blob: 7488ff87c9d5df488273545f2b7fceaf0227296c [file] [log] [blame]
xf.libfc6e712025-02-07 01:54:34 -08001
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 During linktime or runtime, some sections are dropped;
121 any use of code/data previously in these sections would
122 most likely result in an oops.
123 In the code, functions and variables are annotated with
124 __init, __devinit, etc. (see the 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 performed after a full
127 kernel build, and enabling this option causes the following
128 additional steps to occur:
129 - Add the option -fno-inline-functions-called-once to gcc commands.
130 When inlining a function annotated with __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 it does result in
134 a larger kernel).
135 - Run the section mismatch analysis for each module/built-in.o file.
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 tells where the mismatch happens much closer to the
141 source. The drawback is that the same mismatch is
142 reported at least twice.
143 - Enable verbose reporting from modpost in order to help resolve
144 the section mismatches that are 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 && !PREEMPT_RT_BASE
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 20 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 10 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 4 seconds.
180 An NMI is generated every 10 seconds or so to check for hardlockups.
181 If NMIs are not available on the platform, every 12 seconds the
182 hrtimer interrupt on one cpu will be used to check for hardlockups
183 on the next cpu.
184
185 The frequency of hrtimer and NMI events and the soft and hard lockup
186 thresholds can be controlled through the sysctl watchdog_thresh.
187
188config HARDLOCKUP_DETECTOR_NMI
189 def_bool LOCKUP_DETECTOR && PERF_EVENTS && HAVE_PERF_EVENTS_NMI && \
190 !HAVE_NMI_WATCHDOG
191
192config HARDLOCKUP_DETECTOR_OTHER_CPU
193 def_bool LOCKUP_DETECTOR && SMP && !HARDLOCKUP_DETECTOR_NMI && \
194 !HAVE_NMI_WATCHDOG
195
196config HARDLOCKUP_DETECTOR
197 def_bool HARDLOCKUP_DETECTOR_NMI || HARDLOCKUP_DETECTOR_OTHER_CPU
198
199config BOOTPARAM_HARDLOCKUP_PANIC
200 bool "Panic (Reboot) On Hard Lockups"
201 depends on LOCKUP_DETECTOR
202 help
203 Say Y here to enable the kernel to panic on "hard lockups",
204 which are bugs that cause the kernel to loop in kernel
205 mode with interrupts disabled for more than 10 seconds (configurable
206 using the watchdog_thresh sysctl).
207
208 Say N if unsure.
209
210config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
211 int
212 depends on LOCKUP_DETECTOR
213 range 0 1
214 default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
215 default 1 if BOOTPARAM_HARDLOCKUP_PANIC
216
217config BOOTPARAM_SOFTLOCKUP_PANIC
218 bool "Panic (Reboot) On Soft Lockups"
219 depends on LOCKUP_DETECTOR
220 help
221 Say Y here to enable the kernel to panic on "soft lockups",
222 which are bugs that cause the kernel to loop in kernel
223 mode for more than 20 seconds (configurable using the watchdog_thresh
224 sysctl), without giving other tasks a chance to run.
225
226 The panic can be used in combination with panic_timeout,
227 to cause the system to reboot automatically after a
228 lockup has been detected. This feature is useful for
229 high-availability systems that have uptime guarantees and
230 where a lockup must be resolved ASAP.
231
232 Say N if unsure.
233
234config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
235 int
236 depends on LOCKUP_DETECTOR
237 range 0 1
238 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
239 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
240
241config DETECT_HUNG_TASK
242 bool "Detect Hung Tasks"
243 depends on DEBUG_KERNEL
244 default LOCKUP_DETECTOR
245 help
246 Say Y here to enable the kernel to detect "hung tasks",
247 which are bugs that cause the task to be stuck in
248 uninterruptible "D" state indefinitiley.
249
250 When a hung task is detected, the kernel will print the
251 current stack trace (which you should report), but the
252 task will stay in uninterruptible state. If lockdep is
253 enabled then all held locks will also be reported. This
254 feature has negligible overhead.
255
256config DEFAULT_HUNG_TASK_TIMEOUT
257 int "Default timeout for hung task detection (in seconds)"
258 depends on DETECT_HUNG_TASK
259 default 120
260 help
261 This option controls the default timeout (in seconds) used
262 to determine when a task has become non-responsive and should
263 be considered hung.
264
265 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
266 sysctl or by writing a value to
267 /proc/sys/kernel/hung_task_timeout_secs.
268
269 A timeout of 0 disables the check. The default is two minutes.
270 Keeping the default should be fine in most cases.
271
272config BOOTPARAM_HUNG_TASK_PANIC
273 bool "Panic (Reboot) On Hung Tasks"
274 depends on DETECT_HUNG_TASK
275 help
276 Say Y here to enable the kernel to panic on "hung tasks",
277 which are bugs that cause the kernel to leave a task stuck
278 in uninterruptible "D" state.
279
280 The panic can be used in combination with panic_timeout,
281 to cause the system to reboot automatically after a
282 hung task has been detected. This feature is useful for
283 high-availability systems that have uptime guarantees and
284 where a hung tasks must be resolved ASAP.
