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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 | ||
b99b87f7 PO |
19 | config CONSTRUCTORS |
20 | bool | |
21 | depends on !UML | |
b99b87f7 | 22 | |
e360adbe PZ |
23 | config HAVE_IRQ_WORK |
24 | bool | |
25 | ||
26 | config IRQ_WORK | |
27 | bool | |
28 | depends on HAVE_IRQ_WORK | |
29 | ||
1dbdc6f1 DD |
30 | config BUILDTIME_EXTABLE_SORT |
31 | bool | |
32 | ||
ff0cfc66 | 33 | menu "General setup" |
1da177e4 LT |
34 | |
35 | config EXPERIMENTAL | |
36 | bool "Prompt for development and/or incomplete code/drivers" | |
37 | ---help--- | |
38 | Some of the various things that Linux supports (such as network | |
39 | drivers, file systems, network protocols, etc.) can be in a state | |
40 | of development where the functionality, stability, or the level of | |
41 | testing is not yet high enough for general use. This is usually | |
42 | known as the "alpha-test" phase among developers. If a feature is | |
43 | currently in alpha-test, then the developers usually discourage | |
44 | uninformed widespread use of this feature by the general public to | |
45 | avoid "Why doesn't this work?" type mail messages. However, active | |
46 | testing and use of these systems is welcomed. Just be aware that it | |
47 | may not meet the normal level of reliability or it may fail to work | |
48 | in some special cases. Detailed bug reports from people familiar | |
49 | with the kernel internals are usually welcomed by the developers | |
50 | (before submitting bug reports, please read the documents | |
51 | <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>, | |
52 | <file:Documentation/BUG-HUNTING>, and | |
53 | <file:Documentation/oops-tracing.txt> in the kernel source). | |
54 | ||
55 | This option will also make obsoleted drivers available. These are | |
56 | drivers that have been replaced by something else, and/or are | |
57 | scheduled to be removed in a future kernel release. | |
58 | ||
59 | Unless you intend to help test and develop a feature or driver that | |
60 | falls into this category, or you have a situation that requires | |
61 | using these features, you should probably say N here, which will | |
62 | cause the configurator to present you with fewer choices. If | |
63 | you say Y here, you will be offered the choice of using features or | |
64 | drivers that are currently considered to be in the alpha-test phase. | |
65 | ||
1da177e4 LT |
66 | config BROKEN |
67 | bool | |
1da177e4 LT |
68 | |
69 | config BROKEN_ON_SMP | |
70 | bool | |
71 | depends on BROKEN || !SMP | |
72 | default y | |
73 | ||
1da177e4 LT |
74 | config INIT_ENV_ARG_LIMIT |
75 | int | |
dd673bca AB |
76 | default 32 if !UML |
77 | default 128 if UML | |
1da177e4 | 78 | help |
34ad92c2 RD |
79 | Maximum of each of the number of arguments and environment |
80 | variables passed to init from the kernel command line. | |
1da177e4 | 81 | |
1da177e4 | 82 | |
84336466 RM |
83 | config CROSS_COMPILE |
84 | string "Cross-compiler tool prefix" | |
85 | help | |
86 | Same as running 'make CROSS_COMPILE=prefix-' but stored for | |
87 | default make runs in this kernel build directory. You don't | |
88 | need to set this unless you want the configured kernel build | |
89 | directory to select the cross-compiler automatically. | |
90 | ||
1da177e4 LT |
91 | config LOCALVERSION |
92 | string "Local version - append to kernel release" | |
93 | help | |
94 | Append an extra string to the end of your kernel version. | |
95 | This will show up when you type uname, for example. | |
96 | The string you set here will be appended after the contents of | |
97 | any files with a filename matching localversion* in your | |
98 | object and source tree, in that order. Your total string can | |
99 | be a maximum of 64 characters. | |
100 | ||
aaebf433 RA |
101 | config LOCALVERSION_AUTO |
102 | bool "Automatically append version information to the version string" | |
103 | default y | |
104 | help | |
105 | This will try to automatically determine if the current tree is a | |
6e5a5420 RD |
106 | release tree by looking for git tags that belong to the current |
107 | top of tree revision. | |
aaebf433 RA |
108 | |
109 | A string of the format -gxxxxxxxx will be added to the localversion | |
6e5a5420 | 110 | if a git-based tree is found. The string generated by this will be |
aaebf433 | 111 | appended after any matching localversion* files, and after the value |
6e5a5420 | 112 | set in CONFIG_LOCALVERSION. |
aaebf433 | 113 | |
6e5a5420 RD |
114 | (The actual string used here is the first eight characters produced |
115 | by running the command: | |
116 | ||
117 | $ git rev-parse --verify HEAD | |
118 | ||
119 | which is done within the script "scripts/setlocalversion".) | |
aaebf433 | 120 | |
2e9f3bdd PA |
121 | config HAVE_KERNEL_GZIP |
122 | bool | |
123 | ||
124 | config HAVE_KERNEL_BZIP2 | |
125 | bool | |
126 | ||
127 | config HAVE_KERNEL_LZMA | |
128 | bool | |
129 | ||
3ebe1243 LC |
130 | config HAVE_KERNEL_XZ |
131 | bool | |
132 | ||
7dd65feb AT |
133 | config HAVE_KERNEL_LZO |
134 | bool | |
135 | ||
30d65dbf | 136 | choice |
2e9f3bdd PA |
137 | prompt "Kernel compression mode" |
138 | default KERNEL_GZIP | |
3ebe1243 | 139 | depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO |
2e9f3bdd | 140 | help |
30d65dbf AK |
141 | The linux kernel is a kind of self-extracting executable. |
142 | Several compression algorithms are available, which differ | |
143 | in efficiency, compression and decompression speed. | |
144 | Compression speed is only relevant when building a kernel. | |
145 | Decompression speed is relevant at each boot. | |
146 | ||
147 | If you have any problems with bzip2 or lzma compressed | |
148 | kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older | |
149 | version of this functionality (bzip2 only), for 2.4, was | |
150 | supplied by Christian Ludwig) | |
151 | ||
152 | High compression options are mostly useful for users, who | |
153 | are low on disk space (embedded systems), but for whom ram | |
154 | size matters less. | |
155 | ||
156 | If in doubt, select 'gzip' | |
157 | ||
158 | config KERNEL_GZIP | |
2e9f3bdd PA |
159 | bool "Gzip" |
160 | depends on HAVE_KERNEL_GZIP | |
161 | help | |
7dd65feb AT |
162 | The old and tried gzip compression. It provides a good balance |
163 | between compression ratio and decompression speed. | |
30d65dbf AK |
164 | |
165 | config KERNEL_BZIP2 | |
166 | bool "Bzip2" | |
2e9f3bdd | 167 | depends on HAVE_KERNEL_BZIP2 |
30d65dbf AK |
168 | help |
169 | Its compression ratio and speed is intermediate. | |
0a4dd35c | 170 | Decompression speed is slowest among the choices. The kernel |
2e9f3bdd PA |
171 | size is about 10% smaller with bzip2, in comparison to gzip. |
172 | Bzip2 uses a large amount of memory. For modern kernels you | |
173 | will need at least 8MB RAM or more for booting. | |
30d65dbf AK |
174 | |
175 | config KERNEL_LZMA | |
2e9f3bdd PA |
176 | bool "LZMA" |
177 | depends on HAVE_KERNEL_LZMA | |
178 | help | |
0a4dd35c RD |
179 | This compression algorithm's ratio is best. Decompression speed |
180 | is between gzip and bzip2. Compression is slowest. | |
181 | The kernel size is about 33% smaller with LZMA in comparison to gzip. | |
30d65dbf | 182 | |
3ebe1243 LC |
183 | config KERNEL_XZ |
184 | bool "XZ" | |
185 | depends on HAVE_KERNEL_XZ | |
186 | help | |
187 | XZ uses the LZMA2 algorithm and instruction set specific | |
188 | BCJ filters which can improve compression ratio of executable | |
189 | code. The size of the kernel is about 30% smaller with XZ in | |
190 | comparison to gzip. On architectures for which there is a BCJ | |
191 | filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ | |
192 | will create a few percent smaller kernel than plain LZMA. | |
193 | ||
194 | The speed is about the same as with LZMA: The decompression | |
195 | speed of XZ is better than that of bzip2 but worse than gzip | |
196 | and LZO. Compression is slow. | |
197 | ||
7dd65feb AT |
198 | config KERNEL_LZO |
199 | bool "LZO" | |
200 | depends on HAVE_KERNEL_LZO | |
201 | help | |
0a4dd35c | 202 | Its compression ratio is the poorest among the choices. The kernel |
681b3049 | 203 | size is about 10% bigger than gzip; however its speed |
7dd65feb AT |
204 | (both compression and decompression) is the fastest. |
205 | ||
30d65dbf AK |
206 | endchoice |
207 | ||
bd5dc17b JT |
208 | config DEFAULT_HOSTNAME |
209 | string "Default hostname" | |
210 | default "(none)" | |
211 | help | |
212 | This option determines the default system hostname before userspace | |
213 | calls sethostname(2). The kernel traditionally uses "(none)" here, | |
214 | but you may wish to use a different default here to make a minimal | |
215 | system more usable with less configuration. | |
216 | ||
1da177e4 LT |
217 | config SWAP |
218 | bool "Support for paging of anonymous memory (swap)" | |
