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Commit | Line | Data |
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16444a8a | 1 | # |
606576ce SR |
2 | # Architectures that offer an FUNCTION_TRACER implementation should |
3 | # select HAVE_FUNCTION_TRACER: | |
16444a8a | 4 | # |
2a3a4f66 FW |
5 | |
6 | config NOP_TRACER | |
7 | bool | |
8 | ||
606576ce | 9 | config HAVE_FUNCTION_TRACER |
16444a8a | 10 | bool |
bc0c38d1 | 11 | |
15e6cb36 FW |
12 | config HAVE_FUNCTION_RET_TRACER |
13 | bool | |
14 | ||
60a7ecf4 SR |
15 | config HAVE_FUNCTION_TRACE_MCOUNT_TEST |
16 | bool | |
17 | help | |
18 | This gets selected when the arch tests the function_trace_stop | |
19 | variable at the mcount call site. Otherwise, this variable | |
20 | is tested by the called function. | |
21 | ||
677aa9f7 SR |
22 | config HAVE_DYNAMIC_FTRACE |
23 | bool | |
24 | ||
8da3821b SR |
25 | config HAVE_FTRACE_MCOUNT_RECORD |
26 | bool | |
27 | ||
352ad25a SR |
28 | config TRACER_MAX_TRACE |
29 | bool | |
30 | ||
7a8e76a3 SR |
31 | config RING_BUFFER |
32 | bool | |
33 | ||
bc0c38d1 SR |
34 | config TRACING |
35 | bool | |
36 | select DEBUG_FS | |
7a8e76a3 | 37 | select RING_BUFFER |
c2c80529 | 38 | select STACKTRACE if STACKTRACE_SUPPORT |
5f87f112 | 39 | select TRACEPOINTS |
f3384b28 | 40 | select NOP_TRACER |
bc0c38d1 | 41 | |
17d80fd0 PZ |
42 | menu "Tracers" |
43 | ||
606576ce | 44 | config FUNCTION_TRACER |
1b29b018 | 45 | bool "Kernel Function Tracer" |
606576ce | 46 | depends on HAVE_FUNCTION_TRACER |
d3ee6d99 | 47 | depends on DEBUG_KERNEL |
1b29b018 SR |
48 | select FRAME_POINTER |
49 | select TRACING | |
35e8e302 | 50 | select CONTEXT_SWITCH_TRACER |
1b29b018 SR |
51 | help |
52 | Enable the kernel to trace every kernel function. This is done | |
53 | by using a compiler feature to insert a small, 5-byte No-Operation | |
54 | instruction to the beginning of every kernel function, which NOP | |
55 | sequence is then dynamically patched into a tracer call when | |
56 | tracing is enabled by the administrator. If it's runtime disabled | |
57 | (the bootup default), then the overhead of the instructions is very | |
58 | small and not measurable even in micro-benchmarks. | |
35e8e302 | 59 | |
15e6cb36 FW |
60 | config FUNCTION_RET_TRACER |
61 | bool "Kernel Function return Tracer" | |
62 | depends on !DYNAMIC_FTRACE | |
63 | depends on HAVE_FUNCTION_RET_TRACER | |
64 | depends on FUNCTION_TRACER | |
65 | help | |
66 | Enable the kernel to trace a function at its return. | |
67 | It's first purpose is to trace the duration of functions. | |
68 | This is done by setting the current return address on the thread | |
69 | info structure of the current task. | |
70 | ||
81d68a96 SR |
71 | config IRQSOFF_TRACER |
72 | bool "Interrupts-off Latency Tracer" | |
73 | default n | |
74 | depends on TRACE_IRQFLAGS_SUPPORT | |
75 | depends on GENERIC_TIME | |
d3ee6d99 | 76 | depends on DEBUG_KERNEL |
81d68a96 SR |
77 | select TRACE_IRQFLAGS |
78 | select TRACING | |
79 | select TRACER_MAX_TRACE | |
80 | help | |
81 | This option measures the time spent in irqs-off critical | |
82 | sections, with microsecond accuracy. | |
83 | ||
84 | The default measurement method is a maximum search, which is | |
85 | disabled by default and can be runtime (re-)started | |
86 | via: | |
87 | ||
88 | echo 0 > /debugfs/tracing/tracing_max_latency | |
89 | ||
6cd8a4bb SR |
90 | (Note that kernel size and overhead increases with this option |
91 | enabled. This option and the preempt-off timing option can be | |
