Kconfig 28 KB

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  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/$ARCH/defconfig"
  15. menu "General setup"
  16. config EXPERIMENTAL
  17. bool "Prompt for development and/or incomplete code/drivers"
  18. ---help---
  19. Some of the various things that Linux supports (such as network
  20. drivers, file systems, network protocols, etc.) can be in a state
  21. of development where the functionality, stability, or the level of
  22. testing is not yet high enough for general use. This is usually
  23. known as the "alpha-test" phase among developers. If a feature is
  24. currently in alpha-test, then the developers usually discourage
  25. uninformed widespread use of this feature by the general public to
  26. avoid "Why doesn't this work?" type mail messages. However, active
  27. testing and use of these systems is welcomed. Just be aware that it
  28. may not meet the normal level of reliability or it may fail to work
  29. in some special cases. Detailed bug reports from people familiar
  30. with the kernel internals are usually welcomed by the developers
  31. (before submitting bug reports, please read the documents
  32. <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
  33. <file:Documentation/BUG-HUNTING>, and
  34. <file:Documentation/oops-tracing.txt> in the kernel source).
  35. This option will also make obsoleted drivers available. These are
  36. drivers that have been replaced by something else, and/or are
  37. scheduled to be removed in a future kernel release.
  38. Unless you intend to help test and develop a feature or driver that
  39. falls into this category, or you have a situation that requires
  40. using these features, you should probably say N here, which will
  41. cause the configurator to present you with fewer choices. If
  42. you say Y here, you will be offered the choice of using features or
  43. drivers that are currently considered to be in the alpha-test phase.
  44. config BROKEN
  45. bool
  46. config BROKEN_ON_SMP
  47. bool
  48. depends on BROKEN || !SMP
  49. default y
  50. config LOCK_KERNEL
  51. bool
  52. depends on SMP || PREEMPT
  53. default y
  54. config INIT_ENV_ARG_LIMIT
  55. int
  56. default 32 if !UML
  57. default 128 if UML
  58. help
  59. Maximum of each of the number of arguments and environment
  60. variables passed to init from the kernel command line.
  61. config LOCALVERSION
  62. string "Local version - append to kernel release"
  63. help
  64. Append an extra string to the end of your kernel version.
  65. This will show up when you type uname, for example.
  66. The string you set here will be appended after the contents of
  67. any files with a filename matching localversion* in your
  68. object and source tree, in that order. Your total string can
  69. be a maximum of 64 characters.
  70. config LOCALVERSION_AUTO
  71. bool "Automatically append version information to the version string"
  72. default y
  73. help
  74. This will try to automatically determine if the current tree is a
  75. release tree by looking for git tags that belong to the current
  76. top of tree revision.
  77. A string of the format -gxxxxxxxx will be added to the localversion
  78. if a git-based tree is found. The string generated by this will be
  79. appended after any matching localversion* files, and after the value
  80. set in CONFIG_LOCALVERSION.
  81. (The actual string used here is the first eight characters produced
  82. by running the command:
  83. $ git rev-parse --verify HEAD
  84. which is done within the script "scripts/setlocalversion".)
  85. config SWAP
  86. bool "Support for paging of anonymous memory (swap)"
  87. depends on MMU && BLOCK
  88. default y
  89. help
  90. This option allows you to choose whether you want to have support
  91. for so called swap devices or swap files in your kernel that are
  92. used to provide more virtual memory than the actual RAM present
  93. in your computer. If unsure say Y.
  94. config SYSVIPC
  95. bool "System V IPC"
  96. ---help---
  97. Inter Process Communication is a suite of library functions and
  98. system calls which let processes (running programs) synchronize and
  99. exchange information. It is generally considered to be a good thing,
  100. and some programs won't run unless you say Y here. In particular, if
  101. you want to run the DOS emulator dosemu under Linux (read the
  102. DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
  103. you'll need to say Y here.
  104. You can find documentation about IPC with "info ipc" and also in
  105. section 6.4 of the Linux Programmer's Guide, available from
  106. <http://www.tldp.org/guides.html>.
