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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 | |
22 | default y | |
23 | ||
e360adbe PZ |
24 | config HAVE_IRQ_WORK |
25 | bool | |
26 | ||
27 | config IRQ_WORK | |
28 | bool | |
29 | depends on HAVE_IRQ_WORK | |
30 | ||
ff0cfc66 | 31 | menu "General setup" |
1da177e4 LT |
32 | |
33 | config EXPERIMENTAL | |
34 | bool "Prompt for development and/or incomplete code/drivers" | |
35 | ---help--- | |
36 | Some of the various things that Linux supports (such as network | |
37 | drivers, file systems, network protocols, etc.) can be in a state | |
38 | of development where the functionality, stability, or the level of | |
39 | testing is not yet high enough for general use. This is usually | |
40 | known as the "alpha-test" phase among developers. If a feature is | |
41 | currently in alpha-test, then the developers usually discourage | |
42 | uninformed widespread use of this feature by the general public to | |
43 | avoid "Why doesn't this work?" type mail messages. However, active | |
44 | testing and use of these systems is welcomed. Just be aware that it | |
45 | may not meet the normal level of reliability or it may fail to work | |
46 | in some special cases. Detailed bug reports from people familiar | |
47 | with the kernel internals are usually welcomed by the developers | |
48 | (before submitting bug reports, please read the documents | |
49 | <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>, | |
50 | <file:Documentation/BUG-HUNTING>, and | |
51 | <file:Documentation/oops-tracing.txt> in the kernel source). | |
52 | ||
53 | This option will also make obsoleted drivers available. These are | |
54 | drivers that have been replaced by something else, and/or are | |
55 | scheduled to be removed in a future kernel release. | |
56 | ||
57 | Unless you intend to help test and develop a feature or driver that | |
58 | falls into this category, or you have a situation that requires | |
59 | using these features, you should probably say N here, which will | |
60 | cause the configurator to present you with fewer choices. If | |
61 | you say Y here, you will be offered the choice of using features or | |
62 | drivers that are currently considered to be in the alpha-test phase. | |
63 | ||
1da177e4 LT |
64 | config BROKEN |
65 | bool | |
1da177e4 LT |
66 | |
67 | config BROKEN_ON_SMP | |
68 | bool | |
69 | depends on BROKEN || !SMP | |
70 | default y | |
71 | ||
72 | config LOCK_KERNEL | |
73 | bool | |
6de5bd12 | 74 | depends on (SMP || PREEMPT) && BKL |
1da177e4 LT |
75 | default y |
76 | ||
77 | config INIT_ENV_ARG_LIMIT | |
78 | int | |
dd673bca AB |
79 | default 32 if !UML |
80 | default 128 if UML | |
1da177e4 | 81 | help |
34ad92c2 RD |
82 | Maximum of each of the number of arguments and environment |
83 | variables passed to init from the kernel command line. | |
1da177e4 | 84 | |
1da177e4 | 85 | |
84336466 RM |
86 | config CROSS_COMPILE |
87 | string "Cross-compiler tool prefix" | |
88 | help | |
89 | Same as running 'make CROSS_COMPILE=prefix-' but stored for | |
90 | default make runs in this kernel build directory. You don't | |
91 | need to set this unless you want the configured kernel build | |
92 | directory to select the cross-compiler automatically. | |
93 | ||
1da177e4 LT |
94 | config LOCALVERSION |
95 | string "Local version - append to kernel release" | |
96 | help | |
97 | Append an extra string to the end of your kernel version. | |
98 | This will show up when you type uname, for example. | |
99 | The string you set here will be appended after the contents of | |
100 | any files with a filename matching localversion* in your | |
101 | object and source tree, in that order. Your total string can | |
102 | be a maximum of 64 characters. | |
103 | ||
aaebf433 RA |
104 | config LOCALVERSION_AUTO |
105 | bool "Automatically append version information to the version string" | |
106 | default y | |
107 | help | |
108 | This will try to automatically determine if the current tree is a | |
6e5a5420 RD |
109 | release tree by looking for git tags that belong to the current |
110 | top of tree revision. | |
aaebf433 RA |
111 | |
112 | A string of the format -gxxxxxxxx will be added to the localversion | |
6e5a5420 | 113 | if a git-based tree is found. The string generated by this will be |
aaebf433 | 114 | appended after any matching localversion* files, and after the value |
6e5a5420 | 115 | set in CONFIG_LOCALVERSION. |
aaebf433 | 116 | |
6e5a5420 RD |
117 | (The actual string used here is the first eight characters produced |
118 | by running the command: | |
119 | ||
120 | $ git rev-parse --verify HEAD | |
121 | ||
122 | which is done within the script "scripts/setlocalversion".) | |
aaebf433 | 123 | |
2e9f3bdd PA |
124 | config HAVE_KERNEL_GZIP |
125 | bool | |
126 | ||
127 | config HAVE_KERNEL_BZIP2 | |
128 | bool | |
129 | ||
130 | config HAVE_KERNEL_LZMA | |
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 | |
7dd65feb | 139 | depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || 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. | |
2e9f3bdd PA |
170 | Decompression speed is slowest among the three. The kernel |
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 | |
179 | The most recent compression algorithm. | |
180 | Its ratio is best, decompression speed is between the other | |
181 | two. Compression is slowest. The kernel size is about 33% | |
182 | smaller with LZMA in comparison to gzip. | |
30d65dbf | 183 | |
7dd65feb AT |
184 | config KERNEL_LZO |
185 | bool "LZO" | |
186 | depends on HAVE_KERNEL_LZO | |
187 | help | |
188 | Its compression ratio is the poorest among the 4. The kernel | |
681b3049 | 189 | size is about 10% bigger than gzip; however its speed |
7dd65feb AT |
190 | (both compression and decompression) is the fastest. |
191 | ||
30d65dbf AK |
192 | endchoice |
193 | ||
1da177e4 LT |
194 | config SWAP |
195 | bool "Support for paging of anonymous memory (swap)" | |
9361401e | 196 | depends on MMU && BLOCK |
1da177e4 LT |
197 | default y |
198 | help | |
199 | This option allows you to choose whether you want to have support | |
92c3504e | 200 | for so called swap devices or swap files in your kernel that are |
1da177e4 LT |
201 | used to provide more virtual memory than the actual RAM present |
202 | in your computer. If unsure say Y. | |
203 | ||
204 | config SYSVIPC | |
205 | bool "System V IPC" | |
1da177e4 LT |
206 | ---help--- |
207 | Inter Process Communication is a suite of library functions and | |
208 | system calls which let processes (running programs) synchronize and | |
209 | exchange information. It is generally considered to be a good thing, | |
210 | and some programs won't run unless you say Y here. In particular, if | |
