Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | |
2 | config PRINTK_TIME | |
3 | bool "Show timing information on printks" | |
d3b8b6e5 | 4 | depends on PRINTK |
1da177e4 LT |
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. | |
11 | ||
de488443 JG |
12 | config ENABLE_WARN_DEPRECATED |
13 | bool "Enable __deprecated logic" | |
14 | default y | |
15 | help | |
16 | Enable the __deprecated logic in the kernel build. | |
17 | Disable this to suppress the "warning: 'foo' is deprecated | |
18 | (declared at kernel/power/somefile.c:1234)" messages. | |
19 | ||
cebc04ba AM |
20 | config ENABLE_MUST_CHECK |
21 | bool "Enable __must_check logic" | |
22 | default y | |
23 | help | |
24 | Enable the __must_check logic in the kernel build. Disable this to | |
25 | suppress the "warning: ignoring return value of 'foo', declared with | |
26 | attribute warn_unused_result" messages. | |
1da177e4 | 27 | |
35bb5b1e AK |
28 | config FRAME_WARN |
29 | int "Warn for stack frames larger than (needs gcc 4.4)" | |
30 | range 0 8192 | |
31 | default 1024 if !64BIT | |
32 | default 2048 if 64BIT | |
33 | help | |
34 | Tell gcc to warn at build time for stack frames larger than this. | |
35 | Setting this too low will cause a lot of warnings. | |
36 | Setting it to 0 disables the warning. | |
37 | Requires gcc 4.4 | |
38 | ||
1da177e4 LT |
39 | config MAGIC_SYSRQ |
40 | bool "Magic SysRq key" | |
f346f4b3 | 41 | depends on !UML |
1da177e4 LT |
42 | help |
43 | If you say Y here, you will have some control over the system even | |
44 | if the system crashes for example during kernel debugging (e.g., you | |
45 | will be able to flush the buffer cache to disk, reboot the system | |
46 | immediately or dump some status information). This is accomplished | |
47 | by pressing various keys while holding SysRq (Alt+PrintScreen). It | |
48 | also works on a serial console (on PC hardware at least), if you | |
49 | send a BREAK and then within 5 seconds a command keypress. The | |
50 | keys are documented in <file:Documentation/sysrq.txt>. Don't say Y | |
51 | unless you really know what this hack does. | |
52 | ||
99657c78 RD |
53 | config STRIP_ASM_SYMS |
54 | bool "Strip assembler-generated symbols during link" | |
55 | default n | |
56 | help | |
57 | Strip internal assembler-generated symbols during a link (symbols | |
58 | that look like '.Lxxx') so they don't pollute the output of | |
59 | get_wchan() and suchlike. | |
60 | ||
f71d20e9 AV |
61 | config UNUSED_SYMBOLS |
62 | bool "Enable unused/obsolete exported symbols" | |
63 | default y if X86 | |
64 | help | |
65 | Unused but exported symbols make the kernel needlessly bigger. For | |
66 | that reason most of these unused exports will soon be removed. This | |
67 | option is provided temporarily to provide a transition period in case | |
68 | some external kernel module needs one of these symbols anyway. If you | |
69 | encounter such a case in your module, consider if you are actually | |
70 | using the right API. (rationale: since nobody in the kernel is using | |
71 | this in a module, there is a pretty good chance it's actually the | |
72 | wrong interface to use). If you really need the symbol, please send a | |
73 | mail to the linux kernel mailing list mentioning the symbol and why | |
74 | you really need it, and what the merge plan to the mainline kernel for | |
75 | your module is. | |
76 | ||
bf4735a4 DM |
77 | config DEBUG_FS |
78 | bool "Debug Filesystem" | |
bf4735a4 DM |
79 | help |
80 | debugfs is a virtual file system that kernel developers use to put | |
81 | debugging files into. Enable this option to be able to read and | |
82 | write to these files. | |
83 | ||
ff543332 RD |
84 | For detailed documentation on the debugfs API, see |
85 | Documentation/DocBook/filesystems. | |
86 | ||
bf4735a4 DM |
87 | If unsure, say N. |
88 | ||
89 | config HEADERS_CHECK | |
90 | bool "Run 'make headers_check' when building vmlinux" | |
91 | depends on !UML | |
92 | help | |
93 | This option will extract the user-visible kernel headers whenever | |
94 | building the kernel, and will run basic sanity checks on them to | |
95 | ensure that exported files do not attempt to include files which | |
96 | were not exported, etc. | |
97 | ||
98 | If you're making modifications to header files which are | |
99 | relevant for userspace, say 'Y', and check the headers | |
100 | exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in | |
101 | your build tree), to make sure they're suitable. | |
102 | ||
91341d4b SR |
103 | config DEBUG_SECTION_MISMATCH |
104 | bool "Enable full Section mismatch analysis" | |
1d53661d MF |
105 | depends on UNDEFINED || (BLACKFIN) |
106 | default y | |
fa2144ba | 107 | # This option is on purpose disabled for now. |
af901ca1 | 108 | # It will be enabled when we are down to a reasonable number |
fa2144ba | 109 | # of section mismatch warnings (< 10 for an allyesconfig build) |
91341d4b SR |
110 | help |
111 | The section mismatch analysis checks if there are illegal | |
112 | references from one section to another section. | |
113 | Linux will during link or during runtime drop some sections | |
114 | and any use of code/data previously in these sections will | |
115 | most likely result in an oops. | |
116 | In the code functions and variables are annotated with | |
117 | __init, __devinit etc. (see full list in include/linux/init.h) | |
d6fbfa4f GU |
118 | which results in the code/data being placed in specific sections. |
119 | The section mismatch analysis is always done after a full | |
120 | kernel build but enabling this option will in addition | |
91341d4b SR |
121 | do the following: |
122 | - Add the option -fno-inline-functions-called-once to gcc | |
123 | When inlining a function annotated __init in a non-init | |
d6fbfa4f | 124 | function we would lose the section information and thus |
91341d4b | 125 | the analysis would not catch the illegal reference. |
d6fbfa4f | 126 | This option tells gcc to inline less but will also |
91341d4b SR |
127 | result in a larger kernel. |
128 | - Run the section mismatch analysis for each module/built-in.o | |
129 | When we run the section mismatch analysis on vmlinux.o we | |
d6fbfa4f | 130 | lose valueble information about where the mismatch was |
91341d4b SR |
131 | introduced. |
132 | Running the analysis for each module/built-in.o file | |
133 | will tell where the mismatch happens much closer to the | |
134 | source. The drawback is that we will report the same | |
135 | mismatch at least twice. | |
588ccd73 SR |
136 | - Enable verbose reporting from modpost to help solving |
137 | the section mismatches reported. | |
91341d4b | 138 | |
f346f4b3 AB |
139 | config DEBUG_KERNEL |
140 | bool "Kernel debugging" | |
141 | help | |
142 | Say Y here if you are developing drivers or trying to debug and | |
