aboutsummaryrefslogtreecommitdiff
path: root/kernel/trace/Kconfig
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/trace/Kconfig')
-rw-r--r--kernel/trace/Kconfig135
1 files changed, 135 insertions, 0 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
new file mode 100644
index 00000000000..263e9e6bbd6
--- /dev/null
+++ b/kernel/trace/Kconfig
@@ -0,0 +1,135 @@
+#
+# Architectures that offer an FTRACE implementation should select HAVE_FTRACE:
+#
+config HAVE_FTRACE
+ bool
+
+config HAVE_DYNAMIC_FTRACE
+ bool
+
+config TRACER_MAX_TRACE
+ bool
+
+config TRACING
+ bool
+ select DEBUG_FS
+ select STACKTRACE
+
+config FTRACE
+ bool "Kernel Function Tracer"
+ depends on HAVE_FTRACE
+ select FRAME_POINTER
+ select TRACING
+ select CONTEXT_SWITCH_TRACER
+ help
+ Enable the kernel to trace every kernel function. This is done
+ by using a compiler feature to insert a small, 5-byte No-Operation
+ instruction to the beginning of every kernel function, which NOP
+ sequence is then dynamically patched into a tracer call when
+ tracing is enabled by the administrator. If it's runtime disabled
+ (the bootup default), then the overhead of the instructions is very
+ small and not measurable even in micro-benchmarks.
+
+config IRQSOFF_TRACER
+ bool "Interrupts-off Latency Tracer"
+ default n
+ depends on TRACE_IRQFLAGS_SUPPORT
+ depends on GENERIC_TIME
+ depends on HAVE_FTRACE
+ select TRACE_IRQFLAGS
+ select TRACING
+ select TRACER_MAX_TRACE
+ help
+ This option measures the time spent in irqs-off critical
+ sections, with microsecond accuracy.
+
+ The default measurement method is a maximum search, which is
+ disabled by default and can be runtime (re-)started
+ via:
+
+ echo 0 > /debugfs/tracing/tracing_max_latency
+
+ (Note that kernel size and overhead increases with this option
+ enabled. This option and the preempt-off timing option can be
+ used together or separately.)
+
+config PREEMPT_TRACER
+ bool "Preemption-off Latency Tracer"
+ default n
+ depends on GENERIC_TIME
+ depends on PREEMPT
+ depends on HAVE_FTRACE
+ select TRACING
+ select TRACER_MAX_TRACE
+ help
+ This option measures the time spent in preemption off critical
+ sections, with microsecond accuracy.
+
+ The default measurement method is a maximum search, which is
+ disabled by default and can be runtime (re-)started
+ via:
+
+ echo 0 > /debugfs/tracing/tracing_max_latency
+
+ (Note that kernel size and overhead increases with this option
+ enabled. This option and the irqs-off timing option can be
+ used together or separately.)
+
+config SYSPROF_TRACER
+ bool "Sysprof Tracer"
+ depends on X86
+ select TRACING
+ help
+ This tracer provides the trace needed by the 'Sysprof' userspace
+ tool.
+
+config SCHED_TRACER
+ bool "Scheduling Latency Tracer"
+ depends on HAVE_FTRACE
+ select TRACING
+ select CONTEXT_SWITCH_TRACER
+ select TRACER_MAX_TRACE
+ help
+ This tracer tracks the latency of the highest priority task
+ to be scheduled in, starting from the point it has woken up.
+
+config CONTEXT_SWITCH_TRACER
+ bool "Trace process context switches"
+ depends on HAVE_FTRACE
+ select TRACING
+ select MARKERS
+ help
+ This tracer gets called from the context switch and records
+ all switching of tasks.
+
+config DYNAMIC_FTRACE
+ bool "enable/disable ftrace tracepoints dynamically"
+ depends on FTRACE
+ depends on HAVE_DYNAMIC_FTRACE
+ default y
+ help
+ This option will modify all the calls to ftrace dynamically
+ (will patch them out of the binary image and replaces them
+ with a No-Op instruction) as they are called. A table is
+ created to dynamically enable them again.
+
+ This way a CONFIG_FTRACE kernel is slightly larger, but otherwise
+ has native performance as long as no tracing is active.
+
+ The changes to the code are done by a kernel thread that
+ wakes up once a second and checks to see if any ftrace calls
+ were made. If so, it runs stop_machine (stops all CPUS)
+ and modifies the code to jump over the call to ftrace.
+
+config FTRACE_SELFTEST
+ bool
+
+config FTRACE_STARTUP_TEST
+ bool "Perform a startup test on ftrace"
+ depends on TRACING
+ select FTRACE_SELFTEST
+ help
+ This option performs a series of startup tests on ftrace. On bootup
+ a series of tests are made to verify that the tracer is
+ functioning properly. It will do tests on all the configured
+ tracers of ftrace.