211 | you want to run the DOS emulator dosemu under Linux (read the | |
212 | DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>), | |
213 | you'll need to say Y here. | |
214 | ||
215 | You can find documentation about IPC with "info ipc" and also in | |
216 | section 6.4 of the Linux Programmer's Guide, available from | |
217 | <http://www.tldp.org/guides.html>. | |
218 | ||
a5494dcd EB |
219 | config SYSVIPC_SYSCTL |
220 | bool | |
221 | depends on SYSVIPC | |
222 | depends on SYSCTL | |
223 | default y | |
224 | ||
1da177e4 LT |
225 | config POSIX_MQUEUE |
226 | bool "POSIX Message Queues" | |
227 | depends on NET && EXPERIMENTAL | |
228 | ---help--- | |
229 | POSIX variant of message queues is a part of IPC. In POSIX message | |
230 | queues every message has a priority which decides about succession | |
231 | of receiving it by a process. If you want to compile and run | |
232 | programs written e.g. for Solaris with use of its POSIX message | |
b0e37650 | 233 | queues (functions mq_*) say Y here. |
1da177e4 LT |
234 | |
235 | POSIX message queues are visible as a filesystem called 'mqueue' | |
236 | and can be mounted somewhere if you want to do filesystem | |
237 | operations on message queues. | |
238 | ||
239 | If unsure, say Y. | |
240 | ||
bdc8e5f8 SH |
241 | config POSIX_MQUEUE_SYSCTL |
242 | bool | |
243 | depends on POSIX_MQUEUE | |
244 | depends on SYSCTL | |
245 | default y | |
246 | ||
1da177e4 LT |
247 | config BSD_PROCESS_ACCT |
248 | bool "BSD Process Accounting" | |
249 | help | |
250 | If you say Y here, a user level program will be able to instruct the | |
251 | kernel (via a special system call) to write process accounting | |
252 | information to a file: whenever a process exits, information about | |
253 | that process will be appended to the file by the kernel. The | |
254 | information includes things such as creation time, owning user, | |
255 | command name, memory usage, controlling terminal etc. (the complete | |
256 | list is in the struct acct in <file:include/linux/acct.h>). It is | |
257 | up to the user level program to do useful things with this | |
258 | information. This is generally a good idea, so say Y. | |
259 | ||
260 | config BSD_PROCESS_ACCT_V3 | |
261 | bool "BSD Process Accounting version 3 file format" | |
262 | depends on BSD_PROCESS_ACCT | |
263 | default n | |
264 | help | |
265 | If you say Y here, the process accounting information is written | |
266 | in a new file format that also logs the process IDs of each | |
267 | process and it's parent. Note that this file format is incompatible | |
268 | with previous v0/v1/v2 file formats, so you will need updated tools | |
269 | for processing it. A preliminary version of these tools is available | |
37a4c940 | 270 | at <http://www.gnu.org/software/acct/>. |
1da177e4 | 271 | |
c757249a SN |
272 | config TASKSTATS |
273 | bool "Export task/process statistics through netlink (EXPERIMENTAL)" | |
274 | depends on NET | |
275 | default n | |
276 | help | |
277 | Export selected statistics for tasks/processes through the | |
278 | generic netlink interface. Unlike BSD process accounting, the | |
279 | statistics are available during the lifetime of tasks/processes as | |
280 | responses to commands. Like BSD accounting, they are sent to user | |
281 | space on task exit. | |
282 | ||
283 | Say N if unsure. | |
284 | ||
ca74e92b SN |
285 | config TASK_DELAY_ACCT |
286 | bool "Enable per-task delay accounting (EXPERIMENTAL)" | |
6f44993f | 287 | depends on TASKSTATS |
ca74e92b SN |
288 | help |
289 | Collect information on time spent by a task waiting for system | |
290 | resources like cpu, synchronous block I/O completion and swapping | |
291 | in pages. Such statistics can help in setting a task's priorities | |
292 | relative to other tasks for cpu, io, rss limits etc. | |
293 | ||
294 | Say N if unsure. | |
295 | ||
18f705f4 AD |
296 | config TASK_XACCT |
297 | bool "Enable extended accounting over taskstats (EXPERIMENTAL)" | |
298 | depends on TASKSTATS | |
299 | help | |
300 | Collect extended task accounting data and send the data | |
301 | to userland for processing over the taskstats interface. | |
302 | ||
303 | Say N if unsure. | |
304 | ||
305 | config TASK_IO_ACCOUNTING | |
306 | bool "Enable per-task storage I/O accounting (EXPERIMENTAL)" | |
307 | depends on TASK_XACCT | |
308 | help | |
309 | Collect information on the number of bytes of storage I/O which this | |
310 | task has caused. | |
311 | ||
312 | Say N if unsure. | |
313 | ||
1da177e4 LT |
314 | config AUDIT |
315 | bool "Auditing support" | |
804a6a49 | 316 | depends on NET |
1da177e4 LT |
317 | help |
318 | Enable auditing infrastructure that can be used with another | |
319 | kernel subsystem, such as SELinux (which requires this for | |
320 | logging of avc messages output). Does not do system-call | |
321 | auditing without CONFIG_AUDITSYSCALL. | |
322 | ||
323 | config AUDITSYSCALL | |
324 | bool "Enable system-call auditing support" | |
022382a5 | 325 | depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH) |
1da177e4 LT |
326 | default y if SECURITY_SELINUX |
327 | help | |
328 | Enable low-overhead system-call auditing infrastructure that | |
329 | can be used independently or with another kernel subsystem, | |
67640b60 | 330 | such as SELinux. |
1da177e4 | 331 | |
939a67fc EP |
332 | config AUDIT_WATCH |
333 | def_bool y | |
334 | depends on AUDITSYSCALL | |
335 | select FSNOTIFY | |
1da177e4 | 336 | |
74c3cbe3 AV |
337 | config AUDIT_TREE |
338 | def_bool y | |
63c882a0 | 339 | depends on AUDITSYSCALL |
28a3a7eb | 340 | select FSNOTIFY |
74c3cbe3 | 341 | |
d9817ebe TG |
342 | source "kernel/irq/Kconfig" |
343 | ||
c903ff83 MT |
344 | menu "RCU Subsystem" |
345 | ||
346 | choice | |
347 | prompt "RCU Implementation" | |
31c9a24e | 348 | default TREE_RCU |
c903ff83 | 349 | |
c903ff83 MT |
350 | config TREE_RCU |
351 | bool "Tree-based hierarchical RCU" | |
687d7a96 | 352 | depends on !PREEMPT && SMP |
c903ff83 MT |
353 | help |
354 | This option selects the RCU implementation that is | |
355 | designed for very large SMP system with hundreds or | |
c17ef453 PM |
356 | thousands of CPUs. It also scales down nicely to |
357 | smaller systems. | |
c903ff83 | 358 | |
f41d911f | 359 | config TREE_PREEMPT_RCU |
a57eb940 | 360 | bool "Preemptible tree-based hierarchical RCU" |
f41d911f PM |
361 | depends on PREEMPT |
362 | help | |
363 | This option selects the RCU implementation that is | |
364 | designed for very large SMP systems with hundreds or | |
365 | thousands of CPUs, but for which real-time response | |
bbe3eae8 PM |
366 | is also required. It also scales down nicely to |
367 | smaller systems. | |
f41d911f | 368 | |