143 | identify kernel problems. | |
144 | ||
a304e1b8 DW |
145 | config DEBUG_SHIRQ |
146 | bool "Debug shared IRQ handlers" | |
147 | depends on DEBUG_KERNEL && GENERIC_HARDIRQS | |
148 | help | |
149 | Enable this to generate a spurious interrupt as soon as a shared | |
150 | interrupt handler is registered, and just before one is deregistered. | |
151 | Drivers ought to be able to handle interrupts coming in at those | |
152 | points; some don't and need to be caught. | |
153 | ||
58687acb DZ |
154 | config LOCKUP_DETECTOR |
155 | bool "Detect Hard and Soft Lockups" | |
dea20a3f | 156 | depends on DEBUG_KERNEL && !S390 |
8446f1d3 | 157 | help |
58687acb DZ |
158 | Say Y here to enable the kernel to act as a watchdog to detect |
159 | hard and soft lockups. | |
160 | ||
161 | Softlockups are bugs that cause the kernel to loop in kernel | |
9c44bc03 | 162 | mode for more than 60 seconds, without giving other tasks a |
58687acb DZ |
163 | chance to run. The current stack trace is displayed upon |
164 | detection and the system will stay locked up. | |
8446f1d3 | 165 | |
58687acb DZ |
166 | Hardlockups are bugs that cause the CPU to loop in kernel mode |
167 | for more than 60 seconds, without letting other interrupts have a | |
168 | chance to run. The current stack trace is displayed upon detection | |
169 | and the system will stay locked up. | |
8446f1d3 | 170 | |
58687acb DZ |
171 | The overhead should be minimal. A periodic hrtimer runs to |
172 | generate interrupts and kick the watchdog task every 10-12 seconds. | |
173 | An NMI is generated every 60 seconds or so to check for hardlockups. | |
8446f1d3 | 174 | |
23637d47 FW |
175 | config HARDLOCKUP_DETECTOR |
176 | def_bool LOCKUP_DETECTOR && PERF_EVENTS && HAVE_PERF_EVENTS_NMI | |
8446f1d3 | 177 | |
9c44bc03 IM |
178 | config BOOTPARAM_SOFTLOCKUP_PANIC |
179 | bool "Panic (Reboot) On Soft Lockups" | |
89d7ce2a | 180 | depends on LOCKUP_DETECTOR |
9c44bc03 IM |
181 | help |
182 | Say Y here to enable the kernel to panic on "soft lockups", | |
183 | which are bugs that cause the kernel to loop in kernel | |
184 | mode for more than 60 seconds, without giving other tasks a | |
185 | chance to run. | |
186 | ||
187 | The panic can be used in combination with panic_timeout, | |
188 | to cause the system to reboot automatically after a | |
189 | lockup has been detected. This feature is useful for | |
190 | high-availability systems that have uptime guarantees and | |
191 | where a lockup must be resolved ASAP. | |
192 | ||
193 | Say N if unsure. | |
194 | ||
195 | config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE | |
196 | int | |
e16bb1d7 | 197 | depends on LOCKUP_DETECTOR |
9c44bc03 IM |
198 | range 0 1 |
199 | default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC | |
200 | default 1 if BOOTPARAM_SOFTLOCKUP_PANIC | |
201 | ||
e162b39a MSB |
202 | config DETECT_HUNG_TASK |
203 | bool "Detect Hung Tasks" | |
204 | depends on DEBUG_KERNEL | |
77d05632 | 205 | default DETECT_SOFTLOCKUP |
e162b39a MSB |
206 | help |
207 | Say Y here to enable the kernel to detect "hung tasks", | |
208 | which are bugs that cause the task to be stuck in | |
209 | uninterruptible "D" state indefinitiley. | |
210 | ||
211 | When a hung task is detected, the kernel will print the | |
212 | current stack trace (which you should report), but the | |
213 | task will stay in uninterruptible state. If lockdep is | |
214 | enabled then all held locks will also be reported. This | |
215 | feature has negligible overhead. | |
216 | ||
217 | config BOOTPARAM_HUNG_TASK_PANIC | |
218 | bool "Panic (Reboot) On Hung Tasks" | |
219 | depends on DETECT_HUNG_TASK | |
220 | help | |
221 | Say Y here to enable the kernel to panic on "hung tasks", | |
222 | which are bugs that cause the kernel to leave a task stuck | |
223 | in uninterruptible "D" state. | |
224 | ||
225 | The panic can be used in combination with panic_timeout, | |
226 | to cause the system to reboot automatically after a | |
227 | hung task has been detected. This feature is useful for | |
228 | high-availability systems that have uptime guarantees and | |
229 | where a hung tasks must be resolved ASAP. | |
230 | ||
231 | Say N if unsure. | |
232 | ||
233 | config BOOTPARAM_HUNG_TASK_PANIC_VALUE | |
234 | int | |
235 | depends on DETECT_HUNG_TASK | |
236 | range 0 1 | |
237 | default 0 if !BOOTPARAM_HUNG_TASK_PANIC | |
238 | default 1 if BOOTPARAM_HUNG_TASK_PANIC | |
239 | ||
b642b6d3 IM |
240 | config SCHED_DEBUG |
241 | bool "Collect scheduler debugging info" | |
242 | depends on DEBUG_KERNEL && PROC_FS | |
243 | default y | |
244 | help | |
245 | If you say Y here, the /proc/sched_debug file will be provided | |
246 | that can help debug the scheduler. The runtime overhead of this | |
247 | option is minimal. | |
248 | ||
1da177e4 LT |
249 | config SCHEDSTATS |
250 | bool "Collect scheduler statistics" | |
251 | depends on DEBUG_KERNEL && PROC_FS | |
252 | help | |
253 | If you say Y here, additional code will be inserted into the | |
254 | scheduler and related routines to collect statistics about | |
255 | scheduler behavior and provide them in /proc/schedstat. These | |
256 | stats may be useful for both tuning and debugging the scheduler | |
257 | If you aren't debugging the scheduler or trying to tune a specific | |
258 | application, you can say N to avoid the very slight overhead | |
259 | this adds. | |
260 | ||
82f67cd9 IM |
261 | config TIMER_STATS |
262 | bool "Collect kernel timers statistics" | |
263 | depends on DEBUG_KERNEL && PROC_FS | |
264 | help | |
265 | If you say Y here, additional code will be inserted into the | |
266 | timer routines to collect statistics about kernel timers being | |
267 | reprogrammed. The statistics can be read from /proc/timer_stats. | |
268 | The statistics collection is started by writing 1 to /proc/timer_stats, | |
269 | writing 0 stops it. This feature is useful to collect information | |
c1a834dc IM |
270 | about timer usage patterns in kernel and userspace. This feature |
271 | is lightweight if enabled in the kernel config but not activated | |
272 | (it defaults to deactivated on bootup and will only be activated | |
273 | if some application like powertop activates it explicitly). | |
82f67cd9 | 274 | |
3ac7fe5a TG |
275 | config DEBUG_OBJECTS |
276 | bool "Debug object operations" | |
277 | depends on DEBUG_KERNEL | |
278 | help | |
279 | If you say Y here, additional code will be inserted into the | |
280 | kernel to track the life time of various objects and validate | |
281 | the operations on those objects. | |
282 | ||
283 | config DEBUG_OBJECTS_SELFTEST | |
284 | bool "Debug objects selftest" | |
285 | depends on DEBUG_OBJECTS | |
286 | help | |
287 | This enables the selftest of the object debug code. | |
288 | ||
