#

  # Architectures that offer an FUNCTION_TRACER implementation should
  #  select HAVE_FUNCTION_TRACER:

  #

  config USER_STACKTRACE_SUPPORT
  	bool

  config NOP_TRACER
  	bool

  config HAVE_FTRACE_NMI_ENTER
  	bool

  	help

  	  See Documentation/trace/ftrace-design.txt

  config HAVE_FUNCTION_TRACER

  	bool

  	help

  	  See Documentation/trace/ftrace-design.txt

  config HAVE_FUNCTION_GRAPH_TRACER

  	bool

  	help

  	  See Documentation/trace/ftrace-design.txt

  config HAVE_FUNCTION_GRAPH_FP_TEST
  	bool
  	help

  	  See Documentation/trace/ftrace-design.txt

  config HAVE_DYNAMIC_FTRACE
  	bool

  	help

  	  See Documentation/trace/ftrace-design.txt

  config HAVE_DYNAMIC_FTRACE_WITH_REGS
  	bool

  config HAVE_FTRACE_MCOUNT_RECORD
  	bool

  	help

  	  See Documentation/trace/ftrace-design.txt

  config HAVE_SYSCALL_TRACEPOINTS

  	bool

  	help

  	  See Documentation/trace/ftrace-design.txt

  config HAVE_FENTRY
  	bool
  	help
  	  Arch supports the gcc options -pg with -mfentry

  config HAVE_C_RECORDMCOUNT

  	bool
  	help
  	  C version of recordmcount available?

  config TRACER_MAX_TRACE
  	bool

  config TRACE_CLOCK
  	bool

  config RING_BUFFER
  	bool

  	select TRACE_CLOCK

  	select IRQ_WORK

  config FTRACE_NMI_ENTER
         bool
         depends on HAVE_FTRACE_NMI_ENTER
         default y

  config EVENT_TRACING

  	select CONTEXT_SWITCH_TRACER
  	bool

  config GPU_TRACEPOINTS
  	bool

  config CONTEXT_SWITCH_TRACER

  	bool

  config RING_BUFFER_ALLOW_SWAP
  	bool
  	help
  	 Allow the use of ring_buffer_swap_cpu.
  	 Adds a very slight overhead to tracing when enabled.

  # All tracer options should select GENERIC_TRACER. For those options that are
  # enabled by all tracers (context switch and event tracer) they select TRACING.
  # This allows those options to appear when no other tracer is selected. But the
  # options do not appear when something else selects it. We need the two options
  # GENERIC_TRACER and TRACING to avoid circular dependencies to accomplish the

  # hiding of the automatic options.

  config TRACING
  	bool
  	select DEBUG_FS

  	select RING_BUFFER

  	select STACKTRACE if STACKTRACE_SUPPORT

  	select TRACEPOINTS

  	select NOP_TRACER

  	select BINARY_PRINTF

  	select EVENT_TRACING

  	select TRACE_CLOCK

  config GENERIC_TRACER
  	bool
  	select TRACING

  #
  # Minimum requirements an architecture has to meet for us to
  # be able to offer generic tracing facilities:
  #
  config TRACING_SUPPORT
  	bool

  	# PPC32 has no irqflags tracing support, but it can use most of the
  	# tracers anyway, they were tested to build and work. Note that new
  	# exceptions to this list aren't welcomed, better implement the
  	# irqflags tracing for your architecture.
  	depends on TRACE_IRQFLAGS_SUPPORT || PPC32

  	depends on STACKTRACE_SUPPORT

  	default y

  
  if TRACING_SUPPORT

  menuconfig FTRACE
  	bool "Tracers"

  	default y if DEBUG_KERNEL

  	help

  	  Enable the kernel tracing infrastructure.

  
  if FTRACE

  config FUNCTION_TRACER

  	bool "Kernel Function Tracer"

  	depends on HAVE_FUNCTION_TRACER

  	select KALLSYMS

  	select GENERIC_TRACER

  	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 at 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 FUNCTION_GRAPH_TRACER
  	bool "Kernel Function Graph Tracer"
  	depends on HAVE_FUNCTION_GRAPH_TRACER

  	depends on FUNCTION_TRACER

  	depends on !X86_32 || !CC_OPTIMIZE_FOR_SIZE

  	default y

  	help

  	  Enable the kernel to trace a function at both its return
  	  and its entry.

