blob: 5cc3506574e9db654ef058bf73f50e67e07dc9aa [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
Arjan van de Venf71d20e2006-06-28 04:26:45 -070053config UNUSED_SYMBOLS
54 bool "Enable unused/obsolete exported symbols"
55 default y if X86
56 help
57 Unused but exported symbols make the kernel needlessly bigger. For
58 that reason most of these unused exports will soon be removed. This
59 option is provided temporarily to provide a transition period in case
60 some external kernel module needs one of these symbols anyway. If you
61 encounter such a case in your module, consider if you are actually
62 using the right API. (rationale: since nobody in the kernel is using
63 this in a module, there is a pretty good chance it's actually the
64 wrong interface to use). If you really need the symbol, please send a
65 mail to the linux kernel mailing list mentioning the symbol and why
66 you really need it, and what the merge plan to the mainline kernel for
67 your module is.
68
Don Mullisbf4735a2006-12-10 02:18:37 -080069config DEBUG_FS
70 bool "Debug Filesystem"
71 depends on SYSFS
72 help
73 debugfs is a virtual file system that kernel developers use to put
74 debugging files into. Enable this option to be able to read and
75 write to these files.
76
Robert P. J. Dayff543332008-05-20 00:06:00 +020077 For detailed documentation on the debugfs API, see
78 Documentation/DocBook/filesystems.
79
Don Mullisbf4735a2006-12-10 02:18:37 -080080 If unsure, say N.
81
82config HEADERS_CHECK
83 bool "Run 'make headers_check' when building vmlinux"
84 depends on !UML
85 help
86 This option will extract the user-visible kernel headers whenever
87 building the kernel, and will run basic sanity checks on them to
88 ensure that exported files do not attempt to include files which
89 were not exported, etc.
90
91 If you're making modifications to header files which are
92 relevant for userspace, say 'Y', and check the headers
93 exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in
94 your build tree), to make sure they're suitable.
95
Sam Ravnborg91341d42008-01-21 21:31:44 +010096config DEBUG_SECTION_MISMATCH
97 bool "Enable full Section mismatch analysis"
Sam Ravnborge5f95c82008-02-02 18:57:18 +010098 depends on UNDEFINED
Sam Ravnborgfa2144b2008-02-15 13:53:11 +010099 # This option is on purpose disabled for now.
100 # It will be enabled when we are down to a resonable number
101 # of section mismatch warnings (< 10 for an allyesconfig build)
Sam Ravnborg91341d42008-01-21 21:31:44 +0100102 help
103 The section mismatch analysis checks if there are illegal
104 references from one section to another section.
105 Linux will during link or during runtime drop some sections
106 and any use of code/data previously in these sections will
107 most likely result in an oops.
108 In the code functions and variables are annotated with
109 __init, __devinit etc. (see full list in include/linux/init.h)
Geert Uytterhoevend6fbfa42008-01-30 11:13:23 +0100110 which results in the code/data being placed in specific sections.
111 The section mismatch analysis is always done after a full
112 kernel build but enabling this option will in addition
Sam Ravnborg91341d42008-01-21 21:31:44 +0100113 do the following:
114 - Add the option -fno-inline-functions-called-once to gcc
115 When inlining a function annotated __init in a non-init
Geert Uytterhoevend6fbfa42008-01-30 11:13:23 +0100116 function we would lose the section information and thus
Sam Ravnborg91341d42008-01-21 21:31:44 +0100117 the analysis would not catch the illegal reference.
Geert Uytterhoevend6fbfa42008-01-30 11:13:23 +0100118 This option tells gcc to inline less but will also
Sam Ravnborg91341d42008-01-21 21:31:44 +0100119 result in a larger kernel.
120 - Run the section mismatch analysis for each module/built-in.o
121 When we run the section mismatch analysis on vmlinux.o we
Geert Uytterhoevend6fbfa42008-01-30 11:13:23 +0100122 lose valueble information about where the mismatch was
Sam Ravnborg91341d42008-01-21 21:31:44 +0100123 introduced.
124 Running the analysis for each module/built-in.o file
125 will tell where the mismatch happens much closer to the
126 source. The drawback is that we will report the same
127 mismatch at least twice.
Sam Ravnborg588ccd72008-01-24 21:12:37 +0100128 - Enable verbose reporting from modpost to help solving
129 the section mismatches reported.
Sam Ravnborg91341d42008-01-21 21:31:44 +0100130
Adrian Bunkf346f4b2006-01-09 20:54:51 -0800131config DEBUG_KERNEL
132 bool "Kernel debugging"
133 help
134 Say Y here if you are developing drivers or trying to debug and
135 identify kernel problems.
136
David Woodhousea304e1b2007-02-12 00:52:00 -0800137config DEBUG_SHIRQ
138 bool "Debug shared IRQ handlers"
139 depends on DEBUG_KERNEL && GENERIC_HARDIRQS
140 help
141 Enable this to generate a spurious interrupt as soon as a shared
142 interrupt handler is registered, and just before one is deregistered.
143 Drivers ought to be able to handle interrupts coming in at those
144 points; some don't and need to be caught.
145
Ingo Molnar8446f1d2005-09-06 15:16:27 -0700146config DETECT_SOFTLOCKUP
147 bool "Detect Soft Lockups"
Heiko Carstensdea20a32006-10-11 01:20:44 -0700148 depends on DEBUG_KERNEL && !S390
Ingo Molnar8446f1d2005-09-06 15:16:27 -0700149 default y
150 help
151 Say Y here to enable the kernel to detect "soft lockups",
152 which are bugs that cause the kernel to loop in kernel
Ingo Molnar9c44bc02008-05-12 21:21:04 +0200153 mode for more than 60 seconds, without giving other tasks a
Ingo Molnar8446f1d2005-09-06 15:16:27 -0700154 chance to run.