285
286 Say N if unsure.
287
288config BOOTPARAM_HUNG_TASK_PANIC_VALUE
289 int
290 depends on DETECT_HUNG_TASK
291 range 0 1
292 default 0 if !BOOTPARAM_HUNG_TASK_PANIC
293 default 1 if BOOTPARAM_HUNG_TASK_PANIC
294
295config SCHED_DEBUG
296 bool "Collect scheduler debugging info"
297 depends on DEBUG_KERNEL && PROC_FS
298 default y
299 help
300 If you say Y here, the /proc/sched_debug file will be provided
301 that can help debug the scheduler. The runtime overhead of this
302 option is minimal.
303
304config SCHEDSTATS
305 bool "Collect scheduler statistics"
306 depends on DEBUG_KERNEL && PROC_FS
307 help
308 If you say Y here, additional code will be inserted into the
309 scheduler and related routines to collect statistics about
310 scheduler behavior and provide them in /proc/schedstat. These
311 stats may be useful for both tuning and debugging the scheduler
312 If you aren't debugging the scheduler or trying to tune a specific
313 application, you can say N to avoid the very slight overhead
314 this adds.
315
316config TIMER_STATS
317 bool "Collect kernel timers statistics"
318 depends on DEBUG_KERNEL && PROC_FS
319 help
320 If you say Y here, additional code will be inserted into the
321 timer routines to collect statistics about kernel timers being
322 reprogrammed. The statistics can be read from /proc/timer_stats.
323 The statistics collection is started by writing 1 to /proc/timer_stats,
324 writing 0 stops it. This feature is useful to collect information
325 about timer usage patterns in kernel and userspace. This feature
326 is lightweight if enabled in the kernel config but not activated
327 (it defaults to deactivated on bootup and will only be activated
328 if some application like powertop activates it explicitly).
329
330config DEBUG_OBJECTS
331 bool "Debug object operations"
332 depends on DEBUG_KERNEL
333 help
334 If you say Y here, additional code will be inserted into the
335 kernel to track the life time of various objects and validate
336 the operations on those objects.
337
338config DEBUG_OBJECTS_SELFTEST
339 bool "Debug objects selftest"
340 depends on DEBUG_OBJECTS
341 help
342 This enables the selftest of the object debug code.
343
344config DEBUG_OBJECTS_FREE
345 bool "Debug objects in freed memory"
346 depends on DEBUG_OBJECTS
347 help
348 This enables checks whether a k/v free operation frees an area
349 which contains an object which has not been deactivated
350 properly. This can make kmalloc/kfree-intensive workloads
351 much slower.
352
353config DEBUG_OBJECTS_TIMERS
354 bool "Debug timer objects"
355 depends on DEBUG_OBJECTS
356 help
357 If you say Y here, additional code will be inserted into the
358 timer routines to track the life time of timer objects and
359 validate the timer operations.
360
361config DEBUG_OBJECTS_WORK
362 bool "Debug work objects"
363 depends on DEBUG_OBJECTS
364 help
365 If you say Y here, additional code will be inserted into the
366 work queue routines to track the life time of work objects and
367 validate the work operations.
368
369config DEBUG_OBJECTS_RCU_HEAD
370 bool "Debug RCU callbacks objects"
371 depends on DEBUG_OBJECTS
372 help
373 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
374
375config DEBUG_OBJECTS_PERCPU_COUNTER
376 bool "Debug percpu counter objects"
377 depends on DEBUG_OBJECTS
378 help
379 If you say Y here, additional code will be inserted into the
380 percpu counter routines to track the life time of percpu counter
381 objects and validate the percpu counter operations.
382
383config DEBUG_OBJECTS_ENABLE_DEFAULT
384 int "debug_objects bootup default value (0-1)"
385 range 0 1
386 default "1"
387 depends on DEBUG_OBJECTS
388 help
389 Debug objects boot parameter default value
390
391config DEBUG_SLAB
392 bool "Debug slab memory allocations"
393 depends on DEBUG_KERNEL && SLAB && !KMEMCHECK
394 help
395 Say Y here to have the kernel do limited verification on memory
396 allocation as well as poisoning memory on free to catch use of freed
397 memory. This can make kmalloc/kfree-intensive workloads much slower.
398
399config DEBUG_SLAB_LEAK
400 bool "Memory leak debugging"
401 depends on DEBUG_SLAB
402
403config SLUB_DEBUG_ON
404 bool "SLUB debugging on by default"
405 depends on SLUB && SLUB_DEBUG && !KMEMCHECK
406 default n
407 help
408 Boot with debugging on by default. SLUB boots by default with
409 the runtime debug capabilities switched off. Enabling this is
410 equivalent to specifying the "slub_debug" parameter on boot.
411 There is no support for more fine grained debug control like
412 possible with slub_debug=xxx. SLUB debugging may be switched
413 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
414 "slub_debug=-".
415
416config SLUB_STATS
417 default n
418 bool "Enable SLUB performance statistics"
419 depends on SLUB && SYSFS
420 help
421 SLUB statistics are useful to debug SLUBs allocation behavior in
422 order find ways to optimize the allocator. This should never be
423 enabled for production use since keeping statistics slows down
424 the allocator by a few percentage points. The slabinfo command
425 supports the determination of the most active slabs to figure
426 out which slabs are relevant to a particular load.
