Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | |
| 2 | config PRINTK_TIME |
| 3 | bool "Show timing information on printks" |
| 4 | help |
| 5 | Selecting this option causes timing information to be |
| 6 | included in printk output. This allows you to measure |
| 7 | the interval between kernel operations, including bootup |
| 8 | operations. This is useful for identifying long delays |
| 9 | in kernel startup. |
| 10 | |
| 11 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | config MAGIC_SYSRQ |
| 13 | bool "Magic SysRq key" |
Adrian Bunk | f346f4b | 2006-01-09 20:54:51 -0800 | [diff] [blame] | 14 | depends on !UML |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | help |
| 16 | If you say Y here, you will have some control over the system even |
| 17 | if the system crashes for example during kernel debugging (e.g., you |
| 18 | will be able to flush the buffer cache to disk, reboot the system |
| 19 | immediately or dump some status information). This is accomplished |
| 20 | by pressing various keys while holding SysRq (Alt+PrintScreen). It |
| 21 | also works on a serial console (on PC hardware at least), if you |
| 22 | send a BREAK and then within 5 seconds a command keypress. The |
| 23 | keys are documented in <file:Documentation/sysrq.txt>. Don't say Y |
| 24 | unless you really know what this hack does. |
| 25 | |
Adrian Bunk | f346f4b | 2006-01-09 20:54:51 -0800 | [diff] [blame] | 26 | config DEBUG_KERNEL |
| 27 | bool "Kernel debugging" |
| 28 | help |
| 29 | Say Y here if you are developing drivers or trying to debug and |
| 30 | identify kernel problems. |
| 31 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | config LOG_BUF_SHIFT |
| 33 | int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" if DEBUG_KERNEL |
| 34 | range 12 21 |
Martin Schwidefsky | 347a8dc | 2006-01-06 00:19:28 -0800 | [diff] [blame] | 35 | default 17 if S390 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | default 16 if X86_NUMAQ || IA64 |
| 37 | default 15 if SMP |
| 38 | default 14 |
| 39 | help |
| 40 | Select kernel log buffer size as a power of 2. |
| 41 | Defaults and Examples: |
| 42 | 17 => 128 KB for S/390 |
| 43 | 16 => 64 KB for x86 NUMAQ or IA-64 |
| 44 | 15 => 32 KB for SMP |
| 45 | 14 => 16 KB for uniprocessor |
| 46 | 13 => 8 KB |
| 47 | 12 => 4 KB |
| 48 | |
Ingo Molnar | 8446f1d | 2005-09-06 15:16:27 -0700 | [diff] [blame] | 49 | config DETECT_SOFTLOCKUP |
| 50 | bool "Detect Soft Lockups" |
| 51 | depends on DEBUG_KERNEL |
| 52 | default y |
| 53 | help |
| 54 | Say Y here to enable the kernel to detect "soft lockups", |
| 55 | which are bugs that cause the kernel to loop in kernel |
| 56 | mode for more than 10 seconds, without giving other tasks a |
| 57 | chance to run. |
| 58 | |
| 59 | When a soft-lockup is detected, the kernel will print the |
| 60 | current stack trace (which you should report), but the |
| 61 | system will stay locked up. This feature has negligible |
| 62 | overhead. |
| 63 | |
| 64 | (Note that "hard lockups" are separate type of bugs that |
| 65 | can be detected via the NMI-watchdog, on platforms that |
| 66 | support it.) |
| 67 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | config SCHEDSTATS |
| 69 | bool "Collect scheduler statistics" |
| 70 | depends on DEBUG_KERNEL && PROC_FS |
| 71 | help |
| 72 | If you say Y here, additional code will be inserted into the |
| 73 | scheduler and related routines to collect statistics about |
| 74 | scheduler behavior and provide them in /proc/schedstat. These |
| 75 | stats may be useful for both tuning and debugging the scheduler |
| 76 | If you aren't debugging the scheduler or trying to tune a specific |
| 77 | application, you can say N to avoid the very slight overhead |
| 78 | this adds. |
| 79 | |
| 80 | config DEBUG_SLAB |
Andrew Morton | 4a2f0ac | 2006-03-25 03:07:22 -0800 | [diff] [blame] | 81 | bool "Debug slab memory allocations" |
