# select HAVE_FUNCTION_TRACER:
#
+config USER_STACKTRACE_SUPPORT
+ bool
+
config NOP_TRACER
bool
config HAVE_FUNCTION_TRACER
bool
- select NOP_TRACER
+
+config HAVE_FUNCTION_GRAPH_TRACER
+ bool
+
+config HAVE_FUNCTION_TRACE_MCOUNT_TEST
+ bool
+ help
+ This gets selected when the arch tests the function_trace_stop
+ variable at the mcount call site. Otherwise, this variable
+ is tested by the called function.
config HAVE_DYNAMIC_FTRACE
bool
config HAVE_FTRACE_MCOUNT_RECORD
bool
+config HAVE_HW_BRANCH_TRACER
+ bool
+
config TRACER_MAX_TRACE
bool
bool
select DEBUG_FS
select RING_BUFFER
- select STACKTRACE
+ select STACKTRACE if STACKTRACE_SUPPORT
select TRACEPOINTS
+ select NOP_TRACER
+
+menu "Tracers"
config FUNCTION_TRACER
bool "Kernel Function Tracer"
(the bootup default), then the overhead of the instructions is very
small and not measurable even in micro-benchmarks.
+config FUNCTION_GRAPH_TRACER
+ bool "Kernel Function Graph Tracer"
+ depends on HAVE_FUNCTION_GRAPH_TRACER
+ depends on FUNCTION_TRACER
+ default y
+ help
+ Enable the kernel to trace a function at both its return
+ and its entry.
+ It's first purpose is to trace the duration of functions and
+ draw a call graph for each thread with some informations like
+ the return value.
+ This is done by setting the current return address on the current
+ task structure into a stack of calls.
+
config IRQSOFF_TRACER
bool "Interrupts-off Latency Tracer"
default n
bool "Trace boot initcalls"
depends on DEBUG_KERNEL
select TRACING
+ select CONTEXT_SWITCH_TRACER
help
This tracer helps developers to optimize boot times: it records
the timings of the initcalls and traces key events and the identity
selected, because the self-tests are an initcall as well and that
would invalidate the boot trace. )
+config TRACE_BRANCH_PROFILING
+ bool "Trace likely/unlikely profiler"
+ depends on DEBUG_KERNEL
+ select TRACING
+ help
+ This tracer profiles all the the likely and unlikely macros
+ in the kernel. It will display the results in:
+
+ /debugfs/tracing/profile_annotated_branch
+
+ Note: this will add a significant overhead, only turn this
+ on if you need to profile the system's use of these macros.
+
+ Say N if unsure.
+
+config PROFILE_ALL_BRANCHES
+ bool "Profile all if conditionals"
+ depends on TRACE_BRANCH_PROFILING
+ help
+ This tracer profiles all branch conditions. Every if ()
+ taken in the kernel is recorded whether it hit or miss.
+ The results will be displayed in:
+
+ /debugfs/tracing/profile_branch
+
+ This configuration, when enabled, will impose a great overhead
+ on the system. This should only be enabled when the system
+ is to be analyzed
+
+ Say N if unsure.
+
+config TRACING_BRANCHES
+ bool
+ help
+ Selected by tracers that will trace the likely and unlikely
+ conditions. This prevents the tracers themselves from being
+ profiled. Profiling the tracing infrastructure can only happen
+ when the likelys and unlikelys are not being traced.
+
+config BRANCH_TRACER
+ bool "Trace likely/unlikely instances"
+ depends on TRACE_BRANCH_PROFILING
+ select TRACING_BRANCHES
+ help
+ This traces the events of likely and unlikely condition
+ calls in the kernel. The difference between this and the
+ "Trace likely/unlikely profiler" is that this is not a
+ histogram of the callers, but actually places the calling
+ events into a running trace buffer to see when and where the
+ events happened, as well as their results.
+
+ Say N if unsure.
+
+config POWER_TRACER
+ bool "Trace power consumption behavior"
+ depends on DEBUG_KERNEL
+ depends on X86
+ select TRACING
+ help
+ This tracer helps developers to analyze and optimize the kernels
+ power management decisions, specifically the C-state and P-state
+ behavior.
+
+
config STACK_TRACER
bool "Trace max stack"
depends on HAVE_FUNCTION_TRACER
This tracer works by hooking into every function call that the
kernel executes, and keeping a maximum stack depth value and
- stack-trace saved. Because this logic has to execute in every
- kernel function, all the time, this option can slow down the
- kernel measurably and is generally intended for kernel
- developers only.
+ stack-trace saved. If this is configured with DYNAMIC_FTRACE
+ then it will not have any overhead while the stack tracer
+ is disabled.
+
+ To enable the stack tracer on bootup, pass in 'stacktrace'
+ on the kernel command line.
+
+ The stack tracer can also be enabled or disabled via the
+ sysctl kernel.stack_tracer_enabled
Say N if unsure.
+config HW_BRANCH_TRACER
+ depends on HAVE_HW_BRANCH_TRACER
+ bool "Trace hw branches"
+ select TRACING
+ help
+ This tracer records all branches on the system in a circular
+ buffer giving access to the last N branches for each cpu.
+
config DYNAMIC_FTRACE
bool "enable/disable ftrace tracepoints dynamically"
depends on FUNCTION_TRACER
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.
+
+endmenu
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