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 drivers that have been replaced by something else, and/or are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 if S390 || LOCKDEP
  223. default 16 if X86_NUMAQ || IA64
  224. default 15 if SMP
  225. default 14
  226. help
  227. Select kernel log buffer size as a power of 2.
  228. Defaults and Examples:
  229. 17 => 128 KB for S/390
  230. 16 => 64 KB for x86 NUMAQ or IA-64
  231. 15 => 32 KB for SMP
  232. 14 => 16 KB for uniprocessor
  233. 13 => 8 KB
  234. 12 => 4 KB
  235. config CGROUPS
  236. bool "Control Group support"
  237. help
  238. This option will let you use process cgroup subsystems
  239. such as Cpusets
  240. Say N if unsure.
  241. config CGROUP_DEBUG
  242. bool "Example debug cgroup subsystem"
  243. depends on CGROUPS
  244. help
  245. This option enables a simple cgroup subsystem that
  246. exports useful debugging information about the cgroups
  247. framework
  248. Say N if unsure
  249. config CGROUP_NS
  250. bool "Namespace cgroup subsystem"
  251. depends on CGROUPS
  252. help
  253. Provides a simple namespace cgroup subsystem to
  254. provide hierarchical naming of sets of namespaces,
  255. for instance virtual servers and checkpoint/restart
  256. jobs.
  257. config CPUSETS
  258. bool "Cpuset support"
  259. depends on SMP && CGROUPS
  260. help
  261. This option will let you create and manage CPUSETs which
  262. allow dynamically partitioning a system into sets of CPUs and
  263. Memory Nodes and assigning tasks to run only within those sets.
  264. This is primarily useful on large SMP or NUMA systems.
  265. Say N if unsure.
  266. config GROUP_SCHED
  267. bool "Group CPU scheduler"
  268. default y
  269. help
  270. This feature lets CPU scheduler recognize task groups and control CPU
  271. bandwidth allocation to such task groups.
  272. config FAIR_GROUP_SCHED
  273. bool "Group scheduling for SCHED_OTHER"
  274. depends on GROUP_SCHED
  275. default y
  276. config RT_GROUP_SCHED
  277. bool "Group scheduling for SCHED_RR/FIFO"
  278. depends on EXPERIMENTAL
  279. depends on GROUP_SCHED
  280. default n
  281. choice
  282. depends on GROUP_SCHED
  283. prompt "Basis for grouping tasks"
  284. default USER_SCHED
  285. config USER_SCHED
  286. bool "user id"
  287. help
  288. This option will choose userid as the basis for grouping
  289. tasks, thus providing equal CPU bandwidth to each user.
  290. config CGROUP_SCHED
  291. bool "Control groups"
  292. depends on CGROUPS
  293. help
  294. This option allows you to create arbitrary task groups
  295. using the "cgroup" pseudo filesystem and control
  296. the cpu bandwidth allocated to each such task group.
  297. Refer to Documentation/cgroups.txt for more information
  298. on "cgroup" pseudo filesystem.
  299. endchoice
  300. config CGROUP_CPUACCT
  301. bool "Simple CPU accounting cgroup subsystem"
  302. depends on CGROUPS
  303. help
  304. Provides a simple Resource Controller for monitoring the
  305. total CPU consumed by the tasks in a cgroup
  306. config RESOURCE_COUNTERS
  307. bool "Resource counters"
  308. help
  309. This option enables controller independent resource accounting
  310. infrastructure that works with cgroups
  311. depends on CGROUPS
  312. config CGROUP_MEM_RES_CTLR
  313. bool "Memory Resource Controller for Control Groups"
  314. depends on CGROUPS && RESOURCE_COUNTERS
  315. help
  316. Provides a memory resource controller that manages both page cache and
  317. RSS memory.
  318. Note that setting this option increases fixed memory overhead
  319. associated with each page of memory in the system by 4/8 bytes
  320. and also increases cache misses because struct page on many 64bit
  321. systems will not fit into a single cache line anymore.
  322. Only enable when you're ok with these trade offs and really
  323. sure you need the memory resource controller.
