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80daa560 RZ |
1 | config ARCH |
2 | string | |
3 | option env="ARCH" | |
4 | ||
5 | config KERNELVERSION | |
6 | string | |
7 | option env="KERNELVERSION" | |
8 | ||
face4374 RZ |
9 | config DEFCONFIG_LIST |
10 | string | |
b2670eac | 11 | depends on !UML |
face4374 RZ |
12 | option defconfig_list |
13 | default "/lib/modules/$UNAME_RELEASE/.config" | |
14 | default "/etc/kernel-config" | |
15 | default "/boot/config-$UNAME_RELEASE" | |
73531905 | 16 | default "$ARCH_DEFCONFIG" |
face4374 RZ |
17 | default "arch/$ARCH/defconfig" |
18 | ||
ff0cfc66 | 19 | menu "General setup" |
1da177e4 LT |
20 | |
21 | config EXPERIMENTAL | |
22 | bool "Prompt for development and/or incomplete code/drivers" | |
23 | ---help--- | |
24 | Some of the various things that Linux supports (such as network | |
25 | drivers, file systems, network protocols, etc.) can be in a state | |
26 | of development where the functionality, stability, or the level of | |
27 | testing is not yet high enough for general use. This is usually | |
28 | known as the "alpha-test" phase among developers. If a feature is | |
29 | currently in alpha-test, then the developers usually discourage | |
30 | uninformed widespread use of this feature by the general public to | |
31 | avoid "Why doesn't this work?" type mail messages. However, active | |
32 | testing and use of these systems is welcomed. Just be aware that it | |
33 | may not meet the normal level of reliability or it may fail to work | |
34 | in some special cases. Detailed bug reports from people familiar | |
35 | with the kernel internals are usually welcomed by the developers | |
36 | (before submitting bug reports, please read the documents | |
37 | <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>, | |
38 | <file:Documentation/BUG-HUNTING>, and | |
39 | <file:Documentation/oops-tracing.txt> in the kernel source). | |
40 | ||
41 | This option will also make obsoleted drivers available. These are | |
42 | drivers that have been replaced by something else, and/or are | |
43 | scheduled to be removed in a future kernel release. | |
44 | ||
45 | Unless you intend to help test and develop a feature or driver that | |
46 | falls into this category, or you have a situation that requires | |
47 | using these features, you should probably say N here, which will | |
48 | cause the configurator to present you with fewer choices. If | |
49 | you say Y here, you will be offered the choice of using features or | |
50 | drivers that are currently considered to be in the alpha-test phase. | |
51 | ||
1da177e4 LT |
52 | config BROKEN |
53 | bool | |
1da177e4 LT |
54 | |
55 | config BROKEN_ON_SMP | |
56 | bool | |
57 | depends on BROKEN || !SMP | |
58 | default y | |
59 | ||
60 | config LOCK_KERNEL | |
61 | bool | |
62 | depends on SMP || PREEMPT | |
63 | default y | |
64 | ||
65 | config INIT_ENV_ARG_LIMIT | |
66 | int | |
dd673bca AB |
67 | default 32 if !UML |
68 | default 128 if UML | |
1da177e4 | 69 | help |
34ad92c2 RD |
70 | Maximum of each of the number of arguments and environment |
71 | variables passed to init from the kernel command line. | |
1da177e4 | 72 | |
1da177e4 LT |
73 | |
74 | config LOCALVERSION | |
75 | string "Local version - append to kernel release" | |
76 | help | |
77 | Append an extra string to the end of your kernel version. | |
78 | This will show up when you type uname, for example. | |
79 | The string you set here will be appended after the contents of | |
80 | any files with a filename matching localversion* in your | |
81 | object and source tree, in that order. Your total string can | |
82 | be a maximum of 64 characters. | |
83 | ||
aaebf433 RA |
84 | config LOCALVERSION_AUTO |
85 | bool "Automatically append version information to the version string" | |
86 | default y | |
87 | help | |
88 | This will try to automatically determine if the current tree is a | |
6e5a5420 RD |
89 | release tree by looking for git tags that belong to the current |
90 | top of tree revision. | |
aaebf433 RA |
91 | |
92 | A string of the format -gxxxxxxxx will be added to the localversion | |
6e5a5420 | 93 | if a git-based tree is found. The string generated by this will be |
aaebf433 | 94 | appended after any matching localversion* files, and after the value |
6e5a5420 | 95 | set in CONFIG_LOCALVERSION. |
aaebf433 | 96 | |
6e5a5420 RD |
97 | (The actual string used here is the first eight characters produced |
98 | by running the command: | |
99 | ||
100 | $ git rev-parse --verify HEAD | |
101 | ||
102 | which is done within the script "scripts/setlocalversion".) | |
aaebf433 | 103 | |
1da177e4 LT |
104 | config SWAP |
105 | bool "Support for paging of anonymous memory (swap)" | |
9361401e | 106 | depends on MMU && BLOCK |
1da177e4 LT |
107 | default y |
108 | help | |
109 | This option allows you to choose whether you want to have support | |
92c3504e | 110 | for so called swap devices or swap files in your kernel that are |
1da177e4 LT |
111 | used to provide more virtual memory than the actual RAM present |
112 | in your computer. If unsure say Y. | |
113 | ||
114 | config SYSVIPC | |
115 | bool "System V IPC" | |
1da177e4 LT |
116 | ---help--- |
117 | Inter Process Communication is a suite of library functions and | |
118 | system calls which let processes (running programs) synchronize and | |
119 | exchange information. It is generally considered to be a good thing, | |
120 | and some programs won't run unless you say Y here. In particular, if | |
121 | you want to run the DOS emulator dosemu under Linux (read the | |
122 | DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>), | |
123 | you'll need to say Y here. | |
124 | ||
