ftrace: fix depends
[linux-2.6-block.git] / kernel / trace / Kconfig
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1#
2# Architectures that offer an FTRACE implementation should select HAVE_FTRACE:
3#
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4
5config NOP_TRACER
6 bool
7
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8config HAVE_FTRACE
9 bool
2a3a4f66 10 select NOP_TRACER
bc0c38d1 11
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12config HAVE_DYNAMIC_FTRACE
13 bool
14
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15config HAVE_FTRACE_MCOUNT_RECORD
16 bool
17
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18config TRACER_MAX_TRACE
19 bool
20
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21config RING_BUFFER
22 bool
23
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24config TRACING
25 bool
26 select DEBUG_FS
7a8e76a3 27 select RING_BUFFER
86387f7e 28 select STACKTRACE
5f87f112 29 select TRACEPOINTS
bc0c38d1 30
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31config FTRACE
32 bool "Kernel Function Tracer"
694379e9 33 depends on HAVE_FTRACE
d3ee6d99 34 depends on DEBUG_KERNEL
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35 select FRAME_POINTER
36 select TRACING
35e8e302 37 select CONTEXT_SWITCH_TRACER
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38 help
39 Enable the kernel to trace every kernel function. This is done
40 by using a compiler feature to insert a small, 5-byte No-Operation
41 instruction to the beginning of every kernel function, which NOP
42 sequence is then dynamically patched into a tracer call when
43 tracing is enabled by the administrator. If it's runtime disabled
44 (the bootup default), then the overhead of the instructions is very
45 small and not measurable even in micro-benchmarks.
35e8e302 46
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47config IRQSOFF_TRACER
48 bool "Interrupts-off Latency Tracer"
49 default n
50 depends on TRACE_IRQFLAGS_SUPPORT
51 depends on GENERIC_TIME
d3ee6d99 52 depends on DEBUG_KERNEL
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53 select TRACE_IRQFLAGS
54 select TRACING
55 select TRACER_MAX_TRACE
56 help
57 This option measures the time spent in irqs-off critical
58 sections, with microsecond accuracy.
59
60 The default measurement method is a maximum search, which is
61 disabled by default and can be runtime (re-)started
62 via:
63
64 echo 0 > /debugfs/tracing/tracing_max_latency
65
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66 (Note that kernel size and overhead increases with this option
67 enabled. This option and the preempt-off timing option can be
68 used together or separately.)
69
70config PREEMPT_TRACER
71 bool "Preemption-off Latency Tracer"
72 default n
73 depends on GENERIC_TIME
74 depends on PREEMPT
d3ee6d99 75 depends on DEBUG_KERNEL
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76 select TRACING
77 select TRACER_MAX_TRACE
78 help
79 This option measures the time spent in preemption off critical
80 sections, with microsecond accuracy.
81
82 The default measurement method is a maximum search, which is
83 disabled by default and can be runtime (re-)started
84 via:
85
86 echo 0 > /debugfs/tracing/tracing_max_latency
87
88 (Note that kernel size and overhead increases with this option
89 enabled. This option and the irqs-off timing option can be
90 used together or separately.)
91
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92config SYSPROF_TRACER
93 bool "Sysprof Tracer"
4d2df795 94 depends on X86
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95 select TRACING
96 help
97 This tracer provides the trace needed by the 'Sysprof' userspace
98 tool.
99
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100config SCHED_TRACER
101 bool "Scheduling Latency Tracer"
d3ee6d99 102 depends on DEBUG_KERNEL
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103 select TRACING
104 select CONTEXT_SWITCH_TRACER
105 select TRACER_MAX_TRACE
106 help
107 This tracer tracks the latency of the highest priority task
108 to be scheduled in, starting from the point it has woken up.
109
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110config CONTEXT_SWITCH_TRACER
111 bool "Trace process context switches"
d3ee6d99 112 depends on DEBUG_KERNEL
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113 select TRACING
114 select MARKERS
115 help
116 This tracer gets called from the context switch and records
117 all switching of tasks.
118
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119config BOOT_TRACER
120 bool "Trace boot initcalls"
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121 depends on DEBUG_KERNEL
122 select TRACING
123 help
124 This tracer helps developers to optimize boot times: it records
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125 the timings of the initcalls and traces key events and the identity
126 of tasks that can cause boot delays, such as context-switches.
127
128 Its aim is to be parsed by the /scripts/bootgraph.pl tool to
129 produce pretty graphics about boot inefficiencies, giving a visual
130 representation of the delays during initcalls - but the raw
131 /debug/tracing/trace text output is readable too.
132
133 ( Note that tracing self tests can't be enabled if this tracer is
134 selected, because the self-tests are an initcall as well and that
135 would invalidate the boot trace. )
1f5c2abb 136
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137config STACK_TRACER
138 bool "Trace max stack"
139 depends on HAVE_FTRACE
2ff01c6a 140 depends on DEBUG_KERNEL
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141 select FTRACE
142 select STACKTRACE
143 help
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144 This special tracer records the maximum stack footprint of the
145 kernel and displays it in debugfs/tracing/stack_trace.
146
147 This tracer works by hooking into every function call that the
148 kernel executes, and keeping a maximum stack depth value and
149 stack-trace saved. Because this logic has to execute in every
150 kernel function, all the time, this option can slow down the
151 kernel measurably and is generally intended for kernel
152 developers only.
153
154 Say N if unsure.
e5a81b62 155
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156config DYNAMIC_FTRACE
157 bool "enable/disable ftrace tracepoints dynamically"
158 depends on FTRACE
677aa9f7 159 depends on HAVE_DYNAMIC_FTRACE
d3ee6d99 160 depends on DEBUG_KERNEL
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161 default y
162 help
163 This option will modify all the calls to ftrace dynamically
164 (will patch them out of the binary image and replaces them
165 with a No-Op instruction) as they are called. A table is
166 created to dynamically enable them again.
167
168 This way a CONFIG_FTRACE kernel is slightly larger, but otherwise
169 has native performance as long as no tracing is active.
170
171 The changes to the code are done by a kernel thread that
172 wakes up once a second and checks to see if any ftrace calls
173 were made. If so, it runs stop_machine (stops all CPUS)
174 and modifies the code to jump over the call to ftrace.
60a11774 175
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176config FTRACE_MCOUNT_RECORD
177 def_bool y
178 depends on DYNAMIC_FTRACE
179 depends on HAVE_FTRACE_MCOUNT_RECORD
180
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181config FTRACE_SELFTEST
182 bool
183
184config FTRACE_STARTUP_TEST
185 bool "Perform a startup test on ftrace"
3ce2b920 186 depends on TRACING && DEBUG_KERNEL && !BOOT_TRACER
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187 select FTRACE_SELFTEST
188 help
189 This option performs a series of startup tests on ftrace. On bootup
190 a series of tests are made to verify that the tracer is
191 functioning properly. It will do tests on all the configured
192 tracers of ftrace.