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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
150 mode for more than 10 seconds, without giving other tasks a
151 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 Molnarb642b6d2007-07-09 18:52:00 +0200162config SCHED_DEBUG
163 bool "Collect scheduler debugging info"
164 depends on DEBUG_KERNEL && PROC_FS
165 default y
166 help
167 If you say Y here, the /proc/sched_debug file will be provided
168 that can help debug the scheduler. The runtime overhead of this
169 option is minimal.
170
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171config SCHEDSTATS
172 bool "Collect scheduler statistics"
173 depends on DEBUG_KERNEL && PROC_FS
174 help
175 If you say Y here, additional code will be inserted into the
176 scheduler and related routines to collect statistics about
177 scheduler behavior and provide them in /proc/schedstat. These
178 stats may be useful for both tuning and debugging the scheduler
179 If you aren't debugging the scheduler or trying to tune a specific
180 application, you can say N to avoid the very slight overhead
181 this adds.
182
Ingo Molnar82f67cd2007-02-16 01:28:13 -0800183config TIMER_STATS
184 bool "Collect kernel timers statistics"
185 depends on DEBUG_KERNEL && PROC_FS
186 help
187 If you say Y here, additional code will be inserted into the
188 timer routines to collect statistics about kernel timers being
189 reprogrammed. The statistics can be read from /proc/timer_stats.
190 The statistics collection is started by writing 1 to /proc/timer_stats,
191 writing 0 stops it. This feature is useful to collect information
Ingo Molnarc1a834d2007-06-01 00:47:16 -0700192 about timer usage patterns in kernel and userspace. This feature
193 is lightweight if enabled in the kernel config but not activated
194 (it defaults to deactivated on bootup and will only be activated
195 if some application like powertop activates it explicitly).
Ingo Molnar82f67cd2007-02-16 01:28:13 -0800196
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700197config DEBUG_OBJECTS
198 bool "Debug object operations"
199 depends on DEBUG_KERNEL
200 help
201 If you say Y here, additional code will be inserted into the
202 kernel to track the life time of various objects and validate
203 the operations on those objects.
204
205config DEBUG_OBJECTS_SELFTEST
206 bool "Debug objects selftest"
207 depends on DEBUG_OBJECTS
208 help
209 This enables the selftest of the object debug code.
210
211config DEBUG_OBJECTS_FREE
212 bool "Debug objects in freed memory"
213 depends on DEBUG_OBJECTS
214 help
215 This enables checks whether a k/v free operation frees an area
216 which contains an object which has not been deactivated
217 properly. This can make kmalloc/kfree-intensive workloads
218 much slower.
219
Thomas Gleixnerc6f3a972008-04-30 00:55:03 -0700220config DEBUG_OBJECTS_TIMERS
221 bool "Debug timer objects"
222 depends on DEBUG_OBJECTS
223 help
224 If you say Y here, additional code will be inserted into the
225 timer routines to track the life time of timer objects and
226 validate the timer operations.
227
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228config DEBUG_SLAB
Andrew Morton4a2f0ac2006-03-25 03:07:22 -0800229 bool "Debug slab memory allocations"
Ingo Molnar50dd26ba2006-01-08 01:01:42 -0800230 depends on DEBUG_KERNEL && SLAB
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 help
232 Say Y here to have the kernel do limited verification on memory
233 allocation as well as poisoning memory on free to catch use of freed
234 memory. This can make kmalloc/kfree-intensive workloads much slower.
235
Al Viro871751e2006-03-25 03:06:39 -0800236config DEBUG_SLAB_LEAK
237 bool "Memory leak debugging"
238 depends on DEBUG_SLAB
239
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700240config SLUB_DEBUG_ON
241 bool "SLUB debugging on by default"
242 depends on SLUB && SLUB_DEBUG
243 default n
244 help
245 Boot with debugging on by default. SLUB boots by default with
246 the runtime debug capabilities switched off. Enabling this is
247 equivalent to specifying the "slub_debug" parameter on boot.
248 There is no support for more fine grained debug control like
249 possible with slub_debug=xxx. SLUB debugging may be switched
250 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
251 "slub_debug=-".
