blob: 3a18b0b856ce72fbb31dbecddb2a4b512f269071 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001
2config PRINTK_TIME
3 bool "Show timing information on printks"
Randy Dunlapd3b8b6e2006-12-06 20:36:38 -08004 depends on PRINTK
Linus Torvalds1da177e2005-04-16 15:20:36 -07005 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
Jeff Garzikde488442007-10-25 04:06:13 -040012config 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
Andrew Mortoncebc04b2006-08-14 22:43:18 -070020config 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.
Linus Torvalds1da177e2005-04-16 15:20:36 -070027
Andi Kleen35bb5b12008-02-22 15:15:03 +010028config 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070039config MAGIC_SYSRQ
40 bool "Magic SysRq key"
Adrian Bunkf346f4b2006-01-09 20:54:51 -080041 depends on !UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070042 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
Randy Dunlap99657c72009-09-18 12:49:22 -070053config STRIP_ASM_SYMS
54 bool "Strip assembler-generated symbols during link"
55 default n
56 help
57 Strip internal assembler-generated symbols during a link (symbols
58 that look like '.Lxxx') so they don't pollute the output of
59 get_wchan() and suchlike.
60
Arjan van de Venf71d20e2006-06-28 04:26:45 -070061config UNUSED_SYMBOLS
62 bool "Enable unused/obsolete exported symbols"
63 default y if X86
64 help
65 Unused but exported symbols make the kernel needlessly bigger. For
66 that reason most of these unused exports will soon be removed. This
67 option is provided temporarily to provide a transition period in case
68 some external kernel module needs one of these symbols anyway. If you
69 encounter such a case in your module, consider if you are actually
70 using the right API. (rationale: since nobody in the kernel is using
71 this in a module, there is a pretty good chance it's actually the
72 wrong interface to use). If you really need the symbol, please send a
73 mail to the linux kernel mailing list mentioning the symbol and why
74 you really need it, and what the merge plan to the mainline kernel for
75 your module is.
76
Don Mullisbf4735a2006-12-10 02:18:37 -080077config DEBUG_FS
78 bool "Debug Filesystem"
79 depends on SYSFS
80 help
81 debugfs is a virtual file system that kernel developers use to put
82 debugging files into. Enable this option to be able to read and
83 write to these files.
84
Robert P. J. Dayff543332008-05-20 00:06:00 +020085 For detailed documentation on the debugfs API, see
86 Documentation/DocBook/filesystems.
87
Don Mullisbf4735a2006-12-10 02:18:37 -080088 If unsure, say N.
89
90config HEADERS_CHECK
91 bool "Run 'make headers_check' when building vmlinux"
92 depends on !UML
93 help
94 This option will extract the user-visible kernel headers whenever
95 building the kernel, and will run basic sanity checks on them to
96 ensure that exported files do not attempt to include files which
97 were not exported, etc.
98
99 If you're making modifications to header files which are
100 relevant for userspace, say 'Y', and check the headers
101 exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in
102 your build tree), to make sure they're suitable.
103
Sam Ravnborg91341d42008-01-21 21:31:44 +0100104config DEBUG_SECTION_MISMATCH
105 bool "Enable full Section mismatch analysis"
Mike Frysinger1d536612010-03-23 13:35:17 -0700106 depends on UNDEFINED || (BLACKFIN)
107 default y
Sam Ravnborgfa2144b2008-02-15 13:53:11 +0100108 # This option is on purpose disabled for now.
André Goddard Rosaaf901ca2009-11-14 13:09:05 -0200109 # It will be enabled when we are down to a reasonable number
Sam Ravnborgfa2144b2008-02-15 13:53:11 +0100110 # of section mismatch warnings (< 10 for an allyesconfig build)
Sam Ravnborg91341d42008-01-21 21:31:44 +0100111 help
112 The section mismatch analysis checks if there are illegal
113 references from one section to another section.
114 Linux will during link or during runtime drop some sections
115 and any use of code/data previously in these sections will
116 most likely result in an oops.
117 In the code functions and variables are annotated with
118 __init, __devinit etc. (see full list in include/linux/init.h)
Geert Uytterhoevend6fbfa42008-01-30 11:13:23 +0100119 which results in the code/data being placed in specific sections.
120 The section mismatch analysis is always done after a full
121 kernel build but enabling this option will in addition
Sam Ravnborg91341d42008-01-21 21:31:44 +0100122 do the following:
123 - Add the option -fno-inline-functions-called-once to gcc
124 When inlining a function annotated __init in a non-init
Geert Uytterhoevend6fbfa42008-01-30 11:13:23 +0100125 function we would lose the section information and thus
Sam Ravnborg91341d42008-01-21 21:31:44 +0100126 the analysis would not catch the illegal reference.
Geert Uytterhoevend6fbfa42008-01-30 11:13:23 +0100127 This option tells gcc to inline less but will also
Sam Ravnborg91341d42008-01-21 21:31:44 +0100128 result in a larger kernel.
129 - Run the section mismatch analysis for each module/built-in.o
130 When we run the section mismatch analysis on vmlinux.o we
Geert Uytterhoevend6fbfa42008-01-30 11:13:23 +0100131 lose valueble information about where the mismatch was
Sam Ravnborg91341d42008-01-21 21:31:44 +0100132 introduced.
133 Running the analysis for each module/built-in.o file
134 will tell where the mismatch happens much closer to the
135 source. The drawback is that we will report the same
136 mismatch at least twice.
Sam Ravnborg588ccd72008-01-24 21:12:37 +0100137 - Enable verbose reporting from modpost to help solving
138 the section mismatches reported.
Sam Ravnborg91341d42008-01-21 21:31:44 +0100139
Adrian Bunkf346f4b2006-01-09 20:54:51 -0800140config DEBUG_KERNEL
141 bool "Kernel debugging"
142 help
143 Say Y here if you are developing drivers or trying to debug and
144 identify kernel problems.
145
David Woodhousea304e1b2007-02-12 00:52:00 -0800146config DEBUG_SHIRQ
147 bool "Debug shared IRQ handlers"
148 depends on DEBUG_KERNEL && GENERIC_HARDIRQS
149 help
150 Enable this to generate a spurious interrupt as soon as a shared
151 interrupt handler is registered, and just before one is deregistered.
152 Drivers ought to be able to handle interrupts coming in at those
153 points; some don't and need to be caught.
154
Don Zickus58687ac2010-05-07 17:11:44 -0400155config LOCKUP_DETECTOR
156 bool "Detect Hard and Soft Lockups"
Frederic Weisbeckere16bb1d2010-05-15 22:30:22 +0200157 depends on DEBUG_KERNEL && !S390
158 default y
Don Zickus84e478c2010-02-05 21:47:05 -0500159 help
Don Zickus58687ac2010-05-07 17:11:44 -0400160 Say Y here to enable the kernel to act as a watchdog to detect
161 hard and soft lockups.