9361401e | 219 | depends on MMU && BLOCK |
1da177e4 LT |
220 | default y |
221 | help | |
222 | This option allows you to choose whether you want to have support | |
92c3504e | 223 | for so called swap devices or swap files in your kernel that are |
1da177e4 LT |
224 | used to provide more virtual memory than the actual RAM present |
225 | in your computer. If unsure say Y. | |
226 | ||
227 | config SYSVIPC | |
228 | bool "System V IPC" | |
1da177e4 LT |
229 | ---help--- |
230 | Inter Process Communication is a suite of library functions and | |
231 | system calls which let processes (running programs) synchronize and | |
232 | exchange information. It is generally considered to be a good thing, | |
233 | and some programs won't run unless you say Y here. In particular, if | |
234 | you want to run the DOS emulator dosemu under Linux (read the | |
235 | DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>), | |
236 | you'll need to say Y here. | |
237 | ||
238 | You can find documentation about IPC with "info ipc" and also in | |
239 | section 6.4 of the Linux Programmer's Guide, available from | |
240 | <http://www.tldp.org/guides.html>. | |
241 | ||
a5494dcd EB |
242 | config SYSVIPC_SYSCTL |
243 | bool | |
244 | depends on SYSVIPC | |
245 | depends on SYSCTL | |
246 | default y | |
247 | ||
1da177e4 LT |
248 | config POSIX_MQUEUE |
249 | bool "POSIX Message Queues" | |
250 | depends on NET && EXPERIMENTAL | |
251 | ---help--- | |
252 | POSIX variant of message queues is a part of IPC. In POSIX message | |
253 | queues every message has a priority which decides about succession | |
254 | of receiving it by a process. If you want to compile and run | |
255 | programs written e.g. for Solaris with use of its POSIX message | |
b0e37650 | 256 | queues (functions mq_*) say Y here. |
1da177e4 LT |
257 | |
258 | POSIX message queues are visible as a filesystem called 'mqueue' | |
259 | and can be mounted somewhere if you want to do filesystem | |
260 | operations on message queues. | |
261 | ||
262 | If unsure, say Y. | |
263 | ||
bdc8e5f8 SH |
264 | config POSIX_MQUEUE_SYSCTL |
265 | bool | |
266 | depends on POSIX_MQUEUE | |
267 | depends on SYSCTL | |
268 | default y | |
269 | ||
b952741c FW |
270 | config VIRT_CPU_ACCOUNTING |
271 | bool "Deterministic task and CPU time accounting" | |
272 | depends on HAVE_VIRT_CPU_ACCOUNTING | |
273 | default y if PPC64 | |
274 | help | |
275 | Select this option to enable more accurate task and CPU time | |
276 | accounting. This is done by reading a CPU counter on each | |
277 | kernel entry and exit and on transitions within the kernel | |
278 | between system, softirq and hardirq state, so there is a | |
279 | small performance impact. In the case of s390 or IBM POWER > 5, | |
280 | this also enables accounting of stolen time on logically-partitioned | |
281 | systems. | |
282 | ||
1da177e4 LT |
283 | config BSD_PROCESS_ACCT |
284 | bool "BSD Process Accounting" | |
285 | help | |
286 | If you say Y here, a user level program will be able to instruct the | |
287 | kernel (via a special system call) to write process accounting | |
288 | information to a file: whenever a process exits, information about | |
289 | that process will be appended to the file by the kernel. The | |
290 | information includes things such as creation time, owning user, | |
291 | command name, memory usage, controlling terminal etc. (the complete | |
292 | list is in the struct acct in <file:include/linux/acct.h>). It is | |
293 | up to the user level program to do useful things with this | |
294 | information. This is generally a good idea, so say Y. | |
295 | ||
296 | config BSD_PROCESS_ACCT_V3 | |
297 | bool "BSD Process Accounting version 3 file format" | |
298 | depends on BSD_PROCESS_ACCT | |
299 | default n | |
300 | help | |
301 | If you say Y here, the process accounting information is written | |
302 | in a new file format that also logs the process IDs of each | |
303 | process and it's parent. Note that this file format is incompatible | |
304 | with previous v0/v1/v2 file formats, so you will need updated tools | |
305 | for processing it. A preliminary version of these tools is available | |
37a4c940 | 306 | at <http://www.gnu.org/software/acct/>. |
1da177e4 | 307 | |
990d6c2d AK |
308 | config FHANDLE |
309 | bool "open by fhandle syscalls" | |
310 | select EXPORTFS | |
311 | help | |
312 | If you say Y here, a user level program will be able to map | |
313 | file names to handle and then later use the handle for | |
314 | different file system operations. This is useful in implementing | |
315 | userspace file servers, which now track files using handles instead | |
316 | of names. The handle would remain the same even if file names | |
317 | get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2) | |
318 | syscalls. | |
319 | ||
c757249a SN |
320 | config TASKSTATS |
321 | bool "Export task/process statistics through netlink (EXPERIMENTAL)" | |
322 | depends on NET | |
323 | default n | |
324 | help | |
325 | Export selected statistics for tasks/processes through the | |
326 | generic netlink interface. Unlike BSD process accounting, the | |
327 | statistics are available during the lifetime of tasks/processes as | |
328 | responses to commands. Like BSD accounting, they are sent to user | |
329 | space on task exit. | |
330 | ||
331 | Say N if unsure. | |
332 | ||
ca74e92b SN |
333 | config TASK_DELAY_ACCT |
334 | bool "Enable per-task delay accounting (EXPERIMENTAL)" | |
6f44993f | 335 | depends on TASKSTATS |
ca74e92b SN |
336 | help |
337 | Collect information on time spent by a task waiting for system | |
338 | resources like cpu, synchronous block I/O completion and swapping | |
339 | in pages. Such statistics can help in setting a task's priorities | |
340 | relative to other tasks for cpu, io, rss limits etc. | |
341 | ||
342 | Say N if unsure. | |
343 | ||
18f705f4 AD |
344 | config TASK_XACCT |
345 | bool "Enable extended accounting over taskstats (EXPERIMENTAL)" | |
346 | depends on TASKSTATS | |
347 | help | |
348 | Collect extended task accounting data and send the data | |
349 | to userland for processing over the taskstats interface. | |
350 | ||
351 | Say N if unsure. | |
352 | ||
353 | config TASK_IO_ACCOUNTING | |
354 | bool "Enable per-task storage I/O accounting (EXPERIMENTAL)" | |
355 | depends on TASK_XACCT | |
356 | help | |
357 | Collect information on the number of bytes of storage I/O which this | |
358 | task has caused. | |
359 | ||
360 | Say N if unsure. | |
361 | ||
1da177e4 LT |
362 | config AUDIT |
363 | bool "Auditing support" | |
804a6a49 | 364 | depends on NET |
1da177e4 LT |
365 | help |
366 | Enable auditing infrastructure that can be used with another | |
367 | kernel subsystem, such as SELinux (which requires this for | |
368 | logging of avc messages output). Does not do system-call | |
369 | auditing without CONFIG_AUDITSYSCALL. | |
370 | ||
371 | config AUDITSYSCALL | |
372 | bool "Enable system-call auditing support" | |
8f827a14 | 373 | depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH || (ARM && AEABI && !OABI_COMPAT)) |
1da177e4 LT |
374 | default y if SECURITY_SELINUX |
375 | help | |
376 | Enable low-overhead system-call auditing infrastructure that | |
377 | can be used independently or with another kernel subsystem, | |
67640b60 | 378 | such as SELinux. |
1da177e4 | 379 | |
939a67fc EP |
380 | config AUDIT_WATCH |
381 | def_bool y | |
382 | depends on AUDITSYSCALL | |
383 | select FSNOTIFY | |
1da177e4 | 384 | |
74c3cbe3 AV |
385 | config AUDIT_TREE |
386 | def_bool y | |
63c882a0 | 387 | depends on AUDITSYSCALL |
28a3a7eb | 388 | select FSNOTIFY |
74c3cbe3 | 389 | |
633b4545 EP |
390 | config AUDIT_LOGINUID_IMMUTABLE |
391 | bool "Make audit loginuid immutable" | |
392 | depends on AUDIT | |
393 | help | |
f429ee3b | 394 | The config option toggles if a task setting its loginuid requires |
633b4545 EP |
395 | CAP_SYS_AUDITCONTROL or if that task should require no special permissions |
396 | but should instead only allow setting its loginuid if it was never | |
397 | previously set. On systems which use systemd or a similar central | |
398 | process to restart login services this should be set to true. On older | |
399 | systems in which an admin would typically have to directly stop and | |
400 | start processes this should be set to false. Setting this to true allows | |
401 | one to drop potentially dangerous capabilites from the login tasks, | |
402 | but may not be backwards compatible with older init systems. | |
403 | ||
d9817ebe | 404 | source "kernel/irq/Kconfig" |
764e0da1 | 405 | source "kernel/time/Kconfig" |
d9817ebe | 406 | |
c903ff83 MT |
407 | menu "RCU Subsystem" |
408 | ||
409 | choice | |
410 | prompt "RCU Implementation" | |
31c9a24e | 411 | default TREE_RCU |
c903ff83 | 412 | |
