Commit | Line | Data |
---|---|---|
16444a8a ACM |
1 | # |
2 | # Architectures that offer an FTRACE implementation should select HAVE_FTRACE: | |
3 | # | |
2a3a4f66 FW |
4 | |
5 | config NOP_TRACER | |
6 | bool | |
7 | ||
16444a8a ACM |
8 | config HAVE_FTRACE |
9 | bool | |
2a3a4f66 | 10 | select NOP_TRACER |
bc0c38d1 | 11 | |
677aa9f7 SR |
12 | config HAVE_DYNAMIC_FTRACE |
13 | bool | |
14 | ||
8da3821b SR |
15 | config HAVE_FTRACE_MCOUNT_RECORD |
16 | bool | |
17 | ||
352ad25a SR |
18 | config TRACER_MAX_TRACE |
19 | bool | |
20 | ||
7a8e76a3 SR |
21 | config RING_BUFFER |
22 | bool | |
23 | ||
bc0c38d1 SR |
24 | config TRACING |
25 | bool | |
26 | select DEBUG_FS | |
7a8e76a3 | 27 | select RING_BUFFER |
86387f7e | 28 | select STACKTRACE |
5f87f112 | 29 | select TRACEPOINTS |
bc0c38d1 | 30 | |
1b29b018 SR |
31 | config FTRACE |
32 | bool "Kernel Function Tracer" | |
694379e9 | 33 | depends on HAVE_FTRACE |
d3ee6d99 | 34 | depends on DEBUG_KERNEL |
1b29b018 SR |
35 | select FRAME_POINTER |
36 | select TRACING | |
35e8e302 | 37 | select CONTEXT_SWITCH_TRACER |
1b29b018 SR |
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 | |
81d68a96 SR |
47 | config 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 |
81d68a96 SR |
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 | ||
6cd8a4bb SR |
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 | ||
70 | config 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 |
6cd8a4bb SR |
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 | ||
f06c3810 IM |
92 | config SYSPROF_TRACER |
93 | bool "Sysprof Tracer" | |
4d2df795 | 94 | depends on X86 |
f06c3810 IM |
95 | select TRACING |
96 | help | |
97 | This tracer provides the trace needed by the 'Sysprof' userspace | |
98 | tool. | |
99 | ||
352ad25a SR |
100 | config SCHED_TRACER |
101 | bool "Scheduling Latency Tracer" | |
d3ee6d99 | 102 | depends on DEBUG_KERNEL |
352ad25a SR |
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 | ||
35e8e302 SR |
110 | config CONTEXT_SWITCH_TRACER |
111 | bool "Trace process context switches" | |
d3ee6d99 | 112 | depends on DEBUG_KERNEL |
35e8e302 SR |
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 | ||
1f5c2abb FW |
119 | config BOOT_TRACER |
120 | bool "Trace boot initcalls" | |
1f5c2abb FW |
121 | depends on DEBUG_KERNEL |
122 | select TRACING | |
123 | help | |
124 | This tracer helps developers to optimize boot times: it records | |
98d9c66a IM |
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 | |
e5a81b62 SR |
137 | config STACK_TRACER |
138 | bool "Trace max stack" | |
139 | depends on HAVE_FTRACE | |
2ff01c6a | 140 | depends on DEBUG_KERNEL |
e5a81b62 SR |
141 | select FTRACE |
142 | select STACKTRACE | |
143 | help | |
4519d9e5 IM |
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 | |
3d083395 SR |
156 | config 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 |
3d083395 SR |
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 | |
8da3821b SR |
176 | config FTRACE_MCOUNT_RECORD |
177 | def_bool y | |
178 | depends on DYNAMIC_FTRACE | |
179 | depends on HAVE_FTRACE_MCOUNT_RECORD | |
180 | ||
60a11774 SR |
181 | config FTRACE_SELFTEST |
182 | bool | |
183 | ||
184 | config FTRACE_STARTUP_TEST | |
185 | bool "Perform a startup test on ftrace" | |
3ce2b920 | 186 | depends on TRACING && DEBUG_KERNEL && !BOOT_TRACER |
60a11774 SR |
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. |