init/Kconfig

   1 config ARCH
   2         string
   3         option env="ARCH"
   4
   5 config KERNELVERSION
   6         string
   7         option env="KERNELVERSION"
   8
   9 config DEFCONFIG_LIST
  10         string
  11         depends on !UML
  12         option defconfig_list
  13         default "/lib/modules/$UNAME_RELEASE/.config"
  14         default "/etc/kernel-config"
  15         default "/boot/config-$UNAME_RELEASE"
  16         default "$ARCH_DEFCONFIG"
  17         default "arch/$ARCH/defconfig"
  18
  19 config CONSTRUCTORS
  20         bool
  21         depends on !UML
  22         default y
  23
  24 config HAVE_IRQ_WORK
  25         bool
  26
  27 config IRQ_WORK
  28         bool
  29         depends on HAVE_IRQ_WORK
  30
  31 menu "General setup"
  32
  33 config EXPERIMENTAL
  34         bool "Prompt for development and/or incomplete code/drivers"
  35         ---help---
  36           Some of the various things that Linux supports (such as network
  37           drivers, file systems, network protocols, etc.) can be in a state
  38           of development where the functionality, stability, or the level of
  39           testing is not yet high enough for general use. This is usually
  40           known as the "alpha-test" phase among developers. If a feature is
  41           currently in alpha-test, then the developers usually discourage
  42           uninformed widespread use of this feature by the general public to
  43           avoid "Why doesn't this work?" type mail messages. However, active
  44           testing and use of these systems is welcomed. Just be aware that it
  45           may not meet the normal level of reliability or it may fail to work
  46           in some special cases. Detailed bug reports from people familiar
  47           with the kernel internals are usually welcomed by the developers
  48           (before submitting bug reports, please read the documents
  49           <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
  50           <file:Documentation/BUG-HUNTING>, and
  51           <file:Documentation/oops-tracing.txt> in the kernel source).
  52
  53           This option will also make obsoleted drivers available. These are
  54           drivers that have been replaced by something else, and/or are
  55           scheduled to be removed in a future kernel release.
  56
  57           Unless you intend to help test and develop a feature or driver that
  58           falls into this category, or you have a situation that requires
  59           using these features, you should probably say N here, which will
  60           cause the configurator to present you with fewer choices. If
  61           you say Y here, you will be offered the choice of using features or
  62           drivers that are currently considered to be in the alpha-test phase.
  63
  64 config BROKEN
  65         bool
  66
  67 config BROKEN_ON_SMP
  68         bool
  69         depends on BROKEN || !SMP
  70         default y
  71
  72 config LOCK_KERNEL
  73         bool
  74         depends on (SMP || PREEMPT) && BKL
  75         default y
  76
  77 config INIT_ENV_ARG_LIMIT
  78         int
  79         default 32 if !UML
  80         default 128 if UML
  81         help
  82           Maximum of each of the number of arguments and environment
  83           variables passed to init from the kernel command line.
  84
  85
  86 config CROSS_COMPILE
  87         string "Cross-compiler tool prefix"
  88         help
  89           Same as running 'make CROSS_COMPILE=prefix-' but stored for
  90           default make runs in this kernel build directory.  You don't
  91           need to set this unless you want the configured kernel build
  92           directory to select the cross-compiler automatically.
  93
  94 config LOCALVERSION
  95         string "Local version - append to kernel release"
  96         help
  97           Append an extra string to the end of your kernel version.
  98           This will show up when you type uname, for example.
  99           The string you set here will be appended after the contents of
 100           any files with a filename matching localversion* in your
 101           object and source tree, in that order.  Your total string can
 102           be a maximum of 64 characters.
 103
 104 config LOCALVERSION_AUTO
 105         bool "Automatically append version information to the version string"
 106         default y
 107         help
 108           This will try to automatically determine if the current tree is a
 109           release tree by looking for git tags that belong to the current
 110           top of tree revision.
 111
 112           A string of the format -gxxxxxxxx will be added to the localversion
 113           if a git-based tree is found.  The string generated by this will be
 114           appended after any matching localversion* files, and after the value
 115           set in CONFIG_LOCALVERSION.
 116
 117           (The actual string used here is the first eight characters produced
 118           by running the command:
 119
 120             $ git rev-parse --verify HEAD
 121
 122           which is done within the script "scripts/setlocalversion".)
 123
 124 config HAVE_KERNEL_GZIP
 125         bool
 126
 127 config HAVE_KERNEL_BZIP2
 128         bool
 129
 130 config HAVE_KERNEL_LZMA
 131         bool
 132
 133 config HAVE_KERNEL_XZ
 134         bool
 135
 136 config HAVE_KERNEL_LZO
 137         bool
 138
 139 choice
 140         prompt "Kernel compression mode"
 141         default KERNEL_GZIP
 142         depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO
 143         help
 144           The linux kernel is a kind of self-extracting executable.
 145           Several compression algorithms are available, which differ
 146           in efficiency, compression and decompression speed.
 147           Compression speed is only relevant when building a kernel.
 148           Decompression speed is relevant at each boot.
 149
 150           If you have any problems with bzip2 or lzma compressed
 151           kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
 152           version of this functionality (bzip2 only), for 2.4, was
 153           supplied by Christian Ludwig)
 154
 155           High compression options are mostly useful for users, who
 156           are low on disk space (embedded systems), but for whom ram
 157           size matters less.
 158
 159           If in doubt, select 'gzip'
 160
 161 config KERNEL_GZIP
 162         bool "Gzip"
 163         depends on HAVE_KERNEL_GZIP
 164         help
 165           The old and tried gzip compression. It provides a good balance
 166           between compression ratio and decompression speed.
 167
 168 config KERNEL_BZIP2
 169         bool "Bzip2"
 170         depends on HAVE_KERNEL_BZIP2
 171         help
 172           Its compression ratio and speed is intermediate.
 173           Decompression speed is slowest among the three.  The kernel
 174           size is about 10% smaller with bzip2, in comparison to gzip.
 175           Bzip2 uses a large amount of memory. For modern kernels you
 176           will need at least 8MB RAM or more for booting.
