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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_FUNCTION_GRAPH_FP_TEST
28 bool
29 help
30 See Documentation/trace/ftrace-design.txt
31
32config HAVE_FUNCTION_TRACE_MCOUNT_TEST
33 bool
34 help
35 See Documentation/trace/ftrace-design.txt
36
37config HAVE_DYNAMIC_FTRACE
38 bool
39 help
40 See Documentation/trace/ftrace-design.txt
41
42config HAVE_FTRACE_MCOUNT_RECORD
43 bool
44 help
45 See Documentation/trace/ftrace-design.txt
46
47config HAVE_SYSCALL_TRACEPOINTS
48 bool
49 help
50 See Documentation/trace/ftrace-design.txt
51
52config HAVE_C_RECORDMCOUNT
53 bool
54 help
55 C version of recordmcount available?
56
57config TRACER_MAX_TRACE
58 bool
59
60config RING_BUFFER
61 bool
62
63config FTRACE_NMI_ENTER
64 bool
65 depends on HAVE_FTRACE_NMI_ENTER
66 default y
67
68config EVENT_TRACING
69 select CONTEXT_SWITCH_TRACER
70 bool
71
72config EVENT_POWER_TRACING_DEPRECATED
73 depends on EVENT_TRACING
74 bool "Deprecated power event trace API, to be removed"
75 default y
76 help
77 Provides old power event types:
78 C-state/idle accounting events:
79 power:power_start
80 power:power_end
81 and old cpufreq accounting event:
82 power:power_frequency
83 This is for userspace compatibility
84 and will vanish after 5 kernel iterations,
85 namely 3.1.
86
87config CONTEXT_SWITCH_TRACER
88 bool
89
90config RING_BUFFER_ALLOW_SWAP
91 bool
92 help
93 Allow the use of ring_buffer_swap_cpu.
94 Adds a very slight overhead to tracing when enabled.
95
96# All tracer options should select GENERIC_TRACER. For those options that are
97# enabled by all tracers (context switch and event tracer) they select TRACING.
98# This allows those options to appear when no other tracer is selected. But the
99# options do not appear when something else selects it. We need the two options
100# GENERIC_TRACER and TRACING to avoid circular dependencies to accomplish the
101# hiding of the automatic options.
102
103config TRACING
104 bool
105 select DEBUG_FS
106 select RING_BUFFER
107 select STACKTRACE if STACKTRACE_SUPPORT
108 select TRACEPOINTS
109 select NOP_TRACER
110 select BINARY_PRINTF
111 select EVENT_TRACING
112
113config GENERIC_TRACER
114 bool
115 select TRACING
116
117#
118# Minimum requirements an architecture has to meet for us to
119# be able to offer generic tracing facilities:
120#
121config TRACING_SUPPORT
122 bool
123 # PPC32 has no irqflags tracing support, but it can use most of the
124 # tracers anyway, they were tested to build and work. Note that new
125 # exceptions to this list aren't welcomed, better implement the
126 # irqflags tracing for your architecture.
127 depends on TRACE_IRQFLAGS_SUPPORT || PPC32
128 depends on STACKTRACE_SUPPORT
129 default y
130
131if TRACING_SUPPORT
132
133menuconfig FTRACE
134 bool "Tracers"
135 default y if DEBUG_KERNEL
136 help
137 Enable the kernel tracing infrastructure.
138
139if FTRACE
140
141config FUNCTION_TRACER
142 bool "Kernel Function Tracer"
143 depends on HAVE_FUNCTION_TRACER
144 select KALLSYMS
145 select GENERIC_TRACER
146 select CONTEXT_SWITCH_TRACER
147 help
148 Enable the kernel to trace every kernel function. This is done
149 by using a compiler feature to insert a small, 5-byte No-Operation
150 instruction at the beginning of every kernel function, which NOP
151 sequence is then dynamically patched into a tracer call when
152 tracing is enabled by the administrator. If it's runtime disabled
153 (the bootup default), then the overhead of the instructions is very
154 small and not measurable even in micro-benchmarks.