252
Christoph Lameter8ff12cf2008-02-07 17:47:41 -0800253config SLUB_STATS
254 default n
255 bool "Enable SLUB performance statistics"
Christoph Lameter5b06c8532008-04-14 18:51:34 +0300256 depends on SLUB && SLUB_DEBUG && SYSFS
Christoph Lameter8ff12cf2008-02-07 17:47:41 -0800257 help
258 SLUB statistics are useful to debug SLUBs allocation behavior in
259 order find ways to optimize the allocator. This should never be
260 enabled for production use since keeping statistics slows down
261 the allocator by a few percentage points. The slabinfo command
262 supports the determination of the most active slabs to figure
263 out which slabs are relevant to a particular load.
264 Try running: slabinfo -DA
265
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266config DEBUG_PREEMPT
267 bool "Debug preemptible kernel"
Hugh Dickins048c8bc2006-11-01 05:44:54 +1100268 depends on DEBUG_KERNEL && PREEMPT && (TRACE_IRQFLAGS_SUPPORT || PPC64)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269 default y
270 help
271 If you say Y here then the kernel will use a debug variant of the
272 commonly used smp_processor_id() function and will print warnings
273 if kernel code uses it in a preemption-unsafe way. Also, the kernel
274 will detect preemption count underflows.
275
Ingo Molnare7eebaf2006-06-27 02:54:55 -0700276config DEBUG_RT_MUTEXES
277 bool "RT Mutex debugging, deadlock detection"
Ingo Molnare7eebaf2006-06-27 02:54:55 -0700278 depends on DEBUG_KERNEL && RT_MUTEXES
279 help
280 This allows rt mutex semantics violations and rt mutex related
281 deadlocks (lockups) to be detected and reported automatically.
282
283config DEBUG_PI_LIST
284 bool
285 default y
286 depends on DEBUG_RT_MUTEXES
287
Thomas Gleixner61a87122006-06-27 02:54:56 -0700288config RT_MUTEX_TESTER
289 bool "Built-in scriptable tester for rt-mutexes"
Roman Zippela1583d32006-06-27 02:55:00 -0700290 depends on DEBUG_KERNEL && RT_MUTEXES
Thomas Gleixner61a87122006-06-27 02:54:56 -0700291 help
292 This option enables a rt-mutex tester.
293
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294config DEBUG_SPINLOCK
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700295 bool "Spinlock and rw-lock debugging: basic checks"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296 depends on DEBUG_KERNEL
297 help
298 Say Y here and build SMP to catch missing spinlock initialization
299 and certain other kinds of spinlock errors commonly made. This is
300 best used in conjunction with the NMI watchdog so that spinlock
301 deadlocks are also debuggable.
302
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700303config DEBUG_MUTEXES
304 bool "Mutex debugging: basic checks"
305 depends on DEBUG_KERNEL
306 help
307 This feature allows mutex semantics violations to be detected and
308 reported.
309
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700310config DEBUG_LOCK_ALLOC
311 bool "Lock debugging: detect incorrect freeing of live locks"
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700312 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700313 select DEBUG_SPINLOCK
314 select DEBUG_MUTEXES
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700315 select LOCKDEP
316 help
317 This feature will check whether any held lock (spinlock, rwlock,
318 mutex or rwsem) is incorrectly freed by the kernel, via any of the
319 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
320 vfree(), etc.), whether a live lock is incorrectly reinitialized via
321 spin_lock_init()/mutex_init()/etc., or whether there is any lock
322 held during task exit.
323
324config PROVE_LOCKING
325 bool "Lock debugging: prove locking correctness"
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700326 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700327 select LOCKDEP
328 select DEBUG_SPINLOCK
329 select DEBUG_MUTEXES
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700330 select DEBUG_LOCK_ALLOC
331 default n
332 help
333 This feature enables the kernel to prove that all locking
334 that occurs in the kernel runtime is mathematically
335 correct: that under no circumstance could an arbitrary (and
336 not yet triggered) combination of observed locking
337 sequences (on an arbitrary number of CPUs, running an
338 arbitrary number of tasks and interrupt contexts) cause a
339 deadlock.
340
341 In short, this feature enables the kernel to report locking
342 related deadlocks before they actually occur.
