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1 # SPDX-License-Identifier: GPL-2.0-only
2 #
3 # Architectures that offer an FUNCTION_TRACER implementation should
4 # select HAVE_FUNCTION_TRACER:
5 #
7 config USER_STACKTRACE_SUPPORT
8 bool
10 config NOP_TRACER
11 bool
13 config HAVE_FTRACE_NMI_ENTER
14 bool
15 help
16 See Documentation/trace/ftrace-design.rst
18 config HAVE_FUNCTION_TRACER
19 bool
20 help
21 See Documentation/trace/ftrace-design.rst
23 config HAVE_FUNCTION_GRAPH_TRACER
24 bool
25 help
26 See Documentation/trace/ftrace-design.rst
28 config HAVE_DYNAMIC_FTRACE
29 bool
30 help
31 See Documentation/trace/ftrace-design.rst
33 config HAVE_DYNAMIC_FTRACE_WITH_REGS
34 bool
36 config HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
37 bool
39 config HAVE_FTRACE_MCOUNT_RECORD
40 bool
41 help
42 See Documentation/trace/ftrace-design.rst
44 config HAVE_SYSCALL_TRACEPOINTS
45 bool
46 help
47 See Documentation/trace/ftrace-design.rst
49 config HAVE_FENTRY
50 bool
51 help
52 Arch supports the gcc options -pg with -mfentry
54 config HAVE_NOP_MCOUNT
55 bool
56 help
57 Arch supports the gcc options -pg with -mrecord-mcount and -nop-mcount
59 config HAVE_C_RECORDMCOUNT
60 bool
61 help
62 C version of recordmcount available?
64 config TRACER_MAX_TRACE
65 bool
67 config TRACE_CLOCK
68 bool
70 config RING_BUFFER
71 bool
72 select TRACE_CLOCK
73 select IRQ_WORK
75 config FTRACE_NMI_ENTER
76 bool
77 depends on HAVE_FTRACE_NMI_ENTER
78 default y
80 config EVENT_TRACING
81 select CONTEXT_SWITCH_TRACER
82 select GLOB
83 bool
85 config CONTEXT_SWITCH_TRACER
86 bool
88 config RING_BUFFER_ALLOW_SWAP
89 bool
90 help
91 Allow the use of ring_buffer_swap_cpu.
92 Adds a very slight overhead to tracing when enabled.
94 config PREEMPTIRQ_TRACEPOINTS
95 bool
96 depends on TRACE_PREEMPT_TOGGLE || TRACE_IRQFLAGS
97 select TRACING
98 default y
99 help
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.
110 config TRACING
111 bool
112 select RING_BUFFER
113 select STACKTRACE if STACKTRACE_SUPPORT
114 select TRACEPOINTS
115 select NOP_TRACER
116 select BINARY_PRINTF
117 select EVENT_TRACING
118 select TRACE_CLOCK
120 config GENERIC_TRACER
121 bool
122 select TRACING
124 #
125 # Minimum requirements an architecture has to meet for us to
126 # be able to offer generic tracing facilities:
127 #
128 config TRACING_SUPPORT
129 bool
130 depends on TRACE_IRQFLAGS_SUPPORT
131 depends on STACKTRACE_SUPPORT
132 default y
134 if TRACING_SUPPORT
136 menuconfig FTRACE
137 bool "Tracers"
138 default y if DEBUG_KERNEL
139 help
140 Enable the kernel tracing infrastructure.
142 if FTRACE
144 config BOOTTIME_TRACING
145 bool "Boot-time Tracing support"
146 depends on BOOT_CONFIG && TRACING
147 default y
148 help
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
156 select KALLSYMS
157 select GENERIC_TRACER
158 select CONTEXT_SWITCH_TRACER
159 select GLOB
160 select TASKS_RCU if PREEMPTION
161 help
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
175 default y
176 help
177 Enable the kernel to trace a function at both its return
178 and its entry.