155
156config FUNCTION_GRAPH_TRACER
157 bool "Kernel Function Graph Tracer"
158 depends on HAVE_FUNCTION_GRAPH_TRACER
159 depends on FUNCTION_TRACER
160 depends on !X86_32 || !CC_OPTIMIZE_FOR_SIZE
161 default y
162 help
163 Enable the kernel to trace a function at both its return
164 and its entry.
165 Its first purpose is to trace the duration of functions and
166 draw a call graph for each thread with some information like
167 the return value. This is done by setting the current return
168 address on the current task structure into a stack of calls.
169
170
171config IRQSOFF_TRACER
172 bool "Interrupts-off Latency Tracer"
173 default n
174 depends on TRACE_IRQFLAGS_SUPPORT
175 depends on !ARCH_USES_GETTIMEOFFSET
176 select TRACE_IRQFLAGS
177 select GENERIC_TRACER
178 select TRACER_MAX_TRACE
179 select RING_BUFFER_ALLOW_SWAP
180 help
181 This option measures the time spent in irqs-off critical
182 sections, with microsecond accuracy.
183
184 The default measurement method is a maximum search, which is
185 disabled by default and can be runtime (re-)started
186 via:
187
188 echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
189
190 (Note that kernel size and overhead increase with this option
191 enabled. This option and the preempt-off timing option can be
192 used together or separately.)
193
194config PREEMPT_TRACER
195 bool "Preemption-off Latency Tracer"
196 default n
197 depends on !ARCH_USES_GETTIMEOFFSET
198 depends on PREEMPT
199 select GENERIC_TRACER
200 select TRACER_MAX_TRACE
201 select RING_BUFFER_ALLOW_SWAP
202 help
203 This option measures the time spent in preemption-off critical
204 sections, with microsecond accuracy.
205
206 The default measurement method is a maximum search, which is
207 disabled by default and can be runtime (re-)started
208 via:
209
210 echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
211
212 (Note that kernel size and overhead increase with this option
213 enabled. This option and the irqs-off timing option can be
214 used together or separately.)
215
216config SCHED_TRACER
217 bool "Scheduling Latency Tracer"
218 select GENERIC_TRACER
219 select CONTEXT_SWITCH_TRACER
220 select TRACER_MAX_TRACE
221 help
222 This tracer tracks the latency of the highest priority task
223 to be scheduled in, starting from the point it has woken up.
224
225config ENABLE_DEFAULT_TRACERS
226 bool "Trace process context switches and events"
227 depends on !GENERIC_TRACER
228 select TRACING
229 help
230 This tracer hooks to various trace points in the kernel,
231 allowing the user to pick and choose which trace point they
232 want to trace. It also includes the sched_switch tracer plugin.
233
234config FTRACE_SYSCALLS
235 bool "Trace syscalls"
236 depends on HAVE_SYSCALL_TRACEPOINTS
237 select GENERIC_TRACER
238 select KALLSYMS
239 help
240 Basic tracer to catch the syscall entry and exit events.
241
242config TRACE_BRANCH_PROFILING
243 bool
244 select GENERIC_TRACER
245
246choice
247 prompt "Branch Profiling"
248 default BRANCH_PROFILE_NONE
249 help
250 The branch profiling is a software profiler. It will add hooks
251 into the C conditionals to test which path a branch takes.
252
253 The likely/unlikely profiler only looks at the conditions that
254 are annotated with a likely or unlikely macro.
255
256 The "all branch" profiler will profile every if-statement in the
257 kernel. This profiler will also enable the likely/unlikely
258 profiler.
259
260 Either of the above profilers adds a bit of overhead to the system.
261 If unsure, choose "No branch profiling".
262
263config BRANCH_PROFILE_NONE
264 bool "No branch profiling"
265 help
266 No branch profiling. Branch profiling adds a bit of overhead.
267 Only enable it if you want to analyse the branching behavior.
268 Otherwise keep it disabled.
269
270config PROFILE_ANNOTATED_BRANCHES
271 bool "Trace likely/unlikely profiler"
272 select TRACE_BRANCH_PROFILING
273 help
274 This tracer profiles all likely and unlikely macros
275 in the kernel. It will display the results in:
276
277 /sys/kernel/debug/tracing/trace_stat/branch_annotated
278
279 Note: this will add a significant overhead; only turn this
280 on if you need to profile the system's use of these macros.
