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1#
2# Architectures that offer an FUNCTION_TRACER implementation should
3# select HAVE_FUNCTION_TRACER:
4#
5
6config USER_STACKTRACE_SUPPORT
7 bool
8
9config NOP_TRACER
10 bool
11
12config HAVE_FTRACE_NMI_ENTER
13 bool
14 help
15 See Documentation/trace/ftrace-design.txt
16
17config HAVE_FUNCTION_TRACER
18 bool
19 help
20 See Documentation/trace/ftrace-design.txt
21
22config HAVE_FUNCTION_GRAPH_TRACER
23 bool
24 help
25 See Documentation/trace/ftrace-design.txt
26
27config HAVE_DYNAMIC_FTRACE
28 bool
29 help
30 See Documentation/trace/ftrace-design.txt
31
32config HAVE_DYNAMIC_FTRACE_WITH_REGS
33 bool
34
35config HAVE_FTRACE_MCOUNT_RECORD
36 bool
37 help
38 See Documentation/trace/ftrace-design.txt
39
40config HAVE_SYSCALL_TRACEPOINTS
41 bool
42 help
43 See Documentation/trace/ftrace-design.txt
44
45config HAVE_FENTRY
46 bool
47 help
48 Arch supports the gcc options -pg with -mfentry
49
50config HAVE_C_RECORDMCOUNT
51 bool
52 help
53 C version of recordmcount available?
54
55config TRACER_MAX_TRACE
56 bool
57
58config TRACE_CLOCK
59 bool
60
61config RING_BUFFER
62 bool
63 select TRACE_CLOCK
64 select IRQ_WORK
65
66config FTRACE_NMI_ENTER
67 bool
68 depends on HAVE_FTRACE_NMI_ENTER
69 default y
70
71config EVENT_TRACING
72 select CONTEXT_SWITCH_TRACER
73 select GLOB
74 bool
75
76config CONTEXT_SWITCH_TRACER
77 bool
78
79config RING_BUFFER_ALLOW_SWAP
80 bool
81 help
82 Allow the use of ring_buffer_swap_cpu.
83 Adds a very slight overhead to tracing when enabled.
84
85# All tracer options should select GENERIC_TRACER. For those options that are
86# enabled by all tracers (context switch and event tracer) they select TRACING.
87# This allows those options to appear when no other tracer is selected. But the
88# options do not appear when something else selects it. We need the two options
89# GENERIC_TRACER and TRACING to avoid circular dependencies to accomplish the
90# hiding of the automatic options.
91
92config TRACING
93 bool
94 select DEBUG_FS
95 select RING_BUFFER
96 select STACKTRACE if STACKTRACE_SUPPORT
97 select TRACEPOINTS
98 select NOP_TRACER
99 select BINARY_PRINTF
100 select EVENT_TRACING
101 select TRACE_CLOCK
102
103config GENERIC_TRACER
104 bool
105 select TRACING
106
107#
108# Minimum requirements an architecture has to meet for us to
109# be able to offer generic tracing facilities:
110#
111config TRACING_SUPPORT
112 bool
113 # PPC32 has no irqflags tracing support, but it can use most of the
114 # tracers anyway, they were tested to build and work. Note that new
115 # exceptions to this list aren't welcomed, better implement the
116 # irqflags tracing for your architecture.
117 depends on TRACE_IRQFLAGS_SUPPORT || PPC32
118 depends on STACKTRACE_SUPPORT
119 default y
120
121if TRACING_SUPPORT
122
123menuconfig FTRACE
124 bool "Tracers"
125 default y if DEBUG_KERNEL
126 help
127 Enable the kernel tracing infrastructure.
128
129if FTRACE
130
131config FUNCTION_TRACER
132 bool "Kernel Function Tracer"
133 depends on HAVE_FUNCTION_TRACER
134 select KALLSYMS
135 select GENERIC_TRACER
136 select CONTEXT_SWITCH_TRACER
137 select GLOB
138 help
139 Enable the kernel to trace every kernel function. This is done
140 by using a compiler feature to insert a small, 5-byte No-Operation
141 instruction at the beginning of every kernel function, which NOP
142 sequence is then dynamically patched into a tracer call when
143 tracing is enabled by the administrator. If it's runtime disabled
144 (the bootup default), then the overhead of the instructions is very
145 small and not measurable even in micro-benchmarks.
146
147config FUNCTION_GRAPH_TRACER
148 bool "Kernel Function Graph Tracer"
149 depends on HAVE_FUNCTION_GRAPH_TRACER
150 depends on FUNCTION_TRACER
151 depends on !X86_32 || !CC_OPTIMIZE_FOR_SIZE
152 default y
153 help
154 Enable the kernel to trace a function at both its return
155 and its entry.
156 Its first purpose is to trace the duration of functions and
157 draw a call graph for each thread with some information like
158 the return value. This is done by setting the current return
159 address on the current task structure into a stack of calls.
160
161
162config IRQSOFF_TRACER
163 bool "Interrupts-off Latency Tracer"
164 default n
165 depends on TRACE_IRQFLAGS_SUPPORT
166 depends on !ARCH_USES_GETTIMEOFFSET
167 select TRACE_IRQFLAGS
168 select GENERIC_TRACER
169 select TRACER_MAX_TRACE
170 select RING_BUFFER_ALLOW_SWAP
171 select TRACER_SNAPSHOT
172 select TRACER_SNAPSHOT_PER_CPU_SWAP
173 help
174 This option measures the time spent in irqs-off critical
175 sections, with microsecond accuracy.
176
177 The default measurement method is a maximum search, which is
178 disabled by default and can be runtime (re-)started
179 via:
180
181 echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
182
183 (Note that kernel size and overhead increase with this option
184 enabled. This option and the preempt-off timing option can be
185 used together or separately.)
186
187config PREEMPT_TRACER
188 bool "Preemption-off Latency Tracer"
189 default n
190 depends on !ARCH_USES_GETTIMEOFFSET
191 depends on PREEMPT
192 select GENERIC_TRACER
193 select TRACER_MAX_TRACE
194 select RING_BUFFER_ALLOW_SWAP
195 select TRACER_SNAPSHOT
196 select TRACER_SNAPSHOT_PER_CPU_SWAP
197 help
198 This option measures the time spent in preemption-off critical
199 sections, with microsecond accuracy.
