init/Kconfig

   1 config DEFCONFIG_LIST
   2         string
   3         depends on !UML
   4         option defconfig_list
   5         default "/lib/modules/$UNAME_RELEASE/.config"
   6         default "/etc/kernel-config"
   7         default "/boot/config-$UNAME_RELEASE"
   8         default "arch/$ARCH/defconfig"
   9
  10 menu "General setup"
  11
  12 config EXPERIMENTAL
  13         bool "Prompt for development and/or incomplete code/drivers"
  14         ---help---
  15           Some of the various things that Linux supports (such as network
  16           drivers, file systems, network protocols, etc.) can be in a state
  17           of development where the functionality, stability, or the level of
  18           testing is not yet high enough for general use. This is usually
  19           known as the "alpha-test" phase among developers. If a feature is
  20           currently in alpha-test, then the developers usually discourage
  21           uninformed widespread use of this feature by the general public to
  22           avoid "Why doesn't this work?" type mail messages. However, active
  23           testing and use of these systems is welcomed. Just be aware that it
  24           may not meet the normal level of reliability or it may fail to work
  25           in some special cases. Detailed bug reports from people familiar
  26           with the kernel internals are usually welcomed by the developers
  27           (before submitting bug reports, please read the documents
  28           <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
  29           <file:Documentation/BUG-HUNTING>, and
  30           <file:Documentation/oops-tracing.txt> in the kernel source).
  31
  32           This option will also make obsoleted drivers available. These are
  33           drivers that have been replaced by something else, and/or are
  34           scheduled to be removed in a future kernel release.
  35
  36           Unless you intend to help test and develop a feature or driver that
  37           falls into this category, or you have a situation that requires
  38           using these features, you should probably say N here, which will
  39           cause the configurator to present you with fewer choices. If
  40           you say Y here, you will be offered the choice of using features or
  41           drivers that are currently considered to be in the alpha-test phase.
  42
  43 config BROKEN
  44         bool
  45
  46 config BROKEN_ON_SMP
  47         bool
  48         depends on BROKEN || !SMP
  49         default y
  50
  51 config LOCK_KERNEL
  52         bool
  53         depends on SMP || PREEMPT
  54         default y
  55
  56 config INIT_ENV_ARG_LIMIT
  57         int
  58         default 32 if !UML
  59         default 128 if UML
  60         help
  61           Maximum of each of the number of arguments and environment
  62           variables passed to init from the kernel command line.
  63
  64
  65 config LOCALVERSION
  66         string "Local version - append to kernel release"
  67         help
  68           Append an extra string to the end of your kernel version.
  69           This will show up when you type uname, for example.
  70           The string you set here will be appended after the contents of
  71           any files with a filename matching localversion* in your
  72           object and source tree, in that order.  Your total string can
  73           be a maximum of 64 characters.
  74
  75 config LOCALVERSION_AUTO
  76         bool "Automatically append version information to the version string"
  77         default y
  78         help
  79           This will try to automatically determine if the current tree is a
  80           release tree by looking for git tags that belong to the current
  81           top of tree revision.
  82
  83           A string of the format -gxxxxxxxx will be added to the localversion
  84           if a git-based tree is found.  The string generated by this will be
  85           appended after any matching localversion* files, and after the value
  86           set in CONFIG_LOCALVERSION.
  87
  88           (The actual string used here is the first eight characters produced
  89           by running the command:
  90
  91             $ git rev-parse --verify HEAD
  92
  93           which is done within the script "scripts/setlocalversion".)
  94
  95 config SWAP
  96         bool "Support for paging of anonymous memory (swap)"
  97         depends on MMU && BLOCK
  98         default y
  99         help
 100           This option allows you to choose whether you want to have support
 101           for so called swap devices or swap files in your kernel that are
 102           used to provide more virtual memory than the actual RAM present
 103           in your computer.  If unsure say Y.
 104
 105 config SYSVIPC
 106         bool "System V IPC"
 107         ---help---
 108           Inter Process Communication is a suite of library functions and
 109           system calls which let processes (running programs) synchronize and
 110           exchange information. It is generally considered to be a good thing,
 111           and some programs won't run unless you say Y here. In particular, if
 112           you want to run the DOS emulator dosemu under Linux (read the
 113           DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
 114           you'll need to say Y here.
