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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56 | drivers that have been replaced by something else, and/or are | |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 | ||
1da177e4 LT |
270 | config BSD_PROCESS_ACCT |
271 | bool "BSD Process Accounting" | |
272 | help | |
273 | If you say Y here, a user level program will be able to instruct the | |
274 | kernel (via a special system call) to write process accounting | |
275 | information to a file: whenever a process exits, information about | |
276 | that process will be appended to the file by the kernel. The | |
277 | information includes things such as creation time, owning user, | |
278 | command name, memory usage, controlling terminal etc. (the complete | |
279 | list is in the struct acct in <file:include/linux/acct.h>). It is | |
280 | up to the user level program to do useful things with this | |
281 | information. This is generally a good idea, so say Y. | |
282 | ||
283 | config BSD_PROCESS_ACCT_V3 | |
284 | bool "BSD Process Accounting version 3 file format" | |
285 | depends on BSD_PROCESS_ACCT | |
286 | default n | |
287 | help | |
288 | If you say Y here, the process accounting information is written | |
289 | in a new file format that also logs the process IDs of each | |
290 | process and it's parent. Note that this file format is incompatible | |
291 | with previous v0/v1/v2 file formats, so you will need updated tools | |
292 | for processing it. A preliminary version of these tools is available | |
37a4c940 | 293 | at <http://www.gnu.org/software/acct/>. |
1da177e4 | 294 | |
990d6c2d AK |
295 | config FHANDLE |
296 | bool "open by fhandle syscalls" | |
297 | select EXPORTFS | |
298 | help | |
299 | If you say Y here, a user level program will be able to map | |
300 | file names to handle and then later use the handle for | |
301 | different file system operations. This is useful in implementing | |
302 | userspace file servers, which now track files using handles instead | |
303 | of names. The handle would remain the same even if file names | |
304 | get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2) | |
305 | syscalls. | |
306 | ||
c757249a SN |
307 | config TASKSTATS |
308 | bool "Export task/process statistics through netlink (EXPERIMENTAL)" | |
309 | depends on NET | |
310 | default n | |
311 | help | |
312 | Export selected statistics for tasks/processes through the | |
313 | generic netlink interface. Unlike BSD process accounting, the | |
314 | statistics are available during the lifetime of tasks/processes as | |
315 | responses to commands. Like BSD accounting, they are sent to user | |
316 | space on task exit. | |
317 | ||
318 | Say N if unsure. | |
319 | ||
ca74e92b SN |
320 | config TASK_DELAY_ACCT |
321 | bool "Enable per-task delay accounting (EXPERIMENTAL)" | |
6f44993f | 322 | depends on TASKSTATS |
ca74e92b SN |
323 | help |
324 | Collect information on time spent by a task waiting for system | |
325 | resources like cpu, synchronous block I/O completion and swapping | |
326 | in pages. Such statistics can help in setting a task's priorities | |
327 | relative to other tasks for cpu, io, rss limits etc. | |
328 | ||
329 | Say N if unsure. | |
330 | ||
18f705f4 AD |
331 | config TASK_XACCT |
332 | bool "Enable extended accounting over taskstats (EXPERIMENTAL)" | |
333 | depends on TASKSTATS | |
334 | help | |
335 | Collect extended task accounting data and send the data | |
336 | to userland for processing over the taskstats interface. | |
337 | ||
338 | Say N if unsure. | |
339 | ||
340 | config TASK_IO_ACCOUNTING | |
341 | bool "Enable per-task storage I/O accounting (EXPERIMENTAL)" | |
342 | depends on TASK_XACCT | |
343 | help | |
344 | Collect information on the number of bytes of storage I/O which this | |
345 | task has caused. | |
346 | ||
347 | Say N if unsure. | |
348 | ||
1da177e4 LT |
349 | config AUDIT |
350 | bool "Auditing support" | |
804a6a49 | 351 | depends on NET |
1da177e4 LT |
352 | help |
353 | Enable auditing infrastructure that can be used with another | |
354 | kernel subsystem, such as SELinux (which requires this for | |
355 | logging of avc messages output). Does not do system-call | |
356 | auditing without CONFIG_AUDITSYSCALL. | |
357 | ||
358 | config AUDITSYSCALL | |
359 | bool "Enable system-call auditing support" | |
29ef73b7 | 360 | depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH || ARM) |
1da177e4 LT |
361 | default y if SECURITY_SELINUX |
362 | help | |
363 | Enable low-overhead system-call auditing infrastructure that | |
364 | can be used independently or with another kernel subsystem, | |
67640b60 | 365 | such as SELinux. |
1da177e4 | 366 | |
939a67fc EP |
367 | config AUDIT_WATCH |
368 | def_bool y | |
369 | depends on AUDITSYSCALL | |
370 | select FSNOTIFY | |
1da177e4 | 371 | |
74c3cbe3 AV |
372 | config AUDIT_TREE |
373 | def_bool y | |
63c882a0 | 374 | depends on AUDITSYSCALL |
28a3a7eb | 375 | select FSNOTIFY |
74c3cbe3 | 376 | |
633b4545 EP |
377 | config AUDIT_LOGINUID_IMMUTABLE |
378 | bool "Make audit loginuid immutable" | |
379 | depends on AUDIT | |
380 | help | |
f429ee3b | 381 | The config option toggles if a task setting its loginuid requires |
633b4545 EP |
382 | CAP_SYS_AUDITCONTROL or if that task should require no special permissions |
383 | but should instead only allow setting its loginuid if it was never | |
384 | previously set. On systems which use systemd or a similar central | |
385 | process to restart login services this should be set to true. On older | |
386 | systems in which an admin would typically have to directly stop and | |
387 | start processes this should be set to false. Setting this to true allows | |
388 | one to drop potentially dangerous capabilites from the login tasks, | |
389 | but may not be backwards compatible with older init systems. | |
390 | ||
d9817ebe | 391 | source "kernel/irq/Kconfig" |
764e0da1 | 392 | source "kernel/time/Kconfig" |
d9817ebe | 393 | |
c903ff83 MT |
394 | menu "RCU Subsystem" |
395 | ||
396 | choice | |
397 | prompt "RCU Implementation" | |
31c9a24e | 398 | default TREE_RCU |
c903ff83 | 399 | |
c903ff83 MT |
400 | config TREE_RCU |
401 | bool "Tree-based hierarchical RCU" | |
687d7a96 | 402 | depends on !PREEMPT && SMP |
c903ff83 MT |
403 | help |
404 | This option selects the RCU implementation that is | |
405 | designed for very large SMP system with hundreds or | |
c17ef453 PM |
406 | thousands of CPUs. It also scales down nicely to |
407 | smaller systems. | |
c903ff83 | 408 | |
f41d911f | 409 | config TREE_PREEMPT_RCU |
a57eb940 | 410 | bool "Preemptible tree-based hierarchical RCU" |
8008e129 | 411 | depends on PREEMPT && SMP |
f41d911f PM |
412 | help |
413 | This option selects the RCU implementation that is | |
414 | designed for very large SMP systems with hundreds or | |
415 | thousands of CPUs, but for which real-time response | |
bbe3eae8 PM |
416 | is also required. It also scales down nicely to |
417 | smaller systems. | |
f41d911f | 418 | |
9b1d82fa PM |
419 | config TINY_RCU |
420 | bool "UP-only small-memory-footprint RCU" | |
8008e129 | 421 | depends on !PREEMPT && !SMP |
9b1d82fa PM |
422 | help |
423 | This option selects the RCU implementation that is | |
424 | designed for UP systems from which real-time response | |