200
201 The default measurement method is a maximum search, which is
202 disabled by default and can be runtime (re-)started
203 via:
204
205 echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
206
207 (Note that kernel size and overhead increase with this option
208 enabled. This option and the irqs-off timing option can be
209 used together or separately.)
210
211config SCHED_TRACER
212 bool "Scheduling Latency Tracer"
213 select GENERIC_TRACER
214 select CONTEXT_SWITCH_TRACER
215 select TRACER_MAX_TRACE
216 select TRACER_SNAPSHOT
217 help
218 This tracer tracks the latency of the highest priority task
219 to be scheduled in, starting from the point it has woken up.
220
221config HWLAT_TRACER
222 bool "Tracer to detect hardware latencies (like SMIs)"
223 select GENERIC_TRACER
224 help
225 This tracer, when enabled will create one or more kernel threads,
226 depening on what the cpumask file is set to, which each thread
227 spinning in a loop looking for interruptions caused by
228 something other than the kernel. For example, if a
229 System Management Interrupt (SMI) takes a noticeable amount of
230 time, this tracer will detect it. This is useful for testing
231 if a system is reliable for Real Time tasks.
232
233 Some files are created in the tracing directory when this
234 is enabled:
235
236 hwlat_detector/width - time in usecs for how long to spin for
237 hwlat_detector/window - time in usecs between the start of each
238 iteration
239
240 A kernel thread is created that will spin with interrupts disabled
241 for "width" microseconds in every "widow" cycle. It will not spin
242 for "window - width" microseconds, where the system can
243 continue to operate.
244
245 The output will appear in the trace and trace_pipe files.
246
247 When the tracer is not running, it has no affect on the system,
248 but when it is running, it can cause the system to be
249 periodically non responsive. Do not run this tracer on a
250 production system.
251
252 To enable this tracer, echo in "hwlat" into the current_tracer
253 file. Every time a latency is greater than tracing_thresh, it will
254 be recorded into the ring buffer.
255
256config ENABLE_DEFAULT_TRACERS
257 bool "Trace process context switches and events"
258 depends on !GENERIC_TRACER
259 select TRACING
260 help
261 This tracer hooks to various trace points in the kernel,
262 allowing the user to pick and choose which trace point they
263 want to trace. It also includes the sched_switch tracer plugin.
264
265config FTRACE_SYSCALLS
266 bool "Trace syscalls"
267 depends on HAVE_SYSCALL_TRACEPOINTS
268 select GENERIC_TRACER
269 select KALLSYMS
270 help
271 Basic tracer to catch the syscall entry and exit events.
272
273config TRACER_SNAPSHOT
274 bool "Create a snapshot trace buffer"
275 select TRACER_MAX_TRACE
276 help
277 Allow tracing users to take snapshot of the current buffer using the
278 ftrace interface, e.g.:
279
280 echo 1 > /sys/kernel/debug/tracing/snapshot
281 cat snapshot
282
283config TRACER_SNAPSHOT_PER_CPU_SWAP
284 bool "Allow snapshot to swap per CPU"
285 depends on TRACER_SNAPSHOT
286 select RING_BUFFER_ALLOW_SWAP
287 help
288 Allow doing a snapshot of a single CPU buffer instead of a
289 full swap (all buffers). If this is set, then the following is
290 allowed:
291
292 echo 1 > /sys/kernel/debug/tracing/per_cpu/cpu2/snapshot
293
294 After which, only the tracing buffer for CPU 2 was swapped with
295 the main tracing buffer, and the other CPU buffers remain the same.
296
297 When this is enabled, this adds a little more overhead to the
298 trace recording, as it needs to add some checks to synchronize
299 recording with swaps. But this does not affect the performance
300 of the overall system. This is enabled by default when the preempt
301 or irq latency tracers are enabled, as those need to swap as well
302 and already adds the overhead (plus a lot more).
303
304config TRACE_BRANCH_PROFILING
305 bool
306 select GENERIC_TRACER
307
308choice
309 prompt "Branch Profiling"
310 default BRANCH_PROFILE_NONE
311 help
312 The branch profiling is a software profiler. It will add hooks
313 into the C conditionals to test which path a branch takes.
314
315 The likely/unlikely profiler only looks at the conditions that
316 are annotated with a likely or unlikely macro.
317
318 The "all branch" profiler will profile every if-statement in the
319 kernel. This profiler will also enable the likely/unlikely
320 profiler.
321
322 Either of the above profilers adds a bit of overhead to the system.
323 If unsure, choose "No branch profiling".
324
325config BRANCH_PROFILE_NONE
326 bool "No branch profiling"
327 help
328 No branch profiling. Branch profiling adds a bit of overhead.
329 Only enable it if you want to analyse the branching behavior.
330 Otherwise keep it disabled.
331
332config PROFILE_ANNOTATED_BRANCHES
333 bool "Trace likely/unlikely profiler"
334 select TRACE_BRANCH_PROFILING
335 help
336 This tracer profiles all likely and unlikely macros
337 in the kernel. It will display the results in:
338
339 /sys/kernel/debug/tracing/trace_stat/branch_annotated
340
341 Note: this will add a significant overhead; only turn this
342 on if you need to profile the system's use of these macros.
343
344config PROFILE_ALL_BRANCHES
345 bool "Profile all if conditionals"
346 select TRACE_BRANCH_PROFILING
347 help
348 This tracer profiles all branch conditions. Every if ()
349 taken in the kernel is recorded whether it hit or miss.
350 The results will be displayed in:
351
352 /sys/kernel/debug/tracing/trace_stat/branch_all
353
354 This option also enables the likely/unlikely profiler.
355
356 This configuration, when enabled, will impose a great overhead
357 on the system. This should only be enabled when the system
358 is to be analyzed in much detail.
359endchoice
360
361config TRACING_BRANCHES
362 bool
363 help
364 Selected by tracers that will trace the likely and unlikely
365 conditions. This prevents the tracers themselves from being
366 profiled. Profiling the tracing infrastructure can only happen
367 when the likelys and unlikelys are not being traced.
368
369config BRANCH_TRACER
370 bool "Trace likely/unlikely instances"
371 depends on TRACE_BRANCH_PROFILING
372 select TRACING_BRANCHES
373 help
374 This traces the events of likely and unlikely condition
375 calls in the kernel. The difference between this and the
376 "Trace likely/unlikely profiler" is that this is not a
377 histogram of the callers, but actually places the calling
378 events into a running trace buffer to see when and where the
379 events happened, as well as their results.
