Root/
1 | |
2 | config PRINTK_TIME |
3 | bool "Show timing information on printks" |
4 | depends on PRINTK |
5 | 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. Or add printk.time=1 at boot-time. |
11 | See Documentation/kernel-parameters.txt |
12 | |
13 | config DEFAULT_MESSAGE_LOGLEVEL |
14 | int "Default message log level (1-7)" |
15 | range 1 7 |
16 | default "4" |
17 | help |
18 | Default log level for printk statements with no specified priority. |
19 | |
20 | This was hard-coded to KERN_WARNING since at least 2.6.10 but folks |
21 | that are auditing their logs closely may want to set it to a lower |
22 | priority. |
23 | |
24 | config ENABLE_WARN_DEPRECATED |
25 | bool "Enable __deprecated logic" |
26 | default y |
27 | help |
28 | Enable the __deprecated logic in the kernel build. |
29 | Disable this to suppress the "warning: 'foo' is deprecated |
30 | (declared at kernel/power/somefile.c:1234)" messages. |
31 | |
32 | config ENABLE_MUST_CHECK |
33 | bool "Enable __must_check logic" |
34 | default y |
35 | help |
36 | Enable the __must_check logic in the kernel build. Disable this to |
37 | suppress the "warning: ignoring return value of 'foo', declared with |
38 | attribute warn_unused_result" messages. |
39 | |
40 | config FRAME_WARN |
41 | int "Warn for stack frames larger than (needs gcc 4.4)" |
42 | range 0 8192 |
43 | default 1024 if !64BIT |
44 | default 2048 if 64BIT |
45 | help |
46 | Tell gcc to warn at build time for stack frames larger than this. |
47 | Setting this too low will cause a lot of warnings. |
48 | Setting it to 0 disables the warning. |
49 | Requires gcc 4.4 |
50 | |
51 | config MAGIC_SYSRQ |
52 | bool "Magic SysRq key" |
53 | depends on !UML |
54 | help |
55 | If you say Y here, you will have some control over the system even |
56 | if the system crashes for example during kernel debugging (e.g., you |
57 | will be able to flush the buffer cache to disk, reboot the system |
58 | immediately or dump some status information). This is accomplished |
59 | by pressing various keys while holding SysRq (Alt+PrintScreen). It |
60 | also works on a serial console (on PC hardware at least), if you |
61 | send a BREAK and then within 5 seconds a command keypress. The |
62 | keys are documented in <file:Documentation/sysrq.txt>. Don't say Y |
63 | unless you really know what this hack does. |
64 | |
65 | config STRIP_ASM_SYMS |
66 | bool "Strip assembler-generated symbols during link" |
67 | default n |
68 | help |
69 | Strip internal assembler-generated symbols during a link (symbols |
70 | that look like '.Lxxx') so they don't pollute the output of |
71 | get_wchan() and suchlike. |
72 | |
73 | config UNUSED_SYMBOLS |
74 | bool "Enable unused/obsolete exported symbols" |
75 | default y if X86 |
76 | help |
77 | Unused but exported symbols make the kernel needlessly bigger. For |
78 | that reason most of these unused exports will soon be removed. This |
79 | option is provided temporarily to provide a transition period in case |
80 | some external kernel module needs one of these symbols anyway. If you |
81 | encounter such a case in your module, consider if you are actually |
82 | using the right API. (rationale: since nobody in the kernel is using |
83 | this in a module, there is a pretty good chance it's actually the |
84 | wrong interface to use). If you really need the symbol, please send a |
85 | mail to the linux kernel mailing list mentioning the symbol and why |
86 | you really need it, and what the merge plan to the mainline kernel for |
87 | your module is. |
88 | |
89 | config DEBUG_FS |
90 | bool "Debug Filesystem" |
91 | help |
92 | debugfs is a virtual file system that kernel developers use to put |
93 | debugging files into. Enable this option to be able to read and |
94 | write to these files. |
95 | |
96 | For detailed documentation on the debugfs API, see |
97 | Documentation/DocBook/filesystems. |
98 | |
99 | If unsure, say N. |
100 | |
101 | config HEADERS_CHECK |
102 | bool "Run 'make headers_check' when building vmlinux" |
103 | depends on !UML |
104 | help |
105 | This option will extract the user-visible kernel headers whenever |
106 | building the kernel, and will run basic sanity checks on them to |
107 | ensure that exported files do not attempt to include files which |
108 | were not exported, etc. |
109 | |
110 | If you're making modifications to header files which are |
111 | relevant for userspace, say 'Y', and check the headers |
112 | exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in |
113 | your build tree), to make sure they're suitable. |
114 | |
115 | config DEBUG_SECTION_MISMATCH |
116 | bool "Enable full Section mismatch analysis" |
117 | help |
118 | The section mismatch analysis checks if there are illegal |
119 | references from one section to another section. |
120 | During linktime or runtime, some sections are dropped; |
121 | any use of code/data previously in these sections would |
122 | most likely result in an oops. |
123 | In the code, functions and variables are annotated with |
124 | __init, __devinit, etc. (see the full list in include/linux/init.h), |
125 | which results in the code/data being placed in specific sections. |
126 | The section mismatch analysis is always performed after a full |
127 | kernel build, and enabling this option causes the following |
128 | additional steps to occur: |
129 | - Add the option -fno-inline-functions-called-once to gcc commands. |
130 | When inlining a function annotated with __init in a non-init |
131 | function, we would lose the section information and thus |
132 | the analysis would not catch the illegal reference. |
133 | This option tells gcc to inline less (but it does result in |
134 | a larger kernel). |
135 | - Run the section mismatch analysis for each module/built-in.o file. |
136 | When we run the section mismatch analysis on vmlinux.o, we |
137 | lose valueble information about where the mismatch was |
138 | introduced. |
139 | Running the analysis for each module/built-in.o file |
140 | tells where the mismatch happens much closer to the |
141 | source. The drawback is that the same mismatch is |
142 | reported at least twice. |
143 | - Enable verbose reporting from modpost in order to help resolve |
144 | the section mismatches that are reported. |
145 | |
146 | config DEBUG_KERNEL |
147 | bool "Kernel debugging" |
148 | help |
149 | Say Y here if you are developing drivers or trying to debug and |
150 | identify kernel problems. |
151 | |
152 | config DEBUG_SHIRQ |
153 | bool "Debug shared IRQ handlers" |