425 | is not required. This option greatly reduces the | |
426 | memory footprint of RCU. | |
427 | ||
a57eb940 PM |
428 | config TINY_PREEMPT_RCU |
429 | bool "Preemptible UP-only small-memory-footprint RCU" | |
8008e129 | 430 | depends on PREEMPT && !SMP |
a57eb940 PM |
431 | help |
432 | This option selects the RCU implementation that is designed | |
433 | for real-time UP systems. This option greatly reduces the | |
434 | memory footprint of RCU. | |
435 | ||
c903ff83 MT |
436 | endchoice |
437 | ||
a57eb940 PM |
438 | config PREEMPT_RCU |
439 | def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU ) | |
440 | help | |
441 | This option enables preemptible-RCU code that is common between | |
442 | the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations. | |
443 | ||
c903ff83 MT |
444 | config RCU_FANOUT |
445 | int "Tree-based hierarchical RCU fanout value" | |
446 | range 2 64 if 64BIT | |
447 | range 2 32 if !64BIT | |
f41d911f | 448 | depends on TREE_RCU || TREE_PREEMPT_RCU |
c903ff83 MT |
449 | default 64 if 64BIT |
450 | default 32 if !64BIT | |
451 | help | |
452 | This option controls the fanout of hierarchical implementations | |
453 | of RCU, allowing RCU to work efficiently on machines with | |
4d87ffad PM |
454 | large numbers of CPUs. This value must be at least the fourth |
455 | root of NR_CPUS, which allows NR_CPUS to be insanely large. | |
456 | The default value of RCU_FANOUT should be used for production | |
457 | systems, but if you are stress-testing the RCU implementation | |
458 | itself, small RCU_FANOUT values allow you to test large-system | |
459 | code paths on small(er) systems. | |
c903ff83 MT |
460 | |
461 | Select a specific number if testing RCU itself. | |
462 | Take the default if unsure. | |
463 | ||
8932a63d PM |
464 | config RCU_FANOUT_LEAF |
465 | int "Tree-based hierarchical RCU leaf-level fanout value" | |
466 | range 2 RCU_FANOUT if 64BIT | |
467 | range 2 RCU_FANOUT if !64BIT | |
468 | depends on TREE_RCU || TREE_PREEMPT_RCU | |
469 | default 16 | |
470 | help | |
471 | This option controls the leaf-level fanout of hierarchical | |
472 | implementations of RCU, and allows trading off cache misses | |
473 | against lock contention. Systems that synchronize their | |
474 | scheduling-clock interrupts for energy-efficiency reasons will | |
475 | want the default because the smaller leaf-level fanout keeps | |
476 | lock contention levels acceptably low. Very large systems | |
477 | (hundreds or thousands of CPUs) will instead want to set this | |
478 | value to the maximum value possible in order to reduce the | |
479 | number of cache misses incurred during RCU's grace-period | |
480 | initialization. These systems tend to run CPU-bound, and thus | |
481 | are not helped by synchronized interrupts, and thus tend to | |
482 | skew them, which reduces lock contention enough that large | |
483 | leaf-level fanouts work well. | |
484 | ||
485 | Select a specific number if testing RCU itself. | |
486 | ||
487 | Select the maximum permissible value for large systems. | |
488 | ||
489 | Take the default if unsure. | |
490 | ||
c903ff83 MT |
491 | config RCU_FANOUT_EXACT |
492 | bool "Disable tree-based hierarchical RCU auto-balancing" | |
f41d911f | 493 | depends on TREE_RCU || TREE_PREEMPT_RCU |
c903ff83 MT |
494 | default n |
495 | help | |
496 | This option forces use of the exact RCU_FANOUT value specified, | |
497 | regardless of imbalances in the hierarchy. This is useful for | |
498 | testing RCU itself, and might one day be useful on systems with | |
499 | strong NUMA behavior. | |
500 | ||
501 | Without RCU_FANOUT_EXACT, the code will balance the hierarchy. | |
502 | ||
503 | Say N if unsure. | |
504 | ||
8bd93a2c PM |
505 | config RCU_FAST_NO_HZ |
506 | bool "Accelerate last non-dyntick-idle CPU's grace periods" | |
b807fbff | 507 | depends on NO_HZ && SMP |
8bd93a2c PM |
508 | default n |
509 | help | |
510 | This option causes RCU to attempt to accelerate grace periods | |
b807fbff PM |
511 | in order to allow CPUs to enter dynticks-idle state more |
512 | quickly. On the other hand, this option increases the overhead | |
513 | of the dynticks-idle checking, particularly on systems with | |
514 | large numbers of CPUs. | |
8bd93a2c PM |
515 | |
516 | Say Y if energy efficiency is critically important, particularly | |
517 | if you have relatively few CPUs. | |
518 | ||
519 | Say N if you are unsure. | |
520 | ||
c903ff83 | 521 | config TREE_RCU_TRACE |
f41d911f | 522 | def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU ) |
c903ff83 MT |
523 | select DEBUG_FS |
524 | help | |
f41d911f PM |
525 | This option provides tracing for the TREE_RCU and |
526 | TREE_PREEMPT_RCU implementations, permitting Makefile to | |
527 | trivially select kernel/rcutree_trace.c. | |
c903ff83 | 528 | |
24278d14 PM |
529 | config RCU_BOOST |
530 | bool "Enable RCU priority boosting" | |
27f4d280 | 531 | depends on RT_MUTEXES && PREEMPT_RCU |
24278d14 PM |
532 | default n |
533 | help | |
534 | This option boosts the priority of preempted RCU readers that | |
535 | block the current preemptible RCU grace period for too long. | |
536 | This option also prevents heavy loads from blocking RCU | |
537 | callback invocation for all flavors of RCU. | |
538 | ||
539 | Say Y here if you are working with real-time apps or heavy loads | |
540 | Say N here if you are unsure. | |
541 | ||
542 | config RCU_BOOST_PRIO | |
543 | int "Real-time priority to boost RCU readers to" | |
544 | range 1 99 | |
545 | depends on RCU_BOOST | |
546 | default 1 | |
547 | help | |
c9336643 PM |
548 | This option specifies the real-time priority to which long-term |
549 | preempted RCU readers are to be boosted. If you are working | |
550 | with a real-time application that has one or more CPU-bound | |
551 | threads running at a real-time priority level, you should set | |
552 | RCU_BOOST_PRIO to a priority higher then the highest-priority | |
553 | real-time CPU-bound thread. The default RCU_BOOST_PRIO value | |
554 | of 1 is appropriate in the common case, which is real-time | |
555 | applications that do not have any CPU-bound threads. | |
556 | ||
557 | Some real-time applications might not have a single real-time | |
558 | thread that saturates a given CPU, but instead might have | |
559 | multiple real-time threads that, taken together, fully utilize | |
560 | that CPU. In this case, you should set RCU_BOOST_PRIO to | |
561 | a priority higher than the lowest-priority thread that is | |
562 | conspiring to prevent the CPU from running any non-real-time | |
563 | tasks. For example, if one thread at priority 10 and another | |
564 | thread at priority 5 are between themselves fully consuming | |
565 | the CPU time on a given CPU, then RCU_BOOST_PRIO should be | |
566 | set to priority 6 or higher. | |
24278d14 PM |
567 | |
568 | Specify the real-time priority, or take the default if unsure. | |
569 | ||
570 | config RCU_BOOST_DELAY | |
571 | int "Milliseconds to delay boosting after RCU grace-period start" | |
572 | range 0 3000 | |
573 | depends on RCU_BOOST | |
574 | default 500 | |
575 | help | |
576 | This option specifies the time to wait after the beginning of | |
577 | a given grace period before priority-boosting preempted RCU | |