380
381 Say N if unsure.
382
383config STACK_TRACER
384 bool "Trace max stack"
385 depends on HAVE_FUNCTION_TRACER
386 select FUNCTION_TRACER
387 select STACKTRACE
388 select KALLSYMS
389 help
390 This special tracer records the maximum stack footprint of the
391 kernel and displays it in /sys/kernel/debug/tracing/stack_trace.
392
393 This tracer works by hooking into every function call that the
394 kernel executes, and keeping a maximum stack depth value and
395 stack-trace saved. If this is configured with DYNAMIC_FTRACE
396 then it will not have any overhead while the stack tracer
397 is disabled.
398
399 To enable the stack tracer on bootup, pass in 'stacktrace'
400 on the kernel command line.
401
402 The stack tracer can also be enabled or disabled via the
403 sysctl kernel.stack_tracer_enabled
404
405 Say N if unsure.
406
407config BLK_DEV_IO_TRACE
408 bool "Support for tracing block IO actions"
409 depends on SYSFS
410 depends on BLOCK
411 select RELAY
412 select DEBUG_FS
413 select TRACEPOINTS
414 select GENERIC_TRACER
415 select STACKTRACE
416 help
417 Say Y here if you want to be able to trace the block layer actions
418 on a given queue. Tracing allows you to see any traffic happening
419 on a block device queue. For more information (and the userspace
420 support tools needed), fetch the blktrace tools from:
421
422 git://git.kernel.dk/blktrace.git
423
424 Tracing also is possible using the ftrace interface, e.g.:
425
426 echo 1 > /sys/block/sda/sda1/trace/enable
427 echo blk > /sys/kernel/debug/tracing/current_tracer
428 cat /sys/kernel/debug/tracing/trace_pipe
429
430 If unsure, say N.
431
432config KPROBE_EVENT
433 depends on KPROBES
434 depends on HAVE_REGS_AND_STACK_ACCESS_API
435 bool "Enable kprobes-based dynamic events"
436 select TRACING
437 select PROBE_EVENTS
438 default y
439 help
440 This allows the user to add tracing events (similar to tracepoints)
441 on the fly via the ftrace interface. See
442 Documentation/trace/kprobetrace.txt for more details.
443
444 Those events can be inserted wherever kprobes can probe, and record
445 various register and memory values.
446
447 This option is also required by perf-probe subcommand of perf tools.
448 If you want to use perf tools, this option is strongly recommended.
449
450config UPROBE_EVENT
451 bool "Enable uprobes-based dynamic events"
452 depends on ARCH_SUPPORTS_UPROBES
453 depends on MMU
454 depends on PERF_EVENTS
455 select UPROBES
456 select PROBE_EVENTS
457 select TRACING
458 default n
459 help
460 This allows the user to add tracing events on top of userspace
461 dynamic events (similar to tracepoints) on the fly via the trace
462 events interface. Those events can be inserted wherever uprobes
463 can probe, and record various registers.
464 This option is required if you plan to use perf-probe subcommand
465 of perf tools on user space applications.
466
467config BPF_EVENTS
468 depends on BPF_SYSCALL
469 depends on (KPROBE_EVENT || UPROBE_EVENT) && PERF_EVENTS
470 bool
471 default y
472 help
473 This allows the user to attach BPF programs to kprobe events.
474
475config PROBE_EVENTS
476 def_bool n
477
478config DYNAMIC_FTRACE
479 bool "enable/disable function tracing dynamically"
480 depends on FUNCTION_TRACER
481 depends on HAVE_DYNAMIC_FTRACE
482 default y
483 help
484 This option will modify all the calls to function tracing
485 dynamically (will patch them out of the binary image and
486 replace them with a No-Op instruction) on boot up. During
487 compile time, a table is made of all the locations that ftrace
488 can function trace, and this table is linked into the kernel
489 image. When this is enabled, functions can be individually
490 enabled, and the functions not enabled will not affect
491 performance of the system.
492
493 See the files in /sys/kernel/debug/tracing:
494 available_filter_functions
495 set_ftrace_filter
496 set_ftrace_notrace
497
498 This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but
499 otherwise has native performance as long as no tracing is active.
500
501config DYNAMIC_FTRACE_WITH_REGS
502 def_bool y
503 depends on DYNAMIC_FTRACE
504 depends on HAVE_DYNAMIC_FTRACE_WITH_REGS
505
506config FUNCTION_PROFILER
507 bool "Kernel function profiler"
508 depends on FUNCTION_TRACER
509 default n
510 help
511 This option enables the kernel function profiler. A file is created
512 in debugfs called function_profile_enabled which defaults to zero.
513 When a 1 is echoed into this file profiling begins, and when a
514 zero is entered, profiling stops. A "functions" file is created in
515 the trace_stats directory; this file shows the list of functions that
516 have been hit and their counters.
517
518 If in doubt, say N.
519
520config FTRACE_MCOUNT_RECORD
521 def_bool y
522 depends on DYNAMIC_FTRACE
523 depends on HAVE_FTRACE_MCOUNT_RECORD
524
525config FTRACE_SELFTEST
526 bool
527
528config FTRACE_STARTUP_TEST
529 bool "Perform a startup test on ftrace"
530 depends on GENERIC_TRACER
531 select FTRACE_SELFTEST
532 help
533 This option performs a series of startup tests on ftrace. On bootup
534 a series of tests are made to verify that the tracer is
535 functioning properly. It will do tests on all the configured
536 tracers of ftrace.
537
538config EVENT_TRACE_TEST_SYSCALLS
539 bool "Run selftest on syscall events"
540 depends on FTRACE_STARTUP_TEST
541 help
542 This option will also enable testing every syscall event.
543 It only enables the event and disables it and runs various loads
544 with the event enabled. This adds a bit more time for kernel boot
545 up since it runs this on every system call defined.
546
547 TBD - enable a way to actually call the syscalls as we test their
548 events
549
550config MMIOTRACE
551 bool "Memory mapped IO tracing"
552 depends on HAVE_MMIOTRACE_SUPPORT && PCI
553 select GENERIC_TRACER
554 help
555 Mmiotrace traces Memory Mapped I/O access and is meant for
556 debugging and reverse engineering. It is called from the ioremap
557 implementation and works via page faults. Tracing is disabled by
558 default and can be enabled at run-time.
