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
  23 config HAVE_IRQ_WORK
  24         bool
  25
  26 config IRQ_WORK
  27         bool
  28         depends on HAVE_IRQ_WORK
  29
  30 config BUILDTIME_EXTABLE_SORT
  31         bool
  32
  33 menu "General setup"
  34
  35 config EXPERIMENTAL
  36         bool "Prompt for development and/or incomplete code/drivers"
  37         ---help---
  38           Some of the various things that Linux supports (such as network
  39           drivers, file systems, network protocols, etc.) can be in a state
  40           of development where the functionality, stability, or the level of
  41           testing is not yet high enough for general use. This is usually
  42           known as the "alpha-test" phase among developers. If a feature is
  43           currently in alpha-test, then the developers usually discourage
  44           uninformed widespread use of this feature by the general public to
  45           avoid "Why doesn't this work?" type mail messages. However, active
  46           testing and use of these systems is welcomed. Just be aware that it
  47           may not meet the normal level of reliability or it may fail to work
  48           in some special cases. Detailed bug reports from people familiar
  49           with the kernel internals are usually welcomed by the developers
  50           (before submitting bug reports, please read the documents
  51           <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
  52           <file:Documentation/BUG-HUNTING>, and
  53           <file:Documentation/oops-tracing.txt> in the kernel source).
  54
  55           This option will also make obsoleted drivers available. These are
  56           drivers that have been replaced by something else, and/or are
  57           scheduled to be removed in a future kernel release.
  58
  59           Unless you intend to help test and develop a feature or driver that
  60           falls into this category, or you have a situation that requires
  61           using these features, you should probably say N here, which will
  62           cause the configurator to present you with fewer choices. If
  63           you say Y here, you will be offered the choice of using features or
  64           drivers that are currently considered to be in the alpha-test phase.
  65
  66 config BROKEN
  67         bool
  68
  69 config BROKEN_ON_SMP
  70         bool
  71         depends on BROKEN || !SMP
  72         default y
  73
  74 config INIT_ENV_ARG_LIMIT
  75         int
  76         default 32 if !UML
  77         default 128 if UML
  78         help
  79           Maximum of each of the number of arguments and environment
  80           variables passed to init from the kernel command line.
  81
  82
  83 config CROSS_COMPILE
  84         string "Cross-compiler tool prefix"
  85         help
  86           Same as running 'make CROSS_COMPILE=prefix-' but stored for
  87           default make runs in this kernel build directory.  You don't
  88           need to set this unless you want the configured kernel build
  89           directory to select the cross-compiler automatically.
  90
  91 config LOCALVERSION
  92         string "Local version - append to kernel release"
  93         help
  94           Append an extra string to the end of your kernel version.
  95           This will show up when you type uname, for example.
  96           The string you set here will be appended after the contents of
  97           any files with a filename matching localversion* in your
  98           object and source tree, in that order.  Your total string can
  99           be a maximum of 64 characters.
 100
 101 config LOCALVERSION_AUTO
 102         bool "Automatically append version information to the version string"
 103         default y
 104         help
 105           This will try to automatically determine if the current tree is a
 106           release tree by looking for git tags that belong to the current
 107           top of tree revision.
 108
 109           A string of the format -gxxxxxxxx will be added to the localversion
 110           if a git-based tree is found.  The string generated by this will be
 111           appended after any matching localversion* files, and after the value
 112           set in CONFIG_LOCALVERSION.
 113
 114           (The actual string used here is the first eight characters produced
 115           by running the command:
 116
 117             $ git rev-parse --verify HEAD
 118
 119           which is done within the script "scripts/setlocalversion".)
 120
 121 config HAVE_KERNEL_GZIP
 122         bool
 123
 124 config HAVE_KERNEL_BZIP2
 125         bool
 126
 127 config HAVE_KERNEL_LZMA
 128         bool
 129
 130 config HAVE_KERNEL_XZ
 131         bool
 132
 133 config HAVE_KERNEL_LZO
 134         bool
 135
 136 choice
 137         prompt "Kernel compression mode"
 138         default KERNEL_GZIP
 139         depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO
 140         help
 141           The linux kernel is a kind of self-extracting executable.
 142           Several compression algorithms are available, which differ
 143           in efficiency, compression and decompression speed.
 144           Compression speed is only relevant when building a kernel.
 145           Decompression speed is relevant at each boot.
 146
 147           If you have any problems with bzip2 or lzma compressed
 148           kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
 149           version of this functionality (bzip2 only), for 2.4, was
 150           supplied by Christian Ludwig)
 151
 152           High compression options are mostly useful for users, who
 153           are low on disk space (embedded systems), but for whom ram
 154           size matters less.
 155
 156           If in doubt, select 'gzip'
 157
 158 config KERNEL_GZIP
 159         bool "Gzip"
 160         depends on HAVE_KERNEL_GZIP
 161         help
 162           The old and tried gzip compression. It provides a good balance
 163           between compression ratio and decompression speed.
 164
 165 config KERNEL_BZIP2
 166         bool "Bzip2"
 167         depends on HAVE_KERNEL_BZIP2
 168         help
 169           Its compression ratio and speed is intermediate.
 170           Decompression speed is slowest among the three.  The kernel
 171           size is about 10% smaller with bzip2, in comparison to gzip.
 172           Bzip2 uses a large amount of memory. For modern kernels you
 173           will need at least 8MB RAM or more for booting.
 174
 175 config KERNEL_LZMA
 176         bool "LZMA"
 177         depends on HAVE_KERNEL_LZMA
 178         help
 179           The most recent compression algorithm.
 180           Its ratio is best, decompression speed is between the other
 181           two. Compression is slowest.  The kernel size is about 33%
 182           smaller with LZMA in comparison to gzip.
 183
 184 config KERNEL_XZ
 185         bool "XZ"
 186         depends on HAVE_KERNEL_XZ
 187         help
 188           XZ uses the LZMA2 algorithm and instruction set specific
 189           BCJ filters which can improve compression ratio of executable
 190           code. The size of the kernel is about 30% smaller with XZ in
 191           comparison to gzip. On architectures for which there is a BCJ
 192           filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
 193           will create a few percent smaller kernel than plain LZMA.
 194
 195           The speed is about the same as with LZMA: The decompression
 196           speed of XZ is better than that of bzip2 but worse than gzip
 197           and LZO. Compression is slow.
 198
 199 config KERNEL_LZO
 200         bool "LZO"
 201         depends on HAVE_KERNEL_LZO
 202         help
 203           Its compression ratio is the poorest among the 4. The kernel
 204           size is about 10% bigger than gzip; however its speed
 205           (both compression and decompression) is the fastest.