155
156 When a soft-lockup is detected, the kernel will print the
157 current stack trace (which you should report), but the
158 system will stay locked up. This feature has negligible
159 overhead.
160
161 (Note that "hard lockups" are separate type of bugs that
162 can be detected via the NMI-watchdog, on platforms that
163 support it.)
164
Ingo Molnar9c44bc02008-05-12 21:21:04 +0200165config BOOTPARAM_SOFTLOCKUP_PANIC
166 bool "Panic (Reboot) On Soft Lockups"
167 depends on DETECT_SOFTLOCKUP
168 help
169 Say Y here to enable the kernel to panic on "soft lockups",
170 which are bugs that cause the kernel to loop in kernel
171 mode for more than 60 seconds, without giving other tasks a
172 chance to run.
173
174 The panic can be used in combination with panic_timeout,
175 to cause the system to reboot automatically after a
176 lockup has been detected. This feature is useful for
177 high-availability systems that have uptime guarantees and
178 where a lockup must be resolved ASAP.
179
180 Say N if unsure.
181
182config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
183 int
184 depends on DETECT_SOFTLOCKUP
185 range 0 1
186 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
187 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
188
Mandeep Singh Bainese162b392009-01-15 11:08:40 -0800189config DETECT_HUNG_TASK
190 bool "Detect Hung Tasks"
191 depends on DEBUG_KERNEL
Ingo Molnar77d05632009-04-07 08:55:36 +0200192 default DETECT_SOFTLOCKUP
Mandeep Singh Bainese162b392009-01-15 11:08:40 -0800193 help
194 Say Y here to enable the kernel to detect "hung tasks",
195 which are bugs that cause the task to be stuck in
196 uninterruptible "D" state indefinitiley.
197
198 When a hung task is detected, the kernel will print the
199 current stack trace (which you should report), but the
200 task will stay in uninterruptible state. If lockdep is
201 enabled then all held locks will also be reported. This
202 feature has negligible overhead.
203
204config BOOTPARAM_HUNG_TASK_PANIC
205 bool "Panic (Reboot) On Hung Tasks"
206 depends on DETECT_HUNG_TASK
207 help
208 Say Y here to enable the kernel to panic on "hung tasks",
209 which are bugs that cause the kernel to leave a task stuck
210 in uninterruptible "D" state.
211
212 The panic can be used in combination with panic_timeout,
213 to cause the system to reboot automatically after a
214 hung task has been detected. This feature is useful for
215 high-availability systems that have uptime guarantees and
216 where a hung tasks must be resolved ASAP.
217
218 Say N if unsure.
219
220config BOOTPARAM_HUNG_TASK_PANIC_VALUE
221 int
222 depends on DETECT_HUNG_TASK
223 range 0 1
224 default 0 if !BOOTPARAM_HUNG_TASK_PANIC
225 default 1 if BOOTPARAM_HUNG_TASK_PANIC
226
Ingo Molnarb642b6d2007-07-09 18:52:00 +0200227config SCHED_DEBUG
228 bool "Collect scheduler debugging info"
229 depends on DEBUG_KERNEL && PROC_FS
230 default y
231 help
232 If you say Y here, the /proc/sched_debug file will be provided
233 that can help debug the scheduler. The runtime overhead of this
234 option is minimal.
235
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236config SCHEDSTATS
237 bool "Collect scheduler statistics"
238 depends on DEBUG_KERNEL && PROC_FS
239 help
240 If you say Y here, additional code will be inserted into the
241 scheduler and related routines to collect statistics about
242 scheduler behavior and provide them in /proc/schedstat. These
243 stats may be useful for both tuning and debugging the scheduler
244 If you aren't debugging the scheduler or trying to tune a specific
245 application, you can say N to avoid the very slight overhead
246 this adds.
247
Ingo Molnar82f67cd2007-02-16 01:28:13 -0800248config TIMER_STATS
249 bool "Collect kernel timers statistics"
250 depends on DEBUG_KERNEL && PROC_FS
251 help
252 If you say Y here, additional code will be inserted into the
253 timer routines to collect statistics about kernel timers being
254 reprogrammed. The statistics can be read from /proc/timer_stats.
255 The statistics collection is started by writing 1 to /proc/timer_stats,
256 writing 0 stops it. This feature is useful to collect information
Ingo Molnarc1a834d2007-06-01 00:47:16 -0700257 about timer usage patterns in kernel and userspace. This feature
258 is lightweight if enabled in the kernel config but not activated
259 (it defaults to deactivated on bootup and will only be activated
260 if some application like powertop activates it explicitly).
Ingo Molnar82f67cd2007-02-16 01:28:13 -0800261
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700262config DEBUG_OBJECTS
263 bool "Debug object operations"
264 depends on DEBUG_KERNEL
265 help
266 If you say Y here, additional code will be inserted into the
267 kernel to track the life time of various objects and validate
268 the operations on those objects.
269
270config DEBUG_OBJECTS_SELFTEST
271 bool "Debug objects selftest"
272 depends on DEBUG_OBJECTS
273 help
274 This enables the selftest of the object debug code.
275
276config DEBUG_OBJECTS_FREE
277 bool "Debug objects in freed memory"
278 depends on DEBUG_OBJECTS
279 help
280 This enables checks whether a k/v free operation frees an area
281 which contains an object which has not been deactivated
282 properly. This can make kmalloc/kfree-intensive workloads
283 much slower.
284
Thomas Gleixnerc6f3a972008-04-30 00:55:03 -0700285config DEBUG_OBJECTS_TIMERS
286 bool "Debug timer objects"
287 depends on DEBUG_OBJECTS
288 help
289 If you say Y here, additional code will be inserted into the
290 timer routines to track the life time of timer objects and
291 validate the timer operations.
