linux/lib/Kconfig.debug
<<
>>
Prefs
   1
   2config PRINTK_TIME
   3        bool "Show timing information on printks"
   4        depends on PRINTK
   5        help
   6          Selecting this option causes timing information to be
   7          included in printk output.  This allows you to measure
   8          the interval between kernel operations, including bootup
   9          operations.  This is useful for identifying long delays
  10          in kernel startup.  Or add printk.time=1 at boot-time.
  11          See Documentation/kernel-parameters.txt
  12
  13config DEFAULT_MESSAGE_LOGLEVEL
  14        int "Default message log level (1-7)"
  15        range 1 7
  16        default "4"
  17        help
  18          Default log level for printk statements with no specified priority.
  19
  20          This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
  21          that are auditing their logs closely may want to set it to a lower
  22          priority.
  23
  24config ENABLE_WARN_DEPRECATED
  25        bool "Enable __deprecated logic"
  26        default y
  27        help
  28          Enable the __deprecated logic in the kernel build.
  29          Disable this to suppress the "warning: 'foo' is deprecated
  30          (declared at kernel/power/somefile.c:1234)" messages.
  31
  32config ENABLE_MUST_CHECK
  33        bool "Enable __must_check logic"
  34        default y
  35        help
  36          Enable the __must_check logic in the kernel build.  Disable this to
  37          suppress the "warning: ignoring return value of 'foo', declared with
  38          attribute warn_unused_result" messages.
  39
  40config FRAME_WARN
  41        int "Warn for stack frames larger than (needs gcc 4.4)"
  42        range 0 8192
  43        default 1024 if !64BIT
  44        default 2048 if 64BIT
  45        help
  46          Tell gcc to warn at build time for stack frames larger than this.
  47          Setting this too low will cause a lot of warnings.
  48          Setting it to 0 disables the warning.
  49          Requires gcc 4.4
  50
  51config MAGIC_SYSRQ
  52        bool "Magic SysRq key"
  53        depends on !UML
  54        help
  55          If you say Y here, you will have some control over the system even
  56          if the system crashes for example during kernel debugging (e.g., you
  57          will be able to flush the buffer cache to disk, reboot the system
  58          immediately or dump some status information). This is accomplished
  59          by pressing various keys while holding SysRq (Alt+PrintScreen). It
  60          also works on a serial console (on PC hardware at least), if you
  61          send a BREAK and then within 5 seconds a command keypress. The
  62          keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
  63          unless you really know what this hack does.
  64
  65config STRIP_ASM_SYMS
  66        bool "Strip assembler-generated symbols during link"
  67        default n
  68        help
  69          Strip internal assembler-generated symbols during a link (symbols
  70          that look like '.Lxxx') so they don't pollute the output of
  71          get_wchan() and suchlike.
  72
  73config UNUSED_SYMBOLS
  74        bool "Enable unused/obsolete exported symbols"
  75        default y if X86
  76        help
  77          Unused but exported symbols make the kernel needlessly bigger.  For
  78          that reason most of these unused exports will soon be removed.  This
  79          option is provided temporarily to provide a transition period in case
  80          some external kernel module needs one of these symbols anyway. If you
  81          encounter such a case in your module, consider if you are actually
  82          using the right API.  (rationale: since nobody in the kernel is using
  83          this in a module, there is a pretty good chance it's actually the
  84          wrong interface to use).  If you really need the symbol, please send a
  85          mail to the linux kernel mailing list mentioning the symbol and why
  86          you really need it, and what the merge plan to the mainline kernel for
  87          your module is.
  88
  89config DEBUG_FS
  90        bool "Debug Filesystem"
  91        help
  92          debugfs is a virtual file system that kernel developers use to put
  93          debugging files into.  Enable this option to be able to read and
  94          write to these files.
  95
  96          For detailed documentation on the debugfs API, see
  97          Documentation/DocBook/filesystems.
  98
  99          If unsure, say N.
 100
 101config HEADERS_CHECK
 102        bool "Run 'make headers_check' when building vmlinux"
 103        depends on !UML
 104        help
 105          This option will extract the user-visible kernel headers whenever
 106          building the kernel, and will run basic sanity checks on them to
 107          ensure that exported files do not attempt to include files which
 108          were not exported, etc.
 109
 110          If you're making modifications to header files which are
 111          relevant for userspace, say 'Y', and check the headers
 112          exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in
 113          your build tree), to make sure they're suitable.
 114
 115config DEBUG_SECTION_MISMATCH
 116        bool "Enable full Section mismatch analysis"
 117        help
 118          The section mismatch analysis checks if there are illegal
 119          references from one section to another section.
 120          Linux will during link or during runtime drop some sections
 121          and any use of code/data previously in these sections will
 122          most likely result in an oops.
 123          In the code functions and variables are annotated with
 124          __init, __devinit etc. (see full list in include/linux/init.h)
 125          which results in the code/data being placed in specific sections.
 126          The section mismatch analysis is always done after a full
 127          kernel build but enabling this option will in addition
 128          do the following:
 129          - Add the option -fno-inline-functions-called-once to gcc
 130            When inlining a function annotated __init in a non-init
 131            function we would lose the section information and thus
 132            the analysis would not catch the illegal reference.
 133            This option tells gcc to inline less but will also
 134            result in a larger kernel.
 135          - Run the section mismatch analysis for each module/built-in.o
 136            When we run the section mismatch analysis on vmlinux.o we
 137            lose valueble information about where the mismatch was
 138            introduced.
 139            Running the analysis for each module/built-in.o file
 140            will tell where the mismatch happens much closer to the
 141            source. The drawback is that we will report the same
 142            mismatch at least twice.
 143          - Enable verbose reporting from modpost to help solving
 144            the section mismatches reported.
 145
 146config DEBUG_KERNEL
 147        bool "Kernel debugging"
 148        help
 149          Say Y here if you are developing drivers or trying to debug and
 150          identify kernel problems.
 151
 152config DEBUG_SHIRQ
 153        bool "Debug shared IRQ handlers"
 154        depends on DEBUG_KERNEL && GENERIC_HARDIRQS
 155        help
 156          Enable this to generate a spurious interrupt as soon as a shared
 157          interrupt handler is registered, and just before one is deregistered.