c903ff83 MT |
413 | config TREE_RCU |
414 | bool "Tree-based hierarchical RCU" | |
687d7a96 | 415 | depends on !PREEMPT && SMP |
c903ff83 MT |
416 | help |
417 | This option selects the RCU implementation that is | |
418 | designed for very large SMP system with hundreds or | |
c17ef453 PM |
419 | thousands of CPUs. It also scales down nicely to |
420 | smaller systems. | |
c903ff83 | 421 | |
f41d911f | 422 | config TREE_PREEMPT_RCU |
a57eb940 | 423 | bool "Preemptible tree-based hierarchical RCU" |
8008e129 | 424 | depends on PREEMPT && SMP |
f41d911f PM |
425 | help |
426 | This option selects the RCU implementation that is | |
427 | designed for very large SMP systems with hundreds or | |
428 | thousands of CPUs, but for which real-time response | |
bbe3eae8 PM |
429 | is also required. It also scales down nicely to |
430 | smaller systems. | |
f41d911f | 431 | |
9b1d82fa PM |
432 | config TINY_RCU |
433 | bool "UP-only small-memory-footprint RCU" | |
8008e129 | 434 | depends on !PREEMPT && !SMP |
9b1d82fa PM |
435 | help |
436 | This option selects the RCU implementation that is | |
437 | designed for UP systems from which real-time response | |
438 | is not required. This option greatly reduces the | |
439 | memory footprint of RCU. | |
440 | ||
a57eb940 PM |
441 | config TINY_PREEMPT_RCU |
442 | bool "Preemptible UP-only small-memory-footprint RCU" | |
8008e129 | 443 | depends on PREEMPT && !SMP |
a57eb940 PM |
444 | help |
445 | This option selects the RCU implementation that is designed | |
446 | for real-time UP systems. This option greatly reduces the | |
447 | memory footprint of RCU. | |
448 | ||
c903ff83 MT |
449 | endchoice |
450 | ||
a57eb940 PM |
451 | config PREEMPT_RCU |
452 | def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU ) | |
453 | help | |
454 | This option enables preemptible-RCU code that is common between | |
455 | the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations. | |
456 | ||
c903ff83 MT |
457 | config RCU_FANOUT |
458 | int "Tree-based hierarchical RCU fanout value" | |
459 | range 2 64 if 64BIT | |
460 | range 2 32 if !64BIT | |
f41d911f | 461 | depends on TREE_RCU || TREE_PREEMPT_RCU |
c903ff83 MT |
462 | default 64 if 64BIT |
463 | default 32 if !64BIT | |
464 | help | |
465 | This option controls the fanout of hierarchical implementations | |
466 | of RCU, allowing RCU to work efficiently on machines with | |
4d87ffad PM |
467 | large numbers of CPUs. This value must be at least the fourth |
468 | root of NR_CPUS, which allows NR_CPUS to be insanely large. | |
469 | The default value of RCU_FANOUT should be used for production | |
470 | systems, but if you are stress-testing the RCU implementation | |
471 | itself, small RCU_FANOUT values allow you to test large-system | |
472 | code paths on small(er) systems. | |
c903ff83 MT |
473 | |
474 | Select a specific number if testing RCU itself. | |
475 | Take the default if unsure. | |
476 | ||
8932a63d PM |
477 | config RCU_FANOUT_LEAF |
478 | int "Tree-based hierarchical RCU leaf-level fanout value" | |
479 | range 2 RCU_FANOUT if 64BIT | |
480 | range 2 RCU_FANOUT if !64BIT | |
481 | depends on TREE_RCU || TREE_PREEMPT_RCU | |
482 | default 16 | |
483 | help | |
484 | This option controls the leaf-level fanout of hierarchical | |
485 | implementations of RCU, and allows trading off cache misses | |
486 | against lock contention. Systems that synchronize their | |
487 | scheduling-clock interrupts for energy-efficiency reasons will | |
488 | want the default because the smaller leaf-level fanout keeps | |
489 | lock contention levels acceptably low. Very large systems | |
490 | (hundreds or thousands of CPUs) will instead want to set this | |
491 | value to the maximum value possible in order to reduce the | |
492 | number of cache misses incurred during RCU's grace-period | |
493 | initialization. These systems tend to run CPU-bound, and thus | |
494 | are not helped by synchronized interrupts, and thus tend to | |
495 | skew them, which reduces lock contention enough that large | |
496 | leaf-level fanouts work well. | |
497 | ||
498 | Select a specific number if testing RCU itself. | |
499 | ||
500 | Select the maximum permissible value for large systems. | |
501 | ||
502 | Take the default if unsure. | |
503 | ||
c903ff83 MT |
504 | config RCU_FANOUT_EXACT |
505 | bool "Disable tree-based hierarchical RCU auto-balancing" | |
f41d911f | 506 | depends on TREE_RCU || TREE_PREEMPT_RCU |
c903ff83 MT |
507 | default n |
508 | help | |
509 | This option forces use of the exact RCU_FANOUT value specified, | |
510 | regardless of imbalances in the hierarchy. This is useful for | |
511 | testing RCU itself, and might one day be useful on systems with | |
512 | strong NUMA behavior. | |
513 | ||
514 | Without RCU_FANOUT_EXACT, the code will balance the hierarchy. | |
515 | ||
516 | Say N if unsure. | |
517 | ||
8bd93a2c PM |
518 | config RCU_FAST_NO_HZ |
519 | bool "Accelerate last non-dyntick-idle CPU's grace periods" | |
b807fbff | 520 | depends on NO_HZ && SMP |
8bd93a2c PM |
521 | default n |
522 | help | |
523 | This option causes RCU to attempt to accelerate grace periods | |
b807fbff PM |
524 | in order to allow CPUs to enter dynticks-idle state more |
525 | quickly. On the other hand, this option increases the overhead | |
526 | of the dynticks-idle checking, particularly on systems with | |
527 | large numbers of CPUs. | |
8bd93a2c PM |
528 | |
529 | Say Y if energy efficiency is critically important, particularly | |
530 | if you have relatively few CPUs. | |
531 | ||
532 | Say N if you are unsure. | |
533 | ||
c903ff83 | 534 | config TREE_RCU_TRACE |
f41d911f | 535 | def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU ) |
c903ff83 MT |
536 | select DEBUG_FS |
537 | help | |
f41d911f PM |
538 | This option provides tracing for the TREE_RCU and |
539 | TREE_PREEMPT_RCU implementations, permitting Makefile to | |
540 | trivially select kernel/rcutree_trace.c. | |
c903ff83 | 541 | |
24278d14 PM |
542 | config RCU_BOOST |
543 | bool "Enable RCU priority boosting" | |
27f4d280 | 544 | depends on RT_MUTEXES && PREEMPT_RCU |
24278d14 PM |
545 | default n |
546 | help | |
547 | This option boosts the priority of preempted RCU readers that | |
548 | block the current preemptible RCU grace period for too long. | |
549 | This option also prevents heavy loads from blocking RCU | |
550 | callback invocation for all flavors of RCU. | |
551 | ||
552 | Say Y here if you are working with real-time apps or heavy loads | |
553 | Say N here if you are unsure. | |
554 | ||
555 | config RCU_BOOST_PRIO | |
556 | int "Real-time priority to boost RCU readers to" | |
557 | range 1 99 | |
558 | depends on RCU_BOOST | |
559 | default 1 | |
560 | help | |
c9336643 PM |
561 | This option specifies the real-time priority to which long-term |
562 | preempted RCU readers are to be boosted. If you are working | |
563 | with a real-time application that has one or more CPU-bound | |
564 | threads running at a real-time priority level, you should set | |
565 | RCU_BOOST_PRIO to a priority higher then the highest-priority | |
566 | real-time CPU-bound thread. The default RCU_BOOST_PRIO value | |
567 | of 1 is appropriate in the common case, which is real-time | |
568 | applications that do not have any CPU-bound threads. | |
569 | ||
570 | Some real-time applications might not have a single real-time | |
571 | thread that saturates a given CPU, but instead might have | |
572 | multiple real-time threads that, taken together, fully utilize | |
573 | that CPU. In this case, you should set RCU_BOOST_PRIO to | |
574 | a priority higher than the lowest-priority thread that is | |
575 | conspiring to prevent the CPU from running any non-real-time | |
576 | tasks. For example, if one thread at priority 10 and another | |
577 | thread at priority 5 are between themselves fully consuming | |
578 | the CPU time on a given CPU, then RCU_BOOST_PRIO should be | |
579 | set to priority 6 or higher. | |
24278d14 PM |
580 | |
581 | Specify the real-time priority, or take the default if unsure. | |
582 | ||
583 | config RCU_BOOST_DELAY | |
584 | int "Milliseconds to delay boosting after RCU grace-period start" | |
585 | range 0 3000 | |
586 | depends on RCU_BOOST | |
587 | default 500 | |
588 | help | |
589 | This option specifies the time to wait after the beginning of | |
590 | a given grace period before priority-boosting preempted RCU | |
591 | readers blocking that grace period. Note that any RCU reader | |
592 | blocking an expedited RCU grace period is boosted immediately. | |
593 | ||
594 | Accept the default if unsure. | |
595 | ||
c903ff83 MT |
596 | endmenu # "RCU Subsystem" |
597 | ||
1da177e4 | 598 | config IKCONFIG |
f2443ab6 | 599 | tristate "Kernel .config support" |
1da177e4 LT |
600 | ---help--- |
601 | This option enables the complete Linux kernel ".config" file | |