  107. config SYSVIPC_SYSCTL
  108. bool
  109. depends on SYSVIPC
  110. depends on SYSCTL
  111. default y
  112. config POSIX_MQUEUE
  113. bool "POSIX Message Queues"
  114. depends on NET && EXPERIMENTAL
  115. ---help---
  116. POSIX variant of message queues is a part of IPC. In POSIX message
  117. queues every message has a priority which decides about succession
  118. of receiving it by a process. If you want to compile and run
  119. programs written e.g. for Solaris with use of its POSIX message
  120. queues (functions mq_*) say Y here.
  121. POSIX message queues are visible as a filesystem called 'mqueue'
  122. and can be mounted somewhere if you want to do filesystem
  123. operations on message queues.
  124. If unsure, say Y.
  125. config BSD_PROCESS_ACCT
  126. bool "BSD Process Accounting"
  127. help
  128. If you say Y here, a user level program will be able to instruct the
  129. kernel (via a special system call) to write process accounting
  130. information to a file: whenever a process exits, information about
  131. that process will be appended to the file by the kernel. The
  132. information includes things such as creation time, owning user,
  133. command name, memory usage, controlling terminal etc. (the complete
  134. list is in the struct acct in <file:include/linux/acct.h>). It is
  135. up to the user level program to do useful things with this
  136. information. This is generally a good idea, so say Y.
  137. config BSD_PROCESS_ACCT_V3
  138. bool "BSD Process Accounting version 3 file format"
  139. depends on BSD_PROCESS_ACCT
  140. default n
  141. help
  142. If you say Y here, the process accounting information is written
  143. in a new file format that also logs the process IDs of each
  144. process and it's parent. Note that this file format is incompatible
  145. with previous v0/v1/v2 file formats, so you will need updated tools
  146. for processing it. A preliminary version of these tools is available
  147. at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>.
  148. config TASKSTATS
  149. bool "Export task/process statistics through netlink (EXPERIMENTAL)"
  150. depends on NET
  151. default n
  152. help
  153. Export selected statistics for tasks/processes through the
  154. generic netlink interface. Unlike BSD process accounting, the
  155. statistics are available during the lifetime of tasks/processes as
  156. responses to commands. Like BSD accounting, they are sent to user
  157. space on task exit.
  158. Say N if unsure.
  159. config TASK_DELAY_ACCT
  160. bool "Enable per-task delay accounting (EXPERIMENTAL)"
  161. depends on TASKSTATS
  162. help
  163. Collect information on time spent by a task waiting for system
  164. resources like cpu, synchronous block I/O completion and swapping
  165. in pages. Such statistics can help in setting a task's priorities
  166. relative to other tasks for cpu, io, rss limits etc.
  167. Say N if unsure.
  168. config TASK_XACCT
  169. bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
  170. depends on TASKSTATS
  171. help
  172. Collect extended task accounting data and send the data
  173. to userland for processing over the taskstats interface.
  174. Say N if unsure.
  175. config TASK_IO_ACCOUNTING
  176. bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
  177. depends on TASK_XACCT
  178. help
  179. Collect information on the number of bytes of storage I/O which this
  180. task has caused.
  181. Say N if unsure.
  182. config AUDIT
  183. bool "Auditing support"
  184. depends on NET
  185. help
  186. Enable auditing infrastructure that can be used with another
  187. kernel subsystem, such as SELinux (which requires this for
  188. logging of avc messages output). Does not do system-call
  189. auditing without CONFIG_AUDITSYSCALL.
  190. config AUDITSYSCALL
  191. bool "Enable system-call auditing support"
  192. depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64|| SUPERH)
  193. default y if SECURITY_SELINUX
  194. help
  195. Enable low-overhead system-call auditing infrastructure that
  196. can be used independently or with another kernel subsystem,
  197. such as SELinux. To use audit's filesystem watch feature, please
  198. ensure that INOTIFY is configured.
  199. config AUDIT_TREE
  200. def_bool y
  201. depends on AUDITSYSCALL && INOTIFY
  202. config IKCONFIG
  203. tristate "Kernel .config support"
  204. ---help---
  205. This option enables the complete Linux kernel ".config" file
  206. contents to be saved in the kernel. It provides documentation
  207. of which kernel options are used in a running kernel or in an
  208. on-disk kernel. This information can be extracted from the kernel
  209. image file with the script scripts/extract-ikconfig and used as
  210. input to rebuild the current kernel or to build another kernel.
