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 | |
Arjan van de Ven | f71d20e | 2006-06-28 04:26:45 -0700 | [diff] [blame] | 53 | config UNUSED_SYMBOLS |
| 54 | bool "Enable unused/obsolete exported symbols" |
| 55 | default y if X86 |
| 56 | help |
| 57 | Unused but exported symbols make the kernel needlessly bigger. For |
| 58 | that reason most of these unused exports will soon be removed. This |
| 59 | option is provided temporarily to provide a transition period in case |
| 60 | some external kernel module needs one of these symbols anyway. If you |
| 61 | encounter such a case in your module, consider if you are actually |
| 62 | using the right API. (rationale: since nobody in the kernel is using |
| 63 | this in a module, there is a pretty good chance it's actually the |
| 64 | wrong interface to use). If you really need the symbol, please send a |
| 65 | mail to the linux kernel mailing list mentioning the symbol and why |
| 66 | you really need it, and what the merge plan to the mainline kernel for |
| 67 | your module is. |
| 68 | |
Don Mullis | bf4735a | 2006-12-10 02:18:37 -0800 | [diff] [blame] | 69 | config DEBUG_FS |
| 70 | bool "Debug Filesystem" |
| 71 | depends on SYSFS |
| 72 | help |
| 73 | debugfs is a virtual file system that kernel developers use to put |
| 74 | debugging files into. Enable this option to be able to read and |
| 75 | write to these files. |
| 76 | |
Robert P. J. Day | ff54333 | 2008-05-20 00:06:00 +0200 | [diff] [blame] | 77 | For detailed documentation on the debugfs API, see |
| 78 | Documentation/DocBook/filesystems. |
| 79 | |
Don Mullis | bf4735a | 2006-12-10 02:18:37 -0800 | [diff] [blame] | 80 | If unsure, say N. |
| 81 | |
| 82 | config HEADERS_CHECK |
| 83 | bool "Run 'make headers_check' when building vmlinux" |
| 84 | depends on !UML |
| 85 | help |
| 86 | This option will extract the user-visible kernel headers whenever |
| 87 | building the kernel, and will run basic sanity checks on them to |
| 88 | ensure that exported files do not attempt to include files which |
| 89 | were not exported, etc. |
| 90 | |
| 91 | If you're making modifications to header files which are |
| 92 | relevant for userspace, say 'Y', and check the headers |
| 93 | exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in |
| 94 | your build tree), to make sure they're suitable. |
| 95 | |
Sam Ravnborg | 91341d4 | 2008-01-21 21:31:44 +0100 | [diff] [blame] | 96 | config DEBUG_SECTION_MISMATCH |
| 97 | bool "Enable full Section mismatch analysis" |
Sam Ravnborg | e5f95c8 | 2008-02-02 18:57:18 +0100 | [diff] [blame] | 98 | depends on UNDEFINED |
Sam Ravnborg | fa2144b | 2008-02-15 13:53:11 +0100 | [diff] [blame] | 99 | # This option is on purpose disabled for now. |
| 100 | # It will be enabled when we are down to a resonable number |
| 101 | # of section mismatch warnings (< 10 for an allyesconfig build) |
Sam Ravnborg | 91341d4 | 2008-01-21 21:31:44 +0100 | [diff] [blame] | 102 | help |
| 103 | The section mismatch analysis checks if there are illegal |
| 104 | references from one section to another section. |
| 105 | Linux will during link or during runtime drop some sections |
| 106 | and any use of code/data previously in these sections will |
| 107 | most likely result in an oops. |
| 108 | In the code functions and variables are annotated with |
| 109 | __init, __devinit etc. (see full list in include/linux/init.h) |
Geert Uytterhoeven | d6fbfa4 | 2008-01-30 11:13:23 +0100 | [diff] [blame] | 110 | which results in the code/data being placed in specific sections. |
| 111 | The section mismatch analysis is always done after a full |
| 112 | kernel build but enabling this option will in addition |
Sam Ravnborg | 91341d4 | 2008-01-21 21:31:44 +0100 | [diff] [blame] | 113 | do the following: |
| 114 | - Add the option -fno-inline-functions-called-once to gcc |
| 115 | When inlining a function annotated __init in a non-init |
Geert Uytterhoeven | d6fbfa4 | 2008-01-30 11:13:23 +0100 | [diff] [blame] | 116 | function we would lose the section information and thus |
Sam Ravnborg | 91341d4 | 2008-01-21 21:31:44 +0100 | [diff] [blame] | 117 | the analysis would not catch the illegal reference. |
Geert Uytterhoeven | d6fbfa4 | 2008-01-30 11:13:23 +0100 | [diff] [blame] | 118 | This option tells gcc to inline less but will also |
Sam Ravnborg | 91341d4 | 2008-01-21 21:31:44 +0100 | [diff] [blame] | 119 | result in a larger kernel. |
| 120 | - Run the section mismatch analysis for each module/built-in.o |
| 121 | When we run the section mismatch analysis on vmlinux.o we |
Geert Uytterhoeven | d6fbfa4 | 2008-01-30 11:13:23 +0100 | [diff] [blame] | 122 | lose valueble information about where the mismatch was |
Sam Ravnborg | 91341d4 | 2008-01-21 21:31:44 +0100 | [diff] [blame] | 123 | introduced. |
| 124 | Running the analysis for each module/built-in.o file |
| 125 | will tell where the mismatch happens much closer to the |
| 126 | source. The drawback is that we will report the same |
| 127 | mismatch at least twice. |
Sam Ravnborg | 588ccd7 | 2008-01-24 21:12:37 +0100 | [diff] [blame] | 128 | - Enable verbose reporting from modpost to help solving |
| 129 | the section mismatches reported. |
Sam Ravnborg | 91341d4 | 2008-01-21 21:31:44 +0100 | [diff] [blame] | 130 | |
Adrian Bunk | f346f4b | 2006-01-09 20:54:51 -0800 | [diff] [blame] | 131 | config DEBUG_KERNEL |
| 132 | bool "Kernel debugging" |
| 133 | help |
| 134 | Say Y here if you are developing drivers or trying to debug and |
| 135 | identify kernel problems. |
| 136 | |
David Woodhouse | a304e1b | 2007-02-12 00:52:00 -0800 | [diff] [blame] | 137 | config DEBUG_SHIRQ |
| 138 | bool "Debug shared IRQ handlers" |
| 139 | depends on DEBUG_KERNEL && GENERIC_HARDIRQS |
| 140 | help |
| 141 | Enable this to generate a spurious interrupt as soon as a shared |
| 142 | interrupt handler is registered, and just before one is deregistered. |
| 143 | Drivers ought to be able to handle interrupts coming in at those |
| 144 | points; some don't and need to be caught. |
| 145 | |
Ingo Molnar | 8446f1d | 2005-09-06 15:16:27 -0700 | [diff] [blame] | 146 | config DETECT_SOFTLOCKUP |
| 147 | bool "Detect Soft Lockups" |
Heiko Carstens | dea20a3 | 2006-10-11 01:20:44 -0700 | [diff] [blame] | 148 | depends on DEBUG_KERNEL && !S390 |
Ingo Molnar | 8446f1d | 2005-09-06 15:16:27 -0700 | [diff] [blame] | 149 | default y |
| 150 | help |
| 151 | Say Y here to enable the kernel to detect "soft lockups", |
| 152 | which are bugs that cause the kernel to loop in kernel |
Ingo Molnar | 9c44bc0 | 2008-05-12 21:21:04 +0200 | [diff] [blame] | 153 | mode for more than 60 seconds, without giving other tasks a |
Ingo Molnar | 8446f1d | 2005-09-06 15:16:27 -0700 | [diff] [blame] | 154 | chance to run. |
| 155 | |
| 156 | When a soft-lockup is detected, the kernel will print the |