Don Zickus84e478c2010-02-05 21:47:05 -0500162
Don Zickus58687ac2010-05-07 17:11:44 -0400163 Softlockups are bugs that cause the kernel to loop in kernel
164 mode for more than 60 seconds, without giving other tasks a
165 chance to run. The current stack trace is displayed upon
166 detection and the system will stay locked up.
167
168 Hardlockups are bugs that cause the CPU to loop in kernel mode
169 for more than 60 seconds, without letting other interrupts have a
170 chance to run. The current stack trace is displayed upon detection
171 and the system will stay locked up.
172
173 The overhead should be minimal. A periodic hrtimer runs to
174 generate interrupts and kick the watchdog task every 10-12 seconds.
175 An NMI is generated every 60 seconds or so to check for hardlockups.
Don Zickus84e478c2010-02-05 21:47:05 -0500176
Ingo Molnar9c44bc02008-05-12 21:21:04 +0200177config BOOTPARAM_SOFTLOCKUP_PANIC
178 bool "Panic (Reboot) On Soft Lockups"
Frederic Weisbecker89d7ce22010-05-13 00:27:20 +0200179 depends on LOCKUP_DETECTOR
Ingo Molnar9c44bc02008-05-12 21:21:04 +0200180 help
181 Say Y here to enable the kernel to panic on "soft lockups",
182 which are bugs that cause the kernel to loop in kernel
183 mode for more than 60 seconds, without giving other tasks a
184 chance to run.
185
186 The panic can be used in combination with panic_timeout,
187 to cause the system to reboot automatically after a
188 lockup has been detected. This feature is useful for
189 high-availability systems that have uptime guarantees and
190 where a lockup must be resolved ASAP.
191
192 Say N if unsure.
193
194config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
195 int
Frederic Weisbeckere16bb1d2010-05-15 22:30:22 +0200196 depends on LOCKUP_DETECTOR
Ingo Molnar9c44bc02008-05-12 21:21:04 +0200197 range 0 1
198 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
199 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
200
Mandeep Singh Bainese162b392009-01-15 11:08:40 -0800201config DETECT_HUNG_TASK
202 bool "Detect Hung Tasks"
203 depends on DEBUG_KERNEL
Ingo Molnar77d05632009-04-07 08:55:36 +0200204 default DETECT_SOFTLOCKUP
Mandeep Singh Bainese162b392009-01-15 11:08:40 -0800205 help
206 Say Y here to enable the kernel to detect "hung tasks",
207 which are bugs that cause the task to be stuck in
208 uninterruptible "D" state indefinitiley.
209
210 When a hung task is detected, the kernel will print the
211 current stack trace (which you should report), but the
212 task will stay in uninterruptible state. If lockdep is
213 enabled then all held locks will also be reported. This
214 feature has negligible overhead.
215
216config BOOTPARAM_HUNG_TASK_PANIC
217 bool "Panic (Reboot) On Hung Tasks"
218 depends on DETECT_HUNG_TASK
219 help
220 Say Y here to enable the kernel to panic on "hung tasks",
221 which are bugs that cause the kernel to leave a task stuck
222 in uninterruptible "D" state.
223
224 The panic can be used in combination with panic_timeout,
225 to cause the system to reboot automatically after a
226 hung task has been detected. This feature is useful for
227 high-availability systems that have uptime guarantees and
228 where a hung tasks must be resolved ASAP.
229
230 Say N if unsure.
231
232config BOOTPARAM_HUNG_TASK_PANIC_VALUE
233 int
234 depends on DETECT_HUNG_TASK
235 range 0 1
236 default 0 if !BOOTPARAM_HUNG_TASK_PANIC
237 default 1 if BOOTPARAM_HUNG_TASK_PANIC
238
Ingo Molnarb642b6d2007-07-09 18:52:00 +0200239config SCHED_DEBUG
240 bool "Collect scheduler debugging info"
241 depends on DEBUG_KERNEL && PROC_FS
242 default y
243 help
244 If you say Y here, the /proc/sched_debug file will be provided
245 that can help debug the scheduler. The runtime overhead of this
246 option is minimal.
247
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248config SCHEDSTATS
249 bool "Collect scheduler statistics"
250 depends on DEBUG_KERNEL && PROC_FS
251 help
252 If you say Y here, additional code will be inserted into the
253 scheduler and related routines to collect statistics about
254 scheduler behavior and provide them in /proc/schedstat. These
255 stats may be useful for both tuning and debugging the scheduler
256 If you aren't debugging the scheduler or trying to tune a specific
257 application, you can say N to avoid the very slight overhead
258 this adds.
259
Ingo Molnar82f67cd2007-02-16 01:28:13 -0800260config TIMER_STATS
261 bool "Collect kernel timers statistics"
262 depends on DEBUG_KERNEL && PROC_FS
263 help
264 If you say Y here, additional code will be inserted into the
265 timer routines to collect statistics about kernel timers being
266 reprogrammed. The statistics can be read from /proc/timer_stats.
267 The statistics collection is started by writing 1 to /proc/timer_stats,
268 writing 0 stops it. This feature is useful to collect information
Ingo Molnarc1a834d2007-06-01 00:47:16 -0700269 about timer usage patterns in kernel and userspace. This feature
270 is lightweight if enabled in the kernel config but not activated
271 (it defaults to deactivated on bootup and will only be activated
272 if some application like powertop activates it explicitly).
Ingo Molnar82f67cd2007-02-16 01:28:13 -0800273
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700274config DEBUG_OBJECTS
275 bool "Debug object operations"
276 depends on DEBUG_KERNEL
277 help
278 If you say Y here, additional code will be inserted into the
279 kernel to track the life time of various objects and validate
280 the operations on those objects.
281
282config DEBUG_OBJECTS_SELFTEST
283 bool "Debug objects selftest"
284 depends on DEBUG_OBJECTS
285 help
286 This enables the selftest of the object debug code.
287
288config DEBUG_OBJECTS_FREE
289 bool "Debug objects in freed memory"
290 depends on DEBUG_OBJECTS
291 help
292 This enables checks whether a k/v free operation frees an area
293 which contains an object which has not been deactivated
294 properly. This can make kmalloc/kfree-intensive workloads
295 much slower.
296
Thomas Gleixnerc6f3a972008-04-30 00:55:03 -0700297config DEBUG_OBJECTS_TIMERS
298 bool "Debug timer objects"
299 depends on DEBUG_OBJECTS
300 help
301 If you say Y here, additional code will be inserted into the
302 timer routines to track the life time of timer objects and
303 validate the timer operations.
