Kconfig 40.2 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 20 21 22 23
config CONSTRUCTORS
	bool
	depends on !UML
	default y

24 25 26 27 28 29 30
config HAVE_IRQ_WORK
	bool

config IRQ_WORK
	bool
	depends on HAVE_IRQ_WORK

31
menu "General setup"
L
Linus Torvalds 已提交
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 67 68 69 70 71 72 73

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	  drivers that have been replaced by something else, and/or are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
A
Arnd Bergmann 已提交
74
	depends on (SMP || PREEMPT) && BKL
L
Linus Torvalds 已提交
75 76 77 78
	default y

config INIT_ENV_ARG_LIMIT
	int
79 80
	default 32 if !UML
	default 128 if UML
L
Linus Torvalds 已提交
81
	help
82 83
	  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
84 85


R
Roland McGrath 已提交
86 87 88 89 90 91 92 93
config CROSS_COMPILE
	string "Cross-compiler tool prefix"
	help
	  Same as running 'make CROSS_COMPILE=prefix-' but stored for
	  default make runs in this kernel build directory.  You don't
	  need to set this unless you want the configured kernel build
	  directory to select the cross-compiler automatically.

L
Linus Torvalds 已提交
94 95 96 97 98 99 100 101 102 103
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.

104 105 106 107 108
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
109 110
	  release tree by looking for git tags that belong to the current
	  top of tree revision.
111 112

	  A string of the format -gxxxxxxxx will be added to the localversion
113
	  if a git-based tree is found.  The string generated by this will be
114
	  appended after any matching localversion* files, and after the value
115
	  set in CONFIG_LOCALVERSION.
116

117 118 119 120 121 122
	  (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".)
123

124 125 126 127 128 129 130 131 132
config HAVE_KERNEL_GZIP
	bool

config HAVE_KERNEL_BZIP2
	bool

config HAVE_KERNEL_LZMA
	bool

133 134 135
config HAVE_KERNEL_LZO
	bool

136
choice
137 138
	prompt "Kernel compression mode"
	default KERNEL_GZIP
139
	depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_LZO
140
	help
141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158
	  The linux kernel is a kind of self-extracting executable.
	  Several compression algorithms are available, which differ
	  in efficiency, compression and decompression speed.
	  Compression speed is only relevant when building a kernel.
	  Decompression speed is relevant at each boot.

	  If you have any problems with bzip2 or lzma compressed
	  kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
	  version of this functionality (bzip2 only), for 2.4, was
	  supplied by Christian Ludwig)

	  High compression options are mostly useful for users, who
	  are low on disk space (embedded systems), but for whom ram
	  size matters less.

	  If in doubt, select 'gzip'

config KERNEL_GZIP
159 160 161
	bool "Gzip"
	depends on HAVE_KERNEL_GZIP
	help
162 163
	  The old and tried gzip compression. It provides a good balance
	  between compression ratio and decompression speed.
164 165 166

config KERNEL_BZIP2
	bool "Bzip2"
167
	depends on HAVE_KERNEL_BZIP2
168 169
	help
	  Its compression ratio and speed is intermediate.
170 171 172 173
	  Decompression speed is slowest among the three.  The kernel
	  size is about 10% smaller with bzip2, in comparison to gzip.
	  Bzip2 uses a large amount of memory. For modern kernels you
	  will need at least 8MB RAM or more for booting.
174 175

config KERNEL_LZMA
176 177 178 179 180 181 182
	bool "LZMA"
	depends on HAVE_KERNEL_LZMA
	help
	  The most recent compression algorithm.
	  Its ratio is best, decompression speed is between the other
	  two. Compression is slowest.	The kernel size is about 33%
	  smaller with LZMA in comparison to gzip.
183

184 185 186 187 188
config KERNEL_LZO
	bool "LZO"
	depends on HAVE_KERNEL_LZO
	help
	  Its compression ratio is the poorest among the 4. The kernel
S
Stephan Sperber 已提交
189
	  size is about 10% bigger than gzip; however its speed
190 191
	  (both compression and decompression) is the fastest.

192 193
endchoice

L
Linus Torvalds 已提交
194 195
config SWAP
	bool "Support for paging of anonymous memory (swap)"
196
	depends on MMU && BLOCK
L
Linus Torvalds 已提交
197 198 199
	default y
	help
	  This option allows you to choose whether you want to have support
200
	  for so called swap devices or swap files in your kernel that are
L
Linus Torvalds 已提交
201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218
	  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>.