 206
 207 endchoice
 208
 209 config DEFAULT_HOSTNAME
 210         string "Default hostname"
 211         default "(none)"
 212         help
 213           This option determines the default system hostname before userspace
 214           calls sethostname(2). The kernel traditionally uses "(none)" here,
 215           but you may wish to use a different default here to make a minimal
 216           system more usable with less configuration.
 217
 218 config SWAP
 219         bool "Support for paging of anonymous memory (swap)"
 220         depends on MMU && BLOCK
 221         default y
 222         help
 223           This option allows you to choose whether you want to have support
 224           for so called swap devices or swap files in your kernel that are
 225           used to provide more virtual memory than the actual RAM present
 226           in your computer.  If unsure say Y.
 227
 228 config SYSVIPC
 229         bool "System V IPC"
 230         ---help---
 231           Inter Process Communication is a suite of library functions and
 232           system calls which let processes (running programs) synchronize and
 233           exchange information. It is generally considered to be a good thing,
 234           and some programs won't run unless you say Y here. In particular, if
 235           you want to run the DOS emulator dosemu under Linux (read the
 236           DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
 237           you'll need to say Y here.
 238
 239           You can find documentation about IPC with "info ipc" and also in
 240           section 6.4 of the Linux Programmer's Guide, available from
 241           <http://www.tldp.org/guides.html>.
 242
 243 config SYSVIPC_SYSCTL
 244         bool
 245         depends on SYSVIPC
 246         depends on SYSCTL
 247         default y
 248
 249 config POSIX_MQUEUE
 250         bool "POSIX Message Queues"
 251         depends on NET && EXPERIMENTAL
 252         ---help---
 253           POSIX variant of message queues is a part of IPC. In POSIX message
 254           queues every message has a priority which decides about succession
 255           of receiving it by a process. If you want to compile and run
 256           programs written e.g. for Solaris with use of its POSIX message
 257           queues (functions mq_*) say Y here.
 258
 259           POSIX message queues are visible as a filesystem called 'mqueue'
 260           and can be mounted somewhere if you want to do filesystem
 261           operations on message queues.
 262
 263           If unsure, say Y.
 264
 265 config POSIX_MQUEUE_SYSCTL
 266         bool
 267         depends on POSIX_MQUEUE
 268         depends on SYSCTL
 269         default y
 270
 271 config BSD_PROCESS_ACCT
 272         bool "BSD Process Accounting"
 273         help
 274           If you say Y here, a user level program will be able to instruct the
 275           kernel (via a special system call) to write process accounting
 276           information to a file: whenever a process exits, information about
 277           that process will be appended to the file by the kernel.  The
 278           information includes things such as creation time, owning user,
 279           command name, memory usage, controlling terminal etc. (the complete
 280           list is in the struct acct in <file:include/linux/acct.h>).  It is
 281           up to the user level program to do useful things with this
 282           information.  This is generally a good idea, so say Y.
 283
 284 config BSD_PROCESS_ACCT_V3
 285         bool "BSD Process Accounting version 3 file format"
 286         depends on BSD_PROCESS_ACCT
 287         default n
 288         help
 289           If you say Y here, the process accounting information is written
 290           in a new file format that also logs the process IDs of each
 291           process and it's parent. Note that this file format is incompatible
 292           with previous v0/v1/v2 file formats, so you will need updated tools
 293           for processing it. A preliminary version of these tools is available
 294           at <http://www.gnu.org/software/acct/>.
 295
 296 config FHANDLE
 297         bool "open by fhandle syscalls"
 298         select EXPORTFS
 299         help
 300           If you say Y here, a user level program will be able to map
 301           file names to handle and then later use the handle for
 302           different file system operations. This is useful in implementing
 303           userspace file servers, which now track files using handles instead
 304           of names. The handle would remain the same even if file names
 305           get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
 306           syscalls.
 307
 308 config TASKSTATS
 309         bool "Export task/process statistics through netlink (EXPERIMENTAL)"
 310         depends on NET
 311         default n
 312         help
 313           Export selected statistics for tasks/processes through the
 314           generic netlink interface. Unlike BSD process accounting, the
 315           statistics are available during the lifetime of tasks/processes as
 316           responses to commands. Like BSD accounting, they are sent to user
 317           space on task exit.
 318
 319           Say N if unsure.
 320
 321 config TASK_DELAY_ACCT
 322         bool "Enable per-task delay accounting (EXPERIMENTAL)"
 323         depends on TASKSTATS
 324         help
 325           Collect information on time spent by a task waiting for system
 326           resources like cpu, synchronous block I/O completion and swapping
 327           in pages. Such statistics can help in setting a task's priorities
 328           relative to other tasks for cpu, io, rss limits etc.
 329
 330           Say N if unsure.
 331
 332 config TASK_XACCT
 333         bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
 334         depends on TASKSTATS
 335         help
 336           Collect extended task accounting data and send the data
 337           to userland for processing over the taskstats interface.
 338
 339           Say N if unsure.
 340
 341 config TASK_IO_ACCOUNTING
 342         bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
 343         depends on TASK_XACCT
 344         help
 345           Collect information on the number of bytes of storage I/O which this
 346           task has caused.
 347
 348           Say N if unsure.
 349
 350 config AUDIT
 351         bool "Auditing support"
 352         depends on NET
 353         help
 354           Enable auditing infrastructure that can be used with another
 355           kernel subsystem, such as SELinux (which requires this for
 356           logging of avc messages output).  Does not do system-call
 357           auditing without CONFIG_AUDITSYSCALL.
 358
 359 config AUDITSYSCALL
 360         bool "Enable system-call auditing support"
 361         depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH || ARM)
 362         default y if SECURITY_SELINUX
 363         help
 364           Enable low-overhead system-call auditing infrastructure that
 365           can be used independently or with another kernel subsystem,
 366           such as SELinux.
 367
 368 config AUDIT_WATCH
 369         def_bool y
 370         depends on AUDITSYSCALL
 371         select FSNOTIFY
 372
 373 config AUDIT_TREE
 374         def_bool y
 375         depends on AUDITSYSCALL
 376         select FSNOTIFY
 377
 378 config AUDIT_LOGINUID_IMMUTABLE
 379         bool "Make audit loginuid immutable"
 380         depends on AUDIT
 381         help
 382           The config option toggles if a task setting its loginuid requires
 383           CAP_SYS_AUDITCONTROL or if that task should require no special permissions
 384           but should instead only allow setting its loginuid if it was never
 385           previously set.  On systems which use systemd or a similar central
 386           process to restart login services this should be set to true.  On older
 387           systems in which an admin would typically have to directly stop and
 388           start processes this should be set to false.  Setting this to true allows
 389           one to drop potentially dangerous capabilites from the login tasks,
 390           but may not be backwards compatible with older init systems.