343
344 The proof does not depend on how hard and complex a
345 deadlock scenario would be to trigger: how many
346 participant CPUs, tasks and irq-contexts would be needed
347 for it to trigger. The proof also does not depend on
348 timing: if a race and a resulting deadlock is possible
349 theoretically (no matter how unlikely the race scenario
350 is), it will be proven so and will immediately be
351 reported by the kernel (once the event is observed that
352 makes the deadlock theoretically possible).
353
354 If a deadlock is impossible (i.e. the locking rules, as
355 observed by the kernel, are mathematically correct), the
356 kernel reports nothing.
357
358 NOTE: this feature can also be enabled for rwlocks, mutexes
359 and rwsems - in which case all dependencies between these
360 different locking variants are observed and mapped too, and
361 the proof of observed correctness is also maintained for an
362 arbitrary combination of these separate locking variants.
363
364 For more details, see Documentation/lockdep-design.txt.
365
366config LOCKDEP
367 bool
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700368 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700369 select STACKTRACE
Franck Bui-Huu14cf2322007-04-26 00:20:15 -0700370 select FRAME_POINTER if !X86 && !MIPS
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700371 select KALLSYMS
372 select KALLSYMS_ALL
373
Peter Zijlstraf20786f2007-07-19 01:48:56 -0700374config LOCK_STAT
Danny ter Haarfdfb8702007-09-24 21:24:43 -0700375 bool "Lock usage statistics"
Peter Zijlstraf20786f2007-07-19 01:48:56 -0700376 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
377 select LOCKDEP
378 select DEBUG_SPINLOCK
379 select DEBUG_MUTEXES
380 select DEBUG_LOCK_ALLOC
381 default n
382 help
383 This feature enables tracking lock contention points
384
Peter Zijlstraa560aa42007-10-07 00:24:33 -0700385 For more details, see Documentation/lockstat.txt
386
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700387config DEBUG_LOCKDEP
388 bool "Lock dependency engine debugging"
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700389 depends on DEBUG_KERNEL && LOCKDEP
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700390 help
391 If you say Y here, the lock dependency engine will do
392 additional runtime checks to debug itself, at the price
393 of more runtime overhead.
394
395config TRACE_IRQFLAGS
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700396 depends on DEBUG_KERNEL
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700397 bool
398 default y
399 depends on TRACE_IRQFLAGS_SUPPORT
400 depends on PROVE_LOCKING
401
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402config DEBUG_SPINLOCK_SLEEP
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700403 bool "Spinlock debugging: sleep-inside-spinlock checking"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 depends on DEBUG_KERNEL
405 help
406 If you say Y here, various routines which may sleep will become very
407 noisy if they are called with a spinlock held.
408
Ingo Molnarcae2ed92006-07-03 00:24:48 -0700409config DEBUG_LOCKING_API_SELFTESTS
410 bool "Locking API boot-time self-tests"
411 depends on DEBUG_KERNEL
412 help
413 Say Y here if you want the kernel to run a short self-test during
414 bootup. The self-test checks whether common types of locking bugs
415 are detected by debugging mechanisms or not. (if you disable
416 lock debugging then those bugs wont be detected of course.)
417 The following locking APIs are covered: spinlocks, rwlocks,
418 mutexes and rwsems.
419
Ingo Molnar8637c092006-07-03 00:24:38 -0700420config STACKTRACE
421 bool
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700422 depends on DEBUG_KERNEL
Ingo Molnar8637c092006-07-03 00:24:38 -0700423 depends on STACKTRACE_SUPPORT
424
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425config DEBUG_KOBJECT
426 bool "kobject debugging"
427 depends on DEBUG_KERNEL
428 help
429 If you say Y here, some extra kobject debugging messages will be sent
430 to the syslog.
431
432config DEBUG_HIGHMEM
433 bool "Highmem debugging"
434 depends on DEBUG_KERNEL && HIGHMEM
435 help
436 This options enables addition error checking for high memory systems.
437 Disable for production systems.
438
439config DEBUG_BUGVERBOSE
440 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EMBEDDED
Matt Mackallc8538a72005-05-01 08:59:01 -0700441 depends on BUG
David Howellsb920de12008-02-08 04:19:31 -0800442 depends on ARM || AVR32 || M32R || M68K || SPARC32 || SPARC64 || \
443 FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 default !EMBEDDED
445 help
446 Say Y here to make BUG() panics output the file name and line number
447 of the BUG call as well as the EIP and oops trace. This aids
448 debugging but costs about 70-100K of memory.