9b1d82fa PM |
369 | config TINY_RCU |
370 | bool "UP-only small-memory-footprint RCU" | |
371 | depends on !SMP | |
372 | help | |
373 | This option selects the RCU implementation that is | |
374 | designed for UP systems from which real-time response | |
375 | is not required. This option greatly reduces the | |
376 | memory footprint of RCU. | |
377 | ||
a57eb940 PM |
378 | config TINY_PREEMPT_RCU |
379 | bool "Preemptible UP-only small-memory-footprint RCU" | |
380 | depends on !SMP && PREEMPT | |
381 | help | |
382 | This option selects the RCU implementation that is designed | |
383 | for real-time UP systems. This option greatly reduces the | |
384 | memory footprint of RCU. | |
385 | ||
c903ff83 MT |
386 | endchoice |
387 | ||
a57eb940 PM |
388 | config PREEMPT_RCU |
389 | def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU ) | |
390 | help | |
391 | This option enables preemptible-RCU code that is common between | |
392 | the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations. | |
393 | ||
c903ff83 MT |
394 | config RCU_TRACE |
395 | bool "Enable tracing for RCU" | |
6b3ef48a | 396 | depends on TREE_RCU || TREE_PREEMPT_RCU |
c903ff83 MT |
397 | help |
398 | This option provides tracing in RCU which presents stats | |
399 | in debugfs for debugging RCU implementation. | |
400 | ||
401 | Say Y here if you want to enable RCU tracing | |
402 | Say N if you are unsure. | |
403 | ||
404 | config RCU_FANOUT | |
405 | int "Tree-based hierarchical RCU fanout value" | |
406 | range 2 64 if 64BIT | |
407 | range 2 32 if !64BIT | |
f41d911f | 408 | depends on TREE_RCU || TREE_PREEMPT_RCU |
c903ff83 MT |
409 | default 64 if 64BIT |
410 | default 32 if !64BIT | |
411 | help | |
412 | This option controls the fanout of hierarchical implementations | |
413 | of RCU, allowing RCU to work efficiently on machines with | |
4d87ffad PM |
414 | large numbers of CPUs. This value must be at least the fourth |
415 | root of NR_CPUS, which allows NR_CPUS to be insanely large. | |
416 | The default value of RCU_FANOUT should be used for production | |
417 | systems, but if you are stress-testing the RCU implementation | |
418 | itself, small RCU_FANOUT values allow you to test large-system | |
419 | code paths on small(er) systems. | |
c903ff83 MT |
420 | |
421 | Select a specific number if testing RCU itself. | |
422 | Take the default if unsure. | |
423 | ||
424 | config RCU_FANOUT_EXACT | |
425 | bool "Disable tree-based hierarchical RCU auto-balancing" | |
f41d911f | 426 | depends on TREE_RCU || TREE_PREEMPT_RCU |
c903ff83 MT |
427 | default n |
428 | help | |
429 | This option forces use of the exact RCU_FANOUT value specified, | |
430 | regardless of imbalances in the hierarchy. This is useful for | |
431 | testing RCU itself, and might one day be useful on systems with | |
432 | strong NUMA behavior. | |
433 | ||
434 | Without RCU_FANOUT_EXACT, the code will balance the hierarchy. | |
435 | ||
436 | Say N if unsure. | |
437 | ||
8bd93a2c PM |
438 | config RCU_FAST_NO_HZ |
439 | bool "Accelerate last non-dyntick-idle CPU's grace periods" | |
440 | depends on TREE_RCU && NO_HZ && SMP | |
441 | default n | |
442 | help | |
443 | This option causes RCU to attempt to accelerate grace periods | |
444 | in order to allow the final CPU to enter dynticks-idle state | |
445 | more quickly. On the other hand, this option increases the | |
446 | overhead of the dynticks-idle checking, particularly on systems | |
447 | with large numbers of CPUs. | |
448 | ||
449 | Say Y if energy efficiency is critically important, particularly | |
450 | if you have relatively few CPUs. | |
451 | ||
452 | Say N if you are unsure. | |
453 | ||
c903ff83 | 454 | config TREE_RCU_TRACE |
f41d911f | 455 | def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU ) |
c903ff83 MT |
456 | select DEBUG_FS |
457 | help | |
f41d911f PM |
458 | This option provides tracing for the TREE_RCU and |
459 | TREE_PREEMPT_RCU implementations, permitting Makefile to | |
460 | trivially select kernel/rcutree_trace.c. | |
c903ff83 | 461 | |
c903ff83 MT |
462 | endmenu # "RCU Subsystem" |
463 | ||
1da177e4 | 464 | config IKCONFIG |
f2443ab6 | 465 | tristate "Kernel .config support" |
1da177e4 LT |
466 | ---help--- |
467 | This option enables the complete Linux kernel ".config" file | |
468 | contents to be saved in the kernel. It provides documentation | |
469 | of which kernel options are used in a running kernel or in an | |
470 | on-disk kernel. This information can be extracted from the kernel | |
471 | image file with the script scripts/extract-ikconfig and used as | |
472 | input to rebuild the current kernel or to build another kernel. | |
473 | It can also be extracted from a running kernel by reading | |
474 | /proc/config.gz if enabled (below). | |
475 | ||
476 | config IKCONFIG_PROC | |
477 | bool "Enable access to .config through /proc/config.gz" | |
478 | depends on IKCONFIG && PROC_FS | |
479 | ---help--- | |
480 | This option enables access to the kernel configuration file | |
481 | through /proc/config.gz. | |
482 | ||
794543a2 AJS |
483 | config LOG_BUF_SHIFT |
484 | int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" | |
485 | range 12 21 | |
f17a32e9 | 486 | default 17 |
794543a2 AJS |
487 | help |
488 | Select kernel log buffer size as a power of 2. | |
f17a32e9 AB |
489 | Examples: |
490 | 17 => 128 KB | |
491 | 16 => 64 KB | |
492 | 15 => 32 KB | |
493 | 14 => 16 KB | |
794543a2 AJS |
494 | 13 => 8 KB |
495 | 12 => 4 KB | |
496 | ||
a5574cf6 IM |
497 | # |
498 | # Architectures with an unreliable sched_clock() should select this: | |
499 | # | |
500 | config HAVE_UNSTABLE_SCHED_CLOCK | |
501 | bool | |
502 | ||
23964d2d LZ |
503 | menuconfig CGROUPS |
504 | boolean "Control Group support" | |
0dea1168 | 505 | depends on EVENTFD |
5cdc38f9 | 506 | help |
23964d2d | 507 | This option adds support for grouping sets of processes together, for |
5cdc38f9 KH |
508 | use with process control subsystems such as Cpusets, CFS, memory |
509 | controls or device isolation. | |
510 | See | |
5cdc38f9 | 511 | - Documentation/scheduler/sched-design-CFS.txt (CFS) |
45ce80fb LZ |
512 | - Documentation/cgroups/ (features for grouping, isolation |
513 | and resource control) | |
5cdc38f9 KH |
514 | |
515 | Say N if unsure. | |
516 | ||
23964d2d LZ |
517 | if CGROUPS |
518 | ||
5cdc38f9 KH |
519 | config CGROUP_DEBUG |
520 | bool "Example debug cgroup subsystem" | |
5cdc38f9 KH |
521 | default n |
522 | help | |
523 | This option enables a simple cgroup subsystem that | |
524 | exports useful debugging information about the cgroups | |
23964d2d | 525 | framework. |
5cdc38f9 | 526 | |
23964d2d | 527 | Say N if unsure. |
5cdc38f9 KH |
528 | |
529 | config CGROUP_NS | |
