blob: 49e285dcaf579d53e7ef68acebf3b03806b7e0a9 [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
Ingo Molnar8446f1d2005-09-06 15:16:27 -0700155config DETECT_SOFTLOCKUP
Don Zickus58687ac2010-05-07 17:11:44 -0400156 bool
Heiko Carstensdea20a32006-10-11 01:20:44 -0700157 depends on DEBUG_KERNEL && !S390
Ingo Molnar8446f1d2005-09-06 15:16:27 -0700158 default y
159 help
160 Say Y here to enable the kernel to detect "soft lockups",
161 which are bugs that cause the kernel to loop in kernel
Ingo Molnar9c44bc02008-05-12 21:21:04 +0200162 mode for more than 60 seconds, without giving other tasks a
Ingo Molnar8446f1d2005-09-06 15:16:27 -0700163 chance to run.
164
165 When a soft-lockup is detected, the kernel will print the
166 current stack trace (which you should report), but the
167 system will stay locked up. This feature has negligible
168 overhead.
169
170 (Note that "hard lockups" are separate type of bugs that
171 can be detected via the NMI-watchdog, on platforms that
172 support it.)
173
Don Zickus58687ac2010-05-07 17:11:44 -0400174config LOCKUP_DETECTOR
175 bool "Detect Hard and Soft Lockups"
176 depends on DEBUG_KERNEL
177 default DETECT_SOFTLOCKUP
Don Zickus84e478c2010-02-05 21:47:05 -0500178 help
Don Zickus58687ac2010-05-07 17:11:44 -0400179 Say Y here to enable the kernel to act as a watchdog to detect
180 hard and soft lockups.
Don Zickus84e478c2010-02-05 21:47:05 -0500181
Don Zickus58687ac2010-05-07 17:11:44 -0400182 Softlockups 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. The current stack trace is displayed upon
185 detection and the system will stay locked up.
186
187 Hardlockups are bugs that cause the CPU to loop in kernel mode
188 for more than 60 seconds, without letting other interrupts have a
189 chance to run. The current stack trace is displayed upon detection
190 and the system will stay locked up.
191
192 The overhead should be minimal. A periodic hrtimer runs to
193 generate interrupts and kick the watchdog task every 10-12 seconds.
194 An NMI is generated every 60 seconds or so to check for hardlockups.
Don Zickus84e478c2010-02-05 21:47:05 -0500195
Ingo Molnar9c44bc02008-05-12 21:21:04 +0200196config BOOTPARAM_SOFTLOCKUP_PANIC
197 bool "Panic (Reboot) On Soft Lockups"
198 depends on DETECT_SOFTLOCKUP
199 help
200 Say Y here to enable the kernel to panic on "soft lockups",
201 which are bugs that cause the kernel to loop in kernel
202 mode for more than 60 seconds, without giving other tasks a
203 chance to run.
204
205 The panic can be used in combination with panic_timeout,
206 to cause the system to reboot automatically after a
207 lockup has been detected. This feature is useful for
208 high-availability systems that have uptime guarantees and
209 where a lockup must be resolved ASAP.
210
211 Say N if unsure.
212
213config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
214 int
215 depends on DETECT_SOFTLOCKUP
216 range 0 1
217 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
218 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
219
Mandeep Singh Bainese162b392009-01-15 11:08:40 -0800220config DETECT_HUNG_TASK
221 bool "Detect Hung Tasks"
222 depends on DEBUG_KERNEL
Ingo Molnar77d05632009-04-07 08:55:36 +0200223 default DETECT_SOFTLOCKUP
Mandeep Singh Bainese162b392009-01-15 11:08:40 -0800224 help
225 Say Y here to enable the kernel to detect "hung tasks",
226 which are bugs that cause the task to be stuck in
227 uninterruptible "D" state indefinitiley.
228
229 When a hung task is detected, the kernel will print the
230 current stack trace (which you should report), but the
231 task will stay in uninterruptible state. If lockdep is
232 enabled then all held locks will also be reported. This
233 feature has negligible overhead.
234
235config BOOTPARAM_HUNG_TASK_PANIC
236 bool "Panic (Reboot) On Hung Tasks"
237 depends on DETECT_HUNG_TASK
238 help
239 Say Y here to enable the kernel to panic on "hung tasks",
240 which are bugs that cause the kernel to leave a task stuck
241 in uninterruptible "D" state.
242
243 The panic can be used in combination with panic_timeout,
244 to cause the system to reboot automatically after a
245 hung task has been detected. This feature is useful for
246 high-availability systems that have uptime guarantees and
247 where a hung tasks must be resolved ASAP.
248
249 Say N if unsure.
250
251config BOOTPARAM_HUNG_TASK_PANIC_VALUE
252 int
253 depends on DETECT_HUNG_TASK
254 range 0 1
255 default 0 if !BOOTPARAM_HUNG_TASK_PANIC
256 default 1 if BOOTPARAM_HUNG_TASK_PANIC
257
Ingo Molnarb642b6d2007-07-09 18:52:00 +0200258config SCHED_DEBUG
259 bool "Collect scheduler debugging info"
260 depends on DEBUG_KERNEL && PROC_FS
261 default y
262 help
263 If you say Y here, the /proc/sched_debug file will be provided
264 that can help debug the scheduler. The runtime overhead of this
265 option is minimal.
266
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267config SCHEDSTATS
268 bool "Collect scheduler statistics"
269 depends on DEBUG_KERNEL && PROC_FS
270 help
271 If you say Y here, additional code will be inserted into the
272 scheduler and related routines to collect statistics about
273 scheduler behavior and provide them in /proc/schedstat. These
274 stats may be useful for both tuning and debugging the scheduler
275 If you aren't debugging the scheduler or trying to tune a specific
276 application, you can say N to avoid the very slight overhead
277 this adds.
278
Ingo Molnar82f67cd2007-02-16 01:28:13 -0800279config TIMER_STATS
280 bool "Collect kernel timers statistics"
281 depends on DEBUG_KERNEL && PROC_FS
282 help
283 If you say Y here, additional code will be inserted into the
284 timer routines to collect statistics about kernel timers being
285 reprogrammed. The statistics can be read from /proc/timer_stats.