154 | depends on DEBUG_KERNEL && GENERIC_HARDIRQS |
155 | help |
156 | Enable this to generate a spurious interrupt as soon as a shared |
157 | interrupt handler is registered, and just before one is deregistered. |
158 | Drivers ought to be able to handle interrupts coming in at those |
159 | points; some don't and need to be caught. |
160 | |
161 | config LOCKUP_DETECTOR |
162 | bool "Detect Hard and Soft Lockups" |
163 | depends on DEBUG_KERNEL && !S390 |
164 | help |
165 | Say Y here to enable the kernel to act as a watchdog to detect |
166 | hard and soft lockups. |
167 | |
168 | Softlockups are bugs that cause the kernel to loop in kernel |
169 | mode for more than 60 seconds, without giving other tasks a |
170 | chance to run. The current stack trace is displayed upon |
171 | detection and the system will stay locked up. |
172 | |
173 | Hardlockups are bugs that cause the CPU to loop in kernel mode |
174 | for more than 60 seconds, without letting other interrupts have a |
175 | chance to run. The current stack trace is displayed upon detection |
176 | and the system will stay locked up. |
177 | |
178 | The overhead should be minimal. A periodic hrtimer runs to |
179 | generate interrupts and kick the watchdog task every 10-12 seconds. |
180 | An NMI is generated every 60 seconds or so to check for hardlockups. |
181 | |
182 | config HARDLOCKUP_DETECTOR |
183 | def_bool LOCKUP_DETECTOR && PERF_EVENTS && HAVE_PERF_EVENTS_NMI && \ |
184 | !ARCH_HAS_NMI_WATCHDOG |
185 | |
186 | config BOOTPARAM_HARDLOCKUP_PANIC |
187 | bool "Panic (Reboot) On Hard Lockups" |
188 | depends on LOCKUP_DETECTOR |
189 | help |
190 | Say Y here to enable the kernel to panic on "hard lockups", |
191 | which are bugs that cause the kernel to loop in kernel |
192 | mode with interrupts disabled for more than 60 seconds. |
193 | |
194 | Say N if unsure. |
195 | |
196 | config BOOTPARAM_HARDLOCKUP_PANIC_VALUE |
197 | int |
198 | depends on LOCKUP_DETECTOR |
199 | range 0 1 |
200 | default 0 if !BOOTPARAM_HARDLOCKUP_PANIC |
201 | default 1 if BOOTPARAM_HARDLOCKUP_PANIC |
202 | |
203 | config BOOTPARAM_SOFTLOCKUP_PANIC |
204 | bool "Panic (Reboot) On Soft Lockups" |
205 | depends on LOCKUP_DETECTOR |
206 | help |
207 | Say Y here to enable the kernel to panic on "soft lockups", |
208 | which are bugs that cause the kernel to loop in kernel |
209 | mode for more than 60 seconds, without giving other tasks a |
210 | chance to run. |
211 | |
212 | The panic can be used in combination with panic_timeout, |
213 | to cause the system to reboot automatically after a |
214 | lockup has been detected. This feature is useful for |
215 | high-availability systems that have uptime guarantees and |
216 | where a lockup must be resolved ASAP. |
217 | |
218 | Say N if unsure. |
219 | |
220 | config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE |
221 | int |
222 | depends on LOCKUP_DETECTOR |
223 | range 0 1 |
224 | default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC |
225 | default 1 if BOOTPARAM_SOFTLOCKUP_PANIC |
226 | |
227 | config DETECT_HUNG_TASK |
228 | bool "Detect Hung Tasks" |
229 | depends on DEBUG_KERNEL |
230 | default LOCKUP_DETECTOR |
231 | help |
232 | Say Y here to enable the kernel to detect "hung tasks", |
233 | which are bugs that cause the task to be stuck in |
234 | uninterruptible "D" state indefinitiley. |
235 | |
236 | When a hung task is detected, the kernel will print the |
237 | current stack trace (which you should report), but the |
238 | task will stay in uninterruptible state. If lockdep is |
239 | enabled then all held locks will also be reported. This |
240 | feature has negligible overhead. |
241 | |
242 | config DEFAULT_HUNG_TASK_TIMEOUT |
243 | int "Default timeout for hung task detection (in seconds)" |
244 | depends on DETECT_HUNG_TASK |
245 | default 120 |
246 | help |
247 | This option controls the default timeout (in seconds) used |
248 | to determine when a task has become non-responsive and should |
249 | be considered hung. |
250 | |
251 | It can be adjusted at runtime via the kernel.hung_task_timeout_secs |
252 | sysctl or by writing a value to |
253 | /proc/sys/kernel/hung_task_timeout_secs. |
254 | |
255 | A timeout of 0 disables the check. The default is two minutes. |
256 | Keeping the default should be fine in most cases. |
257 | |
258 | config BOOTPARAM_HUNG_TASK_PANIC |
259 | bool "Panic (Reboot) On Hung Tasks" |
260 | depends on DETECT_HUNG_TASK |
261 | help |
262 | Say Y here to enable the kernel to panic on "hung tasks", |
263 | which are bugs that cause the kernel to leave a task stuck |
264 | in uninterruptible "D" state. |
265 | |
266 | The panic can be used in combination with panic_timeout, |
267 | to cause the system to reboot automatically after a |
268 | hung task has been detected. This feature is useful for |
269 | high-availability systems that have uptime guarantees and |
270 | where a hung tasks must be resolved ASAP. |
271 | |
272 | Say N if unsure. |
273 | |
274 | config BOOTPARAM_HUNG_TASK_PANIC_VALUE |
275 | int |
276 | depends on DETECT_HUNG_TASK |
277 | range 0 1 |
278 | default 0 if !BOOTPARAM_HUNG_TASK_PANIC |
279 | default 1 if BOOTPARAM_HUNG_TASK_PANIC |
280 | |
281 | config SCHED_DEBUG |
282 | bool "Collect scheduler debugging info" |
283 | depends on DEBUG_KERNEL && PROC_FS |
284 | default y |
285 | help |
286 | If you say Y here, the /proc/sched_debug file will be provided |
287 | that can help debug the scheduler. The runtime overhead of this |
288 | option is minimal. |
289 | |
290 | config SCHEDSTATS |
291 | bool "Collect scheduler statistics" |
292 | depends on DEBUG_KERNEL && PROC_FS |
293 | help |
294 | If you say Y here, additional code will be inserted into the |
295 | scheduler and related routines to collect statistics about |
296 | scheduler behavior and provide them in /proc/schedstat. These |
297 | stats may be useful for both tuning and debugging the scheduler |
298 | If you aren't debugging the scheduler or trying to tune a specific |
299 | application, you can say N to avoid the very slight overhead |
300 | this adds. |
301 | |
302 | config TIMER_STATS |
303 | bool "Collect kernel timers statistics" |
304 | depends on DEBUG_KERNEL && PROC_FS |
305 | help |
306 | If you say Y here, additional code will be inserted into the |
307 | timer routines to collect statistics about kernel timers being |
308 | reprogrammed. The statistics can be read from /proc/timer_stats. |
309 | The statistics collection is started by writing 1 to /proc/timer_stats, |