| 157 | current stack trace (which you should report), but the |
| 158 | system will stay locked up. This feature has negligible |
| 159 | overhead. |
| 160 | |
| 161 | (Note that "hard lockups" are separate type of bugs that |
| 162 | can be detected via the NMI-watchdog, on platforms that |
| 163 | support it.) |
| 164 | |
Ingo Molnar | 9c44bc0 | 2008-05-12 21:21:04 +0200 | [diff] [blame] | 165 | config BOOTPARAM_SOFTLOCKUP_PANIC |
| 166 | bool "Panic (Reboot) On Soft Lockups" |
| 167 | depends on DETECT_SOFTLOCKUP |
| 168 | help |
| 169 | Say Y here to enable the kernel to panic on "soft lockups", |
| 170 | which are bugs that cause the kernel to loop in kernel |
| 171 | mode for more than 60 seconds, without giving other tasks a |
| 172 | chance to run. |
| 173 | |
| 174 | The panic can be used in combination with panic_timeout, |
| 175 | to cause the system to reboot automatically after a |
| 176 | lockup has been detected. This feature is useful for |
| 177 | high-availability systems that have uptime guarantees and |
| 178 | where a lockup must be resolved ASAP. |
| 179 | |
| 180 | Say N if unsure. |
| 181 | |
| 182 | config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE |
| 183 | int |
| 184 | depends on DETECT_SOFTLOCKUP |
| 185 | range 0 1 |
| 186 | default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC |
| 187 | default 1 if BOOTPARAM_SOFTLOCKUP_PANIC |
| 188 | |
Mandeep Singh Baines | e162b39 | 2009-01-15 11:08:40 -0800 | [diff] [blame] | 189 | config DETECT_HUNG_TASK |
| 190 | bool "Detect Hung Tasks" |
| 191 | depends on DEBUG_KERNEL |
Ingo Molnar | 77d0563 | 2009-04-07 08:55:36 +0200 | [diff] [blame] | 192 | default DETECT_SOFTLOCKUP |
Mandeep Singh Baines | e162b39 | 2009-01-15 11:08:40 -0800 | [diff] [blame] | 193 | help |
| 194 | Say Y here to enable the kernel to detect "hung tasks", |
| 195 | which are bugs that cause the task to be stuck in |
| 196 | uninterruptible "D" state indefinitiley. |
| 197 | |
| 198 | When a hung task is detected, the kernel will print the |
| 199 | current stack trace (which you should report), but the |
| 200 | task will stay in uninterruptible state. If lockdep is |
| 201 | enabled then all held locks will also be reported. This |
| 202 | feature has negligible overhead. |
| 203 | |
| 204 | config BOOTPARAM_HUNG_TASK_PANIC |
| 205 | bool "Panic (Reboot) On Hung Tasks" |
| 206 | depends on DETECT_HUNG_TASK |
| 207 | help |
| 208 | Say Y here to enable the kernel to panic on "hung tasks", |
| 209 | which are bugs that cause the kernel to leave a task stuck |
| 210 | in uninterruptible "D" state. |
| 211 | |
| 212 | The panic can be used in combination with panic_timeout, |
| 213 | to cause the system to reboot automatically after a |
| 214 | hung task has been detected. This feature is useful for |
| 215 | high-availability systems that have uptime guarantees and |
| 216 | where a hung tasks must be resolved ASAP. |
| 217 | |
| 218 | Say N if unsure. |
| 219 | |
| 220 | config BOOTPARAM_HUNG_TASK_PANIC_VALUE |
| 221 | int |
| 222 | depends on DETECT_HUNG_TASK |
| 223 | range 0 1 |
| 224 | default 0 if !BOOTPARAM_HUNG_TASK_PANIC |
| 225 | default 1 if BOOTPARAM_HUNG_TASK_PANIC |
| 226 | |
Ingo Molnar | b642b6d | 2007-07-09 18:52:00 +0200 | [diff] [blame] | 227 | config SCHED_DEBUG |
| 228 | bool "Collect scheduler debugging info" |
| 229 | depends on DEBUG_KERNEL && PROC_FS |
| 230 | default y |
| 231 | help |
| 232 | If you say Y here, the /proc/sched_debug file will be provided |
| 233 | that can help debug the scheduler. The runtime overhead of this |
| 234 | option is minimal. |
| 235 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 236 | config SCHEDSTATS |
| 237 | bool "Collect scheduler statistics" |
| 238 | depends on DEBUG_KERNEL && PROC_FS |
| 239 | help |
| 240 | If you say Y here, additional code will be inserted into the |
| 241 | scheduler and related routines to collect statistics about |
| 242 | scheduler behavior and provide them in /proc/schedstat. These |
| 243 | stats may be useful for both tuning and debugging the scheduler |
| 244 | If you aren't debugging the scheduler or trying to tune a specific |
| 245 | application, you can say N to avoid the very slight overhead |
| 246 | this adds. |
| 247 | |
Ingo Molnar | 82f67cd | 2007-02-16 01:28:13 -0800 | [diff] [blame] | 248 | config TIMER_STATS |
| 249 | bool "Collect kernel timers statistics" |
| 250 | depends on DEBUG_KERNEL && PROC_FS |
| 251 | help |
| 252 | If you say Y here, additional code will be inserted into the |
| 253 | timer routines to collect statistics about kernel timers being |
| 254 | reprogrammed. The statistics can be read from /proc/timer_stats. |
| 255 | The statistics collection is started by writing 1 to /proc/timer_stats, |
| 256 | writing 0 stops it. This feature is useful to collect information |
Ingo Molnar | c1a834d | 2007-06-01 00:47:16 -0700 | [diff] [blame] | 257 | about timer usage patterns in kernel and userspace. This feature |
| 258 | is lightweight if enabled in the kernel config but not activated |
| 259 | (it defaults to deactivated on bootup and will only be activated |
| 260 | if some application like powertop activates it explicitly). |
Ingo Molnar | 82f67cd | 2007-02-16 01:28:13 -0800 | [diff] [blame] | 261 | |
Thomas Gleixner | 3ac7fe5 | 2008-04-30 00:55:01 -0700 | [diff] [blame] | 262 | config DEBUG_OBJECTS |
| 263 | bool "Debug object operations" |
| 264 | depends on DEBUG_KERNEL |
| 265 | help |
| 266 | If you say Y here, additional code will be inserted into the |
| 267 | kernel to track the life time of various objects and validate |
| 268 | the operations on those objects. |
| 269 | |
| 270 | config DEBUG_OBJECTS_SELFTEST |
| 271 | bool "Debug objects selftest" |
| 272 | depends on DEBUG_OBJECTS |
| 273 | help |
| 274 | This enables the selftest of the object debug code. |
| 275 | |
| 276 | config DEBUG_OBJECTS_FREE |
| 277 | bool "Debug objects in freed memory" |
| 278 | depends on DEBUG_OBJECTS |
| 279 | help |
| 280 | This enables checks whether a k/v free operation frees an area |
| 281 | which contains an object which has not been deactivated |
| 282 | properly. This can make kmalloc/kfree-intensive workloads |
| 283 | much slower. |
| 284 | |
Thomas Gleixner | c6f3a97 | 2008-04-30 00:55:03 -0700 | [diff] [blame] | 285 | config DEBUG_OBJECTS_TIMERS |
| 286 | bool "Debug timer objects" |
| 287 | depends on DEBUG_OBJECTS |
| 288 | help |
| 289 | If you say Y here, additional code will be inserted into the |
| 290 | timer routines to track the life time of timer objects and |
| 291 | validate the timer operations. |
| 292 | |
Ingo Molnar | 3ae7020 | 2008-11-26 10:02:00 +0100 | [diff] [blame] | 293 | config DEBUG_OBJECTS_ENABLE_DEFAULT |
| 294 | int "debug_objects bootup default value (0-1)" |
