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 | Linux will during link or during runtime drop some sections |
121 | and any use of code/data previously in these sections will |
122 | most likely result in an oops. |
123 | In the code functions and variables are annotated with |
124 | __init, __devinit etc. (see 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 done after a full |
127 | kernel build but enabling this option will in addition |
128 | do the following: |
129 | - Add the option -fno-inline-functions-called-once to gcc |
130 | When inlining a function annotated __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 will also |
134 | result in a larger kernel. |
135 | - Run the section mismatch analysis for each module/built-in.o |
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 | will tell where the mismatch happens much closer to the |
141 | source. The drawback is that we will report the same |
142 | mismatch at least twice. |
143 | - Enable verbose reporting from modpost to help solving |
144 | the section mismatches 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 DETECT_SOFTLOCKUP |
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 |
252 | sysctl or by writing a value to /proc/sys/kernel/hung_task_timeout. |
253 | |
254 | A timeout of 0 disables the check. The default is two minutes. |
255 | Keeping the default should be fine in most cases. |
256 | |
257 | config BOOTPARAM_HUNG_TASK_PANIC |
258 | bool "Panic (Reboot) On Hung Tasks" |
259 | depends on DETECT_HUNG_TASK |
260 | help |
261 | Say Y here to enable the kernel to panic on "hung tasks", |
262 | which are bugs that cause the kernel to leave a task stuck |
263 | in uninterruptible "D" state. |
264 | |
265 | The panic can be used in combination with panic_timeout, |
266 | to cause the system to reboot automatically after a |
267 | hung task has been detected. This feature is useful for |
268 | high-availability systems that have uptime guarantees and |
269 | where a hung tasks must be resolved ASAP. |
270 | |
271 | Say N if unsure. |
272 | |
273 | config BOOTPARAM_HUNG_TASK_PANIC_VALUE |
274 | int |
275 | depends on DETECT_HUNG_TASK |
276 | range 0 1 |
277 | default 0 if !BOOTPARAM_HUNG_TASK_PANIC |
278 | default 1 if BOOTPARAM_HUNG_TASK_PANIC |
279 | |
280 | config SCHED_DEBUG |
281 | bool "Collect scheduler debugging info" |
282 | depends on DEBUG_KERNEL && PROC_FS |
283 | default y |
284 | help |
285 | If you say Y here, the /proc/sched_debug file will be provided |
286 | that can help debug the scheduler. The runtime overhead of this |
287 | option is minimal. |
288 | |
289 | config SCHEDSTATS |
290 | bool "Collect scheduler statistics" |
291 | depends on DEBUG_KERNEL && PROC_FS |
292 | help |
293 | If you say Y here, additional code will be inserted into the |
294 | scheduler and related routines to collect statistics about |
295 | scheduler behavior and provide them in /proc/schedstat. These |
296 | stats may be useful for both tuning and debugging the scheduler |
297 | If you aren't debugging the scheduler or trying to tune a specific |
298 | application, you can say N to avoid the very slight overhead |
299 | this adds. |
300 | |
301 | config TIMER_STATS |
302 | bool "Collect kernel timers statistics" |
303 | depends on DEBUG_KERNEL && PROC_FS |
304 | help |
305 | If you say Y here, additional code will be inserted into the |
306 | timer routines to collect statistics about kernel timers being |
307 | reprogrammed. The statistics can be read from /proc/timer_stats. |
308 | The statistics collection is started by writing 1 to /proc/timer_stats, |
309 | writing 0 stops it. This feature is useful to collect information |
310 | about timer usage patterns in kernel and userspace. This feature |
311 | is lightweight if enabled in the kernel config but not activated |
312 | (it defaults to deactivated on bootup and will only be activated |
313 | if some application like powertop activates it explicitly). |
314 | |
315 | config DEBUG_OBJECTS |
316 | bool "Debug object operations" |
317 | depends on DEBUG_KERNEL |
318 | help |
319 | If you say Y here, additional code will be inserted into the |
320 | kernel to track the life time of various objects and validate |
321 | the operations on those objects. |
322 | |
323 | config DEBUG_OBJECTS_SELFTEST |
324 | bool "Debug objects selftest" |
325 | depends on DEBUG_OBJECTS |
326 | help |
327 | This enables the selftest of the object debug code. |
328 | |
329 | config DEBUG_OBJECTS_FREE |
330 | bool "Debug objects in freed memory" |
331 | depends on DEBUG_OBJECTS |
332 | help |
333 | This enables checks whether a k/v free operation frees an area |
334 | which contains an object which has not been deactivated |
335 | properly. This can make kmalloc/kfree-intensive workloads |
336 | much slower. |
337 | |
338 | config DEBUG_OBJECTS_TIMERS |
339 | bool "Debug timer objects" |
340 | depends on DEBUG_OBJECTS |
341 | help |
342 | If you say Y here, additional code will be inserted into the |
343 | timer routines to track the life time of timer objects and |
344 | validate the timer operations. |
345 | |
346 | config DEBUG_OBJECTS_WORK |
347 | bool "Debug work objects" |
348 | depends on DEBUG_OBJECTS |
349 | help |
350 | If you say Y here, additional code will be inserted into the |
