blob: 8b5a7d304a5f5709cfb97436396916fc074db428 [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
Ingo Molnarb642b6d2007-07-09 18:52:00 +0200189config SCHED_DEBUG
190 bool "Collect scheduler debugging info"
191 depends on DEBUG_KERNEL && PROC_FS
192 default y
193 help
194 If you say Y here, the /proc/sched_debug file will be provided
195 that can help debug the scheduler. The runtime overhead of this
196 option is minimal.
197
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198config SCHEDSTATS
199 bool "Collect scheduler statistics"
200 depends on DEBUG_KERNEL && PROC_FS
201 help
202 If you say Y here, additional code will be inserted into the
203 scheduler and related routines to collect statistics about
204 scheduler behavior and provide them in /proc/schedstat. These
205 stats may be useful for both tuning and debugging the scheduler
206 If you aren't debugging the scheduler or trying to tune a specific
207 application, you can say N to avoid the very slight overhead
208 this adds.
209
Ingo Molnar82f67cd2007-02-16 01:28:13 -0800210config TIMER_STATS
211 bool "Collect kernel timers statistics"
212 depends on DEBUG_KERNEL && PROC_FS
213 help
214 If you say Y here, additional code will be inserted into the
215 timer routines to collect statistics about kernel timers being
216 reprogrammed. The statistics can be read from /proc/timer_stats.
217 The statistics collection is started by writing 1 to /proc/timer_stats,
218 writing 0 stops it. This feature is useful to collect information
Ingo Molnarc1a834d2007-06-01 00:47:16 -0700219 about timer usage patterns in kernel and userspace. This feature
220 is lightweight if enabled in the kernel config but not activated
221 (it defaults to deactivated on bootup and will only be activated
222 if some application like powertop activates it explicitly).
Ingo Molnar82f67cd2007-02-16 01:28:13 -0800223
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700224config DEBUG_OBJECTS
225 bool "Debug object operations"
226 depends on DEBUG_KERNEL
227 help
228 If you say Y here, additional code will be inserted into the
229 kernel to track the life time of various objects and validate
230 the operations on those objects.
231
232config DEBUG_OBJECTS_SELFTEST
233 bool "Debug objects selftest"
234 depends on DEBUG_OBJECTS
235 help
236 This enables the selftest of the object debug code.
237
238config DEBUG_OBJECTS_FREE
239 bool "Debug objects in freed memory"
240 depends on DEBUG_OBJECTS
241 help
242 This enables checks whether a k/v free operation frees an area
243 which contains an object which has not been deactivated
244 properly. This can make kmalloc/kfree-intensive workloads
245 much slower.
246
Thomas Gleixnerc6f3a972008-04-30 00:55:03 -0700247config DEBUG_OBJECTS_TIMERS
248 bool "Debug timer objects"
249 depends on DEBUG_OBJECTS
250 help
251 If you say Y here, additional code will be inserted into the
252 timer routines to track the life time of timer objects and
253 validate the timer operations.
254
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255config DEBUG_SLAB
Andrew Morton4a2f0ac2006-03-25 03:07:22 -0800256 bool "Debug slab memory allocations"
Ingo Molnar50dd26ba2006-01-08 01:01:42 -0800257 depends on DEBUG_KERNEL && SLAB
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 help
259 Say Y here to have the kernel do limited verification on memory
260 allocation as well as poisoning memory on free to catch use of freed
261 memory. This can make kmalloc/kfree-intensive workloads much slower.
262
Al Viro871751e2006-03-25 03:06:39 -0800263config DEBUG_SLAB_LEAK
264 bool "Memory leak debugging"
265 depends on DEBUG_SLAB
266
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700267config SLUB_DEBUG_ON
268 bool "SLUB debugging on by default"
269 depends on SLUB && SLUB_DEBUG
270 default n
271 help
272 Boot with debugging on by default. SLUB boots by default with
273 the runtime debug capabilities switched off. Enabling this is
274 equivalent to specifying the "slub_debug" parameter on boot.
275 There is no support for more fine grained debug control like
276 possible with slub_debug=xxx. SLUB debugging may be switched
277 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
278 "slub_debug=-".
279
Christoph Lameter8ff12cf2008-02-07 17:47:41 -0800280config SLUB_STATS
281 default n
282 bool "Enable SLUB performance statistics"
Christoph Lameter5b06c8532008-04-14 18:51:34 +0300283 depends on SLUB && SLUB_DEBUG && SYSFS
Christoph Lameter8ff12cf2008-02-07 17:47:41 -0800284 help
285 SLUB statistics are useful to debug SLUBs allocation behavior in
286 order find ways to optimize the allocator. This should never be
287 enabled for production use since keeping statistics slows down
288 the allocator by a few percentage points. The slabinfo command
289 supports the determination of the most active slabs to figure
290 out which slabs are relevant to a particular load.
