3 bool "Show timing information on printks"
5 Selecting this option causes timing information to be
6 included in printk output. This allows you to measure
7 the interval between kernel operations, including bootup
8 operations. This is useful for identifying long delays
13 bool "Kernel debugging"
15 Say Y here if you are developing drivers or trying to debug and
16 identify kernel problems.
19 bool "Magic SysRq key"
20 depends on DEBUG_KERNEL && !UML
22 If you say Y here, you will have some control over the system even
23 if the system crashes for example during kernel debugging (e.g., you
24 will be able to flush the buffer cache to disk, reboot the system
25 immediately or dump some status information). This is accomplished
26 by pressing various keys while holding SysRq (Alt+PrintScreen). It
27 also works on a serial console (on PC hardware at least), if you
28 send a BREAK and then within 5 seconds a command keypress. The
29 keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
30 unless you really know what this hack does.
33 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" if DEBUG_KERNEL
35 default 17 if ARCH_S390
36 default 16 if X86_NUMAQ || IA64
40 Select kernel log buffer size as a power of 2.
41 Defaults and Examples:
42 17 => 128 KB for S/390
43 16 => 64 KB for x86 NUMAQ or IA-64
45 14 => 16 KB for uniprocessor
50 bool "Collect scheduler statistics"
51 depends on DEBUG_KERNEL && PROC_FS
53 If you say Y here, additional code will be inserted into the
54 scheduler and related routines to collect statistics about
55 scheduler behavior and provide them in /proc/schedstat. These
56 stats may be useful for both tuning and debugging the scheduler
57 If you aren't debugging the scheduler or trying to tune a specific
58 application, you can say N to avoid the very slight overhead
62 bool "Debug memory allocations"
63 depends on DEBUG_KERNEL
65 Say Y here to have the kernel do limited verification on memory
66 allocation as well as poisoning memory on free to catch use of freed
67 memory. This can make kmalloc/kfree-intensive workloads much slower.
70 bool "Debug preemptible kernel"
71 depends on DEBUG_KERNEL && PREEMPT
74 If you say Y here then the kernel will use a debug variant of the
75 commonly used smp_processor_id() function and will print warnings
76 if kernel code uses it in a preemption-unsafe way. Also, the kernel
77 will detect preemption count underflows.
80 bool "Spinlock debugging"
81 depends on DEBUG_KERNEL
83 Say Y here and build SMP to catch missing spinlock initialization
84 and certain other kinds of spinlock errors commonly made. This is
85 best used in conjunction with the NMI watchdog so that spinlock
86 deadlocks are also debuggable.
88 config DEBUG_SPINLOCK_SLEEP
89 bool "Sleep-inside-spinlock checking"
90 depends on DEBUG_KERNEL
92 If you say Y here, various routines which may sleep will become very
93 noisy if they are called with a spinlock held.
96 bool "kobject debugging"
97 depends on DEBUG_KERNEL
99 If you say Y here, some extra kobject debugging messages will be sent
103 bool "Highmem debugging"
104 depends on DEBUG_KERNEL && HIGHMEM
106 This options enables addition error checking for high memory systems.
107 Disable for production systems.
109 config DEBUG_BUGVERBOSE
110 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EMBEDDED
112 depends on ARM || ARM26 || M32R || M68K || SPARC32 || SPARC64 || (X86 && !X86_64) || FRV
115 Say Y here to make BUG() panics output the file name and line number
116 of the BUG call as well as the EIP and oops trace. This aids
117 debugging but costs about 70-100K of memory.
120 bool "Compile the kernel with debug info"
121 depends on DEBUG_KERNEL
123 If you say Y here the resulting kernel image will include
124 debugging info resulting in a larger kernel image.
125 Say Y here only if you plan to debug the kernel.
130 bool "Enable ioremap() debugging"
131 depends on DEBUG_KERNEL && PARISC
133 Enabling this option will cause the kernel to distinguish between
134 ioremapped and physical addresses. It will print a backtrace (at
135 most one every 10 seconds), hopefully allowing you to see which
136 drivers need work. Fixing all these problems is a prerequisite
137 for turning on USE_HPPA_IOREMAP. The warnings are harmless;
138 the kernel has enough information to fix the broken drivers
139 automatically, but we'd like to make it more efficient by not
143 bool "Debug Filesystem"
144 depends on DEBUG_KERNEL
146 debugfs is a virtual file system that kernel developers use to put
147 debugging files into. Enable this option to be able to read and
148 write to these files.
153 bool "Compile the kernel with frame pointers"
154 depends on DEBUG_KERNEL && ((X86 && !X86_64) || CRIS || M68K || M68KNOMMU || FRV || UML)
155 default y if DEBUG_INFO && UML
157 If you say Y here the resulting kernel image will be slightly larger
158 and slower, but it will give very useful debugging information.
159 If you don't debug the kernel, you can say N, but we may not be able
160 to solve problems without frame pointers.