351 | work queue routines to track the life time of work objects and |
352 | validate the work operations. |
353 | |
354 | config DEBUG_OBJECTS_RCU_HEAD |
355 | bool "Debug RCU callbacks objects" |
356 | depends on DEBUG_OBJECTS |
357 | help |
358 | Enable this to turn on debugging of RCU list heads (call_rcu() usage). |
359 | |
360 | config DEBUG_OBJECTS_PERCPU_COUNTER |
361 | bool "Debug percpu counter objects" |
362 | depends on DEBUG_OBJECTS |
363 | help |
364 | If you say Y here, additional code will be inserted into the |
365 | percpu counter routines to track the life time of percpu counter |
366 | objects and validate the percpu counter operations. |
367 | |
368 | config DEBUG_OBJECTS_ENABLE_DEFAULT |
369 | int "debug_objects bootup default value (0-1)" |
370 | range 0 1 |
371 | default "1" |
372 | depends on DEBUG_OBJECTS |
373 | help |
374 | Debug objects boot parameter default value |
375 | |
376 | config DEBUG_SLAB |
377 | bool "Debug slab memory allocations" |
378 | depends on DEBUG_KERNEL && SLAB && !KMEMCHECK |
379 | help |
380 | Say Y here to have the kernel do limited verification on memory |
381 | allocation as well as poisoning memory on free to catch use of freed |
382 | memory. This can make kmalloc/kfree-intensive workloads much slower. |
383 | |
384 | config DEBUG_SLAB_LEAK |
385 | bool "Memory leak debugging" |
386 | depends on DEBUG_SLAB |
387 | |
388 | config SLUB_DEBUG_ON |
389 | bool "SLUB debugging on by default" |
390 | depends on SLUB && SLUB_DEBUG && !KMEMCHECK |
391 | default n |
392 | help |
393 | Boot with debugging on by default. SLUB boots by default with |
394 | the runtime debug capabilities switched off. Enabling this is |
395 | equivalent to specifying the "slub_debug" parameter on boot. |
396 | There is no support for more fine grained debug control like |
397 | possible with slub_debug=xxx. SLUB debugging may be switched |
398 | off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying |
399 | "slub_debug=-". |
400 | |
401 | config SLUB_STATS |
402 | default n |
403 | bool "Enable SLUB performance statistics" |
404 | depends on SLUB && SYSFS |
405 | help |
406 | SLUB statistics are useful to debug SLUBs allocation behavior in |
407 | order find ways to optimize the allocator. This should never be |
408 | enabled for production use since keeping statistics slows down |
409 | the allocator by a few percentage points. The slabinfo command |
410 | supports the determination of the most active slabs to figure |
411 | out which slabs are relevant to a particular load. |
412 | Try running: slabinfo -DA |
413 | |
414 | config DEBUG_KMEMLEAK |
415 | bool "Kernel memory leak detector" |
416 | depends on DEBUG_KERNEL && EXPERIMENTAL && !MEMORY_HOTPLUG && \ |
417 | (X86 || ARM || PPC || MIPS || S390 || SPARC64 || SUPERH || MICROBLAZE || TILE) |
418 | |
419 | select DEBUG_FS |
420 | select STACKTRACE if STACKTRACE_SUPPORT |
421 | select KALLSYMS |
422 | select CRC32 |
423 | help |
424 | Say Y here if you want to enable the memory leak |
425 | detector. The memory allocation/freeing is traced in a way |
426 | similar to the Boehm's conservative garbage collector, the |
427 | difference being that the orphan objects are not freed but |
428 | only shown in /sys/kernel/debug/kmemleak. Enabling this |
429 | feature will introduce an overhead to memory |
430 | allocations. See Documentation/kmemleak.txt for more |
431 | details. |
432 | |
433 | Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances |
434 | of finding leaks due to the slab objects poisoning. |
435 | |
436 | In order to access the kmemleak file, debugfs needs to be |
437 | mounted (usually at /sys/kernel/debug). |
438 | |
439 | config DEBUG_KMEMLEAK_EARLY_LOG_SIZE |
440 | int "Maximum kmemleak early log entries" |
441 | depends on DEBUG_KMEMLEAK |
442 | range 200 40000 |
443 | default 400 |
444 | help |
445 | Kmemleak must track all the memory allocations to avoid |
446 | reporting false positives. Since memory may be allocated or |
447 | freed before kmemleak is initialised, an early log buffer is |
448 | used to store these actions. If kmemleak reports "early log |
449 | buffer exceeded", please increase this value. |
450 | |
451 | config DEBUG_KMEMLEAK_TEST |
452 | tristate "Simple test for the kernel memory leak detector" |
453 | depends on DEBUG_KMEMLEAK && m |
454 | help |
455 | This option enables a module that explicitly leaks memory. |
456 | |
457 | If unsure, say N. |
458 | |
459 | config DEBUG_KMEMLEAK_DEFAULT_OFF |
460 | bool "Default kmemleak to off" |
461 | depends on DEBUG_KMEMLEAK |
462 | help |
463 | Say Y here to disable kmemleak by default. It can then be enabled |
464 | on the command line via kmemleak=on. |
465 | |
466 | config DEBUG_PREEMPT |
467 | bool "Debug preemptible kernel" |
468 | depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT |
469 | default y |
470 | help |
471 | If you say Y here then the kernel will use a debug variant of the |
472 | commonly used smp_processor_id() function and will print warnings |
473 | if kernel code uses it in a preemption-unsafe way. Also, the kernel |
474 | will detect preemption count underflows. |
475 | |
476 | config DEBUG_RT_MUTEXES |
477 | bool "RT Mutex debugging, deadlock detection" |
478 | depends on DEBUG_KERNEL && RT_MUTEXES |
479 | help |
