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Commit | Line | Data |
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16444a8a ACM |
1 | # |
2 | # Architectures that offer an FTRACE implementation should select HAVE_FTRACE: | |
3 | # | |
4 | config HAVE_FTRACE | |
5 | bool | |
bc0c38d1 | 6 | |
677aa9f7 SR |
7 | config HAVE_DYNAMIC_FTRACE |
8 | bool | |
9 | ||
352ad25a SR |
10 | config TRACER_MAX_TRACE |
11 | bool | |
12 | ||
bc0c38d1 SR |
13 | config TRACING |
14 | bool | |
15 | select DEBUG_FS | |
86387f7e | 16 | select STACKTRACE |
5f87f112 | 17 | select TRACEPOINTS |
bc0c38d1 | 18 | |
1b29b018 SR |
19 | config FTRACE |
20 | bool "Kernel Function Tracer" | |
694379e9 | 21 | depends on HAVE_FTRACE |
1b29b018 SR |
22 | select FRAME_POINTER |
23 | select TRACING | |
35e8e302 | 24 | select CONTEXT_SWITCH_TRACER |
1b29b018 SR |
25 | help |
26 | Enable the kernel to trace every kernel function. This is done | |
27 | by using a compiler feature to insert a small, 5-byte No-Operation | |
28 | instruction to the beginning of every kernel function, which NOP | |
29 | sequence is then dynamically patched into a tracer call when | |
30 | tracing is enabled by the administrator. If it's runtime disabled | |
31 | (the bootup default), then the overhead of the instructions is very | |
32 | small and not measurable even in micro-benchmarks. | |
35e8e302 | 33 | |
81d68a96 SR |
34 | config IRQSOFF_TRACER |
35 | bool "Interrupts-off Latency Tracer" | |
36 | default n | |
37 | depends on TRACE_IRQFLAGS_SUPPORT | |
38 | depends on GENERIC_TIME | |
c1d2327b | 39 | depends on HAVE_FTRACE |
81d68a96 SR |
40 | select TRACE_IRQFLAGS |
41 | select TRACING | |
42 | select TRACER_MAX_TRACE | |
43 | help | |
44 | This option measures the time spent in irqs-off critical | |
45 | sections, with microsecond accuracy. | |
46 | ||
47 | The default measurement method is a maximum search, which is | |
48 | disabled by default and can be runtime (re-)started | |
49 | via: | |
50 | ||
51 | echo 0 > /debugfs/tracing/tracing_max_latency | |
52 | ||
6cd8a4bb SR |
53 | (Note that kernel size and overhead increases with this option |
54 | enabled. This option and the preempt-off timing option can be | |
55 | used together or separately.) | |
56 | ||
57 | config PREEMPT_TRACER | |
58 | bool "Preemption-off Latency Tracer" | |
59 | default n | |
60 | depends on GENERIC_TIME | |
61 | depends on PREEMPT | |
c1d2327b | 62 | depends on HAVE_FTRACE |
6cd8a4bb SR |
63 | select TRACING |
64 | select TRACER_MAX_TRACE | |
65 | help | |
66 | This option measures the time spent in preemption off critical | |
67 | sections, with microsecond accuracy. | |
68 | ||
69 | The default measurement method is a maximum search, which is | |
70 | disabled by default and can be runtime (re-)started | |
71 | via: | |
72 | ||
73 | echo 0 > /debugfs/tracing/tracing_max_latency | |
74 | ||
75 | (Note that kernel size and overhead increases with this option | |
76 | enabled. This option and the irqs-off timing option can be | |
77 | used together or separately.) | |
78 | ||
f06c3810 IM |
79 | config SYSPROF_TRACER |
80 | bool "Sysprof Tracer" | |
4d2df795 | 81 | depends on X86 |
f06c3810 IM |
82 | select TRACING |
83 | help | |
84 | This tracer provides the trace needed by the 'Sysprof' userspace | |
85 | tool. | |
86 | ||
352ad25a SR |
87 | config SCHED_TRACER |
88 | bool "Scheduling Latency Tracer" | |
c1d2327b | 89 | depends on HAVE_FTRACE |
352ad25a SR |
90 | select TRACING |
91 | select CONTEXT_SWITCH_TRACER | |
92 | select TRACER_MAX_TRACE | |
93 | help | |
94 | This tracer tracks the latency of the highest priority task | |
95 | to be scheduled in, starting from the point it has woken up. | |
96 | ||
35e8e302 SR |
97 | config CONTEXT_SWITCH_TRACER |
98 | bool "Trace process context switches" | |
c1d2327b | 99 | depends on HAVE_FTRACE |
35e8e302 SR |
100 | select TRACING |
101 | select MARKERS | |
102 | help | |
103 | This tracer gets called from the context switch and records | |
104 | all switching of tasks. | |
105 | ||
3d083395 SR |
106 | config DYNAMIC_FTRACE |
107 | bool "enable/disable ftrace tracepoints dynamically" | |
108 | depends on FTRACE | |
677aa9f7 | 109 | depends on HAVE_DYNAMIC_FTRACE |
3d083395 SR |
110 | default y |
111 | help | |
112 | This option will modify all the calls to ftrace dynamically | |
113 | (will patch them out of the binary image and replaces them | |
114 | with a No-Op instruction) as they are called. A table is | |
115 | created to dynamically enable them again. | |
116 | ||
117 | This way a CONFIG_FTRACE kernel is slightly larger, but otherwise | |
118 | has native performance as long as no tracing is active. | |
119 | ||
120 | The changes to the code are done by a kernel thread that | |
121 | wakes up once a second and checks to see if any ftrace calls | |
122 | were made. If so, it runs stop_machine (stops all CPUS) | |
123 | and modifies the code to jump over the call to ftrace. | |
60a11774 SR |
124 | |
125 | config FTRACE_SELFTEST | |
126 | bool | |
127 | ||
128 | config FTRACE_STARTUP_TEST | |
129 | bool "Perform a startup test on ftrace" | |
130 | depends on TRACING | |
131 | select FTRACE_SELFTEST | |
132 | help | |
133 | This option performs a series of startup tests on ftrace. On bootup | |
134 | a series of tests are made to verify that the tracer is | |
135 | functioning properly. It will do tests on all the configured | |
136 | tracers of ftrace. |