 158          Drivers ought to be able to handle interrupts coming in at those
 159          points; some don't and need to be caught.
 160
 161config LOCKUP_DETECTOR
 162        bool "Detect Hard and Soft Lockups"
 163        depends on DEBUG_KERNEL && !S390
 164        help
 165          Say Y here to enable the kernel to act as a watchdog to detect
 166          hard and soft lockups.
 167
 168          Softlockups are bugs that cause the kernel to loop in kernel
 169          mode for more than 60 seconds, without giving other tasks a
 170          chance to run.  The current stack trace is displayed upon
 171          detection and the system will stay locked up.
 172
 173          Hardlockups are bugs that cause the CPU to loop in kernel mode
 174          for more than 60 seconds, without letting other interrupts have a
 175          chance to run.  The current stack trace is displayed upon detection
 176          and the system will stay locked up.
 177
 178          The overhead should be minimal.  A periodic hrtimer runs to
 179          generate interrupts and kick the watchdog task every 10-12 seconds.
 180          An NMI is generated every 60 seconds or so to check for hardlockups.
 181
 182config HARDLOCKUP_DETECTOR
 183        def_bool LOCKUP_DETECTOR && PERF_EVENTS && HAVE_PERF_EVENTS_NMI && \
 184                 !ARCH_HAS_NMI_WATCHDOG
 185
 186config BOOTPARAM_HARDLOCKUP_PANIC
 187        bool "Panic (Reboot) On Hard Lockups"
 188        depends on LOCKUP_DETECTOR
 189        help
 190          Say Y here to enable the kernel to panic on "hard lockups",
 191          which are bugs that cause the kernel to loop in kernel
 192          mode with interrupts disabled for more than 60 seconds.
 193
 194          Say N if unsure.
 195
 196config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
 197        int
 198        depends on LOCKUP_DETECTOR
 199        range 0 1
 200        default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
 201        default 1 if BOOTPARAM_HARDLOCKUP_PANIC
 202
 203config BOOTPARAM_SOFTLOCKUP_PANIC
 204        bool "Panic (Reboot) On Soft Lockups"
 205        depends on LOCKUP_DETECTOR
 206        help
 207          Say Y here to enable the kernel to panic on "soft lockups",
 208          which are bugs that cause the kernel to loop in kernel
 209          mode for more than 60 seconds, without giving other tasks a
 210          chance to run.
 211
 212          The panic can be used in combination with panic_timeout,
 213          to cause the system to reboot automatically after a
 214          lockup has been detected. This feature is useful for
 215          high-availability systems that have uptime guarantees and
 216          where a lockup must be resolved ASAP.
 217
 218          Say N if unsure.
 219
 220config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
 221        int
 222        depends on LOCKUP_DETECTOR
 223        range 0 1
 224        default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
 225        default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
 226
 227config DETECT_HUNG_TASK
 228        bool "Detect Hung Tasks"
 229        depends on DEBUG_KERNEL
 230        default LOCKUP_DETECTOR
 231        help
 232          Say Y here to enable the kernel to detect "hung tasks",
 233          which are bugs that cause the task to be stuck in
 234          uninterruptible "D" state indefinitiley.
 235
 236          When a hung task is detected, the kernel will print the
 237          current stack trace (which you should report), but the
 238          task will stay in uninterruptible state. If lockdep is
 239          enabled then all held locks will also be reported. This
 240          feature has negligible overhead.
 241
 242config DEFAULT_HUNG_TASK_TIMEOUT
 243        int "Default timeout for hung task detection (in seconds)"
 244        depends on DETECT_HUNG_TASK
 245        default 120
 246        help
 247          This option controls the default timeout (in seconds) used
 248          to determine when a task has become non-responsive and should
 249          be considered hung.
 250
 251          It can be adjusted at runtime via the kernel.hung_task_timeout
 252          sysctl or by writing a value to /proc/sys/kernel/hung_task_timeout.
 253
 254          A timeout of 0 disables the check.  The default is two minutes.
 255          Keeping the default should be fine in most cases.
 256
 257config BOOTPARAM_HUNG_TASK_PANIC
 258        bool "Panic (Reboot) On Hung Tasks"
 259        depends on DETECT_HUNG_TASK
 260        help
 261          Say Y here to enable the kernel to panic on "hung tasks",
 262          which are bugs that cause the kernel to leave a task stuck
 263          in uninterruptible "D" state.
 264
 265          The panic can be used in combination with panic_timeout,
 266          to cause the system to reboot automatically after a
 267          hung task has been detected. This feature is useful for
 268          high-availability systems that have uptime guarantees and
 269          where a hung tasks must be resolved ASAP.
 270
 271          Say N if unsure.
 272
 273config BOOTPARAM_HUNG_TASK_PANIC_VALUE
 274        int
 275        depends on DETECT_HUNG_TASK
 276        range 0 1
 277        default 0 if !BOOTPARAM_HUNG_TASK_PANIC
 278        default 1 if BOOTPARAM_HUNG_TASK_PANIC
 279
 280config SCHED_DEBUG
 281        bool "Collect scheduler debugging info"
 282        depends on DEBUG_KERNEL && PROC_FS
 283        default y
 284        help
 285          If you say Y here, the /proc/sched_debug file will be provided
 286          that can help debug the scheduler. The runtime overhead of this
 287          option is minimal.
 288
 289config SCHEDSTATS
 290        bool "Collect scheduler statistics"
 291        depends on DEBUG_KERNEL && PROC_FS
 292        help
 293          If you say Y here, additional code will be inserted into the
 294          scheduler and related routines to collect statistics about
 295          scheduler behavior and provide them in /proc/schedstat.  These
 296          stats may be useful for both tuning and debugging the scheduler
 297          If you aren't debugging the scheduler or trying to tune a specific
 298          application, you can say N to avoid the very slight overhead
 299          this adds.
 300
 301config TIMER_STATS
 302        bool "Collect kernel timers statistics"
 303        depends on DEBUG_KERNEL && PROC_FS
 304        help
 305          If you say Y here, additional code will be inserted into the
 306          timer routines to collect statistics about kernel timers being
 307          reprogrammed. The statistics can be read from /proc/timer_stats.