 391
 392 source "kernel/irq/Kconfig"
 393
 394 menu "RCU Subsystem"
 395
 396 choice
 397         prompt "RCU Implementation"
 398         default TREE_RCU
 399
 400 config TREE_RCU
 401         bool "Tree-based hierarchical RCU"
 402         depends on !PREEMPT && SMP
 403         help
 404           This option selects the RCU implementation that is
 405           designed for very large SMP system with hundreds or
 406           thousands of CPUs.  It also scales down nicely to
 407           smaller systems.
 408
 409 config TREE_PREEMPT_RCU
 410         bool "Preemptible tree-based hierarchical RCU"
 411         depends on PREEMPT && SMP
 412         help
 413           This option selects the RCU implementation that is
 414           designed for very large SMP systems with hundreds or
 415           thousands of CPUs, but for which real-time response
 416           is also required.  It also scales down nicely to
 417           smaller systems.
 418
 419 config TINY_RCU
 420         bool "UP-only small-memory-footprint RCU"
 421         depends on !PREEMPT && !SMP
 422         help
 423           This option selects the RCU implementation that is
 424           designed for UP systems from which real-time response
 425           is not required.  This option greatly reduces the
 426           memory footprint of RCU.
 427
 428 config TINY_PREEMPT_RCU
 429         bool "Preemptible UP-only small-memory-footprint RCU"
 430         depends on PREEMPT && !SMP
 431         help
 432           This option selects the RCU implementation that is designed
 433           for real-time UP systems.  This option greatly reduces the
 434           memory footprint of RCU.
 435
 436 endchoice
 437
 438 config PREEMPT_RCU
 439         def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
 440         help
 441           This option enables preemptible-RCU code that is common between
 442           the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
 443
 444 config RCU_FANOUT
 445         int "Tree-based hierarchical RCU fanout value"
 446         range 2 64 if 64BIT
 447         range 2 32 if !64BIT
 448         depends on TREE_RCU || TREE_PREEMPT_RCU
 449         default 64 if 64BIT
 450         default 32 if !64BIT
 451         help
 452           This option controls the fanout of hierarchical implementations
 453           of RCU, allowing RCU to work efficiently on machines with
 454           large numbers of CPUs.  This value must be at least the fourth
 455           root of NR_CPUS, which allows NR_CPUS to be insanely large.
 456           The default value of RCU_FANOUT should be used for production
 457           systems, but if you are stress-testing the RCU implementation
 458           itself, small RCU_FANOUT values allow you to test large-system
 459           code paths on small(er) systems.
 460
 461           Select a specific number if testing RCU itself.
 462           Take the default if unsure.
 463
 464 config RCU_FANOUT_LEAF
 465         int "Tree-based hierarchical RCU leaf-level fanout value"
 466         range 2 RCU_FANOUT if 64BIT
 467         range 2 RCU_FANOUT if !64BIT
 468         depends on TREE_RCU || TREE_PREEMPT_RCU
 469         default 16
 470         help
 471           This option controls the leaf-level fanout of hierarchical
 472           implementations of RCU, and allows trading off cache misses
 473           against lock contention.  Systems that synchronize their
 474           scheduling-clock interrupts for energy-efficiency reasons will
 475           want the default because the smaller leaf-level fanout keeps
 476           lock contention levels acceptably low.  Very large systems
 477           (hundreds or thousands of CPUs) will instead want to set this
 478           value to the maximum value possible in order to reduce the
 479           number of cache misses incurred during RCU's grace-period
 480           initialization.  These systems tend to run CPU-bound, and thus
 481           are not helped by synchronized interrupts, and thus tend to
 482           skew them, which reduces lock contention enough that large
 483           leaf-level fanouts work well.
 484
 485           Select a specific number if testing RCU itself.
 486
 487           Select the maximum permissible value for large systems.
 488
 489           Take the default if unsure.
 490
 491 config RCU_FANOUT_EXACT
 492         bool "Disable tree-based hierarchical RCU auto-balancing"
 493         depends on TREE_RCU || TREE_PREEMPT_RCU
 494         default n
 495         help
 496           This option forces use of the exact RCU_FANOUT value specified,
 497           regardless of imbalances in the hierarchy.  This is useful for
 498           testing RCU itself, and might one day be useful on systems with
 499           strong NUMA behavior.
 500
 501           Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
 502
 503           Say N if unsure.
 504
 505 config RCU_FAST_NO_HZ
 506         bool "Accelerate last non-dyntick-idle CPU's grace periods"
 507         depends on NO_HZ && SMP
 508         default n
 509         help
 510           This option causes RCU to attempt to accelerate grace periods
 511           in order to allow CPUs to enter dynticks-idle state more
 512           quickly.  On the other hand, this option increases the overhead
 513           of the dynticks-idle checking, particularly on systems with
 514           large numbers of CPUs.
 515
 516           Say Y if energy efficiency is critically important, particularly
 517                 if you have relatively few CPUs.
 518
 519           Say N if you are unsure.
 520
 521 config TREE_RCU_TRACE
 522         def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
 523         select DEBUG_FS
 524         help
 525           This option provides tracing for the TREE_RCU and
 526           TREE_PREEMPT_RCU implementations, permitting Makefile to
 527           trivially select kernel/rcutree_trace.c.
 528
 529 config RCU_BOOST
 530         bool "Enable RCU priority boosting"
 531         depends on RT_MUTEXES && PREEMPT_RCU
 532         default n
 533         help
 534           This option boosts the priority of preempted RCU readers that
 535           block the current preemptible RCU grace period for too long.
 536           This option also prevents heavy loads from blocking RCU
 537           callback invocation for all flavors of RCU.
 538
 539           Say Y here if you are working with real-time apps or heavy loads
 540           Say N here if you are unsure.
 541
 542 config RCU_BOOST_PRIO
 543         int "Real-time priority to boost RCU readers to"
 544         range 1 99
 545         depends on RCU_BOOST
 546         default 1
 547         help
 548           This option specifies the real-time priority to which long-term
 549           preempted RCU readers are to be boosted.  If you are working
 550           with a real-time application that has one or more CPU-bound
 551           threads running at a real-time priority level, you should set
 552           RCU_BOOST_PRIO to a priority higher then the highest-priority
 553           real-time CPU-bound thread.  The default RCU_BOOST_PRIO value
 554           of 1 is appropriate in the common case, which is real-time
 555           applications that do not have any CPU-bound threads.