480 | This allows rt mutex semantics violations and rt mutex related |
481 | deadlocks (lockups) to be detected and reported automatically. |
482 | |
483 | config DEBUG_PI_LIST |
484 | bool |
485 | default y |
486 | depends on DEBUG_RT_MUTEXES |
487 | |
488 | config RT_MUTEX_TESTER |
489 | bool "Built-in scriptable tester for rt-mutexes" |
490 | depends on DEBUG_KERNEL && RT_MUTEXES |
491 | help |
492 | This option enables a rt-mutex tester. |
493 | |
494 | config DEBUG_SPINLOCK |
495 | bool "Spinlock and rw-lock debugging: basic checks" |
496 | depends on DEBUG_KERNEL |
497 | help |
498 | Say Y here and build SMP to catch missing spinlock initialization |
499 | and certain other kinds of spinlock errors commonly made. This is |
500 | best used in conjunction with the NMI watchdog so that spinlock |
501 | deadlocks are also debuggable. |
502 | |
503 | config DEBUG_MUTEXES |
504 | bool "Mutex debugging: basic checks" |
505 | depends on DEBUG_KERNEL |
506 | help |
507 | This feature allows mutex semantics violations to be detected and |
508 | reported. |
509 | |
510 | config DEBUG_LOCK_ALLOC |
511 | bool "Lock debugging: detect incorrect freeing of live locks" |
512 | depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT |
513 | select DEBUG_SPINLOCK |
514 | select DEBUG_MUTEXES |
515 | select LOCKDEP |
516 | help |
517 | This feature will check whether any held lock (spinlock, rwlock, |
518 | mutex or rwsem) is incorrectly freed by the kernel, via any of the |
519 | memory-freeing routines (kfree(), kmem_cache_free(), free_pages(), |
520 | vfree(), etc.), whether a live lock is incorrectly reinitialized via |
521 | spin_lock_init()/mutex_init()/etc., or whether there is any lock |
522 | held during task exit. |
523 | |
524 | config PROVE_LOCKING |
525 | bool "Lock debugging: prove locking correctness" |
526 | depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT |
527 | select LOCKDEP |
528 | select DEBUG_SPINLOCK |
529 | select DEBUG_MUTEXES |
530 | select DEBUG_LOCK_ALLOC |
531 | select TRACE_IRQFLAGS |
532 | default n |
533 | help |
534 | This feature enables the kernel to prove that all locking |
535 | that occurs in the kernel runtime is mathematically |
536 | correct: that under no circumstance could an arbitrary (and |
537 | not yet triggered) combination of observed locking |
538 | sequences (on an arbitrary number of CPUs, running an |
539 | arbitrary number of tasks and interrupt contexts) cause a |
540 | deadlock. |
541 | |
542 | In short, this feature enables the kernel to report locking |
543 | related deadlocks before they actually occur. |
544 | |
545 | The proof does not depend on how hard and complex a |
546 | deadlock scenario would be to trigger: how many |
547 | participant CPUs, tasks and irq-contexts would be needed |
548 | for it to trigger. The proof also does not depend on |
549 | timing: if a race and a resulting deadlock is possible |
550 | theoretically (no matter how unlikely the race scenario |
551 | is), it will be proven so and will immediately be |
552 | reported by the kernel (once the event is observed that |
553 | makes the deadlock theoretically possible). |
554 | |
555 | If a deadlock is impossible (i.e. the locking rules, as |
556 | observed by the kernel, are mathematically correct), the |
557 | kernel reports nothing. |
558 | |
559 | NOTE: this feature can also be enabled for rwlocks, mutexes |
560 | and rwsems - in which case all dependencies between these |
561 | different locking variants are observed and mapped too, and |
562 | the proof of observed correctness is also maintained for an |
563 | arbitrary combination of these separate locking variants. |
564 | |
565 | For more details, see Documentation/lockdep-design.txt. |
566 | |
567 | config PROVE_RCU |
568 | bool "RCU debugging: prove RCU correctness" |
569 | depends on PROVE_LOCKING |
570 | default n |
571 | help |
572 | This feature enables lockdep extensions that check for correct |
573 | use of RCU APIs. This is currently under development. Say Y |
574 | if you want to debug RCU usage or help work on the PROVE_RCU |
575 | feature. |
576 | |
577 | Say N if you are unsure. |
578 | |
579 | config PROVE_RCU_REPEATEDLY |
580 | bool "RCU debugging: don't disable PROVE_RCU on first splat" |
581 | depends on PROVE_RCU |
582 | default n |
583 | help |
584 | By itself, PROVE_RCU will disable checking upon issuing the |
585 | first warning (or "splat"). This feature prevents such |
586 | disabling, allowing multiple RCU-lockdep warnings to be printed |
587 | on a single reboot. |
588 | |
589 | Say Y to allow multiple RCU-lockdep warnings per boot. |
590 | |
591 | Say N if you are unsure. |
592 | |
593 | config SPARSE_RCU_POINTER |
594 | bool "RCU debugging: sparse-based checks for pointer usage" |
595 | default n |
596 | help |
597 | This feature enables the __rcu sparse annotation for |
598 | RCU-protected pointers. This annotation will cause sparse |
599 | to flag any non-RCU used of annotated pointers. This can be |
600 | helpful when debugging RCU usage. Please note that this feature |
601 | is not intended to enforce code cleanliness; it is instead merely |
602 | a debugging aid. |
603 | |
604 | Say Y to make sparse flag questionable use of RCU-protected pointers |
605 | |
606 | Say N if you are unsure. |
