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 10 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 SCHED_DEBUG
 163         bool "Collect scheduler debugging info"
 164         depends on DEBUG_KERNEL && PROC_FS
 165         default y
 166         help
 167           If you say Y here, the /proc/sched_debug file will be provided
 168           that can help debug the scheduler. The runtime overhead of this
 169           option is minimal.
 170
 171 config SCHEDSTATS
 172         bool "Collect scheduler statistics"
 173         depends on DEBUG_KERNEL && PROC_FS
 174         help
 175           If you say Y here, additional code will be inserted into the
 176           scheduler and related routines to collect statistics about
 177           scheduler behavior and provide them in /proc/schedstat.  These
 178           stats may be useful for both tuning and debugging the scheduler
 179           If you aren't debugging the scheduler or trying to tune a specific
 180           application, you can say N to avoid the very slight overhead
 181           this adds.
 182
 183 config TIMER_STATS
 184         bool "Collect kernel timers statistics"
 185         depends on DEBUG_KERNEL && PROC_FS
 186         help
 187           If you say Y here, additional code will be inserted into the
 188           timer routines to collect statistics about kernel timers being
 189           reprogrammed. The statistics can be read from /proc/timer_stats.
 190           The statistics collection is started by writing 1 to /proc/timer_stats,
 191           writing 0 stops it. This feature is useful to collect information
 192           about timer usage patterns in kernel and userspace. This feature
 193           is lightweight if enabled in the kernel config but not activated
 194           (it defaults to deactivated on bootup and will only be activated
 195           if some application like powertop activates it explicitly).
 196
 197 config DEBUG_OBJECTS
 198         bool "Debug object operations"
 199         depends on DEBUG_KERNEL
 200         help
 201           If you say Y here, additional code will be inserted into the
 202           kernel to track the life time of various objects and validate
 203           the operations on those objects.
 204
 205 config DEBUG_OBJECTS_SELFTEST
 206         bool "Debug objects selftest"
 207         depends on DEBUG_OBJECTS
 208         help
 209           This enables the selftest of the object debug code.
 210
 211 config DEBUG_OBJECTS_FREE
 212         bool "Debug objects in freed memory"
 213         depends on DEBUG_OBJECTS
 214         help
 215           This enables checks whether a k/v free operation frees an area
 216           which contains an object which has not been deactivated
 217           properly. This can make kmalloc/kfree-intensive workloads
 218           much slower.
 219
 220 config DEBUG_OBJECTS_TIMERS
 221         bool "Debug timer objects"
 222         depends on DEBUG_OBJECTS
 223         help
 224           If you say Y here, additional code will be inserted into the
 225           timer routines to track the life time of timer objects and
 226           validate the timer operations.
 227
 228 config DEBUG_SLAB
 229         bool "Debug slab memory allocations"
 230         depends on DEBUG_KERNEL && SLAB
 231         help
 232           Say Y here to have the kernel do limited verification on memory
 233           allocation as well as poisoning memory on free to catch use of freed
 234           memory. This can make kmalloc/kfree-intensive workloads much slower.
 235
 236 config DEBUG_SLAB_LEAK
 237         bool "Memory leak debugging"
 238         depends on DEBUG_SLAB
 239
 240 config SLUB_DEBUG_ON
 241         bool "SLUB debugging on by default"
 242         depends on SLUB && SLUB_DEBUG
 243         default n
 244         help
 245           Boot with debugging on by default. SLUB boots by default with
 246           the runtime debug capabilities switched off. Enabling this is
 247           equivalent to specifying the "slub_debug" parameter on boot.
 248           There is no support for more fine grained debug control like
 249           possible with slub_debug=xxx. SLUB debugging may be switched
 250           off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
 251           "slub_debug=-".
 252
 253 config SLUB_STATS
 254         default n
 255         bool "Enable SLUB performance statistics"
 256         depends on SLUB && SLUB_DEBUG && SYSFS
 257         help
 258           SLUB statistics are useful to debug SLUBs allocation behavior in
 259           order find ways to optimize the allocator. This should never be
 260           enabled for production use since keeping statistics slows down
 261           the allocator by a few percentage points. The slabinfo command
 262           supports the determination of the most active slabs to figure
 263           out which slabs are relevant to a particular load.