219 220 221 222 223 224
config SYSVIPC_SYSCTL
	bool
	depends on SYSVIPC
	depends on SYSCTL
	default y

L
Linus Torvalds 已提交
225 226 227 228 229 230 231 232
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
233
	  queues (functions mq_*) say Y here.
L
Linus Torvalds 已提交
234 235 236 237 238 239 240

	  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.

241 242 243 244 245 246
config POSIX_MQUEUE_SYSCTL
	bool
	depends on POSIX_MQUEUE
	depends on SYSCTL
	default y

L
Linus Torvalds 已提交
247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269
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
270
	  at <http://www.gnu.org/software/acct/>.
L
Linus Torvalds 已提交
271

272 273 274 275 276 277 278 279 280 281 282 283 284
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.

285 286
config TASK_DELAY_ACCT
	bool "Enable per-task delay accounting (EXPERIMENTAL)"
287
	depends on TASKSTATS
288 289 290 291 292 293 294 295
	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.

296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313
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
314 315
config AUDIT
	bool "Auditing support"
C
Chris Wright 已提交
316
	depends on NET
L
Linus Torvalds 已提交
317 318 319 320 321 322 323 324
	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"
325
	depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH)
L
Linus Torvalds 已提交
326 327 328 329
	default y if SECURITY_SELINUX
	help
	  Enable low-overhead system-call auditing infrastructure that
	  can be used independently or with another kernel subsystem,
330
	  such as SELinux.
L
Linus Torvalds 已提交
331

E
Eric Paris 已提交
332 333 334 335
config AUDIT_WATCH
	def_bool y
	depends on AUDITSYSCALL
	select FSNOTIFY
L
Linus Torvalds 已提交
336

A
Al Viro 已提交
337 338
config AUDIT_TREE
	def_bool y
339
	depends on AUDITSYSCALL
340
	select FSNOTIFY
A
Al Viro 已提交
341

T
Thomas Gleixner 已提交
342 343
source "kernel/irq/Kconfig"

M
Mike Travis 已提交
344 345 346 347
menu "RCU Subsystem"

choice
	prompt "RCU Implementation"
P
Paul E. McKenney 已提交
348
	default TREE_RCU
M
Mike Travis 已提交
349 350 351

config TREE_RCU
	bool "Tree-based hierarchical RCU"
352
	depends on !PREEMPT && SMP
M
Mike Travis 已提交
353 354 355
	help
	  This option selects the RCU implementation that is
	  designed for very large SMP system with hundreds or
P
Paul E. McKenney 已提交
356 357
	  thousands of CPUs.  It also scales down nicely to
	  smaller systems.
M
Mike Travis 已提交
358

359
config TREE_PREEMPT_RCU
P
Paul E. McKenney 已提交
360
	bool "Preemptible tree-based hierarchical RCU"
361 362 363 364 365
	depends on PREEMPT
	help
	  This option selects the RCU implementation that is
	  designed for very large SMP systems with hundreds or
	  thousands of CPUs, but for which real-time response
366 367
	  is also required.  It also scales down nicely to
	  smaller systems.
368

369 370 371 372 373 374 375 376 377
config TINY_RCU
	bool "UP-only small-memory-footprint RCU"
	depends on !SMP
	help
	  This option selects the RCU implementation that is
	  designed for UP systems from which real-time response
	  is not required.  This option greatly reduces the
	  memory footprint of RCU.

P
Paul E. McKenney 已提交
378 379 380 381 382 383 384 385
config TINY_PREEMPT_RCU
	bool "Preemptible UP-only small-memory-footprint RCU"
	depends on !SMP && PREEMPT
	help
	  This option selects the RCU implementation that is designed
	  for real-time UP systems.  This option greatly reduces the
	  memory footprint of RCU.

M
Mike Travis 已提交
386 387
endchoice

P
Paul E. McKenney 已提交
388 389 390 391 392 393
config PREEMPT_RCU
	def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
	help
	  This option enables preemptible-RCU code that is common between
	  the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.

