Kconfig 39.7 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
menu "General setup"
L
Linus Torvalds 已提交
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 67 68 69 70 71

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	  drivers that have been replaced by something else, and/or are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
72 73
	default 32 if !UML
	default 128 if UML
L
Linus Torvalds 已提交
74
	help
75 76
	  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
77 78


R
Roland McGrath 已提交
79 80 81 82 83 84 85 86
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
87 88 89 90 91 92 93 94 95 96
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.

97 98 99 100 101
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
102 103
	  release tree by looking for git tags that belong to the current
	  top of tree revision.
104 105

	  A string of the format -gxxxxxxxx will be added to the localversion
106
	  if a git-based tree is found.  The string generated by this will be
107
	  appended after any matching localversion* files, and after the value
108
	  set in CONFIG_LOCALVERSION.
109

110 111 112 113 114 115
	  (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".)
116

117 118 119 120 121 122 123 124 125
config HAVE_KERNEL_GZIP
	bool

config HAVE_KERNEL_BZIP2
	bool

config HAVE_KERNEL_LZMA
	bool

126 127 128
config HAVE_KERNEL_LZO
	bool

129
choice
130 131
	prompt "Kernel compression mode"
	default KERNEL_GZIP
132
	depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_LZO
133
	help
134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151
	  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
152 153 154
	bool "Gzip"
	depends on HAVE_KERNEL_GZIP
	help
155 156
	  The old and tried gzip compression. It provides a good balance
	  between compression ratio and decompression speed.
157 158 159

config KERNEL_BZIP2
	bool "Bzip2"
160
	depends on HAVE_KERNEL_BZIP2
161 162
	help
	  Its compression ratio and speed is intermediate.
163 164 165 166
	  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.
167 168

config KERNEL_LZMA
169 170 171 172 173 174 175
	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.
176

177 178 179 180 181 182 183 184
config KERNEL_LZO
	bool "LZO"
	depends on HAVE_KERNEL_LZO
	help
	  Its compression ratio is the poorest among the 4. The kernel
	  size is about about 10% bigger than gzip; however its speed
	  (both compression and decompression) is the fastest.

185 186
endchoice

L
Linus Torvalds 已提交
187 188
config SWAP
	bool "Support for paging of anonymous memory (swap)"
189
	depends on MMU && BLOCK
L
Linus Torvalds 已提交
190 191 192
	default y
	help
	  This option allows you to choose whether you want to have support
193
	  for so called swap devices or swap files in your kernel that are
L
Linus Torvalds 已提交
194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211
	  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>.

212 213 214 215 216 217
config SYSVIPC_SYSCTL
	bool
	depends on SYSVIPC
	depends on SYSCTL
	default y

L
Linus Torvalds 已提交
218 219 220 221 222 223 224 225
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
226
	  queues (functions mq_*) say Y here.
L
Linus Torvalds 已提交
227 228 229 230 231 232 233

	  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.

234 235 236 237 238 239
config POSIX_MQUEUE_SYSCTL
	bool
	depends on POSIX_MQUEUE
	depends on SYSCTL
	default y

L
Linus Torvalds 已提交
240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262
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
263
	  at <http://www.gnu.org/software/acct/>.
L
Linus Torvalds 已提交
264

265 266 267 268 269 270 271 272 273 274 275 276 277
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.

278 279
config TASK_DELAY_ACCT
	bool "Enable per-task delay accounting (EXPERIMENTAL)"
280
	depends on TASKSTATS
281 282 283 284 285 286 287 288
	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.

289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306
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
307 308
config AUDIT
	bool "Auditing support"
C
Chris Wright 已提交
309
	depends on NET
L
Linus Torvalds 已提交
310 311 312 313 314 315 316 317
	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"
318
	depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH)
L
Linus Torvalds 已提交
319 320 321 322
	default y if SECURITY_SELINUX
	help
	  Enable low-overhead system-call auditing infrastructure that
	  can be used independently or with another kernel subsystem,
323
	  such as SELinux.
L
Linus Torvalds 已提交
324

E
Eric Paris 已提交
325 326 327 328
config AUDIT_WATCH
	def_bool y
	depends on AUDITSYSCALL
	select FSNOTIFY
L
Linus Torvalds 已提交
329

A
Al Viro 已提交
330 331
config AUDIT_TREE
	def_bool y
332
	depends on AUDITSYSCALL
333
	select FSNOTIFY
A
Al Viro 已提交
334

M
Mike Travis 已提交
335 336 337 338
menu "RCU Subsystem"

choice
	prompt "RCU Implementation"
P
Paul E. McKenney 已提交
339
	default TREE_RCU
M
Mike Travis 已提交
340 341 342

config TREE_RCU
	bool "Tree-based hierarchical RCU"
343
	depends on !PREEMPT && SMP
M
Mike Travis 已提交
344 345 346
	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
347 348
	  thousands of CPUs.  It also scales down nicely to
	  smaller systems.
M
Mike Travis 已提交
349

350 351 352 353 354 355 356
config TREE_PREEMPT_RCU
	bool "Preemptable tree-based hierarchical RCU"
	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
357 358
	  is also required.  It also scales down nicely to
	  smaller systems.
359

360 361 362 363 364 365 366 367 368
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.