289 | config DEBUG_OBJECTS_FREE | |
290 | bool "Debug objects in freed memory" | |
291 | depends on DEBUG_OBJECTS | |
292 | help | |
293 | This enables checks whether a k/v free operation frees an area | |
294 | which contains an object which has not been deactivated | |
295 | properly. This can make kmalloc/kfree-intensive workloads | |
296 | much slower. | |
297 | ||
c6f3a97f TG |
298 | config DEBUG_OBJECTS_TIMERS |
299 | bool "Debug timer objects" | |
300 | depends on DEBUG_OBJECTS | |
301 | help | |
302 | If you say Y here, additional code will be inserted into the | |
303 | timer routines to track the life time of timer objects and | |
304 | validate the timer operations. | |
305 | ||
dc186ad7 TG |
306 | config DEBUG_OBJECTS_WORK |
307 | bool "Debug work objects" | |
308 | depends on DEBUG_OBJECTS | |
309 | help | |
310 | If you say Y here, additional code will be inserted into the | |
311 | work queue routines to track the life time of work objects and | |
312 | validate the work operations. | |
313 | ||
551d55a9 MD |
314 | config DEBUG_OBJECTS_RCU_HEAD |
315 | bool "Debug RCU callbacks objects" | |
316 | depends on DEBUG_OBJECTS && PREEMPT | |
317 | help | |
318 | Enable this to turn on debugging of RCU list heads (call_rcu() usage). | |
319 | ||
3ae70205 IM |
320 | config DEBUG_OBJECTS_ENABLE_DEFAULT |
321 | int "debug_objects bootup default value (0-1)" | |
322 | range 0 1 | |
323 | default "1" | |
324 | depends on DEBUG_OBJECTS | |
325 | help | |
326 | Debug objects boot parameter default value | |
327 | ||
1da177e4 | 328 | config DEBUG_SLAB |
4a2f0acf | 329 | bool "Debug slab memory allocations" |
7d46d9e6 | 330 | depends on DEBUG_KERNEL && SLAB && !KMEMCHECK |
1da177e4 LT |
331 | help |
332 | Say Y here to have the kernel do limited verification on memory | |
333 | allocation as well as poisoning memory on free to catch use of freed | |
334 | memory. This can make kmalloc/kfree-intensive workloads much slower. | |
335 | ||
871751e2 AV |
336 | config DEBUG_SLAB_LEAK |
337 | bool "Memory leak debugging" | |
338 | depends on DEBUG_SLAB | |
339 | ||
f0630fff CL |
340 | config SLUB_DEBUG_ON |
341 | bool "SLUB debugging on by default" | |
7d46d9e6 | 342 | depends on SLUB && SLUB_DEBUG && !KMEMCHECK |
f0630fff CL |
343 | default n |
344 | help | |
345 | Boot with debugging on by default. SLUB boots by default with | |
346 | the runtime debug capabilities switched off. Enabling this is | |
347 | equivalent to specifying the "slub_debug" parameter on boot. | |
348 | There is no support for more fine grained debug control like | |
349 | possible with slub_debug=xxx. SLUB debugging may be switched | |
350 | off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying | |
351 | "slub_debug=-". | |
352 | ||
8ff12cfc CL |
353 | config SLUB_STATS |
354 | default n | |
355 | bool "Enable SLUB performance statistics" | |
5b06c853 | 356 | depends on SLUB && SLUB_DEBUG && SYSFS |
8ff12cfc CL |
357 | help |
358 | SLUB statistics are useful to debug SLUBs allocation behavior in | |
359 | order find ways to optimize the allocator. This should never be | |
360 | enabled for production use since keeping statistics slows down | |
361 | the allocator by a few percentage points. The slabinfo command | |
362 | supports the determination of the most active slabs to figure | |
363 | out which slabs are relevant to a particular load. | |
364 | Try running: slabinfo -DA | |
365 | ||
3bba00d7 CM |
366 | config DEBUG_KMEMLEAK |
367 | bool "Kernel memory leak detector" | |
dfcc3e6a | 368 | depends on DEBUG_KERNEL && EXPERIMENTAL && !MEMORY_HOTPLUG && \ |
9343af08 | 369 | (X86 || ARM || PPC || S390 || SPARC64 || SUPERH || MICROBLAZE) |
dfcc3e6a | 370 | |
3bba00d7 CM |
371 | select DEBUG_FS if SYSFS |
372 | select STACKTRACE if STACKTRACE_SUPPORT | |
373 | select KALLSYMS | |
b60e26a2 | 374 | select CRC32 |
3bba00d7 CM |
375 | help |
376 | Say Y here if you want to enable the memory leak | |
377 | detector. The memory allocation/freeing is traced in a way | |
378 | similar to the Boehm's conservative garbage collector, the | |
379 | difference being that the orphan objects are not freed but | |
380 | only shown in /sys/kernel/debug/kmemleak. Enabling this | |
381 | feature will introduce an overhead to memory | |
382 | allocations. See Documentation/kmemleak.txt for more | |
383 | details. | |
384 | ||
bf96d1e3 CM |
385 | Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances |
386 | of finding leaks due to the slab objects poisoning. | |
387 | ||
3bba00d7 CM |
388 | In order to access the kmemleak file, debugfs needs to be |
389 | mounted (usually at /sys/kernel/debug). | |
390 | ||
a9d9058a CM |
391 | config DEBUG_KMEMLEAK_EARLY_LOG_SIZE |
392 | int "Maximum kmemleak early log entries" | |
393 | depends on DEBUG_KMEMLEAK | |
dfcc3e6a | 394 | range 200 40000 |
a9d9058a CM |
395 | default 400 |
396 | help | |
397 | Kmemleak must track all the memory allocations to avoid | |
398 | reporting false positives. Since memory may be allocated or | |
399 | freed before kmemleak is initialised, an early log buffer is | |
400 | used to store these actions. If kmemleak reports "early log | |
401 | buffer exceeded", please increase this value. | |
402 | ||
0822ee4a CM |
403 | config DEBUG_KMEMLEAK_TEST |
404 | tristate "Simple test for the kernel memory leak detector" | |
405 | depends on DEBUG_KMEMLEAK | |
406 | help | |
407 | Say Y or M here to build a test for the kernel memory leak | |
408 | detector. This option enables a module that explicitly leaks | |
409 | memory. | |
410 | ||
411 | If unsure, say N. | |
412 | ||
ab0155a2 JB |
413 | config DEBUG_KMEMLEAK_DEFAULT_OFF |
414 | bool "Default kmemleak to off" | |
415 | depends on DEBUG_KMEMLEAK | |
416 | help | |
417 | Say Y here to disable kmemleak by default. It can then be enabled | |
418 | on the command line via kmemleak=on. | |
419 | ||
1da177e4 LT |
420 | config DEBUG_PREEMPT |
421 | bool "Debug preemptible kernel" | |
01deab98 | 422 | depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT |
1da177e4 LT |
423 | default y |
424 | help | |
425 | If you say Y here then the kernel will use a debug variant of the | |
426 | commonly used smp_processor_id() function and will print warnings | |
427 | if kernel code uses it in a preemption-unsafe way. Also, the kernel | |
428 | will detect preemption count underflows. | |
429 | ||
e7eebaf6 IM |
430 | config DEBUG_RT_MUTEXES |
431 | bool "RT Mutex debugging, deadlock detection" | |
e7eebaf6 IM |
432 | depends on DEBUG_KERNEL && RT_MUTEXES |
433 | help | |
434 | This allows rt mutex semantics violations and rt mutex related | |
435 | deadlocks (lockups) to be detected and reported automatically. | |
436 | ||
437 | config DEBUG_PI_LIST | |
438 | bool | |
439 | default y | |
440 | depends on DEBUG_RT_MUTEXES | |
441 | ||
61a87122 TG |
442 | config RT_MUTEX_TESTER |
