blob: 623ef24c23812894c1617f0db781fb3065d6bdf2 [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
Linus Torvalds1da177e2005-04-16 15:20:36 -070028config MAGIC_SYSRQ
29 bool "Magic SysRq key"
Adrian Bunkf346f4b2006-01-09 20:54:51 -080030 depends on !UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070031 help
32 If you say Y here, you will have some control over the system even
33 if the system crashes for example during kernel debugging (e.g., you
34 will be able to flush the buffer cache to disk, reboot the system
35 immediately or dump some status information). This is accomplished
36 by pressing various keys while holding SysRq (Alt+PrintScreen). It
37 also works on a serial console (on PC hardware at least), if you
38 send a BREAK and then within 5 seconds a command keypress. The
39 keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
40 unless you really know what this hack does.
41
Arjan van de Venf71d20e2006-06-28 04:26:45 -070042config UNUSED_SYMBOLS
43 bool "Enable unused/obsolete exported symbols"
44 default y if X86
45 help
46 Unused but exported symbols make the kernel needlessly bigger. For
47 that reason most of these unused exports will soon be removed. This
48 option is provided temporarily to provide a transition period in case
49 some external kernel module needs one of these symbols anyway. If you
50 encounter such a case in your module, consider if you are actually
51 using the right API. (rationale: since nobody in the kernel is using
52 this in a module, there is a pretty good chance it's actually the
53 wrong interface to use). If you really need the symbol, please send a
54 mail to the linux kernel mailing list mentioning the symbol and why
55 you really need it, and what the merge plan to the mainline kernel for
56 your module is.
57
Don Mullisbf4735a2006-12-10 02:18:37 -080058config DEBUG_FS
59 bool "Debug Filesystem"
60 depends on SYSFS
61 help
62 debugfs is a virtual file system that kernel developers use to put
63 debugging files into. Enable this option to be able to read and
64 write to these files.
65
66 If unsure, say N.
67
68config HEADERS_CHECK
69 bool "Run 'make headers_check' when building vmlinux"
70 depends on !UML
71 help
72 This option will extract the user-visible kernel headers whenever
73 building the kernel, and will run basic sanity checks on them to
74 ensure that exported files do not attempt to include files which
75 were not exported, etc.
76
77 If you're making modifications to header files which are
78 relevant for userspace, say 'Y', and check the headers
79 exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in
80 your build tree), to make sure they're suitable.
81
Sam Ravnborg91341d42008-01-21 21:31:44 +010082config DEBUG_SECTION_MISMATCH
83 bool "Enable full Section mismatch analysis"
Sam Ravnborge5f95c82008-02-02 18:57:18 +010084 depends on UNDEFINED
Sam Ravnborgfa2144b2008-02-15 13:53:11 +010085 # This option is on purpose disabled for now.
86 # It will be enabled when we are down to a resonable number
87 # of section mismatch warnings (< 10 for an allyesconfig build)
Sam Ravnborg91341d42008-01-21 21:31:44 +010088 help
89 The section mismatch analysis checks if there are illegal
90 references from one section to another section.
91 Linux will during link or during runtime drop some sections
92 and any use of code/data previously in these sections will
93 most likely result in an oops.
94 In the code functions and variables are annotated with
95 __init, __devinit etc. (see full list in include/linux/init.h)
Geert Uytterhoevend6fbfa42008-01-30 11:13:23 +010096 which results in the code/data being placed in specific sections.
97 The section mismatch analysis is always done after a full
98 kernel build but enabling this option will in addition
Sam Ravnborg91341d42008-01-21 21:31:44 +010099 do the following:
100 - Add the option -fno-inline-functions-called-once to gcc
101 When inlining a function annotated __init in a non-init
Geert Uytterhoevend6fbfa42008-01-30 11:13:23 +0100102 function we would lose the section information and thus
Sam Ravnborg91341d42008-01-21 21:31:44 +0100103 the analysis would not catch the illegal reference.
Geert Uytterhoevend6fbfa42008-01-30 11:13:23 +0100104 This option tells gcc to inline less but will also
Sam Ravnborg91341d42008-01-21 21:31:44 +0100105 result in a larger kernel.