  	  Its first purpose is to trace the duration of functions and
  	  draw a call graph for each thread with some information 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
  	depends on TRACE_IRQFLAGS_SUPPORT

  	depends on !ARCH_USES_GETTIMEOFFSET

  	select TRACE_IRQFLAGS

  	select GENERIC_TRACER

  	select TRACER_MAX_TRACE

  	select RING_BUFFER_ALLOW_SWAP

  	select TRACER_SNAPSHOT

  	select TRACER_SNAPSHOT_PER_CPU_SWAP

  	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 > /sys/kernel/debug/tracing/tracing_max_latency

  	  (Note that kernel size and overhead increase 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 !ARCH_USES_GETTIMEOFFSET

  	depends on PREEMPT

  	select GENERIC_TRACER

  	select TRACER_MAX_TRACE

  	select RING_BUFFER_ALLOW_SWAP

  	select TRACER_SNAPSHOT

  	select TRACER_SNAPSHOT_PER_CPU_SWAP

  	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 > /sys/kernel/debug/tracing/tracing_max_latency

  	  (Note that kernel size and overhead increase with this option

  	  enabled. This option and the irqs-off timing option can be
  	  used together or separately.)

  config SCHED_TRACER
  	bool "Scheduling Latency Tracer"

  	select GENERIC_TRACER

  	select CONTEXT_SWITCH_TRACER
  	select TRACER_MAX_TRACE

  	select TRACER_SNAPSHOT

  	help
  	  This tracer tracks the latency of the highest priority task
  	  to be scheduled in, starting from the point it has woken up.

  config ENABLE_DEFAULT_TRACERS
  	bool "Trace process context switches and events"

  	depends on !GENERIC_TRACER

  	select TRACING
  	help

  	  This tracer hooks to various trace points in the kernel,

  	  allowing the user to pick and choose which trace point they

  	  want to trace. It also includes the sched_switch tracer plugin.

  config FTRACE_SYSCALLS
  	bool "Trace syscalls"

  	depends on HAVE_SYSCALL_TRACEPOINTS

  	select GENERIC_TRACER

  	select KALLSYMS

  	help
  	  Basic tracer to catch the syscall entry and exit events.

  config TRACER_SNAPSHOT
  	bool "Create a snapshot trace buffer"
  	select TRACER_MAX_TRACE
  	help
  	  Allow tracing users to take snapshot of the current buffer using the
  	  ftrace interface, e.g.:
  
  	      echo 1 > /sys/kernel/debug/tracing/snapshot
  	      cat snapshot

  config TRACER_SNAPSHOT_PER_CPU_SWAP
          bool "Allow snapshot to swap per CPU"
  	depends on TRACER_SNAPSHOT
  	select RING_BUFFER_ALLOW_SWAP
  	help
  	  Allow doing a snapshot of a single CPU buffer instead of a
  	  full swap (all buffers). If this is set, then the following is
  	  allowed:
  
  	      echo 1 > /sys/kernel/debug/tracing/per_cpu/cpu2/snapshot
  
  	  After which, only the tracing buffer for CPU 2 was swapped with
  	  the main tracing buffer, and the other CPU buffers remain the same.
  
  	  When this is enabled, this adds a little more overhead to the
  	  trace recording, as it needs to add some checks to synchronize
  	  recording with swaps. But this does not affect the performance
  	  of the overall system. This is enabled by default when the preempt
  	  or irq latency tracers are enabled, as those need to swap as well
  	  and already adds the overhead (plus a lot more).

  config TRACE_BRANCH_PROFILING

  	bool

  	select GENERIC_TRACER

  
  choice
  	prompt "Branch Profiling"
  	default BRANCH_PROFILE_NONE
  	help
  	 The branch profiling is a software profiler. It will add hooks
  	 into the C conditionals to test which path a branch takes.
  
  	 The likely/unlikely profiler only looks at the conditions that
  	 are annotated with a likely or unlikely macro.

  	 The "all branch" profiler will profile every if-statement in the

  	 kernel. This profiler will also enable the likely/unlikely

  	 profiler.

