lib/Kconfig.debug

   1
   2 config 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.
  11
  12 config ENABLE_WARN_DEPRECATED
  13         bool "Enable __deprecated logic"
  14         default y
  15         help
  16           Enable the __deprecated logic in the kernel build.
  17           Disable this to suppress the "warning: 'foo' is deprecated
  18           (declared at kernel/power/somefile.c:1234)" messages.
  19
  20 config ENABLE_MUST_CHECK
  21         bool "Enable __must_check logic"
  22         default y
  23         help
  24           Enable the __must_check logic in the kernel build.  Disable this to
  25           suppress the "warning: ignoring return value of 'foo', declared with
  26           attribute warn_unused_result" messages.
  27
  28 config FRAME_WARN
  29         int "Warn for stack frames larger than (needs gcc 4.4)"
  30         range 0 8192
  31         default 1024 if !64BIT
  32         default 2048 if 64BIT
  33         help
  34           Tell gcc to warn at build time for stack frames larger than this.
  35           Setting this too low will cause a lot of warnings.
  36           Setting it to 0 disables the warning.
  37           Requires gcc 4.4
  38
  39 config MAGIC_SYSRQ
  40         bool "Magic SysRq key"
  41         depends on !UML
  42         help
  43           If you say Y here, you will have some control over the system even
  44           if the system crashes for example during kernel debugging (e.g., you
  45           will be able to flush the buffer cache to disk, reboot the system
  46           immediately or dump some status information). This is accomplished
  47           by pressing various keys while holding SysRq (Alt+PrintScreen). It
  48           also works on a serial console (on PC hardware at least), if you
  49           send a BREAK and then within 5 seconds a command keypress. The
  50           keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
  51           unless you really know what this hack does.
  52
  53 config UNUSED_SYMBOLS
  54         bool "Enable unused/obsolete exported symbols"
  55         default y if X86
  56         help
  57           Unused but exported symbols make the kernel needlessly bigger.  For
  58           that reason most of these unused exports will soon be removed.  This
  59           option is provided temporarily to provide a transition period in case
  60           some external kernel module needs one of these symbols anyway. If you
  61           encounter such a case in your module, consider if you are actually
  62           using the right API.  (rationale: since nobody in the kernel is using
  63           this in a module, there is a pretty good chance it's actually the
  64           wrong interface to use).  If you really need the symbol, please send a
  65           mail to the linux kernel mailing list mentioning the symbol and why
  66           you really need it, and what the merge plan to the mainline kernel for
  67           your module is.
  68
  69 config DEBUG_FS
  70         bool "Debug Filesystem"
  71         depends on SYSFS
  72         help
  73           debugfs is a virtual file system that kernel developers use to put
  74           debugging files into.  Enable this option to be able to read and
  75           write to these files.
  76
  77           If unsure, say N.
  78
  79 config HEADERS_CHECK
  80         bool "Run 'make headers_check' when building vmlinux"
  81         depends on !UML
  82         help
  83           This option will extract the user-visible kernel headers whenever
  84           building the kernel, and will run basic sanity checks on them to
  85           ensure that exported files do not attempt to include files which
  86           were not exported, etc.
  87
  88           If you're making modifications to header files which are
  89           relevant for userspace, say 'Y', and check the headers
  90           exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in
  91           your build tree), to make sure they're suitable.
  92
  93 config DEBUG_SECTION_MISMATCH
  94         bool "Enable full Section mismatch analysis"
  95         depends on UNDEFINED
  96         # This option is on purpose disabled for now.
  97         # It will be enabled when we are down to a resonable number
  98         # of section mismatch warnings (< 10 for an allyesconfig build)
  99         help
 100           The section mismatch analysis checks if there are illegal
 101           references from one section to another section.
 102           Linux will during link or during runtime drop some sections
 103           and any use of code/data previously in these sections will
 104           most likely result in an oops.
 105           In the code functions and variables are annotated with
 106           __init, __devinit etc. (see full list in include/linux/init.h)
 107           which results in the code/data being placed in specific sections.
