Kconfig 29 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 drivers that have been replaced by something else, and/or are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. default n
  242. help
  243. This option enables a simple cgroup subsystem that
  244. exports useful debugging information about the cgroups
  245. framework
  246. Say N if unsure
  247. config CGROUP_NS
  248. bool "Namespace cgroup subsystem"
  249. depends on CGROUPS
  250. help
  251. Provides a simple namespace cgroup subsystem to
  252. provide hierarchical naming of sets of namespaces,
  253. for instance virtual servers and checkpoint/restart
  254. jobs.
  255. config CGROUP_DEVICE
  256. bool "Device controller for cgroups"
  257. depends on CGROUPS && EXPERIMENTAL
  258. help
  259. Provides a cgroup implementing whitelists for devices which
  260. a process in the cgroup can mknod or open.
  261. config CPUSETS
  262. bool "Cpuset support"
  263. depends on SMP && CGROUPS
  264. help
  265. This option will let you create and manage CPUSETs which
  266. allow dynamically partitioning a system into sets of CPUs and
  267. Memory Nodes and assigning tasks to run only within those sets.
  268. This is primarily useful on large SMP or NUMA systems.
  269. Say N if unsure.
  270. config GROUP_SCHED
  271. bool "Group CPU scheduler"
  272. default y
  273. help
  274. This feature lets CPU scheduler recognize task groups and control CPU
  275. bandwidth allocation to such task groups.
  276. config FAIR_GROUP_SCHED
  277. bool "Group scheduling for SCHED_OTHER"
  278. depends on GROUP_SCHED
  279. default y
  280. config RT_GROUP_SCHED
  281. bool "Group scheduling for SCHED_RR/FIFO"
  282. depends on EXPERIMENTAL
  283. depends on GROUP_SCHED
  284. default n
  285. help
  286. This feature lets you explicitly allocate real CPU bandwidth
  287. to users or control groups (depending on the "Basis for grouping tasks"
  288. setting below. If enabled, it will also make it impossible to
  289. schedule realtime tasks for non-root users until you allocate
  290. realtime bandwidth for them.
  291. See Documentation/sched-rt-group.txt for more information.
  292. choice
  293. depends on GROUP_SCHED
  294. prompt "Basis for grouping tasks"
  295. default USER_SCHED
  296. config USER_SCHED
  297. bool "user id"
  298. help
  299. This option will choose userid as the basis for grouping
  300. tasks, thus providing equal CPU bandwidth to each user.
  301. config CGROUP_SCHED
  302. bool "Control groups"
  303. depends on CGROUPS
  304. help
  305. This option allows you to create arbitrary task groups
  306. using the "cgroup" pseudo filesystem and control
  307. the cpu bandwidth allocated to each such task group.
  308. Refer to Documentation/cgroups.txt for more information
  309. on "cgroup" pseudo filesystem.
  310. endchoice
  311. config CGROUP_CPUACCT
  312. bool "Simple CPU accounting cgroup subsystem"
  313. depends on CGROUPS
  314. help
  315. Provides a simple Resource Controller for monitoring the
  316. total CPU consumed by the tasks in a cgroup
  317. config RESOURCE_COUNTERS
  318. bool "Resource counters"
  319. help
  320. This option enables controller independent resource accounting
  321. infrastructure that works with cgroups
  322. depends on CGROUPS
  323. config MM_OWNER
  324. bool
  325. config CGROUP_MEM_RES_CTLR
  326. bool "Memory Resource Controller for Control Groups"
  327. depends on CGROUPS && RESOURCE_COUNTERS
  328. select MM_OWNER
  329. help
  330. Provides a memory resource controller that manages both page cache and
  331. RSS memory.
  332. Note that setting this option increases fixed memory overhead
  333. associated with each page of memory in the system by 4/8 bytes
  334. and also increases cache misses because struct page on many 64bit
  335. systems will not fit into a single cache line anymore.
  336. Only enable when you're ok with these trade offs and really
  337. sure you need the memory resource controller.
  338. This config option also selects MM_OWNER config option, which
  339. could in turn add some fork/exit overhead.