 556
 557           Some real-time applications might not have a single real-time
 558           thread that saturates a given CPU, but instead might have
 559           multiple real-time threads that, taken together, fully utilize
 560           that CPU.  In this case, you should set RCU_BOOST_PRIO to
 561           a priority higher than the lowest-priority thread that is
 562           conspiring to prevent the CPU from running any non-real-time
 563           tasks.  For example, if one thread at priority 10 and another
 564           thread at priority 5 are between themselves fully consuming
 565           the CPU time on a given CPU, then RCU_BOOST_PRIO should be
 566           set to priority 6 or higher.
 567
 568           Specify the real-time priority, or take the default if unsure.
 569
 570 config RCU_BOOST_DELAY
 571         int "Milliseconds to delay boosting after RCU grace-period start"
 572         range 0 3000
 573         depends on RCU_BOOST
 574         default 500
 575         help
 576           This option specifies the time to wait after the beginning of
 577           a given grace period before priority-boosting preempted RCU
 578           readers blocking that grace period.  Note that any RCU reader
 579           blocking an expedited RCU grace period is boosted immediately.
 580
 581           Accept the default if unsure.
 582
 583 endmenu # "RCU Subsystem"
 584
 585 config IKCONFIG
 586         tristate "Kernel .config support"
 587         ---help---
 588           This option enables the complete Linux kernel ".config" file
 589           contents to be saved in the kernel. It provides documentation
 590           of which kernel options are used in a running kernel or in an
 591           on-disk kernel.  This information can be extracted from the kernel
 592           image file with the script scripts/extract-ikconfig and used as
 593           input to rebuild the current kernel or to build another kernel.
 594           It can also be extracted from a running kernel by reading
 595           /proc/config.gz if enabled (below).
 596
 597 config IKCONFIG_PROC
 598         bool "Enable access to .config through /proc/config.gz"
 599         depends on IKCONFIG && PROC_FS
 600         ---help---
 601           This option enables access to the kernel configuration file
 602           through /proc/config.gz.
 603
 604 config LOG_BUF_SHIFT
 605         int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
 606         range 12 21
 607         default 17
 608         help
 609           Select kernel log buffer size as a power of 2.
 610           Examples:
 611                      17 => 128 KB
 612                      16 => 64 KB
 613                      15 => 32 KB
 614                      14 => 16 KB
 615                      13 =>  8 KB
 616                      12 =>  4 KB
 617
 618 #
 619 # Architectures with an unreliable sched_clock() should select this:
 620 #
 621 config HAVE_UNSTABLE_SCHED_CLOCK
 622         bool
 623
 624 menuconfig CGROUPS
 625         boolean "Control Group support"
 626         depends on EVENTFD
 627         help
 628           This option adds support for grouping sets of processes together, for
 629           use with process control subsystems such as Cpusets, CFS, memory
 630           controls or device isolation.
 631           See
 632                 - Documentation/scheduler/sched-design-CFS.txt  (CFS)
 633                 - Documentation/cgroups/ (features for grouping, isolation
 634                                           and resource control)
 635
 636           Say N if unsure.
 637
 638 if CGROUPS
 639
 640 config CGROUP_DEBUG
 641         bool "Example debug cgroup subsystem"
 642         default n
 643         help
 644           This option enables a simple cgroup subsystem that
 645           exports useful debugging information about the cgroups
 646           framework.
 647
 648           Say N if unsure.
 649
 650 config CGROUP_FREEZER
 651         bool "Freezer cgroup subsystem"
 652         help
 653           Provides a way to freeze and unfreeze all tasks in a
 654           cgroup.
 655
 656 config CGROUP_DEVICE
 657         bool "Device controller for cgroups"
 658         help
 659           Provides a cgroup implementing whitelists for devices which
 660           a process in the cgroup can mknod or open.
 661
 662 config CPUSETS
 663         bool "Cpuset support"
 664         help
 665           This option will let you create and manage CPUSETs which
 666           allow dynamically partitioning a system into sets of CPUs and
 667           Memory Nodes and assigning tasks to run only within those sets.
 668           This is primarily useful on large SMP or NUMA systems.
 669
 670           Say N if unsure.
 671
 672 config PROC_PID_CPUSET
 673         bool "Include legacy /proc/<pid>/cpuset file"
 674         depends on CPUSETS
 675         default y
 676
 677 config CGROUP_CPUACCT
 678         bool "Simple CPU accounting cgroup subsystem"
 679         help
 680           Provides a simple Resource Controller for monitoring the
 681           total CPU consumed by the tasks in a cgroup.
 682
 683 config RESOURCE_COUNTERS
 684         bool "Resource counters"
 685         help
 686           This option enables controller independent resource accounting
 687           infrastructure that works with cgroups.
 688
 689 config CGROUP_MEM_RES_CTLR
 690         bool "Memory Resource Controller for Control Groups"
 691         depends on RESOURCE_COUNTERS
 692         select MM_OWNER
 693         help
 694           Provides a memory resource controller that manages both anonymous
 695           memory and page cache. (See Documentation/cgroups/memory.txt)
 696
 697           Note that setting this option increases fixed memory overhead
 698           associated with each page of memory in the system. By this,
 699           20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
 700           usage tracking struct at boot. Total amount of this is printed out
 701           at boot.
 702
 703           Only enable when you're ok with these trade offs and really
 704           sure you need the memory resource controller. Even when you enable
 705           this, you can set "cgroup_disable=memory" at your boot option to
 706           disable memory resource controller and you can avoid overheads.
 707           (and lose benefits of memory resource controller)
 708
 709           This config option also selects MM_OWNER config option, which
 710           could in turn add some fork/exit overhead.
 711
 712 config CGROUP_MEM_RES_CTLR_SWAP
 713         bool "Memory Resource Controller Swap Extension"
 714         depends on CGROUP_MEM_RES_CTLR && SWAP
 715         help
 716           Add swap management feature to memory resource controller. When you
 717           enable this, you can limit mem+swap usage per cgroup. In other words,
 718           when you disable this, memory resource controller has no cares to
 719           usage of swap...a process can exhaust all of the swap. This extension
 720           is useful when you want to avoid exhaustion swap but this itself
 721           adds more overheads and consumes memory for remembering information.
 722           Especially if you use 32bit system or small memory system, please
 723           be careful about enabling this. When memory resource controller
 724           is disabled by boot option, this will be automatically disabled and
 725           there will be no overhead from this. Even when you set this config=y,
 726           if boot option "swapaccount=0" is set, swap will not be accounted.
