Kconfig 28.8 KB
Newer Older
R
Roman Zippel 已提交
1 2 3 4 5 6 7 8
config ARCH
	string
	option env="ARCH"

config KERNELVERSION
	string
	option env="KERNELVERSION"

9 10
config DEFCONFIG_LIST
	string
11
	depends on !UML
12 13 14 15
	option defconfig_list
	default "/lib/modules/$UNAME_RELEASE/.config"
	default "/etc/kernel-config"
	default "/boot/config-$UNAME_RELEASE"
16
	default "$ARCH_DEFCONFIG"
17 18
	default "arch/$ARCH/defconfig"

19
menu "General setup"
L
Linus Torvalds 已提交
20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66

config EXPERIMENTAL
	bool "Prompt for development and/or incomplete code/drivers"
	---help---
	  Some of the various things that Linux supports (such as network
	  drivers, file systems, network protocols, etc.) can be in a state
	  of development where the functionality, stability, or the level of
	  testing is not yet high enough for general use. This is usually
	  known as the "alpha-test" phase among developers. If a feature is
	  currently in alpha-test, then the developers usually discourage
	  uninformed widespread use of this feature by the general public to
	  avoid "Why doesn't this work?" type mail messages. However, active
	  testing and use of these systems is welcomed. Just be aware that it
	  may not meet the normal level of reliability or it may fail to work
	  in some special cases. Detailed bug reports from people familiar
	  with the kernel internals are usually welcomed by the developers
	  (before submitting bug reports, please read the documents
	  <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
	  <file:Documentation/BUG-HUNTING>, and
	  <file:Documentation/oops-tracing.txt> in the kernel source).

	  This option will also make obsoleted drivers available. These are
	  drivers that have been replaced by something else, and/or are
	  scheduled to be removed in a future kernel release.

	  Unless you intend to help test and develop a feature or driver that
	  falls into this category, or you have a situation that requires
	  using these features, you should probably say N here, which will
	  cause the configurator to present you with fewer choices. If
	  you say Y here, you will be offered the choice of using features or
	  drivers that are currently considered to be in the alpha-test phase.

config BROKEN
	bool

config BROKEN_ON_SMP
	bool
	depends on BROKEN || !SMP
	default y

config LOCK_KERNEL
	bool
	depends on SMP || PREEMPT
	default y

config INIT_ENV_ARG_LIMIT
	int
67 68
	default 32 if !UML
	default 128 if UML
L
Linus Torvalds 已提交
69
	help
70 71
	  Maximum of each of the number of arguments and environment
	  variables passed to init from the kernel command line.
L
Linus Torvalds 已提交
72 73 74 75 76 77 78 79 80 81 82 83


config LOCALVERSION
	string "Local version - append to kernel release"
	help
	  Append an extra string to the end of your kernel version.
	  This will show up when you type uname, for example.
	  The string you set here will be appended after the contents of
	  any files with a filename matching localversion* in your
	  object and source tree, in that order.  Your total string can
	  be a maximum of 64 characters.

84 85 86 87 88
config LOCALVERSION_AUTO
	bool "Automatically append version information to the version string"
	default y
	help
	  This will try to automatically determine if the current tree is a
89 90
	  release tree by looking for git tags that belong to the current
	  top of tree revision.
91 92

	  A string of the format -gxxxxxxxx will be added to the localversion
93
	  if a git-based tree is found.  The string generated by this will be
94
	  appended after any matching localversion* files, and after the value
95
	  set in CONFIG_LOCALVERSION.
96

97 98 99 100 101 102
	  (The actual string used here is the first eight characters produced
	  by running the command:

	    $ git rev-parse --verify HEAD

	  which is done within the script "scripts/setlocalversion".)
103

L
Linus Torvalds 已提交
104 105
config SWAP
	bool "Support for paging of anonymous memory (swap)"
106
	depends on MMU && BLOCK
L
Linus Torvalds 已提交
107 108 109
	default y
	help
	  This option allows you to choose whether you want to have support
110
	  for so called swap devices or swap files in your kernel that are
L
Linus Torvalds 已提交
111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128
	  used to provide more virtual memory than the actual RAM present
	  in your computer.  If unsure say Y.

config SYSVIPC
	bool "System V IPC"
	---help---
	  Inter Process Communication is a suite of library functions and
	  system calls which let processes (running programs) synchronize and
	  exchange information. It is generally considered to be a good thing,
	  and some programs won't run unless you say Y here. In particular, if
	  you want to run the DOS emulator dosemu under Linux (read the
	  DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
	  you'll need to say Y here.