607 | |
608 | config LOCKDEP |
609 | bool |
610 | depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT |
611 | select STACKTRACE |
612 | select FRAME_POINTER if !MIPS && !PPC && !ARM_UNWIND && !S390 && !MICROBLAZE |
613 | select KALLSYMS |
614 | select KALLSYMS_ALL |
615 | |
616 | config LOCK_STAT |
617 | bool "Lock usage statistics" |
618 | depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT |
619 | select LOCKDEP |
620 | select DEBUG_SPINLOCK |
621 | select DEBUG_MUTEXES |
622 | select DEBUG_LOCK_ALLOC |
623 | default n |
624 | help |
625 | This feature enables tracking lock contention points |
626 | |
627 | For more details, see Documentation/lockstat.txt |
628 | |
629 | This also enables lock events required by "perf lock", |
630 | subcommand of perf. |
631 | If you want to use "perf lock", you also need to turn on |
632 | CONFIG_EVENT_TRACING. |
633 | |
634 | CONFIG_LOCK_STAT defines "contended" and "acquired" lock events. |
635 | (CONFIG_LOCKDEP defines "acquire" and "release" events.) |
636 | |
637 | config DEBUG_LOCKDEP |
638 | bool "Lock dependency engine debugging" |
639 | depends on DEBUG_KERNEL && LOCKDEP |
640 | help |
641 | If you say Y here, the lock dependency engine will do |
642 | additional runtime checks to debug itself, at the price |
643 | of more runtime overhead. |
644 | |
645 | config TRACE_IRQFLAGS |
646 | bool |
647 | help |
648 | Enables hooks to interrupt enabling and disabling for |
649 | either tracing or lock debugging. |
650 | |
651 | config DEBUG_SPINLOCK_SLEEP |
652 | bool "Spinlock debugging: sleep-inside-spinlock checking" |
653 | depends on DEBUG_KERNEL |
654 | help |
655 | If you say Y here, various routines which may sleep will become very |
656 | noisy if they are called with a spinlock held. |
657 | |
658 | config DEBUG_LOCKING_API_SELFTESTS |
659 | bool "Locking API boot-time self-tests" |
660 | depends on DEBUG_KERNEL |
661 | help |
662 | Say Y here if you want the kernel to run a short self-test during |
663 | bootup. The self-test checks whether common types of locking bugs |
664 | are detected by debugging mechanisms or not. (if you disable |
665 | lock debugging then those bugs wont be detected of course.) |
666 | The following locking APIs are covered: spinlocks, rwlocks, |
667 | mutexes and rwsems. |
668 | |
669 | config STACKTRACE |
670 | bool |
671 | depends on STACKTRACE_SUPPORT |
672 | |
673 | config DEBUG_STACK_USAGE |
674 | bool "Stack utilization instrumentation" |
675 | depends on DEBUG_KERNEL |
676 | help |
677 | Enables the display of the minimum amount of free stack which each |
678 | task has ever had available in the sysrq-T and sysrq-P debug output. |
679 | |
680 | This option will slow down process creation somewhat. |
681 | |
682 | config DEBUG_KOBJECT |
683 | bool "kobject debugging" |
684 | depends on DEBUG_KERNEL |
685 | help |
686 | If you say Y here, some extra kobject debugging messages will be sent |
687 | to the syslog. |
688 | |
689 | config DEBUG_HIGHMEM |
690 | bool "Highmem debugging" |
691 | depends on DEBUG_KERNEL && HIGHMEM |
692 | help |
693 | This options enables addition error checking for high memory systems. |
694 | Disable for production systems. |
695 | |
696 | config DEBUG_BUGVERBOSE |
697 | bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT |
698 | depends on BUG |
699 | depends on ARM || AVR32 || M32R || M68K || SPARC32 || SPARC64 || \ |
700 | FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300 || TILE |
701 | default y |
702 | help |
703 | Say Y here to make BUG() panics output the file name and line number |
704 | of the BUG call as well as the EIP and oops trace. This aids |
705 | debugging but costs about 70-100K of memory. |
706 | |
707 | config DEBUG_INFO |
708 | bool "Compile the kernel with debug info" |
709 | depends on DEBUG_KERNEL |
710 | help |
711 | If you say Y here the resulting kernel image will include |
712 | debugging info resulting in a larger kernel image. |
713 | This adds debug symbols to the kernel and modules (gcc -g), and |
714 | is needed if you intend to use kernel crashdump or binary object |
715 | tools like crash, kgdb, LKCD, gdb, etc on the kernel. |
716 | Say Y here only if you plan to debug the kernel. |
717 | |
718 | If unsure, say N. |
719 | |
720 | config DEBUG_INFO_REDUCED |
721 | bool "Reduce debugging information" |
722 | depends on DEBUG_INFO |
723 | help |
724 | If you say Y here gcc is instructed to generate less debugging |
725 | information for structure types. This means that tools that |
726 | need full debugging information (like kgdb or systemtap) won't |
727 | be happy. But if you merely need debugging information to |
728 | resolve line numbers there is no loss. Advantage is that |
729 | build directory object sizes shrink dramatically over a full |
730 | DEBUG_INFO build and compile times are reduced too. |
731 | Only works with newer gcc versions. |
732 | |
733 | config DEBUG_VM |
734 | bool "Debug VM" |
735 | depends on DEBUG_KERNEL |
736 | help |
737 | Enable this to turn on extended checks in the virtual-memory system |
738 | that may impact performance. |
739 | |
740 | If unsure, say N. |
741 | |
742 | config DEBUG_VIRTUAL |
743 | bool "Debug VM translations" |
744 | depends on DEBUG_KERNEL && X86 |
745 | help |