 264           Try running: slabinfo -DA
 265
 266 config DEBUG_PREEMPT
 267         bool "Debug preemptible kernel"
 268         depends on DEBUG_KERNEL && PREEMPT && (TRACE_IRQFLAGS_SUPPORT || PPC64)
 269         default y
 270         help
 271           If you say Y here then the kernel will use a debug variant of the
 272           commonly used smp_processor_id() function and will print warnings
 273           if kernel code uses it in a preemption-unsafe way. Also, the kernel
 274           will detect preemption count underflows.
 275
 276 config DEBUG_RT_MUTEXES
 277         bool "RT Mutex debugging, deadlock detection"
 278         depends on DEBUG_KERNEL && RT_MUTEXES
 279         help
 280          This allows rt mutex semantics violations and rt mutex related
 281          deadlocks (lockups) to be detected and reported automatically.
 282
 283 config DEBUG_PI_LIST
 284         bool
 285         default y
 286         depends on DEBUG_RT_MUTEXES
 287
 288 config RT_MUTEX_TESTER
 289         bool "Built-in scriptable tester for rt-mutexes"
 290         depends on DEBUG_KERNEL && RT_MUTEXES
 291         help
 292           This option enables a rt-mutex tester.
 293
 294 config DEBUG_SPINLOCK
 295         bool "Spinlock and rw-lock debugging: basic checks"
 296         depends on DEBUG_KERNEL
 297         help
 298           Say Y here and build SMP to catch missing spinlock initialization
 299           and certain other kinds of spinlock errors commonly made.  This is
 300           best used in conjunction with the NMI watchdog so that spinlock
 301           deadlocks are also debuggable.
 302
 303 config DEBUG_MUTEXES
 304         bool "Mutex debugging: basic checks"
 305         depends on DEBUG_KERNEL
 306         help
 307          This feature allows mutex semantics violations to be detected and
 308          reported.
 309
 310 config DEBUG_LOCK_ALLOC
 311         bool "Lock debugging: detect incorrect freeing of live locks"
 312         depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
 313         select DEBUG_SPINLOCK
 314         select DEBUG_MUTEXES
 315         select LOCKDEP
 316         help
 317          This feature will check whether any held lock (spinlock, rwlock,
 318          mutex or rwsem) is incorrectly freed by the kernel, via any of the
 319          memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
 320          vfree(), etc.), whether a live lock is incorrectly reinitialized via
 321          spin_lock_init()/mutex_init()/etc., or whether there is any lock
 322          held during task exit.
 323
 324 config PROVE_LOCKING
 325         bool "Lock debugging: prove locking correctness"
 326         depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
 327         select LOCKDEP
 328         select DEBUG_SPINLOCK
 329         select DEBUG_MUTEXES
 330         select DEBUG_LOCK_ALLOC
 331         default n
 332         help
 333          This feature enables the kernel to prove that all locking
 334          that occurs in the kernel runtime is mathematically
 335          correct: that under no circumstance could an arbitrary (and
 336          not yet triggered) combination of observed locking
 337          sequences (on an arbitrary number of CPUs, running an
 338          arbitrary number of tasks and interrupt contexts) cause a
 339          deadlock.
 340
 341          In short, this feature enables the kernel to report locking
 342          related deadlocks before they actually occur.
 343
 344          The proof does not depend on how hard and complex a
 345          deadlock scenario would be to trigger: how many
 346          participant CPUs, tasks and irq-contexts would be needed
 347          for it to trigger. The proof also does not depend on
 348          timing: if a race and a resulting deadlock is possible
 349          theoretically (no matter how unlikely the race scenario
 350          is), it will be proven so and will immediately be
 351          reported by the kernel (once the event is observed that
 352          makes the deadlock theoretically possible).
 353
 354          If a deadlock is impossible (i.e. the locking rules, as
 355          observed by the kernel, are mathematically correct), the
 356          kernel reports nothing.
 357
 358          NOTE: this feature can also be enabled for rwlocks, mutexes
 359          and rwsems - in which case all dependencies between these
 360          different locking variants are observed and mapped too, and
 361          the proof of observed correctness is also maintained for an
 362          arbitrary combination of these separate locking variants.
