lib/Kconfig.debug

   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
  12 config DEBUG_KERNEL
  13         bool "Kernel debugging"
  14         help
  15           Say Y here if you are developing drivers or trying to debug and
  16           identify kernel problems.
  17
  18 config MAGIC_SYSRQ
  19         bool "Magic SysRq key"
  20         depends on DEBUG_KERNEL && !UML
  21         help
  22           If you say Y here, you will have some control over the system even
  23           if the system crashes for example during kernel debugging (e.g., you
  24           will be able to flush the buffer cache to disk, reboot the system
  25           immediately or dump some status information). This is accomplished
  26           by pressing various keys while holding SysRq (Alt+PrintScreen). It
  27           also works on a serial console (on PC hardware at least), if you
  28           send a BREAK and then within 5 seconds a command keypress. The
  29           keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
  30           unless you really know what this hack does.
  31
  32 config LOG_BUF_SHIFT
  33         int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" if DEBUG_KERNEL
  34         range 12 21
  35         default 17 if ARCH_S390
  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
  49 config SCHEDSTATS
  50         bool "Collect scheduler statistics"
  51         depends on DEBUG_KERNEL && PROC_FS
  52         help
  53           If you say Y here, additional code will be inserted into the
  54           scheduler and related routines to collect statistics about
  55           scheduler behavior and provide them in /proc/schedstat.  These
  56           stats may be useful for both tuning and debugging the scheduler
  57           If you aren't debugging the scheduler or trying to tune a specific
  58           application, you can say N to avoid the very slight overhead
  59           this adds.
  60
  61 config DEBUG_SLAB
  62         bool "Debug memory allocations"
  63         depends on DEBUG_KERNEL
  64         help
  65           Say Y here to have the kernel do limited verification on memory
  66           allocation as well as poisoning memory on free to catch use of freed
  67           memory. This can make kmalloc/kfree-intensive workloads much slower.
  68
  69 config DEBUG_PREEMPT
  70         bool "Debug preemptible kernel"
  71         depends on DEBUG_KERNEL && PREEMPT
  72         default y
  73         help
  74           If you say Y here then the kernel will use a debug variant of the
  75           commonly used smp_processor_id() function and will print warnings
  76           if kernel code uses it in a preemption-unsafe way. Also, the kernel
  77           will detect preemption count underflows.
  78
  79 config DEBUG_SPINLOCK
  80         bool "Spinlock debugging"
  81         depends on DEBUG_KERNEL
  82         help
  83           Say Y here and build SMP to catch missing spinlock initialization
  84           and certain other kinds of spinlock errors commonly made.  This is
  85           best used in conjunction with the NMI watchdog so that spinlock
  86           deadlocks are also debuggable.
  87
  88 config DEBUG_SPINLOCK_SLEEP
  89         bool "Sleep-inside-spinlock checking"
  90         depends on DEBUG_KERNEL
  91         help
  92           If you say Y here, various routines which may sleep will become very
  93           noisy if they are called with a spinlock held.
  94
  95 config DEBUG_KOBJECT
  96         bool "kobject debugging"
  97         depends on DEBUG_KERNEL
  98         help
  99           If you say Y here, some extra kobject debugging messages will be sent
 100           to the syslog.
 101
 102 config DEBUG_HIGHMEM
 103         bool "Highmem debugging"
 104         depends on DEBUG_KERNEL && HIGHMEM
 105         help
 106           This options enables addition error checking for high memory systems.
 107           Disable for production systems.
 108
 109 config DEBUG_BUGVERBOSE
 110         bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EMBEDDED
 111         depends on ARM || ARM26 || M32R || M68K || SPARC32 || SPARC64 || (X86 && !X86_64) || FRV
 112         default !EMBEDDED
 113         help
 114           Say Y here to make BUG() panics output the file name and line number
 115           of the BUG call as well as the EIP and oops trace.  This aids
 116           debugging but costs about 70-100K of memory.
 117
 118 config DEBUG_INFO
 119         bool "Compile the kernel with debug info"
 120         depends on DEBUG_KERNEL
 121         help
 122           If you say Y here the resulting kernel image will include
 123           debugging info resulting in a larger kernel image.
 124           Say Y here only if you plan to debug the kernel.
 125
 126           If unsure, say N.
 127
 128 config DEBUG_IOREMAP
 129         bool "Enable ioremap() debugging"
 130         depends on DEBUG_KERNEL && PARISC
 131         help
 132           Enabling this option will cause the kernel to distinguish between
 133           ioremapped and physical addresses.  It will print a backtrace (at
 134           most one every 10 seconds), hopefully allowing you to see which
 135           drivers need work.  Fixing all these problems is a prerequisite
 136           for turning on USE_HPPA_IOREMAP.  The warnings are harmless;
 137           the kernel has enough information to fix the broken drivers
 138           automatically, but we'd like to make it more efficient by not
 139           having to do that.
 140
 141 config DEBUG_FS
 142         bool "Debug Filesystem"
 143         depends on DEBUG_KERNEL
 144         help
 145           debugfs is a virtual file system that kernel developers use to put
 146           debugging files into.  Enable this option to be able to read and
 147           write to these files.
 148
 149           If unsure, say N.
 150
 151 config FRAME_POINTER
 152         bool "Compile the kernel with frame pointers"
 153         depends on DEBUG_KERNEL && ((X86 && !X86_64) || CRIS || M68K || M68KNOMMU || FRV)
 154         help
 155           If you say Y here the resulting kernel image will be slightly larger
 156           and slower, but it will give very useful debugging information.
 157           If you don't debug the kernel, you can say N, but we may not be able
 158           to solve problems without frame pointers.
 159