Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | |
| 2 | config PRINTK_TIME |
| 3 | bool "Show timing information on printks" |
Randy Dunlap | d3b8b6e | 2006-12-06 20:36:38 -0800 | [diff] [blame] | 4 | depends on PRINTK |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Jeff Garzik | de48844 | 2007-10-25 04:06:13 -0400 | [diff] [blame] | 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 | |
Andrew Morton | cebc04b | 2006-08-14 22:43:18 -0700 | [diff] [blame] | 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. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | |
Andi Kleen | 35bb5b1 | 2008-02-22 15:15:03 +0100 | [diff] [blame] | 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 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | config MAGIC_SYSRQ |
| 40 | bool "Magic SysRq key" |
Adrian Bunk | f346f4b | 2006-01-09 20:54:51 -0800 | [diff] [blame] | 41 | depends on !UML |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Randy Dunlap | 99657c7 | 2009-09-18 12:49:22 -0700 | [diff] [blame] | 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 | |
Arjan van de Ven | f71d20e | 2006-06-28 04:26:45 -0700 | [diff] [blame] | 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 | |
Don Mullis | bf4735a | 2006-12-10 02:18:37 -0800 | [diff] [blame] | 77 | config DEBUG_FS |
| 78 | bool "Debug Filesystem" |
Don Mullis | bf4735a | 2006-12-10 02:18:37 -0800 | [diff] [blame] | 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 | |
Robert P. J. Day | ff54333 | 2008-05-20 00:06:00 +0200 | [diff] [blame] | 84 | For detailed documentation on the debugfs API, see |
| 85 | Documentation/DocBook/filesystems. |
| 86 | |
Don Mullis | bf4735a | 2006-12-10 02:18:37 -0800 | [diff] [blame] | 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 | |
Sam Ravnborg | 91341d4 | 2008-01-21 21:31:44 +0100 | [diff] [blame] | 103 | config DEBUG_SECTION_MISMATCH |
| 104 | bool "Enable full Section mismatch analysis" |
Mike Frysinger | 1d53661 | 2010-03-23 13:35:17 -0700 | [diff] [blame] | 105 | depends on UNDEFINED || (BLACKFIN) |
| 106 | default y |
Sam Ravnborg | fa2144b | 2008-02-15 13:53:11 +0100 | [diff] [blame] | 107 | # This option is on purpose disabled for now. |
André Goddard Rosa | af901ca | 2009-11-14 13:09:05 -0200 | [diff] [blame] | 108 | # It will be enabled when we are down to a reasonable number |
Sam Ravnborg | fa2144b | 2008-02-15 13:53:11 +0100 | [diff] [blame] | 109 | # of section mismatch warnings (< 10 for an allyesconfig build) |
Sam Ravnborg | 91341d4 | 2008-01-21 21:31:44 +0100 | [diff] [blame] | 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) |
Geert Uytterhoeven | d6fbfa4 | 2008-01-30 11:13:23 +0100 | [diff] [blame] | 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 |
Sam Ravnborg | 91341d4 | 2008-01-21 21:31:44 +0100 | [diff] [blame] | 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 |
Geert Uytterhoeven | d6fbfa4 | 2008-01-30 11:13:23 +0100 | [diff] [blame] | 124 | function we would lose the section information and thus |
Sam Ravnborg | 91341d4 | 2008-01-21 21:31:44 +0100 | [diff] [blame] | 125 | the analysis would not catch the illegal reference. |
Geert Uytterhoeven | d6fbfa4 | 2008-01-30 11:13:23 +0100 | [diff] [blame] | 126 | This option tells gcc to inline less but will also |
Sam Ravnborg | 91341d4 | 2008-01-21 21:31:44 +0100 | [diff] [blame] | 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 |
Geert Uytterhoeven | d6fbfa4 | 2008-01-30 11:13:23 +0100 | [diff] [blame] | 130 | lose valueble information about where the mismatch was |
Sam Ravnborg | 91341d4 | 2008-01-21 21:31:44 +0100 | [diff] [blame] | 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. |
Sam Ravnborg | 588ccd7 | 2008-01-24 21:12:37 +0100 | [diff] [blame] | 136 | - Enable verbose reporting from modpost to help solving |
| 137 | the section mismatches reported. |
Sam Ravnborg | 91341d4 | 2008-01-21 21:31:44 +0100 | [diff] [blame] | 138 | |
Adrian Bunk | f346f4b | 2006-01-09 20:54:51 -0800 | [diff] [blame] | 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 | |
David Woodhouse | a304e1b | 2007-02-12 00:52:00 -0800 | [diff] [blame] | 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 | |
Don Zickus | 58687ac | 2010-05-07 17:11:44 -0400 | [diff] [blame] | 154 | config LOCKUP_DETECTOR |
| 155 | bool "Detect Hard and Soft Lockups" |
Heiko Carstens | dea20a3 | 2006-10-11 01:20:44 -0700 | [diff] [blame] | 156 | depends on DEBUG_KERNEL && !S390 |
Ingo Molnar | 8446f1d | 2005-09-06 15:16:27 -0700 | [diff] [blame] | 157 | help |
Don Zickus | 58687ac | 2010-05-07 17:11:44 -0400 | [diff] [blame] | 158 | Say Y here to enable the kernel to act as a watchdog to detect |
| 159 | hard and soft lockups. |
Don Zickus | 84e478c | 2010-02-05 21:47:05 -0500 | [diff] [blame] | 160 | |
Don Zickus | 58687ac | 2010-05-07 17:11:44 -0400 | [diff] [blame] | 161 | Softlockups are bugs that cause the kernel to loop in kernel |
Ingo Molnar | 9c44bc0 | 2008-05-12 21:21:04 +0200 | [diff] [blame] | 162 | mode for more than 60 seconds, without giving other tasks a |
Don Zickus | 58687ac | 2010-05-07 17:11:44 -0400 | [diff] [blame] | 163 | chance to run. The current stack trace is displayed upon |
| 164 | detection and the system will stay locked up. |
Ingo Molnar | 8446f1d | 2005-09-06 15:16:27 -0700 | [diff] [blame] | 165 | |
Don Zickus | 58687ac | 2010-05-07 17:11:44 -0400 | [diff] [blame] | 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. |
Ingo Molnar | 8446f1d | 2005-09-06 15:16:27 -0700 | [diff] [blame] | 170 | |
Don Zickus | 58687ac | 2010-05-07 17:11:44 -0400 | [diff] [blame] | 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. |
Don Zickus | 84e478c | 2010-02-05 21:47:05 -0500 | [diff] [blame] | 174 | |
Frederic Weisbecker | 23637d4 | 2010-05-15 23:15:20 +0200 | [diff] [blame] | 175 | config HARDLOCKUP_DETECTOR |
| 176 | def_bool LOCKUP_DETECTOR && PERF_EVENTS && HAVE_PERF_EVENTS_NMI |
Ingo Molnar | 8446f1d | 2005-09-06 15:16:27 -0700 | [diff] [blame] | 177 | |
Ingo Molnar | 9c44bc0 | 2008-05-12 21:21:04 +0200 | [diff] [blame] | 178 | config BOOTPARAM_SOFTLOCKUP_PANIC |
| 179 | bool "Panic (Reboot) On Soft Lockups" |
Frederic Weisbecker | 89d7ce2 | 2010-05-13 00:27:20 +0200 | [diff] [blame] | 180 | depends on LOCKUP_DETECTOR |
Ingo Molnar | 9c44bc0 | 2008-05-12 21:21:04 +0200 | [diff] [blame] | 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 |
Frederic Weisbecker | e16bb1d | 2010-05-15 22:30:22 +0200 | [diff] [blame] | 197 | depends on LOCKUP_DETECTOR |
Ingo Molnar | 9c44bc0 | 2008-05-12 21:21:04 +0200 | [diff] [blame] | 198 | range 0 1 |
| 199 | default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC |
| 200 | default 1 if BOOTPARAM_SOFTLOCKUP_PANIC |
| 201 | |
Mandeep Singh Baines | e162b39 | 2009-01-15 11:08:40 -0800 | [diff] [blame] | 202 | config DETECT_HUNG_TASK |
| 203 | bool "Detect Hung Tasks" |
| 204 | depends on DEBUG_KERNEL |