 363
 364          For more details, see Documentation/lockdep-design.txt.
 365
 366 config LOCKDEP
 367         bool
 368         depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
 369         select STACKTRACE
 370         select FRAME_POINTER if !X86 && !MIPS
 371         select KALLSYMS
 372         select KALLSYMS_ALL
 373
 374 config LOCK_STAT
 375         bool "Lock usage statistics"
 376         depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
 377         select LOCKDEP
 378         select DEBUG_SPINLOCK
 379         select DEBUG_MUTEXES
 380         select DEBUG_LOCK_ALLOC
 381         default n
 382         help
 383          This feature enables tracking lock contention points
 384
 385          For more details, see Documentation/lockstat.txt
 386
 387 config DEBUG_LOCKDEP
 388         bool "Lock dependency engine debugging"
 389         depends on DEBUG_KERNEL && LOCKDEP
 390         help
 391           If you say Y here, the lock dependency engine will do
 392           additional runtime checks to debug itself, at the price
 393           of more runtime overhead.
 394
 395 config TRACE_IRQFLAGS
 396         depends on DEBUG_KERNEL
 397         bool
 398         default y
 399         depends on TRACE_IRQFLAGS_SUPPORT
 400         depends on PROVE_LOCKING
 401
 402 config DEBUG_SPINLOCK_SLEEP
 403         bool "Spinlock debugging: sleep-inside-spinlock checking"
 404         depends on DEBUG_KERNEL
 405         help
 406           If you say Y here, various routines which may sleep will become very
 407           noisy if they are called with a spinlock held.
 408
 409 config DEBUG_LOCKING_API_SELFTESTS
 410         bool "Locking API boot-time self-tests"
 411         depends on DEBUG_KERNEL
 412         help
 413           Say Y here if you want the kernel to run a short self-test during
 414           bootup. The self-test checks whether common types of locking bugs
 415           are detected by debugging mechanisms or not. (if you disable
 416           lock debugging then those bugs wont be detected of course.)
 417           The following locking APIs are covered: spinlocks, rwlocks,
 418           mutexes and rwsems.
 419
 420 config STACKTRACE
 421         bool
 422         depends on STACKTRACE_SUPPORT
 423
 424 config DEBUG_KOBJECT
 425         bool "kobject debugging"
 426         depends on DEBUG_KERNEL
 427         help
 428           If you say Y here, some extra kobject debugging messages will be sent
 429           to the syslog.
 430
 431 config DEBUG_HIGHMEM
 432         bool "Highmem debugging"
 433         depends on DEBUG_KERNEL && HIGHMEM
 434         help
 435           This options enables addition error checking for high memory systems.
 436           Disable for production systems.
 437
 438 config DEBUG_BUGVERBOSE
 439         bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EMBEDDED
 440         depends on BUG
 441         depends on ARM || AVR32 || M32R || M68K || SPARC32 || SPARC64 || \
 442                    FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300
 443         default !EMBEDDED
 444         help
 445           Say Y here to make BUG() panics output the file name and line number
 446           of the BUG call as well as the EIP and oops trace.  This aids
 447           debugging but costs about 70-100K of memory.
 448
 449 config DEBUG_INFO
 450         bool "Compile the kernel with debug info"
 451         depends on DEBUG_KERNEL
 452         help
 453           If you say Y here the resulting kernel image will include
 454           debugging info resulting in a larger kernel image.
 455           This adds debug symbols to the kernel and modules (gcc -g), and
 456           is needed if you intend to use kernel crashdump or binary object
 457           tools like crash, kgdb, LKCD, gdb, etc on the kernel.
 458           Say Y here only if you plan to debug the kernel.
 459
 460           If unsure, say N.
 461
 462 config DEBUG_VM
 463         bool "Debug VM"
 464         depends on DEBUG_KERNEL
 465         help
 466           Enable this to turn on extended checks in the virtual-memory system
 467           that may impact performance.
 468
 469           If unsure, say N.
 470
 471 config DEBUG_WRITECOUNT
 472         bool "Debug filesystem writers count"
 473         depends on DEBUG_KERNEL
 474         help
 475           Enable this to catch wrong use of the writers count in struct
 476           vfsmount.  This will increase the size of each file struct by
 477           32 bits.
 478
 479           If unsure, say N.
 480
 481 config DEBUG_LIST
 482         bool "Debug linked list manipulation"
 483         depends on DEBUG_KERNEL
 484         help
 485           Enable this to turn on extended checks in the linked-list
 486           walking routines.