286 The statistics collection is started by writing 1 to /proc/timer_stats,
287 writing 0 stops it. This feature is useful to collect information
Ingo Molnarc1a834d2007-06-01 00:47:16 -0700288 about timer usage patterns in kernel and userspace. This feature
289 is lightweight if enabled in the kernel config but not activated
290 (it defaults to deactivated on bootup and will only be activated
291 if some application like powertop activates it explicitly).
Ingo Molnar82f67cd2007-02-16 01:28:13 -0800292
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700293config DEBUG_OBJECTS
294 bool "Debug object operations"
295 depends on DEBUG_KERNEL
296 help
297 If you say Y here, additional code will be inserted into the
298 kernel to track the life time of various objects and validate
299 the operations on those objects.
300
301config DEBUG_OBJECTS_SELFTEST
302 bool "Debug objects selftest"
303 depends on DEBUG_OBJECTS
304 help
305 This enables the selftest of the object debug code.
306
307config DEBUG_OBJECTS_FREE
308 bool "Debug objects in freed memory"
309 depends on DEBUG_OBJECTS
310 help
311 This enables checks whether a k/v free operation frees an area
312 which contains an object which has not been deactivated
313 properly. This can make kmalloc/kfree-intensive workloads
314 much slower.
315
Thomas Gleixnerc6f3a972008-04-30 00:55:03 -0700316config DEBUG_OBJECTS_TIMERS
317 bool "Debug timer objects"
318 depends on DEBUG_OBJECTS
319 help
320 If you say Y here, additional code will be inserted into the
321 timer routines to track the life time of timer objects and
322 validate the timer operations.
323
Thomas Gleixnerdc186ad2009-11-16 01:09:48 +0900324config DEBUG_OBJECTS_WORK
325 bool "Debug work objects"
326 depends on DEBUG_OBJECTS
327 help
328 If you say Y here, additional code will be inserted into the
329 work queue routines to track the life time of work objects and
330 validate the work operations.
331
Ingo Molnar3ae70202008-11-26 10:02:00 +0100332config DEBUG_OBJECTS_ENABLE_DEFAULT
333 int "debug_objects bootup default value (0-1)"
334 range 0 1
335 default "1"
336 depends on DEBUG_OBJECTS
337 help
338 Debug objects boot parameter default value
339
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340config DEBUG_SLAB
Andrew Morton4a2f0ac2006-03-25 03:07:22 -0800341 bool "Debug slab memory allocations"
Vegard Nossum7d46d9e2008-04-04 00:51:41 +0200342 depends on DEBUG_KERNEL && SLAB && !KMEMCHECK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343 help
344 Say Y here to have the kernel do limited verification on memory
345 allocation as well as poisoning memory on free to catch use of freed
346 memory. This can make kmalloc/kfree-intensive workloads much slower.
347
Al Viro871751e2006-03-25 03:06:39 -0800348config DEBUG_SLAB_LEAK
349 bool "Memory leak debugging"
350 depends on DEBUG_SLAB
351
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700352config SLUB_DEBUG_ON
353 bool "SLUB debugging on by default"
Vegard Nossum7d46d9e2008-04-04 00:51:41 +0200354 depends on SLUB && SLUB_DEBUG && !KMEMCHECK
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700355 default n
356 help
357 Boot with debugging on by default. SLUB boots by default with
358 the runtime debug capabilities switched off. Enabling this is
359 equivalent to specifying the "slub_debug" parameter on boot.
360 There is no support for more fine grained debug control like
361 possible with slub_debug=xxx. SLUB debugging may be switched
362 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
363 "slub_debug=-".
364
Christoph Lameter8ff12cf2008-02-07 17:47:41 -0800365config SLUB_STATS
366 default n
367 bool "Enable SLUB performance statistics"
Christoph Lameter5b06c8532008-04-14 18:51:34 +0300368 depends on SLUB && SLUB_DEBUG && SYSFS
Christoph Lameter8ff12cf2008-02-07 17:47:41 -0800369 help
370 SLUB statistics are useful to debug SLUBs allocation behavior in
371 order find ways to optimize the allocator. This should never be
372 enabled for production use since keeping statistics slows down
373 the allocator by a few percentage points. The slabinfo command
374 supports the determination of the most active slabs to figure
375 out which slabs are relevant to a particular load.
376 Try running: slabinfo -DA
377
Catalin Marinas3bba00d2009-06-11 13:24:13 +0100378config DEBUG_KMEMLEAK
379 bool "Kernel memory leak detector"
Heiko Carstensdfcc3e62009-10-06 10:33:57 +0200380 depends on DEBUG_KERNEL && EXPERIMENTAL && !MEMORY_HOTPLUG && \
David S. Miller9343af02010-04-13 00:28:45 -0700381 (X86 || ARM || PPC || S390 || SPARC64 || SUPERH || MICROBLAZE)
Heiko Carstensdfcc3e62009-10-06 10:33:57 +0200382
Catalin Marinas3bba00d2009-06-11 13:24:13 +0100383 select DEBUG_FS if SYSFS
384 select STACKTRACE if STACKTRACE_SUPPORT
385 select KALLSYMS
Randy Dunlapb60e26a2009-11-06 15:33:45 -0800386 select CRC32
Catalin Marinas3bba00d2009-06-11 13:24:13 +0100387 help
388 Say Y here if you want to enable the memory leak
389 detector. The memory allocation/freeing is traced in a way
390 similar to the Boehm's conservative garbage collector, the
391 difference being that the orphan objects are not freed but
392 only shown in /sys/kernel/debug/kmemleak. Enabling this
393 feature will introduce an overhead to memory
394 allocations. See Documentation/kmemleak.txt for more
395 details.
396
Catalin Marinasbf96d1e2009-06-23 14:40:27 +0100397 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
398 of finding leaks due to the slab objects poisoning.
399
Catalin Marinas3bba00d2009-06-11 13:24:13 +0100400 In order to access the kmemleak file, debugfs needs to be
401 mounted (usually at /sys/kernel/debug).