  340. config SYSFS_DEPRECATED
  341. bool
  342. config SYSFS_DEPRECATED_V2
  343. bool "Create deprecated sysfs files"
  344. depends on SYSFS
  345. default y
  346. select SYSFS_DEPRECATED
  347. help
  348. This option creates deprecated symlinks such as the
  349. "device"-link, the <subsystem>:<name>-link, and the
  350. "bus"-link. It may also add deprecated key in the
  351. uevent environment.
  352. None of these features or values should be used today, as
  353. they export driver core implementation details to userspace
  354. or export properties which can't be kept stable across kernel
  355. releases.
  356. If enabled, this option will also move any device structures
  357. that belong to a class, back into the /sys/class hierarchy, in
  358. order to support older versions of udev and some userspace
  359. programs.
  360. If you are using a distro with the most recent userspace
  361. packages, it should be safe to say N here.
  362. config PROC_PID_CPUSET
  363. bool "Include legacy /proc/<pid>/cpuset file"
  364. depends on CPUSETS
  365. default y
  366. config RELAY
  367. bool "Kernel->user space relay support (formerly relayfs)"
  368. help
  369. This option enables support for relay interface support in
  370. certain file systems (such as debugfs).
  371. It is designed to provide an efficient mechanism for tools and
  372. facilities to relay large amounts of data from kernel space to
  373. user space.
  374. If unsure, say N.
  375. config NAMESPACES
  376. bool "Namespaces support" if EMBEDDED
  377. default !EMBEDDED
  378. help
  379. Provides the way to make tasks work with different objects using
  380. the same id. For example same IPC id may refer to different objects
  381. or same user id or pid may refer to different tasks when used in
  382. different namespaces.
  383. config UTS_NS
  384. bool "UTS namespace"
  385. depends on NAMESPACES
  386. help
  387. In this namespace tasks see different info provided with the
  388. uname() system call
  389. config IPC_NS
  390. bool "IPC namespace"
  391. depends on NAMESPACES && SYSVIPC
  392. help
  393. In this namespace tasks work with IPC ids which correspond to
  394. different IPC objects in different namespaces
  395. config USER_NS
  396. bool "User namespace (EXPERIMENTAL)"
  397. depends on NAMESPACES && EXPERIMENTAL
  398. help
  399. This allows containers, i.e. vservers, to use user namespaces
  400. to provide different user info for different servers.
  401. If unsure, say N.
  402. config PID_NS
  403. bool "PID Namespaces (EXPERIMENTAL)"
  404. default n
  405. depends on NAMESPACES && EXPERIMENTAL
  406. help
  407. Suport process id namespaces. This allows having multiple
  408. process with the same pid as long as they are in different
  409. pid namespaces. This is a building block of containers.
  410. Unless you want to work with an experimental feature
  411. say N here.
  412. config BLK_DEV_INITRD
  413. bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
  414. depends on BROKEN || !FRV
  415. help
  416. The initial RAM filesystem is a ramfs which is loaded by the
  417. boot loader (loadlin or lilo) and that is mounted as root
  418. before the normal boot procedure. It is typically used to
  419. load modules needed to mount the "real" root file system,
  420. etc. See <file:Documentation/initrd.txt> for details.
  421. If RAM disk support (BLK_DEV_RAM) is also included, this
  422. also enables initial RAM disk (initrd) support and adds
  423. 15 Kbytes (more on some other architectures) to the kernel size.
  424. If unsure say Y.
  425. if BLK_DEV_INITRD
  426. source "usr/Kconfig"
  427. endif
  428. config CC_OPTIMIZE_FOR_SIZE
  429. bool "Optimize for size"
  430. default y
  431. help
  432. Enabling this option will pass "-Os" instead of "-O2" to gcc
  433. resulting in a smaller kernel.
  434. If unsure, say N.
  435. config SYSCTL
  436. bool
  437. menuconfig EMBEDDED
  438. bool "Configure standard kernel features (for small systems)"
  439. help
  440. This option allows certain base kernel options and settings
  441. to be disabled or tweaked. This is for specialized
  442. environments which can tolerate a "non-standard" kernel.
  443. Only use this if you really know what you are doing.
  444. config UID16
  445. bool "Enable 16-bit UID system calls" if EMBEDDED
  446. depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION)
  447. default y
  448. help
  449. This enables the legacy 16-bit UID syscall wrappers.
  450. config SYSCTL_SYSCALL
  451. bool "Sysctl syscall support" if EMBEDDED
  452. default y
  453. select SYSCTL
  454. ---help---
  455. sys_sysctl uses binary paths that have been found challenging
  456. to properly maintain and use. The interface in /proc/sys
  457. using paths with ascii names is now the primary path to this
  458. information.