 727           Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
 728           size is 4096bytes, 512k per 1Gbytes of swap.
 729 config CGROUP_MEM_RES_CTLR_SWAP_ENABLED
 730         bool "Memory Resource Controller Swap Extension enabled by default"
 731         depends on CGROUP_MEM_RES_CTLR_SWAP
 732         default y
 733         help
 734           Memory Resource Controller Swap Extension comes with its price in
 735           a bigger memory consumption. General purpose distribution kernels
 736           which want to enable the feature but keep it disabled by default
 737           and let the user enable it by swapaccount boot command line
 738           parameter should have this option unselected.
 739           For those who want to have the feature enabled by default should
 740           select this option (if, for some reason, they need to disable it
 741           then swapaccount=0 does the trick).
 742 config CGROUP_MEM_RES_CTLR_KMEM
 743         bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
 744         depends on CGROUP_MEM_RES_CTLR && EXPERIMENTAL
 745         default n
 746         help
 747           The Kernel Memory extension for Memory Resource Controller can limit
 748           the amount of memory used by kernel objects in the system. Those are
 749           fundamentally different from the entities handled by the standard
 750           Memory Controller, which are page-based, and can be swapped. Users of
 751           the kmem extension can use it to guarantee that no group of processes
 752           will ever exhaust kernel resources alone.
 753
 754 config CGROUP_PERF
 755         bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
 756         depends on PERF_EVENTS && CGROUPS
 757         help
 758           This option extends the per-cpu mode to restrict monitoring to
 759           threads which belong to the cgroup specified and run on the
 760           designated cpu.
 761
 762           Say N if unsure.
 763
 764 menuconfig CGROUP_SCHED
 765         bool "Group CPU scheduler"
 766         default n
 767         help
 768           This feature lets CPU scheduler recognize task groups and control CPU
 769           bandwidth allocation to such task groups. It uses cgroups to group
 770           tasks.
 771
 772 if CGROUP_SCHED
 773 config FAIR_GROUP_SCHED
 774         bool "Group scheduling for SCHED_OTHER"
 775         depends on CGROUP_SCHED
 776         default CGROUP_SCHED
 777
 778 config CFS_BANDWIDTH
 779         bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
 780         depends on EXPERIMENTAL
 781         depends on FAIR_GROUP_SCHED
 782         default n
 783         help
 784           This option allows users to define CPU bandwidth rates (limits) for
 785           tasks running within the fair group scheduler.  Groups with no limit
 786           set are considered to be unconstrained and will run with no
 787           restriction.
 788           See tip/Documentation/scheduler/sched-bwc.txt for more information.
 789
 790 config RT_GROUP_SCHED
 791         bool "Group scheduling for SCHED_RR/FIFO"
 792         depends on EXPERIMENTAL
 793         depends on CGROUP_SCHED
 794         default n
 795         help
 796           This feature lets you explicitly allocate real CPU bandwidth
 797           to task groups. If enabled, it will also make it impossible to
 798           schedule realtime tasks for non-root users until you allocate
 799           realtime bandwidth for them.
 800           See Documentation/scheduler/sched-rt-group.txt for more information.
 801
 802 endif #CGROUP_SCHED
 803
 804 config BLK_CGROUP
 805         tristate "Block IO controller"
 806         depends on BLOCK
 807         default n
 808         ---help---
 809         Generic block IO controller cgroup interface. This is the common
 810         cgroup interface which should be used by various IO controlling
 811         policies.
 812
 813         Currently, CFQ IO scheduler uses it to recognize task groups and
 814         control disk bandwidth allocation (proportional time slice allocation)
 815         to such task groups. It is also used by bio throttling logic in
 816         block layer to implement upper limit in IO rates on a device.
 817
 818         This option only enables generic Block IO controller infrastructure.
 819         One needs to also enable actual IO controlling logic/policy. For
 820         enabling proportional weight division of disk bandwidth in CFQ, set
 821         CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
 822         CONFIG_BLK_DEV_THROTTLING=y.
 823
 824         See Documentation/cgroups/blkio-controller.txt for more information.
 825
 826 config DEBUG_BLK_CGROUP
 827         bool "Enable Block IO controller debugging"
 828         depends on BLK_CGROUP
 829         default n
 830         ---help---
 831         Enable some debugging help. Currently it exports additional stat
 832         files in a cgroup which can be useful for debugging.
 833
 834 endif # CGROUPS
 835
 836 config CHECKPOINT_RESTORE
 837         bool "Checkpoint/restore support" if EXPERT
 838         default n
 839         help
 840           Enables additional kernel features in a sake of checkpoint/restore.
 841           In particular it adds auxiliary prctl codes to setup process text,
 842           data and heap segment sizes, and a few additional /proc filesystem
 843           entries.
 844
 845           If unsure, say N here.
 846
 847 menuconfig NAMESPACES
 848         bool "Namespaces support" if EXPERT
 849         default !EXPERT
 850         help
 851           Provides the way to make tasks work with different objects using
 852           the same id. For example same IPC id may refer to different objects
 853           or same user id or pid may refer to different tasks when used in
 854           different namespaces.
 855
 856 if NAMESPACES
 857
 858 config UTS_NS
 859         bool "UTS namespace"
 860         default y
 861         help
 862           In this namespace tasks see different info provided with the
 863           uname() system call
 864
 865 config IPC_NS
 866         bool "IPC namespace"
 867         depends on (SYSVIPC || POSIX_MQUEUE)
 868         default y
 869         help
 870           In this namespace tasks work with IPC ids which correspond to
 871           different IPC objects in different namespaces.
 872
 873 config USER_NS
 874         bool "User namespace (EXPERIMENTAL)"
 875         depends on EXPERIMENTAL
 876         default y
 877         help
 878           This allows containers, i.e. vservers, to use user namespaces
 879           to provide different user info for different servers.
 880           If unsure, say N.
 881
 882 config PID_NS
 883         bool "PID Namespaces"
 884         default y
 885         help
 886           Support process id namespaces.  This allows having multiple
 887           processes with the same pid as long as they are in different
 888           pid namespaces.  This is a building block of containers.
 889
 890 config NET_NS
 891         bool "Network namespace"
 892         depends on NET
 893         default y
 894         help
 895           Allow user space to create what appear to be multiple instances
 896           of the network stack.
 897
 898 endif # NAMESPACES
 899
 900 config SCHED_AUTOGROUP
 901         bool "Automatic process group scheduling"
 902         select EVENTFD
 903         select CGROUPS
 904         select CGROUP_SCHED
 905         select FAIR_GROUP_SCHED
 906         help
 907           This option optimizes the scheduler for common desktop workloads by
 908           automatically creating and populating task groups.  This separation
 909           of workloads isolates aggressive CPU burners (like build jobs) from
 910           desktop applications.  Task group autogeneration is currently based
 911           upon task session.
