcc7e8 PM |
289 | config CGROUPS |
290 | bool "Control Group support" | |
291 | help | |
292 | This option will let you use process cgroup subsystems | |
293 | such as Cpusets | |
294 | ||
295 | Say N if unsure. | |
296 | ||
006cb992 PM |
297 | config CGROUP_DEBUG |
298 | bool "Example debug cgroup subsystem" | |
299 | depends on CGROUPS | |
300 | help | |
301 | This option enables a simple cgroup subsystem that | |
302 | exports useful debugging information about the cgroups | |
303 | framework | |
304 | ||
305 | Say N if unsure | |
306 | ||
858d72ea SH |
307 | config CGROUP_NS |
308 | bool "Namespace cgroup subsystem" | |
309 | depends on CGROUPS | |
310 | help | |
311 | Provides a simple namespace cgroup subsystem to | |
312 | provide hierarchical naming of sets of namespaces, | |
313 | for instance virtual servers and checkpoint/restart | |
314 | jobs. | |
315 | ||
1da177e4 LT |
316 | config CPUSETS |
317 | bool "Cpuset support" | |
8793d854 | 318 | depends on SMP && CGROUPS |
1da177e4 | 319 | help |
d9fd8a6d | 320 | This option will let you create and manage CPUSETs which |
1da177e4 LT |
321 | allow dynamically partitioning a system into sets of CPUs and |
322 | Memory Nodes and assigning tasks to run only within those sets. | |
323 | This is primarily useful on large SMP or NUMA systems. | |
324 | ||
325 | Say N if unsure. | |
326 | ||
29f59db3 | 327 | config FAIR_GROUP_SCHED |
fb615581 | 328 | bool "Fair group CPU scheduler" |
de8d585a | 329 | default y |
29f59db3 | 330 | help |
fb615581 | 331 | This feature lets CPU scheduler recognize task groups and control CPU |
9b5b7751 | 332 | bandwidth allocation to such task groups. |
29f59db3 | 333 | |
24e377a8 SV |
334 | choice |
335 | depends on FAIR_GROUP_SCHED | |
336 | prompt "Basis for grouping tasks" | |
337 | default FAIR_USER_SCHED | |
338 | ||
fb615581 SV |
339 | config FAIR_USER_SCHED |
340 | bool "user id" | |
341 | help | |
342 | This option will choose userid as the basis for grouping | |
343 | tasks, thus providing equal CPU bandwidth to each user. | |
24e377a8 | 344 | |
68318b8e SV |
345 | config FAIR_CGROUP_SCHED |
346 | bool "Control groups" | |
347 | depends on CGROUPS | |
348 | help | |
349 | This option allows you to create arbitrary task groups | |
350 | using the "cgroup" pseudo filesystem and control | |
351 | the cpu bandwidth allocated to each such task group. | |
352 | Refer to Documentation/cgroups.txt for more information | |
353 | on "cgroup" pseudo filesystem. | |
354 | ||
24e377a8 SV |
355 | endchoice |
356 | ||
d842de87 SV |
357 | config CGROUP_CPUACCT |
358 | bool "Simple CPU accounting cgroup subsystem" | |
359 | depends on CGROUPS | |
360 | help | |
361 | Provides a simple Resource Controller for monitoring the | |
362 | total CPU consumed by the tasks in a cgroup | |
363 | ||
88a22c98 KS |
364 | config SYSFS_DEPRECATED |
365 | bool "Create deprecated sysfs files" | |
9148fe87 | 366 | depends on SYSFS |
88a22c98 KS |
367 | default y |
368 | help | |
369 | This option creates deprecated symlinks such as the | |
370 | "device"-link, the <subsystem>:<name>-link, and the | |
371 | "bus"-link. It may also add deprecated key in the | |
372 | uevent environment. | |
373 | None of these features or values should be used today, as | |
374 | they export driver core implementation details to userspace | |
375 | or export properties which can't be kept stable across kernel | |
376 | releases. | |
377 | ||
378 | If enabled, this option will also move any device structures | |
3dde6ad8 | 379 | that belong to a class, back into the /sys/class hierarchy, in |
88a22c98 KS |
380 | order to support older versions of udev. |
381 | ||
382 | If you are using a distro that was released in 2006 or later, | |
383 | it should be safe to say N here. | |
384 | ||
8793d854 PM |
385 | config PROC_PID_CPUSET |
386 | bool "Include legacy /proc/<pid>/cpuset file" | |
387 | depends on CPUSETS | |
388 | default y | |
389 | ||
b86ff981 JA |
390 | config RELAY |
391 | bool "Kernel->user space relay support (formerly relayfs)" | |
392 | help | |
393 | This option enables support for relay interface support in | |
394 | certain file systems (such as debugfs). | |