 115
 116           You can find documentation about IPC with "info ipc" and also in
 117           section 6.4 of the Linux Programmer's Guide, available from
 118           <http://www.tldp.org/guides.html>.
 119
 120 config SYSVIPC_SYSCTL
 121         bool
 122         depends on SYSVIPC
 123         depends on SYSCTL
 124         default y
 125
 126 config POSIX_MQUEUE
 127         bool "POSIX Message Queues"
 128         depends on NET && EXPERIMENTAL
 129         ---help---
 130           POSIX variant of message queues is a part of IPC. In POSIX message
 131           queues every message has a priority which decides about succession
 132           of receiving it by a process. If you want to compile and run
 133           programs written e.g. for Solaris with use of its POSIX message
 134           queues (functions mq_*) say Y here.
 135
 136           POSIX message queues are visible as a filesystem called 'mqueue'
 137           and can be mounted somewhere if you want to do filesystem
 138           operations on message queues.
 139
 140           If unsure, say Y.
 141
 142 config BSD_PROCESS_ACCT
 143         bool "BSD Process Accounting"
 144         help
 145           If you say Y here, a user level program will be able to instruct the
 146           kernel (via a special system call) to write process accounting
 147           information to a file: whenever a process exits, information about
 148           that process will be appended to the file by the kernel.  The
 149           information includes things such as creation time, owning user,
 150           command name, memory usage, controlling terminal etc. (the complete
 151           list is in the struct acct in <file:include/linux/acct.h>).  It is
 152           up to the user level program to do useful things with this
 153           information.  This is generally a good idea, so say Y.
 154
 155 config BSD_PROCESS_ACCT_V3
 156         bool "BSD Process Accounting version 3 file format"
 157         depends on BSD_PROCESS_ACCT
 158         default n
 159         help
 160           If you say Y here, the process accounting information is written
 161           in a new file format that also logs the process IDs of each
 162           process and it's parent. Note that this file format is incompatible
 163           with previous v0/v1/v2 file formats, so you will need updated tools
 164           for processing it. A preliminary version of these tools is available
 165           at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>.
 166
 167 config TASKSTATS
 168         bool "Export task/process statistics through netlink (EXPERIMENTAL)"
 169         depends on NET
 170         default n
 171         help
 172           Export selected statistics for tasks/processes through the
 173           generic netlink interface. Unlike BSD process accounting, the
 174           statistics are available during the lifetime of tasks/processes as
 175           responses to commands. Like BSD accounting, they are sent to user
 176           space on task exit.
 177
 178           Say N if unsure.
 179
 180 config TASK_DELAY_ACCT
 181         bool "Enable per-task delay accounting (EXPERIMENTAL)"
 182         depends on TASKSTATS
 183         help
 184           Collect information on time spent by a task waiting for system
 185           resources like cpu, synchronous block I/O completion and swapping
 186           in pages. Such statistics can help in setting a task's priorities
 187           relative to other tasks for cpu, io, rss limits etc.
 188
 189           Say N if unsure.
 190
 191 config TASK_XACCT
 192         bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
 193         depends on TASKSTATS
 194         help
 195           Collect extended task accounting data and send the data
 196           to userland for processing over the taskstats interface.
 197
 198           Say N if unsure.
 199
 200 config TASK_IO_ACCOUNTING
 201         bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
 202         depends on TASK_XACCT
 203         help
 204           Collect information on the number of bytes of storage I/O which this
 205           task has caused.
 206
 207           Say N if unsure.
 208
 209 config USER_NS
 210         bool "User Namespaces (EXPERIMENTAL)"
 211         default n
 212         depends on EXPERIMENTAL
 213         help
 214           Support user namespaces.  This allows containers, i.e.
 215           vservers, to use user namespaces to provide different
 216           user info for different servers.  If unsure, say N.
 217
 218 config AUDIT
 219         bool "Auditing support"
 220         depends on NET
 221         help
 222           Enable auditing infrastructure that can be used with another
 223           kernel subsystem, such as SELinux (which requires this for
 224           logging of avc messages output).  Does not do system-call
 225           auditing without CONFIG_AUDITSYSCALL.