  	 Either of the above profilers adds a bit of overhead to the system.
  	 If unsure, choose "No branch profiling".

  
  config BRANCH_PROFILE_NONE
  	bool "No branch profiling"
  	help

  	  No branch profiling. Branch profiling adds a bit of overhead.
  	  Only enable it if you want to analyse the branching behavior.
  	  Otherwise keep it disabled.

  
  config PROFILE_ANNOTATED_BRANCHES
  	bool "Trace likely/unlikely profiler"
  	select TRACE_BRANCH_PROFILING

  	help

  	  This tracer profiles all likely and unlikely macros

  	  in the kernel. It will display the results in:

  	  /sys/kernel/debug/tracing/trace_stat/branch_annotated

  	  Note: this will add a significant overhead; only turn this

  	  on if you need to profile the system's use of these macros.

  config PROFILE_ALL_BRANCHES
  	bool "Profile all if conditionals"

  	select 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:

  	  /sys/kernel/debug/tracing/trace_stat/branch_all

  	  This option also enables the likely/unlikely profiler.

  	  This configuration, when enabled, will impose a great overhead
  	  on the system. This should only be enabled when the system

  	  is to be analyzed in much detail.

  endchoice

  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 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

  	depends on BLOCK

  	select RELAY
  	select DEBUG_FS
  	select TRACEPOINTS

  	select GENERIC_TRACER

  	select STACKTRACE
  	help
  	  Say Y here if you want to be able to trace the block layer actions
  	  on a given queue. Tracing allows you to see any traffic happening
  	  on a block device queue. For more information (and the userspace
  	  support tools needed), fetch the blktrace tools from:
  
  	  git://git.kernel.dk/blktrace.git
  
  	  Tracing also is possible using the ftrace interface, e.g.:
  
  	    echo 1 > /sys/block/sda/sda1/trace/enable
  	    echo blk > /sys/kernel/debug/tracing/current_tracer
  	    cat /sys/kernel/debug/tracing/trace_pipe
  
  	  If unsure, say N.

  config KPROBE_EVENT

  	depends on KPROBES

  	depends on HAVE_REGS_AND_STACK_ACCESS_API

  	bool "Enable kprobes-based dynamic events"

  	select TRACING

  	select PROBE_EVENTS

  	default y

  	help

  	  This allows the user to add tracing events (similar to tracepoints)
  	  on the fly via the ftrace interface. See
  	  Documentation/trace/kprobetrace.txt for more details.

  
  	  Those events can be inserted wherever kprobes can probe, and record
  	  various register and memory values.

  	  This option is also required by perf-probe subcommand of perf tools.
  	  If you want to use perf tools, this option is strongly recommended.

  config UPROBE_EVENT
  	bool "Enable uprobes-based dynamic events"
  	depends on ARCH_SUPPORTS_UPROBES
  	depends on MMU

  	depends on PERF_EVENTS

  	select UPROBES
  	select PROBE_EVENTS
  	select TRACING
  	default n
  	help
  	  This allows the user to add tracing events on top of userspace
  	  dynamic events (similar to tracepoints) on the fly via the trace
  	  events interface. Those events can be inserted wherever uprobes
  	  can probe, and record various registers.
  	  This option is required if you plan to use perf-probe subcommand
  	  of perf tools on user space applications.

  config BPF_EVENTS
  	depends on BPF_SYSCALL
  	depends on KPROBE_EVENT
  	bool
  	default y
  	help
  	  This allows the user to attach BPF programs to kprobe 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 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_stats directory; this file shows the list of functions that
  	  have been hit and their counters.

  	  If in doubt, say N.

  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 GENERIC_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.

  config EVENT_TRACE_TEST_SYSCALLS
  	bool "Run selftest on syscall events"
  	depends on FTRACE_STARTUP_TEST
  	help
  	 This option will also enable testing every syscall event.
  	 It only enables the event and disables it and runs various loads
  	 with the event enabled. This adds a bit more time for kernel boot
  	 up since it runs this on every system call defined.
  
  	 TBD - enable a way to actually call the syscalls as we test their
  	       events

  config MMIOTRACE
  	bool "Memory mapped IO tracing"

  	depends on HAVE_MMIOTRACE_SUPPORT && PCI

  	select GENERIC_TRACER

  	help
  	  Mmiotrace traces Memory Mapped I/O access and is meant for
  	  debugging and reverse engineering. It is called from the ioremap
  	  implementation and works via page faults. Tracing is disabled by
  	  default and can be enabled at run-time.

  	  See Documentation/trace/mmiotrace.txt.

  	  If you are not helping to develop drivers, say N.
  
  config MMIOTRACE_TEST
  	tristate "Test module for mmiotrace"
  	depends on MMIOTRACE && m
  	help
  	  This is a dumb module for testing mmiotrace. It is very dangerous
  	  as it will write garbage to IO memory starting at a given address.
  	  However, it should be safe to use on e.g. unused portion of VRAM.
  
