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  33           drivers that have been replaced by something else, and/or are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 CPUSETS
 274         bool "Cpuset support"
 275         depends on SMP
 276         help
 277           This option will let you create and manage CPUSETs which
 278           allow dynamically partitioning a system into sets of CPUs and
 279           Memory Nodes and assigning tasks to run only within those sets.
 280           This is primarily useful on large SMP or NUMA systems.
 281
 282           Say N if unsure.
 283
 284 config FAIR_GROUP_SCHED
 285         bool "Fair group scheduler"
 286         depends on EXPERIMENTAL && CONTAINERS
 287         help
 288           This option enables you to group tasks and control CPU resource
 289           allocation to such groups.
 290
 291           Say N if unsure.
 292
 293 config SYSFS_DEPRECATED
 294         bool "Create deprecated sysfs files"
 295         default y
 296         help
 297           This option creates deprecated symlinks such as the
 298           "device"-link, the <subsystem>:<name>-link, and the
 299           "bus"-link. It may also add deprecated key in the
 300           uevent environment.
 301           None of these features or values should be used today, as
 302           they export driver core implementation details to userspace
 303           or export properties which can't be kept stable across kernel
 304           releases.
 305
 306           If enabled, this option will also move any device structures
 307           that belong to a class, back into the /sys/class hierarchy, in
 308           order to support older versions of udev.
 309
 310           If you are using a distro that was released in 2006 or later,
 311           it should be safe to say N here.
 312
 313 config RELAY
 314         bool "Kernel->user space relay support (formerly relayfs)"
 315         help
 316           This option enables support for relay interface support in
 317           certain file systems (such as debugfs).
 318           It is designed to provide an efficient mechanism for tools and
 319           facilities to relay large amounts of data from kernel space to
 320           user space.
 321
 322           If unsure, say N.
 323
 324 config BLK_DEV_INITRD
 325         bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
 326         depends on BROKEN || !FRV
 327         help
 328           The initial RAM filesystem is a ramfs which is loaded by the
 329           boot loader (loadlin or lilo) and that is mounted as root
 330           before the normal boot procedure. It is typically used to
 331           load modules needed to mount the "real" root file system,
 332           etc. See <file:Documentation/initrd.txt> for details.
 333
 334           If RAM disk support (BLK_DEV_RAM) is also included, this
 335           also enables initial RAM disk (initrd) support and adds
 336           15 Kbytes (more on some other architectures) to the kernel size.
 337
 338           If unsure say Y.
 339
 340 if BLK_DEV_INITRD
 341
 342 source "usr/Kconfig"
 343
 344 endif
 345
 346 config CC_OPTIMIZE_FOR_SIZE
 347         bool "Optimize for size (Look out for broken compilers!)"
 348         default y
 349         depends on ARM || H8300 || SUPERH || EXPERIMENTAL
 350         help
 351           Enabling this option will pass "-Os" instead of "-O2" to gcc
 352           resulting in a smaller kernel.
 353
 354           WARNING: some versions of gcc may generate incorrect code with this
 355           option.  If problems are observed, a gcc upgrade may be needed.
 356
 357           If unsure, say N.
 358
 359 config SYSCTL
 360         bool
 361
 362 menuconfig EMBEDDED
 363         bool "Configure standard kernel features (for small systems)"
 364         help
 365           This option allows certain base kernel options and settings
 366           to be disabled or tweaked. This is for specialized
 367           environments which can tolerate a "non-standard" kernel.
 368           Only use this if you really know what you are doing.
 369
 370 config UID16
 371         bool "Enable 16-bit UID system calls" if EMBEDDED
 372         depends on ARM || BFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION)
 373         default y
 374         help
 375           This enables the legacy 16-bit UID syscall wrappers.
 376
 377 config SYSCTL_SYSCALL
 378         bool "Sysctl syscall support" if EMBEDDED
 379         default y
 380         select SYSCTL
 381         ---help---
 382           sys_sysctl uses binary paths that have been found challenging
 383           to properly maintain and use.  The interface in /proc/sys
 384           using paths with ascii names is now the primary path to this
 385           information.
 386
 387           Almost nothing using the binary sysctl interface so if you are
 388           trying to save some space it is probably safe to disable this,
 389           making your kernel marginally smaller.
 390
 391           If unsure say Y here.
 392
 393 config KALLSYMS
 394          bool "Load all symbols for debugging/ksymoops" if EMBEDDED
 395          default y
 396          help
 397            Say Y here to let the kernel print out symbolic crash information and
 398            symbolic stack backtraces. This increases the size of the kernel
 399            somewhat, as all symbols have to be loaded into the kernel image.
 400
 401 config KALLSYMS_ALL
 402         bool "Include all symbols in kallsyms"
 403         depends on DEBUG_KERNEL && KALLSYMS
 404         help
 405            Normally kallsyms only contains the symbols of functions, for nicer
 406            OOPS messages.  Some debuggers can use kallsyms for other
 407            symbols too: say Y here to include all symbols, if you need them
 408            and you don't care about adding 300k to the size of your kernel.