M
Mike Travis 已提交
369 370 371 372
endchoice

config RCU_TRACE
	bool "Enable tracing for RCU"
373
	depends on TREE_RCU || TREE_PREEMPT_RCU
M
Mike Travis 已提交
374 375 376 377 378 379 380 381 382 383 384
	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
385
	depends on TREE_RCU || TREE_PREEMPT_RCU
M
Mike Travis 已提交
386 387 388 389 390 391 392 393 394 395 396 397 398 399
	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
	  large numbers of CPUs.  This value must be at least the cube
	  root of NR_CPUS, which allows NR_CPUS up to 32,768 for 32-bit
	  systems and up to 262,144 for 64-bit systems.

	  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"
400
	depends on TREE_RCU || TREE_PREEMPT_RCU
M
Mike Travis 已提交
401 402 403 404 405 406 407 408 409 410 411
	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.

412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427
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
428
config TREE_RCU_TRACE
429
	def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
M
Mike Travis 已提交
430 431
	select DEBUG_FS
	help
432 433 434
	  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
435 436 437

endmenu # "RCU Subsystem"

L
Linus Torvalds 已提交
438
config IKCONFIG
439
	tristate "Kernel .config support"
L
Linus Torvalds 已提交
440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456
	---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.

457 458 459
config LOG_BUF_SHIFT
	int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
	range 12 21
A
Adrian Bunk 已提交
460
	default 17
461 462
	help
	  Select kernel log buffer size as a power of 2.
A
Adrian Bunk 已提交
463 464 465 466 467
	  Examples:
	  	     17 => 128 KB
		     16 => 64 KB
	             15 => 32 KB
	             14 => 16 KB
468 469 470
		     13 =>  8 KB
		     12 =>  4 KB

471 472 473 474 475 476
#
# Architectures with an unreliable sched_clock() should select this:
#
config HAVE_UNSTABLE_SCHED_CLOCK
	bool

L
Li Zefan 已提交
477 478
menuconfig CGROUPS
	boolean "Control Group support"
479
	depends on EVENTFD
480
	help
L
Li Zefan 已提交
481
	  This option adds support for grouping sets of processes together, for
482 483 484 485
	  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
486 487
		- Documentation/cgroups/ (features for grouping, isolation
					  and resource control)
488 489 490

	  Say N if unsure.

L
Li Zefan 已提交
491 492
if CGROUPS

493 494 495 496 497 498 499
config CGROUP_DEBUG
	bool "Example debug cgroup subsystem"
	depends on CGROUPS
	default n
	help
	  This option enables a simple cgroup subsystem that
	  exports useful debugging information about the cgroups
L
Li Zefan 已提交
500
	  framework.
501

L
Li Zefan 已提交
502
	  Say N if unsure.
503 504

config CGROUP_NS
L
Li Zefan 已提交
505 506 507 508 509 510 511
	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.
512 513

config CGROUP_FREEZER
L
Li Zefan 已提交
514 515 516 517
	bool "Freezer cgroup subsystem"
	depends on CGROUPS
	help
	  Provides a way to freeze and unfreeze all tasks in a
518 519 520 521 522 523 524 525 526 527 528
	  cgroup.

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.

config CPUSETS
	bool "Cpuset support"
529
	depends on CGROUPS
530 531 532 533 534 535 536 537
	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
538 539 540 541 542
config PROC_PID_CPUSET
	bool "Include legacy /proc/<pid>/cpuset file"
	depends on CPUSETS
	default y

543 544 545 546 547
config CGROUP_CPUACCT
	bool "Simple CPU accounting cgroup subsystem"
	depends on CGROUPS
	help
	  Provides a simple Resource Controller for monitoring the
L
Li Zefan 已提交
548
	  total CPU consumed by the tasks in a cgroup.
549