	  You can find documentation about IPC with "info ipc" and also in
	  section 6.4 of the Linux Programmer's Guide, available from
	  <http://www.tldp.org/guides.html>.

129 130 131 132 133 134
config SYSVIPC_SYSCTL
	bool
	depends on SYSVIPC
	depends on SYSCTL
	default y

L
Linus Torvalds 已提交
135 136 137 138 139 140 141 142
config POSIX_MQUEUE
	bool "POSIX Message Queues"
	depends on NET && EXPERIMENTAL
	---help---
	  POSIX variant of message queues is a part of IPC. In POSIX message
	  queues every message has a priority which decides about succession
	  of receiving it by a process. If you want to compile and run
	  programs written e.g. for Solaris with use of its POSIX message
143
	  queues (functions mq_*) say Y here.
L
Linus Torvalds 已提交
144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173

	  POSIX message queues are visible as a filesystem called 'mqueue'
	  and can be mounted somewhere if you want to do filesystem
	  operations on message queues.

	  If unsure, say Y.

config BSD_PROCESS_ACCT
	bool "BSD Process Accounting"
	help
	  If you say Y here, a user level program will be able to instruct the
	  kernel (via a special system call) to write process accounting
	  information to a file: whenever a process exits, information about
	  that process will be appended to the file by the kernel.  The
	  information includes things such as creation time, owning user,
	  command name, memory usage, controlling terminal etc. (the complete
	  list is in the struct acct in <file:include/linux/acct.h>).  It is
	  up to the user level program to do useful things with this
	  information.  This is generally a good idea, so say Y.

config BSD_PROCESS_ACCT_V3
	bool "BSD Process Accounting version 3 file format"
	depends on BSD_PROCESS_ACCT
	default n
	help
	  If you say Y here, the process accounting information is written
	  in a new file format that also logs the process IDs of each
	  process and it's parent. Note that this file format is incompatible
	  with previous v0/v1/v2 file formats, so you will need updated tools
	  for processing it. A preliminary version of these tools is available
174
	  at <http://www.gnu.org/software/acct/>.
L
Linus Torvalds 已提交
175

176 177 178 179 180 181 182 183 184 185 186 187 188
config TASKSTATS
	bool "Export task/process statistics through netlink (EXPERIMENTAL)"
	depends on NET
	default n
	help
	  Export selected statistics for tasks/processes through the
	  generic netlink interface. Unlike BSD process accounting, the
	  statistics are available during the lifetime of tasks/processes as
	  responses to commands. Like BSD accounting, they are sent to user
	  space on task exit.

	  Say N if unsure.

189 190
config TASK_DELAY_ACCT
	bool "Enable per-task delay accounting (EXPERIMENTAL)"
191
	depends on TASKSTATS
192 193 194 195 196 197 198 199
	help
	  Collect information on time spent by a task waiting for system
	  resources like cpu, synchronous block I/O completion and swapping
	  in pages. Such statistics can help in setting a task's priorities
	  relative to other tasks for cpu, io, rss limits etc.

	  Say N if unsure.

200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217
config TASK_XACCT
	bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
	depends on TASKSTATS
	help
	  Collect extended task accounting data and send the data
	  to userland for processing over the taskstats interface.

	  Say N if unsure.

config TASK_IO_ACCOUNTING
	bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
	depends on TASK_XACCT
	help
	  Collect information on the number of bytes of storage I/O which this
	  task has caused.

	  Say N if unsure.

L
Linus Torvalds 已提交
218 219
config AUDIT
	bool "Auditing support"
C
Chris Wright 已提交
220
	depends on NET
L
Linus Torvalds 已提交
221 222 223 224 225 226 227 228
	help
	  Enable auditing infrastructure that can be used with another
	  kernel subsystem, such as SELinux (which requires this for
	  logging of avc messages output).  Does not do system-call
	  auditing without CONFIG_AUDITSYSCALL.

config AUDITSYSCALL
	bool "Enable system-call auditing support"
Y
Yuichi Nakamura 已提交
229
	depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64|| SUPERH)
L
Linus Torvalds 已提交
230 231 232 233
	default y if SECURITY_SELINUX
	help
	  Enable low-overhead system-call auditing infrastructure that
	  can be used independently or with another kernel subsystem,
A
Amy Griffis 已提交
234 235
	  such as SELinux.  To use audit's filesystem watch feature, please
	  ensure that INOTIFY is configured.
L
Linus Torvalds 已提交
236