395 | It is designed to provide an efficient mechanism for tools and | |
396 | facilities to relay large amounts of data from kernel space to | |
397 | user space. | |
398 | ||
399 | If unsure, say N. | |
400 | ||
f991633d DG |
401 | config BLK_DEV_INITRD |
402 | bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support" | |
403 | depends on BROKEN || !FRV | |
404 | help | |
405 | The initial RAM filesystem is a ramfs which is loaded by the | |
406 | boot loader (loadlin or lilo) and that is mounted as root | |
407 | before the normal boot procedure. It is typically used to | |
408 | load modules needed to mount the "real" root file system, | |
409 | etc. See <file:Documentation/initrd.txt> for details. | |
410 | ||
411 | If RAM disk support (BLK_DEV_RAM) is also included, this | |
412 | also enables initial RAM disk (initrd) support and adds | |
413 | 15 Kbytes (more on some other architectures) to the kernel size. | |
414 | ||
415 | If unsure say Y. | |
416 | ||
c33df4ea JPS |
417 | if BLK_DEV_INITRD |
418 | ||
dbec4866 SR |
419 | source "usr/Kconfig" |
420 | ||
c33df4ea JPS |
421 | endif |
422 | ||
c45b4f1f LT |
423 | config CC_OPTIMIZE_FOR_SIZE |
424 | bool "Optimize for size (Look out for broken compilers!)" | |
425 | default y | |
32582fa4 | 426 | depends on ARM || H8300 || SUPERH || EXPERIMENTAL |
c45b4f1f LT |
427 | help |
428 | Enabling this option will pass "-Os" instead of "-O2" to gcc | |
429 | resulting in a smaller kernel. | |
430 | ||
431 | WARNING: some versions of gcc may generate incorrect code with this | |
432 | option. If problems are observed, a gcc upgrade may be needed. | |
433 | ||
434 | If unsure, say N. | |
435 | ||
0847062a RD |
436 | config SYSCTL |
437 | bool | |
438 | ||
1da177e4 LT |
439 | menuconfig EMBEDDED |
440 | bool "Configure standard kernel features (for small systems)" | |
441 | help | |
442 | This option allows certain base kernel options and settings | |
443 | to be disabled or tweaked. This is for specialized | |
444 | environments which can tolerate a "non-standard" kernel. | |
445 | Only use this if you really know what you are doing. | |
446 | ||
ae81f9e3 CE |
447 | config UID16 |
448 | bool "Enable 16-bit UID system calls" if EMBEDDED | |
529a73fb | 449 | depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION) |
ae81f9e3 CE |
450 | default y |
451 | help | |
452 | This enables the legacy 16-bit UID syscall wrappers. | |
453 | ||
b89a8171 | 454 | config SYSCTL_SYSCALL |
0847062a | 455 | bool "Sysctl syscall support" if EMBEDDED |
13bb7e37 | 456 | default y |
b89a8171 | 457 | select SYSCTL |
ae81f9e3 | 458 | ---help--- |
13bb7e37 EB |
459 | sys_sysctl uses binary paths that have been found challenging |
460 | to properly maintain and use. The interface in /proc/sys | |
461 | using paths with ascii names is now the primary path to this | |
462 | information. | |
b89a8171 | 463 | |
13bb7e37 EB |
464 | Almost nothing using the binary sysctl interface so if you are |
465 | trying to save some space it is probably safe to disable this, | |
466 | making your kernel marginally smaller. | |
b89a8171 | 467 | |
13bb7e37 | 468 | If unsure say Y here. |
ae81f9e3 | 469 | |
1da177e4 | 470 | config KALLSYMS |
979c6a1e | 471 | bool "Load all symbols for debugging/ksymoops" if EMBEDDED |
1da177e4 LT |
472 | default y |
473 | help | |
474 | Say Y here to let the kernel print out symbolic crash information and | |
475 | symbolic stack backtraces. This increases the size of the kernel | |
476 | somewhat, as all symbols have to be loaded into the kernel image. | |
477 | ||
478 | config KALLSYMS_ALL | |
479 | bool "Include all symbols in kallsyms" | |
480 | depends on DEBUG_KERNEL && KALLSYMS | |
481 | help | |
482 | Normally kallsyms only contains the symbols of functions, for nicer | |
483 | OOPS messages. Some debuggers can use kallsyms for other | |
f9f97bc0 JJ |
484 | symbols too: say Y here to include all symbols, if you need them |
485 | and you don't care about adding 300k to the size of your kernel. | |
1da177e4 LT |
486 | |
487 | Say N. | |
488 | ||
489 | config KALLSYMS_EXTRA_PASS | |
490 | bool "Do an extra kallsyms pass" | |
491 | depends on KALLSYMS | |