 409
 410            Say N.
 411
 412 config KALLSYMS_EXTRA_PASS
 413         bool "Do an extra kallsyms pass"
 414         depends on KALLSYMS
 415         help
 416            If kallsyms is not working correctly, the build will fail with
 417            inconsistent kallsyms data.  If that occurs, log a bug report and
 418            turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
 419            Always say N here unless you find a bug in kallsyms, which must be
 420            reported.  KALLSYMS_EXTRA_PASS is only a temporary workaround while
 421            you wait for kallsyms to be fixed.
 422
 423
 424 config HOTPLUG
 425         bool "Support for hot-pluggable devices" if EMBEDDED
 426         default y
 427         help
 428           This option is provided for the case where no hotplug or uevent
 429           capabilities is wanted by the kernel.  You should only consider
 430           disabling this option for embedded systems that do not use modules, a
 431           dynamic /dev tree, or dynamic device discovery.  Just say Y.
 432
 433 config PRINTK
 434         default y
 435         bool "Enable support for printk" if EMBEDDED
 436         help
 437           This option enables normal printk support. Removing it
 438           eliminates most of the message strings from the kernel image
 439           and makes the kernel more or less silent. As this makes it
 440           very difficult to diagnose system problems, saying N here is
 441           strongly discouraged.
 442
 443 config BUG
 444         bool "BUG() support" if EMBEDDED
 445         default y
 446         help
 447           Disabling this option eliminates support for BUG and WARN, reducing
 448           the size of your kernel image and potentially quietly ignoring
 449           numerous fatal conditions. You should only consider disabling this
 450           option for embedded systems with no facilities for reporting errors.
 451           Just say Y.
 452
 453 config ELF_CORE
 454         default y
 455         bool "Enable ELF core dumps" if EMBEDDED
 456         help
 457           Enable support for generating core dumps. Disabling saves about 4k.
 458
 459 config BASE_FULL
 460         default y
 461         bool "Enable full-sized data structures for core" if EMBEDDED
 462         help
 463           Disabling this option reduces the size of miscellaneous core
 464           kernel data structures. This saves memory on small machines,
 465           but may reduce performance.
 466
 467 config FUTEX
 468         bool "Enable futex support" if EMBEDDED
 469         default y
 470         select RT_MUTEXES
 471         help
 472           Disabling this option will cause the kernel to be built without
 473           support for "fast userspace mutexes".  The resulting kernel may not
 474           run glibc-based applications correctly.
 475
 476 config ANON_INODES
 477         bool
 478
 479 config EPOLL
 480         bool "Enable eventpoll support" if EMBEDDED
 481         default y
 482         select ANON_INODES
 483         help
 484           Disabling this option will cause the kernel to be built without
 485           support for epoll family of system calls.
 486
 487 config SIGNALFD
 488         bool "Enable signalfd() system call" if EMBEDDED
 489         select ANON_INODES
 490         default y
 491         help
 492           Enable the signalfd() system call that allows to receive signals
 493           on a file descriptor.
 494
 495           If unsure, say Y.
 496
 497 config TIMERFD
 498         bool "Enable timerfd() system call" if EMBEDDED
 499         select ANON_INODES
 500         depends on BROKEN
 501         default y
 502         help
 503           Enable the timerfd() system call that allows to receive timer
 504           events on a file descriptor.
 505
 506           If unsure, say Y.
 507
 508 config EVENTFD
 509         bool "Enable eventfd() system call" if EMBEDDED
 510         select ANON_INODES
 511         default y
 512         help
 513           Enable the eventfd() system call that allows to receive both
 514           kernel notification (ie. KAIO) or userspace notifications.
 515
 516           If unsure, say Y.
 517
 518 config SHMEM
 519         bool "Use full shmem filesystem" if EMBEDDED
 520         default y
 521         depends on MMU
 522         help
 523           The shmem is an internal filesystem used to manage shared memory.
 524           It is backed by swap and manages resource limits. It is also exported
 525           to userspace as tmpfs if TMPFS is enabled. Disabling this
 526           option replaces shmem and tmpfs with the much simpler ramfs code,
 527           which may be appropriate on small systems without swap.
 528
 529 config VM_EVENT_COUNTERS
 530         default y
 531         bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
 532         help
 533           VM event counters are needed for event counts to be shown.
 534           This option allows the disabling of the VM event counters
 535           on EMBEDDED systems.  /proc/vmstat will only show page counts
 536           if VM event counters are disabled.
 537
 538 config SLUB_DEBUG
 539         default y
 540         bool "Enable SLUB debugging support" if EMBEDDED
 541         depends on SLUB
 542         help
 543           SLUB has extensive debug support features. Disabling these can
 544           result in significant savings in code size. This also disables
 545           SLUB sysfs support. /sys/slab will not exist and there will be
 546           no support for cache validation etc.