291 Try running: slabinfo -DA
292
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293config DEBUG_PREEMPT
294 bool "Debug preemptible kernel"
Hugh Dickins048c8bc2006-11-01 05:44:54 +1100295 depends on DEBUG_KERNEL && PREEMPT && (TRACE_IRQFLAGS_SUPPORT || PPC64)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296 default y
297 help
298 If you say Y here then the kernel will use a debug variant of the
299 commonly used smp_processor_id() function and will print warnings
300 if kernel code uses it in a preemption-unsafe way. Also, the kernel
301 will detect preemption count underflows.
302
Ingo Molnare7eebaf2006-06-27 02:54:55 -0700303config DEBUG_RT_MUTEXES
304 bool "RT Mutex debugging, deadlock detection"
Ingo Molnare7eebaf2006-06-27 02:54:55 -0700305 depends on DEBUG_KERNEL && RT_MUTEXES
306 help
307 This allows rt mutex semantics violations and rt mutex related
308 deadlocks (lockups) to be detected and reported automatically.
309
310config DEBUG_PI_LIST
311 bool
312 default y
313 depends on DEBUG_RT_MUTEXES
314
Thomas Gleixner61a87122006-06-27 02:54:56 -0700315config RT_MUTEX_TESTER
316 bool "Built-in scriptable tester for rt-mutexes"
Roman Zippela1583d32006-06-27 02:55:00 -0700317 depends on DEBUG_KERNEL && RT_MUTEXES
Thomas Gleixner61a87122006-06-27 02:54:56 -0700318 help
319 This option enables a rt-mutex tester.
320
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321config DEBUG_SPINLOCK
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700322 bool "Spinlock and rw-lock debugging: basic checks"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323 depends on DEBUG_KERNEL
324 help
325 Say Y here and build SMP to catch missing spinlock initialization
326 and certain other kinds of spinlock errors commonly made. This is
327 best used in conjunction with the NMI watchdog so that spinlock
328 deadlocks are also debuggable.
329
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700330config DEBUG_MUTEXES
331 bool "Mutex debugging: basic checks"
332 depends on DEBUG_KERNEL
333 help
334 This feature allows mutex semantics violations to be detected and
335 reported.
336
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700337config DEBUG_LOCK_ALLOC
338 bool "Lock debugging: detect incorrect freeing of live locks"
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700339 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700340 select DEBUG_SPINLOCK
341 select DEBUG_MUTEXES
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700342 select LOCKDEP
343 help
344 This feature will check whether any held lock (spinlock, rwlock,
345 mutex or rwsem) is incorrectly freed by the kernel, via any of the
346 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
347 vfree(), etc.), whether a live lock is incorrectly reinitialized via
348 spin_lock_init()/mutex_init()/etc., or whether there is any lock
349 held during task exit.
350
351config PROVE_LOCKING
352 bool "Lock debugging: prove locking correctness"
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700353 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700354 select LOCKDEP
355 select DEBUG_SPINLOCK
356 select DEBUG_MUTEXES
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700357 select DEBUG_LOCK_ALLOC
358 default n
359 help
360 This feature enables the kernel to prove that all locking
361 that occurs in the kernel runtime is mathematically
362 correct: that under no circumstance could an arbitrary (and
363 not yet triggered) combination of observed locking
364 sequences (on an arbitrary number of CPUs, running an
365 arbitrary number of tasks and interrupt contexts) cause a
366 deadlock.
367
368 In short, this feature enables the kernel to report locking
369 related deadlocks before they actually occur.
370
371 The proof does not depend on how hard and complex a
372 deadlock scenario would be to trigger: how many
373 participant CPUs, tasks and irq-contexts would be needed
374 for it to trigger. The proof also does not depend on
375 timing: if a race and a resulting deadlock is possible
376 theoretically (no matter how unlikely the race scenario
377 is), it will be proven so and will immediately be
378 reported by the kernel (once the event is observed that
379 makes the deadlock theoretically possible).
380
381 If a deadlock is impossible (i.e. the locking rules, as
382 observed by the kernel, are mathematically correct), the
383 kernel reports nothing.