106 - Run the section mismatch analysis for each module/built-in.o
107 When we run the section mismatch analysis on vmlinux.o we
Geert Uytterhoevend6fbfa42008-01-30 11:13:23 +0100108 lose valueble information about where the mismatch was
Sam Ravnborg91341d42008-01-21 21:31:44 +0100109 introduced.
110 Running the analysis for each module/built-in.o file
111 will tell where the mismatch happens much closer to the
112 source. The drawback is that we will report the same
113 mismatch at least twice.
Sam Ravnborg588ccd72008-01-24 21:12:37 +0100114 - Enable verbose reporting from modpost to help solving
115 the section mismatches reported.
Sam Ravnborg91341d42008-01-21 21:31:44 +0100116
Adrian Bunkf346f4b2006-01-09 20:54:51 -0800117config DEBUG_KERNEL
118 bool "Kernel debugging"
119 help
120 Say Y here if you are developing drivers or trying to debug and
121 identify kernel problems.
122
David Woodhousea304e1b2007-02-12 00:52:00 -0800123config DEBUG_SHIRQ
124 bool "Debug shared IRQ handlers"
125 depends on DEBUG_KERNEL && GENERIC_HARDIRQS
126 help
127 Enable this to generate a spurious interrupt as soon as a shared
128 interrupt handler is registered, and just before one is deregistered.
129 Drivers ought to be able to handle interrupts coming in at those
130 points; some don't and need to be caught.
131
Ingo Molnar8446f1d2005-09-06 15:16:27 -0700132config DETECT_SOFTLOCKUP
133 bool "Detect Soft Lockups"
Heiko Carstensdea20a32006-10-11 01:20:44 -0700134 depends on DEBUG_KERNEL && !S390
Ingo Molnar8446f1d2005-09-06 15:16:27 -0700135 default y
136 help
137 Say Y here to enable the kernel to detect "soft lockups",
138 which are bugs that cause the kernel to loop in kernel
139 mode for more than 10 seconds, without giving other tasks a
140 chance to run.
141
142 When a soft-lockup is detected, the kernel will print the
143 current stack trace (which you should report), but the
144 system will stay locked up. This feature has negligible
145 overhead.
146
147 (Note that "hard lockups" are separate type of bugs that
148 can be detected via the NMI-watchdog, on platforms that
149 support it.)
150
Ingo Molnarb642b6d2007-07-09 18:52:00 +0200151config SCHED_DEBUG
152 bool "Collect scheduler debugging info"
153 depends on DEBUG_KERNEL && PROC_FS
154 default y
155 help
156 If you say Y here, the /proc/sched_debug file will be provided
157 that can help debug the scheduler. The runtime overhead of this
158 option is minimal.
159
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160config SCHEDSTATS
161 bool "Collect scheduler statistics"
162 depends on DEBUG_KERNEL && PROC_FS
163 help
164 If you say Y here, additional code will be inserted into the
165 scheduler and related routines to collect statistics about
166 scheduler behavior and provide them in /proc/schedstat. These
167 stats may be useful for both tuning and debugging the scheduler
168 If you aren't debugging the scheduler or trying to tune a specific
169 application, you can say N to avoid the very slight overhead
170 this adds.
171
Ingo Molnar82f67cd2007-02-16 01:28:13 -0800172config TIMER_STATS
173 bool "Collect kernel timers statistics"
174 depends on DEBUG_KERNEL && PROC_FS
175 help
176 If you say Y here, additional code will be inserted into the
177 timer routines to collect statistics about kernel timers being
178 reprogrammed. The statistics can be read from /proc/timer_stats.
179 The statistics collection is started by writing 1 to /proc/timer_stats,
180 writing 0 stops it. This feature is useful to collect information
Ingo Molnarc1a834d2007-06-01 00:47:16 -0700181 about timer usage patterns in kernel and userspace. This feature
182 is lightweight if enabled in the kernel config but not activated
183 (it defaults to deactivated on bootup and will only be activated
184 if some application like powertop activates it explicitly).
Ingo Molnar82f67cd2007-02-16 01:28:13 -0800185
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186config DEBUG_SLAB
Andrew Morton4a2f0ac2006-03-25 03:07:22 -0800187 bool "Debug slab memory allocations"
Ingo Molnar50dd26b2006-01-08 01:01:42 -0800188 depends on DEBUG_KERNEL && SLAB
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 help
190 Say Y here to have the kernel do limited verification on memory
191 allocation as well as poisoning memory on free to catch use of freed
192 memory. This can make kmalloc/kfree-intensive workloads much slower.