23964d2d | 530 | bool "Namespace cgroup subsystem" |
23964d2d LZ |
531 | help |
532 | Provides a simple namespace cgroup subsystem to | |
533 | provide hierarchical naming of sets of namespaces, | |
534 | for instance virtual servers and checkpoint/restart | |
535 | jobs. | |
5cdc38f9 KH |
536 | |
537 | config CGROUP_FREEZER | |
23964d2d | 538 | bool "Freezer cgroup subsystem" |
23964d2d LZ |
539 | help |
540 | Provides a way to freeze and unfreeze all tasks in a | |
5cdc38f9 KH |
541 | cgroup. |
542 | ||
543 | config CGROUP_DEVICE | |
544 | bool "Device controller for cgroups" | |
5cdc38f9 KH |
545 | help |
546 | Provides a cgroup implementing whitelists for devices which | |
547 | a process in the cgroup can mknod or open. | |
548 | ||
549 | config CPUSETS | |
550 | bool "Cpuset support" | |
5cdc38f9 KH |
551 | help |
552 | This option will let you create and manage CPUSETs which | |
553 | allow dynamically partitioning a system into sets of CPUs and | |
554 | Memory Nodes and assigning tasks to run only within those sets. | |
555 | This is primarily useful on large SMP or NUMA systems. | |
556 | ||
557 | Say N if unsure. | |
558 | ||
23964d2d LZ |
559 | config PROC_PID_CPUSET |
560 | bool "Include legacy /proc/<pid>/cpuset file" | |
561 | depends on CPUSETS | |
562 | default y | |
563 | ||
d842de87 SV |
564 | config CGROUP_CPUACCT |
565 | bool "Simple CPU accounting cgroup subsystem" | |
d842de87 SV |
566 | help |
567 | Provides a simple Resource Controller for monitoring the | |
23964d2d | 568 | total CPU consumed by the tasks in a cgroup. |
d842de87 | 569 | |
e552b661 PE |
570 | config RESOURCE_COUNTERS |
571 | bool "Resource counters" | |
572 | help | |
573 | This option enables controller independent resource accounting | |
23964d2d | 574 | infrastructure that works with cgroups. |
e552b661 | 575 | |
00f0b825 BS |
576 | config CGROUP_MEM_RES_CTLR |
577 | bool "Memory Resource Controller for Control Groups" | |
79ae9c29 | 578 | depends on RESOURCE_COUNTERS |
cf475ad2 | 579 | select MM_OWNER |
00f0b825 | 580 | help |
84ad6d70 | 581 | Provides a memory resource controller that manages both anonymous |
21acb9ca | 582 | memory and page cache. (See Documentation/cgroups/memory.txt) |
00f0b825 BS |
583 | |
584 | Note that setting this option increases fixed memory overhead | |
84ad6d70 KH |
585 | associated with each page of memory in the system. By this, |
586 | 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory | |
587 | usage tracking struct at boot. Total amount of this is printed out | |
588 | at boot. | |
00f0b825 BS |
589 | |
590 | Only enable when you're ok with these trade offs and really | |
84ad6d70 KH |
591 | sure you need the memory resource controller. Even when you enable |
592 | this, you can set "cgroup_disable=memory" at your boot option to | |
593 | disable memory resource controller and you can avoid overheads. | |
c9d5409f | 594 | (and lose benefits of memory resource controller) |
00f0b825 | 595 | |
cf475ad2 BS |
596 | This config option also selects MM_OWNER config option, which |
597 | could in turn add some fork/exit overhead. | |
598 | ||
c077719b | 599 | config CGROUP_MEM_RES_CTLR_SWAP |
65e0e811 KH |
600 | bool "Memory Resource Controller Swap Extension" |
601 | depends on CGROUP_MEM_RES_CTLR && SWAP | |
c077719b KH |
602 | help |
603 | Add swap management feature to memory resource controller. When you | |
604 | enable this, you can limit mem+swap usage per cgroup. In other words, | |
605 | when you disable this, memory resource controller has no cares to | |
606 | usage of swap...a process can exhaust all of the swap. This extension | |
607 | is useful when you want to avoid exhaustion swap but this itself | |
608 | adds more overheads and consumes memory for remembering information. | |
609 | Especially if you use 32bit system or small memory system, please | |
610 | be careful about enabling this. When memory resource controller | |
611 | is disabled by boot option, this will be automatically disabled and | |
612 | there will be no overhead from this. Even when you set this config=y, | |
613 | if boot option "noswapaccount" is set, swap will not be accounted. | |
627991a2 KH |
614 | Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page |
615 | size is 4096bytes, 512k per 1Gbytes of swap. | |
a42c390c MH |
616 | config CGROUP_MEM_RES_CTLR_SWAP_ENABLED |
617 | bool "Memory Resource Controller Swap Extension enabled by default" | |
618 | depends on CGROUP_MEM_RES_CTLR_SWAP | |
619 | default y | |
620 | help | |
621 | Memory Resource Controller Swap Extension comes with its price in | |
622 | a bigger memory consumption. General purpose distribution kernels | |
623 | which want to enable the feautre but keep it disabled by default | |
624 | and let the user enable it by swapaccount boot command line | |
625 | parameter should have this option unselected. | |
626 | For those who want to have the feature enabled by default should | |
627 | select this option (if, for some reason, they need to disable it | |
628 | then noswapaccount does the trick). | |
c077719b | 629 | |
7c941438 DG |
630 | menuconfig CGROUP_SCHED |
631 | bool "Group CPU scheduler" | |
79ae9c29 | 632 | depends on EXPERIMENTAL |
7c941438 DG |
633 | default n |
634 | help | |
635 | This feature lets CPU scheduler recognize task groups and control CPU | |
636 | bandwidth allocation to such task groups. It uses cgroups to group | |
637 | tasks. | |
638 | ||
639 | if CGROUP_SCHED | |
640 | config FAIR_GROUP_SCHED | |
641 | bool "Group scheduling for SCHED_OTHER" | |
642 | depends on CGROUP_SCHED | |
643 | default CGROUP_SCHED | |
644 | ||
645 | config RT_GROUP_SCHED | |
646 | bool "Group scheduling for SCHED_RR/FIFO" | |
647 | depends on EXPERIMENTAL | |
648 | depends on CGROUP_SCHED | |
649 | default n | |
650 | help | |
651 | This feature lets you explicitly allocate real CPU bandwidth | |
32bd7eb5 | 652 | to task groups. If enabled, it will also make it impossible to |
7c941438 DG |
653 | schedule realtime tasks for non-root users until you allocate |
654 | realtime bandwidth for them. | |
655 | See Documentation/scheduler/sched-rt-group.txt for more information. | |
656 | ||
657 | endif #CGROUP_SCHED | |
658 | ||
afc24d49 VG |
659 | config BLK_CGROUP |
660 | tristate "Block IO controller" | |
79ae9c29 | 661 | depends on BLOCK |
afc24d49 VG |
662 | default n |
663 | ---help--- | |
664 | Generic block IO controller cgroup interface. This is the common | |
665 | cgroup interface which should be used by various IO controlling | |
666 | policies. | |
667 | ||
668 | Currently, CFQ IO scheduler uses it to recognize task groups and | |
669 | control disk bandwidth allocation (proportional time slice allocation) | |
e43473b7 VG |