A
Al Viro 已提交
237 238 239 240
config AUDIT_TREE
	def_bool y
	depends on AUDITSYSCALL && INOTIFY

L
Linus Torvalds 已提交
241
config IKCONFIG
242
	tristate "Kernel .config support"
L
Linus Torvalds 已提交
243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259
	---help---
	  This option enables the complete Linux kernel ".config" file
	  contents to be saved in the kernel. It provides documentation
	  of which kernel options are used in a running kernel or in an
	  on-disk kernel.  This information can be extracted from the kernel
	  image file with the script scripts/extract-ikconfig and used as
	  input to rebuild the current kernel or to build another kernel.
	  It can also be extracted from a running kernel by reading
	  /proc/config.gz if enabled (below).

config IKCONFIG_PROC
	bool "Enable access to .config through /proc/config.gz"
	depends on IKCONFIG && PROC_FS
	---help---
	  This option enables access to the kernel configuration file
	  through /proc/config.gz.

260 261 262
config LOG_BUF_SHIFT
	int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
	range 12 21
A
Adrian Bunk 已提交
263
	default 17
264 265
	help
	  Select kernel log buffer size as a power of 2.
A
Adrian Bunk 已提交
266 267 268 269 270
	  Examples:
	  	     17 => 128 KB
		     16 => 64 KB
	             15 => 32 KB
	             14 => 16 KB
271 272 273
		     13 =>  8 KB
		     12 =>  4 KB

274 275 276 277 278 279 280 281
config CGROUPS
	bool "Control Group support"
	help
	  This option will let you use process cgroup subsystems
	  such as Cpusets

	  Say N if unsure.

282 283 284
config CGROUP_DEBUG
	bool "Example debug cgroup subsystem"
	depends on CGROUPS
285
	default n
286 287 288 289 290 291 292
	help
	  This option enables a simple cgroup subsystem that
	  exports useful debugging information about the cgroups
	  framework

	  Say N if unsure

293 294 295 296 297 298 299 300 301
config CGROUP_NS
        bool "Namespace cgroup subsystem"
        depends on CGROUPS
        help
          Provides a simple namespace cgroup subsystem to
          provide hierarchical naming of sets of namespaces,
          for instance virtual servers and checkpoint/restart
          jobs.

302 303 304 305 306 307 308
config CGROUP_DEVICE
	bool "Device controller for cgroups"
	depends on CGROUPS && EXPERIMENTAL
	help
	  Provides a cgroup implementing whitelists for devices which
	  a process in the cgroup can mknod or open.

L
Linus Torvalds 已提交
309 310
config CPUSETS
	bool "Cpuset support"
311
	depends on SMP && CGROUPS
L
Linus Torvalds 已提交
312
	help
313
	  This option will let you create and manage CPUSETs which
L
Linus Torvalds 已提交
314 315 316 317 318 319
	  allow dynamically partitioning a system into sets of CPUs and
	  Memory Nodes and assigning tasks to run only within those sets.
	  This is primarily useful on large SMP or NUMA systems.

	  Say N if unsure.

320 321 322 323 324 325
#
# Architectures with an unreliable sched_clock() should select this:
#
config HAVE_UNSTABLE_SCHED_CLOCK
	bool

326 327
config GROUP_SCHED
	bool "Group CPU scheduler"
328 329
	depends on EXPERIMENTAL
	default n
S
Srivatsa Vaddagiri 已提交
330
	help
331
	  This feature lets CPU scheduler recognize task groups and control CPU
332
	  bandwidth allocation to such task groups.
S
Srivatsa Vaddagiri 已提交
333

334 335 336
config FAIR_GROUP_SCHED
	bool "Group scheduling for SCHED_OTHER"
	depends on GROUP_SCHED
337
	default GROUP_SCHED
338 339 340 341 342 343

config RT_GROUP_SCHED
	bool "Group scheduling for SCHED_RR/FIFO"
	depends on EXPERIMENTAL
	depends on GROUP_SCHED
	default n
344 345 346 347 348 349 350
	help
	  This feature lets you explicitly allocate real CPU bandwidth
	  to users or control groups (depending on the "Basis for grouping tasks"
	  setting below. If enabled, it will also make it impossible to
	  schedule realtime tasks for non-root users until you allocate
	  realtime bandwidth for them.
	  See Documentation/sched-rt-group.txt for more information.
351