 308          The statistics collection is started by writing 1 to /proc/timer_stats,
 309          writing 0 stops it. This feature is useful to collect information
 310          about timer usage patterns in kernel and userspace. This feature
 311          is lightweight if enabled in the kernel config but not activated
 312          (it defaults to deactivated on bootup and will only be activated
 313          if some application like powertop activates it explicitly).
 314
 315config DEBUG_OBJECTS
 316        bool "Debug object operations"
 317        depends on DEBUG_KERNEL
 318        help
 319          If you say Y here, additional code will be inserted into the
 320          kernel to track the life time of various objects and validate
 321          the operations on those objects.
 322
 323config DEBUG_OBJECTS_SELFTEST
 324        bool "Debug objects selftest"
 325        depends on DEBUG_OBJECTS
 326        help
 327          This enables the selftest of the object debug code.
 328
 329config DEBUG_OBJECTS_FREE
 330        bool "Debug objects in freed memory"
 331        depends on DEBUG_OBJECTS
 332        help
 333          This enables checks whether a k/v free operation frees an area
 334          which contains an object which has not been deactivated
 335          properly. This can make kmalloc/kfree-intensive workloads
 336          much slower.
 337
 338config DEBUG_OBJECTS_TIMERS
 339        bool "Debug timer objects"
 340        depends on DEBUG_OBJECTS
 341        help
 342          If you say Y here, additional code will be inserted into the
 343          timer routines to track the life time of timer objects and
 344          validate the timer operations.
 345
 346config DEBUG_OBJECTS_WORK
 347        bool "Debug work objects"
 348        depends on DEBUG_OBJECTS
 349        help
 350          If you say Y here, additional code will be inserted into the
 351          work queue routines to track the life time of work objects and
 352          validate the work operations.
 353
 354config DEBUG_OBJECTS_RCU_HEAD
 355        bool "Debug RCU callbacks objects"
 356        depends on DEBUG_OBJECTS
 357        help
 358          Enable this to turn on debugging of RCU list heads (call_rcu() usage).
 359
 360config DEBUG_OBJECTS_PERCPU_COUNTER
 361        bool "Debug percpu counter objects"
 362        depends on DEBUG_OBJECTS
 363        help
 364          If you say Y here, additional code will be inserted into the
 365          percpu counter routines to track the life time of percpu counter
 366          objects and validate the percpu counter operations.
 367
 368config DEBUG_OBJECTS_ENABLE_DEFAULT
 369        int "debug_objects bootup default value (0-1)"
 370        range 0 1
 371        default "1"
 372        depends on DEBUG_OBJECTS
 373        help
 374          Debug objects boot parameter default value
 375
 376config DEBUG_SLAB
 377        bool "Debug slab memory allocations"
 378        depends on DEBUG_KERNEL && SLAB && !KMEMCHECK
 379        help
 380          Say Y here to have the kernel do limited verification on memory
 381          allocation as well as poisoning memory on free to catch use of freed
 382          memory. This can make kmalloc/kfree-intensive workloads much slower.
 383
 384config DEBUG_SLAB_LEAK
 385        bool "Memory leak debugging"
 386        depends on DEBUG_SLAB
 387
 388config SLUB_DEBUG_ON
 389        bool "SLUB debugging on by default"
 390        depends on SLUB && SLUB_DEBUG && !KMEMCHECK
 391        default n
 392        help
 393          Boot with debugging on by default. SLUB boots by default with
 394          the runtime debug capabilities switched off. Enabling this is
 395          equivalent to specifying the "slub_debug" parameter on boot.
 396          There is no support for more fine grained debug control like
 397          possible with slub_debug=xxx. SLUB debugging may be switched
 398          off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
 399          "slub_debug=-".
 400
 401config SLUB_STATS
 402        default n
 403        bool "Enable SLUB performance statistics"
 404        depends on SLUB && SYSFS
 405        help
 406          SLUB statistics are useful to debug SLUBs allocation behavior in
 407          order find ways to optimize the allocator. This should never be
 408          enabled for production use since keeping statistics slows down
 409          the allocator by a few percentage points. The slabinfo command
 410          supports the determination of the most active slabs to figure
 411          out which slabs are relevant to a particular load.
 412          Try running: slabinfo -DA
 413
 414config DEBUG_KMEMLEAK
 415        bool "Kernel memory leak detector"
 416        depends on DEBUG_KERNEL && EXPERIMENTAL && !MEMORY_HOTPLUG && \
 417                (X86 || ARM || PPC || MIPS || S390 || SPARC64 || SUPERH || MICROBLAZE || TILE)
 418
 419        select DEBUG_FS
 420        select STACKTRACE if STACKTRACE_SUPPORT
 421        select KALLSYMS
 422        select CRC32
 423        help
 424          Say Y here if you want to enable the memory leak
 425          detector. The memory allocation/freeing is traced in a way
 426          similar to the Boehm's conservative garbage collector, the
 427          difference being that the orphan objects are not freed but
 428          only shown in /sys/kernel/debug/kmemleak. Enabling this
 429          feature will introduce an overhead to memory
 430          allocations. See Documentation/kmemleak.txt for more
 431          details.
 432
 433          Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
 434          of finding leaks due to the slab objects poisoning.
 435
 436          In order to access the kmemleak file, debugfs needs to be
 437          mounted (usually at /sys/kernel/debug).
 438
 439config DEBUG_KMEMLEAK_EARLY_LOG_SIZE
 440        int "Maximum kmemleak early log entries"
 441        depends on DEBUG_KMEMLEAK
 442        range 200 40000
 443        default 400
 444        help
 445          Kmemleak must track all the memory allocations to avoid
 446          reporting false positives. Since memory may be allocated or
 447          freed before kmemleak is initialised, an early log buffer is
 448          used to store these actions. If kmemleak reports "early log
 449          buffer exceeded", please increase this value.
 450
 451config DEBUG_KMEMLEAK_TEST
 452        tristate "Simple test for the kernel memory leak detector"
 453        depends on DEBUG_KMEMLEAK && m
 454        help
 455          This option enables a module that explicitly leaks memory.
 456
 457          If unsure, say N.
 458
 459config DEBUG_KMEMLEAK_DEFAULT_OFF
 460        bool "Default kmemleak to off"
 461        depends on DEBUG_KMEMLEAK
 462        help
 463          Say Y here to disable kmemleak by default. It can then be enabled
 464          on the command line via kmemleak=on.