578 | readers blocking that grace period. Note that any RCU reader | |
579 | blocking an expedited RCU grace period is boosted immediately. | |
580 | ||
581 | Accept the default if unsure. | |
582 | ||
c903ff83 MT |
583 | endmenu # "RCU Subsystem" |
584 | ||
1da177e4 | 585 | config IKCONFIG |
f2443ab6 | 586 | tristate "Kernel .config support" |
1da177e4 LT |
587 | ---help--- |
588 | This option enables the complete Linux kernel ".config" file | |
589 | contents to be saved in the kernel. It provides documentation | |
590 | of which kernel options are used in a running kernel or in an | |
591 | on-disk kernel. This information can be extracted from the kernel | |
592 | image file with the script scripts/extract-ikconfig and used as | |
593 | input to rebuild the current kernel or to build another kernel. | |
594 | It can also be extracted from a running kernel by reading | |
595 | /proc/config.gz if enabled (below). | |
596 | ||
597 | config IKCONFIG_PROC | |
598 | bool "Enable access to .config through /proc/config.gz" | |
599 | depends on IKCONFIG && PROC_FS | |
600 | ---help--- | |
601 | This option enables access to the kernel configuration file | |
602 | through /proc/config.gz. | |
603 | ||
794543a2 AJS |
604 | config LOG_BUF_SHIFT |
605 | int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" | |
606 | range 12 21 | |
f17a32e9 | 607 | default 17 |
794543a2 AJS |
608 | help |
609 | Select kernel log buffer size as a power of 2. | |
f17a32e9 AB |
610 | Examples: |
611 | 17 => 128 KB | |
612 | 16 => 64 KB | |
613 | 15 => 32 KB | |
614 | 14 => 16 KB | |
794543a2 AJS |
615 | 13 => 8 KB |
616 | 12 => 4 KB | |
617 | ||
a5574cf6 IM |
618 | # |
619 | # Architectures with an unreliable sched_clock() should select this: | |
620 | # | |
621 | config HAVE_UNSTABLE_SCHED_CLOCK | |
622 | bool | |
623 | ||
23964d2d LZ |
624 | menuconfig CGROUPS |
625 | boolean "Control Group support" | |
0dea1168 | 626 | depends on EVENTFD |
5cdc38f9 | 627 | help |
23964d2d | 628 | This option adds support for grouping sets of processes together, for |
5cdc38f9 KH |
629 | use with process control subsystems such as Cpusets, CFS, memory |
630 | controls or device isolation. | |
631 | See | |
5cdc38f9 | 632 | - Documentation/scheduler/sched-design-CFS.txt (CFS) |
45ce80fb LZ |
633 | - Documentation/cgroups/ (features for grouping, isolation |
634 | and resource control) | |
5cdc38f9 KH |
635 | |
636 | Say N if unsure. | |
637 | ||
23964d2d LZ |
638 | if CGROUPS |
639 | ||
5cdc38f9 KH |
640 | config CGROUP_DEBUG |
641 | bool "Example debug cgroup subsystem" | |
5cdc38f9 KH |
642 | default n |
643 | help | |
644 | This option enables a simple cgroup subsystem that | |
645 | exports useful debugging information about the cgroups | |
23964d2d | 646 | framework. |
5cdc38f9 | 647 | |
23964d2d | 648 | Say N if unsure. |
5cdc38f9 | 649 | |
5cdc38f9 | 650 | config CGROUP_FREEZER |
23964d2d | 651 | bool "Freezer cgroup subsystem" |
23964d2d LZ |
652 | help |
653 | Provides a way to freeze and unfreeze all tasks in a | |
5cdc38f9 KH |
654 | cgroup. |
655 | ||
656 | config CGROUP_DEVICE | |
657 | bool "Device controller for cgroups" | |
5cdc38f9 KH |
658 | help |
659 | Provides a cgroup implementing whitelists for devices which | |
660 | a process in the cgroup can mknod or open. | |
661 | ||
662 | config CPUSETS | |
663 | bool "Cpuset support" | |
5cdc38f9 KH |
664 | help |
665 | This option will let you create and manage CPUSETs which | |
666 | allow dynamically partitioning a system into sets of CPUs and | |
667 | Memory Nodes and assigning tasks to run only within those sets. | |
668 | This is primarily useful on large SMP or NUMA systems. | |
669 | ||
670 | Say N if unsure. | |
671 | ||
23964d2d LZ |
672 | config PROC_PID_CPUSET |
673 | bool "Include legacy /proc/<pid>/cpuset file" | |
674 | depends on CPUSETS | |
675 | default y | |
676 | ||
d842de87 SV |
677 | config CGROUP_CPUACCT |
678 | bool "Simple CPU accounting cgroup subsystem" | |
d842de87 SV |
679 | help |
680 | Provides a simple Resource Controller for monitoring the | |
23964d2d | 681 | total CPU consumed by the tasks in a cgroup. |
d842de87 | 682 | |
e552b661 PE |
683 | config RESOURCE_COUNTERS |
684 | bool "Resource counters" | |
685 | help | |
686 | This option enables controller independent resource accounting | |
23964d2d | 687 | infrastructure that works with cgroups. |
e552b661 | 688 | |
00f0b825 BS |
689 | config CGROUP_MEM_RES_CTLR |
690 | bool "Memory Resource Controller for Control Groups" | |
79ae9c29 | 691 | depends on RESOURCE_COUNTERS |
cf475ad2 | 692 | select MM_OWNER |
00f0b825 | 693 | help |
84ad6d70 | 694 | Provides a memory resource controller that manages both anonymous |
21acb9ca | 695 | memory and page cache. (See Documentation/cgroups/memory.txt) |
00f0b825 BS |
696 | |
697 | Note that setting this option increases fixed memory overhead | |
84ad6d70 KH |
698 | associated with each page of memory in the system. By this, |
699 | 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory | |
700 | usage tracking struct at boot. Total amount of this is printed out | |
701 | at boot. | |
00f0b825 BS |
702 | |
703 | Only enable when you're ok with these trade offs and really | |
84ad6d70 KH |
704 | sure you need the memory resource controller. Even when you enable |
705 | this, you can set "cgroup_disable=memory" at your boot option to | |
706 | disable memory resource controller and you can avoid overheads. | |
c9d5409f | 707 | (and lose benefits of memory resource controller) |
00f0b825 | 708 | |
cf475ad2 BS |
709 | This config option also selects MM_OWNER config option, which |
710 | could in turn add some fork/exit overhead. | |
711 | ||
c077719b | 712 | config CGROUP_MEM_RES_CTLR_SWAP |
65e0e811 KH |
713 | bool "Memory Resource Controller Swap Extension" |
714 | depends on CGROUP_MEM_RES_CTLR && SWAP | |
c077719b KH |
715 | help |
716 | Add swap management feature to memory resource controller. When you | |
717 | enable this, you can limit mem+swap usage per cgroup. In other words, | |
718 | when you disable this, memory resource controller has no cares to | |
719 | usage of swap...a process can exhaust all of the swap. This extension | |
720 | is useful when you want to avoid exhaustion swap but this itself | |
721 | adds more overheads and consumes memory for remembering information. | |
722 | Especially if you use 32bit system or small memory system, please | |
723 | be careful about enabling this. When memory resource controller | |
724 | is disabled by boot option, this will be automatically disabled and | |
725 | there will be no overhead from this. Even when you set this config=y, | |
00a66d29 | 726 | if boot option "swapaccount=0" is set, swap will not be accounted. |
627991a2 KH |
727 | Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page |
728 | size is 4096bytes, 512k per 1Gbytes of swap. | |
a42c390c MH |
729 | config CGROUP_MEM_RES_CTLR_SWAP_ENABLED |
730 | bool "Memory Resource Controller Swap Extension enabled by default" | |
731 | depends on CGROUP_MEM_RES_CTLR_SWAP | |
732 | default y | |
733 | help | |
734 | Memory Resource Controller Swap Extension comes with its price in | |
735 | a bigger memory consumption. General purpose distribution kernels | |
43d547f9 | 736 | which want to enable the feature but keep it disabled by default |