Ingo Molnar | 50dd26b | 2006-01-08 01:01:42 -0800 | [diff] [blame] | 82 | depends on DEBUG_KERNEL && SLAB |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | help |
| 84 | Say Y here to have the kernel do limited verification on memory |
| 85 | allocation as well as poisoning memory on free to catch use of freed |
| 86 | memory. This can make kmalloc/kfree-intensive workloads much slower. |
| 87 | |
Al Viro | 871751e | 2006-03-25 03:06:39 -0800 | [diff] [blame] | 88 | config DEBUG_SLAB_LEAK |
| 89 | bool "Memory leak debugging" |
| 90 | depends on DEBUG_SLAB |
| 91 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 92 | config DEBUG_PREEMPT |
| 93 | bool "Debug preemptible kernel" |
| 94 | depends on DEBUG_KERNEL && PREEMPT |
| 95 | default y |
| 96 | help |
| 97 | If you say Y here then the kernel will use a debug variant of the |
| 98 | commonly used smp_processor_id() function and will print warnings |
| 99 | if kernel code uses it in a preemption-unsafe way. Also, the kernel |
| 100 | will detect preemption count underflows. |
| 101 | |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 102 | config DEBUG_MUTEXES |
| 103 | bool "Mutex debugging, deadlock detection" |
Tim Chen | cca57c5 | 2006-04-18 22:21:47 -0700 | [diff] [blame] | 104 | default n |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 105 | depends on DEBUG_KERNEL |
| 106 | help |
| 107 | This allows mutex semantics violations and mutex related deadlocks |
| 108 | (lockups) to be detected and reported automatically. |
| 109 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 110 | config DEBUG_SPINLOCK |
| 111 | bool "Spinlock debugging" |
| 112 | depends on DEBUG_KERNEL |
| 113 | help |
| 114 | Say Y here and build SMP to catch missing spinlock initialization |
| 115 | and certain other kinds of spinlock errors commonly made. This is |
| 116 | best used in conjunction with the NMI watchdog so that spinlock |
| 117 | deadlocks are also debuggable. |
| 118 | |
| 119 | config DEBUG_SPINLOCK_SLEEP |
| 120 | bool "Sleep-inside-spinlock checking" |
| 121 | depends on DEBUG_KERNEL |
| 122 | help |
| 123 | If you say Y here, various routines which may sleep will become very |
| 124 | noisy if they are called with a spinlock held. |
| 125 | |
| 126 | config DEBUG_KOBJECT |
| 127 | bool "kobject debugging" |
| 128 | depends on DEBUG_KERNEL |
| 129 | help |
| 130 | If you say Y here, some extra kobject debugging messages will be sent |
| 131 | to the syslog. |
| 132 | |
| 133 | config DEBUG_HIGHMEM |
| 134 | bool "Highmem debugging" |
| 135 | depends on DEBUG_KERNEL && HIGHMEM |
| 136 | help |
| 137 | This options enables addition error checking for high memory systems. |
| 138 | Disable for production systems. |
| 139 | |
| 140 | config DEBUG_BUGVERBOSE |
| 141 | bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EMBEDDED |
Matt Mackall | c8538a7 | 2005-05-01 08:59:01 -0700 | [diff] [blame] | 142 | depends on BUG |
Brian Gerst | 0d078f6 | 2005-10-30 14:59:20 -0800 | [diff] [blame] | 143 | depends on ARM || ARM26 || M32R || M68K || SPARC32 || SPARC64 || X86_32 || FRV |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 144 | default !EMBEDDED |
| 145 | help |
| 146 | Say Y here to make BUG() panics output the file name and line number |
| 147 | of the BUG call as well as the EIP and oops trace. This aids |
| 148 | debugging but costs about 70-100K of memory. |
| 149 | |
| 150 | config DEBUG_INFO |
| 151 | bool "Compile the kernel with debug info" |
| 152 | depends on DEBUG_KERNEL |
| 153 | help |
| 154 | If you say Y here the resulting kernel image will include |
| 155 | debugging info resulting in a larger kernel image. |
| 156 | Say Y here only if you plan to debug the kernel. |
| 157 | |
| 158 | If unsure, say N. |
| 159 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 160 | config DEBUG_FS |
| 161 | bool "Debug Filesystem" |