281
282config PROFILE_ALL_BRANCHES
283 bool "Profile all if conditionals"
284 select TRACE_BRANCH_PROFILING
285 help
286 This tracer profiles all branch conditions. Every if ()
287 taken in the kernel is recorded whether it hit or miss.
288 The results will be displayed in:
289
290 /sys/kernel/debug/tracing/trace_stat/branch_all
291
292 This option also enables the likely/unlikely profiler.
293
294 This configuration, when enabled, will impose a great overhead
295 on the system. This should only be enabled when the system
296 is to be analyzed in much detail.
297endchoice
298
299config TRACING_BRANCHES
300 bool
301 help
302 Selected by tracers that will trace the likely and unlikely
303 conditions. This prevents the tracers themselves from being
304 profiled. Profiling the tracing infrastructure can only happen
305 when the likelys and unlikelys are not being traced.
306
307config BRANCH_TRACER
308 bool "Trace likely/unlikely instances"
309 depends on TRACE_BRANCH_PROFILING
310 select TRACING_BRANCHES
311 help
312 This traces the events of likely and unlikely condition
313 calls in the kernel. The difference between this and the
314 "Trace likely/unlikely profiler" is that this is not a
315 histogram of the callers, but actually places the calling
316 events into a running trace buffer to see when and where the
317 events happened, as well as their results.
318
319 Say N if unsure.
320
321config STACK_TRACER
322 bool "Trace max stack"
323 depends on HAVE_FUNCTION_TRACER
324 select FUNCTION_TRACER
325 select STACKTRACE
326 select KALLSYMS
327 help
328 This special tracer records the maximum stack footprint of the
329 kernel and displays it in /sys/kernel/debug/tracing/stack_trace.
330
331 This tracer works by hooking into every function call that the
332 kernel executes, and keeping a maximum stack depth value and
333 stack-trace saved. If this is configured with DYNAMIC_FTRACE
334 then it will not have any overhead while the stack tracer
335 is disabled.
336
337 To enable the stack tracer on bootup, pass in 'stacktrace'
338 on the kernel command line.
339
340 The stack tracer can also be enabled or disabled via the
341 sysctl kernel.stack_tracer_enabled
342
343 Say N if unsure.
344
345config BLK_DEV_IO_TRACE
346 bool "Support for tracing block IO actions"
347 depends on SYSFS
348 depends on BLOCK
349 select RELAY
350 select DEBUG_FS
351 select TRACEPOINTS
352 select GENERIC_TRACER
353 select STACKTRACE
354 help
355 Say Y here if you want to be able to trace the block layer actions
356 on a given queue. Tracing allows you to see any traffic happening
357 on a block device queue. For more information (and the userspace
358 support tools needed), fetch the blktrace tools from:
359
360 git://git.kernel.dk/blktrace.git
361
362 Tracing also is possible using the ftrace interface, e.g.:
363
364 echo 1 > /sys/block/sda/sda1/trace/enable
365 echo blk > /sys/kernel/debug/tracing/current_tracer
366 cat /sys/kernel/debug/tracing/trace_pipe
367
368 If unsure, say N.
369
370config KPROBE_EVENT
371 depends on KPROBES
372 depends on HAVE_REGS_AND_STACK_ACCESS_API
373 bool "Enable kprobes-based dynamic events"
374 select TRACING
375 select PROBE_EVENTS
376 default y
377 help
378 This allows the user to add tracing events (similar to tracepoints)
379 on the fly via the ftrace interface. See
380 Documentation/trace/kprobetrace.txt for more details.
381
382 Those events can be inserted wherever kprobes can probe, and record
383 various register and memory values.
384
385 This option is also required by perf-probe subcommand of perf tools.
386 If you want to use perf tools, this option is strongly recommended.
387
388config UPROBE_EVENT
389 bool "Enable uprobes-based dynamic events"
390 depends on ARCH_SUPPORTS_UPROBES
391 depends on MMU
392 select UPROBES
393 select PROBE_EVENTS
394 select TRACING
395 default n
396 help
397 This allows the user to add tracing events on top of userspace
398 dynamic events (similar to tracepoints) on the fly via the trace
399 events interface. Those events can be inserted wherever uprobes
400 can probe, and record various registers.