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
188 default y
189 help
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
201 set_ftrace_filter
202 set_ftrace_notrace
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
208 def_bool y
209 depends on DYNAMIC_FTRACE
210 depends on HAVE_DYNAMIC_FTRACE_WITH_REGS
212 config DYNAMIC_FTRACE_WITH_DIRECT_CALLS
213 def_bool y
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
220 default n
221 help
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.
229 If in doubt, say N.
231 config STACK_TRACER
232 bool "Trace max stack"
233 depends on HAVE_FUNCTION_TRACER
234 select FUNCTION_TRACER
235 select STACKTRACE
236 select KALLSYMS
237 help
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
245 is disabled.
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
253 Say N if unsure.
255 config TRACE_PREEMPT_TOGGLE
256 bool
257 help
258 Enables hooks which will be called when preemption is first disabled,
259 and last enabled.
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
266 default n
267 help
268 Enable tracing of disable and enable events for preemption and irqs.
270 config IRQSOFF_TRACER
271 bool "Interrupts-off Latency Tracer"
272 default n
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
281 help
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
287 via:
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"
297 default n
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
306 help
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
312 via:
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.)
320 config SCHED_TRACER
321 bool "Scheduling Latency Tracer"
322 select GENERIC_TRACER
323 select CONTEXT_SWITCH_TRACER
324 select TRACER_MAX_TRACE
325 select TRACER_SNAPSHOT
326 help
327 This tracer tracks the latency of the highest priority task
328 to be scheduled in, starting from the point it has woken up.
330 config HWLAT_TRACER
331 bool "Tracer to detect hardware latencies (like SMIs)"
332 select GENERIC_TRACER
333 help
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
343 is enabled:
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
347 iteration
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
352 continue to operate.
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
359 production system.
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.
365 config MMIOTRACE
366 bool "Memory mapped IO tracing"
367 depends on HAVE_MMIOTRACE_SUPPORT && PCI
368 select GENERIC_TRACER
369 help
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
381 select TRACING
382 help
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
391 select KALLSYMS
392 help
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
398 help
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
403 cat 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
409 help
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
412 allowed:
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
427 bool
428 select GENERIC_TRACER
430 choice
431 prompt "Branch Profiling"
432 default BRANCH_PROFILE_NONE
433 help
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
442 profiler.
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"
449 help
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
457 help
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
469 imply CC_DISABLE_WARN_MAYBE_UNINITIALIZED # avoid false positives
470 help
471 This tracer profiles all branch conditions. Every if ()
472 taken in the kernel is recorded whether it hit or miss.
473 The results will be displayed in:
475 /sys/kernel/debug/tracing/trace_stat/branch_all
477 This option also enables the likely/unlikely profiler.
479 This configuration, when enabled, will impose a great overhead
480 on the system. This should only be enabled when the system
481 is to be analyzed in much detail.
482 endchoice
484 config TRACING_BRANCHES
485 bool
486 help
487 Selected by tracers that will trace the likely and unlikely
488 conditions. This prevents the tracers themselves from being
489 profiled. Profiling the tracing infrastructure can only happen
490 when the likelys and unlikelys are not being traced.
492 config BRANCH_TRACER
493 bool "Trace likely/unlikely instances"
494 depends on TRACE_BRANCH_PROFILING
495 select TRACING_BRANCHES
496 help
497 This traces the events of likely and unlikely condition
498 calls in the kernel. The difference between this and the
499 "Trace likely/unlikely profiler" is that this is not a
500 histogram of the callers, but actually places the calling
501 events into a running trace buffer to see when and where the
502 events happened, as well as their results.