670 | to such task groups. It is also used by bio throttling logic in |
671 | block layer to implement upper limit in IO rates on a device. | |
afc24d49 VG |
672 | |
673 | This option only enables generic Block IO controller infrastructure. | |
e43473b7 VG |
674 | One needs to also enable actual IO controlling logic/policy. For |
675 | enabling proportional weight division of disk bandwidth in CFQ seti | |
676 | CONFIG_CFQ_GROUP_IOSCHED=y and for enabling throttling policy set | |
677 | CONFIG_BLK_THROTTLE=y. | |
afc24d49 VG |
678 | |
679 | See Documentation/cgroups/blkio-controller.txt for more information. | |
680 | ||
681 | config DEBUG_BLK_CGROUP | |
682 | bool "Enable Block IO controller debugging" | |
683 | depends on BLK_CGROUP | |
684 | default n | |
685 | ---help--- | |
686 | Enable some debugging help. Currently it exports additional stat | |
687 | files in a cgroup which can be useful for debugging. | |
688 | ||
23964d2d | 689 | endif # CGROUPS |
c077719b | 690 | |
8dd2a82c | 691 | menuconfig NAMESPACES |
c5289a69 PE |
692 | bool "Namespaces support" if EMBEDDED |
693 | default !EMBEDDED | |
694 | help | |
695 | Provides the way to make tasks work with different objects using | |
696 | the same id. For example same IPC id may refer to different objects | |
697 | or same user id or pid may refer to different tasks when used in | |
698 | different namespaces. | |
699 | ||
8dd2a82c DL |
700 | if NAMESPACES |
701 | ||
58bfdd6d PE |
702 | config UTS_NS |
703 | bool "UTS namespace" | |
17a6d441 | 704 | default y |
58bfdd6d PE |
705 | help |
706 | In this namespace tasks see different info provided with the | |
707 | uname() system call | |
708 | ||
ae5e1b22 PE |
709 | config IPC_NS |
710 | bool "IPC namespace" | |
8dd2a82c | 711 | depends on (SYSVIPC || POSIX_MQUEUE) |
17a6d441 | 712 | default y |
ae5e1b22 PE |
713 | help |
714 | In this namespace tasks work with IPC ids which correspond to | |
614b84cf | 715 | different IPC objects in different namespaces. |
ae5e1b22 | 716 | |
aee16ce7 PE |
717 | config USER_NS |
718 | bool "User namespace (EXPERIMENTAL)" | |
8dd2a82c | 719 | depends on EXPERIMENTAL |
17a6d441 | 720 | default y |
aee16ce7 PE |
721 | help |
722 | This allows containers, i.e. vservers, to use user namespaces | |
723 | to provide different user info for different servers. | |
724 | If unsure, say N. | |
725 | ||
74bd59bb | 726 | config PID_NS |
9bd38c2c | 727 | bool "PID Namespaces" |
17a6d441 | 728 | default y |
74bd59bb | 729 | help |
12d2b8f9 | 730 | Support process id namespaces. This allows having multiple |
692105b8 | 731 | processes with the same pid as long as they are in different |
74bd59bb PE |
732 | pid namespaces. This is a building block of containers. |
733 | ||
d6eb633f MH |
734 | config NET_NS |
735 | bool "Network namespace" | |
8dd2a82c | 736 | depends on NET |
17a6d441 | 737 | default y |
d6eb633f MH |
738 | help |
739 | Allow user space to create what appear to be multiple instances | |
740 | of the network stack. | |
741 | ||
8dd2a82c DL |
742 | endif # NAMESPACES |
743 | ||
7af37bec DL |
744 | config MM_OWNER |
745 | bool | |
746 | ||
747 | config SYSFS_DEPRECATED | |
748 | bool "enable deprecated sysfs features to support old userspace tools" | |
749 | depends on SYSFS | |
750 | default n | |
751 | help | |
752 | This option adds code that switches the layout of the "block" class | |
753 | devices, to not show up in /sys/class/block/, but only in | |
754 | /sys/block/. | |
755 | ||
756 | This switch is only active when the sysfs.deprecated=1 boot option is | |
757 | passed or the SYSFS_DEPRECATED_V2 option is set. | |
758 | ||
759 | This option allows new kernels to run on old distributions and tools, | |
760 | which might get confused by /sys/class/block/. Since 2007/2008 all | |
761 | major distributions and tools handle this just fine. | |
762 | ||
763 | Recent distributions and userspace tools after 2009/2010 depend on | |
764 | the existence of /sys/class/block/, and will not work with this | |
765 | option enabled. | |
766 | ||
767 | Only if you are using a new kernel on an old distribution, you might | |
768 | need to say Y here. | |
769 | ||
770 | config SYSFS_DEPRECATED_V2 | |
771 | bool "enabled deprecated sysfs features by default" | |
772 | default n | |
773 | depends on SYSFS | |
774 | depends on SYSFS_DEPRECATED | |
775 | help | |
776 | Enable deprecated sysfs by default. | |
777 | ||
778 | See the CONFIG_SYSFS_DEPRECATED option for more details about this | |
779 | option. | |
780 | ||
781 | Only if you are using a new kernel on an old distribution, you might | |
782 | need to say Y here. Even then, odds are you would not need it | |
783 | enabled, you can always pass the boot option if absolutely necessary. | |
784 | ||
785 | config RELAY | |
786 | bool "Kernel->user space relay support (formerly relayfs)" | |
787 | help | |
788 | This option enables support for relay interface support in | |
789 | certain file systems (such as debugfs). | |
790 | It is designed to provide an efficient mechanism for tools and | |
791 | facilities to relay large amounts of data from kernel space to | |
792 | user space. | |
793 | ||
794 | If unsure, say N. | |
795 | ||
f991633d DG |
796 | config BLK_DEV_INITRD |
797 | bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support" | |
798 | depends on BROKEN || !FRV | |
799 | help | |
800 | The initial RAM filesystem is a ramfs which is loaded by the | |
801 | boot loader (loadlin or lilo) and that is mounted as root | |
802 | before the normal boot procedure. It is typically used to | |
803 | load modules needed to mount the "real" root file system, | |
804 | etc. See <file:Documentation/initrd.txt> for details. | |
805 | ||
806 | If RAM disk support (BLK_DEV_RAM) is also included, this | |
807 | also enables initial RAM disk (initrd) support and adds | |
808 | 15 Kbytes (more on some other architectures) to the kernel size. | |
809 | ||
810 | If unsure say Y. | |
811 | ||
c33df4ea JPS |
812 | if BLK_DEV_INITRD |
813 | ||
dbec4866 SR |
814 | source "usr/Kconfig" |
815 | ||
c33df4ea JPS |
816 | endif |
817 | ||
c45b4f1f | 818 | config CC_OPTIMIZE_FOR_SIZE |
96fffeb4 | 819 | bool "Optimize for size" |
c45b4f1f | 820 | default y |
c45b4f1f LT |
821 | help |
822 | Enabling this option will pass "-Os" instead of "-O2" to gcc | |
823 | resulting in a smaller kernel. | |
824 | ||
775a7229 | 825 | If unsure, say Y. |
c45b4f1f | 826 | |
0847062a RD |
827 | config SYSCTL |
828 | bool | |
829 | ||
b943c460 RD |
830 | config ANON_INODES |
831 | bool | |
832 | ||
1da177e4 LT |
833 | menuconfig EMBEDDED |
834 | bool "Configure standard kernel features (for small systems)" | |
835 | help | |
836 | This option allows certain base kernel options and settings | |
