Commit | Line | Data |
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1da177e4 LT |
1 | menu "Kernel hacking" |
2 | ||
55f327fa | 3 | config TRACE_IRQFLAGS_SUPPORT |
d013a27c | 4 | def_bool y |
55f327fa | 5 | |
1da177e4 LT |
6 | source "lib/Kconfig.debug" |
7 | ||
8 | config EARLY_PRINTK | |
076f9776 | 9 | bool "Early printk" if EMBEDDED |
1da177e4 LT |
10 | default y |
11 | help | |
12 | Write kernel log output directly into the VGA buffer or to a serial | |
13 | port. | |
14 | ||
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. | |
20 | ||
21 | config DEBUG_STACKOVERFLOW | |
22 | bool "Check for stack overflows" | |
23 | depends on DEBUG_KERNEL | |
dab175f3 AB |
24 | help |
25 | This option will cause messages to be printed if free stack space | |
26 | drops below a certain limit. | |
1da177e4 | 27 | |
1da177e4 LT |
28 | config DEBUG_STACK_USAGE |
29 | bool "Stack utilization instrumentation" | |
30 | depends on DEBUG_KERNEL | |
31 | help | |
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. | |
34 | ||
35 | This option will slow down process creation somewhat. | |
36 | ||
37 | comment "Page alloc debug is incompatible with Software Suspend on i386" | |
b0cb1a19 | 38 | depends on DEBUG_KERNEL && HIBERNATION |
d013a27c | 39 | depends on X86_32 |
1da177e4 LT |
40 | |
41 | config DEBUG_PAGEALLOC | |
4a2f0acf | 42 | bool "Debug page memory allocations" |
b0cb1a19 | 43 | depends on DEBUG_KERNEL && !HIBERNATION && !HUGETLBFS |
1da177e4 LT |
44 | help |
45 | Unmap pages from the kernel linear mapping after free_pages(). | |
46 | This results in a large slowdown, but helps to find certain types | |
47 | of memory corruptions. | |
48 | ||
c49a4955 | 49 | config DEBUG_PER_CPU_MAPS |
50 | bool "Debug access to per_cpu maps" | |
51 | depends on DEBUG_KERNEL | |
52 | depends on X86_64_SMP | |
53 | default n | |
54 | help | |
55 | Say Y to verify that the per_cpu map being accessed has | |
56 | been setup. Adds a fair amount of code to kernel memory | |
57 | and decreases performance. | |
58 | ||
59 | Say N if unsure. | |
60 | ||
63aaf308 AV |
61 | config DEBUG_RODATA |
62 | bool "Write protect kernel read-only data structures" | |
11201e60 | 63 | default y |
63aaf308 AV |
64 | depends on DEBUG_KERNEL |
65 | help | |
66 | Mark the kernel read-only data as write-protected in the pagetables, | |
67 | in order to catch accidental (and incorrect) writes to such const | |
11201e60 IM |
68 | data. This is recommended so that we can catch kernel bugs sooner. |
69 | If in doubt, say "Y". | |
63aaf308 | 70 | |
1da177e4 LT |
71 | config 4KSTACKS |
72 | bool "Use 4Kb for kernel stacks instead of 8Kb" | |
73 | depends on DEBUG_KERNEL | |
d013a27c | 74 | depends on X86_32 |
1da177e4 LT |
75 | help |
76 | If you say Y here the kernel will use a 4Kb stacksize for the | |
77 | kernel stack attached to each process/thread. This facilitates | |
78 | running more threads on a system and also reduces the pressure | |
79 | on the VM subsystem for higher order allocations. This option | |
80 | will also use IRQ stacks to compensate for the reduced stackspace. | |
81 | ||
82 | config X86_FIND_SMP_CONFIG | |
d013a27c | 83 | def_bool y |
1da177e4 | 84 | depends on X86_LOCAL_APIC || X86_VOYAGER |
d013a27c | 85 | depends on X86_32 |
1da177e4 LT |
86 | |
87 | config X86_MPPARSE | |
d013a27c | 88 | def_bool y |
6b0c3d44 | 89 | depends on (X86_32 && (X86_LOCAL_APIC && !X86_VISWS)) || X86_64 |
1da177e4 | 90 | |
102e41fd AK |
91 | config DOUBLEFAULT |
92 | default y | |
93 | bool "Enable doublefault exception handler" if EMBEDDED | |
d013a27c RD |
94 | depends on X86_32 |
95 | help | |
96 | This option allows trapping of rare doublefault exceptions that | |
97 | would otherwise cause a system to silently reboot. Disabling this | |