a42c390c MH |
737 | and let the user enable it by swapaccount boot command line |
738 | parameter should have this option unselected. | |
739 | For those who want to have the feature enabled by default should | |
740 | select this option (if, for some reason, they need to disable it | |
00a66d29 | 741 | then swapaccount=0 does the trick). |
e5671dfa GC |
742 | config CGROUP_MEM_RES_CTLR_KMEM |
743 | bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)" | |
744 | depends on CGROUP_MEM_RES_CTLR && EXPERIMENTAL | |
745 | default n | |
746 | help | |
747 | The Kernel Memory extension for Memory Resource Controller can limit | |
748 | the amount of memory used by kernel objects in the system. Those are | |
749 | fundamentally different from the entities handled by the standard | |
750 | Memory Controller, which are page-based, and can be swapped. Users of | |
751 | the kmem extension can use it to guarantee that no group of processes | |
752 | will ever exhaust kernel resources alone. | |
c077719b | 753 | |
e5d1367f SE |
754 | config CGROUP_PERF |
755 | bool "Enable perf_event per-cpu per-container group (cgroup) monitoring" | |
756 | depends on PERF_EVENTS && CGROUPS | |
757 | help | |
758 | This option extends the per-cpu mode to restrict monitoring to | |
2d0f2520 | 759 | threads which belong to the cgroup specified and run on the |
e5d1367f SE |
760 | designated cpu. |
761 | ||
762 | Say N if unsure. | |
763 | ||
7c941438 DG |
764 | menuconfig CGROUP_SCHED |
765 | bool "Group CPU scheduler" | |
7c941438 DG |
766 | default n |
767 | help | |
768 | This feature lets CPU scheduler recognize task groups and control CPU | |
769 | bandwidth allocation to such task groups. It uses cgroups to group | |
770 | tasks. | |
771 | ||
772 | if CGROUP_SCHED | |
773 | config FAIR_GROUP_SCHED | |
774 | bool "Group scheduling for SCHED_OTHER" | |
775 | depends on CGROUP_SCHED | |
776 | default CGROUP_SCHED | |
777 | ||
ab84d31e PT |
778 | config CFS_BANDWIDTH |
779 | bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED" | |
780 | depends on EXPERIMENTAL | |
781 | depends on FAIR_GROUP_SCHED | |
782 | default n | |
783 | help | |
784 | This option allows users to define CPU bandwidth rates (limits) for | |
785 | tasks running within the fair group scheduler. Groups with no limit | |
786 | set are considered to be unconstrained and will run with no | |
787 | restriction. | |
788 | See tip/Documentation/scheduler/sched-bwc.txt for more information. | |
789 | ||
7c941438 DG |
790 | config RT_GROUP_SCHED |
791 | bool "Group scheduling for SCHED_RR/FIFO" | |
792 | depends on EXPERIMENTAL | |
793 | depends on CGROUP_SCHED | |
794 | default n | |
795 | help | |
796 | This feature lets you explicitly allocate real CPU bandwidth | |
32bd7eb5 | 797 | to task groups. If enabled, it will also make it impossible to |
7c941438 DG |
798 | schedule realtime tasks for non-root users until you allocate |
799 | realtime bandwidth for them. | |
800 | See Documentation/scheduler/sched-rt-group.txt for more information. | |
801 | ||
802 | endif #CGROUP_SCHED | |
803 | ||
afc24d49 | 804 | config BLK_CGROUP |
32e380ae | 805 | bool "Block IO controller" |
79ae9c29 | 806 | depends on BLOCK |
afc24d49 VG |
807 | default n |
808 | ---help--- | |
809 | Generic block IO controller cgroup interface. This is the common | |
810 | cgroup interface which should be used by various IO controlling | |
811 | policies. | |
812 | ||
813 | Currently, CFQ IO scheduler uses it to recognize task groups and | |
814 | control disk bandwidth allocation (proportional time slice allocation) | |
e43473b7 VG |
815 | to such task groups. It is also used by bio throttling logic in |
816 | block layer to implement upper limit in IO rates on a device. | |
afc24d49 VG |
817 | |
818 | This option only enables generic Block IO controller infrastructure. | |
e43473b7 | 819 | One needs to also enable actual IO controlling logic/policy. For |
79e2e759 MW |
820 | enabling proportional weight division of disk bandwidth in CFQ, set |
821 | CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set | |
c5e0591a | 822 | CONFIG_BLK_DEV_THROTTLING=y. |
afc24d49 VG |
823 | |
824 | See Documentation/cgroups/blkio-controller.txt for more information. | |
825 | ||
826 | config DEBUG_BLK_CGROUP | |
827 | bool "Enable Block IO controller debugging" | |
828 | depends on BLK_CGROUP | |
829 | default n | |
830 | ---help--- | |
831 | Enable some debugging help. Currently it exports additional stat | |
832 | files in a cgroup which can be useful for debugging. | |
833 | ||
23964d2d | 834 | endif # CGROUPS |
c077719b | 835 | |
067bce1a CG |
836 | config CHECKPOINT_RESTORE |
837 | bool "Checkpoint/restore support" if EXPERT | |
838 | default n | |
839 | help | |
840 | Enables additional kernel features in a sake of checkpoint/restore. | |
841 | In particular it adds auxiliary prctl codes to setup process text, | |
842 | data and heap segment sizes, and a few additional /proc filesystem | |
843 | entries. | |
844 | ||
845 | If unsure, say N here. | |
846 | ||
8dd2a82c | 847 | menuconfig NAMESPACES |
6a108a14 DR |
848 | bool "Namespaces support" if EXPERT |
849 | default !EXPERT | |
c5289a69 PE |
850 | help |
851 | Provides the way to make tasks work with different objects using | |
852 | the same id. For example same IPC id may refer to different objects | |
853 | or same user id or pid may refer to different tasks when used in | |
854 | different namespaces. | |
855 | ||
8dd2a82c DL |
856 | if NAMESPACES |
857 | ||
58bfdd6d PE |
858 | config UTS_NS |
859 | bool "UTS namespace" | |
17a6d441 | 860 | default y |
58bfdd6d PE |
861 | help |
862 | In this namespace tasks see different info provided with the | |
863 | uname() system call | |
864 | ||
ae5e1b22 PE |
865 | config IPC_NS |
866 | bool "IPC namespace" | |
8dd2a82c | 867 | depends on (SYSVIPC || POSIX_MQUEUE) |
17a6d441 | 868 | default y |
ae5e1b22 PE |
869 | help |
870 | In this namespace tasks work with IPC ids which correspond to | |
614b84cf | 871 | different IPC objects in different namespaces. |
ae5e1b22 | 872 | |
aee16ce7 PE |
873 | config USER_NS |
874 | bool "User namespace (EXPERIMENTAL)" | |
8dd2a82c | 875 | depends on EXPERIMENTAL |
e1c972b6 | 876 | depends on UIDGID_CONVERTED |
5673a94c | 877 | select UIDGID_STRICT_TYPE_CHECKS |
e1c972b6 | 878 | |
5673a94c | 879 | default n |
aee16ce7 PE |
880 | help |
881 | This allows containers, i.e. vservers, to use user namespaces | |
882 | to provide different user info for different servers. | |
883 | If unsure, say N. | |
884 | ||
74bd59bb | 885 | config PID_NS |
9bd38c2c | 886 | bool "PID Namespaces" |
17a6d441 | 887 | default y |
74bd59bb | 888 | help |
12d2b8f9 | 889 | Support process id namespaces. This allows having multiple |
692105b8 | 890 | processes with the same pid as long as they are in different |
74bd59bb PE |
891 | pid namespaces. This is a building block of containers. |
892 | ||
d6eb633f MH |
893 | config NET_NS |
894 | bool "Network namespace" | |
8dd2a82c | 895 | depends on NET |
17a6d441 | 896 | default y |
d6eb633f MH |
897 | help |
898 | Allow user space to create what appear to be multiple instances | |
899 | of the network stack. | |
900 | ||
8dd2a82c DL |
901 | endif # NAMESPACES |
902 | ||
e1c972b6 EB |
903 | config UIDGID_CONVERTED |
