1 # SPDX-License-Identifier: GPL-2.0-only
3 # Architectures that offer an FUNCTION_TRACER implementation should
4 # select HAVE_FUNCTION_TRACER:
7 config USER_STACKTRACE_SUPPORT
13 config HAVE_FTRACE_NMI_ENTER
16 See Documentation/trace/ftrace-design.rst
18 config HAVE_FUNCTION_TRACER
21 See Documentation/trace/ftrace-design.rst
23 config HAVE_FUNCTION_GRAPH_TRACER
26 See Documentation/trace/ftrace-design.rst
28 config HAVE_DYNAMIC_FTRACE
31 See Documentation/trace/ftrace-design.rst
33 config HAVE_DYNAMIC_FTRACE_WITH_REGS
36 config HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
39 config HAVE_FTRACE_MCOUNT_RECORD
42 See Documentation/trace/ftrace-design.rst
44 config HAVE_SYSCALL_TRACEPOINTS
47 See Documentation/trace/ftrace-design.rst
52 Arch supports the gcc options -pg with -mfentry
54 config HAVE_NOP_MCOUNT
57 Arch supports the gcc options -pg with -mrecord-mcount and -nop-mcount
59 config HAVE_C_RECORDMCOUNT
62 C version of recordmcount available?
64 config TRACER_MAX_TRACE
75 config FTRACE_NMI_ENTER
77 depends on HAVE_FTRACE_NMI_ENTER
81 select CONTEXT_SWITCH_TRACER
85 config CONTEXT_SWITCH_TRACER
88 config RING_BUFFER_ALLOW_SWAP
91 Allow the use of ring_buffer_swap_cpu.
92 Adds a very slight overhead to tracing when enabled.
94 config PREEMPTIRQ_TRACEPOINTS
96 depends on TRACE_PREEMPT_TOGGLE || TRACE_IRQFLAGS
100 Create preempt/irq toggle tracepoints if needed, so that other parts
101 of the kernel can use them to generate or add hooks to them.
103 # All tracer options should select GENERIC_TRACER. For those options that are
104 # enabled by all tracers (context switch and event tracer) they select TRACING.
105 # This allows those options to appear when no other tracer is selected. But the
106 # options do not appear when something else selects it. We need the two options
107 # GENERIC_TRACER and TRACING to avoid circular dependencies to accomplish the
108 # hiding of the automatic options.
113 select STACKTRACE if STACKTRACE_SUPPORT
120 config GENERIC_TRACER
125 # Minimum requirements an architecture has to meet for us to
126 # be able to offer generic tracing facilities:
128 config TRACING_SUPPORT
130 depends on TRACE_IRQFLAGS_SUPPORT
131 depends on STACKTRACE_SUPPORT
138 default y if DEBUG_KERNEL
140 Enable the kernel tracing infrastructure.
144 config BOOTTIME_TRACING
145 bool "Boot-time Tracing support"
149 Enable developer to setup ftrace subsystem via supplemental
150 kernel cmdline at boot time for debugging (tracing) driver
151 initialization and boot process.
153 config FUNCTION_TRACER
154 bool "Kernel Function Tracer"
155 depends on HAVE_FUNCTION_TRACER
157 select GENERIC_TRACER
158 select CONTEXT_SWITCH_TRACER
160 select TASKS_RCU if PREEMPTION
162 Enable the kernel to trace every kernel function. This is done
163 by using a compiler feature to insert a small, 5-byte No-Operation
164 instruction at the beginning of every kernel function, which NOP
165 sequence is then dynamically patched into a tracer call when
166 tracing is enabled by the administrator. If it's runtime disabled
167 (the bootup default), then the overhead of the instructions is very
168 small and not measurable even in micro-benchmarks.
170 config FUNCTION_GRAPH_TRACER
171 bool "Kernel Function Graph Tracer"
172 depends on HAVE_FUNCTION_GRAPH_TRACER
173 depends on FUNCTION_TRACER
174 depends on !X86_32 || !CC_OPTIMIZE_FOR_SIZE
177 Enable the kernel to trace a function at both its return
179 Its first purpose is to trace the duration of functions and
180 draw a call graph for each thread with some information like
181 the return value. This is done by setting the current return
182 address on the current task structure into a stack of calls.