  211. It can also be extracted from a running kernel by reading
  212. /proc/config.gz if enabled (below).
  213. config IKCONFIG_PROC
  214. bool "Enable access to .config through /proc/config.gz"
  215. depends on IKCONFIG && PROC_FS
  216. ---help---
  217. This option enables access to the kernel configuration file
  218. through /proc/config.gz.
  219. config LOG_BUF_SHIFT
  220. int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
  221. range 12 21
  222. default 17
  223. help
  224. Select kernel log buffer size as a power of 2.
  225. Examples:
  226. 17 => 128 KB
  227. 16 => 64 KB
  228. 15 => 32 KB
  229. 14 => 16 KB
  230. 13 => 8 KB
  231. 12 => 4 KB
  232. config CGROUPS
  233. bool "Control Group support"
  234. help
  235. This option will let you use process cgroup subsystems
  236. such as Cpusets
  237. Say N if unsure.
  238. config CGROUP_DEBUG
  239. bool "Example debug cgroup subsystem"
  240. depends on CGROUPS
  241. help
  242. This option enables a simple cgroup subsystem that
  243. exports useful debugging information about the cgroups
  244. framework
  245. Say N if unsure
  246. config CGROUP_NS
  247. bool "Namespace cgroup subsystem"
  248. depends on CGROUPS
  249. help
  250. Provides a simple namespace cgroup subsystem to
  251. provide hierarchical naming of sets of namespaces,
  252. for instance virtual servers and checkpoint/restart
  253. jobs.
  254. config CPUSETS
  255. bool "Cpuset support"
  256. depends on SMP && CGROUPS
  257. help
  258. This option will let you create and manage CPUSETs which
  259. allow dynamically partitioning a system into sets of CPUs and
  260. Memory Nodes and assigning tasks to run only within those sets.
  261. This is primarily useful on large SMP or NUMA systems.
  262. Say N if unsure.
  263. config GROUP_SCHED
  264. bool "Group CPU scheduler"
  265. default y
  266. help
  267. This feature lets CPU scheduler recognize task groups and control CPU
  268. bandwidth allocation to such task groups.
  269. config FAIR_GROUP_SCHED
  270. bool "Group scheduling for SCHED_OTHER"
  271. depends on GROUP_SCHED
  272. default y
  273. config RT_GROUP_SCHED
  274. bool "Group scheduling for SCHED_RR/FIFO"
  275. depends on EXPERIMENTAL
  276. depends on GROUP_SCHED
  277. default n
  278. help
  279. This feature lets you explicitly allocate real CPU bandwidth
  280. to users or control groups (depending on the "Basis for grouping tasks"
  281. setting below. If enabled, it will also make it impossible to
  282. schedule realtime tasks for non-root users until you allocate
  283. realtime bandwidth for them.
  284. See Documentation/sched-rt-group.txt for more information.
  285. choice
  286. depends on GROUP_SCHED
  287. prompt "Basis for grouping tasks"
  288. default USER_SCHED
  289. config USER_SCHED
  290. bool "user id"
  291. help
  292. This option will choose userid as the basis for grouping
  293. tasks, thus providing equal CPU bandwidth to each user.
  294. config CGROUP_SCHED
  295. bool "Control groups"
  296. depends on CGROUPS
  297. help
  298. This option allows you to create arbitrary task groups
  299. using the "cgroup" pseudo filesystem and control
  300. the cpu bandwidth allocated to each such task group.
  301. Refer to Documentation/cgroups.txt for more information
  302. on "cgroup" pseudo filesystem.
  303. endchoice
  304. config CGROUP_CPUACCT
  305. bool "Simple CPU accounting cgroup subsystem"
  306. depends on CGROUPS
  307. help
  308. Provides a simple Resource Controller for monitoring the
  309. total CPU consumed by the tasks in a cgroup
  310. config RESOURCE_COUNTERS
  311. bool "Resource counters"
  312. help
  313. This option enables controller independent resource accounting
  314. infrastructure that works with cgroups
  315. depends on CGROUPS
  316. config CGROUP_MEM_RES_CTLR
  317. bool "Memory Resource Controller for Control Groups"
  318. depends on CGROUPS && RESOURCE_COUNTERS
  319. help
  320. Provides a memory resource controller that manages both page cache and
  321. RSS memory.
  322. Note that setting this option increases fixed memory overhead
  323. associated with each page of memory in the system by 4/8 bytes
  324. and also increases cache misses because struct page on many 64bit
  325. systems will not fit into a single cache line anymore.