92 | used together or separately.) | |
93 | ||
94 | config PREEMPT_TRACER | |
95 | bool "Preemption-off Latency Tracer" | |
96 | default n | |
97 | depends on GENERIC_TIME | |
98 | depends on PREEMPT | |
d3ee6d99 | 99 | depends on DEBUG_KERNEL |
6cd8a4bb SR |
100 | select TRACING |
101 | select TRACER_MAX_TRACE | |
102 | help | |
103 | This option measures the time spent in preemption off critical | |
104 | sections, with microsecond accuracy. | |
105 | ||
106 | The default measurement method is a maximum search, which is | |
107 | disabled by default and can be runtime (re-)started | |
108 | via: | |
109 | ||
110 | echo 0 > /debugfs/tracing/tracing_max_latency | |
111 | ||
112 | (Note that kernel size and overhead increases with this option | |
113 | enabled. This option and the irqs-off timing option can be | |
114 | used together or separately.) | |
115 | ||
f06c3810 IM |
116 | config SYSPROF_TRACER |
117 | bool "Sysprof Tracer" | |
4d2df795 | 118 | depends on X86 |
f06c3810 IM |
119 | select TRACING |
120 | help | |
121 | This tracer provides the trace needed by the 'Sysprof' userspace | |
122 | tool. | |
123 | ||
352ad25a SR |
124 | config SCHED_TRACER |
125 | bool "Scheduling Latency Tracer" | |
d3ee6d99 | 126 | depends on DEBUG_KERNEL |
352ad25a SR |
127 | select TRACING |
128 | select CONTEXT_SWITCH_TRACER | |
129 | select TRACER_MAX_TRACE | |
130 | help | |
131 | This tracer tracks the latency of the highest priority task | |
132 | to be scheduled in, starting from the point it has woken up. | |
133 | ||
35e8e302 SR |
134 | config CONTEXT_SWITCH_TRACER |
135 | bool "Trace process context switches" | |
d3ee6d99 | 136 | depends on DEBUG_KERNEL |
35e8e302 SR |
137 | select TRACING |
138 | select MARKERS | |
139 | help | |
140 | This tracer gets called from the context switch and records | |
141 | all switching of tasks. | |
142 | ||
1f5c2abb FW |
143 | config BOOT_TRACER |
144 | bool "Trace boot initcalls" | |
1f5c2abb FW |
145 | depends on DEBUG_KERNEL |
146 | select TRACING | |
ea31e72d | 147 | select CONTEXT_SWITCH_TRACER |
1f5c2abb FW |
148 | help |
149 | This tracer helps developers to optimize boot times: it records | |
98d9c66a IM |
150 | the timings of the initcalls and traces key events and the identity |
151 | of tasks that can cause boot delays, such as context-switches. | |
152 | ||
153 | Its aim is to be parsed by the /scripts/bootgraph.pl tool to | |
154 | produce pretty graphics about boot inefficiencies, giving a visual | |
155 | representation of the delays during initcalls - but the raw | |
156 | /debug/tracing/trace text output is readable too. | |
157 | ||
158 | ( Note that tracing self tests can't be enabled if this tracer is | |
159 | selected, because the self-tests are an initcall as well and that | |
160 | would invalidate the boot trace. ) | |
1f5c2abb | 161 | |
1f0d69a9 SR |
162 | config TRACE_UNLIKELY_PROFILE |
163 | bool "Trace likely/unlikely profiler" | |
164 | depends on DEBUG_KERNEL | |
165 | select TRACING | |
166 | help | |
167 | This tracer profiles all the the likely and unlikely macros | |
168 | in the kernel. It will display the results in: | |
169 | ||
170 | /debugfs/tracing/profile_likely | |
171 | /debugfs/tracing/profile_unlikely | |
172 | ||
173 | Note: this will add a significant overhead, only turn this | |
174 | on if you need to profile the system's use of these macros. | |
175 | ||
176 | Say N if unsure. | |
177 | ||
52f232cb SR |
178 | config TRACING_UNLIKELY |
179 | bool | |