| 295 | range 0 1 |
| 296 | default "1" |
| 297 | depends on DEBUG_OBJECTS |
| 298 | help |
| 299 | Debug objects boot parameter default value |
| 300 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 301 | config DEBUG_SLAB |
Andrew Morton | 4a2f0ac | 2006-03-25 03:07:22 -0800 | [diff] [blame] | 302 | bool "Debug slab memory allocations" |
Vegard Nossum | 7d46d9e | 2008-04-04 00:51:41 +0200 | [diff] [blame] | 303 | depends on DEBUG_KERNEL && SLAB && !KMEMCHECK |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 304 | help |
| 305 | Say Y here to have the kernel do limited verification on memory |
| 306 | allocation as well as poisoning memory on free to catch use of freed |
| 307 | memory. This can make kmalloc/kfree-intensive workloads much slower. |
| 308 | |
Al Viro | 871751e | 2006-03-25 03:06:39 -0800 | [diff] [blame] | 309 | config DEBUG_SLAB_LEAK |
| 310 | bool "Memory leak debugging" |
| 311 | depends on DEBUG_SLAB |
| 312 | |
Christoph Lameter | f0630ff | 2007-07-15 23:38:14 -0700 | [diff] [blame] | 313 | config SLUB_DEBUG_ON |
| 314 | bool "SLUB debugging on by default" |
Vegard Nossum | 7d46d9e | 2008-04-04 00:51:41 +0200 | [diff] [blame] | 315 | depends on SLUB && SLUB_DEBUG && !KMEMCHECK |
Christoph Lameter | f0630ff | 2007-07-15 23:38:14 -0700 | [diff] [blame] | 316 | default n |
| 317 | help |
| 318 | Boot with debugging on by default. SLUB boots by default with |
| 319 | the runtime debug capabilities switched off. Enabling this is |
| 320 | equivalent to specifying the "slub_debug" parameter on boot. |
| 321 | There is no support for more fine grained debug control like |
| 322 | possible with slub_debug=xxx. SLUB debugging may be switched |
| 323 | off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying |
| 324 | "slub_debug=-". |
| 325 | |
Christoph Lameter | 8ff12cf | 2008-02-07 17:47:41 -0800 | [diff] [blame] | 326 | config SLUB_STATS |
| 327 | default n |
| 328 | bool "Enable SLUB performance statistics" |
Christoph Lameter | 5b06c853 | 2008-04-14 18:51:34 +0300 | [diff] [blame] | 329 | depends on SLUB && SLUB_DEBUG && SYSFS |
Christoph Lameter | 8ff12cf | 2008-02-07 17:47:41 -0800 | [diff] [blame] | 330 | help |
| 331 | SLUB statistics are useful to debug SLUBs allocation behavior in |
| 332 | order find ways to optimize the allocator. This should never be |
| 333 | enabled for production use since keeping statistics slows down |
| 334 | the allocator by a few percentage points. The slabinfo command |
| 335 | supports the determination of the most active slabs to figure |
| 336 | out which slabs are relevant to a particular load. |
| 337 | Try running: slabinfo -DA |
| 338 | |
Catalin Marinas | 3bba00d | 2009-06-11 13:24:13 +0100 | [diff] [blame] | 339 | config DEBUG_KMEMLEAK |
| 340 | bool "Kernel memory leak detector" |
| 341 | depends on DEBUG_KERNEL && EXPERIMENTAL && (X86 || ARM) && \ |
| 342 | !MEMORY_HOTPLUG |
Catalin Marinas | 3bba00d | 2009-06-11 13:24:13 +0100 | [diff] [blame] | 343 | select DEBUG_FS if SYSFS |
| 344 | select STACKTRACE if STACKTRACE_SUPPORT |
| 345 | select KALLSYMS |
| 346 | help |
| 347 | Say Y here if you want to enable the memory leak |
| 348 | detector. The memory allocation/freeing is traced in a way |
| 349 | similar to the Boehm's conservative garbage collector, the |
| 350 | difference being that the orphan objects are not freed but |
| 351 | only shown in /sys/kernel/debug/kmemleak. Enabling this |
| 352 | feature will introduce an overhead to memory |
| 353 | allocations. See Documentation/kmemleak.txt for more |
| 354 | details. |
| 355 | |
Catalin Marinas | bf96d1e | 2009-06-23 14:40:27 +0100 | [diff] [blame] | 356 | Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances |
| 357 | of finding leaks due to the slab objects poisoning. |
| 358 | |
Catalin Marinas | 3bba00d | 2009-06-11 13:24:13 +0100 | [diff] [blame] | 359 | In order to access the kmemleak file, debugfs needs to be |
| 360 | mounted (usually at /sys/kernel/debug). |
| 361 | |
Catalin Marinas | 0822ee4 | 2009-06-11 13:24:14 +0100 | [diff] [blame] | 362 | config DEBUG_KMEMLEAK_TEST |
| 363 | tristate "Simple test for the kernel memory leak detector" |
| 364 | depends on DEBUG_KMEMLEAK |
| 365 | help |
| 366 | Say Y or M here to build a test for the kernel memory leak |
| 367 | detector. This option enables a module that explicitly leaks |
| 368 | memory. |
| 369 | |
| 370 | If unsure, say N. |
| 371 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 372 | config DEBUG_PREEMPT |
| 373 | bool "Debug preemptible kernel" |
Hugh Dickins | 048c8bc | 2006-11-01 05:44:54 +1100 | [diff] [blame] | 374 | depends on DEBUG_KERNEL && PREEMPT && (TRACE_IRQFLAGS_SUPPORT || PPC64) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 375 | default y |
| 376 | help |
| 377 | If you say Y here then the kernel will use a debug variant of the |
| 378 | commonly used smp_processor_id() function and will print warnings |
| 379 | if kernel code uses it in a preemption-unsafe way. Also, the kernel |
| 380 | will detect preemption count underflows. |
| 381 | |
Ingo Molnar | e7eebaf | 2006-06-27 02:54:55 -0700 | [diff] [blame] | 382 | config DEBUG_RT_MUTEXES |
| 383 | bool "RT Mutex debugging, deadlock detection" |
Ingo Molnar | e7eebaf | 2006-06-27 02:54:55 -0700 | [diff] [blame] | 384 | depends on DEBUG_KERNEL && RT_MUTEXES |
| 385 | help |
| 386 | This allows rt mutex semantics violations and rt mutex related |
| 387 | deadlocks (lockups) to be detected and reported automatically. |
| 388 | |
| 389 | config DEBUG_PI_LIST |
| 390 | bool |
| 391 | default y |
| 392 | depends on DEBUG_RT_MUTEXES |
| 393 | |
Thomas Gleixner | 61a8712 | 2006-06-27 02:54:56 -0700 | [diff] [blame] | 394 | config RT_MUTEX_TESTER |
| 395 | bool "Built-in scriptable tester for rt-mutexes" |
Roman Zippel | a1583d3 | 2006-06-27 02:55:00 -0700 | [diff] [blame] | 396 | depends on DEBUG_KERNEL && RT_MUTEXES |
Thomas Gleixner | 61a8712 | 2006-06-27 02:54:56 -0700 | [diff] [blame] | 397 | help |
| 398 | This option enables a rt-mutex tester. |
| 399 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 400 | config DEBUG_SPINLOCK |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 401 | bool "Spinlock and rw-lock debugging: basic checks" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 402 | depends on DEBUG_KERNEL |
| 403 | help |
| 404 | Say Y here and build SMP to catch missing spinlock initialization |
| 405 | and certain other kinds of spinlock errors commonly made. This is |
| 406 | best used in conjunction with the NMI watchdog so that spinlock |
| 407 | deadlocks are also debuggable. |
| 408 | |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 409 | config DEBUG_MUTEXES |
| 410 | bool "Mutex debugging: basic checks" |
| 411 | depends on DEBUG_KERNEL |
| 412 | help |