  324. config SYSFS_DEPRECATED
  325. bool
  326. config SYSFS_DEPRECATED_V2
  327. bool "Create deprecated sysfs files"
  328. depends on SYSFS
  329. default y
  330. select SYSFS_DEPRECATED
  331. help
  332. This option creates deprecated symlinks such as the
  333. "device"-link, the <subsystem>:<name>-link, and the
  334. "bus"-link. It may also add deprecated key in the
  335. uevent environment.
  336. None of these features or values should be used today, as
  337. they export driver core implementation details to userspace
  338. or export properties which can't be kept stable across kernel
  339. releases.
  340. If enabled, this option will also move any device structures
  341. that belong to a class, back into the /sys/class hierarchy, in
  342. order to support older versions of udev and some userspace
  343. programs.
  344. If you are using a distro with the most recent userspace
  345. packages, it should be safe to say N here.
  346. config PROC_PID_CPUSET
  347. bool "Include legacy /proc/<pid>/cpuset file"
  348. depends on CPUSETS
  349. default y
  350. config RELAY
  351. bool "Kernel->user space relay support (formerly relayfs)"
  352. help
  353. This option enables support for relay interface support in
  354. certain file systems (such as debugfs).
  355. It is designed to provide an efficient mechanism for tools and
  356. facilities to relay large amounts of data from kernel space to
  357. user space.
  358. If unsure, say N.
  359. config NAMESPACES
  360. bool "Namespaces support" if EMBEDDED
  361. default !EMBEDDED
  362. help
  363. Provides the way to make tasks work with different objects using
  364. the same id. For example same IPC id may refer to different objects
  365. or same user id or pid may refer to different tasks when used in
  366. different namespaces.
  367. config UTS_NS
  368. bool "UTS namespace"
  369. depends on NAMESPACES
  370. help
  371. In this namespace tasks see different info provided with the
  372. uname() system call
  373. config IPC_NS
  374. bool "IPC namespace"
  375. depends on NAMESPACES && SYSVIPC
  376. help
  377. In this namespace tasks work with IPC ids which correspond to
  378. different IPC objects in different namespaces
  379. config USER_NS
  380. bool "User namespace (EXPERIMENTAL)"
  381. depends on NAMESPACES && EXPERIMENTAL
  382. help
  383. This allows containers, i.e. vservers, to use user namespaces
  384. to provide different user info for different servers.
  385. If unsure, say N.
  386. config PID_NS
  387. bool "PID Namespaces (EXPERIMENTAL)"
  388. default n
  389. depends on NAMESPACES && EXPERIMENTAL
  390. help
  391. Suport process id namespaces. This allows having multiple
  392. process with the same pid as long as they are in different
  393. pid namespaces. This is a building block of containers.
  394. Unless you want to work with an experimental feature
  395. say N here.
  396. config BLK_DEV_INITRD
  397. bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
  398. depends on BROKEN || !FRV
  399. help
  400. The initial RAM filesystem is a ramfs which is loaded by the
  401. boot loader (loadlin or lilo) and that is mounted as root
  402. before the normal boot procedure. It is typically used to
  403. load modules needed to mount the "real" root file system,
  404. etc. See <file:Documentation/initrd.txt> for details.
  405. If RAM disk support (BLK_DEV_RAM) is also included, this
  406. also enables initial RAM disk (initrd) support and adds
  407. 15 Kbytes (more on some other architectures) to the kernel size.
  408. If unsure say Y.
  409. if BLK_DEV_INITRD
  410. source "usr/Kconfig"
  411. endif
  412. config CC_OPTIMIZE_FOR_SIZE
  413. bool "Optimize for size (Look out for broken compilers!)"
  414. default y
  415. depends on ARM || H8300 || SUPERH || EXPERIMENTAL
  416. help
  417. Enabling this option will pass "-Os" instead of "-O2" to gcc
  418. resulting in a smaller kernel.
  419. WARNING: some versions of gcc may generate incorrect code with this
  420. option. If problems are observed, a gcc upgrade may be needed.
  421. If unsure, say N.
  422. config SYSCTL
  423. bool
  424. menuconfig EMBEDDED
  425. bool "Configure standard kernel features (for small systems)"
  426. help
  427. This option allows certain base kernel options and settings
  428. to be disabled or tweaked. This is for specialized
  429. environments which can tolerate a "non-standard" kernel.
