Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
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linux
1
2config PRINTK_TIME
3 bool "Show timing information on printks"
4 help
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
9 in kernel startup.
10
11
12config MAGIC_SYSRQ
13 bool "Magic SysRq key"
14 depends on !UML
15 help
16 If you say Y here, you will have some control over the system even
17 if the system crashes for example during kernel debugging (e.g., you
18 will be able to flush the buffer cache to disk, reboot the system
19 immediately or dump some status information). This is accomplished
20 by pressing various keys while holding SysRq (Alt+PrintScreen). It
21 also works on a serial console (on PC hardware at least), if you
22 send a BREAK and then within 5 seconds a command keypress. The
23 keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
24 unless you really know what this hack does.
25
26config DEBUG_KERNEL
27 bool "Kernel debugging"
28 help
29 Say Y here if you are developing drivers or trying to debug and
30 identify kernel problems.
31
32config LOG_BUF_SHIFT
33 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" if DEBUG_KERNEL
34 range 12 21
35 default 17 if S390
36 default 16 if X86_NUMAQ || IA64
37 default 15 if SMP
38 default 14
39 help
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
44 15 => 32 KB for SMP
45 14 => 16 KB for uniprocessor
46 13 => 8 KB
47 12 => 4 KB
48
49config DETECT_SOFTLOCKUP
50 bool "Detect Soft Lockups"
51 depends on DEBUG_KERNEL
52 default y
53 help
54 Say Y here to enable the kernel to detect "soft lockups",
55 which are bugs that cause the kernel to loop in kernel
56 mode for more than 10 seconds, without giving other tasks a
57 chance to run.
58
59 When a soft-lockup is detected, the kernel will print the
60 current stack trace (which you should report), but the
61 system will stay locked up. This feature has negligible
62 overhead.
63
64 (Note that "hard lockups" are separate type of bugs that
65 can be detected via the NMI-watchdog, on platforms that
66 support it.)
67
68config SCHEDSTATS
69 bool "Collect scheduler statistics"
70 depends on DEBUG_KERNEL && PROC_FS
71 help
72 If you say Y here, additional code will be inserted into the
73 scheduler and related routines to collect statistics about
74 scheduler behavior and provide them in /proc/schedstat. These
75 stats may be useful for both tuning and debugging the scheduler
76 If you aren't debugging the scheduler or trying to tune a specific
77 application, you can say N to avoid the very slight overhead
78 this adds.
79
80config DEBUG_SLAB
81 bool "Debug memory allocations"
82 depends on DEBUG_KERNEL && SLAB
83 help
84 Say Y here to have the kernel do limited verification on memory
85 allocation as well as poisoning memory on free to catch use of freed
86 memory. This can make kmalloc/kfree-intensive workloads much slower.
87
88config DEBUG_PREEMPT
89 bool "Debug preemptible kernel"
90 depends on DEBUG_KERNEL && PREEMPT
91 default y
92 help
93 If you say Y here then the kernel will use a debug variant of the
94 commonly used smp_processor_id() function and will print warnings
95 if kernel code uses it in a preemption-unsafe way. Also, the kernel
96 will detect preemption count underflows.
97
98config DEBUG_MUTEXES
99 bool "Mutex debugging, deadlock detection"
100 default y
101 depends on DEBUG_KERNEL
102 help
103 This allows mutex semantics violations and mutex related deadlocks
104 (lockups) to be detected and reported automatically.
105
106config DEBUG_SPINLOCK
107 bool "Spinlock debugging"
108 depends on DEBUG_KERNEL
109 help
110 Say Y here and build SMP to catch missing spinlock initialization
111 and certain other kinds of spinlock errors commonly made. This is
112 best used in conjunction with the NMI watchdog so that spinlock
113 deadlocks are also debuggable.
114
115config DEBUG_SPINLOCK_SLEEP
116 bool "Sleep-inside-spinlock checking"
117 depends on DEBUG_KERNEL
118 help
119 If you say Y here, various routines which may sleep will become very
120 noisy if they are called with a spinlock held.