449
450config DEBUG_INFO
451 bool "Compile the kernel with debug info"
452 depends on DEBUG_KERNEL
453 help
454 If you say Y here the resulting kernel image will include
455 debugging info resulting in a larger kernel image.
Andreas Dilgerb72e53f2007-03-27 15:21:33 -0600456 This adds debug symbols to the kernel and modules (gcc -g), and
457 is needed if you intend to use kernel crashdump or binary object
458 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459 Say Y here only if you plan to debug the kernel.
460
461 If unsure, say N.
462
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800463config DEBUG_VM
464 bool "Debug VM"
465 depends on DEBUG_KERNEL
466 help
Nick Piggin13e74442006-01-06 00:10:58 -0800467 Enable this to turn on extended checks in the virtual-memory system
468 that may impact performance.
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800469
470 If unsure, say N.
471
Dave Hansenad775f52008-02-15 14:38:01 -0800472config DEBUG_WRITECOUNT
473 bool "Debug filesystem writers count"
474 depends on DEBUG_KERNEL
475 help
476 Enable this to catch wrong use of the writers count in struct
477 vfsmount. This will increase the size of each file struct by
478 32 bits.
479
480 If unsure, say N.
481
Dave Jones199a9af2006-09-29 01:59:00 -0700482config DEBUG_LIST
483 bool "Debug linked list manipulation"
484 depends on DEBUG_KERNEL
485 help
486 Enable this to turn on extended checks in the linked-list
487 walking routines.
488
489 If unsure, say N.
490
Jens Axboed6ec0842007-10-22 20:01:06 +0200491config DEBUG_SG
492 bool "Debug SG table operations"
493 depends on DEBUG_KERNEL
494 help
495 Enable this to turn on checks on scatter-gather tables. This can
496 help find problems with drivers that do not properly initialize
497 their sg tables.
498
499 If unsure, say N.
500
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501config FRAME_POINTER
502 bool "Compile the kernel with frame pointers"
David Howellsb920de12008-02-08 04:19:31 -0800503 depends on DEBUG_KERNEL && \
504 (X86 || CRIS || M68K || M68KNOMMU || FRV || UML || S390 || \
505 AVR32 || SUPERH || BLACKFIN || MN10300)
Paolo 'Blaisorblade' Giarrusso37fce852005-05-28 15:51:59 -0700506 default y if DEBUG_INFO && UML
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507 help
508 If you say Y here the resulting kernel image will be slightly larger
Jesper Juhl2a38bcc2005-10-30 15:02:51 -0800509 and slower, but it might give very useful debugging information on
510 some architectures or if you use external debuggers.
Andi Kleenaeb39982005-09-12 18:49:25 +0200511 If you don't debug the kernel, you can say N.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512
Randy Dunlapbfe8df32007-10-16 01:23:46 -0700513config BOOT_PRINTK_DELAY
514 bool "Delay each boot printk message by N milliseconds"
515 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
516 help
517 This build option allows you to read kernel boot messages
518 by inserting a short delay after each one. The delay is
519 specified in milliseconds on the kernel command line,
520 using "boot_delay=N".
521
522 It is likely that you would also need to use "lpj=M" to preset
523 the "loops per jiffie" value.
524 See a previous boot log for the "lpj" value to use for your
525 system, and then set "lpj=M" before setting "boot_delay=N".
526 NOTE: Using this option may adversely affect SMP systems.
527 I.e., processors other than the first one may not boot up.
528 BOOT_PRINTK_DELAY also may cause DETECT_SOFTLOCKUP to detect
529 what it believes to be lockup conditions.
530
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800531config RCU_TORTURE_TEST
532 tristate "torture tests for RCU"
533 depends on DEBUG_KERNEL
534 default n
535 help
536 This option provides a kernel module that runs torture tests
537 on the RCU infrastructure. The kernel module may be built
538 after the fact on the running kernel to be tested, if desired.
539
Paul E. McKenney31a72bc2008-06-18 09:26:49 -0700540 Say Y here if you want RCU torture tests to be built into
541 the kernel.
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800542 Say M if you want the RCU torture tests to build as a module.