193
Al Viro871751e2006-03-25 03:06:39 -0800194config DEBUG_SLAB_LEAK
195 bool "Memory leak debugging"
196 depends on DEBUG_SLAB
197
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700198config SLUB_DEBUG_ON
199 bool "SLUB debugging on by default"
200 depends on SLUB && SLUB_DEBUG
201 default n
202 help
203 Boot with debugging on by default. SLUB boots by default with
204 the runtime debug capabilities switched off. Enabling this is
205 equivalent to specifying the "slub_debug" parameter on boot.
206 There is no support for more fine grained debug control like
207 possible with slub_debug=xxx. SLUB debugging may be switched
208 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
209 "slub_debug=-".
210
Christoph Lameter8ff12cf2008-02-07 17:47:41 -0800211config SLUB_STATS
212 default n
213 bool "Enable SLUB performance statistics"
Christoph Lameter5b06c8532008-04-14 18:51:34 +0300214 depends on SLUB && SLUB_DEBUG && SYSFS
Christoph Lameter8ff12cf2008-02-07 17:47:41 -0800215 help
216 SLUB statistics are useful to debug SLUBs allocation behavior in
217 order find ways to optimize the allocator. This should never be
218 enabled for production use since keeping statistics slows down
219 the allocator by a few percentage points. The slabinfo command
220 supports the determination of the most active slabs to figure
221 out which slabs are relevant to a particular load.
222 Try running: slabinfo -DA
223
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224config DEBUG_PREEMPT
225 bool "Debug preemptible kernel"
Hugh Dickins048c8bc2006-11-01 05:44:54 +1100226 depends on DEBUG_KERNEL && PREEMPT && (TRACE_IRQFLAGS_SUPPORT || PPC64)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 default y
228 help
229 If you say Y here then the kernel will use a debug variant of the
230 commonly used smp_processor_id() function and will print warnings
231 if kernel code uses it in a preemption-unsafe way. Also, the kernel
232 will detect preemption count underflows.
233
Ingo Molnare7eebaf2006-06-27 02:54:55 -0700234config DEBUG_RT_MUTEXES
235 bool "RT Mutex debugging, deadlock detection"
Ingo Molnare7eebaf2006-06-27 02:54:55 -0700236 depends on DEBUG_KERNEL && RT_MUTEXES
237 help
238 This allows rt mutex semantics violations and rt mutex related
239 deadlocks (lockups) to be detected and reported automatically.
240
241config DEBUG_PI_LIST
242 bool
243 default y
244 depends on DEBUG_RT_MUTEXES
245
Thomas Gleixner61a87122006-06-27 02:54:56 -0700246config RT_MUTEX_TESTER
247 bool "Built-in scriptable tester for rt-mutexes"
Roman Zippela1583d32006-06-27 02:55:00 -0700248 depends on DEBUG_KERNEL && RT_MUTEXES
Thomas Gleixner61a87122006-06-27 02:54:56 -0700249 help
250 This option enables a rt-mutex tester.
251
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252config DEBUG_SPINLOCK
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700253 bool "Spinlock and rw-lock debugging: basic checks"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 depends on DEBUG_KERNEL
255 help
256 Say Y here and build SMP to catch missing spinlock initialization
257 and certain other kinds of spinlock errors commonly made. This is
258 best used in conjunction with the NMI watchdog so that spinlock
259 deadlocks are also debuggable.
260
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700261config DEBUG_MUTEXES
262 bool "Mutex debugging: basic checks"
263 depends on DEBUG_KERNEL
264 help
265 This feature allows mutex semantics violations to be detected and
266 reported.
267
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700268config DEBUG_LOCK_ALLOC
269 bool "Lock debugging: detect incorrect freeing of live locks"
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700270 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700271 select DEBUG_SPINLOCK
272 select DEBUG_MUTEXES
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700273 select LOCKDEP
274 help
275 This feature will check whether any held lock (spinlock, rwlock,
276 mutex or rwsem) is incorrectly freed by the kernel, via any of the
277 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
278 vfree(), etc.), whether a live lock is incorrectly reinitialized via
279 spin_lock_init()/mutex_init()/etc., or whether there is any lock
280 held during task exit.