492 | help | |
493 | If kallsyms is not working correctly, the build will fail with | |
494 | inconsistent kallsyms data. If that occurs, log a bug report and | |
495 | turn on KALLSYMS_EXTRA_PASS which should result in a stable build. | |
496 | Always say N here unless you find a bug in kallsyms, which must be | |
497 | reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while | |
498 | you wait for kallsyms to be fixed. | |
499 | ||
d59745ce | 500 | |
712f47ce GKH |
501 | config HOTPLUG |
502 | bool "Support for hot-pluggable devices" if EMBEDDED | |
503 | default y | |
504 | help | |
505 | This option is provided for the case where no hotplug or uevent | |
506 | capabilities is wanted by the kernel. You should only consider | |
507 | disabling this option for embedded systems that do not use modules, a | |
508 | dynamic /dev tree, or dynamic device discovery. Just say Y. | |
509 | ||
d59745ce MM |
510 | config PRINTK |
511 | default y | |
512 | bool "Enable support for printk" if EMBEDDED | |
513 | help | |
514 | This option enables normal printk support. Removing it | |
515 | eliminates most of the message strings from the kernel image | |
516 | and makes the kernel more or less silent. As this makes it | |
517 | very difficult to diagnose system problems, saying N here is | |
518 | strongly discouraged. | |
519 | ||
c8538a7a MM |
520 | config BUG |
521 | bool "BUG() support" if EMBEDDED | |
522 | default y | |
523 | help | |
524 | Disabling this option eliminates support for BUG and WARN, reducing | |
525 | the size of your kernel image and potentially quietly ignoring | |
526 | numerous fatal conditions. You should only consider disabling this | |
527 | option for embedded systems with no facilities for reporting errors. | |
528 | Just say Y. | |
529 | ||
708e9a79 MM |
530 | config ELF_CORE |
531 | default y | |
532 | bool "Enable ELF core dumps" if EMBEDDED | |
533 | help | |
534 | Enable support for generating core dumps. Disabling saves about 4k. | |
535 | ||
1da177e4 LT |
536 | config BASE_FULL |
537 | default y | |
538 | bool "Enable full-sized data structures for core" if EMBEDDED | |
539 | help | |
540 | Disabling this option reduces the size of miscellaneous core | |
541 | kernel data structures. This saves memory on small machines, | |
542 | but may reduce performance. | |
543 | ||
544 | config FUTEX | |
545 | bool "Enable futex support" if EMBEDDED | |
546 | default y | |
23f78d4a | 547 | select RT_MUTEXES |
1da177e4 LT |
548 | help |
549 | Disabling this option will cause the kernel to be built without | |
550 | support for "fast userspace mutexes". The resulting kernel may not | |
551 | run glibc-based applications correctly. | |
552 | ||
5dc8bf81 | 553 | config ANON_INODES |
448e3cee | 554 | bool |
5dc8bf81 | 555 | |
1da177e4 LT |
556 | config EPOLL |
557 | bool "Enable eventpoll support" if EMBEDDED | |
558 | default y | |
448e3cee | 559 | select ANON_INODES |
1da177e4 LT |
560 | help |
561 | Disabling this option will cause the kernel to be built without | |
562 | support for epoll family of system calls. | |
563 | ||
fba2afaa DL |
564 | config SIGNALFD |
565 | bool "Enable signalfd() system call" if EMBEDDED | |
448e3cee | 566 | select ANON_INODES |
fba2afaa DL |
567 | default y |
568 | help | |
569 | Enable the signalfd() system call that allows to receive signals | |
570 | on a file descriptor. | |
571 | ||
572 | If unsure, say Y. | |
573 | ||
b215e283 DL |
574 | config TIMERFD |
575 | bool "Enable timerfd() system call" if EMBEDDED | |
448e3cee | 576 | select ANON_INODES |
e4260197 | 577 | depends on BROKEN |
b215e283 DL |
578 | default y |
579 | help | |
580 | Enable the timerfd() system call that allows to receive timer | |
581 | events on a file descriptor. | |
582 | ||
583 | If unsure, say Y. | |
584 | ||
e1ad7468 DL |
585 | config EVENTFD |
586 | bool "Enable eventfd() system call" if EMBEDDED | |
448e3cee | 587 | select ANON_INODES |
e1ad7468 DL |
588 | default y |
589 | help | |
590 | Enable the eventfd() system call that allows to receive both | |
591 | kernel notification (ie. KAIO) or userspace notifications. | |
592 | ||
593 | If unsure, say Y. | |