402
Catalin Marinasa9d90582009-06-25 10:16:11 +0100403config DEBUG_KMEMLEAK_EARLY_LOG_SIZE
404 int "Maximum kmemleak early log entries"
405 depends on DEBUG_KMEMLEAK
Heiko Carstensdfcc3e62009-10-06 10:33:57 +0200406 range 200 40000
Catalin Marinasa9d90582009-06-25 10:16:11 +0100407 default 400
408 help
409 Kmemleak must track all the memory allocations to avoid
410 reporting false positives. Since memory may be allocated or
411 freed before kmemleak is initialised, an early log buffer is
412 used to store these actions. If kmemleak reports "early log
413 buffer exceeded", please increase this value.
414
Catalin Marinas0822ee42009-06-11 13:24:14 +0100415config DEBUG_KMEMLEAK_TEST
416 tristate "Simple test for the kernel memory leak detector"
417 depends on DEBUG_KMEMLEAK
418 help
419 Say Y or M here to build a test for the kernel memory leak
420 detector. This option enables a module that explicitly leaks
421 memory.
422
423 If unsure, say N.
424
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425config DEBUG_PREEMPT
426 bool "Debug preemptible kernel"
Kumar Gala01deab92009-10-16 07:21:39 +0000427 depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 default y
429 help
430 If you say Y here then the kernel will use a debug variant of the
431 commonly used smp_processor_id() function and will print warnings
432 if kernel code uses it in a preemption-unsafe way. Also, the kernel
433 will detect preemption count underflows.
434
Ingo Molnare7eebaf2006-06-27 02:54:55 -0700435config DEBUG_RT_MUTEXES
436 bool "RT Mutex debugging, deadlock detection"
Ingo Molnare7eebaf2006-06-27 02:54:55 -0700437 depends on DEBUG_KERNEL && RT_MUTEXES
438 help
439 This allows rt mutex semantics violations and rt mutex related
440 deadlocks (lockups) to be detected and reported automatically.
441
442config DEBUG_PI_LIST
443 bool
444 default y
445 depends on DEBUG_RT_MUTEXES
446
Thomas Gleixner61a87122006-06-27 02:54:56 -0700447config RT_MUTEX_TESTER
448 bool "Built-in scriptable tester for rt-mutexes"
Roman Zippela1583d32006-06-27 02:55:00 -0700449 depends on DEBUG_KERNEL && RT_MUTEXES
Thomas Gleixner61a87122006-06-27 02:54:56 -0700450 help
451 This option enables a rt-mutex tester.
452
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453config DEBUG_SPINLOCK
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700454 bool "Spinlock and rw-lock debugging: basic checks"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455 depends on DEBUG_KERNEL
456 help
457 Say Y here and build SMP to catch missing spinlock initialization
458 and certain other kinds of spinlock errors commonly made. This is
459 best used in conjunction with the NMI watchdog so that spinlock
460 deadlocks are also debuggable.
461
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700462config DEBUG_MUTEXES
463 bool "Mutex debugging: basic checks"
464 depends on DEBUG_KERNEL
465 help
466 This feature allows mutex semantics violations to be detected and
467 reported.
468
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700469config DEBUG_LOCK_ALLOC
470 bool "Lock debugging: detect incorrect freeing of live locks"
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700471 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700472 select DEBUG_SPINLOCK
473 select DEBUG_MUTEXES
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700474 select LOCKDEP
475 help
476 This feature will check whether any held lock (spinlock, rwlock,
477 mutex or rwsem) is incorrectly freed by the kernel, via any of the
478 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
479 vfree(), etc.), whether a live lock is incorrectly reinitialized via
480 spin_lock_init()/mutex_init()/etc., or whether there is any lock
481 held during task exit.
482
483config PROVE_LOCKING
484 bool "Lock debugging: prove locking correctness"
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700485 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700486 select LOCKDEP
487 select DEBUG_SPINLOCK
488 select DEBUG_MUTEXES
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700489 select DEBUG_LOCK_ALLOC
490 default n
491 help
492 This feature enables the kernel to prove that all locking
493 that occurs in the kernel runtime is mathematically
494 correct: that under no circumstance could an arbitrary (and
495 not yet triggered) combination of observed locking
496 sequences (on an arbitrary number of CPUs, running an
497 arbitrary number of tasks and interrupt contexts) cause a
498 deadlock.
499
500 In short, this feature enables the kernel to report locking
501 related deadlocks before they actually occur.
502
503 The proof does not depend on how hard and complex a
504 deadlock scenario would be to trigger: how many
505 participant CPUs, tasks and irq-contexts would be needed
506 for it to trigger. The proof also does not depend on
507 timing: if a race and a resulting deadlock is possible
508 theoretically (no matter how unlikely the race scenario
509 is), it will be proven so and will immediately be
510 reported by the kernel (once the event is observed that
511 makes the deadlock theoretically possible).
512
513 If a deadlock is impossible (i.e. the locking rules, as
514 observed by the kernel, are mathematically correct), the
515 kernel reports nothing.
516
517 NOTE: this feature can also be enabled for rwlocks, mutexes
518 and rwsems - in which case all dependencies between these
519 different locking variants are observed and mapped too, and
520 the proof of observed correctness is also maintained for an
521 arbitrary combination of these separate locking variants.
522
523 For more details, see Documentation/lockdep-design.txt.
524
Paul E. McKenney632ee202010-02-22 17:04:45 -0800525config PROVE_RCU
526 bool "RCU debugging: prove RCU correctness"
527 depends on PROVE_LOCKING
528 default n
529 help
530 This feature enables lockdep extensions that check for correct
531 use of RCU APIs. This is currently under development. Say Y
532 if you want to debug RCU usage or help work on the PROVE_RCU
533 feature.