98 | option saves about 4k and might cause you much additional grey | |
99 | hair. | |
100 | ||
101 | config IOMMU_DEBUG | |
102 | bool "Enable IOMMU debugging" | |
966396d3 | 103 | depends on GART_IOMMU && DEBUG_KERNEL |
d013a27c | 104 | depends on X86_64 |
102e41fd | 105 | help |
d013a27c RD |
106 | Force the IOMMU to on even when you have less than 4GB of |
107 | memory and add debugging code. On overflow always panic. And | |
108 | allow to enable IOMMU leak tracing. Can be disabled at boot | |
109 | time with iommu=noforce. This will also enable scatter gather | |
110 | list merging. Currently not recommended for production | |
111 | code. When you use it make sure you have a big enough | |
112 | IOMMU/AGP aperture. Most of the options enabled by this can | |
113 | be set more finegrained using the iommu= command line | |
114 | options. See Documentation/x86_64/boot-options.txt for more | |
115 | details. | |
116 | ||
117 | config IOMMU_LEAK | |
118 | bool "IOMMU leak tracing" | |
119 | depends on DEBUG_KERNEL | |
120 | depends on IOMMU_DEBUG | |
121 | help | |
122 | Add a simple leak tracer to the IOMMU code. This is useful when you | |
123 | are debugging a buggy device driver that leaks IOMMU mappings. | |
124 | ||
6e7c4025 IM |
125 | # |
126 | # IO delay types: | |
127 | # | |
128 | ||
129 | config IO_DELAY_TYPE_0X80 | |
130 | int | |
131 | default "0" | |
132 | ||
133 | config IO_DELAY_TYPE_0XED | |
134 | int | |
135 | default "1" | |
136 | ||
137 | config IO_DELAY_TYPE_UDELAY | |
138 | int | |
139 | default "2" | |
140 | ||
141 | config IO_DELAY_TYPE_NONE | |
142 | int | |
143 | default "3" | |
144 | ||
145 | choice | |
146 | prompt "IO delay type" | |
d0049e71 | 147 | default IO_DELAY_0XED |
6e7c4025 IM |
148 | |
149 | config IO_DELAY_0X80 | |
150 | bool "port 0x80 based port-IO delay [recommended]" | |
151 | help | |
152 | This is the traditional Linux IO delay used for in/out_p. | |
153 | It is the most tested hence safest selection here. | |
154 | ||
155 | config IO_DELAY_0XED | |
156 | bool "port 0xed based port-IO delay" | |
157 | help | |
158 | Use port 0xed as the IO delay. This frees up port 0x80 which is | |
159 | often used as a hardware-debug port. | |
160 | ||
161 | config IO_DELAY_UDELAY | |
162 | bool "udelay based port-IO delay" | |
163 | help | |
164 | Use udelay(2) as the IO delay method. This provides the delay | |
165 | while not having any side-effect on the IO port space. | |
166 | ||
167 | config IO_DELAY_NONE | |
168 | bool "no port-IO delay" | |
b02aae9c | 169 | help |
6e7c4025 IM |
170 | No port-IO delay. Will break on old boxes that require port-IO |
171 | delay for certain operations. Should work on most new machines. | |
172 | ||
173 | endchoice | |
174 | ||
175 | if IO_DELAY_0X80 | |
176 | config DEFAULT_IO_DELAY_TYPE | |
177 | int | |
178 | default IO_DELAY_TYPE_0X80 | |
179 | endif | |
180 | ||
181 | if IO_DELAY_0XED | |
182 | config DEFAULT_IO_DELAY_TYPE | |
183 | int | |
184 | default IO_DELAY_TYPE_0XED | |
185 | endif | |
186 | ||
187 | if IO_DELAY_UDELAY | |
188 | config DEFAULT_IO_DELAY_TYPE | |
189 | int | |
190 | default IO_DELAY_TYPE_UDELAY | |
191 | endif | |
192 | ||
193 | if IO_DELAY_NONE | |
194 | config DEFAULT_IO_DELAY_TYPE | |
195 | int | |
196 | default IO_DELAY_TYPE_NONE | |
197 | endif | |
b02aae9c | 198 | |
6d7d7433 HY |
199 | config DEBUG_BOOT_PARAMS |
200 | bool "Debug boot parameters" | |
201 | depends on DEBUG_KERNEL | |
202 | depends on DEBUG_FS | |
203 | help | |
204 | This option will cause struct boot_params to be exported via debugfs. | |
205 | ||
0c42f392 AK |
206 | config CPA_DEBUG |
207 | bool "CPA self test code" | |
208 | help | |
209 | Do change_page_attr self tests at boot. | |
210 | ||
1da177e4 | 211 | endmenu |