427 Try running: slabinfo -DA
428
429config DEBUG_KMEMLEAK
430 bool "Kernel memory leak detector"
431 depends on DEBUG_KERNEL && EXPERIMENTAL && \
432 (X86 || ARM || PPC || MIPS || S390 || SPARC64 || SUPERH || MICROBLAZE || TILE)
433
434 select DEBUG_FS
435 select STACKTRACE if STACKTRACE_SUPPORT
436 select KALLSYMS
437 select CRC32
438 help
439 Say Y here if you want to enable the memory leak
440 detector. The memory allocation/freeing is traced in a way
441 similar to the Boehm's conservative garbage collector, the
442 difference being that the orphan objects are not freed but
443 only shown in /sys/kernel/debug/kmemleak. Enabling this
444 feature will introduce an overhead to memory
445 allocations. See Documentation/kmemleak.txt for more
446 details.
447
448 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
449 of finding leaks due to the slab objects poisoning.
450
451 In order to access the kmemleak file, debugfs needs to be
452 mounted (usually at /sys/kernel/debug).
453
454config DEBUG_KMEMLEAK_EARLY_LOG_SIZE
455 int "Maximum kmemleak early log entries"
456 depends on DEBUG_KMEMLEAK
457 range 200 40000
458 default 400
459 help
460 Kmemleak must track all the memory allocations to avoid
461 reporting false positives. Since memory may be allocated or
462 freed before kmemleak is initialised, an early log buffer is
463 used to store these actions. If kmemleak reports "early log
464 buffer exceeded", please increase this value.
465
466config DEBUG_KMEMLEAK_TEST
467 tristate "Simple test for the kernel memory leak detector"
468 depends on DEBUG_KMEMLEAK && m
469 help
470 This option enables a module that explicitly leaks memory.
471
472 If unsure, say N.
473
474config DEBUG_KMEMLEAK_DEFAULT_OFF
475 bool "Default kmemleak to off"
476 depends on DEBUG_KMEMLEAK
477 help
478 Say Y here to disable kmemleak by default. It can then be enabled
479 on the command line via kmemleak=on.
480
481config DEBUG_PREEMPT
482 bool "Debug preemptible kernel"
483 depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT
484 default y
485 help
486 If you say Y here then the kernel will use a debug variant of the
487 commonly used smp_processor_id() function and will print warnings
488 if kernel code uses it in a preemption-unsafe way. Also, the kernel
489 will detect preemption count underflows.
490
491config DEBUG_RT_MUTEXES
492 bool "RT Mutex debugging, deadlock detection"
493 depends on DEBUG_KERNEL && RT_MUTEXES
494 help
495 This allows rt mutex semantics violations and rt mutex related
496 deadlocks (lockups) to be detected and reported automatically.
497
498config DEBUG_PI_LIST
499 bool
500 default y
501 depends on DEBUG_RT_MUTEXES
502
503config RT_MUTEX_TESTER
504 bool "Built-in scriptable tester for rt-mutexes"
505 depends on DEBUG_KERNEL && RT_MUTEXES
506 help
507 This option enables a rt-mutex tester.
508
509config DEBUG_SPINLOCK
510 bool "Spinlock and rw-lock debugging: basic checks"
511 depends on DEBUG_KERNEL
512 select UNINLINE_SPIN_UNLOCK
513 help
514 Say Y here and build SMP to catch missing spinlock initialization
515 and certain other kinds of spinlock errors commonly made. This is
516 best used in conjunction with the NMI watchdog so that spinlock
517 deadlocks are also debuggable.
518
519config DEBUG_MUTEXES
520 bool "Mutex debugging: basic checks"
521 depends on DEBUG_KERNEL
522 help
523 This feature allows mutex semantics violations to be detected and
524 reported.
525
526config DEBUG_LOCK_ALLOC
527 bool "Lock debugging: detect incorrect freeing of live locks"
528 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
529 select DEBUG_SPINLOCK
530 select DEBUG_MUTEXES
531 select LOCKDEP
532 help
533 This feature will check whether any held lock (spinlock, rwlock,
534 mutex or rwsem) is incorrectly freed by the kernel, via any of the
535 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
536 vfree(), etc.), whether a live lock is incorrectly reinitialized via
537 spin_lock_init()/mutex_init()/etc., or whether there is any lock
538 held during task exit.
539
540config PROVE_LOCKING
541 bool "Lock debugging: prove locking correctness"
542 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
543 select LOCKDEP
544 select DEBUG_SPINLOCK
545 select DEBUG_MUTEXES
546 select DEBUG_LOCK_ALLOC
547 select TRACE_IRQFLAGS
548 default n
549 help
550 This feature enables the kernel to prove that all locking
551 that occurs in the kernel runtime is mathematically
552 correct: that under no circumstance could an arbitrary (and
553 not yet triggered) combination of observed locking
554 sequences (on an arbitrary number of CPUs, running an
555 arbitrary number of tasks and interrupt contexts) cause a
556 deadlock.
557
558 In short, this feature enables the kernel to report locking
559 related deadlocks before they actually occur.
560
561 The proof does not depend on how hard and complex a
562 deadlock scenario would be to trigger: how many
563 participant CPUs, tasks and irq-contexts would be needed
564 for it to trigger. The proof also does not depend on
565 timing: if a race and a resulting deadlock is possible
566 theoretically (no matter how unlikely the race scenario
567 is), it will be proven so and will immediately be
568 reported by the kernel (once the event is observed that
569 makes the deadlock theoretically possible).
570
571 If a deadlock is impossible (i.e. the locking rules, as
572 observed by the kernel, are mathematically correct), the
573 kernel reports nothing.