292
Ingo Molnar3ae70202008-11-26 10:02:00 +0100293config DEBUG_OBJECTS_ENABLE_DEFAULT
294 int "debug_objects bootup default value (0-1)"
295 range 0 1
296 default "1"
297 depends on DEBUG_OBJECTS
298 help
299 Debug objects boot parameter default value
300
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301config DEBUG_SLAB
Andrew Morton4a2f0ac2006-03-25 03:07:22 -0800302 bool "Debug slab memory allocations"
Ingo Molnar50dd26b2006-01-08 01:01:42 -0800303 depends on DEBUG_KERNEL && SLAB
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304 help
305 Say Y here to have the kernel do limited verification on memory
306 allocation as well as poisoning memory on free to catch use of freed
307 memory. This can make kmalloc/kfree-intensive workloads much slower.
308
Al Viro871751e2006-03-25 03:06:39 -0800309config DEBUG_SLAB_LEAK
310 bool "Memory leak debugging"
311 depends on DEBUG_SLAB
312
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700313config SLUB_DEBUG_ON
314 bool "SLUB debugging on by default"
315 depends on SLUB && SLUB_DEBUG
316 default n
317 help
318 Boot with debugging on by default. SLUB boots by default with
319 the runtime debug capabilities switched off. Enabling this is
320 equivalent to specifying the "slub_debug" parameter on boot.
321 There is no support for more fine grained debug control like
322 possible with slub_debug=xxx. SLUB debugging may be switched
323 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
324 "slub_debug=-".
325
Christoph Lameter8ff12cf2008-02-07 17:47:41 -0800326config SLUB_STATS
327 default n
328 bool "Enable SLUB performance statistics"
Christoph Lameter5b06c8532008-04-14 18:51:34 +0300329 depends on SLUB && SLUB_DEBUG && SYSFS
Christoph Lameter8ff12cf2008-02-07 17:47:41 -0800330 help
331 SLUB statistics are useful to debug SLUBs allocation behavior in
332 order find ways to optimize the allocator. This should never be
333 enabled for production use since keeping statistics slows down
334 the allocator by a few percentage points. The slabinfo command
335 supports the determination of the most active slabs to figure
336 out which slabs are relevant to a particular load.
337 Try running: slabinfo -DA
338
Catalin Marinas3bba00d2009-06-11 13:24:13 +0100339config DEBUG_KMEMLEAK
340 bool "Kernel memory leak detector"
341 depends on DEBUG_KERNEL && EXPERIMENTAL && (X86 || ARM) && \
342 !MEMORY_HOTPLUG
343 select DEBUG_SLAB if SLAB
344 select SLUB_DEBUG if SLUB
345 select DEBUG_FS if SYSFS
346 select STACKTRACE if STACKTRACE_SUPPORT
347 select KALLSYMS
348 help
349 Say Y here if you want to enable the memory leak
350 detector. The memory allocation/freeing is traced in a way
351 similar to the Boehm's conservative garbage collector, the
352 difference being that the orphan objects are not freed but
353 only shown in /sys/kernel/debug/kmemleak. Enabling this
354 feature will introduce an overhead to memory
355 allocations. See Documentation/kmemleak.txt for more
356 details.
357
358 In order to access the kmemleak file, debugfs needs to be
359 mounted (usually at /sys/kernel/debug).
360
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361config DEBUG_PREEMPT
362 bool "Debug preemptible kernel"
Hugh Dickins048c8bc2006-11-01 05:44:54 +1100363 depends on DEBUG_KERNEL && PREEMPT && (TRACE_IRQFLAGS_SUPPORT || PPC64)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 default y
365 help
366 If you say Y here then the kernel will use a debug variant of the
367 commonly used smp_processor_id() function and will print warnings
368 if kernel code uses it in a preemption-unsafe way. Also, the kernel
369 will detect preemption count underflows.
370
Ingo Molnare7eebaf2006-06-27 02:54:55 -0700371config DEBUG_RT_MUTEXES
372 bool "RT Mutex debugging, deadlock detection"
Ingo Molnare7eebaf2006-06-27 02:54:55 -0700373 depends on DEBUG_KERNEL && RT_MUTEXES
374 help
375 This allows rt mutex semantics violations and rt mutex related
376 deadlocks (lockups) to be detected and reported automatically.
377
378config DEBUG_PI_LIST
379 bool
380 default y
381 depends on DEBUG_RT_MUTEXES
382
Thomas Gleixner61a87122006-06-27 02:54:56 -0700383config RT_MUTEX_TESTER
384 bool "Built-in scriptable tester for rt-mutexes"
Roman Zippela1583d32006-06-27 02:55:00 -0700385 depends on DEBUG_KERNEL && RT_MUTEXES
Thomas Gleixner61a87122006-06-27 02:54:56 -0700386 help
387 This option enables a rt-mutex tester.
388
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389config DEBUG_SPINLOCK
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700390 bool "Spinlock and rw-lock debugging: basic checks"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391 depends on DEBUG_KERNEL
392 help
393 Say Y here and build SMP to catch missing spinlock initialization
394 and certain other kinds of spinlock errors commonly made. This is
395 best used in conjunction with the NMI watchdog so that spinlock
396 deadlocks are also debuggable.
397
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700398config DEBUG_MUTEXES
399 bool "Mutex debugging: basic checks"
400 depends on DEBUG_KERNEL
401 help
402 This feature allows mutex semantics violations to be detected and
403 reported.
404
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700405config DEBUG_LOCK_ALLOC
406 bool "Lock debugging: detect incorrect freeing of live locks"
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700407 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700408 select DEBUG_SPINLOCK
409 select DEBUG_MUTEXES
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700410 select LOCKDEP
411 help
412 This feature will check whether any held lock (spinlock, rwlock,
413 mutex or rwsem) is incorrectly freed by the kernel, via any of the
414 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
415 vfree(), etc.), whether a live lock is incorrectly reinitialized via
416 spin_lock_init()/mutex_init()/etc., or whether there is any lock
417 held during task exit.
