| menu "Kernel hacking" |
| |
| source "lib/Kconfig.debug" |
| |
| config EARLY_PRINTK |
| bool "Early printk" if EMBEDDED && DEBUG_KERNEL |
| default y |
| help |
| Write kernel log output directly into the VGA buffer or to a serial |
| port. |
| |
| This is useful for kernel debugging when your machine crashes very |
| early before the console code is initialized. For normal operation |
| it is not recommended because it looks ugly and doesn't cooperate |
| with klogd/syslogd or the X server. You should normally N here, |
| unless you want to debug such a crash. |
| |
| config DEBUG_STACKOVERFLOW |
| bool "Check for stack overflows" |
| depends on DEBUG_KERNEL |
| help |
| This option will cause messages to be printed if free stack space |
| drops below a certain limit. |
| |
| config DEBUG_STACK_USAGE |
| bool "Stack utilization instrumentation" |
| depends on DEBUG_KERNEL |
| help |
| Enables the display of the minimum amount of free stack which each |
| task has ever had available in the sysrq-T and sysrq-P debug output. |
| |
| This option will slow down process creation somewhat. |
| |
| config STACK_BACKTRACE_COLS |
| int "Stack backtraces per line" if DEBUG_KERNEL |
| range 1 3 |
| default 2 |
| help |
| Selects how many stack backtrace entries per line to display. |
| |
| This can save screen space when displaying traces. |
| |
| comment "Page alloc debug is incompatible with Software Suspend on i386" |
| depends on DEBUG_KERNEL && SOFTWARE_SUSPEND |
| |
| config DEBUG_PAGEALLOC |
| bool "Debug page memory allocations" |
| depends on DEBUG_KERNEL && !SOFTWARE_SUSPEND && !HUGETLBFS |
| help |
| Unmap pages from the kernel linear mapping after free_pages(). |
| This results in a large slowdown, but helps to find certain types |
| of memory corruptions. |
| |
| config DEBUG_RODATA |
| bool "Write protect kernel read-only data structures" |
| depends on DEBUG_KERNEL |
| help |
| Mark the kernel read-only data as write-protected in the pagetables, |
| in order to catch accidental (and incorrect) writes to such const |
| data. This option may have a slight performance impact because a |
| portion of the kernel code won't be covered by a 2MB TLB anymore. |
| If in doubt, say "N". |
| |
| config 4KSTACKS |
| bool "Use 4Kb for kernel stacks instead of 8Kb" |
| depends on DEBUG_KERNEL |
| help |
| If you say Y here the kernel will use a 4Kb stacksize for the |
| kernel stack attached to each process/thread. This facilitates |
| running more threads on a system and also reduces the pressure |
| on the VM subsystem for higher order allocations. This option |
| will also use IRQ stacks to compensate for the reduced stackspace. |
| |
| config X86_FIND_SMP_CONFIG |
| bool |
| depends on X86_LOCAL_APIC || X86_VOYAGER |
| default y |
| |
| config X86_MPPARSE |
| bool |
| depends on X86_LOCAL_APIC && !X86_VISWS |
| default y |
| |
| config DOUBLEFAULT |
| default y |
| bool "Enable doublefault exception handler" if EMBEDDED |
| help |
| This option allows trapping of rare doublefault exceptions that |
| would otherwise cause a system to silently reboot. Disabling this |
| option saves about 4k and might cause you much additional grey |
| hair. |
| |
| endmenu |