352
choice
353
	depends on GROUP_SCHED
354
	prompt "Basis for grouping tasks"
355
	default USER_SCHED
356

357
config USER_SCHED
358 359 360 361
	bool "user id"
	help
	  This option will choose userid as the basis for grouping
	  tasks, thus providing equal CPU bandwidth to each user.
362

363
config CGROUP_SCHED
364 365 366 367 368 369 370 371 372
	bool "Control groups"
 	depends on CGROUPS
 	help
	  This option allows you to create arbitrary task groups
	  using the "cgroup" pseudo filesystem and control
	  the cpu bandwidth allocated to each such task group.
	  Refer to Documentation/cgroups.txt for more information
	  on "cgroup" pseudo filesystem.

373 374
endchoice

375 376 377 378 379 380 381
config CGROUP_CPUACCT
	bool "Simple CPU accounting cgroup subsystem"
	depends on CGROUPS
	help
	  Provides a simple Resource Controller for monitoring the
	  total CPU consumed by the tasks in a cgroup

382 383 384 385 386 387 388
config RESOURCE_COUNTERS
	bool "Resource counters"
	help
	  This option enables controller independent resource accounting
          infrastructure that works with cgroups
	depends on CGROUPS

389 390 391
config MM_OWNER
	bool

392 393 394
config CGROUP_MEM_RES_CTLR
	bool "Memory Resource Controller for Control Groups"
	depends on CGROUPS && RESOURCE_COUNTERS
395
	select MM_OWNER
396 397 398 399 400 401 402 403 404 405 406 407
	help
	  Provides a memory resource controller that manages both page cache and
	  RSS memory.

	  Note that setting this option increases fixed memory overhead
	  associated with each page of memory in the system by 4/8 bytes
	  and also increases cache misses because struct page on many 64bit
	  systems will not fit into a single cache line anymore.

	  Only enable when you're ok with these trade offs and really
	  sure you need the memory resource controller.

408 409 410
	  This config option also selects MM_OWNER config option, which
	  could in turn add some fork/exit overhead.

K
Kay Sievers 已提交
411
config SYSFS_DEPRECATED
I
Ingo Molnar 已提交
412 413 414
	bool

config SYSFS_DEPRECATED_V2
K
Kay Sievers 已提交
415
	bool "Create deprecated sysfs files"
416
	depends on SYSFS
K
Kay Sievers 已提交
417
	default y
I
Ingo Molnar 已提交
418
	select SYSFS_DEPRECATED
K
Kay Sievers 已提交
419 420 421 422 423 424 425 426 427 428 429
	help
	  This option creates deprecated symlinks such as the
	  "device"-link, the <subsystem>:<name>-link, and the
	  "bus"-link. It may also add deprecated key in the
	  uevent environment.
	  None of these features or values should be used today, as
	  they export driver core implementation details to userspace
	  or export properties which can't be kept stable across kernel
	  releases.

	  If enabled, this option will also move any device structures
430
	  that belong to a class, back into the /sys/class hierarchy, in
431 432
	  order to support older versions of udev and some userspace
	  programs.
K
Kay Sievers 已提交
433

434 435
	  If you are using a distro with the most recent userspace
	  packages, it should be safe to say N here.
K
Kay Sievers 已提交
436

437 438 439 440 441
config PROC_PID_CPUSET
	bool "Include legacy /proc/<pid>/cpuset file"
	depends on CPUSETS
	default y

442 443 444 445 446 447 448 449 450 451 452
config RELAY
	bool "Kernel->user space relay support (formerly relayfs)"
	help
	  This option enables support for relay interface support in
	  certain file systems (such as debugfs).
	  It is designed to provide an efficient mechanism for tools and
	  facilities to relay large amounts of data from kernel space to
	  user space.

	  If unsure, say N.

453 454 455 456 457 458 459 460 461
config NAMESPACES
	bool "Namespaces support" if EMBEDDED
	default !EMBEDDED
	help
	  Provides the way to make tasks work with different objects using
	  the same id. For example same IPC id may refer to different objects
	  or same user id or pid may refer to different tasks when used in
	  different namespaces.