 226
 227 config AUDITSYSCALL
 228         bool "Enable system-call auditing support"
 229         depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64)
 230         default y if SECURITY_SELINUX
 231         help
 232           Enable low-overhead system-call auditing infrastructure that
 233           can be used independently or with another kernel subsystem,
 234           such as SELinux.  To use audit's filesystem watch feature, please
 235           ensure that INOTIFY is configured.
 236
 237 config IKCONFIG
 238         tristate "Kernel .config support"
 239         ---help---
 240           This option enables the complete Linux kernel ".config" file
 241           contents to be saved in the kernel. It provides documentation
 242           of which kernel options are used in a running kernel or in an
 243           on-disk kernel.  This information can be extracted from the kernel
 244           image file with the script scripts/extract-ikconfig and used as
 245           input to rebuild the current kernel or to build another kernel.
 246           It can also be extracted from a running kernel by reading
 247           /proc/config.gz if enabled (below).
 248
 249 config IKCONFIG_PROC
 250         bool "Enable access to .config through /proc/config.gz"
 251         depends on IKCONFIG && PROC_FS
 252         ---help---
 253           This option enables access to the kernel configuration file
 254           through /proc/config.gz.
 255
 256 config LOG_BUF_SHIFT
 257         int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
 258         range 12 21
 259         default 17 if S390 || LOCKDEP
 260         default 16 if X86_NUMAQ || IA64
 261         default 15 if SMP
 262         default 14
 263         help
 264           Select kernel log buffer size as a power of 2.
 265           Defaults and Examples:
 266                      17 => 128 KB for S/390
 267                      16 => 64 KB for x86 NUMAQ or IA-64
 268                      15 => 32 KB for SMP
 269                      14 => 16 KB for uniprocessor
 270                      13 =>  8 KB
 271                      12 =>  4 KB
 272
 273 config CGROUPS
 274         bool "Control Group support"
 275         help
 276           This option will let you use process cgroup subsystems
 277           such as Cpusets
 278
 279           Say N if unsure.
 280
 281 config CPUSETS
 282         bool "Cpuset support"
 283         depends on SMP
 284         help
 285           This option will let you create and manage CPUSETs which
 286           allow dynamically partitioning a system into sets of CPUs and
 287           Memory Nodes and assigning tasks to run only within those sets.
 288           This is primarily useful on large SMP or NUMA systems.
 289
 290           Say N if unsure.
 291
 292 config FAIR_GROUP_SCHED
 293         bool "Fair group CPU scheduler"
 294         default y
 295         depends on EXPERIMENTAL
 296         help
 297           This feature lets CPU scheduler recognize task groups and control CPU
 298           bandwidth allocation to such task groups.
 299
 300 choice
 301         depends on FAIR_GROUP_SCHED
 302         prompt "Basis for grouping tasks"
 303         default FAIR_USER_SCHED
 304
 305 config FAIR_USER_SCHED
 306         bool "user id"
 307         help
 308           This option will choose userid as the basis for grouping
 309           tasks, thus providing equal CPU bandwidth to each user.
 310
 311 endchoice
 312
 313 config SYSFS_DEPRECATED
 314         bool "Create deprecated sysfs files"
 315         default y
 316         help
 317           This option creates deprecated symlinks such as the
 318           "device"-link, the <subsystem>:<name>-link, and the
 319           "bus"-link. It may also add deprecated key in the
 320           uevent environment.
 321           None of these features or values should be used today, as
 322           they export driver core implementation details to userspace
 323           or export properties which can't be kept stable across kernel
 324           releases.
 325
 326           If enabled, this option will also move any device structures
 327           that belong to a class, back into the /sys/class hierarchy, in
 328           order to support older versions of udev.
 329
 330           If you are using a distro that was released in 2006 or later,
 331           it should be safe to say N here.
 332
 333 config RELAY
 334         bool "Kernel->user space relay support (formerly relayfs)"
 335         help
 336           This option enables support for relay interface support in
 337           certain file systems (such as debugfs).
 338           It is designed to provide an efficient mechanism for tools and
 339           facilities to relay large amounts of data from kernel space to
 340           user space.
 341
 342           If unsure, say N.
 343
 344 config BLK_DEV_INITRD
 345         bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
 346         depends on BROKEN || !FRV
 347         help
 348           The initial RAM filesystem is a ramfs which is loaded by the
 349           boot loader (loadlin or lilo) and that is mounted as root
 350           before the normal boot procedure. It is typically used to
 351           load modules needed to mount the "real" root file system,
 352           etc. See <file:Documentation/initrd.txt> for details.
