Commit 61778cd7 authored by Steven Rostedt (VMware)'s avatar Steven Rostedt (VMware)
Browse files

tracing: Move all function tracing configs together 



The features that depend on the function tracer were spread out through the
tracing menu, pull them together as it is easier to manage.

Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent 34ed6357

kernel/trace/Kconfig

+71 −71
Original line number Diff line number Diff line
@@ -172,6 +172,77 @@ config FUNCTION_GRAPH_TRACER 
	  the return value. This is done by setting the current return

	  address on the current task structure into a stack of calls.



config DYNAMIC_FTRACE

	bool "enable/disable function tracing dynamically"

	depends on FUNCTION_TRACER

	depends on HAVE_DYNAMIC_FTRACE

	default y

	help

	  This option will modify all the calls to function tracing

	  dynamically (will patch them out of the binary image and

	  replace them with a No-Op instruction) on boot up. During

	  compile time, a table is made of all the locations that ftrace

	  can function trace, and this table is linked into the kernel

	  image. When this is enabled, functions can be individually

	  enabled, and the functions not enabled will not affect

	  performance of the system.



	  See the files in /sys/kernel/debug/tracing:

	    available_filter_functions

	    set_ftrace_filter

	    set_ftrace_notrace



	  This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but

	  otherwise has native performance as long as no tracing is active.



config DYNAMIC_FTRACE_WITH_REGS

	def_bool y

	depends on DYNAMIC_FTRACE

	depends on HAVE_DYNAMIC_FTRACE_WITH_REGS



config DYNAMIC_FTRACE_WITH_DIRECT_CALLS

	def_bool y

	depends on DYNAMIC_FTRACE

	depends on HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS



config FUNCTION_PROFILER

	bool "Kernel function profiler"

	depends on FUNCTION_TRACER

	default n

	help

	  This option enables the kernel function profiler. A file is created

	  in debugfs called function_profile_enabled which defaults to zero.

	  When a 1 is echoed into this file profiling begins, and when a

	  zero is entered, profiling stops. A "functions" file is created in

	  the trace_stat directory; this file shows the list of functions that

	  have been hit and their counters.



	  If in doubt, say N.



config STACK_TRACER

	bool "Trace max stack"

	depends on HAVE_FUNCTION_TRACER

	select FUNCTION_TRACER

	select STACKTRACE

	select KALLSYMS

	help

	  This special tracer records the maximum stack footprint of the

	  kernel and displays it in /sys/kernel/debug/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.  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 TRACE_PREEMPT_TOGGLE

	bool

	help
@@ -410,30 +481,6 @@ config BRANCH_TRACER 


	  Say N if unsure.



config STACK_TRACER

	bool "Trace max stack"

	depends on HAVE_FUNCTION_TRACER

	select FUNCTION_TRACER

	select STACKTRACE

	select KALLSYMS

	help

	  This special tracer records the maximum stack footprint of the

	  kernel and displays it in /sys/kernel/debug/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.  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 BLK_DEV_IO_TRACE

	bool "Support for tracing block IO actions"

	depends on SYSFS
@@ -531,53 +578,6 @@ config DYNAMIC_EVENTS 
config PROBE_EVENTS

	def_bool n



config DYNAMIC_FTRACE

	bool "enable/disable function tracing dynamically"

	depends on FUNCTION_TRACER

	depends on HAVE_DYNAMIC_FTRACE

	default y

	help

	  This option will modify all the calls to function tracing

	  dynamically (will patch them out of the binary image and

	  replace them with a No-Op instruction) on boot up. During

	  compile time, a table is made of all the locations that ftrace

	  can function trace, and this table is linked into the kernel

	  image. When this is enabled, functions can be individually

	  enabled, and the functions not enabled will not affect

	  performance of the system.



	  See the files in /sys/kernel/debug/tracing:

	    available_filter_functions

	    set_ftrace_filter

	    set_ftrace_notrace



	  This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but

	  otherwise has native performance as long as no tracing is active.



config DYNAMIC_FTRACE_WITH_REGS

	def_bool y

	depends on DYNAMIC_FTRACE

	depends on HAVE_DYNAMIC_FTRACE_WITH_REGS



config DYNAMIC_FTRACE_WITH_DIRECT_CALLS

	def_bool y

	depends on DYNAMIC_FTRACE

	depends on HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS



config FUNCTION_PROFILER

	bool "Kernel function profiler"

	depends on FUNCTION_TRACER

	default n

	help

	  This option enables the kernel function profiler. A file is created

	  in debugfs called function_profile_enabled which defaults to zero.

	  When a 1 is echoed into this file profiling begins, and when a

	  zero is entered, profiling stops. A "functions" file is created in

	  the trace_stat directory; this file shows the list of functions that

	  have been hit and their counters.



	  If in doubt, say N.



config BPF_KPROBE_OVERRIDE

	bool "Enable BPF programs to override a kprobed function"

	depends on BPF_EVENTS

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