 487
 488           If unsure, say N.
 489
 490 config DEBUG_SG
 491         bool "Debug SG table operations"
 492         depends on DEBUG_KERNEL
 493         help
 494           Enable this to turn on checks on scatter-gather tables. This can
 495           help find problems with drivers that do not properly initialize
 496           their sg tables.
 497
 498           If unsure, say N.
 499
 500 config FRAME_POINTER
 501         bool "Compile the kernel with frame pointers"
 502         depends on DEBUG_KERNEL && \
 503                 (X86 || CRIS || M68K || M68KNOMMU || FRV || UML || S390 || \
 504                  AVR32 || SUPERH || BLACKFIN || MN10300)
 505         default y if DEBUG_INFO && UML
 506         help
 507           If you say Y here the resulting kernel image will be slightly larger
 508           and slower, but it might give very useful debugging information on
 509           some architectures or if you use external debuggers.
 510           If you don't debug the kernel, you can say N.
 511
 512 config BOOT_PRINTK_DELAY
 513         bool "Delay each boot printk message by N milliseconds"
 514         depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
 515         help
 516           This build option allows you to read kernel boot messages
 517           by inserting a short delay after each one.  The delay is
 518           specified in milliseconds on the kernel command line,
 519           using "boot_delay=N".
 520
 521           It is likely that you would also need to use "lpj=M" to preset
 522           the "loops per jiffie" value.
 523           See a previous boot log for the "lpj" value to use for your
 524           system, and then set "lpj=M" before setting "boot_delay=N".
 525           NOTE:  Using this option may adversely affect SMP systems.
 526           I.e., processors other than the first one may not boot up.
 527           BOOT_PRINTK_DELAY also may cause DETECT_SOFTLOCKUP to detect
 528           what it believes to be lockup conditions.
 529
 530 config RCU_TORTURE_TEST
 531         tristate "torture tests for RCU"
 532         depends on DEBUG_KERNEL
 533         default n
 534         help
 535           This option provides a kernel module that runs torture tests
 536           on the RCU infrastructure.  The kernel module may be built
 537           after the fact on the running kernel to be tested, if desired.
 538
 539           Say Y here if you want RCU torture tests to be built into
 540           the kernel.
 541           Say M if you want the RCU torture tests to build as a module.
 542           Say N if you are unsure.
 543
 544 config RCU_TORTURE_TEST_RUNNABLE
 545         bool "torture tests for RCU runnable by default"
 546         depends on RCU_TORTURE_TEST = y
 547         default n
 548         help
 549           This option provides a way to build the RCU torture tests
 550           directly into the kernel without them starting up at boot
 551           time.  You can use /proc/sys/kernel/rcutorture_runnable
 552           to manually override this setting.  This /proc file is
 553           available only when the RCU torture tests have been built
 554           into the kernel.
 555
 556           Say Y here if you want the RCU torture tests to start during
 557           boot (you probably don't).
 558           Say N here if you want the RCU torture tests to start only
 559           after being manually enabled via /proc.
 560
 561 config KPROBES_SANITY_TEST
 562         bool "Kprobes sanity tests"
 563         depends on DEBUG_KERNEL
 564         depends on KPROBES
 565         default n
 566         help
 567           This option provides for testing basic kprobes functionality on
 568           boot. A sample kprobe, jprobe and kretprobe are inserted and
 569           verified for functionality.
 570
 571           Say N if you are unsure.
 572
 573 config BACKTRACE_SELF_TEST
 574         tristate "Self test for the backtrace code"
 575         depends on DEBUG_KERNEL
 576         default n
 577         help
 578           This option provides a kernel module that can be used to test
 579           the kernel stack backtrace code. This option is not useful
 580           for distributions or general kernels, but only for kernel
 581           developers working on architecture code.
 582
 583           Note that if you want to also test saved backtraces, you will
 584           have to enable STACKTRACE as well.
 585
 586           Say N if you are unsure.
 587
 588 config LKDTM
 589         tristate "Linux Kernel Dump Test Tool Module"
 590         depends on DEBUG_KERNEL
 591         depends on KPROBES
 592         depends on BLOCK
 593         default n
 594         help
 595         This module enables testing of the different dumping mechanisms by
 596         inducing system failures at predefined crash points.