401 This option is required if you plan to use perf-probe subcommand
402 of perf tools on user space applications.
403
404config PROBE_EVENTS
405 def_bool n
406
407config DYNAMIC_FTRACE
408 bool "enable/disable ftrace tracepoints dynamically"
409 depends on FUNCTION_TRACER
410 depends on HAVE_DYNAMIC_FTRACE
411 default y
412 help
413 This option will modify all the calls to ftrace dynamically
414 (will patch them out of the binary image and replace them
415 with a No-Op instruction) as they are called. A table is
416 created to dynamically enable them again.
417
418 This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but
419 otherwise has native performance as long as no tracing is active.
420
421 The changes to the code are done by a kernel thread that
422 wakes up once a second and checks to see if any ftrace calls
423 were made. If so, it runs stop_machine (stops all CPUS)
424 and modifies the code to jump over the call to ftrace.
425
426config FUNCTION_PROFILER
427 bool "Kernel function profiler"
428 depends on FUNCTION_TRACER
429 default n
430 help
431 This option enables the kernel function profiler. A file is created
432 in debugfs called function_profile_enabled which defaults to zero.
433 When a 1 is echoed into this file profiling begins, and when a
434 zero is entered, profiling stops. A "functions" file is created in
435 the trace_stats directory; this file shows the list of functions that
436 have been hit and their counters.
437
438 If in doubt, say N.
439
440config FTRACE_MCOUNT_RECORD
441 def_bool y
442 depends on DYNAMIC_FTRACE
443 depends on HAVE_FTRACE_MCOUNT_RECORD
444
445config FTRACE_SELFTEST
446 bool
447
448config FTRACE_STARTUP_TEST
449 bool "Perform a startup test on ftrace"
450 depends on GENERIC_TRACER
451 select FTRACE_SELFTEST
452 help
453 This option performs a series of startup tests on ftrace. On bootup
454 a series of tests are made to verify that the tracer is
455 functioning properly. It will do tests on all the configured
456 tracers of ftrace.
457
458config EVENT_TRACE_TEST_SYSCALLS
459 bool "Run selftest on syscall events"
460 depends on FTRACE_STARTUP_TEST
461 help
462 This option will also enable testing every syscall event.
463 It only enables the event and disables it and runs various loads
464 with the event enabled. This adds a bit more time for kernel boot
465 up since it runs this on every system call defined.
466
467 TBD - enable a way to actually call the syscalls as we test their
468 events
469
470config MMIOTRACE
471 bool "Memory mapped IO tracing"
472 depends on HAVE_MMIOTRACE_SUPPORT && PCI
473 select GENERIC_TRACER
474 help
475 Mmiotrace traces Memory Mapped I/O access and is meant for
476 debugging and reverse engineering. It is called from the ioremap
477 implementation and works via page faults. Tracing is disabled by
478 default and can be enabled at run-time.
479
480 See Documentation/trace/mmiotrace.txt.
481 If you are not helping to develop drivers, say N.
482
483config MMIOTRACE_TEST
484 tristate "Test module for mmiotrace"
485 depends on MMIOTRACE && m
486 help
487 This is a dumb module for testing mmiotrace. It is very dangerous
488 as it will write garbage to IO memory starting at a given address.
489 However, it should be safe to use on e.g. unused portion of VRAM.
490
491 Say N, unless you absolutely know what you are doing.
492
493config RING_BUFFER_BENCHMARK
494 tristate "Ring buffer benchmark stress tester"
495 depends on RING_BUFFER
496 help
497 This option creates a test to stress the ring buffer and benchmark it.
498 It creates its own ring buffer such that it will not interfere with
499 any other users of the ring buffer (such as ftrace). It then creates
500 a producer and consumer that will run for 10 seconds and sleep for
501 10 seconds. Each interval it will print out the number of events
502 it recorded and give a rough estimate of how long each iteration took.
503
504 It does not disable interrupts or raise its priority, so it may be
505 affected by processes that are running.