304
Thomas Gleixnerdc186ad2009-11-16 01:09:48 +0900305config DEBUG_OBJECTS_WORK
306 bool "Debug work objects"
307 depends on DEBUG_OBJECTS
308 help
309 If you say Y here, additional code will be inserted into the
310 work queue routines to track the life time of work objects and
311 validate the work operations.
312
Ingo Molnar3ae70202008-11-26 10:02:00 +0100313config DEBUG_OBJECTS_ENABLE_DEFAULT
314 int "debug_objects bootup default value (0-1)"
315 range 0 1
316 default "1"
317 depends on DEBUG_OBJECTS
318 help
319 Debug objects boot parameter default value
320
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321config DEBUG_SLAB
Andrew Morton4a2f0ac2006-03-25 03:07:22 -0800322 bool "Debug slab memory allocations"
Vegard Nossum7d46d9e2008-04-04 00:51:41 +0200323 depends on DEBUG_KERNEL && SLAB && !KMEMCHECK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324 help
325 Say Y here to have the kernel do limited verification on memory
326 allocation as well as poisoning memory on free to catch use of freed
327 memory. This can make kmalloc/kfree-intensive workloads much slower.
328
Al Viro871751e2006-03-25 03:06:39 -0800329config DEBUG_SLAB_LEAK
330 bool "Memory leak debugging"
331 depends on DEBUG_SLAB
332
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700333config SLUB_DEBUG_ON
334 bool "SLUB debugging on by default"
Vegard Nossum7d46d9e2008-04-04 00:51:41 +0200335 depends on SLUB && SLUB_DEBUG && !KMEMCHECK
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700336 default n
337 help
338 Boot with debugging on by default. SLUB boots by default with
339 the runtime debug capabilities switched off. Enabling this is
340 equivalent to specifying the "slub_debug" parameter on boot.
341 There is no support for more fine grained debug control like
342 possible with slub_debug=xxx. SLUB debugging may be switched
343 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
344 "slub_debug=-".
345
Christoph Lameter8ff12cf2008-02-07 17:47:41 -0800346config SLUB_STATS
347 default n
348 bool "Enable SLUB performance statistics"
Christoph Lameter5b06c8532008-04-14 18:51:34 +0300349 depends on SLUB && SLUB_DEBUG && SYSFS
Christoph Lameter8ff12cf2008-02-07 17:47:41 -0800350 help
351 SLUB statistics are useful to debug SLUBs allocation behavior in
352 order find ways to optimize the allocator. This should never be
353 enabled for production use since keeping statistics slows down
354 the allocator by a few percentage points. The slabinfo command
355 supports the determination of the most active slabs to figure
356 out which slabs are relevant to a particular load.
357 Try running: slabinfo -DA
358
Catalin Marinas3bba00d2009-06-11 13:24:13 +0100359config DEBUG_KMEMLEAK
360 bool "Kernel memory leak detector"
Heiko Carstensdfcc3e62009-10-06 10:33:57 +0200361 depends on DEBUG_KERNEL && EXPERIMENTAL && !MEMORY_HOTPLUG && \
David S. Miller9343af02010-04-13 00:28:45 -0700362 (X86 || ARM || PPC || S390 || SPARC64 || SUPERH || MICROBLAZE)
Heiko Carstensdfcc3e62009-10-06 10:33:57 +0200363
Catalin Marinas3bba00d2009-06-11 13:24:13 +0100364 select DEBUG_FS if SYSFS
365 select STACKTRACE if STACKTRACE_SUPPORT
366 select KALLSYMS
Randy Dunlapb60e26a2009-11-06 15:33:45 -0800367 select CRC32
Catalin Marinas3bba00d2009-06-11 13:24:13 +0100368 help
369 Say Y here if you want to enable the memory leak
370 detector. The memory allocation/freeing is traced in a way
371 similar to the Boehm's conservative garbage collector, the
372 difference being that the orphan objects are not freed but
373 only shown in /sys/kernel/debug/kmemleak. Enabling this
374 feature will introduce an overhead to memory
375 allocations. See Documentation/kmemleak.txt for more
376 details.
377
Catalin Marinasbf96d1e2009-06-23 14:40:27 +0100378 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
379 of finding leaks due to the slab objects poisoning.
380
Catalin Marinas3bba00d2009-06-11 13:24:13 +0100381 In order to access the kmemleak file, debugfs needs to be
382 mounted (usually at /sys/kernel/debug).
383
Catalin Marinasa9d90582009-06-25 10:16:11 +0100384config DEBUG_KMEMLEAK_EARLY_LOG_SIZE
385 int "Maximum kmemleak early log entries"
386 depends on DEBUG_KMEMLEAK
Heiko Carstensdfcc3e62009-10-06 10:33:57 +0200387 range 200 40000
Catalin Marinasa9d90582009-06-25 10:16:11 +0100388 default 400
389 help
390 Kmemleak must track all the memory allocations to avoid
391 reporting false positives. Since memory may be allocated or
392 freed before kmemleak is initialised, an early log buffer is
393 used to store these actions. If kmemleak reports "early log
394 buffer exceeded", please increase this value.
395
Catalin Marinas0822ee42009-06-11 13:24:14 +0100396config DEBUG_KMEMLEAK_TEST
397 tristate "Simple test for the kernel memory leak detector"
398 depends on DEBUG_KMEMLEAK
399 help
400 Say Y or M here to build a test for the kernel memory leak
401 detector. This option enables a module that explicitly leaks
402 memory.
403
404 If unsure, say N.
405
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406config DEBUG_PREEMPT
407 bool "Debug preemptible kernel"
Kumar Gala01deab92009-10-16 07:21:39 +0000408 depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409 default y
410 help
411 If you say Y here then the kernel will use a debug variant of the
412 commonly used smp_processor_id() function and will print warnings
413 if kernel code uses it in a preemption-unsafe way. Also, the kernel
414 will detect preemption count underflows.
415
Ingo Molnare7eebaf2006-06-27 02:54:55 -0700416config DEBUG_RT_MUTEXES
417 bool "RT Mutex debugging, deadlock detection"
Ingo Molnare7eebaf2006-06-27 02:54:55 -0700418 depends on DEBUG_KERNEL && RT_MUTEXES
419 help
420 This allows rt mutex semantics violations and rt mutex related
421 deadlocks (lockups) to be detected and reported automatically.
422
423config DEBUG_PI_LIST
424 bool
425 default y
426 depends on DEBUG_RT_MUTEXES
427
Thomas Gleixner61a87122006-06-27 02:54:56 -0700428config RT_MUTEX_TESTER
429 bool "Built-in scriptable tester for rt-mutexes"
Roman Zippela1583d32006-06-27 02:55:00 -0700430 depends on DEBUG_KERNEL && RT_MUTEXES
Thomas Gleixner61a87122006-06-27 02:54:56 -0700431 help
432 This option enables a rt-mutex tester.
433
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434config DEBUG_SPINLOCK
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700435 bool "Spinlock and rw-lock debugging: basic checks"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436 depends on DEBUG_KERNEL
437 help
438 Say Y here and build SMP to catch missing spinlock initialization
439 and certain other kinds of spinlock errors commonly made. This is
440 best used in conjunction with the NMI watchdog so that spinlock
441 deadlocks are also debuggable.