M
Mike Travis 已提交
394 395
config RCU_TRACE
	bool "Enable tracing for RCU"
396
	depends on TREE_RCU || TREE_PREEMPT_RCU
M
Mike Travis 已提交
397 398 399 400 401 402 403 404 405 406 407
	help
	  This option provides tracing in RCU which presents stats
	  in debugfs for debugging RCU implementation.

	  Say Y here if you want to enable RCU tracing
	  Say N if you are unsure.

config RCU_FANOUT
	int "Tree-based hierarchical RCU fanout value"
	range 2 64 if 64BIT
	range 2 32 if !64BIT
408
	depends on TREE_RCU || TREE_PREEMPT_RCU
M
Mike Travis 已提交
409 410 411 412 413
	default 64 if 64BIT
	default 32 if !64BIT
	help
	  This option controls the fanout of hierarchical implementations
	  of RCU, allowing RCU to work efficiently on machines with
414 415 416 417 418 419
	  large numbers of CPUs.  This value must be at least the fourth
	  root of NR_CPUS, which allows NR_CPUS to be insanely large.
	  The default value of RCU_FANOUT should be used for production
	  systems, but if you are stress-testing the RCU implementation
	  itself, small RCU_FANOUT values allow you to test large-system
	  code paths on small(er) systems.
M
Mike Travis 已提交
420 421 422 423 424 425

	  Select a specific number if testing RCU itself.
	  Take the default if unsure.

config RCU_FANOUT_EXACT
	bool "Disable tree-based hierarchical RCU auto-balancing"
426
	depends on TREE_RCU || TREE_PREEMPT_RCU
M
Mike Travis 已提交
427 428 429 430 431 432 433 434 435 436 437
	default n
	help
	  This option forces use of the exact RCU_FANOUT value specified,
	  regardless of imbalances in the hierarchy.  This is useful for
	  testing RCU itself, and might one day be useful on systems with
	  strong NUMA behavior.

	  Without RCU_FANOUT_EXACT, the code will balance the hierarchy.

	  Say N if unsure.

438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453
config RCU_FAST_NO_HZ
	bool "Accelerate last non-dyntick-idle CPU's grace periods"
	depends on TREE_RCU && NO_HZ && SMP
	default n
	help
	  This option causes RCU to attempt to accelerate grace periods
	  in order to allow the final CPU to enter dynticks-idle state
	  more quickly.  On the other hand, this option increases the
	  overhead of the dynticks-idle checking, particularly on systems
	  with large numbers of CPUs.

	  Say Y if energy efficiency is critically important, particularly
	  	if you have relatively few CPUs.

	  Say N if you are unsure.

M
Mike Travis 已提交
454
config TREE_RCU_TRACE
455
	def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
M
Mike Travis 已提交
456 457
	select DEBUG_FS
	help
458 459 460
	  This option provides tracing for the TREE_RCU and
	  TREE_PREEMPT_RCU implementations, permitting Makefile to
	  trivially select kernel/rcutree_trace.c.
M
Mike Travis 已提交
461 462 463

endmenu # "RCU Subsystem"

L
Linus Torvalds 已提交
464
config IKCONFIG
465
	tristate "Kernel .config support"
L
Linus Torvalds 已提交
466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482
	---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.

483 484 485
config LOG_BUF_SHIFT
	int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
	range 12 21
A
Adrian Bunk 已提交
486
	default 17
487 488
	help
	  Select kernel log buffer size as a power of 2.
A
Adrian Bunk 已提交
489 490 491 492 493
	  Examples:
	  	     17 => 128 KB
		     16 => 64 KB
	             15 => 32 KB
	             14 => 16 KB
494 495 496
		     13 =>  8 KB
		     12 =>  4 KB

497 498 499 500 501 502
#
# Architectures with an unreliable sched_clock() should select this:
#
config HAVE_UNSTABLE_SCHED_CLOCK
	bool

L
Li Zefan 已提交
503 504
menuconfig CGROUPS
	boolean "Control Group support"
505
	depends on EVENTFD
506
	help
L
Li Zefan 已提交
507
	  This option adds support for grouping sets of processes together, for
508 509 510 511
	  use with process control subsystems such as Cpusets, CFS, memory
	  controls or device isolation.
	  See
		- Documentation/scheduler/sched-design-CFS.txt	(CFS)
L
Li Zefan 已提交
512 513
		- Documentation/cgroups/ (features for grouping, isolation
					  and resource control)
514 515 516

	  Say N if unsure.