574
575 NOTE: this feature can also be enabled for rwlocks, mutexes
576 and rwsems - in which case all dependencies between these
577 different locking variants are observed and mapped too, and
578 the proof of observed correctness is also maintained for an
579 arbitrary combination of these separate locking variants.
580
581 For more details, see Documentation/lockdep-design.txt.
582
583config PROVE_RCU
584 bool "RCU debugging: prove RCU correctness"
585 depends on PROVE_LOCKING
586 default n
587 help
588 This feature enables lockdep extensions that check for correct
589 use of RCU APIs. This is currently under development. Say Y
590 if you want to debug RCU usage or help work on the PROVE_RCU
591 feature.
592
593 Say N if you are unsure.
594
595config PROVE_RCU_REPEATEDLY
596 bool "RCU debugging: don't disable PROVE_RCU on first splat"
597 depends on PROVE_RCU
598 default n
599 help
600 By itself, PROVE_RCU will disable checking upon issuing the
601 first warning (or "splat"). This feature prevents such
602 disabling, allowing multiple RCU-lockdep warnings to be printed
603 on a single reboot.
604
605 Say Y to allow multiple RCU-lockdep warnings per boot.
606
607 Say N if you are unsure.
608
609config SPARSE_RCU_POINTER
610 bool "RCU debugging: sparse-based checks for pointer usage"
611 default n
612 help
613 This feature enables the __rcu sparse annotation for
614 RCU-protected pointers. This annotation will cause sparse
615 to flag any non-RCU used of annotated pointers. This can be
616 helpful when debugging RCU usage. Please note that this feature
617 is not intended to enforce code cleanliness; it is instead merely
618 a debugging aid.
619
620 Say Y to make sparse flag questionable use of RCU-protected pointers
621
622 Say N if you are unsure.
623
624config LOCKDEP
625 bool
626 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
627 select STACKTRACE
628 select FRAME_POINTER if !MIPS && !PPC && !ARM_UNWIND && !S390 && !MICROBLAZE
629 select KALLSYMS
630 select KALLSYMS_ALL
631
632config LOCK_STAT
633 bool "Lock usage statistics"
634 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
635 select LOCKDEP
636 select DEBUG_SPINLOCK
637 select DEBUG_MUTEXES
638 select DEBUG_LOCK_ALLOC
639 default n
640 help
641 This feature enables tracking lock contention points
642
643 For more details, see Documentation/lockstat.txt
644
645 This also enables lock events required by "perf lock",
646 subcommand of perf.
647 If you want to use "perf lock", you also need to turn on
648 CONFIG_EVENT_TRACING.
649
650 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
651 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
652
653config DEBUG_LOCKDEP
654 bool "Lock dependency engine debugging"
655 depends on DEBUG_KERNEL && LOCKDEP
656 help
657 If you say Y here, the lock dependency engine will do
658 additional runtime checks to debug itself, at the price
659 of more runtime overhead.
660
661config TRACE_IRQFLAGS
662 bool
663 help
664 Enables hooks to interrupt enabling and disabling for
665 either tracing or lock debugging.
666
667config DEBUG_ATOMIC_SLEEP
668 bool "Sleep inside atomic section checking"
669 select PREEMPT_COUNT
670 depends on DEBUG_KERNEL
671 help
672 If you say Y here, various routines which may sleep will become very
673 noisy if they are called inside atomic sections: when a spinlock is
674 held, inside an rcu read side critical section, inside preempt disabled
675 sections, inside an interrupt, etc...
676
677config DEBUG_LOCKING_API_SELFTESTS
678 bool "Locking API boot-time self-tests"
679 depends on DEBUG_KERNEL
680 help
681 Say Y here if you want the kernel to run a short self-test during
682 bootup. The self-test checks whether common types of locking bugs
683 are detected by debugging mechanisms or not. (if you disable
684 lock debugging then those bugs wont be detected of course.)
685 The following locking APIs are covered: spinlocks, rwlocks,
686 mutexes and rwsems.
687
688config STACKTRACE
689 bool "Stacktrace"
690 depends on STACKTRACE_SUPPORT
691 default y
692
693config DEBUG_STACK_USAGE
694 bool "Stack utilization instrumentation"
695 depends on DEBUG_KERNEL
696 help
697 Enables the display of the minimum amount of free stack which each
698 task has ever had available in the sysrq-T and sysrq-P debug output.
699
700 This option will slow down process creation somewhat.
701
702config DEBUG_KOBJECT
703 bool "kobject debugging"
704 depends on DEBUG_KERNEL
705 help
706 If you say Y here, some extra kobject debugging messages will be sent
707 to the syslog.
708
709config DEBUG_HIGHMEM
710 bool "Highmem debugging"
711 depends on DEBUG_KERNEL && HIGHMEM
712 help
713 This options enables addition error checking for high memory systems.
714 Disable for production systems.
715
716config DEBUG_BUGVERBOSE
717 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
718 depends on BUG
719 depends on ARM || AVR32 || M32R || M68K || SPARC32 || SPARC64 || \
720 FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300 || TILE
721 default y
722 help
723 Say Y here to make BUG() panics output the file name and line number
724 of the BUG call as well as the EIP and oops trace. This aids
725 debugging but costs about 70-100K of memory.
726
727config DEBUG_INFO
728 bool "Compile the kernel with debug info"
729 depends on DEBUG_KERNEL
730 help
731 If you say Y here the resulting kernel image will include
732 debugging info resulting in a larger kernel image.