559
560 See Documentation/trace/mmiotrace.txt.
561 If you are not helping to develop drivers, say N.
562
563config TRACING_MAP
564 bool
565 depends on ARCH_HAVE_NMI_SAFE_CMPXCHG
566 help
567 tracing_map is a special-purpose lock-free map for tracing,
568 separated out as a stand-alone facility in order to allow it
569 to be shared between multiple tracers. It isn't meant to be
570 generally used outside of that context, and is normally
571 selected by tracers that use it.
572
573config HIST_TRIGGERS
574 bool "Histogram triggers"
575 depends on ARCH_HAVE_NMI_SAFE_CMPXCHG
576 select TRACING_MAP
577 select TRACING
578 default n
579 help
580 Hist triggers allow one or more arbitrary trace event fields
581 to be aggregated into hash tables and dumped to stdout by
582 reading a debugfs/tracefs file. They're useful for
583 gathering quick and dirty (though precise) summaries of
584 event activity as an initial guide for further investigation
585 using more advanced tools.
586
587 See Documentation/trace/events.txt.
588 If in doubt, say N.
589
590config MMIOTRACE_TEST
591 tristate "Test module for mmiotrace"
592 depends on MMIOTRACE && m
593 help
594 This is a dumb module for testing mmiotrace. It is very dangerous
595 as it will write garbage to IO memory starting at a given address.
596 However, it should be safe to use on e.g. unused portion of VRAM.
597
598 Say N, unless you absolutely know what you are doing.
599
600config TRACEPOINT_BENCHMARK
601 bool "Add tracepoint that benchmarks tracepoints"
602 help
603 This option creates the tracepoint "benchmark:benchmark_event".
604 When the tracepoint is enabled, it kicks off a kernel thread that
605 goes into an infinite loop (calling cond_sched() to let other tasks
606 run), and calls the tracepoint. Each iteration will record the time
607 it took to write to the tracepoint and the next iteration that
608 data will be passed to the tracepoint itself. That is, the tracepoint
609 will report the time it took to do the previous tracepoint.
610 The string written to the tracepoint is a static string of 128 bytes
611 to keep the time the same. The initial string is simply a write of
612 "START". The second string records the cold cache time of the first
613 write which is not added to the rest of the calculations.
614
615 As it is a tight loop, it benchmarks as hot cache. That's fine because
616 we care most about hot paths that are probably in cache already.
617
618 An example of the output:
619
620 START
621 first=3672 [COLD CACHED]
622 last=632 first=3672 max=632 min=632 avg=316 std=446 std^2=199712
623 last=278 first=3672 max=632 min=278 avg=303 std=316 std^2=100337
624 last=277 first=3672 max=632 min=277 avg=296 std=258 std^2=67064
625 last=273 first=3672 max=632 min=273 avg=292 std=224 std^2=50411
626 last=273 first=3672 max=632 min=273 avg=288 std=200 std^2=40389
627 last=281 first=3672 max=632 min=273 avg=287 std=183 std^2=33666
628
629
630config RING_BUFFER_BENCHMARK
631 tristate "Ring buffer benchmark stress tester"
632 depends on RING_BUFFER
633 help
634 This option creates a test to stress the ring buffer and benchmark it.
635 It creates its own ring buffer such that it will not interfere with
636 any other users of the ring buffer (such as ftrace). It then creates
637 a producer and consumer that will run for 10 seconds and sleep for
638 10 seconds. Each interval it will print out the number of events
639 it recorded and give a rough estimate of how long each iteration took.
640
641 It does not disable interrupts or raise its priority, so it may be
642 affected by processes that are running.
643
644 If unsure, say N.
645
646config RING_BUFFER_STARTUP_TEST
647 bool "Ring buffer startup self test"
648 depends on RING_BUFFER
649 help
650 Run a simple self test on the ring buffer on boot up. Late in the
651 kernel boot sequence, the test will start that kicks off
652 a thread per cpu. Each thread will write various size events
653 into the ring buffer. Another thread is created to send IPIs
654 to each of the threads, where the IPI handler will also write
655 to the ring buffer, to test/stress the nesting ability.
656 If any anomalies are discovered, a warning will be displayed
657 and all ring buffers will be disabled.
658
659 The test runs for 10 seconds. This will slow your boot time
660 by at least 10 more seconds.
661
662 At the end of the test, statics and more checks are done.
663 It will output the stats of each per cpu buffer. What
664 was written, the sizes, what was read, what was lost, and
665 other similar details.
666
667 If unsure, say N
668
669config TRACE_ENUM_MAP_FILE
670 bool "Show enum mappings for trace events"
671 depends on TRACING
672 help
673 The "print fmt" of the trace events will show the enum names instead
674 of their values. This can cause problems for user space tools that
675 use this string to parse the raw data as user space does not know
676 how to convert the string to its value.
677
678 To fix this, there's a special macro in the kernel that can be used
679 to convert the enum into its value. If this macro is used, then the
680 print fmt strings will have the enums converted to their values.
681
682 If something does not get converted properly, this option can be
683 used to show what enums the kernel tried to convert.
684
685 This option is for debugging the enum conversions. A file is created
686 in the tracing directory called "enum_map" that will show the enum
687 names matched with their values and what trace event system they
688 belong too.
689
690 Normally, the mapping of the strings to values will be freed after
691 boot up or module load. With this option, they will not be freed, as
692 they are needed for the "enum_map" file. Enabling this option will
693 increase the memory footprint of the running kernel.
