diff options
Diffstat (limited to 'kernel/trace/Kconfig')
-rw-r--r-- | kernel/trace/Kconfig | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig new file mode 100644 index 000000000000..5c2295b29f2c --- /dev/null +++ b/kernel/trace/Kconfig | |||
@@ -0,0 +1,127 @@ | |||
1 | # | ||
2 | # Architectures that offer an FTRACE implementation should select HAVE_FTRACE: | ||
3 | # | ||
4 | config HAVE_FTRACE | ||
5 | bool | ||
6 | |||
7 | config HAVE_DYNAMIC_FTRACE | ||
8 | bool | ||
9 | |||
10 | config TRACER_MAX_TRACE | ||
11 | bool | ||
12 | |||
13 | config TRACING | ||
14 | bool | ||
15 | select DEBUG_FS | ||
16 | select STACKTRACE | ||
17 | |||
18 | config FTRACE | ||
19 | bool "Kernel Function Tracer" | ||
20 | depends on HAVE_FTRACE | ||
21 | select FRAME_POINTER | ||
22 | select TRACING | ||
23 | select CONTEXT_SWITCH_TRACER | ||
24 | help | ||
25 | Enable the kernel to trace every kernel function. This is done | ||
26 | by using a compiler feature to insert a small, 5-byte No-Operation | ||
27 | instruction to the beginning of every kernel function, which NOP | ||
28 | sequence is then dynamically patched into a tracer call when | ||
29 | tracing is enabled by the administrator. If it's runtime disabled | ||
30 | (the bootup default), then the overhead of the instructions is very | ||
31 | small and not measurable even in micro-benchmarks. | ||
32 | |||
33 | config IRQSOFF_TRACER | ||
34 | bool "Interrupts-off Latency Tracer" | ||
35 | default n | ||
36 | depends on TRACE_IRQFLAGS_SUPPORT | ||
37 | depends on GENERIC_TIME | ||
38 | depends on HAVE_FTRACE | ||
39 | select TRACE_IRQFLAGS | ||
40 | select TRACING | ||
41 | select TRACER_MAX_TRACE | ||
42 | help | ||
43 | This option measures the time spent in irqs-off critical | ||
44 | sections, with microsecond accuracy. | ||
45 | |||
46 | The default measurement method is a maximum search, which is | ||
47 | disabled by default and can be runtime (re-)started | ||
48 | via: | ||
49 | |||
50 | echo 0 > /debugfs/tracing/tracing_max_latency | ||
51 | |||
52 | (Note that kernel size and overhead increases with this option | ||
53 | enabled. This option and the preempt-off timing option can be | ||
54 | used together or separately.) | ||
55 | |||
56 | config PREEMPT_TRACER | ||
57 | bool "Preemption-off Latency Tracer" | ||
58 | default n | ||
59 | depends on GENERIC_TIME | ||
60 | depends on PREEMPT | ||
61 | depends on HAVE_FTRACE | ||
62 | select TRACING | ||
63 | select TRACER_MAX_TRACE | ||
64 | help | ||
65 | This option measures the time spent in preemption off critical | ||
66 | sections, with microsecond accuracy. | ||
67 | |||
68 | The default measurement method is a maximum search, which is | ||
69 | disabled by default and can be runtime (re-)started | ||
70 | via: | ||
71 | |||
72 | echo 0 > /debugfs/tracing/tracing_max_latency | ||
73 | |||
74 | (Note that kernel size and overhead increases with this option | ||
75 | enabled. This option and the irqs-off timing option can be | ||
76 | used together or separately.) | ||
77 | |||
78 | config SCHED_TRACER | ||
79 | bool "Scheduling Latency Tracer" | ||
80 | depends on HAVE_FTRACE | ||
81 | select TRACING | ||
82 | select CONTEXT_SWITCH_TRACER | ||
83 | select TRACER_MAX_TRACE | ||
84 | help | ||
85 | This tracer tracks the latency of the highest priority task | ||
86 | to be scheduled in, starting from the point it has woken up. | ||
87 | |||
88 | config CONTEXT_SWITCH_TRACER | ||
89 | bool "Trace process context switches" | ||
90 | depends on HAVE_FTRACE | ||
91 | select TRACING | ||
92 | select MARKERS | ||
93 | help | ||
94 | This tracer gets called from the context switch and records | ||
95 | all switching of tasks. | ||
96 | |||
97 | config DYNAMIC_FTRACE | ||
98 | bool "enable/disable ftrace tracepoints dynamically" | ||
99 | depends on FTRACE | ||
100 | depends on HAVE_DYNAMIC_FTRACE | ||
101 | default y | ||
102 | help | ||
103 | This option will modify all the calls to ftrace dynamically | ||
104 | (will patch them out of the binary image and replaces them | ||
105 | with a No-Op instruction) as they are called. A table is | ||
106 | created to dynamically enable them again. | ||
107 | |||
108 | This way a CONFIG_FTRACE kernel is slightly larger, but otherwise | ||
109 | has native performance as long as no tracing is active. | ||
110 | |||
111 | The changes to the code are done by a kernel thread that | ||
112 | wakes up once a second and checks to see if any ftrace calls | ||
113 | were made. If so, it runs stop_machine (stops all CPUS) | ||
114 | and modifies the code to jump over the call to ftrace. | ||
115 | |||
116 | config FTRACE_SELFTEST | ||
117 | bool | ||
118 | |||
119 | config FTRACE_STARTUP_TEST | ||
120 | bool "Perform a startup test on ftrace" | ||
121 | depends on TRACING | ||
122 | select FTRACE_SELFTEST | ||
123 | help | ||
124 | This option performs a series of startup tests on ftrace. On bootup | ||
125 | a series of tests are made to verify that the tracer is | ||
126 | functioning properly. It will do tests on all the configured | ||
127 | tracers of ftrace. | ||