Ingo Molnar | 77d0563 | 2009-04-07 08:55:36 +0200 | [diff] [blame] | 205 | default DETECT_SOFTLOCKUP |
Mandeep Singh Baines | e162b39 | 2009-01-15 11:08:40 -0800 | [diff] [blame] | 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 | |
Ingo Molnar | b642b6d | 2007-07-09 18:52:00 +0200 | [diff] [blame] | 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 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Ingo Molnar | 82f67cd | 2007-02-16 01:28:13 -0800 | [diff] [blame] | 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 |
Ingo Molnar | c1a834d | 2007-06-01 00:47:16 -0700 | [diff] [blame] | 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). |
Ingo Molnar | 82f67cd | 2007-02-16 01:28:13 -0800 | [diff] [blame] | 274 | |
Thomas Gleixner | 3ac7fe5 | 2008-04-30 00:55:01 -0700 | [diff] [blame] | 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 | |
Thomas Gleixner | c6f3a97 | 2008-04-30 00:55:03 -0700 | [diff] [blame] | 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 | |
Thomas Gleixner | dc186ad | 2009-11-16 01:09:48 +0900 | [diff] [blame] | 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 | |
Mathieu Desnoyers | 551d55a | 2010-04-17 08:48:42 -0400 | [diff] [blame] | 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 | |
Ingo Molnar | 3ae7020 | 2008-11-26 10:02:00 +0100 | [diff] [blame] | 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 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 328 | config DEBUG_SLAB |
Andrew Morton | 4a2f0ac | 2006-03-25 03:07:22 -0800 | [diff] [blame] | 329 | bool "Debug slab memory allocations" |
Vegard Nossum | 7d46d9e | 2008-04-04 00:51:41 +0200 | [diff] [blame] | 330 | depends on DEBUG_KERNEL && SLAB && !KMEMCHECK |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Al Viro | 871751e | 2006-03-25 03:06:39 -0800 | [diff] [blame] | 336 | config DEBUG_SLAB_LEAK |
| 337 | bool "Memory leak debugging" |
| 338 | depends on DEBUG_SLAB |
| 339 | |
Christoph Lameter | f0630ff | 2007-07-15 23:38:14 -0700 | [diff] [blame] | 340 | config SLUB_DEBUG_ON |
| 341 | bool "SLUB debugging on by default" |
Vegard Nossum | 7d46d9e | 2008-04-04 00:51:41 +0200 | [diff] [blame] | 342 | depends on SLUB && SLUB_DEBUG && !KMEMCHECK |
Christoph Lameter | f0630ff | 2007-07-15 23:38:14 -0700 | [diff] [blame] | 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 | |
Christoph Lameter | 8ff12cf | 2008-02-07 17:47:41 -0800 | [diff] [blame] | 353 | config SLUB_STATS |
| 354 | default n |
| 355 | bool "Enable SLUB performance statistics" |
Christoph Lameter | 5b06c853 | 2008-04-14 18:51:34 +0300 | [diff] [blame] | 356 | depends on SLUB && SLUB_DEBUG && SYSFS |
Christoph Lameter | 8ff12cf | 2008-02-07 17:47:41 -0800 | [diff] [blame] | 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 | |
Catalin Marinas | 3bba00d | 2009-06-11 13:24:13 +0100 | [diff] [blame] | 366 | config DEBUG_KMEMLEAK |
| 367 | bool "Kernel memory leak detector" |
Heiko Carstens | dfcc3e6 | 2009-10-06 10:33:57 +0200 | [diff] [blame] | 368 | depends on DEBUG_KERNEL && EXPERIMENTAL && !MEMORY_HOTPLUG && \ |
David S. Miller | 9343af0 | 2010-04-13 00:28:45 -0700 | [diff] [blame] | 369 | (X86 || ARM || PPC || S390 || SPARC64 || SUPERH || MICROBLAZE) |
Heiko Carstens | dfcc3e6 | 2009-10-06 10:33:57 +0200 | [diff] [blame] | 370 | |
Catalin Marinas | 3bba00d | 2009-06-11 13:24:13 +0100 | [diff] [blame] | 371 | select DEBUG_FS if SYSFS |
| 372 | select STACKTRACE if STACKTRACE_SUPPORT |
| 373 | select KALLSYMS |
Randy Dunlap | b60e26a | 2009-11-06 15:33:45 -0800 | [diff] [blame] | 374 | select CRC32 |
Catalin Marinas | 3bba00d | 2009-06-11 13:24:13 +0100 | [diff] [blame] | 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 | |
Catalin Marinas | bf96d1e | 2009-06-23 14:40:27 +0100 | [diff] [blame] | 385 | Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances |
| 386 | of finding leaks due to the slab objects poisoning. |
| 387 | |
Catalin Marinas | 3bba00d | 2009-06-11 13:24:13 +0100 | [diff] [blame] | 388 | In order to access the kmemleak file, debugfs needs to be |
| 389 | mounted (usually at /sys/kernel/debug). |
| 390 | |
Catalin Marinas | a9d9058 | 2009-06-25 10:16:11 +0100 | [diff] [blame] | 391 | config DEBUG_KMEMLEAK_EARLY_LOG_SIZE |
| 392 | int "Maximum kmemleak early log entries" |
| 393 | depends on DEBUG_KMEMLEAK |
Heiko Carstens | dfcc3e6 | 2009-10-06 10:33:57 +0200 | [diff] [blame] | 394 | range 200 40000 |
Catalin Marinas | a9d9058 | 2009-06-25 10:16:11 +0100 | [diff] [blame] | 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 | |
Catalin Marinas | 0822ee4 | 2009-06-11 13:24:14 +0100 | [diff] [blame] | 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 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 413 | config DEBUG_PREEMPT |
| 414 | bool "Debug preemptible kernel" |
Kumar Gala | 01deab9 | 2009-10-16 07:21:39 +0000 | [diff] [blame] | 415 | depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 416 | default y |
| 417 | help |
| 418 | If you say Y here then the kernel will use a debug variant of the |
| 419 | commonly used smp_processor_id() function and will print warnings |
| 420 | if kernel code uses it in a preemption-unsafe way. Also, the kernel |
| 421 | will detect preemption count underflows. |
| 422 | |
Ingo Molnar | e7eebaf | 2006-06-27 02:54:55 -0700 | [diff] [blame] | 423 | config DEBUG_RT_MUTEXES |
| 424 | bool "RT Mutex debugging, deadlock detection" |
Ingo Molnar | e7eebaf | 2006-06-27 02:54:55 -0700 | [diff] [blame] | 425 | depends on DEBUG_KERNEL && RT_MUTEXES |
| 426 | help |
| 427 | This allows rt mutex semantics violations and rt mutex related |
| 428 | deadlocks (lockups) to be detected and reported automatically. |
| 429 | |
| 430 | config DEBUG_PI_LIST |
| 431 | bool |
| 432 | default y |
| 433 | depends on DEBUG_RT_MUTEXES |
| 434 | |
Thomas Gleixner | 61a8712 | 2006-06-27 02:54:56 -0700 | [diff] [blame] | 435 | config RT_MUTEX_TESTER |
| 436 | bool "Built-in scriptable tester for rt-mutexes" |
Roman Zippel | a1583d3 | 2006-06-27 02:55:00 -0700 | [diff] [blame] | 437 | depends on DEBUG_KERNEL && RT_MUTEXES |
Thomas Gleixner | 61a8712 | 2006-06-27 02:54:56 -0700 | [diff] [blame] | 438 | help |
| 439 | This option enables a rt-mutex tester. |
| 440 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 441 | config DEBUG_SPINLOCK |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 442 | bool "Spinlock and rw-lock debugging: basic checks" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 443 | depends on DEBUG_KERNEL |
| 444 | help |
| 445 | Say Y here and build SMP to catch missing spinlock initialization |
| 446 | and certain other kinds of spinlock errors commonly made. This is |
| 447 | best used in conjunction with the NMI watchdog so that spinlock |
| 448 | deadlocks are also debuggable. |
| 449 | |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 450 | config DEBUG_MUTEXES |
| 451 | bool "Mutex debugging: basic checks" |
