Kconfig 44 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741742743744745746747748749750751752753754755756757758759760761762763764765766767768769770771772773774775776777778779780781782783784785786787788789790791792793794795796797798799800801802803804805806807808809810811812813814815816817818819820821822823824825826827828829830831832833834835836837838839840841842843844845846847848849850851852853854855856857858859860861862863864865866867868869870871872873874875876877878879880881882883884885886887888889890891892893894895896897898899900901902903904905906907908909910911912913914915916917918919920921922923924925926927928929930931932933934935936937938939940941942943944945946947948949950951952953954955956957958959960961962963964965966967968969970971972973974975976977978979980981982983984985986987988989990991992993994995996997998999100010011002100310041005100610071008100910101011101210131014101510161017101810191020102110221023102410251026102710281029103010311032103310341035103610371038103910401041104210431044104510461047104810491050105110521053105410551056105710581059106010611062106310641065106610671068106910701071107210731074107510761077107810791080108110821083108410851086108710881089109010911092109310941095109610971098109911001101110211031104110511061107110811091110111111121113111411151116111711181119112011211122112311241125112611271128112911301131113211331134113511361137113811391140114111421143114411451146114711481149115011511152115311541155115611571158115911601161116211631164116511661167116811691170117111721173117411751176117711781179118011811182118311841185118611871188118911901191119211931194119511961197119811991200120112021203120412051206120712081209121012111212121312141215121612171218121912201221122212231224122512261227122812291230123112321233123412351236123712381239124012411242124312441245124612471248124912501251125212531254125512561257125812591260126112621263126412651266126712681269127012711272127312741275127612771278127912801281128212831284128512861287128812891290129112921293129412951296129712981299130013011302130313041305130613071308130913101311131213131314131513161317131813191320132113221323132413251326132713281329133013311332133313341335133613371338133913401341134213431344134513461347134813491350135113521353135413551356135713581359136013611362136313641365136613671368136913701371137213731374137513761377137813791380138113821383138413851386138713881389139013911392139313941395139613971398139914001401
  1. config ARCH
  2. string
  3. option env="ARCH"
  4. config KERNELVERSION
  5. string
  6. option env="KERNELVERSION"
  7. config DEFCONFIG_LIST
  8. string
  9. depends on !UML
  10. option defconfig_list
  11. default "/lib/modules/$UNAME_RELEASE/.config"
  12. default "/etc/kernel-config"
  13. default "/boot/config-$UNAME_RELEASE"
  14. default "$ARCH_DEFCONFIG"
  15. default "arch/$ARCH/defconfig"
  16. config CONSTRUCTORS
  17. bool
  18. depends on !UML
  19. config HAVE_IRQ_WORK
  20. bool
  21. config IRQ_WORK
  22. bool
  23. depends on HAVE_IRQ_WORK
  24. menu "General setup"
  25. config EXPERIMENTAL
  26. bool "Prompt for development and/or incomplete code/drivers"
  27. ---help---
  28. Some of the various things that Linux supports (such as network
  29. drivers, file systems, network protocols, etc.) can be in a state
  30. of development where the functionality, stability, or the level of
  31. testing is not yet high enough for general use. This is usually
  32. known as the "alpha-test" phase among developers. If a feature is
  33. currently in alpha-test, then the developers usually discourage
  34. uninformed widespread use of this feature by the general public to
  35. avoid "Why doesn't this work?" type mail messages. However, active
  36. testing and use of these systems is welcomed. Just be aware that it
  37. may not meet the normal level of reliability or it may fail to work
  38. in some special cases. Detailed bug reports from people familiar
  39. with the kernel internals are usually welcomed by the developers
  40. (before submitting bug reports, please read the documents
  41. <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
  42. <file:Documentation/BUG-HUNTING>, and
  43. <file:Documentation/oops-tracing.txt> in the kernel source).
  44. This option will also make obsoleted drivers available. These are
  45. drivers that have been replaced by something else, and/or are
  46. scheduled to be removed in a future kernel release.
  47. Unless you intend to help test and develop a feature or driver that
  48. falls into this category, or you have a situation that requires
  49. using these features, you should probably say N here, which will
  50. cause the configurator to present you with fewer choices. If
  51. you say Y here, you will be offered the choice of using features or
  52. drivers that are currently considered to be in the alpha-test phase.
  53. config BROKEN
  54. bool
  55. config BROKEN_ON_SMP
  56. bool
  57. depends on BROKEN || !SMP
  58. default y
  59. config INIT_ENV_ARG_LIMIT
  60. int
  61. default 32 if !UML
  62. default 128 if UML
  63. help
  64. Maximum of each of the number of arguments and environment
  65. variables passed to init from the kernel command line.
  66. config CROSS_COMPILE
  67. string "Cross-compiler tool prefix"
  68. help
  69. Same as running 'make CROSS_COMPILE=prefix-' but stored for
  70. default make runs in this kernel build directory. You don't
  71. need to set this unless you want the configured kernel build
  72. directory to select the cross-compiler automatically.
  73. config LOCALVERSION
  74. string "Local version - append to kernel release"
  75. help
  76. Append an extra string to the end of your kernel version.
  77. This will show up when you type uname, for example.
  78. The string you set here will be appended after the contents of
  79. any files with a filename matching localversion* in your
  80. object and source tree, in that order. Your total string can
  81. be a maximum of 64 characters.
  82. config LOCALVERSION_AUTO
  83. bool "Automatically append version information to the version string"
  84. default y
  85. help
  86. This will try to automatically determine if the current tree is a
  87. release tree by looking for git tags that belong to the current
  88. top of tree revision.
  89. A string of the format -gxxxxxxxx will be added to the localversion
  90. if a git-based tree is found. The string generated by this will be
  91. appended after any matching localversion* files, and after the value
  92. set in CONFIG_LOCALVERSION.
  93. (The actual string used here is the first eight characters produced
  94. by running the command:
  95. $ git rev-parse --verify HEAD
  96. which is done within the script "scripts/setlocalversion".)
  97. config HAVE_KERNEL_GZIP
  98. bool
  99. config HAVE_KERNEL_BZIP2
  100. bool
  101. config HAVE_KERNEL_LZMA
  102. bool
  103. config HAVE_KERNEL_XZ
  104. bool
  105. config HAVE_KERNEL_LZO
  106. bool
  107. choice
  108. prompt "Kernel compression mode"
  109. default KERNEL_GZIP
  110. depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO
  111. help
  112. The linux kernel is a kind of self-extracting executable.
  113. Several compression algorithms are available, which differ
  114. in efficiency, compression and decompression speed.