602 | contents to be saved in the kernel. It provides documentation | |
603 | of which kernel options are used in a running kernel or in an | |
604 | on-disk kernel. This information can be extracted from the kernel | |
605 | image file with the script scripts/extract-ikconfig and used as | |
606 | input to rebuild the current kernel or to build another kernel. | |
607 | It can also be extracted from a running kernel by reading | |
608 | /proc/config.gz if enabled (below). | |
609 | ||
610 | config IKCONFIG_PROC | |
611 | bool "Enable access to .config through /proc/config.gz" | |
612 | depends on IKCONFIG && PROC_FS | |
613 | ---help--- | |
614 | This option enables access to the kernel configuration file | |
615 | through /proc/config.gz. | |
616 | ||
794543a2 AJS |
617 | config LOG_BUF_SHIFT |
618 | int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" | |
619 | range 12 21 | |
f17a32e9 | 620 | default 17 |
794543a2 AJS |
621 | help |
622 | Select kernel log buffer size as a power of 2. | |
f17a32e9 AB |
623 | Examples: |
624 | 17 => 128 KB | |
625 | 16 => 64 KB | |
626 | 15 => 32 KB | |
627 | 14 => 16 KB | |
794543a2 AJS |
628 | 13 => 8 KB |
629 | 12 => 4 KB | |
630 | ||
a5574cf6 IM |
631 | # |
632 | # Architectures with an unreliable sched_clock() should select this: | |
633 | # | |
634 | config HAVE_UNSTABLE_SCHED_CLOCK | |
635 | bool | |
636 | ||
23964d2d LZ |
637 | menuconfig CGROUPS |
638 | boolean "Control Group support" | |
0dea1168 | 639 | depends on EVENTFD |
5cdc38f9 | 640 | help |
23964d2d | 641 | This option adds support for grouping sets of processes together, for |
5cdc38f9 KH |
642 | use with process control subsystems such as Cpusets, CFS, memory |
643 | controls or device isolation. | |
644 | See | |
5cdc38f9 | 645 | - Documentation/scheduler/sched-design-CFS.txt (CFS) |
45ce80fb LZ |
646 | - Documentation/cgroups/ (features for grouping, isolation |
647 | and resource control) | |
5cdc38f9 KH |
648 | |
649 | Say N if unsure. | |
650 | ||
23964d2d LZ |
651 | if CGROUPS |
652 | ||
5cdc38f9 KH |
653 | config CGROUP_DEBUG |
654 | bool "Example debug cgroup subsystem" | |
5cdc38f9 KH |
655 | default n |
656 | help | |
657 | This option enables a simple cgroup subsystem that | |
658 | exports useful debugging information about the cgroups | |
23964d2d | 659 | framework. |
5cdc38f9 | 660 | |
23964d2d | 661 | Say N if unsure. |
5cdc38f9 | 662 | |
5cdc38f9 | 663 | config CGROUP_FREEZER |
23964d2d | 664 | bool "Freezer cgroup subsystem" |
23964d2d LZ |
665 | help |
666 | Provides a way to freeze and unfreeze all tasks in a | |
5cdc38f9 KH |
667 | cgroup. |
668 | ||
669 | config CGROUP_DEVICE | |
670 | bool "Device controller for cgroups" | |
5cdc38f9 KH |
671 | help |
672 | Provides a cgroup implementing whitelists for devices which | |
673 | a process in the cgroup can mknod or open. | |
674 | ||
675 | config CPUSETS | |
676 | bool "Cpuset support" | |
5cdc38f9 KH |
677 | help |
678 | This option will let you create and manage CPUSETs which | |
679 | allow dynamically partitioning a system into sets of CPUs and | |
680 | Memory Nodes and assigning tasks to run only within those sets. | |
681 | This is primarily useful on large SMP or NUMA systems. | |
682 | ||
683 | Say N if unsure. | |
684 | ||
23964d2d LZ |
685 | config PROC_PID_CPUSET |
686 | bool "Include legacy /proc/<pid>/cpuset file" | |
687 | depends on CPUSETS | |
688 | default y | |
689 | ||
d842de87 SV |
690 | config CGROUP_CPUACCT |
691 | bool "Simple CPU accounting cgroup subsystem" | |
d842de87 SV |
692 | help |
693 | Provides a simple Resource Controller for monitoring the | |
23964d2d | 694 | total CPU consumed by the tasks in a cgroup. |
d842de87 | 695 | |
e552b661 PE |
696 | config RESOURCE_COUNTERS |
697 | bool "Resource counters" | |
698 | help | |
699 | This option enables controller independent resource accounting | |
23964d2d | 700 | infrastructure that works with cgroups. |
e552b661 | 701 | |
c255a458 | 702 | config MEMCG |
00f0b825 | 703 | bool "Memory Resource Controller for Control Groups" |
79ae9c29 | 704 | depends on RESOURCE_COUNTERS |
cf475ad2 | 705 | select MM_OWNER |
00f0b825 | 706 | help |
84ad6d70 | 707 | Provides a memory resource controller that manages both anonymous |
21acb9ca | 708 | memory and page cache. (See Documentation/cgroups/memory.txt) |
00f0b825 BS |
709 | |
710 | Note that setting this option increases fixed memory overhead | |
84ad6d70 KH |
711 | associated with each page of memory in the system. By this, |
712 | 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory | |
713 | usage tracking struct at boot. Total amount of this is printed out | |
714 | at boot. | |
00f0b825 BS |
715 | |
716 | Only enable when you're ok with these trade offs and really | |
84ad6d70 KH |
717 | sure you need the memory resource controller. Even when you enable |
718 | this, you can set "cgroup_disable=memory" at your boot option to | |
719 | disable memory resource controller and you can avoid overheads. | |
c9d5409f | 720 | (and lose benefits of memory resource controller) |
00f0b825 | 721 | |
cf475ad2 BS |
722 | This config option also selects MM_OWNER config option, which |
723 | could in turn add some fork/exit overhead. | |
724 | ||
c255a458 | 725 | config MEMCG_SWAP |
65e0e811 | 726 | bool "Memory Resource Controller Swap Extension" |
c255a458 | 727 | depends on MEMCG && SWAP |
c077719b KH |
728 | help |
729 | Add swap management feature to memory resource controller. When you | |
730 | enable this, you can limit mem+swap usage per cgroup. In other words, | |
731 | when you disable this, memory resource controller has no cares to | |
732 | usage of swap...a process can exhaust all of the swap. This extension | |
733 | is useful when you want to avoid exhaustion swap but this itself | |
734 | adds more overheads and consumes memory for remembering information. | |
735 | Especially if you use 32bit system or small memory system, please | |
736 | be careful about enabling this. When memory resource controller | |
737 | is disabled by boot option, this will be automatically disabled and | |
738 | there will be no overhead from this. Even when you set this config=y, | |
00a66d29 | 739 | if boot option "swapaccount=0" is set, swap will not be accounted. |
627991a2 KH |
740 | Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page |
741 | size is 4096bytes, 512k per 1Gbytes of swap. | |
c255a458 | 742 | config MEMCG_SWAP_ENABLED |
a42c390c | 743 | bool "Memory Resource Controller Swap Extension enabled by default" |
c255a458 | 744 | depends on MEMCG_SWAP |
a42c390c MH |
745 | default y |
746 | help | |
747 | Memory Resource Controller Swap Extension comes with its price in | |
748 | a bigger memory consumption. General purpose distribution kernels | |
43d547f9 | 749 | which want to enable the feature but keep it disabled by default |
a42c390c MH |
750 | and let the user enable it by swapaccount boot command line |
751 | parameter should have this option unselected. | |
752 | For those who want to have the feature enabled by default should | |
753 | select this option (if, for some reason, they need to disable it | |
00a66d29 | 754 | then swapaccount=0 does the trick). |
c255a458 | 755 | config MEMCG_KMEM |
e5671dfa | 756 | bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)" |
c255a458 | 757 | depends on MEMCG && EXPERIMENTAL |
e5671dfa GC |
758 | default n |
759 | help | |
760 | The Kernel Memory extension for Memory Resource Controller can limit | |
761 | the amount of memory used by kernel objects in the system. Those are | |
762 | fundamentally different from the entities handled by the standard | |
763 | Memory Controller, which are page-based, and can be swapped. Users of | |
764 | the kmem extension can use it to guarantee that no group of processes | |
765 | will ever exhaust kernel resources alone. | |
c077719b | 766 | |
2bc64a20 AK |
767 | config CGROUP_HUGETLB |
768 | bool "HugeTLB Resource Controller for Control Groups" | |
769 | depends on RESOURCE_COUNTERS && HUGETLB_PAGE && EXPERIMENTAL | |
770 | default n | |
771 | help | |
772 | Provides a cgroup Resource Controller for HugeTLB pages. | |
773 | When you enable this, you can put a per cgroup limit on HugeTLB usage. | |
774 | The limit is enforced during page fault. Since HugeTLB doesn't | |
775 | support page reclaim, enforcing the limit at page fault time implies | |
776 | that, the application will get SIGBUS signal if it tries to access | |
777 | HugeTLB pages beyond its limit. This requires the application to know | |
778 | beforehand how much HugeTLB pages it would require for its use. The | |
779 | control group is tracked in the third page lru pointer. This means | |
780 | that we cannot use the controller with huge page less than 3 pages. | |
781 | ||
e5d1367f SE |
782 | config CGROUP_PERF |
783 | bool "Enable perf_event per-cpu per-container group (cgroup) monitoring" | |