462 463 464 465 466 467 468
config UTS_NS
	bool "UTS namespace"
	depends on NAMESPACES
	help
	  In this namespace tasks see different info provided with the
	  uname() system call

469 470 471 472 473 474 475
config IPC_NS
	bool "IPC namespace"
	depends on NAMESPACES && SYSVIPC
	help
	  In this namespace tasks work with IPC ids which correspond to
	  different IPC objects in different namespaces

476 477 478 479 480 481 482 483
config USER_NS
	bool "User namespace (EXPERIMENTAL)"
	depends on NAMESPACES && EXPERIMENTAL
	help
	  This allows containers, i.e. vservers, to use user namespaces
	  to provide different user info for different servers.
	  If unsure, say N.

484 485 486 487 488
config PID_NS
	bool "PID Namespaces (EXPERIMENTAL)"
	default n
	depends on NAMESPACES && EXPERIMENTAL
	help
489
	  Support process id namespaces.  This allows having multiple
490 491 492 493 494 495
	  process with the same pid as long as they are in different
	  pid namespaces.  This is a building block of containers.

	  Unless you want to work with an experimental feature
	  say N here.

496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511
config BLK_DEV_INITRD
	bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
	depends on BROKEN || !FRV
	help
	  The initial RAM filesystem is a ramfs which is loaded by the
	  boot loader (loadlin or lilo) and that is mounted as root
	  before the normal boot procedure. It is typically used to
	  load modules needed to mount the "real" root file system,
	  etc. See <file:Documentation/initrd.txt> for details.

	  If RAM disk support (BLK_DEV_RAM) is also included, this
	  also enables initial RAM disk (initrd) support and adds
	  15 Kbytes (more on some other architectures) to the kernel size.

	  If unsure say Y.

512 513
if BLK_DEV_INITRD

514 515
source "usr/Kconfig"

516 517
endif

518
config CC_OPTIMIZE_FOR_SIZE
519
	bool "Optimize for size"
520 521 522 523 524 525 526
	default y
	help
	  Enabling this option will pass "-Os" instead of "-O2" to gcc
	  resulting in a smaller kernel.

	  If unsure, say N.

R
Randy Dunlap 已提交
527 528 529
config SYSCTL
	bool

L
Linus Torvalds 已提交
530 531 532 533 534 535 536 537
menuconfig EMBEDDED
	bool "Configure standard kernel features (for small systems)"
	help
	  This option allows certain base kernel options and settings
          to be disabled or tweaked. This is for specialized
          environments which can tolerate a "non-standard" kernel.
          Only use this if you really know what you are doing.

538 539
config UID16
	bool "Enable 16-bit UID system calls" if EMBEDDED
540
	depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION)
541 542 543 544
	default y
	help
	  This enables the legacy 16-bit UID syscall wrappers.

545
config SYSCTL_SYSCALL
R
Randy Dunlap 已提交
546
	bool "Sysctl syscall support" if EMBEDDED
547
	default y
548
	select SYSCTL
549
	---help---
550 551 552 553
	  sys_sysctl uses binary paths that have been found challenging
	  to properly maintain and use.  The interface in /proc/sys
	  using paths with ascii names is now the primary path to this
	  information.
554

555 556 557
	  Almost nothing using the binary sysctl interface so if you are
	  trying to save some space it is probably safe to disable this,
	  making your kernel marginally smaller.
558

559
	  If unsure say Y here.
560

561 562 563 564 565 566 567 568 569 570 571
config SYSCTL_SYSCALL_CHECK
	bool "Sysctl checks" if EMBEDDED
	depends on SYSCTL_SYSCALL
	default y
	---help---
	  sys_sysctl uses binary paths that have been found challenging
	  to properly maintain and use. This enables checks that help
	  you to keep things correct.

	  If unsure say Y here.

L
Linus Torvalds 已提交
572
config KALLSYMS
573
	 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
L
Linus Torvalds 已提交
574 575 576 577 578 579 580 581 582 583 584 585
	 default y
	 help
	   Say Y here to let the kernel print out symbolic crash information and
	   symbolic stack backtraces. This increases the size of the kernel
	   somewhat, as all symbols have to be loaded into the kernel image.

config KALLSYMS_ALL
	bool "Include all symbols in kallsyms"
	depends on DEBUG_KERNEL && KALLSYMS
	help
	   Normally kallsyms only contains the symbols of functions, for nicer
	   OOPS messages.  Some debuggers can use kallsyms for other
586 587
	   symbols too: say Y here to include all symbols, if you need them 
	   and you don't care about adding 300k to the size of your kernel.
L
Linus Torvalds 已提交
588 589 590 591 592 593 594 595 596 597 598 599 600 601