733 This adds debug symbols to the kernel and modules (gcc -g), and
734 is needed if you intend to use kernel crashdump or binary object
735 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
736 Say Y here only if you plan to debug the kernel.
737
738 If unsure, say N.
739
740config DEBUG_INFO_REDUCED
741 bool "Reduce debugging information"
742 depends on DEBUG_INFO
743 help
744 If you say Y here gcc is instructed to generate less debugging
745 information for structure types. This means that tools that
746 need full debugging information (like kgdb or systemtap) won't
747 be happy. But if you merely need debugging information to
748 resolve line numbers there is no loss. Advantage is that
749 build directory object sizes shrink dramatically over a full
750 DEBUG_INFO build and compile times are reduced too.
751 Only works with newer gcc versions.
752
753config DEBUG_VM
754 bool "Debug VM"
755 depends on DEBUG_KERNEL
756 help
757 Enable this to turn on extended checks in the virtual-memory system
758 that may impact performance.
759
760 If unsure, say N.
761
762config DEBUG_VIRTUAL
763 bool "Debug VM translations"
764 depends on DEBUG_KERNEL && X86
765 help
766 Enable some costly sanity checks in virtual to page code. This can
767 catch mistakes with virt_to_page() and friends.
768
769 If unsure, say N.
770
771config DEBUG_NOMMU_REGIONS
772 bool "Debug the global anon/private NOMMU mapping region tree"
773 depends on DEBUG_KERNEL && !MMU
774 help
775 This option causes the global tree of anonymous and private mapping
776 regions to be regularly checked for invalid topology.
777
778config DEBUG_WRITECOUNT
779 bool "Debug filesystem writers count"
780 depends on DEBUG_KERNEL
781 help
782 Enable this to catch wrong use of the writers count in struct
783 vfsmount. This will increase the size of each file struct by
784 32 bits.
785
786 If unsure, say N.
787
788config DEBUG_MEMORY_INIT
789 bool "Debug memory initialisation" if EXPERT
790 default !EXPERT
791 help
792 Enable this for additional checks during memory initialisation.
793 The sanity checks verify aspects of the VM such as the memory model
794 and other information provided by the architecture. Verbose
795 information will be printed at KERN_DEBUG loglevel depending
796 on the mminit_loglevel= command-line option.
797
798 If unsure, say Y
799
800config DEBUG_LIST
801 bool "Debug linked list manipulation"
802 depends on DEBUG_KERNEL
803 help
804 Enable this to turn on extended checks in the linked-list
805 walking routines.
806
807 If unsure, say N.
808
809config TEST_LIST_SORT
810 bool "Linked list sorting test"
811 depends on DEBUG_KERNEL
812 help
813 Enable this to turn on 'list_sort()' function test. This test is
814 executed only once during system boot, so affects only boot time.
815
816 If unsure, say N.
817
818config DEBUG_SG
819 bool "Debug SG table operations"
820 depends on DEBUG_KERNEL
821 help
822 Enable this to turn on checks on scatter-gather tables. This can
823 help find problems with drivers that do not properly initialize
824 their sg tables.
825
826 If unsure, say N.
827
828config DEBUG_NOTIFIERS
829 bool "Debug notifier call chains"
830 depends on DEBUG_KERNEL
831 help
832 Enable this to turn on sanity checking for notifier call chains.
833 This is most useful for kernel developers to make sure that
834 modules properly unregister themselves from notifier chains.
835 This is a relatively cheap check but if you care about maximum
836 performance, say N.
837
838config DEBUG_CREDENTIALS
839 bool "Debug credential management"
840 depends on DEBUG_KERNEL
841 help
842 Enable this to turn on some debug checking for credential
843 management. The additional code keeps track of the number of
844 pointers from task_structs to any given cred struct, and checks to
845 see that this number never exceeds the usage count of the cred
846 struct.
847
848 Furthermore, if SELinux is enabled, this also checks that the
849 security pointer in the cred struct is never seen to be invalid.
850
851 If unsure, say N.
852
853#
854# Select this config option from the architecture Kconfig, if it
855# is preferred to always offer frame pointers as a config
856# option on the architecture (regardless of KERNEL_DEBUG):
857#
858config ARCH_WANT_FRAME_POINTERS
859 bool
860 help
861
862config FRAME_POINTER
863 bool "Compile the kernel with frame pointers"
864 depends on DEBUG_KERNEL && \
865 (CRIS || M68K || FRV || UML || \
866 AVR32 || SUPERH || BLACKFIN || MN10300) || \
867 ARCH_WANT_FRAME_POINTERS
868 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
869 help
870 If you say Y here the resulting kernel image will be slightly
871 larger and slower, but it gives very useful debugging information
872 in case of kernel bugs. (precise oopses/stacktraces/warnings)
873
874config BOOT_PRINTK_DELAY
875 bool "Delay each boot printk message by N milliseconds"
876 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
877 help
878 This build option allows you to read kernel boot messages
879 by inserting a short delay after each one. The delay is
880 specified in milliseconds on the kernel command line,
881 using "boot_delay=N".
882
883 It is likely that you would also need to use "lpj=M" to preset
884 the "loops per jiffie" value.
885 See a previous boot log for the "lpj" value to use for your
886 system, and then set "lpj=M" before setting "boot_delay=N".