784 | depends on PERF_EVENTS && CGROUPS | |
785 | help | |
786 | This option extends the per-cpu mode to restrict monitoring to | |
2d0f2520 | 787 | threads which belong to the cgroup specified and run on the |
e5d1367f SE |
788 | designated cpu. |
789 | ||
790 | Say N if unsure. | |
791 | ||
7c941438 DG |
792 | menuconfig CGROUP_SCHED |
793 | bool "Group CPU scheduler" | |
7c941438 DG |
794 | default n |
795 | help | |
796 | This feature lets CPU scheduler recognize task groups and control CPU | |
797 | bandwidth allocation to such task groups. It uses cgroups to group | |
798 | tasks. | |
799 | ||
800 | if CGROUP_SCHED | |
801 | config FAIR_GROUP_SCHED | |
802 | bool "Group scheduling for SCHED_OTHER" | |
803 | depends on CGROUP_SCHED | |
804 | default CGROUP_SCHED | |
805 | ||
ab84d31e PT |
806 | config CFS_BANDWIDTH |
807 | bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED" | |
808 | depends on EXPERIMENTAL | |
809 | depends on FAIR_GROUP_SCHED | |
810 | default n | |
811 | help | |
812 | This option allows users to define CPU bandwidth rates (limits) for | |
813 | tasks running within the fair group scheduler. Groups with no limit | |
814 | set are considered to be unconstrained and will run with no | |
815 | restriction. | |
816 | See tip/Documentation/scheduler/sched-bwc.txt for more information. | |
817 | ||
7c941438 DG |
818 | config RT_GROUP_SCHED |
819 | bool "Group scheduling for SCHED_RR/FIFO" | |
820 | depends on EXPERIMENTAL | |
821 | depends on CGROUP_SCHED | |
822 | default n | |
823 | help | |
824 | This feature lets you explicitly allocate real CPU bandwidth | |
32bd7eb5 | 825 | to task groups. If enabled, it will also make it impossible to |
7c941438 DG |
826 | schedule realtime tasks for non-root users until you allocate |
827 | realtime bandwidth for them. | |
828 | See Documentation/scheduler/sched-rt-group.txt for more information. | |
829 | ||
830 | endif #CGROUP_SCHED | |
831 | ||
afc24d49 | 832 | config BLK_CGROUP |
32e380ae | 833 | bool "Block IO controller" |
79ae9c29 | 834 | depends on BLOCK |
afc24d49 VG |
835 | default n |
836 | ---help--- | |
837 | Generic block IO controller cgroup interface. This is the common | |
838 | cgroup interface which should be used by various IO controlling | |
839 | policies. | |
840 | ||
841 | Currently, CFQ IO scheduler uses it to recognize task groups and | |
842 | control disk bandwidth allocation (proportional time slice allocation) | |
e43473b7 VG |
843 | to such task groups. It is also used by bio throttling logic in |
844 | block layer to implement upper limit in IO rates on a device. | |
afc24d49 VG |
845 | |
846 | This option only enables generic Block IO controller infrastructure. | |
e43473b7 | 847 | One needs to also enable actual IO controlling logic/policy. For |
79e2e759 MW |
848 | enabling proportional weight division of disk bandwidth in CFQ, set |
849 | CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set | |
c5e0591a | 850 | CONFIG_BLK_DEV_THROTTLING=y. |
afc24d49 VG |
851 | |
852 | See Documentation/cgroups/blkio-controller.txt for more information. | |
853 | ||
854 | config DEBUG_BLK_CGROUP | |
855 | bool "Enable Block IO controller debugging" | |
856 | depends on BLK_CGROUP | |
857 | default n | |
858 | ---help--- | |
859 | Enable some debugging help. Currently it exports additional stat | |
860 | files in a cgroup which can be useful for debugging. | |
861 | ||
23964d2d | 862 | endif # CGROUPS |
c077719b | 863 | |
067bce1a CG |
864 | config CHECKPOINT_RESTORE |
865 | bool "Checkpoint/restore support" if EXPERT | |
866 | default n | |
867 | help | |
868 | Enables additional kernel features in a sake of checkpoint/restore. | |
869 | In particular it adds auxiliary prctl codes to setup process text, | |
870 | data and heap segment sizes, and a few additional /proc filesystem | |
871 | entries. | |
872 | ||
873 | If unsure, say N here. | |
874 | ||
8dd2a82c | 875 | menuconfig NAMESPACES |
6a108a14 DR |
876 | bool "Namespaces support" if EXPERT |
877 | default !EXPERT | |
c5289a69 PE |
878 | help |
879 | Provides the way to make tasks work with different objects using | |
880 | the same id. For example same IPC id may refer to different objects | |
881 | or same user id or pid may refer to different tasks when used in | |
882 | different namespaces. | |
883 | ||
8dd2a82c DL |
884 | if NAMESPACES |
885 | ||
58bfdd6d PE |
886 | config UTS_NS |
887 | bool "UTS namespace" | |
17a6d441 | 888 | default y |
58bfdd6d PE |
889 | help |
890 | In this namespace tasks see different info provided with the | |
891 | uname() system call | |
892 | ||
ae5e1b22 PE |
893 | config IPC_NS |
894 | bool "IPC namespace" | |
8dd2a82c | 895 | depends on (SYSVIPC || POSIX_MQUEUE) |
17a6d441 | 896 | default y |
ae5e1b22 PE |
897 | help |
898 | In this namespace tasks work with IPC ids which correspond to | |
614b84cf | 899 | different IPC objects in different namespaces. |
ae5e1b22 | 900 | |
aee16ce7 PE |
901 | config USER_NS |
902 | bool "User namespace (EXPERIMENTAL)" | |
8dd2a82c | 903 | depends on EXPERIMENTAL |
e1c972b6 | 904 | depends on UIDGID_CONVERTED |
5673a94c | 905 | select UIDGID_STRICT_TYPE_CHECKS |
e1c972b6 | 906 | |
5673a94c | 907 | default n |
aee16ce7 PE |
908 | help |
909 | This allows containers, i.e. vservers, to use user namespaces | |
910 | to provide different user info for different servers. | |
911 | If unsure, say N. | |
912 | ||
74bd59bb | 913 | config PID_NS |
9bd38c2c | 914 | bool "PID Namespaces" |
17a6d441 | 915 | default y |
74bd59bb | 916 | help |
12d2b8f9 | 917 | Support process id namespaces. This allows having multiple |
692105b8 | 918 | processes with the same pid as long as they are in different |
74bd59bb PE |
919 | pid namespaces. This is a building block of containers. |
920 | ||
d6eb633f MH |
921 | config NET_NS |
922 | bool "Network namespace" | |
8dd2a82c | 923 | depends on NET |
17a6d441 | 924 | default y |
d6eb633f MH |
925 | help |
926 | Allow user space to create what appear to be multiple instances | |
927 | of the network stack. | |
928 | ||
8dd2a82c DL |
929 | endif # NAMESPACES |
930 | ||
e1c972b6 EB |
931 | config UIDGID_CONVERTED |
932 | # True if all of the selected software conmponents are known | |
933 | # to have uid_t and gid_t converted to kuid_t and kgid_t | |
934 | # where appropriate and are otherwise safe to use with | |
935 | # the user namespace. | |
936 | bool | |
937 | default y | |
938 | ||
939 | # List of kernel pieces that need user namespace work | |
940 | # Features | |
e1c972b6 EB |
941 | depends on SYSVIPC = n |
942 | depends on IMA = n | |
943 | depends on EVM = n | |
944 | depends on KEYS = n | |
945 | depends on AUDIT = n | |
946 | depends on AUDITSYSCALL = n | |
947 | depends on TASKSTATS = n | |
948 | depends on TRACING = n | |
949 | depends on FS_POSIX_ACL = n | |
950 | depends on QUOTA = n | |
951 | depends on QUOTACTL = n | |
952 | depends on DEBUG_CREDENTIALS = n | |
953 | depends on BSD_PROCESS_ACCT = n | |
954 | depends on DRM = n | |
955 | depends on PROC_EVENTS = n | |
956 | ||
957 | # Networking | |
958 | depends on NET = n | |
959 | depends on NET_9P = n | |
960 | depends on IPX = n | |
961 | depends on PHONET = n | |
962 | depends on NET_CLS_FLOW = n | |
963 | depends on NETFILTER_XT_MATCH_OWNER = n | |
964 | depends on NETFILTER_XT_MATCH_RECENT = n | |
965 | depends on NETFILTER_XT_TARGET_LOG = n | |
966 | depends on NETFILTER_NETLINK_LOG = n | |
967 | depends on INET = n | |
968 | depends on IPV6 = n | |
969 | depends on IP_SCTP = n | |
970 | depends on AF_RXRPC = n | |
971 | depends on LLC2 = n | |
972 | depends on NET_KEY = n | |
973 | depends on INET_DIAG = n | |
974 | depends on DNS_RESOLVER = n | |
975 | depends on AX25 = n | |
976 | depends on ATALK = n | |
977 | ||
978 | # Filesystems | |
979 | depends on USB_DEVICEFS = n | |
980 | depends on USB_GADGETFS = n | |
981 | depends on USB_FUNCTIONFS = n | |
982 | depends on DEVTMPFS = n | |
983 | depends on XENFS = n | |
984 | ||
985 | depends on 9P_FS = n | |
986 | depends on ADFS_FS = n | |
987 | depends on AFFS_FS = n | |
988 | depends on AFS_FS = n | |
989 | depends on AUTOFS4_FS = n | |
990 | depends on BEFS_FS = n | |
991 | depends on BFS_FS = n | |
992 | depends on BTRFS_FS = n | |
993 | depends on CEPH_FS = n | |
994 | depends on CIFS = n | |
995 | depends on CODA_FS = n | |
996 | depends on CONFIGFS_FS = n | |
997 | depends on CRAMFS = n | |
998 | depends on DEBUG_FS = n | |
999 | depends on ECRYPT_FS = n | |
1000 | depends on EFS_FS = n | |
1001 | depends on EXOFS_FS = n | |
e1c972b6 EB |
1002 | depends on FAT_FS = n |
1003 | depends on FUSE_FS = n | |
1004 | depends on GFS2_FS = n | |
1005 | depends on HFS_FS = n | |
1006 | depends on HFSPLUS_FS = n | |
1007 | depends on HPFS_FS = n | |
1008 | depends on HUGETLBFS = n | |
1009 | depends on ISO9660_FS = n | |
