LXR linux/arch/x86/Kconfig.debug

   1menu "Kernel hacking"
   2
   3config TRACE_IRQFLAGS_SUPPORT
   4        def_bool y
   5
   6source "lib/Kconfig.debug"
   7
   8config EARLY_PRINTK
   9        bool "Early printk" if EMBEDDED && DEBUG_KERNEL && X86_32
  10        default y
  11        help
  12          Write kernel log output directly into the VGA buffer or to a serial
  13          port.
  14
  15          This is useful for kernel debugging when your machine crashes very
  16          early before the console code is initialized. For normal operation
  17          it is not recommended because it looks ugly and doesn't cooperate
  18          with klogd/syslogd or the X server. You should normally N here,
  19          unless you want to debug such a crash.
  20
  21config DEBUG_STACKOVERFLOW
  22        bool "Check for stack overflows"
  23        depends on DEBUG_KERNEL
  24        help
  25          This option will cause messages to be printed if free stack space
  26          drops below a certain limit.
  27
  28config DEBUG_STACK_USAGE
  29        bool "Stack utilization instrumentation"
  30        depends on DEBUG_KERNEL
  31        help
  32          Enables the display of the minimum amount of free stack which each
  33          task has ever had available in the sysrq-T and sysrq-P debug output.
  34
  35          This option will slow down process creation somewhat.
  36
  37comment "Page alloc debug is incompatible with Software Suspend on i386"
  38        depends on DEBUG_KERNEL && HIBERNATION
  39        depends on X86_32
  40
  41config DEBUG_PAGEALLOC
  42        bool "Debug page memory allocations"
  43        depends on DEBUG_KERNEL && !HIBERNATION && !HUGETLBFS
  44        depends on X86_32
  45        help
  46          Unmap pages from the kernel linear mapping after free_pages().
  47          This results in a large slowdown, but helps to find certain types
  48          of memory corruptions.
  49
  50config DEBUG_RODATA
  51        bool "Write protect kernel read-only data structures"
  52        depends on DEBUG_KERNEL
  53        help
  54          Mark the kernel read-only data as write-protected in the pagetables,
  55          in order to catch accidental (and incorrect) writes to such const
  56          data. This option may have a slight performance impact because a
  57          portion of the kernel code won't be covered by a 2MB TLB anymore.
  58          If in doubt, say "N".
  59
  60config 4KSTACKS
  61        bool "Use 4Kb for kernel stacks instead of 8Kb"
  62        depends on DEBUG_KERNEL
  63        depends on X86_32
  64        help
  65          If you say Y here the kernel will use a 4Kb stacksize for the
  66          kernel stack attached to each process/thread. This facilitates
  67          running more threads on a system and also reduces the pressure
  68          on the VM subsystem for higher order allocations. This option
  69          will also use IRQ stacks to compensate for the reduced stackspace.
  70
  71config X86_FIND_SMP_CONFIG
  72        def_bool y
  73        depends on X86_LOCAL_APIC || X86_VOYAGER
  74        depends on X86_32
  75
  76config X86_MPPARSE
  77        def_bool y
  78        depends on X86_LOCAL_APIC && !X86_VISWS
  79        depends on X86_32
  80
  81config DOUBLEFAULT
  82        default y
  83        bool "Enable doublefault exception handler" if EMBEDDED
  84        depends on X86_32
  85        help
  86          This option allows trapping of rare doublefault exceptions that
  87          would otherwise cause a system to silently reboot. Disabling this
  88          option saves about 4k and might cause you much additional grey
  89          hair.
  90
  91config IOMMU_DEBUG
  92        bool "Enable IOMMU debugging"
  93        depends on GART_IOMMU && DEBUG_KERNEL
  94        depends on X86_64
  95        help
  96          Force the IOMMU to on even when you have less than 4GB of
  97          memory and add debugging code. On overflow always panic. And
  98          allow to enable IOMMU leak tracing. Can be disabled at boot
  99          time with iommu=noforce. This will also enable scatter gather
 100          list merging.  Currently not recommended for production
 101          code. When you use it make sure you have a big enough
 102          IOMMU/AGP aperture.  Most of the options enabled by this can
 103          be set more finegrained using the iommu= command line
 104          options. See Documentation/x86_64/boot-options.txt for more
 105          details.
 106
 107config IOMMU_LEAK
 108        bool "IOMMU leak tracing"
 109        depends on DEBUG_KERNEL
 110        depends on IOMMU_DEBUG
 111        help
 112          Add a simple leak tracer to the IOMMU code. This is useful when you
 113          are debugging a buggy device driver that leaks IOMMU mappings.
 114
 115endmenu
 116