blob: 509ae35a9ef5c71371e5c86451bf59ec45953227 [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
77 If unsure, say N.
78
79config HEADERS_CHECK
80 bool "Run 'make headers_check' when building vmlinux"
81 depends on !UML
82 help
83 This option will extract the user-visible kernel headers whenever
84 building the kernel, and will run basic sanity checks on them to
85 ensure that exported files do not attempt to include files which
86 were not exported, etc.
87
88 If you're making modifications to header files which are
89 relevant for userspace, say 'Y', and check the headers
90 exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in
91 your build tree), to make sure they're suitable.
92
Sam Ravnborg91341d42008-01-21 21:31:44 +010093config DEBUG_SECTION_MISMATCH
94 bool "Enable full Section mismatch analysis"
Sam Ravnborge5f95c82008-02-02 18:57:18 +010095 depends on UNDEFINED
Sam Ravnborgfa2144b2008-02-15 13:53:11 +010096 # This option is on purpose disabled for now.
97 # It will be enabled when we are down to a resonable number
98 # of section mismatch warnings (< 10 for an allyesconfig build)
Sam Ravnborg91341d42008-01-21 21:31:44 +010099 help
100 The section mismatch analysis checks if there are illegal
101 references from one section to another section.
102 Linux will during link or during runtime drop some sections
103 and any use of code/data previously in these sections will
104 most likely result in an oops.
105 In the code functions and variables are annotated with
106 __init, __devinit etc. (see full list in include/linux/init.h)
Geert Uytterhoevend6fbfa42008-01-30 11:13:23 +0100107 which results in the code/data being placed in specific sections.
108 The section mismatch analysis is always done after a full
109 kernel build but enabling this option will in addition
Sam Ravnborg91341d42008-01-21 21:31:44 +0100110 do the following:
111 - Add the option -fno-inline-functions-called-once to gcc
112 When inlining a function annotated __init in a non-init
Geert Uytterhoevend6fbfa42008-01-30 11:13:23 +0100113 function we would lose the section information and thus
Sam Ravnborg91341d42008-01-21 21:31:44 +0100114 the analysis would not catch the illegal reference.
Geert Uytterhoevend6fbfa42008-01-30 11:13:23 +0100115 This option tells gcc to inline less but will also
Sam Ravnborg91341d42008-01-21 21:31:44 +0100116 result in a larger kernel.
117 - Run the section mismatch analysis for each module/built-in.o
118 When we run the section mismatch analysis on vmlinux.o we
Geert Uytterhoevend6fbfa42008-01-30 11:13:23 +0100119 lose valueble information about where the mismatch was
Sam Ravnborg91341d42008-01-21 21:31:44 +0100120 introduced.
121 Running the analysis for each module/built-in.o file
122 will tell where the mismatch happens much closer to the
123 source. The drawback is that we will report the same
124 mismatch at least twice.
Sam Ravnborg588ccd72008-01-24 21:12:37 +0100125 - Enable verbose reporting from modpost to help solving
126 the section mismatches reported.
Sam Ravnborg91341d42008-01-21 21:31:44 +0100127
Adrian Bunkf346f4b2006-01-09 20:54:51 -0800128config DEBUG_KERNEL
129 bool "Kernel debugging"
130 help
131 Say Y here if you are developing drivers or trying to debug and
132 identify kernel problems.
133
David Woodhousea304e1b2007-02-12 00:52:00 -0800134config DEBUG_SHIRQ
135 bool "Debug shared IRQ handlers"
136 depends on DEBUG_KERNEL && GENERIC_HARDIRQS
137 help
138 Enable this to generate a spurious interrupt as soon as a shared
139 interrupt handler is registered, and just before one is deregistered.
140 Drivers ought to be able to handle interrupts coming in at those
141 points; some don't and need to be caught.
142
Ingo Molnar8446f1d2005-09-06 15:16:27 -0700143config DETECT_SOFTLOCKUP
144 bool "Detect Soft Lockups"
Heiko Carstensdea20a32006-10-11 01:20:44 -0700145 depends on DEBUG_KERNEL && !S390
Ingo Molnar8446f1d2005-09-06 15:16:27 -0700146 default y
147 help
148 Say Y here to enable the kernel to detect "soft lockups",
149 which are bugs that cause the kernel to loop in kernel
Ingo Molnar9c44bc02008-05-12 21:21:04 +0200150 mode for more than 60 seconds, without giving other tasks a
Ingo Molnar8446f1d2005-09-06 15:16:27 -0700151 chance to run.