 465
 466config DEBUG_PREEMPT
 467        bool "Debug preemptible kernel"
 468        depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT
 469        default y
 470        help
 471          If you say Y here then the kernel will use a debug variant of the
 472          commonly used smp_processor_id() function and will print warnings
 473          if kernel code uses it in a preemption-unsafe way. Also, the kernel
 474          will detect preemption count underflows.
 475
 476config DEBUG_RT_MUTEXES
 477        bool "RT Mutex debugging, deadlock detection"
 478        depends on DEBUG_KERNEL && RT_MUTEXES
 479        help
 480         This allows rt mutex semantics violations and rt mutex related
 481         deadlocks (lockups) to be detected and reported automatically.
 482
 483config DEBUG_PI_LIST
 484        bool
 485        default y
 486        depends on DEBUG_RT_MUTEXES
 487
 488config RT_MUTEX_TESTER
 489        bool "Built-in scriptable tester for rt-mutexes"
 490        depends on DEBUG_KERNEL && RT_MUTEXES
 491        help
 492          This option enables a rt-mutex tester.
 493
 494config DEBUG_SPINLOCK
 495        bool "Spinlock and rw-lock debugging: basic checks"
 496        depends on DEBUG_KERNEL
 497        help
 498          Say Y here and build SMP to catch missing spinlock initialization
 499          and certain other kinds of spinlock errors commonly made.  This is
 500          best used in conjunction with the NMI watchdog so that spinlock
 501          deadlocks are also debuggable.
 502
 503config DEBUG_MUTEXES
 504        bool "Mutex debugging: basic checks"
 505        depends on DEBUG_KERNEL
 506        help
 507         This feature allows mutex semantics violations to be detected and
 508         reported.
 509
 510config DEBUG_LOCK_ALLOC
 511        bool "Lock debugging: detect incorrect freeing of live locks"
 512        depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
 513        select DEBUG_SPINLOCK
 514        select DEBUG_MUTEXES
 515        select LOCKDEP
 516        help
 517         This feature will check whether any held lock (spinlock, rwlock,
 518         mutex or rwsem) is incorrectly freed by the kernel, via any of the
 519         memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
 520         vfree(), etc.), whether a live lock is incorrectly reinitialized via
 521         spin_lock_init()/mutex_init()/etc., or whether there is any lock
 522         held during task exit.
 523
 524config PROVE_LOCKING
 525        bool "Lock debugging: prove locking correctness"
 526        depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
 527        select LOCKDEP
 528        select DEBUG_SPINLOCK
 529        select DEBUG_MUTEXES
 530        select DEBUG_LOCK_ALLOC
 531        select TRACE_IRQFLAGS
 532        default n
 533        help
 534         This feature enables the kernel to prove that all locking
 535         that occurs in the kernel runtime is mathematically
 536         correct: that under no circumstance could an arbitrary (and
 537         not yet triggered) combination of observed locking
 538         sequences (on an arbitrary number of CPUs, running an
 539         arbitrary number of tasks and interrupt contexts) cause a
 540         deadlock.
 541
 542         In short, this feature enables the kernel to report locking
 543         related deadlocks before they actually occur.
 544
 545         The proof does not depend on how hard and complex a
 546         deadlock scenario would be to trigger: how many
 547         participant CPUs, tasks and irq-contexts would be needed
 548         for it to trigger. The proof also does not depend on
 549         timing: if a race and a resulting deadlock is possible
 550         theoretically (no matter how unlikely the race scenario
 551         is), it will be proven so and will immediately be
 552         reported by the kernel (once the event is observed that
 553         makes the deadlock theoretically possible).
 554
 555         If a deadlock is impossible (i.e. the locking rules, as
 556         observed by the kernel, are mathematically correct), the
 557         kernel reports nothing.
 558
 559         NOTE: this feature can also be enabled for rwlocks, mutexes
 560         and rwsems - in which case all dependencies between these
 561         different locking variants are observed and mapped too, and
 562         the proof of observed correctness is also maintained for an
 563         arbitrary combination of these separate locking variants.
 564
 565         For more details, see Documentation/lockdep-design.txt.
 566
 567config PROVE_RCU
 568        bool "RCU debugging: prove RCU correctness"
 569        depends on PROVE_LOCKING
 570        default n
 571        help
 572         This feature enables lockdep extensions that check for correct
 573         use of RCU APIs.  This is currently under development.  Say Y
 574         if you want to debug RCU usage or help work on the PROVE_RCU
 575         feature.
 576
 577         Say N if you are unsure.
 578
 579config PROVE_RCU_REPEATEDLY
 580        bool "RCU debugging: don't disable PROVE_RCU on first splat"
 581        depends on PROVE_RCU
 582        default n
 583        help
 584         By itself, PROVE_RCU will disable checking upon issuing the
 585         first warning (or "splat").  This feature prevents such
 586         disabling, allowing multiple RCU-lockdep warnings to be printed
 587         on a single reboot.
 588
 589         Say Y to allow multiple RCU-lockdep warnings per boot.
 590
 591         Say N if you are unsure.
 592
 593config SPARSE_RCU_POINTER
 594        bool "RCU debugging: sparse-based checks for pointer usage"
 595        default n
 596        help
 597         This feature enables the __rcu sparse annotation for
 598         RCU-protected pointers.  This annotation will cause sparse
 599         to flag any non-RCU used of annotated pointers.  This can be
 600         helpful when debugging RCU usage.  Please note that this feature
 601         is not intended to enforce code cleanliness; it is instead merely
 602         a debugging aid.
 603
 604         Say Y to make sparse flag questionable use of RCU-protected pointers
 605
 606         Say N if you are unsure.
 607
 608config LOCKDEP
 609        bool
 610        depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
 611        select STACKTRACE
 612        select FRAME_POINTER if !MIPS && !PPC && !ARM_UNWIND && !S390 && !MICROBLAZE
 613        select KALLSYMS
 614        select KALLSYMS_ALL
 615
 616config LOCK_STAT
 617        bool "Lock usage statistics"
 618        depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
 619        select LOCKDEP
 620        select DEBUG_SPINLOCK
 621        select DEBUG_MUTEXES
 622        select DEBUG_LOCK_ALLOC
 623        default n
 624        help
 625         This feature enables tracking lock contention points
 626
 627         For more details, see Documentation/lockstat.txt
 628
 629         This also enables lock events required by "perf lock",
 630         subcommand of perf.