594 | ||
1da177e4 LT |
595 | config SHMEM |
596 | bool "Use full shmem filesystem" if EMBEDDED | |
597 | default y | |
598 | depends on MMU | |
599 | help | |
600 | The shmem is an internal filesystem used to manage shared memory. | |
601 | It is backed by swap and manages resource limits. It is also exported | |
602 | to userspace as tmpfs if TMPFS is enabled. Disabling this | |
603 | option replaces shmem and tmpfs with the much simpler ramfs code, | |
604 | which may be appropriate on small systems without swap. | |
605 | ||
f8891e5e CL |
606 | config VM_EVENT_COUNTERS |
607 | default y | |
608 | bool "Enable VM event counters for /proc/vmstat" if EMBEDDED | |
609 | help | |
2aea4fb6 PJ |
610 | VM event counters are needed for event counts to be shown. |
611 | This option allows the disabling of the VM event counters | |
612 | on EMBEDDED systems. /proc/vmstat will only show page counts | |
613 | if VM event counters are disabled. | |
f8891e5e | 614 | |
41ecc55b CL |
615 | config SLUB_DEBUG |
616 | default y | |
617 | bool "Enable SLUB debugging support" if EMBEDDED | |
d4751a27 | 618 | depends on SLUB |
41ecc55b CL |
619 | help |
620 | SLUB has extensive debug support features. Disabling these can | |
621 | result in significant savings in code size. This also disables | |
622 | SLUB sysfs support. /sys/slab will not exist and there will be | |
623 | no support for cache validation etc. | |
624 | ||
81819f0f CL |
625 | choice |
626 | prompt "Choose SLAB allocator" | |
a0acd820 | 627 | default SLUB |
81819f0f CL |
628 | help |
629 | This option allows to select a slab allocator. | |
630 | ||
631 | config SLAB | |
632 | bool "SLAB" | |
633 | help | |
634 | The regular slab allocator that is established and known to work | |
34013886 | 635 | well in all environments. It organizes cache hot objects in |
81819f0f | 636 | per cpu and per node queues. SLAB is the default choice for |
34013886 | 637 | a slab allocator. |
81819f0f CL |
638 | |
639 | config SLUB | |
81819f0f CL |
640 | bool "SLUB (Unqueued Allocator)" |
641 | help | |
642 | SLUB is a slab allocator that minimizes cache line usage | |
643 | instead of managing queues of cached objects (SLAB approach). | |
644 | Per cpu caching is realized using slabs of objects instead | |
645 | of queues of objects. SLUB can use memory efficiently | |
34013886 | 646 | and has enhanced diagnostics. |
81819f0f CL |
647 | |
648 | config SLOB | |
84a01c2f | 649 | depends on EMBEDDED |
81819f0f CL |
650 | bool "SLOB (Simple Allocator)" |
651 | help | |
652 | SLOB replaces the SLAB allocator with a drastically simpler | |
afc0cedb | 653 | allocator. SLOB is more space efficient than SLAB but does not |
34013886 CL |
654 | scale well (single lock for all operations) and is also highly |
655 | susceptible to fragmentation. SLUB can accomplish a higher object | |
656 | density. It is usually better to use SLUB instead of SLOB. | |
81819f0f CL |
657 | |
658 | endchoice | |
659 | ||
1da177e4 LT |
660 | endmenu # General setup |
661 | ||
158a9624 LT |
662 | config SLABINFO |
663 | bool | |
664 | depends on PROC_FS | |
665 | depends on SLAB || SLUB | |
666 | default y | |
667 | ||
ae81f9e3 CE |
668 | config RT_MUTEXES |
669 | boolean | |
670 | select PLIST | |
671 | ||
1da177e4 LT |
672 | config TINY_SHMEM |
673 | default !SHMEM | |
674 | bool | |
675 | ||
676 | config BASE_SMALL | |
677 | int | |
678 | default 0 if BASE_FULL | |
679 | default 1 if !BASE_FULL | |
680 | ||
66da5733 | 681 | menuconfig MODULES |
1da177e4 LT |
682 | bool "Enable loadable module support" |
683 | help | |
684 | Kernel modules are small pieces of compiled code which can | |
685 | be inserted in the running kernel, rather than being | |
686 | permanently built into the kernel. You use the "modprobe" | |
687 | tool to add (and sometimes remove) them. If you say Y here, | |
688 | many parts of the kernel can be built as modules (by | |
689 | answering M instead of Y where indicated): this is most | |
690 | useful for infrequently used options which are not required | |
691 | for booting. For more information, see the man pages for | |
692 | modprobe, lsmod, modinfo, insmod and rmmod. | |