 177
 178 config KERNEL_LZMA
 179         bool "LZMA"
 180         depends on HAVE_KERNEL_LZMA
 181         help
 182           The most recent compression algorithm.
 183           Its ratio is best, decompression speed is between the other
 184           two. Compression is slowest.  The kernel size is about 33%
 185           smaller with LZMA in comparison to gzip.
 186
 187 config KERNEL_XZ
 188         bool "XZ"
 189         depends on HAVE_KERNEL_XZ
 190         help
 191           XZ uses the LZMA2 algorithm and instruction set specific
 192           BCJ filters which can improve compression ratio of executable
 193           code. The size of the kernel is about 30% smaller with XZ in
 194           comparison to gzip. On architectures for which there is a BCJ
 195           filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
 196           will create a few percent smaller kernel than plain LZMA.
 197
 198           The speed is about the same as with LZMA: The decompression
 199           speed of XZ is better than that of bzip2 but worse than gzip
 200           and LZO. Compression is slow.
 201
 202 config KERNEL_LZO
 203         bool "LZO"
 204         depends on HAVE_KERNEL_LZO
 205         help
 206           Its compression ratio is the poorest among the 4. The kernel
 207           size is about 10% bigger than gzip; however its speed
 208           (both compression and decompression) is the fastest.
 209
 210 endchoice
 211
 212 config SWAP
 213         bool "Support for paging of anonymous memory (swap)"
 214         depends on MMU && BLOCK
 215         default y
 216         help
 217           This option allows you to choose whether you want to have support
 218           for so called swap devices or swap files in your kernel that are
 219           used to provide more virtual memory than the actual RAM present
 220           in your computer.  If unsure say Y.
 221
 222 config SYSVIPC
 223         bool "System V IPC"
 224         ---help---
 225           Inter Process Communication is a suite of library functions and
 226           system calls which let processes (running programs) synchronize and
 227           exchange information. It is generally considered to be a good thing,
 228           and some programs won't run unless you say Y here. In particular, if
 229           you want to run the DOS emulator dosemu under Linux (read the
 230           DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
 231           you'll need to say Y here.
 232
 233           You can find documentation about IPC with "info ipc" and also in
 234           section 6.4 of the Linux Programmer's Guide, available from
 235           <http://www.tldp.org/guides.html>.
 236
 237 config SYSVIPC_SYSCTL
 238         bool
 239         depends on SYSVIPC
 240         depends on SYSCTL
 241         default y
 242
 243 config POSIX_MQUEUE
 244         bool "POSIX Message Queues"
 245         depends on NET && EXPERIMENTAL
 246         ---help---
 247           POSIX variant of message queues is a part of IPC. In POSIX message
 248           queues every message has a priority which decides about succession
 249           of receiving it by a process. If you want to compile and run
 250           programs written e.g. for Solaris with use of its POSIX message
 251           queues (functions mq_*) say Y here.
 252
 253           POSIX message queues are visible as a filesystem called 'mqueue'
 254           and can be mounted somewhere if you want to do filesystem
 255           operations on message queues.
 256
 257           If unsure, say Y.
 258
 259 config POSIX_MQUEUE_SYSCTL
 260         bool
 261         depends on POSIX_MQUEUE
 262         depends on SYSCTL
 263         default y
 264
 265 config BSD_PROCESS_ACCT
 266         bool "BSD Process Accounting"
 267         help
 268           If you say Y here, a user level program will be able to instruct the
 269           kernel (via a special system call) to write process accounting
 270           information to a file: whenever a process exits, information about
 271           that process will be appended to the file by the kernel.  The
 272           information includes things such as creation time, owning user,
 273           command name, memory usage, controlling terminal etc. (the complete
 274           list is in the struct acct in <file:include/linux/acct.h>).  It is
 275           up to the user level program to do useful things with this
 276           information.  This is generally a good idea, so say Y.
 277
 278 config BSD_PROCESS_ACCT_V3
 279         bool "BSD Process Accounting version 3 file format"
 280         depends on BSD_PROCESS_ACCT
 281         default n
 282         help
 283           If you say Y here, the process accounting information is written
 284           in a new file format that also logs the process IDs of each
 285           process and it's parent. Note that this file format is incompatible
 286           with previous v0/v1/v2 file formats, so you will need updated tools
 287           for processing it. A preliminary version of these tools is available
 288           at <http://www.gnu.org/software/acct/>.
 289
 290 config TASKSTATS
 291         bool "Export task/process statistics through netlink (EXPERIMENTAL)"
 292         depends on NET
 293         default n
 294         help
 295           Export selected statistics for tasks/processes through the
 296           generic netlink interface. Unlike BSD process accounting, the
 297           statistics are available during the lifetime of tasks/processes as
 298           responses to commands. Like BSD accounting, they are sent to user
 299           space on task exit.
 300
 301           Say N if unsure.
 302
 303 config TASK_DELAY_ACCT
 304         bool "Enable per-task delay accounting (EXPERIMENTAL)"
 305         depends on TASKSTATS
 306         help
 307           Collect information on time spent by a task waiting for system
 308           resources like cpu, synchronous block I/O completion and swapping
 309           in pages. Such statistics can help in setting a task's priorities
 310           relative to other tasks for cpu, io, rss limits etc.
 311
 312           Say N if unsure.
 313
 314 config TASK_XACCT
 315         bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
 316         depends on TASKSTATS
 317         help
 318           Collect extended task accounting data and send the data
 319           to userland for processing over the taskstats interface.
 320
 321           Say N if unsure.
 322
 323 config TASK_IO_ACCOUNTING
 324         bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
 325         depends on TASK_XACCT
 326         help
 327           Collect information on the number of bytes of storage I/O which this
 328           task has caused.
 329
 330           Say N if unsure.
 331
 332 config AUDIT
 333         bool "Auditing support"
 334         depends on NET
 335         help
 336           Enable auditing infrastructure that can be used with another
 337           kernel subsystem, such as SELinux (which requires this for
 338           logging of avc messages output).  Does not do system-call
 339           auditing without CONFIG_AUDITSYSCALL.
 340
 341 config AUDITSYSCALL
 342         bool "Enable system-call auditing support"
 343         depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH)
 344         default y if SECURITY_SELINUX
 345         help
 346           Enable low-overhead system-call auditing infrastructure that
 347           can be used independently or with another kernel subsystem,
 348           such as SELinux.