418
419config PROVE_LOCKING
420 bool "Lock debugging: prove locking correctness"
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700421 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700422 select LOCKDEP
423 select DEBUG_SPINLOCK
424 select DEBUG_MUTEXES
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700425 select DEBUG_LOCK_ALLOC
426 default n
427 help
428 This feature enables the kernel to prove that all locking
429 that occurs in the kernel runtime is mathematically
430 correct: that under no circumstance could an arbitrary (and
431 not yet triggered) combination of observed locking
432 sequences (on an arbitrary number of CPUs, running an
433 arbitrary number of tasks and interrupt contexts) cause a
434 deadlock.
435
436 In short, this feature enables the kernel to report locking
437 related deadlocks before they actually occur.
438
439 The proof does not depend on how hard and complex a
440 deadlock scenario would be to trigger: how many
441 participant CPUs, tasks and irq-contexts would be needed
442 for it to trigger. The proof also does not depend on
443 timing: if a race and a resulting deadlock is possible
444 theoretically (no matter how unlikely the race scenario
445 is), it will be proven so and will immediately be
446 reported by the kernel (once the event is observed that
447 makes the deadlock theoretically possible).
448
449 If a deadlock is impossible (i.e. the locking rules, as
450 observed by the kernel, are mathematically correct), the
451 kernel reports nothing.
452
453 NOTE: this feature can also be enabled for rwlocks, mutexes
454 and rwsems - in which case all dependencies between these
455 different locking variants are observed and mapped too, and
456 the proof of observed correctness is also maintained for an
457 arbitrary combination of these separate locking variants.
458
459 For more details, see Documentation/lockdep-design.txt.
460
461config LOCKDEP
462 bool
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700463 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700464 select STACKTRACE
Heiko Carstens75ee0342009-04-23 13:58:10 +0200465 select FRAME_POINTER if !X86 && !MIPS && !PPC && !ARM_UNWIND && !S390
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700466 select KALLSYMS
467 select KALLSYMS_ALL
468
Peter Zijlstraf20786f2007-07-19 01:48:56 -0700469config LOCK_STAT
Danny ter Haarfdfb8702007-09-24 21:24:43 -0700470 bool "Lock usage statistics"
Peter Zijlstraf20786f2007-07-19 01:48:56 -0700471 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
472 select LOCKDEP
473 select DEBUG_SPINLOCK
474 select DEBUG_MUTEXES
475 select DEBUG_LOCK_ALLOC
476 default n
477 help
478 This feature enables tracking lock contention points
479
Peter Zijlstraa560aa42007-10-07 00:24:33 -0700480 For more details, see Documentation/lockstat.txt
481
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700482config DEBUG_LOCKDEP
483 bool "Lock dependency engine debugging"
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700484 depends on DEBUG_KERNEL && LOCKDEP
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700485 help
486 If you say Y here, the lock dependency engine will do
487 additional runtime checks to debug itself, at the price
488 of more runtime overhead.
489
490config TRACE_IRQFLAGS
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700491 depends on DEBUG_KERNEL
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700492 bool
493 default y
494 depends on TRACE_IRQFLAGS_SUPPORT
495 depends on PROVE_LOCKING
496
Linus Torvalds1da177e2005-04-16 15:20:36 -0700497config DEBUG_SPINLOCK_SLEEP
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700498 bool "Spinlock debugging: sleep-inside-spinlock checking"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499 depends on DEBUG_KERNEL
500 help
501 If you say Y here, various routines which may sleep will become very
502 noisy if they are called with a spinlock held.
503
Ingo Molnarcae2ed92006-07-03 00:24:48 -0700504config DEBUG_LOCKING_API_SELFTESTS
505 bool "Locking API boot-time self-tests"
506 depends on DEBUG_KERNEL
507 help
508 Say Y here if you want the kernel to run a short self-test during
509 bootup. The self-test checks whether common types of locking bugs
510 are detected by debugging mechanisms or not. (if you disable
511 lock debugging then those bugs wont be detected of course.)
512 The following locking APIs are covered: spinlocks, rwlocks,
513 mutexes and rwsems.
514
Ingo Molnar8637c092006-07-03 00:24:38 -0700515config STACKTRACE
516 bool
517 depends on STACKTRACE_SUPPORT
518
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519config DEBUG_KOBJECT
520 bool "kobject debugging"
521 depends on DEBUG_KERNEL
522 help
523 If you say Y here, some extra kobject debugging messages will be sent
524 to the syslog.
525
526config DEBUG_HIGHMEM
527 bool "Highmem debugging"
528 depends on DEBUG_KERNEL && HIGHMEM
529 help
530 This options enables addition error checking for high memory systems.
531 Disable for production systems.
532
533config DEBUG_BUGVERBOSE
534 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EMBEDDED
Matt Mackallc8538a72005-05-01 08:59:01 -0700535 depends on BUG
David Howellsb920de12008-02-08 04:19:31 -0800536 depends on ARM || AVR32 || M32R || M68K || SPARC32 || SPARC64 || \
537 FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538 default !EMBEDDED
539 help
540 Say Y here to make BUG() panics output the file name and line number
541 of the BUG call as well as the EIP and oops trace. This aids
542 debugging but costs about 70-100K of memory.
543
544config DEBUG_INFO
545 bool "Compile the kernel with debug info"
546 depends on DEBUG_KERNEL
547 help
548 If you say Y here the resulting kernel image will include
549 debugging info resulting in a larger kernel image.
Andreas Dilgerb72e53f2007-03-27 15:21:33 -0600550 This adds debug symbols to the kernel and modules (gcc -g), and
551 is needed if you intend to use kernel crashdump or binary object
552 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 Say Y here only if you plan to debug the kernel.