152
153 When a soft-lockup is detected, the kernel will print the
154 current stack trace (which you should report), but the
155 system will stay locked up. This feature has negligible
156 overhead.
157
158 (Note that "hard lockups" are separate type of bugs that
159 can be detected via the NMI-watchdog, on platforms that
160 support it.)
161
Ingo Molnar9c44bc02008-05-12 21:21:04 +0200162config BOOTPARAM_SOFTLOCKUP_PANIC
163 bool "Panic (Reboot) On Soft Lockups"
164 depends on DETECT_SOFTLOCKUP
165 help
166 Say Y here to enable the kernel to panic on "soft lockups",
167 which are bugs that cause the kernel to loop in kernel
168 mode for more than 60 seconds, without giving other tasks a
169 chance to run.
170
171 The panic can be used in combination with panic_timeout,
172 to cause the system to reboot automatically after a
173 lockup has been detected. This feature is useful for
174 high-availability systems that have uptime guarantees and
175 where a lockup must be resolved ASAP.
176
177 Say N if unsure.
178
179config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
180 int
181 depends on DETECT_SOFTLOCKUP
182 range 0 1
183 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
184 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
185
Ingo Molnarb642b6d2007-07-09 18:52:00 +0200186config SCHED_DEBUG
187 bool "Collect scheduler debugging info"
188 depends on DEBUG_KERNEL && PROC_FS
189 default y
190 help
191 If you say Y here, the /proc/sched_debug file will be provided
192 that can help debug the scheduler. The runtime overhead of this
193 option is minimal.
194
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195config SCHEDSTATS
196 bool "Collect scheduler statistics"
197 depends on DEBUG_KERNEL && PROC_FS
198 help
199 If you say Y here, additional code will be inserted into the
200 scheduler and related routines to collect statistics about
201 scheduler behavior and provide them in /proc/schedstat. These
202 stats may be useful for both tuning and debugging the scheduler
203 If you aren't debugging the scheduler or trying to tune a specific
204 application, you can say N to avoid the very slight overhead
205 this adds.
206
Ingo Molnar82f67cd2007-02-16 01:28:13 -0800207config TIMER_STATS
208 bool "Collect kernel timers statistics"
209 depends on DEBUG_KERNEL && PROC_FS
210 help
211 If you say Y here, additional code will be inserted into the
212 timer routines to collect statistics about kernel timers being
213 reprogrammed. The statistics can be read from /proc/timer_stats.
214 The statistics collection is started by writing 1 to /proc/timer_stats,
215 writing 0 stops it. This feature is useful to collect information
Ingo Molnarc1a834d2007-06-01 00:47:16 -0700216 about timer usage patterns in kernel and userspace. This feature
217 is lightweight if enabled in the kernel config but not activated
218 (it defaults to deactivated on bootup and will only be activated
219 if some application like powertop activates it explicitly).
Ingo Molnar82f67cd2007-02-16 01:28:13 -0800220
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700221config DEBUG_OBJECTS
222 bool "Debug object operations"
223 depends on DEBUG_KERNEL
224 help
225 If you say Y here, additional code will be inserted into the
226 kernel to track the life time of various objects and validate
227 the operations on those objects.
228
229config DEBUG_OBJECTS_SELFTEST
230 bool "Debug objects selftest"
231 depends on DEBUG_OBJECTS
232 help
233 This enables the selftest of the object debug code.
234
235config DEBUG_OBJECTS_FREE
236 bool "Debug objects in freed memory"
237 depends on DEBUG_OBJECTS
238 help
239 This enables checks whether a k/v free operation frees an area
240 which contains an object which has not been deactivated
241 properly. This can make kmalloc/kfree-intensive workloads
242 much slower.
243
Thomas Gleixnerc6f3a972008-04-30 00:55:03 -0700244config DEBUG_OBJECTS_TIMERS
245 bool "Debug timer objects"
246 depends on DEBUG_OBJECTS
247 help
248 If you say Y here, additional code will be inserted into the
249 timer routines to track the life time of timer objects and
250 validate the timer operations.