310 | writing 0 stops it. This feature is useful to collect information |
311 | about timer usage patterns in kernel and userspace. This feature |
312 | is lightweight if enabled in the kernel config but not activated |
313 | (it defaults to deactivated on bootup and will only be activated |
314 | if some application like powertop activates it explicitly). |
315 | |
316 | config DEBUG_OBJECTS |
317 | bool "Debug object operations" |
318 | depends on DEBUG_KERNEL |
319 | help |
320 | If you say Y here, additional code will be inserted into the |
321 | kernel to track the life time of various objects and validate |
322 | the operations on those objects. |
323 | |
324 | config DEBUG_OBJECTS_SELFTEST |
325 | bool "Debug objects selftest" |
326 | depends on DEBUG_OBJECTS |
327 | help |
328 | This enables the selftest of the object debug code. |
329 | |
330 | config DEBUG_OBJECTS_FREE |
331 | bool "Debug objects in freed memory" |
332 | depends on DEBUG_OBJECTS |
333 | help |
334 | This enables checks whether a k/v free operation frees an area |
335 | which contains an object which has not been deactivated |
336 | properly. This can make kmalloc/kfree-intensive workloads |
337 | much slower. |
338 | |
339 | config DEBUG_OBJECTS_TIMERS |
340 | bool "Debug timer objects" |
341 | depends on DEBUG_OBJECTS |
342 | help |
343 | If you say Y here, additional code will be inserted into the |
344 | timer routines to track the life time of timer objects and |
345 | validate the timer operations. |
346 | |
347 | config DEBUG_OBJECTS_WORK |
348 | bool "Debug work objects" |
349 | depends on DEBUG_OBJECTS |
350 | help |
351 | If you say Y here, additional code will be inserted into the |
352 | work queue routines to track the life time of work objects and |
353 | validate the work operations. |
354 | |
355 | config DEBUG_OBJECTS_RCU_HEAD |
356 | bool "Debug RCU callbacks objects" |
357 | depends on DEBUG_OBJECTS |
358 | help |
359 | Enable this to turn on debugging of RCU list heads (call_rcu() usage). |
360 | |
361 | config DEBUG_OBJECTS_PERCPU_COUNTER |
362 | bool "Debug percpu counter objects" |
363 | depends on DEBUG_OBJECTS |
364 | help |
365 | If you say Y here, additional code will be inserted into the |
366 | percpu counter routines to track the life time of percpu counter |
367 | objects and validate the percpu counter operations. |
368 | |
369 | config DEBUG_OBJECTS_ENABLE_DEFAULT |
370 | int "debug_objects bootup default value (0-1)" |
371 | range 0 1 |
372 | default "1" |
373 | depends on DEBUG_OBJECTS |
374 | help |
375 | Debug objects boot parameter default value |
376 | |
377 | config DEBUG_SLAB |
378 | bool "Debug slab memory allocations" |
379 | depends on DEBUG_KERNEL && SLAB && !KMEMCHECK |
380 | help |
381 | Say Y here to have the kernel do limited verification on memory |
382 | allocation as well as poisoning memory on free to catch use of freed |
383 | memory. This can make kmalloc/kfree-intensive workloads much slower. |
384 | |
385 | config DEBUG_SLAB_LEAK |
386 | bool "Memory leak debugging" |
387 | depends on DEBUG_SLAB |
388 | |
389 | config SLUB_DEBUG_ON |
390 | bool "SLUB debugging on by default" |
391 | depends on SLUB && SLUB_DEBUG && !KMEMCHECK |
392 | default n |
393 | help |
394 | Boot with debugging on by default. SLUB boots by default with |
395 | the runtime debug capabilities switched off. Enabling this is |
396 | equivalent to specifying the "slub_debug" parameter on boot. |
397 | There is no support for more fine grained debug control like |
398 | possible with slub_debug=xxx. SLUB debugging may be switched |
399 | off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying |
400 | "slub_debug=-". |
401 | |
402 | config SLUB_STATS |
403 | default n |
404 | bool "Enable SLUB performance statistics" |
405 | depends on SLUB && SYSFS |
406 | help |
407 | SLUB statistics are useful to debug SLUBs allocation behavior in |
408 | order find ways to optimize the allocator. This should never be |
409 | enabled for production use since keeping statistics slows down |
410 | the allocator by a few percentage points. The slabinfo command |
411 | supports the determination of the most active slabs to figure |
412 | out which slabs are relevant to a particular load. |
413 | Try running: slabinfo -DA |
414 | |
415 | config DEBUG_KMEMLEAK |
416 | bool "Kernel memory leak detector" |
417 | depends on DEBUG_KERNEL && EXPERIMENTAL && !MEMORY_HOTPLUG && \ |
418 | (X86 || ARM || PPC || MIPS || S390 || SPARC64 || SUPERH || MICROBLAZE || TILE) |
419 | |
420 | select DEBUG_FS |
421 | select STACKTRACE if STACKTRACE_SUPPORT |
422 | select KALLSYMS |
423 | select CRC32 |
424 | help |
425 | Say Y here if you want to enable the memory leak |
426 | detector. The memory allocation/freeing is traced in a way |
427 | similar to the Boehm's conservative garbage collector, the |
428 | difference being that the orphan objects are not freed but |
429 | only shown in /sys/kernel/debug/kmemleak. Enabling this |
430 | feature will introduce an overhead to memory |
431 | allocations. See Documentation/kmemleak.txt for more |
432 | details. |
433 | |
434 | Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances |
435 | of finding leaks due to the slab objects poisoning. |
436 | |
437 | In order to access the kmemleak file, debugfs needs to be |
438 | mounted (usually at /sys/kernel/debug). |
439 | |
440 | config DEBUG_KMEMLEAK_EARLY_LOG_SIZE |
441 | int "Maximum kmemleak early log entries" |
442 | depends on DEBUG_KMEMLEAK |
443 | range 200 40000 |
444 | default 400 |
445 | help |
446 | Kmemleak must track all the memory allocations to avoid |
447 | reporting false positives. Since memory may be allocated or |
448 | freed before kmemleak is initialised, an early log buffer is |
449 | used to store these actions. If kmemleak reports "early log |
450 | buffer exceeded", please increase this value. |
451 | |
452 | config DEBUG_KMEMLEAK_TEST |
453 | tristate "Simple test for the kernel memory leak detector" |
454 | depends on DEBUG_KMEMLEAK && m |
455 | help |
456 | This option enables a module that explicitly leaks memory. |
457 | |
458 | If unsure, say N. |
459 | |
460 | config DEBUG_KMEMLEAK_DEFAULT_OFF |
461 | bool "Default kmemleak to off" |
462 | depends on DEBUG_KMEMLEAK |
463 | help |
464 | Say Y here to disable kmemleak by default. It can then be enabled |
465 | on the command line via kmemleak=on. |
466 | |
467 | config DEBUG_PREEMPT |
468 | bool "Debug preemptible kernel" |
469 | depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT |
470 | default y |
471 | help |