 108           The section mismatch analysis is always done after a full
 109           kernel build but enabling this option will in addition
 110           do the following:
 111           - Add the option -fno-inline-functions-called-once to gcc
 112             When inlining a function annotated __init in a non-init
 113             function we would lose the section information and thus
 114             the analysis would not catch the illegal reference.
 115             This option tells gcc to inline less but will also
 116             result in a larger kernel.
 117           - Run the section mismatch analysis for each module/built-in.o
 118             When we run the section mismatch analysis on vmlinux.o we
 119             lose valueble information about where the mismatch was
 120             introduced.
 121             Running the analysis for each module/built-in.o file
 122             will tell where the mismatch happens much closer to the
 123             source. The drawback is that we will report the same
 124             mismatch at least twice.
 125           - Enable verbose reporting from modpost to help solving
 126             the section mismatches reported.
 127
 128 config DEBUG_KERNEL
 129         bool "Kernel debugging"
 130         help
 131           Say Y here if you are developing drivers or trying to debug and
 132           identify kernel problems.
 133
 134 config DEBUG_SHIRQ
 135         bool "Debug shared IRQ handlers"
 136         depends on DEBUG_KERNEL && GENERIC_HARDIRQS
 137         help
 138           Enable this to generate a spurious interrupt as soon as a shared
 139           interrupt handler is registered, and just before one is deregistered.
 140           Drivers ought to be able to handle interrupts coming in at those
 141           points; some don't and need to be caught.
 142
 143 config DETECT_SOFTLOCKUP
 144         bool "Detect Soft Lockups"
 145         depends on DEBUG_KERNEL && !S390
 146         default y
 147         help
 148           Say Y here to enable the kernel to detect "soft lockups",
 149           which are bugs that cause the kernel to loop in kernel
 150           mode for more than 60 seconds, without giving other tasks a
 151           chance to run.
 152
 153           When a soft-lockup is detected, the kernel will print the
 154           current stack trace (which you should report), but the
 155           system will stay locked up. This feature has negligible
 156           overhead.
 157
 158           (Note that "hard lockups" are separate type of bugs that
 159            can be detected via the NMI-watchdog, on platforms that
 160            support it.)
 161
 162 config BOOTPARAM_SOFTLOCKUP_PANIC
 163         bool "Panic (Reboot) On Soft Lockups"
 164         depends on DETECT_SOFTLOCKUP
 165         help
 166           Say Y here to enable the kernel to panic on "soft lockups",
 167           which are bugs that cause the kernel to loop in kernel
 168           mode for more than 60 seconds, without giving other tasks a
 169           chance to run.
 170
 171           The panic can be used in combination with panic_timeout,
 172           to cause the system to reboot automatically after a
 173           lockup has been detected. This feature is useful for
 174           high-availability systems that have uptime guarantees and
 175           where a lockup must be resolved ASAP.
 176
 177           Say N if unsure.
 178
 179 config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
 180         int
 181         depends on DETECT_SOFTLOCKUP
 182         range 0 1
 183         default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
 184         default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
 185
 186 config SCHED_DEBUG
 187         bool "Collect scheduler debugging info"
 188         depends on DEBUG_KERNEL && PROC_FS
 189         default y
 190         help
 191           If you say Y here, the /proc/sched_debug file will be provided
 192           that can help debug the scheduler. The runtime overhead of this
 193           option is minimal.
 194
 195 config SCHEDSTATS
 196         bool "Collect scheduler statistics"
 197         depends on DEBUG_KERNEL && PROC_FS
 198         help
 199           If you say Y here, additional code will be inserted into the
 200           scheduler and related routines to collect statistics about
 201           scheduler behavior and provide them in /proc/schedstat.  These
 202           stats may be useful for both tuning and debugging the scheduler
 203           If you aren't debugging the scheduler or trying to tune a specific
 204           application, you can say N to avoid the very slight overhead
 205           this adds.