184 config DYNAMIC_FTRACE
185 bool "enable/disable function tracing dynamically"
186 depends on FUNCTION_TRACER
187 depends on HAVE_DYNAMIC_FTRACE
190 This option will modify all the calls to function tracing
191 dynamically (will patch them out of the binary image and
192 replace them with a No-Op instruction) on boot up. During
193 compile time, a table is made of all the locations that ftrace
194 can function trace, and this table is linked into the kernel
195 image. When this is enabled, functions can be individually
196 enabled, and the functions not enabled will not affect
197 performance of the system.
199 See the files in /sys/kernel/debug/tracing:
200 available_filter_functions
204 This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but
205 otherwise has native performance as long as no tracing is active.
207 config DYNAMIC_FTRACE_WITH_REGS
209 depends on DYNAMIC_FTRACE
210 depends on HAVE_DYNAMIC_FTRACE_WITH_REGS
212 config DYNAMIC_FTRACE_WITH_DIRECT_CALLS
214 depends on DYNAMIC_FTRACE
215 depends on HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
217 config FUNCTION_PROFILER
218 bool "Kernel function profiler"
219 depends on FUNCTION_TRACER
222 This option enables the kernel function profiler. A file is created
223 in debugfs called function_profile_enabled which defaults to zero.
224 When a 1 is echoed into this file profiling begins, and when a
225 zero is entered, profiling stops. A "functions" file is created in
226 the trace_stat directory; this file shows the list of functions that
227 have been hit and their counters.
232 bool "Trace max stack"
233 depends on HAVE_FUNCTION_TRACER
234 select FUNCTION_TRACER
238 This special tracer records the maximum stack footprint of the
239 kernel and displays it in /sys/kernel/debug/tracing/stack_trace.
241 This tracer works by hooking into every function call that the
242 kernel executes, and keeping a maximum stack depth value and
243 stack-trace saved. If this is configured with DYNAMIC_FTRACE
244 then it will not have any overhead while the stack tracer
247 To enable the stack tracer on bootup, pass in 'stacktrace'
248 on the kernel command line.
250 The stack tracer can also be enabled or disabled via the
251 sysctl kernel.stack_tracer_enabled
255 config TRACE_PREEMPT_TOGGLE
258 Enables hooks which will be called when preemption is first disabled,
261 config PREEMPTIRQ_EVENTS
262 bool "Enable trace events for preempt and irq disable/enable"
263 select TRACE_IRQFLAGS
264 select TRACE_PREEMPT_TOGGLE if PREEMPTION
265 select GENERIC_TRACER
268 Enable tracing of disable and enable events for preemption and irqs.
270 config IRQSOFF_TRACER
271 bool "Interrupts-off Latency Tracer"
273 depends on TRACE_IRQFLAGS_SUPPORT
274 depends on !ARCH_USES_GETTIMEOFFSET
275 select TRACE_IRQFLAGS
276 select GENERIC_TRACER
277 select TRACER_MAX_TRACE
278 select RING_BUFFER_ALLOW_SWAP
279 select TRACER_SNAPSHOT
280 select TRACER_SNAPSHOT_PER_CPU_SWAP
282 This option measures the time spent in irqs-off critical
283 sections, with microsecond accuracy.
285 The default measurement method is a maximum search, which is
286 disabled by default and can be runtime (re-)started
289 echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
291 (Note that kernel size and overhead increase with this option
292 enabled. This option and the preempt-off timing option can be
293 used together or separately.)
295 config PREEMPT_TRACER
296 bool "Preemption-off Latency Tracer"
298 depends on !ARCH_USES_GETTIMEOFFSET
299 depends on PREEMPTION
300 select GENERIC_TRACER
301 select TRACER_MAX_TRACE
302 select RING_BUFFER_ALLOW_SWAP
303 select TRACER_SNAPSHOT
304 select TRACER_SNAPSHOT_PER_CPU_SWAP
305 select TRACE_PREEMPT_TOGGLE
307 This option measures the time spent in preemption-off critical
308 sections, with microsecond accuracy.
310 The default measurement method is a maximum search, which is
311 disabled by default and can be runtime (re-)started
314 echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
316 (Note that kernel size and overhead increase with this option
317 enabled. This option and the irqs-off timing option can be
318 used together or separately.)