472 | If you say Y here then the kernel will use a debug variant of the |
473 | commonly used smp_processor_id() function and will print warnings |
474 | if kernel code uses it in a preemption-unsafe way. Also, the kernel |
475 | will detect preemption count underflows. |
476 | |
477 | config DEBUG_RT_MUTEXES |
478 | bool "RT Mutex debugging, deadlock detection" |
479 | depends on DEBUG_KERNEL && RT_MUTEXES |
480 | help |
481 | This allows rt mutex semantics violations and rt mutex related |
482 | deadlocks (lockups) to be detected and reported automatically. |
483 | |
484 | config DEBUG_PI_LIST |
485 | bool |
486 | default y |
487 | depends on DEBUG_RT_MUTEXES |
488 | |
489 | config RT_MUTEX_TESTER |
490 | bool "Built-in scriptable tester for rt-mutexes" |
491 | depends on DEBUG_KERNEL && RT_MUTEXES |
492 | help |
493 | This option enables a rt-mutex tester. |
494 | |
495 | config DEBUG_SPINLOCK |
496 | bool "Spinlock and rw-lock debugging: basic checks" |
497 | depends on DEBUG_KERNEL |
498 | help |
499 | Say Y here and build SMP to catch missing spinlock initialization |
500 | and certain other kinds of spinlock errors commonly made. This is |
501 | best used in conjunction with the NMI watchdog so that spinlock |
502 | deadlocks are also debuggable. |
503 | |
504 | config DEBUG_MUTEXES |
505 | bool "Mutex debugging: basic checks" |
506 | depends on DEBUG_KERNEL |
507 | help |
508 | This feature allows mutex semantics violations to be detected and |
509 | reported. |
510 | |
511 | config DEBUG_LOCK_ALLOC |
512 | bool "Lock debugging: detect incorrect freeing of live locks" |
513 | depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT |
514 | select DEBUG_SPINLOCK |
515 | select DEBUG_MUTEXES |
516 | select LOCKDEP |
517 | help |
518 | This feature will check whether any held lock (spinlock, rwlock, |
519 | mutex or rwsem) is incorrectly freed by the kernel, via any of the |
520 | memory-freeing routines (kfree(), kmem_cache_free(), free_pages(), |
521 | vfree(), etc.), whether a live lock is incorrectly reinitialized via |
522 | spin_lock_init()/mutex_init()/etc., or whether there is any lock |
523 | held during task exit. |
524 | |
525 | config PROVE_LOCKING |
526 | bool "Lock debugging: prove locking correctness" |
527 | depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT |
528 | select LOCKDEP |
529 | select DEBUG_SPINLOCK |
530 | select DEBUG_MUTEXES |
531 | select DEBUG_LOCK_ALLOC |
532 | select TRACE_IRQFLAGS |
533 | default n |
534 | help |
535 | This feature enables the kernel to prove that all locking |
536 | that occurs in the kernel runtime is mathematically |
537 | correct: that under no circumstance could an arbitrary (and |
538 | not yet triggered) combination of observed locking |
539 | sequences (on an arbitrary number of CPUs, running an |
540 | arbitrary number of tasks and interrupt contexts) cause a |
541 | deadlock. |
542 | |
543 | In short, this feature enables the kernel to report locking |
544 | related deadlocks before they actually occur. |
545 | |
546 | The proof does not depend on how hard and complex a |
547 | deadlock scenario would be to trigger: how many |
548 | participant CPUs, tasks and irq-contexts would be needed |
549 | for it to trigger. The proof also does not depend on |
550 | timing: if a race and a resulting deadlock is possible |
551 | theoretically (no matter how unlikely the race scenario |
552 | is), it will be proven so and will immediately be |
553 | reported by the kernel (once the event is observed that |
554 | makes the deadlock theoretically possible). |
555 | |
556 | If a deadlock is impossible (i.e. the locking rules, as |
557 | observed by the kernel, are mathematically correct), the |
558 | kernel reports nothing. |
559 | |
560 | NOTE: this feature can also be enabled for rwlocks, mutexes |
561 | and rwsems - in which case all dependencies between these |
562 | different locking variants are observed and mapped too, and |
563 | the proof of observed correctness is also maintained for an |
564 | arbitrary combination of these separate locking variants. |
565 | |
566 | For more details, see Documentation/lockdep-design.txt. |
567 | |
568 | config PROVE_RCU |
569 | bool "RCU debugging: prove RCU correctness" |
570 | depends on PROVE_LOCKING |
571 | default n |
572 | help |
573 | This feature enables lockdep extensions that check for correct |
574 | use of RCU APIs. This is currently under development. Say Y |
575 | if you want to debug RCU usage or help work on the PROVE_RCU |
576 | feature. |
577 | |
578 | Say N if you are unsure. |
579 | |
580 | config PROVE_RCU_REPEATEDLY |
581 | bool "RCU debugging: don't disable PROVE_RCU on first splat" |
582 | depends on PROVE_RCU |
583 | default n |
584 | help |
585 | By itself, PROVE_RCU will disable checking upon issuing the |
586 | first warning (or "splat"). This feature prevents such |
587 | disabling, allowing multiple RCU-lockdep warnings to be printed |
588 | on a single reboot. |
589 | |
590 | Say Y to allow multiple RCU-lockdep warnings per boot. |
591 | |
592 | Say N if you are unsure. |
593 | |
594 | config SPARSE_RCU_POINTER |
595 | bool "RCU debugging: sparse-based checks for pointer usage" |
596 | default n |
597 | help |
598 | This feature enables the __rcu sparse annotation for |
599 | RCU-protected pointers. This annotation will cause sparse |
600 | to flag any non-RCU used of annotated pointers. This can be |
601 | helpful when debugging RCU usage. Please note that this feature |
602 | is not intended to enforce code cleanliness; it is instead merely |
603 | a debugging aid. |
604 | |
605 | Say Y to make sparse flag questionable use of RCU-protected pointers |
606 | |
607 | Say N if you are unsure. |
608 | |
609 | config LOCKDEP |
610 | bool |
611 | depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT |
612 | select STACKTRACE |
613 | select FRAME_POINTER if !MIPS && !PPC && !ARM_UNWIND && !S390 && !MICROBLAZE |
614 | select KALLSYMS |
615 | select KALLSYMS_ALL |
616 | |
617 | config LOCK_STAT |
618 | bool "Lock usage statistics" |
619 | depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT |
620 | select LOCKDEP |
621 | select DEBUG_SPINLOCK |
622 | select DEBUG_MUTEXES |
623 | select DEBUG_LOCK_ALLOC |
624 | default n |
625 | help |
626 | This feature enables tracking lock contention points |
627 | |
628 | For more details, see Documentation/lockstat.txt |
629 | |
630 | This also enables lock events required by "perf lock", |
631 | subcommand of perf. |
632 | If you want to use "perf lock", you also need to turn on |