534
535 Say N if you are unsure.
536
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700537config LOCKDEP
538 bool
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700539 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700540 select STACKTRACE
Peter Zijlstra00540e52009-06-12 10:04:01 +0200541 select FRAME_POINTER if !MIPS && !PPC && !ARM_UNWIND && !S390
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700542 select KALLSYMS
543 select KALLSYMS_ALL
544
Peter Zijlstraf20786f2007-07-19 01:48:56 -0700545config LOCK_STAT
Danny ter Haarfdfb8702007-09-24 21:24:43 -0700546 bool "Lock usage statistics"
Peter Zijlstraf20786f2007-07-19 01:48:56 -0700547 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
548 select LOCKDEP
549 select DEBUG_SPINLOCK
550 select DEBUG_MUTEXES
551 select DEBUG_LOCK_ALLOC
552 default n
553 help
554 This feature enables tracking lock contention points
555
Peter Zijlstraa560aa42007-10-07 00:24:33 -0700556 For more details, see Documentation/lockstat.txt
557
Frederic Weisbeckerdd8b1cf2010-02-27 17:10:39 +0100558 This also enables lock events required by "perf lock",
559 subcommand of perf.
560 If you want to use "perf lock", you also need to turn on
561 CONFIG_EVENT_TRACING.
Hitoshi Mitake84c6f882010-02-04 16:08:15 +0900562
563 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
Frederic Weisbeckerdd8b1cf2010-02-27 17:10:39 +0100564 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
Hitoshi Mitake84c6f882010-02-04 16:08:15 +0900565
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700566config DEBUG_LOCKDEP
567 bool "Lock dependency engine debugging"
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700568 depends on DEBUG_KERNEL && LOCKDEP
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700569 help
570 If you say Y here, the lock dependency engine will do
571 additional runtime checks to debug itself, at the price
572 of more runtime overhead.
573
574config TRACE_IRQFLAGS
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700575 depends on DEBUG_KERNEL
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700576 bool
577 default y
578 depends on TRACE_IRQFLAGS_SUPPORT
579 depends on PROVE_LOCKING
580
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581config DEBUG_SPINLOCK_SLEEP
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700582 bool "Spinlock debugging: sleep-inside-spinlock checking"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583 depends on DEBUG_KERNEL
584 help
585 If you say Y here, various routines which may sleep will become very
586 noisy if they are called with a spinlock held.
587
Ingo Molnarcae2ed92006-07-03 00:24:48 -0700588config DEBUG_LOCKING_API_SELFTESTS
589 bool "Locking API boot-time self-tests"
590 depends on DEBUG_KERNEL
591 help
592 Say Y here if you want the kernel to run a short self-test during
593 bootup. The self-test checks whether common types of locking bugs
594 are detected by debugging mechanisms or not. (if you disable
595 lock debugging then those bugs wont be detected of course.)
596 The following locking APIs are covered: spinlocks, rwlocks,
597 mutexes and rwsems.
598
Ingo Molnar8637c092006-07-03 00:24:38 -0700599config STACKTRACE
600 bool
601 depends on STACKTRACE_SUPPORT
602
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603config DEBUG_KOBJECT
604 bool "kobject debugging"
605 depends on DEBUG_KERNEL
606 help
607 If you say Y here, some extra kobject debugging messages will be sent
608 to the syslog.
609
610config DEBUG_HIGHMEM
611 bool "Highmem debugging"
612 depends on DEBUG_KERNEL && HIGHMEM
613 help
614 This options enables addition error checking for high memory systems.
615 Disable for production systems.
616
617config DEBUG_BUGVERBOSE
618 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EMBEDDED
Matt Mackallc8538a72005-05-01 08:59:01 -0700619 depends on BUG
David Howellsb920de12008-02-08 04:19:31 -0800620 depends on ARM || AVR32 || M32R || M68K || SPARC32 || SPARC64 || \
621 FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300
Alexey Dobriyan8420e7e2009-12-14 18:00:25 -0800622 default y
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623 help
624 Say Y here to make BUG() panics output the file name and line number
625 of the BUG call as well as the EIP and oops trace. This aids
626 debugging but costs about 70-100K of memory.
627
628config DEBUG_INFO
629 bool "Compile the kernel with debug info"
630 depends on DEBUG_KERNEL
631 help
632 If you say Y here the resulting kernel image will include
633 debugging info resulting in a larger kernel image.
Andreas Dilgerb72e53f2007-03-27 15:21:33 -0600634 This adds debug symbols to the kernel and modules (gcc -g), and
635 is needed if you intend to use kernel crashdump or binary object
636 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 Say Y here only if you plan to debug the kernel.
638
639 If unsure, say N.
640
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800641config DEBUG_VM
642 bool "Debug VM"
643 depends on DEBUG_KERNEL
644 help
Nick Piggin13e74442006-01-06 00:10:58 -0800645 Enable this to turn on extended checks in the virtual-memory system
646 that may impact performance.
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800647
648 If unsure, say N.
649
Jiri Slaby59ea7462008-06-12 13:56:40 +0200650config DEBUG_VIRTUAL
651 bool "Debug VM translations"
652 depends on DEBUG_KERNEL && X86
653 help
654 Enable some costly sanity checks in virtual to page code. This can
655 catch mistakes with virt_to_page() and friends.
656
657 If unsure, say N.
658
David Howells8feae132009-01-08 12:04:47 +0000659config DEBUG_NOMMU_REGIONS
660 bool "Debug the global anon/private NOMMU mapping region tree"
661 depends on DEBUG_KERNEL && !MMU
662 help
663 This option causes the global tree of anonymous and private mapping
664 regions to be regularly checked for invalid topology.
665
Dave Hansenad775f52008-02-15 14:38:01 -0800666config DEBUG_WRITECOUNT
667 bool "Debug filesystem writers count"
668 depends on DEBUG_KERNEL
669 help
670 Enable this to catch wrong use of the writers count in struct
671 vfsmount. This will increase the size of each file struct by
672 32 bits.
673
674 If unsure, say N.
675
Mel Gorman6b74ab92008-07-23 21:26:49 -0700676config DEBUG_MEMORY_INIT
677 bool "Debug memory initialisation" if EMBEDDED
678 default !EMBEDDED
679 help
680 Enable this for additional checks during memory initialisation.
681 The sanity checks verify aspects of the VM such as the memory model
682 and other information provided by the architecture. Verbose
683 information will be printed at KERN_DEBUG loglevel depending
684 on the mminit_loglevel= command-line option.