 206
 207 config TIMER_STATS
 208         bool "Collect kernel timers statistics"
 209         depends on DEBUG_KERNEL && PROC_FS
 210         help
 211           If you say Y here, additional code will be inserted into the
 212           timer routines to collect statistics about kernel timers being
 213           reprogrammed. The statistics can be read from /proc/timer_stats.
 214           The statistics collection is started by writing 1 to /proc/timer_stats,
 215           writing 0 stops it. This feature is useful to collect information
 216           about timer usage patterns in kernel and userspace. This feature
 217           is lightweight if enabled in the kernel config but not activated
 218           (it defaults to deactivated on bootup and will only be activated
 219           if some application like powertop activates it explicitly).
 220
 221 config DEBUG_OBJECTS
 222         bool "Debug object operations"
 223         depends on DEBUG_KERNEL
 224         help
 225           If you say Y here, additional code will be inserted into the
 226           kernel to track the life time of various objects and validate
 227           the operations on those objects.
 228
 229 config DEBUG_OBJECTS_SELFTEST
 230         bool "Debug objects selftest"
 231         depends on DEBUG_OBJECTS
 232         help
 233           This enables the selftest of the object debug code.
 234
 235 config DEBUG_OBJECTS_FREE
 236         bool "Debug objects in freed memory"
 237         depends on DEBUG_OBJECTS
 238         help
 239           This enables checks whether a k/v free operation frees an area
 240           which contains an object which has not been deactivated
 241           properly. This can make kmalloc/kfree-intensive workloads
 242           much slower.
 243
 244 config DEBUG_OBJECTS_TIMERS
 245         bool "Debug timer objects"
 246         depends on DEBUG_OBJECTS
 247         help
 248           If you say Y here, additional code will be inserted into the
 249           timer routines to track the life time of timer objects and
 250           validate the timer operations.
 251
 252 config DEBUG_SLAB
 253         bool "Debug slab memory allocations"
 254         depends on DEBUG_KERNEL && SLAB
 255         help
 256           Say Y here to have the kernel do limited verification on memory
 257           allocation as well as poisoning memory on free to catch use of freed
 258           memory. This can make kmalloc/kfree-intensive workloads much slower.
 259
 260 config DEBUG_SLAB_LEAK
 261         bool "Memory leak debugging"
 262         depends on DEBUG_SLAB
 263
 264 config SLUB_DEBUG_ON
 265         bool "SLUB debugging on by default"
 266         depends on SLUB && SLUB_DEBUG
 267         default n
 268         help
 269           Boot with debugging on by default. SLUB boots by default with
 270           the runtime debug capabilities switched off. Enabling this is
 271           equivalent to specifying the "slub_debug" parameter on boot.
 272           There is no support for more fine grained debug control like
 273           possible with slub_debug=xxx. SLUB debugging may be switched
 274           off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
 275           "slub_debug=-".
 276
 277 config SLUB_STATS
 278         default n
 279         bool "Enable SLUB performance statistics"
 280         depends on SLUB && SLUB_DEBUG && SYSFS
 281         help
 282           SLUB statistics are useful to debug SLUBs allocation behavior in
 283           order find ways to optimize the allocator. This should never be
 284           enabled for production use since keeping statistics slows down
 285           the allocator by a few percentage points. The slabinfo command
 286           supports the determination of the most active slabs to figure
 287           out which slabs are relevant to a particular load.
 288           Try running: slabinfo -DA
 289
 290 config DEBUG_PREEMPT
 291         bool "Debug preemptible kernel"
 292         depends on DEBUG_KERNEL && PREEMPT && (TRACE_IRQFLAGS_SUPPORT || PPC64)
 293         default y
 294         help
 295           If you say Y here then the kernel will use a debug variant of the
 296           commonly used smp_processor_id() function and will print warnings
 297           if kernel code uses it in a preemption-unsafe way. Also, the kernel
 298           will detect preemption count underflows.