  115. Compression speed is only relevant when building a kernel.
  116. Decompression speed is relevant at each boot.
  117. If you have any problems with bzip2 or lzma compressed
  118. kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
  119. version of this functionality (bzip2 only), for 2.4, was
  120. supplied by Christian Ludwig)
  121. High compression options are mostly useful for users, who
  122. are low on disk space (embedded systems), but for whom ram
  123. size matters less.
  124. If in doubt, select 'gzip'
  125. config KERNEL_GZIP
  126. bool "Gzip"
  127. depends on HAVE_KERNEL_GZIP
  128. help
  129. The old and tried gzip compression. It provides a good balance
  130. between compression ratio and decompression speed.
  131. config KERNEL_BZIP2
  132. bool "Bzip2"
  133. depends on HAVE_KERNEL_BZIP2
  134. help
  135. Its compression ratio and speed is intermediate.
  136. Decompression speed is slowest among the three. The kernel
  137. size is about 10% smaller with bzip2, in comparison to gzip.
  138. Bzip2 uses a large amount of memory. For modern kernels you
  139. will need at least 8MB RAM or more for booting.
  140. config KERNEL_LZMA
  141. bool "LZMA"
  142. depends on HAVE_KERNEL_LZMA
  143. help
  144. The most recent compression algorithm.
  145. Its ratio is best, decompression speed is between the other
  146. two. Compression is slowest. The kernel size is about 33%
  147. smaller with LZMA in comparison to gzip.
  148. config KERNEL_XZ
  149. bool "XZ"
  150. depends on HAVE_KERNEL_XZ
  151. help
  152. XZ uses the LZMA2 algorithm and instruction set specific
  153. BCJ filters which can improve compression ratio of executable
  154. code. The size of the kernel is about 30% smaller with XZ in
  155. comparison to gzip. On architectures for which there is a BCJ
  156. filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
  157. will create a few percent smaller kernel than plain LZMA.
  158. The speed is about the same as with LZMA: The decompression
  159. speed of XZ is better than that of bzip2 but worse than gzip
  160. and LZO. Compression is slow.
  161. config KERNEL_LZO
  162. bool "LZO"
  163. depends on HAVE_KERNEL_LZO
  164. help
  165. Its compression ratio is the poorest among the 4. The kernel
  166. size is about 10% bigger than gzip; however its speed
  167. (both compression and decompression) is the fastest.
  168. endchoice
  169. config DEFAULT_HOSTNAME
  170. string "Default hostname"
  171. default "(none)"
  172. help
  173. This option determines the default system hostname before userspace
  174. calls sethostname(2). The kernel traditionally uses "(none)" here,
  175. but you may wish to use a different default here to make a minimal
  176. system more usable with less configuration.
  177. config SWAP
  178. bool "Support for paging of anonymous memory (swap)"
  179. depends on MMU && BLOCK
  180. default y
  181. help
  182. This option allows you to choose whether you want to have support
  183. for so called swap devices or swap files in your kernel that are
  184. used to provide more virtual memory than the actual RAM present
  185. in your computer. If unsure say Y.
  186. config SYSVIPC
  187. bool "System V IPC"
  188. ---help---
  189. Inter Process Communication is a suite of library functions and
  190. system calls which let processes (running programs) synchronize and
  191. exchange information. It is generally considered to be a good thing,
  192. and some programs won't run unless you say Y here. In particular, if
  193. you want to run the DOS emulator dosemu under Linux (read the
  194. DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
  195. you'll need to say Y here.
  196. You can find documentation about IPC with "info ipc" and also in
  197. section 6.4 of the Linux Programmer's Guide, available from
  198. <http://www.tldp.org/guides.html>.
  199. config SYSVIPC_SYSCTL
  200. bool
  201. depends on SYSVIPC
  202. depends on SYSCTL
  203. default y
  204. config POSIX_MQUEUE
  205. bool "POSIX Message Queues"
  206. depends on NET && EXPERIMENTAL
  207. ---help---
  208. POSIX variant of message queues is a part of IPC. In POSIX message
  209. queues every message has a priority which decides about succession
  210. of receiving it by a process. If you want to compile and run
  211. programs written e.g. for Solaris with use of its POSIX message
  212. queues (functions mq_*) say Y here.
  213. POSIX message queues are visible as a filesystem called 'mqueue'
  214. and can be mounted somewhere if you want to do filesystem
  215. operations on message queues.
  216. If unsure, say Y.
  217. config POSIX_MQUEUE_SYSCTL
  218. bool
  219. depends on POSIX_MQUEUE
  220. depends on SYSCTL
  221. default y
  222. config BSD_PROCESS_ACCT
  223. bool "BSD Process Accounting"
  224. help
  225. If you say Y here, a user level program will be able to instruct the
  226. kernel (via a special system call) to write process accounting
  227. information to a file: whenever a process exits, information about
  228. that process will be appended to the file by the kernel. The
  229. information includes things such as creation time, owning user,
  230. command name, memory usage, controlling terminal etc. (the complete
  231. list is in the struct acct in <file:include/linux/acct.h>). It is
  232. up to the user level program to do useful things with this
  233. information. This is generally a good idea, so say Y.
  234. config BSD_PROCESS_ACCT_V3
  235. bool "BSD Process Accounting version 3 file format"
  236. depends on BSD_PROCESS_ACCT
  237. default n
  238. help
  239. If you say Y here, the process accounting information is written
  240. in a new file format that also logs the process IDs of each
  241. process and it's parent. Note that this file format is incompatible
  242. with previous v0/v1/v2 file formats, so you will need updated tools
  243. for processing it. A preliminary version of these tools is available
  244. at <http://www.gnu.org/software/acct/>.
  245. config FHANDLE
  246. bool "open by fhandle syscalls"
  247. select EXPORTFS
  248. help
  249. If you say Y here, a user level program will be able to map
  250. file names to handle and then later use the handle for
  251. different file system operations. This is useful in implementing
  252. userspace file servers, which now track files using handles instead
  253. of names. The handle would remain the same even if file names
  254. get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
  255. syscalls.