 353
 354           If RAM disk support (BLK_DEV_RAM) is also included, this
 355           also enables initial RAM disk (initrd) support and adds
 356           15 Kbytes (more on some other architectures) to the kernel size.
 357
 358           If unsure say Y.
 359
 360 if BLK_DEV_INITRD
 361
 362 source "usr/Kconfig"
 363
 364 endif
 365
 366 config CC_OPTIMIZE_FOR_SIZE
 367         bool "Optimize for size (Look out for broken compilers!)"
 368         default y
 369         depends on ARM || H8300 || SUPERH || EXPERIMENTAL
 370         help
 371           Enabling this option will pass "-Os" instead of "-O2" to gcc
 372           resulting in a smaller kernel.
 373
 374           WARNING: some versions of gcc may generate incorrect code with this
 375           option.  If problems are observed, a gcc upgrade may be needed.
 376
 377           If unsure, say N.
 378
 379 config SYSCTL
 380         bool
 381
 382 menuconfig EMBEDDED
 383         bool "Configure standard kernel features (for small systems)"
 384         help
 385           This option allows certain base kernel options and settings
 386           to be disabled or tweaked. This is for specialized
 387           environments which can tolerate a "non-standard" kernel.
 388           Only use this if you really know what you are doing.
 389
 390 config UID16
 391         bool "Enable 16-bit UID system calls" if EMBEDDED
 392         depends on ARM || BFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION)
 393         default y
 394         help
 395           This enables the legacy 16-bit UID syscall wrappers.
 396
 397 config SYSCTL_SYSCALL
 398         bool "Sysctl syscall support" if EMBEDDED
 399         default y
 400         select SYSCTL
 401         ---help---
 402           sys_sysctl uses binary paths that have been found challenging
 403           to properly maintain and use.  The interface in /proc/sys
 404           using paths with ascii names is now the primary path to this
 405           information.
 406
 407           Almost nothing using the binary sysctl interface so if you are
 408           trying to save some space it is probably safe to disable this,
 409           making your kernel marginally smaller.
 410
 411           If unsure say Y here.
 412
 413 config KALLSYMS
 414          bool "Load all symbols for debugging/ksymoops" if EMBEDDED
 415          default y
 416          help
 417            Say Y here to let the kernel print out symbolic crash information and
 418            symbolic stack backtraces. This increases the size of the kernel
 419            somewhat, as all symbols have to be loaded into the kernel image.
 420
 421 config KALLSYMS_ALL
 422         bool "Include all symbols in kallsyms"
 423         depends on DEBUG_KERNEL && KALLSYMS
 424         help
 425            Normally kallsyms only contains the symbols of functions, for nicer
 426            OOPS messages.  Some debuggers can use kallsyms for other
 427            symbols too: say Y here to include all symbols, if you need them
 428            and you don't care about adding 300k to the size of your kernel.
 429
 430            Say N.
 431
 432 config KALLSYMS_EXTRA_PASS
 433         bool "Do an extra kallsyms pass"
 434         depends on KALLSYMS
 435         help
 436            If kallsyms is not working correctly, the build will fail with
 437            inconsistent kallsyms data.  If that occurs, log a bug report and
 438            turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
 439            Always say N here unless you find a bug in kallsyms, which must be
 440            reported.  KALLSYMS_EXTRA_PASS is only a temporary workaround while
 441            you wait for kallsyms to be fixed.
 442
 443
 444 config HOTPLUG
 445         bool "Support for hot-pluggable devices" if EMBEDDED
 446         default y
 447         help
 448           This option is provided for the case where no hotplug or uevent
 449           capabilities is wanted by the kernel.  You should only consider
 450           disabling this option for embedded systems that do not use modules, a
 451           dynamic /dev tree, or dynamic device discovery.  Just say Y.
 452
 453 config PRINTK
 454         default y
 455         bool "Enable support for printk" if EMBEDDED
 456         help
 457           This option enables normal printk support. Removing it
 458           eliminates most of the message strings from the kernel image
 459           and makes the kernel more or less silent. As this makes it
 460           very difficult to diagnose system problems, saying N here is
 461           strongly discouraged.