887 NOTE: Using this option may adversely affect SMP systems.
888 I.e., processors other than the first one may not boot up.
889 BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
890 what it believes to be lockup conditions.
891
892config RCU_TORTURE_TEST
893 tristate "torture tests for RCU"
894 depends on DEBUG_KERNEL
895 default n
896 help
897 This option provides a kernel module that runs torture tests
898 on the RCU infrastructure. The kernel module may be built
899 after the fact on the running kernel to be tested, if desired.
900
901 Say Y here if you want RCU torture tests to be built into
902 the kernel.
903 Say M if you want the RCU torture tests to build as a module.
904 Say N if you are unsure.
905
906config RCU_TORTURE_TEST_RUNNABLE
907 bool "torture tests for RCU runnable by default"
908 depends on RCU_TORTURE_TEST = y
909 default n
910 help
911 This option provides a way to build the RCU torture tests
912 directly into the kernel without them starting up at boot
913 time. You can use /proc/sys/kernel/rcutorture_runnable
914 to manually override this setting. This /proc file is
915 available only when the RCU torture tests have been built
916 into the kernel.
917
918 Say Y here if you want the RCU torture tests to start during
919 boot (you probably don't).
920 Say N here if you want the RCU torture tests to start only
921 after being manually enabled via /proc.
922
923config RCU_CPU_STALL_TIMEOUT
924 int "RCU CPU stall timeout in seconds"
925 depends on TREE_RCU || TREE_PREEMPT_RCU
926 range 3 300
927 default 60
928 help
929 If a given RCU grace period extends more than the specified
930 number of seconds, a CPU stall warning is printed. If the
931 RCU grace period persists, additional CPU stall warnings are
932 printed at more widely spaced intervals.
933
934config RCU_CPU_STALL_VERBOSE
935 bool "Print additional per-task information for RCU_CPU_STALL_DETECTOR"
936 depends on TREE_PREEMPT_RCU
937 default y
938 help
939 This option causes RCU to printk detailed per-task information
940 for any tasks that are stalling the current RCU grace period.
941
942 Say N if you are unsure.
943
944 Say Y if you want to enable such checks.
945
946config RCU_CPU_STALL_INFO
947 bool "Print additional diagnostics on RCU CPU stall"
948 depends on (TREE_RCU || TREE_PREEMPT_RCU) && DEBUG_KERNEL
949 default n
950 help
951 For each stalled CPU that is aware of the current RCU grace
952 period, print out additional per-CPU diagnostic information
953 regarding scheduling-clock ticks, idle state, and,
954 for RCU_FAST_NO_HZ kernels, idle-entry state.
955
956 Say N if you are unsure.
957
958 Say Y if you want to enable such diagnostics.
959
960config RCU_TRACE
961 bool "Enable tracing for RCU"
962 depends on DEBUG_KERNEL
963 help
964 This option provides tracing in RCU which presents stats
965 in debugfs for debugging RCU implementation.
966
967 Say Y here if you want to enable RCU tracing
968 Say N if you are unsure.
969
970config KPROBES_SANITY_TEST
971 bool "Kprobes sanity tests"
972 depends on DEBUG_KERNEL
973 depends on KPROBES
974 default n
975 help
976 This option provides for testing basic kprobes functionality on
977 boot. A sample kprobe, jprobe and kretprobe are inserted and
978 verified for functionality.
979
980 Say N if you are unsure.
981
982config BACKTRACE_SELF_TEST
983 tristate "Self test for the backtrace code"
984 depends on DEBUG_KERNEL
985 default n
986 help
987 This option provides a kernel module that can be used to test
988 the kernel stack backtrace code. This option is not useful
989 for distributions or general kernels, but only for kernel
990 developers working on architecture code.
991
992 Note that if you want to also test saved backtraces, you will
993 have to enable STACKTRACE as well.
994
995 Say N if you are unsure.
996
997config DEBUG_BLOCK_EXT_DEVT
998 bool "Force extended block device numbers and spread them"
999 depends on DEBUG_KERNEL
1000 depends on BLOCK
1001 default n
1002 help
1003 BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
1004 SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
1005 YOU ARE DOING. Distros, please enable this and fix whatever
1006 is broken.
1007
1008 Conventionally, block device numbers are allocated from
1009 predetermined contiguous area. However, extended block area
1010 may introduce non-contiguous block device numbers. This
1011 option forces most block device numbers to be allocated from
1012 the extended space and spreads them to discover kernel or
1013 userland code paths which assume predetermined contiguous
1014 device number allocation.
1015
1016 Note that turning on this debug option shuffles all the
1017 device numbers for all IDE and SCSI devices including libata
1018 ones, so root partition specified using device number
1019 directly (via rdev or root=MAJ:MIN) won't work anymore.
1020 Textual device names (root=/dev/sdXn) will continue to work.
1021
1022 Say N if you are unsure.
1023
1024config DEBUG_FORCE_WEAK_PER_CPU
1025 bool "Force weak per-cpu definitions"
1026 depends on DEBUG_KERNEL
1027 help
1028 s390 and alpha require percpu variables in modules to be
1029 defined weak to work around addressing range issue which
1030 puts the following two restrictions on percpu variable
1031 definitions.
1032
1033 1. percpu symbols must be unique whether static or not
1034 2. percpu variables can't be defined inside a function
1035
1036 To ensure that generic code follows the above rules, this
1037 option forces all percpu variables to be defined as weak.