694
695 If unsure, say N
696
697config TRACING_EVENTS_GPIO
698 bool "Trace gpio events"
699 depends on GPIOLIB
700 default y
701 help
702 Enable tracing events for gpio subsystem
703
704endif # FTRACE
705
706endif # TRACING_SUPPORT
707
1#
2# Architectures that offer an FUNCTION_TRACER implementation should
3# select HAVE_FUNCTION_TRACER:
4#
5
6config USER_STACKTRACE_SUPPORT
7 bool
8
9config NOP_TRACER
10 bool
11
12config HAVE_FTRACE_NMI_ENTER
13 bool
14 help
15 See Documentation/trace/ftrace-design.txt
16
17config HAVE_FUNCTION_TRACER
18 bool
19 help
20 See Documentation/trace/ftrace-design.txt
21
22config HAVE_FUNCTION_GRAPH_TRACER
23 bool
24 help
25 See Documentation/trace/ftrace-design.txt
26
27config HAVE_DYNAMIC_FTRACE
28 bool
29 help
30 See Documentation/trace/ftrace-design.txt
31
32config HAVE_DYNAMIC_FTRACE_WITH_REGS
33 bool
34
35config HAVE_FTRACE_MCOUNT_RECORD
36 bool
37 help
38 See Documentation/trace/ftrace-design.txt
39
40config HAVE_SYSCALL_TRACEPOINTS
41 bool
42 help
43 See Documentation/trace/ftrace-design.txt
44
45config HAVE_FENTRY
46 bool
47 help
48 Arch supports the gcc options -pg with -mfentry
49
50config HAVE_C_RECORDMCOUNT
51 bool
52 help
53 C version of recordmcount available?
54
55config TRACER_MAX_TRACE
56 bool
57
58config TRACE_CLOCK
59 bool
60
61config RING_BUFFER
62 bool
63 select TRACE_CLOCK
64 select IRQ_WORK
65
66config FTRACE_NMI_ENTER
67 bool
68 depends on HAVE_FTRACE_NMI_ENTER
69 default y
70
71config EVENT_TRACING
72 select CONTEXT_SWITCH_TRACER
73 select GLOB
74 bool
75
76config CONTEXT_SWITCH_TRACER
77 bool
78
79config RING_BUFFER_ALLOW_SWAP
80 bool
81 help
82 Allow the use of ring_buffer_swap_cpu.
83 Adds a very slight overhead to tracing when enabled.
84
85# All tracer options should select GENERIC_TRACER. For those options that are
86# enabled by all tracers (context switch and event tracer) they select TRACING.
87# This allows those options to appear when no other tracer is selected. But the
88# options do not appear when something else selects it. We need the two options
89# GENERIC_TRACER and TRACING to avoid circular dependencies to accomplish the
90# hiding of the automatic options.
91
92config TRACING
93 bool
94 select DEBUG_FS
95 select RING_BUFFER
96 select STACKTRACE if STACKTRACE_SUPPORT
97 select TRACEPOINTS
98 select NOP_TRACER
99 select BINARY_PRINTF
100 select EVENT_TRACING
101 select TRACE_CLOCK
102
103config GENERIC_TRACER
104 bool
105 select TRACING
106
107#
108# Minimum requirements an architecture has to meet for us to
109# be able to offer generic tracing facilities:
110#
111config TRACING_SUPPORT
112 bool
113 # PPC32 has no irqflags tracing support, but it can use most of the
114 # tracers anyway, they were tested to build and work. Note that new
115 # exceptions to this list aren't welcomed, better implement the
116 # irqflags tracing for your architecture.
117 depends on TRACE_IRQFLAGS_SUPPORT || PPC32
118 depends on STACKTRACE_SUPPORT
119 default y
120
121if TRACING_SUPPORT
122
123menuconfig FTRACE
124 bool "Tracers"
125 default y if DEBUG_KERNEL
126 help
127 Enable the kernel tracing infrastructure.
128
129if FTRACE
130
131config FUNCTION_TRACER
132 bool "Kernel Function Tracer"
133 depends on HAVE_FUNCTION_TRACER
134 select KALLSYMS
135 select GENERIC_TRACER
136 select CONTEXT_SWITCH_TRACER
137 select GLOB
138 select TASKS_RCU if PREEMPT
139 help
140 Enable the kernel to trace every kernel function. This is done
141 by using a compiler feature to insert a small, 5-byte No-Operation
142 instruction at the beginning of every kernel function, which NOP
143 sequence is then dynamically patched into a tracer call when
144 tracing is enabled by the administrator. If it's runtime disabled
145 (the bootup default), then the overhead of the instructions is very
146 small and not measurable even in micro-benchmarks.
147
148config FUNCTION_GRAPH_TRACER
149 bool "Kernel Function Graph Tracer"
150 depends on HAVE_FUNCTION_GRAPH_TRACER
151 depends on FUNCTION_TRACER
152 depends on !X86_32 || !CC_OPTIMIZE_FOR_SIZE
153 default y
154 help
155 Enable the kernel to trace a function at both its return
156 and its entry.
157 Its first purpose is to trace the duration of functions and
158 draw a call graph for each thread with some information like
159 the return value. This is done by setting the current return
160 address on the current task structure into a stack of calls.
161
162
163config PREEMPTIRQ_EVENTS
164 bool "Enable trace events for preempt and irq disable/enable"
165 select TRACE_IRQFLAGS
166 depends on DEBUG_PREEMPT || !PROVE_LOCKING
167 depends on TRACING
168 default n
169 help
170 Enable tracing of disable and enable events for preemption and irqs.
171 For tracing preempt disable/enable events, DEBUG_PREEMPT must be
172 enabled. For tracing irq disable/enable events, PROVE_LOCKING must
173 be disabled.
174
175config IRQSOFF_TRACER
176 bool "Interrupts-off Latency Tracer"
177 default n
178 depends on TRACE_IRQFLAGS_SUPPORT
179 depends on !ARCH_USES_GETTIMEOFFSET
180 select TRACE_IRQFLAGS
181 select GENERIC_TRACER
182 select TRACER_MAX_TRACE
183 select RING_BUFFER_ALLOW_SWAP
184 select TRACER_SNAPSHOT
185 select TRACER_SNAPSHOT_PER_CPU_SWAP
186 help
187 This option measures the time spent in irqs-off critical
188 sections, with microsecond accuracy.
189
190 The default measurement method is a maximum search, which is
191 disabled by default and can be runtime (re-)started
192 via:
193
194 echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
195
196 (Note that kernel size and overhead increase with this option
197 enabled. This option and the preempt-off timing option can be
198 used together or separately.)
199
200config PREEMPT_TRACER
201 bool "Preemption-off Latency Tracer"
202 default n
203 depends on !ARCH_USES_GETTIMEOFFSET
204 depends on PREEMPT
205 select GENERIC_TRACER
206 select TRACER_MAX_TRACE
207 select RING_BUFFER_ALLOW_SWAP
208 select TRACER_SNAPSHOT
209 select TRACER_SNAPSHOT_PER_CPU_SWAP
210 help
211 This option measures the time spent in preemption-off critical
212 sections, with microsecond accuracy.