| 452 | depends on DEBUG_KERNEL |
| 453 | help |
| 454 | This feature allows mutex semantics violations to be detected and |
| 455 | reported. |
| 456 | |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 457 | config DEBUG_LOCK_ALLOC |
| 458 | bool "Lock debugging: detect incorrect freeing of live locks" |
Adrian Bunk | 517e7aa | 2006-07-14 00:24:32 -0700 | [diff] [blame] | 459 | depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 460 | select DEBUG_SPINLOCK |
| 461 | select DEBUG_MUTEXES |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 462 | select LOCKDEP |
| 463 | help |
| 464 | This feature will check whether any held lock (spinlock, rwlock, |
| 465 | mutex or rwsem) is incorrectly freed by the kernel, via any of the |
| 466 | memory-freeing routines (kfree(), kmem_cache_free(), free_pages(), |
| 467 | vfree(), etc.), whether a live lock is incorrectly reinitialized via |
| 468 | spin_lock_init()/mutex_init()/etc., or whether there is any lock |
| 469 | held during task exit. |
| 470 | |
| 471 | config PROVE_LOCKING |
| 472 | bool "Lock debugging: prove locking correctness" |
Adrian Bunk | 517e7aa | 2006-07-14 00:24:32 -0700 | [diff] [blame] | 473 | depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 474 | select LOCKDEP |
| 475 | select DEBUG_SPINLOCK |
| 476 | select DEBUG_MUTEXES |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 477 | select DEBUG_LOCK_ALLOC |
| 478 | default n |
| 479 | help |
| 480 | This feature enables the kernel to prove that all locking |
| 481 | that occurs in the kernel runtime is mathematically |
| 482 | correct: that under no circumstance could an arbitrary (and |
| 483 | not yet triggered) combination of observed locking |
| 484 | sequences (on an arbitrary number of CPUs, running an |
| 485 | arbitrary number of tasks and interrupt contexts) cause a |
| 486 | deadlock. |
| 487 | |
| 488 | In short, this feature enables the kernel to report locking |
| 489 | related deadlocks before they actually occur. |
| 490 | |
| 491 | The proof does not depend on how hard and complex a |
| 492 | deadlock scenario would be to trigger: how many |
| 493 | participant CPUs, tasks and irq-contexts would be needed |
| 494 | for it to trigger. The proof also does not depend on |
| 495 | timing: if a race and a resulting deadlock is possible |
| 496 | theoretically (no matter how unlikely the race scenario |
| 497 | is), it will be proven so and will immediately be |
| 498 | reported by the kernel (once the event is observed that |
| 499 | makes the deadlock theoretically possible). |
| 500 | |
| 501 | If a deadlock is impossible (i.e. the locking rules, as |
| 502 | observed by the kernel, are mathematically correct), the |
| 503 | kernel reports nothing. |
| 504 | |
| 505 | NOTE: this feature can also be enabled for rwlocks, mutexes |
| 506 | and rwsems - in which case all dependencies between these |
| 507 | different locking variants are observed and mapped too, and |
| 508 | the proof of observed correctness is also maintained for an |
| 509 | arbitrary combination of these separate locking variants. |
| 510 | |
| 511 | For more details, see Documentation/lockdep-design.txt. |
| 512 | |
Paul E. McKenney | 632ee20 | 2010-02-22 17:04:45 -0800 | [diff] [blame] | 513 | config PROVE_RCU |
| 514 | bool "RCU debugging: prove RCU correctness" |
| 515 | depends on PROVE_LOCKING |
| 516 | default n |
| 517 | help |
| 518 | This feature enables lockdep extensions that check for correct |
| 519 | use of RCU APIs. This is currently under development. Say Y |
| 520 | if you want to debug RCU usage or help work on the PROVE_RCU |
| 521 | feature. |
| 522 | |
| 523 | Say N if you are unsure. |
| 524 | |
Lai Jiangshan | 2b3fc35 | 2010-04-20 16:23:07 +0800 | [diff] [blame] | 525 | config PROVE_RCU_REPEATEDLY |
| 526 | bool "RCU debugging: don't disable PROVE_RCU on first splat" |
| 527 | depends on PROVE_RCU |
| 528 | default n |
| 529 | help |
| 530 | By itself, PROVE_RCU will disable checking upon issuing the |
| 531 | first warning (or "splat"). This feature prevents such |
| 532 | disabling, allowing multiple RCU-lockdep warnings to be printed |
| 533 | on a single reboot. |
| 534 | |
| 535 | Say N if you are unsure. |
| 536 | |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 537 | config LOCKDEP |
| 538 | bool |
Adrian Bunk | 517e7aa | 2006-07-14 00:24:32 -0700 | [diff] [blame] | 539 | depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 540 | select STACKTRACE |
Michal Simek | 79aac88 | 2010-05-25 11:33:26 +0200 | [diff] [blame] | 541 | select FRAME_POINTER if !MIPS && !PPC && !ARM_UNWIND && !S390 && !MICROBLAZE |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 542 | select KALLSYMS |
| 543 | select KALLSYMS_ALL |
| 544 | |
Peter Zijlstra | f20786f | 2007-07-19 01:48:56 -0700 | [diff] [blame] | 545 | config LOCK_STAT |
Danny ter Haar | fdfb870 | 2007-09-24 21:24:43 -0700 | [diff] [blame] | 546 | bool "Lock usage statistics" |
Peter Zijlstra | f20786f | 2007-07-19 01:48:56 -0700 | [diff] [blame] | 547 | depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT |
| 548 | select LOCKDEP |
| 549 | select DEBUG_SPINLOCK |
| 550 | select DEBUG_MUTEXES |
| 551 | select DEBUG_LOCK_ALLOC |
| 552 | default n |
| 553 | help |
| 554 | This feature enables tracking lock contention points |
| 555 | |
Peter Zijlstra | a560aa4 | 2007-10-07 00:24:33 -0700 | [diff] [blame] | 556 | For more details, see Documentation/lockstat.txt |
| 557 | |
Frederic Weisbecker | dd8b1cf | 2010-02-27 17:10:39 +0100 | [diff] [blame] | 558 | This also enables lock events required by "perf lock", |
| 559 | subcommand of perf. |
| 560 | If you want to use "perf lock", you also need to turn on |
| 561 | CONFIG_EVENT_TRACING. |
Hitoshi Mitake | 84c6f88 | 2010-02-04 16:08:15 +0900 | [diff] [blame] | 562 | |
| 563 | CONFIG_LOCK_STAT defines "contended" and "acquired" lock events. |
Frederic Weisbecker | dd8b1cf | 2010-02-27 17:10:39 +0100 | [diff] [blame] | 564 | (CONFIG_LOCKDEP defines "acquire" and "release" events.) |
Hitoshi Mitake | 84c6f88 | 2010-02-04 16:08:15 +0900 | [diff] [blame] | 565 | |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 566 | config DEBUG_LOCKDEP |
| 567 | bool "Lock dependency engine debugging" |
Adrian Bunk | 517e7aa | 2006-07-14 00:24:32 -0700 | [diff] [blame] | 568 | depends on DEBUG_KERNEL && LOCKDEP |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 569 | help |
| 570 | If you say Y here, the lock dependency engine will do |
| 571 | additional runtime checks to debug itself, at the price |
| 572 | of more runtime overhead. |
| 573 | |
| 574 | config TRACE_IRQFLAGS |
Adrian Bunk | 517e7aa | 2006-07-14 00:24:32 -0700 | [diff] [blame] | 575 | depends on DEBUG_KERNEL |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 576 | bool |
| 577 | default y |
| 578 | depends on TRACE_IRQFLAGS_SUPPORT |
| 579 | depends on PROVE_LOCKING |