| 413 | This feature allows mutex semantics violations to be detected and |
| 414 | reported. |
| 415 | |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 416 | config DEBUG_LOCK_ALLOC |
| 417 | bool "Lock debugging: detect incorrect freeing of live locks" |
Adrian Bunk | 517e7aa | 2006-07-14 00:24:32 -0700 | [diff] [blame] | 418 | depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 419 | select DEBUG_SPINLOCK |
| 420 | select DEBUG_MUTEXES |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 421 | select LOCKDEP |
| 422 | help |
| 423 | This feature will check whether any held lock (spinlock, rwlock, |
| 424 | mutex or rwsem) is incorrectly freed by the kernel, via any of the |
| 425 | memory-freeing routines (kfree(), kmem_cache_free(), free_pages(), |
| 426 | vfree(), etc.), whether a live lock is incorrectly reinitialized via |
| 427 | spin_lock_init()/mutex_init()/etc., or whether there is any lock |
| 428 | held during task exit. |
| 429 | |
| 430 | config PROVE_LOCKING |
| 431 | bool "Lock debugging: prove locking correctness" |
Adrian Bunk | 517e7aa | 2006-07-14 00:24:32 -0700 | [diff] [blame] | 432 | depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 433 | select LOCKDEP |
| 434 | select DEBUG_SPINLOCK |
| 435 | select DEBUG_MUTEXES |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 436 | select DEBUG_LOCK_ALLOC |
| 437 | default n |
| 438 | help |
| 439 | This feature enables the kernel to prove that all locking |
| 440 | that occurs in the kernel runtime is mathematically |
| 441 | correct: that under no circumstance could an arbitrary (and |
| 442 | not yet triggered) combination of observed locking |
| 443 | sequences (on an arbitrary number of CPUs, running an |
| 444 | arbitrary number of tasks and interrupt contexts) cause a |
| 445 | deadlock. |
| 446 | |
| 447 | In short, this feature enables the kernel to report locking |
| 448 | related deadlocks before they actually occur. |
| 449 | |
| 450 | The proof does not depend on how hard and complex a |
| 451 | deadlock scenario would be to trigger: how many |
| 452 | participant CPUs, tasks and irq-contexts would be needed |
| 453 | for it to trigger. The proof also does not depend on |
| 454 | timing: if a race and a resulting deadlock is possible |
| 455 | theoretically (no matter how unlikely the race scenario |
| 456 | is), it will be proven so and will immediately be |
| 457 | reported by the kernel (once the event is observed that |
| 458 | makes the deadlock theoretically possible). |
| 459 | |
| 460 | If a deadlock is impossible (i.e. the locking rules, as |
| 461 | observed by the kernel, are mathematically correct), the |
| 462 | kernel reports nothing. |
| 463 | |
| 464 | NOTE: this feature can also be enabled for rwlocks, mutexes |
| 465 | and rwsems - in which case all dependencies between these |
| 466 | different locking variants are observed and mapped too, and |
| 467 | the proof of observed correctness is also maintained for an |
| 468 | arbitrary combination of these separate locking variants. |
| 469 | |
| 470 | For more details, see Documentation/lockdep-design.txt. |
| 471 | |
| 472 | config LOCKDEP |
| 473 | bool |
Adrian Bunk | 517e7aa | 2006-07-14 00:24:32 -0700 | [diff] [blame] | 474 | depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 475 | select STACKTRACE |
Peter Zijlstra | 00540e5 | 2009-06-12 10:04:01 +0200 | [diff] [blame] | 476 | select FRAME_POINTER if !MIPS && !PPC && !ARM_UNWIND && !S390 |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 477 | select KALLSYMS |
| 478 | select KALLSYMS_ALL |
| 479 | |
Peter Zijlstra | f20786f | 2007-07-19 01:48:56 -0700 | [diff] [blame] | 480 | config LOCK_STAT |
Danny ter Haar | fdfb870 | 2007-09-24 21:24:43 -0700 | [diff] [blame] | 481 | bool "Lock usage statistics" |
Peter Zijlstra | f20786f | 2007-07-19 01:48:56 -0700 | [diff] [blame] | 482 | depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT |
| 483 | select LOCKDEP |
| 484 | select DEBUG_SPINLOCK |
| 485 | select DEBUG_MUTEXES |
| 486 | select DEBUG_LOCK_ALLOC |
| 487 | default n |
| 488 | help |
| 489 | This feature enables tracking lock contention points |
| 490 | |
Peter Zijlstra | a560aa4 | 2007-10-07 00:24:33 -0700 | [diff] [blame] | 491 | For more details, see Documentation/lockstat.txt |
| 492 | |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 493 | config DEBUG_LOCKDEP |
| 494 | bool "Lock dependency engine debugging" |
Adrian Bunk | 517e7aa | 2006-07-14 00:24:32 -0700 | [diff] [blame] | 495 | depends on DEBUG_KERNEL && LOCKDEP |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 496 | help |
| 497 | If you say Y here, the lock dependency engine will do |
| 498 | additional runtime checks to debug itself, at the price |
| 499 | of more runtime overhead. |
| 500 | |
| 501 | config TRACE_IRQFLAGS |
Adrian Bunk | 517e7aa | 2006-07-14 00:24:32 -0700 | [diff] [blame] | 502 | depends on DEBUG_KERNEL |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 503 | bool |
| 504 | default y |
| 505 | depends on TRACE_IRQFLAGS_SUPPORT |
| 506 | depends on PROVE_LOCKING |
| 507 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 508 | config DEBUG_SPINLOCK_SLEEP |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 509 | bool "Spinlock debugging: sleep-inside-spinlock checking" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 510 | depends on DEBUG_KERNEL |
| 511 | help |
| 512 | If you say Y here, various routines which may sleep will become very |
| 513 | noisy if they are called with a spinlock held. |
| 514 | |
Ingo Molnar | cae2ed9 | 2006-07-03 00:24:48 -0700 | [diff] [blame] | 515 | config DEBUG_LOCKING_API_SELFTESTS |
| 516 | bool "Locking API boot-time self-tests" |
| 517 | depends on DEBUG_KERNEL |
| 518 | help |
| 519 | Say Y here if you want the kernel to run a short self-test during |
| 520 | bootup. The self-test checks whether common types of locking bugs |
| 521 | are detected by debugging mechanisms or not. (if you disable |
| 522 | lock debugging then those bugs wont be detected of course.) |
| 523 | The following locking APIs are covered: spinlocks, rwlocks, |
| 524 | mutexes and rwsems. |
| 525 | |
Ingo Molnar | 8637c09 | 2006-07-03 00:24:38 -0700 | [diff] [blame] | 526 | config STACKTRACE |
| 527 | bool |
| 528 | depends on STACKTRACE_SUPPORT |
| 529 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 530 | config DEBUG_KOBJECT |
| 531 | bool "kobject debugging" |
| 532 | depends on DEBUG_KERNEL |
| 533 | help |
| 534 | If you say Y here, some extra kobject debugging messages will be sent |
| 535 | to the syslog. |
| 536 | |
| 537 | config DEBUG_HIGHMEM |
| 538 | bool "Highmem debugging" |
| 539 | depends on DEBUG_KERNEL && HIGHMEM |
| 540 | help |
| 541 | This options enables addition error checking for high memory systems. |
| 542 | Disable for production systems. |