442
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700443config DEBUG_MUTEXES
444 bool "Mutex debugging: basic checks"
445 depends on DEBUG_KERNEL
446 help
447 This feature allows mutex semantics violations to be detected and
448 reported.
449
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700450config DEBUG_LOCK_ALLOC
451 bool "Lock debugging: detect incorrect freeing of live locks"
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700452 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700453 select DEBUG_SPINLOCK
454 select DEBUG_MUTEXES
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700455 select LOCKDEP
456 help
457 This feature will check whether any held lock (spinlock, rwlock,
458 mutex or rwsem) is incorrectly freed by the kernel, via any of the
459 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
460 vfree(), etc.), whether a live lock is incorrectly reinitialized via
461 spin_lock_init()/mutex_init()/etc., or whether there is any lock
462 held during task exit.
463
464config PROVE_LOCKING
465 bool "Lock debugging: prove locking correctness"
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700466 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700467 select LOCKDEP
468 select DEBUG_SPINLOCK
469 select DEBUG_MUTEXES
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700470 select DEBUG_LOCK_ALLOC
471 default n
472 help
473 This feature enables the kernel to prove that all locking
474 that occurs in the kernel runtime is mathematically
475 correct: that under no circumstance could an arbitrary (and
476 not yet triggered) combination of observed locking
477 sequences (on an arbitrary number of CPUs, running an
478 arbitrary number of tasks and interrupt contexts) cause a
479 deadlock.
480
481 In short, this feature enables the kernel to report locking
482 related deadlocks before they actually occur.
483
484 The proof does not depend on how hard and complex a
485 deadlock scenario would be to trigger: how many
486 participant CPUs, tasks and irq-contexts would be needed
487 for it to trigger. The proof also does not depend on
488 timing: if a race and a resulting deadlock is possible
489 theoretically (no matter how unlikely the race scenario
490 is), it will be proven so and will immediately be
491 reported by the kernel (once the event is observed that
492 makes the deadlock theoretically possible).
493
494 If a deadlock is impossible (i.e. the locking rules, as
495 observed by the kernel, are mathematically correct), the
496 kernel reports nothing.
497
498 NOTE: this feature can also be enabled for rwlocks, mutexes
499 and rwsems - in which case all dependencies between these
500 different locking variants are observed and mapped too, and
501 the proof of observed correctness is also maintained for an
502 arbitrary combination of these separate locking variants.
503
504 For more details, see Documentation/lockdep-design.txt.
505
Paul E. McKenney632ee202010-02-22 17:04:45 -0800506config PROVE_RCU
507 bool "RCU debugging: prove RCU correctness"
508 depends on PROVE_LOCKING
509 default n
510 help
511 This feature enables lockdep extensions that check for correct
512 use of RCU APIs. This is currently under development. Say Y
513 if you want to debug RCU usage or help work on the PROVE_RCU
514 feature.
515
516 Say N if you are unsure.
517
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700518config LOCKDEP
519 bool
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700520 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700521 select STACKTRACE
Peter Zijlstra00540e52009-06-12 10:04:01 +0200522 select FRAME_POINTER if !MIPS && !PPC && !ARM_UNWIND && !S390
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700523 select KALLSYMS
524 select KALLSYMS_ALL
525
Peter Zijlstraf20786f2007-07-19 01:48:56 -0700526config LOCK_STAT
Danny ter Haarfdfb8702007-09-24 21:24:43 -0700527 bool "Lock usage statistics"
Peter Zijlstraf20786f2007-07-19 01:48:56 -0700528 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
529 select LOCKDEP
530 select DEBUG_SPINLOCK
531 select DEBUG_MUTEXES
532 select DEBUG_LOCK_ALLOC
533 default n
534 help
535 This feature enables tracking lock contention points
536
Peter Zijlstraa560aa42007-10-07 00:24:33 -0700537 For more details, see Documentation/lockstat.txt
538
Frederic Weisbeckerdd8b1cf2010-02-27 17:10:39 +0100539 This also enables lock events required by "perf lock",
540 subcommand of perf.
541 If you want to use "perf lock", you also need to turn on
542 CONFIG_EVENT_TRACING.
Hitoshi Mitake84c6f882010-02-04 16:08:15 +0900543
544 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
Frederic Weisbeckerdd8b1cf2010-02-27 17:10:39 +0100545 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
Hitoshi Mitake84c6f882010-02-04 16:08:15 +0900546
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700547config DEBUG_LOCKDEP
548 bool "Lock dependency engine debugging"
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700549 depends on DEBUG_KERNEL && LOCKDEP
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700550 help
551 If you say Y here, the lock dependency engine will do
552 additional runtime checks to debug itself, at the price
553 of more runtime overhead.
554
555config TRACE_IRQFLAGS
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700556 depends on DEBUG_KERNEL
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700557 bool
558 default y
559 depends on TRACE_IRQFLAGS_SUPPORT
560 depends on PROVE_LOCKING
561
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562config DEBUG_SPINLOCK_SLEEP
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700563 bool "Spinlock debugging: sleep-inside-spinlock checking"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564 depends on DEBUG_KERNEL
565 help
566 If you say Y here, various routines which may sleep will become very
567 noisy if they are called with a spinlock held.
568
Ingo Molnarcae2ed92006-07-03 00:24:48 -0700569config DEBUG_LOCKING_API_SELFTESTS
570 bool "Locking API boot-time self-tests"
571 depends on DEBUG_KERNEL
572 help
573 Say Y here if you want the kernel to run a short self-test during
574 bootup. The self-test checks whether common types of locking bugs
575 are detected by debugging mechanisms or not. (if you disable
576 lock debugging then those bugs wont be detected of course.)
577 The following locking APIs are covered: spinlocks, rwlocks,
578 mutexes and rwsems.
579
Ingo Molnar8637c092006-07-03 00:24:38 -0700580config STACKTRACE
581 bool
582 depends on STACKTRACE_SUPPORT
583
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584config DEBUG_KOBJECT
585 bool "kobject debugging"
586 depends on DEBUG_KERNEL
587 help
588 If you say Y here, some extra kobject debugging messages will be sent
589 to the syslog.