125 | You can find documentation about IPC with "info ipc" and also in | |
126 | section 6.4 of the Linux Programmer's Guide, available from | |
127 | <http://www.tldp.org/guides.html>. | |
128 | ||
a5494dcd EB |
129 | config SYSVIPC_SYSCTL |
130 | bool | |
131 | depends on SYSVIPC | |
132 | depends on SYSCTL | |
133 | default y | |
134 | ||
1da177e4 LT |
135 | config POSIX_MQUEUE |
136 | bool "POSIX Message Queues" | |
137 | depends on NET && EXPERIMENTAL | |
138 | ---help--- | |
139 | POSIX variant of message queues is a part of IPC. In POSIX message | |
140 | queues every message has a priority which decides about succession | |
141 | of receiving it by a process. If you want to compile and run | |
142 | programs written e.g. for Solaris with use of its POSIX message | |
b0e37650 | 143 | queues (functions mq_*) say Y here. |
1da177e4 LT |
144 | |
145 | POSIX message queues are visible as a filesystem called 'mqueue' | |
146 | and can be mounted somewhere if you want to do filesystem | |
147 | operations on message queues. | |
148 | ||
149 | If unsure, say Y. | |
150 | ||
151 | config BSD_PROCESS_ACCT | |
152 | bool "BSD Process Accounting" | |
153 | help | |
154 | If you say Y here, a user level program will be able to instruct the | |
155 | kernel (via a special system call) to write process accounting | |
156 | information to a file: whenever a process exits, information about | |
157 | that process will be appended to the file by the kernel. The | |
158 | information includes things such as creation time, owning user, | |
159 | command name, memory usage, controlling terminal etc. (the complete | |
160 | list is in the struct acct in <file:include/linux/acct.h>). It is | |
161 | up to the user level program to do useful things with this | |
162 | information. This is generally a good idea, so say Y. | |
163 | ||
164 | config BSD_PROCESS_ACCT_V3 | |
165 | bool "BSD Process Accounting version 3 file format" | |
166 | depends on BSD_PROCESS_ACCT | |
167 | default n | |
168 | help | |
169 | If you say Y here, the process accounting information is written | |
170 | in a new file format that also logs the process IDs of each | |
171 | process and it's parent. Note that this file format is incompatible | |
172 | with previous v0/v1/v2 file formats, so you will need updated tools | |
173 | for processing it. A preliminary version of these tools is available | |
37a4c940 | 174 | at <http://www.gnu.org/software/acct/>. |
1da177e4 | 175 | |
c757249a SN |
176 | config TASKSTATS |
177 | bool "Export task/process statistics through netlink (EXPERIMENTAL)" | |
178 | depends on NET | |
179 | default n | |
180 | help | |
181 | Export selected statistics for tasks/processes through the | |
182 | generic netlink interface. Unlike BSD process accounting, the | |
183 | statistics are available during the lifetime of tasks/processes as | |
184 | responses to commands. Like BSD accounting, they are sent to user | |
185 | space on task exit. | |
186 | ||
187 | Say N if unsure. | |
188 | ||
ca74e92b SN |
189 | config TASK_DELAY_ACCT |
190 | bool "Enable per-task delay accounting (EXPERIMENTAL)" | |
6f44993f | 191 | depends on TASKSTATS |
ca74e92b SN |
192 | help |
193 | Collect information on time spent by a task waiting for system | |
194 | resources like cpu, synchronous block I/O completion and swapping | |
195 | in pages. Such statistics can help in setting a task's priorities | |
196 | relative to other tasks for cpu, io, rss limits etc. | |
197 | ||
198 | Say N if unsure. | |
199 | ||
18f705f4 AD |
200 | config TASK_XACCT |
201 | bool "Enable extended accounting over taskstats (EXPERIMENTAL)" | |
202 | depends on TASKSTATS | |
203 | help | |
204 | Collect extended task accounting data and send the data | |
205 | to userland for processing over the taskstats interface. | |
206 | ||
207 | Say N if unsure. | |
208 | ||
209 | config TASK_IO_ACCOUNTING | |
210 | bool "Enable per-task storage I/O accounting (EXPERIMENTAL)" | |
211 | depends on TASK_XACCT | |
212 | help | |
213 | Collect information on the number of bytes of storage I/O which this | |
214 | task has caused. | |
215 | ||
216 | Say N if unsure. | |
217 | ||
1da177e4 LT |
218 | config AUDIT |
219 | bool "Auditing support" | |
804a6a49 | 220 | depends on NET |
1da177e4 LT |
221 | help |
222 | Enable auditing infrastructure that can be used with another | |
223 | kernel subsystem, such as SELinux (which requires this for | |
224 | logging of avc messages output). Does not do system-call | |
225 | auditing without CONFIG_AUDITSYSCALL. | |
226 | ||
227 | config AUDITSYSCALL | |
228 | bool "Enable system-call auditing support" | |
1322b9de | 229 | depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64|| SUPERH) |
1da177e4 LT |
230 | default y if SECURITY_SELINUX |
231 | help | |
232 | Enable low-overhead system-call auditing infrastructure that | |
233 | can be used independently or with another kernel subsystem, | |
f368c07d AG |
234 | such as SELinux. To use audit's filesystem watch feature, please |
235 | ensure that INOTIFY is configured. | |
1da177e4 | 236 | |
74c3cbe3 AV |
237 | config AUDIT_TREE |
238 | def_bool y | |
239 | depends on AUDITSYSCALL && INOTIFY | |
240 | ||
c903ff83 MT |
241 | menu "RCU Subsystem" |
242 | ||
243 | choice | |
244 | prompt "RCU Implementation" | |
245 | default CLASSIC_RCU | |
246 | ||
247 | config CLASSIC_RCU | |
248 | bool "Classic RCU" | |
249 | help | |
250 | This option selects the classic RCU implementation that is | |
251 | designed for best read-side performance on non-realtime | |
252 | systems. | |
253 | ||
254 | Select this option if you are unsure. | |
255 | ||
256 | config TREE_RCU | |
257 | bool "Tree-based hierarchical RCU" | |