| 543 | |
| 544 | config DEBUG_BUGVERBOSE |
| 545 | bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EMBEDDED |
Matt Mackall | c8538a7 | 2005-05-01 08:59:01 -0700 | [diff] [blame] | 546 | depends on BUG |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 547 | depends on ARM || AVR32 || M32R || M68K || SPARC32 || SPARC64 || \ |
| 548 | FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 549 | default !EMBEDDED |
| 550 | help |
| 551 | Say Y here to make BUG() panics output the file name and line number |
| 552 | of the BUG call as well as the EIP and oops trace. This aids |
| 553 | debugging but costs about 70-100K of memory. |
| 554 | |
| 555 | config DEBUG_INFO |
| 556 | bool "Compile the kernel with debug info" |
| 557 | depends on DEBUG_KERNEL |
| 558 | help |
| 559 | If you say Y here the resulting kernel image will include |
| 560 | debugging info resulting in a larger kernel image. |
Andreas Dilger | b72e53f | 2007-03-27 15:21:33 -0600 | [diff] [blame] | 561 | This adds debug symbols to the kernel and modules (gcc -g), and |
| 562 | is needed if you intend to use kernel crashdump or binary object |
| 563 | tools like crash, kgdb, LKCD, gdb, etc on the kernel. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 564 | Say Y here only if you plan to debug the kernel. |
| 565 | |
| 566 | If unsure, say N. |
| 567 | |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 568 | config DEBUG_VM |
| 569 | bool "Debug VM" |
| 570 | depends on DEBUG_KERNEL |
| 571 | help |
Nick Piggin | 13e7444 | 2006-01-06 00:10:58 -0800 | [diff] [blame] | 572 | Enable this to turn on extended checks in the virtual-memory system |
| 573 | that may impact performance. |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 574 | |
| 575 | If unsure, say N. |
| 576 | |
Jiri Slaby | 59ea746 | 2008-06-12 13:56:40 +0200 | [diff] [blame] | 577 | config DEBUG_VIRTUAL |
| 578 | bool "Debug VM translations" |
| 579 | depends on DEBUG_KERNEL && X86 |
| 580 | help |
| 581 | Enable some costly sanity checks in virtual to page code. This can |
| 582 | catch mistakes with virt_to_page() and friends. |
| 583 | |
| 584 | If unsure, say N. |
| 585 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 586 | config DEBUG_NOMMU_REGIONS |
| 587 | bool "Debug the global anon/private NOMMU mapping region tree" |
| 588 | depends on DEBUG_KERNEL && !MMU |
| 589 | help |
| 590 | This option causes the global tree of anonymous and private mapping |
| 591 | regions to be regularly checked for invalid topology. |
| 592 | |
Dave Hansen | ad775f5 | 2008-02-15 14:38:01 -0800 | [diff] [blame] | 593 | config DEBUG_WRITECOUNT |
| 594 | bool "Debug filesystem writers count" |
| 595 | depends on DEBUG_KERNEL |
| 596 | help |
| 597 | Enable this to catch wrong use of the writers count in struct |
| 598 | vfsmount. This will increase the size of each file struct by |
| 599 | 32 bits. |
| 600 | |
| 601 | If unsure, say N. |
| 602 | |
Mel Gorman | 6b74ab9 | 2008-07-23 21:26:49 -0700 | [diff] [blame] | 603 | config DEBUG_MEMORY_INIT |
| 604 | bool "Debug memory initialisation" if EMBEDDED |
| 605 | default !EMBEDDED |
| 606 | help |
| 607 | Enable this for additional checks during memory initialisation. |
| 608 | The sanity checks verify aspects of the VM such as the memory model |
| 609 | and other information provided by the architecture. Verbose |
| 610 | information will be printed at KERN_DEBUG loglevel depending |
| 611 | on the mminit_loglevel= command-line option. |
| 612 | |
| 613 | If unsure, say Y |
| 614 | |
Dave Jones | 199a9af | 2006-09-29 01:59:00 -0700 | [diff] [blame] | 615 | config DEBUG_LIST |
| 616 | bool "Debug linked list manipulation" |
| 617 | depends on DEBUG_KERNEL |
| 618 | help |
| 619 | Enable this to turn on extended checks in the linked-list |
| 620 | walking routines. |
| 621 | |
| 622 | If unsure, say N. |
| 623 | |
Jens Axboe | d6ec084 | 2007-10-22 20:01:06 +0200 | [diff] [blame] | 624 | config DEBUG_SG |
| 625 | bool "Debug SG table operations" |
| 626 | depends on DEBUG_KERNEL |
| 627 | help |
| 628 | Enable this to turn on checks on scatter-gather tables. This can |
| 629 | help find problems with drivers that do not properly initialize |
| 630 | their sg tables. |
| 631 | |
| 632 | If unsure, say N. |
| 633 | |
Arjan van de Ven | 1b2439d | 2008-08-15 15:29:38 -0700 | [diff] [blame] | 634 | config DEBUG_NOTIFIERS |
| 635 | bool "Debug notifier call chains" |
| 636 | depends on DEBUG_KERNEL |
| 637 | help |
| 638 | Enable this to turn on sanity checking for notifier call chains. |
| 639 | This is most useful for kernel developers to make sure that |
| 640 | modules properly unregister themselves from notifier chains. |
| 641 | This is a relatively cheap check but if you care about maximum |
| 642 | performance, say N. |
| 643 | |
Jeff Mahoney | 64dec40 | 2009-01-16 13:23:35 -0500 | [diff] [blame] | 644 | # |
| 645 | # Select this config option from the architecture Kconfig, if it |
| 646 | # it is preferred to always offer frame pointers as a config |
| 647 | # option on the architecture (regardless of KERNEL_DEBUG): |
| 648 | # |
| 649 | config ARCH_WANT_FRAME_POINTERS |
| 650 | bool |
| 651 | help |
| 652 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 653 | config FRAME_POINTER |
| 654 | bool "Compile the kernel with frame pointers" |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 655 | depends on DEBUG_KERNEL && \ |
Heiko Carstens | 75ee034 | 2009-04-23 13:58:10 +0200 | [diff] [blame] | 656 | (CRIS || M68K || M68KNOMMU || FRV || UML || \ |
Ingo Molnar | da4276b | 2009-01-07 11:05:10 +0100 | [diff] [blame] | 657 | AVR32 || SUPERH || BLACKFIN || MN10300) || \ |
| 658 | ARCH_WANT_FRAME_POINTERS |
| 659 | default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 660 | help |
Ingo Molnar | da4276b | 2009-01-07 11:05:10 +0100 | [diff] [blame] | 661 | If you say Y here the resulting kernel image will be slightly |
| 662 | larger and slower, but it gives very useful debugging information |
| 663 | in case of kernel bugs. (precise oopses/stacktraces/warnings) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 664 | |
Randy Dunlap | bfe8df3 | 2007-10-16 01:23:46 -0700 | [diff] [blame] | 665 | config BOOT_PRINTK_DELAY |
| 666 | bool "Delay each boot printk message by N milliseconds" |
| 667 | depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY |
| 668 | help |
| 669 | This build option allows you to read kernel boot messages |
| 670 | by inserting a short delay after each one. The delay is |
| 671 | specified in milliseconds on the kernel command line, |
| 672 | using "boot_delay=N". |
| 673 | |
| 674 | It is likely that you would also need to use "lpj=M" to preset |
| 675 | the "loops per jiffie" value. |
| 676 | See a previous boot log for the "lpj" value to use for your |