281
282config PROVE_LOCKING
283 bool "Lock debugging: prove locking correctness"
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700284 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700285 select LOCKDEP
286 select DEBUG_SPINLOCK
287 select DEBUG_MUTEXES
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700288 select DEBUG_LOCK_ALLOC
289 default n
290 help
291 This feature enables the kernel to prove that all locking
292 that occurs in the kernel runtime is mathematically
293 correct: that under no circumstance could an arbitrary (and
294 not yet triggered) combination of observed locking
295 sequences (on an arbitrary number of CPUs, running an
296 arbitrary number of tasks and interrupt contexts) cause a
297 deadlock.
298
299 In short, this feature enables the kernel to report locking
300 related deadlocks before they actually occur.
301
302 The proof does not depend on how hard and complex a
303 deadlock scenario would be to trigger: how many
304 participant CPUs, tasks and irq-contexts would be needed
305 for it to trigger. The proof also does not depend on
306 timing: if a race and a resulting deadlock is possible
307 theoretically (no matter how unlikely the race scenario
308 is), it will be proven so and will immediately be
309 reported by the kernel (once the event is observed that
310 makes the deadlock theoretically possible).
311
312 If a deadlock is impossible (i.e. the locking rules, as
313 observed by the kernel, are mathematically correct), the
314 kernel reports nothing.
315
316 NOTE: this feature can also be enabled for rwlocks, mutexes
317 and rwsems - in which case all dependencies between these
318 different locking variants are observed and mapped too, and
319 the proof of observed correctness is also maintained for an
320 arbitrary combination of these separate locking variants.
321
322 For more details, see Documentation/lockdep-design.txt.
323
324config LOCKDEP
325 bool
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 STACKTRACE
Franck Bui-Huu14cf2322007-04-26 00:20:15 -0700328 select FRAME_POINTER if !X86 && !MIPS
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700329 select KALLSYMS
330 select KALLSYMS_ALL
331
Peter Zijlstraf20786f2007-07-19 01:48:56 -0700332config LOCK_STAT
Danny ter Haarfdfb8702007-09-24 21:24:43 -0700333 bool "Lock usage statistics"
Peter Zijlstraf20786f2007-07-19 01:48:56 -0700334 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
335 select LOCKDEP
336 select DEBUG_SPINLOCK
337 select DEBUG_MUTEXES
338 select DEBUG_LOCK_ALLOC
339 default n
340 help
341 This feature enables tracking lock contention points
342
Peter Zijlstraa560aa42007-10-07 00:24:33 -0700343 For more details, see Documentation/lockstat.txt
344
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700345config DEBUG_LOCKDEP
346 bool "Lock dependency engine debugging"
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700347 depends on DEBUG_KERNEL && LOCKDEP
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700348 help
349 If you say Y here, the lock dependency engine will do
350 additional runtime checks to debug itself, at the price
351 of more runtime overhead.
352
353config TRACE_IRQFLAGS
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700354 depends on DEBUG_KERNEL
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700355 bool
356 default y
357 depends on TRACE_IRQFLAGS_SUPPORT
358 depends on PROVE_LOCKING
359
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360config DEBUG_SPINLOCK_SLEEP
Ingo Molnar4d9f34a2006-07-03 00:24:55 -0700361 bool "Spinlock debugging: sleep-inside-spinlock checking"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362 depends on DEBUG_KERNEL
363 help
364 If you say Y here, various routines which may sleep will become very
365 noisy if they are called with a spinlock held.
366
Ingo Molnarcae2ed92006-07-03 00:24:48 -0700367config DEBUG_LOCKING_API_SELFTESTS
368 bool "Locking API boot-time self-tests"
369 depends on DEBUG_KERNEL
370 help
371 Say Y here if you want the kernel to run a short self-test during
372 bootup. The self-test checks whether common types of locking bugs
373 are detected by debugging mechanisms or not. (if you disable
374 lock debugging then those bugs wont be detected of course.)
375 The following locking APIs are covered: spinlocks, rwlocks,
376 mutexes and rwsems.
377
Ingo Molnar8637c092006-07-03 00:24:38 -0700378config STACKTRACE
379 bool
Adrian Bunk517e7aa2006-07-14 00:24:32 -0700380 depends on DEBUG_KERNEL
Ingo Molnar8637c092006-07-03 00:24:38 -0700381 depends on STACKTRACE_SUPPORT
382
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383config DEBUG_KOBJECT
384 bool "kobject debugging"
385 depends on DEBUG_KERNEL
386 help
387 If you say Y here, some extra kobject debugging messages will be sent
388 to the syslog.