| 580 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 581 | config DEBUG_SPINLOCK_SLEEP |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 582 | bool "Spinlock debugging: sleep-inside-spinlock checking" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 583 | depends on DEBUG_KERNEL |
| 584 | help |
| 585 | If you say Y here, various routines which may sleep will become very |
| 586 | noisy if they are called with a spinlock held. |
| 587 | |
Ingo Molnar | cae2ed9 | 2006-07-03 00:24:48 -0700 | [diff] [blame] | 588 | config DEBUG_LOCKING_API_SELFTESTS |
| 589 | bool "Locking API boot-time self-tests" |
| 590 | depends on DEBUG_KERNEL |
| 591 | help |
| 592 | Say Y here if you want the kernel to run a short self-test during |
| 593 | bootup. The self-test checks whether common types of locking bugs |
| 594 | are detected by debugging mechanisms or not. (if you disable |
| 595 | lock debugging then those bugs wont be detected of course.) |
| 596 | The following locking APIs are covered: spinlocks, rwlocks, |
| 597 | mutexes and rwsems. |
| 598 | |
Ingo Molnar | 8637c09 | 2006-07-03 00:24:38 -0700 | [diff] [blame] | 599 | config STACKTRACE |
| 600 | bool |
| 601 | depends on STACKTRACE_SUPPORT |
| 602 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 603 | config DEBUG_KOBJECT |
| 604 | bool "kobject debugging" |
| 605 | depends on DEBUG_KERNEL |
| 606 | help |
| 607 | If you say Y here, some extra kobject debugging messages will be sent |
| 608 | to the syslog. |
| 609 | |
| 610 | config DEBUG_HIGHMEM |
| 611 | bool "Highmem debugging" |
| 612 | depends on DEBUG_KERNEL && HIGHMEM |
| 613 | help |
| 614 | This options enables addition error checking for high memory systems. |
| 615 | Disable for production systems. |
| 616 | |
| 617 | config DEBUG_BUGVERBOSE |
| 618 | bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EMBEDDED |
Matt Mackall | c8538a7 | 2005-05-01 08:59:01 -0700 | [diff] [blame] | 619 | depends on BUG |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 620 | depends on ARM || AVR32 || M32R || M68K || SPARC32 || SPARC64 || \ |
| 621 | FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300 |
Alexey Dobriyan | 8420e7e | 2009-12-14 18:00:25 -0800 | [diff] [blame] | 622 | default y |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 623 | help |
| 624 | Say Y here to make BUG() panics output the file name and line number |
| 625 | of the BUG call as well as the EIP and oops trace. This aids |
| 626 | debugging but costs about 70-100K of memory. |
| 627 | |
| 628 | config DEBUG_INFO |
| 629 | bool "Compile the kernel with debug info" |
| 630 | depends on DEBUG_KERNEL |
| 631 | help |
| 632 | If you say Y here the resulting kernel image will include |
| 633 | debugging info resulting in a larger kernel image. |
Andreas Dilger | b72e53f | 2007-03-27 15:21:33 -0600 | [diff] [blame] | 634 | This adds debug symbols to the kernel and modules (gcc -g), and |
| 635 | is needed if you intend to use kernel crashdump or binary object |
| 636 | tools like crash, kgdb, LKCD, gdb, etc on the kernel. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 637 | Say Y here only if you plan to debug the kernel. |
| 638 | |
| 639 | If unsure, say N. |
| 640 | |
Andi Kleen | d6f4ceb | 2010-07-14 15:43:52 +0200 | [diff] [blame] | 641 | config DEBUG_INFO_REDUCED |
| 642 | bool "Reduce debugging information" |
| 643 | depends on DEBUG_INFO |
| 644 | help |
| 645 | If you say Y here gcc is instructed to generate less debugging |
| 646 | information for structure types. This means that tools that |
| 647 | need full debugging information (like kgdb or systemtap) won't |
| 648 | be happy. But if you merely need debugging information to |
| 649 | resolve line numbers there is no loss. Advantage is that |
| 650 | build directory object sizes shrink dramatically over a full |
| 651 | DEBUG_INFO build and compile times are reduced too. |
| 652 | Only works with newer gcc versions. |
| 653 | |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 654 | config DEBUG_VM |
| 655 | bool "Debug VM" |
| 656 | depends on DEBUG_KERNEL |
| 657 | help |
Nick Piggin | 13e7444 | 2006-01-06 00:10:58 -0800 | [diff] [blame] | 658 | Enable this to turn on extended checks in the virtual-memory system |
| 659 | that may impact performance. |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 660 | |
| 661 | If unsure, say N. |
| 662 | |
Jiri Slaby | 59ea746 | 2008-06-12 13:56:40 +0200 | [diff] [blame] | 663 | config DEBUG_VIRTUAL |
| 664 | bool "Debug VM translations" |
| 665 | depends on DEBUG_KERNEL && X86 |
| 666 | help |
| 667 | Enable some costly sanity checks in virtual to page code. This can |
| 668 | catch mistakes with virt_to_page() and friends. |
| 669 | |
| 670 | If unsure, say N. |
| 671 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 672 | config DEBUG_NOMMU_REGIONS |
| 673 | bool "Debug the global anon/private NOMMU mapping region tree" |
| 674 | depends on DEBUG_KERNEL && !MMU |
| 675 | help |
| 676 | This option causes the global tree of anonymous and private mapping |
| 677 | regions to be regularly checked for invalid topology. |
| 678 | |
Dave Hansen | ad775f5 | 2008-02-15 14:38:01 -0800 | [diff] [blame] | 679 | config DEBUG_WRITECOUNT |
| 680 | bool "Debug filesystem writers count" |
| 681 | depends on DEBUG_KERNEL |
| 682 | help |
| 683 | Enable this to catch wrong use of the writers count in struct |
| 684 | vfsmount. This will increase the size of each file struct by |
| 685 | 32 bits. |
| 686 | |
| 687 | If unsure, say N. |
| 688 | |
Mel Gorman | 6b74ab9 | 2008-07-23 21:26:49 -0700 | [diff] [blame] | 689 | config DEBUG_MEMORY_INIT |
| 690 | bool "Debug memory initialisation" if EMBEDDED |
| 691 | default !EMBEDDED |
| 692 | help |
| 693 | Enable this for additional checks during memory initialisation. |
| 694 | The sanity checks verify aspects of the VM such as the memory model |
| 695 | and other information provided by the architecture. Verbose |
| 696 | information will be printed at KERN_DEBUG loglevel depending |
| 697 | on the mminit_loglevel= command-line option. |
| 698 | |
| 699 | If unsure, say Y |
| 700 | |
Dave Jones | 199a9af | 2006-09-29 01:59:00 -0700 | [diff] [blame] | 701 | config DEBUG_LIST |
| 702 | bool "Debug linked list manipulation" |
| 703 | depends on DEBUG_KERNEL |
| 704 | help |
| 705 | Enable this to turn on extended checks in the linked-list |
| 706 | walking routines. |
| 707 | |
| 708 | If unsure, say N. |
| 709 | |
Jens Axboe | d6ec084 | 2007-10-22 20:01:06 +0200 | [diff] [blame] | 710 | config DEBUG_SG |
| 711 | bool "Debug SG table operations" |
| 712 | depends on DEBUG_KERNEL |
| 713 | help |
| 714 | Enable this to turn on checks on scatter-gather tables. This can |
| 715 | help find problems with drivers that do not properly initialize |
| 716 | their sg tables. |
| 717 | |
| 718 | If unsure, say N. |
| 719 | |