 349
 350 config AUDIT_WATCH
 351         def_bool y
 352         depends on AUDITSYSCALL
 353         select FSNOTIFY
 354
 355 config AUDIT_TREE
 356         def_bool y
 357         depends on AUDITSYSCALL
 358         select FSNOTIFY
 359
 360 source "kernel/irq/Kconfig"
 361
 362 menu "RCU Subsystem"
 363
 364 choice
 365         prompt "RCU Implementation"
 366         default TREE_RCU
 367
 368 config TREE_RCU
 369         bool "Tree-based hierarchical RCU"
 370         depends on !PREEMPT && SMP
 371         help
 372           This option selects the RCU implementation that is
 373           designed for very large SMP system with hundreds or
 374           thousands of CPUs.  It also scales down nicely to
 375           smaller systems.
 376
 377 config TREE_PREEMPT_RCU
 378         bool "Preemptible tree-based hierarchical RCU"
 379         depends on PREEMPT
 380         help
 381           This option selects the RCU implementation that is
 382           designed for very large SMP systems with hundreds or
 383           thousands of CPUs, but for which real-time response
 384           is also required.  It also scales down nicely to
 385           smaller systems.
 386
 387 config TINY_RCU
 388         bool "UP-only small-memory-footprint RCU"
 389         depends on !SMP
 390         help
 391           This option selects the RCU implementation that is
 392           designed for UP systems from which real-time response
 393           is not required.  This option greatly reduces the
 394           memory footprint of RCU.
 395
 396 config TINY_PREEMPT_RCU
 397         bool "Preemptible UP-only small-memory-footprint RCU"
 398         depends on !SMP && PREEMPT
 399         help
 400           This option selects the RCU implementation that is designed
 401           for real-time UP systems.  This option greatly reduces the
 402           memory footprint of RCU.
 403
 404 endchoice
 405
 406 config PREEMPT_RCU
 407         def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
 408         help
 409           This option enables preemptible-RCU code that is common between
 410           the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
 411
 412 config RCU_TRACE
 413         bool "Enable tracing for RCU"
 414         help
 415           This option provides tracing in RCU which presents stats
 416           in debugfs for debugging RCU implementation.
 417
 418           Say Y here if you want to enable RCU tracing
 419           Say N if you are unsure.
 420
 421 config RCU_FANOUT
 422         int "Tree-based hierarchical RCU fanout value"
 423         range 2 64 if 64BIT
 424         range 2 32 if !64BIT
 425         depends on TREE_RCU || TREE_PREEMPT_RCU
 426         default 64 if 64BIT
 427         default 32 if !64BIT
 428         help
 429           This option controls the fanout of hierarchical implementations
 430           of RCU, allowing RCU to work efficiently on machines with
 431           large numbers of CPUs.  This value must be at least the fourth
 432           root of NR_CPUS, which allows NR_CPUS to be insanely large.
 433           The default value of RCU_FANOUT should be used for production
 434           systems, but if you are stress-testing the RCU implementation
 435           itself, small RCU_FANOUT values allow you to test large-system
 436           code paths on small(er) systems.
 437
 438           Select a specific number if testing RCU itself.
 439           Take the default if unsure.
 440
 441 config RCU_FANOUT_EXACT
 442         bool "Disable tree-based hierarchical RCU auto-balancing"
 443         depends on TREE_RCU || TREE_PREEMPT_RCU
 444         default n
 445         help
 446           This option forces use of the exact RCU_FANOUT value specified,
 447           regardless of imbalances in the hierarchy.  This is useful for
 448           testing RCU itself, and might one day be useful on systems with
 449           strong NUMA behavior.
 450
 451           Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
 452
 453           Say N if unsure.
 454
 455 config RCU_FAST_NO_HZ
 456         bool "Accelerate last non-dyntick-idle CPU's grace periods"
 457         depends on TREE_RCU && NO_HZ && SMP
 458         default n
 459         help
 460           This option causes RCU to attempt to accelerate grace periods
 461           in order to allow the final CPU to enter dynticks-idle state
 462           more quickly.  On the other hand, this option increases the
 463           overhead of the dynticks-idle checking, particularly on systems
 464           with large numbers of CPUs.
 465
 466           Say Y if energy efficiency is critically important, particularly
 467                 if you have relatively few CPUs.
 468
 469           Say N if you are unsure.
 470
 471 config TREE_RCU_TRACE
 472         def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
 473         select DEBUG_FS
 474         help
 475           This option provides tracing for the TREE_RCU and
 476           TREE_PREEMPT_RCU implementations, permitting Makefile to
 477           trivially select kernel/rcutree_trace.c.
 478
 479 config RCU_BOOST
 480         bool "Enable RCU priority boosting"
 481         depends on RT_MUTEXES && TINY_PREEMPT_RCU
 482         default n
 483         help
 484           This option boosts the priority of preempted RCU readers that
 485           block the current preemptible RCU grace period for too long.
 486           This option also prevents heavy loads from blocking RCU
 487           callback invocation for all flavors of RCU.
 488
 489           Say Y here if you are working with real-time apps or heavy loads
 490           Say N here if you are unsure.
 491
 492 config RCU_BOOST_PRIO
 493         int "Real-time priority to boost RCU readers to"
 494         range 1 99
 495         depends on RCU_BOOST
 496         default 1
 497         help
 498           This option specifies the real-time priority to which preempted
 499           RCU readers are to be boosted.  If you are working with CPU-bound
 500           real-time applications, you should specify a priority higher then
 501           the highest-priority CPU-bound application.
 502
 503           Specify the real-time priority, or take the default if unsure.
 504
 505 config RCU_BOOST_DELAY
 506         int "Milliseconds to delay boosting after RCU grace-period start"
 507         range 0 3000
 508         depends on RCU_BOOST
 509         default 500
 510         help
 511           This option specifies the time to wait after the beginning of
 512           a given grace period before priority-boosting preempted RCU
 513           readers blocking that grace period.  Note that any RCU reader
 514           blocking an expedited RCU grace period is boosted immediately.