904 | # True if all of the selected software conmponents are known | |
905 | # to have uid_t and gid_t converted to kuid_t and kgid_t | |
906 | # where appropriate and are otherwise safe to use with | |
907 | # the user namespace. | |
908 | bool | |
909 | default y | |
910 | ||
911 | # List of kernel pieces that need user namespace work | |
912 | # Features | |
e1c972b6 EB |
913 | depends on SYSVIPC = n |
914 | depends on IMA = n | |
915 | depends on EVM = n | |
916 | depends on KEYS = n | |
917 | depends on AUDIT = n | |
918 | depends on AUDITSYSCALL = n | |
919 | depends on TASKSTATS = n | |
920 | depends on TRACING = n | |
921 | depends on FS_POSIX_ACL = n | |
922 | depends on QUOTA = n | |
923 | depends on QUOTACTL = n | |
924 | depends on DEBUG_CREDENTIALS = n | |
925 | depends on BSD_PROCESS_ACCT = n | |
926 | depends on DRM = n | |
927 | depends on PROC_EVENTS = n | |
928 | ||
929 | # Networking | |
930 | depends on NET = n | |
931 | depends on NET_9P = n | |
932 | depends on IPX = n | |
933 | depends on PHONET = n | |
934 | depends on NET_CLS_FLOW = n | |
935 | depends on NETFILTER_XT_MATCH_OWNER = n | |
936 | depends on NETFILTER_XT_MATCH_RECENT = n | |
937 | depends on NETFILTER_XT_TARGET_LOG = n | |
938 | depends on NETFILTER_NETLINK_LOG = n | |
939 | depends on INET = n | |
940 | depends on IPV6 = n | |
941 | depends on IP_SCTP = n | |
942 | depends on AF_RXRPC = n | |
943 | depends on LLC2 = n | |
944 | depends on NET_KEY = n | |
945 | depends on INET_DIAG = n | |
946 | depends on DNS_RESOLVER = n | |
947 | depends on AX25 = n | |
948 | depends on ATALK = n | |
949 | ||
950 | # Filesystems | |
951 | depends on USB_DEVICEFS = n | |
952 | depends on USB_GADGETFS = n | |
953 | depends on USB_FUNCTIONFS = n | |
954 | depends on DEVTMPFS = n | |
955 | depends on XENFS = n | |
956 | ||
957 | depends on 9P_FS = n | |
958 | depends on ADFS_FS = n | |
959 | depends on AFFS_FS = n | |
960 | depends on AFS_FS = n | |
961 | depends on AUTOFS4_FS = n | |
962 | depends on BEFS_FS = n | |
963 | depends on BFS_FS = n | |
964 | depends on BTRFS_FS = n | |
965 | depends on CEPH_FS = n | |
966 | depends on CIFS = n | |
967 | depends on CODA_FS = n | |
968 | depends on CONFIGFS_FS = n | |
969 | depends on CRAMFS = n | |
970 | depends on DEBUG_FS = n | |
971 | depends on ECRYPT_FS = n | |
972 | depends on EFS_FS = n | |
973 | depends on EXOFS_FS = n | |
e1c972b6 EB |
974 | depends on FAT_FS = n |
975 | depends on FUSE_FS = n | |
976 | depends on GFS2_FS = n | |
977 | depends on HFS_FS = n | |
978 | depends on HFSPLUS_FS = n | |
979 | depends on HPFS_FS = n | |
980 | depends on HUGETLBFS = n | |
981 | depends on ISO9660_FS = n | |
982 | depends on JFFS2_FS = n | |
983 | depends on JFS_FS = n | |
984 | depends on LOGFS = n | |
985 | depends on MINIX_FS = n | |
986 | depends on NCP_FS = n | |
987 | depends on NFSD = n | |
988 | depends on NFS_FS = n | |
989 | depends on NILFS2_FS = n | |
990 | depends on NTFS_FS = n | |
991 | depends on OCFS2_FS = n | |
992 | depends on OMFS_FS = n | |
e1c972b6 EB |
993 | depends on QNX4FS_FS = n |
994 | depends on QNX6FS_FS = n | |
995 | depends on REISERFS_FS = n | |
996 | depends on SQUASHFS = n | |
e1c972b6 | 997 | depends on SYSV_FS = n |
e1c972b6 EB |
998 | depends on UBIFS_FS = n |
999 | depends on UDF_FS = n | |
1000 | depends on UFS_FS = n | |
1001 | depends on VXFS_FS = n | |
1002 | depends on XFS_FS = n | |
1003 | ||
1004 | depends on !UML || HOSTFS = n | |
1005 | ||
1006 | # The rare drivers that won't build | |
1007 | depends on AIRO = n | |
1008 | depends on AIRO_CS = n | |
1009 | depends on TUN = n | |
1010 | depends on INFINIBAND_QIB = n | |
1011 | depends on BLK_DEV_LOOP = n | |
1012 | depends on ANDROID_BINDER_IPC = n | |
1013 | ||
1014 | # Security modules | |
1015 | depends on SECURITY_TOMOYO = n | |
1016 | depends on SECURITY_APPARMOR = n | |
1017 | ||
5673a94c EB |
1018 | config UIDGID_STRICT_TYPE_CHECKS |
1019 | bool "Require conversions between uid/gids and their internal representation" | |
e1c972b6 | 1020 | depends on UIDGID_CONVERTED |
5673a94c EB |
1021 | default n |
1022 | help | |
1023 | While the nececessary conversions are being added to all subsystems this option allows | |
1024 | the code to continue to build for unconverted subsystems. | |
1025 | ||
1026 | Say Y here if you want the strict type checking enabled | |
1027 | ||
5091faa4 MG |
1028 | config SCHED_AUTOGROUP |
1029 | bool "Automatic process group scheduling" | |
1030 | select EVENTFD | |
1031 | select CGROUPS | |
1032 | select CGROUP_SCHED | |
1033 | select FAIR_GROUP_SCHED | |
1034 | help | |
1035 | This option optimizes the scheduler for common desktop workloads by | |
1036 | automatically creating and populating task groups. This separation | |
1037 | of workloads isolates aggressive CPU burners (like build jobs) from | |
1038 | desktop applications. Task group autogeneration is currently based | |
1039 | upon task session. | |
1040 | ||
7af37bec DL |
1041 | config MM_OWNER |
1042 | bool | |
1043 | ||
1044 | config SYSFS_DEPRECATED | |
5d6a4ea5 | 1045 | bool "Enable deprecated sysfs features to support old userspace tools" |
7af37bec DL |
1046 | depends on SYSFS |
1047 | default n | |
1048 | help | |
1049 | This option adds code that switches the layout of the "block" class | |
1050 | devices, to not show up in /sys/class/block/, but only in | |
1051 | /sys/block/. | |
1052 | ||
1053 | This switch is only active when the sysfs.deprecated=1 boot option is | |
1054 | passed or the SYSFS_DEPRECATED_V2 option is set. | |
1055 | ||
1056 | This option allows new kernels to run on old distributions and tools, | |
1057 | which might get confused by /sys/class/block/. Since 2007/2008 all | |
1058 | major distributions and tools handle this just fine. | |
1059 | ||
1060 | Recent distributions and userspace tools after 2009/2010 depend on | |
1061 | the existence of /sys/class/block/, and will not work with this | |
1062 | option enabled. | |
1063 | ||
1064 | Only if you are using a new kernel on an old distribution, you might | |
1065 | need to say Y here. | |
1066 | ||
1067 | config SYSFS_DEPRECATED_V2 | |
5d6a4ea5 | 1068 | bool "Enable deprecated sysfs features by default" |
7af37bec DL |
1069 | default n |
1070 | depends on SYSFS | |
1071 | depends on SYSFS_DEPRECATED | |
1072 | help | |
1073 | Enable deprecated sysfs by default. | |
1074 | ||
1075 | See the CONFIG_SYSFS_DEPRECATED option for more details about this | |
1076 | option. | |
1077 | ||
1078 | Only if you are using a new kernel on an old distribution, you might | |
1079 | need to say Y here. Even then, odds are you would not need it | |
1080 | enabled, you can always pass the boot option if absolutely necessary. | |
1081 | ||
1082 | config RELAY | |
1083 | bool "Kernel->user space relay support (formerly relayfs)" | |
1084 | help | |
1085 | This option enables support for relay interface support in | |
1086 | certain file systems (such as debugfs). | |
1087 | It is designed to provide an efficient mechanism for tools and | |
1088 | facilities to relay large amounts of data from kernel space to | |
1089 | user space. | |
1090 | ||
1091 | If unsure, say N. | |
1092 | ||
f991633d DG |
1093 | config BLK_DEV_INITRD |
1094 | bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support" | |
1095 | depends on BROKEN || !FRV | |
1096 | help | |