  459. Almost nothing using the binary sysctl interface so if you are
  460. trying to save some space it is probably safe to disable this,
  461. making your kernel marginally smaller.
  462. If unsure say Y here.
  463. config SYSCTL_SYSCALL_CHECK
  464. bool "Sysctl checks" if EMBEDDED
  465. depends on SYSCTL_SYSCALL
  466. default y
  467. ---help---
  468. sys_sysctl uses binary paths that have been found challenging
  469. to properly maintain and use. This enables checks that help
  470. you to keep things correct.
  471. If unsure say Y here.
  472. config KALLSYMS
  473. bool "Load all symbols for debugging/ksymoops" if EMBEDDED
  474. default y
  475. help
  476. Say Y here to let the kernel print out symbolic crash information and
  477. symbolic stack backtraces. This increases the size of the kernel
  478. somewhat, as all symbols have to be loaded into the kernel image.
  479. config KALLSYMS_ALL
  480. bool "Include all symbols in kallsyms"
  481. depends on DEBUG_KERNEL && KALLSYMS
  482. help
  483. Normally kallsyms only contains the symbols of functions, for nicer
  484. OOPS messages. Some debuggers can use kallsyms for other
  485. symbols too: say Y here to include all symbols, if you need them
  486. and you don't care about adding 300k to the size of your kernel.
  487. Say N.
  488. config KALLSYMS_EXTRA_PASS
  489. bool "Do an extra kallsyms pass"
  490. depends on KALLSYMS
  491. help
  492. If kallsyms is not working correctly, the build will fail with
  493. inconsistent kallsyms data. If that occurs, log a bug report and
  494. turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
  495. Always say N here unless you find a bug in kallsyms, which must be
  496. reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
  497. you wait for kallsyms to be fixed.
  498. config HOTPLUG
  499. bool "Support for hot-pluggable devices" if EMBEDDED
  500. default y
  501. help
  502. This option is provided for the case where no hotplug or uevent
  503. capabilities is wanted by the kernel. You should only consider
  504. disabling this option for embedded systems that do not use modules, a
  505. dynamic /dev tree, or dynamic device discovery. Just say Y.
  506. config PRINTK
  507. default y
  508. bool "Enable support for printk" if EMBEDDED
  509. help
  510. This option enables normal printk support. Removing it
  511. eliminates most of the message strings from the kernel image
  512. and makes the kernel more or less silent. As this makes it
  513. very difficult to diagnose system problems, saying N here is
  514. strongly discouraged.
  515. config BUG
  516. bool "BUG() support" if EMBEDDED
  517. default y
  518. help
  519. Disabling this option eliminates support for BUG and WARN, reducing
  520. the size of your kernel image and potentially quietly ignoring
  521. numerous fatal conditions. You should only consider disabling this
  522. option for embedded systems with no facilities for reporting errors.
  523. Just say Y.
  524. config ELF_CORE
  525. default y
  526. bool "Enable ELF core dumps" if EMBEDDED
  527. help
  528. Enable support for generating core dumps. Disabling saves about 4k.
  529. config COMPAT_BRK
  530. bool "Disable heap randomization"
  531. default y
  532. help
  533. Randomizing heap placement makes heap exploits harder, but it
  534. also breaks ancient binaries (including anything libc5 based).
  535. This option changes the bootup default to heap randomization
  536. disabled, and can be overriden runtime by setting
  537. /proc/sys/kernel/randomize_va_space to 2.
  538. On non-ancient distros (post-2000 ones) N is usually a safe choice.
  539. config BASE_FULL
  540. default y
  541. bool "Enable full-sized data structures for core" if EMBEDDED
  542. help
  543. Disabling this option reduces the size of miscellaneous core
  544. kernel data structures. This saves memory on small machines,
  545. but may reduce performance.
  546. config FUTEX
  547. bool "Enable futex support" if EMBEDDED
  548. default y
  549. select RT_MUTEXES
  550. help
  551. Disabling this option will cause the kernel to be built without
  552. support for "fast userspace mutexes". The resulting kernel may not
  553. run glibc-based applications correctly.