504 Say N if unsure.
506 config BLK_DEV_IO_TRACE
507 bool "Support for tracing block IO actions"
508 depends on SYSFS
509 depends on BLOCK
510 select RELAY
511 select DEBUG_FS
512 select TRACEPOINTS
513 select GENERIC_TRACER
514 select STACKTRACE
515 help
516 Say Y here if you want to be able to trace the block layer actions
517 on a given queue. Tracing allows you to see any traffic happening
518 on a block device queue. For more information (and the userspace
519 support tools needed), fetch the blktrace tools from:
521 git://git.kernel.dk/blktrace.git
523 Tracing also is possible using the ftrace interface, e.g.:
525 echo 1 > /sys/block/sda/sda1/trace/enable
526 echo blk > /sys/kernel/debug/tracing/current_tracer
527 cat /sys/kernel/debug/tracing/trace_pipe
529 If unsure, say N.
531 config KPROBE_EVENTS
532 depends on KPROBES
533 depends on HAVE_REGS_AND_STACK_ACCESS_API
534 bool "Enable kprobes-based dynamic events"
535 select TRACING
536 select PROBE_EVENTS
537 select DYNAMIC_EVENTS
538 default y
539 help
540 This allows the user to add tracing events (similar to tracepoints)
541 on the fly via the ftrace interface. See
542 Documentation/trace/kprobetrace.rst for more details.
544 Those events can be inserted wherever kprobes can probe, and record
545 various register and memory values.
547 This option is also required by perf-probe subcommand of perf tools.
548 If you want to use perf tools, this option is strongly recommended.
550 config KPROBE_EVENTS_ON_NOTRACE
551 bool "Do NOT protect notrace function from kprobe events"
552 depends on KPROBE_EVENTS
553 depends on KPROBES_ON_FTRACE
554 default n
555 help
556 This is only for the developers who want to debug ftrace itself
557 using kprobe events.
559 If kprobes can use ftrace instead of breakpoint, ftrace related
560 functions are protected from kprobe-events to prevent an infinit
561 recursion or any unexpected execution path which leads to a kernel
562 crash.
564 This option disables such protection and allows you to put kprobe
565 events on ftrace functions for debugging ftrace by itself.
566 Note that this might let you shoot yourself in the foot.
568 If unsure, say N.
570 config UPROBE_EVENTS
571 bool "Enable uprobes-based dynamic events"
572 depends on ARCH_SUPPORTS_UPROBES
573 depends on MMU
574 depends on PERF_EVENTS
575 select UPROBES
576 select PROBE_EVENTS
577 select DYNAMIC_EVENTS
578 select TRACING
579 default y
580 help
581 This allows the user to add tracing events on top of userspace
582 dynamic events (similar to tracepoints) on the fly via the trace
583 events interface. Those events can be inserted wherever uprobes
584 can probe, and record various registers.
585 This option is required if you plan to use perf-probe subcommand
586 of perf tools on user space applications.
588 config BPF_EVENTS
589 depends on BPF_SYSCALL
590 depends on (KPROBE_EVENTS || UPROBE_EVENTS) && PERF_EVENTS
591 bool
592 default y
593 help
594 This allows the user to attach BPF programs to kprobe, uprobe, and
595 tracepoint events.
597 config DYNAMIC_EVENTS
598 def_bool n
600 config PROBE_EVENTS
601 def_bool n
603 config BPF_KPROBE_OVERRIDE
604 bool "Enable BPF programs to override a kprobed function"
605 depends on BPF_EVENTS
606 depends on FUNCTION_ERROR_INJECTION
607 default n
608 help
609 Allows BPF to override the execution of a probed function and
610 set a different return value. This is used for error injection.
612 config FTRACE_MCOUNT_RECORD
613 def_bool y
614 depends on DYNAMIC_FTRACE
615 depends on HAVE_FTRACE_MCOUNT_RECORD
617 config TRACING_MAP
618 bool
619 depends on ARCH_HAVE_NMI_SAFE_CMPXCHG
620 help
621 tracing_map is a special-purpose lock-free map for tracing,
622 separated out as a stand-alone facility in order to allow it
623 to be shared between multiple tracers. It isn't meant to be
624 generally used outside of that context, and is normally
625 selected by tracers that use it.