1097 | The initial RAM filesystem is a ramfs which is loaded by the | |
1098 | boot loader (loadlin or lilo) and that is mounted as root | |
1099 | before the normal boot procedure. It is typically used to | |
1100 | load modules needed to mount the "real" root file system, | |
1101 | etc. See <file:Documentation/initrd.txt> for details. | |
1102 | ||
1103 | If RAM disk support (BLK_DEV_RAM) is also included, this | |
1104 | also enables initial RAM disk (initrd) support and adds | |
1105 | 15 Kbytes (more on some other architectures) to the kernel size. | |
1106 | ||
1107 | If unsure say Y. | |
1108 | ||
c33df4ea JPS |
1109 | if BLK_DEV_INITRD |
1110 | ||
dbec4866 SR |
1111 | source "usr/Kconfig" |
1112 | ||
c33df4ea JPS |
1113 | endif |
1114 | ||
c45b4f1f | 1115 | config CC_OPTIMIZE_FOR_SIZE |
96fffeb4 | 1116 | bool "Optimize for size" |
c45b4f1f LT |
1117 | help |
1118 | Enabling this option will pass "-Os" instead of "-O2" to gcc | |
1119 | resulting in a smaller kernel. | |
1120 | ||
775a7229 | 1121 | If unsure, say Y. |
c45b4f1f | 1122 | |
0847062a RD |
1123 | config SYSCTL |
1124 | bool | |
1125 | ||
b943c460 RD |
1126 | config ANON_INODES |
1127 | bool | |
1128 | ||
6a108a14 DR |
1129 | menuconfig EXPERT |
1130 | bool "Configure standard kernel features (expert users)" | |
f505c553 JT |
1131 | # Unhide debug options, to make the on-by-default options visible |
1132 | select DEBUG_KERNEL | |
1da177e4 LT |
1133 | help |
1134 | This option allows certain base kernel options and settings | |
1135 | to be disabled or tweaked. This is for specialized | |
1136 | environments which can tolerate a "non-standard" kernel. | |
1137 | Only use this if you really know what you are doing. | |
1138 | ||
ae81f9e3 | 1139 | config UID16 |
6a108a14 | 1140 | bool "Enable 16-bit UID system calls" if EXPERT |
09337f50 | 1141 | depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION) |
ae81f9e3 CE |
1142 | default y |
1143 | help | |
1144 | This enables the legacy 16-bit UID syscall wrappers. | |
1145 | ||
b89a8171 | 1146 | config SYSCTL_SYSCALL |
6a108a14 | 1147 | bool "Sysctl syscall support" if EXPERT |
26a7034b | 1148 | depends on PROC_SYSCTL |
c736de60 | 1149 | default n |
b89a8171 | 1150 | select SYSCTL |
ae81f9e3 | 1151 | ---help--- |
13bb7e37 EB |
1152 | sys_sysctl uses binary paths that have been found challenging |
1153 | to properly maintain and use. The interface in /proc/sys | |
1154 | using paths with ascii names is now the primary path to this | |
1155 | information. | |
b89a8171 | 1156 | |
13bb7e37 EB |
1157 | Almost nothing using the binary sysctl interface so if you are |
1158 | trying to save some space it is probably safe to disable this, | |
1159 | making your kernel marginally smaller. | |
b89a8171 | 1160 | |
c736de60 | 1161 | If unsure say N here. |
ae81f9e3 | 1162 | |
1da177e4 | 1163 | config KALLSYMS |
6a108a14 | 1164 | bool "Load all symbols for debugging/ksymoops" if EXPERT |
1da177e4 LT |
1165 | default y |
1166 | help | |
1167 | Say Y here to let the kernel print out symbolic crash information and | |
1168 | symbolic stack backtraces. This increases the size of the kernel | |
1169 | somewhat, as all symbols have to be loaded into the kernel image. | |
1170 | ||
1171 | config KALLSYMS_ALL | |
1172 | bool "Include all symbols in kallsyms" | |
1173 | depends on DEBUG_KERNEL && KALLSYMS | |
1174 | help | |
71a83ec7 AB |
1175 | Normally kallsyms only contains the symbols of functions for nicer |
1176 | OOPS messages and backtraces (i.e., symbols from the text and inittext | |
1177 | sections). This is sufficient for most cases. And only in very rare | |
1178 | cases (e.g., when a debugger is used) all symbols are required (e.g., | |
1179 | names of variables from the data sections, etc). | |
1180 | ||
1181 | This option makes sure that all symbols are loaded into the kernel | |
1182 | image (i.e., symbols from all sections) in cost of increased kernel | |
1183 | size (depending on the kernel configuration, it may be 300KiB or | |
1184 | something like this). | |
1185 | ||
1186 | Say N unless you really need all symbols. | |
d59745ce | 1187 | |
712f47ce | 1188 | config HOTPLUG |
6a108a14 | 1189 | bool "Support for hot-pluggable devices" if EXPERT |
712f47ce GKH |
1190 | default y |
1191 | help | |
1192 | This option is provided for the case where no hotplug or uevent | |
1193 | capabilities is wanted by the kernel. You should only consider | |
1194 | disabling this option for embedded systems that do not use modules, a | |
1195 | dynamic /dev tree, or dynamic device discovery. Just say Y. | |
1196 | ||
d59745ce MM |
1197 | config PRINTK |
1198 | default y | |
6a108a14 | 1199 | bool "Enable support for printk" if EXPERT |
d59745ce MM |
1200 | help |
1201 | This option enables normal printk support. Removing it | |
1202 | eliminates most of the message strings from the kernel image | |
1203 | and makes the kernel more or less silent. As this makes it | |
1204 | very difficult to diagnose system problems, saying N here is | |
1205 | strongly discouraged. | |
1206 | ||
c8538a7a | 1207 | config BUG |
6a108a14 | 1208 | bool "BUG() support" if EXPERT |
c8538a7a MM |
1209 | default y |
1210 | help | |
1211 | Disabling this option eliminates support for BUG and WARN, reducing | |
1212 | the size of your kernel image and potentially quietly ignoring | |
1213 | numerous fatal conditions. You should only consider disabling this | |
1214 | option for embedded systems with no facilities for reporting errors. | |
1215 | Just say Y. | |
1216 | ||
708e9a79 MM |
1217 | config ELF_CORE |
1218 | default y | |
6a108a14 | 1219 | bool "Enable ELF core dumps" if EXPERT |
708e9a79 MM |
1220 | help |
1221 | Enable support for generating core dumps. Disabling saves about 4k. | |
1222 | ||
8761f1ab | 1223 | |
e5e1d3cb | 1224 | config PCSPKR_PLATFORM |
6a108a14 | 1225 | bool "Enable PC-Speaker support" if EXPERT |
8761f1ab | 1226 | depends on HAVE_PCSPKR_PLATFORM |
15f304b6 | 1227 | select I8253_LOCK |
e5e1d3cb SS |
1228 | default y |
1229 | help | |
1230 | This option allows to disable the internal PC-Speaker | |
1231 | support, saving some memory. | |
1232 | ||
8761f1ab RB |
1233 | config HAVE_PCSPKR_PLATFORM |
1234 | bool | |
1235 | ||
1da177e4 LT |
1236 | config BASE_FULL |
1237 | default y | |
6a108a14 | 1238 | bool "Enable full-sized data structures for core" if EXPERT |
1da177e4 LT |
1239 | help |
1240 | Disabling this option reduces the size of miscellaneous core | |
1241 | kernel data structures. This saves memory on small machines, | |
1242 | but may reduce performance. | |
1243 | ||
1244 | config FUTEX | |
6a108a14 | 1245 | bool "Enable futex support" if EXPERT |
1da177e4 | 1246 | default y |
23f78d4a | 1247 | select RT_MUTEXES |
1da177e4 LT |
1248 | help |
1249 | Disabling this option will cause the kernel to be built without | |
1250 | support for "fast userspace mutexes". The resulting kernel may not | |
1251 | run glibc-based applications correctly. | |
1252 | ||
1253 | config EPOLL | |
6a108a14 | 1254 | bool "Enable eventpoll support" if EXPERT |
1da177e4 | 1255 | default y |
448e3cee | 1256 | select ANON_INODES |
1da177e4 LT |
1257 | help |
1258 | Disabling this option will cause the kernel to be built without | |
1259 | support for epoll family of system calls. | |
1260 | ||
fba2afaa | 1261 | config SIGNALFD |