685
686 If unsure, say Y
687
Dave Jones199a9af2006-09-29 01:59:00 -0700688config DEBUG_LIST
689 bool "Debug linked list manipulation"
690 depends on DEBUG_KERNEL
691 help
692 Enable this to turn on extended checks in the linked-list
693 walking routines.
694
695 If unsure, say N.
696
Jens Axboed6ec0842007-10-22 20:01:06 +0200697config DEBUG_SG
698 bool "Debug SG table operations"
699 depends on DEBUG_KERNEL
700 help
701 Enable this to turn on checks on scatter-gather tables. This can
702 help find problems with drivers that do not properly initialize
703 their sg tables.
704
705 If unsure, say N.
706
Arjan van de Ven1b2439d2008-08-15 15:29:38 -0700707config DEBUG_NOTIFIERS
708 bool "Debug notifier call chains"
709 depends on DEBUG_KERNEL
710 help
711 Enable this to turn on sanity checking for notifier call chains.
712 This is most useful for kernel developers to make sure that
713 modules properly unregister themselves from notifier chains.
714 This is a relatively cheap check but if you care about maximum
715 performance, say N.
716
David Howellse0e81732009-09-02 09:13:40 +0100717config DEBUG_CREDENTIALS
718 bool "Debug credential management"
719 depends on DEBUG_KERNEL
720 help
721 Enable this to turn on some debug checking for credential
722 management. The additional code keeps track of the number of
723 pointers from task_structs to any given cred struct, and checks to
724 see that this number never exceeds the usage count of the cred
725 struct.
726
727 Furthermore, if SELinux is enabled, this also checks that the
728 security pointer in the cred struct is never seen to be invalid.
729
730 If unsure, say N.
731
Jeff Mahoney64dec402009-01-16 13:23:35 -0500732#
733# Select this config option from the architecture Kconfig, if it
734# it is preferred to always offer frame pointers as a config
735# option on the architecture (regardless of KERNEL_DEBUG):
736#
737config ARCH_WANT_FRAME_POINTERS
738 bool
739 help
740
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741config FRAME_POINTER
742 bool "Compile the kernel with frame pointers"
David Howellsb920de12008-02-08 04:19:31 -0800743 depends on DEBUG_KERNEL && \
Heiko Carstens75ee0342009-04-23 13:58:10 +0200744 (CRIS || M68K || M68KNOMMU || FRV || UML || \
Ingo Molnarda4276b2009-01-07 11:05:10 +0100745 AVR32 || SUPERH || BLACKFIN || MN10300) || \
746 ARCH_WANT_FRAME_POINTERS
747 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748 help
Ingo Molnarda4276b2009-01-07 11:05:10 +0100749 If you say Y here the resulting kernel image will be slightly
750 larger and slower, but it gives very useful debugging information
751 in case of kernel bugs. (precise oopses/stacktraces/warnings)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700752
Randy Dunlapbfe8df32007-10-16 01:23:46 -0700753config BOOT_PRINTK_DELAY
754 bool "Delay each boot printk message by N milliseconds"
755 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
756 help
757 This build option allows you to read kernel boot messages
758 by inserting a short delay after each one. The delay is
759 specified in milliseconds on the kernel command line,
760 using "boot_delay=N".
761
762 It is likely that you would also need to use "lpj=M" to preset
763 the "loops per jiffie" value.
764 See a previous boot log for the "lpj" value to use for your
765 system, and then set "lpj=M" before setting "boot_delay=N".
766 NOTE: Using this option may adversely affect SMP systems.
767 I.e., processors other than the first one may not boot up.
768 BOOT_PRINTK_DELAY also may cause DETECT_SOFTLOCKUP to detect
769 what it believes to be lockup conditions.
770
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800771config RCU_TORTURE_TEST
772 tristate "torture tests for RCU"
773 depends on DEBUG_KERNEL
774 default n
775 help
776 This option provides a kernel module that runs torture tests
777 on the RCU infrastructure. The kernel module may be built
778 after the fact on the running kernel to be tested, if desired.
779
Paul E. McKenney31a72bc2008-06-18 09:26:49 -0700780 Say Y here if you want RCU torture tests to be built into
781 the kernel.
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800782 Say M if you want the RCU torture tests to build as a module.
783 Say N if you are unsure.
Ankita Garg8bb31b92006-10-02 02:17:36 -0700784
Paul E. McKenney31a72bc2008-06-18 09:26:49 -0700785config RCU_TORTURE_TEST_RUNNABLE
786 bool "torture tests for RCU runnable by default"
787 depends on RCU_TORTURE_TEST = y
788 default n
789 help
790 This option provides a way to build the RCU torture tests
791 directly into the kernel without them starting up at boot
792 time. You can use /proc/sys/kernel/rcutorture_runnable
793 to manually override this setting. This /proc file is
794 available only when the RCU torture tests have been built
795 into the kernel.
796
797 Say Y here if you want the RCU torture tests to start during
798 boot (you probably don't).
799 Say N here if you want the RCU torture tests to start only
800 after being manually enabled via /proc.
801
Paul E. McKenney2133b5d2008-10-02 16:06:39 -0700802config RCU_CPU_STALL_DETECTOR
Paul E. McKenney67182ae2008-08-10 18:35:38 -0700803 bool "Check for stalled CPUs delaying RCU grace periods"
Paul E. McKenney6b3ef482009-08-22 13:56:53 -0700804 depends on TREE_RCU || TREE_PREEMPT_RCU
Paul E. McKenney8bfb2f82009-12-02 12:10:16 -0800805 default y
Paul E. McKenney64db4cf2008-12-18 21:55:32 +0100806 help
807 This option causes RCU to printk information on which
808 CPUs are delaying the current grace period, but only when
809 the grace period extends for excessive time periods.
810
Paul E. McKenney4c540052010-01-14 16:10:57 -0800811 Say N if you want to disable such checks.