633 | CONFIG_EVENT_TRACING. |
634 | |
635 | CONFIG_LOCK_STAT defines "contended" and "acquired" lock events. |
636 | (CONFIG_LOCKDEP defines "acquire" and "release" events.) |
637 | |
638 | config DEBUG_LOCKDEP |
639 | bool "Lock dependency engine debugging" |
640 | depends on DEBUG_KERNEL && LOCKDEP |
641 | help |
642 | If you say Y here, the lock dependency engine will do |
643 | additional runtime checks to debug itself, at the price |
644 | of more runtime overhead. |
645 | |
646 | config TRACE_IRQFLAGS |
647 | bool |
648 | help |
649 | Enables hooks to interrupt enabling and disabling for |
650 | either tracing or lock debugging. |
651 | |
652 | config DEBUG_ATOMIC_SLEEP |
653 | bool "Sleep inside atomic section checking" |
654 | select PREEMPT_COUNT |
655 | depends on DEBUG_KERNEL |
656 | help |
657 | If you say Y here, various routines which may sleep will become very |
658 | noisy if they are called inside atomic sections: when a spinlock is |
659 | held, inside an rcu read side critical section, inside preempt disabled |
660 | sections, inside an interrupt, etc... |
661 | |
662 | config DEBUG_LOCKING_API_SELFTESTS |
663 | bool "Locking API boot-time self-tests" |
664 | depends on DEBUG_KERNEL |
665 | help |
666 | Say Y here if you want the kernel to run a short self-test during |
667 | bootup. The self-test checks whether common types of locking bugs |
668 | are detected by debugging mechanisms or not. (if you disable |
669 | lock debugging then those bugs wont be detected of course.) |
670 | The following locking APIs are covered: spinlocks, rwlocks, |
671 | mutexes and rwsems. |
672 | |
673 | config STACKTRACE |
674 | bool |
675 | depends on STACKTRACE_SUPPORT |
676 | |
677 | config DEBUG_STACK_USAGE |
678 | bool "Stack utilization instrumentation" |
679 | depends on DEBUG_KERNEL |
680 | help |
681 | Enables the display of the minimum amount of free stack which each |
682 | task has ever had available in the sysrq-T and sysrq-P debug output. |
683 | |
684 | This option will slow down process creation somewhat. |
685 | |
686 | config DEBUG_KOBJECT |
687 | bool "kobject debugging" |
688 | depends on DEBUG_KERNEL |
689 | help |
690 | If you say Y here, some extra kobject debugging messages will be sent |
691 | to the syslog. |
692 | |
693 | config DEBUG_HIGHMEM |
694 | bool "Highmem debugging" |
695 | depends on DEBUG_KERNEL && HIGHMEM |
696 | help |
697 | This options enables addition error checking for high memory systems. |
698 | Disable for production systems. |
699 | |
700 | config DEBUG_BUGVERBOSE |
701 | bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT |
702 | depends on BUG |
703 | depends on ARM || AVR32 || M32R || M68K || SPARC32 || SPARC64 || \ |
704 | FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300 || TILE |
705 | default y |
706 | help |
707 | Say Y here to make BUG() panics output the file name and line number |
708 | of the BUG call as well as the EIP and oops trace. This aids |
709 | debugging but costs about 70-100K of memory. |
710 | |
711 | config DEBUG_INFO |
712 | bool "Compile the kernel with debug info" |
713 | depends on DEBUG_KERNEL |
714 | help |
715 | If you say Y here the resulting kernel image will include |
716 | debugging info resulting in a larger kernel image. |
717 | This adds debug symbols to the kernel and modules (gcc -g), and |
718 | is needed if you intend to use kernel crashdump or binary object |
719 | tools like crash, kgdb, LKCD, gdb, etc on the kernel. |
720 | Say Y here only if you plan to debug the kernel. |
721 | |
722 | If unsure, say N. |
723 | |
724 | config DEBUG_INFO_REDUCED |
725 | bool "Reduce debugging information" |
726 | depends on DEBUG_INFO |
727 | help |
728 | If you say Y here gcc is instructed to generate less debugging |
729 | information for structure types. This means that tools that |
730 | need full debugging information (like kgdb or systemtap) won't |
731 | be happy. But if you merely need debugging information to |
732 | resolve line numbers there is no loss. Advantage is that |
733 | build directory object sizes shrink dramatically over a full |
734 | DEBUG_INFO build and compile times are reduced too. |
735 | Only works with newer gcc versions. |
736 | |
737 | config DEBUG_VM |
738 | bool "Debug VM" |
739 | depends on DEBUG_KERNEL |
740 | help |
741 | Enable this to turn on extended checks in the virtual-memory system |
742 | that may impact performance. |
743 | |
744 | If unsure, say N. |
745 | |
746 | config DEBUG_VIRTUAL |
747 | bool "Debug VM translations" |
748 | depends on DEBUG_KERNEL && X86 |
749 | help |
750 | Enable some costly sanity checks in virtual to page code. This can |
751 | catch mistakes with virt_to_page() and friends. |
752 | |
753 | If unsure, say N. |
754 | |
755 | config DEBUG_NOMMU_REGIONS |
756 | bool "Debug the global anon/private NOMMU mapping region tree" |
757 | depends on DEBUG_KERNEL && !MMU |
758 | help |
759 | This option causes the global tree of anonymous and private mapping |
760 | regions to be regularly checked for invalid topology. |
761 | |
762 | config DEBUG_WRITECOUNT |
763 | bool "Debug filesystem writers count" |
764 | depends on DEBUG_KERNEL |
765 | help |
766 | Enable this to catch wrong use of the writers count in struct |
767 | vfsmount. This will increase the size of each file struct by |
768 | 32 bits. |
769 | |
770 | If unsure, say N. |
771 | |
772 | config DEBUG_MEMORY_INIT |
773 | bool "Debug memory initialisation" if EXPERT |
774 | default !EXPERT |
775 | help |
776 | Enable this for additional checks during memory initialisation. |
777 | The sanity checks verify aspects of the VM such as the memory model |
778 | and other information provided by the architecture. Verbose |
779 | information will be printed at KERN_DEBUG loglevel depending |
780 | on the mminit_loglevel= command-line option. |
781 | |
782 | If unsure, say Y |
783 | |
784 | config DEBUG_LIST |
785 | bool "Debug linked list manipulation" |
786 | depends on DEBUG_KERNEL |
787 | help |
788 | Enable this to turn on extended checks in the linked-list |
789 | walking routines. |
790 | |
791 | If unsure, say N. |
792 | |
793 | config TEST_LIST_SORT |
794 | bool "Linked list sorting test" |
795 | depends on DEBUG_KERNEL |
796 | help |
797 | Enable this to turn on 'list_sort()' function test. This test is |
798 | executed only once during system boot, so affects only boot time. |
799 | |
800 | If unsure, say N. |
801 | |
802 | config DEBUG_SG |
803 | bool "Debug SG table operations" |
804 | depends on DEBUG_KERNEL |
805 | help |