627 config HIST_TRIGGERS
628 bool "Histogram triggers"
629 depends on ARCH_HAVE_NMI_SAFE_CMPXCHG
630 select TRACING_MAP
631 select TRACING
632 select DYNAMIC_EVENTS
633 default n
634 help
635 Hist triggers allow one or more arbitrary trace event fields
636 to be aggregated into hash tables and dumped to stdout by
637 reading a debugfs/tracefs file. They're useful for
638 gathering quick and dirty (though precise) summaries of
639 event activity as an initial guide for further investigation
640 using more advanced tools.
642 Inter-event tracing of quantities such as latencies is also
643 supported using hist triggers under this option.
645 See Documentation/trace/histogram.rst.
646 If in doubt, say N.
648 config TRACE_EVENT_INJECT
649 bool "Trace event injection"
650 depends on TRACING
651 help
652 Allow user-space to inject a specific trace event into the ring
653 buffer. This is mainly used for testing purpose.
655 If unsure, say N.
657 config TRACEPOINT_BENCHMARK
658 bool "Add tracepoint that benchmarks tracepoints"
659 help
660 This option creates the tracepoint "benchmark:benchmark_event".
661 When the tracepoint is enabled, it kicks off a kernel thread that
662 goes into an infinite loop (calling cond_sched() to let other tasks
663 run), and calls the tracepoint. Each iteration will record the time
664 it took to write to the tracepoint and the next iteration that
665 data will be passed to the tracepoint itself. That is, the tracepoint
666 will report the time it took to do the previous tracepoint.
667 The string written to the tracepoint is a static string of 128 bytes
668 to keep the time the same. The initial string is simply a write of
669 "START". The second string records the cold cache time of the first
670 write which is not added to the rest of the calculations.
672 As it is a tight loop, it benchmarks as hot cache. That's fine because
673 we care most about hot paths that are probably in cache already.
675 An example of the output:
677 START
678 first=3672 [COLD CACHED]
679 last=632 first=3672 max=632 min=632 avg=316 std=446 std^2=199712
680 last=278 first=3672 max=632 min=278 avg=303 std=316 std^2=100337
681 last=277 first=3672 max=632 min=277 avg=296 std=258 std^2=67064
682 last=273 first=3672 max=632 min=273 avg=292 std=224 std^2=50411
683 last=273 first=3672 max=632 min=273 avg=288 std=200 std^2=40389
684 last=281 first=3672 max=632 min=273 avg=287 std=183 std^2=33666
687 config RING_BUFFER_BENCHMARK
688 tristate "Ring buffer benchmark stress tester"
689 depends on RING_BUFFER
690 help
691 This option creates a test to stress the ring buffer and benchmark it.
692 It creates its own ring buffer such that it will not interfere with
693 any other users of the ring buffer (such as ftrace). It then creates
694 a producer and consumer that will run for 10 seconds and sleep for
695 10 seconds. Each interval it will print out the number of events
696 it recorded and give a rough estimate of how long each iteration took.
698 It does not disable interrupts or raise its priority, so it may be
699 affected by processes that are running.
701 If unsure, say N.
703 config TRACE_EVAL_MAP_FILE
704 bool "Show eval mappings for trace events"
705 depends on TRACING
706 help
707 The "print fmt" of the trace events will show the enum/sizeof names
708 instead of their values. This can cause problems for user space tools
709 that use this string to parse the raw data as user space does not know
710 how to convert the string to its value.
712 To fix this, there's a special macro in the kernel that can be used
713 to convert an enum/sizeof into its value. If this macro is used, then
714 the print fmt strings will be converted to their values.
716 If something does not get converted properly, this option can be
717 used to show what enums/sizeof the kernel tried to convert.
719 This option is for debugging the conversions. A file is created
720 in the tracing directory called "eval_map" that will show the
721 names matched with their values and what trace event system they
722 belong too.
724 Normally, the mapping of the strings to values will be freed after
725 boot up or module load. With this option, they will not be freed, as
726 they are needed for the "eval_map" file. Enabling this option will
727 increase the memory footprint of the running kernel.
729 If unsure, say N.
731 config GCOV_PROFILE_FTRACE
732 bool "Enable GCOV profiling on ftrace subsystem"
733 depends on GCOV_KERNEL
734 help
735 Enable GCOV profiling on ftrace subsystem for checking
736 which functions/lines are tested.