 547
 548 choice
 549         prompt "Choose SLAB allocator"
 550         default SLUB
 551         help
 552            This option allows to select a slab allocator.
 553
 554 config SLAB
 555         bool "SLAB"
 556         help
 557           The regular slab allocator that is established and known to work
 558           well in all environments. It organizes cache hot objects in
 559           per cpu and per node queues. SLAB is the default choice for
 560           a slab allocator.
 561
 562 config SLUB
 563         bool "SLUB (Unqueued Allocator)"
 564         help
 565            SLUB is a slab allocator that minimizes cache line usage
 566            instead of managing queues of cached objects (SLAB approach).
 567            Per cpu caching is realized using slabs of objects instead
 568            of queues of objects. SLUB can use memory efficiently
 569            and has enhanced diagnostics.
 570
 571 config SLOB
 572         depends on EMBEDDED
 573         bool "SLOB (Simple Allocator)"
 574         help
 575            SLOB replaces the SLAB allocator with a drastically simpler
 576            allocator.  SLOB is more space efficient than SLAB but does not
 577            scale well (single lock for all operations) and is also highly
 578            susceptible to fragmentation. SLUB can accomplish a higher object
 579            density. It is usually better to use SLUB instead of SLOB.
 580
 581 endchoice
 582
 583 endmenu         # General setup
 584
 585 config RT_MUTEXES
 586         boolean
 587         select PLIST
 588
 589 config TINY_SHMEM
 590         default !SHMEM
 591         bool
 592
 593 config BASE_SMALL
 594         int
 595         default 0 if BASE_FULL
 596         default 1 if !BASE_FULL
 597
 598 menuconfig MODULES
 599         bool "Enable loadable module support"
 600         help
 601           Kernel modules are small pieces of compiled code which can
 602           be inserted in the running kernel, rather than being
 603           permanently built into the kernel.  You use the "modprobe"
 604           tool to add (and sometimes remove) them.  If you say Y here,
 605           many parts of the kernel can be built as modules (by
 606           answering M instead of Y where indicated): this is most
 607           useful for infrequently used options which are not required
 608           for booting.  For more information, see the man pages for
 609           modprobe, lsmod, modinfo, insmod and rmmod.
 610
 611           If you say Y here, you will need to run "make
 612           modules_install" to put the modules under /lib/modules/
 613           where modprobe can find them (you may need to be root to do
 614           this).
 615
 616           If unsure, say Y.
 617
 618 config MODULE_UNLOAD
 619         bool "Module unloading"
 620         depends on MODULES
 621         help
 622           Without this option you will not be able to unload any
 623           modules (note that some modules may not be unloadable
 624           anyway), which makes your kernel slightly smaller and
 625           simpler.  If unsure, say Y.
 626
 627 config MODULE_FORCE_UNLOAD
 628         bool "Forced module unloading"
 629         depends on MODULE_UNLOAD && EXPERIMENTAL
 630         help
 631           This option allows you to force a module to unload, even if the
 632           kernel believes it is unsafe: the kernel will remove the module
 633           without waiting for anyone to stop using it (using the -f option to
 634           rmmod).  This is mainly for kernel developers and desperate users.
 635           If unsure, say N.
 636
 637 config MODVERSIONS
 638         bool "Module versioning support"
 639         depends on MODULES
 640         help
 641           Usually, you have to use modules compiled with your kernel.
 642           Saying Y here makes it sometimes possible to use modules
 643           compiled for different kernels, by adding enough information
 644           to the modules to (hopefully) spot any changes which would
 645           make them incompatible with the kernel you are running.  If
 646           unsure, say N.
 647
 648 config MODULE_SRCVERSION_ALL
 649         bool "Source checksum for all modules"
 650         depends on MODULES
 651         help
 652           Modules which contain a MODULE_VERSION get an extra "srcversion"
 653           field inserted into their modinfo section, which contains a
 654           sum of the source files which made it.  This helps maintainers
 655           see exactly which source was used to build a module (since
 656           others sometimes change the module source without updating
 657           the version).  With this option, such a "srcversion" field
 658           will be created for all modules.  If unsure, say N.
 659
 660 config KMOD
 661         bool "Automatic kernel module loading"
 662         depends on MODULES
 663         help
 664           Normally when you have selected some parts of the kernel to
 665           be created as kernel modules, you must load them (using the
 666           "modprobe" command) before you can use them. If you say Y
 667           here, some parts of the kernel will be able to load modules
 668           automatically: when a part of the kernel needs a module, it
 669           runs modprobe with the appropriate arguments, thereby
 670           loading the module if it is available.  If unsure, say Y.
 671
 672 config STOP_MACHINE
 673         bool
 674         default y
 675         depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
 676         help
 677           Need stop_machine() primitive.
 678
 679 source "block/Kconfig"