1010 | depends on JFFS2_FS = n | |
1011 | depends on JFS_FS = n | |
1012 | depends on LOGFS = n | |
1013 | depends on MINIX_FS = n | |
1014 | depends on NCP_FS = n | |
1015 | depends on NFSD = n | |
1016 | depends on NFS_FS = n | |
1017 | depends on NILFS2_FS = n | |
1018 | depends on NTFS_FS = n | |
1019 | depends on OCFS2_FS = n | |
1020 | depends on OMFS_FS = n | |
e1c972b6 EB |
1021 | depends on QNX4FS_FS = n |
1022 | depends on QNX6FS_FS = n | |
1023 | depends on REISERFS_FS = n | |
1024 | depends on SQUASHFS = n | |
e1c972b6 | 1025 | depends on SYSV_FS = n |
e1c972b6 EB |
1026 | depends on UBIFS_FS = n |
1027 | depends on UDF_FS = n | |
1028 | depends on UFS_FS = n | |
1029 | depends on VXFS_FS = n | |
1030 | depends on XFS_FS = n | |
1031 | ||
1032 | depends on !UML || HOSTFS = n | |
1033 | ||
1034 | # The rare drivers that won't build | |
1035 | depends on AIRO = n | |
1036 | depends on AIRO_CS = n | |
1037 | depends on TUN = n | |
1038 | depends on INFINIBAND_QIB = n | |
1039 | depends on BLK_DEV_LOOP = n | |
1040 | depends on ANDROID_BINDER_IPC = n | |
1041 | ||
1042 | # Security modules | |
1043 | depends on SECURITY_TOMOYO = n | |
1044 | depends on SECURITY_APPARMOR = n | |
1045 | ||
5673a94c EB |
1046 | config UIDGID_STRICT_TYPE_CHECKS |
1047 | bool "Require conversions between uid/gids and their internal representation" | |
e1c972b6 | 1048 | depends on UIDGID_CONVERTED |
5673a94c EB |
1049 | default n |
1050 | help | |
1051 | While the nececessary conversions are being added to all subsystems this option allows | |
1052 | the code to continue to build for unconverted subsystems. | |
1053 | ||
1054 | Say Y here if you want the strict type checking enabled | |
1055 | ||
5091faa4 MG |
1056 | config SCHED_AUTOGROUP |
1057 | bool "Automatic process group scheduling" | |
1058 | select EVENTFD | |
1059 | select CGROUPS | |
1060 | select CGROUP_SCHED | |
1061 | select FAIR_GROUP_SCHED | |
1062 | help | |
1063 | This option optimizes the scheduler for common desktop workloads by | |
1064 | automatically creating and populating task groups. This separation | |
1065 | of workloads isolates aggressive CPU burners (like build jobs) from | |
1066 | desktop applications. Task group autogeneration is currently based | |
1067 | upon task session. | |
1068 | ||
7af37bec DL |
1069 | config MM_OWNER |
1070 | bool | |
1071 | ||
1072 | config SYSFS_DEPRECATED | |
5d6a4ea5 | 1073 | bool "Enable deprecated sysfs features to support old userspace tools" |
7af37bec DL |
1074 | depends on SYSFS |
1075 | default n | |
1076 | help | |
1077 | This option adds code that switches the layout of the "block" class | |
1078 | devices, to not show up in /sys/class/block/, but only in | |
1079 | /sys/block/. | |
1080 | ||
1081 | This switch is only active when the sysfs.deprecated=1 boot option is | |
1082 | passed or the SYSFS_DEPRECATED_V2 option is set. | |
1083 | ||
1084 | This option allows new kernels to run on old distributions and tools, | |
1085 | which might get confused by /sys/class/block/. Since 2007/2008 all | |
1086 | major distributions and tools handle this just fine. | |
1087 | ||
1088 | Recent distributions and userspace tools after 2009/2010 depend on | |
1089 | the existence of /sys/class/block/, and will not work with this | |
1090 | option enabled. | |
1091 | ||
1092 | Only if you are using a new kernel on an old distribution, you might | |
1093 | need to say Y here. | |
1094 | ||
1095 | config SYSFS_DEPRECATED_V2 | |
5d6a4ea5 | 1096 | bool "Enable deprecated sysfs features by default" |
7af37bec DL |
1097 | default n |
1098 | depends on SYSFS | |
1099 | depends on SYSFS_DEPRECATED | |
1100 | help | |
1101 | Enable deprecated sysfs by default. | |
1102 | ||
1103 | See the CONFIG_SYSFS_DEPRECATED option for more details about this | |
1104 | option. | |
1105 | ||
1106 | Only if you are using a new kernel on an old distribution, you might | |
1107 | need to say Y here. Even then, odds are you would not need it | |
1108 | enabled, you can always pass the boot option if absolutely necessary. | |
1109 | ||
1110 | config RELAY | |
1111 | bool "Kernel->user space relay support (formerly relayfs)" | |
1112 | help | |
1113 | This option enables support for relay interface support in | |
1114 | certain file systems (such as debugfs). | |
1115 | It is designed to provide an efficient mechanism for tools and | |
1116 | facilities to relay large amounts of data from kernel space to | |
1117 | user space. | |
1118 | ||
1119 | If unsure, say N. | |
1120 | ||
f991633d DG |
1121 | config BLK_DEV_INITRD |
1122 | bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support" | |
1123 | depends on BROKEN || !FRV | |
1124 | help | |
1125 | The initial RAM filesystem is a ramfs which is loaded by the | |
1126 | boot loader (loadlin or lilo) and that is mounted as root | |
1127 | before the normal boot procedure. It is typically used to | |
1128 | load modules needed to mount the "real" root file system, | |
1129 | etc. See <file:Documentation/initrd.txt> for details. | |
1130 | ||
1131 | If RAM disk support (BLK_DEV_RAM) is also included, this | |
1132 | also enables initial RAM disk (initrd) support and adds | |
1133 | 15 Kbytes (more on some other architectures) to the kernel size. | |
1134 | ||
1135 | If unsure say Y. | |
1136 | ||
c33df4ea JPS |
1137 | if BLK_DEV_INITRD |
1138 | ||
dbec4866 SR |
1139 | source "usr/Kconfig" |
1140 | ||
c33df4ea JPS |
1141 | endif |
1142 | ||
c45b4f1f | 1143 | config CC_OPTIMIZE_FOR_SIZE |
96fffeb4 | 1144 | bool "Optimize for size" |
c45b4f1f LT |
1145 | help |
1146 | Enabling this option will pass "-Os" instead of "-O2" to gcc | |
1147 | resulting in a smaller kernel. | |
1148 | ||
775a7229 | 1149 | If unsure, say Y. |
c45b4f1f | 1150 | |
0847062a RD |
1151 | config SYSCTL |
1152 | bool | |
1153 | ||
b943c460 RD |
1154 | config ANON_INODES |
1155 | bool | |
1156 | ||
6a108a14 DR |
1157 | menuconfig EXPERT |
1158 | bool "Configure standard kernel features (expert users)" | |
f505c553 JT |
1159 | # Unhide debug options, to make the on-by-default options visible |
1160 | select DEBUG_KERNEL | |
1da177e4 LT |
1161 | help |
1162 | This option allows certain base kernel options and settings | |
1163 | to be disabled or tweaked. This is for specialized | |
1164 | environments which can tolerate a "non-standard" kernel. | |
1165 | Only use this if you really know what you are doing. | |
1166 | ||
ae81f9e3 | 1167 | config UID16 |
6a108a14 | 1168 | bool "Enable 16-bit UID system calls" if EXPERT |
09337f50 | 1169 | depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION) |
ae81f9e3 CE |
1170 | default y |
1171 | help | |
1172 | This enables the legacy 16-bit UID syscall wrappers. | |
1173 | ||
b89a8171 | 1174 | config SYSCTL_SYSCALL |
6a108a14 | 1175 | bool "Sysctl syscall support" if EXPERT |
26a7034b | 1176 | depends on PROC_SYSCTL |
c736de60 | 1177 | default n |
b89a8171 | 1178 | select SYSCTL |
ae81f9e3 | 1179 | ---help--- |
13bb7e37 EB |
1180 | sys_sysctl uses binary paths that have been found challenging |
1181 | to properly maintain and use. The interface in /proc/sys | |
1182 | using paths with ascii names is now the primary path to this | |
1183 | information. | |
b89a8171 | 1184 | |
13bb7e37 EB |
1185 | Almost nothing using the binary sysctl interface so if you are |
1186 | trying to save some space it is probably safe to disable this, | |
1187 | making your kernel marginally smaller. | |
b89a8171 | 1188 | |
c736de60 | 1189 | If unsure say N here. |
ae81f9e3 | 1190 | |
1da177e4 | 1191 | config KALLSYMS |
6a108a14 | 1192 | bool "Load all symbols for debugging/ksymoops" if EXPERT |
1da177e4 LT |
1193 | default y |
1194 | help | |
1195 | Say Y here to let the kernel print out symbolic crash information and | |
1196 | symbolic stack backtraces. This increases the size of the kernel | |
1197 | somewhat, as all symbols have to be loaded into the kernel image. | |
1198 | ||
1199 | config KALLSYMS_ALL | |
1200 | bool "Include all symbols in kallsyms" | |
1201 | depends on DEBUG_KERNEL && KALLSYMS | |
1202 | help | |
71a83ec7 AB |
1203 | Normally kallsyms only contains the symbols of functions for nicer |
1204 | OOPS messages and backtraces (i.e., symbols from the text and inittext | |
1205 | sections). This is sufficient for most cases. And only in very rare | |
1206 | cases (e.g., when a debugger is used) all symbols are required (e.g., | |
1207 | names of variables from the data sections, etc). | |
1208 | ||
1209 | This option makes sure that all symbols are loaded into the kernel | |
1210 | image (i.e., symbols from all sections) in cost of increased kernel | |
1211 | size (depending on the kernel configuration, it may be 300KiB or | |
1212 | something like this). | |
1213 | ||
1214 | Say N unless you really need all symbols. | |
d59745ce | 1215 | |
712f47ce | 1216 | config HOTPLUG |
6a108a14 | 1217 | bool "Support for hot-pluggable devices" if EXPERT |