 515
 516           Accept the default if unsure.
 517
 518 endmenu # "RCU Subsystem"
 519
 520 config IKCONFIG
 521         tristate "Kernel .config support"
 522         ---help---
 523           This option enables the complete Linux kernel ".config" file
 524           contents to be saved in the kernel. It provides documentation
 525           of which kernel options are used in a running kernel or in an
 526           on-disk kernel.  This information can be extracted from the kernel
 527           image file with the script scripts/extract-ikconfig and used as
 528           input to rebuild the current kernel or to build another kernel.
 529           It can also be extracted from a running kernel by reading
 530           /proc/config.gz if enabled (below).
 531
 532 config IKCONFIG_PROC
 533         bool "Enable access to .config through /proc/config.gz"
 534         depends on IKCONFIG && PROC_FS
 535         ---help---
 536           This option enables access to the kernel configuration file
 537           through /proc/config.gz.
 538
 539 config LOG_BUF_SHIFT
 540         int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
 541         range 12 21
 542         default 17
 543         help
 544           Select kernel log buffer size as a power of 2.
 545           Examples:
 546                      17 => 128 KB
 547                      16 => 64 KB
 548                      15 => 32 KB
 549                      14 => 16 KB
 550                      13 =>  8 KB
 551                      12 =>  4 KB
 552
 553 #
 554 # Architectures with an unreliable sched_clock() should select this:
 555 #
 556 config HAVE_UNSTABLE_SCHED_CLOCK
 557         bool
 558
 559 menuconfig CGROUPS
 560         boolean "Control Group support"
 561         depends on EVENTFD
 562         help
 563           This option adds support for grouping sets of processes together, for
 564           use with process control subsystems such as Cpusets, CFS, memory
 565           controls or device isolation.
 566           See
 567                 - Documentation/scheduler/sched-design-CFS.txt  (CFS)
 568                 - Documentation/cgroups/ (features for grouping, isolation
 569                                           and resource control)
 570
 571           Say N if unsure.
 572
 573 if CGROUPS
 574
 575 config CGROUP_DEBUG
 576         bool "Example debug cgroup subsystem"
 577         default n
 578         help
 579           This option enables a simple cgroup subsystem that
 580           exports useful debugging information about the cgroups
 581           framework.
 582
 583           Say N if unsure.
 584
 585 config CGROUP_NS
 586         bool "Namespace cgroup subsystem"
 587         help
 588           Provides a simple namespace cgroup subsystem to
 589           provide hierarchical naming of sets of namespaces,
 590           for instance virtual servers and checkpoint/restart
 591           jobs.
 592
 593 config CGROUP_FREEZER
 594         bool "Freezer cgroup subsystem"
 595         help
 596           Provides a way to freeze and unfreeze all tasks in a
 597           cgroup.
 598
 599 config CGROUP_DEVICE
 600         bool "Device controller for cgroups"
 601         help
 602           Provides a cgroup implementing whitelists for devices which
 603           a process in the cgroup can mknod or open.
 604
 605 config CPUSETS
 606         bool "Cpuset support"
 607         help
 608           This option will let you create and manage CPUSETs which
 609           allow dynamically partitioning a system into sets of CPUs and
 610           Memory Nodes and assigning tasks to run only within those sets.
 611           This is primarily useful on large SMP or NUMA systems.
 612
 613           Say N if unsure.
 614
 615 config PROC_PID_CPUSET
 616         bool "Include legacy /proc/<pid>/cpuset file"
 617         depends on CPUSETS
 618         default y
 619
 620 config CGROUP_CPUACCT
 621         bool "Simple CPU accounting cgroup subsystem"
 622         help
 623           Provides a simple Resource Controller for monitoring the
 624           total CPU consumed by the tasks in a cgroup.
 625
 626 config RESOURCE_COUNTERS
 627         bool "Resource counters"
 628         help
 629           This option enables controller independent resource accounting
 630           infrastructure that works with cgroups.
 631
 632 config CGROUP_MEM_RES_CTLR
 633         bool "Memory Resource Controller for Control Groups"
 634         depends on RESOURCE_COUNTERS
 635         select MM_OWNER
 636         help
 637           Provides a memory resource controller that manages both anonymous
 638           memory and page cache. (See Documentation/cgroups/memory.txt)
 639
 640           Note that setting this option increases fixed memory overhead
 641           associated with each page of memory in the system. By this,
 642           20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
 643           usage tracking struct at boot. Total amount of this is printed out
 644           at boot.
 645
 646           Only enable when you're ok with these trade offs and really
 647           sure you need the memory resource controller. Even when you enable
 648           this, you can set "cgroup_disable=memory" at your boot option to
 649           disable memory resource controller and you can avoid overheads.
 650           (and lose benefits of memory resource controller)
 651
 652           This config option also selects MM_OWNER config option, which
 653           could in turn add some fork/exit overhead.
 654
 655 config CGROUP_MEM_RES_CTLR_SWAP
 656         bool "Memory Resource Controller Swap Extension"
 657         depends on CGROUP_MEM_RES_CTLR && SWAP
 658         help
 659           Add swap management feature to memory resource controller. When you
 660           enable this, you can limit mem+swap usage per cgroup. In other words,
 661           when you disable this, memory resource controller has no cares to
 662           usage of swap...a process can exhaust all of the swap. This extension
 663           is useful when you want to avoid exhaustion swap but this itself
 664           adds more overheads and consumes memory for remembering information.
 665           Especially if you use 32bit system or small memory system, please
 666           be careful about enabling this. When memory resource controller
 667           is disabled by boot option, this will be automatically disabled and
 668           there will be no overhead from this. Even when you set this config=y,
 669           if boot option "noswapaccount" is set, swap will not be accounted.
 670           Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
 671           size is 4096bytes, 512k per 1Gbytes of swap.
 672 config CGROUP_MEM_RES_CTLR_SWAP_ENABLED
 673         bool "Memory Resource Controller Swap Extension enabled by default"
 674         depends on CGROUP_MEM_RES_CTLR_SWAP
 675         default y
 676         help
 677           Memory Resource Controller Swap Extension comes with its price in
 678           a bigger memory consumption. General purpose distribution kernels
 679           which want to enable the feature but keep it disabled by default
 680           and let the user enable it by swapaccount boot command line
 681           parameter should have this option unselected.