L
Li Zefan 已提交
517 518
if CGROUPS

519 520 521 522 523 524
config CGROUP_DEBUG
	bool "Example debug cgroup subsystem"
	default n
	help
	  This option enables a simple cgroup subsystem that
	  exports useful debugging information about the cgroups
L
Li Zefan 已提交
525
	  framework.
526

L
Li Zefan 已提交
527
	  Say N if unsure.
528 529

config CGROUP_NS
L
Li Zefan 已提交
530 531 532 533 534 535
	bool "Namespace cgroup subsystem"
	help
	  Provides a simple namespace cgroup subsystem to
	  provide hierarchical naming of sets of namespaces,
	  for instance virtual servers and checkpoint/restart
	  jobs.
536 537

config CGROUP_FREEZER
L
Li Zefan 已提交
538 539 540
	bool "Freezer cgroup subsystem"
	help
	  Provides a way to freeze and unfreeze all tasks in a
541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558
	  cgroup.

config CGROUP_DEVICE
	bool "Device controller for cgroups"
	help
	  Provides a cgroup implementing whitelists for devices which
	  a process in the cgroup can mknod or open.

config CPUSETS
	bool "Cpuset support"
	help
	  This option will let you create and manage CPUSETs which
	  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.

L
Li Zefan 已提交
559 560 561 562 563
config PROC_PID_CPUSET
	bool "Include legacy /proc/<pid>/cpuset file"
	depends on CPUSETS
	default y

564 565 566 567
config CGROUP_CPUACCT
	bool "Simple CPU accounting cgroup subsystem"
	help
	  Provides a simple Resource Controller for monitoring the
L
Li Zefan 已提交
568
	  total CPU consumed by the tasks in a cgroup.
569

570 571 572 573
config RESOURCE_COUNTERS
	bool "Resource counters"
	help
	  This option enables controller independent resource accounting
L
Li Zefan 已提交
574
	  infrastructure that works with cgroups.
575

576 577
config CGROUP_MEM_RES_CTLR
	bool "Memory Resource Controller for Control Groups"
578
	depends on RESOURCE_COUNTERS
579
	select MM_OWNER
580
	help
581
	  Provides a memory resource controller that manages both anonymous
582
	  memory and page cache. (See Documentation/cgroups/memory.txt)
583 584

	  Note that setting this option increases fixed memory overhead
585 586 587 588
	  associated with each page of memory in the system. By this,
	  20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
	  usage tracking struct at boot. Total amount of this is printed out
	  at boot.
589 590

	  Only enable when you're ok with these trade offs and really
591 592 593
	  sure you need the memory resource controller. Even when you enable
	  this, you can set "cgroup_disable=memory" at your boot option to
	  disable memory resource controller and you can avoid overheads.
L
Li Zefan 已提交
594
	  (and lose benefits of memory resource controller)
595

596 597 598
	  This config option also selects MM_OWNER config option, which
	  could in turn add some fork/exit overhead.

599
config CGROUP_MEM_RES_CTLR_SWAP
600 601
	bool "Memory Resource Controller Swap Extension"
	depends on CGROUP_MEM_RES_CTLR && SWAP
602 603 604 605 606 607 608 609 610 611 612 613
	help
	  Add swap management feature to memory resource controller. When you
	  enable this, you can limit mem+swap usage per cgroup. In other words,
	  when you disable this, memory resource controller has no cares to
	  usage of swap...a process can exhaust all of the swap. This extension
	  is useful when you want to avoid exhaustion swap but this itself
	  adds more overheads and consumes memory for remembering information.
	  Especially if you use 32bit system or small memory system, please
	  be careful about enabling this. When memory resource controller
	  is disabled by boot option, this will be automatically disabled and
	  there will be no overhead from this. Even when you set this config=y,
	  if boot option "noswapaccount" is set, swap will not be accounted.
614 615
	  Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
	  size is 4096bytes, 512k per 1Gbytes of swap.
616

D
Dhaval Giani 已提交
617 618
menuconfig CGROUP_SCHED
	bool "Group CPU scheduler"
619
	depends on EXPERIMENTAL
D
Dhaval Giani 已提交
620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638
	default n
	help
	  This feature lets CPU scheduler recognize task groups and control CPU
	  bandwidth allocation to such task groups. It uses cgroups to group
	  tasks.