258 | help | |
259 | This option selects the RCU implementation that is | |
260 | designed for very large SMP system with hundreds or | |
261 | thousands of CPUs. | |
262 | ||
263 | config PREEMPT_RCU | |
264 | bool "Preemptible RCU" | |
265 | depends on PREEMPT | |
266 | help | |
267 | This option reduces the latency of the kernel by making certain | |
268 | RCU sections preemptible. Normally RCU code is non-preemptible, if | |
269 | this option is selected then read-only RCU sections become | |
270 | preemptible. This helps latency, but may expose bugs due to | |
271 | now-naive assumptions about each RCU read-side critical section | |
272 | remaining on a given CPU through its execution. | |
273 | ||
274 | endchoice | |
275 | ||
276 | config RCU_TRACE | |
277 | bool "Enable tracing for RCU" | |
278 | depends on TREE_RCU || PREEMPT_RCU | |
279 | help | |
280 | This option provides tracing in RCU which presents stats | |
281 | in debugfs for debugging RCU implementation. | |
282 | ||
283 | Say Y here if you want to enable RCU tracing | |
284 | Say N if you are unsure. | |
285 | ||
286 | config RCU_FANOUT | |
287 | int "Tree-based hierarchical RCU fanout value" | |
288 | range 2 64 if 64BIT | |
289 | range 2 32 if !64BIT | |
290 | depends on TREE_RCU | |
291 | default 64 if 64BIT | |
292 | default 32 if !64BIT | |
293 | help | |
294 | This option controls the fanout of hierarchical implementations | |
295 | of RCU, allowing RCU to work efficiently on machines with | |
296 | large numbers of CPUs. This value must be at least the cube | |
297 | root of NR_CPUS, which allows NR_CPUS up to 32,768 for 32-bit | |
298 | systems and up to 262,144 for 64-bit systems. | |
299 | ||
300 | Select a specific number if testing RCU itself. | |
301 | Take the default if unsure. | |
302 | ||
303 | config RCU_FANOUT_EXACT | |
304 | bool "Disable tree-based hierarchical RCU auto-balancing" | |
305 | depends on TREE_RCU | |
306 | default n | |
307 | help | |
308 | This option forces use of the exact RCU_FANOUT value specified, | |
309 | regardless of imbalances in the hierarchy. This is useful for | |
310 | testing RCU itself, and might one day be useful on systems with | |
311 | strong NUMA behavior. | |
312 | ||
313 | Without RCU_FANOUT_EXACT, the code will balance the hierarchy. | |
314 | ||
315 | Say N if unsure. | |
316 | ||
317 | config TREE_RCU_TRACE | |
318 | def_bool RCU_TRACE && TREE_RCU | |
319 | select DEBUG_FS | |
320 | help | |
321 | This option provides tracing for the TREE_RCU implementation, | |
322 | permitting Makefile to trivially select kernel/rcutree_trace.c. | |
323 | ||
324 | config PREEMPT_RCU_TRACE | |
325 | def_bool RCU_TRACE && PREEMPT_RCU | |
326 | select DEBUG_FS | |
327 | help | |
328 | This option provides tracing for the PREEMPT_RCU implementation, | |
329 | permitting Makefile to trivially select kernel/rcupreempt_trace.c. | |
330 | ||
331 | endmenu # "RCU Subsystem" | |
332 | ||
1da177e4 | 333 | config IKCONFIG |
f2443ab6 | 334 | tristate "Kernel .config support" |
1da177e4 LT |
335 | ---help--- |
336 | This option enables the complete Linux kernel ".config" file | |
337 | contents to be saved in the kernel. It provides documentation | |
338 | of which kernel options are used in a running kernel or in an | |
339 | on-disk kernel. This information can be extracted from the kernel | |
340 | image file with the script scripts/extract-ikconfig and used as | |
341 | input to rebuild the current kernel or to build another kernel. | |
342 | It can also be extracted from a running kernel by reading | |
343 | /proc/config.gz if enabled (below). | |
344 | ||
345 | config IKCONFIG_PROC | |
346 | bool "Enable access to .config through /proc/config.gz" | |
347 | depends on IKCONFIG && PROC_FS | |
348 | ---help--- | |
349 | This option enables access to the kernel configuration file | |
350 | through /proc/config.gz. | |
351 | ||
794543a2 AJS |
352 | config LOG_BUF_SHIFT |
353 | int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" | |
354 | range 12 21 | |
f17a32e9 | 355 | default 17 |
794543a2 AJS |
356 | help |
357 | Select kernel log buffer size as a power of 2. | |
f17a32e9 AB |
358 | Examples: |
359 | 17 => 128 KB | |
360 | 16 => 64 KB | |
361 | 15 => 32 KB | |
362 | 14 => 16 KB | |
794543a2 AJS |
363 | 13 => 8 KB |
364 | 12 => 4 KB | |
365 | ||
a5574cf6 IM |
366 | # |
367 | # Architectures with an unreliable sched_clock() should select this: | |
368 | # | |
369 | config HAVE_UNSTABLE_SCHED_CLOCK | |
370 | bool | |
371 | ||
052f1dc7 PZ |
372 | config GROUP_SCHED |
373 | bool "Group CPU scheduler" | |
aac6abca PW |
374 | depends on EXPERIMENTAL |
375 | default n | |
29f59db3 | 376 | help |
fb615581 | 377 | This feature lets CPU scheduler recognize task groups and control CPU |
9b5b7751 | 378 | bandwidth allocation to such task groups. |
5cdc38f9 KH |
379 | In order to create a group from arbitrary set of processes, use |
380 | CONFIG_CGROUPS. (See Control Group support.) | |
29f59db3 | 381 | |
052f1dc7 PZ |
382 | config FAIR_GROUP_SCHED |
383 | bool "Group scheduling for SCHED_OTHER" | |
384 | depends on GROUP_SCHED | |
aac6abca | 385 | default GROUP_SCHED |
052f1dc7 PZ |
386 | |
387 | config RT_GROUP_SCHED | |
388 | bool "Group scheduling for SCHED_RR/FIFO" | |
389 | depends on EXPERIMENTAL | |
390 | depends on GROUP_SCHED | |
391 | default n | |
b9b158fe VR |
392 | help |
393 | This feature lets you explicitly allocate real CPU bandwidth | |
394 | to users or control groups (depending on the "Basis for grouping tasks" | |
395 | setting below. If enabled, it will also make it impossible to | |
396 | schedule realtime tasks for non-root users until you allocate | |
397 | realtime bandwidth for them. | |