 631         If you want to use "perf lock", you also need to turn on
 632         CONFIG_EVENT_TRACING.
 633
 634         CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
 635         (CONFIG_LOCKDEP defines "acquire" and "release" events.)
 636
 637config DEBUG_LOCKDEP
 638        bool "Lock dependency engine debugging"
 639        depends on DEBUG_KERNEL && LOCKDEP
 640        help
 641          If you say Y here, the lock dependency engine will do
 642          additional runtime checks to debug itself, at the price
 643          of more runtime overhead.
 644
 645config TRACE_IRQFLAGS
 646        bool
 647        help
 648          Enables hooks to interrupt enabling and disabling for
 649          either tracing or lock debugging.
 650
 651config DEBUG_ATOMIC_SLEEP
 652        bool "Sleep inside atomic section checking"
 653        select PREEMPT_COUNT
 654        depends on DEBUG_KERNEL
 655        help
 656          If you say Y here, various routines which may sleep will become very
 657          noisy if they are called inside atomic sections: when a spinlock is
 658          held, inside an rcu read side critical section, inside preempt disabled
 659          sections, inside an interrupt, etc...
 660
 661config DEBUG_LOCKING_API_SELFTESTS
 662        bool "Locking API boot-time self-tests"
 663        depends on DEBUG_KERNEL
 664        help
 665          Say Y here if you want the kernel to run a short self-test during
 666          bootup. The self-test checks whether common types of locking bugs
 667          are detected by debugging mechanisms or not. (if you disable
 668          lock debugging then those bugs wont be detected of course.)
 669          The following locking APIs are covered: spinlocks, rwlocks,
 670          mutexes and rwsems.
 671
 672config STACKTRACE
 673        bool
 674        depends on STACKTRACE_SUPPORT
 675
 676config DEBUG_STACK_USAGE
 677        bool "Stack utilization instrumentation"
 678        depends on DEBUG_KERNEL
 679        help
 680          Enables the display of the minimum amount of free stack which each
 681          task has ever had available in the sysrq-T and sysrq-P debug output.
 682
 683          This option will slow down process creation somewhat.
 684
 685config DEBUG_KOBJECT
 686        bool "kobject debugging"
 687        depends on DEBUG_KERNEL
 688        help
 689          If you say Y here, some extra kobject debugging messages will be sent
 690          to the syslog. 
 691
 692config DEBUG_HIGHMEM
 693        bool "Highmem debugging"
 694        depends on DEBUG_KERNEL && HIGHMEM
 695        help
 696          This options enables addition error checking for high memory systems.
 697          Disable for production systems.
 698
 699config DEBUG_BUGVERBOSE
 700        bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
 701        depends on BUG
 702        depends on ARM || AVR32 || M32R || M68K || SPARC32 || SPARC64 || \
 703                   FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300 || TILE
 704        default y
 705        help
 706          Say Y here to make BUG() panics output the file name and line number
 707          of the BUG call as well as the EIP and oops trace.  This aids
 708          debugging but costs about 70-100K of memory.
 709
 710config DEBUG_INFO
 711        bool "Compile the kernel with debug info"
 712        depends on DEBUG_KERNEL
 713        help
 714          If you say Y here the resulting kernel image will include
 715          debugging info resulting in a larger kernel image.
 716          This adds debug symbols to the kernel and modules (gcc -g), and
 717          is needed if you intend to use kernel crashdump or binary object
 718          tools like crash, kgdb, LKCD, gdb, etc on the kernel.
 719          Say Y here only if you plan to debug the kernel.
 720
 721          If unsure, say N.
 722
 723config DEBUG_INFO_REDUCED
 724        bool "Reduce debugging information"
 725        depends on DEBUG_INFO
 726        help
 727          If you say Y here gcc is instructed to generate less debugging
 728          information for structure types. This means that tools that
 729          need full debugging information (like kgdb or systemtap) won't
 730          be happy. But if you merely need debugging information to
 731          resolve line numbers there is no loss. Advantage is that
 732          build directory object sizes shrink dramatically over a full
 733          DEBUG_INFO build and compile times are reduced too.
 734          Only works with newer gcc versions.
 735
 736config DEBUG_VM
 737        bool "Debug VM"
 738        depends on DEBUG_KERNEL
 739        help
 740          Enable this to turn on extended checks in the virtual-memory system
 741          that may impact performance.
 742
 743          If unsure, say N.
 744
 745config DEBUG_VIRTUAL
 746        bool "Debug VM translations"
 747        depends on DEBUG_KERNEL && X86
 748        help
 749          Enable some costly sanity checks in virtual to page code. This can
 750          catch mistakes with virt_to_page() and friends.
 751
 752          If unsure, say N.
 753
 754config DEBUG_NOMMU_REGIONS
 755        bool "Debug the global anon/private NOMMU mapping region tree"
 756        depends on DEBUG_KERNEL && !MMU
 757        help
 758          This option causes the global tree of anonymous and private mapping
 759          regions to be regularly checked for invalid topology.
 760
 761config DEBUG_WRITECOUNT
 762        bool "Debug filesystem writers count"
 763        depends on DEBUG_KERNEL
 764        help
 765          Enable this to catch wrong use of the writers count in struct
 766          vfsmount.  This will increase the size of each file struct by
 767          32 bits.
 768
 769          If unsure, say N.
 770
 771config DEBUG_MEMORY_INIT
 772        bool "Debug memory initialisation" if EXPERT
 773        default !EXPERT
 774        help
 775          Enable this for additional checks during memory initialisation.
 776          The sanity checks verify aspects of the VM such as the memory model
 777          and other information provided by the architecture. Verbose
 778          information will be printed at KERN_DEBUG loglevel depending
 779          on the mminit_loglevel= command-line option.