Paul E. McKenney64db4cf2008-12-18 21:55:32 +0100812
Paul E. McKenney4c540052010-01-14 16:10:57 -0800813 Say Y if you are unsure.
Paul E. McKenney64db4cf2008-12-18 21:55:32 +0100814
Paul E. McKenney1ed509a2010-02-22 17:05:05 -0800815config RCU_CPU_STALL_VERBOSE
816 bool "Print additional per-task information for RCU_CPU_STALL_DETECTOR"
817 depends on RCU_CPU_STALL_DETECTOR && TREE_PREEMPT_RCU
818 default n
819 help
820 This option causes RCU to printk detailed per-task information
821 for any tasks that are stalling the current RCU grace period.
Arjan van de Ven6dab2772008-01-30 13:33:08 +0100822
823 Say N if you are unsure.
824
Paul E. McKenney1ed509a2010-02-22 17:05:05 -0800825 Say Y if you want to enable such checks.
826
Ananth N Mavinakayanahalli8c1c9352008-01-30 13:32:53 +0100827config KPROBES_SANITY_TEST
828 bool "Kprobes sanity tests"
829 depends on DEBUG_KERNEL
830 depends on KPROBES
831 default n
832 help
833 This option provides for testing basic kprobes functionality on
834 boot. A sample kprobe, jprobe and kretprobe are inserted and
835 verified for functionality.
836
837 Say N if you are unsure.
838
Arjan van de Ven6dab2772008-01-30 13:33:08 +0100839config BACKTRACE_SELF_TEST
840 tristate "Self test for the backtrace code"
841 depends on DEBUG_KERNEL
842 default n
843 help
844 This option provides a kernel module that can be used to test
845 the kernel stack backtrace code. This option is not useful
846 for distributions or general kernels, but only for kernel
847 developers working on architecture code.
848
Vegard Nossumad118c52008-06-27 18:04:48 +0200849 Note that if you want to also test saved backtraces, you will
850 have to enable STACKTRACE as well.
851
Arjan van de Ven6dab2772008-01-30 13:33:08 +0100852 Say N if you are unsure.
853
Tejun Heo870d6652008-08-25 19:47:25 +0900854config DEBUG_BLOCK_EXT_DEVT
855 bool "Force extended block device numbers and spread them"
856 depends on DEBUG_KERNEL
857 depends on BLOCK
Jens Axboe759f8ca2008-08-29 09:06:29 +0200858 default n
Tejun Heo870d6652008-08-25 19:47:25 +0900859 help
Tejun Heo0e11e342008-10-13 10:46:01 +0200860 BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
861 SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
862 YOU ARE DOING. Distros, please enable this and fix whatever
863 is broken.
864
Tejun Heo870d6652008-08-25 19:47:25 +0900865 Conventionally, block device numbers are allocated from
866 predetermined contiguous area. However, extended block area
867 may introduce non-contiguous block device numbers. This
868 option forces most block device numbers to be allocated from
869 the extended space and spreads them to discover kernel or
870 userland code paths which assume predetermined contiguous
871 device number allocation.
872
Tejun Heo55dc7db2008-09-01 13:44:35 +0200873 Note that turning on this debug option shuffles all the
874 device numbers for all IDE and SCSI devices including libata
875 ones, so root partition specified using device number
876 directly (via rdev or root=MAJ:MIN) won't work anymore.
877 Textual device names (root=/dev/sdXn) will continue to work.
878
Tejun Heo870d6652008-08-25 19:47:25 +0900879 Say N if you are unsure.
880
Tejun Heo7c756e62009-06-24 15:13:50 +0900881config DEBUG_FORCE_WEAK_PER_CPU
882 bool "Force weak per-cpu definitions"
883 depends on DEBUG_KERNEL
884 help
885 s390 and alpha require percpu variables in modules to be
886 defined weak to work around addressing range issue which
887 puts the following two restrictions on percpu variable
888 definitions.
889
890 1. percpu symbols must be unique whether static or not
891 2. percpu variables can't be defined inside a function
892
893 To ensure that generic code follows the above rules, this
894 option forces all percpu variables to be defined as weak.
895
Ankita Garg8bb31b92006-10-02 02:17:36 -0700896config LKDTM
897 tristate "Linux Kernel Dump Test Tool Module"
Simon Kagstrom0347af42010-03-05 13:42:49 -0800898 depends on DEBUG_FS
Chris Snookfddd9cf2008-02-23 15:23:26 -0800899 depends on BLOCK
Ankita Garg8bb31b92006-10-02 02:17:36 -0700900 default n
901 help
902 This module enables testing of the different dumping mechanisms by
903 inducing system failures at predefined crash points.
904 If you don't need it: say N
905 Choose M here to compile this code as a module. The module will be
906 called lkdtm.
907
908 Documentation on how to use the module can be found in
Simon Kagstrom0347af42010-03-05 13:42:49 -0800909 Documentation/fault-injection/provoke-crashes.txt
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800910
911config FAULT_INJECTION
Andrew Morton1ab85092006-12-08 02:39:49 -0800912 bool "Fault-injection framework"
913 depends on DEBUG_KERNEL
Akinobu Mita329409a2006-12-08 02:39:48 -0800914 help
915 Provide fault-injection framework.
916 For more details, see Documentation/fault-injection/.
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800917
Akinobu Mita8a8b6502006-12-08 02:39:44 -0800918config FAILSLAB
Andrew Morton1ab85092006-12-08 02:39:49 -0800919 bool "Fault-injection capability for kmalloc"
920 depends on FAULT_INJECTION
Akinobu Mita773ff602008-12-23 19:37:01 +0900921 depends on SLAB || SLUB
Akinobu Mita8a8b6502006-12-08 02:39:44 -0800922 help
Andrew Morton1ab85092006-12-08 02:39:49 -0800923 Provide fault-injection capability for kmalloc.