550 551 552 553
config RESOURCE_COUNTERS
	bool "Resource counters"
	help
	  This option enables controller independent resource accounting
L
Li Zefan 已提交
554
	  infrastructure that works with cgroups.
555 556
	depends on CGROUPS

557 558 559
config CGROUP_MEM_RES_CTLR
	bool "Memory Resource Controller for Control Groups"
	depends on CGROUPS && RESOURCE_COUNTERS
560
	select MM_OWNER
561
	help
562
	  Provides a memory resource controller that manages both anonymous
563
	  memory and page cache. (See Documentation/cgroups/memory.txt)
564 565

	  Note that setting this option increases fixed memory overhead
566 567 568 569
	  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.
570 571

	  Only enable when you're ok with these trade offs and really
572 573 574
	  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
575
	  (and lose benefits of memory resource controller)
576

577 578 579
	  This config option also selects MM_OWNER config option, which
	  could in turn add some fork/exit overhead.

580
config CGROUP_MEM_RES_CTLR_SWAP
581 582
	bool "Memory Resource Controller Swap Extension"
	depends on CGROUP_MEM_RES_CTLR && SWAP
583 584 585 586 587 588 589 590 591 592 593 594
	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.
595 596
	  Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
	  size is 4096bytes, 512k per 1Gbytes of swap.
597

D
Dhaval Giani 已提交
598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619
menuconfig CGROUP_SCHED
	bool "Group CPU scheduler"
	depends on EXPERIMENTAL && CGROUPS
	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
620
	  to task groups. If enabled, it will also make it impossible to
D
Dhaval Giani 已提交
621 622 623 624 625 626
	  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

627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653
config BLK_CGROUP
	tristate "Block IO controller"
	depends on CGROUPS && BLOCK
	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)
	to such task groups.

	This option only enables generic Block IO controller infrastructure.
	One needs to also enable actual IO controlling logic in CFQ for it
	to take effect. (CONFIG_CFQ_GROUP_IOSCHED=y).

	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
654
endif # CGROUPS
655

L
Li Zefan 已提交
656 657
config MM_OWNER
	bool
658

K
Kay Sievers 已提交
659
config SYSFS_DEPRECATED
I
Ingo Molnar 已提交
660 661 662
	bool

config SYSFS_DEPRECATED_V2
663
	bool "enable deprecated sysfs features to support old userspace tools"
664
	depends on SYSFS
665
	default n
I
Ingo Molnar 已提交
666
	select SYSFS_DEPRECATED
K
Kay Sievers 已提交
667
	help
668
	  This option switches the layout of sysfs to the deprecated
669
	  version. Do not use it on recent distributions.
670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693

	  The current sysfs layout features a unified device tree at
	  /sys/devices/, which is able to express a hierarchy between
	  class devices. If the deprecated option is set to Y, the
	  unified device tree is split into a bus device tree at
	  /sys/devices/ and several individual class device trees at
	  /sys/class/. The class and bus devices will be connected by
	  "<subsystem>:<name>" and the "device" links. The "block"
	  class devices, will not show up in /sys/class/block/. Some
	  subsystems will suppress the creation of some devices which
	  depend on the unified device tree.

	  This option is not a pure compatibility option that can
	  be safely enabled on newer distributions. It will change the
	  layout of sysfs to the non-extensible deprecated version,
	  and disable some features, which can not be exported without
	  confusing older userspace tools. Since 2007/2008 all major
	  distributions do not enable this option, and ship no tools which
	  depend on the deprecated layout or this option.

	  If you are using a new kernel on an older distribution, or use
	  older userspace tools, you might need to say Y here. Do not say Y,
	  if the original kernel, that came with your distribution, has
	  this option set to N.
K
Kay Sievers 已提交
694

695 696 697 698 699 700 701 702 703 704 705
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.

706 707 708 709 710 711 712 713 714
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.

715 716 717 718 719 720 721
config UTS_NS
	bool "UTS namespace"
	depends on NAMESPACES
	help
	  In this namespace tasks see different info provided with the
	  uname() system call

722 723
config IPC_NS
	bool "IPC namespace"
724
	depends on NAMESPACES && (SYSVIPC || POSIX_MQUEUE)
725 726
	help
	  In this namespace tasks work with IPC ids which correspond to
727
	  different IPC objects in different namespaces.
728

729 730 731 732 733 734 735 736
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.

737 738 739 740 741
config PID_NS
	bool "PID Namespaces (EXPERIMENTAL)"
	default n
	depends on NAMESPACES && EXPERIMENTAL
	help
742
	  Support process id namespaces.  This allows having multiple
743
	  processes with the same pid as long as they are in different
744 745 746 747 748
	  pid namespaces.  This is a building block of containers.