if CGROUP_SCHED
config FAIR_GROUP_SCHED
	bool "Group scheduling for SCHED_OTHER"
	depends on CGROUP_SCHED
	default CGROUP_SCHED

config RT_GROUP_SCHED
	bool "Group scheduling for SCHED_RR/FIFO"
	depends on EXPERIMENTAL
	depends on CGROUP_SCHED
	default n
	help
	  This feature lets you explicitly allocate real CPU bandwidth
639
	  to task groups. If enabled, it will also make it impossible to
D
Dhaval Giani 已提交
640 641 642 643 644 645
	  schedule realtime tasks for non-root users until you allocate
	  realtime bandwidth for them.
	  See Documentation/scheduler/sched-rt-group.txt for more information.

endif #CGROUP_SCHED

646 647
config BLK_CGROUP
	tristate "Block IO controller"
648
	depends on BLOCK
649 650 651 652 653 654 655 656
	default n
	---help---
	Generic block IO controller cgroup interface. This is the common
	cgroup interface which should be used by various IO controlling
	policies.

	Currently, CFQ IO scheduler uses it to recognize task groups and
	control disk bandwidth allocation (proportional time slice allocation)
657 658
	to such task groups. It is also used by bio throttling logic in
	block layer to implement upper limit in IO rates on a device.
659 660

	This option only enables generic Block IO controller infrastructure.
661 662 663 664
	One needs to also enable actual IO controlling logic/policy. For
	enabling proportional weight division of disk bandwidth in CFQ seti
	CONFIG_CFQ_GROUP_IOSCHED=y and for enabling throttling policy set
	CONFIG_BLK_THROTTLE=y.
665 666 667 668 669 670 671 672 673 674 675

	See Documentation/cgroups/blkio-controller.txt for more information.

config DEBUG_BLK_CGROUP
	bool "Enable Block IO controller debugging"
	depends on BLK_CGROUP
	default n
	---help---
	Enable some debugging help. Currently it exports additional stat
	files in a cgroup which can be useful for debugging.

L
Li Zefan 已提交
676
endif # CGROUPS
677

678
menuconfig NAMESPACES
679 680 681 682 683 684 685 686
	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.

687 688
if NAMESPACES

689 690
config UTS_NS
	bool "UTS namespace"
691
	default y
692 693 694 695
	help
	  In this namespace tasks see different info provided with the
	  uname() system call

696 697
config IPC_NS
	bool "IPC namespace"
698
	depends on (SYSVIPC || POSIX_MQUEUE)
699
	default y
700 701
	help
	  In this namespace tasks work with IPC ids which correspond to
702
	  different IPC objects in different namespaces.
703

704 705
config USER_NS
	bool "User namespace (EXPERIMENTAL)"
706
	depends on EXPERIMENTAL
707
	default y
708 709 710 711 712
	help
	  This allows containers, i.e. vservers, to use user namespaces
	  to provide different user info for different servers.
	  If unsure, say N.

713
config PID_NS
714
	bool "PID Namespaces"
715
	default y
716
	help
717
	  Support process id namespaces.  This allows having multiple
718
	  processes with the same pid as long as they are in different
719 720
	  pid namespaces.  This is a building block of containers.

721 722
config NET_NS
	bool "Network namespace"
723
	depends on NET
724
	default y
725 726 727 728
	help
	  Allow user space to create what appear to be multiple instances
	  of the network stack.

729 730
endif # NAMESPACES

731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782
config MM_OWNER
	bool

config SYSFS_DEPRECATED
	bool "enable deprecated sysfs features to support old userspace tools"
	depends on SYSFS
	default n
	help
	  This option adds code that switches the layout of the "block" class
	  devices, to not show up in /sys/class/block/, but only in
	  /sys/block/.

	  This switch is only active when the sysfs.deprecated=1 boot option is
	  passed or the SYSFS_DEPRECATED_V2 option is set.

	  This option allows new kernels to run on old distributions and tools,
	  which might get confused by /sys/class/block/. Since 2007/2008 all
	  major distributions and tools handle this just fine.

	  Recent distributions and userspace tools after 2009/2010 depend on
	  the existence of /sys/class/block/, and will not work with this
	  option enabled.