| 677 | system, and then set "lpj=M" before setting "boot_delay=N". |
| 678 | NOTE: Using this option may adversely affect SMP systems. |
| 679 | I.e., processors other than the first one may not boot up. |
| 680 | BOOT_PRINTK_DELAY also may cause DETECT_SOFTLOCKUP to detect |
| 681 | what it believes to be lockup conditions. |
| 682 | |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 683 | config RCU_TORTURE_TEST |
| 684 | tristate "torture tests for RCU" |
| 685 | depends on DEBUG_KERNEL |
| 686 | default n |
| 687 | help |
| 688 | This option provides a kernel module that runs torture tests |
| 689 | on the RCU infrastructure. The kernel module may be built |
| 690 | after the fact on the running kernel to be tested, if desired. |
| 691 | |
Paul E. McKenney | 31a72bc | 2008-06-18 09:26:49 -0700 | [diff] [blame] | 692 | Say Y here if you want RCU torture tests to be built into |
| 693 | the kernel. |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 694 | Say M if you want the RCU torture tests to build as a module. |
| 695 | Say N if you are unsure. |
Ankita Garg | 8bb31b9 | 2006-10-02 02:17:36 -0700 | [diff] [blame] | 696 | |
Paul E. McKenney | 31a72bc | 2008-06-18 09:26:49 -0700 | [diff] [blame] | 697 | config RCU_TORTURE_TEST_RUNNABLE |
| 698 | bool "torture tests for RCU runnable by default" |
| 699 | depends on RCU_TORTURE_TEST = y |
| 700 | default n |
| 701 | help |
| 702 | This option provides a way to build the RCU torture tests |
| 703 | directly into the kernel without them starting up at boot |
| 704 | time. You can use /proc/sys/kernel/rcutorture_runnable |
| 705 | to manually override this setting. This /proc file is |
| 706 | available only when the RCU torture tests have been built |
| 707 | into the kernel. |
| 708 | |
| 709 | Say Y here if you want the RCU torture tests to start during |
| 710 | boot (you probably don't). |
| 711 | Say N here if you want the RCU torture tests to start only |
| 712 | after being manually enabled via /proc. |
| 713 | |
Paul E. McKenney | 2133b5d | 2008-10-02 16:06:39 -0700 | [diff] [blame] | 714 | config RCU_CPU_STALL_DETECTOR |
Paul E. McKenney | 67182ae | 2008-08-10 18:35:38 -0700 | [diff] [blame] | 715 | bool "Check for stalled CPUs delaying RCU grace periods" |
Paul E. McKenney | 64db4cf | 2008-12-18 21:55:32 +0100 | [diff] [blame] | 716 | depends on CLASSIC_RCU || TREE_RCU |
| 717 | default n |
| 718 | help |
| 719 | This option causes RCU to printk information on which |
| 720 | CPUs are delaying the current grace period, but only when |
| 721 | the grace period extends for excessive time periods. |
| 722 | |
| 723 | Say Y if you want RCU to perform such checks. |
| 724 | |
| 725 | Say N if you are unsure. |
| 726 | |
Ananth N Mavinakayanahalli | 8c1c935 | 2008-01-30 13:32:53 +0100 | [diff] [blame] | 727 | config KPROBES_SANITY_TEST |
| 728 | bool "Kprobes sanity tests" |
| 729 | depends on DEBUG_KERNEL |
| 730 | depends on KPROBES |
| 731 | default n |
| 732 | help |
| 733 | This option provides for testing basic kprobes functionality on |
| 734 | boot. A sample kprobe, jprobe and kretprobe are inserted and |
| 735 | verified for functionality. |
| 736 | |
| 737 | Say N if you are unsure. |
| 738 | |
Arjan van de Ven | 6dab277 | 2008-01-30 13:33:08 +0100 | [diff] [blame] | 739 | config BACKTRACE_SELF_TEST |
| 740 | tristate "Self test for the backtrace code" |
| 741 | depends on DEBUG_KERNEL |
| 742 | default n |
| 743 | help |
| 744 | This option provides a kernel module that can be used to test |
| 745 | the kernel stack backtrace code. This option is not useful |
| 746 | for distributions or general kernels, but only for kernel |
| 747 | developers working on architecture code. |
| 748 | |
Vegard Nossum | ad118c5 | 2008-06-27 18:04:48 +0200 | [diff] [blame] | 749 | Note that if you want to also test saved backtraces, you will |
| 750 | have to enable STACKTRACE as well. |
| 751 | |
Arjan van de Ven | 6dab277 | 2008-01-30 13:33:08 +0100 | [diff] [blame] | 752 | Say N if you are unsure. |
| 753 | |
Tejun Heo | 870d665 | 2008-08-25 19:47:25 +0900 | [diff] [blame] | 754 | config DEBUG_BLOCK_EXT_DEVT |
| 755 | bool "Force extended block device numbers and spread them" |
| 756 | depends on DEBUG_KERNEL |
| 757 | depends on BLOCK |
Jens Axboe | 759f8ca | 2008-08-29 09:06:29 +0200 | [diff] [blame] | 758 | default n |
Tejun Heo | 870d665 | 2008-08-25 19:47:25 +0900 | [diff] [blame] | 759 | help |
Tejun Heo | 0e11e34 | 2008-10-13 10:46:01 +0200 | [diff] [blame] | 760 | BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON |
| 761 | SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT |
| 762 | YOU ARE DOING. Distros, please enable this and fix whatever |
| 763 | is broken. |
| 764 | |
Tejun Heo | 870d665 | 2008-08-25 19:47:25 +0900 | [diff] [blame] | 765 | Conventionally, block device numbers are allocated from |
| 766 | predetermined contiguous area. However, extended block area |
| 767 | may introduce non-contiguous block device numbers. This |
| 768 | option forces most block device numbers to be allocated from |
| 769 | the extended space and spreads them to discover kernel or |
| 770 | userland code paths which assume predetermined contiguous |
| 771 | device number allocation. |
| 772 | |
Tejun Heo | 55dc7db | 2008-09-01 13:44:35 +0200 | [diff] [blame] | 773 | Note that turning on this debug option shuffles all the |
| 774 | device numbers for all IDE and SCSI devices including libata |
| 775 | ones, so root partition specified using device number |
| 776 | directly (via rdev or root=MAJ:MIN) won't work anymore. |
| 777 | Textual device names (root=/dev/sdXn) will continue to work. |
| 778 | |
Tejun Heo | 870d665 | 2008-08-25 19:47:25 +0900 | [diff] [blame] | 779 | Say N if you are unsure. |
| 780 | |
Ankita Garg | 8bb31b9 | 2006-10-02 02:17:36 -0700 | [diff] [blame] | 781 | config LKDTM |
| 782 | tristate "Linux Kernel Dump Test Tool Module" |
Don Mullis | bf4735a | 2006-12-10 02:18:37 -0800 | [diff] [blame] | 783 | depends on DEBUG_KERNEL |
Ankita Garg | 8bb31b9 | 2006-10-02 02:17:36 -0700 | [diff] [blame] | 784 | depends on KPROBES |
Chris Snook | fddd9cf | 2008-02-23 15:23:26 -0800 | [diff] [blame] | 785 | depends on BLOCK |
Ankita Garg | 8bb31b9 | 2006-10-02 02:17:36 -0700 | [diff] [blame] | 786 | default n |
| 787 | help |
| 788 | This module enables testing of the different dumping mechanisms by |
| 789 | inducing system failures at predefined crash points. |
| 790 | If you don't need it: say N |
| 791 | Choose M here to compile this code as a module. The module will be |
| 792 | called lkdtm. |
| 793 | |
| 794 | Documentation on how to use the module can be found in |
| 795 | drivers/misc/lkdtm.c |
Akinobu Mita | 6ff1cb3 | 2006-12-08 02:39:43 -0800 | [diff] [blame] | 796 | |