712f47ce GKH |
1218 | default y |
1219 | help | |
1220 | This option is provided for the case where no hotplug or uevent | |
1221 | capabilities is wanted by the kernel. You should only consider | |
1222 | disabling this option for embedded systems that do not use modules, a | |
1223 | dynamic /dev tree, or dynamic device discovery. Just say Y. | |
1224 | ||
d59745ce MM |
1225 | config PRINTK |
1226 | default y | |
6a108a14 | 1227 | bool "Enable support for printk" if EXPERT |
d59745ce MM |
1228 | help |
1229 | This option enables normal printk support. Removing it | |
1230 | eliminates most of the message strings from the kernel image | |
1231 | and makes the kernel more or less silent. As this makes it | |
1232 | very difficult to diagnose system problems, saying N here is | |
1233 | strongly discouraged. | |
1234 | ||
c8538a7a | 1235 | config BUG |
6a108a14 | 1236 | bool "BUG() support" if EXPERT |
c8538a7a MM |
1237 | default y |
1238 | help | |
1239 | Disabling this option eliminates support for BUG and WARN, reducing | |
1240 | the size of your kernel image and potentially quietly ignoring | |
1241 | numerous fatal conditions. You should only consider disabling this | |
1242 | option for embedded systems with no facilities for reporting errors. | |
1243 | Just say Y. | |
1244 | ||
708e9a79 MM |
1245 | config ELF_CORE |
1246 | default y | |
6a108a14 | 1247 | bool "Enable ELF core dumps" if EXPERT |
708e9a79 MM |
1248 | help |
1249 | Enable support for generating core dumps. Disabling saves about 4k. | |
1250 | ||
8761f1ab | 1251 | |
e5e1d3cb | 1252 | config PCSPKR_PLATFORM |
6a108a14 | 1253 | bool "Enable PC-Speaker support" if EXPERT |
8761f1ab | 1254 | depends on HAVE_PCSPKR_PLATFORM |
15f304b6 | 1255 | select I8253_LOCK |
e5e1d3cb SS |
1256 | default y |
1257 | help | |
1258 | This option allows to disable the internal PC-Speaker | |
1259 | support, saving some memory. | |
1260 | ||
8761f1ab RB |
1261 | config HAVE_PCSPKR_PLATFORM |
1262 | bool | |
1263 | ||
1da177e4 LT |
1264 | config BASE_FULL |
1265 | default y | |
6a108a14 | 1266 | bool "Enable full-sized data structures for core" if EXPERT |
1da177e4 LT |
1267 | help |
1268 | Disabling this option reduces the size of miscellaneous core | |
1269 | kernel data structures. This saves memory on small machines, | |
1270 | but may reduce performance. | |
1271 | ||
1272 | config FUTEX | |
6a108a14 | 1273 | bool "Enable futex support" if EXPERT |
1da177e4 | 1274 | default y |
23f78d4a | 1275 | select RT_MUTEXES |
1da177e4 LT |
1276 | help |
1277 | Disabling this option will cause the kernel to be built without | |
1278 | support for "fast userspace mutexes". The resulting kernel may not | |
1279 | run glibc-based applications correctly. | |
1280 | ||
1281 | config EPOLL | |
6a108a14 | 1282 | bool "Enable eventpoll support" if EXPERT |
1da177e4 | 1283 | default y |
448e3cee | 1284 | select ANON_INODES |
1da177e4 LT |
1285 | help |
1286 | Disabling this option will cause the kernel to be built without | |
1287 | support for epoll family of system calls. | |
1288 | ||
fba2afaa | 1289 | config SIGNALFD |
6a108a14 | 1290 | bool "Enable signalfd() system call" if EXPERT |
448e3cee | 1291 | select ANON_INODES |
fba2afaa DL |
1292 | default y |
1293 | help | |
1294 | Enable the signalfd() system call that allows to receive signals | |
1295 | on a file descriptor. | |
1296 | ||
1297 | If unsure, say Y. | |
1298 | ||
b215e283 | 1299 | config TIMERFD |
6a108a14 | 1300 | bool "Enable timerfd() system call" if EXPERT |
448e3cee | 1301 | select ANON_INODES |
b215e283 DL |
1302 | default y |
1303 | help | |
1304 | Enable the timerfd() system call that allows to receive timer | |
1305 | events on a file descriptor. | |
1306 | ||
1307 | If unsure, say Y. | |
1308 | ||
e1ad7468 | 1309 | config EVENTFD |
6a108a14 | 1310 | bool "Enable eventfd() system call" if EXPERT |
448e3cee | 1311 | select ANON_INODES |
e1ad7468 DL |
1312 | default y |
1313 | help | |
1314 | Enable the eventfd() system call that allows to receive both | |
1315 | kernel notification (ie. KAIO) or userspace notifications. | |
1316 | ||
1317 | If unsure, say Y. | |
1318 | ||
1da177e4 | 1319 | config SHMEM |
6a108a14 | 1320 | bool "Use full shmem filesystem" if EXPERT |
1da177e4 LT |
1321 | default y |
1322 | depends on MMU | |
1323 | help | |
1324 | The shmem is an internal filesystem used to manage shared memory. | |
1325 | It is backed by swap and manages resource limits. It is also exported | |
1326 | to userspace as tmpfs if TMPFS is enabled. Disabling this | |
1327 | option replaces shmem and tmpfs with the much simpler ramfs code, | |
1328 | which may be appropriate on small systems without swap. | |
1329 | ||
ebf3f09c | 1330 | config AIO |
6a108a14 | 1331 | bool "Enable AIO support" if EXPERT |
ebf3f09c TP |
1332 | default y |
1333 | help | |
1334 | This option enables POSIX asynchronous I/O which may by used | |
1335 | by some high performance threaded applications. Disabling | |
1336 | this option saves about 7k. | |
1337 | ||
6befe5f6 RD |
1338 | config EMBEDDED |
1339 | bool "Embedded system" | |
1340 | select EXPERT | |
1341 | help | |
1342 | This option should be enabled if compiling the kernel for | |
1343 | an embedded system so certain expert options are available | |
1344 | for configuration. | |
1345 | ||
cdd6c482 | 1346 | config HAVE_PERF_EVENTS |
0793a61d | 1347 | bool |
018df72d MF |
1348 | help |
1349 | See tools/perf/design.txt for details. | |
0793a61d | 1350 | |
906010b2 PZ |
1351 | config PERF_USE_VMALLOC |
1352 | bool | |
1353 | help | |
1354 | See tools/perf/design.txt for details | |
1355 | ||
57c0c15b | 1356 | menu "Kernel Performance Events And Counters" |
0793a61d | 1357 | |
cdd6c482 | 1358 | config PERF_EVENTS |
57c0c15b | 1359 | bool "Kernel performance events and counters" |
392d65a9 | 1360 | default y if PROFILING |
cdd6c482 | 1361 | depends on HAVE_PERF_EVENTS |
4c59e467 | 1362 | select ANON_INODES |
e360adbe | 1363 | select IRQ_WORK |
0793a61d | 1364 | help |
57c0c15b IM |
1365 | Enable kernel support for various performance events provided |
1366 | by software and hardware. | |
0793a61d | 1367 | |
dd77038d | 1368 | Software events are supported either built-in or via the |
57c0c15b | 1369 | use of generic tracepoints. |
0793a61d | 1370 | |
57c0c15b IM |
1371 | Most modern CPUs support performance events via performance |
1372 | counter registers. These registers count the number of certain | |
0793a61d TG |
1373 | types of hw events: such as instructions executed, cachemisses |
1374 | suffered, or branches mis-predicted - without slowing down the | |
1375 | kernel or applications. These registers can also trigger interrupts | |
1376 | when a threshold number of events have passed - and can thus be | |
1377 | used to profile the code that runs on that CPU. | |
1378 | ||
57c0c15b | 1379 | The Linux Performance Event subsystem provides an abstraction of |
dd77038d | 1380 | these software and hardware event capabilities, available via a |
57c0c15b | 1381 | system call and used by the "perf" utility in tools/perf/. It |
0793a61d TG |
1382 | provides per task and per CPU counters, and it provides event |
1383 | capabilities on top of those. | |
1384 | ||
1385 | Say Y if unsure. | |
1386 | ||
906010b2 PZ |
1387 | config DEBUG_PERF_USE_VMALLOC |
1388 | default n | |
1389 | bool "Debug: use vmalloc to back perf mmap() buffers" | |
1390 | depends on PERF_EVENTS && DEBUG_KERNEL | |
1391 | select PERF_USE_VMALLOC | |
1392 | help | |
1393 | Use vmalloc memory to back perf mmap() buffers. | |
1394 | ||
1395 | Mostly useful for debugging the vmalloc code on platforms | |
1396 | that don't require it. | |
1397 | ||
1398 | Say N if unsure. | |
1399 | ||
0793a61d TG |
1400 | endmenu |
1401 | ||
f8891e5e CL |
1402 | config VM_EVENT_COUNTERS |
1403 | default y | |
6a108a14 | 1404 | bool "Enable VM event counters for /proc/vmstat" if EXPERT |
f8891e5e | 1405 | help |
2aea4fb6 PJ |
1406 | VM event counters are needed for event counts to be shown. |
1407 | This option allows the disabling of the VM event counters | |
6a108a14 | 1408 | on EXPERT systems. /proc/vmstat will only show page counts |
2aea4fb6 | 1409 | if VM event counters are disabled. |
f8891e5e | 1410 | |
3d137310 TP |
1411 | config PCI_QUIRKS |
1412 | default y | |
6a108a14 | 1413 | bool "Enable PCI quirk workarounds" if EXPERT |
61cfc7e4 | 1414 | depends on PCI |
3d137310 TP |
1415 | help |
1416 | This enables workarounds for various PCI chipset | |
1417 | bugs/quirks. Disable this only if your target machine is | |
1418 | unaffected by PCI quirks. | |
1419 | ||
41ecc55b CL |
1420 | config SLUB_DEBUG |
1421 | default y | |
6a108a14 | 1422 | bool "Enable SLUB debugging support" if EXPERT |
f6acb635 | 1423 | depends on SLUB && SYSFS |
41ecc55b CL |
1424 | help |
1425 | SLUB has extensive debug support features. Disabling these can | |