806 | Enable this to turn on checks on scatter-gather tables. This can |
807 | help find problems with drivers that do not properly initialize |
808 | their sg tables. |
809 | |
810 | If unsure, say N. |
811 | |
812 | config DEBUG_NOTIFIERS |
813 | bool "Debug notifier call chains" |
814 | depends on DEBUG_KERNEL |
815 | help |
816 | Enable this to turn on sanity checking for notifier call chains. |
817 | This is most useful for kernel developers to make sure that |
818 | modules properly unregister themselves from notifier chains. |
819 | This is a relatively cheap check but if you care about maximum |
820 | performance, say N. |
821 | |
822 | config DEBUG_CREDENTIALS |
823 | bool "Debug credential management" |
824 | depends on DEBUG_KERNEL |
825 | help |
826 | Enable this to turn on some debug checking for credential |
827 | management. The additional code keeps track of the number of |
828 | pointers from task_structs to any given cred struct, and checks to |
829 | see that this number never exceeds the usage count of the cred |
830 | struct. |
831 | |
832 | Furthermore, if SELinux is enabled, this also checks that the |
833 | security pointer in the cred struct is never seen to be invalid. |
834 | |
835 | If unsure, say N. |
836 | |
837 | # |
838 | # Select this config option from the architecture Kconfig, if it |
839 | # is preferred to always offer frame pointers as a config |
840 | # option on the architecture (regardless of KERNEL_DEBUG): |
841 | # |
842 | config ARCH_WANT_FRAME_POINTERS |
843 | bool |
844 | help |
845 | |
846 | config FRAME_POINTER |
847 | bool "Compile the kernel with frame pointers" |
848 | depends on DEBUG_KERNEL && \ |
849 | (CRIS || M68K || FRV || UML || \ |
850 | AVR32 || SUPERH || BLACKFIN || MN10300) || \ |
851 | ARCH_WANT_FRAME_POINTERS |
852 | default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS |
853 | help |
854 | If you say Y here the resulting kernel image will be slightly |
855 | larger and slower, but it gives very useful debugging information |
856 | in case of kernel bugs. (precise oopses/stacktraces/warnings) |
857 | |
858 | config BOOT_PRINTK_DELAY |
859 | bool "Delay each boot printk message by N milliseconds" |
860 | depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY |
861 | help |
862 | This build option allows you to read kernel boot messages |
863 | by inserting a short delay after each one. The delay is |
864 | specified in milliseconds on the kernel command line, |
865 | using "boot_delay=N". |
866 | |
867 | It is likely that you would also need to use "lpj=M" to preset |
868 | the "loops per jiffie" value. |
869 | See a previous boot log for the "lpj" value to use for your |
870 | system, and then set "lpj=M" before setting "boot_delay=N". |
871 | NOTE: Using this option may adversely affect SMP systems. |
872 | I.e., processors other than the first one may not boot up. |
873 | BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect |
874 | what it believes to be lockup conditions. |
875 | |
876 | config RCU_TORTURE_TEST |
877 | tristate "torture tests for RCU" |
878 | depends on DEBUG_KERNEL |
879 | default n |
880 | help |
881 | This option provides a kernel module that runs torture tests |
882 | on the RCU infrastructure. The kernel module may be built |
883 | after the fact on the running kernel to be tested, if desired. |
884 | |
885 | Say Y here if you want RCU torture tests to be built into |
886 | the kernel. |
887 | Say M if you want the RCU torture tests to build as a module. |
888 | Say N if you are unsure. |
889 | |
890 | config RCU_TORTURE_TEST_RUNNABLE |
891 | bool "torture tests for RCU runnable by default" |
892 | depends on RCU_TORTURE_TEST = y |
893 | default n |
894 | help |
895 | This option provides a way to build the RCU torture tests |
896 | directly into the kernel without them starting up at boot |
897 | time. You can use /proc/sys/kernel/rcutorture_runnable |
898 | to manually override this setting. This /proc file is |
899 | available only when the RCU torture tests have been built |
900 | into the kernel. |
901 | |
902 | Say Y here if you want the RCU torture tests to start during |
903 | boot (you probably don't). |
904 | Say N here if you want the RCU torture tests to start only |
905 | after being manually enabled via /proc. |
906 | |
907 | config RCU_CPU_STALL_TIMEOUT |
908 | int "RCU CPU stall timeout in seconds" |
909 | depends on TREE_RCU || TREE_PREEMPT_RCU |
910 | range 3 300 |
911 | default 60 |
912 | help |
913 | If a given RCU grace period extends more than the specified |
914 | number of seconds, a CPU stall warning is printed. If the |
915 | RCU grace period persists, additional CPU stall warnings are |
916 | printed at more widely spaced intervals. |
917 | |
918 | config RCU_CPU_STALL_VERBOSE |
919 | bool "Print additional per-task information for RCU_CPU_STALL_DETECTOR" |
920 | depends on TREE_PREEMPT_RCU |
921 | default y |
922 | help |
923 | This option causes RCU to printk detailed per-task information |
924 | for any tasks that are stalling the current RCU grace period. |
925 | |
926 | Say N if you are unsure. |
927 | |
928 | Say Y if you want to enable such checks. |
929 | |
930 | config KPROBES_SANITY_TEST |
931 | bool "Kprobes sanity tests" |
932 | depends on DEBUG_KERNEL |
933 | depends on KPROBES |
934 | default n |
935 | help |
936 | This option provides for testing basic kprobes functionality on |
937 | boot. A sample kprobe, jprobe and kretprobe are inserted and |
938 | verified for functionality. |
939 | |
940 | Say N if you are unsure. |
941 | |
942 | config BACKTRACE_SELF_TEST |
943 | tristate "Self test for the backtrace code" |
944 | depends on DEBUG_KERNEL |
945 | default n |
946 | help |
947 | This option provides a kernel module that can be used to test |
948 | the kernel stack backtrace code. This option is not useful |
949 | for distributions or general kernels, but only for kernel |
950 | developers working on architecture code. |
951 | |
952 | Note that if you want to also test saved backtraces, you will |
953 | have to enable STACKTRACE as well. |
954 | |
955 | Say N if you are unsure. |
956 | |
957 | config DEBUG_BLOCK_EXT_DEVT |
958 | bool "Force extended block device numbers and spread them" |
959 | depends on DEBUG_KERNEL |
960 | depends on BLOCK |
961 | default n |
962 | help |
963 | BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON |
964 | SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT |
965 | YOU ARE DOING. Distros, please enable this and fix whatever |
966 | is broken. |
967 | |