Arjan van de Ven | 1b2439d | 2008-08-15 15:29:38 -0700 | [diff] [blame] | 720 | config DEBUG_NOTIFIERS |
| 721 | bool "Debug notifier call chains" |
| 722 | depends on DEBUG_KERNEL |
| 723 | help |
| 724 | Enable this to turn on sanity checking for notifier call chains. |
| 725 | This is most useful for kernel developers to make sure that |
| 726 | modules properly unregister themselves from notifier chains. |
| 727 | This is a relatively cheap check but if you care about maximum |
| 728 | performance, say N. |
| 729 | |
David Howells | e0e8173 | 2009-09-02 09:13:40 +0100 | [diff] [blame] | 730 | config DEBUG_CREDENTIALS |
| 731 | bool "Debug credential management" |
| 732 | depends on DEBUG_KERNEL |
| 733 | help |
| 734 | Enable this to turn on some debug checking for credential |
| 735 | management. The additional code keeps track of the number of |
| 736 | pointers from task_structs to any given cred struct, and checks to |
| 737 | see that this number never exceeds the usage count of the cred |
| 738 | struct. |
| 739 | |
| 740 | Furthermore, if SELinux is enabled, this also checks that the |
| 741 | security pointer in the cred struct is never seen to be invalid. |
| 742 | |
| 743 | If unsure, say N. |
| 744 | |
Jeff Mahoney | 64dec40 | 2009-01-16 13:23:35 -0500 | [diff] [blame] | 745 | # |
| 746 | # Select this config option from the architecture Kconfig, if it |
| 747 | # it is preferred to always offer frame pointers as a config |
| 748 | # option on the architecture (regardless of KERNEL_DEBUG): |
| 749 | # |
| 750 | config ARCH_WANT_FRAME_POINTERS |
| 751 | bool |
| 752 | help |
| 753 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 754 | config FRAME_POINTER |
| 755 | bool "Compile the kernel with frame pointers" |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 756 | depends on DEBUG_KERNEL && \ |
Heiko Carstens | 75ee034 | 2009-04-23 13:58:10 +0200 | [diff] [blame] | 757 | (CRIS || M68K || M68KNOMMU || FRV || UML || \ |
Ingo Molnar | da4276b | 2009-01-07 11:05:10 +0100 | [diff] [blame] | 758 | AVR32 || SUPERH || BLACKFIN || MN10300) || \ |
| 759 | ARCH_WANT_FRAME_POINTERS |
| 760 | default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 761 | help |
Ingo Molnar | da4276b | 2009-01-07 11:05:10 +0100 | [diff] [blame] | 762 | If you say Y here the resulting kernel image will be slightly |
| 763 | larger and slower, but it gives very useful debugging information |
| 764 | in case of kernel bugs. (precise oopses/stacktraces/warnings) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 765 | |
Randy Dunlap | bfe8df3 | 2007-10-16 01:23:46 -0700 | [diff] [blame] | 766 | config BOOT_PRINTK_DELAY |
| 767 | bool "Delay each boot printk message by N milliseconds" |
| 768 | depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY |
| 769 | help |
| 770 | This build option allows you to read kernel boot messages |
| 771 | by inserting a short delay after each one. The delay is |
| 772 | specified in milliseconds on the kernel command line, |
| 773 | using "boot_delay=N". |
| 774 | |
| 775 | It is likely that you would also need to use "lpj=M" to preset |
| 776 | the "loops per jiffie" value. |
| 777 | See a previous boot log for the "lpj" value to use for your |
| 778 | system, and then set "lpj=M" before setting "boot_delay=N". |
| 779 | NOTE: Using this option may adversely affect SMP systems. |
| 780 | I.e., processors other than the first one may not boot up. |
| 781 | BOOT_PRINTK_DELAY also may cause DETECT_SOFTLOCKUP to detect |
| 782 | what it believes to be lockup conditions. |
| 783 | |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 784 | config RCU_TORTURE_TEST |
| 785 | tristate "torture tests for RCU" |
| 786 | depends on DEBUG_KERNEL |
| 787 | default n |
| 788 | help |
| 789 | This option provides a kernel module that runs torture tests |
| 790 | on the RCU infrastructure. The kernel module may be built |
| 791 | after the fact on the running kernel to be tested, if desired. |
| 792 | |
Paul E. McKenney | 31a72bc | 2008-06-18 09:26:49 -0700 | [diff] [blame] | 793 | Say Y here if you want RCU torture tests to be built into |
| 794 | the kernel. |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 795 | Say M if you want the RCU torture tests to build as a module. |
| 796 | Say N if you are unsure. |
Ankita Garg | 8bb31b9 | 2006-10-02 02:17:36 -0700 | [diff] [blame] | 797 | |
Paul E. McKenney | 31a72bc | 2008-06-18 09:26:49 -0700 | [diff] [blame] | 798 | config RCU_TORTURE_TEST_RUNNABLE |
| 799 | bool "torture tests for RCU runnable by default" |
| 800 | depends on RCU_TORTURE_TEST = y |
| 801 | default n |
| 802 | help |
| 803 | This option provides a way to build the RCU torture tests |
| 804 | directly into the kernel without them starting up at boot |
| 805 | time. You can use /proc/sys/kernel/rcutorture_runnable |
| 806 | to manually override this setting. This /proc file is |
| 807 | available only when the RCU torture tests have been built |
| 808 | into the kernel. |
| 809 | |
| 810 | Say Y here if you want the RCU torture tests to start during |
| 811 | boot (you probably don't). |
| 812 | Say N here if you want the RCU torture tests to start only |
| 813 | after being manually enabled via /proc. |
| 814 | |
Paul E. McKenney | 2133b5d | 2008-10-02 16:06:39 -0700 | [diff] [blame] | 815 | config RCU_CPU_STALL_DETECTOR |
Paul E. McKenney | 67182ae | 2008-08-10 18:35:38 -0700 | [diff] [blame] | 816 | bool "Check for stalled CPUs delaying RCU grace periods" |
Paul E. McKenney | 6b3ef48 | 2009-08-22 13:56:53 -0700 | [diff] [blame] | 817 | depends on TREE_RCU || TREE_PREEMPT_RCU |
Paul E. McKenney | 8bfb2f8 | 2009-12-02 12:10:16 -0800 | [diff] [blame] | 818 | default y |
Paul E. McKenney | 64db4cf | 2008-12-18 21:55:32 +0100 | [diff] [blame] | 819 | help |
| 820 | This option causes RCU to printk information on which |
| 821 | CPUs are delaying the current grace period, but only when |
| 822 | the grace period extends for excessive time periods. |
| 823 | |
Paul E. McKenney | 4c54005 | 2010-01-14 16:10:57 -0800 | [diff] [blame] | 824 | Say N if you want to disable such checks. |
Paul E. McKenney | 64db4cf | 2008-12-18 21:55:32 +0100 | [diff] [blame] | 825 | |
Paul E. McKenney | 4c54005 | 2010-01-14 16:10:57 -0800 | [diff] [blame] | 826 | Say Y if you are unsure. |
Paul E. McKenney | 64db4cf | 2008-12-18 21:55:32 +0100 | [diff] [blame] | 827 | |
Paul E. McKenney | 1ed509a | 2010-02-22 17:05:05 -0800 | [diff] [blame] | 828 | config RCU_CPU_STALL_VERBOSE |
| 829 | bool "Print additional per-task information for RCU_CPU_STALL_DETECTOR" |
| 830 | depends on RCU_CPU_STALL_DETECTOR && TREE_PREEMPT_RCU |
Paul E. McKenney | 55ec936 | 2010-04-13 12:22:33 -0700 | [diff] [blame] | 831 | default y |
Paul E. McKenney | 1ed509a | 2010-02-22 17:05:05 -0800 | [diff] [blame] | 832 | help |
| 833 | This option causes RCU to printk detailed per-task information |
| 834 | for any tasks that are stalling the current RCU grace period. |