 462
 463 config BUG
 464         bool "BUG() support" if EMBEDDED
 465         default y
 466         help
 467           Disabling this option eliminates support for BUG and WARN, reducing
 468           the size of your kernel image and potentially quietly ignoring
 469           numerous fatal conditions. You should only consider disabling this
 470           option for embedded systems with no facilities for reporting errors.
 471           Just say Y.
 472
 473 config ELF_CORE
 474         default y
 475         bool "Enable ELF core dumps" if EMBEDDED
 476         help
 477           Enable support for generating core dumps. Disabling saves about 4k.
 478
 479 config BASE_FULL
 480         default y
 481         bool "Enable full-sized data structures for core" if EMBEDDED
 482         help
 483           Disabling this option reduces the size of miscellaneous core
 484           kernel data structures. This saves memory on small machines,
 485           but may reduce performance.
 486
 487 config FUTEX
 488         bool "Enable futex support" if EMBEDDED
 489         default y
 490         select RT_MUTEXES
 491         help
 492           Disabling this option will cause the kernel to be built without
 493           support for "fast userspace mutexes".  The resulting kernel may not
 494           run glibc-based applications correctly.
 495
 496 config ANON_INODES
 497         bool
 498
 499 config EPOLL
 500         bool "Enable eventpoll support" if EMBEDDED
 501         default y
 502         select ANON_INODES
 503         help
 504           Disabling this option will cause the kernel to be built without
 505           support for epoll family of system calls.
 506
 507 config SIGNALFD
 508         bool "Enable signalfd() system call" if EMBEDDED
 509         select ANON_INODES
 510         default y
 511         help
 512           Enable the signalfd() system call that allows to receive signals
 513           on a file descriptor.
 514
 515           If unsure, say Y.
 516
 517 config TIMERFD
 518         bool "Enable timerfd() system call" if EMBEDDED
 519         select ANON_INODES
 520         depends on BROKEN
 521         default y
 522         help
 523           Enable the timerfd() system call that allows to receive timer
 524           events on a file descriptor.
 525
 526           If unsure, say Y.
 527
 528 config EVENTFD
 529         bool "Enable eventfd() system call" if EMBEDDED
 530         select ANON_INODES
 531         default y
 532         help
 533           Enable the eventfd() system call that allows to receive both
 534           kernel notification (ie. KAIO) or userspace notifications.
 535
 536           If unsure, say Y.
 537
 538 config SHMEM
 539         bool "Use full shmem filesystem" if EMBEDDED
 540         default y
 541         depends on MMU
 542         help
 543           The shmem is an internal filesystem used to manage shared memory.
 544           It is backed by swap and manages resource limits. It is also exported
 545           to userspace as tmpfs if TMPFS is enabled. Disabling this
 546           option replaces shmem and tmpfs with the much simpler ramfs code,
 547           which may be appropriate on small systems without swap.
 548
 549 config VM_EVENT_COUNTERS
 550         default y
 551         bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
 552         help
 553           VM event counters are needed for event counts to be shown.
 554           This option allows the disabling of the VM event counters
 555           on EMBEDDED systems.  /proc/vmstat will only show page counts
 556           if VM event counters are disabled.
 557
 558 config SLUB_DEBUG
 559         default y
 560         bool "Enable SLUB debugging support" if EMBEDDED
 561         depends on SLUB
 562         help
 563           SLUB has extensive debug support features. Disabling these can
 564           result in significant savings in code size. This also disables
 565           SLUB sysfs support. /sys/slab will not exist and there will be
 566           no support for cache validation etc.
 567
 568 choice
 569         prompt "Choose SLAB allocator"
 570         default SLUB
 571         help
 572            This option allows to select a slab allocator.
 573
 574 config SLAB
 575         bool "SLAB"
 576         help
 577           The regular slab allocator that is established and known to work
 578           well in all environments. It organizes cache hot objects in
 579           per cpu and per node queues. SLAB is the default choice for
 580           a slab allocator.
 581
 582 config SLUB
 583         bool "SLUB (Unqueued Allocator)"
 584         help
 585            SLUB is a slab allocator that minimizes cache line usage
 586            instead of managing queues of cached objects (SLAB approach).