968 | Conventionally, block device numbers are allocated from |
969 | predetermined contiguous area. However, extended block area |
970 | may introduce non-contiguous block device numbers. This |
971 | option forces most block device numbers to be allocated from |
972 | the extended space and spreads them to discover kernel or |
973 | userland code paths which assume predetermined contiguous |
974 | device number allocation. |
975 | |
976 | Note that turning on this debug option shuffles all the |
977 | device numbers for all IDE and SCSI devices including libata |
978 | ones, so root partition specified using device number |
979 | directly (via rdev or root=MAJ:MIN) won't work anymore. |
980 | Textual device names (root=/dev/sdXn) will continue to work. |
981 | |
982 | Say N if you are unsure. |
983 | |
984 | config DEBUG_FORCE_WEAK_PER_CPU |
985 | bool "Force weak per-cpu definitions" |
986 | depends on DEBUG_KERNEL |
987 | help |
988 | s390 and alpha require percpu variables in modules to be |
989 | defined weak to work around addressing range issue which |
990 | puts the following two restrictions on percpu variable |
991 | definitions. |
992 | |
993 | 1. percpu symbols must be unique whether static or not |
994 | 2. percpu variables can't be defined inside a function |
995 | |
996 | To ensure that generic code follows the above rules, this |
997 | option forces all percpu variables to be defined as weak. |
998 | |
999 | config DEBUG_PER_CPU_MAPS |
1000 | bool "Debug access to per_cpu maps" |
1001 | depends on DEBUG_KERNEL |
1002 | depends on SMP |
1003 | help |
1004 | Say Y to verify that the per_cpu map being accessed has |
1005 | been set up. This adds a fair amount of code to kernel memory |
1006 | and decreases performance. |
1007 | |
1008 | Say N if unsure. |
1009 | |
1010 | config LKDTM |
1011 | tristate "Linux Kernel Dump Test Tool Module" |
1012 | depends on DEBUG_FS |
1013 | depends on BLOCK |
1014 | default n |
1015 | help |
1016 | This module enables testing of the different dumping mechanisms by |
1017 | inducing system failures at predefined crash points. |
1018 | If you don't need it: say N |
1019 | Choose M here to compile this code as a module. The module will be |
1020 | called lkdtm. |
1021 | |
1022 | Documentation on how to use the module can be found in |
1023 | Documentation/fault-injection/provoke-crashes.txt |
1024 | |
1025 | config CPU_NOTIFIER_ERROR_INJECT |
1026 | tristate "CPU notifier error injection module" |
1027 | depends on HOTPLUG_CPU && DEBUG_KERNEL |
1028 | help |
1029 | This option provides a kernel module that can be used to test |
1030 | the error handling of the cpu notifiers |
1031 | |
1032 | To compile this code as a module, choose M here: the module will |
1033 | be called cpu-notifier-error-inject. |
1034 | |
1035 | If unsure, say N. |
1036 | |
1037 | config FAULT_INJECTION |
1038 | bool "Fault-injection framework" |
1039 | depends on DEBUG_KERNEL |
1040 | help |
1041 | Provide fault-injection framework. |
1042 | For more details, see Documentation/fault-injection/. |
1043 | |
1044 | config FAILSLAB |
1045 | bool "Fault-injection capability for kmalloc" |
1046 | depends on FAULT_INJECTION |
1047 | depends on SLAB || SLUB |
1048 | help |
1049 | Provide fault-injection capability for kmalloc. |
1050 | |
1051 | config FAIL_PAGE_ALLOC |
1052 | bool "Fault-injection capabilitiy for alloc_pages()" |
1053 | depends on FAULT_INJECTION |
1054 | help |
1055 | Provide fault-injection capability for alloc_pages(). |
1056 | |
1057 | config FAIL_MAKE_REQUEST |
1058 | bool "Fault-injection capability for disk IO" |
1059 | depends on FAULT_INJECTION && BLOCK |
1060 | help |
1061 | Provide fault-injection capability for disk IO. |
1062 | |
1063 | config FAIL_IO_TIMEOUT |
1064 | bool "Fault-injection capability for faking disk interrupts" |
1065 | depends on FAULT_INJECTION && BLOCK |
1066 | help |
1067 | Provide fault-injection capability on end IO handling. This |
1068 | will make the block layer "forget" an interrupt as configured, |
1069 | thus exercising the error handling. |
1070 | |
1071 | Only works with drivers that use the generic timeout handling, |
1072 | for others it wont do anything. |
1073 | |
1074 | config FAIL_MMC_REQUEST |
1075 | bool "Fault-injection capability for MMC IO" |
1076 | select DEBUG_FS |
1077 | depends on FAULT_INJECTION && MMC |
1078 | help |
1079 | Provide fault-injection capability for MMC IO. |
1080 | This will make the mmc core return data errors. This is |
1081 | useful to test the error handling in the mmc block device |
1082 | and to test how the mmc host driver handles retries from |
1083 | the block device. |
1084 | |
1085 | config FAULT_INJECTION_DEBUG_FS |
1086 | bool "Debugfs entries for fault-injection capabilities" |
1087 | depends on FAULT_INJECTION && SYSFS && DEBUG_FS |
1088 | help |
1089 | Enable configuration of fault-injection capabilities via debugfs. |
1090 | |
1091 | config FAULT_INJECTION_STACKTRACE_FILTER |
1092 | bool "stacktrace filter for fault-injection capabilities" |
1093 | depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT |
1094 | depends on !X86_64 |
1095 | select STACKTRACE |
1096 | select FRAME_POINTER if !PPC && !S390 && !MICROBLAZE && !ARM_UNWIND |
1097 | help |
1098 | Provide stacktrace filter for fault-injection capabilities |
1099 | |
1100 | config LATENCYTOP |
1101 | bool "Latency measuring infrastructure" |
1102 | depends on HAVE_LATENCYTOP_SUPPORT |
1103 | depends on DEBUG_KERNEL |
1104 | depends on STACKTRACE_SUPPORT |
1105 | depends on PROC_FS |
1106 | select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM_UNWIND |
1107 | select KALLSYMS |
1108 | select KALLSYMS_ALL |
1109 | select STACKTRACE |
1110 | select SCHEDSTATS |
1111 | select SCHED_DEBUG |
1112 | help |
1113 | Enable this option if you want to use the LatencyTOP tool |
1114 | to find out which userspace is blocking on what kernel operations. |
1115 | |
1116 | config SYSCTL_SYSCALL_CHECK |
1117 | bool "Sysctl checks" |
1118 | depends on SYSCTL |
1119 | ---help--- |
1120 | sys_sysctl uses binary paths that have been found challenging |
1121 | to properly maintain and use. This enables checks that help |
1122 | you to keep things correct. |
1123 | |
1124 | source mm/Kconfig.debug |
1125 | source kernel/trace/Kconfig |
1126 | |
1127 | config PROVIDE_OHCI1394_DMA_INIT |
1128 | bool "Remote debugging over FireWire early on boot" |
1129 | depends on PCI && X86 |
1130 | help |
1131 | If you want to debug problems which hang or crash the kernel early |