 299
 300 config DEBUG_RT_MUTEXES
 301         bool "RT Mutex debugging, deadlock detection"
 302         depends on DEBUG_KERNEL && RT_MUTEXES
 303         help
 304          This allows rt mutex semantics violations and rt mutex related
 305          deadlocks (lockups) to be detected and reported automatically.
 306
 307 config DEBUG_PI_LIST
 308         bool
 309         default y
 310         depends on DEBUG_RT_MUTEXES
 311
 312 config RT_MUTEX_TESTER
 313         bool "Built-in scriptable tester for rt-mutexes"
 314         depends on DEBUG_KERNEL && RT_MUTEXES
 315         help
 316           This option enables a rt-mutex tester.
 317
 318 config DEBUG_SPINLOCK
 319         bool "Spinlock and rw-lock debugging: basic checks"
 320         depends on DEBUG_KERNEL
 321         help
 322           Say Y here and build SMP to catch missing spinlock initialization
 323           and certain other kinds of spinlock errors commonly made.  This is
 324           best used in conjunction with the NMI watchdog so that spinlock
 325           deadlocks are also debuggable.
 326
 327 config DEBUG_MUTEXES
 328         bool "Mutex debugging: basic checks"
 329         depends on DEBUG_KERNEL
 330         help
 331          This feature allows mutex semantics violations to be detected and
 332          reported.
 333
 334 config DEBUG_LOCK_ALLOC
 335         bool "Lock debugging: detect incorrect freeing of live locks"
 336         depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
 337         select DEBUG_SPINLOCK
 338         select DEBUG_MUTEXES
 339         select LOCKDEP
 340         help
 341          This feature will check whether any held lock (spinlock, rwlock,
 342          mutex or rwsem) is incorrectly freed by the kernel, via any of the
 343          memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
 344          vfree(), etc.), whether a live lock is incorrectly reinitialized via
 345          spin_lock_init()/mutex_init()/etc., or whether there is any lock
 346          held during task exit.
 347
 348 config PROVE_LOCKING
 349         bool "Lock debugging: prove locking correctness"
 350         depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
 351         select LOCKDEP
 352         select DEBUG_SPINLOCK
 353         select DEBUG_MUTEXES
 354         select DEBUG_LOCK_ALLOC
 355         default n
 356         help
 357          This feature enables the kernel to prove that all locking
 358          that occurs in the kernel runtime is mathematically
 359          correct: that under no circumstance could an arbitrary (and
 360          not yet triggered) combination of observed locking
 361          sequences (on an arbitrary number of CPUs, running an
 362          arbitrary number of tasks and interrupt contexts) cause a
 363          deadlock.
 364
 365          In short, this feature enables the kernel to report locking
 366          related deadlocks before they actually occur.
 367
 368          The proof does not depend on how hard and complex a
 369          deadlock scenario would be to trigger: how many
 370          participant CPUs, tasks and irq-contexts would be needed
 371          for it to trigger. The proof also does not depend on
 372          timing: if a race and a resulting deadlock is possible
 373          theoretically (no matter how unlikely the race scenario
 374          is), it will be proven so and will immediately be
 375          reported by the kernel (once the event is observed that
 376          makes the deadlock theoretically possible).
 377
 378          If a deadlock is impossible (i.e. the locking rules, as
 379          observed by the kernel, are mathematically correct), the
 380          kernel reports nothing.
 381
 382          NOTE: this feature can also be enabled for rwlocks, mutexes
 383          and rwsems - in which case all dependencies between these
 384          different locking variants are observed and mapped too, and
 385          the proof of observed correctness is also maintained for an
 386          arbitrary combination of these separate locking variants.