2fe401e3 | 398 | See Documentation/scheduler/sched-rt-group.txt for more information. |
052f1dc7 | 399 | |
24e377a8 | 400 | choice |
052f1dc7 | 401 | depends on GROUP_SCHED |
24e377a8 | 402 | prompt "Basis for grouping tasks" |
052f1dc7 | 403 | default USER_SCHED |
24e377a8 | 404 | |
052f1dc7 | 405 | config USER_SCHED |
fb615581 SV |
406 | bool "user id" |
407 | help | |
408 | This option will choose userid as the basis for grouping | |
409 | tasks, thus providing equal CPU bandwidth to each user. | |
24e377a8 | 410 | |
052f1dc7 | 411 | config CGROUP_SCHED |
68318b8e SV |
412 | bool "Control groups" |
413 | depends on CGROUPS | |
414 | help | |
415 | This option allows you to create arbitrary task groups | |
416 | using the "cgroup" pseudo filesystem and control | |
417 | the cpu bandwidth allocated to each such task group. | |
45ce80fb LZ |
418 | Refer to Documentation/cgroups/cgroups.txt for more |
419 | information on "cgroup" pseudo filesystem. | |
68318b8e | 420 | |
24e377a8 SV |
421 | endchoice |
422 | ||
23964d2d LZ |
423 | menuconfig CGROUPS |
424 | boolean "Control Group support" | |
5cdc38f9 | 425 | help |
23964d2d | 426 | This option adds support for grouping sets of processes together, for |
5cdc38f9 KH |
427 | use with process control subsystems such as Cpusets, CFS, memory |
428 | controls or device isolation. | |
429 | See | |
5cdc38f9 | 430 | - Documentation/scheduler/sched-design-CFS.txt (CFS) |
45ce80fb LZ |
431 | - Documentation/cgroups/ (features for grouping, isolation |
432 | and resource control) | |
5cdc38f9 KH |
433 | |
434 | Say N if unsure. | |
435 | ||
23964d2d LZ |
436 | if CGROUPS |
437 | ||
5cdc38f9 KH |
438 | config CGROUP_DEBUG |
439 | bool "Example debug cgroup subsystem" | |
440 | depends on CGROUPS | |
441 | default n | |
442 | help | |
443 | This option enables a simple cgroup subsystem that | |
444 | exports useful debugging information about the cgroups | |
23964d2d | 445 | framework. |
5cdc38f9 | 446 | |
23964d2d | 447 | Say N if unsure. |
5cdc38f9 KH |
448 | |
449 | config CGROUP_NS | |
23964d2d LZ |
450 | bool "Namespace cgroup subsystem" |
451 | depends on CGROUPS | |
452 | help | |
453 | Provides a simple namespace cgroup subsystem to | |
454 | provide hierarchical naming of sets of namespaces, | |
455 | for instance virtual servers and checkpoint/restart | |
456 | jobs. | |
5cdc38f9 KH |
457 | |
458 | config CGROUP_FREEZER | |
23964d2d LZ |
459 | bool "Freezer cgroup subsystem" |
460 | depends on CGROUPS | |
461 | help | |
462 | Provides a way to freeze and unfreeze all tasks in a | |
5cdc38f9 KH |
463 | cgroup. |
464 | ||
465 | config CGROUP_DEVICE | |
466 | bool "Device controller for cgroups" | |
467 | depends on CGROUPS && EXPERIMENTAL | |
468 | help | |
469 | Provides a cgroup implementing whitelists for devices which | |
470 | a process in the cgroup can mknod or open. | |
471 | ||
472 | config CPUSETS | |
473 | bool "Cpuset support" | |
474 | depends on SMP && CGROUPS | |
475 | help | |
476 | This option will let you create and manage CPUSETs which | |
477 | allow dynamically partitioning a system into sets of CPUs and | |
478 | Memory Nodes and assigning tasks to run only within those sets. | |
479 | This is primarily useful on large SMP or NUMA systems. | |
480 | ||
481 | Say N if unsure. | |
482 | ||
23964d2d LZ |
483 | config PROC_PID_CPUSET |
484 | bool "Include legacy /proc/<pid>/cpuset file" | |
485 | depends on CPUSETS | |
486 | default y | |
487 | ||
d842de87 SV |
488 | config CGROUP_CPUACCT |
489 | bool "Simple CPU accounting cgroup subsystem" | |
490 | depends on CGROUPS | |
491 | help | |
492 | Provides a simple Resource Controller for monitoring the | |
23964d2d | 493 | total CPU consumed by the tasks in a cgroup. |
d842de87 | 494 | |
e552b661 PE |
495 | config RESOURCE_COUNTERS |
496 | bool "Resource counters" | |
497 | help | |
498 | This option enables controller independent resource accounting | |
23964d2d | 499 | infrastructure that works with cgroups. |
e552b661 PE |
500 | depends on CGROUPS |
501 | ||
00f0b825 BS |
502 | config CGROUP_MEM_RES_CTLR |
503 | bool "Memory Resource Controller for Control Groups" | |
504 | depends on CGROUPS && RESOURCE_COUNTERS | |
cf475ad2 | 505 | select MM_OWNER |
00f0b825 | 506 | help |
84ad6d70 KH |
507 | Provides a memory resource controller that manages both anonymous |
508 | memory and page cache. (See Documentation/controllers/memory.txt) | |
00f0b825 BS |
509 | |
510 | Note that setting this option increases fixed memory overhead | |
84ad6d70 KH |
511 | associated with each page of memory in the system. By this, |
512 | 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory | |
513 | usage tracking struct at boot. Total amount of this is printed out | |
514 | at boot. | |
00f0b825 BS |
515 | |
516 | Only enable when you're ok with these trade offs and really | |
84ad6d70 KH |
517 | sure you need the memory resource controller. Even when you enable |
518 | this, you can set "cgroup_disable=memory" at your boot option to | |
519 | disable memory resource controller and you can avoid overheads. | |
c9d5409f | 520 | (and lose benefits of memory resource controller) |
00f0b825 | 521 | |
cf475ad2 BS |
522 | This config option also selects MM_OWNER config option, which |
523 | could in turn add some fork/exit overhead. | |
524 | ||
c077719b KH |
525 | config CGROUP_MEM_RES_CTLR_SWAP |
526 | bool "Memory Resource Controller Swap Extension(EXPERIMENTAL)" | |
527 | depends on CGROUP_MEM_RES_CTLR && SWAP && EXPERIMENTAL | |
528 | help | |
529 | Add swap management feature to memory resource controller. When you | |
530 | enable this, you can limit mem+swap usage per cgroup. In other words, | |
