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Diffstat (limited to 'kernel/trace/Kconfig')
| -rw-r--r-- | kernel/trace/Kconfig | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig new file mode 100644 index 0000000..33dbefd --- /dev/null +++ b/kernel/trace/Kconfig @@ -0,0 +1,198 @@ +# +# Architectures that offer an FUNCTION_TRACER implementation should +# select HAVE_FUNCTION_TRACER: +# + +config NOP_TRACER + bool + +config HAVE_FUNCTION_TRACER + bool + +config HAVE_DYNAMIC_FTRACE + bool + +config HAVE_FTRACE_MCOUNT_RECORD + bool + +config TRACER_MAX_TRACE + bool + +config RING_BUFFER + bool + +config TRACING + bool + select DEBUG_FS + select RING_BUFFER + select STACKTRACE if STACKTRACE_SUPPORT + select TRACEPOINTS + select NOP_TRACER + +menu "Tracers" + +config FUNCTION_TRACER + bool "Kernel Function Tracer" + depends on HAVE_FUNCTION_TRACER + depends on DEBUG_KERNEL + 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 DEBUG_KERNEL + 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 DEBUG_KERNEL + 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 DEBUG_KERNEL + 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 DEBUG_KERNEL + select TRACING + select MARKERS + help + This tracer gets called from the context switch and records + all switching of tasks. + +config BOOT_TRACER + 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 + of tasks that can cause boot delays, such as context-switches. + + Its aim is to be parsed by the /scripts/bootgraph.pl tool to + produce pretty graphics about boot inefficiencies, giving a visual + representation of the delays during initcalls - but the raw + /debug/tracing/trace text output is readable too. + + ( Note that tracing self tests can't be enabled if this tracer is + selected, because the self-tests are an initcall as well and that + would invalidate the boot trace. ) + +config STACK_TRACER + bool "Trace max stack" + depends on HAVE_FUNCTION_TRACER + depends on DEBUG_KERNEL + select FUNCTION_TRACER + select STACKTRACE + help + This special tracer records the maximum stack footprint of the + kernel and displays it in debugfs/tracing/stack_trace. + + 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. + + Say N if unsure. + +config DYNAMIC_FTRACE + bool "enable/disable ftrace tracepoints dynamically" + depends on FUNCTION_TRACER + depends on HAVE_DYNAMIC_FTRACE + depends on DEBUG_KERNEL + 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_FUNCTION_TRACER 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_MCOUNT_RECORD + def_bool y + depends on DYNAMIC_FTRACE + depends on HAVE_FTRACE_MCOUNT_RECORD + +config FTRACE_SELFTEST + bool + +config FTRACE_STARTUP_TEST + bool "Perform a startup test on ftrace" + depends on TRACING && DEBUG_KERNEL && !BOOT_TRACER + 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. + +endmenu |