746 | Enable some costly sanity checks in virtual to page code. This can |
747 | catch mistakes with virt_to_page() and friends. |
748 | |
749 | If unsure, say N. |
750 | |
751 | config DEBUG_NOMMU_REGIONS |
752 | bool "Debug the global anon/private NOMMU mapping region tree" |
753 | depends on DEBUG_KERNEL && !MMU |
754 | help |
755 | This option causes the global tree of anonymous and private mapping |
756 | regions to be regularly checked for invalid topology. |
757 | |
758 | config DEBUG_WRITECOUNT |
759 | bool "Debug filesystem writers count" |
760 | depends on DEBUG_KERNEL |
761 | help |
762 | Enable this to catch wrong use of the writers count in struct |
763 | vfsmount. This will increase the size of each file struct by |
764 | 32 bits. |
765 | |
766 | If unsure, say N. |
767 | |
768 | config DEBUG_MEMORY_INIT |
769 | bool "Debug memory initialisation" if EXPERT |
770 | default !EXPERT |
771 | help |
772 | Enable this for additional checks during memory initialisation. |
773 | The sanity checks verify aspects of the VM such as the memory model |
774 | and other information provided by the architecture. Verbose |
775 | information will be printed at KERN_DEBUG loglevel depending |
776 | on the mminit_loglevel= command-line option. |
777 | |
778 | If unsure, say Y |
779 | |
780 | config DEBUG_LIST |
781 | bool "Debug linked list manipulation" |
782 | depends on DEBUG_KERNEL |
783 | help |
784 | Enable this to turn on extended checks in the linked-list |
785 | walking routines. |
786 | |
787 | If unsure, say N. |
788 | |
789 | config TEST_LIST_SORT |
790 | bool "Linked list sorting test" |
791 | depends on DEBUG_KERNEL |
792 | help |
793 | Enable this to turn on 'list_sort()' function test. This test is |
794 | executed only once during system boot, so affects only boot time. |
795 | |
796 | If unsure, say N. |
797 | |
798 | config DEBUG_SG |
799 | bool "Debug SG table operations" |
800 | depends on DEBUG_KERNEL |
801 | help |
802 | Enable this to turn on checks on scatter-gather tables. This can |
803 | help find problems with drivers that do not properly initialize |
804 | their sg tables. |
805 | |
806 | If unsure, say N. |
807 | |
808 | config DEBUG_NOTIFIERS |
809 | bool "Debug notifier call chains" |
810 | depends on DEBUG_KERNEL |
811 | help |
812 | Enable this to turn on sanity checking for notifier call chains. |
813 | This is most useful for kernel developers to make sure that |
814 | modules properly unregister themselves from notifier chains. |
815 | This is a relatively cheap check but if you care about maximum |
816 | performance, say N. |
817 | |
818 | config DEBUG_CREDENTIALS |
819 | bool "Debug credential management" |
820 | depends on DEBUG_KERNEL |
821 | help |
822 | Enable this to turn on some debug checking for credential |
823 | management. The additional code keeps track of the number of |
824 | pointers from task_structs to any given cred struct, and checks to |
825 | see that this number never exceeds the usage count of the cred |
826 | struct. |
827 | |
828 | Furthermore, if SELinux is enabled, this also checks that the |
829 | security pointer in the cred struct is never seen to be invalid. |
830 | |
831 | If unsure, say N. |
832 | |
833 | # |
834 | # Select this config option from the architecture Kconfig, if it |
835 | # it is preferred to always offer frame pointers as a config |
836 | # option on the architecture (regardless of KERNEL_DEBUG): |
837 | # |
838 | config ARCH_WANT_FRAME_POINTERS |
839 | bool |
840 | help |
841 | |
842 | config FRAME_POINTER |
843 | bool "Compile the kernel with frame pointers" |
844 | depends on DEBUG_KERNEL && \ |
845 | (CRIS || M68K || FRV || UML || \ |
846 | AVR32 || SUPERH || BLACKFIN || MN10300) || \ |
847 | ARCH_WANT_FRAME_POINTERS |
848 | default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS |
849 | help |
850 | If you say Y here the resulting kernel image will be slightly |
851 | larger and slower, but it gives very useful debugging information |
852 | in case of kernel bugs. (precise oopses/stacktraces/warnings) |
853 | |
854 | config BOOT_PRINTK_DELAY |
855 | bool "Delay each boot printk message by N milliseconds" |
856 | depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY |
857 | help |
858 | This build option allows you to read kernel boot messages |
859 | by inserting a short delay after each one. The delay is |
860 | specified in milliseconds on the kernel command line, |
861 | using "boot_delay=N". |
862 | |
863 | It is likely that you would also need to use "lpj=M" to preset |
864 | the "loops per jiffie" value. |
865 | See a previous boot log for the "lpj" value to use for your |
866 | system, and then set "lpj=M" before setting "boot_delay=N". |
867 | NOTE: Using this option may adversely affect SMP systems. |
868 | I.e., processors other than the first one may not boot up. |
869 | BOOT_PRINTK_DELAY also may cause DETECT_SOFTLOCKUP to detect |
870 | what it believes to be lockup conditions. |
871 | |
872 | config RCU_TORTURE_TEST |
873 | tristate "torture tests for RCU" |
874 | depends on DEBUG_KERNEL |
875 | default n |
876 | help |
877 | This option provides a kernel module that runs torture tests |
878 | on the RCU infrastructure. The kernel module may be built |
879 | after the fact on the running kernel to be tested, if desired. |
880 | |