554
555 If unsure, say N.
556
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800557config DEBUG_VM
558 bool "Debug VM"
559 depends on DEBUG_KERNEL
560 help
Nick Piggin13e74442006-01-06 00:10:58 -0800561 Enable this to turn on extended checks in the virtual-memory system
562 that may impact performance.
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800563
564 If unsure, say N.
565
Jiri Slaby59ea7462008-06-12 13:56:40 +0200566config DEBUG_VIRTUAL
567 bool "Debug VM translations"
568 depends on DEBUG_KERNEL && X86
569 help
570 Enable some costly sanity checks in virtual to page code. This can
571 catch mistakes with virt_to_page() and friends.
572
573 If unsure, say N.
574
David Howells8feae132009-01-08 12:04:47 +0000575config DEBUG_NOMMU_REGIONS
576 bool "Debug the global anon/private NOMMU mapping region tree"
577 depends on DEBUG_KERNEL && !MMU
578 help
579 This option causes the global tree of anonymous and private mapping
580 regions to be regularly checked for invalid topology.
581
Dave Hansenad775f52008-02-15 14:38:01 -0800582config DEBUG_WRITECOUNT
583 bool "Debug filesystem writers count"
584 depends on DEBUG_KERNEL
585 help
586 Enable this to catch wrong use of the writers count in struct
587 vfsmount. This will increase the size of each file struct by
588 32 bits.
589
590 If unsure, say N.
591
Mel Gorman6b74ab92008-07-23 21:26:49 -0700592config DEBUG_MEMORY_INIT
593 bool "Debug memory initialisation" if EMBEDDED
594 default !EMBEDDED
595 help
596 Enable this for additional checks during memory initialisation.
597 The sanity checks verify aspects of the VM such as the memory model
598 and other information provided by the architecture. Verbose
599 information will be printed at KERN_DEBUG loglevel depending
600 on the mminit_loglevel= command-line option.
601
602 If unsure, say Y
603
Dave Jones199a9af2006-09-29 01:59:00 -0700604config DEBUG_LIST
605 bool "Debug linked list manipulation"
606 depends on DEBUG_KERNEL
607 help
608 Enable this to turn on extended checks in the linked-list
609 walking routines.
610
611 If unsure, say N.
612
Jens Axboed6ec0842007-10-22 20:01:06 +0200613config DEBUG_SG
614 bool "Debug SG table operations"
615 depends on DEBUG_KERNEL
616 help
617 Enable this to turn on checks on scatter-gather tables. This can
618 help find problems with drivers that do not properly initialize
619 their sg tables.
620
621 If unsure, say N.
622
Arjan van de Ven1b2439d2008-08-15 15:29:38 -0700623config DEBUG_NOTIFIERS
624 bool "Debug notifier call chains"
625 depends on DEBUG_KERNEL
626 help
627 Enable this to turn on sanity checking for notifier call chains.
628 This is most useful for kernel developers to make sure that
629 modules properly unregister themselves from notifier chains.
630 This is a relatively cheap check but if you care about maximum
631 performance, say N.
632
Jeff Mahoney64dec402009-01-16 13:23:35 -0500633#
634# Select this config option from the architecture Kconfig, if it
635# it is preferred to always offer frame pointers as a config
636# option on the architecture (regardless of KERNEL_DEBUG):
637#
638config ARCH_WANT_FRAME_POINTERS
639 bool
640 help
641
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642config FRAME_POINTER
643 bool "Compile the kernel with frame pointers"
David Howellsb920de12008-02-08 04:19:31 -0800644 depends on DEBUG_KERNEL && \
Heiko Carstens75ee0342009-04-23 13:58:10 +0200645 (CRIS || M68K || M68KNOMMU || FRV || UML || \
Ingo Molnarda4276b2009-01-07 11:05:10 +0100646 AVR32 || SUPERH || BLACKFIN || MN10300) || \
647 ARCH_WANT_FRAME_POINTERS
648 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649 help
Ingo Molnarda4276b2009-01-07 11:05:10 +0100650 If you say Y here the resulting kernel image will be slightly
651 larger and slower, but it gives very useful debugging information
652 in case of kernel bugs. (precise oopses/stacktraces/warnings)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653
Randy Dunlapbfe8df32007-10-16 01:23:46 -0700654config BOOT_PRINTK_DELAY
655 bool "Delay each boot printk message by N milliseconds"
656 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
657 help
658 This build option allows you to read kernel boot messages
659 by inserting a short delay after each one. The delay is
660 specified in milliseconds on the kernel command line,
661 using "boot_delay=N".
662
663 It is likely that you would also need to use "lpj=M" to preset
664 the "loops per jiffie" value.
665 See a previous boot log for the "lpj" value to use for your
666 system, and then set "lpj=M" before setting "boot_delay=N".
667 NOTE: Using this option may adversely affect SMP systems.
668 I.e., processors other than the first one may not boot up.
669 BOOT_PRINTK_DELAY also may cause DETECT_SOFTLOCKUP to detect
670 what it believes to be lockup conditions.
671
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800672config RCU_TORTURE_TEST
673 tristate "torture tests for RCU"
674 depends on DEBUG_KERNEL
675 default n
676 help
677 This option provides a kernel module that runs torture tests
678 on the RCU infrastructure. The kernel module may be built
679 after the fact on the running kernel to be tested, if desired.
680
Paul E. McKenney31a72bc2008-06-18 09:26:49 -0700681 Say Y here if you want RCU torture tests to be built into
682 the kernel.
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800683 Say M if you want the RCU torture tests to build as a module.