Jens Axboe | ae36b88 | 2006-03-26 14:38:54 +0200 | [diff] [blame] | 162 | depends on SYSFS |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 163 | help |
| 164 | debugfs is a virtual file system that kernel developers use to put |
| 165 | debugging files into. Enable this option to be able to read and |
| 166 | write to these files. |
| 167 | |
| 168 | If unsure, say N. |
| 169 | |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 170 | config DEBUG_VM |
| 171 | bool "Debug VM" |
| 172 | depends on DEBUG_KERNEL |
| 173 | help |
Nick Piggin | 13e7444 | 2006-01-06 00:10:58 -0800 | [diff] [blame] | 174 | Enable this to turn on extended checks in the virtual-memory system |
| 175 | that may impact performance. |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 176 | |
| 177 | If unsure, say N. |
| 178 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 179 | config FRAME_POINTER |
| 180 | bool "Compile the kernel with frame pointers" |
Andi Kleen | aeb3998 | 2005-09-12 18:49:25 +0200 | [diff] [blame] | 181 | depends on DEBUG_KERNEL && (X86 || CRIS || M68K || M68KNOMMU || FRV || UML) |
Paolo 'Blaisorblade' Giarrusso | 37fce85 | 2005-05-28 15:51:59 -0700 | [diff] [blame] | 182 | default y if DEBUG_INFO && UML |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 183 | help |
| 184 | If you say Y here the resulting kernel image will be slightly larger |
Jesper Juhl | 2a38bcc | 2005-10-30 15:02:51 -0800 | [diff] [blame] | 185 | and slower, but it might give very useful debugging information on |
| 186 | some architectures or if you use external debuggers. |
Andi Kleen | aeb3998 | 2005-09-12 18:49:25 +0200 | [diff] [blame] | 187 | If you don't debug the kernel, you can say N. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 188 | |
Jan Beulich | 604bf5a | 2006-03-24 03:16:19 -0800 | [diff] [blame] | 189 | config UNWIND_INFO |
| 190 | bool "Compile the kernel with frame unwind information" |
| 191 | depends on !IA64 |
David S. Miller | 06a1be1 | 2006-05-12 12:45:50 -0700 | [diff] [blame] | 192 | depends on !MODULES || !(MIPS || PARISC || PPC || SUPERH || V850) |
Jan Beulich | 604bf5a | 2006-03-24 03:16:19 -0800 | [diff] [blame] | 193 | help |
| 194 | If you say Y here the resulting kernel image will be slightly larger |
| 195 | but not slower, and it will give very useful debugging information. |
| 196 | If you don't debug the kernel, you can say N, but we may not be able |
| 197 | to solve problems without frame unwind information or frame pointers. |
| 198 | |
Ingo Molnar | a9df3d0 | 2006-01-14 13:21:33 -0800 | [diff] [blame] | 199 | config FORCED_INLINING |
| 200 | bool "Force gcc to inline functions marked 'inline'" |
| 201 | depends on DEBUG_KERNEL |
| 202 | default y |
| 203 | help |
| 204 | This option determines if the kernel forces gcc to inline the functions |
| 205 | developers have marked 'inline'. Doing so takes away freedom from gcc to |
| 206 | do what it thinks is best, which is desirable for the gcc 3.x series of |
| 207 | compilers. The gcc 4.x series have a rewritten inlining algorithm and |
| 208 | disabling this option will generate a smaller kernel there. Hopefully |
| 209 | this algorithm is so good that allowing gcc4 to make the decision can |
| 210 | become the default in the future, until then this option is there to |
| 211 | test gcc for this. |
| 212 | |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 213 | config RCU_TORTURE_TEST |
| 214 | tristate "torture tests for RCU" |
| 215 | depends on DEBUG_KERNEL |
| 216 | default n |
| 217 | help |
| 218 | This option provides a kernel module that runs torture tests |
| 219 | on the RCU infrastructure. The kernel module may be built |
| 220 | after the fact on the running kernel to be tested, if desired. |
| 221 | |
| 222 | Say Y here if you want RCU torture tests to start automatically |
| 223 | at boot time (you probably don't). |
| 224 | Say M if you want the RCU torture tests to build as a module. |
| 225 | Say N if you are unsure. |