 780
 781          If unsure, say Y
 782
 783config DEBUG_LIST
 784        bool "Debug linked list manipulation"
 785        depends on DEBUG_KERNEL
 786        help
 787          Enable this to turn on extended checks in the linked-list
 788          walking routines.
 789
 790          If unsure, say N.
 791
 792config TEST_LIST_SORT
 793        bool "Linked list sorting test"
 794        depends on DEBUG_KERNEL
 795        help
 796          Enable this to turn on 'list_sort()' function test. This test is
 797          executed only once during system boot, so affects only boot time.
 798
 799          If unsure, say N.
 800
 801config DEBUG_SG
 802        bool "Debug SG table operations"
 803        depends on DEBUG_KERNEL
 804        help
 805          Enable this to turn on checks on scatter-gather tables. This can
 806          help find problems with drivers that do not properly initialize
 807          their sg tables.
 808
 809          If unsure, say N.
 810
 811config DEBUG_NOTIFIERS
 812        bool "Debug notifier call chains"
 813        depends on DEBUG_KERNEL
 814        help
 815          Enable this to turn on sanity checking for notifier call chains.
 816          This is most useful for kernel developers to make sure that
 817          modules properly unregister themselves from notifier chains.
 818          This is a relatively cheap check but if you care about maximum
 819          performance, say N.
 820
 821config DEBUG_CREDENTIALS
 822        bool "Debug credential management"
 823        depends on DEBUG_KERNEL
 824        help
 825          Enable this to turn on some debug checking for credential
 826          management.  The additional code keeps track of the number of
 827          pointers from task_structs to any given cred struct, and checks to
 828          see that this number never exceeds the usage count of the cred
 829          struct.
 830
 831          Furthermore, if SELinux is enabled, this also checks that the
 832          security pointer in the cred struct is never seen to be invalid.
 833
 834          If unsure, say N.
 835
 836#
 837# Select this config option from the architecture Kconfig, if it
 838# it is preferred to always offer frame pointers as a config
 839# option on the architecture (regardless of KERNEL_DEBUG):
 840#
 841config ARCH_WANT_FRAME_POINTERS
 842        bool
 843        help
 844
 845config FRAME_POINTER
 846        bool "Compile the kernel with frame pointers"
 847        depends on DEBUG_KERNEL && \
 848                (CRIS || M68K || FRV || UML || \
 849                 AVR32 || SUPERH || BLACKFIN || MN10300) || \
 850                ARCH_WANT_FRAME_POINTERS
 851        default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
 852        help
 853          If you say Y here the resulting kernel image will be slightly
 854          larger and slower, but it gives very useful debugging information
 855          in case of kernel bugs. (precise oopses/stacktraces/warnings)
 856
 857config BOOT_PRINTK_DELAY
 858        bool "Delay each boot printk message by N milliseconds"
 859        depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
 860        help
 861          This build option allows you to read kernel boot messages
 862          by inserting a short delay after each one.  The delay is
 863          specified in milliseconds on the kernel command line,
 864          using "boot_delay=N".
 865
 866          It is likely that you would also need to use "lpj=M" to preset
 867          the "loops per jiffie" value.
 868          See a previous boot log for the "lpj" value to use for your
 869          system, and then set "lpj=M" before setting "boot_delay=N".
 870          NOTE:  Using this option may adversely affect SMP systems.
 871          I.e., processors other than the first one may not boot up.
 872          BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
 873          what it believes to be lockup conditions.
 874
 875config RCU_TORTURE_TEST
 876        tristate "torture tests for RCU"
 877        depends on DEBUG_KERNEL
 878        default n
 879        help
 880          This option provides a kernel module that runs torture tests
 881          on the RCU infrastructure.  The kernel module may be built
 882          after the fact on the running kernel to be tested, if desired.
 883
 884          Say Y here if you want RCU torture tests to be built into
 885          the kernel.
 886          Say M if you want the RCU torture tests to build as a module.
 887          Say N if you are unsure.
 888
 889config RCU_TORTURE_TEST_RUNNABLE
 890        bool "torture tests for RCU runnable by default"
 891        depends on RCU_TORTURE_TEST = y
 892        default n
 893        help
 894          This option provides a way to build the RCU torture tests
 895          directly into the kernel without them starting up at boot
 896          time.  You can use /proc/sys/kernel/rcutorture_runnable
 897          to manually override this setting.  This /proc file is
 898          available only when the RCU torture tests have been built
 899          into the kernel.
 900
 901          Say Y here if you want the RCU torture tests to start during
 902          boot (you probably don't).
 903          Say N here if you want the RCU torture tests to start only
 904          after being manually enabled via /proc.
 905
 906config RCU_CPU_STALL_TIMEOUT
 907        int "RCU CPU stall timeout in seconds"
 908        depends on TREE_RCU || TREE_PREEMPT_RCU
 909        range 3 300
 910        default 60
 911        help
 912          If a given RCU grace period extends more than the specified
 913          number of seconds, a CPU stall warning is printed.  If the
 914          RCU grace period persists, additional CPU stall warnings are
 915          printed at more widely spaced intervals.
 916
 917config RCU_CPU_STALL_VERBOSE
 918        bool "Print additional per-task information for RCU_CPU_STALL_DETECTOR"
 919        depends on TREE_PREEMPT_RCU
 920        default y
 921        help
 922          This option causes RCU to printk detailed per-task information
 923          for any tasks that are stalling the current RCU grace period.
 924
 925          Say N if you are unsure.
 926
 927          Say Y if you want to enable such checks.
 928
 929config KPROBES_SANITY_TEST
 930        bool "Kprobes sanity tests"
 931        depends on DEBUG_KERNEL
 932        depends on KPROBES
 933        default n
 934        help
 935          This option provides for testing basic kprobes functionality on
 936          boot. A sample kprobe, jprobe and kretprobe are inserted and
 937          verified for functionality.
 938
 939          Say N if you are unsure.
 940
 941config BACKTRACE_SELF_TEST
 942        tristate "Self test for the backtrace code"
 943        depends on DEBUG_KERNEL
 944        default n
 945        help
 946          This option provides a kernel module that can be used to test
 947          the kernel stack backtrace code. This option is not useful
 948          for distributions or general kernels, but only for kernel
 949          developers working on architecture code.