 682           For those who want to have the feature enabled by default should
 683           select this option (if, for some reason, they need to disable it
 684           then noswapaccount does the trick).
 685
 686 config CGROUP_PERF
 687         bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
 688         depends on PERF_EVENTS && CGROUPS
 689         help
 690           This option extends the per-cpu mode to restrict monitoring to
 691           threads which belong to the cgroup specificied and run on the
 692           designated cpu.
 693
 694           Say N if unsure.
 695
 696 menuconfig CGROUP_SCHED
 697         bool "Group CPU scheduler"
 698         depends on EXPERIMENTAL
 699         default n
 700         help
 701           This feature lets CPU scheduler recognize task groups and control CPU
 702           bandwidth allocation to such task groups. It uses cgroups to group
 703           tasks.
 704
 705 if CGROUP_SCHED
 706 config FAIR_GROUP_SCHED
 707         bool "Group scheduling for SCHED_OTHER"
 708         depends on CGROUP_SCHED
 709         default CGROUP_SCHED
 710
 711 config RT_GROUP_SCHED
 712         bool "Group scheduling for SCHED_RR/FIFO"
 713         depends on EXPERIMENTAL
 714         depends on CGROUP_SCHED
 715         default n
 716         help
 717           This feature lets you explicitly allocate real CPU bandwidth
 718           to task groups. If enabled, it will also make it impossible to
 719           schedule realtime tasks for non-root users until you allocate
 720           realtime bandwidth for them.
 721           See Documentation/scheduler/sched-rt-group.txt for more information.
 722
 723 endif #CGROUP_SCHED
 724
 725 config BLK_CGROUP
 726         tristate "Block IO controller"
 727         depends on BLOCK
 728         default n
 729         ---help---
 730         Generic block IO controller cgroup interface. This is the common
 731         cgroup interface which should be used by various IO controlling
 732         policies.
 733
 734         Currently, CFQ IO scheduler uses it to recognize task groups and
 735         control disk bandwidth allocation (proportional time slice allocation)
 736         to such task groups. It is also used by bio throttling logic in
 737         block layer to implement upper limit in IO rates on a device.
 738
 739         This option only enables generic Block IO controller infrastructure.
 740         One needs to also enable actual IO controlling logic/policy. For
 741         enabling proportional weight division of disk bandwidth in CFQ seti
 742         CONFIG_CFQ_GROUP_IOSCHED=y and for enabling throttling policy set
 743         CONFIG_BLK_THROTTLE=y.
 744
 745         See Documentation/cgroups/blkio-controller.txt for more information.
 746
 747 config DEBUG_BLK_CGROUP
 748         bool "Enable Block IO controller debugging"
 749         depends on BLK_CGROUP
 750         default n
 751         ---help---
 752         Enable some debugging help. Currently it exports additional stat
 753         files in a cgroup which can be useful for debugging.
 754
 755 endif # CGROUPS
 756
 757 menuconfig NAMESPACES
 758         bool "Namespaces support" if EXPERT
 759         default !EXPERT
 760         help
 761           Provides the way to make tasks work with different objects using
 762           the same id. For example same IPC id may refer to different objects
 763           or same user id or pid may refer to different tasks when used in
 764           different namespaces.
 765
 766 if NAMESPACES
 767
 768 config UTS_NS
 769         bool "UTS namespace"
 770         default y
 771         help
 772           In this namespace tasks see different info provided with the
 773           uname() system call
 774
 775 config IPC_NS
 776         bool "IPC namespace"
 777         depends on (SYSVIPC || POSIX_MQUEUE)
 778         default y
 779         help
 780           In this namespace tasks work with IPC ids which correspond to
 781           different IPC objects in different namespaces.
 782
 783 config USER_NS
 784         bool "User namespace (EXPERIMENTAL)"
 785         depends on EXPERIMENTAL
 786         default y
 787         help
 788           This allows containers, i.e. vservers, to use user namespaces
 789           to provide different user info for different servers.
 790           If unsure, say N.
 791
 792 config PID_NS
 793         bool "PID Namespaces"
 794         default y
 795         help
 796           Support process id namespaces.  This allows having multiple
 797           processes with the same pid as long as they are in different
 798           pid namespaces.  This is a building block of containers.
 799
 800 config NET_NS
 801         bool "Network namespace"
 802         depends on NET
 803         default y
 804         help
 805           Allow user space to create what appear to be multiple instances
 806           of the network stack.
 807
 808 endif # NAMESPACES
 809
 810 config SCHED_AUTOGROUP
 811         bool "Automatic process group scheduling"
 812         select EVENTFD
 813         select CGROUPS
 814         select CGROUP_SCHED
 815         select FAIR_GROUP_SCHED
 816         help
 817           This option optimizes the scheduler for common desktop workloads by
 818           automatically creating and populating task groups.  This separation
 819           of workloads isolates aggressive CPU burners (like build jobs) from
 820           desktop applications.  Task group autogeneration is currently based
 821           upon task session.
 822
 823 config MM_OWNER
 824         bool
 825
 826 config SYSFS_DEPRECATED
 827         bool "enable deprecated sysfs features to support old userspace tools"
 828         depends on SYSFS
 829         default n
 830         help
 831           This option adds code that switches the layout of the "block" class
 832           devices, to not show up in /sys/class/block/, but only in
 833           /sys/block/.
 834
 835           This switch is only active when the sysfs.deprecated=1 boot option is
 836           passed or the SYSFS_DEPRECATED_V2 option is set.
 837
 838           This option allows new kernels to run on old distributions and tools,
 839           which might get confused by /sys/class/block/. Since 2007/2008 all
 840           major distributions and tools handle this just fine.
 841
 842           Recent distributions and userspace tools after 2009/2010 depend on
 843           the existence of /sys/class/block/, and will not work with this
 844           option enabled.
 845
 846           Only if you are using a new kernel on an old distribution, you might
 847           need to say Y here.
 848
 849 config SYSFS_DEPRECATED_V2
 850         bool "enabled deprecated sysfs features by default"
 851         default n
 852         depends on SYSFS
 853         depends on SYSFS_DEPRECATED
 854         help
 855           Enable deprecated sysfs by default.
 856
 857           See the CONFIG_SYSFS_DEPRECATED option for more details about this
 858           option.