881 | Say Y here if you want RCU torture tests to be built into |
882 | the kernel. |
883 | Say M if you want the RCU torture tests to build as a module. |
884 | Say N if you are unsure. |
885 | |
886 | config RCU_TORTURE_TEST_RUNNABLE |
887 | bool "torture tests for RCU runnable by default" |
888 | depends on RCU_TORTURE_TEST = y |
889 | default n |
890 | help |
891 | This option provides a way to build the RCU torture tests |
892 | directly into the kernel without them starting up at boot |
893 | time. You can use /proc/sys/kernel/rcutorture_runnable |
894 | to manually override this setting. This /proc file is |
895 | available only when the RCU torture tests have been built |
896 | into the kernel. |
897 | |
898 | Say Y here if you want the RCU torture tests to start during |
899 | boot (you probably don't). |
900 | Say N here if you want the RCU torture tests to start only |
901 | after being manually enabled via /proc. |
902 | |
903 | config RCU_CPU_STALL_TIMEOUT |
904 | int "RCU CPU stall timeout in seconds" |
905 | depends on TREE_RCU || TREE_PREEMPT_RCU |
906 | range 3 300 |
907 | default 60 |
908 | help |
909 | If a given RCU grace period extends more than the specified |
910 | number of seconds, a CPU stall warning is printed. If the |
911 | RCU grace period persists, additional CPU stall warnings are |
912 | printed at more widely spaced intervals. |
913 | |
914 | config RCU_CPU_STALL_VERBOSE |
915 | bool "Print additional per-task information for RCU_CPU_STALL_DETECTOR" |
916 | depends on TREE_PREEMPT_RCU |
917 | default y |
918 | help |
919 | This option causes RCU to printk detailed per-task information |
920 | for any tasks that are stalling the current RCU grace period. |
921 | |
922 | Say N if you are unsure. |
923 | |
924 | Say Y if you want to enable such checks. |
925 | |
926 | config KPROBES_SANITY_TEST |
927 | bool "Kprobes sanity tests" |
928 | depends on DEBUG_KERNEL |
929 | depends on KPROBES |
930 | default n |
931 | help |
932 | This option provides for testing basic kprobes functionality on |
933 | boot. A sample kprobe, jprobe and kretprobe are inserted and |
934 | verified for functionality. |
935 | |
936 | Say N if you are unsure. |
937 | |
938 | config BACKTRACE_SELF_TEST |
939 | tristate "Self test for the backtrace code" |
940 | depends on DEBUG_KERNEL |
941 | default n |
942 | help |
943 | This option provides a kernel module that can be used to test |
944 | the kernel stack backtrace code. This option is not useful |
945 | for distributions or general kernels, but only for kernel |
946 | developers working on architecture code. |
947 | |
948 | Note that if you want to also test saved backtraces, you will |
949 | have to enable STACKTRACE as well. |
950 | |
951 | Say N if you are unsure. |
952 | |
953 | config DEBUG_BLOCK_EXT_DEVT |
954 | bool "Force extended block device numbers and spread them" |
955 | depends on DEBUG_KERNEL |
956 | depends on BLOCK |
957 | default n |
958 | help |
959 | BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON |
960 | SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT |
961 | YOU ARE DOING. Distros, please enable this and fix whatever |
962 | is broken. |
963 | |
964 | Conventionally, block device numbers are allocated from |
965 | predetermined contiguous area. However, extended block area |
966 | may introduce non-contiguous block device numbers. This |
967 | option forces most block device numbers to be allocated from |
968 | the extended space and spreads them to discover kernel or |
969 | userland code paths which assume predetermined contiguous |
970 | device number allocation. |
971 | |
972 | Note that turning on this debug option shuffles all the |
973 | device numbers for all IDE and SCSI devices including libata |
974 | ones, so root partition specified using device number |
975 | directly (via rdev or root=MAJ:MIN) won't work anymore. |
976 | Textual device names (root=/dev/sdXn) will continue to work. |
977 | |
978 | Say N if you are unsure. |
979 | |
980 | config DEBUG_FORCE_WEAK_PER_CPU |
981 | bool "Force weak per-cpu definitions" |
982 | depends on DEBUG_KERNEL |
983 | help |
984 | s390 and alpha require percpu variables in modules to be |
985 | defined weak to work around addressing range issue which |
986 | puts the following two restrictions on percpu variable |
987 | definitions. |
988 | |
989 | 1. percpu symbols must be unique whether static or not |
990 | 2. percpu variables can't be defined inside a function |
991 | |
992 | To ensure that generic code follows the above rules, this |
993 | option forces all percpu variables to be defined as weak. |
994 | |
995 | config DEBUG_PER_CPU_MAPS |
996 | bool "Debug access to per_cpu maps" |
997 | depends on DEBUG_KERNEL |
998 | depends on SMP |
999 | help |
1000 | Say Y to verify that the per_cpu map being accessed has |
1001 | been set up. This adds a fair amount of code to kernel memory |
1002 | and decreases performance. |
1003 | |
1004 | Say N if unsure. |
1005 | |
1006 | config LKDTM |
1007 | tristate "Linux Kernel Dump Test Tool Module" |
1008 | depends on DEBUG_FS |
1009 | depends on BLOCK |
1010 | default n |
1011 | help |
1012 | This module enables testing of the different dumping mechanisms by |
1013 | inducing system failures at predefined crash points. |