384
385 NOTE: this feature can also be enabled for rwlocks, mutexes
386 and rwsems - in which case all dependencies between these
387 different locking variants are observed and mapped too, and
388 the proof of observed correctness is also maintained for an
389 arbitrary combination of these separate locking variants.
390
391 For more details, see Documentation/lockdep-design.txt.
392
393config LOCKDEP
394 bool
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700395 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700396 select STACKTRACE
Franck Bui-Huu14cf2322007-04-26 00:20:15 -0700397 select FRAME_POINTER if !X86 && !MIPS
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700398 select KALLSYMS
399 select KALLSYMS_ALL
400
Peter Zijlstraf20786f2007-07-19 01:48:56 -0700401config LOCK_STAT
Danny ter Haarfdfb8702007-09-24 21:24:43 -0700402 bool "Lock usage statistics"
Peter Zijlstraf20786f2007-07-19 01:48:56 -0700403 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
404 select LOCKDEP
405 select DEBUG_SPINLOCK
406 select DEBUG_MUTEXES
407 select DEBUG_LOCK_ALLOC
408 default n
409 help
410 This feature enables tracking lock contention points
411
Peter Zijlstraa560aa42007-10-07 00:24:33 -0700412 For more details, see Documentation/lockstat.txt
413
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700414config DEBUG_LOCKDEP
415 bool "Lock dependency engine debugging"
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700416 depends on DEBUG_KERNEL && LOCKDEP
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700417 help
418 If you say Y here, the lock dependency engine will do
419 additional runtime checks to debug itself, at the price
420 of more runtime overhead.
421
422config TRACE_IRQFLAGS
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700423 depends on DEBUG_KERNEL
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700424 bool
425 default y
426 depends on TRACE_IRQFLAGS_SUPPORT
427 depends on PROVE_LOCKING
428
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429config DEBUG_SPINLOCK_SLEEP
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700430 bool "Spinlock debugging: sleep-inside-spinlock checking"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 depends on DEBUG_KERNEL
432 help
433 If you say Y here, various routines which may sleep will become very
434 noisy if they are called with a spinlock held.
435
Ingo Molnarcae2ed92006-07-03 00:24:48 -0700436config DEBUG_LOCKING_API_SELFTESTS
437 bool "Locking API boot-time self-tests"
438 depends on DEBUG_KERNEL
439 help
440 Say Y here if you want the kernel to run a short self-test during
441 bootup. The self-test checks whether common types of locking bugs
442 are detected by debugging mechanisms or not. (if you disable
443 lock debugging then those bugs wont be detected of course.)
444 The following locking APIs are covered: spinlocks, rwlocks,
445 mutexes and rwsems.
446
Ingo Molnar8637c092006-07-03 00:24:38 -0700447config STACKTRACE
448 bool
449 depends on STACKTRACE_SUPPORT
450
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451config DEBUG_KOBJECT
452 bool "kobject debugging"
453 depends on DEBUG_KERNEL
454 help
455 If you say Y here, some extra kobject debugging messages will be sent
456 to the syslog.
457
458config DEBUG_HIGHMEM
459 bool "Highmem debugging"
460 depends on DEBUG_KERNEL && HIGHMEM
461 help
462 This options enables addition error checking for high memory systems.
463 Disable for production systems.
464
465config DEBUG_BUGVERBOSE
466 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EMBEDDED
Matt Mackallc8538a72005-05-01 08:59:01 -0700467 depends on BUG
David Howellsb920de12008-02-08 04:19:31 -0800468 depends on ARM || AVR32 || M32R || M68K || SPARC32 || SPARC64 || \
469 FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 default !EMBEDDED
471 help
472 Say Y here to make BUG() panics output the file name and line number
473 of the BUG call as well as the EIP and oops trace. This aids
474 debugging but costs about 70-100K of memory.
475
476config DEBUG_INFO
477 bool "Compile the kernel with debug info"
478 depends on DEBUG_KERNEL
479 help
480 If you say Y here the resulting kernel image will include
481 debugging info resulting in a larger kernel image.
Andreas Dilgerb72e53f2007-03-27 15:21:33 -0600482 This adds debug symbols to the kernel and modules (gcc -g), and
483 is needed if you intend to use kernel crashdump or binary object
484 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485 Say Y here only if you plan to debug the kernel.
486
487 If unsure, say N.
488
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800489config DEBUG_VM
490 bool "Debug VM"
491 depends on DEBUG_KERNEL
492 help
Nick Piggin13e74442006-01-06 00:10:58 -0800493 Enable this to turn on extended checks in the virtual-memory system
494 that may impact performance.