  430. Only use this if you really know what you are doing.
  431. config UID16
  432. bool "Enable 16-bit UID system calls" if EMBEDDED
  433. depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION)
  434. default y
  435. help
  436. This enables the legacy 16-bit UID syscall wrappers.
  437. config SYSCTL_SYSCALL
  438. bool "Sysctl syscall support" if EMBEDDED
  439. default y
  440. select SYSCTL
  441. ---help---
  442. sys_sysctl uses binary paths that have been found challenging
  443. to properly maintain and use. The interface in /proc/sys
  444. using paths with ascii names is now the primary path to this
  445. information.
  446. Almost nothing using the binary sysctl interface so if you are
  447. trying to save some space it is probably safe to disable this,
  448. making your kernel marginally smaller.
  449. If unsure say Y here.
  450. config KALLSYMS
  451. bool "Load all symbols for debugging/ksymoops" if EMBEDDED
  452. default y
  453. help
  454. Say Y here to let the kernel print out symbolic crash information and
  455. symbolic stack backtraces. This increases the size of the kernel
  456. somewhat, as all symbols have to be loaded into the kernel image.
  457. config KALLSYMS_ALL
  458. bool "Include all symbols in kallsyms"
  459. depends on DEBUG_KERNEL && KALLSYMS
  460. help
  461. Normally kallsyms only contains the symbols of functions, for nicer
  462. OOPS messages. Some debuggers can use kallsyms for other
  463. symbols too: say Y here to include all symbols, if you need them
  464. and you don't care about adding 300k to the size of your kernel.
  465. Say N.
  466. config KALLSYMS_EXTRA_PASS
  467. bool "Do an extra kallsyms pass"
  468. depends on KALLSYMS
  469. help
  470. If kallsyms is not working correctly, the build will fail with
  471. inconsistent kallsyms data. If that occurs, log a bug report and
  472. turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
  473. Always say N here unless you find a bug in kallsyms, which must be
  474. reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
  475. you wait for kallsyms to be fixed.
  476. config HOTPLUG
  477. bool "Support for hot-pluggable devices" if EMBEDDED
  478. default y
  479. help
  480. This option is provided for the case where no hotplug or uevent
  481. capabilities is wanted by the kernel. You should only consider
  482. disabling this option for embedded systems that do not use modules, a
  483. dynamic /dev tree, or dynamic device discovery. Just say Y.
  484. config PRINTK
  485. default y
  486. bool "Enable support for printk" if EMBEDDED
  487. help
  488. This option enables normal printk support. Removing it
  489. eliminates most of the message strings from the kernel image
  490. and makes the kernel more or less silent. As this makes it
  491. very difficult to diagnose system problems, saying N here is
  492. strongly discouraged.
  493. config BUG
  494. bool "BUG() support" if EMBEDDED
  495. default y
  496. help
  497. Disabling this option eliminates support for BUG and WARN, reducing
  498. the size of your kernel image and potentially quietly ignoring
  499. numerous fatal conditions. You should only consider disabling this
  500. option for embedded systems with no facilities for reporting errors.
  501. Just say Y.
  502. config ELF_CORE
  503. default y
  504. bool "Enable ELF core dumps" if EMBEDDED
  505. help
  506. Enable support for generating core dumps. Disabling saves about 4k.
  507. config COMPAT_BRK
  508. bool "Disable heap randomization"
  509. default y
  510. help
  511. Randomizing heap placement makes heap exploits harder, but it
  512. also breaks ancient binaries (including anything libc5 based).
  513. This option changes the bootup default to heap randomization
  514. disabled, and can be overriden runtime by setting
  515. /proc/sys/kernel/randomize_va_space to 2.
  516. On non-ancient distros (post-2000 ones) N is usually a safe choice.
  517. config BASE_FULL
  518. default y
  519. bool "Enable full-sized data structures for core" if EMBEDDED
  520. help
  521. Disabling this option reduces the size of miscellaneous core
  522. kernel data structures. This saves memory on small machines,
  523. but may reduce performance.