251
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252config DEBUG_SLAB
Andrew Morton4a2f0ac2006-03-25 03:07:22 -0800253 bool "Debug slab memory allocations"
Ingo Molnar50dd26ba2006-01-08 01:01:42 -0800254 depends on DEBUG_KERNEL && SLAB
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 help
256 Say Y here to have the kernel do limited verification on memory
257 allocation as well as poisoning memory on free to catch use of freed
258 memory. This can make kmalloc/kfree-intensive workloads much slower.
259
Al Viro871751e2006-03-25 03:06:39 -0800260config DEBUG_SLAB_LEAK
261 bool "Memory leak debugging"
262 depends on DEBUG_SLAB
263
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700264config SLUB_DEBUG_ON
265 bool "SLUB debugging on by default"
266 depends on SLUB && SLUB_DEBUG
267 default n
268 help
269 Boot with debugging on by default. SLUB boots by default with
270 the runtime debug capabilities switched off. Enabling this is
271 equivalent to specifying the "slub_debug" parameter on boot.
272 There is no support for more fine grained debug control like
273 possible with slub_debug=xxx. SLUB debugging may be switched
274 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
275 "slub_debug=-".
276
Christoph Lameter8ff12cf2008-02-07 17:47:41 -0800277config SLUB_STATS
278 default n
279 bool "Enable SLUB performance statistics"
Christoph Lameter5b06c8532008-04-14 18:51:34 +0300280 depends on SLUB && SLUB_DEBUG && SYSFS
Christoph Lameter8ff12cf2008-02-07 17:47:41 -0800281 help
282 SLUB statistics are useful to debug SLUBs allocation behavior in
283 order find ways to optimize the allocator. This should never be
284 enabled for production use since keeping statistics slows down
285 the allocator by a few percentage points. The slabinfo command
286 supports the determination of the most active slabs to figure
287 out which slabs are relevant to a particular load.
288 Try running: slabinfo -DA
289
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290config DEBUG_PREEMPT
291 bool "Debug preemptible kernel"
Hugh Dickins048c8bc2006-11-01 05:44:54 +1100292 depends on DEBUG_KERNEL && PREEMPT && (TRACE_IRQFLAGS_SUPPORT || PPC64)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293 default y
294 help
295 If you say Y here then the kernel will use a debug variant of the
296 commonly used smp_processor_id() function and will print warnings
297 if kernel code uses it in a preemption-unsafe way. Also, the kernel
298 will detect preemption count underflows.
299
Ingo Molnare7eebaf2006-06-27 02:54:55 -0700300config DEBUG_RT_MUTEXES
301 bool "RT Mutex debugging, deadlock detection"
Ingo Molnare7eebaf2006-06-27 02:54:55 -0700302 depends on DEBUG_KERNEL && RT_MUTEXES
303 help
304 This allows rt mutex semantics violations and rt mutex related
305 deadlocks (lockups) to be detected and reported automatically.
306
307config DEBUG_PI_LIST
308 bool
309 default y
310 depends on DEBUG_RT_MUTEXES
311
Thomas Gleixner61a87122006-06-27 02:54:56 -0700312config RT_MUTEX_TESTER
313 bool "Built-in scriptable tester for rt-mutexes"
Roman Zippela1583d32006-06-27 02:55:00 -0700314 depends on DEBUG_KERNEL && RT_MUTEXES
Thomas Gleixner61a87122006-06-27 02:54:56 -0700315 help
316 This option enables a rt-mutex tester.
317
Linus Torvalds1da177e2005-04-16 15:20:36 -0700318config DEBUG_SPINLOCK
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700319 bool "Spinlock and rw-lock debugging: basic checks"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320 depends on DEBUG_KERNEL
321 help
322 Say Y here and build SMP to catch missing spinlock initialization
323 and certain other kinds of spinlock errors commonly made. This is
324 best used in conjunction with the NMI watchdog so that spinlock
325 deadlocks are also debuggable.
326
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700327config DEBUG_MUTEXES
328 bool "Mutex debugging: basic checks"
329 depends on DEBUG_KERNEL
330 help
331 This feature allows mutex semantics violations to be detected and
332 reported.
333
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700334config DEBUG_LOCK_ALLOC
335 bool "Lock debugging: detect incorrect freeing of live locks"
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700336 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700337 select DEBUG_SPINLOCK
338 select DEBUG_MUTEXES
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700339 select LOCKDEP
340 help
341 This feature will check whether any held lock (spinlock, rwlock,
342 mutex or rwsem) is incorrectly freed by the kernel, via any of the
343 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
344 vfree(), etc.), whether a live lock is incorrectly reinitialized via
345 spin_lock_init()/mutex_init()/etc., or whether there is any lock
346 held during task exit.