443 | bool "Built-in scriptable tester for rt-mutexes" | |
a1583d3e | 444 | depends on DEBUG_KERNEL && RT_MUTEXES |
61a87122 TG |
445 | help |
446 | This option enables a rt-mutex tester. | |
447 | ||
1da177e4 | 448 | config DEBUG_SPINLOCK |
4d9f34ad | 449 | bool "Spinlock and rw-lock debugging: basic checks" |
1da177e4 LT |
450 | depends on DEBUG_KERNEL |
451 | help | |
452 | Say Y here and build SMP to catch missing spinlock initialization | |
453 | and certain other kinds of spinlock errors commonly made. This is | |
454 | best used in conjunction with the NMI watchdog so that spinlock | |
455 | deadlocks are also debuggable. | |
456 | ||
4d9f34ad IM |
457 | config DEBUG_MUTEXES |
458 | bool "Mutex debugging: basic checks" | |
459 | depends on DEBUG_KERNEL | |
460 | help | |
461 | This feature allows mutex semantics violations to be detected and | |
462 | reported. | |
463 | ||
4d9f34ad IM |
464 | config DEBUG_LOCK_ALLOC |
465 | bool "Lock debugging: detect incorrect freeing of live locks" | |
517e7aa5 | 466 | depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT |
4d9f34ad IM |
467 | select DEBUG_SPINLOCK |
468 | select DEBUG_MUTEXES | |
4d9f34ad IM |
469 | select LOCKDEP |
470 | help | |
471 | This feature will check whether any held lock (spinlock, rwlock, | |
472 | mutex or rwsem) is incorrectly freed by the kernel, via any of the | |
473 | memory-freeing routines (kfree(), kmem_cache_free(), free_pages(), | |
474 | vfree(), etc.), whether a live lock is incorrectly reinitialized via | |
475 | spin_lock_init()/mutex_init()/etc., or whether there is any lock | |
476 | held during task exit. | |
477 | ||
478 | config PROVE_LOCKING | |
479 | bool "Lock debugging: prove locking correctness" | |
517e7aa5 | 480 | depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT |
4d9f34ad IM |
481 | select LOCKDEP |
482 | select DEBUG_SPINLOCK | |
483 | select DEBUG_MUTEXES | |
4d9f34ad | 484 | select DEBUG_LOCK_ALLOC |
46b93b74 | 485 | select TRACE_IRQFLAGS |
4d9f34ad IM |
486 | default n |
487 | help | |
488 | This feature enables the kernel to prove that all locking | |
489 | that occurs in the kernel runtime is mathematically | |
490 | correct: that under no circumstance could an arbitrary (and | |
491 | not yet triggered) combination of observed locking | |
492 | sequences (on an arbitrary number of CPUs, running an | |
493 | arbitrary number of tasks and interrupt contexts) cause a | |
494 | deadlock. | |
495 | ||
496 | In short, this feature enables the kernel to report locking | |
497 | related deadlocks before they actually occur. | |
498 | ||
499 | The proof does not depend on how hard and complex a | |
500 | deadlock scenario would be to trigger: how many | |
501 | participant CPUs, tasks and irq-contexts would be needed | |
502 | for it to trigger. The proof also does not depend on | |
503 | timing: if a race and a resulting deadlock is possible | |
504 | theoretically (no matter how unlikely the race scenario | |
505 | is), it will be proven so and will immediately be | |
506 | reported by the kernel (once the event is observed that | |
507 | makes the deadlock theoretically possible). | |
508 | ||
509 | If a deadlock is impossible (i.e. the locking rules, as | |
510 | observed by the kernel, are mathematically correct), the | |
511 | kernel reports nothing. | |
512 | ||
513 | NOTE: this feature can also be enabled for rwlocks, mutexes | |
514 | and rwsems - in which case all dependencies between these | |
515 | different locking variants are observed and mapped too, and | |
516 | the proof of observed correctness is also maintained for an | |
517 | arbitrary combination of these separate locking variants. | |
518 | ||
519 | For more details, see Documentation/lockdep-design.txt. | |
520 | ||
632ee200 PM |
521 | config PROVE_RCU |
522 | bool "RCU debugging: prove RCU correctness" | |
523 | depends on PROVE_LOCKING | |
524 | default n | |
525 | help | |
526 | This feature enables lockdep extensions that check for correct | |
527 | use of RCU APIs. This is currently under development. Say Y | |
528 | if you want to debug RCU usage or help work on the PROVE_RCU | |
529 | feature. | |
530 | ||
531 | Say N if you are unsure. | |
532 | ||
2b3fc35f LJ |
533 | config PROVE_RCU_REPEATEDLY |
534 | bool "RCU debugging: don't disable PROVE_RCU on first splat" | |
535 | depends on PROVE_RCU | |
536 | default n | |
537 | help | |
538 | By itself, PROVE_RCU will disable checking upon issuing the | |
539 | first warning (or "splat"). This feature prevents such | |
540 | disabling, allowing multiple RCU-lockdep warnings to be printed | |
541 | on a single reboot. | |
542 | ||
2dfbf4df PM |
543 | Say Y to allow multiple RCU-lockdep warnings per boot. |
544 | ||
545 | Say N if you are unsure. | |
546 | ||
ca5ecddf PM |
547 | config SPARSE_RCU_POINTER |
548 | bool "RCU debugging: sparse-based checks for pointer usage" | |
549 | default n | |
550 | help | |
551 | This feature enables the __rcu sparse annotation for | |
552 | RCU-protected pointers. This annotation will cause sparse | |
553 | to flag any non-RCU used of annotated pointers. This can be | |
554 | helpful when debugging RCU usage. Please note that this feature | |
555 | is not intended to enforce code cleanliness; it is instead merely | |
556 | a debugging aid. | |
557 | ||
558 | Say Y to make sparse flag questionable use of RCU-protected pointers | |
559 | ||
2b3fc35f LJ |
560 | Say N if you are unsure. |
561 | ||
4d9f34ad IM |
562 | config LOCKDEP |
563 | bool | |
517e7aa5 | 564 | depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT |
4d9f34ad | 565 | select STACKTRACE |
79aac889 | 566 | select FRAME_POINTER if !MIPS && !PPC && !ARM_UNWIND && !S390 && !MICROBLAZE |
4d9f34ad IM |
567 | select KALLSYMS |
568 | select KALLSYMS_ALL | |
569 | ||
f20786ff | 570 | config LOCK_STAT |
fdfb870f | 571 | bool "Lock usage statistics" |
f20786ff PZ |
572 | depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT |
573 | select LOCKDEP | |
574 | select DEBUG_SPINLOCK | |
575 | select DEBUG_MUTEXES | |
576 | select DEBUG_LOCK_ALLOC | |
577 | default n | |
578 | help | |
579 | This feature enables tracking lock contention points | |
580 | ||
a560aa48 PZ |
581 | For more details, see Documentation/lockstat.txt |
582 | ||
dd8b1cf6 FW |
583 | This also enables lock events required by "perf lock", |
584 | subcommand of perf. | |
585 | If you want to use "perf lock", you also need to turn on | |
586 | CONFIG_EVENT_TRACING. | |
84c6f88f HM |
587 | |
588 | CONFIG_LOCK_STAT defines "contended" and "acquired" lock events. | |
dd8b1cf6 | 589 | (CONFIG_LOCKDEP defines "acquire" and "release" events.) |
84c6f88f | 590 | |
4d9f34ad IM |
591 | config DEBUG_LOCKDEP |
592 | bool "Lock dependency engine debugging" | |
517e7aa5 | 593 | depends on DEBUG_KERNEL && LOCKDEP |