| 797 | config FAULT_INJECTION |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 798 | bool "Fault-injection framework" |
| 799 | depends on DEBUG_KERNEL |
Akinobu Mita | 329409a | 2006-12-08 02:39:48 -0800 | [diff] [blame] | 800 | help |
| 801 | Provide fault-injection framework. |
| 802 | For more details, see Documentation/fault-injection/. |
Akinobu Mita | 6ff1cb3 | 2006-12-08 02:39:43 -0800 | [diff] [blame] | 803 | |
Akinobu Mita | 8a8b650 | 2006-12-08 02:39:44 -0800 | [diff] [blame] | 804 | config FAILSLAB |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 805 | bool "Fault-injection capability for kmalloc" |
| 806 | depends on FAULT_INJECTION |
Akinobu Mita | 773ff60 | 2008-12-23 19:37:01 +0900 | [diff] [blame] | 807 | depends on SLAB || SLUB |
Akinobu Mita | 8a8b650 | 2006-12-08 02:39:44 -0800 | [diff] [blame] | 808 | help |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 809 | Provide fault-injection capability for kmalloc. |
Akinobu Mita | 8a8b650 | 2006-12-08 02:39:44 -0800 | [diff] [blame] | 810 | |
Akinobu Mita | 933e312 | 2006-12-08 02:39:45 -0800 | [diff] [blame] | 811 | config FAIL_PAGE_ALLOC |
| 812 | bool "Fault-injection capabilitiy for alloc_pages()" |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 813 | depends on FAULT_INJECTION |
Akinobu Mita | 933e312 | 2006-12-08 02:39:45 -0800 | [diff] [blame] | 814 | help |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 815 | Provide fault-injection capability for alloc_pages(). |
Akinobu Mita | 933e312 | 2006-12-08 02:39:45 -0800 | [diff] [blame] | 816 | |
Akinobu Mita | c17bb49 | 2006-12-08 02:39:46 -0800 | [diff] [blame] | 817 | config FAIL_MAKE_REQUEST |
Dave Jones | 86327d1 | 2006-12-12 20:16:36 +0100 | [diff] [blame] | 818 | bool "Fault-injection capability for disk IO" |
Jens Axboe | 581d4e2 | 2008-09-14 05:56:33 -0700 | [diff] [blame] | 819 | depends on FAULT_INJECTION && BLOCK |
Akinobu Mita | c17bb49 | 2006-12-08 02:39:46 -0800 | [diff] [blame] | 820 | help |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 821 | Provide fault-injection capability for disk IO. |
Akinobu Mita | c17bb49 | 2006-12-08 02:39:46 -0800 | [diff] [blame] | 822 | |
Jens Axboe | 581d4e2 | 2008-09-14 05:56:33 -0700 | [diff] [blame] | 823 | config FAIL_IO_TIMEOUT |
| 824 | bool "Faul-injection capability for faking disk interrupts" |
| 825 | depends on FAULT_INJECTION && BLOCK |
| 826 | help |
| 827 | Provide fault-injection capability on end IO handling. This |
| 828 | will make the block layer "forget" an interrupt as configured, |
| 829 | thus exercising the error handling. |
| 830 | |
| 831 | Only works with drivers that use the generic timeout handling, |
| 832 | for others it wont do anything. |
| 833 | |
Akinobu Mita | 6ff1cb3 | 2006-12-08 02:39:43 -0800 | [diff] [blame] | 834 | config FAULT_INJECTION_DEBUG_FS |
| 835 | bool "Debugfs entries for fault-injection capabilities" |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 836 | depends on FAULT_INJECTION && SYSFS && DEBUG_FS |
Akinobu Mita | 6ff1cb3 | 2006-12-08 02:39:43 -0800 | [diff] [blame] | 837 | help |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 838 | Enable configuration of fault-injection capabilities via debugfs. |
Akinobu Mita | 1df4900 | 2007-02-20 13:57:56 -0800 | [diff] [blame] | 839 | |
| 840 | config FAULT_INJECTION_STACKTRACE_FILTER |
| 841 | bool "stacktrace filter for fault-injection capabilities" |
| 842 | depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT |
Akinobu Mita | 6d690dc | 2007-05-12 10:36:53 -0700 | [diff] [blame] | 843 | depends on !X86_64 |
Akinobu Mita | 1df4900 | 2007-02-20 13:57:56 -0800 | [diff] [blame] | 844 | select STACKTRACE |
Heiko Carstens | 75ee034 | 2009-04-23 13:58:10 +0200 | [diff] [blame] | 845 | select FRAME_POINTER if !PPC && !S390 |
Akinobu Mita | 1df4900 | 2007-02-20 13:57:56 -0800 | [diff] [blame] | 846 | help |
| 847 | Provide stacktrace filter for fault-injection capabilities |
Mathieu Desnoyers | 267c402 | 2007-10-18 23:41:07 -0700 | [diff] [blame] | 848 | |
Arjan van de Ven | 9745512 | 2008-01-25 21:08:34 +0100 | [diff] [blame] | 849 | config LATENCYTOP |
| 850 | bool "Latency measuring infrastructure" |
Heiko Carstens | 75ee034 | 2009-04-23 13:58:10 +0200 | [diff] [blame] | 851 | select FRAME_POINTER if !MIPS && !PPC && !S390 |
Arjan van de Ven | 9745512 | 2008-01-25 21:08:34 +0100 | [diff] [blame] | 852 | select KALLSYMS |
| 853 | select KALLSYMS_ALL |
| 854 | select STACKTRACE |
| 855 | select SCHEDSTATS |
| 856 | select SCHED_DEBUG |
Heiko Carstens | aa7d935 | 2008-02-01 17:45:14 +0100 | [diff] [blame] | 857 | depends on HAVE_LATENCYTOP_SUPPORT |
Arjan van de Ven | 9745512 | 2008-01-25 21:08:34 +0100 | [diff] [blame] | 858 | help |
| 859 | Enable this option if you want to use the LatencyTOP tool |
| 860 | to find out which userspace is blocking on what kernel operations. |
| 861 | |
Andi Kleen | 9e94cd3 | 2008-08-16 07:53:05 +0200 | [diff] [blame] | 862 | config SYSCTL_SYSCALL_CHECK |
| 863 | bool "Sysctl checks" |
| 864 | depends on SYSCTL_SYSCALL |
| 865 | ---help--- |
| 866 | sys_sysctl uses binary paths that have been found challenging |
| 867 | to properly maintain and use. This enables checks that help |
| 868 | you to keep things correct. |
| 869 | |
Akinobu Mita | 6a11f75 | 2009-03-31 15:23:17 -0700 | [diff] [blame] | 870 | source mm/Kconfig.debug |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 871 | source kernel/trace/Kconfig |
| 872 | |
Bernhard Kaindl | f212ec4 | 2008-01-30 13:34:11 +0100 | [diff] [blame] | 873 | config PROVIDE_OHCI1394_DMA_INIT |
Stefan Richter | 080de8c | 2008-02-28 20:54:43 +0100 | [diff] [blame] | 874 | bool "Remote debugging over FireWire early on boot" |
Bernhard Kaindl | f212ec4 | 2008-01-30 13:34:11 +0100 | [diff] [blame] | 875 | depends on PCI && X86 |
| 876 | help |
| 877 | If you want to debug problems which hang or crash the kernel early |
| 878 | on boot and the crashing machine has a FireWire port, you can use |
| 879 | this feature to remotely access the memory of the crashed machine |
| 880 | over FireWire. This employs remote DMA as part of the OHCI1394 |
| 881 | specification which is now the standard for FireWire controllers. |
| 882 | |
| 883 | With remote DMA, you can monitor the printk buffer remotely using |
| 884 | firescope and access all memory below 4GB using fireproxy from gdb. |
| 885 | Even controlling a kernel debugger is possible using remote DMA. |
| 886 | |
| 887 | Usage: |
| 888 | |
| 889 | If ohci1394_dma=early is used as boot parameter, it will initialize |
| 890 | all OHCI1394 controllers which are found in the PCI config space. |
| 891 | |
| 892 | As all changes to the FireWire bus such as enabling and disabling |
| 893 | devices cause a bus reset and thereby disable remote DMA for all |
| 894 | devices, be sure to have the cable plugged and FireWire enabled on |
