## 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_FUNCTION_TRACE_MCOUNT_TEST	bool	help	  See Documentation/trace/ftrace-design.txt config HAVE_DYNAMIC_FTRACE	bool	help	  See Documentation/trace/ftrace-design.txt 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 TRACER_MAX_TRACE	bool config RING_BUFFER	bool config FTRACE_NMI_ENTER       bool       depends on HAVE_FTRACE_NMI_ENTER       default y config EVENT_TRACING	select CONTEXT_SWITCH_TRACER	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 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 FRAME_POINTER	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 GENERIC_TIME	select TRACE_IRQFLAGS	select GENERIC_TRACER	select TRACER_MAX_TRACE	select RING_BUFFER_ALLOW_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 GENERIC_TIME	depends on PREEMPT	select GENERIC_TRACER	select TRACER_MAX_TRACE	select RING_BUFFER_ALLOW_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 SYSPROF_TRACER	bool "Sysprof Tracer"	depends on X86	select GENERIC_TRACER	select CONTEXT_SWITCH_TRACER	help	  This tracer provides the trace needed by the 'Sysprof' userspace	  tool. config SCHED_TRACER	bool "Scheduling Latency Tracer"	select GENERIC_TRACER	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 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 BOOT_TRACER	bool "Trace boot initcalls"	select GENERIC_TRACER	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. 	  You must pass in initcall_debug and ftrace=initcall to the kernel	  command line to enable this on bootup. 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 the the likely and unlikely macros	  in the kernel. It will display the results in: 	  /sys/kernel/debug/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. 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/profile_branch 	  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 KSYM_TRACER	bool "Trace read and write access on kernel memory locations"	depends on HAVE_HW_BREAKPOINT	select TRACING	help	  This tracer helps find read and write operations on any given kernel	  symbol i.e. /proc/kallsyms. config PROFILE_KSYM_TRACER	bool "Profile all kernel memory accesses on 'watched' variables"	depends on KSYM_TRACER	help	  This tracer profiles kernel accesses on variables watched through the	  ksym tracer ftrace plugin. Depending upon the hardware, all read	  and write operations on kernel variables can be monitored for	  accesses. 	  The results will be displayed in:	  /debugfs/tracing/profile_ksym 	  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 KMEMTRACE	bool "Trace SLAB allocations"	select GENERIC_TRACER	help	  kmemtrace provides tracing for slab allocator functions, such as	  kmalloc, kfree, kmem_cache_alloc, kmem_cache_free, etc. Collected	  data is then fed to the userspace application in order to analyse	  allocation hotspots, internal fragmentation and so on, making it	  possible to see how well an allocator performs, as well as debug	  and profile kernel code. 	  This requires an userspace application to use. See	  Documentation/trace/kmemtrace.txt for more information. 	  Saying Y will make the kernel somewhat larger and slower. However,	  if you disable kmemtrace at run-time or boot-time, the performance	  impact is minimal (depending on the arch the kernel is built for). 	  If unsure, say N. config WORKQUEUE_TRACER	bool "Trace workqueues"	select GENERIC_TRACER	help	  The workqueue tracer provides some statistical information          about each cpu workqueue thread such as the number of the          works inserted and executed since their creation. It can help          to evaluate the amount of work each of them has to perform.          For example it can help a developer to decide whether he should          choose a per-cpu workqueue instead of a singlethreaded one. 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	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 DYNAMIC_FTRACE	bool "enable/disable ftrace tracepoints dynamically"	depends on FUNCTION_TRACER	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 replace 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 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

Lines 1–500 of 552. Load more