1038
1039config DEBUG_PER_CPU_MAPS
1040 bool "Debug access to per_cpu maps"
1041 depends on DEBUG_KERNEL
1042 depends on SMP
1043 help
1044 Say Y to verify that the per_cpu map being accessed has
1045 been set up. This adds a fair amount of code to kernel memory
1046 and decreases performance.
1047
1048 Say N if unsure.
1049
1050config LKDTM
1051 tristate "Linux Kernel Dump Test Tool Module"
1052 depends on DEBUG_FS
1053 depends on BLOCK
1054 default n
1055 help
1056 This module enables testing of the different dumping mechanisms by
1057 inducing system failures at predefined crash points.
1058 If you don't need it: say N
1059 Choose M here to compile this code as a module. The module will be
1060 called lkdtm.
1061
1062 Documentation on how to use the module can be found in
1063 Documentation/fault-injection/provoke-crashes.txt
1064
1065config CPU_NOTIFIER_ERROR_INJECT
1066 tristate "CPU notifier error injection module"
1067 depends on HOTPLUG_CPU && DEBUG_KERNEL
1068 help
1069 This option provides a kernel module that can be used to test
1070 the error handling of the cpu notifiers
1071
1072 To compile this code as a module, choose M here: the module will
1073 be called cpu-notifier-error-inject.
1074
1075 If unsure, say N.
1076
1077config FAULT_INJECTION
1078 bool "Fault-injection framework"
1079 depends on DEBUG_KERNEL
1080 help
1081 Provide fault-injection framework.
1082 For more details, see Documentation/fault-injection/.
1083
1084config FAILSLAB
1085 bool "Fault-injection capability for kmalloc"
1086 depends on FAULT_INJECTION
1087 depends on SLAB || SLUB
1088 help
1089 Provide fault-injection capability for kmalloc.
1090
1091config FAIL_PAGE_ALLOC
1092 bool "Fault-injection capabilitiy for alloc_pages()"
1093 depends on FAULT_INJECTION
1094 help
1095 Provide fault-injection capability for alloc_pages().
1096
1097config FAIL_MAKE_REQUEST
1098 bool "Fault-injection capability for disk IO"
1099 depends on FAULT_INJECTION && BLOCK
1100 help
1101 Provide fault-injection capability for disk IO.
1102
1103config FAIL_IO_TIMEOUT
1104 bool "Fault-injection capability for faking disk interrupts"
1105 depends on FAULT_INJECTION && BLOCK
1106 help
1107 Provide fault-injection capability on end IO handling. This
1108 will make the block layer "forget" an interrupt as configured,
1109 thus exercising the error handling.
1110
1111 Only works with drivers that use the generic timeout handling,
1112 for others it wont do anything.
1113
1114config FAIL_MMC_REQUEST
1115 bool "Fault-injection capability for MMC IO"
1116 select DEBUG_FS
1117 depends on FAULT_INJECTION && MMC
1118 help
1119 Provide fault-injection capability for MMC IO.
1120 This will make the mmc core return data errors. This is
1121 useful to test the error handling in the mmc block device
1122 and to test how the mmc host driver handles retries from
1123 the block device.
1124
1125config FAULT_INJECTION_DEBUG_FS
1126 bool "Debugfs entries for fault-injection capabilities"
1127 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
1128 help
1129 Enable configuration of fault-injection capabilities via debugfs.
1130
1131config FAULT_INJECTION_STACKTRACE_FILTER
1132 bool "stacktrace filter for fault-injection capabilities"
1133 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
1134 depends on !X86_64
1135 select STACKTRACE
1136 select FRAME_POINTER if !PPC && !S390 && !MICROBLAZE && !ARM_UNWIND
1137 help
1138 Provide stacktrace filter for fault-injection capabilities
1139
1140config LATENCYTOP
1141 bool "Latency measuring infrastructure"
1142 depends on HAVE_LATENCYTOP_SUPPORT
1143 depends on DEBUG_KERNEL
1144 depends on STACKTRACE_SUPPORT
1145 depends on PROC_FS
1146 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM_UNWIND
1147 select KALLSYMS
1148 select KALLSYMS_ALL
1149 select STACKTRACE
1150 select SCHEDSTATS
1151 select SCHED_DEBUG
1152 help
1153 Enable this option if you want to use the LatencyTOP tool
1154 to find out which userspace is blocking on what kernel operations.
1155
1156source mm/Kconfig.debug
1157source kernel/trace/Kconfig
1158
1159config PROVIDE_OHCI1394_DMA_INIT
1160 bool "Remote debugging over FireWire early on boot"
1161 depends on PCI && X86
1162 help
1163 If you want to debug problems which hang or crash the kernel early
1164 on boot and the crashing machine has a FireWire port, you can use
1165 this feature to remotely access the memory of the crashed machine
1166 over FireWire. This employs remote DMA as part of the OHCI1394
1167 specification which is now the standard for FireWire controllers.
1168
1169 With remote DMA, you can monitor the printk buffer remotely using
1170 firescope and access all memory below 4GB using fireproxy from gdb.
1171 Even controlling a kernel debugger is possible using remote DMA.
1172
1173 Usage:
1174
1175 If ohci1394_dma=early is used as boot parameter, it will initialize
1176 all OHCI1394 controllers which are found in the PCI config space.