590
591config DEBUG_HIGHMEM
592 bool "Highmem debugging"
593 depends on DEBUG_KERNEL && HIGHMEM
594 help
595 This options enables addition error checking for high memory systems.
596 Disable for production systems.
597
598config DEBUG_BUGVERBOSE
599 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EMBEDDED
Matt Mackallc8538a72005-05-01 08:59:01 -0700600 depends on BUG
David Howellsb920de12008-02-08 04:19:31 -0800601 depends on ARM || AVR32 || M32R || M68K || SPARC32 || SPARC64 || \
602 FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300
Alexey Dobriyan8420e7e2009-12-14 18:00:25 -0800603 default y
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604 help
605 Say Y here to make BUG() panics output the file name and line number
606 of the BUG call as well as the EIP and oops trace. This aids
607 debugging but costs about 70-100K of memory.
608
609config DEBUG_INFO
610 bool "Compile the kernel with debug info"
611 depends on DEBUG_KERNEL
612 help
613 If you say Y here the resulting kernel image will include
614 debugging info resulting in a larger kernel image.
Andreas Dilgerb72e53f2007-03-27 15:21:33 -0600615 This adds debug symbols to the kernel and modules (gcc -g), and
616 is needed if you intend to use kernel crashdump or binary object
617 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618 Say Y here only if you plan to debug the kernel.
619
620 If unsure, say N.
621
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800622config DEBUG_VM
623 bool "Debug VM"
624 depends on DEBUG_KERNEL
625 help
Nick Piggin13e74442006-01-06 00:10:58 -0800626 Enable this to turn on extended checks in the virtual-memory system
627 that may impact performance.
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800628
629 If unsure, say N.
630
Jiri Slaby59ea7462008-06-12 13:56:40 +0200631config DEBUG_VIRTUAL
632 bool "Debug VM translations"
633 depends on DEBUG_KERNEL && X86
634 help
635 Enable some costly sanity checks in virtual to page code. This can
636 catch mistakes with virt_to_page() and friends.
637
638 If unsure, say N.
639
David Howells8feae132009-01-08 12:04:47 +0000640config DEBUG_NOMMU_REGIONS
641 bool "Debug the global anon/private NOMMU mapping region tree"
642 depends on DEBUG_KERNEL && !MMU
643 help
644 This option causes the global tree of anonymous and private mapping
645 regions to be regularly checked for invalid topology.
646
Dave Hansenad775f52008-02-15 14:38:01 -0800647config DEBUG_WRITECOUNT
648 bool "Debug filesystem writers count"
649 depends on DEBUG_KERNEL
650 help
651 Enable this to catch wrong use of the writers count in struct
652 vfsmount. This will increase the size of each file struct by
653 32 bits.
654
655 If unsure, say N.
656
Mel Gorman6b74ab92008-07-23 21:26:49 -0700657config DEBUG_MEMORY_INIT
658 bool "Debug memory initialisation" if EMBEDDED
659 default !EMBEDDED
660 help
661 Enable this for additional checks during memory initialisation.
662 The sanity checks verify aspects of the VM such as the memory model
663 and other information provided by the architecture. Verbose
664 information will be printed at KERN_DEBUG loglevel depending
665 on the mminit_loglevel= command-line option.
666
667 If unsure, say Y
668
Dave Jones199a9af2006-09-29 01:59:00 -0700669config DEBUG_LIST
670 bool "Debug linked list manipulation"
671 depends on DEBUG_KERNEL
672 help
673 Enable this to turn on extended checks in the linked-list
674 walking routines.
675
676 If unsure, say N.
677
Jens Axboed6ec0842007-10-22 20:01:06 +0200678config DEBUG_SG
679 bool "Debug SG table operations"
680 depends on DEBUG_KERNEL
681 help
682 Enable this to turn on checks on scatter-gather tables. This can
683 help find problems with drivers that do not properly initialize
684 their sg tables.
685
686 If unsure, say N.
687
Arjan van de Ven1b2439d2008-08-15 15:29:38 -0700688config DEBUG_NOTIFIERS
689 bool "Debug notifier call chains"
690 depends on DEBUG_KERNEL
691 help
692 Enable this to turn on sanity checking for notifier call chains.
693 This is most useful for kernel developers to make sure that
694 modules properly unregister themselves from notifier chains.
695 This is a relatively cheap check but if you care about maximum
696 performance, say N.
697
David Howellse0e81732009-09-02 09:13:40 +0100698config DEBUG_CREDENTIALS
699 bool "Debug credential management"
700 depends on DEBUG_KERNEL
701 help
702 Enable this to turn on some debug checking for credential
703 management. The additional code keeps track of the number of
704 pointers from task_structs to any given cred struct, and checks to
705 see that this number never exceeds the usage count of the cred
706 struct.
707
708 Furthermore, if SELinux is enabled, this also checks that the
709 security pointer in the cred struct is never seen to be invalid.
710
711 If unsure, say N.
712
Jeff Mahoney64dec402009-01-16 13:23:35 -0500713#
714# Select this config option from the architecture Kconfig, if it
715# it is preferred to always offer frame pointers as a config
716# option on the architecture (regardless of KERNEL_DEBUG):
717#
718config ARCH_WANT_FRAME_POINTERS
719 bool
720 help
721
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722config FRAME_POINTER
723 bool "Compile the kernel with frame pointers"
David Howellsb920de12008-02-08 04:19:31 -0800724 depends on DEBUG_KERNEL && \
Heiko Carstens75ee0342009-04-23 13:58:10 +0200725 (CRIS || M68K || M68KNOMMU || FRV || UML || \
Ingo Molnarda4276b2009-01-07 11:05:10 +0100726 AVR32 || SUPERH || BLACKFIN || MN10300) || \
727 ARCH_WANT_FRAME_POINTERS
728 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729 help
Ingo Molnarda4276b2009-01-07 11:05:10 +0100730 If you say Y here the resulting kernel image will be slightly
731 larger and slower, but it gives very useful debugging information
732 in case of kernel bugs. (precise oopses/stacktraces/warnings)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733
Randy Dunlapbfe8df32007-10-16 01:23:46 -0700734config BOOT_PRINTK_DELAY
735 bool "Delay each boot printk message by N milliseconds"
736 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
737 help
738 This build option allows you to read kernel boot messages
739 by inserting a short delay after each one. The delay is
740 specified in milliseconds on the kernel command line,
741 using "boot_delay=N".
742
743 It is likely that you would also need to use "lpj=M" to preset
744 the "loops per jiffie" value.
745 See a previous boot log for the "lpj" value to use for your
746 system, and then set "lpj=M" before setting "boot_delay=N".
747 NOTE: Using this option may adversely affect SMP systems.
748 I.e., processors other than the first one may not boot up.
749 BOOT_PRINTK_DELAY also may cause DETECT_SOFTLOCKUP to detect
750 what it believes to be lockup conditions.