 587            Per cpu caching is realized using slabs of objects instead
 588            of queues of objects. SLUB can use memory efficiently
 589            and has enhanced diagnostics.
 590
 591 config SLOB
 592         depends on EMBEDDED
 593         bool "SLOB (Simple Allocator)"
 594         help
 595            SLOB replaces the SLAB allocator with a drastically simpler
 596            allocator.  SLOB is more space efficient than SLAB but does not
 597            scale well (single lock for all operations) and is also highly
 598            susceptible to fragmentation. SLUB can accomplish a higher object
 599            density. It is usually better to use SLUB instead of SLOB.
 600
 601 endchoice
 602
 603 endmenu         # General setup
 604
 605 config RT_MUTEXES
 606         boolean
 607         select PLIST
 608
 609 config TINY_SHMEM
 610         default !SHMEM
 611         bool
 612
 613 config BASE_SMALL
 614         int
 615         default 0 if BASE_FULL
 616         default 1 if !BASE_FULL
 617
 618 menuconfig MODULES
 619         bool "Enable loadable module support"
 620         help
 621           Kernel modules are small pieces of compiled code which can
 622           be inserted in the running kernel, rather than being
 623           permanently built into the kernel.  You use the "modprobe"
 624           tool to add (and sometimes remove) them.  If you say Y here,
 625           many parts of the kernel can be built as modules (by
 626           answering M instead of Y where indicated): this is most
 627           useful for infrequently used options which are not required
 628           for booting.  For more information, see the man pages for
 629           modprobe, lsmod, modinfo, insmod and rmmod.
 630
 631           If you say Y here, you will need to run "make
 632           modules_install" to put the modules under /lib/modules/
 633           where modprobe can find them (you may need to be root to do
 634           this).
 635
 636           If unsure, say Y.
 637
 638 config MODULE_UNLOAD
 639         bool "Module unloading"
 640         depends on MODULES
 641         help
 642           Without this option you will not be able to unload any
 643           modules (note that some modules may not be unloadable
 644           anyway), which makes your kernel slightly smaller and
 645           simpler.  If unsure, say Y.
 646
 647 config MODULE_FORCE_UNLOAD
 648         bool "Forced module unloading"
 649         depends on MODULE_UNLOAD && EXPERIMENTAL
 650         help
 651           This option allows you to force a module to unload, even if the
 652           kernel believes it is unsafe: the kernel will remove the module
 653           without waiting for anyone to stop using it (using the -f option to
 654           rmmod).  This is mainly for kernel developers and desperate users.
 655           If unsure, say N.
 656
 657 config MODVERSIONS
 658         bool "Module versioning support"
 659         depends on MODULES
 660         help
 661           Usually, you have to use modules compiled with your kernel.
 662           Saying Y here makes it sometimes possible to use modules
 663           compiled for different kernels, by adding enough information
 664           to the modules to (hopefully) spot any changes which would
 665           make them incompatible with the kernel you are running.  If
 666           unsure, say N.
 667
 668 config MODULE_SRCVERSION_ALL
 669         bool "Source checksum for all modules"
 670         depends on MODULES
 671         help
 672           Modules which contain a MODULE_VERSION get an extra "srcversion"
 673           field inserted into their modinfo section, which contains a
 674           sum of the source files which made it.  This helps maintainers
 675           see exactly which source was used to build a module (since
 676           others sometimes change the module source without updating
 677           the version).  With this option, such a "srcversion" field
 678           will be created for all modules.  If unsure, say N.
 679
 680 config KMOD
 681         bool "Automatic kernel module loading"
 682         depends on MODULES
 683         help
 684           Normally when you have selected some parts of the kernel to
 685           be created as kernel modules, you must load them (using the
 686           "modprobe" command) before you can use them. If you say Y
 687           here, some parts of the kernel will be able to load modules
 688           automatically: when a part of the kernel needs a module, it
 689           runs modprobe with the appropriate arguments, thereby
 690           loading the module if it is available.  If unsure, say Y.
 691
 692 config STOP_MACHINE
 693         bool
 694         default y
 695         depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
 696         help
 697           Need stop_machine() primitive.
 698
 699 source "block/Kconfig"
 700
 701 config PREEMPT_NOTIFIERS
 702         bool