1014 | If you don't need it: say N |
1015 | Choose M here to compile this code as a module. The module will be |
1016 | called lkdtm. |
1017 | |
1018 | Documentation on how to use the module can be found in |
1019 | Documentation/fault-injection/provoke-crashes.txt |
1020 | |
1021 | config CPU_NOTIFIER_ERROR_INJECT |
1022 | tristate "CPU notifier error injection module" |
1023 | depends on HOTPLUG_CPU && DEBUG_KERNEL |
1024 | help |
1025 | This option provides a kernel module that can be used to test |
1026 | the error handling of the cpu notifiers |
1027 | |
1028 | To compile this code as a module, choose M here: the module will |
1029 | be called cpu-notifier-error-inject. |
1030 | |
1031 | If unsure, say N. |
1032 | |
1033 | config FAULT_INJECTION |
1034 | bool "Fault-injection framework" |
1035 | depends on DEBUG_KERNEL |
1036 | help |
1037 | Provide fault-injection framework. |
1038 | For more details, see Documentation/fault-injection/. |
1039 | |
1040 | config FAILSLAB |
1041 | bool "Fault-injection capability for kmalloc" |
1042 | depends on FAULT_INJECTION |
1043 | depends on SLAB || SLUB |
1044 | help |
1045 | Provide fault-injection capability for kmalloc. |
1046 | |
1047 | config FAIL_PAGE_ALLOC |
1048 | bool "Fault-injection capabilitiy for alloc_pages()" |
1049 | depends on FAULT_INJECTION |
1050 | help |
1051 | Provide fault-injection capability for alloc_pages(). |
1052 | |
1053 | config FAIL_MAKE_REQUEST |
1054 | bool "Fault-injection capability for disk IO" |
1055 | depends on FAULT_INJECTION && BLOCK |
1056 | help |
1057 | Provide fault-injection capability for disk IO. |
1058 | |
1059 | config FAIL_IO_TIMEOUT |
1060 | bool "Fault-injection capability for faking disk interrupts" |
1061 | depends on FAULT_INJECTION && BLOCK |
1062 | help |
1063 | Provide fault-injection capability on end IO handling. This |
1064 | will make the block layer "forget" an interrupt as configured, |
1065 | thus exercising the error handling. |
1066 | |
1067 | Only works with drivers that use the generic timeout handling, |
1068 | for others it wont do anything. |
1069 | |
1070 | config FAULT_INJECTION_DEBUG_FS |
1071 | bool "Debugfs entries for fault-injection capabilities" |
1072 | depends on FAULT_INJECTION && SYSFS && DEBUG_FS |
1073 | help |
1074 | Enable configuration of fault-injection capabilities via debugfs. |
1075 | |
1076 | config FAULT_INJECTION_STACKTRACE_FILTER |
1077 | bool "stacktrace filter for fault-injection capabilities" |
1078 | depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT |
1079 | depends on !X86_64 |
1080 | select STACKTRACE |
1081 | select FRAME_POINTER if !PPC && !S390 && !MICROBLAZE |
1082 | help |
1083 | Provide stacktrace filter for fault-injection capabilities |
1084 | |
1085 | config LATENCYTOP |
1086 | bool "Latency measuring infrastructure" |
1087 | depends on HAVE_LATENCYTOP_SUPPORT |
1088 | depends on DEBUG_KERNEL |
1089 | depends on STACKTRACE_SUPPORT |
1090 | depends on PROC_FS |
1091 | select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE |
1092 | select KALLSYMS |
1093 | select KALLSYMS_ALL |
1094 | select STACKTRACE |
1095 | select SCHEDSTATS |
1096 | select SCHED_DEBUG |
1097 | help |
1098 | Enable this option if you want to use the LatencyTOP tool |
1099 | to find out which userspace is blocking on what kernel operations. |
1100 | |
1101 | config SYSCTL_SYSCALL_CHECK |
1102 | bool "Sysctl checks" |
1103 | depends on SYSCTL |
1104 | ---help--- |
1105 | sys_sysctl uses binary paths that have been found challenging |
1106 | to properly maintain and use. This enables checks that help |
1107 | you to keep things correct. |
1108 | |
1109 | source mm/Kconfig.debug |
1110 | source kernel/trace/Kconfig |
1111 | |
1112 | config PROVIDE_OHCI1394_DMA_INIT |
1113 | bool "Remote debugging over FireWire early on boot" |
1114 | depends on PCI && X86 |
1115 | help |
1116 | If you want to debug problems which hang or crash the kernel early |
1117 | on boot and the crashing machine has a FireWire port, you can use |
1118 | this feature to remotely access the memory of the crashed machine |
1119 | over FireWire. This employs remote DMA as part of the OHCI1394 |
1120 | specification which is now the standard for FireWire controllers. |
1121 | |
1122 | With remote DMA, you can monitor the printk buffer remotely using |
1123 | firescope and access all memory below 4GB using fireproxy from gdb. |
1124 | Even controlling a kernel debugger is possible using remote DMA. |
1125 | |
1126 | Usage: |
1127 | |
1128 | If ohci1394_dma=early is used as boot parameter, it will initialize |
1129 | all OHCI1394 controllers which are found in the PCI config space. |
1130 | |
1131 | As all changes to the FireWire bus such as enabling and disabling |
1132 | devices cause a bus reset and thereby disable remote DMA for all |
1133 | devices, be sure to have the cable plugged and FireWire enabled on |
1134 | the debugging host before booting the debug target for debugging. |
1135 | |
1136 | This code (~1k) is freed after boot. By then, the firewire stack |
1137 | in charge of the OHCI-1394 controllers should be used instead. |
1138 | |
1139 | See Documentation/debugging-via-ohci1394.txt for more information. |
1140 | |
1141 | config FIREWIRE_OHCI_REMOTE_DMA |
1142 | bool "Remote debugging over FireWire with firewire-ohci" |