  326. Only enable when you're ok with these trade offs and really
  327. sure you need the memory resource controller.
  328. config SYSFS_DEPRECATED
  329. bool
  330. config SYSFS_DEPRECATED_V2
  331. bool "Create deprecated sysfs files"
  332. depends on SYSFS
  333. default y
  334. select SYSFS_DEPRECATED
  335. help
  336. This option creates deprecated symlinks such as the
  337. "device"-link, the <subsystem>:<name>-link, and the
  338. "bus"-link. It may also add deprecated key in the
  339. uevent environment.
  340. None of these features or values should be used today, as
  341. they export driver core implementation details to userspace
  342. or export properties which can't be kept stable across kernel
  343. releases.
  344. If enabled, this option will also move any device structures
  345. that belong to a class, back into the /sys/class hierarchy, in
  346. order to support older versions of udev and some userspace
  347. programs.
  348. If you are using a distro with the most recent userspace
  349. packages, it should be safe to say N here.
  350. config PROC_PID_CPUSET
  351. bool "Include legacy /proc/<pid>/cpuset file"
  352. depends on CPUSETS
  353. default y
  354. config RELAY
  355. bool "Kernel->user space relay support (formerly relayfs)"
  356. help
  357. This option enables support for relay interface support in
  358. certain file systems (such as debugfs).
  359. It is designed to provide an efficient mechanism for tools and
  360. facilities to relay large amounts of data from kernel space to
  361. user space.
  362. If unsure, say N.
  363. config NAMESPACES
  364. bool "Namespaces support" if EMBEDDED
  365. default !EMBEDDED
  366. help
  367. Provides the way to make tasks work with different objects using
  368. the same id. For example same IPC id may refer to different objects
  369. or same user id or pid may refer to different tasks when used in
  370. different namespaces.
  371. config UTS_NS
  372. bool "UTS namespace"
  373. depends on NAMESPACES
  374. help
  375. In this namespace tasks see different info provided with the
  376. uname() system call
  377. config IPC_NS
  378. bool "IPC namespace"
  379. depends on NAMESPACES && SYSVIPC
  380. help
  381. In this namespace tasks work with IPC ids which correspond to
  382. different IPC objects in different namespaces
  383. config USER_NS
  384. bool "User namespace (EXPERIMENTAL)"
  385. depends on NAMESPACES && EXPERIMENTAL
  386. help
  387. This allows containers, i.e. vservers, to use user namespaces
  388. to provide different user info for different servers.
  389. If unsure, say N.
  390. config PID_NS
  391. bool "PID Namespaces (EXPERIMENTAL)"
  392. default n
  393. depends on NAMESPACES && EXPERIMENTAL
  394. help
  395. Suport process id namespaces. This allows having multiple
  396. process with the same pid as long as they are in different
  397. pid namespaces. This is a building block of containers.
  398. Unless you want to work with an experimental feature
  399. say N here.
  400. config BLK_DEV_INITRD
  401. bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
  402. depends on BROKEN || !FRV
  403. help
  404. The initial RAM filesystem is a ramfs which is loaded by the
  405. boot loader (loadlin or lilo) and that is mounted as root
  406. before the normal boot procedure. It is typically used to
  407. load modules needed to mount the "real" root file system,
  408. etc. See <file:Documentation/initrd.txt> for details.
  409. If RAM disk support (BLK_DEV_RAM) is also included, this
  410. also enables initial RAM disk (initrd) support and adds
  411. 15 Kbytes (more on some other architectures) to the kernel size.
  412. If unsure say Y.
  413. if BLK_DEV_INITRD
  414. source "usr/Kconfig"
  415. endif
  416. config CC_OPTIMIZE_FOR_SIZE
  417. bool "Optimize for size"
  418. default y
  419. help
  420. Enabling this option will pass "-Os" instead of "-O2" to gcc
  421. resulting in a smaller kernel.