738 If unsure, say N.
740 Note that on a kernel compiled with this config, ftrace will
741 run significantly slower.
743 config FTRACE_SELFTEST
744 bool
746 config FTRACE_STARTUP_TEST
747 bool "Perform a startup test on ftrace"
748 depends on GENERIC_TRACER
749 select FTRACE_SELFTEST
750 help
751 This option performs a series of startup tests on ftrace. On bootup
752 a series of tests are made to verify that the tracer is
753 functioning properly. It will do tests on all the configured
754 tracers of ftrace.
756 config EVENT_TRACE_STARTUP_TEST
757 bool "Run selftest on trace events"
758 depends on FTRACE_STARTUP_TEST
759 default y
760 help
761 This option performs a test on all trace events in the system.
762 It basically just enables each event and runs some code that
763 will trigger events (not necessarily the event it enables)
764 This may take some time run as there are a lot of events.
766 config EVENT_TRACE_TEST_SYSCALLS
767 bool "Run selftest on syscall events"
768 depends on EVENT_TRACE_STARTUP_TEST
769 help
770 This option will also enable testing every syscall event.
771 It only enables the event and disables it and runs various loads
772 with the event enabled. This adds a bit more time for kernel boot
773 up since it runs this on every system call defined.
775 TBD - enable a way to actually call the syscalls as we test their
776 events
778 config RING_BUFFER_STARTUP_TEST
779 bool "Ring buffer startup self test"
780 depends on RING_BUFFER
781 help
782 Run a simple self test on the ring buffer on boot up. Late in the
783 kernel boot sequence, the test will start that kicks off
784 a thread per cpu. Each thread will write various size events
785 into the ring buffer. Another thread is created to send IPIs
786 to each of the threads, where the IPI handler will also write
787 to the ring buffer, to test/stress the nesting ability.
788 If any anomalies are discovered, a warning will be displayed
789 and all ring buffers will be disabled.
791 The test runs for 10 seconds. This will slow your boot time
792 by at least 10 more seconds.
794 At the end of the test, statics and more checks are done.
795 It will output the stats of each per cpu buffer. What
796 was written, the sizes, what was read, what was lost, and
797 other similar details.
799 If unsure, say N
801 config MMIOTRACE_TEST
802 tristate "Test module for mmiotrace"
803 depends on MMIOTRACE && m
804 help
805 This is a dumb module for testing mmiotrace. It is very dangerous
806 as it will write garbage to IO memory starting at a given address.
807 However, it should be safe to use on e.g. unused portion of VRAM.
809 Say N, unless you absolutely know what you are doing.
811 config PREEMPTIRQ_DELAY_TEST
812 tristate "Test module to create a preempt / IRQ disable delay thread to test latency tracers"
813 depends on m
814 help
815 Select this option to build a test module that can help test latency
816 tracers by executing a preempt or irq disable section with a user
817 configurable delay. The module busy waits for the duration of the
818 critical section.
820 For example, the following invocation generates a burst of three
821 irq-disabled critical sections for 500us:
822 modprobe preemptirq_delay_test test_mode=irq delay=500 burst_size=3
824 If unsure, say N
826 config SYNTH_EVENT_GEN_TEST
827 tristate "Test module for in-kernel synthetic event generation"
828 depends on HIST_TRIGGERS
829 help
830 This option creates a test module to check the base
831 functionality of in-kernel synthetic event definition and
832 generation.
834 To test, insert the module, and then check the trace buffer
835 for the generated sample events.
837 If unsure, say N.
839 config KPROBE_EVENT_GEN_TEST
840 tristate "Test module for in-kernel kprobe event generation"
841 depends on KPROBE_EVENTS
842 help
843 This option creates a test module to check the base
844 functionality of in-kernel kprobe event definition.
846 To test, insert the module, and then check the trace buffer
847 for the generated kprobe events.
849 If unsure, say N.
851 endif # FTRACE
853 endif # TRACING_SUPPORT