  256. config TASKSTATS
  257. bool "Export task/process statistics through netlink (EXPERIMENTAL)"
  258. depends on NET
  259. default n
  260. help
  261. Export selected statistics for tasks/processes through the
  262. generic netlink interface. Unlike BSD process accounting, the
  263. statistics are available during the lifetime of tasks/processes as
  264. responses to commands. Like BSD accounting, they are sent to user
  265. space on task exit.
  266. Say N if unsure.
  267. config TASK_DELAY_ACCT
  268. bool "Enable per-task delay accounting (EXPERIMENTAL)"
  269. depends on TASKSTATS
  270. help
  271. Collect information on time spent by a task waiting for system
  272. resources like cpu, synchronous block I/O completion and swapping
  273. in pages. Such statistics can help in setting a task's priorities
  274. relative to other tasks for cpu, io, rss limits etc.
  275. Say N if unsure.
  276. config TASK_XACCT
  277. bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
  278. depends on TASKSTATS
  279. help
  280. Collect extended task accounting data and send the data
  281. to userland for processing over the taskstats interface.
  282. Say N if unsure.
  283. config TASK_IO_ACCOUNTING
  284. bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
  285. depends on TASK_XACCT
  286. help
  287. Collect information on the number of bytes of storage I/O which this
  288. task has caused.
  289. Say N if unsure.
  290. config AUDIT
  291. bool "Auditing support"
  292. depends on NET
  293. help
  294. Enable auditing infrastructure that can be used with another
  295. kernel subsystem, such as SELinux (which requires this for
  296. logging of avc messages output). Does not do system-call
  297. auditing without CONFIG_AUDITSYSCALL.
  298. config AUDITSYSCALL
  299. bool "Enable system-call auditing support"
  300. depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH)
  301. default y if SECURITY_SELINUX
  302. help
  303. Enable low-overhead system-call auditing infrastructure that
  304. can be used independently or with another kernel subsystem,
  305. such as SELinux.
  306. config AUDIT_WATCH
  307. def_bool y
  308. depends on AUDITSYSCALL
  309. select FSNOTIFY
  310. config AUDIT_TREE
  311. def_bool y
  312. depends on AUDITSYSCALL
  313. select FSNOTIFY
  314. source "kernel/irq/Kconfig"
  315. menu "RCU Subsystem"
  316. choice
  317. prompt "RCU Implementation"
  318. default TREE_RCU
  319. config TREE_RCU
  320. bool "Tree-based hierarchical RCU"
  321. depends on !PREEMPT && SMP
  322. help
  323. This option selects the RCU implementation that is
  324. designed for very large SMP system with hundreds or
  325. thousands of CPUs. It also scales down nicely to
  326. smaller systems.
  327. config TREE_PREEMPT_RCU
  328. bool "Preemptible tree-based hierarchical RCU"
  329. depends on PREEMPT
  330. help
  331. This option selects the RCU implementation that is
  332. designed for very large SMP systems with hundreds or
  333. thousands of CPUs, but for which real-time response
  334. is also required. It also scales down nicely to
  335. smaller systems.
  336. config TINY_RCU
  337. bool "UP-only small-memory-footprint RCU"
  338. depends on !SMP
  339. help
  340. This option selects the RCU implementation that is
  341. designed for UP systems from which real-time response
  342. is not required. This option greatly reduces the
  343. memory footprint of RCU.
  344. config TINY_PREEMPT_RCU
  345. bool "Preemptible UP-only small-memory-footprint RCU"
  346. depends on !SMP && PREEMPT
  347. help
  348. This option selects the RCU implementation that is designed
  349. for real-time UP systems. This option greatly reduces the
  350. memory footprint of RCU.
  351. endchoice
  352. config PREEMPT_RCU
  353. def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
  354. help
  355. This option enables preemptible-RCU code that is common between
  356. the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
  357. config RCU_TRACE
  358. bool "Enable tracing for RCU"
  359. help
  360. This option provides tracing in RCU which presents stats
  361. in debugfs for debugging RCU implementation.
  362. Say Y here if you want to enable RCU tracing
  363. Say N if you are unsure.
  364. config RCU_FANOUT
  365. int "Tree-based hierarchical RCU fanout value"
  366. range 2 64 if 64BIT
  367. range 2 32 if !64BIT
  368. depends on TREE_RCU || TREE_PREEMPT_RCU
  369. default 64 if 64BIT
  370. default 32 if !64BIT
  371. help
  372. This option controls the fanout of hierarchical implementations
  373. of RCU, allowing RCU to work efficiently on machines with
  374. large numbers of CPUs. This value must be at least the fourth
  375. root of NR_CPUS, which allows NR_CPUS to be insanely large.
  376. The default value of RCU_FANOUT should be used for production
  377. systems, but if you are stress-testing the RCU implementation
  378. itself, small RCU_FANOUT values allow you to test large-system
  379. code paths on small(er) systems.
  380. Select a specific number if testing RCU itself.
  381. Take the default if unsure.
  382. config RCU_FANOUT_EXACT
  383. bool "Disable tree-based hierarchical RCU auto-balancing"
  384. depends on TREE_RCU || TREE_PREEMPT_RCU
  385. default n
  386. help
  387. This option forces use of the exact RCU_FANOUT value specified,
  388. regardless of imbalances in the hierarchy. This is useful for
  389. testing RCU itself, and might one day be useful on systems with
  390. strong NUMA behavior.
  391. Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
  392. Say N if unsure.
  393. config RCU_FAST_NO_HZ
  394. bool "Accelerate last non-dyntick-idle CPU's grace periods"
  395. depends on TREE_RCU && NO_HZ && SMP
  396. default n
  397. help
  398. This option causes RCU to attempt to accelerate grace periods
  399. in order to allow the final CPU to enter dynticks-idle state
  400. more quickly. On the other hand, this option increases the
  401. overhead of the dynticks-idle checking, particularly on systems
  402. with large numbers of CPUs.
  403. Say Y if energy efficiency is critically important, particularly
  404. if you have relatively few CPUs.
  405. Say N if you are unsure.
  406. config TREE_RCU_TRACE
  407. def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
  408. select DEBUG_FS
  409. help
  410. This option provides tracing for the TREE_RCU and
  411. TREE_PREEMPT_RCU implementations, permitting Makefile to
  412. trivially select kernel/rcutree_trace.c.