 950
 951          Note that if you want to also test saved backtraces, you will
 952          have to enable STACKTRACE as well.
 953
 954          Say N if you are unsure.
 955
 956config DEBUG_BLOCK_EXT_DEVT
 957        bool "Force extended block device numbers and spread them"
 958        depends on DEBUG_KERNEL
 959        depends on BLOCK
 960        default n
 961        help
 962          BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
 963          SOME DISTRIBUTIONS.  DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
 964          YOU ARE DOING.  Distros, please enable this and fix whatever
 965          is broken.
 966
 967          Conventionally, block device numbers are allocated from
 968          predetermined contiguous area.  However, extended block area
 969          may introduce non-contiguous block device numbers.  This
 970          option forces most block device numbers to be allocated from
 971          the extended space and spreads them to discover kernel or
 972          userland code paths which assume predetermined contiguous
 973          device number allocation.
 974
 975          Note that turning on this debug option shuffles all the
 976          device numbers for all IDE and SCSI devices including libata
 977          ones, so root partition specified using device number
 978          directly (via rdev or root=MAJ:MIN) won't work anymore.
 979          Textual device names (root=/dev/sdXn) will continue to work.
 980
 981          Say N if you are unsure.
 982
 983config DEBUG_FORCE_WEAK_PER_CPU
 984        bool "Force weak per-cpu definitions"
 985        depends on DEBUG_KERNEL
 986        help
 987          s390 and alpha require percpu variables in modules to be
 988          defined weak to work around addressing range issue which
 989          puts the following two restrictions on percpu variable
 990          definitions.
 991
 992          1. percpu symbols must be unique whether static or not
 993          2. percpu variables can't be defined inside a function
 994
 995          To ensure that generic code follows the above rules, this
 996          option forces all percpu variables to be defined as weak.
 997
 998config DEBUG_PER_CPU_MAPS
 999        bool "Debug access to per_cpu maps"
1000        depends on DEBUG_KERNEL
1001        depends on SMP
1002        help
1003          Say Y to verify that the per_cpu map being accessed has
1004          been set up. This adds a fair amount of code to kernel memory
1005          and decreases performance.
1006
1007          Say N if unsure.
1008
1009config LKDTM
1010        tristate "Linux Kernel Dump Test Tool Module"
1011        depends on DEBUG_FS
1012        depends on BLOCK
1013        default n
1014        help
1015        This module enables testing of the different dumping mechanisms by
1016        inducing system failures at predefined crash points.
1017        If you don't need it: say N
1018        Choose M here to compile this code as a module. The module will be
1019        called lkdtm.
1020
1021        Documentation on how to use the module can be found in
1022        Documentation/fault-injection/provoke-crashes.txt
1023
1024config CPU_NOTIFIER_ERROR_INJECT
1025        tristate "CPU notifier error injection module"
1026        depends on HOTPLUG_CPU && DEBUG_KERNEL
1027        help
1028          This option provides a kernel module that can be used to test
1029          the error handling of the cpu notifiers
1030
1031          To compile this code as a module, choose M here: the module will
1032          be called cpu-notifier-error-inject.
1033
1034          If unsure, say N.
1035
1036config FAULT_INJECTION
1037        bool "Fault-injection framework"
1038        depends on DEBUG_KERNEL
1039        help
1040          Provide fault-injection framework.
1041          For more details, see Documentation/fault-injection/.
1042
1043config FAILSLAB
1044        bool "Fault-injection capability for kmalloc"
1045        depends on FAULT_INJECTION
1046        depends on SLAB || SLUB
1047        help
1048          Provide fault-injection capability for kmalloc.
1049
1050config FAIL_PAGE_ALLOC
1051        bool "Fault-injection capabilitiy for alloc_pages()"
1052        depends on FAULT_INJECTION
1053        help
1054          Provide fault-injection capability for alloc_pages().
1055
1056config FAIL_MAKE_REQUEST
1057        bool "Fault-injection capability for disk IO"
1058        depends on FAULT_INJECTION && BLOCK
1059        help
1060          Provide fault-injection capability for disk IO.
1061
1062config FAIL_IO_TIMEOUT
1063        bool "Fault-injection capability for faking disk interrupts"
1064        depends on FAULT_INJECTION && BLOCK
1065        help
1066          Provide fault-injection capability on end IO handling. This
1067          will make the block layer "forget" an interrupt as configured,
1068          thus exercising the error handling.
1069
1070          Only works with drivers that use the generic timeout handling,
1071          for others it wont do anything.
1072
1073config FAULT_INJECTION_DEBUG_FS
1074        bool "Debugfs entries for fault-injection capabilities"
1075        depends on FAULT_INJECTION && SYSFS && DEBUG_FS
1076        help
1077          Enable configuration of fault-injection capabilities via debugfs.
1078
1079config FAULT_INJECTION_STACKTRACE_FILTER
1080        bool "stacktrace filter for fault-injection capabilities"
1081        depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
1082        depends on !X86_64
1083        select STACKTRACE
1084        select FRAME_POINTER if !PPC && !S390 && !MICROBLAZE
1085        help
1086          Provide stacktrace filter for fault-injection capabilities
1087
1088config LATENCYTOP
1089        bool "Latency measuring infrastructure"
1090        depends on HAVE_LATENCYTOP_SUPPORT
1091        depends on DEBUG_KERNEL
1092        depends on STACKTRACE_SUPPORT
1093        depends on PROC_FS
1094        select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE
1095        select KALLSYMS
1096        select KALLSYMS_ALL
1097        select STACKTRACE
1098        select SCHEDSTATS
1099        select SCHED_DEBUG
1100        help
1101          Enable this option if you want to use the LatencyTOP tool
1102          to find out which userspace is blocking on what kernel operations.
1103
1104config SYSCTL_SYSCALL_CHECK
1105        bool "Sysctl checks"
1106        depends on SYSCTL
1107        ---help---
1108          sys_sysctl uses binary paths that have been found challenging
1109          to properly maintain and use. This enables checks that help
1110          you to keep things correct.