4d9f34ad IM |
594 | help |
595 | If you say Y here, the lock dependency engine will do | |
596 | additional runtime checks to debug itself, at the price | |
597 | of more runtime overhead. | |
598 | ||
599 | config TRACE_IRQFLAGS | |
600 | bool | |
46b93b74 SR |
601 | help |
602 | Enables hooks to interrupt enabling and disabling for | |
603 | either tracing or lock debugging. | |
4d9f34ad | 604 | |
1da177e4 | 605 | config DEBUG_SPINLOCK_SLEEP |
4d9f34ad | 606 | bool "Spinlock debugging: sleep-inside-spinlock checking" |
1da177e4 LT |
607 | depends on DEBUG_KERNEL |
608 | help | |
609 | If you say Y here, various routines which may sleep will become very | |
610 | noisy if they are called with a spinlock held. | |
611 | ||
cae2ed9a IM |
612 | config DEBUG_LOCKING_API_SELFTESTS |
613 | bool "Locking API boot-time self-tests" | |
614 | depends on DEBUG_KERNEL | |
615 | help | |
616 | Say Y here if you want the kernel to run a short self-test during | |
617 | bootup. The self-test checks whether common types of locking bugs | |
618 | are detected by debugging mechanisms or not. (if you disable | |
619 | lock debugging then those bugs wont be detected of course.) | |
620 | The following locking APIs are covered: spinlocks, rwlocks, | |
621 | mutexes and rwsems. | |
622 | ||
8637c099 IM |
623 | config STACKTRACE |
624 | bool | |
625 | depends on STACKTRACE_SUPPORT | |
626 | ||
1da177e4 LT |
627 | config DEBUG_KOBJECT |
628 | bool "kobject debugging" | |
629 | depends on DEBUG_KERNEL | |
630 | help | |
631 | If you say Y here, some extra kobject debugging messages will be sent | |
632 | to the syslog. | |
633 | ||
634 | config DEBUG_HIGHMEM | |
635 | bool "Highmem debugging" | |
636 | depends on DEBUG_KERNEL && HIGHMEM | |
637 | help | |
638 | This options enables addition error checking for high memory systems. | |
639 | Disable for production systems. | |
640 | ||
641 | config DEBUG_BUGVERBOSE | |
642 | bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EMBEDDED | |
c8538a7a | 643 | depends on BUG |
b920de1b DH |
644 | depends on ARM || AVR32 || M32R || M68K || SPARC32 || SPARC64 || \ |
645 | FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300 | |
8420e7ef | 646 | default y |
1da177e4 LT |
647 | help |
648 | Say Y here to make BUG() panics output the file name and line number | |
649 | of the BUG call as well as the EIP and oops trace. This aids | |
650 | debugging but costs about 70-100K of memory. | |
651 | ||
652 | config DEBUG_INFO | |
653 | bool "Compile the kernel with debug info" | |
654 | depends on DEBUG_KERNEL | |
655 | help | |
656 | If you say Y here the resulting kernel image will include | |
657 | debugging info resulting in a larger kernel image. | |
b72e53f8 AD |
658 | This adds debug symbols to the kernel and modules (gcc -g), and |
659 | is needed if you intend to use kernel crashdump or binary object | |
660 | tools like crash, kgdb, LKCD, gdb, etc on the kernel. | |
1da177e4 LT |
661 | Say Y here only if you plan to debug the kernel. |
662 | ||
663 | If unsure, say N. | |
664 | ||
d6f4ceb7 AK |
665 | config DEBUG_INFO_REDUCED |
666 | bool "Reduce debugging information" | |
667 | depends on DEBUG_INFO | |
668 | help | |
669 | If you say Y here gcc is instructed to generate less debugging | |
670 | information for structure types. This means that tools that | |
671 | need full debugging information (like kgdb or systemtap) won't | |
672 | be happy. But if you merely need debugging information to | |
673 | resolve line numbers there is no loss. Advantage is that | |
674 | build directory object sizes shrink dramatically over a full | |
675 | DEBUG_INFO build and compile times are reduced too. | |
676 | Only works with newer gcc versions. | |
677 | ||
a241ec65 PM |
678 | config DEBUG_VM |
679 | bool "Debug VM" | |
680 | depends on DEBUG_KERNEL | |
681 | help | |
13e7444b NP |
682 | Enable this to turn on extended checks in the virtual-memory system |
683 | that may impact performance. | |
a241ec65 PM |
684 | |
685 | If unsure, say N. | |
686 | ||
59ea7463 JS |
687 | config DEBUG_VIRTUAL |
688 | bool "Debug VM translations" | |
689 | depends on DEBUG_KERNEL && X86 | |
690 | help | |
691 | Enable some costly sanity checks in virtual to page code. This can | |
692 | catch mistakes with virt_to_page() and friends. | |
693 | ||
694 | If unsure, say N. | |
695 | ||
8feae131 DH |
696 | config DEBUG_NOMMU_REGIONS |
697 | bool "Debug the global anon/private NOMMU mapping region tree" | |
698 | depends on DEBUG_KERNEL && !MMU | |
699 | help | |
700 | This option causes the global tree of anonymous and private mapping | |
701 | regions to be regularly checked for invalid topology. | |
702 | ||
ad775f5a DH |
703 | config DEBUG_WRITECOUNT |
704 | bool "Debug filesystem writers count" | |
705 | depends on DEBUG_KERNEL | |
706 | help | |
707 | Enable this to catch wrong use of the writers count in struct | |
708 | vfsmount. This will increase the size of each file struct by | |
709 | 32 bits. | |
710 | ||
711 | If unsure, say N. | |
712 | ||
6b74ab97 MG |
713 | config DEBUG_MEMORY_INIT |
714 | bool "Debug memory initialisation" if EMBEDDED | |
715 | default !EMBEDDED | |
716 | help | |
717 | Enable this for additional checks during memory initialisation. | |
718 | The sanity checks verify aspects of the VM such as the memory model | |
719 | and other information provided by the architecture. Verbose | |
720 | information will be printed at KERN_DEBUG loglevel depending | |
721 | on the mminit_loglevel= command-line option. | |
722 | ||
723 | If unsure, say Y | |
724 | ||
199a9afc DJ |
725 | config DEBUG_LIST |
726 | bool "Debug linked list manipulation" | |
727 | depends on DEBUG_KERNEL | |
728 | help | |
729 | Enable this to turn on extended checks in the linked-list | |
730 | walking routines. | |
731 | ||
732 | If unsure, say N. | |
733 | ||
d6ec0842 JA |
734 | config DEBUG_SG |
735 | bool "Debug SG table operations" | |
736 | depends on DEBUG_KERNEL | |
737 | help | |
738 | Enable this to turn on checks on scatter-gather tables. This can | |
739 | help find problems with drivers that do not properly initialize | |
740 | their sg tables. | |
741 | ||
742 | If unsure, say N. | |
743 | ||
1b2439db AV |
744 | config DEBUG_NOTIFIERS |
745 | bool "Debug notifier call chains" | |
746 | depends on DEBUG_KERNEL | |
747 | help | |
748 | Enable this to turn on sanity checking for notifier call chains. | |
749 | This is most useful for kernel developers to make sure that | |
750 | modules properly unregister themselves from notifier chains. | |
751 | This is a relatively cheap check but if you care about maximum | |
752 | performance, say N. | |
753 | ||
e0e81739 DH |
754 | config DEBUG_CREDENTIALS |
755 | bool "Debug credential management" | |
756 | depends on DEBUG_KERNEL | |
757 | help | |