751
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800752config RCU_TORTURE_TEST
753 tristate "torture tests for RCU"
754 depends on DEBUG_KERNEL
755 default n
756 help
757 This option provides a kernel module that runs torture tests
758 on the RCU infrastructure. The kernel module may be built
759 after the fact on the running kernel to be tested, if desired.
760
Paul E. McKenney31a72bc2008-06-18 09:26:49 -0700761 Say Y here if you want RCU torture tests to be built into
762 the kernel.
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800763 Say M if you want the RCU torture tests to build as a module.
764 Say N if you are unsure.
Ankita Garg8bb31b92006-10-02 02:17:36 -0700765
Paul E. McKenney31a72bc2008-06-18 09:26:49 -0700766config RCU_TORTURE_TEST_RUNNABLE
767 bool "torture tests for RCU runnable by default"
768 depends on RCU_TORTURE_TEST = y
769 default n
770 help
771 This option provides a way to build the RCU torture tests
772 directly into the kernel without them starting up at boot
773 time. You can use /proc/sys/kernel/rcutorture_runnable
774 to manually override this setting. This /proc file is
775 available only when the RCU torture tests have been built
776 into the kernel.
777
778 Say Y here if you want the RCU torture tests to start during
779 boot (you probably don't).
780 Say N here if you want the RCU torture tests to start only
781 after being manually enabled via /proc.
782
Paul E. McKenney2133b5d2008-10-02 16:06:39 -0700783config RCU_CPU_STALL_DETECTOR
Paul E. McKenney67182ae2008-08-10 18:35:38 -0700784 bool "Check for stalled CPUs delaying RCU grace periods"
Paul E. McKenney6b3ef482009-08-22 13:56:53 -0700785 depends on TREE_RCU || TREE_PREEMPT_RCU
Paul E. McKenney8bfb2f82009-12-02 12:10:16 -0800786 default y
Paul E. McKenney64db4cf2008-12-18 21:55:32 +0100787 help
788 This option causes RCU to printk information on which
789 CPUs are delaying the current grace period, but only when
790 the grace period extends for excessive time periods.
791
Paul E. McKenney4c540052010-01-14 16:10:57 -0800792 Say N if you want to disable such checks.
Paul E. McKenney64db4cf2008-12-18 21:55:32 +0100793
Paul E. McKenney4c540052010-01-14 16:10:57 -0800794 Say Y if you are unsure.
Paul E. McKenney64db4cf2008-12-18 21:55:32 +0100795
Paul E. McKenney1ed509a2010-02-22 17:05:05 -0800796config RCU_CPU_STALL_VERBOSE
797 bool "Print additional per-task information for RCU_CPU_STALL_DETECTOR"
798 depends on RCU_CPU_STALL_DETECTOR && TREE_PREEMPT_RCU
799 default n
800 help
801 This option causes RCU to printk detailed per-task information
802 for any tasks that are stalling the current RCU grace period.
Arjan van de Ven6dab2772008-01-30 13:33:08 +0100803
804 Say N if you are unsure.
805
Paul E. McKenney1ed509a2010-02-22 17:05:05 -0800806 Say Y if you want to enable such checks.
807
Ananth N Mavinakayanahalli8c1c9352008-01-30 13:32:53 +0100808config KPROBES_SANITY_TEST
809 bool "Kprobes sanity tests"
810 depends on DEBUG_KERNEL
811 depends on KPROBES
812 default n
813 help
814 This option provides for testing basic kprobes functionality on
815 boot. A sample kprobe, jprobe and kretprobe are inserted and
816 verified for functionality.
817
818 Say N if you are unsure.
819
Arjan van de Ven6dab2772008-01-30 13:33:08 +0100820config BACKTRACE_SELF_TEST
821 tristate "Self test for the backtrace code"
822 depends on DEBUG_KERNEL
823 default n
824 help
825 This option provides a kernel module that can be used to test
826 the kernel stack backtrace code. This option is not useful
827 for distributions or general kernels, but only for kernel
828 developers working on architecture code.
829
Vegard Nossumad118c52008-06-27 18:04:48 +0200830 Note that if you want to also test saved backtraces, you will
831 have to enable STACKTRACE as well.
832
Arjan van de Ven6dab2772008-01-30 13:33:08 +0100833 Say N if you are unsure.
834
Tejun Heo870d6652008-08-25 19:47:25 +0900835config DEBUG_BLOCK_EXT_DEVT
836 bool "Force extended block device numbers and spread them"
837 depends on DEBUG_KERNEL
838 depends on BLOCK
Jens Axboe759f8ca2008-08-29 09:06:29 +0200839 default n
Tejun Heo870d6652008-08-25 19:47:25 +0900840 help
Tejun Heo0e11e342008-10-13 10:46:01 +0200841 BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
842 SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
843 YOU ARE DOING. Distros, please enable this and fix whatever
844 is broken.
845
Tejun Heo870d6652008-08-25 19:47:25 +0900846 Conventionally, block device numbers are allocated from
847 predetermined contiguous area. However, extended block area
848 may introduce non-contiguous block device numbers. This
849 option forces most block device numbers to be allocated from
850 the extended space and spreads them to discover kernel or
851 userland code paths which assume predetermined contiguous
852 device number allocation.
853
Tejun Heo55dc7db2008-09-01 13:44:35 +0200854 Note that turning on this debug option shuffles all the
855 device numbers for all IDE and SCSI devices including libata
856 ones, so root partition specified using device number
857 directly (via rdev or root=MAJ:MIN) won't work anymore.
858 Textual device names (root=/dev/sdXn) will continue to work.
859
Tejun Heo870d6652008-08-25 19:47:25 +0900860 Say N if you are unsure.
861
Tejun Heo7c756e62009-06-24 15:13:50 +0900862config DEBUG_FORCE_WEAK_PER_CPU
863 bool "Force weak per-cpu definitions"
864 depends on DEBUG_KERNEL
865 help
866 s390 and alpha require percpu variables in modules to be
867 defined weak to work around addressing range issue which
868 puts the following two restrictions on percpu variable
869 definitions.
870
871 1. percpu symbols must be unique whether static or not
872 2. percpu variables can't be defined inside a function
873
874 To ensure that generic code follows the above rules, this
875 option forces all percpu variables to be defined as weak.
876
Ankita Garg8bb31b92006-10-02 02:17:36 -0700877config LKDTM
878 tristate "Linux Kernel Dump Test Tool Module"
Simon Kagstrom0347af42010-03-05 13:42:49 -0800879 depends on DEBUG_FS
Chris Snookfddd9cf2008-02-23 15:23:26 -0800880 depends on BLOCK
Ankita Garg8bb31b92006-10-02 02:17:36 -0700881 default n
882 help
883 This module enables testing of the different dumping mechanisms by
884 inducing system failures at predefined crash points.