  422. If unsure, say N.
  423. config SYSCTL
  424. bool
  425. menuconfig EMBEDDED
  426. bool "Configure standard kernel features (for small systems)"
  427. help
  428. This option allows certain base kernel options and settings
  429. to be disabled or tweaked. This is for specialized
  430. environments which can tolerate a "non-standard" kernel.
  431. Only use this if you really know what you are doing.
  432. config UID16
  433. bool "Enable 16-bit UID system calls" if EMBEDDED
  434. depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION)
  435. default y
  436. help
  437. This enables the legacy 16-bit UID syscall wrappers.
  438. config SYSCTL_SYSCALL
  439. bool "Sysctl syscall support" if EMBEDDED
  440. default y
  441. select SYSCTL
  442. ---help---
  443. sys_sysctl uses binary paths that have been found challenging
  444. to properly maintain and use. The interface in /proc/sys
  445. using paths with ascii names is now the primary path to this
  446. information.
  447. Almost nothing using the binary sysctl interface so if you are
  448. trying to save some space it is probably safe to disable this,
  449. making your kernel marginally smaller.
  450. If unsure say Y here.
  451. config KALLSYMS
  452. bool "Load all symbols for debugging/ksymoops" if EMBEDDED
  453. default y
  454. help
  455. Say Y here to let the kernel print out symbolic crash information and
  456. symbolic stack backtraces. This increases the size of the kernel
  457. somewhat, as all symbols have to be loaded into the kernel image.
  458. config KALLSYMS_ALL
  459. bool "Include all symbols in kallsyms"
  460. depends on DEBUG_KERNEL && KALLSYMS
  461. help
  462. Normally kallsyms only contains the symbols of functions, for nicer
  463. OOPS messages. Some debuggers can use kallsyms for other
  464. symbols too: say Y here to include all symbols, if you need them
  465. and you don't care about adding 300k to the size of your kernel.
  466. Say N.
  467. config KALLSYMS_EXTRA_PASS
  468. bool "Do an extra kallsyms pass"
  469. depends on KALLSYMS
  470. help
  471. If kallsyms is not working correctly, the build will fail with
  472. inconsistent kallsyms data. If that occurs, log a bug report and
  473. turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
  474. Always say N here unless you find a bug in kallsyms, which must be
  475. reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
  476. you wait for kallsyms to be fixed.
  477. config HOTPLUG
  478. bool "Support for hot-pluggable devices" if EMBEDDED
  479. default y
  480. help
  481. This option is provided for the case where no hotplug or uevent
  482. capabilities is wanted by the kernel. You should only consider
  483. disabling this option for embedded systems that do not use modules, a
  484. dynamic /dev tree, or dynamic device discovery. Just say Y.
  485. config PRINTK
  486. default y
  487. bool "Enable support for printk" if EMBEDDED
  488. help
  489. This option enables normal printk support. Removing it
  490. eliminates most of the message strings from the kernel image
  491. and makes the kernel more or less silent. As this makes it
  492. very difficult to diagnose system problems, saying N here is
  493. strongly discouraged.
  494. config BUG
  495. bool "BUG() support" if EMBEDDED
  496. default y
  497. help
  498. Disabling this option eliminates support for BUG and WARN, reducing
  499. the size of your kernel image and potentially quietly ignoring
  500. numerous fatal conditions. You should only consider disabling this
  501. option for embedded systems with no facilities for reporting errors.
  502. Just say Y.
  503. config ELF_CORE
  504. default y
  505. bool "Enable ELF core dumps" if EMBEDDED
  506. help
  507. Enable support for generating core dumps. Disabling saves about 4k.
  508. config COMPAT_BRK
  509. bool "Disable heap randomization"
  510. default y
  511. help
  512. Randomizing heap placement makes heap exploits harder, but it
  513. also breaks ancient binaries (including anything libc5 based).
  514. This option changes the bootup default to heap randomization
  515. disabled, and can be overriden runtime by setting
  516. /proc/sys/kernel/randomize_va_space to 2.
  517. On non-ancient distros (post-2000 ones) N is usually a safe choice.
  518. config BASE_FULL
  519. default y
  520. bool "Enable full-sized data structures for core" if EMBEDDED
  521. help
  522. Disabling this option reduces the size of miscellaneous core
  523. kernel data structures. This saves memory on small machines,
  524. but may reduce performance.