| 895 | the debugging host before booting the debug target for debugging. |
| 896 | |
| 897 | This code (~1k) is freed after boot. By then, the firewire stack |
| 898 | in charge of the OHCI-1394 controllers should be used instead. |
| 899 | |
| 900 | See Documentation/debugging-via-ohci1394.txt for more information. |
Arjan van de Ven | 9745512 | 2008-01-25 21:08:34 +0100 | [diff] [blame] | 901 | |
Stefan Richter | 080de8c | 2008-02-28 20:54:43 +0100 | [diff] [blame] | 902 | config FIREWIRE_OHCI_REMOTE_DMA |
| 903 | bool "Remote debugging over FireWire with firewire-ohci" |
| 904 | depends on FIREWIRE_OHCI |
| 905 | help |
| 906 | This option lets you use the FireWire bus for remote debugging |
| 907 | with help of the firewire-ohci driver. It enables unfiltered |
| 908 | remote DMA in firewire-ohci. |
| 909 | See Documentation/debugging-via-ohci1394.txt for more information. |
| 910 | |
| 911 | If unsure, say N. |
| 912 | |
Randy Dunlap | 152de30 | 2009-02-20 15:38:47 -0800 | [diff] [blame] | 913 | config BUILD_DOCSRC |
Randy Dunlap | 3794f3e | 2008-08-12 15:09:06 -0700 | [diff] [blame] | 914 | bool "Build targets in Documentation/ tree" |
| 915 | depends on HEADERS_CHECK |
| 916 | help |
| 917 | This option attempts to build objects from the source files in the |
| 918 | kernel Documentation/ tree. |
| 919 | |
| 920 | Say N if you are unsure. |
| 921 | |
Jason Baron | e9d376f | 2009-02-05 11:51:38 -0500 | [diff] [blame] | 922 | config DYNAMIC_DEBUG |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 923 | bool "Enable dynamic printk() support" |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 924 | default n |
| 925 | depends on PRINTK |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 926 | depends on DEBUG_FS |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 927 | help |
| 928 | |
| 929 | Compiles debug level messages into the kernel, which would not |
| 930 | otherwise be available at runtime. These messages can then be |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 931 | enabled/disabled based on various levels of scope - per source file, |
| 932 | function, module, format string, and line number. This mechanism |
| 933 | implicitly enables all pr_debug() and dev_dbg() calls. The impact of |
| 934 | this compile option is a larger kernel text size of about 2%. |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 935 | |
| 936 | Usage: |
| 937 | |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 938 | Dynamic debugging is controlled via the 'dynamic_debug/ddebug' file, |
| 939 | which is contained in the 'debugfs' filesystem. Thus, the debugfs |
| 940 | filesystem must first be mounted before making use of this feature. |
| 941 | We refer the control file as: <debugfs>/dynamic_debug/ddebug. This |
| 942 | file contains a list of the debug statements that can be enabled. The |
| 943 | format for each line of the file is: |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 944 | |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 945 | filename:lineno [module]function flags format |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 946 | |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 947 | filename : source file of the debug statement |
| 948 | lineno : line number of the debug statement |
| 949 | module : module that contains the debug statement |
| 950 | function : function that contains the debug statement |
| 951 | flags : 'p' means the line is turned 'on' for printing |
| 952 | format : the format used for the debug statement |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 953 | |
| 954 | From a live system: |
| 955 | |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 956 | nullarbor:~ # cat <debugfs>/dynamic_debug/ddebug |
| 957 | # filename:lineno [module]function flags format |
| 958 | fs/aio.c:222 [aio]__put_ioctx - "__put_ioctx:\040freeing\040%p\012" |
| 959 | fs/aio.c:248 [aio]ioctx_alloc - "ENOMEM:\040nr_events\040too\040high\012" |
| 960 | fs/aio.c:1770 [aio]sys_io_cancel - "calling\040cancel\012" |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 961 | |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 962 | Example usage: |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 963 | |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 964 | // enable the message at line 1603 of file svcsock.c |
| 965 | nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' > |
| 966 | <debugfs>/dynamic_debug/ddebug |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 967 | |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 968 | // enable all the messages in file svcsock.c |
| 969 | nullarbor:~ # echo -n 'file svcsock.c +p' > |
| 970 | <debugfs>/dynamic_debug/ddebug |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 971 | |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 972 | // enable all the messages in the NFS server module |
| 973 | nullarbor:~ # echo -n 'module nfsd +p' > |
| 974 | <debugfs>/dynamic_debug/ddebug |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 975 | |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 976 | // enable all 12 messages in the function svc_process() |
| 977 | nullarbor:~ # echo -n 'func svc_process +p' > |
| 978 | <debugfs>/dynamic_debug/ddebug |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 979 | |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 980 | // disable all 12 messages in the function svc_process() |
| 981 | nullarbor:~ # echo -n 'func svc_process -p' > |
| 982 | <debugfs>/dynamic_debug/ddebug |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 983 | |
Jason Baron | 86151fd | 2009-02-05 11:53:15 -0500 | [diff] [blame] | 984 | See Documentation/dynamic-debug-howto.txt for additional information. |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 985 | |
Joerg Roedel | 5ee00bd | 2009-01-09 12:14:24 +0100 | [diff] [blame] | 986 | config DMA_API_DEBUG |
| 987 | bool "Enable debugging of DMA-API usage" |
| 988 | depends on HAVE_DMA_API_DEBUG |
| 989 | help |
| 990 | Enable this option to debug the use of the DMA API by device drivers. |
| 991 | With this option you will be able to detect common bugs in device |
| 992 | drivers like double-freeing of DMA mappings or freeing mappings that |
| 993 | were never allocated. |
| 994 | This option causes a performance degredation. Use only if you want |
| 995 | to debug device drivers. If unsure, say N. |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 996 | |
Mathieu Desnoyers | 267c402 | 2007-10-18 23:41:07 -0700 | [diff] [blame] | 997 | source "samples/Kconfig" |
Jason Wessel | dc7d552 | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 998 | |
| 999 | source "lib/Kconfig.kgdb" |
Pekka Enberg | 0a4af3b | 2009-02-26 21:38:56 +0200 | [diff] [blame] | 1000 | |
| 1001 | source "lib/Kconfig.kmemcheck" |