  524. config FUTEX
  525. bool "Enable futex support" if EMBEDDED
  526. default y
  527. select RT_MUTEXES
  528. help
  529. Disabling this option will cause the kernel to be built without
  530. support for "fast userspace mutexes". The resulting kernel may not
  531. run glibc-based applications correctly.
  532. config ANON_INODES
  533. bool
  534. config EPOLL
  535. bool "Enable eventpoll support" if EMBEDDED
  536. default y
  537. select ANON_INODES
  538. help
  539. Disabling this option will cause the kernel to be built without
  540. support for epoll family of system calls.
  541. config SIGNALFD
  542. bool "Enable signalfd() system call" if EMBEDDED
  543. select ANON_INODES
  544. default y
  545. help
  546. Enable the signalfd() system call that allows to receive signals
  547. on a file descriptor.
  548. If unsure, say Y.
  549. config TIMERFD
  550. bool "Enable timerfd() system call" if EMBEDDED
  551. select ANON_INODES
  552. default y
  553. help
  554. Enable the timerfd() system call that allows to receive timer
  555. events on a file descriptor.
  556. If unsure, say Y.
  557. config EVENTFD
  558. bool "Enable eventfd() system call" if EMBEDDED
  559. select ANON_INODES
  560. default y
  561. help
  562. Enable the eventfd() system call that allows to receive both
  563. kernel notification (ie. KAIO) or userspace notifications.
  564. If unsure, say Y.
  565. config SHMEM
  566. bool "Use full shmem filesystem" if EMBEDDED
  567. default y
  568. depends on MMU
  569. help
  570. The shmem is an internal filesystem used to manage shared memory.
  571. It is backed by swap and manages resource limits. It is also exported
  572. to userspace as tmpfs if TMPFS is enabled. Disabling this
  573. option replaces shmem and tmpfs with the much simpler ramfs code,
  574. which may be appropriate on small systems without swap.
  575. config VM_EVENT_COUNTERS
  576. default y
  577. bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
  578. help
  579. VM event counters are needed for event counts to be shown.
  580. This option allows the disabling of the VM event counters
  581. on EMBEDDED systems. /proc/vmstat will only show page counts
  582. if VM event counters are disabled.
  583. config SLUB_DEBUG
  584. default y
  585. bool "Enable SLUB debugging support" if EMBEDDED
  586. depends on SLUB
  587. help
  588. SLUB has extensive debug support features. Disabling these can
  589. result in significant savings in code size. This also disables
  590. SLUB sysfs support. /sys/slab will not exist and there will be
  591. no support for cache validation etc.
  592. choice
  593. prompt "Choose SLAB allocator"
  594. default SLUB
  595. help
  596. This option allows to select a slab allocator.
  597. config SLAB
  598. bool "SLAB"
  599. help
  600. The regular slab allocator that is established and known to work
  601. well in all environments. It organizes cache hot objects in
  602. per cpu and per node queues. SLAB is the default choice for
  603. a slab allocator.
  604. config SLUB
  605. bool "SLUB (Unqueued Allocator)"
  606. help
  607. SLUB is a slab allocator that minimizes cache line usage
  608. instead of managing queues of cached objects (SLAB approach).
  609. Per cpu caching is realized using slabs of objects instead
  610. of queues of objects. SLUB can use memory efficiently
  611. and has enhanced diagnostics.
  612. config SLOB
  613. depends on EMBEDDED
  614. bool "SLOB (Simple Allocator)"
  615. help
  616. SLOB replaces the stock allocator with a drastically simpler
  617. allocator. SLOB is generally more space efficient but
  618. does not perform as well on large systems.
  619. endchoice
  620. config PROFILING
  621. bool "Profiling support (EXPERIMENTAL)"
  622. help
  623. Say Y here to enable the extended profiling support mechanisms used
  624. by profilers such as OProfile.
  625. config MARKERS
  626. bool "Activate markers"
  627. help
  628. Place an empty function call at each marker site. Can be
  629. dynamically changed for a probe function.