347
348config PROVE_LOCKING
349 bool "Lock debugging: prove locking correctness"
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700350 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700351 select LOCKDEP
352 select DEBUG_SPINLOCK
353 select DEBUG_MUTEXES
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700354 select DEBUG_LOCK_ALLOC
355 default n
356 help
357 This feature enables the kernel to prove that all locking
358 that occurs in the kernel runtime is mathematically
359 correct: that under no circumstance could an arbitrary (and
360 not yet triggered) combination of observed locking
361 sequences (on an arbitrary number of CPUs, running an
362 arbitrary number of tasks and interrupt contexts) cause a
363 deadlock.
364
365 In short, this feature enables the kernel to report locking
366 related deadlocks before they actually occur.
367
368 The proof does not depend on how hard and complex a
369 deadlock scenario would be to trigger: how many
370 participant CPUs, tasks and irq-contexts would be needed
371 for it to trigger. The proof also does not depend on
372 timing: if a race and a resulting deadlock is possible
373 theoretically (no matter how unlikely the race scenario
374 is), it will be proven so and will immediately be
375 reported by the kernel (once the event is observed that
376 makes the deadlock theoretically possible).
377
378 If a deadlock is impossible (i.e. the locking rules, as
379 observed by the kernel, are mathematically correct), the
380 kernel reports nothing.
381
382 NOTE: this feature can also be enabled for rwlocks, mutexes
383 and rwsems - in which case all dependencies between these
384 different locking variants are observed and mapped too, and
385 the proof of observed correctness is also maintained for an
386 arbitrary combination of these separate locking variants.
387
388 For more details, see Documentation/lockdep-design.txt.
389
390config LOCKDEP
391 bool
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700392 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700393 select STACKTRACE
Franck Bui-Huu14cf2322007-04-26 00:20:15 -0700394 select FRAME_POINTER if !X86 && !MIPS
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700395 select KALLSYMS
396 select KALLSYMS_ALL
397
Peter Zijlstraf20786f2007-07-19 01:48:56 -0700398config LOCK_STAT
Danny ter Haarfdfb8702007-09-24 21:24:43 -0700399 bool "Lock usage statistics"
Peter Zijlstraf20786f2007-07-19 01:48:56 -0700400 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
401 select LOCKDEP
402 select DEBUG_SPINLOCK
403 select DEBUG_MUTEXES
404 select DEBUG_LOCK_ALLOC
405 default n
406 help
407 This feature enables tracking lock contention points
408
Peter Zijlstraa560aa42007-10-07 00:24:33 -0700409 For more details, see Documentation/lockstat.txt
410
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700411config DEBUG_LOCKDEP
412 bool "Lock dependency engine debugging"
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700413 depends on DEBUG_KERNEL && LOCKDEP
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700414 help
415 If you say Y here, the lock dependency engine will do
416 additional runtime checks to debug itself, at the price
417 of more runtime overhead.
418
419config TRACE_IRQFLAGS
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700420 depends on DEBUG_KERNEL
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700421 bool
422 default y
423 depends on TRACE_IRQFLAGS_SUPPORT
424 depends on PROVE_LOCKING
425
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426config DEBUG_SPINLOCK_SLEEP
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700427 bool "Spinlock debugging: sleep-inside-spinlock checking"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 depends on DEBUG_KERNEL
429 help
430 If you say Y here, various routines which may sleep will become very
431 noisy if they are called with a spinlock held.
432
Ingo Molnarcae2ed92006-07-03 00:24:48 -0700433config DEBUG_LOCKING_API_SELFTESTS
434 bool "Locking API boot-time self-tests"
435 depends on DEBUG_KERNEL
436 help
437 Say Y here if you want the kernel to run a short self-test during
438 bootup. The self-test checks whether common types of locking bugs
439 are detected by debugging mechanisms or not. (if you disable
440 lock debugging then those bugs wont be detected of course.)
441 The following locking APIs are covered: spinlocks, rwlocks,
442 mutexes and rwsems.