684 Say N if you are unsure.
Ankita Garg8bb31b92006-10-02 02:17:36 -0700685
Paul E. McKenney31a72bc2008-06-18 09:26:49 -0700686config RCU_TORTURE_TEST_RUNNABLE
687 bool "torture tests for RCU runnable by default"
688 depends on RCU_TORTURE_TEST = y
689 default n
690 help
691 This option provides a way to build the RCU torture tests
692 directly into the kernel without them starting up at boot
693 time. You can use /proc/sys/kernel/rcutorture_runnable
694 to manually override this setting. This /proc file is
695 available only when the RCU torture tests have been built
696 into the kernel.
697
698 Say Y here if you want the RCU torture tests to start during
699 boot (you probably don't).
700 Say N here if you want the RCU torture tests to start only
701 after being manually enabled via /proc.
702
Paul E. McKenney2133b5d2008-10-02 16:06:39 -0700703config RCU_CPU_STALL_DETECTOR
Paul E. McKenney67182ae2008-08-10 18:35:38 -0700704 bool "Check for stalled CPUs delaying RCU grace periods"
Paul E. McKenney64db4cf2008-12-18 21:55:32 +0100705 depends on CLASSIC_RCU || TREE_RCU
706 default n
707 help
708 This option causes RCU to printk information on which
709 CPUs are delaying the current grace period, but only when
710 the grace period extends for excessive time periods.
711
712 Say Y if you want RCU to perform such checks.
713
714 Say N if you are unsure.
715
Ananth N Mavinakayanahalli8c1c9352008-01-30 13:32:53 +0100716config KPROBES_SANITY_TEST
717 bool "Kprobes sanity tests"
718 depends on DEBUG_KERNEL
719 depends on KPROBES
720 default n
721 help
722 This option provides for testing basic kprobes functionality on
723 boot. A sample kprobe, jprobe and kretprobe are inserted and
724 verified for functionality.
725
726 Say N if you are unsure.
727
Arjan van de Ven6dab2772008-01-30 13:33:08 +0100728config BACKTRACE_SELF_TEST
729 tristate "Self test for the backtrace code"
730 depends on DEBUG_KERNEL
731 default n
732 help
733 This option provides a kernel module that can be used to test
734 the kernel stack backtrace code. This option is not useful
735 for distributions or general kernels, but only for kernel
736 developers working on architecture code.
737
Vegard Nossumad118c52008-06-27 18:04:48 +0200738 Note that if you want to also test saved backtraces, you will
739 have to enable STACKTRACE as well.
740
Arjan van de Ven6dab2772008-01-30 13:33:08 +0100741 Say N if you are unsure.
742
Tejun Heo870d6652008-08-25 19:47:25 +0900743config DEBUG_BLOCK_EXT_DEVT
744 bool "Force extended block device numbers and spread them"
745 depends on DEBUG_KERNEL
746 depends on BLOCK
Jens Axboe759f8ca2008-08-29 09:06:29 +0200747 default n
Tejun Heo870d6652008-08-25 19:47:25 +0900748 help
Tejun Heo0e11e342008-10-13 10:46:01 +0200749 BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
750 SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
751 YOU ARE DOING. Distros, please enable this and fix whatever
752 is broken.
753
Tejun Heo870d6652008-08-25 19:47:25 +0900754 Conventionally, block device numbers are allocated from
755 predetermined contiguous area. However, extended block area
756 may introduce non-contiguous block device numbers. This
757 option forces most block device numbers to be allocated from
758 the extended space and spreads them to discover kernel or
759 userland code paths which assume predetermined contiguous
760 device number allocation.
761
Tejun Heo55dc7db2008-09-01 13:44:35 +0200762 Note that turning on this debug option shuffles all the
763 device numbers for all IDE and SCSI devices including libata
764 ones, so root partition specified using device number
765 directly (via rdev or root=MAJ:MIN) won't work anymore.
766 Textual device names (root=/dev/sdXn) will continue to work.
767
Tejun Heo870d6652008-08-25 19:47:25 +0900768 Say N if you are unsure.
769
Ankita Garg8bb31b92006-10-02 02:17:36 -0700770config LKDTM
771 tristate "Linux Kernel Dump Test Tool Module"
Don Mullisbf4735a2006-12-10 02:18:37 -0800772 depends on DEBUG_KERNEL
Ankita Garg8bb31b92006-10-02 02:17:36 -0700773 depends on KPROBES
Chris Snookfddd9cf2008-02-23 15:23:26 -0800774 depends on BLOCK
Ankita Garg8bb31b92006-10-02 02:17:36 -0700775 default n
776 help
777 This module enables testing of the different dumping mechanisms by
778 inducing system failures at predefined crash points.
779 If you don't need it: say N
780 Choose M here to compile this code as a module. The module will be
781 called lkdtm.
782
783 Documentation on how to use the module can be found in
784 drivers/misc/lkdtm.c
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800785
786config FAULT_INJECTION
Andrew Morton1ab85092006-12-08 02:39:49 -0800787 bool "Fault-injection framework"
788 depends on DEBUG_KERNEL
Akinobu Mita329409a2006-12-08 02:39:48 -0800789 help
790 Provide fault-injection framework.
791 For more details, see Documentation/fault-injection/.
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800792
Akinobu Mita8a8b6502006-12-08 02:39:44 -0800793config FAILSLAB
Andrew Morton1ab85092006-12-08 02:39:49 -0800794 bool "Fault-injection capability for kmalloc"
795 depends on FAULT_INJECTION
Akinobu Mita773ff602008-12-23 19:37:01 +0900796 depends on SLAB || SLUB
Akinobu Mita8a8b6502006-12-08 02:39:44 -0800797 help
Andrew Morton1ab85092006-12-08 02:39:49 -0800798 Provide fault-injection capability for kmalloc.
Akinobu Mita8a8b6502006-12-08 02:39:44 -0800799
Akinobu Mita933e3122006-12-08 02:39:45 -0800800config FAIL_PAGE_ALLOC
801 bool "Fault-injection capabilitiy for alloc_pages()"
Andrew Morton1ab85092006-12-08 02:39:49 -0800802 depends on FAULT_INJECTION
Akinobu Mita933e3122006-12-08 02:39:45 -0800803 help
Andrew Morton1ab85092006-12-08 02:39:49 -0800804 Provide fault-injection capability for alloc_pages().