885 If you don't need it: say N
886 Choose M here to compile this code as a module. The module will be
887 called lkdtm.
888
889 Documentation on how to use the module can be found in
Simon Kagstrom0347af42010-03-05 13:42:49 -0800890 Documentation/fault-injection/provoke-crashes.txt
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800891
892config FAULT_INJECTION
Andrew Morton1ab85092006-12-08 02:39:49 -0800893 bool "Fault-injection framework"
894 depends on DEBUG_KERNEL
Akinobu Mita329409a2006-12-08 02:39:48 -0800895 help
896 Provide fault-injection framework.
897 For more details, see Documentation/fault-injection/.
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800898
Akinobu Mita8a8b6502006-12-08 02:39:44 -0800899config FAILSLAB
Andrew Morton1ab85092006-12-08 02:39:49 -0800900 bool "Fault-injection capability for kmalloc"
901 depends on FAULT_INJECTION
Akinobu Mita773ff602008-12-23 19:37:01 +0900902 depends on SLAB || SLUB
Akinobu Mita8a8b6502006-12-08 02:39:44 -0800903 help
Andrew Morton1ab85092006-12-08 02:39:49 -0800904 Provide fault-injection capability for kmalloc.
Akinobu Mita8a8b6502006-12-08 02:39:44 -0800905
Akinobu Mita933e3122006-12-08 02:39:45 -0800906config FAIL_PAGE_ALLOC
907 bool "Fault-injection capabilitiy for alloc_pages()"
Andrew Morton1ab85092006-12-08 02:39:49 -0800908 depends on FAULT_INJECTION
Akinobu Mita933e3122006-12-08 02:39:45 -0800909 help
Andrew Morton1ab85092006-12-08 02:39:49 -0800910 Provide fault-injection capability for alloc_pages().
Akinobu Mita933e3122006-12-08 02:39:45 -0800911
Akinobu Mitac17bb492006-12-08 02:39:46 -0800912config FAIL_MAKE_REQUEST
Dave Jones86327d12006-12-12 20:16:36 +0100913 bool "Fault-injection capability for disk IO"
Jens Axboe581d4e22008-09-14 05:56:33 -0700914 depends on FAULT_INJECTION && BLOCK
Akinobu Mitac17bb492006-12-08 02:39:46 -0800915 help
Andrew Morton1ab85092006-12-08 02:39:49 -0800916 Provide fault-injection capability for disk IO.
Akinobu Mitac17bb492006-12-08 02:39:46 -0800917
Jens Axboe581d4e22008-09-14 05:56:33 -0700918config FAIL_IO_TIMEOUT
919 bool "Faul-injection capability for faking disk interrupts"
920 depends on FAULT_INJECTION && BLOCK
921 help
922 Provide fault-injection capability on end IO handling. This
923 will make the block layer "forget" an interrupt as configured,
924 thus exercising the error handling.
925
926 Only works with drivers that use the generic timeout handling,
927 for others it wont do anything.
928
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800929config FAULT_INJECTION_DEBUG_FS
930 bool "Debugfs entries for fault-injection capabilities"
Andrew Morton1ab85092006-12-08 02:39:49 -0800931 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800932 help
Andrew Morton1ab85092006-12-08 02:39:49 -0800933 Enable configuration of fault-injection capabilities via debugfs.
Akinobu Mita1df49002007-02-20 13:57:56 -0800934
935config FAULT_INJECTION_STACKTRACE_FILTER
936 bool "stacktrace filter for fault-injection capabilities"
937 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
Akinobu Mita6d690dc2007-05-12 10:36:53 -0700938 depends on !X86_64
Akinobu Mita1df49002007-02-20 13:57:56 -0800939 select STACKTRACE
Heiko Carstens75ee0342009-04-23 13:58:10 +0200940 select FRAME_POINTER if !PPC && !S390
Akinobu Mita1df49002007-02-20 13:57:56 -0800941 help
942 Provide stacktrace filter for fault-injection capabilities
Mathieu Desnoyers267c4022007-10-18 23:41:07 -0700943
Arjan van de Ven97455122008-01-25 21:08:34 +0100944config LATENCYTOP
945 bool "Latency measuring infrastructure"
Heiko Carstens75ee0342009-04-23 13:58:10 +0200946 select FRAME_POINTER if !MIPS && !PPC && !S390
Arjan van de Ven97455122008-01-25 21:08:34 +0100947 select KALLSYMS
948 select KALLSYMS_ALL
949 select STACKTRACE
950 select SCHEDSTATS
951 select SCHED_DEBUG
Heiko Carstensaa7d9352008-02-01 17:45:14 +0100952 depends on HAVE_LATENCYTOP_SUPPORT
Arjan van de Ven97455122008-01-25 21:08:34 +0100953 help
954 Enable this option if you want to use the LatencyTOP tool
955 to find out which userspace is blocking on what kernel operations.
956
Andi Kleen9e94cd32008-08-16 07:53:05 +0200957config SYSCTL_SYSCALL_CHECK
958 bool "Sysctl checks"
Eric W. Biederman83ac2012009-04-03 02:22:26 -0700959 depends on SYSCTL
Andi Kleen9e94cd32008-08-16 07:53:05 +0200960 ---help---
961 sys_sysctl uses binary paths that have been found challenging
962 to properly maintain and use. This enables checks that help
963 you to keep things correct.
964
Akinobu Mita6a11f752009-03-31 15:23:17 -0700965source mm/Kconfig.debug
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200966source kernel/trace/Kconfig
967
Bernhard Kaindlf212ec42008-01-30 13:34:11 +0100968config PROVIDE_OHCI1394_DMA_INIT
Stefan Richter080de8c2008-02-28 20:54:43 +0100969 bool "Remote debugging over FireWire early on boot"
Bernhard Kaindlf212ec42008-01-30 13:34:11 +0100970 depends on PCI && X86
971 help
972 If you want to debug problems which hang or crash the kernel early
973 on boot and the crashing machine has a FireWire port, you can use
974 this feature to remotely access the memory of the crashed machine
975 over FireWire. This employs remote DMA as part of the OHCI1394
976 specification which is now the standard for FireWire controllers.
977
978 With remote DMA, you can monitor the printk buffer remotely using
979 firescope and access all memory below 4GB using fireproxy from gdb.
980 Even controlling a kernel debugger is possible using remote DMA.
981
982 Usage:
983
984 If ohci1394_dma=early is used as boot parameter, it will initialize
985 all OHCI1394 controllers which are found in the PCI config space.
986
987 As all changes to the FireWire bus such as enabling and disabling
988 devices cause a bus reset and thereby disable remote DMA for all
989 devices, be sure to have the cable plugged and FireWire enabled on
990 the debugging host before booting the debug target for debugging.