443
Ingo Molnar8637c092006-07-03 00:24:38 -0700444config STACKTRACE
445 bool
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700446 depends on DEBUG_KERNEL
Ingo Molnar8637c092006-07-03 00:24:38 -0700447 depends on STACKTRACE_SUPPORT
448
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449config DEBUG_KOBJECT
450 bool "kobject debugging"
451 depends on DEBUG_KERNEL
452 help
453 If you say Y here, some extra kobject debugging messages will be sent
454 to the syslog.
455
456config DEBUG_HIGHMEM
457 bool "Highmem debugging"
458 depends on DEBUG_KERNEL && HIGHMEM
459 help
460 This options enables addition error checking for high memory systems.
461 Disable for production systems.
462
463config DEBUG_BUGVERBOSE
464 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EMBEDDED
Matt Mackallc8538a72005-05-01 08:59:01 -0700465 depends on BUG
David Howellsb920de12008-02-08 04:19:31 -0800466 depends on ARM || AVR32 || M32R || M68K || SPARC32 || SPARC64 || \
467 FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468 default !EMBEDDED
469 help
470 Say Y here to make BUG() panics output the file name and line number
471 of the BUG call as well as the EIP and oops trace. This aids
472 debugging but costs about 70-100K of memory.
473
474config DEBUG_INFO
475 bool "Compile the kernel with debug info"
476 depends on DEBUG_KERNEL
477 help
478 If you say Y here the resulting kernel image will include
479 debugging info resulting in a larger kernel image.
Andreas Dilgerb72e53f2007-03-27 15:21:33 -0600480 This adds debug symbols to the kernel and modules (gcc -g), and
481 is needed if you intend to use kernel crashdump or binary object
482 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483 Say Y here only if you plan to debug the kernel.
484
485 If unsure, say N.
486
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800487config DEBUG_VM
488 bool "Debug VM"
489 depends on DEBUG_KERNEL
490 help
Nick Piggin13e74442006-01-06 00:10:58 -0800491 Enable this to turn on extended checks in the virtual-memory system
492 that may impact performance.
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800493
494 If unsure, say N.
495
Dave Hansenad775f52008-02-15 14:38:01 -0800496config DEBUG_WRITECOUNT
497 bool "Debug filesystem writers count"
498 depends on DEBUG_KERNEL
499 help
500 Enable this to catch wrong use of the writers count in struct
501 vfsmount. This will increase the size of each file struct by
502 32 bits.
503
504 If unsure, say N.
505
Dave Jones199a9af2006-09-29 01:59:00 -0700506config DEBUG_LIST
507 bool "Debug linked list manipulation"
508 depends on DEBUG_KERNEL
509 help
510 Enable this to turn on extended checks in the linked-list
511 walking routines.
512
513 If unsure, say N.
514
Jens Axboed6ec0842007-10-22 20:01:06 +0200515config DEBUG_SG
516 bool "Debug SG table operations"
517 depends on DEBUG_KERNEL
518 help
519 Enable this to turn on checks on scatter-gather tables. This can
520 help find problems with drivers that do not properly initialize
521 their sg tables.
522
523 If unsure, say N.
524
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525config FRAME_POINTER
526 bool "Compile the kernel with frame pointers"
David Howellsb920de12008-02-08 04:19:31 -0800527 depends on DEBUG_KERNEL && \
528 (X86 || CRIS || M68K || M68KNOMMU || FRV || UML || S390 || \
529 AVR32 || SUPERH || BLACKFIN || MN10300)
Paolo 'Blaisorblade' Giarrusso37fce852005-05-28 15:51:59 -0700530 default y if DEBUG_INFO && UML
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531 help
532 If you say Y here the resulting kernel image will be slightly larger
Jesper Juhl2a38bcc2005-10-30 15:02:51 -0800533 and slower, but it might give very useful debugging information on
534 some architectures or if you use external debuggers.
Andi Kleenaeb39982005-09-12 18:49:25 +0200535 If you don't debug the kernel, you can say N.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536
Randy Dunlapbfe8df32007-10-16 01:23:46 -0700537config BOOT_PRINTK_DELAY
538 bool "Delay each boot printk message by N milliseconds"
539 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
540 help
541 This build option allows you to read kernel boot messages
542 by inserting a short delay after each one. The delay is
543 specified in milliseconds on the kernel command line,
544 using "boot_delay=N".
545
546 It is likely that you would also need to use "lpj=M" to preset
547 the "loops per jiffie" value.