Akinobu Mita933e3122006-12-08 02:39:45 -0800805
Akinobu Mitac17bb492006-12-08 02:39:46 -0800806config FAIL_MAKE_REQUEST
Dave Jones86327d12006-12-12 20:16:36 +0100807 bool "Fault-injection capability for disk IO"
Jens Axboe581d4e22008-09-14 05:56:33 -0700808 depends on FAULT_INJECTION && BLOCK
Akinobu Mitac17bb492006-12-08 02:39:46 -0800809 help
Andrew Morton1ab85092006-12-08 02:39:49 -0800810 Provide fault-injection capability for disk IO.
Akinobu Mitac17bb492006-12-08 02:39:46 -0800811
Jens Axboe581d4e22008-09-14 05:56:33 -0700812config FAIL_IO_TIMEOUT
813 bool "Faul-injection capability for faking disk interrupts"
814 depends on FAULT_INJECTION && BLOCK
815 help
816 Provide fault-injection capability on end IO handling. This
817 will make the block layer "forget" an interrupt as configured,
818 thus exercising the error handling.
819
820 Only works with drivers that use the generic timeout handling,
821 for others it wont do anything.
822
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800823config FAULT_INJECTION_DEBUG_FS
824 bool "Debugfs entries for fault-injection capabilities"
Andrew Morton1ab85092006-12-08 02:39:49 -0800825 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800826 help
Andrew Morton1ab85092006-12-08 02:39:49 -0800827 Enable configuration of fault-injection capabilities via debugfs.
Akinobu Mita1df49002007-02-20 13:57:56 -0800828
829config FAULT_INJECTION_STACKTRACE_FILTER
830 bool "stacktrace filter for fault-injection capabilities"
831 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
Akinobu Mita6d690dc2007-05-12 10:36:53 -0700832 depends on !X86_64
Akinobu Mita1df49002007-02-20 13:57:56 -0800833 select STACKTRACE
Heiko Carstens75ee0342009-04-23 13:58:10 +0200834 select FRAME_POINTER if !PPC && !S390
Akinobu Mita1df49002007-02-20 13:57:56 -0800835 help
836 Provide stacktrace filter for fault-injection capabilities
Mathieu Desnoyers267c4022007-10-18 23:41:07 -0700837
Arjan van de Ven97455122008-01-25 21:08:34 +0100838config LATENCYTOP
839 bool "Latency measuring infrastructure"
Heiko Carstens75ee0342009-04-23 13:58:10 +0200840 select FRAME_POINTER if !MIPS && !PPC && !S390
Arjan van de Ven97455122008-01-25 21:08:34 +0100841 select KALLSYMS
842 select KALLSYMS_ALL
843 select STACKTRACE
844 select SCHEDSTATS
845 select SCHED_DEBUG
Heiko Carstensaa7d9352008-02-01 17:45:14 +0100846 depends on HAVE_LATENCYTOP_SUPPORT
Arjan van de Ven97455122008-01-25 21:08:34 +0100847 help
848 Enable this option if you want to use the LatencyTOP tool
849 to find out which userspace is blocking on what kernel operations.
850
Andi Kleen9e94cd32008-08-16 07:53:05 +0200851config SYSCTL_SYSCALL_CHECK
852 bool "Sysctl checks"
853 depends on SYSCTL_SYSCALL
854 ---help---
855 sys_sysctl uses binary paths that have been found challenging
856 to properly maintain and use. This enables checks that help
857 you to keep things correct.
858
Akinobu Mita6a11f752009-03-31 15:23:17 -0700859source mm/Kconfig.debug
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200860source kernel/trace/Kconfig
861
Bernhard Kaindlf212ec42008-01-30 13:34:11 +0100862config PROVIDE_OHCI1394_DMA_INIT
Stefan Richter080de8c2008-02-28 20:54:43 +0100863 bool "Remote debugging over FireWire early on boot"
Bernhard Kaindlf212ec42008-01-30 13:34:11 +0100864 depends on PCI && X86
865 help
866 If you want to debug problems which hang or crash the kernel early
867 on boot and the crashing machine has a FireWire port, you can use
868 this feature to remotely access the memory of the crashed machine
869 over FireWire. This employs remote DMA as part of the OHCI1394
870 specification which is now the standard for FireWire controllers.
871
872 With remote DMA, you can monitor the printk buffer remotely using
873 firescope and access all memory below 4GB using fireproxy from gdb.
874 Even controlling a kernel debugger is possible using remote DMA.
875
876 Usage:
877
878 If ohci1394_dma=early is used as boot parameter, it will initialize
879 all OHCI1394 controllers which are found in the PCI config space.
880
881 As all changes to the FireWire bus such as enabling and disabling
882 devices cause a bus reset and thereby disable remote DMA for all
883 devices, be sure to have the cable plugged and FireWire enabled on
884 the debugging host before booting the debug target for debugging.
885
886 This code (~1k) is freed after boot. By then, the firewire stack
887 in charge of the OHCI-1394 controllers should be used instead.
888
889 See Documentation/debugging-via-ohci1394.txt for more information.
Arjan van de Ven97455122008-01-25 21:08:34 +0100890
Stefan Richter080de8c2008-02-28 20:54:43 +0100891config FIREWIRE_OHCI_REMOTE_DMA
892 bool "Remote debugging over FireWire with firewire-ohci"
893 depends on FIREWIRE_OHCI
894 help
895 This option lets you use the FireWire bus for remote debugging
896 with help of the firewire-ohci driver. It enables unfiltered
897 remote DMA in firewire-ohci.