180 | help | |
181 | Selected by tracers that will trace the likely and unlikely | |
182 | conditions. This prevents the tracers themselves from being | |
183 | profiled. Profiling the tracing infrastructure can only happen | |
184 | when the likelys and unlikelys are not being traced. | |
185 | ||
186 | config UNLIKELY_TRACER | |
187 | bool "Trace likely/unlikely instances" | |
188 | depends on TRACE_UNLIKELY_PROFILE | |
189 | select TRACING_UNLIKELY | |
190 | help | |
191 | This traces the events of likely and unlikely condition | |
192 | calls in the kernel. The difference between this and the | |
193 | "Trace likely/unlikely profiler" is that this is not a | |
194 | histogram of the callers, but actually places the calling | |
195 | events into a running trace buffer to see when and where the | |
196 | events happened, as well as their results. | |
197 | ||
198 | Say N if unsure. | |
199 | ||
e5a81b62 SR |
200 | config STACK_TRACER |
201 | bool "Trace max stack" | |
606576ce | 202 | depends on HAVE_FUNCTION_TRACER |
2ff01c6a | 203 | depends on DEBUG_KERNEL |
606576ce | 204 | select FUNCTION_TRACER |
e5a81b62 SR |
205 | select STACKTRACE |
206 | help | |
4519d9e5 IM |
207 | This special tracer records the maximum stack footprint of the |
208 | kernel and displays it in debugfs/tracing/stack_trace. | |
209 | ||
210 | This tracer works by hooking into every function call that the | |
211 | kernel executes, and keeping a maximum stack depth value and | |
212 | stack-trace saved. Because this logic has to execute in every | |
213 | kernel function, all the time, this option can slow down the | |
214 | kernel measurably and is generally intended for kernel | |
215 | developers only. | |
216 | ||
217 | Say N if unsure. | |
e5a81b62 | 218 | |
3d083395 SR |
219 | config DYNAMIC_FTRACE |
220 | bool "enable/disable ftrace tracepoints dynamically" | |
606576ce | 221 | depends on FUNCTION_TRACER |
677aa9f7 | 222 | depends on HAVE_DYNAMIC_FTRACE |
d3ee6d99 | 223 | depends on DEBUG_KERNEL |
3d083395 SR |
224 | default y |
225 | help | |
226 | This option will modify all the calls to ftrace dynamically | |
227 | (will patch them out of the binary image and replaces them | |
228 | with a No-Op instruction) as they are called. A table is | |
229 | created to dynamically enable them again. | |
230 | ||
606576ce | 231 | This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but otherwise |
3d083395 SR |
232 | has native performance as long as no tracing is active. |
233 | ||
234 | The changes to the code are done by a kernel thread that | |
235 | wakes up once a second and checks to see if any ftrace calls | |
236 | were made. If so, it runs stop_machine (stops all CPUS) | |
237 | and modifies the code to jump over the call to ftrace. | |
60a11774 | 238 | |
8da3821b SR |
239 | config FTRACE_MCOUNT_RECORD |
240 | def_bool y | |
241 | depends on DYNAMIC_FTRACE | |
242 | depends on HAVE_FTRACE_MCOUNT_RECORD | |
243 | ||
60a11774 SR |
244 | config FTRACE_SELFTEST |
245 | bool | |
246 | ||
247 | config FTRACE_STARTUP_TEST | |
248 | bool "Perform a startup test on ftrace" | |
3ce2b920 | 249 | depends on TRACING && DEBUG_KERNEL && !BOOT_TRACER |
60a11774 SR |
250 | select FTRACE_SELFTEST |
251 | help | |
252 | This option performs a series of startup tests on ftrace. On bootup | |
253 | a series of tests are made to verify that the tracer is | |
254 | functioning properly. It will do tests on all the configured | |
255 | tracers of ftrace. | |
17d80fd0 PZ |
256 | |
257 | endmenu |