1132 | on boot and the crashing machine has a FireWire port, you can use |
1133 | this feature to remotely access the memory of the crashed machine |
1134 | over FireWire. This employs remote DMA as part of the OHCI1394 |
1135 | specification which is now the standard for FireWire controllers. |
1136 | |
1137 | With remote DMA, you can monitor the printk buffer remotely using |
1138 | firescope and access all memory below 4GB using fireproxy from gdb. |
1139 | Even controlling a kernel debugger is possible using remote DMA. |
1140 | |
1141 | Usage: |
1142 | |
1143 | If ohci1394_dma=early is used as boot parameter, it will initialize |
1144 | all OHCI1394 controllers which are found in the PCI config space. |
1145 | |
1146 | As all changes to the FireWire bus such as enabling and disabling |
1147 | devices cause a bus reset and thereby disable remote DMA for all |
1148 | devices, be sure to have the cable plugged and FireWire enabled on |
1149 | the debugging host before booting the debug target for debugging. |
1150 | |
1151 | This code (~1k) is freed after boot. By then, the firewire stack |
1152 | in charge of the OHCI-1394 controllers should be used instead. |
1153 | |
1154 | See Documentation/debugging-via-ohci1394.txt for more information. |
1155 | |
1156 | config FIREWIRE_OHCI_REMOTE_DMA |
1157 | bool "Remote debugging over FireWire with firewire-ohci" |
1158 | depends on FIREWIRE_OHCI |
1159 | help |
1160 | This option lets you use the FireWire bus for remote debugging |
1161 | with help of the firewire-ohci driver. It enables unfiltered |
1162 | remote DMA in firewire-ohci. |
1163 | See Documentation/debugging-via-ohci1394.txt for more information. |
1164 | |
1165 | If unsure, say N. |
1166 | |
1167 | config BUILD_DOCSRC |
1168 | bool "Build targets in Documentation/ tree" |
1169 | depends on HEADERS_CHECK |
1170 | help |
1171 | This option attempts to build objects from the source files in the |
1172 | kernel Documentation/ tree. |
1173 | |
1174 | Say N if you are unsure. |
1175 | |
1176 | config DYNAMIC_DEBUG |
1177 | bool "Enable dynamic printk() support" |
1178 | default n |
1179 | depends on PRINTK |
1180 | depends on DEBUG_FS |
1181 | help |
1182 | |
1183 | Compiles debug level messages into the kernel, which would not |
1184 | otherwise be available at runtime. These messages can then be |
1185 | enabled/disabled based on various levels of scope - per source file, |
1186 | function, module, format string, and line number. This mechanism |
1187 | implicitly enables all pr_debug() and dev_dbg() calls. The impact of |
1188 | this compile option is a larger kernel text size of about 2%. |
1189 | |
1190 | Usage: |
1191 | |
1192 | Dynamic debugging is controlled via the 'dynamic_debug/control' file, |
1193 | which is contained in the 'debugfs' filesystem. Thus, the debugfs |
1194 | filesystem must first be mounted before making use of this feature. |
1195 | We refer the control file as: <debugfs>/dynamic_debug/control. This |
1196 | file contains a list of the debug statements that can be enabled. The |
1197 | format for each line of the file is: |
1198 | |
1199 | filename:lineno [module]function flags format |
1200 | |
1201 | filename : source file of the debug statement |
1202 | lineno : line number of the debug statement |
1203 | module : module that contains the debug statement |
1204 | function : function that contains the debug statement |
1205 | flags : 'p' means the line is turned 'on' for printing |
1206 | format : the format used for the debug statement |
1207 | |
1208 | From a live system: |
1209 | |
1210 | nullarbor:~ # cat <debugfs>/dynamic_debug/control |
1211 | # filename:lineno [module]function flags format |
1212 | fs/aio.c:222 [aio]__put_ioctx - "__put_ioctx:\040freeing\040%p\012" |
1213 | fs/aio.c:248 [aio]ioctx_alloc - "ENOMEM:\040nr_events\040too\040high\012" |
1214 | fs/aio.c:1770 [aio]sys_io_cancel - "calling\040cancel\012" |
1215 | |
1216 | Example usage: |
1217 | |
1218 | // enable the message at line 1603 of file svcsock.c |
1219 | nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' > |
1220 | <debugfs>/dynamic_debug/control |
1221 | |
1222 | // enable all the messages in file svcsock.c |
1223 | nullarbor:~ # echo -n 'file svcsock.c +p' > |
1224 | <debugfs>/dynamic_debug/control |
1225 | |
1226 | // enable all the messages in the NFS server module |
1227 | nullarbor:~ # echo -n 'module nfsd +p' > |
1228 | <debugfs>/dynamic_debug/control |
1229 | |
1230 | // enable all 12 messages in the function svc_process() |
1231 | nullarbor:~ # echo -n 'func svc_process +p' > |
1232 | <debugfs>/dynamic_debug/control |
1233 | |
1234 | // disable all 12 messages in the function svc_process() |
1235 | nullarbor:~ # echo -n 'func svc_process -p' > |
1236 | <debugfs>/dynamic_debug/control |
1237 | |
1238 | See Documentation/dynamic-debug-howto.txt for additional information. |
1239 | |
1240 | config DMA_API_DEBUG |
1241 | bool "Enable debugging of DMA-API usage" |
1242 | depends on HAVE_DMA_API_DEBUG |
1243 | help |
1244 | Enable this option to debug the use of the DMA API by device drivers. |
1245 | With this option you will be able to detect common bugs in device |
1246 | drivers like double-freeing of DMA mappings or freeing mappings that |
1247 | were never allocated. |
1248 | This option causes a performance degredation. Use only if you want |
1249 | to debug device drivers. If unsure, say N. |
1250 | |
1251 | config ATOMIC64_SELFTEST |
1252 | bool "Perform an atomic64_t self-test at boot" |
1253 | help |
1254 | Enable this option to test the atomic64_t functions at boot. |
1255 | |
1256 | If unsure, say N. |
1257 | |
1258 | config ASYNC_RAID6_TEST |
1259 | tristate "Self test for hardware accelerated raid6 recovery" |
1260 | depends on ASYNC_RAID6_RECOV |
1261 | select ASYNC_MEMCPY |
1262 | ---help--- |
1263 | This is a one-shot self test that permutes through the |
1264 | recovery of all the possible two disk failure scenarios for a |
1265 | N-disk array. Recovery is performed with the asynchronous |
1266 | raid6 recovery routines, and will optionally use an offload |
1267 | engine if one is available. |
1268 | |
1269 | If unsure, say N. |
1270 | |
1271 | source "samples/Kconfig" |
1272 | |
1273 | source "lib/Kconfig.kgdb" |
1274 | |
1275 | source "lib/Kconfig.kmemcheck" |
1276 | |
1277 | config TEST_KSTRTOX |
1278 | tristate "Test kstrto*() family of functions at runtime" |
1279 |
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Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
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