  554. config ANON_INODES
  555. bool
  556. config EPOLL
  557. bool "Enable eventpoll support" if EMBEDDED
  558. default y
  559. select ANON_INODES
  560. help
  561. Disabling this option will cause the kernel to be built without
  562. support for epoll family of system calls.
  563. config SIGNALFD
  564. bool "Enable signalfd() system call" if EMBEDDED
  565. select ANON_INODES
  566. default y
  567. help
  568. Enable the signalfd() system call that allows to receive signals
  569. on a file descriptor.
  570. If unsure, say Y.
  571. config TIMERFD
  572. bool "Enable timerfd() system call" if EMBEDDED
  573. select ANON_INODES
  574. default y
  575. help
  576. Enable the timerfd() system call that allows to receive timer
  577. events on a file descriptor.
  578. If unsure, say Y.
  579. config EVENTFD
  580. bool "Enable eventfd() system call" if EMBEDDED
  581. select ANON_INODES
  582. default y
  583. help
  584. Enable the eventfd() system call that allows to receive both
  585. kernel notification (ie. KAIO) or userspace notifications.
  586. If unsure, say Y.
  587. config SHMEM
  588. bool "Use full shmem filesystem" if EMBEDDED
  589. default y
  590. depends on MMU
  591. help
  592. The shmem is an internal filesystem used to manage shared memory.
  593. It is backed by swap and manages resource limits. It is also exported
  594. to userspace as tmpfs if TMPFS is enabled. Disabling this
  595. option replaces shmem and tmpfs with the much simpler ramfs code,
  596. which may be appropriate on small systems without swap.
  597. config VM_EVENT_COUNTERS
  598. default y
  599. bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
  600. help
  601. VM event counters are needed for event counts to be shown.
  602. This option allows the disabling of the VM event counters
  603. on EMBEDDED systems. /proc/vmstat will only show page counts
  604. if VM event counters are disabled.
  605. config SLUB_DEBUG
  606. default y
  607. bool "Enable SLUB debugging support" if EMBEDDED
  608. depends on SLUB && SYSFS
  609. help
  610. SLUB has extensive debug support features. Disabling these can
  611. result in significant savings in code size. This also disables
  612. SLUB sysfs support. /sys/slab will not exist and there will be
  613. no support for cache validation etc.
  614. choice
  615. prompt "Choose SLAB allocator"
  616. default SLUB
  617. help
  618. This option allows to select a slab allocator.
  619. config SLAB
  620. bool "SLAB"
  621. help
  622. The regular slab allocator that is established and known to work
  623. well in all environments. It organizes cache hot objects in
  624. per cpu and per node queues. SLAB is the default choice for
  625. a slab allocator.
  626. config SLUB
  627. bool "SLUB (Unqueued Allocator)"
  628. help
  629. SLUB is a slab allocator that minimizes cache line usage
  630. instead of managing queues of cached objects (SLAB approach).
  631. Per cpu caching is realized using slabs of objects instead
  632. of queues of objects. SLUB can use memory efficiently
  633. and has enhanced diagnostics.
  634. config SLOB
  635. depends on EMBEDDED
  636. bool "SLOB (Simple Allocator)"
  637. help
  638. SLOB replaces the stock allocator with a drastically simpler
  639. allocator. SLOB is generally more space efficient but
  640. does not perform as well on large systems.
  641. endchoice
  642. config PROFILING
  643. bool "Profiling support (EXPERIMENTAL)"
  644. help
  645. Say Y here to enable the extended profiling support mechanisms used
  646. by profilers such as OProfile.
  647. config MARKERS
  648. bool "Activate markers"
  649. help
  650. Place an empty function call at each marker site. Can be
  651. dynamically changed for a probe function.
  652. source "arch/Kconfig"
  653. config PROC_PAGE_MONITOR
  654. default y
  655. depends on PROC_FS && MMU
  656. bool "Enable /proc page monitoring" if EMBEDDED
  657. help
  658. Various /proc files exist to monitor process memory utilization:
  659. /proc/pid/smaps, /proc/pid/clear_refs, /proc/pid/pagemap,
  660. /proc/kpagecount, and /proc/kpageflags. Disabling these
  661. interfaces will reduce the size of the kernel by approximately 4kb.