321 bool "Scheduling Latency Tracer"
322 select GENERIC_TRACER
323 select CONTEXT_SWITCH_TRACER
324 select TRACER_MAX_TRACE
325 select TRACER_SNAPSHOT
327 This tracer tracks the latency of the highest priority task
328 to be scheduled in, starting from the point it has woken up.
331 bool "Tracer to detect hardware latencies (like SMIs)"
332 select GENERIC_TRACER
334 This tracer, when enabled will create one or more kernel threads,
335 depending on what the cpumask file is set to, which each thread
336 spinning in a loop looking for interruptions caused by
337 something other than the kernel. For example, if a
338 System Management Interrupt (SMI) takes a noticeable amount of
339 time, this tracer will detect it. This is useful for testing
340 if a system is reliable for Real Time tasks.
342 Some files are created in the tracing directory when this
345 hwlat_detector/width - time in usecs for how long to spin for
346 hwlat_detector/window - time in usecs between the start of each
349 A kernel thread is created that will spin with interrupts disabled
350 for "width" microseconds in every "window" cycle. It will not spin
351 for "window - width" microseconds, where the system can
354 The output will appear in the trace and trace_pipe files.
356 When the tracer is not running, it has no affect on the system,
357 but when it is running, it can cause the system to be
358 periodically non responsive. Do not run this tracer on a
361 To enable this tracer, echo in "hwlat" into the current_tracer
362 file. Every time a latency is greater than tracing_thresh, it will
363 be recorded into the ring buffer.
366 bool "Memory mapped IO tracing"
367 depends on HAVE_MMIOTRACE_SUPPORT && PCI
368 select GENERIC_TRACER
370 Mmiotrace traces Memory Mapped I/O access and is meant for
371 debugging and reverse engineering. It is called from the ioremap
372 implementation and works via page faults. Tracing is disabled by
373 default and can be enabled at run-time.
375 See Documentation/trace/mmiotrace.rst.
376 If you are not helping to develop drivers, say N.
378 config ENABLE_DEFAULT_TRACERS
379 bool "Trace process context switches and events"
380 depends on !GENERIC_TRACER
383 This tracer hooks to various trace points in the kernel,
384 allowing the user to pick and choose which trace point they
385 want to trace. It also includes the sched_switch tracer plugin.
387 config FTRACE_SYSCALLS
388 bool "Trace syscalls"
389 depends on HAVE_SYSCALL_TRACEPOINTS
390 select GENERIC_TRACER
393 Basic tracer to catch the syscall entry and exit events.
395 config TRACER_SNAPSHOT
396 bool "Create a snapshot trace buffer"
397 select TRACER_MAX_TRACE
399 Allow tracing users to take snapshot of the current buffer using the
400 ftrace interface, e.g.:
402 echo 1 > /sys/kernel/debug/tracing/snapshot
405 config TRACER_SNAPSHOT_PER_CPU_SWAP
406 bool "Allow snapshot to swap per CPU"
407 depends on TRACER_SNAPSHOT
408 select RING_BUFFER_ALLOW_SWAP
410 Allow doing a snapshot of a single CPU buffer instead of a
411 full swap (all buffers). If this is set, then the following is
414 echo 1 > /sys/kernel/debug/tracing/per_cpu/cpu2/snapshot
416 After which, only the tracing buffer for CPU 2 was swapped with
417 the main tracing buffer, and the other CPU buffers remain the same.
419 When this is enabled, this adds a little more overhead to the
420 trace recording, as it needs to add some checks to synchronize
421 recording with swaps. But this does not affect the performance
422 of the overall system. This is enabled by default when the preempt
423 or irq latency tracers are enabled, as those need to swap as well
424 and already adds the overhead (plus a lot more).
426 config TRACE_BRANCH_PROFILING
428 select GENERIC_TRACER
431 prompt "Branch Profiling"
432 default BRANCH_PROFILE_NONE
434 The branch profiling is a software profiler. It will add hooks
435 into the C conditionals to test which path a branch takes.
437 The likely/unlikely profiler only looks at the conditions that
438 are annotated with a likely or unlikely macro.