389
390config DEBUG_HIGHMEM
391 bool "Highmem debugging"
392 depends on DEBUG_KERNEL && HIGHMEM
393 help
394 This options enables addition error checking for high memory systems.
395 Disable for production systems.
396
397config DEBUG_BUGVERBOSE
398 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EMBEDDED
Matt Mackallc8538a72005-05-01 08:59:01 -0700399 depends on BUG
David Howellsb920de12008-02-08 04:19:31 -0800400 depends on ARM || AVR32 || M32R || M68K || SPARC32 || SPARC64 || \
401 FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 default !EMBEDDED
403 help
404 Say Y here to make BUG() panics output the file name and line number
405 of the BUG call as well as the EIP and oops trace. This aids
406 debugging but costs about 70-100K of memory.
407
408config DEBUG_INFO
409 bool "Compile the kernel with debug info"
410 depends on DEBUG_KERNEL
411 help
412 If you say Y here the resulting kernel image will include
413 debugging info resulting in a larger kernel image.
Andreas Dilgerb72e53f2007-03-27 15:21:33 -0600414 This adds debug symbols to the kernel and modules (gcc -g), and
415 is needed if you intend to use kernel crashdump or binary object
416 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417 Say Y here only if you plan to debug the kernel.
418
419 If unsure, say N.
420
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800421config DEBUG_VM
422 bool "Debug VM"
423 depends on DEBUG_KERNEL
424 help
Nick Piggin13e74442006-01-06 00:10:58 -0800425 Enable this to turn on extended checks in the virtual-memory system
426 that may impact performance.
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800427
428 If unsure, say N.
429
Dave Hansenad775f52008-02-15 14:38:01 -0800430config DEBUG_WRITECOUNT
431 bool "Debug filesystem writers count"
432 depends on DEBUG_KERNEL
433 help
434 Enable this to catch wrong use of the writers count in struct
435 vfsmount. This will increase the size of each file struct by
436 32 bits.
437
438 If unsure, say N.
439
Dave Jones199a9af2006-09-29 01:59:00 -0700440config DEBUG_LIST
441 bool "Debug linked list manipulation"
442 depends on DEBUG_KERNEL
443 help
444 Enable this to turn on extended checks in the linked-list
445 walking routines.
446
447 If unsure, say N.
448
Jens Axboed6ec0842007-10-22 20:01:06 +0200449config DEBUG_SG
450 bool "Debug SG table operations"
451 depends on DEBUG_KERNEL
452 help
453 Enable this to turn on checks on scatter-gather tables. This can
454 help find problems with drivers that do not properly initialize
455 their sg tables.
456
457 If unsure, say N.
458
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459config FRAME_POINTER
460 bool "Compile the kernel with frame pointers"
David Howellsb920de12008-02-08 04:19:31 -0800461 depends on DEBUG_KERNEL && \
462 (X86 || CRIS || M68K || M68KNOMMU || FRV || UML || S390 || \
463 AVR32 || SUPERH || BLACKFIN || MN10300)
Paolo 'Blaisorblade' Giarrusso37fce852005-05-28 15:51:59 -0700464 default y if DEBUG_INFO && UML
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 help
466 If you say Y here the resulting kernel image will be slightly larger
Jesper Juhl2a38bcc2005-10-30 15:02:51 -0800467 and slower, but it might give very useful debugging information on
468 some architectures or if you use external debuggers.
Andi Kleenaeb39982005-09-12 18:49:25 +0200469 If you don't debug the kernel, you can say N.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470
Randy Dunlapbfe8df32007-10-16 01:23:46 -0700471config BOOT_PRINTK_DELAY
472 bool "Delay each boot printk message by N milliseconds"
473 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
474 help
475 This build option allows you to read kernel boot messages
476 by inserting a short delay after each one. The delay is
477 specified in milliseconds on the kernel command line,
478 using "boot_delay=N".
479
480 It is likely that you would also need to use "lpj=M" to preset
481 the "loops per jiffie" value.
482 See a previous boot log for the "lpj" value to use for your
483 system, and then set "lpj=M" before setting "boot_delay=N".