 912
 913 config MM_OWNER
 914         bool
 915
 916 config SYSFS_DEPRECATED
 917         bool "Enable deprecated sysfs features to support old userspace tools"
 918         depends on SYSFS
 919         default n
 920         help
 921           This option adds code that switches the layout of the "block" class
 922           devices, to not show up in /sys/class/block/, but only in
 923           /sys/block/.
 924
 925           This switch is only active when the sysfs.deprecated=1 boot option is
 926           passed or the SYSFS_DEPRECATED_V2 option is set.
 927
 928           This option allows new kernels to run on old distributions and tools,
 929           which might get confused by /sys/class/block/. Since 2007/2008 all
 930           major distributions and tools handle this just fine.
 931
 932           Recent distributions and userspace tools after 2009/2010 depend on
 933           the existence of /sys/class/block/, and will not work with this
 934           option enabled.
 935
 936           Only if you are using a new kernel on an old distribution, you might
 937           need to say Y here.
 938
 939 config SYSFS_DEPRECATED_V2
 940         bool "Enable deprecated sysfs features by default"
 941         default n
 942         depends on SYSFS
 943         depends on SYSFS_DEPRECATED
 944         help
 945           Enable deprecated sysfs by default.
 946
 947           See the CONFIG_SYSFS_DEPRECATED option for more details about this
 948           option.
 949
 950           Only if you are using a new kernel on an old distribution, you might
 951           need to say Y here. Even then, odds are you would not need it
 952           enabled, you can always pass the boot option if absolutely necessary.
 953
 954 config RELAY
 955         bool "Kernel->user space relay support (formerly relayfs)"
 956         help
 957           This option enables support for relay interface support in
 958           certain file systems (such as debugfs).
 959           It is designed to provide an efficient mechanism for tools and
 960           facilities to relay large amounts of data from kernel space to
 961           user space.
 962
 963           If unsure, say N.
 964
 965 config BLK_DEV_INITRD
 966         bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
 967         depends on BROKEN || !FRV
 968         help
 969           The initial RAM filesystem is a ramfs which is loaded by the
 970           boot loader (loadlin or lilo) and that is mounted as root
 971           before the normal boot procedure. It is typically used to
 972           load modules needed to mount the "real" root file system,
 973           etc. See <file:Documentation/initrd.txt> for details.
 974
 975           If RAM disk support (BLK_DEV_RAM) is also included, this
 976           also enables initial RAM disk (initrd) support and adds
 977           15 Kbytes (more on some other architectures) to the kernel size.
 978
 979           If unsure say Y.
 980
 981 if BLK_DEV_INITRD
 982
 983 source "usr/Kconfig"
 984
 985 endif
 986
 987 config CC_OPTIMIZE_FOR_SIZE
 988         bool "Optimize for size"
 989         help
 990           Enabling this option will pass "-Os" instead of "-O2" to gcc
 991           resulting in a smaller kernel.
 992
 993           If unsure, say Y.
 994
 995 config SYSCTL
 996         bool
 997
 998 config ANON_INODES
 999         bool
1000
1001 menuconfig EXPERT
1002         bool "Configure standard kernel features (expert users)"
1003         # Unhide debug options, to make the on-by-default options visible
1004         select DEBUG_KERNEL
1005         help
1006           This option allows certain base kernel options and settings
1007           to be disabled or tweaked. This is for specialized
1008           environments which can tolerate a "non-standard" kernel.
1009           Only use this if you really know what you are doing.
1010
1011 config UID16
1012         bool "Enable 16-bit UID system calls" if EXPERT
1013         depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION)
1014         default y
1015         help
1016           This enables the legacy 16-bit UID syscall wrappers.
1017
1018 config SYSCTL_SYSCALL
1019         bool "Sysctl syscall support" if EXPERT
1020         depends on PROC_SYSCTL
1021         default n
1022         select SYSCTL
1023         ---help---
1024           sys_sysctl uses binary paths that have been found challenging
1025           to properly maintain and use.  The interface in /proc/sys
1026           using paths with ascii names is now the primary path to this
1027           information.
1028
1029           Almost nothing using the binary sysctl interface so if you are
1030           trying to save some space it is probably safe to disable this,
1031           making your kernel marginally smaller.
1032
1033           If unsure say N here.
1034
1035 config KALLSYMS
1036          bool "Load all symbols for debugging/ksymoops" if EXPERT
1037          default y
1038          help
1039            Say Y here to let the kernel print out symbolic crash information and
1040            symbolic stack backtraces. This increases the size of the kernel
1041            somewhat, as all symbols have to be loaded into the kernel image.
1042
1043 config KALLSYMS_ALL
1044         bool "Include all symbols in kallsyms"
1045         depends on DEBUG_KERNEL && KALLSYMS
1046         help
1047            Normally kallsyms only contains the symbols of functions for nicer
1048            OOPS messages and backtraces (i.e., symbols from the text and inittext
1049            sections). This is sufficient for most cases. And only in very rare
1050            cases (e.g., when a debugger is used) all symbols are required (e.g.,
1051            names of variables from the data sections, etc).
1052
1053            This option makes sure that all symbols are loaded into the kernel
1054            image (i.e., symbols from all sections) in cost of increased kernel
1055            size (depending on the kernel configuration, it may be 300KiB or
1056            something like this).
1057
1058            Say N unless you really need all symbols.
1059
1060 config HOTPLUG
1061         bool "Support for hot-pluggable devices" if EXPERT
1062         default y
1063         help
1064           This option is provided for the case where no hotplug or uevent
1065           capabilities is wanted by the kernel.  You should only consider
1066           disabling this option for embedded systems that do not use modules, a
1067           dynamic /dev tree, or dynamic device discovery.  Just say Y.
1068
1069 config PRINTK
1070         default y
1071         bool "Enable support for printk" if EXPERT
1072         help
1073           This option enables normal printk support. Removing it
1074           eliminates most of the message strings from the kernel image
1075           and makes the kernel more or less silent. As this makes it
1076           very difficult to diagnose system problems, saying N here is
1077           strongly discouraged.
1078
1079 config BUG
1080         bool "BUG() support" if EXPERT
1081         default y
1082         help
1083           Disabling this option eliminates support for BUG and WARN, reducing
1084           the size of your kernel image and potentially quietly ignoring
1085           numerous fatal conditions. You should only consider disabling this
1086           option for embedded systems with no facilities for reporting errors.