 387
 388          For more details, see Documentation/lockdep-design.txt.
 389
 390 config LOCKDEP
 391         bool
 392         depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
 393         select STACKTRACE
 394         select FRAME_POINTER if !X86 && !MIPS
 395         select KALLSYMS
 396         select KALLSYMS_ALL
 397
 398 config LOCK_STAT
 399         bool "Lock usage statistics"
 400         depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
 401         select LOCKDEP
 402         select DEBUG_SPINLOCK
 403         select DEBUG_MUTEXES
 404         select DEBUG_LOCK_ALLOC
 405         default n
 406         help
 407          This feature enables tracking lock contention points
 408
 409          For more details, see Documentation/lockstat.txt
 410
 411 config DEBUG_LOCKDEP
 412         bool "Lock dependency engine debugging"
 413         depends on DEBUG_KERNEL && LOCKDEP
 414         help
 415           If you say Y here, the lock dependency engine will do
 416           additional runtime checks to debug itself, at the price
 417           of more runtime overhead.
 418
 419 config TRACE_IRQFLAGS
 420         depends on DEBUG_KERNEL
 421         bool
 422         default y
 423         depends on TRACE_IRQFLAGS_SUPPORT
 424         depends on PROVE_LOCKING
 425
 426 config DEBUG_SPINLOCK_SLEEP
 427         bool "Spinlock debugging: sleep-inside-spinlock checking"
 428         depends on DEBUG_KERNEL
 429         help
 430           If you say Y here, various routines which may sleep will become very
 431           noisy if they are called with a spinlock held.
 432
 433 config DEBUG_LOCKING_API_SELFTESTS
 434         bool "Locking API boot-time self-tests"
 435         depends on DEBUG_KERNEL
 436         help
 437           Say Y here if you want the kernel to run a short self-test during
 438           bootup. The self-test checks whether common types of locking bugs
 439           are detected by debugging mechanisms or not. (if you disable
 440           lock debugging then those bugs wont be detected of course.)
 441           The following locking APIs are covered: spinlocks, rwlocks,
 442           mutexes and rwsems.
 443
 444 config STACKTRACE
 445         bool
 446         depends on STACKTRACE_SUPPORT
 447
 448 config DEBUG_KOBJECT
 449         bool "kobject debugging"
 450         depends on DEBUG_KERNEL
 451         help
 452           If you say Y here, some extra kobject debugging messages will be sent
 453           to the syslog.
 454
 455 config DEBUG_HIGHMEM
 456         bool "Highmem debugging"
 457         depends on DEBUG_KERNEL && HIGHMEM
 458         help
 459           This options enables addition error checking for high memory systems.
 460           Disable for production systems.
 461
 462 config DEBUG_BUGVERBOSE
 463         bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EMBEDDED
 464         depends on BUG
 465         depends on ARM || AVR32 || M32R || M68K || SPARC32 || SPARC64 || \
 466                    FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300
 467         default !EMBEDDED
 468         help
 469           Say Y here to make BUG() panics output the file name and line number
 470           of the BUG call as well as the EIP and oops trace.  This aids
 471           debugging but costs about 70-100K of memory.
 472
 473 config DEBUG_INFO
 474         bool "Compile the kernel with debug info"
 475         depends on DEBUG_KERNEL
 476         help
 477           If you say Y here the resulting kernel image will include
 478           debugging info resulting in a larger kernel image.
 479           This adds debug symbols to the kernel and modules (gcc -g), and
 480           is needed if you intend to use kernel crashdump or binary object
 481           tools like crash, kgdb, LKCD, gdb, etc on the kernel.
 482           Say Y here only if you plan to debug the kernel.
 483
 484           If unsure, say N.
 485
 486 config DEBUG_VM
 487         bool "Debug VM"
 488         depends on DEBUG_KERNEL
 489         help
 490           Enable this to turn on extended checks in the virtual-memory system
 491           that may impact performance.
 492
 493           If unsure, say N.
 494
 495 config DEBUG_WRITECOUNT
 496         bool "Debug filesystem writers count"
 497         depends on DEBUG_KERNEL
 498         help
 499           Enable this to catch wrong use of the writers count in struct
 500           vfsmount.  This will increase the size of each file struct by
 501           32 bits.
