Commit | Line | Data |
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1da177e4 LT |
1 | menu "Kernel hacking" |
2 | ||
3 | source "lib/Kconfig.debug" | |
4 | ||
5 | config EARLY_PRINTK | |
6 | bool "Early printk" if EMBEDDED && DEBUG_KERNEL | |
7 | default y | |
8 | help | |
9 | Write kernel log output directly into the VGA buffer or to a serial | |
10 | port. | |
11 | ||
12 | This is useful for kernel debugging when your machine crashes very | |
13 | early before the console code is initialized. For normal operation | |
14 | it is not recommended because it looks ugly and doesn't cooperate | |
15 | with klogd/syslogd or the X server. You should normally N here, | |
16 | unless you want to debug such a crash. | |
17 | ||
18 | config DEBUG_STACKOVERFLOW | |
19 | bool "Check for stack overflows" | |
20 | depends on DEBUG_KERNEL | |
dab175f3 AB |
21 | help |
22 | This option will cause messages to be printed if free stack space | |
23 | drops below a certain limit. | |
1da177e4 | 24 | |
1da177e4 LT |
25 | config DEBUG_STACK_USAGE |
26 | bool "Stack utilization instrumentation" | |
27 | depends on DEBUG_KERNEL | |
28 | help | |
29 | Enables the display of the minimum amount of free stack which each | |
30 | task has ever had available in the sysrq-T and sysrq-P debug output. | |
31 | ||
32 | This option will slow down process creation somewhat. | |
33 | ||
4d7d8c82 CE |
34 | config STACK_BACKTRACE_COLS |
35 | int "Stack backtraces per line" if DEBUG_KERNEL | |
36 | range 1 3 | |
37 | default 2 | |
38 | help | |
39 | Selects how many stack backtrace entries per line to display. | |
40 | ||
41 | This can save screen space when displaying traces. | |
42 | ||
1da177e4 LT |
43 | comment "Page alloc debug is incompatible with Software Suspend on i386" |
44 | depends on DEBUG_KERNEL && SOFTWARE_SUSPEND | |
45 | ||
46 | config DEBUG_PAGEALLOC | |
4a2f0acf | 47 | bool "Debug page memory allocations" |
a7d06ca7 | 48 | depends on DEBUG_KERNEL && !SOFTWARE_SUSPEND && !HUGETLBFS |
1da177e4 LT |
49 | help |
50 | Unmap pages from the kernel linear mapping after free_pages(). | |
51 | This results in a large slowdown, but helps to find certain types | |
52 | of memory corruptions. | |
53 | ||
63aaf308 AV |
54 | config DEBUG_RODATA |
55 | bool "Write protect kernel read-only data structures" | |
56 | depends on DEBUG_KERNEL | |
57 | help | |
58 | Mark the kernel read-only data as write-protected in the pagetables, | |
59 | in order to catch accidental (and incorrect) writes to such const | |
60 | data. This option may have a slight performance impact because a | |
61 | portion of the kernel code won't be covered by a 2MB TLB anymore. | |
62 | If in doubt, say "N". | |
63 | ||
1da177e4 LT |
64 | config 4KSTACKS |
65 | bool "Use 4Kb for kernel stacks instead of 8Kb" | |
66 | depends on DEBUG_KERNEL | |
67 | help | |
68 | If you say Y here the kernel will use a 4Kb stacksize for the | |
69 | kernel stack attached to each process/thread. This facilitates | |
70 | running more threads on a system and also reduces the pressure | |
71 | on the VM subsystem for higher order allocations. This option | |
72 | will also use IRQ stacks to compensate for the reduced stackspace. | |
73 | ||
74 | config X86_FIND_SMP_CONFIG | |
75 | bool | |
76 | depends on X86_LOCAL_APIC || X86_VOYAGER | |
77 | default y | |
78 | ||
79 | config X86_MPPARSE | |
80 | bool | |
81 | depends on X86_LOCAL_APIC && !X86_VISWS | |
82 | default y | |
83 | ||
102e41fd AK |
84 | config DOUBLEFAULT |
85 | default y | |
86 | bool "Enable doublefault exception handler" if EMBEDDED | |
87 | help | |
88 | This option allows trapping of rare doublefault exceptions that | |
89 | would otherwise cause a system to silently reboot. Disabling this | |
90 | option saves about 4k and might cause you much additional grey | |
91 | hair. | |
92 | ||
1da177e4 | 93 | endmenu |