484 NOTE: Using this option may adversely affect SMP systems.
485 I.e., processors other than the first one may not boot up.
486 BOOT_PRINTK_DELAY also may cause DETECT_SOFTLOCKUP to detect
487 what it believes to be lockup conditions.
488
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800489config RCU_TORTURE_TEST
490 tristate "torture tests for RCU"
491 depends on DEBUG_KERNEL
Paul E. McKenney9aaffc82007-05-23 13:57:41 -0700492 depends on m
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800493 default n
494 help
495 This option provides a kernel module that runs torture tests
496 on the RCU infrastructure. The kernel module may be built
497 after the fact on the running kernel to be tested, if desired.
498
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800499 Say M if you want the RCU torture tests to build as a module.
500 Say N if you are unsure.
Ankita Garg8bb31b92006-10-02 02:17:36 -0700501
Ananth N Mavinakayanahalli8c1c9352008-01-30 13:32:53 +0100502config KPROBES_SANITY_TEST
503 bool "Kprobes sanity tests"
504 depends on DEBUG_KERNEL
505 depends on KPROBES
506 default n
507 help
508 This option provides for testing basic kprobes functionality on
509 boot. A sample kprobe, jprobe and kretprobe are inserted and
510 verified for functionality.
511
512 Say N if you are unsure.
513
Arjan van de Ven6dab2772008-01-30 13:33:08 +0100514config BACKTRACE_SELF_TEST
515 tristate "Self test for the backtrace code"
516 depends on DEBUG_KERNEL
517 default n
518 help
519 This option provides a kernel module that can be used to test
520 the kernel stack backtrace code. This option is not useful
521 for distributions or general kernels, but only for kernel
522 developers working on architecture code.
523
524 Say N if you are unsure.
525
Ankita Garg8bb31b92006-10-02 02:17:36 -0700526config LKDTM
527 tristate "Linux Kernel Dump Test Tool Module"
Don Mullisbf4735a2006-12-10 02:18:37 -0800528 depends on DEBUG_KERNEL
Ankita Garg8bb31b92006-10-02 02:17:36 -0700529 depends on KPROBES
Chris Snookfddd9cf2008-02-23 15:23:26 -0800530 depends on BLOCK
Ankita Garg8bb31b92006-10-02 02:17:36 -0700531 default n
532 help
533 This module enables testing of the different dumping mechanisms by
534 inducing system failures at predefined crash points.
535 If you don't need it: say N
536 Choose M here to compile this code as a module. The module will be
537 called lkdtm.
538
539 Documentation on how to use the module can be found in
540 drivers/misc/lkdtm.c
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800541
542config FAULT_INJECTION
Andrew Morton1ab85092006-12-08 02:39:49 -0800543 bool "Fault-injection framework"
544 depends on DEBUG_KERNEL
Akinobu Mita329409a2006-12-08 02:39:48 -0800545 help
546 Provide fault-injection framework.
547 For more details, see Documentation/fault-injection/.
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800548
Akinobu Mita8a8b6502006-12-08 02:39:44 -0800549config FAILSLAB
Andrew Morton1ab85092006-12-08 02:39:49 -0800550 bool "Fault-injection capability for kmalloc"
551 depends on FAULT_INJECTION
Akinobu Mita8a8b6502006-12-08 02:39:44 -0800552 help
Andrew Morton1ab85092006-12-08 02:39:49 -0800553 Provide fault-injection capability for kmalloc.
Akinobu Mita8a8b6502006-12-08 02:39:44 -0800554
Akinobu Mita933e3122006-12-08 02:39:45 -0800555config FAIL_PAGE_ALLOC
556 bool "Fault-injection capabilitiy for alloc_pages()"
Andrew Morton1ab85092006-12-08 02:39:49 -0800557 depends on FAULT_INJECTION
Akinobu Mita933e3122006-12-08 02:39:45 -0800558 help
Andrew Morton1ab85092006-12-08 02:39:49 -0800559 Provide fault-injection capability for alloc_pages().
Akinobu Mita933e3122006-12-08 02:39:45 -0800560
Akinobu Mitac17bb492006-12-08 02:39:46 -0800561config FAIL_MAKE_REQUEST
Dave Jones86327d12006-12-12 20:16:36 +0100562 bool "Fault-injection capability for disk IO"
Andrew Morton1ab85092006-12-08 02:39:49 -0800563 depends on FAULT_INJECTION
Akinobu Mitac17bb492006-12-08 02:39:46 -0800564 help
Andrew Morton1ab85092006-12-08 02:39:49 -0800565 Provide fault-injection capability for disk IO.