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

749 750 751 752 753 754 755 756
config NET_NS
	bool "Network namespace"
	default n
	depends on NAMESPACES && EXPERIMENTAL && NET
	help
	  Allow user space to create what appear to be multiple instances
	  of the network stack.

757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772
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.

773 774
if BLK_DEV_INITRD

775 776
source "usr/Kconfig"

777 778
endif

779
config CC_OPTIMIZE_FOR_SIZE
780
	bool "Optimize for size"
781 782 783 784 785
	default y
	help
	  Enabling this option will pass "-Os" instead of "-O2" to gcc
	  resulting in a smaller kernel.

786
	  If unsure, say Y.
787

R
Randy Dunlap 已提交
788 789 790
config SYSCTL
	bool

R
Randy Dunlap 已提交
791 792 793
config ANON_INODES
	bool

L
Linus Torvalds 已提交
794 795 796 797 798 799 800 801
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.

802 803
config UID16
	bool "Enable 16-bit UID system calls" if EMBEDDED
804
	depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION)
805 806 807 808
	default y
	help
	  This enables the legacy 16-bit UID syscall wrappers.

809
config SYSCTL_SYSCALL
R
Randy Dunlap 已提交
810
	bool "Sysctl syscall support" if EMBEDDED
811
	depends on PROC_SYSCTL
812
	default y
813
	select SYSCTL
814
	---help---
815 816 817 818
	  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.
819

820 821 822
	  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.
823

824
	  If unsure say Y here.
825

L
Linus Torvalds 已提交
826
config KALLSYMS
827
	 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
L
Linus Torvalds 已提交
828 829 830 831 832 833 834 835 836 837 838 839
	 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
840 841
	   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
842 843 844 845 846 847 848 849 850 851 852 853 854 855

	   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
856

857 858 859 860 861 862 863 864 865
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
866 867 868 869 870 871 872 873 874 875
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
876 877 878 879 880 881 882 883 884 885
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.

886 887 888 889 890 891
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
892 893 894 895 896 897 898 899
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
900 901 902 903 904 905 906 907 908 909 910
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
911
	select RT_MUTEXES
L
Linus Torvalds 已提交
912 913 914 915 916 917 918 919
	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
920
	select ANON_INODES
L
Linus Torvalds 已提交
921 922 923 924
	help
	  Disabling this option will cause the kernel to be built without
	  support for epoll family of system calls.

925 926
config SIGNALFD
	bool "Enable signalfd() system call" if EMBEDDED
927
	select ANON_INODES
928 929 930 931 932 933 934
	default y
	help
	  Enable the signalfd() system call that allows to receive signals
	  on a file descriptor.

	  If unsure, say Y.

935 936
config TIMERFD
	bool "Enable timerfd() system call" if EMBEDDED
937
	select ANON_INODES
938 939 940 941 942 943 944
	default y
	help
	  Enable the timerfd() system call that allows to receive timer
	  events on a file descriptor.

	  If unsure, say Y.

945 946
config EVENTFD
	bool "Enable eventfd() system call" if EMBEDDED
947
	select ANON_INODES
948 949 950 951 952 953 954
	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
955 956 957 958 959 960 961 962 963 964 965
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
966 967 968 969 970 971 972 973
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.

974
config HAVE_PERF_EVENTS
T
Thomas Gleixner 已提交
975
	bool
976 977
	help
	  See tools/perf/design.txt for details.
T
Thomas Gleixner 已提交
978

979 980 981 982 983
config PERF_USE_VMALLOC
	bool
	help
	  See tools/perf/design.txt for details

I
Ingo Molnar 已提交
984
menu "Kernel Performance Events And Counters"
T
Thomas Gleixner 已提交
985

986
config PERF_EVENTS
I
Ingo Molnar 已提交
987 988
	bool "Kernel performance events and counters"
	default y if (PROFILING || PERF_COUNTERS)
989
	depends on HAVE_PERF_EVENTS
I
Ingo Molnar 已提交
990
	select ANON_INODES
T
Thomas Gleixner 已提交
991
	help
I
Ingo Molnar 已提交
992 993
	  Enable kernel support for various performance events provided
	  by software and hardware.
T
Thomas Gleixner 已提交
994

995
	  Software events are supported either built-in or via the
I
Ingo Molnar 已提交
996
	  use of generic tracepoints.
T
Thomas Gleixner 已提交
997

I
Ingo Molnar 已提交
998 999
	  Most modern CPUs support performance events via performance
	  counter registers. These registers count the number of certain
T
Thomas Gleixner 已提交
1000 1001 1002 1003 1004 1005
	  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
1006
	  The Linux Performance Event subsystem provides an abstraction of
1007
	  these software and hardware event capabilities, available via a
I
Ingo Molnar 已提交
1008
	  system call and used by the "perf" utility in tools/perf/. It
T
Thomas Gleixner 已提交
1009 1010 1011 1012 1013
	  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
1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025
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.