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800495
496 If unsure, say N.
497
Dave Hansenad775f52008-02-15 14:38:01 -0800498config DEBUG_WRITECOUNT
499 bool "Debug filesystem writers count"
500 depends on DEBUG_KERNEL
501 help
502 Enable this to catch wrong use of the writers count in struct
503 vfsmount. This will increase the size of each file struct by
504 32 bits.
505
506 If unsure, say N.
507
Mel Gorman6b74ab92008-07-23 21:26:49 -0700508config DEBUG_MEMORY_INIT
509 bool "Debug memory initialisation" if EMBEDDED
510 default !EMBEDDED
511 help
512 Enable this for additional checks during memory initialisation.
513 The sanity checks verify aspects of the VM such as the memory model
514 and other information provided by the architecture. Verbose
515 information will be printed at KERN_DEBUG loglevel depending
516 on the mminit_loglevel= command-line option.
517
518 If unsure, say Y
519
Dave Jones199a9af2006-09-29 01:59:00 -0700520config DEBUG_LIST
521 bool "Debug linked list manipulation"
522 depends on DEBUG_KERNEL
523 help
524 Enable this to turn on extended checks in the linked-list
525 walking routines.
526
527 If unsure, say N.
528
Jens Axboed6ec0842007-10-22 20:01:06 +0200529config DEBUG_SG
530 bool "Debug SG table operations"
531 depends on DEBUG_KERNEL
532 help
533 Enable this to turn on checks on scatter-gather tables. This can
534 help find problems with drivers that do not properly initialize
535 their sg tables.
536
537 If unsure, say N.
538
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539config FRAME_POINTER
540 bool "Compile the kernel with frame pointers"
David Howellsb920de12008-02-08 04:19:31 -0800541 depends on DEBUG_KERNEL && \
542 (X86 || CRIS || M68K || M68KNOMMU || FRV || UML || S390 || \
543 AVR32 || SUPERH || BLACKFIN || MN10300)
Paolo 'Blaisorblade' Giarrusso37fce852005-05-28 15:51:59 -0700544 default y if DEBUG_INFO && UML
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545 help
546 If you say Y here the resulting kernel image will be slightly larger
Jesper Juhl2a38bcc2005-10-30 15:02:51 -0800547 and slower, but it might give very useful debugging information on
548 some architectures or if you use external debuggers.
Andi Kleenaeb39982005-09-12 18:49:25 +0200549 If you don't debug the kernel, you can say N.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550
Randy Dunlapbfe8df32007-10-16 01:23:46 -0700551config BOOT_PRINTK_DELAY
552 bool "Delay each boot printk message by N milliseconds"
553 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
554 help
555 This build option allows you to read kernel boot messages
556 by inserting a short delay after each one. The delay is
557 specified in milliseconds on the kernel command line,
558 using "boot_delay=N".
559
560 It is likely that you would also need to use "lpj=M" to preset
561 the "loops per jiffie" value.
562 See a previous boot log for the "lpj" value to use for your
563 system, and then set "lpj=M" before setting "boot_delay=N".
564 NOTE: Using this option may adversely affect SMP systems.
565 I.e., processors other than the first one may not boot up.
566 BOOT_PRINTK_DELAY also may cause DETECT_SOFTLOCKUP to detect
567 what it believes to be lockup conditions.
568
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800569config RCU_TORTURE_TEST
570 tristate "torture tests for RCU"
571 depends on DEBUG_KERNEL
572 default n
573 help
574 This option provides a kernel module that runs torture tests
575 on the RCU infrastructure. The kernel module may be built
576 after the fact on the running kernel to be tested, if desired.
577
Paul E. McKenney31a72bc2008-06-18 09:26:49 -0700578 Say Y here if you want RCU torture tests to be built into
579 the kernel.
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800580 Say M if you want the RCU torture tests to build as a module.
581 Say N if you are unsure.
Ankita Garg8bb31b92006-10-02 02:17:36 -0700582
Paul E. McKenney31a72bc2008-06-18 09:26:49 -0700583config RCU_TORTURE_TEST_RUNNABLE
584 bool "torture tests for RCU runnable by default"
585 depends on RCU_TORTURE_TEST = y
586 default n
587 help
588 This option provides a way to build the RCU torture tests
589 directly into the kernel without them starting up at boot
590 time. You can use /proc/sys/kernel/rcutorture_runnable
591 to manually override this setting. This /proc file is
592 available only when the RCU torture tests have been built
593 into the kernel.