Arjan van de Ven | 6dab277 | 2008-01-30 13:33:08 +0100 | [diff] [blame] | 835 | |
| 836 | Say N if you are unsure. |
| 837 | |
Paul E. McKenney | 1ed509a | 2010-02-22 17:05:05 -0800 | [diff] [blame] | 838 | Say Y if you want to enable such checks. |
| 839 | |
Ananth N Mavinakayanahalli | 8c1c935 | 2008-01-30 13:32:53 +0100 | [diff] [blame] | 840 | config KPROBES_SANITY_TEST |
| 841 | bool "Kprobes sanity tests" |
| 842 | depends on DEBUG_KERNEL |
| 843 | depends on KPROBES |
| 844 | default n |
| 845 | help |
| 846 | This option provides for testing basic kprobes functionality on |
| 847 | boot. A sample kprobe, jprobe and kretprobe are inserted and |
| 848 | verified for functionality. |
| 849 | |
| 850 | Say N if you are unsure. |
| 851 | |
Arjan van de Ven | 6dab277 | 2008-01-30 13:33:08 +0100 | [diff] [blame] | 852 | config BACKTRACE_SELF_TEST |
| 853 | tristate "Self test for the backtrace code" |
| 854 | depends on DEBUG_KERNEL |
| 855 | default n |
| 856 | help |
| 857 | This option provides a kernel module that can be used to test |
| 858 | the kernel stack backtrace code. This option is not useful |
| 859 | for distributions or general kernels, but only for kernel |
| 860 | developers working on architecture code. |
| 861 | |
Vegard Nossum | ad118c5 | 2008-06-27 18:04:48 +0200 | [diff] [blame] | 862 | Note that if you want to also test saved backtraces, you will |
| 863 | have to enable STACKTRACE as well. |
| 864 | |
Arjan van de Ven | 6dab277 | 2008-01-30 13:33:08 +0100 | [diff] [blame] | 865 | Say N if you are unsure. |
| 866 | |
Tejun Heo | 870d665 | 2008-08-25 19:47:25 +0900 | [diff] [blame] | 867 | config DEBUG_BLOCK_EXT_DEVT |
| 868 | bool "Force extended block device numbers and spread them" |
| 869 | depends on DEBUG_KERNEL |
| 870 | depends on BLOCK |
Jens Axboe | 759f8ca | 2008-08-29 09:06:29 +0200 | [diff] [blame] | 871 | default n |
Tejun Heo | 870d665 | 2008-08-25 19:47:25 +0900 | [diff] [blame] | 872 | help |
Tejun Heo | 0e11e34 | 2008-10-13 10:46:01 +0200 | [diff] [blame] | 873 | BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON |
| 874 | SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT |
| 875 | YOU ARE DOING. Distros, please enable this and fix whatever |
| 876 | is broken. |
| 877 | |
Tejun Heo | 870d665 | 2008-08-25 19:47:25 +0900 | [diff] [blame] | 878 | Conventionally, block device numbers are allocated from |
| 879 | predetermined contiguous area. However, extended block area |
| 880 | may introduce non-contiguous block device numbers. This |
| 881 | option forces most block device numbers to be allocated from |
| 882 | the extended space and spreads them to discover kernel or |
| 883 | userland code paths which assume predetermined contiguous |
| 884 | device number allocation. |
| 885 | |
Tejun Heo | 55dc7db | 2008-09-01 13:44:35 +0200 | [diff] [blame] | 886 | Note that turning on this debug option shuffles all the |
| 887 | device numbers for all IDE and SCSI devices including libata |
| 888 | ones, so root partition specified using device number |
| 889 | directly (via rdev or root=MAJ:MIN) won't work anymore. |
| 890 | Textual device names (root=/dev/sdXn) will continue to work. |
| 891 | |
Tejun Heo | 870d665 | 2008-08-25 19:47:25 +0900 | [diff] [blame] | 892 | Say N if you are unsure. |
| 893 | |
Tejun Heo | 7c756e6 | 2009-06-24 15:13:50 +0900 | [diff] [blame] | 894 | config DEBUG_FORCE_WEAK_PER_CPU |
| 895 | bool "Force weak per-cpu definitions" |
| 896 | depends on DEBUG_KERNEL |
| 897 | help |
| 898 | s390 and alpha require percpu variables in modules to be |
| 899 | defined weak to work around addressing range issue which |
| 900 | puts the following two restrictions on percpu variable |
| 901 | definitions. |
| 902 | |
| 903 | 1. percpu symbols must be unique whether static or not |
| 904 | 2. percpu variables can't be defined inside a function |
| 905 | |
| 906 | To ensure that generic code follows the above rules, this |
| 907 | option forces all percpu variables to be defined as weak. |
| 908 | |
Ankita Garg | 8bb31b9 | 2006-10-02 02:17:36 -0700 | [diff] [blame] | 909 | config LKDTM |
| 910 | tristate "Linux Kernel Dump Test Tool Module" |
Simon Kagstrom | 0347af4 | 2010-03-05 13:42:49 -0800 | [diff] [blame] | 911 | depends on DEBUG_FS |
Chris Snook | fddd9cf | 2008-02-23 15:23:26 -0800 | [diff] [blame] | 912 | depends on BLOCK |
Ankita Garg | 8bb31b9 | 2006-10-02 02:17:36 -0700 | [diff] [blame] | 913 | default n |
| 914 | help |
| 915 | This module enables testing of the different dumping mechanisms by |
| 916 | inducing system failures at predefined crash points. |
| 917 | If you don't need it: say N |
| 918 | Choose M here to compile this code as a module. The module will be |
| 919 | called lkdtm. |
| 920 | |
| 921 | Documentation on how to use the module can be found in |
Simon Kagstrom | 0347af4 | 2010-03-05 13:42:49 -0800 | [diff] [blame] | 922 | Documentation/fault-injection/provoke-crashes.txt |
Akinobu Mita | 6ff1cb3 | 2006-12-08 02:39:43 -0800 | [diff] [blame] | 923 | |
Akinobu Mita | c9d221f | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 924 | config CPU_NOTIFIER_ERROR_INJECT |
| 925 | tristate "CPU notifier error injection module" |
| 926 | depends on HOTPLUG_CPU && DEBUG_KERNEL |
| 927 | help |
| 928 | This option provides a kernel module that can be used to test |
| 929 | the error handling of the cpu notifiers |
| 930 | |
| 931 | To compile this code as a module, choose M here: the module will |
| 932 | be called cpu-notifier-error-inject. |
| 933 | |
| 934 | If unsure, say N. |
| 935 | |
Akinobu Mita | 6ff1cb3 | 2006-12-08 02:39:43 -0800 | [diff] [blame] | 936 | config FAULT_INJECTION |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 937 | bool "Fault-injection framework" |
| 938 | depends on DEBUG_KERNEL |
Akinobu Mita | 329409a | 2006-12-08 02:39:48 -0800 | [diff] [blame] | 939 | help |
| 940 | Provide fault-injection framework. |
| 941 | For more details, see Documentation/fault-injection/. |
Akinobu Mita | 6ff1cb3 | 2006-12-08 02:39:43 -0800 | [diff] [blame] | 942 | |
Akinobu Mita | 8a8b650 | 2006-12-08 02:39:44 -0800 | [diff] [blame] | 943 | config FAILSLAB |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 944 | bool "Fault-injection capability for kmalloc" |
| 945 | depends on FAULT_INJECTION |
Akinobu Mita | 773ff60 | 2008-12-23 19:37:01 +0900 | [diff] [blame] | 946 | depends on SLAB || SLUB |
Akinobu Mita | 8a8b650 | 2006-12-08 02:39:44 -0800 | [diff] [blame] | 947 | help |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 948 | Provide fault-injection capability for kmalloc. |
Akinobu Mita | 8a8b650 | 2006-12-08 02:39:44 -0800 | [diff] [blame] | 949 | |
Akinobu Mita | 933e312 | 2006-12-08 02:39:45 -0800 | [diff] [blame] | 950 | config FAIL_PAGE_ALLOC |
| 951 | bool "Fault-injection capabilitiy for alloc_pages()" |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 952 | depends on FAULT_INJECTION |