991
992 This code (~1k) is freed after boot. By then, the firewire stack
993 in charge of the OHCI-1394 controllers should be used instead.
994
995 See Documentation/debugging-via-ohci1394.txt for more information.
Arjan van de Ven97455122008-01-25 21:08:34 +0100996
Stefan Richter080de8c2008-02-28 20:54:43 +0100997config FIREWIRE_OHCI_REMOTE_DMA
998 bool "Remote debugging over FireWire with firewire-ohci"
999 depends on FIREWIRE_OHCI
1000 help
1001 This option lets you use the FireWire bus for remote debugging
1002 with help of the firewire-ohci driver. It enables unfiltered
1003 remote DMA in firewire-ohci.
1004 See Documentation/debugging-via-ohci1394.txt for more information.
1005
1006 If unsure, say N.
1007
Randy Dunlap152de302009-02-20 15:38:47 -08001008config BUILD_DOCSRC
Randy Dunlap3794f3e2008-08-12 15:09:06 -07001009 bool "Build targets in Documentation/ tree"
1010 depends on HEADERS_CHECK
1011 help
1012 This option attempts to build objects from the source files in the
1013 kernel Documentation/ tree.
1014
1015 Say N if you are unsure.
1016
Jason Barone9d376f2009-02-05 11:51:38 -05001017config DYNAMIC_DEBUG
Jason Baron86151fd2009-02-05 11:53:15 -05001018 bool "Enable dynamic printk() support"
Jason Baron346e15b2008-08-12 16:46:19 -04001019 default n
1020 depends on PRINTK
Jason Baron86151fd2009-02-05 11:53:15 -05001021 depends on DEBUG_FS
Jason Baron346e15b2008-08-12 16:46:19 -04001022 help
1023
1024 Compiles debug level messages into the kernel, which would not
1025 otherwise be available at runtime. These messages can then be
Jason Baron86151fd2009-02-05 11:53:15 -05001026 enabled/disabled based on various levels of scope - per source file,
1027 function, module, format string, and line number. This mechanism
1028 implicitly enables all pr_debug() and dev_dbg() calls. The impact of
1029 this compile option is a larger kernel text size of about 2%.
Jason Baron346e15b2008-08-12 16:46:19 -04001030
1031 Usage:
1032
Jason Baron86151fd2009-02-05 11:53:15 -05001033 Dynamic debugging is controlled via the 'dynamic_debug/ddebug' file,
1034 which is contained in the 'debugfs' filesystem. Thus, the debugfs
1035 filesystem must first be mounted before making use of this feature.
1036 We refer the control file as: <debugfs>/dynamic_debug/ddebug. This
1037 file contains a list of the debug statements that can be enabled. The
1038 format for each line of the file is:
Jason Baron346e15b2008-08-12 16:46:19 -04001039
Jason Baron86151fd2009-02-05 11:53:15 -05001040 filename:lineno [module]function flags format
Jason Baron346e15b2008-08-12 16:46:19 -04001041
Jason Baron86151fd2009-02-05 11:53:15 -05001042 filename : source file of the debug statement
1043 lineno : line number of the debug statement
1044 module : module that contains the debug statement
1045 function : function that contains the debug statement
1046 flags : 'p' means the line is turned 'on' for printing
1047 format : the format used for the debug statement
Jason Baron346e15b2008-08-12 16:46:19 -04001048
1049 From a live system:
1050
Jason Baron86151fd2009-02-05 11:53:15 -05001051 nullarbor:~ # cat <debugfs>/dynamic_debug/ddebug
1052 # filename:lineno [module]function flags format
1053 fs/aio.c:222 [aio]__put_ioctx - "__put_ioctx:\040freeing\040%p\012"
1054 fs/aio.c:248 [aio]ioctx_alloc - "ENOMEM:\040nr_events\040too\040high\012"
1055 fs/aio.c:1770 [aio]sys_io_cancel - "calling\040cancel\012"
Jason Baron346e15b2008-08-12 16:46:19 -04001056
Jason Baron86151fd2009-02-05 11:53:15 -05001057 Example usage:
Jason Baron346e15b2008-08-12 16:46:19 -04001058
Jason Baron86151fd2009-02-05 11:53:15 -05001059 // enable the message at line 1603 of file svcsock.c
1060 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
1061 <debugfs>/dynamic_debug/ddebug
Jason Baron346e15b2008-08-12 16:46:19 -04001062
Jason Baron86151fd2009-02-05 11:53:15 -05001063 // enable all the messages in file svcsock.c
1064 nullarbor:~ # echo -n 'file svcsock.c +p' >
1065 <debugfs>/dynamic_debug/ddebug
Jason Baron346e15b2008-08-12 16:46:19 -04001066
Jason Baron86151fd2009-02-05 11:53:15 -05001067 // enable all the messages in the NFS server module
1068 nullarbor:~ # echo -n 'module nfsd +p' >
1069 <debugfs>/dynamic_debug/ddebug
Jason Baron346e15b2008-08-12 16:46:19 -04001070
Jason Baron86151fd2009-02-05 11:53:15 -05001071 // enable all 12 messages in the function svc_process()
1072 nullarbor:~ # echo -n 'func svc_process +p' >
1073 <debugfs>/dynamic_debug/ddebug
Jason Baron346e15b2008-08-12 16:46:19 -04001074
Jason Baron86151fd2009-02-05 11:53:15 -05001075 // disable all 12 messages in the function svc_process()
1076 nullarbor:~ # echo -n 'func svc_process -p' >
1077 <debugfs>/dynamic_debug/ddebug
Jason Baron346e15b2008-08-12 16:46:19 -04001078
Jason Baron86151fd2009-02-05 11:53:15 -05001079 See Documentation/dynamic-debug-howto.txt for additional information.
Jason Baron346e15b2008-08-12 16:46:19 -04001080
Joerg Roedel5ee00bd2009-01-09 12:14:24 +01001081config DMA_API_DEBUG
1082 bool "Enable debugging of DMA-API usage"
1083 depends on HAVE_DMA_API_DEBUG
1084 help
1085 Enable this option to debug the use of the DMA API by device drivers.
1086 With this option you will be able to detect common bugs in device
1087 drivers like double-freeing of DMA mappings or freeing mappings that
1088 were never allocated.
1089 This option causes a performance degredation. Use only if you want
1090 to debug device drivers. If unsure, say N.
Jason Baron346e15b2008-08-12 16:46:19 -04001091
Mathieu Desnoyers267c4022007-10-18 23:41:07 -07001092source "samples/Kconfig"
Jason Wesseldc7d5522008-04-17 20:05:37 +02001093
1094source "lib/Kconfig.kgdb"
Pekka Enberg0a4af3b2009-02-26 21:38:56 +02001095
1096source "lib/Kconfig.kmemcheck"