594
595 Say Y here if you want the RCU torture tests to start during
596 boot (you probably don't).
597 Say N here if you want the RCU torture tests to start only
598 after being manually enabled via /proc.
599
Ananth N Mavinakayanahalli8c1c9352008-01-30 13:32:53 +0100600config KPROBES_SANITY_TEST
601 bool "Kprobes sanity tests"
602 depends on DEBUG_KERNEL
603 depends on KPROBES
604 default n
605 help
606 This option provides for testing basic kprobes functionality on
607 boot. A sample kprobe, jprobe and kretprobe are inserted and
608 verified for functionality.
609
610 Say N if you are unsure.
611
Arjan van de Ven6dab2772008-01-30 13:33:08 +0100612config BACKTRACE_SELF_TEST
613 tristate "Self test for the backtrace code"
614 depends on DEBUG_KERNEL
615 default n
616 help
617 This option provides a kernel module that can be used to test
618 the kernel stack backtrace code. This option is not useful
619 for distributions or general kernels, but only for kernel
620 developers working on architecture code.
621
Vegard Nossumad118c52008-06-27 18:04:48 +0200622 Note that if you want to also test saved backtraces, you will
623 have to enable STACKTRACE as well.
624
Arjan van de Ven6dab2772008-01-30 13:33:08 +0100625 Say N if you are unsure.
626
Ankita Garg8bb31b92006-10-02 02:17:36 -0700627config LKDTM
628 tristate "Linux Kernel Dump Test Tool Module"
Don Mullisbf4735a2006-12-10 02:18:37 -0800629 depends on DEBUG_KERNEL
Ankita Garg8bb31b92006-10-02 02:17:36 -0700630 depends on KPROBES
Chris Snookfddd9cf2008-02-23 15:23:26 -0800631 depends on BLOCK
Ankita Garg8bb31b92006-10-02 02:17:36 -0700632 default n
633 help
634 This module enables testing of the different dumping mechanisms by
635 inducing system failures at predefined crash points.
636 If you don't need it: say N
637 Choose M here to compile this code as a module. The module will be
638 called lkdtm.
639
640 Documentation on how to use the module can be found in
641 drivers/misc/lkdtm.c
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800642
643config FAULT_INJECTION
Andrew Morton1ab8509a2006-12-08 02:39:49 -0800644 bool "Fault-injection framework"
645 depends on DEBUG_KERNEL
Akinobu Mita329409a2006-12-08 02:39:48 -0800646 help
647 Provide fault-injection framework.
648 For more details, see Documentation/fault-injection/.
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800649
Akinobu Mita8a8b6502006-12-08 02:39:44 -0800650config FAILSLAB
Andrew Morton1ab8509a2006-12-08 02:39:49 -0800651 bool "Fault-injection capability for kmalloc"
652 depends on FAULT_INJECTION
Akinobu Mita8a8b6502006-12-08 02:39:44 -0800653 help
Andrew Morton1ab8509a2006-12-08 02:39:49 -0800654 Provide fault-injection capability for kmalloc.
Akinobu Mita8a8b6502006-12-08 02:39:44 -0800655
Akinobu Mita933e3122006-12-08 02:39:45 -0800656config FAIL_PAGE_ALLOC
657 bool "Fault-injection capabilitiy for alloc_pages()"
Andrew Morton1ab8509a2006-12-08 02:39:49 -0800658 depends on FAULT_INJECTION
Akinobu Mita933e3122006-12-08 02:39:45 -0800659 help
Andrew Morton1ab8509a2006-12-08 02:39:49 -0800660 Provide fault-injection capability for alloc_pages().
Akinobu Mita933e3122006-12-08 02:39:45 -0800661
Akinobu Mitac17bb492006-12-08 02:39:46 -0800662config FAIL_MAKE_REQUEST
Dave Jones86327d12006-12-12 20:16:36 +0100663 bool "Fault-injection capability for disk IO"
Andrew Morton1ab8509a2006-12-08 02:39:49 -0800664 depends on FAULT_INJECTION
Akinobu Mitac17bb492006-12-08 02:39:46 -0800665 help
Andrew Morton1ab8509a2006-12-08 02:39:49 -0800666 Provide fault-injection capability for disk IO.
Akinobu Mitac17bb492006-12-08 02:39:46 -0800667
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800668config FAULT_INJECTION_DEBUG_FS
669 bool "Debugfs entries for fault-injection capabilities"
Andrew Morton1ab8509a2006-12-08 02:39:49 -0800670 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800671 help
Andrew Morton1ab8509a2006-12-08 02:39:49 -0800672 Enable configuration of fault-injection capabilities via debugfs.