Akinobu Mita | 933e312 | 2006-12-08 02:39:45 -0800 | [diff] [blame] | 953 | help |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 954 | Provide fault-injection capability for alloc_pages(). |
Akinobu Mita | 933e312 | 2006-12-08 02:39:45 -0800 | [diff] [blame] | 955 | |
Akinobu Mita | c17bb49 | 2006-12-08 02:39:46 -0800 | [diff] [blame] | 956 | config FAIL_MAKE_REQUEST |
Dave Jones | 86327d1 | 2006-12-12 20:16:36 +0100 | [diff] [blame] | 957 | bool "Fault-injection capability for disk IO" |
Jens Axboe | 581d4e2 | 2008-09-14 05:56:33 -0700 | [diff] [blame] | 958 | depends on FAULT_INJECTION && BLOCK |
Akinobu Mita | c17bb49 | 2006-12-08 02:39:46 -0800 | [diff] [blame] | 959 | help |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 960 | Provide fault-injection capability for disk IO. |
Akinobu Mita | c17bb49 | 2006-12-08 02:39:46 -0800 | [diff] [blame] | 961 | |
Jens Axboe | 581d4e2 | 2008-09-14 05:56:33 -0700 | [diff] [blame] | 962 | config FAIL_IO_TIMEOUT |
Takuya Yoshikawa | f4d01439 | 2010-07-21 16:05:53 +0900 | [diff] [blame] | 963 | bool "Fault-injection capability for faking disk interrupts" |
Jens Axboe | 581d4e2 | 2008-09-14 05:56:33 -0700 | [diff] [blame] | 964 | depends on FAULT_INJECTION && BLOCK |
| 965 | help |
| 966 | Provide fault-injection capability on end IO handling. This |
| 967 | will make the block layer "forget" an interrupt as configured, |
| 968 | thus exercising the error handling. |
| 969 | |
| 970 | Only works with drivers that use the generic timeout handling, |
| 971 | for others it wont do anything. |
| 972 | |
Akinobu Mita | 6ff1cb3 | 2006-12-08 02:39:43 -0800 | [diff] [blame] | 973 | config FAULT_INJECTION_DEBUG_FS |
| 974 | bool "Debugfs entries for fault-injection capabilities" |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 975 | depends on FAULT_INJECTION && SYSFS && DEBUG_FS |
Akinobu Mita | 6ff1cb3 | 2006-12-08 02:39:43 -0800 | [diff] [blame] | 976 | help |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 977 | Enable configuration of fault-injection capabilities via debugfs. |
Akinobu Mita | 1df4900 | 2007-02-20 13:57:56 -0800 | [diff] [blame] | 978 | |
| 979 | config FAULT_INJECTION_STACKTRACE_FILTER |
| 980 | bool "stacktrace filter for fault-injection capabilities" |
| 981 | depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT |
Akinobu Mita | 6d690dc | 2007-05-12 10:36:53 -0700 | [diff] [blame] | 982 | depends on !X86_64 |
Akinobu Mita | 1df4900 | 2007-02-20 13:57:56 -0800 | [diff] [blame] | 983 | select STACKTRACE |
Michal Simek | 79aac88 | 2010-05-25 11:33:26 +0200 | [diff] [blame] | 984 | select FRAME_POINTER if !PPC && !S390 && !MICROBLAZE |
Akinobu Mita | 1df4900 | 2007-02-20 13:57:56 -0800 | [diff] [blame] | 985 | help |
| 986 | Provide stacktrace filter for fault-injection capabilities |
Mathieu Desnoyers | 267c402 | 2007-10-18 23:41:07 -0700 | [diff] [blame] | 987 | |
Arjan van de Ven | 9745512 | 2008-01-25 21:08:34 +0100 | [diff] [blame] | 988 | config LATENCYTOP |
| 989 | bool "Latency measuring infrastructure" |
Michal Simek | 79aac88 | 2010-05-25 11:33:26 +0200 | [diff] [blame] | 990 | select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE |
Arjan van de Ven | 9745512 | 2008-01-25 21:08:34 +0100 | [diff] [blame] | 991 | select KALLSYMS |
| 992 | select KALLSYMS_ALL |
| 993 | select STACKTRACE |
| 994 | select SCHEDSTATS |
| 995 | select SCHED_DEBUG |
Heiko Carstens | aa7d935 | 2008-02-01 17:45:14 +0100 | [diff] [blame] | 996 | depends on HAVE_LATENCYTOP_SUPPORT |
Arjan van de Ven | 9745512 | 2008-01-25 21:08:34 +0100 | [diff] [blame] | 997 | help |
| 998 | Enable this option if you want to use the LatencyTOP tool |
| 999 | to find out which userspace is blocking on what kernel operations. |
| 1000 | |
Andi Kleen | 9e94cd3 | 2008-08-16 07:53:05 +0200 | [diff] [blame] | 1001 | config SYSCTL_SYSCALL_CHECK |
| 1002 | bool "Sysctl checks" |
Eric W. Biederman | 83ac201 | 2009-04-03 02:22:26 -0700 | [diff] [blame] | 1003 | depends on SYSCTL |
Andi Kleen | 9e94cd3 | 2008-08-16 07:53:05 +0200 | [diff] [blame] | 1004 | ---help--- |
| 1005 | sys_sysctl uses binary paths that have been found challenging |
| 1006 | to properly maintain and use. This enables checks that help |
| 1007 | you to keep things correct. |
| 1008 | |
Akinobu Mita | 6a11f75 | 2009-03-31 15:23:17 -0700 | [diff] [blame] | 1009 | source mm/Kconfig.debug |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1010 | source kernel/trace/Kconfig |
| 1011 | |
Bernhard Kaindl | f212ec4 | 2008-01-30 13:34:11 +0100 | [diff] [blame] | 1012 | config PROVIDE_OHCI1394_DMA_INIT |
Stefan Richter | 080de8c | 2008-02-28 20:54:43 +0100 | [diff] [blame] | 1013 | bool "Remote debugging over FireWire early on boot" |
Bernhard Kaindl | f212ec4 | 2008-01-30 13:34:11 +0100 | [diff] [blame] | 1014 | depends on PCI && X86 |
| 1015 | help |
| 1016 | If you want to debug problems which hang or crash the kernel early |
| 1017 | on boot and the crashing machine has a FireWire port, you can use |
| 1018 | this feature to remotely access the memory of the crashed machine |
| 1019 | over FireWire. This employs remote DMA as part of the OHCI1394 |
| 1020 | specification which is now the standard for FireWire controllers. |
| 1021 | |
| 1022 | With remote DMA, you can monitor the printk buffer remotely using |
| 1023 | firescope and access all memory below 4GB using fireproxy from gdb. |
| 1024 | Even controlling a kernel debugger is possible using remote DMA. |
| 1025 | |
| 1026 | Usage: |
| 1027 | |
| 1028 | If ohci1394_dma=early is used as boot parameter, it will initialize |
| 1029 | all OHCI1394 controllers which are found in the PCI config space. |
| 1030 | |
| 1031 | As all changes to the FireWire bus such as enabling and disabling |
| 1032 | devices cause a bus reset and thereby disable remote DMA for all |
| 1033 | devices, be sure to have the cable plugged and FireWire enabled on |
| 1034 | the debugging host before booting the debug target for debugging. |
| 1035 | |
| 1036 | This code (~1k) is freed after boot. By then, the firewire stack |
| 1037 | in charge of the OHCI-1394 controllers should be used instead. |
| 1038 | |
| 1039 | See Documentation/debugging-via-ohci1394.txt for more information. |
Arjan van de Ven | 9745512 | 2008-01-25 21:08:34 +0100 | [diff] [blame] | 1040 | |
Stefan Richter | 080de8c | 2008-02-28 20:54:43 +0100 | [diff] [blame] | 1041 | config FIREWIRE_OHCI_REMOTE_DMA |
| 1042 | bool "Remote debugging over FireWire with firewire-ohci" |
| 1043 | depends on FIREWIRE_OHCI |
| 1044 | help |
| 1045 | This option lets you use the FireWire bus for remote debugging |
| 1046 | with help of the firewire-ohci driver. It enables unfiltered |
| 1047 | remote DMA in firewire-ohci. |
| 1048 | See Documentation/debugging-via-ohci1394.txt for more information. |
| 1049 | |
| 1050 | If unsure, say N. |