531 | when you disable this, memory resource controller has no cares to | |
532 | usage of swap...a process can exhaust all of the swap. This extension | |
533 | is useful when you want to avoid exhaustion swap but this itself | |
534 | adds more overheads and consumes memory for remembering information. | |
535 | Especially if you use 32bit system or small memory system, please | |
536 | be careful about enabling this. When memory resource controller | |
537 | is disabled by boot option, this will be automatically disabled and | |
538 | there will be no overhead from this. Even when you set this config=y, | |
539 | if boot option "noswapaccount" is set, swap will not be accounted. | |
540 | ||
23964d2d | 541 | endif # CGROUPS |
c077719b | 542 | |
23964d2d LZ |
543 | config MM_OWNER |
544 | bool | |
5cdc38f9 | 545 | |
88a22c98 | 546 | config SYSFS_DEPRECATED |
d47846c5 IM |
547 | bool |
548 | ||
549 | config SYSFS_DEPRECATED_V2 | |
fce3e804 | 550 | bool "Create deprecated sysfs layout for older userspace tools" |
9148fe87 | 551 | depends on SYSFS |
88a22c98 | 552 | default y |
d47846c5 | 553 | select SYSFS_DEPRECATED |
88a22c98 | 554 | help |
fce3e804 KS |
555 | This option switches the layout of sysfs to the deprecated |
556 | version. | |
557 | ||
558 | The current sysfs layout features a unified device tree at | |
559 | /sys/devices/, which is able to express a hierarchy between | |
560 | class devices. If the deprecated option is set to Y, the | |
561 | unified device tree is split into a bus device tree at | |
562 | /sys/devices/ and several individual class device trees at | |
563 | /sys/class/. The class and bus devices will be connected by | |
564 | "<subsystem>:<name>" and the "device" links. The "block" | |
565 | class devices, will not show up in /sys/class/block/. Some | |
566 | subsystems will suppress the creation of some devices which | |
567 | depend on the unified device tree. | |
568 | ||
569 | This option is not a pure compatibility option that can | |
570 | be safely enabled on newer distributions. It will change the | |
571 | layout of sysfs to the non-extensible deprecated version, | |
572 | and disable some features, which can not be exported without | |
573 | confusing older userspace tools. Since 2007/2008 all major | |
574 | distributions do not enable this option, and ship no tools which | |
575 | depend on the deprecated layout or this option. | |
576 | ||
577 | If you are using a new kernel on an older distribution, or use | |
578 | older userspace tools, you might need to say Y here. Do not say Y, | |
579 | if the original kernel, that came with your distribution, has | |
580 | this option set to N. | |
88a22c98 | 581 | |
b86ff981 JA |
582 | config RELAY |
583 | bool "Kernel->user space relay support (formerly relayfs)" | |
584 | help | |
585 | This option enables support for relay interface support in | |
586 | certain file systems (such as debugfs). | |
587 | It is designed to provide an efficient mechanism for tools and | |
588 | facilities to relay large amounts of data from kernel space to | |
589 | user space. | |
590 | ||
591 | If unsure, say N. | |
592 | ||
c5289a69 PE |
593 | config NAMESPACES |
594 | bool "Namespaces support" if EMBEDDED | |
595 | default !EMBEDDED | |
596 | help | |
597 | Provides the way to make tasks work with different objects using | |
598 | the same id. For example same IPC id may refer to different objects | |
599 | or same user id or pid may refer to different tasks when used in | |
600 | different namespaces. | |
601 | ||
58bfdd6d PE |
602 | config UTS_NS |
603 | bool "UTS namespace" | |
604 | depends on NAMESPACES | |
605 | help | |
606 | In this namespace tasks see different info provided with the | |
607 | uname() system call | |
608 | ||
ae5e1b22 PE |
609 | config IPC_NS |
610 | bool "IPC namespace" | |
611 | depends on NAMESPACES && SYSVIPC | |
612 | help | |
613 | In this namespace tasks work with IPC ids which correspond to | |
614 | different IPC objects in different namespaces | |
615 | ||
aee16ce7 PE |
616 | config USER_NS |
617 | bool "User namespace (EXPERIMENTAL)" | |
618 | depends on NAMESPACES && EXPERIMENTAL | |
619 | help | |
620 | This allows containers, i.e. vservers, to use user namespaces | |
621 | to provide different user info for different servers. | |
622 | If unsure, say N. | |
623 | ||
74bd59bb PE |
624 | config PID_NS |
625 | bool "PID Namespaces (EXPERIMENTAL)" | |
626 | default n | |
627 | depends on NAMESPACES && EXPERIMENTAL | |
628 | help | |
12d2b8f9 | 629 | Support process id namespaces. This allows having multiple |
74bd59bb PE |
630 | process with the same pid as long as they are in different |
631 | pid namespaces. This is a building block of containers. | |
632 | ||
633 | Unless you want to work with an experimental feature | |
634 | say N here. | |
635 | ||
d6eb633f MH |
636 | config NET_NS |
637 | bool "Network namespace" | |
638 | default n | |
639 | depends on NAMESPACES && EXPERIMENTAL && NET | |
640 | help | |
641 | Allow user space to create what appear to be multiple instances | |
642 | of the network stack. | |
643 | ||
f991633d DG |
644 | config BLK_DEV_INITRD |
645 | bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support" | |
646 | depends on BROKEN || !FRV | |
647 | help | |
648 | The initial RAM filesystem is a ramfs which is loaded by the | |
649 | boot loader (loadlin or lilo) and that is mounted as root | |
650 | before the normal boot procedure. It is typically used to | |
651 | load modules needed to mount the "real" root file system, | |
652 | etc. See <file:Documentation/initrd.txt> for details. | |
653 | ||
654 | If RAM disk support (BLK_DEV_RAM) is also included, this | |