Akinobu Mita8a8b6502006-12-08 02:39:44 -0800924
Akinobu Mita933e3122006-12-08 02:39:45 -0800925config FAIL_PAGE_ALLOC
926 bool "Fault-injection capabilitiy for alloc_pages()"
Andrew Morton1ab85092006-12-08 02:39:49 -0800927 depends on FAULT_INJECTION
Akinobu Mita933e3122006-12-08 02:39:45 -0800928 help
Andrew Morton1ab85092006-12-08 02:39:49 -0800929 Provide fault-injection capability for alloc_pages().
Akinobu Mita933e3122006-12-08 02:39:45 -0800930
Akinobu Mitac17bb492006-12-08 02:39:46 -0800931config FAIL_MAKE_REQUEST
Dave Jones86327d12006-12-12 20:16:36 +0100932 bool "Fault-injection capability for disk IO"
Jens Axboe581d4e22008-09-14 05:56:33 -0700933 depends on FAULT_INJECTION && BLOCK
Akinobu Mitac17bb492006-12-08 02:39:46 -0800934 help
Andrew Morton1ab85092006-12-08 02:39:49 -0800935 Provide fault-injection capability for disk IO.
Akinobu Mitac17bb492006-12-08 02:39:46 -0800936
Jens Axboe581d4e22008-09-14 05:56:33 -0700937config FAIL_IO_TIMEOUT
938 bool "Faul-injection capability for faking disk interrupts"
939 depends on FAULT_INJECTION && BLOCK
940 help
941 Provide fault-injection capability on end IO handling. This
942 will make the block layer "forget" an interrupt as configured,
943 thus exercising the error handling.
944
945 Only works with drivers that use the generic timeout handling,
946 for others it wont do anything.
947
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800948config FAULT_INJECTION_DEBUG_FS
949 bool "Debugfs entries for fault-injection capabilities"
Andrew Morton1ab85092006-12-08 02:39:49 -0800950 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800951 help
Andrew Morton1ab85092006-12-08 02:39:49 -0800952 Enable configuration of fault-injection capabilities via debugfs.
Akinobu Mita1df49002007-02-20 13:57:56 -0800953
954config FAULT_INJECTION_STACKTRACE_FILTER
955 bool "stacktrace filter for fault-injection capabilities"
956 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
Akinobu Mita6d690dc2007-05-12 10:36:53 -0700957 depends on !X86_64
Akinobu Mita1df49002007-02-20 13:57:56 -0800958 select STACKTRACE
Heiko Carstens75ee0342009-04-23 13:58:10 +0200959 select FRAME_POINTER if !PPC && !S390
Akinobu Mita1df49002007-02-20 13:57:56 -0800960 help
961 Provide stacktrace filter for fault-injection capabilities
Mathieu Desnoyers267c4022007-10-18 23:41:07 -0700962
Arjan van de Ven97455122008-01-25 21:08:34 +0100963config LATENCYTOP
964 bool "Latency measuring infrastructure"
Heiko Carstens75ee0342009-04-23 13:58:10 +0200965 select FRAME_POINTER if !MIPS && !PPC && !S390
Arjan van de Ven97455122008-01-25 21:08:34 +0100966 select KALLSYMS
967 select KALLSYMS_ALL
968 select STACKTRACE
969 select SCHEDSTATS
970 select SCHED_DEBUG
Heiko Carstensaa7d9352008-02-01 17:45:14 +0100971 depends on HAVE_LATENCYTOP_SUPPORT
Arjan van de Ven97455122008-01-25 21:08:34 +0100972 help
973 Enable this option if you want to use the LatencyTOP tool
974 to find out which userspace is blocking on what kernel operations.
975
Andi Kleen9e94cd32008-08-16 07:53:05 +0200976config SYSCTL_SYSCALL_CHECK
977 bool "Sysctl checks"
Eric W. Biederman83ac2012009-04-03 02:22:26 -0700978 depends on SYSCTL
Andi Kleen9e94cd32008-08-16 07:53:05 +0200979 ---help---
980 sys_sysctl uses binary paths that have been found challenging
981 to properly maintain and use. This enables checks that help
982 you to keep things correct.
983
Akinobu Mita6a11f752009-03-31 15:23:17 -0700984source mm/Kconfig.debug
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200985source kernel/trace/Kconfig
986
Bernhard Kaindlf212ec42008-01-30 13:34:11 +0100987config PROVIDE_OHCI1394_DMA_INIT
Stefan Richter080de8c2008-02-28 20:54:43 +0100988 bool "Remote debugging over FireWire early on boot"
Bernhard Kaindlf212ec42008-01-30 13:34:11 +0100989 depends on PCI && X86
990 help
991 If you want to debug problems which hang or crash the kernel early
992 on boot and the crashing machine has a FireWire port, you can use
993 this feature to remotely access the memory of the crashed machine
994 over FireWire. This employs remote DMA as part of the OHCI1394
995 specification which is now the standard for FireWire controllers.
996
997 With remote DMA, you can monitor the printk buffer remotely using
998 firescope and access all memory below 4GB using fireproxy from gdb.
999 Even controlling a kernel debugger is possible using remote DMA.
1000
1001 Usage:
1002
1003 If ohci1394_dma=early is used as boot parameter, it will initialize
1004 all OHCI1394 controllers which are found in the PCI config space.
1005
1006 As all changes to the FireWire bus such as enabling and disabling
1007 devices cause a bus reset and thereby disable remote DMA for all
1008 devices, be sure to have the cable plugged and FireWire enabled on
1009 the debugging host before booting the debug target for debugging.
1010
1011 This code (~1k) is freed after boot. By then, the firewire stack
1012 in charge of the OHCI-1394 controllers should be used instead.
1013
1014 See Documentation/debugging-via-ohci1394.txt for more information.
Arjan van de Ven97455122008-01-25 21:08:34 +01001015
Stefan Richter080de8c2008-02-28 20:54:43 +01001016config FIREWIRE_OHCI_REMOTE_DMA
1017 bool "Remote debugging over FireWire with firewire-ohci"
1018 depends on FIREWIRE_OHCI
1019 help
1020 This option lets you use the FireWire bus for remote debugging
1021 with help of the firewire-ohci driver. It enables unfiltered
1022 remote DMA in firewire-ohci.