 502
 503           If unsure, say N.
 504
 505 config DEBUG_LIST
 506         bool "Debug linked list manipulation"
 507         depends on DEBUG_KERNEL
 508         help
 509           Enable this to turn on extended checks in the linked-list
 510           walking routines.
 511
 512           If unsure, say N.
 513
 514 config DEBUG_SG
 515         bool "Debug SG table operations"
 516         depends on DEBUG_KERNEL
 517         help
 518           Enable this to turn on checks on scatter-gather tables. This can
 519           help find problems with drivers that do not properly initialize
 520           their sg tables.
 521
 522           If unsure, say N.
 523
 524 config FRAME_POINTER
 525         bool "Compile the kernel with frame pointers"
 526         depends on DEBUG_KERNEL && \
 527                 (X86 || CRIS || M68K || M68KNOMMU || FRV || UML || S390 || \
 528                  AVR32 || SUPERH || BLACKFIN || MN10300)
 529         default y if DEBUG_INFO && UML
 530         help
 531           If you say Y here the resulting kernel image will be slightly larger
 532           and slower, but it might give very useful debugging information on
 533           some architectures or if you use external debuggers.
 534           If you don't debug the kernel, you can say N.
 535
 536 config BOOT_PRINTK_DELAY
 537         bool "Delay each boot printk message by N milliseconds"
 538         depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
 539         help
 540           This build option allows you to read kernel boot messages
 541           by inserting a short delay after each one.  The delay is
 542           specified in milliseconds on the kernel command line,
 543           using "boot_delay=N".
 544
 545           It is likely that you would also need to use "lpj=M" to preset
 546           the "loops per jiffie" value.
 547           See a previous boot log for the "lpj" value to use for your
 548           system, and then set "lpj=M" before setting "boot_delay=N".
 549           NOTE:  Using this option may adversely affect SMP systems.
 550           I.e., processors other than the first one may not boot up.
 551           BOOT_PRINTK_DELAY also may cause DETECT_SOFTLOCKUP to detect
 552           what it believes to be lockup conditions.
 553
 554 config RCU_TORTURE_TEST
 555         tristate "torture tests for RCU"
 556         depends on DEBUG_KERNEL
 557         depends on m
 558         default n
 559         help
 560           This option provides a kernel module that runs torture tests
 561           on the RCU infrastructure.  The kernel module may be built
 562           after the fact on the running kernel to be tested, if desired.
 563
 564           Say M if you want the RCU torture tests to build as a module.
 565           Say N if you are unsure.
 566
 567 config KPROBES_SANITY_TEST
 568         bool "Kprobes sanity tests"
 569         depends on DEBUG_KERNEL
 570         depends on KPROBES
 571         default n
 572         help
 573           This option provides for testing basic kprobes functionality on
 574           boot. A sample kprobe, jprobe and kretprobe are inserted and
 575           verified for functionality.
 576
 577           Say N if you are unsure.
 578
 579 config BACKTRACE_SELF_TEST
 580         tristate "Self test for the backtrace code"
 581         depends on DEBUG_KERNEL
 582         default n
 583         help
 584           This option provides a kernel module that can be used to test
 585           the kernel stack backtrace code. This option is not useful
 586           for distributions or general kernels, but only for kernel
 587           developers working on architecture code.
 588
 589           Note that if you want to also test saved backtraces, you will
 590           have to enable STACKTRACE as well.
 591
 592           Say N if you are unsure.
 593
 594 config LKDTM
 595         tristate "Linux Kernel Dump Test Tool Module"
 596         depends on DEBUG_KERNEL
 597         depends on KPROBES
 598         depends on BLOCK
 599         default n
 600         help
 601         This module enables testing of the different dumping mechanisms by
 602         inducing system failures at predefined crash points.
 603         If you don't need it: say N
 604         Choose M here to compile this code as a module. The module will be
 605         called lkdtm.