898 See Documentation/debugging-via-ohci1394.txt for more information.
899
900 If unsure, say N.
901
Randy Dunlap152de302009-02-20 15:38:47 -0800902config BUILD_DOCSRC
Randy Dunlap3794f3e2008-08-12 15:09:06 -0700903 bool "Build targets in Documentation/ tree"
904 depends on HEADERS_CHECK
905 help
906 This option attempts to build objects from the source files in the
907 kernel Documentation/ tree.
908
909 Say N if you are unsure.
910
Jason Barone9d376f2009-02-05 11:51:38 -0500911config DYNAMIC_DEBUG
Jason Baron86151fd2009-02-05 11:53:15 -0500912 bool "Enable dynamic printk() support"
Jason Baron346e15b2008-08-12 16:46:19 -0400913 default n
914 depends on PRINTK
Jason Baron86151fd2009-02-05 11:53:15 -0500915 depends on DEBUG_FS
Jason Baron346e15b2008-08-12 16:46:19 -0400916 help
917
918 Compiles debug level messages into the kernel, which would not
919 otherwise be available at runtime. These messages can then be
Jason Baron86151fd2009-02-05 11:53:15 -0500920 enabled/disabled based on various levels of scope - per source file,
921 function, module, format string, and line number. This mechanism
922 implicitly enables all pr_debug() and dev_dbg() calls. The impact of
923 this compile option is a larger kernel text size of about 2%.
Jason Baron346e15b2008-08-12 16:46:19 -0400924
925 Usage:
926
Jason Baron86151fd2009-02-05 11:53:15 -0500927 Dynamic debugging is controlled via the 'dynamic_debug/ddebug' file,
928 which is contained in the 'debugfs' filesystem. Thus, the debugfs
929 filesystem must first be mounted before making use of this feature.
930 We refer the control file as: <debugfs>/dynamic_debug/ddebug. This
931 file contains a list of the debug statements that can be enabled. The
932 format for each line of the file is:
Jason Baron346e15b2008-08-12 16:46:19 -0400933
Jason Baron86151fd2009-02-05 11:53:15 -0500934 filename:lineno [module]function flags format
Jason Baron346e15b2008-08-12 16:46:19 -0400935
Jason Baron86151fd2009-02-05 11:53:15 -0500936 filename : source file of the debug statement
937 lineno : line number of the debug statement
938 module : module that contains the debug statement
939 function : function that contains the debug statement
940 flags : 'p' means the line is turned 'on' for printing
941 format : the format used for the debug statement
Jason Baron346e15b2008-08-12 16:46:19 -0400942
943 From a live system:
944
Jason Baron86151fd2009-02-05 11:53:15 -0500945 nullarbor:~ # cat <debugfs>/dynamic_debug/ddebug
946 # filename:lineno [module]function flags format
947 fs/aio.c:222 [aio]__put_ioctx - "__put_ioctx:\040freeing\040%p\012"
948 fs/aio.c:248 [aio]ioctx_alloc - "ENOMEM:\040nr_events\040too\040high\012"
949 fs/aio.c:1770 [aio]sys_io_cancel - "calling\040cancel\012"
Jason Baron346e15b2008-08-12 16:46:19 -0400950
Jason Baron86151fd2009-02-05 11:53:15 -0500951 Example usage:
Jason Baron346e15b2008-08-12 16:46:19 -0400952
Jason Baron86151fd2009-02-05 11:53:15 -0500953 // enable the message at line 1603 of file svcsock.c
954 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
955 <debugfs>/dynamic_debug/ddebug
Jason Baron346e15b2008-08-12 16:46:19 -0400956
Jason Baron86151fd2009-02-05 11:53:15 -0500957 // enable all the messages in file svcsock.c
958 nullarbor:~ # echo -n 'file svcsock.c +p' >
959 <debugfs>/dynamic_debug/ddebug
Jason Baron346e15b2008-08-12 16:46:19 -0400960
Jason Baron86151fd2009-02-05 11:53:15 -0500961 // enable all the messages in the NFS server module
962 nullarbor:~ # echo -n 'module nfsd +p' >
963 <debugfs>/dynamic_debug/ddebug
Jason Baron346e15b2008-08-12 16:46:19 -0400964
Jason Baron86151fd2009-02-05 11:53:15 -0500965 // enable all 12 messages in the function svc_process()
966 nullarbor:~ # echo -n 'func svc_process +p' >
967 <debugfs>/dynamic_debug/ddebug
Jason Baron346e15b2008-08-12 16:46:19 -0400968
Jason Baron86151fd2009-02-05 11:53:15 -0500969 // disable all 12 messages in the function svc_process()
970 nullarbor:~ # echo -n 'func svc_process -p' >
971 <debugfs>/dynamic_debug/ddebug
Jason Baron346e15b2008-08-12 16:46:19 -0400972
Jason Baron86151fd2009-02-05 11:53:15 -0500973 See Documentation/dynamic-debug-howto.txt for additional information.
Jason Baron346e15b2008-08-12 16:46:19 -0400974
Joerg Roedel5ee00bd2009-01-09 12:14:24 +0100975config DMA_API_DEBUG
976 bool "Enable debugging of DMA-API usage"
977 depends on HAVE_DMA_API_DEBUG
978 help
979 Enable this option to debug the use of the DMA API by device drivers.
980 With this option you will be able to detect common bugs in device
981 drivers like double-freeing of DMA mappings or freeing mappings that
982 were never allocated.
983 This option causes a performance degredation. Use only if you want
984 to debug device drivers. If unsure, say N.
Jason Baron346e15b2008-08-12 16:46:19 -0400985
Mathieu Desnoyers267c4022007-10-18 23:41:07 -0700986source "samples/Kconfig"
Jason Wesseldc7d5522008-04-17 20:05:37 +0200987
988source "lib/Kconfig.kgdb"