  413. config RCU_BOOST
  414. bool "Enable RCU priority boosting"
  415. depends on RT_MUTEXES && PREEMPT_RCU
  416. default n
  417. help
  418. This option boosts the priority of preempted RCU readers that
  419. block the current preemptible RCU grace period for too long.
  420. This option also prevents heavy loads from blocking RCU
  421. callback invocation for all flavors of RCU.
  422. Say Y here if you are working with real-time apps or heavy loads
  423. Say N here if you are unsure.
  424. config RCU_BOOST_PRIO
  425. int "Real-time priority to boost RCU readers to"
  426. range 1 99
  427. depends on RCU_BOOST
  428. default 1
  429. help
  430. This option specifies the real-time priority to which preempted
  431. RCU readers are to be boosted. If you are working with CPU-bound
  432. real-time applications, you should specify a priority higher then
  433. the highest-priority CPU-bound application.
  434. Specify the real-time priority, or take the default if unsure.
  435. config RCU_BOOST_DELAY
  436. int "Milliseconds to delay boosting after RCU grace-period start"
  437. range 0 3000
  438. depends on RCU_BOOST
  439. default 500
  440. help
  441. This option specifies the time to wait after the beginning of
  442. a given grace period before priority-boosting preempted RCU
  443. readers blocking that grace period. Note that any RCU reader
  444. blocking an expedited RCU grace period is boosted immediately.
  445. Accept the default if unsure.
  446. endmenu # "RCU Subsystem"
  447. config IKCONFIG
  448. tristate "Kernel .config support"
  449. ---help---
  450. This option enables the complete Linux kernel ".config" file
  451. contents to be saved in the kernel. It provides documentation
  452. of which kernel options are used in a running kernel or in an
  453. on-disk kernel. This information can be extracted from the kernel
  454. image file with the script scripts/extract-ikconfig and used as
  455. input to rebuild the current kernel or to build another kernel.
  456. It can also be extracted from a running kernel by reading
  457. /proc/config.gz if enabled (below).
  458. config IKCONFIG_PROC
  459. bool "Enable access to .config through /proc/config.gz"
  460. depends on IKCONFIG && PROC_FS
  461. ---help---
  462. This option enables access to the kernel configuration file
  463. through /proc/config.gz.
  464. config LOG_BUF_SHIFT
  465. int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
  466. range 12 21
  467. default 17
  468. help
  469. Select kernel log buffer size as a power of 2.
  470. Examples:
  471. 17 => 128 KB
  472. 16 => 64 KB
  473. 15 => 32 KB
  474. 14 => 16 KB
  475. 13 => 8 KB
  476. 12 => 4 KB
  477. #
  478. # Architectures with an unreliable sched_clock() should select this:
  479. #
  480. config HAVE_UNSTABLE_SCHED_CLOCK
  481. bool
  482. menuconfig CGROUPS
  483. boolean "Control Group support"
  484. depends on EVENTFD
  485. help
  486. This option adds support for grouping sets of processes together, for
  487. use with process control subsystems such as Cpusets, CFS, memory
  488. controls or device isolation.
  489. See
  490. - Documentation/scheduler/sched-design-CFS.txt (CFS)
  491. - Documentation/cgroups/ (features for grouping, isolation
  492. and resource control)
  493. Say N if unsure.
  494. if CGROUPS
  495. config CGROUP_DEBUG
  496. bool "Example debug cgroup subsystem"
  497. default n
  498. help
  499. This option enables a simple cgroup subsystem that
  500. exports useful debugging information about the cgroups
  501. framework.
  502. Say N if unsure.
  503. config CGROUP_FREEZER
  504. bool "Freezer cgroup subsystem"
  505. help
  506. Provides a way to freeze and unfreeze all tasks in a
  507. cgroup.
  508. config CGROUP_DEVICE
  509. bool "Device controller for cgroups"
  510. help
  511. Provides a cgroup implementing whitelists for devices which
  512. a process in the cgroup can mknod or open.
  513. config CPUSETS
  514. bool "Cpuset support"
  515. help
  516. This option will let you create and manage CPUSETs which
  517. allow dynamically partitioning a system into sets of CPUs and
  518. Memory Nodes and assigning tasks to run only within those sets.
  519. This is primarily useful on large SMP or NUMA systems.
  520. Say N if unsure.
  521. config PROC_PID_CPUSET
  522. bool "Include legacy /proc/<pid>/cpuset file"
  523. depends on CPUSETS
  524. default y
  525. config CGROUP_CPUACCT
  526. bool "Simple CPU accounting cgroup subsystem"
  527. help
  528. Provides a simple Resource Controller for monitoring the
  529. total CPU consumed by the tasks in a cgroup.
  530. config RESOURCE_COUNTERS
  531. bool "Resource counters"
  532. help
  533. This option enables controller independent resource accounting
  534. infrastructure that works with cgroups.
  535. config CGROUP_MEM_RES_CTLR
  536. bool "Memory Resource Controller for Control Groups"
  537. depends on RESOURCE_COUNTERS
  538. select MM_OWNER
  539. help
  540. Provides a memory resource controller that manages both anonymous
  541. memory and page cache. (See Documentation/cgroups/memory.txt)
  542. Note that setting this option increases fixed memory overhead
  543. associated with each page of memory in the system. By this,
  544. 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
  545. usage tracking struct at boot. Total amount of this is printed out
  546. at boot.
  547. Only enable when you're ok with these trade offs and really
  548. sure you need the memory resource controller. Even when you enable
  549. this, you can set "cgroup_disable=memory" at your boot option to
  550. disable memory resource controller and you can avoid overheads.
  551. (and lose benefits of memory resource controller)
  552. This config option also selects MM_OWNER config option, which
  553. could in turn add some fork/exit overhead.
  554. config CGROUP_MEM_RES_CTLR_SWAP
  555. bool "Memory Resource Controller Swap Extension"
  556. depends on CGROUP_MEM_RES_CTLR && SWAP
  557. help
  558. Add swap management feature to memory resource controller. When you
  559. enable this, you can limit mem+swap usage per cgroup. In other words,
  560. when you disable this, memory resource controller has no cares to
  561. usage of swap...a process can exhaust all of the swap. This extension
  562. is useful when you want to avoid exhaustion swap but this itself
  563. adds more overheads and consumes memory for remembering information.