1177
1178 As all changes to the FireWire bus such as enabling and disabling
1179 devices cause a bus reset and thereby disable remote DMA for all
1180 devices, be sure to have the cable plugged and FireWire enabled on
1181 the debugging host before booting the debug target for debugging.
1182
1183 This code (~1k) is freed after boot. By then, the firewire stack
1184 in charge of the OHCI-1394 controllers should be used instead.
1185
1186 See Documentation/debugging-via-ohci1394.txt for more information.
1187
1188config FIREWIRE_OHCI_REMOTE_DMA
1189 bool "Remote debugging over FireWire with firewire-ohci"
1190 depends on FIREWIRE_OHCI
1191 help
1192 This option lets you use the FireWire bus for remote debugging
1193 with help of the firewire-ohci driver. It enables unfiltered
1194 remote DMA in firewire-ohci.
1195 See Documentation/debugging-via-ohci1394.txt for more information.
1196
1197 If unsure, say N.
1198
1199config BUILD_DOCSRC
1200 bool "Build targets in Documentation/ tree"
1201 depends on HEADERS_CHECK
1202 help
1203 This option attempts to build objects from the source files in the
1204 kernel Documentation/ tree.
1205
1206 Say N if you are unsure.
1207
1208config DYNAMIC_DEBUG
1209 bool "Enable dynamic printk() support"
1210 default n
1211 depends on PRINTK
1212 depends on DEBUG_FS
1213 help
1214
1215 Compiles debug level messages into the kernel, which would not
1216 otherwise be available at runtime. These messages can then be
1217 enabled/disabled based on various levels of scope - per source file,
1218 function, module, format string, and line number. This mechanism
1219 implicitly enables all pr_debug() and dev_dbg() calls. The impact of
1220 this compile option is a larger kernel text size of about 2%.
1221
1222 Usage:
1223
1224 Dynamic debugging is controlled via the 'dynamic_debug/control' file,
1225 which is contained in the 'debugfs' filesystem. Thus, the debugfs
1226 filesystem must first be mounted before making use of this feature.
1227 We refer the control file as: <debugfs>/dynamic_debug/control. This
1228 file contains a list of the debug statements that can be enabled. The
1229 format for each line of the file is:
1230
1231 filename:lineno [module]function flags format
1232
1233 filename : source file of the debug statement
1234 lineno : line number of the debug statement
1235 module : module that contains the debug statement
1236 function : function that contains the debug statement
1237 flags : 'p' means the line is turned 'on' for printing
1238 format : the format used for the debug statement
1239
1240 From a live system:
1241
1242 nullarbor:~ # cat <debugfs>/dynamic_debug/control
1243 # filename:lineno [module]function flags format
1244 fs/aio.c:222 [aio]__put_ioctx - "__put_ioctx:\040freeing\040%p\012"
1245 fs/aio.c:248 [aio]ioctx_alloc - "ENOMEM:\040nr_events\040too\040high\012"
1246 fs/aio.c:1770 [aio]sys_io_cancel - "calling\040cancel\012"
1247
1248 Example usage:
1249
1250 // enable the message at line 1603 of file svcsock.c
1251 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
1252 <debugfs>/dynamic_debug/control
1253
1254 // enable all the messages in file svcsock.c
1255 nullarbor:~ # echo -n 'file svcsock.c +p' >
1256 <debugfs>/dynamic_debug/control
1257
1258 // enable all the messages in the NFS server module
1259 nullarbor:~ # echo -n 'module nfsd +p' >
1260 <debugfs>/dynamic_debug/control
1261
1262 // enable all 12 messages in the function svc_process()
1263 nullarbor:~ # echo -n 'func svc_process +p' >
1264 <debugfs>/dynamic_debug/control
1265
1266 // disable all 12 messages in the function svc_process()
1267 nullarbor:~ # echo -n 'func svc_process -p' >
1268 <debugfs>/dynamic_debug/control
1269
1270 See Documentation/dynamic-debug-howto.txt for additional information.
1271
1272config DMA_API_DEBUG
1273 bool "Enable debugging of DMA-API usage"
1274 depends on HAVE_DMA_API_DEBUG
1275 help
1276 Enable this option to debug the use of the DMA API by device drivers.
1277 With this option you will be able to detect common bugs in device
1278 drivers like double-freeing of DMA mappings or freeing mappings that
1279 were never allocated.
1280 This option causes a performance degredation. Use only if you want
1281 to debug device drivers. If unsure, say N.
1282
1283config ATOMIC64_SELFTEST
1284 bool "Perform an atomic64_t self-test at boot"
1285 help
1286 Enable this option to test the atomic64_t functions at boot.
1287
1288 If unsure, say N.
1289
1290config ASYNC_RAID6_TEST
1291 tristate "Self test for hardware accelerated raid6 recovery"
1292 depends on ASYNC_RAID6_RECOV
1293 select ASYNC_MEMCPY
1294 ---help---
1295 This is a one-shot self test that permutes through the
1296 recovery of all the possible two disk failure scenarios for a
1297 N-disk array. Recovery is performed with the asynchronous
1298 raid6 recovery routines, and will optionally use an offload
1299 engine if one is available.
1300
1301 If unsure, say N.
1302
1303source "samples/Kconfig"
1304
1305source "lib/Kconfig.kgdb"
1306
1307source "lib/Kconfig.kmemcheck"
1308
1309config TEST_KSTRTOX
1310 tristate "Test kstrto*() family of functions at runtime"