1023 See Documentation/debugging-via-ohci1394.txt for more information.
1024
1025 If unsure, say N.
1026
Randy Dunlap152de302009-02-20 15:38:47 -08001027config BUILD_DOCSRC
Randy Dunlap3794f3e2008-08-12 15:09:06 -07001028 bool "Build targets in Documentation/ tree"
1029 depends on HEADERS_CHECK
1030 help
1031 This option attempts to build objects from the source files in the
1032 kernel Documentation/ tree.
1033
1034 Say N if you are unsure.
1035
Jason Barone9d376f2009-02-05 11:51:38 -05001036config DYNAMIC_DEBUG
Jason Baron86151fd2009-02-05 11:53:15 -05001037 bool "Enable dynamic printk() support"
Jason Baron346e15b2008-08-12 16:46:19 -04001038 default n
1039 depends on PRINTK
Jason Baron86151fd2009-02-05 11:53:15 -05001040 depends on DEBUG_FS
Jason Baron346e15b2008-08-12 16:46:19 -04001041 help
1042
1043 Compiles debug level messages into the kernel, which would not
1044 otherwise be available at runtime. These messages can then be
Jason Baron86151fd2009-02-05 11:53:15 -05001045 enabled/disabled based on various levels of scope - per source file,
1046 function, module, format string, and line number. This mechanism
1047 implicitly enables all pr_debug() and dev_dbg() calls. The impact of
1048 this compile option is a larger kernel text size of about 2%.
Jason Baron346e15b2008-08-12 16:46:19 -04001049
1050 Usage:
1051
Jason Baron86151fd2009-02-05 11:53:15 -05001052 Dynamic debugging is controlled via the 'dynamic_debug/ddebug' file,
1053 which is contained in the 'debugfs' filesystem. Thus, the debugfs
1054 filesystem must first be mounted before making use of this feature.
1055 We refer the control file as: <debugfs>/dynamic_debug/ddebug. This
1056 file contains a list of the debug statements that can be enabled. The
1057 format for each line of the file is:
Jason Baron346e15b2008-08-12 16:46:19 -04001058
Jason Baron86151fd2009-02-05 11:53:15 -05001059 filename:lineno [module]function flags format
Jason Baron346e15b2008-08-12 16:46:19 -04001060
Jason Baron86151fd2009-02-05 11:53:15 -05001061 filename : source file of the debug statement
1062 lineno : line number of the debug statement
1063 module : module that contains the debug statement
1064 function : function that contains the debug statement
1065 flags : 'p' means the line is turned 'on' for printing
1066 format : the format used for the debug statement
Jason Baron346e15b2008-08-12 16:46:19 -04001067
1068 From a live system:
1069
Jason Baron86151fd2009-02-05 11:53:15 -05001070 nullarbor:~ # cat <debugfs>/dynamic_debug/ddebug
1071 # filename:lineno [module]function flags format
1072 fs/aio.c:222 [aio]__put_ioctx - "__put_ioctx:\040freeing\040%p\012"
1073 fs/aio.c:248 [aio]ioctx_alloc - "ENOMEM:\040nr_events\040too\040high\012"
1074 fs/aio.c:1770 [aio]sys_io_cancel - "calling\040cancel\012"
Jason Baron346e15b2008-08-12 16:46:19 -04001075
Jason Baron86151fd2009-02-05 11:53:15 -05001076 Example usage:
Jason Baron346e15b2008-08-12 16:46:19 -04001077
Jason Baron86151fd2009-02-05 11:53:15 -05001078 // enable the message at line 1603 of file svcsock.c
1079 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
1080 <debugfs>/dynamic_debug/ddebug
Jason Baron346e15b2008-08-12 16:46:19 -04001081
Jason Baron86151fd2009-02-05 11:53:15 -05001082 // enable all the messages in file svcsock.c
1083 nullarbor:~ # echo -n 'file svcsock.c +p' >
1084 <debugfs>/dynamic_debug/ddebug
Jason Baron346e15b2008-08-12 16:46:19 -04001085
Jason Baron86151fd2009-02-05 11:53:15 -05001086 // enable all the messages in the NFS server module
1087 nullarbor:~ # echo -n 'module nfsd +p' >
1088 <debugfs>/dynamic_debug/ddebug
Jason Baron346e15b2008-08-12 16:46:19 -04001089
Jason Baron86151fd2009-02-05 11:53:15 -05001090 // enable all 12 messages in the function svc_process()
1091 nullarbor:~ # echo -n 'func svc_process +p' >
1092 <debugfs>/dynamic_debug/ddebug
Jason Baron346e15b2008-08-12 16:46:19 -04001093
Jason Baron86151fd2009-02-05 11:53:15 -05001094 // disable all 12 messages in the function svc_process()
1095 nullarbor:~ # echo -n 'func svc_process -p' >
1096 <debugfs>/dynamic_debug/ddebug
Jason Baron346e15b2008-08-12 16:46:19 -04001097
Jason Baron86151fd2009-02-05 11:53:15 -05001098 See Documentation/dynamic-debug-howto.txt for additional information.
Jason Baron346e15b2008-08-12 16:46:19 -04001099
Joerg Roedel5ee00bd2009-01-09 12:14:24 +01001100config DMA_API_DEBUG
1101 bool "Enable debugging of DMA-API usage"
1102 depends on HAVE_DMA_API_DEBUG
1103 help
1104 Enable this option to debug the use of the DMA API by device drivers.
1105 With this option you will be able to detect common bugs in device
1106 drivers like double-freeing of DMA mappings or freeing mappings that
1107 were never allocated.
1108 This option causes a performance degredation. Use only if you want
1109 to debug device drivers. If unsure, say N.
Jason Baron346e15b2008-08-12 16:46:19 -04001110
Mathieu Desnoyers267c4022007-10-18 23:41:07 -07001111source "samples/Kconfig"
Jason Wesseldc7d5522008-04-17 20:05:37 +02001112
1113source "lib/Kconfig.kgdb"
Pekka Enberg0a4af3b2009-02-26 21:38:56 +02001114
1115source "lib/Kconfig.kmemcheck"