 606
 607         Documentation on how to use the module can be found in
 608         drivers/misc/lkdtm.c
 609
 610 config FAULT_INJECTION
 611         bool "Fault-injection framework"
 612         depends on DEBUG_KERNEL
 613         help
 614           Provide fault-injection framework.
 615           For more details, see Documentation/fault-injection/.
 616
 617 config FAILSLAB
 618         bool "Fault-injection capability for kmalloc"
 619         depends on FAULT_INJECTION
 620         help
 621           Provide fault-injection capability for kmalloc.
 622
 623 config FAIL_PAGE_ALLOC
 624         bool "Fault-injection capabilitiy for alloc_pages()"
 625         depends on FAULT_INJECTION
 626         help
 627           Provide fault-injection capability for alloc_pages().
 628
 629 config FAIL_MAKE_REQUEST
 630         bool "Fault-injection capability for disk IO"
 631         depends on FAULT_INJECTION
 632         help
 633           Provide fault-injection capability for disk IO.
 634
 635 config FAULT_INJECTION_DEBUG_FS
 636         bool "Debugfs entries for fault-injection capabilities"
 637         depends on FAULT_INJECTION && SYSFS && DEBUG_FS
 638         help
 639           Enable configuration of fault-injection capabilities via debugfs.
 640
 641 config FAULT_INJECTION_STACKTRACE_FILTER
 642         bool "stacktrace filter for fault-injection capabilities"
 643         depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
 644         depends on !X86_64
 645         select STACKTRACE
 646         select FRAME_POINTER
 647         help
 648           Provide stacktrace filter for fault-injection capabilities
 649
 650 config LATENCYTOP
 651         bool "Latency measuring infrastructure"
 652         select FRAME_POINTER if !MIPS
 653         select KALLSYMS
 654         select KALLSYMS_ALL
 655         select STACKTRACE
 656         select SCHEDSTATS
 657         select SCHED_DEBUG
 658         depends on HAVE_LATENCYTOP_SUPPORT
 659         help
 660           Enable this option if you want to use the LatencyTOP tool
 661           to find out which userspace is blocking on what kernel operations.
 662
 663 source kernel/trace/Kconfig
 664
 665 config PROVIDE_OHCI1394_DMA_INIT
 666         bool "Remote debugging over FireWire early on boot"
 667         depends on PCI && X86
 668         help
 669           If you want to debug problems which hang or crash the kernel early
 670           on boot and the crashing machine has a FireWire port, you can use
 671           this feature to remotely access the memory of the crashed machine
 672           over FireWire. This employs remote DMA as part of the OHCI1394
 673           specification which is now the standard for FireWire controllers.
 674
 675           With remote DMA, you can monitor the printk buffer remotely using
 676           firescope and access all memory below 4GB using fireproxy from gdb.
 677           Even controlling a kernel debugger is possible using remote DMA.
 678
 679           Usage:
 680
 681           If ohci1394_dma=early is used as boot parameter, it will initialize
 682           all OHCI1394 controllers which are found in the PCI config space.
 683
 684           As all changes to the FireWire bus such as enabling and disabling
 685           devices cause a bus reset and thereby disable remote DMA for all
 686           devices, be sure to have the cable plugged and FireWire enabled on
 687           the debugging host before booting the debug target for debugging.
 688
 689           This code (~1k) is freed after boot. By then, the firewire stack
 690           in charge of the OHCI-1394 controllers should be used instead.
 691
 692           See Documentation/debugging-via-ohci1394.txt for more information.
 693
 694 config FIREWIRE_OHCI_REMOTE_DMA
 695         bool "Remote debugging over FireWire with firewire-ohci"
 696         depends on FIREWIRE_OHCI
 697         help
 698           This option lets you use the FireWire bus for remote debugging
 699           with help of the firewire-ohci driver. It enables unfiltered
 700           remote DMA in firewire-ohci.
 701           See Documentation/debugging-via-ohci1394.txt for more information.
 702
 703           If unsure, say N.
 704
 705 source "samples/Kconfig"
 706
 707 source "lib/Kconfig.kgdb"