  564. Especially if you use 32bit system or small memory system, please
  565. be careful about enabling this. When memory resource controller
  566. is disabled by boot option, this will be automatically disabled and
  567. there will be no overhead from this. Even when you set this config=y,
  568. if boot option "swapaccount=0" is set, swap will not be accounted.
  569. Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
  570. size is 4096bytes, 512k per 1Gbytes of swap.
  571. config CGROUP_MEM_RES_CTLR_SWAP_ENABLED
  572. bool "Memory Resource Controller Swap Extension enabled by default"
  573. depends on CGROUP_MEM_RES_CTLR_SWAP
  574. default y
  575. help
  576. Memory Resource Controller Swap Extension comes with its price in
  577. a bigger memory consumption. General purpose distribution kernels
  578. which want to enable the feature but keep it disabled by default
  579. and let the user enable it by swapaccount boot command line
  580. parameter should have this option unselected.
  581. For those who want to have the feature enabled by default should
  582. select this option (if, for some reason, they need to disable it
  583. then swapaccount=0 does the trick).
  584. config CGROUP_PERF
  585. bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
  586. depends on PERF_EVENTS && CGROUPS
  587. help
  588. This option extends the per-cpu mode to restrict monitoring to
  589. threads which belong to the cgroup specified and run on the
  590. designated cpu.
  591. Say N if unsure.
  592. menuconfig CGROUP_SCHED
  593. bool "Group CPU scheduler"
  594. depends on EXPERIMENTAL
  595. default n
  596. help
  597. This feature lets CPU scheduler recognize task groups and control CPU
  598. bandwidth allocation to such task groups. It uses cgroups to group
  599. tasks.
  600. if CGROUP_SCHED
  601. config FAIR_GROUP_SCHED
  602. bool "Group scheduling for SCHED_OTHER"
  603. depends on CGROUP_SCHED
  604. default CGROUP_SCHED
  605. config RT_GROUP_SCHED
  606. bool "Group scheduling for SCHED_RR/FIFO"
  607. depends on EXPERIMENTAL
  608. depends on CGROUP_SCHED
  609. default n
  610. help
  611. This feature lets you explicitly allocate real CPU bandwidth
  612. to task groups. If enabled, it will also make it impossible to
  613. schedule realtime tasks for non-root users until you allocate
  614. realtime bandwidth for them.
  615. See Documentation/scheduler/sched-rt-group.txt for more information.
  616. endif #CGROUP_SCHED
  617. config BLK_CGROUP
  618. tristate "Block IO controller"
  619. depends on BLOCK
  620. default n
  621. ---help---
  622. Generic block IO controller cgroup interface. This is the common
  623. cgroup interface which should be used by various IO controlling
  624. policies.
  625. Currently, CFQ IO scheduler uses it to recognize task groups and
  626. control disk bandwidth allocation (proportional time slice allocation)
  627. to such task groups. It is also used by bio throttling logic in
  628. block layer to implement upper limit in IO rates on a device.
  629. This option only enables generic Block IO controller infrastructure.
  630. One needs to also enable actual IO controlling logic/policy. For
  631. enabling proportional weight division of disk bandwidth in CFQ, set
  632. CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
  633. CONFIG_BLK_DEV_THROTTLING=y.
  634. See Documentation/cgroups/blkio-controller.txt for more information.
  635. config DEBUG_BLK_CGROUP
  636. bool "Enable Block IO controller debugging"
  637. depends on BLK_CGROUP
  638. default n
  639. ---help---
  640. Enable some debugging help. Currently it exports additional stat
  641. files in a cgroup which can be useful for debugging.
  642. endif # CGROUPS
  643. menuconfig NAMESPACES
  644. bool "Namespaces support" if EXPERT
  645. default !EXPERT
  646. help
  647. Provides the way to make tasks work with different objects using
  648. the same id. For example same IPC id may refer to different objects
  649. or same user id or pid may refer to different tasks when used in
  650. different namespaces.
  651. if NAMESPACES
  652. config UTS_NS
  653. bool "UTS namespace"
  654. default y
  655. help
  656. In this namespace tasks see different info provided with the
  657. uname() system call
  658. config IPC_NS
  659. bool "IPC namespace"
  660. depends on (SYSVIPC || POSIX_MQUEUE)
  661. default y
  662. help
  663. In this namespace tasks work with IPC ids which correspond to
  664. different IPC objects in different namespaces.
  665. config USER_NS
  666. bool "User namespace (EXPERIMENTAL)"
  667. depends on EXPERIMENTAL
  668. default y
  669. help
  670. This allows containers, i.e. vservers, to use user namespaces
  671. to provide different user info for different servers.
  672. If unsure, say N.
  673. config PID_NS
  674. bool "PID Namespaces"
  675. default y
  676. help
  677. Support process id namespaces. This allows having multiple
  678. processes with the same pid as long as they are in different
  679. pid namespaces. This is a building block of containers.
  680. config NET_NS
  681. bool "Network namespace"
  682. depends on NET
  683. default y
  684. help
  685. Allow user space to create what appear to be multiple instances
  686. of the network stack.
  687. endif # NAMESPACES
  688. config SCHED_AUTOGROUP
  689. bool "Automatic process group scheduling"
  690. select EVENTFD
  691. select CGROUPS
  692. select CGROUP_SCHED
  693. select FAIR_GROUP_SCHED
  694. help
  695. This option optimizes the scheduler for common desktop workloads by
  696. automatically creating and populating task groups. This separation
  697. of workloads isolates aggressive CPU burners (like build jobs) from
  698. desktop applications. Task group autogeneration is currently based
  699. upon task session.
  700. config MM_OWNER
  701. bool
  702. config SYSFS_DEPRECATED
  703. bool "Enable deprecated sysfs features to support old userspace tools"
  704. depends on SYSFS
  705. default n
  706. help
  707. This option adds code that switches the layout of the "block" class
  708. devices, to not show up in /sys/class/block/, but only in
  709. /sys/block/.
  710. This switch is only active when the sysfs.deprecated=1 boot option is
  711. passed or the SYSFS_DEPRECATED_V2 option is set.
  712. This option allows new kernels to run on old distributions and tools,
  713. which might get confused by /sys/class/block/. Since 2007/2008 all
  714. major distributions and tools handle this just fine.