1426 | result in significant savings in code size. This also disables | |
1427 | SLUB sysfs support. /sys/slab will not exist and there will be | |
1428 | no support for cache validation etc. | |
1429 | ||
b943c460 RD |
1430 | config COMPAT_BRK |
1431 | bool "Disable heap randomization" | |
1432 | default y | |
1433 | help | |
1434 | Randomizing heap placement makes heap exploits harder, but it | |
1435 | also breaks ancient binaries (including anything libc5 based). | |
1436 | This option changes the bootup default to heap randomization | |
692105b8 | 1437 | disabled, and can be overridden at runtime by setting |
b943c460 RD |
1438 | /proc/sys/kernel/randomize_va_space to 2. |
1439 | ||
1440 | On non-ancient distros (post-2000 ones) N is usually a safe choice. | |
1441 | ||
81819f0f CL |
1442 | choice |
1443 | prompt "Choose SLAB allocator" | |
a0acd820 | 1444 | default SLUB |
81819f0f CL |
1445 | help |
1446 | This option allows to select a slab allocator. | |
1447 | ||
1448 | config SLAB | |
1449 | bool "SLAB" | |
1450 | help | |
1451 | The regular slab allocator that is established and known to work | |
34013886 | 1452 | well in all environments. It organizes cache hot objects in |
02f56210 | 1453 | per cpu and per node queues. |
81819f0f CL |
1454 | |
1455 | config SLUB | |
81819f0f CL |
1456 | bool "SLUB (Unqueued Allocator)" |
1457 | help | |
1458 | SLUB is a slab allocator that minimizes cache line usage | |
1459 | instead of managing queues of cached objects (SLAB approach). | |
1460 | Per cpu caching is realized using slabs of objects instead | |
1461 | of queues of objects. SLUB can use memory efficiently | |
02f56210 SA |
1462 | and has enhanced diagnostics. SLUB is the default choice for |
1463 | a slab allocator. | |
81819f0f CL |
1464 | |
1465 | config SLOB | |
6a108a14 | 1466 | depends on EXPERT |
81819f0f CL |
1467 | bool "SLOB (Simple Allocator)" |
1468 | help | |
37291458 MM |
1469 | SLOB replaces the stock allocator with a drastically simpler |
1470 | allocator. SLOB is generally more space efficient but | |
1471 | does not perform as well on large systems. | |
81819f0f CL |
1472 | |
1473 | endchoice | |
1474 | ||
ea637639 JZ |
1475 | config MMAP_ALLOW_UNINITIALIZED |
1476 | bool "Allow mmapped anonymous memory to be uninitialized" | |
6a108a14 | 1477 | depends on EXPERT && !MMU |
ea637639 JZ |
1478 | default n |
1479 | help | |
1480 | Normally, and according to the Linux spec, anonymous memory obtained | |
1481 | from mmap() has it's contents cleared before it is passed to | |
1482 | userspace. Enabling this config option allows you to request that | |
1483 | mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus | |
1484 | providing a huge performance boost. If this option is not enabled, | |
1485 | then the flag will be ignored. | |
1486 | ||
1487 | This is taken advantage of by uClibc's malloc(), and also by | |
1488 | ELF-FDPIC binfmt's brk and stack allocator. | |
1489 | ||
1490 | Because of the obvious security issues, this option should only be | |
1491 | enabled on embedded devices where you control what is run in | |
1492 | userspace. Since that isn't generally a problem on no-MMU systems, | |
1493 | it is normally safe to say Y here. | |
1494 | ||
1495 | See Documentation/nommu-mmap.txt for more information. | |
1496 | ||
125e5645 | 1497 | config PROFILING |
b309a294 | 1498 | bool "Profiling support" |
125e5645 MD |
1499 | help |
1500 | Say Y here to enable the extended profiling support mechanisms used | |
1501 | by profilers such as OProfile. | |
1502 | ||
5f87f112 IM |
1503 | # |
1504 | # Place an empty function call at each tracepoint site. Can be | |
1505 | # dynamically changed for a probe function. | |
1506 | # | |
97e1c18e | 1507 | config TRACEPOINTS |
5f87f112 | 1508 | bool |
97e1c18e | 1509 | |
fb32e03f MD |
1510 | source "arch/Kconfig" |
1511 | ||
1da177e4 LT |
1512 | endmenu # General setup |
1513 | ||
ee7e5516 DB |
1514 | config HAVE_GENERIC_DMA_COHERENT |
1515 | bool | |
1516 | default n | |
1517 | ||
158a9624 LT |
1518 | config SLABINFO |
1519 | bool | |
1520 | depends on PROC_FS | |
0f389ec6 | 1521 | depends on SLAB || SLUB_DEBUG |
158a9624 LT |
1522 | default y |
1523 | ||
ae81f9e3 CE |
1524 | config RT_MUTEXES |
1525 | boolean | |
ae81f9e3 | 1526 | |
1da177e4 LT |
1527 | config BASE_SMALL |
1528 | int | |
1529 | default 0 if BASE_FULL | |
1530 | default 1 if !BASE_FULL | |
1531 | ||
66da5733 | 1532 | menuconfig MODULES |
1da177e4 LT |
1533 | bool "Enable loadable module support" |
1534 | help | |
1535 | Kernel modules are small pieces of compiled code which can | |
1536 | be inserted in the running kernel, rather than being | |
1537 | permanently built into the kernel. You use the "modprobe" | |
1538 | tool to add (and sometimes remove) them. If you say Y here, | |
1539 | many parts of the kernel can be built as modules (by | |
1540 | answering M instead of Y where indicated): this is most | |
1541 | useful for infrequently used options which are not required | |
1542 | for booting. For more information, see the man pages for | |
1543 | modprobe, lsmod, modinfo, insmod and rmmod. | |
1544 | ||
1545 | If you say Y here, you will need to run "make | |
1546 | modules_install" to put the modules under /lib/modules/ | |
1547 | where modprobe can find them (you may need to be root to do | |
1548 | this). | |
1549 | ||
1550 | If unsure, say Y. | |
1551 | ||
0b0de144 RD |
1552 | if MODULES |
1553 | ||
826e4506 LT |
1554 | config MODULE_FORCE_LOAD |
1555 | bool "Forced module loading" | |
826e4506 LT |
1556 | default n |
1557 | help | |
91e37a79 RR |
1558 | Allow loading of modules without version information (ie. modprobe |
1559 | --force). Forced module loading sets the 'F' (forced) taint flag and | |
1560 | is usually a really bad idea. | |
826e4506 | 1561 | |
1da177e4 LT |
1562 | config MODULE_UNLOAD |
1563 | bool "Module unloading" | |
1da177e4 LT |
1564 | help |
1565 | Without this option you will not be able to unload any | |
1566 | modules (note that some modules may not be unloadable | |
f7f5b675 DV |
1567 | anyway), which makes your kernel smaller, faster |
1568 | and simpler. If unsure, say Y. | |
1da177e4 LT |
1569 | |
1570 | config MODULE_FORCE_UNLOAD | |
1571 | bool "Forced module unloading" | |
1572 | depends on MODULE_UNLOAD && EXPERIMENTAL | |
1573 | help | |
1574 | This option allows you to force a module to unload, even if the | |
1575 | kernel believes it is unsafe: the kernel will remove the module | |
1576 | without waiting for anyone to stop using it (using the -f option to | |
1577 | rmmod). This is mainly for kernel developers and desperate users. | |
1578 | If unsure, say N. | |
1579 | ||
1da177e4 | 1580 | config MODVERSIONS |
0d541643 | 1581 | bool "Module versioning support" |
1da177e4 LT |
1582 | help |
1583 | Usually, you have to use modules compiled with your kernel. | |
1584 | Saying Y here makes it sometimes possible to use modules | |
1585 | compiled for different kernels, by adding enough information | |
1586 | to the modules to (hopefully) spot any changes which would | |
1587 | make them incompatible with the kernel you are running. If | |
1588 | unsure, say N. | |
1589 | ||
1590 | config MODULE_SRCVERSION_ALL | |
1591 | bool "Source checksum for all modules" | |
1da177e4 LT |
1592 | help |
1593 | Modules which contain a MODULE_VERSION get an extra "srcversion" | |
1594 | field inserted into their modinfo section, which contains a | |
1595 | sum of the source files which made it. This helps maintainers | |
1596 | see exactly which source was used to build a module (since | |
1597 | others sometimes change the module source without updating | |
1598 | the version). With this option, such a "srcversion" field | |
1599 | will be created for all modules. If unsure, say N. | |
1600 | ||
0b0de144 RD |
1601 | endif # MODULES |
1602 | ||
98a79d6a RR |
1603 | config INIT_ALL_POSSIBLE |
1604 | bool | |
1605 | help | |
5f054e31 RR |
1606 | Back when each arch used to define their own cpu_online_mask and |
1607 | cpu_possible_mask, some of them chose to initialize cpu_possible_mask | |
98a79d6a RR |
1608 | with all 1s, and others with all 0s. When they were centralised, |
1609 | it was better to provide this option than to break all the archs | |
692105b8 | 1610 | and have several arch maintainers pursuing me down dark alleys. |
98a79d6a | 1611 | |
1da177e4 LT |
1612 | config STOP_MACHINE |
1613 | bool | |
1614 | default y | |
1615 | depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU | |
1616 | help | |
1617 | Need stop_machine() primitive. | |
3a65dfe8 | 1618 | |
3a65dfe8 | 1619 | source "block/Kconfig" |
e98c3202 AK |
1620 | |
1621 | config PREEMPT_NOTIFIERS | |
1622 | bool | |
e260be67 | 1623 | |
16295bec SK |
1624 | config PADATA |
1625 | depends on SMP | |
1626 | bool | |
1627 | ||
6beb0009 | 1628 | source "kernel/Kconfig.locks" |