Akinobu Mita1df49002007-02-20 13:57:56 -0800673
674config FAULT_INJECTION_STACKTRACE_FILTER
675 bool "stacktrace filter for fault-injection capabilities"
676 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
Akinobu Mita6d690dc2007-05-12 10:36:53 -0700677 depends on !X86_64
Akinobu Mita1df49002007-02-20 13:57:56 -0800678 select STACKTRACE
679 select FRAME_POINTER
680 help
681 Provide stacktrace filter for fault-injection capabilities
Mathieu Desnoyers267c4022007-10-18 23:41:07 -0700682
Arjan van de Ven97455122008-01-25 21:08:34 +0100683config LATENCYTOP
684 bool "Latency measuring infrastructure"
685 select FRAME_POINTER if !MIPS
686 select KALLSYMS
687 select KALLSYMS_ALL
688 select STACKTRACE
689 select SCHEDSTATS
690 select SCHED_DEBUG
Heiko Carstensaa7d9352008-02-01 17:45:14 +0100691 depends on HAVE_LATENCYTOP_SUPPORT
Arjan van de Ven97455122008-01-25 21:08:34 +0100692 help
693 Enable this option if you want to use the LatencyTOP tool
694 to find out which userspace is blocking on what kernel operations.
695
Andi Kleen9e94cd32008-08-16 07:53:05 +0200696config SYSCTL_SYSCALL_CHECK
697 bool "Sysctl checks"
698 depends on SYSCTL_SYSCALL
699 ---help---
700 sys_sysctl uses binary paths that have been found challenging
701 to properly maintain and use. This enables checks that help
702 you to keep things correct.
703
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200704source kernel/trace/Kconfig
705
Bernhard Kaindlf212ec42008-01-30 13:34:11 +0100706config PROVIDE_OHCI1394_DMA_INIT
Stefan Richter080de8c2008-02-28 20:54:43 +0100707 bool "Remote debugging over FireWire early on boot"
Bernhard Kaindlf212ec42008-01-30 13:34:11 +0100708 depends on PCI && X86
709 help
710 If you want to debug problems which hang or crash the kernel early
711 on boot and the crashing machine has a FireWire port, you can use
712 this feature to remotely access the memory of the crashed machine
713 over FireWire. This employs remote DMA as part of the OHCI1394
714 specification which is now the standard for FireWire controllers.
715
716 With remote DMA, you can monitor the printk buffer remotely using
717 firescope and access all memory below 4GB using fireproxy from gdb.
718 Even controlling a kernel debugger is possible using remote DMA.
719
720 Usage:
721
722 If ohci1394_dma=early is used as boot parameter, it will initialize
723 all OHCI1394 controllers which are found in the PCI config space.
724
725 As all changes to the FireWire bus such as enabling and disabling
726 devices cause a bus reset and thereby disable remote DMA for all
727 devices, be sure to have the cable plugged and FireWire enabled on
728 the debugging host before booting the debug target for debugging.
729
730 This code (~1k) is freed after boot. By then, the firewire stack
731 in charge of the OHCI-1394 controllers should be used instead.
732
733 See Documentation/debugging-via-ohci1394.txt for more information.
Arjan van de Ven97455122008-01-25 21:08:34 +0100734
Stefan Richter080de8c2008-02-28 20:54:43 +0100735config FIREWIRE_OHCI_REMOTE_DMA
736 bool "Remote debugging over FireWire with firewire-ohci"
737 depends on FIREWIRE_OHCI
738 help
739 This option lets you use the FireWire bus for remote debugging
740 with help of the firewire-ohci driver. It enables unfiltered
741 remote DMA in firewire-ohci.
742 See Documentation/debugging-via-ohci1394.txt for more information.
743
744 If unsure, say N.
745
Randy Dunlap3794f3e2008-08-12 15:09:06 -0700746menuconfig BUILD_DOCSRC
747 bool "Build targets in Documentation/ tree"
748 depends on HEADERS_CHECK
749 help
750 This option attempts to build objects from the source files in the
751 kernel Documentation/ tree.
752
753 Say N if you are unsure.
754
Mathieu Desnoyers267c4022007-10-18 23:41:07 -0700755source "samples/Kconfig"
Jason Wesseldc7d5522008-04-17 20:05:37 +0200756
757source "lib/Kconfig.kgdb"