  662. endmenu # General setup
  663. config SLABINFO
  664. bool
  665. depends on PROC_FS
  666. depends on SLAB || SLUB_DEBUG
  667. default y
  668. config RT_MUTEXES
  669. boolean
  670. select PLIST
  671. config TINY_SHMEM
  672. default !SHMEM
  673. bool
  674. config BASE_SMALL
  675. int
  676. default 0 if BASE_FULL
  677. default 1 if !BASE_FULL
  678. menuconfig MODULES
  679. bool "Enable loadable module support"
  680. help
  681. Kernel modules are small pieces of compiled code which can
  682. be inserted in the running kernel, rather than being
  683. permanently built into the kernel. You use the "modprobe"
  684. tool to add (and sometimes remove) them. If you say Y here,
  685. many parts of the kernel can be built as modules (by
  686. answering M instead of Y where indicated): this is most
  687. useful for infrequently used options which are not required
  688. for booting. For more information, see the man pages for
  689. modprobe, lsmod, modinfo, insmod and rmmod.
  690. If you say Y here, you will need to run "make
  691. modules_install" to put the modules under /lib/modules/
  692. where modprobe can find them (you may need to be root to do
  693. this).
  694. If unsure, say Y.
  695. config MODULE_FORCE_LOAD
  696. bool "Forced module loading"
  697. depends on MODULES
  698. default n
  699. help
  700. This option allows loading of modules even if that would set the
  701. 'F' (forced) taint, due to lack of version info. Which is
  702. usually a really bad idea.
  703. config MODULE_UNLOAD
  704. bool "Module unloading"
  705. depends on MODULES
  706. help
  707. Without this option you will not be able to unload any
  708. modules (note that some modules may not be unloadable
  709. anyway), which makes your kernel slightly smaller and
  710. simpler. If unsure, say Y.
  711. config MODULE_FORCE_UNLOAD
  712. bool "Forced module unloading"
  713. depends on MODULE_UNLOAD && EXPERIMENTAL
  714. help
  715. This option allows you to force a module to unload, even if the
  716. kernel believes it is unsafe: the kernel will remove the module
  717. without waiting for anyone to stop using it (using the -f option to
  718. rmmod). This is mainly for kernel developers and desperate users.
  719. If unsure, say N.
  720. config MODVERSIONS
  721. bool "Module versioning support"
  722. depends on MODULES
  723. help
  724. Usually, you have to use modules compiled with your kernel.
  725. Saying Y here makes it sometimes possible to use modules
  726. compiled for different kernels, by adding enough information
  727. to the modules to (hopefully) spot any changes which would
  728. make them incompatible with the kernel you are running. If
  729. unsure, say N.
  730. config MODULE_SRCVERSION_ALL
  731. bool "Source checksum for all modules"
  732. depends on MODULES
  733. help
  734. Modules which contain a MODULE_VERSION get an extra "srcversion"
  735. field inserted into their modinfo section, which contains a
  736. sum of the source files which made it. This helps maintainers
  737. see exactly which source was used to build a module (since
  738. others sometimes change the module source without updating
  739. the version). With this option, such a "srcversion" field
  740. will be created for all modules. If unsure, say N.
  741. config KMOD
  742. bool "Automatic kernel module loading"
  743. depends on MODULES
  744. help
  745. Normally when you have selected some parts of the kernel to
  746. be created as kernel modules, you must load them (using the
  747. "modprobe" command) before you can use them. If you say Y
  748. here, some parts of the kernel will be able to load modules
  749. automatically: when a part of the kernel needs a module, it
  750. runs modprobe with the appropriate arguments, thereby
  751. loading the module if it is available. If unsure, say Y.
  752. config STOP_MACHINE
  753. bool
  754. default y
  755. depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
  756. help
  757. Need stop_machine() primitive.
  758. source "block/Kconfig"
  759. config PREEMPT_NOTIFIERS
  760. bool
  761. config CLASSIC_RCU
  762. def_bool !PREEMPT_RCU
  763. help
  764. This option selects the classic RCU implementation that is
  765. designed for best read-side performance on non-realtime
  766. systems. Classic RCU is the default. Note that the
  767. PREEMPT_RCU symbol is used to select/deselect this option.