1087           Just say Y.
1088
1089 config ELF_CORE
1090         default y
1091         bool "Enable ELF core dumps" if EXPERT
1092         help
1093           Enable support for generating core dumps. Disabling saves about 4k.
1094
1095
1096 config PCSPKR_PLATFORM
1097         bool "Enable PC-Speaker support" if EXPERT
1098         depends on HAVE_PCSPKR_PLATFORM
1099         select I8253_LOCK
1100         default y
1101         help
1102           This option allows to disable the internal PC-Speaker
1103           support, saving some memory.
1104
1105 config HAVE_PCSPKR_PLATFORM
1106         bool
1107
1108 config BASE_FULL
1109         default y
1110         bool "Enable full-sized data structures for core" if EXPERT
1111         help
1112           Disabling this option reduces the size of miscellaneous core
1113           kernel data structures. This saves memory on small machines,
1114           but may reduce performance.
1115
1116 config FUTEX
1117         bool "Enable futex support" if EXPERT
1118         default y
1119         select RT_MUTEXES
1120         help
1121           Disabling this option will cause the kernel to be built without
1122           support for "fast userspace mutexes".  The resulting kernel may not
1123           run glibc-based applications correctly.
1124
1125 config EPOLL
1126         bool "Enable eventpoll support" if EXPERT
1127         default y
1128         select ANON_INODES
1129         help
1130           Disabling this option will cause the kernel to be built without
1131           support for epoll family of system calls.
1132
1133 config SIGNALFD
1134         bool "Enable signalfd() system call" if EXPERT
1135         select ANON_INODES
1136         default y
1137         help
1138           Enable the signalfd() system call that allows to receive signals
1139           on a file descriptor.
1140
1141           If unsure, say Y.
1142
1143 config TIMERFD
1144         bool "Enable timerfd() system call" if EXPERT
1145         select ANON_INODES
1146         default y
1147         help
1148           Enable the timerfd() system call that allows to receive timer
1149           events on a file descriptor.
1150
1151           If unsure, say Y.
1152
1153 config EVENTFD
1154         bool "Enable eventfd() system call" if EXPERT
1155         select ANON_INODES
1156         default y
1157         help
1158           Enable the eventfd() system call that allows to receive both
1159           kernel notification (ie. KAIO) or userspace notifications.
1160
1161           If unsure, say Y.
1162
1163 config SHMEM
1164         bool "Use full shmem filesystem" if EXPERT
1165         default y
1166         depends on MMU
1167         help
1168           The shmem is an internal filesystem used to manage shared memory.
1169           It is backed by swap and manages resource limits. It is also exported
1170           to userspace as tmpfs if TMPFS is enabled. Disabling this
1171           option replaces shmem and tmpfs with the much simpler ramfs code,
1172           which may be appropriate on small systems without swap.
1173
1174 config AIO
1175         bool "Enable AIO support" if EXPERT
1176         default y
1177         help
1178           This option enables POSIX asynchronous I/O which may by used
1179           by some high performance threaded applications. Disabling
1180           this option saves about 7k.
1181
1182 config EMBEDDED
1183         bool "Embedded system"
1184         select EXPERT
1185         help
1186           This option should be enabled if compiling the kernel for
1187           an embedded system so certain expert options are available
1188           for configuration.
1189
1190 config HAVE_PERF_EVENTS
1191         bool
1192         help
1193           See tools/perf/design.txt for details.
1194
1195 config PERF_USE_VMALLOC
1196         bool
1197         help
1198           See tools/perf/design.txt for details
1199
1200 menu "Kernel Performance Events And Counters"
1201
1202 config PERF_EVENTS
1203         bool "Kernel performance events and counters"
1204         default y if PROFILING
1205         depends on HAVE_PERF_EVENTS
1206         select ANON_INODES
1207         select IRQ_WORK
1208         help
1209           Enable kernel support for various performance events provided
1210           by software and hardware.
1211
1212           Software events are supported either built-in or via the
1213           use of generic tracepoints.
1214
1215           Most modern CPUs support performance events via performance
1216           counter registers. These registers count the number of certain
1217           types of hw events: such as instructions executed, cachemisses
1218           suffered, or branches mis-predicted - without slowing down the
1219           kernel or applications. These registers can also trigger interrupts
1220           when a threshold number of events have passed - and can thus be
1221           used to profile the code that runs on that CPU.
1222
1223           The Linux Performance Event subsystem provides an abstraction of
1224           these software and hardware event capabilities, available via a
1225           system call and used by the "perf" utility in tools/perf/. It
1226           provides per task and per CPU counters, and it provides event
1227           capabilities on top of those.
1228
1229           Say Y if unsure.
1230
1231 config DEBUG_PERF_USE_VMALLOC
1232         default n
1233         bool "Debug: use vmalloc to back perf mmap() buffers"
1234         depends on PERF_EVENTS && DEBUG_KERNEL
1235         select PERF_USE_VMALLOC
1236         help
1237          Use vmalloc memory to back perf mmap() buffers.
1238
1239          Mostly useful for debugging the vmalloc code on platforms
1240          that don't require it.
1241
1242          Say N if unsure.
1243
1244 endmenu
1245
1246 config VM_EVENT_COUNTERS
1247         default y
1248         bool "Enable VM event counters for /proc/vmstat" if EXPERT
1249         help
1250           VM event counters are needed for event counts to be shown.
1251           This option allows the disabling of the VM event counters
1252           on EXPERT systems.  /proc/vmstat will only show page counts
1253           if VM event counters are disabled.
1254
1255 config PCI_QUIRKS
1256         default y
1257         bool "Enable PCI quirk workarounds" if EXPERT
1258         depends on PCI
1259         help
1260           This enables workarounds for various PCI chipset
1261           bugs/quirks. Disable this only if your target machine is
1262           unaffected by PCI quirks.
1263
1264 config SLUB_DEBUG
1265         default y
1266         bool "Enable SLUB debugging support" if EXPERT
1267         depends on SLUB && SYSFS
1268         help
1269           SLUB has extensive debug support features. Disabling these can
1270           result in significant savings in code size. This also disables
1271           SLUB sysfs support. /sys/slab will not exist and there will be
1272           no support for cache validation etc.
1273
1274 config COMPAT_BRK
1275         bool "Disable heap randomization"
1276         default y
1277         help
1278           Randomizing heap placement makes heap exploits harder, but it
1279           also breaks ancient binaries (including anything libc5 based).
1280           This option changes the bootup default to heap randomization
1281           disabled, and can be overridden at runtime by setting
1282           /proc/sys/kernel/randomize_va_space to 2.