  	  Say N, unless you absolutely know what you are doing.

  config TRACEPOINT_BENCHMARK
          bool "Add tracepoint that benchmarks tracepoints"
  	help
  	 This option creates the tracepoint "benchmark:benchmark_event".
  	 When the tracepoint is enabled, it kicks off a kernel thread that
  	 goes into an infinite loop (calling cond_sched() to let other tasks
  	 run), and calls the tracepoint. Each iteration will record the time
  	 it took to write to the tracepoint and the next iteration that
  	 data will be passed to the tracepoint itself. That is, the tracepoint
  	 will report the time it took to do the previous tracepoint.
  	 The string written to the tracepoint is a static string of 128 bytes
  	 to keep the time the same. The initial string is simply a write of
  	 "START". The second string records the cold cache time of the first
  	 write which is not added to the rest of the calculations.
  
  	 As it is a tight loop, it benchmarks as hot cache. That's fine because
  	 we care most about hot paths that are probably in cache already.
  
  	 An example of the output:
  
  	      START
  	      first=3672 [COLD CACHED]
  	      last=632 first=3672 max=632 min=632 avg=316 std=446 std^2=199712
  	      last=278 first=3672 max=632 min=278 avg=303 std=316 std^2=100337
  	      last=277 first=3672 max=632 min=277 avg=296 std=258 std^2=67064
  	      last=273 first=3672 max=632 min=273 avg=292 std=224 std^2=50411
  	      last=273 first=3672 max=632 min=273 avg=288 std=200 std^2=40389
  	      last=281 first=3672 max=632 min=273 avg=287 std=183 std^2=33666

  config RING_BUFFER_BENCHMARK
  	tristate "Ring buffer benchmark stress tester"
  	depends on RING_BUFFER
  	help

  	  This option creates a test to stress the ring buffer and benchmark it.
  	  It creates its own ring buffer such that it will not interfere with

  	  any other users of the ring buffer (such as ftrace). It then creates
  	  a producer and consumer that will run for 10 seconds and sleep for
  	  10 seconds. Each interval it will print out the number of events
  	  it recorded and give a rough estimate of how long each iteration took.
  
  	  It does not disable interrupts or raise its priority, so it may be
  	  affected by processes that are running.

  	  If unsure, say N.

  config RING_BUFFER_STARTUP_TEST
         bool "Ring buffer startup self test"
         depends on RING_BUFFER
         help
           Run a simple self test on the ring buffer on boot up. Late in the
  	 kernel boot sequence, the test will start that kicks off
  	 a thread per cpu. Each thread will write various size events
  	 into the ring buffer. Another thread is created to send IPIs
  	 to each of the threads, where the IPI handler will also write
  	 to the ring buffer, to test/stress the nesting ability.
  	 If any anomalies are discovered, a warning will be displayed
  	 and all ring buffers will be disabled.
  
  	 The test runs for 10 seconds. This will slow your boot time
  	 by at least 10 more seconds.
  
  	 At the end of the test, statics and more checks are done.
  	 It will output the stats of each per cpu buffer. What
  	 was written, the sizes, what was read, what was lost, and
  	 other similar details.
  
  	 If unsure, say N

  config TRACE_ENUM_MAP_FILE
         bool "Show enum mappings for trace events"
         depends on TRACING
         help
          The "print fmt" of the trace events will show the enum names instead
  	of their values. This can cause problems for user space tools that
  	use this string to parse the raw data as user space does not know
  	how to convert the string to its value.
  
  	To fix this, there's a special macro in the kernel that can be used
  	to convert the enum into its value. If this macro is used, then the
  	print fmt strings will have the enums converted to their values.
  
  	If something does not get converted properly, this option can be
  	used to show what enums the kernel tried to convert.
  
  	This option is for debugging the enum conversions. A file is created
  	in the tracing directory called "enum_map" that will show the enum
  	names matched with their values and what trace event system they
  	belong too.
  
  	Normally, the mapping of the strings to values will be freed after
  	boot up or module load. With this option, they will not be freed, as
  	they are needed for the "enum_map" file. Enabling this option will
  	increase the memory footprint of the running kernel.
  
  	If unsure, say N

  endif # FTRACE

  
  endif # TRACING_SUPPORT