655 | also enables initial RAM disk (initrd) support and adds | |
656 | 15 Kbytes (more on some other architectures) to the kernel size. | |
657 | ||
658 | If unsure say Y. | |
659 | ||
c33df4ea JPS |
660 | if BLK_DEV_INITRD |
661 | ||
dbec4866 SR |
662 | source "usr/Kconfig" |
663 | ||
c33df4ea JPS |
664 | endif |
665 | ||
c45b4f1f | 666 | config CC_OPTIMIZE_FOR_SIZE |
96fffeb4 | 667 | bool "Optimize for size" |
c45b4f1f | 668 | default y |
c45b4f1f LT |
669 | help |
670 | Enabling this option will pass "-Os" instead of "-O2" to gcc | |
671 | resulting in a smaller kernel. | |
672 | ||
775a7229 | 673 | If unsure, say Y. |
c45b4f1f | 674 | |
0847062a RD |
675 | config SYSCTL |
676 | bool | |
677 | ||
b943c460 RD |
678 | config ANON_INODES |
679 | bool | |
680 | ||
1da177e4 LT |
681 | menuconfig EMBEDDED |
682 | bool "Configure standard kernel features (for small systems)" | |
683 | help | |
684 | This option allows certain base kernel options and settings | |
685 | to be disabled or tweaked. This is for specialized | |
686 | environments which can tolerate a "non-standard" kernel. | |
687 | Only use this if you really know what you are doing. | |
688 | ||
ae81f9e3 CE |
689 | config UID16 |
690 | bool "Enable 16-bit UID system calls" if EMBEDDED | |
09337f50 | 691 | depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION) |
ae81f9e3 CE |
692 | default y |
693 | help | |
694 | This enables the legacy 16-bit UID syscall wrappers. | |
695 | ||
b89a8171 | 696 | config SYSCTL_SYSCALL |
0847062a | 697 | bool "Sysctl syscall support" if EMBEDDED |
13bb7e37 | 698 | default y |
b89a8171 | 699 | select SYSCTL |
ae81f9e3 | 700 | ---help--- |
13bb7e37 EB |
701 | sys_sysctl uses binary paths that have been found challenging |
702 | to properly maintain and use. The interface in /proc/sys | |
703 | using paths with ascii names is now the primary path to this | |
704 | information. | |
b89a8171 | 705 | |
13bb7e37 EB |
706 | Almost nothing using the binary sysctl interface so if you are |
707 | trying to save some space it is probably safe to disable this, | |
708 | making your kernel marginally smaller. | |
b89a8171 | 709 | |
13bb7e37 | 710 | If unsure say Y here. |
ae81f9e3 | 711 | |
1da177e4 | 712 | config KALLSYMS |
979c6a1e | 713 | bool "Load all symbols for debugging/ksymoops" if EMBEDDED |
1da177e4 LT |
714 | default y |
715 | help | |
716 | Say Y here to let the kernel print out symbolic crash information and | |
717 | symbolic stack backtraces. This increases the size of the kernel | |
718 | somewhat, as all symbols have to be loaded into the kernel image. | |
719 | ||
720 | config KALLSYMS_ALL | |
721 | bool "Include all symbols in kallsyms" | |
722 | depends on DEBUG_KERNEL && KALLSYMS | |
723 | help | |
724 | Normally kallsyms only contains the symbols of functions, for nicer | |
725 | OOPS messages. Some debuggers can use kallsyms for other | |
f9f97bc0 JJ |
726 | symbols too: say Y here to include all symbols, if you need them |
727 | and you don't care about adding 300k to the size of your kernel. | |
1da177e4 LT |
728 | |
729 | Say N. | |
730 | ||
731 | config KALLSYMS_EXTRA_PASS | |
732 | bool "Do an extra kallsyms pass" | |
733 | depends on KALLSYMS | |
734 | help | |
735 | If kallsyms is not working correctly, the build will fail with | |
736 | inconsistent kallsyms data. If that occurs, log a bug report and | |
737 | turn on KALLSYMS_EXTRA_PASS which should result in a stable build. | |
738 | Always say N here unless you find a bug in kallsyms, which must be | |
739 | reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while | |
740 | you wait for kallsyms to be fixed. | |
741 | ||
d59745ce | 742 | |
712f47ce GKH |
743 | config HOTPLUG |
744 | bool "Support for hot-pluggable devices" if EMBEDDED | |
745 | default y | |
746 | help | |
747 | This option is provided for the case where no hotplug or uevent | |
748 | capabilities is wanted by the kernel. You should only consider | |
749 | disabling this option for embedded systems that do not use modules, a | |
750 | dynamic /dev tree, or dynamic device discovery. Just say Y. | |
751 | ||
d59745ce MM |
752 | config PRINTK |
753 | default y | |
754 | bool "Enable support for printk" if EMBEDDED | |
755 | help | |
756 | This option enables normal printk support. Removing it | |
757 | eliminates most of the message strings from the kernel image | |
758 | and makes the kernel more or less silent. As this makes it | |
759 | very difficult to diagnose system problems, saying N here is | |
760 | strongly discouraged. | |
761 | ||
c8538a7a MM |
762 | config BUG |
763 | bool "BUG() support" if EMBEDDED | |
764 | default y | |
765 | help | |
766 | Disabling this option eliminates support for BUG and WARN, reducing | |
767 | the size of your kernel image and potentially quietly ignoring | |
768 | numerous fatal conditions. You should only consider disabling this | |
769 | option for embedded systems with no facilities for reporting errors. | |
770 | Just say Y. | |
771 | ||
708e9a79 MM |
772 | config ELF_CORE |
773 | default y | |
774 | bool "Enable ELF core dumps" if EMBEDDED | |
775 | help | |
776 | Enable support for generating core dumps. Disabling saves about 4k. | |
777 | ||
e5e1d3cb SS |
778 | config PCSPKR_PLATFORM |
779 | bool "Enable PC-Speaker support" if EMBEDDED | |
780 | depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES | |
781 | default y | |
782 | help | |
783 | This option allows to disable the internal PC-Speaker | |
784 | support, saving some memory. | |
785 | ||
1da177e4 LT |
786 | config BASE_FULL |
787 | default y | |
788 | bool "Enable full-sized data structures for core" if EMBEDDED | |
789 | help | |