121
122config DEBUG_KOBJECT
123 bool "kobject debugging"
124 depends on DEBUG_KERNEL
125 help
126 If you say Y here, some extra kobject debugging messages will be sent
127 to the syslog.
128
129config DEBUG_HIGHMEM
130 bool "Highmem debugging"
131 depends on DEBUG_KERNEL && HIGHMEM
132 help
133 This options enables addition error checking for high memory systems.
134 Disable for production systems.
135
136config DEBUG_BUGVERBOSE
137 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EMBEDDED
138 depends on BUG
139 depends on ARM || ARM26 || M32R || M68K || SPARC32 || SPARC64 || X86_32 || FRV
140 default !EMBEDDED
141 help
142 Say Y here to make BUG() panics output the file name and line number
143 of the BUG call as well as the EIP and oops trace. This aids
144 debugging but costs about 70-100K of memory.
145
146config DEBUG_INFO
147 bool "Compile the kernel with debug info"
148 depends on DEBUG_KERNEL
149 help
150 If you say Y here the resulting kernel image will include
151 debugging info resulting in a larger kernel image.
152 Say Y here only if you plan to debug the kernel.
153
154 If unsure, say N.
155
156config DEBUG_IOREMAP
157 bool "Enable ioremap() debugging"
158 depends on DEBUG_KERNEL && PARISC
159 help
160 Enabling this option will cause the kernel to distinguish between
161 ioremapped and physical addresses. It will print a backtrace (at
162 most one every 10 seconds), hopefully allowing you to see which
163 drivers need work. Fixing all these problems is a prerequisite
164 for turning on USE_HPPA_IOREMAP. The warnings are harmless;
165 the kernel has enough information to fix the broken drivers
166 automatically, but we'd like to make it more efficient by not
167 having to do that.
168
169config DEBUG_FS
170 bool "Debug Filesystem"
171 depends on DEBUG_KERNEL && SYSFS
172 help
173 debugfs is a virtual file system that kernel developers use to put
174 debugging files into. Enable this option to be able to read and
175 write to these files.
176
177 If unsure, say N.
178
179config DEBUG_VM
180 bool "Debug VM"
181 depends on DEBUG_KERNEL
182 help
183 Enable this to turn on extended checks in the virtual-memory system
184 that may impact performance.
185
186 If unsure, say N.
187
188config FRAME_POINTER
189 bool "Compile the kernel with frame pointers"
190 depends on DEBUG_KERNEL && (X86 || CRIS || M68K || M68KNOMMU || FRV || UML)
191 default y if DEBUG_INFO && UML
192 help
193 If you say Y here the resulting kernel image will be slightly larger
194 and slower, but it might give very useful debugging information on
195 some architectures or if you use external debuggers.
196 If you don't debug the kernel, you can say N.
197
198config FORCED_INLINING
199 bool "Force gcc to inline functions marked 'inline'"
200 depends on DEBUG_KERNEL
201 default y
202 help
203 This option determines if the kernel forces gcc to inline the functions
204 developers have marked 'inline'. Doing so takes away freedom from gcc to
205 do what it thinks is best, which is desirable for the gcc 3.x series of
206 compilers. The gcc 4.x series have a rewritten inlining algorithm and
207 disabling this option will generate a smaller kernel there. Hopefully
208 this algorithm is so good that allowing gcc4 to make the decision can
209 become the default in the future, until then this option is there to
210 test gcc for this.
211
212config RCU_TORTURE_TEST
213 tristate "torture tests for RCU"
214 depends on DEBUG_KERNEL
215 default n
216 help
217 This option provides a kernel module that runs torture tests
218 on the RCU infrastructure. The kernel module may be built
219 after the fact on the running kernel to be tested, if desired.
220
221 Say Y here if you want RCU torture tests to start automatically
222 at boot time (you probably don't).
223 Say M if you want the RCU torture tests to build as a module.
224 Say N if you are unsure.