 859
 860           Only if you are using a new kernel on an old distribution, you might
 861           need to say Y here. Even then, odds are you would not need it
 862           enabled, you can always pass the boot option if absolutely necessary.
 863
 864 config RELAY
 865         bool "Kernel->user space relay support (formerly relayfs)"
 866         help
 867           This option enables support for relay interface support in
 868           certain file systems (such as debugfs).
 869           It is designed to provide an efficient mechanism for tools and
 870           facilities to relay large amounts of data from kernel space to
 871           user space.
 872
 873           If unsure, say N.
 874
 875 config BLK_DEV_INITRD
 876         bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
 877         depends on BROKEN || !FRV
 878         help
 879           The initial RAM filesystem is a ramfs which is loaded by the
 880           boot loader (loadlin or lilo) and that is mounted as root
 881           before the normal boot procedure. It is typically used to
 882           load modules needed to mount the "real" root file system,
 883           etc. See <file:Documentation/initrd.txt> for details.
 884
 885           If RAM disk support (BLK_DEV_RAM) is also included, this
 886           also enables initial RAM disk (initrd) support and adds
 887           15 Kbytes (more on some other architectures) to the kernel size.
 888
 889           If unsure say Y.
 890
 891 if BLK_DEV_INITRD
 892
 893 source "usr/Kconfig"
 894
 895 endif
 896
 897 config CC_OPTIMIZE_FOR_SIZE
 898         bool "Optimize for size"
 899         default y
 900         help
 901           Enabling this option will pass "-Os" instead of "-O2" to gcc
 902           resulting in a smaller kernel.
 903
 904           If unsure, say Y.
 905
 906 config SYSCTL
 907         bool
 908
 909 config ANON_INODES
 910         bool
 911
 912 menuconfig EXPERT
 913         bool "Configure standard kernel features (expert users)"
 914         help
 915           This option allows certain base kernel options and settings
 916           to be disabled or tweaked. This is for specialized
 917           environments which can tolerate a "non-standard" kernel.
 918           Only use this if you really know what you are doing.
 919
 920 config EMBEDDED
 921         bool "Embedded system"
 922         select EXPERT
 923         help
 924           This option should be enabled if compiling the kernel for
 925           an embedded system so certain expert options are available
 926           for configuration.
 927
 928 config UID16
 929         bool "Enable 16-bit UID system calls" if EXPERT
 930         depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION)
 931         default y
 932         help
 933           This enables the legacy 16-bit UID syscall wrappers.
 934
 935 config SYSCTL_SYSCALL
 936         bool "Sysctl syscall support" if EXPERT
 937         depends on PROC_SYSCTL
 938         default y
 939         select SYSCTL
 940         ---help---
 941           sys_sysctl uses binary paths that have been found challenging
 942           to properly maintain and use.  The interface in /proc/sys
 943           using paths with ascii names is now the primary path to this
 944           information.
 945
 946           Almost nothing using the binary sysctl interface so if you are
 947           trying to save some space it is probably safe to disable this,
 948           making your kernel marginally smaller.
 949
 950           If unsure say Y here.
 951
 952 config KALLSYMS
 953          bool "Load all symbols for debugging/ksymoops" if EXPERT
 954          default y
 955          help
 956            Say Y here to let the kernel print out symbolic crash information and
 957            symbolic stack backtraces. This increases the size of the kernel
 958            somewhat, as all symbols have to be loaded into the kernel image.
 959
 960 config KALLSYMS_ALL
 961         bool "Include all symbols in kallsyms"
 962         depends on DEBUG_KERNEL && KALLSYMS
 963         help
 964            Normally kallsyms only contains the symbols of functions, for nicer
 965            OOPS messages.  Some debuggers can use kallsyms for other
 966            symbols too: say Y here to include all symbols, if you need them
 967            and you don't care about adding 300k to the size of your kernel.
 968
 969            Say N.
 970
 971 config KALLSYMS_EXTRA_PASS
 972         bool "Do an extra kallsyms pass"
 973         depends on KALLSYMS
 974         help
 975            If kallsyms is not working correctly, the build will fail with
 976            inconsistent kallsyms data.  If that occurs, log a bug report and
 977            turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
 978            Always say N here unless you find a bug in kallsyms, which must be
 979            reported.  KALLSYMS_EXTRA_PASS is only a temporary workaround while
 980            you wait for kallsyms to be fixed.
 981
 982
 983 config HOTPLUG
 984         bool "Support for hot-pluggable devices" if EXPERT
 985         default y
 986         help
 987           This option is provided for the case where no hotplug or uevent
 988           capabilities is wanted by the kernel.  You should only consider
 989           disabling this option for embedded systems that do not use modules, a
 990           dynamic /dev tree, or dynamic device discovery.  Just say Y.
 991
 992 config PRINTK
 993         default y
 994         bool "Enable support for printk" if EXPERT
 995         help
 996           This option enables normal printk support. Removing it
 997           eliminates most of the message strings from the kernel image
 998           and makes the kernel more or less silent. As this makes it
 999           very difficult to diagnose system problems, saying N here is
1000           strongly discouraged.
1001
1002 config BUG
1003         bool "BUG() support" if EXPERT
1004         default y
1005         help
1006           Disabling this option eliminates support for BUG and WARN, reducing
1007           the size of your kernel image and potentially quietly ignoring
1008           numerous fatal conditions. You should only consider disabling this
1009           option for embedded systems with no facilities for reporting errors.
1010           Just say Y.
1011
1012 config ELF_CORE
1013         default y
1014         bool "Enable ELF core dumps" if EXPERT
1015         help
1016           Enable support for generating core dumps. Disabling saves about 4k.
1017
1018 config PCSPKR_PLATFORM
1019         bool "Enable PC-Speaker support" if EXPERT
1020         depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES
1021         default y
1022         help
1023           This option allows to disable the internal PC-Speaker
1024           support, saving some memory.
1025
1026 config BASE_FULL
1027         default y
1028         bool "Enable full-sized data structures for core" if EXPERT
1029         help
1030           Disabling this option reduces the size of miscellaneous core
1031           kernel data structures. This saves memory on small machines,
1032           but may reduce performance.