213
214 The default measurement method is a maximum search, which is
215 disabled by default and can be runtime (re-)started
216 via:
217
218 echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
219
220 (Note that kernel size and overhead increase with this option
221 enabled. This option and the irqs-off timing option can be
222 used together or separately.)
223
224config SCHED_TRACER
225 bool "Scheduling Latency Tracer"
226 select GENERIC_TRACER
227 select CONTEXT_SWITCH_TRACER
228 select TRACER_MAX_TRACE
229 select TRACER_SNAPSHOT
230 help
231 This tracer tracks the latency of the highest priority task
232 to be scheduled in, starting from the point it has woken up.
233
234config HWLAT_TRACER
235 bool "Tracer to detect hardware latencies (like SMIs)"
236 select GENERIC_TRACER
237 help
238 This tracer, when enabled will create one or more kernel threads,
239 depending on what the cpumask file is set to, which each thread
240 spinning in a loop looking for interruptions caused by
241 something other than the kernel. For example, if a
242 System Management Interrupt (SMI) takes a noticeable amount of
243 time, this tracer will detect it. This is useful for testing
244 if a system is reliable for Real Time tasks.
245
246 Some files are created in the tracing directory when this
247 is enabled:
248
249 hwlat_detector/width - time in usecs for how long to spin for
250 hwlat_detector/window - time in usecs between the start of each
251 iteration
252
253 A kernel thread is created that will spin with interrupts disabled
254 for "width" microseconds in every "window" cycle. It will not spin
255 for "window - width" microseconds, where the system can
256 continue to operate.
257
258 The output will appear in the trace and trace_pipe files.
259
260 When the tracer is not running, it has no affect on the system,
261 but when it is running, it can cause the system to be
262 periodically non responsive. Do not run this tracer on a
263 production system.
264
265 To enable this tracer, echo in "hwlat" into the current_tracer
266 file. Every time a latency is greater than tracing_thresh, it will
267 be recorded into the ring buffer.
268
269config ENABLE_DEFAULT_TRACERS
270 bool "Trace process context switches and events"
271 depends on !GENERIC_TRACER
272 select TRACING
273 help
274 This tracer hooks to various trace points in the kernel,
275 allowing the user to pick and choose which trace point they
276 want to trace. It also includes the sched_switch tracer plugin.
277
278config FTRACE_SYSCALLS
279 bool "Trace syscalls"
280 depends on HAVE_SYSCALL_TRACEPOINTS
281 select GENERIC_TRACER
282 select KALLSYMS
283 help
284 Basic tracer to catch the syscall entry and exit events.
285
286config TRACER_SNAPSHOT
287 bool "Create a snapshot trace buffer"
288 select TRACER_MAX_TRACE
289 help
290 Allow tracing users to take snapshot of the current buffer using the
291 ftrace interface, e.g.:
292
293 echo 1 > /sys/kernel/debug/tracing/snapshot
294 cat snapshot
295
296config TRACER_SNAPSHOT_PER_CPU_SWAP
297 bool "Allow snapshot to swap per CPU"
298 depends on TRACER_SNAPSHOT
299 select RING_BUFFER_ALLOW_SWAP
300 help
301 Allow doing a snapshot of a single CPU buffer instead of a
302 full swap (all buffers). If this is set, then the following is
303 allowed:
304
305 echo 1 > /sys/kernel/debug/tracing/per_cpu/cpu2/snapshot
306
307 After which, only the tracing buffer for CPU 2 was swapped with
308 the main tracing buffer, and the other CPU buffers remain the same.
309
310 When this is enabled, this adds a little more overhead to the
311 trace recording, as it needs to add some checks to synchronize
312 recording with swaps. But this does not affect the performance
313 of the overall system. This is enabled by default when the preempt
314 or irq latency tracers are enabled, as those need to swap as well
315 and already adds the overhead (plus a lot more).
316
317config TRACE_BRANCH_PROFILING
318 bool
319 select GENERIC_TRACER
320
321choice
322 prompt "Branch Profiling"
323 default BRANCH_PROFILE_NONE
324 help
325 The branch profiling is a software profiler. It will add hooks
326 into the C conditionals to test which path a branch takes.
327
328 The likely/unlikely profiler only looks at the conditions that
329 are annotated with a likely or unlikely macro.
330
331 The "all branch" profiler will profile every if-statement in the
332 kernel. This profiler will also enable the likely/unlikely
333 profiler.
334
335 Either of the above profilers adds a bit of overhead to the system.
336 If unsure, choose "No branch profiling".
337
338config BRANCH_PROFILE_NONE
339 bool "No branch profiling"
340 help
341 No branch profiling. Branch profiling adds a bit of overhead.
342 Only enable it if you want to analyse the branching behavior.
343 Otherwise keep it disabled.
344
345config PROFILE_ANNOTATED_BRANCHES
346 bool "Trace likely/unlikely profiler"
347 select TRACE_BRANCH_PROFILING
348 help
349 This tracer profiles all likely and unlikely macros
350 in the kernel. It will display the results in:
351
352 /sys/kernel/debug/tracing/trace_stat/branch_annotated
353
354 Note: this will add a significant overhead; only turn this
355 on if you need to profile the system's use of these macros.
356
357config PROFILE_ALL_BRANCHES
358 bool "Profile all if conditionals" if !FORTIFY_SOURCE
359 select TRACE_BRANCH_PROFILING
360 help
361 This tracer profiles all branch conditions. Every if ()
362 taken in the kernel is recorded whether it hit or miss.
363 The results will be displayed in:
364
365 /sys/kernel/debug/tracing/trace_stat/branch_all
366
367 This option also enables the likely/unlikely profiler.
368
369 This configuration, when enabled, will impose a great overhead
370 on the system. This should only be enabled when the system
371 is to be analyzed in much detail.
372endchoice
373
374config TRACING_BRANCHES
375 bool
376 help
377 Selected by tracers that will trace the likely and unlikely
378 conditions. This prevents the tracers themselves from being
379 profiled. Profiling the tracing infrastructure can only happen
380 when the likelys and unlikelys are not being traced.
381
382config BRANCH_TRACER
383 bool "Trace likely/unlikely instances"
384 depends on TRACE_BRANCH_PROFILING
385 select TRACING_BRANCHES
386 help
387 This traces the events of likely and unlikely condition
388 calls in the kernel. The difference between this and the
389 "Trace likely/unlikely profiler" is that this is not a
390 histogram of the callers, but actually places the calling
391 events into a running trace buffer to see when and where the
392 events happened, as well as their results.