6a108a14 | 1262 | bool "Enable signalfd() system call" if EXPERT |
448e3cee | 1263 | select ANON_INODES |
fba2afaa DL |
1264 | default y |
1265 | help | |
1266 | Enable the signalfd() system call that allows to receive signals | |
1267 | on a file descriptor. | |
1268 | ||
1269 | If unsure, say Y. | |
1270 | ||
b215e283 | 1271 | config TIMERFD |
6a108a14 | 1272 | bool "Enable timerfd() system call" if EXPERT |
448e3cee | 1273 | select ANON_INODES |
b215e283 DL |
1274 | default y |
1275 | help | |
1276 | Enable the timerfd() system call that allows to receive timer | |
1277 | events on a file descriptor. | |
1278 | ||
1279 | If unsure, say Y. | |
1280 | ||
e1ad7468 | 1281 | config EVENTFD |
6a108a14 | 1282 | bool "Enable eventfd() system call" if EXPERT |
448e3cee | 1283 | select ANON_INODES |
e1ad7468 DL |
1284 | default y |
1285 | help | |
1286 | Enable the eventfd() system call that allows to receive both | |
1287 | kernel notification (ie. KAIO) or userspace notifications. | |
1288 | ||
1289 | If unsure, say Y. | |
1290 | ||
1da177e4 | 1291 | config SHMEM |
6a108a14 | 1292 | bool "Use full shmem filesystem" if EXPERT |
1da177e4 LT |
1293 | default y |
1294 | depends on MMU | |
1295 | help | |
1296 | The shmem is an internal filesystem used to manage shared memory. | |
1297 | It is backed by swap and manages resource limits. It is also exported | |
1298 | to userspace as tmpfs if TMPFS is enabled. Disabling this | |
1299 | option replaces shmem and tmpfs with the much simpler ramfs code, | |
1300 | which may be appropriate on small systems without swap. | |
1301 | ||
ebf3f09c | 1302 | config AIO |
6a108a14 | 1303 | bool "Enable AIO support" if EXPERT |
ebf3f09c TP |
1304 | default y |
1305 | help | |
1306 | This option enables POSIX asynchronous I/O which may by used | |
1307 | by some high performance threaded applications. Disabling | |
1308 | this option saves about 7k. | |
1309 | ||
6befe5f6 RD |
1310 | config EMBEDDED |
1311 | bool "Embedded system" | |
1312 | select EXPERT | |
1313 | help | |
1314 | This option should be enabled if compiling the kernel for | |
1315 | an embedded system so certain expert options are available | |
1316 | for configuration. | |
1317 | ||
cdd6c482 | 1318 | config HAVE_PERF_EVENTS |
0793a61d | 1319 | bool |
018df72d MF |
1320 | help |
1321 | See tools/perf/design.txt for details. | |
0793a61d | 1322 | |
906010b2 PZ |
1323 | config PERF_USE_VMALLOC |
1324 | bool | |
1325 | help | |
1326 | See tools/perf/design.txt for details | |
1327 | ||
57c0c15b | 1328 | menu "Kernel Performance Events And Counters" |
0793a61d | 1329 | |
cdd6c482 | 1330 | config PERF_EVENTS |
57c0c15b | 1331 | bool "Kernel performance events and counters" |
392d65a9 | 1332 | default y if PROFILING |
cdd6c482 | 1333 | depends on HAVE_PERF_EVENTS |
4c59e467 | 1334 | select ANON_INODES |
e360adbe | 1335 | select IRQ_WORK |
0793a61d | 1336 | help |
57c0c15b IM |
1337 | Enable kernel support for various performance events provided |
1338 | by software and hardware. | |
0793a61d | 1339 | |
dd77038d | 1340 | Software events are supported either built-in or via the |
57c0c15b | 1341 | use of generic tracepoints. |
0793a61d | 1342 | |
57c0c15b IM |
1343 | Most modern CPUs support performance events via performance |
1344 | counter registers. These registers count the number of certain | |
0793a61d TG |
1345 | types of hw events: such as instructions executed, cachemisses |
1346 | suffered, or branches mis-predicted - without slowing down the | |
1347 | kernel or applications. These registers can also trigger interrupts | |
1348 | when a threshold number of events have passed - and can thus be | |
1349 | used to profile the code that runs on that CPU. | |
1350 | ||
57c0c15b | 1351 | The Linux Performance Event subsystem provides an abstraction of |
dd77038d | 1352 | these software and hardware event capabilities, available via a |
57c0c15b | 1353 | system call and used by the "perf" utility in tools/perf/. It |
0793a61d TG |
1354 | provides per task and per CPU counters, and it provides event |
1355 | capabilities on top of those. | |
1356 | ||
1357 | Say Y if unsure. | |
1358 | ||
906010b2 PZ |
1359 | config DEBUG_PERF_USE_VMALLOC |
1360 | default n | |
1361 | bool "Debug: use vmalloc to back perf mmap() buffers" | |
1362 | depends on PERF_EVENTS && DEBUG_KERNEL | |
1363 | select PERF_USE_VMALLOC | |
1364 | help | |
1365 | Use vmalloc memory to back perf mmap() buffers. | |
1366 | ||
1367 | Mostly useful for debugging the vmalloc code on platforms | |
1368 | that don't require it. | |
1369 | ||
1370 | Say N if unsure. | |
1371 | ||
0793a61d TG |
1372 | endmenu |
1373 | ||
f8891e5e CL |
1374 | config VM_EVENT_COUNTERS |
1375 | default y | |
6a108a14 | 1376 | bool "Enable VM event counters for /proc/vmstat" if EXPERT |
f8891e5e | 1377 | help |
2aea4fb6 PJ |
1378 | VM event counters are needed for event counts to be shown. |
1379 | This option allows the disabling of the VM event counters | |
6a108a14 | 1380 | on EXPERT systems. /proc/vmstat will only show page counts |
2aea4fb6 | 1381 | if VM event counters are disabled. |
f8891e5e | 1382 | |
3d137310 TP |
1383 | config PCI_QUIRKS |
1384 | default y | |
6a108a14 | 1385 | bool "Enable PCI quirk workarounds" if EXPERT |
61cfc7e4 | 1386 | depends on PCI |
3d137310 TP |
1387 | help |
1388 | This enables workarounds for various PCI chipset | |
1389 | bugs/quirks. Disable this only if your target machine is | |
1390 | unaffected by PCI quirks. | |
1391 | ||
41ecc55b CL |
1392 | config SLUB_DEBUG |
1393 | default y | |
6a108a14 | 1394 | bool "Enable SLUB debugging support" if EXPERT |
f6acb635 | 1395 | depends on SLUB && SYSFS |
41ecc55b CL |
1396 | help |
1397 | SLUB has extensive debug support features. Disabling these can | |
1398 | result in significant savings in code size. This also disables | |
1399 | SLUB sysfs support. /sys/slab will not exist and there will be | |
1400 | no support for cache validation etc. | |
1401 | ||
b943c460 RD |
1402 | config COMPAT_BRK |
1403 | bool "Disable heap randomization" | |
1404 | default y | |
1405 | help | |
1406 | Randomizing heap placement makes heap exploits harder, but it | |
1407 | also breaks ancient binaries (including anything libc5 based). | |
1408 | This option changes the bootup default to heap randomization | |
692105b8 | 1409 | disabled, and can be overridden at runtime by setting |
b943c460 RD |
1410 | /proc/sys/kernel/randomize_va_space to 2. |
1411 | ||
1412 | On non-ancient distros (post-2000 ones) N is usually a safe choice. | |
1413 | ||
81819f0f CL |
1414 | choice |
1415 | prompt "Choose SLAB allocator" | |
a0acd820 | 1416 | default SLUB |
81819f0f CL |
1417 | help |
1418 | This option allows to select a slab allocator. | |
1419 | ||
1420 | config SLAB | |
1421 | bool "SLAB" | |
1422 | help | |
1423 | The regular slab allocator that is established and known to work | |
34013886 | 1424 | well in all environments. It organizes cache hot objects in |
02f56210 | 1425 | per cpu and per node queues. |
81819f0f CL |
1426 | |
1427 | config SLUB | |
81819f0f CL |
1428 | bool "SLUB (Unqueued Allocator)" |
1429 | help | |
1430 | SLUB is a slab allocator that minimizes cache line usage | |
1431 | instead of managing queues of cached objects (SLAB approach). | |