548 See a previous boot log for the "lpj" value to use for your
549 system, and then set "lpj=M" before setting "boot_delay=N".
550 NOTE: Using this option may adversely affect SMP systems.
551 I.e., processors other than the first one may not boot up.
552 BOOT_PRINTK_DELAY also may cause DETECT_SOFTLOCKUP to detect
553 what it believes to be lockup conditions.
554
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800555config RCU_TORTURE_TEST
556 tristate "torture tests for RCU"
557 depends on DEBUG_KERNEL
Paul E. McKenney9aaffc82007-05-23 13:57:41 -0700558 depends on m
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800559 default n
560 help
561 This option provides a kernel module that runs torture tests
562 on the RCU infrastructure. The kernel module may be built
563 after the fact on the running kernel to be tested, if desired.
564
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800565 Say M if you want the RCU torture tests to build as a module.
566 Say N if you are unsure.
Ankita Garg8bb31b92006-10-02 02:17:36 -0700567
Ananth N Mavinakayanahalli8c1c9352008-01-30 13:32:53 +0100568config KPROBES_SANITY_TEST
569 bool "Kprobes sanity tests"
570 depends on DEBUG_KERNEL
571 depends on KPROBES
572 default n
573 help
574 This option provides for testing basic kprobes functionality on
575 boot. A sample kprobe, jprobe and kretprobe are inserted and
576 verified for functionality.
577
578 Say N if you are unsure.
579
Arjan van de Ven6dab2772008-01-30 13:33:08 +0100580config BACKTRACE_SELF_TEST
581 tristate "Self test for the backtrace code"
582 depends on DEBUG_KERNEL
583 default n
584 help
585 This option provides a kernel module that can be used to test
586 the kernel stack backtrace code. This option is not useful
587 for distributions or general kernels, but only for kernel
588 developers working on architecture code.
589
590 Say N if you are unsure.
591
Ankita Garg8bb31b92006-10-02 02:17:36 -0700592config LKDTM
593 tristate "Linux Kernel Dump Test Tool Module"
Don Mullisbf4735a2006-12-10 02:18:37 -0800594 depends on DEBUG_KERNEL
Ankita Garg8bb31b92006-10-02 02:17:36 -0700595 depends on KPROBES
Chris Snookfddd9cf2008-02-23 15:23:26 -0800596 depends on BLOCK
Ankita Garg8bb31b92006-10-02 02:17:36 -0700597 default n
598 help
599 This module enables testing of the different dumping mechanisms by
600 inducing system failures at predefined crash points.
601 If you don't need it: say N
602 Choose M here to compile this code as a module. The module will be
603 called lkdtm.
604
605 Documentation on how to use the module can be found in
606 drivers/misc/lkdtm.c
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800607
608config FAULT_INJECTION
Andrew Morton1ab8509a2006-12-08 02:39:49 -0800609 bool "Fault-injection framework"
610 depends on DEBUG_KERNEL
Akinobu Mita329409a2006-12-08 02:39:48 -0800611 help
612 Provide fault-injection framework.
613 For more details, see Documentation/fault-injection/.
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800614
Akinobu Mita8a8b6502006-12-08 02:39:44 -0800615config FAILSLAB
Andrew Morton1ab8509a2006-12-08 02:39:49 -0800616 bool "Fault-injection capability for kmalloc"
617 depends on FAULT_INJECTION
Akinobu Mita8a8b6502006-12-08 02:39:44 -0800618 help
Andrew Morton1ab8509a2006-12-08 02:39:49 -0800619 Provide fault-injection capability for kmalloc.
Akinobu Mita8a8b6502006-12-08 02:39:44 -0800620
Akinobu Mita933e3122006-12-08 02:39:45 -0800621config FAIL_PAGE_ALLOC
622 bool "Fault-injection capabilitiy for alloc_pages()"
Andrew Morton1ab8509a2006-12-08 02:39:49 -0800623 depends on FAULT_INJECTION
Akinobu Mita933e3122006-12-08 02:39:45 -0800624 help
Andrew Morton1ab8509a2006-12-08 02:39:49 -0800625 Provide fault-injection capability for alloc_pages().
