![Ingo Molnar](/assets/img/avatar_default.png)
make io_delay=0xed the default. This frees up port 0x80 which is a debug port on some machines and locks up certain laptops. Testing only for now. Try the io_delay=0x80 boot option if this does not work for you. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
190 lines
5.1 KiB
Text
190 lines
5.1 KiB
Text
menu "Kernel hacking"
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config TRACE_IRQFLAGS_SUPPORT
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def_bool y
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source "lib/Kconfig.debug"
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config EARLY_PRINTK
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bool "Early printk" if EMBEDDED && DEBUG_KERNEL && X86_32
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default y
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help
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Write kernel log output directly into the VGA buffer or to a serial
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port.
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This is useful for kernel debugging when your machine crashes very
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early before the console code is initialized. For normal operation
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it is not recommended because it looks ugly and doesn't cooperate
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with klogd/syslogd or the X server. You should normally N here,
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unless you want to debug such a crash.
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config DEBUG_STACKOVERFLOW
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bool "Check for stack overflows"
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depends on DEBUG_KERNEL
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help
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This option will cause messages to be printed if free stack space
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drops below a certain limit.
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config DEBUG_STACK_USAGE
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bool "Stack utilization instrumentation"
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depends on DEBUG_KERNEL
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help
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Enables the display of the minimum amount of free stack which each
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task has ever had available in the sysrq-T and sysrq-P debug output.
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This option will slow down process creation somewhat.
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comment "Page alloc debug is incompatible with Software Suspend on i386"
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depends on DEBUG_KERNEL && HIBERNATION
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depends on X86_32
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config DEBUG_PAGEALLOC
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bool "Debug page memory allocations"
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depends on DEBUG_KERNEL && !HIBERNATION && !HUGETLBFS
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depends on X86_32
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help
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Unmap pages from the kernel linear mapping after free_pages().
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This results in a large slowdown, but helps to find certain types
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of memory corruptions.
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config DEBUG_RODATA
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bool "Write protect kernel read-only data structures"
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depends on DEBUG_KERNEL
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help
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Mark the kernel read-only data as write-protected in the pagetables,
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in order to catch accidental (and incorrect) writes to such const
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data. This option may have a slight performance impact because a
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portion of the kernel code won't be covered by a 2MB TLB anymore.
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If in doubt, say "N".
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config 4KSTACKS
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bool "Use 4Kb for kernel stacks instead of 8Kb"
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depends on DEBUG_KERNEL
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depends on X86_32
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help
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If you say Y here the kernel will use a 4Kb stacksize for the
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kernel stack attached to each process/thread. This facilitates
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running more threads on a system and also reduces the pressure
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on the VM subsystem for higher order allocations. This option
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will also use IRQ stacks to compensate for the reduced stackspace.
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config X86_FIND_SMP_CONFIG
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def_bool y
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depends on X86_LOCAL_APIC || X86_VOYAGER
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depends on X86_32
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config X86_MPPARSE
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def_bool y
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depends on X86_LOCAL_APIC && !X86_VISWS
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depends on X86_32
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config DOUBLEFAULT
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default y
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bool "Enable doublefault exception handler" if EMBEDDED
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depends on X86_32
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help
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This option allows trapping of rare doublefault exceptions that
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would otherwise cause a system to silently reboot. Disabling this
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option saves about 4k and might cause you much additional grey
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hair.
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config IOMMU_DEBUG
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bool "Enable IOMMU debugging"
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depends on GART_IOMMU && DEBUG_KERNEL
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depends on X86_64
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help
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Force the IOMMU to on even when you have less than 4GB of
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memory and add debugging code. On overflow always panic. And
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allow to enable IOMMU leak tracing. Can be disabled at boot
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time with iommu=noforce. This will also enable scatter gather
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list merging. Currently not recommended for production
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code. When you use it make sure you have a big enough
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IOMMU/AGP aperture. Most of the options enabled by this can
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be set more finegrained using the iommu= command line
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options. See Documentation/x86_64/boot-options.txt for more
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details.
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config IOMMU_LEAK
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bool "IOMMU leak tracing"
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depends on DEBUG_KERNEL
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depends on IOMMU_DEBUG
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help
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Add a simple leak tracer to the IOMMU code. This is useful when you
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are debugging a buggy device driver that leaks IOMMU mappings.
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#
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# IO delay types:
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#
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config IO_DELAY_TYPE_0X80
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int
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default "0"
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config IO_DELAY_TYPE_0XED
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int
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default "1"
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config IO_DELAY_TYPE_UDELAY
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int
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default "2"
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config IO_DELAY_TYPE_NONE
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int
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default "3"
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choice
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prompt "IO delay type"
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default IO_DELAY_0XED
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config IO_DELAY_0X80
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bool "port 0x80 based port-IO delay [recommended]"
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help
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This is the traditional Linux IO delay used for in/out_p.
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It is the most tested hence safest selection here.
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config IO_DELAY_0XED
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bool "port 0xed based port-IO delay"
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help
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Use port 0xed as the IO delay. This frees up port 0x80 which is
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often used as a hardware-debug port.
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config IO_DELAY_UDELAY
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bool "udelay based port-IO delay"
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help
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Use udelay(2) as the IO delay method. This provides the delay
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while not having any side-effect on the IO port space.
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config IO_DELAY_NONE
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bool "no port-IO delay"
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help
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No port-IO delay. Will break on old boxes that require port-IO
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delay for certain operations. Should work on most new machines.
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endchoice
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if IO_DELAY_0X80
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config DEFAULT_IO_DELAY_TYPE
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int
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default IO_DELAY_TYPE_0X80
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endif
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if IO_DELAY_0XED
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config DEFAULT_IO_DELAY_TYPE
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int
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default IO_DELAY_TYPE_0XED
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endif
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if IO_DELAY_UDELAY
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config DEFAULT_IO_DELAY_TYPE
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int
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default IO_DELAY_TYPE_UDELAY
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endif
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if IO_DELAY_NONE
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config DEFAULT_IO_DELAY_TYPE
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int
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default IO_DELAY_TYPE_NONE
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endif
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endmenu
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