| menu "Kernel hacking" |
| |
| config TRACE_IRQFLAGS_SUPPORT |
| def_bool y |
| |
| source "lib/Kconfig.debug" |
| |
| config EARLY_PRINTK |
| bool "Early printk" if EMBEDDED && DEBUG_KERNEL && X86_32 |
| 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. |
| |
| comment "Page alloc debug is incompatible with Software Suspend on i386" |
| depends on DEBUG_KERNEL && HIBERNATION |
| depends on X86_32 |
| |
| config DEBUG_PAGEALLOC |
| bool "Debug page memory allocations" |
| depends on DEBUG_KERNEL && !HIBERNATION && !HUGETLBFS |
| depends on X86_32 |
| 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 |
| depends on X86_32 |
| 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 |
| def_bool y |
| depends on X86_LOCAL_APIC || X86_VOYAGER |
| depends on X86_32 |
| |
| config X86_MPPARSE |
| def_bool y |
| depends on X86_LOCAL_APIC && !X86_VISWS |
| depends on X86_32 |
| |
| config DOUBLEFAULT |
| default y |
| bool "Enable doublefault exception handler" if EMBEDDED |
| depends on X86_32 |
| 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. |
| |
| config IOMMU_DEBUG |
| bool "Enable IOMMU debugging" |
| depends on GART_IOMMU && DEBUG_KERNEL |
| depends on X86_64 |
| help |
| Force the IOMMU to on even when you have less than 4GB of |
| memory and add debugging code. On overflow always panic. And |
| allow to enable IOMMU leak tracing. Can be disabled at boot |
| time with iommu=noforce. This will also enable scatter gather |
| list merging. Currently not recommended for production |
| code. When you use it make sure you have a big enough |
| IOMMU/AGP aperture. Most of the options enabled by this can |
| be set more finegrained using the iommu= command line |
| options. See Documentation/x86_64/boot-options.txt for more |
| details. |
| |
| config IOMMU_LEAK |
| bool "IOMMU leak tracing" |
| depends on DEBUG_KERNEL |
| depends on IOMMU_DEBUG |
| help |
| Add a simple leak tracer to the IOMMU code. This is useful when you |
| are debugging a buggy device driver that leaks IOMMU mappings. |
| |
| endmenu |