440 The "all branch" profiler will profile every if-statement in the
441 kernel. This profiler will also enable the likely/unlikely
444 Either of the above profilers adds a bit of overhead to the system.
445 If unsure, choose "No branch profiling".
447 config BRANCH_PROFILE_NONE
448 bool "No branch profiling"
450 No branch profiling. Branch profiling adds a bit of overhead.
451 Only enable it if you want to analyse the branching behavior.
452 Otherwise keep it disabled.
454 config PROFILE_ANNOTATED_BRANCHES
455 bool "Trace likely/unlikely profiler"
456 select TRACE_BRANCH_PROFILING
458 This tracer profiles all likely and unlikely macros
459 in the kernel. It will display the results in:
461 /sys/kernel/debug/tracing/trace_stat/branch_annotated
463 Note: this will add a significant overhead; only turn this
464 on if you need to profile the system's use of these macros.
466 config PROFILE_ALL_BRANCHES
467 bool "Profile all if conditionals" if !FORTIFY_SOURCE
468 select TRACE_BRANCH_PROFILING
470 This tracer profiles all branch conditions. Every if ()
471 taken in the kernel is recorded whether it hit or miss.
472 The results will be displayed in:
474 /sys/kernel/debug/tracing/trace_stat/branch_all
476 This option also enables the likely/unlikely profiler.
478 This configuration, when enabled, will impose a great overhead
479 on the system. This should only be enabled when the system
480 is to be analyzed in much detail.
483 config TRACING_BRANCHES
486 Selected by tracers that will trace the likely and unlikely
487 conditions. This prevents the tracers themselves from being
488 profiled. Profiling the tracing infrastructure can only happen
489 when the likelys and unlikelys are not being traced.
492 bool "Trace likely/unlikely instances"
493 depends on TRACE_BRANCH_PROFILING
494 select TRACING_BRANCHES
496 This traces the events of likely and unlikely condition
497 calls in the kernel. The difference between this and the
498 "Trace likely/unlikely profiler" is that this is not a
499 histogram of the callers, but actually places the calling
500 events into a running trace buffer to see when and where the
501 events happened, as well as their results.
505 config BLK_DEV_IO_TRACE
506 bool "Support for tracing block IO actions"
512 select GENERIC_TRACER
515 Say Y here if you want to be able to trace the block layer actions
516 on a given queue. Tracing allows you to see any traffic happening
517 on a block device queue. For more information (and the userspace
518 support tools needed), fetch the blktrace tools from:
520 git://git.kernel.dk/blktrace.git
522 Tracing also is possible using the ftrace interface, e.g.:
524 echo 1 > /sys/block/sda/sda1/trace/enable
525 echo blk > /sys/kernel/debug/tracing/current_tracer
526 cat /sys/kernel/debug/tracing/trace_pipe
532 depends on HAVE_REGS_AND_STACK_ACCESS_API
533 bool "Enable kprobes-based dynamic events"
536 select DYNAMIC_EVENTS
539 This allows the user to add tracing events (similar to tracepoints)
540 on the fly via the ftrace interface. See
541 Documentation/trace/kprobetrace.rst for more details.
543 Those events can be inserted wherever kprobes can probe, and record
544 various register and memory values.
546 This option is also required by perf-probe subcommand of perf tools.
547 If you want to use perf tools, this option is strongly recommended.
549 config KPROBE_EVENTS_ON_NOTRACE
550 bool "Do NOT protect notrace function from kprobe events"
551 depends on KPROBE_EVENTS
552 depends on KPROBES_ON_FTRACE
555 This is only for the developers who want to debug ftrace itself
558 If kprobes can use ftrace instead of breakpoint, ftrace related
559 functions are protected from kprobe-events to prevent an infinit
560 recursion or any unexpected execution path which leads to a kernel
563 This option disables such protection and allows you to put kprobe
564 events on ftrace functions for debugging ftrace by itself.
565 Note that this might let you shoot yourself in the foot.
570 bool "Enable uprobes-based dynamic events"
571 depends on ARCH_SUPPORTS_UPROBES
573 depends on PERF_EVENTS
576 select DYNAMIC_EVENTS
580 This allows the user to add tracing events on top of userspace
581 dynamic events (similar to tracepoints) on the fly via the trace
582 events interface. Those events can be inserted wherever uprobes
583 can probe, and record various registers.
584 This option is required if you plan to use perf-probe subcommand
585 of perf tools on user space applications.