790 | Disabling this option reduces the size of miscellaneous core | |
791 | kernel data structures. This saves memory on small machines, | |
792 | but may reduce performance. | |
793 | ||
794 | config FUTEX | |
795 | bool "Enable futex support" if EMBEDDED | |
796 | default y | |
23f78d4a | 797 | select RT_MUTEXES |
1da177e4 LT |
798 | help |
799 | Disabling this option will cause the kernel to be built without | |
800 | support for "fast userspace mutexes". The resulting kernel may not | |
801 | run glibc-based applications correctly. | |
802 | ||
803 | config EPOLL | |
804 | bool "Enable eventpoll support" if EMBEDDED | |
805 | default y | |
448e3cee | 806 | select ANON_INODES |
1da177e4 LT |
807 | help |
808 | Disabling this option will cause the kernel to be built without | |
809 | support for epoll family of system calls. | |
810 | ||
fba2afaa DL |
811 | config SIGNALFD |
812 | bool "Enable signalfd() system call" if EMBEDDED | |
448e3cee | 813 | select ANON_INODES |
fba2afaa DL |
814 | default y |
815 | help | |
816 | Enable the signalfd() system call that allows to receive signals | |
817 | on a file descriptor. | |
818 | ||
819 | If unsure, say Y. | |
820 | ||
b215e283 DL |
821 | config TIMERFD |
822 | bool "Enable timerfd() system call" if EMBEDDED | |
448e3cee | 823 | select ANON_INODES |
b215e283 DL |
824 | default y |
825 | help | |
826 | Enable the timerfd() system call that allows to receive timer | |
827 | events on a file descriptor. | |
828 | ||
829 | If unsure, say Y. | |
830 | ||
e1ad7468 DL |
831 | config EVENTFD |
832 | bool "Enable eventfd() system call" if EMBEDDED | |
448e3cee | 833 | select ANON_INODES |
e1ad7468 DL |
834 | default y |
835 | help | |
836 | Enable the eventfd() system call that allows to receive both | |
837 | kernel notification (ie. KAIO) or userspace notifications. | |
838 | ||
839 | If unsure, say Y. | |
840 | ||
1da177e4 LT |
841 | config SHMEM |
842 | bool "Use full shmem filesystem" if EMBEDDED | |
843 | default y | |
844 | depends on MMU | |
845 | help | |
846 | The shmem is an internal filesystem used to manage shared memory. | |
847 | It is backed by swap and manages resource limits. It is also exported | |
848 | to userspace as tmpfs if TMPFS is enabled. Disabling this | |
849 | option replaces shmem and tmpfs with the much simpler ramfs code, | |
850 | which may be appropriate on small systems without swap. | |
851 | ||
ebf3f09c TP |
852 | config AIO |
853 | bool "Enable AIO support" if EMBEDDED | |
854 | default y | |
855 | help | |
856 | This option enables POSIX asynchronous I/O which may by used | |
857 | by some high performance threaded applications. Disabling | |
858 | this option saves about 7k. | |
859 | ||
f8891e5e CL |
860 | config VM_EVENT_COUNTERS |
861 | default y | |
862 | bool "Enable VM event counters for /proc/vmstat" if EMBEDDED | |
863 | help | |
2aea4fb6 PJ |
864 | VM event counters are needed for event counts to be shown. |
865 | This option allows the disabling of the VM event counters | |
866 | on EMBEDDED systems. /proc/vmstat will only show page counts | |
867 | if VM event counters are disabled. | |
f8891e5e | 868 | |
3d137310 TP |
869 | config PCI_QUIRKS |
870 | default y | |
61cfc7e4 GU |
871 | bool "Enable PCI quirk workarounds" if EMBEDDED |
872 | depends on PCI | |
3d137310 TP |
873 | help |
874 | This enables workarounds for various PCI chipset | |
875 | bugs/quirks. Disable this only if your target machine is | |
876 | unaffected by PCI quirks. | |
877 | ||
41ecc55b CL |
878 | config SLUB_DEBUG |
879 | default y | |
880 | bool "Enable SLUB debugging support" if EMBEDDED | |
f6acb635 | 881 | depends on SLUB && SYSFS |
41ecc55b CL |
882 | help |
883 | SLUB has extensive debug support features. Disabling these can | |
884 | result in significant savings in code size. This also disables | |
885 | SLUB sysfs support. /sys/slab will not exist and there will be | |
886 | no support for cache validation etc. | |
887 | ||
b943c460 RD |
888 | config COMPAT_BRK |
889 | bool "Disable heap randomization" | |
890 | default y | |
891 | help | |
892 | Randomizing heap placement makes heap exploits harder, but it | |
893 | also breaks ancient binaries (including anything libc5 based). | |
894 | This option changes the bootup default to heap randomization | |
895 | disabled, and can be overriden runtime by setting | |
896 | /proc/sys/kernel/randomize_va_space to 2. | |
897 | ||
898 | On non-ancient distros (post-2000 ones) N is usually a safe choice. | |
899 | ||
81819f0f CL |
900 | choice |
901 | prompt "Choose SLAB allocator" | |
a0acd820 | 902 | default SLUB |
81819f0f CL |
903 | help |
904 | This option allows to select a slab allocator. | |
905 | ||
906 | config SLAB | |
907 | bool "SLAB" | |
908 | help | |
909 | The regular slab allocator that is established and known to work | |
34013886 | 910 | well in all environments. It organizes cache hot objects in |
02f56210 | 911 | per cpu and per node queues. |
81819f0f CL |
912 | |
913 | config SLUB | |
81819f0f CL |
914 | bool "SLUB (Unqueued Allocator)" |
915 | help | |
916 | SLUB is a slab allocator that minimizes cache line usage | |
917 | instead of managing queues of cached objects (SLAB approach). | |
918 | Per cpu caching is realized using slabs of objects instead | |
919 | of queues of objects. SLUB can use memory efficiently | |
02f56210 SA |
920 | and has enhanced diagnostics. SLUB is the default choice for |
921 | a slab allocator. | |
81819f0f CL |
922 | |
923 | config SLOB | |
84a01c2f | 924 | depends on EMBEDDED |
81819f0f CL |
925 | bool "SLOB (Simple Allocator)" |
926 | help | |
37291458 MM |
927 | SLOB replaces the stock allocator with a drastically simpler |
928 | allocator. SLOB is generally more space efficient but | |