	   Say N.

config KALLSYMS_EXTRA_PASS
	bool "Do an extra kallsyms pass"
	depends on KALLSYMS
	help
	   If kallsyms is not working correctly, the build will fail with
	   inconsistent kallsyms data.  If that occurs, log a bug report and
	   turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
	   Always say N here unless you find a bug in kallsyms, which must be
	   reported.  KALLSYMS_EXTRA_PASS is only a temporary workaround while
	   you wait for kallsyms to be fixed.

M
Matt Mackall 已提交
602

603 604 605 606 607 608 609 610 611
config HOTPLUG
	bool "Support for hot-pluggable devices" if EMBEDDED
	default y
	help
	  This option is provided for the case where no hotplug or uevent
	  capabilities is wanted by the kernel.  You should only consider
	  disabling this option for embedded systems that do not use modules, a
	  dynamic /dev tree, or dynamic device discovery.  Just say Y.

M
Matt Mackall 已提交
612 613 614 615 616 617 618 619 620 621
config PRINTK
	default y
	bool "Enable support for printk" if EMBEDDED
	help
	  This option enables normal printk support. Removing it
	  eliminates most of the message strings from the kernel image
	  and makes the kernel more or less silent. As this makes it
	  very difficult to diagnose system problems, saying N here is
	  strongly discouraged.

M
Matt Mackall 已提交
622 623 624 625 626 627 628 629 630 631
config BUG
	bool "BUG() support" if EMBEDDED
	default y
	help
          Disabling this option eliminates support for BUG and WARN, reducing
          the size of your kernel image and potentially quietly ignoring
          numerous fatal conditions. You should only consider disabling this
          option for embedded systems with no facilities for reporting errors.
          Just say Y.

632 633 634 635 636 637
config ELF_CORE
	default y
	bool "Enable ELF core dumps" if EMBEDDED
	help
	  Enable support for generating core dumps. Disabling saves about 4k.

S
Stas Sergeev 已提交
638 639 640 641 642 643 644 645
config PCSPKR_PLATFORM
	bool "Enable PC-Speaker support" if EMBEDDED
	depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES
	default y
	help
          This option allows to disable the internal PC-Speaker
          support, saving some memory.

646 647 648 649 650 651 652 653 654 655
config COMPAT_BRK
	bool "Disable heap randomization"
	default y
	help
	  Randomizing heap placement makes heap exploits harder, but it
	  also breaks ancient binaries (including anything libc5 based).
	  This option changes the bootup default to heap randomization
	  disabled, and can be overriden runtime by setting
	  /proc/sys/kernel/randomize_va_space to 2.

I
Ingo Molnar 已提交
656
	  On non-ancient distros (post-2000 ones) N is usually a safe choice.
657

L
Linus Torvalds 已提交
658 659 660 661 662 663 664 665 666 667 668
config BASE_FULL
	default y
	bool "Enable full-sized data structures for core" if EMBEDDED
	help
	  Disabling this option reduces the size of miscellaneous core
	  kernel data structures. This saves memory on small machines,
	  but may reduce performance.

config FUTEX
	bool "Enable futex support" if EMBEDDED
	default y
I
Ingo Molnar 已提交
669
	select RT_MUTEXES
L
Linus Torvalds 已提交
670 671 672 673 674
	help
	  Disabling this option will cause the kernel to be built without
	  support for "fast userspace mutexes".  The resulting kernel may not
	  run glibc-based applications correctly.

675
config ANON_INODES
676
	bool
677

L
Linus Torvalds 已提交
678 679 680
config EPOLL
	bool "Enable eventpoll support" if EMBEDDED
	default y
681
	select ANON_INODES
L
Linus Torvalds 已提交
682 683 684 685
	help
	  Disabling this option will cause the kernel to be built without
	  support for epoll family of system calls.

686 687
config SIGNALFD
	bool "Enable signalfd() system call" if EMBEDDED
688
	select ANON_INODES
689 690 691 692 693 694 695
	default y
	help
	  Enable the signalfd() system call that allows to receive signals
	  on a file descriptor.

	  If unsure, say Y.