506
507 If unsure, say N.
508
509endif # FTRACE
510
511endif # TRACING_SUPPORT
512
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_FUNCTION_GRAPH_FP_TEST
28 bool
29 help
30 See Documentation/trace/ftrace-design.txt
31
32config HAVE_DYNAMIC_FTRACE
33 bool
34 help
35 See Documentation/trace/ftrace-design.txt
36
37config HAVE_DYNAMIC_FTRACE_WITH_REGS
38 bool
39
40config HAVE_FTRACE_MCOUNT_RECORD
41 bool
42 help
43 See Documentation/trace/ftrace-design.txt
44
45config HAVE_SYSCALL_TRACEPOINTS
46 bool
47 help
48 See Documentation/trace/ftrace-design.txt
49
50config HAVE_FENTRY
51 bool
52 help
53 Arch supports the gcc options -pg with -mfentry
54
55config HAVE_C_RECORDMCOUNT
56 bool
57 help
58 C version of recordmcount available?
59
60config TRACER_MAX_TRACE
61 bool
62
63config TRACE_CLOCK
64 bool
65
66config RING_BUFFER
67 bool
68 select TRACE_CLOCK
69 select IRQ_WORK
70
71config FTRACE_NMI_ENTER
72 bool
73 depends on HAVE_FTRACE_NMI_ENTER
74 default y
75
76config EVENT_TRACING
77 select CONTEXT_SWITCH_TRACER
78 bool
79
80config CONTEXT_SWITCH_TRACER
81 bool
82
83config RING_BUFFER_ALLOW_SWAP
84 bool
85 help
86 Allow the use of ring_buffer_swap_cpu.
87 Adds a very slight overhead to tracing when enabled.
88
89# All tracer options should select GENERIC_TRACER. For those options that are
90# enabled by all tracers (context switch and event tracer) they select TRACING.
91# This allows those options to appear when no other tracer is selected. But the
92# options do not appear when something else selects it. We need the two options
93# GENERIC_TRACER and TRACING to avoid circular dependencies to accomplish the
94# hiding of the automatic options.
95
96config TRACING
97 bool
98 select DEBUG_FS
99 select RING_BUFFER
100 select STACKTRACE if STACKTRACE_SUPPORT
101 select TRACEPOINTS
102 select NOP_TRACER
103 select BINARY_PRINTF
104 select EVENT_TRACING
105 select TRACE_CLOCK
106
107config GENERIC_TRACER
108 bool
109 select TRACING
110
111#
112# Minimum requirements an architecture has to meet for us to
113# be able to offer generic tracing facilities:
114#
115config TRACING_SUPPORT
116 bool
117 # PPC32 has no irqflags tracing support, but it can use most of the
118 # tracers anyway, they were tested to build and work. Note that new
119 # exceptions to this list aren't welcomed, better implement the
120 # irqflags tracing for your architecture.
121 depends on TRACE_IRQFLAGS_SUPPORT || PPC32
122 depends on STACKTRACE_SUPPORT
123 default y
124
125if TRACING_SUPPORT
126
127menuconfig FTRACE
128 bool "Tracers"
129 default y if DEBUG_KERNEL
130 help
131 Enable the kernel tracing infrastructure.
132
133if FTRACE
134
135config FUNCTION_TRACER
136 bool "Kernel Function Tracer"
137 depends on HAVE_FUNCTION_TRACER
138 select KALLSYMS
139 select GENERIC_TRACER
140 select CONTEXT_SWITCH_TRACER
141 help
142 Enable the kernel to trace every kernel function. This is done
143 by using a compiler feature to insert a small, 5-byte No-Operation
144 instruction at the beginning of every kernel function, which NOP
145 sequence is then dynamically patched into a tracer call when
146 tracing is enabled by the administrator. If it's runtime disabled
147 (the bootup default), then the overhead of the instructions is very
148 small and not measurable even in micro-benchmarks.
149
150config FUNCTION_GRAPH_TRACER
151 bool "Kernel Function Graph Tracer"
152 depends on HAVE_FUNCTION_GRAPH_TRACER
153 depends on FUNCTION_TRACER
154 depends on !X86_32 || !CC_OPTIMIZE_FOR_SIZE
155 default y
156 help
157 Enable the kernel to trace a function at both its return
158 and its entry.
159 Its first purpose is to trace the duration of functions and
160 draw a call graph for each thread with some information like
161 the return value. This is done by setting the current return
162 address on the current task structure into a stack of calls.