1432 | Per cpu caching is realized using slabs of objects instead | |
1433 | of queues of objects. SLUB can use memory efficiently | |
02f56210 SA |
1434 | and has enhanced diagnostics. SLUB is the default choice for |
1435 | a slab allocator. | |
81819f0f CL |
1436 | |
1437 | config SLOB | |
6a108a14 | 1438 | depends on EXPERT |
81819f0f CL |
1439 | bool "SLOB (Simple Allocator)" |
1440 | help | |
37291458 MM |
1441 | SLOB replaces the stock allocator with a drastically simpler |
1442 | allocator. SLOB is generally more space efficient but | |
1443 | does not perform as well on large systems. | |
81819f0f CL |
1444 | |
1445 | endchoice | |
1446 | ||
ea637639 JZ |
1447 | config MMAP_ALLOW_UNINITIALIZED |
1448 | bool "Allow mmapped anonymous memory to be uninitialized" | |
6a108a14 | 1449 | depends on EXPERT && !MMU |
ea637639 JZ |
1450 | default n |
1451 | help | |
1452 | Normally, and according to the Linux spec, anonymous memory obtained | |
1453 | from mmap() has it's contents cleared before it is passed to | |
1454 | userspace. Enabling this config option allows you to request that | |
1455 | mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus | |
1456 | providing a huge performance boost. If this option is not enabled, | |
1457 | then the flag will be ignored. | |
1458 | ||
1459 | This is taken advantage of by uClibc's malloc(), and also by | |
1460 | ELF-FDPIC binfmt's brk and stack allocator. | |
1461 | ||
1462 | Because of the obvious security issues, this option should only be | |
1463 | enabled on embedded devices where you control what is run in | |
1464 | userspace. Since that isn't generally a problem on no-MMU systems, | |
1465 | it is normally safe to say Y here. | |
1466 | ||
1467 | See Documentation/nommu-mmap.txt for more information. | |
1468 | ||
125e5645 | 1469 | config PROFILING |
b309a294 | 1470 | bool "Profiling support" |
125e5645 MD |
1471 | help |
1472 | Say Y here to enable the extended profiling support mechanisms used | |
1473 | by profilers such as OProfile. | |
1474 | ||
5f87f112 IM |
1475 | # |
1476 | # Place an empty function call at each tracepoint site. Can be | |
1477 | # dynamically changed for a probe function. | |
1478 | # | |
97e1c18e | 1479 | config TRACEPOINTS |
5f87f112 | 1480 | bool |
97e1c18e | 1481 | |
fb32e03f MD |
1482 | source "arch/Kconfig" |
1483 | ||
1da177e4 LT |
1484 | endmenu # General setup |
1485 | ||
ee7e5516 DB |
1486 | config HAVE_GENERIC_DMA_COHERENT |
1487 | bool | |
1488 | default n | |
1489 | ||
158a9624 LT |
1490 | config SLABINFO |
1491 | bool | |
1492 | depends on PROC_FS | |
0f389ec6 | 1493 | depends on SLAB || SLUB_DEBUG |
158a9624 LT |
1494 | default y |
1495 | ||
ae81f9e3 CE |
1496 | config RT_MUTEXES |
1497 | boolean | |
ae81f9e3 | 1498 | |
1da177e4 LT |
1499 | config BASE_SMALL |
1500 | int | |
1501 | default 0 if BASE_FULL | |
1502 | default 1 if !BASE_FULL | |
1503 | ||
66da5733 | 1504 | menuconfig MODULES |
1da177e4 LT |
1505 | bool "Enable loadable module support" |
1506 | help | |
1507 | Kernel modules are small pieces of compiled code which can | |
1508 | be inserted in the running kernel, rather than being | |
1509 | permanently built into the kernel. You use the "modprobe" | |
1510 | tool to add (and sometimes remove) them. If you say Y here, | |
1511 | many parts of the kernel can be built as modules (by | |
1512 | answering M instead of Y where indicated): this is most | |
1513 | useful for infrequently used options which are not required | |
1514 | for booting. For more information, see the man pages for | |
1515 | modprobe, lsmod, modinfo, insmod and rmmod. | |
1516 | ||
1517 | If you say Y here, you will need to run "make | |
1518 | modules_install" to put the modules under /lib/modules/ | |
1519 | where modprobe can find them (you may need to be root to do | |
1520 | this). | |
1521 | ||
1522 | If unsure, say Y. | |
1523 | ||
0b0de144 RD |
1524 | if MODULES |
1525 | ||
826e4506 LT |
1526 | config MODULE_FORCE_LOAD |
1527 | bool "Forced module loading" | |
826e4506 LT |
1528 | default n |
1529 | help | |
91e37a79 RR |
1530 | Allow loading of modules without version information (ie. modprobe |
1531 | --force). Forced module loading sets the 'F' (forced) taint flag and | |
1532 | is usually a really bad idea. | |
826e4506 | 1533 | |
1da177e4 LT |
1534 | config MODULE_UNLOAD |
1535 | bool "Module unloading" | |
1da177e4 LT |
1536 | help |
1537 | Without this option you will not be able to unload any | |
1538 | modules (note that some modules may not be unloadable | |
f7f5b675 DV |
1539 | anyway), which makes your kernel smaller, faster |
1540 | and simpler. If unsure, say Y. | |
1da177e4 LT |
1541 | |
1542 | config MODULE_FORCE_UNLOAD | |
1543 | bool "Forced module unloading" | |
1544 | depends on MODULE_UNLOAD && EXPERIMENTAL | |
1545 | help | |
1546 | This option allows you to force a module to unload, even if the | |
1547 | kernel believes it is unsafe: the kernel will remove the module | |
1548 | without waiting for anyone to stop using it (using the -f option to | |
1549 | rmmod). This is mainly for kernel developers and desperate users. | |
1550 | If unsure, say N. | |
1551 | ||
1da177e4 | 1552 | config MODVERSIONS |
0d541643 | 1553 | bool "Module versioning support" |
1da177e4 LT |
1554 | help |
1555 | Usually, you have to use modules compiled with your kernel. | |
1556 | Saying Y here makes it sometimes possible to use modules | |
1557 | compiled for different kernels, by adding enough information | |
1558 | to the modules to (hopefully) spot any changes which would | |
1559 | make them incompatible with the kernel you are running. If | |
1560 | unsure, say N. | |
1561 | ||
1562 | config MODULE_SRCVERSION_ALL | |
1563 | bool "Source checksum for all modules" | |
1da177e4 LT |
1564 | help |
1565 | Modules which contain a MODULE_VERSION get an extra "srcversion" | |
1566 | field inserted into their modinfo section, which contains a | |
1567 | sum of the source files which made it. This helps maintainers | |
1568 | see exactly which source was used to build a module (since | |
1569 | others sometimes change the module source without updating | |
1570 | the version). With this option, such a "srcversion" field | |
1571 | will be created for all modules. If unsure, say N. | |
1572 | ||
0b0de144 RD |
1573 | endif # MODULES |
1574 | ||
98a79d6a RR |
1575 | config INIT_ALL_POSSIBLE |
1576 | bool | |
1577 | help | |
5f054e31 RR |
1578 | Back when each arch used to define their own cpu_online_mask and |
1579 | cpu_possible_mask, some of them chose to initialize cpu_possible_mask | |
98a79d6a RR |
1580 | with all 1s, and others with all 0s. When they were centralised, |
1581 | it was better to provide this option than to break all the archs | |
692105b8 | 1582 | and have several arch maintainers pursuing me down dark alleys. |
98a79d6a | 1583 | |
1da177e4 LT |
1584 | config STOP_MACHINE |
1585 | bool | |
1586 | default y | |
1587 | depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU | |
1588 | help | |
1589 | Need stop_machine() primitive. | |
3a65dfe8 | 1590 | |
3a65dfe8 | 1591 | source "block/Kconfig" |
e98c3202 AK |
1592 | |
1593 | config PREEMPT_NOTIFIERS | |
1594 | bool | |
e260be67 | 1595 | |
16295bec SK |
1596 | config PADATA |
1597 | depends on SMP | |
1598 | bool | |
1599 | ||
6beb0009 | 1600 | source "kernel/Kconfig.locks" |