  525. config FUTEX
  526. bool "Enable futex support" if EMBEDDED
  527. default y
  528. select RT_MUTEXES
  529. help
  530. Disabling this option will cause the kernel to be built without
  531. support for "fast userspace mutexes". The resulting kernel may not
  532. run glibc-based applications correctly.
  533. config ANON_INODES
  534. bool
  535. config EPOLL
  536. bool "Enable eventpoll support" if EMBEDDED
  537. default y
  538. select ANON_INODES
  539. help
  540. Disabling this option will cause the kernel to be built without
  541. support for epoll family of system calls.
  542. config SIGNALFD
  543. bool "Enable signalfd() system call" if EMBEDDED
  544. select ANON_INODES
  545. default y
  546. help
  547. Enable the signalfd() system call that allows to receive signals
  548. on a file descriptor.
  549. If unsure, say Y.
  550. config TIMERFD
  551. bool "Enable timerfd() system call" if EMBEDDED
  552. select ANON_INODES
  553. default y
  554. help
  555. Enable the timerfd() system call that allows to receive timer
  556. events on a file descriptor.
  557. If unsure, say Y.
  558. config EVENTFD
  559. bool "Enable eventfd() system call" if EMBEDDED
  560. select ANON_INODES
  561. default y
  562. help
  563. Enable the eventfd() system call that allows to receive both
  564. kernel notification (ie. KAIO) or userspace notifications.
  565. If unsure, say Y.
  566. config SHMEM
  567. bool "Use full shmem filesystem" if EMBEDDED
  568. default y
  569. depends on MMU
  570. help
  571. The shmem is an internal filesystem used to manage shared memory.
  572. It is backed by swap and manages resource limits. It is also exported
  573. to userspace as tmpfs if TMPFS is enabled. Disabling this
  574. option replaces shmem and tmpfs with the much simpler ramfs code,
  575. which may be appropriate on small systems without swap.
  576. config VM_EVENT_COUNTERS
  577. default y
  578. bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
  579. help
  580. VM event counters are needed for event counts to be shown.
  581. This option allows the disabling of the VM event counters
  582. on EMBEDDED systems. /proc/vmstat will only show page counts
  583. if VM event counters are disabled.
  584. config SLUB_DEBUG
  585. default y
  586. bool "Enable SLUB debugging support" if EMBEDDED
  587. depends on SLUB
  588. help
  589. SLUB has extensive debug support features. Disabling these can
  590. result in significant savings in code size. This also disables
  591. SLUB sysfs support. /sys/slab will not exist and there will be
  592. no support for cache validation etc.
  593. choice
  594. prompt "Choose SLAB allocator"
  595. default SLUB
  596. help
  597. This option allows to select a slab allocator.
  598. config SLAB
  599. bool "SLAB"
  600. help
  601. The regular slab allocator that is established and known to work
  602. well in all environments. It organizes cache hot objects in
  603. per cpu and per node queues. SLAB is the default choice for
  604. a slab allocator.
  605. config SLUB
  606. bool "SLUB (Unqueued Allocator)"
  607. help
  608. SLUB is a slab allocator that minimizes cache line usage
  609. instead of managing queues of cached objects (SLAB approach).
  610. Per cpu caching is realized using slabs of objects instead
  611. of queues of objects. SLUB can use memory efficiently
  612. and has enhanced diagnostics.
  613. config SLOB
  614. depends on EMBEDDED
  615. bool "SLOB (Simple Allocator)"
  616. help
  617. SLOB replaces the stock allocator with a drastically simpler
  618. allocator. SLOB is generally more space efficient but
  619. does not perform as well on large systems.
  620. endchoice
  621. config PROFILING
  622. bool "Profiling support (EXPERIMENTAL)"
  623. help
  624. Say Y here to enable the extended profiling support mechanisms used
  625. by profilers such as OProfile.
  626. config MARKERS
  627. bool "Activate markers"
  628. help
  629. Place an empty function call at each marker site. Can be
  630. dynamically changed for a probe function.