696 697
config TIMERFD
	bool "Enable timerfd() system call" if EMBEDDED
698
	select ANON_INODES
699 700 701 702 703 704 705
	default y
	help
	  Enable the timerfd() system call that allows to receive timer
	  events on a file descriptor.

	  If unsure, say Y.

706 707
config EVENTFD
	bool "Enable eventfd() system call" if EMBEDDED
708
	select ANON_INODES
709 710 711 712 713 714 715
	default y
	help
	  Enable the eventfd() system call that allows to receive both
	  kernel notification (ie. KAIO) or userspace notifications.

	  If unsure, say Y.

L
Linus Torvalds 已提交
716 717 718 719 720 721 722 723 724 725 726
config SHMEM
	bool "Use full shmem filesystem" if EMBEDDED
	default y
	depends on MMU
	help
	  The shmem is an internal filesystem used to manage shared memory.
	  It is backed by swap and manages resource limits. It is also exported
	  to userspace as tmpfs if TMPFS is enabled. Disabling this
	  option replaces shmem and tmpfs with the much simpler ramfs code,
	  which may be appropriate on small systems without swap.

727 728 729 730
config VM_EVENT_COUNTERS
	default y
	bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
	help
731 732 733 734
	  VM event counters are needed for event counts to be shown.
	  This option allows the disabling of the VM event counters
	  on EMBEDDED systems.  /proc/vmstat will only show page counts
	  if VM event counters are disabled.
735

C
Christoph Lameter 已提交
736 737 738
config SLUB_DEBUG
	default y
	bool "Enable SLUB debugging support" if EMBEDDED
C
Christoph Lameter 已提交
739
	depends on SLUB && SYSFS
C
Christoph Lameter 已提交
740 741 742 743 744 745
	help
	  SLUB has extensive debug support features. Disabling these can
	  result in significant savings in code size. This also disables
	  SLUB sysfs support. /sys/slab will not exist and there will be
	  no support for cache validation etc.

C
Christoph Lameter 已提交
746 747
choice
	prompt "Choose SLAB allocator"
748
	default SLUB
C
Christoph Lameter 已提交
749 750 751 752 753 754 755
	help
	   This option allows to select a slab allocator.

config SLAB
	bool "SLAB"
	help
	  The regular slab allocator that is established and known to work
756
	  well in all environments. It organizes cache hot objects in
C
Christoph Lameter 已提交
757
	  per cpu and per node queues. SLAB is the default choice for
758
	  a slab allocator.
C
Christoph Lameter 已提交
759 760 761 762 763 764 765 766

config SLUB
	bool "SLUB (Unqueued Allocator)"
	help
	   SLUB is a slab allocator that minimizes cache line usage
	   instead of managing queues of cached objects (SLAB approach).
	   Per cpu caching is realized using slabs of objects instead
	   of queues of objects. SLUB can use memory efficiently
767
	   and has enhanced diagnostics.
C
Christoph Lameter 已提交
768 769

config SLOB
P
Paul Mundt 已提交
770
	depends on EMBEDDED
C
Christoph Lameter 已提交
771 772
	bool "SLOB (Simple Allocator)"
	help
M
Matt Mackall 已提交
773 774 775
	   SLOB replaces the stock allocator with a drastically simpler
	   allocator. SLOB is generally more space efficient but
	   does not perform as well on large systems.
C
Christoph Lameter 已提交
776 777 778

endchoice

779 780 781 782 783 784 785 786 787 788 789 790
config PROFILING
	bool "Profiling support (EXPERIMENTAL)"
	help
	  Say Y here to enable the extended profiling support mechanisms used
	  by profilers such as OProfile.

config MARKERS
	bool "Activate markers"
	help
	  Place an empty function call at each marker site. Can be
	  dynamically changed for a probe function.

M
Mathieu Desnoyers 已提交
791 792
source "arch/Kconfig"

793 794 795 796 797 798 799 800 801 802
config PROC_PAGE_MONITOR
 	default y
	depends on PROC_FS && MMU
	bool "Enable /proc page monitoring" if EMBEDDED
 	help
	  Various /proc files exist to monitor process memory utilization:
	  /proc/pid/smaps, /proc/pid/clear_refs, /proc/pid/pagemap,
	  /proc/kpagecount, and /proc/kpageflags. Disabling these
          interfaces will reduce the size of the kernel by approximately 4kb.