| 1051 | |
Randy Dunlap | 152de30 | 2009-02-20 15:38:47 -0800 | [diff] [blame] | 1052 | config BUILD_DOCSRC |
Randy Dunlap | 3794f3e | 2008-08-12 15:09:06 -0700 | [diff] [blame] | 1053 | bool "Build targets in Documentation/ tree" |
| 1054 | depends on HEADERS_CHECK |
| 1055 | help |
| 1056 | This option attempts to build objects from the source files in the |
| 1057 | kernel Documentation/ tree. |
| 1058 | |
| 1059 | Say N if you are unsure. |
| 1060 | |
Jason Baron | e9d376f | 2009-02-05 11:51:38 -0500 | [diff] [blame] | 1061 | config DYNAMIC_DEBUG |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 1062 | bool "Enable dynamic printk() support" |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 1063 | default n |
| 1064 | depends on PRINTK |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 1065 | depends on DEBUG_FS |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 1066 | help |
| 1067 | |
| 1068 | Compiles debug level messages into the kernel, which would not |
| 1069 | otherwise be available at runtime. These messages can then be |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 1070 | enabled/disabled based on various levels of scope - per source file, |
| 1071 | function, module, format string, and line number. This mechanism |
| 1072 | implicitly enables all pr_debug() and dev_dbg() calls. The impact of |
| 1073 | this compile option is a larger kernel text size of about 2%. |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 1074 | |
| 1075 | Usage: |
| 1076 | |
Florian Ragwitz | 2b2f68b | 2010-05-24 14:33:21 -0700 | [diff] [blame] | 1077 | Dynamic debugging is controlled via the 'dynamic_debug/control' file, |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 1078 | which is contained in the 'debugfs' filesystem. Thus, the debugfs |
| 1079 | filesystem must first be mounted before making use of this feature. |
Florian Ragwitz | 2b2f68b | 2010-05-24 14:33:21 -0700 | [diff] [blame] | 1080 | We refer the control file as: <debugfs>/dynamic_debug/control. This |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 1081 | file contains a list of the debug statements that can be enabled. The |
| 1082 | format for each line of the file is: |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 1083 | |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 1084 | filename:lineno [module]function flags format |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 1085 | |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 1086 | filename : source file of the debug statement |
| 1087 | lineno : line number of the debug statement |
| 1088 | module : module that contains the debug statement |
| 1089 | function : function that contains the debug statement |
| 1090 | flags : 'p' means the line is turned 'on' for printing |
| 1091 | format : the format used for the debug statement |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 1092 | |
| 1093 | From a live system: |
| 1094 | |
Florian Ragwitz | 2b2f68b | 2010-05-24 14:33:21 -0700 | [diff] [blame] | 1095 | nullarbor:~ # cat <debugfs>/dynamic_debug/control |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 1096 | # filename:lineno [module]function flags format |
| 1097 | fs/aio.c:222 [aio]__put_ioctx - "__put_ioctx:\040freeing\040%p\012" |
| 1098 | fs/aio.c:248 [aio]ioctx_alloc - "ENOMEM:\040nr_events\040too\040high\012" |
| 1099 | fs/aio.c:1770 [aio]sys_io_cancel - "calling\040cancel\012" |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 1100 | |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 1101 | Example usage: |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 1102 | |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 1103 | // enable the message at line 1603 of file svcsock.c |
| 1104 | nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' > |
Florian Ragwitz | 2b2f68b | 2010-05-24 14:33:21 -0700 | [diff] [blame] | 1105 | <debugfs>/dynamic_debug/control |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 1106 | |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 1107 | // enable all the messages in file svcsock.c |
| 1108 | nullarbor:~ # echo -n 'file svcsock.c +p' > |
Florian Ragwitz | 2b2f68b | 2010-05-24 14:33:21 -0700 | [diff] [blame] | 1109 | <debugfs>/dynamic_debug/control |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 1110 | |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 1111 | // enable all the messages in the NFS server module |
| 1112 | nullarbor:~ # echo -n 'module nfsd +p' > |
Florian Ragwitz | 2b2f68b | 2010-05-24 14:33:21 -0700 | [diff] [blame] | 1113 | <debugfs>/dynamic_debug/control |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 1114 | |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 1115 | // enable all 12 messages in the function svc_process() |
| 1116 | nullarbor:~ # echo -n 'func svc_process +p' > |
Florian Ragwitz | 2b2f68b | 2010-05-24 14:33:21 -0700 | [diff] [blame] | 1117 | <debugfs>/dynamic_debug/control |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 1118 | |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 1119 | // disable all 12 messages in the function svc_process() |
| 1120 | nullarbor:~ # echo -n 'func svc_process -p' > |
Florian Ragwitz | 2b2f68b | 2010-05-24 14:33:21 -0700 | [diff] [blame] | 1121 | <debugfs>/dynamic_debug/control |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 1122 | |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 1123 | See Documentation/dynamic-debug-howto.txt for additional information. |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 1124 | |
Joerg Roedel | 5ee00bd | 2009-01-09 12:14:24 +0100 | [diff] [blame] | 1125 | config DMA_API_DEBUG |
| 1126 | bool "Enable debugging of DMA-API usage" |
| 1127 | depends on HAVE_DMA_API_DEBUG |
| 1128 | help |
| 1129 | Enable this option to debug the use of the DMA API by device drivers. |
| 1130 | With this option you will be able to detect common bugs in device |
| 1131 | drivers like double-freeing of DMA mappings or freeing mappings that |
| 1132 | were never allocated. |
| 1133 | This option causes a performance degredation. Use only if you want |
| 1134 | to debug device drivers. If unsure, say N. |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 1135 | |
Luca Barbieri | 86a8938 | 2010-02-24 10:54:24 +0100 | [diff] [blame] | 1136 | config ATOMIC64_SELFTEST |
| 1137 | bool "Perform an atomic64_t self-test at boot" |
| 1138 | help |
| 1139 | Enable this option to test the atomic64_t functions at boot. |
| 1140 | |
| 1141 | If unsure, say N. |
| 1142 | |
Mathieu Desnoyers | 267c402 | 2007-10-18 23:41:07 -0700 | [diff] [blame] | 1143 | source "samples/Kconfig" |
Jason Wessel | dc7d552 | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 1144 | |
| 1145 | source "lib/Kconfig.kgdb" |
Pekka Enberg | 0a4af3b | 2009-02-26 21:38:56 +0200 | [diff] [blame] | 1146 | |
| 1147 | source "lib/Kconfig.kmemcheck" |