  715. Recent distributions and userspace tools after 2009/2010 depend on
  716. the existence of /sys/class/block/, and will not work with this
  717. option enabled.
  718. Only if you are using a new kernel on an old distribution, you might
  719. need to say Y here.
  720. config SYSFS_DEPRECATED_V2
  721. bool "Enable deprecated sysfs features by default"
  722. default n
  723. depends on SYSFS
  724. depends on SYSFS_DEPRECATED
  725. help
  726. Enable deprecated sysfs by default.
  727. See the CONFIG_SYSFS_DEPRECATED option for more details about this
  728. option.
  729. Only if you are using a new kernel on an old distribution, you might
  730. need to say Y here. Even then, odds are you would not need it
  731. enabled, you can always pass the boot option if absolutely necessary.
  732. config RELAY
  733. bool "Kernel->user space relay support (formerly relayfs)"
  734. help
  735. This option enables support for relay interface support in
  736. certain file systems (such as debugfs).
  737. It is designed to provide an efficient mechanism for tools and
  738. facilities to relay large amounts of data from kernel space to
  739. user space.
  740. If unsure, say N.
  741. config BLK_DEV_INITRD
  742. bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
  743. depends on BROKEN || !FRV
  744. help
  745. The initial RAM filesystem is a ramfs which is loaded by the
  746. boot loader (loadlin or lilo) and that is mounted as root
  747. before the normal boot procedure. It is typically used to
  748. load modules needed to mount the "real" root file system,
  749. etc. See <file:Documentation/initrd.txt> for details.
  750. If RAM disk support (BLK_DEV_RAM) is also included, this
  751. also enables initial RAM disk (initrd) support and adds
  752. 15 Kbytes (more on some other architectures) to the kernel size.
  753. If unsure say Y.
  754. if BLK_DEV_INITRD
  755. source "usr/Kconfig"
  756. endif
  757. config CC_OPTIMIZE_FOR_SIZE
  758. bool "Optimize for size"
  759. help
  760. Enabling this option will pass "-Os" instead of "-O2" to gcc
  761. resulting in a smaller kernel.
  762. If unsure, say Y.
  763. config SYSCTL
  764. bool
  765. config ANON_INODES
  766. bool
  767. menuconfig EXPERT
  768. bool "Configure standard kernel features (expert users)"
  769. # Unhide debug options, to make the on-by-default options visible
  770. select DEBUG_KERNEL
  771. help
  772. This option allows certain base kernel options and settings
  773. to be disabled or tweaked. This is for specialized
  774. environments which can tolerate a "non-standard" kernel.
  775. Only use this if you really know what you are doing.
  776. config UID16
  777. bool "Enable 16-bit UID system calls" if EXPERT
  778. depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION)
  779. default y
  780. help
  781. This enables the legacy 16-bit UID syscall wrappers.
  782. config SYSCTL_SYSCALL
  783. bool "Sysctl syscall support" if EXPERT
  784. depends on PROC_SYSCTL
  785. default y
  786. select SYSCTL
  787. ---help---
  788. sys_sysctl uses binary paths that have been found challenging
  789. to properly maintain and use. The interface in /proc/sys
  790. using paths with ascii names is now the primary path to this
  791. information.
  792. Almost nothing using the binary sysctl interface so if you are
  793. trying to save some space it is probably safe to disable this,
  794. making your kernel marginally smaller.
  795. If unsure say Y here.
  796. config KALLSYMS
  797. bool "Load all symbols for debugging/ksymoops" if EXPERT
  798. default y
  799. help
  800. Say Y here to let the kernel print out symbolic crash information and
  801. symbolic stack backtraces. This increases the size of the kernel
  802. somewhat, as all symbols have to be loaded into the kernel image.
  803. config KALLSYMS_ALL
  804. bool "Include all symbols in kallsyms"
  805. depends on DEBUG_KERNEL && KALLSYMS
  806. help
  807. Normally kallsyms only contains the symbols of functions for nicer
  808. OOPS messages and backtraces (i.e., symbols from the text and inittext
  809. sections). This is sufficient for most cases. And only in very rare
  810. cases (e.g., when a debugger is used) all symbols are required (e.g.,
  811. names of variables from the data sections, etc).
  812. This option makes sure that all symbols are loaded into the kernel
  813. image (i.e., symbols from all sections) in cost of increased kernel
  814. size (depending on the kernel configuration, it may be 300KiB or
  815. something like this).
  816. Say N unless you really need all symbols.
  817. config HOTPLUG
  818. bool "Support for hot-pluggable devices" if EXPERT
  819. default y
  820. help
  821. This option is provided for the case where no hotplug or uevent
  822. capabilities is wanted by the kernel. You should only consider
  823. disabling this option for embedded systems that do not use modules, a
  824. dynamic /dev tree, or dynamic device discovery. Just say Y.
  825. config PRINTK
  826. default y
  827. bool "Enable support for printk" if EXPERT
  828. help
  829. This option enables normal printk support. Removing it
  830. eliminates most of the message strings from the kernel image
  831. and makes the kernel more or less silent. As this makes it
  832. very difficult to diagnose system problems, saying N here is
  833. strongly discouraged.
  834. config BUG
  835. bool "BUG() support" if EXPERT
  836. default y
  837. help
  838. Disabling this option eliminates support for BUG and WARN, reducing
  839. the size of your kernel image and potentially quietly ignoring
  840. numerous fatal conditions. You should only consider disabling this
  841. option for embedded systems with no facilities for reporting errors.
  842. Just say Y.
  843. config ELF_CORE
  844. default y
  845. bool "Enable ELF core dumps" if EXPERT
  846. help
  847. Enable support for generating core dumps. Disabling saves about 4k.
  848. config PCSPKR_PLATFORM
  849. bool "Enable PC-Speaker support" if EXPERT
  850. depends on HAVE_PCSPKR_PLATFORM
  851. select I8253_LOCK
  852. default y
  853. help
  854. This option allows to disable the internal PC-Speaker
  855. support, saving some memory.
  856. config HAVE_PCSPKR_PLATFORM
  857. bool
  858. config BASE_FULL
  859. default y
  860. bool "Enable full-sized data structures for core" if EXPERT
  861. help
  862. Disabling this option reduces the size of miscellaneous core
  863. kernel data structures. This saves memory on small machines,
  864. but may reduce performance.