758 | Enable this to turn on some debug checking for credential | |
759 | management. The additional code keeps track of the number of | |
760 | pointers from task_structs to any given cred struct, and checks to | |
761 | see that this number never exceeds the usage count of the cred | |
762 | struct. | |
763 | ||
764 | Furthermore, if SELinux is enabled, this also checks that the | |
765 | security pointer in the cred struct is never seen to be invalid. | |
766 | ||
767 | If unsure, say N. | |
768 | ||
64dec40d JM |
769 | # |
770 | # Select this config option from the architecture Kconfig, if it | |
771 | # it is preferred to always offer frame pointers as a config | |
772 | # option on the architecture (regardless of KERNEL_DEBUG): | |
773 | # | |
774 | config ARCH_WANT_FRAME_POINTERS | |
775 | bool | |
776 | help | |
777 | ||
1da177e4 LT |
778 | config FRAME_POINTER |
779 | bool "Compile the kernel with frame pointers" | |
b920de1b | 780 | depends on DEBUG_KERNEL && \ |
75ee034a | 781 | (CRIS || M68K || M68KNOMMU || FRV || UML || \ |
da4276b8 IM |
782 | AVR32 || SUPERH || BLACKFIN || MN10300) || \ |
783 | ARCH_WANT_FRAME_POINTERS | |
784 | default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS | |
785 | help | |
786 | If you say Y here the resulting kernel image will be slightly | |
787 | larger and slower, but it gives very useful debugging information | |
788 | in case of kernel bugs. (precise oopses/stacktraces/warnings) | |
1da177e4 | 789 | |
bfe8df3d RD |
790 | config BOOT_PRINTK_DELAY |
791 | bool "Delay each boot printk message by N milliseconds" | |
792 | depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY | |
793 | help | |
794 | This build option allows you to read kernel boot messages | |
795 | by inserting a short delay after each one. The delay is | |
796 | specified in milliseconds on the kernel command line, | |
797 | using "boot_delay=N". | |
798 | ||
799 | It is likely that you would also need to use "lpj=M" to preset | |
800 | the "loops per jiffie" value. | |
801 | See a previous boot log for the "lpj" value to use for your | |
802 | system, and then set "lpj=M" before setting "boot_delay=N". | |
803 | NOTE: Using this option may adversely affect SMP systems. | |
804 | I.e., processors other than the first one may not boot up. | |
805 | BOOT_PRINTK_DELAY also may cause DETECT_SOFTLOCKUP to detect | |
806 | what it believes to be lockup conditions. | |
807 | ||
a241ec65 PM |
808 | config RCU_TORTURE_TEST |
809 | tristate "torture tests for RCU" | |
810 | depends on DEBUG_KERNEL | |
811 | default n | |
812 | help | |
813 | This option provides a kernel module that runs torture tests | |
814 | on the RCU infrastructure. The kernel module may be built | |
815 | after the fact on the running kernel to be tested, if desired. | |
816 | ||
31a72bce PM |
817 | Say Y here if you want RCU torture tests to be built into |
818 | the kernel. | |
a241ec65 PM |
819 | Say M if you want the RCU torture tests to build as a module. |
820 | Say N if you are unsure. | |
8bb31b9d | 821 | |
31a72bce PM |
822 | config RCU_TORTURE_TEST_RUNNABLE |
823 | bool "torture tests for RCU runnable by default" | |
824 | depends on RCU_TORTURE_TEST = y | |
825 | default n | |
826 | help | |
827 | This option provides a way to build the RCU torture tests | |
828 | directly into the kernel without them starting up at boot | |
829 | time. You can use /proc/sys/kernel/rcutorture_runnable | |
830 | to manually override this setting. This /proc file is | |
831 | available only when the RCU torture tests have been built | |
832 | into the kernel. | |
833 | ||
834 | Say Y here if you want the RCU torture tests to start during | |
835 | boot (you probably don't). | |
836 | Say N here if you want the RCU torture tests to start only | |
837 | after being manually enabled via /proc. | |
838 | ||
64db4cff PM |
839 | config RCU_CPU_STALL_DETECTOR |
840 | bool "Check for stalled CPUs delaying RCU grace periods" | |
6b3ef48a | 841 | depends on TREE_RCU || TREE_PREEMPT_RCU |
8bfb2f8e | 842 | default y |
64db4cff PM |
843 | help |
844 | This option causes RCU to printk information on which | |
845 | CPUs are delaying the current grace period, but only when | |
846 | the grace period extends for excessive time periods. | |
67182ae1 | 847 | |
4c54005c | 848 | Say N if you want to disable such checks. |
67182ae1 | 849 | |
4c54005c | 850 | Say Y if you are unsure. |
67182ae1 | 851 | |
b163760e PM |
852 | config RCU_CPU_STALL_TIMEOUT |
853 | int "RCU CPU stall timeout in seconds" | |
854 | depends on RCU_CPU_STALL_DETECTOR | |
855 | range 3 300 | |
856 | default 60 | |
857 | help | |
858 | If a given RCU grace period extends more than the specified | |
859 | number of seconds, a CPU stall warning is printed. If the | |
860 | RCU grace period persists, additional CPU stall warnings are | |
861 | printed at more widely spaced intervals. | |
862 | ||
910b1b7e PM |
863 | config RCU_CPU_STALL_DETECTOR_RUNNABLE |
864 | bool "RCU CPU stall checking starts automatically at boot" | |
865 | depends on RCU_CPU_STALL_DETECTOR | |
866 | default y | |
867 | help | |
868 | If set, start checking for RCU CPU stalls immediately on | |
869 | boot. Otherwise, RCU CPU stall checking must be manually | |
870 | enabled. | |
871 | ||
872 | Say Y if you are unsure. | |
873 | ||
874 | Say N if you wish to suppress RCU CPU stall checking during boot. | |
875 | ||
1ed509a2 PM |
876 | config RCU_CPU_STALL_VERBOSE |
877 | bool "Print additional per-task information for RCU_CPU_STALL_DETECTOR" | |
878 | depends on RCU_CPU_STALL_DETECTOR && TREE_PREEMPT_RCU | |
55ec936f | 879 | default y |
1ed509a2 PM |
880 | help |
881 | This option causes RCU to printk detailed per-task information | |
882 | for any tasks that are stalling the current RCU grace period. | |
67182ae1 PM |
883 | |
884 | Say N if you are unsure. | |
885 | ||
1ed509a2 PM |
886 | Say Y if you want to enable such checks. |
887 | ||
8c1c9356 AM |
888 | config KPROBES_SANITY_TEST |
889 | bool "Kprobes sanity tests" | |
890 | depends on DEBUG_KERNEL | |
891 | depends on KPROBES | |
892 | default n | |
893 | help | |
894 | This option provides for testing basic kprobes functionality on | |
895 | boot. A sample kprobe, jprobe and kretprobe are inserted and | |
896 | verified for functionality. | |
897 | ||
898 | Say N if you are unsure. | |
899 | ||
6dab2778 AV |
900 | config BACKTRACE_SELF_TEST |
901 | tristate "Self test for the backtrace code" | |
902 | depends on DEBUG_KERNEL | |
903 | default n | |
904 | help | |
905 | This option provides a kernel module that can be used to test | |
906 | the kernel stack backtrace code. This option is not useful | |
907 | for distributions or general kernels, but only for kernel | |
908 | developers working on architecture code. | |
909 | ||
ad118c54 VN |
