| # |
| # 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 if (!ARM_UNWIND) |
| 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 |
| 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 |
| 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 |
| 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 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 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 |
| 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 |
| 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 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. |
| |
| endif # FTRACE |
| |
| endif # TRACING_SUPPORT |
| |