Akinobu Mita933e3122006-12-08 02:39:45 -0800626
Akinobu Mitac17bb492006-12-08 02:39:46 -0800627config FAIL_MAKE_REQUEST
Dave Jones86327d12006-12-12 20:16:36 +0100628 bool "Fault-injection capability for disk IO"
Andrew Morton1ab8509a2006-12-08 02:39:49 -0800629 depends on FAULT_INJECTION
Akinobu Mitac17bb492006-12-08 02:39:46 -0800630 help
Andrew Morton1ab8509a2006-12-08 02:39:49 -0800631 Provide fault-injection capability for disk IO.
Akinobu Mitac17bb492006-12-08 02:39:46 -0800632
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800633config FAULT_INJECTION_DEBUG_FS
634 bool "Debugfs entries for fault-injection capabilities"
Andrew Morton1ab8509a2006-12-08 02:39:49 -0800635 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800636 help
Andrew Morton1ab8509a2006-12-08 02:39:49 -0800637 Enable configuration of fault-injection capabilities via debugfs.
Akinobu Mita1df49002007-02-20 13:57:56 -0800638
639config FAULT_INJECTION_STACKTRACE_FILTER
640 bool "stacktrace filter for fault-injection capabilities"
641 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
Akinobu Mita6d690dc2007-05-12 10:36:53 -0700642 depends on !X86_64
Akinobu Mita1df49002007-02-20 13:57:56 -0800643 select STACKTRACE
644 select FRAME_POINTER
645 help
646 Provide stacktrace filter for fault-injection capabilities
Mathieu Desnoyers267c4022007-10-18 23:41:07 -0700647
Arjan van de Ven97455122008-01-25 21:08:34 +0100648config LATENCYTOP
649 bool "Latency measuring infrastructure"
650 select FRAME_POINTER if !MIPS
651 select KALLSYMS
652 select KALLSYMS_ALL
653 select STACKTRACE
654 select SCHEDSTATS
655 select SCHED_DEBUG
Heiko Carstensaa7d9352008-02-01 17:45:14 +0100656 depends on HAVE_LATENCYTOP_SUPPORT
Arjan van de Ven97455122008-01-25 21:08:34 +0100657 help
658 Enable this option if you want to use the LatencyTOP tool
659 to find out which userspace is blocking on what kernel operations.
660
Bernhard Kaindlf212ec42008-01-30 13:34:11 +0100661config PROVIDE_OHCI1394_DMA_INIT
Stefan Richter080de8c2008-02-28 20:54:43 +0100662 bool "Remote debugging over FireWire early on boot"
Bernhard Kaindlf212ec42008-01-30 13:34:11 +0100663 depends on PCI && X86
664 help
665 If you want to debug problems which hang or crash the kernel early
666 on boot and the crashing machine has a FireWire port, you can use
667 this feature to remotely access the memory of the crashed machine
668 over FireWire. This employs remote DMA as part of the OHCI1394
669 specification which is now the standard for FireWire controllers.
670
671 With remote DMA, you can monitor the printk buffer remotely using
672 firescope and access all memory below 4GB using fireproxy from gdb.
673 Even controlling a kernel debugger is possible using remote DMA.
674
675 Usage:
676
677 If ohci1394_dma=early is used as boot parameter, it will initialize
678 all OHCI1394 controllers which are found in the PCI config space.
679
680 As all changes to the FireWire bus such as enabling and disabling
681 devices cause a bus reset and thereby disable remote DMA for all
682 devices, be sure to have the cable plugged and FireWire enabled on
683 the debugging host before booting the debug target for debugging.
684
685 This code (~1k) is freed after boot. By then, the firewire stack
686 in charge of the OHCI-1394 controllers should be used instead.
687
688 See Documentation/debugging-via-ohci1394.txt for more information.
Arjan van de Ven97455122008-01-25 21:08:34 +0100689
Stefan Richter080de8c2008-02-28 20:54:43 +0100690config FIREWIRE_OHCI_REMOTE_DMA
691 bool "Remote debugging over FireWire with firewire-ohci"
692 depends on FIREWIRE_OHCI
693 help
694 This option lets you use the FireWire bus for remote debugging
695 with help of the firewire-ohci driver. It enables unfiltered
696 remote DMA in firewire-ohci.
697 See Documentation/debugging-via-ohci1394.txt for more information.
698
699 If unsure, say N.
700
Mathieu Desnoyers267c4022007-10-18 23:41:07 -0700701source "samples/Kconfig"
Jason Wesseldc7d5522008-04-17 20:05:37 +0200702
703source "lib/Kconfig.kgdb"