1111
1112source mm/Kconfig.debug
1113source kernel/trace/Kconfig
1114
1115config PROVIDE_OHCI1394_DMA_INIT
1116        bool "Remote debugging over FireWire early on boot"
1117        depends on PCI && X86
1118        help
1119          If you want to debug problems which hang or crash the kernel early
1120          on boot and the crashing machine has a FireWire port, you can use
1121          this feature to remotely access the memory of the crashed machine
1122          over FireWire. This employs remote DMA as part of the OHCI1394
1123          specification which is now the standard for FireWire controllers.
1124
1125          With remote DMA, you can monitor the printk buffer remotely using
1126          firescope and access all memory below 4GB using fireproxy from gdb.
1127          Even controlling a kernel debugger is possible using remote DMA.
1128
1129          Usage:
1130
1131          If ohci1394_dma=early is used as boot parameter, it will initialize
1132          all OHCI1394 controllers which are found in the PCI config space.
1133
1134          As all changes to the FireWire bus such as enabling and disabling
1135          devices cause a bus reset and thereby disable remote DMA for all
1136          devices, be sure to have the cable plugged and FireWire enabled on
1137          the debugging host before booting the debug target for debugging.
1138
1139          This code (~1k) is freed after boot. By then, the firewire stack
1140          in charge of the OHCI-1394 controllers should be used instead.
1141
1142          See Documentation/debugging-via-ohci1394.txt for more information.
1143
1144config FIREWIRE_OHCI_REMOTE_DMA
1145        bool "Remote debugging over FireWire with firewire-ohci"
1146        depends on FIREWIRE_OHCI
1147        help
1148          This option lets you use the FireWire bus for remote debugging
1149          with help of the firewire-ohci driver. It enables unfiltered
1150          remote DMA in firewire-ohci.
1151          See Documentation/debugging-via-ohci1394.txt for more information.
1152
1153          If unsure, say N.
1154
1155config BUILD_DOCSRC
1156        bool "Build targets in Documentation/ tree"
1157        depends on HEADERS_CHECK
1158        help
1159          This option attempts to build objects from the source files in the
1160          kernel Documentation/ tree.
1161
1162          Say N if you are unsure.
1163
1164config DYNAMIC_DEBUG
1165        bool "Enable dynamic printk() support"
1166        default n
1167        depends on PRINTK
1168        depends on DEBUG_FS
1169        help
1170
1171          Compiles debug level messages into the kernel, which would not
1172          otherwise be available at runtime. These messages can then be
1173          enabled/disabled based on various levels of scope - per source file,
1174          function, module, format string, and line number. This mechanism
1175          implicitly enables all pr_debug() and dev_dbg() calls. The impact of
1176          this compile option is a larger kernel text size of about 2%.
1177
1178          Usage:
1179
1180          Dynamic debugging is controlled via the 'dynamic_debug/control' file,
1181          which is contained in the 'debugfs' filesystem. Thus, the debugfs
1182          filesystem must first be mounted before making use of this feature.
1183          We refer the control file as: <debugfs>/dynamic_debug/control. This
1184          file contains a list of the debug statements that can be enabled. The
1185          format for each line of the file is:
1186
1187                filename:lineno [module]function flags format
1188
1189          filename : source file of the debug statement
1190          lineno : line number of the debug statement
1191          module : module that contains the debug statement
1192          function : function that contains the debug statement
1193          flags : 'p' means the line is turned 'on' for printing
1194          format : the format used for the debug statement
1195
1196          From a live system:
1197
1198                nullarbor:~ # cat <debugfs>/dynamic_debug/control
1199                # filename:lineno [module]function flags format
1200                fs/aio.c:222 [aio]__put_ioctx - "__put_ioctx:\040freeing\040%p\012"
1201                fs/aio.c:248 [aio]ioctx_alloc - "ENOMEM:\040nr_events\040too\040high\012"
1202                fs/aio.c:1770 [aio]sys_io_cancel - "calling\040cancel\012"
1203
1204          Example usage:
1205
1206                // enable the message at line 1603 of file svcsock.c
1207                nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
1208                                                <debugfs>/dynamic_debug/control
1209
1210                // enable all the messages in file svcsock.c
1211                nullarbor:~ # echo -n 'file svcsock.c +p' >
1212                                                <debugfs>/dynamic_debug/control
1213
1214                // enable all the messages in the NFS server module
1215                nullarbor:~ # echo -n 'module nfsd +p' >
1216                                                <debugfs>/dynamic_debug/control
1217
1218                // enable all 12 messages in the function svc_process()
1219                nullarbor:~ # echo -n 'func svc_process +p' >
1220                                                <debugfs>/dynamic_debug/control
1221
1222                // disable all 12 messages in the function svc_process()
1223                nullarbor:~ # echo -n 'func svc_process -p' >
1224                                                <debugfs>/dynamic_debug/control
1225
1226          See Documentation/dynamic-debug-howto.txt for additional information.
1227
1228config DMA_API_DEBUG
1229        bool "Enable debugging of DMA-API usage"
1230        depends on HAVE_DMA_API_DEBUG
1231        help
1232          Enable this option to debug the use of the DMA API by device drivers.
1233          With this option you will be able to detect common bugs in device
1234          drivers like double-freeing of DMA mappings or freeing mappings that
1235          were never allocated.
1236          This option causes a performance degredation.  Use only if you want
1237          to debug device drivers. If unsure, say N.
1238
1239config ATOMIC64_SELFTEST
1240        bool "Perform an atomic64_t self-test at boot"
1241        help
1242          Enable this option to test the atomic64_t functions at boot.
1243
1244          If unsure, say N.
1245
1246config ASYNC_RAID6_TEST
1247        tristate "Self test for hardware accelerated raid6 recovery"
1248        depends on ASYNC_RAID6_RECOV
1249        select ASYNC_MEMCPY
1250        ---help---
1251          This is a one-shot self test that permutes through the
1252          recovery of all the possible two disk failure scenarios for a
1253          N-disk array.  Recovery is performed with the asynchronous
1254          raid6 recovery routines, and will optionally use an offload
1255          engine if one is available.
1256
1257          If unsure, say N.
1258
1259source "samples/Kconfig"
1260
1261source "lib/Kconfig.kgdb"
1262
1263source "lib/Kconfig.kmemcheck"
1264
1265config TEST_KSTRTOX
1266        tristate "Test kstrto*() family of functions at runtime"
1267
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.