  631. source "arch/Kconfig"
  632. config PROC_PAGE_MONITOR
  633. default y
  634. depends on PROC_FS && MMU
  635. bool "Enable /proc page monitoring" if EMBEDDED
  636. help
  637. Various /proc files exist to monitor process memory utilization:
  638. /proc/pid/smaps, /proc/pid/clear_refs, /proc/pid/pagemap,
  639. /proc/kpagecount, and /proc/kpageflags. Disabling these
  640. interfaces will reduce the size of the kernel by approximately 4kb.
  641. endmenu # General setup
  642. config SLABINFO
  643. bool
  644. depends on PROC_FS
  645. depends on SLAB || SLUB_DEBUG
  646. default y
  647. config RT_MUTEXES
  648. boolean
  649. select PLIST
  650. config TINY_SHMEM
  651. default !SHMEM
  652. bool
  653. config BASE_SMALL
  654. int
  655. default 0 if BASE_FULL
  656. default 1 if !BASE_FULL
  657. menuconfig MODULES
  658. bool "Enable loadable module support"
  659. help
  660. Kernel modules are small pieces of compiled code which can
  661. be inserted in the running kernel, rather than being
  662. permanently built into the kernel. You use the "modprobe"
  663. tool to add (and sometimes remove) them. If you say Y here,
  664. many parts of the kernel can be built as modules (by
  665. answering M instead of Y where indicated): this is most
  666. useful for infrequently used options which are not required
  667. for booting. For more information, see the man pages for
  668. modprobe, lsmod, modinfo, insmod and rmmod.
  669. If you say Y here, you will need to run "make
  670. modules_install" to put the modules under /lib/modules/
  671. where modprobe can find them (you may need to be root to do
  672. this).
  673. If unsure, say Y.
  674. config MODULE_UNLOAD
  675. bool "Module unloading"
  676. depends on MODULES
  677. help
  678. Without this option you will not be able to unload any
  679. modules (note that some modules may not be unloadable
  680. anyway), which makes your kernel slightly smaller and
  681. simpler. If unsure, say Y.
  682. config MODULE_FORCE_UNLOAD
  683. bool "Forced module unloading"
  684. depends on MODULE_UNLOAD && EXPERIMENTAL
  685. help
  686. This option allows you to force a module to unload, even if the
  687. kernel believes it is unsafe: the kernel will remove the module
  688. without waiting for anyone to stop using it (using the -f option to
  689. rmmod). This is mainly for kernel developers and desperate users.
  690. If unsure, say N.
  691. config MODVERSIONS
  692. bool "Module versioning support"
  693. depends on MODULES
  694. help
  695. Usually, you have to use modules compiled with your kernel.
  696. Saying Y here makes it sometimes possible to use modules
  697. compiled for different kernels, by adding enough information
  698. to the modules to (hopefully) spot any changes which would
  699. make them incompatible with the kernel you are running. If
  700. unsure, say N.
  701. config MODULE_SRCVERSION_ALL
  702. bool "Source checksum for all modules"
  703. depends on MODULES
  704. help
  705. Modules which contain a MODULE_VERSION get an extra "srcversion"
  706. field inserted into their modinfo section, which contains a
  707. sum of the source files which made it. This helps maintainers
  708. see exactly which source was used to build a module (since
  709. others sometimes change the module source without updating
  710. the version). With this option, such a "srcversion" field
  711. will be created for all modules. If unsure, say N.
  712. config KMOD
  713. bool "Automatic kernel module loading"
  714. depends on MODULES
  715. help
  716. Normally when you have selected some parts of the kernel to
  717. be created as kernel modules, you must load them (using the
  718. "modprobe" command) before you can use them. If you say Y
  719. here, some parts of the kernel will be able to load modules
  720. automatically: when a part of the kernel needs a module, it
  721. runs modprobe with the appropriate arguments, thereby
  722. loading the module if it is available. If unsure, say Y.
  723. config STOP_MACHINE
  724. bool
  725. default y
  726. depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
  727. help
  728. Need stop_machine() primitive.
  729. source "block/Kconfig"
  730. config PREEMPT_NOTIFIERS
  731. bool
  732. config CLASSIC_RCU
  733. def_bool !PREEMPT_RCU
  734. help
  735. This option selects the classic RCU implementation that is
  736. designed for best read-side performance on non-realtime
  737. systems. Classic RCU is the default. Note that the
  738. PREEMPT_RCU symbol is used to select/deselect this option.