L
Linus Torvalds 已提交
803 804
endmenu		# General setup

805 806 807 808
config HAVE_GENERIC_DMA_COHERENT
	bool
	default n

809 810 811
config SLABINFO
	bool
	depends on PROC_FS
812
	depends on SLAB || SLUB_DEBUG
813 814
	default y

815 816 817 818
config RT_MUTEXES
	boolean
	select PLIST

L
Linus Torvalds 已提交
819 820 821 822 823 824 825 826 827
config TINY_SHMEM
	default !SHMEM
	bool

config BASE_SMALL
	int
	default 0 if BASE_FULL
	default 1 if !BASE_FULL

828
menuconfig MODULES
L
Linus Torvalds 已提交
829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847
	bool "Enable loadable module support"
	help
	  Kernel modules are small pieces of compiled code which can
	  be inserted in the running kernel, rather than being
	  permanently built into the kernel.  You use the "modprobe"
	  tool to add (and sometimes remove) them.  If you say Y here,
	  many parts of the kernel can be built as modules (by
	  answering M instead of Y where indicated): this is most
	  useful for infrequently used options which are not required
	  for booting.  For more information, see the man pages for
	  modprobe, lsmod, modinfo, insmod and rmmod.

	  If you say Y here, you will need to run "make
	  modules_install" to put the modules under /lib/modules/
	  where modprobe can find them (you may need to be root to do
	  this).

	  If unsure, say Y.

848 849 850 851 852
config MODULE_FORCE_LOAD
	bool "Forced module loading"
	depends on MODULES
	default n
	help
853 854 855
	  Allow loading of modules without version information (ie. modprobe
	  --force).  Forced module loading sets the 'F' (forced) taint flag and
	  is usually a really bad idea.
856

L
Linus Torvalds 已提交
857 858 859 860 861 862
config MODULE_UNLOAD
	bool "Module unloading"
	depends on MODULES
	help
	  Without this option you will not be able to unload any
	  modules (note that some modules may not be unloadable
863 864
	  anyway), which makes your kernel smaller, faster
	  and simpler.  If unsure, say Y.
L
Linus Torvalds 已提交
865 866 867 868 869 870 871 872 873 874 875 876

config MODULE_FORCE_UNLOAD
	bool "Forced module unloading"
	depends on MODULE_UNLOAD && EXPERIMENTAL
	help
	  This option allows you to force a module to unload, even if the
	  kernel believes it is unsafe: the kernel will remove the module
	  without waiting for anyone to stop using it (using the -f option to
	  rmmod).  This is mainly for kernel developers and desperate users.
	  If unsure, say N.

config MODVERSIONS
877 878
	bool "Module versioning support"
	depends on MODULES
L
Linus Torvalds 已提交
879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899
	help
	  Usually, you have to use modules compiled with your kernel.
	  Saying Y here makes it sometimes possible to use modules
	  compiled for different kernels, by adding enough information
	  to the modules to (hopefully) spot any changes which would
	  make them incompatible with the kernel you are running.  If
	  unsure, say N.

config MODULE_SRCVERSION_ALL
	bool "Source checksum for all modules"
	depends on MODULES
	help
	  Modules which contain a MODULE_VERSION get an extra "srcversion"
	  field inserted into their modinfo section, which contains a
    	  sum of the source files which made it.  This helps maintainers
	  see exactly which source was used to build a module (since
	  others sometimes change the module source without updating
	  the version).  With this option, such a "srcversion" field
	  will be created for all modules.  If unsure, say N.

config KMOD
J
Johannes Berg 已提交
900
	def_bool y
L
Linus Torvalds 已提交
901 902
	depends on MODULES
	help
J
Johannes Berg 已提交
903 904
	  This is being removed soon.  These days, CONFIG_MODULES
	  implies CONFIG_KMOD, so use that instead.
L
Linus Torvalds 已提交
905 906 907 908 909 910 911

config STOP_MACHINE
	bool
	default y
	depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
	help
	  Need stop_machine() primitive.
912 913

source "block/Kconfig"
914 915 916

config PREEMPT_NOTIFIERS
	bool
P
Paul E. McKenney 已提交
917 918

config CLASSIC_RCU
919
	def_bool !PREEMPT_RCU
P
Paul E. McKenney 已提交
920 921 922
	help
	  This option selects the classic RCU implementation that is
	  designed for best read-side performance on non-realtime
923 924
	  systems.  Classic RCU is the default.  Note that the
	  PREEMPT_RCU symbol is used to select/deselect this option.