588 depends on BPF_SYSCALL
589 depends on (KPROBE_EVENTS || UPROBE_EVENTS) && PERF_EVENTS
593 This allows the user to attach BPF programs to kprobe, uprobe, and
596 config DYNAMIC_EVENTS
602 config BPF_KPROBE_OVERRIDE
603 bool "Enable BPF programs to override a kprobed function"
604 depends on BPF_EVENTS
605 depends on FUNCTION_ERROR_INJECTION
608 Allows BPF to override the execution of a probed function and
609 set a different return value. This is used for error injection.
611 config FTRACE_MCOUNT_RECORD
613 depends on DYNAMIC_FTRACE
614 depends on HAVE_FTRACE_MCOUNT_RECORD
618 depends on ARCH_HAVE_NMI_SAFE_CMPXCHG
620 tracing_map is a special-purpose lock-free map for tracing,
621 separated out as a stand-alone facility in order to allow it
622 to be shared between multiple tracers. It isn't meant to be
623 generally used outside of that context, and is normally
624 selected by tracers that use it.
627 bool "Histogram triggers"
628 depends on ARCH_HAVE_NMI_SAFE_CMPXCHG
631 select DYNAMIC_EVENTS
634 Hist triggers allow one or more arbitrary trace event fields
635 to be aggregated into hash tables and dumped to stdout by
636 reading a debugfs/tracefs file. They're useful for
637 gathering quick and dirty (though precise) summaries of
638 event activity as an initial guide for further investigation
639 using more advanced tools.
641 Inter-event tracing of quantities such as latencies is also
642 supported using hist triggers under this option.
644 See Documentation/trace/histogram.rst.
647 config TRACE_EVENT_INJECT
648 bool "Trace event injection"
651 Allow user-space to inject a specific trace event into the ring
652 buffer. This is mainly used for testing purpose.
656 config TRACEPOINT_BENCHMARK
657 bool "Add tracepoint that benchmarks tracepoints"
659 This option creates the tracepoint "benchmark:benchmark_event".
660 When the tracepoint is enabled, it kicks off a kernel thread that
661 goes into an infinite loop (calling cond_sched() to let other tasks
662 run), and calls the tracepoint. Each iteration will record the time
663 it took to write to the tracepoint and the next iteration that
664 data will be passed to the tracepoint itself. That is, the tracepoint
665 will report the time it took to do the previous tracepoint.
666 The string written to the tracepoint is a static string of 128 bytes
667 to keep the time the same. The initial string is simply a write of
668 "START". The second string records the cold cache time of the first
669 write which is not added to the rest of the calculations.
671 As it is a tight loop, it benchmarks as hot cache. That's fine because
672 we care most about hot paths that are probably in cache already.
674 An example of the output:
677 first=3672 [COLD CACHED]
678 last=632 first=3672 max=632 min=632 avg=316 std=446 std^2=199712
679 last=278 first=3672 max=632 min=278 avg=303 std=316 std^2=100337
680 last=277 first=3672 max=632 min=277 avg=296 std=258 std^2=67064
681 last=273 first=3672 max=632 min=273 avg=292 std=224 std^2=50411
682 last=273 first=3672 max=632 min=273 avg=288 std=200 std^2=40389
683 last=281 first=3672 max=632 min=273 avg=287 std=183 std^2=33666
686 config RING_BUFFER_BENCHMARK
687 tristate "Ring buffer benchmark stress tester"
688 depends on RING_BUFFER
690 This option creates a test to stress the ring buffer and benchmark it.
691 It creates its own ring buffer such that it will not interfere with
692 any other users of the ring buffer (such as ftrace). It then creates
693 a producer and consumer that will run for 10 seconds and sleep for
694 10 seconds. Each interval it will print out the number of events
695 it recorded and give a rough estimate of how long each iteration took.
697 It does not disable interrupts or raise its priority, so it may be
698 affected by processes that are running.
702 config TRACE_EVAL_MAP_FILE
703 bool "Show eval mappings for trace events"
706 The "print fmt" of the trace events will show the enum/sizeof names
707 instead of their values. This can cause problems for user space tools
708 that use this string to parse the raw data as user space does not know
709 how to convert the string to its value.
711 To fix this, there's a special macro in the kernel that can be used
712 to convert an enum/sizeof into its value. If this macro is used, then
713 the print fmt strings will be converted to their values.