	  Only if you are using a new kernel on an old distribution, you might
	  need to say Y here.

config SYSFS_DEPRECATED_V2
	bool "enabled deprecated sysfs features by default"
	default n
	depends on SYSFS
	depends on SYSFS_DEPRECATED
	help
	  Enable deprecated sysfs by default.

	  See the CONFIG_SYSFS_DEPRECATED option for more details about this
	  option.

	  Only if you are using a new kernel on an old distribution, you might
	  need to say Y here. Even then, odds are you would not need it
	  enabled, you can always pass the boot option if absolutely necessary.

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.

783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798
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.

799 800
if BLK_DEV_INITRD

801 802
source "usr/Kconfig"

803 804
endif

805
config CC_OPTIMIZE_FOR_SIZE
806
	bool "Optimize for size"
807 808 809 810 811
	default y
	help
	  Enabling this option will pass "-Os" instead of "-O2" to gcc
	  resulting in a smaller kernel.

812
	  If unsure, say Y.
813

R
Randy Dunlap 已提交
814 815 816
config SYSCTL
	bool

R
Randy Dunlap 已提交
817 818 819
config ANON_INODES
	bool

L
Linus Torvalds 已提交
820 821 822 823 824 825 826 827
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.

828 829
config UID16
	bool "Enable 16-bit UID system calls" if EMBEDDED
830
	depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION)
831 832 833 834
	default y
	help
	  This enables the legacy 16-bit UID syscall wrappers.

835
config SYSCTL_SYSCALL
R
Randy Dunlap 已提交
836
	bool "Sysctl syscall support" if EMBEDDED
837
	depends on PROC_SYSCTL
838
	default y
839
	select SYSCTL
840
	---help---
841 842 843 844
	  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.
845

846 847 848
	  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.
849

850
	  If unsure say Y here.
851

L
Linus Torvalds 已提交
852
config KALLSYMS
853
	 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
L
Linus Torvalds 已提交
854 855 856 857 858 859 860 861 862 863 864 865
	 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
866 867
	   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
868 869 870 871 872 873 874 875 876 877 878 879 880 881

	   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
882

883 884 885 886 887 888 889 890 891
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
892 893 894 895 896 897 898 899 900 901
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
902 903 904 905 906 907 908 909 910 911
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.

912 913 914 915 916 917
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
918 919 920 921 922 923 924 925
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.

L
Linus Torvalds 已提交
926 927 928 929 930 931 932 933 934 935 936
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
937
	select RT_MUTEXES
L
Linus Torvalds 已提交
938 939 940 941 942 943 944 945
	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.

config EPOLL
	bool "Enable eventpoll support" if EMBEDDED
	default y
946
	select ANON_INODES
L
Linus Torvalds 已提交
947 948 949 950
	help
	  Disabling this option will cause the kernel to be built without
	  support for epoll family of system calls.

951 952
config SIGNALFD
	bool "Enable signalfd() system call" if EMBEDDED
953
	select ANON_INODES
954 955 956 957 958 959 960
	default y
	help
	  Enable the signalfd() system call that allows to receive signals
	  on a file descriptor.

	  If unsure, say Y.

961 962
config TIMERFD
	bool "Enable timerfd() system call" if EMBEDDED
963
	select ANON_INODES
964 965 966 967 968 969 970
	default y
	help
	  Enable the timerfd() system call that allows to receive timer
	  events on a file descriptor.

	  If unsure, say Y.

971 972
config EVENTFD
	bool "Enable eventfd() system call" if EMBEDDED
973
	select ANON_INODES
974 975 976 977 978 979 980
	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
981 982 983 984 985 986 987 988 989 990 991
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.

T
Thomas Petazzoni 已提交
992 993 994 995 996 997 998 999
config AIO
	bool "Enable AIO support" if EMBEDDED
	default y
	help
	  This option enables POSIX asynchronous I/O which may by used
          by some high performance threaded applications. Disabling
          this option saves about 7k.