393
394 Say N if unsure.
395
396config STACK_TRACER
397 bool "Trace max stack"
398 depends on HAVE_FUNCTION_TRACER
399 select FUNCTION_TRACER
400 select STACKTRACE
401 select KALLSYMS
402 help
403 This special tracer records the maximum stack footprint of the
404 kernel and displays it in /sys/kernel/debug/tracing/stack_trace.
405
406 This tracer works by hooking into every function call that the
407 kernel executes, and keeping a maximum stack depth value and
408 stack-trace saved. If this is configured with DYNAMIC_FTRACE
409 then it will not have any overhead while the stack tracer
410 is disabled.
411
412 To enable the stack tracer on bootup, pass in 'stacktrace'
413 on the kernel command line.
414
415 The stack tracer can also be enabled or disabled via the
416 sysctl kernel.stack_tracer_enabled
417
418 Say N if unsure.
419
420config BLK_DEV_IO_TRACE
421 bool "Support for tracing block IO actions"
422 depends on SYSFS
423 depends on BLOCK
424 select RELAY
425 select DEBUG_FS
426 select TRACEPOINTS
427 select GENERIC_TRACER
428 select STACKTRACE
429 help
430 Say Y here if you want to be able to trace the block layer actions
431 on a given queue. Tracing allows you to see any traffic happening
432 on a block device queue. For more information (and the userspace
433 support tools needed), fetch the blktrace tools from:
434
435 git://git.kernel.dk/blktrace.git
436
437 Tracing also is possible using the ftrace interface, e.g.:
438
439 echo 1 > /sys/block/sda/sda1/trace/enable
440 echo blk > /sys/kernel/debug/tracing/current_tracer
441 cat /sys/kernel/debug/tracing/trace_pipe
442
443 If unsure, say N.
444
445config KPROBE_EVENTS
446 depends on KPROBES
447 depends on HAVE_REGS_AND_STACK_ACCESS_API
448 bool "Enable kprobes-based dynamic events"
449 select TRACING
450 select PROBE_EVENTS
451 default y
452 help
453 This allows the user to add tracing events (similar to tracepoints)
454 on the fly via the ftrace interface. See
455 Documentation/trace/kprobetrace.txt for more details.
456
457 Those events can be inserted wherever kprobes can probe, and record
458 various register and memory values.
459
460 This option is also required by perf-probe subcommand of perf tools.
461 If you want to use perf tools, this option is strongly recommended.
462
463config UPROBE_EVENTS
464 bool "Enable uprobes-based dynamic events"
465 depends on ARCH_SUPPORTS_UPROBES
466 depends on MMU
467 depends on PERF_EVENTS
468 select UPROBES
469 select PROBE_EVENTS
470 select TRACING
471 default y
472 help
473 This allows the user to add tracing events on top of userspace
474 dynamic events (similar to tracepoints) on the fly via the trace
475 events interface. Those events can be inserted wherever uprobes
476 can probe, and record various registers.
477 This option is required if you plan to use perf-probe subcommand
478 of perf tools on user space applications.
479
480config BPF_EVENTS
481 depends on BPF_SYSCALL
482 depends on (KPROBE_EVENTS || UPROBE_EVENTS) && PERF_EVENTS
483 bool
484 default y
485 help
486 This allows the user to attach BPF programs to kprobe events.
487
488config PROBE_EVENTS
489 def_bool n
490
491config DYNAMIC_FTRACE
492 bool "enable/disable function tracing dynamically"
493 depends on FUNCTION_TRACER
494 depends on HAVE_DYNAMIC_FTRACE
495 default y
496 help
497 This option will modify all the calls to function tracing
498 dynamically (will patch them out of the binary image and
499 replace them with a No-Op instruction) on boot up. During
500 compile time, a table is made of all the locations that ftrace
501 can function trace, and this table is linked into the kernel
502 image. When this is enabled, functions can be individually
503 enabled, and the functions not enabled will not affect
504 performance of the system.
505
506 See the files in /sys/kernel/debug/tracing:
507 available_filter_functions
508 set_ftrace_filter
509 set_ftrace_notrace
510
511 This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but
512 otherwise has native performance as long as no tracing is active.
513
514config DYNAMIC_FTRACE_WITH_REGS
515 def_bool y
516 depends on DYNAMIC_FTRACE
517 depends on HAVE_DYNAMIC_FTRACE_WITH_REGS
518
519config FUNCTION_PROFILER
520 bool "Kernel function profiler"
521 depends on FUNCTION_TRACER
522 default n
523 help
524 This option enables the kernel function profiler. A file is created
525 in debugfs called function_profile_enabled which defaults to zero.
526 When a 1 is echoed into this file profiling begins, and when a
527 zero is entered, profiling stops. A "functions" file is created in
528 the trace_stats directory; this file shows the list of functions that
529 have been hit and their counters.
530
531 If in doubt, say N.
532
533config BPF_KPROBE_OVERRIDE
534 bool "Enable BPF programs to override a kprobed function"
535 depends on BPF_EVENTS
536 depends on FUNCTION_ERROR_INJECTION
537 default n
538 help
539 Allows BPF to override the execution of a probed function and
540 set a different return value. This is used for error injection.
541
542config FTRACE_MCOUNT_RECORD
543 def_bool y
544 depends on DYNAMIC_FTRACE
545 depends on HAVE_FTRACE_MCOUNT_RECORD
546
547config FTRACE_SELFTEST
548 bool
549
550config FTRACE_STARTUP_TEST
551 bool "Perform a startup test on ftrace"
552 depends on GENERIC_TRACER
553 select FTRACE_SELFTEST
554 help
555 This option performs a series of startup tests on ftrace. On bootup
556 a series of tests are made to verify that the tracer is
557 functioning properly. It will do tests on all the configured
558 tracers of ftrace.
559
560config EVENT_TRACE_TEST_SYSCALLS
561 bool "Run selftest on syscall events"
562 depends on FTRACE_STARTUP_TEST
563 help
564 This option will also enable testing every syscall event.
565 It only enables the event and disables it and runs various loads
566 with the event enabled. This adds a bit more time for kernel boot
567 up since it runs this on every system call defined.