1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038
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
1039 1040
endmenu

1041 1042 1043 1044
config VM_EVENT_COUNTERS
	default y
	bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
	help
1045 1046 1047 1048
	  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.
1049

1050 1051
config PCI_QUIRKS
	default y
1052 1053
	bool "Enable PCI quirk workarounds" if EMBEDDED
	depends on PCI
1054 1055 1056 1057 1058
	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
1059 1060 1061
config SLUB_DEBUG
	default y
	bool "Enable SLUB debugging support" if EMBEDDED
C
Christoph Lameter 已提交
1062
	depends on SLUB && SYSFS
C
Christoph Lameter 已提交
1063 1064 1065 1066 1067 1068
	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
1069 1070 1071 1072 1073 1074 1075
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
1076
	  disabled, and can be overridden at runtime by setting
R
Randy Dunlap 已提交
1077 1078 1079 1080
	  /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
1081 1082
choice
	prompt "Choose SLAB allocator"
1083
	default SLUB
C
Christoph Lameter 已提交
1084 1085 1086 1087 1088 1089 1090
	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
1091
	  well in all environments. It organizes cache hot objects in
1092
	  per cpu and per node queues.
C
Christoph Lameter 已提交
1093 1094 1095 1096 1097 1098 1099 1100

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
1101 1102
	   and has enhanced diagnostics. SLUB is the default choice for
	   a slab allocator.
C
Christoph Lameter 已提交
1103 1104

config SLOB
P
Paul Mundt 已提交
1105
	depends on EMBEDDED
C
Christoph Lameter 已提交
1106 1107
	bool "SLOB (Simple Allocator)"
	help
M
Matt Mackall 已提交
1108 1109 1110
	   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
1111 1112 1113

endchoice

1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135
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.

1136
config PROFILING
1137
	bool "Profiling support"
1138 1139 1140 1141
	help
	  Say Y here to enable the extended profiling support mechanisms used
	  by profilers such as OProfile.

1142 1143 1144 1145
#
# Place an empty function call at each tracepoint site. Can be
# dynamically changed for a probe function.
#
M
Mathieu Desnoyers 已提交
1146
config TRACEPOINTS
1147
	bool
M
Mathieu Desnoyers 已提交
1148

M
Mathieu Desnoyers 已提交
1149 1150
source "arch/Kconfig"

L
Linus Torvalds 已提交
1151 1152
endmenu		# General setup

1153 1154 1155 1156
config HAVE_GENERIC_DMA_COHERENT
	bool
	default n

1157 1158 1159
config SLABINFO
	bool
	depends on PROC_FS
1160
	depends on SLAB || SLUB_DEBUG
1161 1162
	default y

1163 1164 1165
config RT_MUTEXES
	boolean

L
Linus Torvalds 已提交
1166 1167 1168 1169 1170
config BASE_SMALL
	int
	default 0 if BASE_FULL
	default 1 if !BASE_FULL

1171
menuconfig MODULES
L
Linus Torvalds 已提交
1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190
	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.

1191 1192
if MODULES

1193 1194 1195 1196
config MODULE_FORCE_LOAD
	bool "Forced module loading"
	default n
	help
1197 1198 1199
	  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.
1200

L
Linus Torvalds 已提交
1201 1202 1203 1204 1205
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
1206 1207
	  anyway), which makes your kernel smaller, faster
	  and simpler.  If unsure, say Y.
L
Linus Torvalds 已提交
1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219

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
1220
	bool "Module versioning support"
L
Linus Torvalds 已提交
1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239
	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.

1240 1241
endif # MODULES

1242 1243 1244 1245 1246 1247 1248
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
1249
	  and have several arch maintainers pursuing me down dark alleys.
1250

L
Linus Torvalds 已提交
1251 1252 1253 1254 1255 1256
config STOP_MACHINE
	bool
	default y
	depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
	help
	  Need stop_machine() primitive.
1257 1258

source "block/Kconfig"
1259 1260 1261

config PREEMPT_NOTIFIERS
	bool
P
Paul E. McKenney 已提交
1262

1263 1264 1265 1266
config PADATA
	depends on SMP
	bool

1267
source "kernel/Kconfig.locks"