543 Say N if you are unsure.
Ankita Garg8bb31b92006-10-02 02:17:36 -0700544
Paul E. McKenney31a72bc2008-06-18 09:26:49 -0700545config RCU_TORTURE_TEST_RUNNABLE
546 bool "torture tests for RCU runnable by default"
547 depends on RCU_TORTURE_TEST = y
548 default n
549 help
550 This option provides a way to build the RCU torture tests
551 directly into the kernel without them starting up at boot
552 time. You can use /proc/sys/kernel/rcutorture_runnable
553 to manually override this setting. This /proc file is
554 available only when the RCU torture tests have been built
555 into the kernel.
556
557 Say Y here if you want the RCU torture tests to start during
558 boot (you probably don't).
559 Say N here if you want the RCU torture tests to start only
560 after being manually enabled via /proc.
561
Ananth N Mavinakayanahalli8c1c9352008-01-30 13:32:53 +0100562config KPROBES_SANITY_TEST
563 bool "Kprobes sanity tests"
564 depends on DEBUG_KERNEL
565 depends on KPROBES
566 default n
567 help
568 This option provides for testing basic kprobes functionality on
569 boot. A sample kprobe, jprobe and kretprobe are inserted and
570 verified for functionality.
571
572 Say N if you are unsure.
573
Arjan van de Ven6dab2772008-01-30 13:33:08 +0100574config BACKTRACE_SELF_TEST
575 tristate "Self test for the backtrace code"
576 depends on DEBUG_KERNEL
577 default n
578 help
579 This option provides a kernel module that can be used to test
580 the kernel stack backtrace code. This option is not useful
581 for distributions or general kernels, but only for kernel
582 developers working on architecture code.
583
584 Say N if you are unsure.
585
Ankita Garg8bb31b92006-10-02 02:17:36 -0700586config LKDTM
587 tristate "Linux Kernel Dump Test Tool Module"
Don Mullisbf4735a2006-12-10 02:18:37 -0800588 depends on DEBUG_KERNEL
Ankita Garg8bb31b92006-10-02 02:17:36 -0700589 depends on KPROBES
Chris Snookfddd9cf2008-02-23 15:23:26 -0800590 depends on BLOCK
Ankita Garg8bb31b92006-10-02 02:17:36 -0700591 default n
592 help
593 This module enables testing of the different dumping mechanisms by
594 inducing system failures at predefined crash points.
595 If you don't need it: say N
596 Choose M here to compile this code as a module. The module will be
597 called lkdtm.
598
599 Documentation on how to use the module can be found in
600 drivers/misc/lkdtm.c
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800601
602config FAULT_INJECTION
Andrew Morton1ab8509a2006-12-08 02:39:49 -0800603 bool "Fault-injection framework"
604 depends on DEBUG_KERNEL
Akinobu Mita329409a2006-12-08 02:39:48 -0800605 help
606 Provide fault-injection framework.
607 For more details, see Documentation/fault-injection/.
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800608
Akinobu Mita8a8b6502006-12-08 02:39:44 -0800609config FAILSLAB
Andrew Morton1ab8509a2006-12-08 02:39:49 -0800610 bool "Fault-injection capability for kmalloc"
611 depends on FAULT_INJECTION
Akinobu Mita8a8b6502006-12-08 02:39:44 -0800612 help
Andrew Morton1ab8509a2006-12-08 02:39:49 -0800613 Provide fault-injection capability for kmalloc.
Akinobu Mita8a8b6502006-12-08 02:39:44 -0800614
Akinobu Mita933e3122006-12-08 02:39:45 -0800615config FAIL_PAGE_ALLOC
616 bool "Fault-injection capabilitiy for alloc_pages()"
Andrew Morton1ab8509a2006-12-08 02:39:49 -0800617 depends on FAULT_INJECTION
Akinobu Mita933e3122006-12-08 02:39:45 -0800618 help
Andrew Morton1ab8509a2006-12-08 02:39:49 -0800619 Provide fault-injection capability for alloc_pages().
Akinobu Mita933e3122006-12-08 02:39:45 -0800620
Akinobu Mitac17bb492006-12-08 02:39:46 -0800621config FAIL_MAKE_REQUEST
Dave Jones86327d12006-12-12 20:16:36 +0100622 bool "Fault-injection capability for disk IO"
Andrew Morton1ab8509a2006-12-08 02:39:49 -0800623 depends on FAULT_INJECTION
Akinobu Mitac17bb492006-12-08 02:39:46 -0800624 help
Andrew Morton1ab8509a2006-12-08 02:39:49 -0800625 Provide fault-injection capability for disk IO.