837 | to be disabled or tweaked. This is for specialized | |
838 | environments which can tolerate a "non-standard" kernel. | |
839 | Only use this if you really know what you are doing. | |
840 | ||
ae81f9e3 CE |
841 | config UID16 |
842 | bool "Enable 16-bit UID system calls" if EMBEDDED | |
09337f50 | 843 | depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION) |
ae81f9e3 CE |
844 | default y |
845 | help | |
846 | This enables the legacy 16-bit UID syscall wrappers. | |
847 | ||
b89a8171 | 848 | config SYSCTL_SYSCALL |
0847062a | 849 | bool "Sysctl syscall support" if EMBEDDED |
26a7034b | 850 | depends on PROC_SYSCTL |
13bb7e37 | 851 | default y |
b89a8171 | 852 | select SYSCTL |
ae81f9e3 | 853 | ---help--- |
13bb7e37 EB |
854 | sys_sysctl uses binary paths that have been found challenging |
855 | to properly maintain and use. The interface in /proc/sys | |
856 | using paths with ascii names is now the primary path to this | |
857 | information. | |
b89a8171 | 858 | |
13bb7e37 EB |
859 | Almost nothing using the binary sysctl interface so if you are |
860 | trying to save some space it is probably safe to disable this, | |
861 | making your kernel marginally smaller. | |
b89a8171 | 862 | |
13bb7e37 | 863 | If unsure say Y here. |
ae81f9e3 | 864 | |
1da177e4 | 865 | config KALLSYMS |
979c6a1e | 866 | bool "Load all symbols for debugging/ksymoops" if EMBEDDED |
1da177e4 LT |
867 | default y |
868 | help | |
869 | Say Y here to let the kernel print out symbolic crash information and | |
870 | symbolic stack backtraces. This increases the size of the kernel | |
871 | somewhat, as all symbols have to be loaded into the kernel image. | |
872 | ||
873 | config KALLSYMS_ALL | |
874 | bool "Include all symbols in kallsyms" | |
875 | depends on DEBUG_KERNEL && KALLSYMS | |
876 | help | |
877 | Normally kallsyms only contains the symbols of functions, for nicer | |
878 | OOPS messages. Some debuggers can use kallsyms for other | |
f9f97bc0 JJ |
879 | symbols too: say Y here to include all symbols, if you need them |
880 | and you don't care about adding 300k to the size of your kernel. | |
1da177e4 LT |
881 | |
882 | Say N. | |
883 | ||
884 | config KALLSYMS_EXTRA_PASS | |
885 | bool "Do an extra kallsyms pass" | |
886 | depends on KALLSYMS | |
887 | help | |
888 | If kallsyms is not working correctly, the build will fail with | |
889 | inconsistent kallsyms data. If that occurs, log a bug report and | |
890 | turn on KALLSYMS_EXTRA_PASS which should result in a stable build. | |
891 | Always say N here unless you find a bug in kallsyms, which must be | |
892 | reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while | |
893 | you wait for kallsyms to be fixed. | |
894 | ||
d59745ce | 895 | |
712f47ce GKH |
896 | config HOTPLUG |
897 | bool "Support for hot-pluggable devices" if EMBEDDED | |
898 | default y | |
899 | help | |
900 | This option is provided for the case where no hotplug or uevent | |
901 | capabilities is wanted by the kernel. You should only consider | |
902 | disabling this option for embedded systems that do not use modules, a | |
903 | dynamic /dev tree, or dynamic device discovery. Just say Y. | |
904 | ||
d59745ce MM |
905 | config PRINTK |
906 | default y | |
907 | bool "Enable support for printk" if EMBEDDED | |
908 | help | |
909 | This option enables normal printk support. Removing it | |
910 | eliminates most of the message strings from the kernel image | |
911 | and makes the kernel more or less silent. As this makes it | |
912 | very difficult to diagnose system problems, saying N here is | |
913 | strongly discouraged. | |
914 | ||
c8538a7a MM |
915 | config BUG |
916 | bool "BUG() support" if EMBEDDED | |
917 | default y | |
918 | help | |
919 | Disabling this option eliminates support for BUG and WARN, reducing | |
920 | the size of your kernel image and potentially quietly ignoring | |
921 | numerous fatal conditions. You should only consider disabling this | |
922 | option for embedded systems with no facilities for reporting errors. | |
923 | Just say Y. | |
924 | ||
708e9a79 MM |
925 | config ELF_CORE |
926 | default y | |
927 | bool "Enable ELF core dumps" if EMBEDDED | |
928 | help | |
929 | Enable support for generating core dumps. Disabling saves about 4k. | |
930 | ||
e5e1d3cb SS |
931 | config PCSPKR_PLATFORM |
932 | bool "Enable PC-Speaker support" if EMBEDDED | |
933 | depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES | |
934 | default y | |
935 | help | |
936 | This option allows to disable the internal PC-Speaker | |
937 | support, saving some memory. | |
938 | ||
1da177e4 LT |
939 | config BASE_FULL |
940 | default y | |
941 | bool "Enable full-sized data structures for core" if EMBEDDED | |
942 | help | |
943 | Disabling this option reduces the size of miscellaneous core | |
944 | kernel data structures. This saves memory on small machines, | |
945 | but may reduce performance. | |
946 | ||
947 | config FUTEX | |
948 | bool "Enable futex support" if EMBEDDED | |
949 | default y | |
23f78d4a | 950 | select RT_MUTEXES |
1da177e4 LT |
951 | help |
952 | Disabling this option will cause the kernel to be built without | |
953 | support for "fast userspace mutexes". The resulting kernel may not | |
954 | run glibc-based applications correctly. | |
955 | ||
956 | config EPOLL | |
957 | bool "Enable eventpoll support" if EMBEDDED | |
958 | default y | |
448e3cee | 959 | select ANON_INODES |
1da177e4 LT |
960 | help |
961 | Disabling this option will cause the kernel to be built without | |
962 | support for epoll family of system calls. | |
963 | ||
fba2afaa DL |
964 | config SIGNALFD |
965 | bool "Enable signalfd() system call" if EMBEDDED | |
448e3cee | 966 | select ANON_INODES |
fba2afaa DL |
967 | default y |
968 | help | |
969 | Enable the signalfd() system call that allows to receive signals | |
970 | on a file descriptor. | |
971 | ||
972 | If unsure, say Y. | |
973 | ||
b215e283 DL |
974 | config TIMERFD |
975 | bool "Enable timerfd() system call" if EMBEDDED | |
448e3cee | 976 | select ANON_INODES |
b215e283 DL |
977 | default y |
978 | help | |
979 | Enable the timerfd() system call that allows to receive timer | |
980 | events on a file descriptor. | |
981 | ||
982 | If unsure, say Y. | |
983 | ||
e1ad7468 DL |
984 | config EVENTFD |
985 | bool "Enable eventfd() system call" if EMBEDDED | |
448e3cee | 986 | select ANON_INODES |
e1ad7468 DL |
987 | default y |
988 | help | |
989 | Enable the eventfd() system call that allows to receive both | |
990 | kernel notification (ie. KAIO) or userspace notifications. | |
991 | ||
992 | If unsure, say Y. | |
993 | ||
1da177e4 LT |
994 | config SHMEM |
995 | bool "Use full shmem filesystem" if EMBEDDED | |
996 | default y | |
997 | depends on MMU | |