568
569 TBD - enable a way to actually call the syscalls as we test their
570 events
571
572config MMIOTRACE
573 bool "Memory mapped IO tracing"
574 depends on HAVE_MMIOTRACE_SUPPORT && PCI
575 select GENERIC_TRACER
576 help
577 Mmiotrace traces Memory Mapped I/O access and is meant for
578 debugging and reverse engineering. It is called from the ioremap
579 implementation and works via page faults. Tracing is disabled by
580 default and can be enabled at run-time.
581
582 See Documentation/trace/mmiotrace.txt.
583 If you are not helping to develop drivers, say N.
584
585config TRACING_MAP
586 bool
587 depends on ARCH_HAVE_NMI_SAFE_CMPXCHG
588 help
589 tracing_map is a special-purpose lock-free map for tracing,
590 separated out as a stand-alone facility in order to allow it
591 to be shared between multiple tracers. It isn't meant to be
592 generally used outside of that context, and is normally
593 selected by tracers that use it.
594
595config HIST_TRIGGERS
596 bool "Histogram triggers"
597 depends on ARCH_HAVE_NMI_SAFE_CMPXCHG
598 select TRACING_MAP
599 select TRACING
600 default n
601 help
602 Hist triggers allow one or more arbitrary trace event fields
603 to be aggregated into hash tables and dumped to stdout by
604 reading a debugfs/tracefs file. They're useful for
605 gathering quick and dirty (though precise) summaries of
606 event activity as an initial guide for further investigation
607 using more advanced tools.
608
609 Inter-event tracing of quantities such as latencies is also
610 supported using hist triggers under this option.
611
612 See Documentation/trace/histogram.txt.
613 If in doubt, say N.
614
615config MMIOTRACE_TEST
616 tristate "Test module for mmiotrace"
617 depends on MMIOTRACE && m
618 help
619 This is a dumb module for testing mmiotrace. It is very dangerous
620 as it will write garbage to IO memory starting at a given address.
621 However, it should be safe to use on e.g. unused portion of VRAM.
622
623 Say N, unless you absolutely know what you are doing.
624
625config TRACEPOINT_BENCHMARK
626 bool "Add tracepoint that benchmarks tracepoints"
627 help
628 This option creates the tracepoint "benchmark:benchmark_event".
629 When the tracepoint is enabled, it kicks off a kernel thread that
630 goes into an infinite loop (calling cond_sched() to let other tasks
631 run), and calls the tracepoint. Each iteration will record the time
632 it took to write to the tracepoint and the next iteration that
633 data will be passed to the tracepoint itself. That is, the tracepoint
634 will report the time it took to do the previous tracepoint.
635 The string written to the tracepoint is a static string of 128 bytes
636 to keep the time the same. The initial string is simply a write of
637 "START". The second string records the cold cache time of the first
638 write which is not added to the rest of the calculations.
639
640 As it is a tight loop, it benchmarks as hot cache. That's fine because
641 we care most about hot paths that are probably in cache already.
642
643 An example of the output:
644
645 START
646 first=3672 [COLD CACHED]
647 last=632 first=3672 max=632 min=632 avg=316 std=446 std^2=199712
648 last=278 first=3672 max=632 min=278 avg=303 std=316 std^2=100337
649 last=277 first=3672 max=632 min=277 avg=296 std=258 std^2=67064
650 last=273 first=3672 max=632 min=273 avg=292 std=224 std^2=50411
651 last=273 first=3672 max=632 min=273 avg=288 std=200 std^2=40389
652 last=281 first=3672 max=632 min=273 avg=287 std=183 std^2=33666
653
654
655config RING_BUFFER_BENCHMARK
656 tristate "Ring buffer benchmark stress tester"
657 depends on RING_BUFFER
658 help
659 This option creates a test to stress the ring buffer and benchmark it.
660 It creates its own ring buffer such that it will not interfere with
661 any other users of the ring buffer (such as ftrace). It then creates
662 a producer and consumer that will run for 10 seconds and sleep for
663 10 seconds. Each interval it will print out the number of events
664 it recorded and give a rough estimate of how long each iteration took.
665
666 It does not disable interrupts or raise its priority, so it may be
667 affected by processes that are running.
668
669 If unsure, say N.
670
671config RING_BUFFER_STARTUP_TEST
672 bool "Ring buffer startup self test"
673 depends on RING_BUFFER
674 help
675 Run a simple self test on the ring buffer on boot up. Late in the
676 kernel boot sequence, the test will start that kicks off
677 a thread per cpu. Each thread will write various size events
678 into the ring buffer. Another thread is created to send IPIs
679 to each of the threads, where the IPI handler will also write
680 to the ring buffer, to test/stress the nesting ability.
681 If any anomalies are discovered, a warning will be displayed
682 and all ring buffers will be disabled.
683
684 The test runs for 10 seconds. This will slow your boot time
685 by at least 10 more seconds.
686
687 At the end of the test, statics and more checks are done.
688 It will output the stats of each per cpu buffer. What
689 was written, the sizes, what was read, what was lost, and
690 other similar details.
691
692 If unsure, say N
693
694config TRACE_EVAL_MAP_FILE
695 bool "Show eval mappings for trace events"
696 depends on TRACING
697 help
698 The "print fmt" of the trace events will show the enum/sizeof names
699 instead of their values. This can cause problems for user space tools
700 that use this string to parse the raw data as user space does not know
701 how to convert the string to its value.
702
703 To fix this, there's a special macro in the kernel that can be used
704 to convert an enum/sizeof into its value. If this macro is used, then
705 the print fmt strings will be converted to their values.
706
707 If something does not get converted properly, this option can be
708 used to show what enums/sizeof the kernel tried to convert.
709
710 This option is for debugging the conversions. A file is created
711 in the tracing directory called "eval_map" that will show the
712 names matched with their values and what trace event system they
713 belong too.
714
715 Normally, the mapping of the strings to values will be freed after
716 boot up or module load. With this option, they will not be freed, as
717 they are needed for the "eval_map" file. Enabling this option will
718 increase the memory footprint of the running kernel.
719
720 If unsure, say N
721
722config TRACING_EVENTS_GPIO
723 bool "Trace gpio events"
724 depends on GPIOLIB
725 default y
726 help
727 Enable tracing events for gpio subsystem
728
729endif # FTRACE
730
731endif # TRACING_SUPPORT
732