3 config TRACE_IRQFLAGS_SUPPORT
6 source "lib/Kconfig.debug"
9 bool "Early printk" if EMBEDDED
12 Write kernel log output directly into the VGA buffer or to a serial
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.
21 config DEBUG_STACKOVERFLOW
22 bool "Check for stack overflows"
23 depends on DEBUG_KERNEL
25 This option will cause messages to be printed if free stack space
26 drops below a certain limit.
28 config DEBUG_STACK_USAGE
29 bool "Stack utilization instrumentation"
30 depends on DEBUG_KERNEL
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.
35 This option will slow down process creation somewhat.
37 comment "Page alloc debug is incompatible with Software Suspend on i386"
38 depends on DEBUG_KERNEL && HIBERNATION
41 config DEBUG_PAGEALLOC
42 bool "Debug page memory allocations"
43 depends on DEBUG_KERNEL && !HIBERNATION && !HUGETLBFS
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.
51 bool "Write protect kernel read-only data structures"
52 depends on DEBUG_KERNEL
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.
61 bool "Use 4Kb for kernel stacks instead of 8Kb"
62 depends on DEBUG_KERNEL
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.
71 config X86_FIND_SMP_CONFIG
73 depends on X86_LOCAL_APIC || X86_VOYAGER
78 depends on (X86_32 && (X86_LOCAL_APIC && !X86_VISWS)) || X86_64
82 bool "Enable doublefault exception handler" if EMBEDDED
85 This option allows trapping of rare doublefault exceptions that
86 would otherwise cause a system to silently reboot. Disabling this
87 option saves about 4k and might cause you much additional grey
91 bool "Enable IOMMU debugging"
92 depends on GART_IOMMU && DEBUG_KERNEL
95 Force the IOMMU to on even when you have less than 4GB of
96 memory and add debugging code. On overflow always panic. And
97 allow to enable IOMMU leak tracing. Can be disabled at boot
98 time with iommu=noforce. This will also enable scatter gather
99 list merging. Currently not recommended for production
100 code. When you use it make sure you have a big enough
101 IOMMU/AGP aperture. Most of the options enabled by this can
102 be set more finegrained using the iommu= command line
103 options. See Documentation/x86_64/boot-options.txt for more
107 bool "IOMMU leak tracing"
108 depends on DEBUG_KERNEL
109 depends on IOMMU_DEBUG
111 Add a simple leak tracer to the IOMMU code. This is useful when you
112 are debugging a buggy device driver that leaks IOMMU mappings.
118 config IO_DELAY_TYPE_0X80
122 config IO_DELAY_TYPE_0XED
126 config IO_DELAY_TYPE_UDELAY
130 config IO_DELAY_TYPE_NONE
135 prompt "IO delay type"
136 default IO_DELAY_0XED
139 bool "port 0x80 based port-IO delay [recommended]"
141 This is the traditional Linux IO delay used for in/out_p.
142 It is the most tested hence safest selection here.
145 bool "port 0xed based port-IO delay"
147 Use port 0xed as the IO delay. This frees up port 0x80 which is
148 often used as a hardware-debug port.
150 config IO_DELAY_UDELAY
151 bool "udelay based port-IO delay"
153 Use udelay(2) as the IO delay method. This provides the delay
154 while not having any side-effect on the IO port space.
157 bool "no port-IO delay"
159 No port-IO delay. Will break on old boxes that require port-IO
160 delay for certain operations. Should work on most new machines.
165 config DEFAULT_IO_DELAY_TYPE
167 default IO_DELAY_TYPE_0X80
171 config DEFAULT_IO_DELAY_TYPE
173 default IO_DELAY_TYPE_0XED
177 config DEFAULT_IO_DELAY_TYPE
179 default IO_DELAY_TYPE_UDELAY
183 config DEFAULT_IO_DELAY_TYPE
185 default IO_DELAY_TYPE_NONE
188 config DEBUG_BOOT_PARAMS
189 bool "Debug boot parameters"
190 depends on DEBUG_KERNEL
193 This option will cause struct boot_params to be exported via debugfs.