998 | help | |
999 | The shmem is an internal filesystem used to manage shared memory. | |
1000 | It is backed by swap and manages resource limits. It is also exported | |
1001 | to userspace as tmpfs if TMPFS is enabled. Disabling this | |
1002 | option replaces shmem and tmpfs with the much simpler ramfs code, | |
1003 | which may be appropriate on small systems without swap. | |
1004 | ||
ebf3f09c TP |
1005 | config AIO |
1006 | bool "Enable AIO support" if EMBEDDED | |
1007 | default y | |
1008 | help | |
1009 | This option enables POSIX asynchronous I/O which may by used | |
1010 | by some high performance threaded applications. Disabling | |
1011 | this option saves about 7k. | |
1012 | ||
cdd6c482 | 1013 | config HAVE_PERF_EVENTS |
0793a61d | 1014 | bool |
018df72d MF |
1015 | help |
1016 | See tools/perf/design.txt for details. | |
0793a61d | 1017 | |
906010b2 PZ |
1018 | config PERF_USE_VMALLOC |
1019 | bool | |
1020 | help | |
1021 | See tools/perf/design.txt for details | |
1022 | ||
57c0c15b | 1023 | menu "Kernel Performance Events And Counters" |
0793a61d | 1024 | |
cdd6c482 | 1025 | config PERF_EVENTS |
57c0c15b IM |
1026 | bool "Kernel performance events and counters" |
1027 | default y if (PROFILING || PERF_COUNTERS) | |
cdd6c482 | 1028 | depends on HAVE_PERF_EVENTS |
4c59e467 | 1029 | select ANON_INODES |
e360adbe | 1030 | select IRQ_WORK |
0793a61d | 1031 | help |
57c0c15b IM |
1032 | Enable kernel support for various performance events provided |
1033 | by software and hardware. | |
0793a61d | 1034 | |
dd77038d | 1035 | Software events are supported either built-in or via the |
57c0c15b | 1036 | use of generic tracepoints. |
0793a61d | 1037 | |
57c0c15b IM |
1038 | Most modern CPUs support performance events via performance |
1039 | counter registers. These registers count the number of certain | |
0793a61d TG |
1040 | types of hw events: such as instructions executed, cachemisses |
1041 | suffered, or branches mis-predicted - without slowing down the | |
1042 | kernel or applications. These registers can also trigger interrupts | |
1043 | when a threshold number of events have passed - and can thus be | |
1044 | used to profile the code that runs on that CPU. | |
1045 | ||
57c0c15b | 1046 | The Linux Performance Event subsystem provides an abstraction of |
dd77038d | 1047 | these software and hardware event capabilities, available via a |
57c0c15b | 1048 | system call and used by the "perf" utility in tools/perf/. It |
0793a61d TG |
1049 | provides per task and per CPU counters, and it provides event |
1050 | capabilities on top of those. | |
1051 | ||
1052 | Say Y if unsure. | |
1053 | ||
57c0c15b IM |
1054 | config PERF_COUNTERS |
1055 | bool "Kernel performance counters (old config option)" | |
1056 | depends on HAVE_PERF_EVENTS | |
1057 | help | |
1058 | This config has been obsoleted by the PERF_EVENTS | |
1059 | config option - please see that one for details. | |
1060 | ||
1061 | It has no effect on the kernel whether you enable | |
1062 | it or not, it is a compatibility placeholder. | |
1063 | ||
1064 | Say N if unsure. | |
1065 | ||
906010b2 PZ |
1066 | config DEBUG_PERF_USE_VMALLOC |
1067 | default n | |
1068 | bool "Debug: use vmalloc to back perf mmap() buffers" | |
1069 | depends on PERF_EVENTS && DEBUG_KERNEL | |
1070 | select PERF_USE_VMALLOC | |
1071 | help | |
1072 | Use vmalloc memory to back perf mmap() buffers. | |
1073 | ||
1074 | Mostly useful for debugging the vmalloc code on platforms | |
1075 | that don't require it. | |
1076 | ||
1077 | Say N if unsure. | |
1078 | ||
0793a61d TG |
1079 | endmenu |
1080 | ||
f8891e5e CL |
1081 | config VM_EVENT_COUNTERS |
1082 | default y | |
1083 | bool "Enable VM event counters for /proc/vmstat" if EMBEDDED | |
1084 | help | |
2aea4fb6 PJ |
1085 | VM event counters are needed for event counts to be shown. |
1086 | This option allows the disabling of the VM event counters | |
1087 | on EMBEDDED systems. /proc/vmstat will only show page counts | |
1088 | if VM event counters are disabled. | |
f8891e5e | 1089 | |
3d137310 TP |
1090 | config PCI_QUIRKS |
1091 | default y | |
61cfc7e4 GU |
1092 | bool "Enable PCI quirk workarounds" if EMBEDDED |
1093 | depends on PCI | |
3d137310 TP |
1094 | help |
1095 | This enables workarounds for various PCI chipset | |
1096 | bugs/quirks. Disable this only if your target machine is | |
1097 | unaffected by PCI quirks. | |
1098 | ||
41ecc55b CL |
1099 | config SLUB_DEBUG |
1100 | default y | |
1101 | bool "Enable SLUB debugging support" if EMBEDDED | |
f6acb635 | 1102 | depends on SLUB && SYSFS |
41ecc55b CL |
1103 | help |
1104 | SLUB has extensive debug support features. Disabling these can | |
1105 | result in significant savings in code size. This also disables | |
1106 | SLUB sysfs support. /sys/slab will not exist and there will be | |
1107 | no support for cache validation etc. | |
1108 | ||
b943c460 RD |
1109 | config COMPAT_BRK |
1110 | bool "Disable heap randomization" | |
1111 | default y | |
1112 | help | |
1113 | Randomizing heap placement makes heap exploits harder, but it | |
1114 | also breaks ancient binaries (including anything libc5 based). | |
1115 | This option changes the bootup default to heap randomization | |
692105b8 | 1116 | disabled, and can be overridden at runtime by setting |
b943c460 RD |
1117 | /proc/sys/kernel/randomize_va_space to 2. |
1118 | ||
1119 | On non-ancient distros (post-2000 ones) N is usually a safe choice. | |
1120 | ||
81819f0f CL |
1121 | choice |
1122 | prompt "Choose SLAB allocator" | |
a0acd820 | 1123 | default SLUB |
81819f0f CL |
1124 | help |
1125 | This option allows to select a slab allocator. | |
1126 | ||
1127 | config SLAB | |
1128 | bool "SLAB" | |
1129 | help | |
1130 | The regular slab allocator that is established and known to work | |
34013886 | 1131 | well in all environments. It organizes cache hot objects in |
02f56210 | 1132 | per cpu and per node queues. |
81819f0f CL |
1133 | |
1134 | config SLUB | |
81819f0f CL |
1135 | bool "SLUB (Unqueued Allocator)" |
1136 | help | |
1137 | SLUB is a slab allocator that minimizes cache line usage | |
1138 | instead of managing queues of cached objects (SLAB approach). | |
1139 | Per cpu caching is realized using slabs of objects instead | |
1140 | of queues of objects. SLUB can use memory efficiently | |
02f56210 SA |
1141 | and has enhanced diagnostics. SLUB is the default choice for |
1142 | a slab allocator. | |
81819f0f CL |
1143 | |
1144 | config SLOB | |
84a01c2f | 1145 | depends on EMBEDDED |
81819f0f CL |
1146 | bool "SLOB (Simple Allocator)" |
1147 | help | |
37291458 MM |
1148 | SLOB replaces the stock allocator with a drastically simpler |
1149 | allocator. SLOB is generally more space efficient but | |