910 | Note that if you want to also test saved backtraces, you will |
911 | have to enable STACKTRACE as well. | |
912 | ||
6dab2778 AV |
913 | Say N if you are unsure. |
914 | ||
870d6656 TH |
915 | config DEBUG_BLOCK_EXT_DEVT |
916 | bool "Force extended block device numbers and spread them" | |
917 | depends on DEBUG_KERNEL | |
918 | depends on BLOCK | |
759f8ca3 | 919 | default n |
870d6656 | 920 | help |
0e11e342 TH |
921 | BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON |
922 | SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT | |
923 | YOU ARE DOING. Distros, please enable this and fix whatever | |
924 | is broken. | |
925 | ||
870d6656 TH |
926 | Conventionally, block device numbers are allocated from |
927 | predetermined contiguous area. However, extended block area | |
928 | may introduce non-contiguous block device numbers. This | |
929 | option forces most block device numbers to be allocated from | |
930 | the extended space and spreads them to discover kernel or | |
931 | userland code paths which assume predetermined contiguous | |
932 | device number allocation. | |
933 | ||
55dc7db7 TH |
934 | Note that turning on this debug option shuffles all the |
935 | device numbers for all IDE and SCSI devices including libata | |
936 | ones, so root partition specified using device number | |
937 | directly (via rdev or root=MAJ:MIN) won't work anymore. | |
938 | Textual device names (root=/dev/sdXn) will continue to work. | |
939 | ||
870d6656 TH |
940 | Say N if you are unsure. |
941 | ||
7c756e6e TH |
942 | config DEBUG_FORCE_WEAK_PER_CPU |
943 | bool "Force weak per-cpu definitions" | |
944 | depends on DEBUG_KERNEL | |
945 | help | |
946 | s390 and alpha require percpu variables in modules to be | |
947 | defined weak to work around addressing range issue which | |
948 | puts the following two restrictions on percpu variable | |
949 | definitions. | |
950 | ||
951 | 1. percpu symbols must be unique whether static or not | |
952 | 2. percpu variables can't be defined inside a function | |
953 | ||
954 | To ensure that generic code follows the above rules, this | |
955 | option forces all percpu variables to be defined as weak. | |
956 | ||
8bb31b9d AG |
957 | config LKDTM |
958 | tristate "Linux Kernel Dump Test Tool Module" | |
0347af4e | 959 | depends on DEBUG_FS |
fddd9cf8 | 960 | depends on BLOCK |
8bb31b9d AG |
961 | default n |
962 | help | |
963 | This module enables testing of the different dumping mechanisms by | |
964 | inducing system failures at predefined crash points. | |
965 | If you don't need it: say N | |
966 | Choose M here to compile this code as a module. The module will be | |
967 | called lkdtm. | |
968 | ||
969 | Documentation on how to use the module can be found in | |
0347af4e | 970 | Documentation/fault-injection/provoke-crashes.txt |
6ff1cb35 | 971 | |
c9d221f8 AM |
972 | config CPU_NOTIFIER_ERROR_INJECT |
973 | tristate "CPU notifier error injection module" | |
974 | depends on HOTPLUG_CPU && DEBUG_KERNEL | |
975 | help | |
976 | This option provides a kernel module that can be used to test | |
977 | the error handling of the cpu notifiers | |
978 | ||
979 | To compile this code as a module, choose M here: the module will | |
980 | be called cpu-notifier-error-inject. | |
981 | ||
982 | If unsure, say N. | |
983 | ||
6ff1cb35 | 984 | config FAULT_INJECTION |
1ab8509a AM |
985 | bool "Fault-injection framework" |
986 | depends on DEBUG_KERNEL | |
329409ae AM |
987 | help |
988 | Provide fault-injection framework. | |
989 | For more details, see Documentation/fault-injection/. | |
6ff1cb35 | 990 | |
8a8b6502 | 991 | config FAILSLAB |
1ab8509a AM |
992 | bool "Fault-injection capability for kmalloc" |
993 | depends on FAULT_INJECTION | |
773ff60e | 994 | depends on SLAB || SLUB |
8a8b6502 | 995 | help |
1ab8509a | 996 | Provide fault-injection capability for kmalloc. |
8a8b6502 | 997 | |
933e312e AM |
998 | config FAIL_PAGE_ALLOC |
999 | bool "Fault-injection capabilitiy for alloc_pages()" | |
1ab8509a | 1000 | depends on FAULT_INJECTION |
933e312e | 1001 | help |
1ab8509a | 1002 | Provide fault-injection capability for alloc_pages(). |
933e312e | 1003 | |
c17bb495 | 1004 | config FAIL_MAKE_REQUEST |
86327d19 | 1005 | bool "Fault-injection capability for disk IO" |
581d4e28 | 1006 | depends on FAULT_INJECTION && BLOCK |
c17bb495 | 1007 | help |
1ab8509a | 1008 | Provide fault-injection capability for disk IO. |
c17bb495 | 1009 | |
581d4e28 | 1010 | config FAIL_IO_TIMEOUT |
f4d01439 | 1011 | bool "Fault-injection capability for faking disk interrupts" |
581d4e28 JA |
1012 | depends on FAULT_INJECTION && BLOCK |
1013 | help | |
1014 | Provide fault-injection capability on end IO handling. This | |
1015 | will make the block layer "forget" an interrupt as configured, | |
1016 | thus exercising the error handling. | |
1017 | ||
1018 | Only works with drivers that use the generic timeout handling, | |
1019 | for others it wont do anything. | |
1020 | ||
6ff1cb35 AM |
1021 | config FAULT_INJECTION_DEBUG_FS |
1022 | bool "Debugfs entries for fault-injection capabilities" | |
1ab8509a | 1023 | depends on FAULT_INJECTION && SYSFS && DEBUG_FS |
6ff1cb35 | 1024 | help |
1ab8509a | 1025 | Enable configuration of fault-injection capabilities via debugfs. |
1df49008 AM |
1026 | |
1027 | config FAULT_INJECTION_STACKTRACE_FILTER | |
1028 | bool "stacktrace filter for fault-injection capabilities" | |
1029 | depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT | |
6d690dca | 1030 | depends on !X86_64 |
1df49008 | 1031 | select STACKTRACE |
79aac889 | 1032 | select FRAME_POINTER if !PPC && !S390 && !MICROBLAZE |
1df49008 AM |
1033 | help |
1034 | Provide stacktrace filter for fault-injection capabilities | |
267c4025 | 1035 | |
9745512c AV |
1036 | config LATENCYTOP |
1037 | bool "Latency measuring infrastructure" | |
625fdcaa RD |
1038 | depends on HAVE_LATENCYTOP_SUPPORT |
1039 | depends on DEBUG_KERNEL | |
1040 | depends on STACKTRACE_SUPPORT | |
1041 | depends on PROC_FS | |
79aac889 | 1042 | select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE |
9745512c AV |
1043 | select KALLSYMS |
1044 | select KALLSYMS_ALL | |
1045 | select STACKTRACE | |
1046 | select SCHEDSTATS | |
1047 | select SCHED_DEBUG | |
9745512c AV |
1048 | help |
1049 | Enable this option if you want to use the LatencyTOP tool | |
1050 | to find out which userspace is blocking on what kernel operations. | |
1051 | ||
9e94cd32 AK |
1052 | config SYSCTL_SYSCALL_CHECK |
1053 | bool "Sysctl checks" | |
83ac201b | 1054 | depends on SYSCTL |
9e94cd32 AK |
1055 | ---help--- |
1056 | sys_sysctl uses binary paths that have been found challenging | |
1057 | to properly maintain and use. This enables checks that help | |
1058 | you to keep things correct. | |
1059 | ||
6a11f75b | 1060 | source mm/Kconfig.debug |