1283
1284           On non-ancient distros (post-2000 ones) N is usually a safe choice.
1285
1286 choice
1287         prompt "Choose SLAB allocator"
1288         default SLUB
1289         help
1290            This option allows to select a slab allocator.
1291
1292 config SLAB
1293         bool "SLAB"
1294         help
1295           The regular slab allocator that is established and known to work
1296           well in all environments. It organizes cache hot objects in
1297           per cpu and per node queues.
1298
1299 config SLUB
1300         bool "SLUB (Unqueued Allocator)"
1301         help
1302            SLUB is a slab allocator that minimizes cache line usage
1303            instead of managing queues of cached objects (SLAB approach).
1304            Per cpu caching is realized using slabs of objects instead
1305            of queues of objects. SLUB can use memory efficiently
1306            and has enhanced diagnostics. SLUB is the default choice for
1307            a slab allocator.
1308
1309 config SLOB
1310         depends on EXPERT
1311         bool "SLOB (Simple Allocator)"
1312         help
1313            SLOB replaces the stock allocator with a drastically simpler
1314            allocator. SLOB is generally more space efficient but
1315            does not perform as well on large systems.
1316
1317 endchoice
1318
1319 config MMAP_ALLOW_UNINITIALIZED
1320         bool "Allow mmapped anonymous memory to be uninitialized"
1321         depends on EXPERT && !MMU
1322         default n
1323         help
1324           Normally, and according to the Linux spec, anonymous memory obtained
1325           from mmap() has it's contents cleared before it is passed to
1326           userspace.  Enabling this config option allows you to request that
1327           mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1328           providing a huge performance boost.  If this option is not enabled,
1329           then the flag will be ignored.
1330
1331           This is taken advantage of by uClibc's malloc(), and also by
1332           ELF-FDPIC binfmt's brk and stack allocator.
1333
1334           Because of the obvious security issues, this option should only be
1335           enabled on embedded devices where you control what is run in
1336           userspace.  Since that isn't generally a problem on no-MMU systems,
1337           it is normally safe to say Y here.
1338
1339           See Documentation/nommu-mmap.txt for more information.
1340
1341 config PROFILING
1342         bool "Profiling support"
1343         help
1344           Say Y here to enable the extended profiling support mechanisms used
1345           by profilers such as OProfile.
1346
1347 #
1348 # Place an empty function call at each tracepoint site. Can be
1349 # dynamically changed for a probe function.
1350 #
1351 config TRACEPOINTS
1352         bool
1353
1354 source "arch/Kconfig"
1355
1356 endmenu         # General setup
1357
1358 config HAVE_GENERIC_DMA_COHERENT
1359         bool
1360         default n
1361
1362 config SLABINFO
1363         bool
1364         depends on PROC_FS
1365         depends on SLAB || SLUB_DEBUG
1366         default y
1367
1368 config RT_MUTEXES
1369         boolean
1370
1371 config BASE_SMALL
1372         int
1373         default 0 if BASE_FULL
1374         default 1 if !BASE_FULL
1375
1376 menuconfig MODULES
1377         bool "Enable loadable module support"
1378         help
1379           Kernel modules are small pieces of compiled code which can
1380           be inserted in the running kernel, rather than being
1381           permanently built into the kernel.  You use the "modprobe"
1382           tool to add (and sometimes remove) them.  If you say Y here,
1383           many parts of the kernel can be built as modules (by
1384           answering M instead of Y where indicated): this is most
1385           useful for infrequently used options which are not required
1386           for booting.  For more information, see the man pages for
1387           modprobe, lsmod, modinfo, insmod and rmmod.
1388
1389           If you say Y here, you will need to run "make
1390           modules_install" to put the modules under /lib/modules/
1391           where modprobe can find them (you may need to be root to do
1392           this).
1393
1394           If unsure, say Y.
1395
1396 if MODULES
1397
1398 config MODULE_FORCE_LOAD
1399         bool "Forced module loading"
1400         default n
1401         help
1402           Allow loading of modules without version information (ie. modprobe
1403           --force).  Forced module loading sets the 'F' (forced) taint flag and
1404           is usually a really bad idea.
1405
1406 config MODULE_UNLOAD
1407         bool "Module unloading"
1408         help
1409           Without this option you will not be able to unload any
1410           modules (note that some modules may not be unloadable
1411           anyway), which makes your kernel smaller, faster
1412           and simpler.  If unsure, say Y.
1413
1414 config MODULE_FORCE_UNLOAD
1415         bool "Forced module unloading"
1416         depends on MODULE_UNLOAD && EXPERIMENTAL
1417         help
1418           This option allows you to force a module to unload, even if the
1419           kernel believes it is unsafe: the kernel will remove the module
1420           without waiting for anyone to stop using it (using the -f option to
1421           rmmod).  This is mainly for kernel developers and desperate users.
1422           If unsure, say N.
1423
1424 config MODVERSIONS
1425         bool "Module versioning support"
1426         help
1427           Usually, you have to use modules compiled with your kernel.
1428           Saying Y here makes it sometimes possible to use modules
1429           compiled for different kernels, by adding enough information
1430           to the modules to (hopefully) spot any changes which would
1431           make them incompatible with the kernel you are running.  If
1432           unsure, say N.
1433
1434 config MODULE_SRCVERSION_ALL
1435         bool "Source checksum for all modules"
1436         help
1437           Modules which contain a MODULE_VERSION get an extra "srcversion"
1438           field inserted into their modinfo section, which contains a
1439           sum of the source files which made it.  This helps maintainers
1440           see exactly which source was used to build a module (since
1441           others sometimes change the module source without updating
1442           the version).  With this option, such a "srcversion" field
1443           will be created for all modules.  If unsure, say N.
1444
1445 endif # MODULES
1446
1447 config INIT_ALL_POSSIBLE
1448         bool
1449         help
1450           Back when each arch used to define their own cpu_online_mask and
1451           cpu_possible_mask, some of them chose to initialize cpu_possible_mask
1452           with all 1s, and others with all 0s.  When they were centralised,
1453           it was better to provide this option than to break all the archs
1454           and have several arch maintainers pursuing me down dark alleys.
1455
1456 config STOP_MACHINE
1457         bool
1458         default y
1459         depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1460         help
1461           Need stop_machine() primitive.
1462
1463 source "block/Kconfig"
1464
1465 config PREEMPT_NOTIFIERS
1466         bool
1467
1468 config PADATA
1469         depends on SMP
1470         bool
1471
1472 source "kernel/Kconfig.locks"