715 If something does not get converted properly, this option can be
716 used to show what enums/sizeof the kernel tried to convert.
718 This option is for debugging the conversions. A file is created
719 in the tracing directory called "eval_map" that will show the
720 names matched with their values and what trace event system they
723 Normally, the mapping of the strings to values will be freed after
724 boot up or module load. With this option, they will not be freed, as
725 they are needed for the "eval_map" file. Enabling this option will
726 increase the memory footprint of the running kernel.
730 config GCOV_PROFILE_FTRACE
731 bool "Enable GCOV profiling on ftrace subsystem"
732 depends on GCOV_KERNEL
734 Enable GCOV profiling on ftrace subsystem for checking
735 which functions/lines are tested.
739 Note that on a kernel compiled with this config, ftrace will
740 run significantly slower.
742 config FTRACE_SELFTEST
745 config FTRACE_STARTUP_TEST
746 bool "Perform a startup test on ftrace"
747 depends on GENERIC_TRACER
748 select FTRACE_SELFTEST
750 This option performs a series of startup tests on ftrace. On bootup
751 a series of tests are made to verify that the tracer is
752 functioning properly. It will do tests on all the configured
755 config EVENT_TRACE_STARTUP_TEST
756 bool "Run selftest on trace events"
757 depends on FTRACE_STARTUP_TEST
760 This option performs a test on all trace events in the system.
761 It basically just enables each event and runs some code that
762 will trigger events (not necessarily the event it enables)
763 This may take some time run as there are a lot of events.
765 config EVENT_TRACE_TEST_SYSCALLS
766 bool "Run selftest on syscall events"
767 depends on EVENT_TRACE_STARTUP_TEST
769 This option will also enable testing every syscall event.
770 It only enables the event and disables it and runs various loads
771 with the event enabled. This adds a bit more time for kernel boot
772 up since it runs this on every system call defined.
774 TBD - enable a way to actually call the syscalls as we test their
777 config RING_BUFFER_STARTUP_TEST
778 bool "Ring buffer startup self test"
779 depends on RING_BUFFER
781 Run a simple self test on the ring buffer on boot up. Late in the
782 kernel boot sequence, the test will start that kicks off
783 a thread per cpu. Each thread will write various size events
784 into the ring buffer. Another thread is created to send IPIs
785 to each of the threads, where the IPI handler will also write
786 to the ring buffer, to test/stress the nesting ability.
787 If any anomalies are discovered, a warning will be displayed
788 and all ring buffers will be disabled.
790 The test runs for 10 seconds. This will slow your boot time
791 by at least 10 more seconds.
793 At the end of the test, statics and more checks are done.
794 It will output the stats of each per cpu buffer. What
795 was written, the sizes, what was read, what was lost, and
796 other similar details.
800 config MMIOTRACE_TEST
801 tristate "Test module for mmiotrace"
802 depends on MMIOTRACE && m
804 This is a dumb module for testing mmiotrace. It is very dangerous
805 as it will write garbage to IO memory starting at a given address.
806 However, it should be safe to use on e.g. unused portion of VRAM.
808 Say N, unless you absolutely know what you are doing.
810 config PREEMPTIRQ_DELAY_TEST
811 tristate "Test module to create a preempt / IRQ disable delay thread to test latency tracers"
814 Select this option to build a test module that can help test latency
815 tracers by executing a preempt or irq disable section with a user
816 configurable delay. The module busy waits for the duration of the
819 For example, the following invocation generates a burst of three
820 irq-disabled critical sections for 500us:
821 modprobe preemptirq_delay_test test_mode=irq delay=500 burst_size=3
825 config SYNTH_EVENT_GEN_TEST
826 tristate "Test module for in-kernel synthetic event generation"
827 depends on HIST_TRIGGERS
829 This option creates a test module to check the base
830 functionality of in-kernel synthetic event definition and
833 To test, insert the module, and then check the trace buffer
834 for the generated sample events.
838 config KPROBE_EVENT_GEN_TEST
839 tristate "Test module for in-kernel kprobe event generation"
840 depends on KPROBE_EVENTS
842 This option creates a test module to check the base
843 functionality of in-kernel kprobe event definition.
845 To test, insert the module, and then check the trace buffer
846 for the generated kprobe events.
852 endif # TRACING_SUPPORT