16444a8a ACM |
1061 | source kernel/trace/Kconfig |
1062 | ||
f212ec4b | 1063 | config PROVIDE_OHCI1394_DMA_INIT |
080de8c2 | 1064 | bool "Remote debugging over FireWire early on boot" |
f212ec4b BK |
1065 | depends on PCI && X86 |
1066 | help | |
1067 | If you want to debug problems which hang or crash the kernel early | |
1068 | on boot and the crashing machine has a FireWire port, you can use | |
1069 | this feature to remotely access the memory of the crashed machine | |
1070 | over FireWire. This employs remote DMA as part of the OHCI1394 | |
1071 | specification which is now the standard for FireWire controllers. | |
1072 | ||
1073 | With remote DMA, you can monitor the printk buffer remotely using | |
1074 | firescope and access all memory below 4GB using fireproxy from gdb. | |
1075 | Even controlling a kernel debugger is possible using remote DMA. | |
1076 | ||
1077 | Usage: | |
1078 | ||
1079 | If ohci1394_dma=early is used as boot parameter, it will initialize | |
1080 | all OHCI1394 controllers which are found in the PCI config space. | |
1081 | ||
1082 | As all changes to the FireWire bus such as enabling and disabling | |
1083 | devices cause a bus reset and thereby disable remote DMA for all | |
1084 | devices, be sure to have the cable plugged and FireWire enabled on | |
1085 | the debugging host before booting the debug target for debugging. | |
1086 | ||
1087 | This code (~1k) is freed after boot. By then, the firewire stack | |
1088 | in charge of the OHCI-1394 controllers should be used instead. | |
1089 | ||
1090 | See Documentation/debugging-via-ohci1394.txt for more information. | |
9745512c | 1091 | |
080de8c2 SR |
1092 | config FIREWIRE_OHCI_REMOTE_DMA |
1093 | bool "Remote debugging over FireWire with firewire-ohci" | |
1094 | depends on FIREWIRE_OHCI | |
1095 | help | |
1096 | This option lets you use the FireWire bus for remote debugging | |
1097 | with help of the firewire-ohci driver. It enables unfiltered | |
1098 | remote DMA in firewire-ohci. | |
1099 | See Documentation/debugging-via-ohci1394.txt for more information. | |
1100 | ||
1101 | If unsure, say N. | |
1102 | ||
152de30b | 1103 | config BUILD_DOCSRC |
3794f3e8 RD |
1104 | bool "Build targets in Documentation/ tree" |
1105 | depends on HEADERS_CHECK | |
1106 | help | |
1107 | This option attempts to build objects from the source files in the | |
1108 | kernel Documentation/ tree. | |
1109 | ||
1110 | Say N if you are unsure. | |
1111 | ||
e9d376f0 | 1112 | config DYNAMIC_DEBUG |
86151fdf | 1113 | bool "Enable dynamic printk() support" |
346e15be JB |
1114 | default n |
1115 | depends on PRINTK | |
86151fdf | 1116 | depends on DEBUG_FS |
346e15be JB |
1117 | help |
1118 | ||
1119 | Compiles debug level messages into the kernel, which would not | |
1120 | otherwise be available at runtime. These messages can then be | |
86151fdf JB |
1121 | enabled/disabled based on various levels of scope - per source file, |
1122 | function, module, format string, and line number. This mechanism | |
1123 | implicitly enables all pr_debug() and dev_dbg() calls. The impact of | |
1124 | this compile option is a larger kernel text size of about 2%. | |
346e15be JB |
1125 | |
1126 | Usage: | |
1127 | ||
2b2f68b5 | 1128 | Dynamic debugging is controlled via the 'dynamic_debug/control' file, |
86151fdf JB |
1129 | which is contained in the 'debugfs' filesystem. Thus, the debugfs |
1130 | filesystem must first be mounted before making use of this feature. | |
2b2f68b5 | 1131 | We refer the control file as: <debugfs>/dynamic_debug/control. This |
86151fdf JB |
1132 | file contains a list of the debug statements that can be enabled. The |
1133 | format for each line of the file is: | |
346e15be | 1134 | |
86151fdf | 1135 | filename:lineno [module]function flags format |
346e15be | 1136 | |
86151fdf JB |
1137 | filename : source file of the debug statement |
1138 | lineno : line number of the debug statement | |
1139 | module : module that contains the debug statement | |
1140 | function : function that contains the debug statement | |
1141 | flags : 'p' means the line is turned 'on' for printing | |
1142 | format : the format used for the debug statement | |
346e15be JB |
1143 | |
1144 | From a live system: | |
1145 | ||
2b2f68b5 | 1146 | nullarbor:~ # cat <debugfs>/dynamic_debug/control |
86151fdf JB |
1147 | # filename:lineno [module]function flags format |
1148 | fs/aio.c:222 [aio]__put_ioctx - "__put_ioctx:\040freeing\040%p\012" | |
1149 | fs/aio.c:248 [aio]ioctx_alloc - "ENOMEM:\040nr_events\040too\040high\012" | |
1150 | fs/aio.c:1770 [aio]sys_io_cancel - "calling\040cancel\012" | |
346e15be | 1151 | |
86151fdf | 1152 | Example usage: |
346e15be | 1153 | |
86151fdf JB |
1154 | // enable the message at line 1603 of file svcsock.c |
1155 | nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' > | |
2b2f68b5 | 1156 | <debugfs>/dynamic_debug/control |
346e15be | 1157 | |
86151fdf JB |
1158 | // enable all the messages in file svcsock.c |
1159 | nullarbor:~ # echo -n 'file svcsock.c +p' > | |
2b2f68b5 | 1160 | <debugfs>/dynamic_debug/control |
346e15be | 1161 | |
86151fdf JB |
1162 | // enable all the messages in the NFS server module |
1163 | nullarbor:~ # echo -n 'module nfsd +p' > | |
2b2f68b5 | 1164 | <debugfs>/dynamic_debug/control |
346e15be | 1165 | |
86151fdf JB |
1166 | // enable all 12 messages in the function svc_process() |
1167 | nullarbor:~ # echo -n 'func svc_process +p' > | |
2b2f68b5 | 1168 | <debugfs>/dynamic_debug/control |
346e15be | 1169 | |
86151fdf JB |
1170 | // disable all 12 messages in the function svc_process() |
1171 | nullarbor:~ # echo -n 'func svc_process -p' > | |
2b2f68b5 | 1172 | <debugfs>/dynamic_debug/control |
346e15be | 1173 | |
86151fdf | 1174 | See Documentation/dynamic-debug-howto.txt for additional information. |
346e15be | 1175 | |
5ee00bd4 JR |
1176 | config DMA_API_DEBUG |
1177 | bool "Enable debugging of DMA-API usage" | |
1178 | depends on HAVE_DMA_API_DEBUG | |
1179 | help | |
1180 | Enable this option to debug the use of the DMA API by device drivers. | |
1181 | With this option you will be able to detect common bugs in device | |
1182 | drivers like double-freeing of DMA mappings or freeing mappings that | |
1183 | were never allocated. | |
1184 | This option causes a performance degredation. Use only if you want | |
1185 | to debug device drivers. If unsure, say N. | |
346e15be | 1186 | |
86a89380 LB |
1187 | config ATOMIC64_SELFTEST |
1188 | bool "Perform an atomic64_t self-test at boot" | |
1189 | help | |
1190 | Enable this option to test the atomic64_t functions at boot. | |
1191 | ||
1192 | If unsure, say N. | |
1193 | ||
267c4025 | 1194 | source "samples/Kconfig" |
dc7d5527 JW |
1195 | |
1196 | source "lib/Kconfig.kgdb" | |
0a4af3b0 PE |
1197 | |
1198 | source "lib/Kconfig.kmemcheck" |