Akinobu Mitac17bb492006-12-08 02:39:46 -0800626
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800627config FAULT_INJECTION_DEBUG_FS
628 bool "Debugfs entries for fault-injection capabilities"
Andrew Morton1ab8509a2006-12-08 02:39:49 -0800629 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800630 help
Andrew Morton1ab8509a2006-12-08 02:39:49 -0800631 Enable configuration of fault-injection capabilities via debugfs.
Akinobu Mita1df49002007-02-20 13:57:56 -0800632
633config FAULT_INJECTION_STACKTRACE_FILTER
634 bool "stacktrace filter for fault-injection capabilities"
635 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
Akinobu Mita6d690dc2007-05-12 10:36:53 -0700636 depends on !X86_64
Akinobu Mita1df49002007-02-20 13:57:56 -0800637 select STACKTRACE
638 select FRAME_POINTER
639 help
640 Provide stacktrace filter for fault-injection capabilities
Mathieu Desnoyers267c4022007-10-18 23:41:07 -0700641
Arjan van de Ven97455122008-01-25 21:08:34 +0100642config LATENCYTOP
643 bool "Latency measuring infrastructure"
644 select FRAME_POINTER if !MIPS
645 select KALLSYMS
646 select KALLSYMS_ALL
647 select STACKTRACE
648 select SCHEDSTATS
649 select SCHED_DEBUG
Heiko Carstensaa7d9352008-02-01 17:45:14 +0100650 depends on HAVE_LATENCYTOP_SUPPORT
Arjan van de Ven97455122008-01-25 21:08:34 +0100651 help
652 Enable this option if you want to use the LatencyTOP tool
653 to find out which userspace is blocking on what kernel operations.
654
Bernhard Kaindlf212ec42008-01-30 13:34:11 +0100655config PROVIDE_OHCI1394_DMA_INIT
Stefan Richter080de8c2008-02-28 20:54:43 +0100656 bool "Remote debugging over FireWire early on boot"
Bernhard Kaindlf212ec42008-01-30 13:34:11 +0100657 depends on PCI && X86
658 help
659 If you want to debug problems which hang or crash the kernel early
660 on boot and the crashing machine has a FireWire port, you can use
661 this feature to remotely access the memory of the crashed machine
662 over FireWire. This employs remote DMA as part of the OHCI1394
663 specification which is now the standard for FireWire controllers.
664
665 With remote DMA, you can monitor the printk buffer remotely using
666 firescope and access all memory below 4GB using fireproxy from gdb.
667 Even controlling a kernel debugger is possible using remote DMA.
668
669 Usage:
670
671 If ohci1394_dma=early is used as boot parameter, it will initialize
672 all OHCI1394 controllers which are found in the PCI config space.
673
674 As all changes to the FireWire bus such as enabling and disabling
675 devices cause a bus reset and thereby disable remote DMA for all
676 devices, be sure to have the cable plugged and FireWire enabled on
677 the debugging host before booting the debug target for debugging.
678
679 This code (~1k) is freed after boot. By then, the firewire stack
680 in charge of the OHCI-1394 controllers should be used instead.
681
682 See Documentation/debugging-via-ohci1394.txt for more information.
Arjan van de Ven97455122008-01-25 21:08:34 +0100683
Stefan Richter080de8c2008-02-28 20:54:43 +0100684config FIREWIRE_OHCI_REMOTE_DMA
685 bool "Remote debugging over FireWire with firewire-ohci"
686 depends on FIREWIRE_OHCI
687 help
688 This option lets you use the FireWire bus for remote debugging
689 with help of the firewire-ohci driver. It enables unfiltered
690 remote DMA in firewire-ohci.
691 See Documentation/debugging-via-ohci1394.txt for more information.
692
693 If unsure, say N.
694
Mathieu Desnoyers267c4022007-10-18 23:41:07 -0700695source "samples/Kconfig"
Jason Wesseldc7d5522008-04-17 20:05:37 +0200696
697source "lib/Kconfig.kgdb"