arch/i386/Kconfig.debug

   1 menu "Kernel hacking"
   2
   3 source "lib/Kconfig.debug"
   4
   5 config EARLY_PRINTK
   6         bool "Early printk" if EMBEDDED && DEBUG_KERNEL
   7         default y
   8         help
   9           Write kernel log output directly into the VGA buffer or to a serial
  10           port.
  11
  12           This is useful for kernel debugging when your machine crashes very
  13           early before the console code is initialized. For normal operation
  14           it is not recommended because it looks ugly and doesn't cooperate
  15           with klogd/syslogd or the X server. You should normally N here,
  16           unless you want to debug such a crash.
  17
  18 config DEBUG_STACKOVERFLOW
  19         bool "Check for stack overflows"
  20         depends on DEBUG_KERNEL
  21         help
  22           This option will cause messages to be printed if free stack space
  23           drops below a certain limit.
  24
  25 config DEBUG_STACK_USAGE
  26         bool "Stack utilization instrumentation"
  27         depends on DEBUG_KERNEL
  28         help
  29           Enables the display of the minimum amount of free stack which each
  30           task has ever had available in the sysrq-T and sysrq-P debug output.
  31
  32           This option will slow down process creation somewhat.
  33
  34 config STACK_BACKTRACE_COLS
  35         int "Stack backtraces per line" if DEBUG_KERNEL
  36         range 1 3
  37         default 2
  38         help
  39           Selects how many stack backtrace entries per line to display.
  40
  41           This can save screen space when displaying traces.
  42
  43 comment "Page alloc debug is incompatible with Software Suspend on i386"
  44         depends on DEBUG_KERNEL && SOFTWARE_SUSPEND
  45
  46 config DEBUG_PAGEALLOC
  47         bool "Debug page memory allocations"
  48         depends on DEBUG_KERNEL && !SOFTWARE_SUSPEND && !HUGETLBFS
  49         help
  50           Unmap pages from the kernel linear mapping after free_pages().
  51           This results in a large slowdown, but helps to find certain types
  52           of memory corruptions.
  53
  54 config DEBUG_RODATA
  55         bool "Write protect kernel read-only data structures"
  56         depends on DEBUG_KERNEL
  57         help
  58           Mark the kernel read-only data as write-protected in the pagetables,
  59           in order to catch accidental (and incorrect) writes to such const
  60           data. This option may have a slight performance impact because a
  61           portion of the kernel code won't be covered by a 2MB TLB anymore.
  62           If in doubt, say "N".
  63
  64 config 4KSTACKS
  65         bool "Use 4Kb for kernel stacks instead of 8Kb"
  66         depends on DEBUG_KERNEL
  67         help
  68           If you say Y here the kernel will use a 4Kb stacksize for the
  69           kernel stack attached to each process/thread. This facilitates
  70           running more threads on a system and also reduces the pressure
  71           on the VM subsystem for higher order allocations. This option
  72           will also use IRQ stacks to compensate for the reduced stackspace.
  73
  74 config X86_FIND_SMP_CONFIG
  75         bool
  76         depends on X86_LOCAL_APIC || X86_VOYAGER
  77         default y
  78
  79 config X86_MPPARSE
  80         bool
  81         depends on X86_LOCAL_APIC && !X86_VISWS
  82         default y
  83
  84 endmenu