929 | does not perform as well on large systems. | |
81819f0f CL |
930 | |
931 | endchoice | |
932 | ||
125e5645 MD |
933 | config PROFILING |
934 | bool "Profiling support (EXPERIMENTAL)" | |
935 | help | |
936 | Say Y here to enable the extended profiling support mechanisms used | |
937 | by profilers such as OProfile. | |
938 | ||
5f87f112 IM |
939 | # |
940 | # Place an empty function call at each tracepoint site. Can be | |
941 | # dynamically changed for a probe function. | |
942 | # | |
97e1c18e | 943 | config TRACEPOINTS |
5f87f112 | 944 | bool |
97e1c18e | 945 | |
125e5645 MD |
946 | config MARKERS |
947 | bool "Activate markers" | |
c1df1bd2 | 948 | depends on TRACEPOINTS |
125e5645 MD |
949 | help |
950 | Place an empty function call at each marker site. Can be | |
951 | dynamically changed for a probe function. | |
952 | ||
fb32e03f MD |
953 | source "arch/Kconfig" |
954 | ||
1da177e4 LT |
955 | endmenu # General setup |
956 | ||
ee7e5516 DB |
957 | config HAVE_GENERIC_DMA_COHERENT |
958 | bool | |
959 | default n | |
960 | ||
158a9624 LT |
961 | config SLABINFO |
962 | bool | |
963 | depends on PROC_FS | |
0f389ec6 | 964 | depends on SLAB || SLUB_DEBUG |
158a9624 LT |
965 | default y |
966 | ||
ae81f9e3 CE |
967 | config RT_MUTEXES |
968 | boolean | |
969 | select PLIST | |
970 | ||
1da177e4 LT |
971 | config BASE_SMALL |
972 | int | |
973 | default 0 if BASE_FULL | |
974 | default 1 if !BASE_FULL | |
975 | ||
66da5733 | 976 | menuconfig MODULES |
1da177e4 LT |
977 | bool "Enable loadable module support" |
978 | help | |
979 | Kernel modules are small pieces of compiled code which can | |
980 | be inserted in the running kernel, rather than being | |
981 | permanently built into the kernel. You use the "modprobe" | |
982 | tool to add (and sometimes remove) them. If you say Y here, | |
983 | many parts of the kernel can be built as modules (by | |
984 | answering M instead of Y where indicated): this is most | |
985 | useful for infrequently used options which are not required | |
986 | for booting. For more information, see the man pages for | |
987 | modprobe, lsmod, modinfo, insmod and rmmod. | |
988 | ||
989 | If you say Y here, you will need to run "make | |
990 | modules_install" to put the modules under /lib/modules/ | |
991 | where modprobe can find them (you may need to be root to do | |
992 | this). | |
993 | ||
994 | If unsure, say Y. | |
995 | ||
0b0de144 RD |
996 | if MODULES |
997 | ||
826e4506 LT |
998 | config MODULE_FORCE_LOAD |
999 | bool "Forced module loading" | |
826e4506 LT |
1000 | default n |
1001 | help | |
91e37a79 RR |
1002 | Allow loading of modules without version information (ie. modprobe |
1003 | --force). Forced module loading sets the 'F' (forced) taint flag and | |
1004 | is usually a really bad idea. | |
826e4506 | 1005 | |
1da177e4 LT |
1006 | config MODULE_UNLOAD |
1007 | bool "Module unloading" | |
1da177e4 LT |
1008 | help |
1009 | Without this option you will not be able to unload any | |
1010 | modules (note that some modules may not be unloadable | |
f7f5b675 DV |
1011 | anyway), which makes your kernel smaller, faster |
1012 | and simpler. If unsure, say Y. | |
1da177e4 LT |
1013 | |
1014 | config MODULE_FORCE_UNLOAD | |
1015 | bool "Forced module unloading" | |
1016 | depends on MODULE_UNLOAD && EXPERIMENTAL | |
1017 | help | |
1018 | This option allows you to force a module to unload, even if the | |
1019 | kernel believes it is unsafe: the kernel will remove the module | |
1020 | without waiting for anyone to stop using it (using the -f option to | |
1021 | rmmod). This is mainly for kernel developers and desperate users. | |
1022 | If unsure, say N. | |
1023 | ||
1da177e4 | 1024 | config MODVERSIONS |
0d541643 | 1025 | bool "Module versioning support" |
1da177e4 LT |
1026 | help |
1027 | Usually, you have to use modules compiled with your kernel. | |
1028 | Saying Y here makes it sometimes possible to use modules | |
1029 | compiled for different kernels, by adding enough information | |
1030 | to the modules to (hopefully) spot any changes which would | |
1031 | make them incompatible with the kernel you are running. If | |
1032 | unsure, say N. | |
1033 | ||
1034 | config MODULE_SRCVERSION_ALL | |
1035 | bool "Source checksum for all modules" | |
1da177e4 LT |
1036 | help |
1037 | Modules which contain a MODULE_VERSION get an extra "srcversion" | |
1038 | field inserted into their modinfo section, which contains a | |
1039 | sum of the source files which made it. This helps maintainers | |
1040 | see exactly which source was used to build a module (since | |
1041 | others sometimes change the module source without updating | |
1042 | the version). With this option, such a "srcversion" field | |
1043 | will be created for all modules. If unsure, say N. | |
1044 | ||
0b0de144 RD |
1045 | endif # MODULES |
1046 | ||
98a79d6a RR |
1047 | config INIT_ALL_POSSIBLE |
1048 | bool | |
1049 | help | |
1050 | Back when each arch used to define their own cpu_online_map and | |
1051 | cpu_possible_map, some of them chose to initialize cpu_possible_map | |
1052 | with all 1s, and others with all 0s. When they were centralised, | |
1053 | it was better to provide this option than to break all the archs | |
1054 | and have several arch maintainers persuing me down dark alleys. | |
1055 | ||
1da177e4 LT |
1056 | config STOP_MACHINE |
1057 | bool | |
1058 | default y | |
1059 | depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU | |
1060 | help | |
1061 | Need stop_machine() primitive. | |
3a65dfe8 | 1062 | |
3a65dfe8 | 1063 | source "block/Kconfig" |
e98c3202 AK |
1064 | |
1065 | config PREEMPT_NOTIFIERS | |
1066 | bool | |
e260be67 | 1067 |