1033
1034 config FUTEX
1035         bool "Enable futex support" if EXPERT
1036         default y
1037         select RT_MUTEXES
1038         help
1039           Disabling this option will cause the kernel to be built without
1040           support for "fast userspace mutexes".  The resulting kernel may not
1041           run glibc-based applications correctly.
1042
1043 config EPOLL
1044         bool "Enable eventpoll support" if EXPERT
1045         default y
1046         select ANON_INODES
1047         help
1048           Disabling this option will cause the kernel to be built without
1049           support for epoll family of system calls.
1050
1051 config SIGNALFD
1052         bool "Enable signalfd() system call" if EXPERT
1053         select ANON_INODES
1054         default y
1055         help
1056           Enable the signalfd() system call that allows to receive signals
1057           on a file descriptor.
1058
1059           If unsure, say Y.
1060
1061 config TIMERFD
1062         bool "Enable timerfd() system call" if EXPERT
1063         select ANON_INODES
1064         default y
1065         help
1066           Enable the timerfd() system call that allows to receive timer
1067           events on a file descriptor.
1068
1069           If unsure, say Y.
1070
1071 config EVENTFD
1072         bool "Enable eventfd() system call" if EXPERT
1073         select ANON_INODES
1074         default y
1075         help
1076           Enable the eventfd() system call that allows to receive both
1077           kernel notification (ie. KAIO) or userspace notifications.
1078
1079           If unsure, say Y.
1080
1081 config SHMEM
1082         bool "Use full shmem filesystem" if EXPERT
1083         default y
1084         depends on MMU
1085         help
1086           The shmem is an internal filesystem used to manage shared memory.
1087           It is backed by swap and manages resource limits. It is also exported
1088           to userspace as tmpfs if TMPFS is enabled. Disabling this
1089           option replaces shmem and tmpfs with the much simpler ramfs code,
1090           which may be appropriate on small systems without swap.
1091
1092 config AIO
1093         bool "Enable AIO support" if EXPERT
1094         default y
1095         help
1096           This option enables POSIX asynchronous I/O which may by used
1097           by some high performance threaded applications. Disabling
1098           this option saves about 7k.
1099
1100 config HAVE_PERF_EVENTS
1101         bool
1102         help
1103           See tools/perf/design.txt for details.
1104
1105 config PERF_USE_VMALLOC
1106         bool
1107         help
1108           See tools/perf/design.txt for details
1109
1110 menu "Kernel Performance Events And Counters"
1111
1112 config PERF_EVENTS
1113         bool "Kernel performance events and counters"
1114         default y if (PROFILING || PERF_COUNTERS)
1115         depends on HAVE_PERF_EVENTS
1116         select ANON_INODES
1117         select IRQ_WORK
1118         help
1119           Enable kernel support for various performance events provided
1120           by software and hardware.
1121
1122           Software events are supported either built-in or via the
1123           use of generic tracepoints.
1124
1125           Most modern CPUs support performance events via performance
1126           counter registers. These registers count the number of certain
1127           types of hw events: such as instructions executed, cachemisses
1128           suffered, or branches mis-predicted - without slowing down the
1129           kernel or applications. These registers can also trigger interrupts
1130           when a threshold number of events have passed - and can thus be
1131           used to profile the code that runs on that CPU.
1132
1133           The Linux Performance Event subsystem provides an abstraction of
1134           these software and hardware event capabilities, available via a
1135           system call and used by the "perf" utility in tools/perf/. It
1136           provides per task and per CPU counters, and it provides event
1137           capabilities on top of those.
1138
1139           Say Y if unsure.
1140
1141 config PERF_COUNTERS
1142         bool "Kernel performance counters (old config option)"
1143         depends on HAVE_PERF_EVENTS
1144         help
1145           This config has been obsoleted by the PERF_EVENTS
1146           config option - please see that one for details.
1147
1148           It has no effect on the kernel whether you enable
1149           it or not, it is a compatibility placeholder.
1150
1151           Say N if unsure.
1152
1153 config DEBUG_PERF_USE_VMALLOC
1154         default n
1155         bool "Debug: use vmalloc to back perf mmap() buffers"
1156         depends on PERF_EVENTS && DEBUG_KERNEL
1157         select PERF_USE_VMALLOC
1158         help
1159          Use vmalloc memory to back perf mmap() buffers.
1160
1161          Mostly useful for debugging the vmalloc code on platforms
1162          that don't require it.
1163
1164          Say N if unsure.
1165
1166 endmenu
1167
1168 config VM_EVENT_COUNTERS
1169         default y
1170         bool "Enable VM event counters for /proc/vmstat" if EXPERT
1171         help
1172           VM event counters are needed for event counts to be shown.
1173           This option allows the disabling of the VM event counters
1174           on EXPERT systems.  /proc/vmstat will only show page counts
1175           if VM event counters are disabled.
1176
1177 config PCI_QUIRKS
1178         default y
1179         bool "Enable PCI quirk workarounds" if EXPERT
1180         depends on PCI
1181         help
1182           This enables workarounds for various PCI chipset
1183           bugs/quirks. Disable this only if your target machine is
1184           unaffected by PCI quirks.
1185
1186 config SLUB_DEBUG
1187         default y
1188         bool "Enable SLUB debugging support" if EXPERT
1189         depends on SLUB && SYSFS
1190         help
1191           SLUB has extensive debug support features. Disabling these can
1192           result in significant savings in code size. This also disables
1193           SLUB sysfs support. /sys/slab will not exist and there will be
1194           no support for cache validation etc.
1195
1196 config COMPAT_BRK
1197         bool "Disable heap randomization"
1198         default y
1199         help
1200           Randomizing heap placement makes heap exploits harder, but it
1201           also breaks ancient binaries (including anything libc5 based).
1202           This option changes the bootup default to heap randomization
1203           disabled, and can be overridden at runtime by setting
1204           /proc/sys/kernel/randomize_va_space to 2.
1205
1206           On non-ancient distros (post-2000 ones) N is usually a safe choice.
1207
1208 choice
1209         prompt "Choose SLAB allocator"
1210         default SLUB
1211         help
1212            This option allows to select a slab allocator.
1213
1214 config SLAB
1215         bool "SLAB"
1216         help
1217           The regular slab allocator that is established and known to work
1218           well in all environments. It organizes cache hot objects in
1219           per cpu and per node queues.