1143 | depends on FIREWIRE_OHCI |
1144 | help |
1145 | This option lets you use the FireWire bus for remote debugging |
1146 | with help of the firewire-ohci driver. It enables unfiltered |
1147 | remote DMA in firewire-ohci. |
1148 | See Documentation/debugging-via-ohci1394.txt for more information. |
1149 | |
1150 | If unsure, say N. |
1151 | |
1152 | config BUILD_DOCSRC |
1153 | bool "Build targets in Documentation/ tree" |
1154 | depends on HEADERS_CHECK |
1155 | help |
1156 | This option attempts to build objects from the source files in the |
1157 | kernel Documentation/ tree. |
1158 | |
1159 | Say N if you are unsure. |
1160 | |
1161 | config DYNAMIC_DEBUG |
1162 | bool "Enable dynamic printk() support" |
1163 | default n |
1164 | depends on PRINTK |
1165 | depends on DEBUG_FS |
1166 | help |
1167 | |
1168 | Compiles debug level messages into the kernel, which would not |
1169 | otherwise be available at runtime. These messages can then be |
1170 | enabled/disabled based on various levels of scope - per source file, |
1171 | function, module, format string, and line number. This mechanism |
1172 | implicitly enables all pr_debug() and dev_dbg() calls. The impact of |
1173 | this compile option is a larger kernel text size of about 2%. |
1174 | |
1175 | Usage: |
1176 | |
1177 | Dynamic debugging is controlled via the 'dynamic_debug/control' file, |
1178 | which is contained in the 'debugfs' filesystem. Thus, the debugfs |
1179 | filesystem must first be mounted before making use of this feature. |
1180 | We refer the control file as: <debugfs>/dynamic_debug/control. This |
1181 | file contains a list of the debug statements that can be enabled. The |
1182 | format for each line of the file is: |
1183 | |
1184 | filename:lineno [module]function flags format |
1185 | |
1186 | filename : source file of the debug statement |
1187 | lineno : line number of the debug statement |
1188 | module : module that contains the debug statement |
1189 | function : function that contains the debug statement |
1190 | flags : 'p' means the line is turned 'on' for printing |
1191 | format : the format used for the debug statement |
1192 | |
1193 | From a live system: |
1194 | |
1195 | nullarbor:~ # cat <debugfs>/dynamic_debug/control |
1196 | # filename:lineno [module]function flags format |
1197 | fs/aio.c:222 [aio]__put_ioctx - "__put_ioctx:\040freeing\040%p\012" |
1198 | fs/aio.c:248 [aio]ioctx_alloc - "ENOMEM:\040nr_events\040too\040high\012" |
1199 | fs/aio.c:1770 [aio]sys_io_cancel - "calling\040cancel\012" |
1200 | |
1201 | Example usage: |
1202 | |
1203 | // enable the message at line 1603 of file svcsock.c |
1204 | nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' > |
1205 | <debugfs>/dynamic_debug/control |
1206 | |
1207 | // enable all the messages in file svcsock.c |
1208 | nullarbor:~ # echo -n 'file svcsock.c +p' > |
1209 | <debugfs>/dynamic_debug/control |
1210 | |
1211 | // enable all the messages in the NFS server module |
1212 | nullarbor:~ # echo -n 'module nfsd +p' > |
1213 | <debugfs>/dynamic_debug/control |
1214 | |
1215 | // enable all 12 messages in the function svc_process() |
1216 | nullarbor:~ # echo -n 'func svc_process +p' > |
1217 | <debugfs>/dynamic_debug/control |
1218 | |
1219 | // disable all 12 messages in the function svc_process() |
1220 | nullarbor:~ # echo -n 'func svc_process -p' > |
1221 | <debugfs>/dynamic_debug/control |
1222 | |
1223 | See Documentation/dynamic-debug-howto.txt for additional information. |
1224 | |
1225 | config DMA_API_DEBUG |
1226 | bool "Enable debugging of DMA-API usage" |
1227 | depends on HAVE_DMA_API_DEBUG |
1228 | help |
1229 | Enable this option to debug the use of the DMA API by device drivers. |
1230 | With this option you will be able to detect common bugs in device |
1231 | drivers like double-freeing of DMA mappings or freeing mappings that |
1232 | were never allocated. |
1233 | This option causes a performance degredation. Use only if you want |
1234 | to debug device drivers. If unsure, say N. |
1235 | |
1236 | config ATOMIC64_SELFTEST |
1237 | bool "Perform an atomic64_t self-test at boot" |
1238 | help |
1239 | Enable this option to test the atomic64_t functions at boot. |
1240 | |
1241 | If unsure, say N. |
1242 | |
1243 | config ASYNC_RAID6_TEST |
1244 | tristate "Self test for hardware accelerated raid6 recovery" |
1245 | depends on ASYNC_RAID6_RECOV |
1246 | select ASYNC_MEMCPY |
1247 | ---help--- |
1248 | This is a one-shot self test that permutes through the |
1249 | recovery of all the possible two disk failure scenarios for a |
1250 | N-disk array. Recovery is performed with the asynchronous |
1251 | raid6 recovery routines, and will optionally use an offload |
1252 | engine if one is available. |
1253 | |
1254 | If unsure, say N. |
1255 | |
1256 | source "samples/Kconfig" |
1257 | |
1258 | source "lib/Kconfig.kgdb" |
1259 | |
1260 | source "lib/Kconfig.kmemcheck" |
1261 | |
1262 | config TEST_KSTRTOX |
1263 | tristate "Test kstrto*() family of functions at runtime" |
1264 |
Branches:
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javiroman/ks7010
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Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
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v3.9