1000
config HAVE_PERF_EVENTS
T
Thomas Gleixner 已提交
1001
	bool
1002 1003
	help
	  See tools/perf/design.txt for details.
T
Thomas Gleixner 已提交
1004

1005 1006 1007 1008 1009
config PERF_USE_VMALLOC
	bool
	help
	  See tools/perf/design.txt for details

I
Ingo Molnar 已提交
1010
menu "Kernel Performance Events And Counters"
T
Thomas Gleixner 已提交
1011

1012
config PERF_EVENTS
I
Ingo Molnar 已提交
1013 1014
	bool "Kernel performance events and counters"
	default y if (PROFILING || PERF_COUNTERS)
1015
	depends on HAVE_PERF_EVENTS
I
Ingo Molnar 已提交
1016
	select ANON_INODES
1017
	select IRQ_WORK
T
Thomas Gleixner 已提交
1018
	help
I
Ingo Molnar 已提交
1019 1020
	  Enable kernel support for various performance events provided
	  by software and hardware.
T
Thomas Gleixner 已提交
1021

1022
	  Software events are supported either built-in or via the
I
Ingo Molnar 已提交
1023
	  use of generic tracepoints.
T
Thomas Gleixner 已提交
1024

I
Ingo Molnar 已提交
1025 1026
	  Most modern CPUs support performance events via performance
	  counter registers. These registers count the number of certain
T
Thomas Gleixner 已提交
1027 1028 1029 1030 1031 1032
	  types of hw events: such as instructions executed, cachemisses
	  suffered, or branches mis-predicted - without slowing down the
	  kernel or applications. These registers can also trigger interrupts
	  when a threshold number of events have passed - and can thus be
	  used to profile the code that runs on that CPU.

I
Ingo Molnar 已提交
1033
	  The Linux Performance Event subsystem provides an abstraction of
1034
	  these software and hardware event capabilities, available via a
I
Ingo Molnar 已提交
1035
	  system call and used by the "perf" utility in tools/perf/. It
T
Thomas Gleixner 已提交
1036 1037 1038 1039 1040
	  provides per task and per CPU counters, and it provides event
	  capabilities on top of those.

	  Say Y if unsure.

I
Ingo Molnar 已提交
1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052
config PERF_COUNTERS
	bool "Kernel performance counters (old config option)"
	depends on HAVE_PERF_EVENTS
	help
	  This config has been obsoleted by the PERF_EVENTS
	  config option - please see that one for details.

	  It has no effect on the kernel whether you enable
	  it or not, it is a compatibility placeholder.

	  Say N if unsure.

1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065
config DEBUG_PERF_USE_VMALLOC
	default n
	bool "Debug: use vmalloc to back perf mmap() buffers"
	depends on PERF_EVENTS && DEBUG_KERNEL
	select PERF_USE_VMALLOC
	help
	 Use vmalloc memory to back perf mmap() buffers.

	 Mostly useful for debugging the vmalloc code on platforms
	 that don't require it.

	 Say N if unsure.

T
Thomas Gleixner 已提交
1066 1067
endmenu

1068 1069 1070 1071
config VM_EVENT_COUNTERS
	default y
	bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
	help
1072 1073 1074 1075
	  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.
1076

1077 1078
config PCI_QUIRKS
	default y
1079 1080
	bool "Enable PCI quirk workarounds" if EMBEDDED
	depends on PCI
1081 1082 1083 1084 1085
	help
	  This enables workarounds for various PCI chipset
          bugs/quirks. Disable this only if your target machine is
          unaffected by PCI quirks.

C
Christoph Lameter 已提交
1086 1087 1088
config SLUB_DEBUG
	default y
	bool "Enable SLUB debugging support" if EMBEDDED
C
Christoph Lameter 已提交
1089
	depends on SLUB && SYSFS
C
Christoph Lameter 已提交
1090 1091 1092 1093 1094 1095
	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.

R
Randy Dunlap 已提交
1096 1097 1098 1099 1100 1101 1102
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
1103
	  disabled, and can be overridden at runtime by setting
R
Randy Dunlap 已提交
1104 1105 1106 1107
	  /proc/sys/kernel/randomize_va_space to 2.

	  On non-ancient distros (post-2000 ones) N is usually a safe choice.