  630. source "arch/Kconfig"
  631. config PROC_PAGE_MONITOR
  632. default y
  633. depends on PROC_FS && MMU
  634. bool "Enable /proc page monitoring" if EMBEDDED
  635. help
  636. Various /proc files exist to monitor process memory utilization:
  637. /proc/pid/smaps, /proc/pid/clear_refs, /proc/pid/pagemap,
  638. /proc/kpagecount, and /proc/kpageflags. Disabling these
  639. interfaces will reduce the size of the kernel by approximately 4kb.
  640. endmenu # General setup
  641. config SLABINFO
  642. bool
  643. depends on PROC_FS
  644. depends on SLAB || SLUB
  645. default y
  646. config RT_MUTEXES
  647. boolean
  648. select PLIST
  649. config TINY_SHMEM
  650. default !SHMEM
  651. bool
  652. config BASE_SMALL
  653. int
  654. default 0 if BASE_FULL
  655. default 1 if !BASE_FULL
  656. menuconfig MODULES
  657. bool "Enable loadable module support"
  658. help
  659. Kernel modules are small pieces of compiled code which can
  660. be inserted in the running kernel, rather than being
  661. permanently built into the kernel. You use the "modprobe"
  662. tool to add (and sometimes remove) them. If you say Y here,
  663. many parts of the kernel can be built as modules (by
  664. answering M instead of Y where indicated): this is most
  665. useful for infrequently used options which are not required
  666. for booting. For more information, see the man pages for
  667. modprobe, lsmod, modinfo, insmod and rmmod.
  668. If you say Y here, you will need to run "make
  669. modules_install" to put the modules under /lib/modules/
  670. where modprobe can find them (you may need to be root to do
  671. this).
  672. If unsure, say Y.
  673. config MODULE_UNLOAD
  674. bool "Module unloading"
  675. depends on MODULES
  676. help
  677. Without this option you will not be able to unload any
  678. modules (note that some modules may not be unloadable
  679. anyway), which makes your kernel slightly smaller and
  680. simpler. If unsure, say Y.
  681. config MODULE_FORCE_UNLOAD
  682. bool "Forced module unloading"
  683. depends on MODULE_UNLOAD && EXPERIMENTAL
  684. help
  685. This option allows you to force a module to unload, even if the
  686. kernel believes it is unsafe: the kernel will remove the module
  687. without waiting for anyone to stop using it (using the -f option to
  688. rmmod). This is mainly for kernel developers and desperate users.
  689. If unsure, say N.
  690. config MODVERSIONS
  691. bool "Module versioning support"
  692. depends on MODULES
  693. help
  694. Usually, you have to use modules compiled with your kernel.
  695. Saying Y here makes it sometimes possible to use modules
  696. compiled for different kernels, by adding enough information
  697. to the modules to (hopefully) spot any changes which would
  698. make them incompatible with the kernel you are running. If
  699. unsure, say N.
  700. config MODULE_SRCVERSION_ALL
  701. bool "Source checksum for all modules"
  702. depends on MODULES
  703. help
  704. Modules which contain a MODULE_VERSION get an extra "srcversion"
  705. field inserted into their modinfo section, which contains a
  706. sum of the source files which made it. This helps maintainers
  707. see exactly which source was used to build a module (since
  708. others sometimes change the module source without updating
  709. the version). With this option, such a "srcversion" field
  710. will be created for all modules. If unsure, say N.
  711. config KMOD
  712. bool "Automatic kernel module loading"
  713. depends on MODULES
  714. help
  715. Normally when you have selected some parts of the kernel to
  716. be created as kernel modules, you must load them (using the
  717. "modprobe" command) before you can use them. If you say Y
  718. here, some parts of the kernel will be able to load modules
  719. automatically: when a part of the kernel needs a module, it
  720. runs modprobe with the appropriate arguments, thereby
  721. loading the module if it is available. If unsure, say Y.
  722. config STOP_MACHINE
  723. bool
  724. default y
  725. depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
  726. help
  727. Need stop_machine() primitive.
  728. source "block/Kconfig"
  729. config PREEMPT_NOTIFIERS
  730. bool
  731. config CLASSIC_RCU
  732. def_bool !PREEMPT_RCU
  733. help
  734. This option selects the classic RCU implementation that is
  735. designed for best read-side performance on non-realtime
  736. systems. Classic RCU is the default. Note that the
  737. PREEMPT_RCU symbol is used to select/deselect this option.