 597         If you don't need it: say N
 598         Choose M here to compile this code as a module. The module will be
 599         called lkdtm.
 600
 601         Documentation on how to use the module can be found in
 602         drivers/misc/lkdtm.c
 603
 604 config FAULT_INJECTION
 605         bool "Fault-injection framework"
 606         depends on DEBUG_KERNEL
 607         help
 608           Provide fault-injection framework.
 609           For more details, see Documentation/fault-injection/.
 610
 611 config FAILSLAB
 612         bool "Fault-injection capability for kmalloc"
 613         depends on FAULT_INJECTION
 614         help
 615           Provide fault-injection capability for kmalloc.
 616
 617 config FAIL_PAGE_ALLOC
 618         bool "Fault-injection capabilitiy for alloc_pages()"
 619         depends on FAULT_INJECTION
 620         help
 621           Provide fault-injection capability for alloc_pages().
 622
 623 config FAIL_MAKE_REQUEST
 624         bool "Fault-injection capability for disk IO"
 625         depends on FAULT_INJECTION
 626         help
 627           Provide fault-injection capability for disk IO.
 628
 629 config FAULT_INJECTION_DEBUG_FS
 630         bool "Debugfs entries for fault-injection capabilities"
 631         depends on FAULT_INJECTION && SYSFS && DEBUG_FS
 632         help
 633           Enable configuration of fault-injection capabilities via debugfs.
 634
 635 config FAULT_INJECTION_STACKTRACE_FILTER
 636         bool "stacktrace filter for fault-injection capabilities"
 637         depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
 638         depends on !X86_64
 639         select STACKTRACE
 640         select FRAME_POINTER
 641         help
 642           Provide stacktrace filter for fault-injection capabilities
 643
 644 config LATENCYTOP
 645         bool "Latency measuring infrastructure"
 646         select FRAME_POINTER if !MIPS
 647         select KALLSYMS
 648         select KALLSYMS_ALL
 649         select STACKTRACE
 650         select SCHEDSTATS
 651         select SCHED_DEBUG
 652         depends on HAVE_LATENCYTOP_SUPPORT
 653         help
 654           Enable this option if you want to use the LatencyTOP tool
 655           to find out which userspace is blocking on what kernel operations.
 656
 657 source kernel/trace/Kconfig
 658
 659 config PROVIDE_OHCI1394_DMA_INIT
 660         bool "Remote debugging over FireWire early on boot"
 661         depends on PCI && X86
 662         help
 663           If you want to debug problems which hang or crash the kernel early
 664           on boot and the crashing machine has a FireWire port, you can use
 665           this feature to remotely access the memory of the crashed machine
 666           over FireWire. This employs remote DMA as part of the OHCI1394
 667           specification which is now the standard for FireWire controllers.
 668
 669           With remote DMA, you can monitor the printk buffer remotely using
 670           firescope and access all memory below 4GB using fireproxy from gdb.
 671           Even controlling a kernel debugger is possible using remote DMA.
 672
 673           Usage:
 674
 675           If ohci1394_dma=early is used as boot parameter, it will initialize
 676           all OHCI1394 controllers which are found in the PCI config space.
 677
 678           As all changes to the FireWire bus such as enabling and disabling
 679           devices cause a bus reset and thereby disable remote DMA for all
 680           devices, be sure to have the cable plugged and FireWire enabled on
 681           the debugging host before booting the debug target for debugging.
 682
 683           This code (~1k) is freed after boot. By then, the firewire stack
 684           in charge of the OHCI-1394 controllers should be used instead.
 685
 686           See Documentation/debugging-via-ohci1394.txt for more information.
 687
 688 config FIREWIRE_OHCI_REMOTE_DMA
 689         bool "Remote debugging over FireWire with firewire-ohci"
 690         depends on FIREWIRE_OHCI
 691         help
 692           This option lets you use the FireWire bus for remote debugging
 693           with help of the firewire-ohci driver. It enables unfiltered
 694           remote DMA in firewire-ohci.
 695           See Documentation/debugging-via-ohci1394.txt for more information.
 696
 697           If unsure, say N.
 698
 699 source "samples/Kconfig"
 700
 701 source "lib/Kconfig.kgdb"