  865. config FUTEX
  866. bool "Enable futex support" if EXPERT
  867. default y
  868. select RT_MUTEXES
  869. help
  870. Disabling this option will cause the kernel to be built without
  871. support for "fast userspace mutexes". The resulting kernel may not
  872. run glibc-based applications correctly.
  873. config EPOLL
  874. bool "Enable eventpoll support" if EXPERT
  875. default y
  876. select ANON_INODES
  877. help
  878. Disabling this option will cause the kernel to be built without
  879. support for epoll family of system calls.
  880. config SIGNALFD
  881. bool "Enable signalfd() system call" if EXPERT
  882. select ANON_INODES
  883. default y
  884. help
  885. Enable the signalfd() system call that allows to receive signals
  886. on a file descriptor.
  887. If unsure, say Y.
  888. config TIMERFD
  889. bool "Enable timerfd() system call" if EXPERT
  890. select ANON_INODES
  891. default y
  892. help
  893. Enable the timerfd() system call that allows to receive timer
  894. events on a file descriptor.
  895. If unsure, say Y.
  896. config EVENTFD
  897. bool "Enable eventfd() system call" if EXPERT
  898. select ANON_INODES
  899. default y
  900. help
  901. Enable the eventfd() system call that allows to receive both
  902. kernel notification (ie. KAIO) or userspace notifications.
  903. If unsure, say Y.
  904. config SHMEM
  905. bool "Use full shmem filesystem" if EXPERT
  906. default y
  907. depends on MMU
  908. help
  909. The shmem is an internal filesystem used to manage shared memory.
  910. It is backed by swap and manages resource limits. It is also exported
  911. to userspace as tmpfs if TMPFS is enabled. Disabling this
  912. option replaces shmem and tmpfs with the much simpler ramfs code,
  913. which may be appropriate on small systems without swap.
  914. config AIO
  915. bool "Enable AIO support" if EXPERT
  916. default y
  917. help
  918. This option enables POSIX asynchronous I/O which may by used
  919. by some high performance threaded applications. Disabling
  920. this option saves about 7k.
  921. config EMBEDDED
  922. bool "Embedded system"
  923. select EXPERT
  924. help
  925. This option should be enabled if compiling the kernel for
  926. an embedded system so certain expert options are available
  927. for configuration.
  928. config HAVE_PERF_EVENTS
  929. bool
  930. help
  931. See tools/perf/design.txt for details.
  932. config PERF_USE_VMALLOC
  933. bool
  934. help
  935. See tools/perf/design.txt for details
  936. menu "Kernel Performance Events And Counters"
  937. config PERF_EVENTS
  938. bool "Kernel performance events and counters"
  939. default y if (PROFILING || PERF_COUNTERS)
  940. depends on HAVE_PERF_EVENTS
  941. select ANON_INODES
  942. select IRQ_WORK
  943. help
  944. Enable kernel support for various performance events provided
  945. by software and hardware.
  946. Software events are supported either built-in or via the
  947. use of generic tracepoints.
  948. Most modern CPUs support performance events via performance
  949. counter registers. These registers count the number of certain
  950. types of hw events: such as instructions executed, cachemisses
  951. suffered, or branches mis-predicted - without slowing down the
  952. kernel or applications. These registers can also trigger interrupts
  953. when a threshold number of events have passed - and can thus be
  954. used to profile the code that runs on that CPU.
  955. The Linux Performance Event subsystem provides an abstraction of
  956. these software and hardware event capabilities, available via a
  957. system call and used by the "perf" utility in tools/perf/. It
  958. provides per task and per CPU counters, and it provides event
  959. capabilities on top of those.
  960. Say Y if unsure.
  961. config PERF_COUNTERS
  962. bool "Kernel performance counters (old config option)"
  963. depends on HAVE_PERF_EVENTS
  964. help
  965. This config has been obsoleted by the PERF_EVENTS
  966. config option - please see that one for details.
  967. It has no effect on the kernel whether you enable
  968. it or not, it is a compatibility placeholder.
  969. Say N if unsure.
  970. config DEBUG_PERF_USE_VMALLOC
  971. default n
  972. bool "Debug: use vmalloc to back perf mmap() buffers"
  973. depends on PERF_EVENTS && DEBUG_KERNEL
  974. select PERF_USE_VMALLOC
  975. help
  976. Use vmalloc memory to back perf mmap() buffers.
  977. Mostly useful for debugging the vmalloc code on platforms
  978. that don't require it.
  979. Say N if unsure.
  980. endmenu
  981. config VM_EVENT_COUNTERS
  982. default y
  983. bool "Enable VM event counters for /proc/vmstat" if EXPERT
  984. help
  985. VM event counters are needed for event counts to be shown.
  986. This option allows the disabling of the VM event counters
  987. on EXPERT systems. /proc/vmstat will only show page counts
  988. if VM event counters are disabled.
  989. config PCI_QUIRKS
  990. default y
  991. bool "Enable PCI quirk workarounds" if EXPERT
  992. depends on PCI
  993. help
  994. This enables workarounds for various PCI chipset
  995. bugs/quirks. Disable this only if your target machine is
  996. unaffected by PCI quirks.
  997. config SLUB_DEBUG
  998. default y
  999. bool "Enable SLUB debugging support" if EXPERT
  1000. depends on SLUB && SYSFS
  1001. help
  1002. SLUB has extensive debug support features. Disabling these can
  1003. result in significant savings in code size. This also disables
  1004. SLUB sysfs support. /sys/slab will not exist and there will be
  1005. no support for cache validation etc.
  1006. config COMPAT_BRK
  1007. bool "Disable heap randomization"
  1008. default y
  1009. help
  1010. Randomizing heap placement makes heap exploits harder, but it
  1011. also breaks ancient binaries (including anything libc5 based).
  1012. This option changes the bootup default to heap randomization
  1013. disabled, and can be overridden at runtime by setting
  1014. /proc/sys/kernel/randomize_va_space to 2.
  1015. On non-ancient distros (post-2000 ones) N is usually a safe choice.
  1016. choice
  1017. prompt "Choose SLAB allocator"
  1018. default SLUB
  1019. help
  1020. This option allows to select a slab allocator.
  1021. config SLAB
  1022. bool "SLAB"
  1023. help
  1024. The regular slab allocator that is established and known to work
  1025. well in all environments. It organizes cache hot objects in
  1026. per cpu and per node queues.