693 | ||
694 | If you say Y here, you will need to run "make | |
695 | modules_install" to put the modules under /lib/modules/ | |
696 | where modprobe can find them (you may need to be root to do | |
697 | this). | |
698 | ||
699 | If unsure, say Y. | |
700 | ||
701 | config MODULE_UNLOAD | |
702 | bool "Module unloading" | |
703 | depends on MODULES | |
704 | help | |
705 | Without this option you will not be able to unload any | |
706 | modules (note that some modules may not be unloadable | |
707 | anyway), which makes your kernel slightly smaller and | |
708 | simpler. If unsure, say Y. | |
709 | ||
710 | config MODULE_FORCE_UNLOAD | |
711 | bool "Forced module unloading" | |
712 | depends on MODULE_UNLOAD && EXPERIMENTAL | |
713 | help | |
714 | This option allows you to force a module to unload, even if the | |
715 | kernel believes it is unsafe: the kernel will remove the module | |
716 | without waiting for anyone to stop using it (using the -f option to | |
717 | rmmod). This is mainly for kernel developers and desperate users. | |
718 | If unsure, say N. | |
719 | ||
1da177e4 | 720 | config MODVERSIONS |
0d541643 SR |
721 | bool "Module versioning support" |
722 | depends on MODULES | |
1da177e4 LT |
723 | help |
724 | Usually, you have to use modules compiled with your kernel. | |
725 | Saying Y here makes it sometimes possible to use modules | |
726 | compiled for different kernels, by adding enough information | |
727 | to the modules to (hopefully) spot any changes which would | |
728 | make them incompatible with the kernel you are running. If | |
729 | unsure, say N. | |
730 | ||
731 | config MODULE_SRCVERSION_ALL | |
732 | bool "Source checksum for all modules" | |
733 | depends on MODULES | |
734 | help | |
735 | Modules which contain a MODULE_VERSION get an extra "srcversion" | |
736 | field inserted into their modinfo section, which contains a | |
737 | sum of the source files which made it. This helps maintainers | |
738 | see exactly which source was used to build a module (since | |
739 | others sometimes change the module source without updating | |
740 | the version). With this option, such a "srcversion" field | |
741 | will be created for all modules. If unsure, say N. | |
742 | ||
743 | config KMOD | |
744 | bool "Automatic kernel module loading" | |
745 | depends on MODULES | |
746 | help | |
747 | Normally when you have selected some parts of the kernel to | |
748 | be created as kernel modules, you must load them (using the | |
749 | "modprobe" command) before you can use them. If you say Y | |
750 | here, some parts of the kernel will be able to load modules | |
751 | automatically: when a part of the kernel needs a module, it | |
752 | runs modprobe with the appropriate arguments, thereby | |
753 | loading the module if it is available. If unsure, say Y. | |
754 | ||
755 | config STOP_MACHINE | |
756 | bool | |
757 | default y | |
758 | depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU | |
759 | help | |
760 | Need stop_machine() primitive. | |
3a65dfe8 | 761 | |
3a65dfe8 | 762 | source "block/Kconfig" |
e98c3202 AK |
763 | |
764 | config PREEMPT_NOTIFIERS | |
765 | bool | |
e260be67 PM |
766 | |
767 | choice | |
768 | prompt "RCU implementation type:" | |
769 | default CLASSIC_RCU | |
770 | ||
771 | config CLASSIC_RCU | |
772 | bool "Classic RCU" | |
773 | help | |
774 | This option selects the classic RCU implementation that is | |
775 | designed for best read-side performance on non-realtime | |
776 | systems. | |
777 | ||
778 | Say Y if you are unsure. | |
779 | ||
780 | config PREEMPT_RCU | |
781 | bool "Preemptible RCU" | |
782 | depends on PREEMPT | |
783 | help | |
784 | This option reduces the latency of the kernel by making certain | |
785 | RCU sections preemptible. Normally RCU code is non-preemptible, if | |
786 | this option is selected then read-only RCU sections become | |
787 | preemptible. This helps latency, but may expose bugs due to | |
788 | now-naive assumptions about each RCU read-side critical section | |
789 | remaining on a given CPU through its execution. | |
790 | ||
791 | Say N if you are unsure. | |
792 | ||
793 | endchoice |