1220
1221 config SLUB
1222         bool "SLUB (Unqueued Allocator)"
1223         help
1224            SLUB is a slab allocator that minimizes cache line usage
1225            instead of managing queues of cached objects (SLAB approach).
1226            Per cpu caching is realized using slabs of objects instead
1227            of queues of objects. SLUB can use memory efficiently
1228            and has enhanced diagnostics. SLUB is the default choice for
1229            a slab allocator.
1230
1231 config SLOB
1232         depends on EXPERT
1233         bool "SLOB (Simple Allocator)"
1234         help
1235            SLOB replaces the stock allocator with a drastically simpler
1236            allocator. SLOB is generally more space efficient but
1237            does not perform as well on large systems.
1238
1239 endchoice
1240
1241 config MMAP_ALLOW_UNINITIALIZED
1242         bool "Allow mmapped anonymous memory to be uninitialized"
1243         depends on EXPERT && !MMU
1244         default n
1245         help
1246           Normally, and according to the Linux spec, anonymous memory obtained
1247           from mmap() has it's contents cleared before it is passed to
1248           userspace.  Enabling this config option allows you to request that
1249           mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1250           providing a huge performance boost.  If this option is not enabled,
1251           then the flag will be ignored.
1252
1253           This is taken advantage of by uClibc's malloc(), and also by
1254           ELF-FDPIC binfmt's brk and stack allocator.
1255
1256           Because of the obvious security issues, this option should only be
1257           enabled on embedded devices where you control what is run in
1258           userspace.  Since that isn't generally a problem on no-MMU systems,
1259           it is normally safe to say Y here.
1260
1261           See Documentation/nommu-mmap.txt for more information.
1262
1263 config PROFILING
1264         bool "Profiling support"
1265         help
1266           Say Y here to enable the extended profiling support mechanisms used
1267           by profilers such as OProfile.
1268
1269 #
1270 # Place an empty function call at each tracepoint site. Can be
1271 # dynamically changed for a probe function.
1272 #
1273 config TRACEPOINTS
1274         bool
1275
1276 source "arch/Kconfig"
1277
1278 endmenu         # General setup
1279
1280 config HAVE_GENERIC_DMA_COHERENT
1281         bool
1282         default n
1283
1284 config SLABINFO
1285         bool
1286         depends on PROC_FS
1287         depends on SLAB || SLUB_DEBUG
1288         default y
1289
1290 config RT_MUTEXES
1291         boolean
1292
1293 config BASE_SMALL
1294         int
1295         default 0 if BASE_FULL
1296         default 1 if !BASE_FULL
1297
1298 menuconfig MODULES
1299         bool "Enable loadable module support"
1300         help
1301           Kernel modules are small pieces of compiled code which can
1302           be inserted in the running kernel, rather than being
1303           permanently built into the kernel.  You use the "modprobe"
1304           tool to add (and sometimes remove) them.  If you say Y here,
1305           many parts of the kernel can be built as modules (by
1306           answering M instead of Y where indicated): this is most
1307           useful for infrequently used options which are not required
1308           for booting.  For more information, see the man pages for
1309           modprobe, lsmod, modinfo, insmod and rmmod.
1310
1311           If you say Y here, you will need to run "make
1312           modules_install" to put the modules under /lib/modules/
1313           where modprobe can find them (you may need to be root to do
1314           this).
1315
1316           If unsure, say Y.
1317
1318 if MODULES
1319
1320 config MODULE_FORCE_LOAD
1321         bool "Forced module loading"
1322         default n
1323         help
1324           Allow loading of modules without version information (ie. modprobe
1325           --force).  Forced module loading sets the 'F' (forced) taint flag and
1326           is usually a really bad idea.
1327
1328 config MODULE_UNLOAD
1329         bool "Module unloading"
1330         help
1331           Without this option you will not be able to unload any
1332           modules (note that some modules may not be unloadable
1333           anyway), which makes your kernel smaller, faster
1334           and simpler.  If unsure, say Y.
1335
1336 config MODULE_FORCE_UNLOAD
1337         bool "Forced module unloading"
1338         depends on MODULE_UNLOAD && EXPERIMENTAL
1339         help
1340           This option allows you to force a module to unload, even if the
1341           kernel believes it is unsafe: the kernel will remove the module
1342           without waiting for anyone to stop using it (using the -f option to
1343           rmmod).  This is mainly for kernel developers and desperate users.
1344           If unsure, say N.
1345
1346 config MODVERSIONS
1347         bool "Module versioning support"
1348         help
1349           Usually, you have to use modules compiled with your kernel.
1350           Saying Y here makes it sometimes possible to use modules
1351           compiled for different kernels, by adding enough information
1352           to the modules to (hopefully) spot any changes which would
1353           make them incompatible with the kernel you are running.  If
1354           unsure, say N.
1355
1356 config MODULE_SRCVERSION_ALL
1357         bool "Source checksum for all modules"
1358         help
1359           Modules which contain a MODULE_VERSION get an extra "srcversion"
1360           field inserted into their modinfo section, which contains a
1361           sum of the source files which made it.  This helps maintainers
1362           see exactly which source was used to build a module (since
1363           others sometimes change the module source without updating
1364           the version).  With this option, such a "srcversion" field
1365           will be created for all modules.  If unsure, say N.
1366
1367 endif # MODULES
1368
1369 config INIT_ALL_POSSIBLE
1370         bool
1371         help
1372           Back when each arch used to define their own cpu_online_map and
1373           cpu_possible_map, some of them chose to initialize cpu_possible_map
1374           with all 1s, and others with all 0s.  When they were centralised,
1375           it was better to provide this option than to break all the archs
1376           and have several arch maintainers pursuing me down dark alleys.
1377
1378 config STOP_MACHINE
1379         bool
1380         default y
1381         depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1382         help
1383           Need stop_machine() primitive.
1384
1385 source "block/Kconfig"
1386
1387 config PREEMPT_NOTIFIERS
1388         bool
1389
1390 config PADATA
1391         depends on SMP
1392         bool
1393
1394 source "kernel/Kconfig.locks"