  1027. config SLUB
  1028. bool "SLUB (Unqueued Allocator)"
  1029. help
  1030. SLUB is a slab allocator that minimizes cache line usage
  1031. instead of managing queues of cached objects (SLAB approach).
  1032. Per cpu caching is realized using slabs of objects instead
  1033. of queues of objects. SLUB can use memory efficiently
  1034. and has enhanced diagnostics. SLUB is the default choice for
  1035. a slab allocator.
  1036. config SLOB
  1037. depends on EXPERT
  1038. bool "SLOB (Simple Allocator)"
  1039. help
  1040. SLOB replaces the stock allocator with a drastically simpler
  1041. allocator. SLOB is generally more space efficient but
  1042. does not perform as well on large systems.
  1043. endchoice
  1044. config MMAP_ALLOW_UNINITIALIZED
  1045. bool "Allow mmapped anonymous memory to be uninitialized"
  1046. depends on EXPERT && !MMU
  1047. default n
  1048. help
  1049. Normally, and according to the Linux spec, anonymous memory obtained
  1050. from mmap() has it's contents cleared before it is passed to
  1051. userspace. Enabling this config option allows you to request that
  1052. mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
  1053. providing a huge performance boost. If this option is not enabled,
  1054. then the flag will be ignored.
  1055. This is taken advantage of by uClibc's malloc(), and also by
  1056. ELF-FDPIC binfmt's brk and stack allocator.
  1057. Because of the obvious security issues, this option should only be
  1058. enabled on embedded devices where you control what is run in
  1059. userspace. Since that isn't generally a problem on no-MMU systems,
  1060. it is normally safe to say Y here.
  1061. See Documentation/nommu-mmap.txt for more information.
  1062. config PROFILING
  1063. bool "Profiling support"
  1064. help
  1065. Say Y here to enable the extended profiling support mechanisms used
  1066. by profilers such as OProfile.
  1067. #
  1068. # Place an empty function call at each tracepoint site. Can be
  1069. # dynamically changed for a probe function.
  1070. #
  1071. config TRACEPOINTS
  1072. bool
  1073. source "arch/Kconfig"
  1074. endmenu # General setup
  1075. config HAVE_GENERIC_DMA_COHERENT
  1076. bool
  1077. default n
  1078. config SLABINFO
  1079. bool
  1080. depends on PROC_FS
  1081. depends on SLAB || SLUB_DEBUG
  1082. default y
  1083. config RT_MUTEXES
  1084. boolean
  1085. config BASE_SMALL
  1086. int
  1087. default 0 if BASE_FULL
  1088. default 1 if !BASE_FULL
  1089. menuconfig MODULES
  1090. bool "Enable loadable module support"
  1091. help
  1092. Kernel modules are small pieces of compiled code which can
  1093. be inserted in the running kernel, rather than being
  1094. permanently built into the kernel. You use the "modprobe"
  1095. tool to add (and sometimes remove) them. If you say Y here,
  1096. many parts of the kernel can be built as modules (by
  1097. answering M instead of Y where indicated): this is most
  1098. useful for infrequently used options which are not required
  1099. for booting. For more information, see the man pages for
  1100. modprobe, lsmod, modinfo, insmod and rmmod.
  1101. If you say Y here, you will need to run "make
  1102. modules_install" to put the modules under /lib/modules/
  1103. where modprobe can find them (you may need to be root to do
  1104. this).
  1105. If unsure, say Y.
  1106. if MODULES
  1107. config MODULE_FORCE_LOAD
  1108. bool "Forced module loading"
  1109. default n
  1110. help
  1111. Allow loading of modules without version information (ie. modprobe
  1112. --force). Forced module loading sets the 'F' (forced) taint flag and
  1113. is usually a really bad idea.
  1114. config MODULE_UNLOAD
  1115. bool "Module unloading"
  1116. help
  1117. Without this option you will not be able to unload any
  1118. modules (note that some modules may not be unloadable
  1119. anyway), which makes your kernel smaller, faster
  1120. and simpler. If unsure, say Y.
  1121. config MODULE_FORCE_UNLOAD
  1122. bool "Forced module unloading"
  1123. depends on MODULE_UNLOAD && EXPERIMENTAL
  1124. help
  1125. This option allows you to force a module to unload, even if the
  1126. kernel believes it is unsafe: the kernel will remove the module
  1127. without waiting for anyone to stop using it (using the -f option to
  1128. rmmod). This is mainly for kernel developers and desperate users.
  1129. If unsure, say N.
  1130. config MODVERSIONS
  1131. bool "Module versioning support"
  1132. help
  1133. Usually, you have to use modules compiled with your kernel.
  1134. Saying Y here makes it sometimes possible to use modules
  1135. compiled for different kernels, by adding enough information
  1136. to the modules to (hopefully) spot any changes which would
  1137. make them incompatible with the kernel you are running. If
  1138. unsure, say N.
  1139. config MODULE_SRCVERSION_ALL
  1140. bool "Source checksum for all modules"
  1141. help
  1142. Modules which contain a MODULE_VERSION get an extra "srcversion"
  1143. field inserted into their modinfo section, which contains a
  1144. sum of the source files which made it. This helps maintainers
  1145. see exactly which source was used to build a module (since
  1146. others sometimes change the module source without updating
  1147. the version). With this option, such a "srcversion" field
  1148. will be created for all modules. If unsure, say N.
  1149. endif # MODULES
  1150. config INIT_ALL_POSSIBLE
  1151. bool
  1152. help
  1153. Back when each arch used to define their own cpu_online_map and
  1154. cpu_possible_map, some of them chose to initialize cpu_possible_map
  1155. with all 1s, and others with all 0s. When they were centralised,
  1156. it was better to provide this option than to break all the archs
  1157. and have several arch maintainers pursuing me down dark alleys.
  1158. config STOP_MACHINE
  1159. bool
  1160. default y
  1161. depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
  1162. help
  1163. Need stop_machine() primitive.
  1164. source "block/Kconfig"
  1165. config PREEMPT_NOTIFIERS
  1166. bool
  1167. config PADATA
  1168. depends on SMP
  1169. bool
  1170. source "kernel/Kconfig.locks"