1150 | does not perform as well on large systems. | |
81819f0f CL |
1151 | |
1152 | endchoice | |
1153 | ||
ea637639 JZ |
1154 | config MMAP_ALLOW_UNINITIALIZED |
1155 | bool "Allow mmapped anonymous memory to be uninitialized" | |
1156 | depends on EMBEDDED && !MMU | |
1157 | default n | |
1158 | help | |
1159 | Normally, and according to the Linux spec, anonymous memory obtained | |
1160 | from mmap() has it's contents cleared before it is passed to | |
1161 | userspace. Enabling this config option allows you to request that | |
1162 | mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus | |
1163 | providing a huge performance boost. If this option is not enabled, | |
1164 | then the flag will be ignored. | |
1165 | ||
1166 | This is taken advantage of by uClibc's malloc(), and also by | |
1167 | ELF-FDPIC binfmt's brk and stack allocator. | |
1168 | ||
1169 | Because of the obvious security issues, this option should only be | |
1170 | enabled on embedded devices where you control what is run in | |
1171 | userspace. Since that isn't generally a problem on no-MMU systems, | |
1172 | it is normally safe to say Y here. | |
1173 | ||
1174 | See Documentation/nommu-mmap.txt for more information. | |
1175 | ||
125e5645 | 1176 | config PROFILING |
b309a294 | 1177 | bool "Profiling support" |
125e5645 MD |
1178 | help |
1179 | Say Y here to enable the extended profiling support mechanisms used | |
1180 | by profilers such as OProfile. | |
1181 | ||
5f87f112 IM |
1182 | # |
1183 | # Place an empty function call at each tracepoint site. Can be | |
1184 | # dynamically changed for a probe function. | |
1185 | # | |
97e1c18e | 1186 | config TRACEPOINTS |
5f87f112 | 1187 | bool |
97e1c18e | 1188 | |
fb32e03f MD |
1189 | source "arch/Kconfig" |
1190 | ||
1da177e4 LT |
1191 | endmenu # General setup |
1192 | ||
ee7e5516 DB |
1193 | config HAVE_GENERIC_DMA_COHERENT |
1194 | bool | |
1195 | default n | |
1196 | ||
158a9624 LT |
1197 | config SLABINFO |
1198 | bool | |
1199 | depends on PROC_FS | |
0f389ec6 | 1200 | depends on SLAB || SLUB_DEBUG |
158a9624 LT |
1201 | default y |
1202 | ||
ae81f9e3 CE |
1203 | config RT_MUTEXES |
1204 | boolean | |
ae81f9e3 | 1205 | |
1da177e4 LT |
1206 | config BASE_SMALL |
1207 | int | |
1208 | default 0 if BASE_FULL | |
1209 | default 1 if !BASE_FULL | |
1210 | ||
66da5733 | 1211 | menuconfig MODULES |
1da177e4 LT |
1212 | bool "Enable loadable module support" |
1213 | help | |
1214 | Kernel modules are small pieces of compiled code which can | |
1215 | be inserted in the running kernel, rather than being | |
1216 | permanently built into the kernel. You use the "modprobe" | |
1217 | tool to add (and sometimes remove) them. If you say Y here, | |
1218 | many parts of the kernel can be built as modules (by | |
1219 | answering M instead of Y where indicated): this is most | |
1220 | useful for infrequently used options which are not required | |
1221 | for booting. For more information, see the man pages for | |
1222 | modprobe, lsmod, modinfo, insmod and rmmod. | |
1223 | ||
1224 | If you say Y here, you will need to run "make | |
1225 | modules_install" to put the modules under /lib/modules/ | |
1226 | where modprobe can find them (you may need to be root to do | |
1227 | this). | |
1228 | ||
1229 | If unsure, say Y. | |
1230 | ||
0b0de144 RD |
1231 | if MODULES |
1232 | ||
826e4506 LT |
1233 | config MODULE_FORCE_LOAD |
1234 | bool "Forced module loading" | |
826e4506 LT |
1235 | default n |
1236 | help | |
91e37a79 RR |
1237 | Allow loading of modules without version information (ie. modprobe |
1238 | --force). Forced module loading sets the 'F' (forced) taint flag and | |
1239 | is usually a really bad idea. | |
826e4506 | 1240 | |
1da177e4 LT |
1241 | config MODULE_UNLOAD |
1242 | bool "Module unloading" | |
1da177e4 LT |
1243 | help |
1244 | Without this option you will not be able to unload any | |
1245 | modules (note that some modules may not be unloadable | |
f7f5b675 DV |
1246 | anyway), which makes your kernel smaller, faster |
1247 | and simpler. If unsure, say Y. | |
1da177e4 LT |
1248 | |
1249 | config MODULE_FORCE_UNLOAD | |
1250 | bool "Forced module unloading" | |
1251 | depends on MODULE_UNLOAD && EXPERIMENTAL | |
1252 | help | |
1253 | This option allows you to force a module to unload, even if the | |
1254 | kernel believes it is unsafe: the kernel will remove the module | |
1255 | without waiting for anyone to stop using it (using the -f option to | |
1256 | rmmod). This is mainly for kernel developers and desperate users. | |
1257 | If unsure, say N. | |
1258 | ||
1da177e4 | 1259 | config MODVERSIONS |
0d541643 | 1260 | bool "Module versioning support" |
1da177e4 LT |
1261 | help |
1262 | Usually, you have to use modules compiled with your kernel. | |
1263 | Saying Y here makes it sometimes possible to use modules | |
1264 | compiled for different kernels, by adding enough information | |
1265 | to the modules to (hopefully) spot any changes which would | |
1266 | make them incompatible with the kernel you are running. If | |
1267 | unsure, say N. | |
1268 | ||
1269 | config MODULE_SRCVERSION_ALL | |
1270 | bool "Source checksum for all modules" | |
1da177e4 LT |
1271 | help |
1272 | Modules which contain a MODULE_VERSION get an extra "srcversion" | |
1273 | field inserted into their modinfo section, which contains a | |
1274 | sum of the source files which made it. This helps maintainers | |
1275 | see exactly which source was used to build a module (since | |
1276 | others sometimes change the module source without updating | |
1277 | the version). With this option, such a "srcversion" field | |
1278 | will be created for all modules. If unsure, say N. | |
1279 | ||
0b0de144 RD |
1280 | endif # MODULES |
1281 | ||
98a79d6a RR |
1282 | config INIT_ALL_POSSIBLE |
1283 | bool | |
1284 | help | |
1285 | Back when each arch used to define their own cpu_online_map and | |
1286 | cpu_possible_map, some of them chose to initialize cpu_possible_map | |
1287 | with all 1s, and others with all 0s. When they were centralised, | |
1288 | it was better to provide this option than to break all the archs | |
692105b8 | 1289 | and have several arch maintainers pursuing me down dark alleys. |
98a79d6a | 1290 | |
1da177e4 LT |
1291 | config STOP_MACHINE |
1292 | bool | |
1293 | default y | |
1294 | depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU | |
1295 | help | |
1296 | Need stop_machine() primitive. | |
3a65dfe8 | 1297 | |
3a65dfe8 | 1298 | source "block/Kconfig" |
e98c3202 AK |
1299 | |
1300 | config PREEMPT_NOTIFIERS | |
1301 | bool | |
e260be67 | 1302 | |
16295bec SK |
1303 | config PADATA |
1304 | depends on SMP | |
1305 | bool | |
1306 | ||
6beb0009 | 1307 | source "kernel/Kconfig.locks" |