C
Christoph Lameter 已提交
1108 1109
choice
	prompt "Choose SLAB allocator"
1110
	default SLUB
C
Christoph Lameter 已提交
1111 1112 1113 1114 1115 1116 1117
	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
1118
	  well in all environments. It organizes cache hot objects in
1119
	  per cpu and per node queues.
C
Christoph Lameter 已提交
1120 1121 1122 1123 1124 1125 1126 1127

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
1128 1129
	   and has enhanced diagnostics. SLUB is the default choice for
	   a slab allocator.
C
Christoph Lameter 已提交
1130 1131

config SLOB
P
Paul Mundt 已提交
1132
	depends on EMBEDDED
C
Christoph Lameter 已提交
1133 1134
	bool "SLOB (Simple Allocator)"
	help
M
Matt Mackall 已提交
1135 1136 1137
	   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
1138 1139 1140

endchoice

1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162
config MMAP_ALLOW_UNINITIALIZED
	bool "Allow mmapped anonymous memory to be uninitialized"
	depends on EMBEDDED && !MMU
	default n
	help
	  Normally, and according to the Linux spec, anonymous memory obtained
	  from mmap() has it's contents cleared before it is passed to
	  userspace.  Enabling this config option allows you to request that
	  mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
	  providing a huge performance boost.  If this option is not enabled,
	  then the flag will be ignored.

	  This is taken advantage of by uClibc's malloc(), and also by
	  ELF-FDPIC binfmt's brk and stack allocator.

	  Because of the obvious security issues, this option should only be
	  enabled on embedded devices where you control what is run in
	  userspace.  Since that isn't generally a problem on no-MMU systems,
	  it is normally safe to say Y here.

	  See Documentation/nommu-mmap.txt for more information.

1163
config PROFILING
1164
	bool "Profiling support"
1165 1166 1167 1168
	help
	  Say Y here to enable the extended profiling support mechanisms used
	  by profilers such as OProfile.

1169 1170 1171 1172
#
# Place an empty function call at each tracepoint site. Can be
# dynamically changed for a probe function.
#
M
Mathieu Desnoyers 已提交
1173
config TRACEPOINTS
1174
	bool
M
Mathieu Desnoyers 已提交
1175

M
Mathieu Desnoyers 已提交
1176 1177
source "arch/Kconfig"

L
Linus Torvalds 已提交
1178 1179
endmenu		# General setup

1180 1181 1182 1183
config HAVE_GENERIC_DMA_COHERENT
	bool
	default n

1184 1185 1186
config SLABINFO
	bool
	depends on PROC_FS
1187
	depends on SLAB || SLUB_DEBUG
1188 1189
	default y

1190 1191 1192
config RT_MUTEXES
	boolean

L
Linus Torvalds 已提交
1193 1194 1195 1196 1197
config BASE_SMALL
	int
	default 0 if BASE_FULL
	default 1 if !BASE_FULL

1198
menuconfig MODULES
L
Linus Torvalds 已提交
1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217
	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.

1218 1219
if MODULES

1220 1221 1222 1223
config MODULE_FORCE_LOAD
	bool "Forced module loading"
	default n
	help
1224 1225 1226
	  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.
1227

L
Linus Torvalds 已提交
1228 1229 1230 1231 1232
config MODULE_UNLOAD
	bool "Module unloading"
	help
	  Without this option you will not be able to unload any
	  modules (note that some modules may not be unloadable
1233 1234
	  anyway), which makes your kernel smaller, faster
	  and simpler.  If unsure, say Y.
L
Linus Torvalds 已提交
1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246

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
1247
	bool "Module versioning support"
L
Linus Torvalds 已提交
1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266
	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"
	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.

1267 1268
endif # MODULES

1269 1270 1271 1272 1273 1274 1275
config INIT_ALL_POSSIBLE
	bool
	help
	  Back when each arch used to define their own cpu_online_map and
	  cpu_possible_map, some of them chose to initialize cpu_possible_map
	  with all 1s, and others with all 0s.  When they were centralised,
	  it was better to provide this option than to break all the archs
1276
	  and have several arch maintainers pursuing me down dark alleys.
1277

L
Linus Torvalds 已提交
1278 1279 1280 1281 1282 1283
config STOP_MACHINE
	bool
	default y
	depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
	help
	  Need stop_machine() primitive.
1284 1285

source "block/Kconfig"
1286 1287 1288

config PREEMPT_NOTIFIERS
	bool
P
Paul E. McKenney 已提交
1289

1290 1291 1292 1293
config PADATA
	depends on SMP
	bool

1294
source "kernel/Kconfig.locks"