Akinobu Mitac17bb492006-12-08 02:39:46 -0800566
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800567config FAULT_INJECTION_DEBUG_FS
568 bool "Debugfs entries for fault-injection capabilities"
Andrew Morton1ab85092006-12-08 02:39:49 -0800569 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
Akinobu Mita6ff1cb32006-12-08 02:39:43 -0800570 help
Andrew Morton1ab85092006-12-08 02:39:49 -0800571 Enable configuration of fault-injection capabilities via debugfs.
Akinobu Mita1df49002007-02-20 13:57:56 -0800572
573config FAULT_INJECTION_STACKTRACE_FILTER
574 bool "stacktrace filter for fault-injection capabilities"
575 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
Akinobu Mita6d690dc2007-05-12 10:36:53 -0700576 depends on !X86_64
Akinobu Mita1df49002007-02-20 13:57:56 -0800577 select STACKTRACE
578 select FRAME_POINTER
579 help
580 Provide stacktrace filter for fault-injection capabilities
Mathieu Desnoyers267c4022007-10-18 23:41:07 -0700581
Arjan van de Ven97455122008-01-25 21:08:34 +0100582config LATENCYTOP
583 bool "Latency measuring infrastructure"
584 select FRAME_POINTER if !MIPS
585 select KALLSYMS
586 select KALLSYMS_ALL
587 select STACKTRACE
588 select SCHEDSTATS
589 select SCHED_DEBUG
Heiko Carstensaa7d9352008-02-01 17:45:14 +0100590 depends on HAVE_LATENCYTOP_SUPPORT
Arjan van de Ven97455122008-01-25 21:08:34 +0100591 help
592 Enable this option if you want to use the LatencyTOP tool
593 to find out which userspace is blocking on what kernel operations.
594
Bernhard Kaindlf212ec42008-01-30 13:34:11 +0100595config PROVIDE_OHCI1394_DMA_INIT
Stefan Richter080de8c2008-02-28 20:54:43 +0100596 bool "Remote debugging over FireWire early on boot"
Bernhard Kaindlf212ec42008-01-30 13:34:11 +0100597 depends on PCI && X86
598 help
599 If you want to debug problems which hang or crash the kernel early
600 on boot and the crashing machine has a FireWire port, you can use
601 this feature to remotely access the memory of the crashed machine
602 over FireWire. This employs remote DMA as part of the OHCI1394
603 specification which is now the standard for FireWire controllers.
604
605 With remote DMA, you can monitor the printk buffer remotely using
606 firescope and access all memory below 4GB using fireproxy from gdb.
607 Even controlling a kernel debugger is possible using remote DMA.
608
609 Usage:
610
611 If ohci1394_dma=early is used as boot parameter, it will initialize
612 all OHCI1394 controllers which are found in the PCI config space.
613
614 As all changes to the FireWire bus such as enabling and disabling
615 devices cause a bus reset and thereby disable remote DMA for all
616 devices, be sure to have the cable plugged and FireWire enabled on
617 the debugging host before booting the debug target for debugging.
618
619 This code (~1k) is freed after boot. By then, the firewire stack
620 in charge of the OHCI-1394 controllers should be used instead.
621
622 See Documentation/debugging-via-ohci1394.txt for more information.
Arjan van de Ven97455122008-01-25 21:08:34 +0100623
Stefan Richter080de8c2008-02-28 20:54:43 +0100624config FIREWIRE_OHCI_REMOTE_DMA
625 bool "Remote debugging over FireWire with firewire-ohci"
626 depends on FIREWIRE_OHCI
627 help
628 This option lets you use the FireWire bus for remote debugging
629 with help of the firewire-ohci driver. It enables unfiltered
630 remote DMA in firewire-ohci.
631 See Documentation/debugging-via-ohci1394.txt for more information.
632
633 If unsure, say N.
634
Mathieu Desnoyers267c4022007-10-18 23:41:07 -0700635source "samples/Kconfig"
Jason Wesseldc7d5522008-04-17 20:05:37 +0200636
637source "lib/Kconfig.kgdb"