163
164
165config IRQSOFF_TRACER
166 bool "Interrupts-off Latency Tracer"
167 default n
168 depends on TRACE_IRQFLAGS_SUPPORT
169 depends on !ARCH_USES_GETTIMEOFFSET
170 select TRACE_IRQFLAGS
171 select GENERIC_TRACER
172 select TRACER_MAX_TRACE
173 select RING_BUFFER_ALLOW_SWAP
174 select TRACER_SNAPSHOT
175 select TRACER_SNAPSHOT_PER_CPU_SWAP
176 help
177 This option measures the time spent in irqs-off critical
178 sections, with microsecond accuracy.
179
180 The default measurement method is a maximum search, which is
181 disabled by default and can be runtime (re-)started
182 via:
183
184 echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
185
186 (Note that kernel size and overhead increase with this option
187 enabled. This option and the preempt-off timing option can be
188 used together or separately.)
189
190config PREEMPT_TRACER
191 bool "Preemption-off Latency Tracer"
192 default n
193 depends on !ARCH_USES_GETTIMEOFFSET
194 depends on PREEMPT
195 select GENERIC_TRACER
196 select TRACER_MAX_TRACE
197 select RING_BUFFER_ALLOW_SWAP
198 select TRACER_SNAPSHOT
199 select TRACER_SNAPSHOT_PER_CPU_SWAP
200 help
201 This option measures the time spent in preemption-off critical
202 sections, with microsecond accuracy.
203
204 The default measurement method is a maximum search, which is
205 disabled by default and can be runtime (re-)started
206 via:
207
208 echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
209
210 (Note that kernel size and overhead increase with this option
211 enabled. This option and the irqs-off timing option can be
212 used together or separately.)
213
214config SCHED_TRACER
215 bool "Scheduling Latency Tracer"
216 select GENERIC_TRACER
217 select CONTEXT_SWITCH_TRACER
218 select TRACER_MAX_TRACE
219 select TRACER_SNAPSHOT
220 help
221 This tracer tracks the latency of the highest priority task
222 to be scheduled in, starting from the point it has woken up.
223
224config ENABLE_DEFAULT_TRACERS
225 bool "Trace process context switches and events"
226 depends on !GENERIC_TRACER
227 select TRACING
228 help
229 This tracer hooks to various trace points in the kernel,
230 allowing the user to pick and choose which trace point they
231 want to trace. It also includes the sched_switch tracer plugin.
232
233config FTRACE_SYSCALLS
234 bool "Trace syscalls"
235 depends on HAVE_SYSCALL_TRACEPOINTS
236 select GENERIC_TRACER
237 select KALLSYMS
238 help
239 Basic tracer to catch the syscall entry and exit events.
240
241config TRACER_SNAPSHOT
242 bool "Create a snapshot trace buffer"
243 select TRACER_MAX_TRACE
244 help
245 Allow tracing users to take snapshot of the current buffer using the
246 ftrace interface, e.g.:
247
248 echo 1 > /sys/kernel/debug/tracing/snapshot
249 cat snapshot
250
251config TRACER_SNAPSHOT_PER_CPU_SWAP
252 bool "Allow snapshot to swap per CPU"
253 depends on TRACER_SNAPSHOT
254 select RING_BUFFER_ALLOW_SWAP
255 help
256 Allow doing a snapshot of a single CPU buffer instead of a
257 full swap (all buffers). If this is set, then the following is
258 allowed:
259
260 echo 1 > /sys/kernel/debug/tracing/per_cpu/cpu2/snapshot
261
262 After which, only the tracing buffer for CPU 2 was swapped with
263 the main tracing buffer, and the other CPU buffers remain the same.
264
265 When this is enabled, this adds a little more overhead to the
266 trace recording, as it needs to add some checks to synchronize
267 recording with swaps. But this does not affect the performance
268 of the overall system. This is enabled by default when the preempt
269 or irq latency tracers are enabled, as those need to swap as well
270 and already adds the overhead (plus a lot more).
271
272config TRACE_BRANCH_PROFILING
273 bool
274 select GENERIC_TRACER
275
276choice
277 prompt "Branch Profiling"
278 default BRANCH_PROFILE_NONE
279 help
280 The branch profiling is a software profiler. It will add hooks
281 into the C conditionals to test which path a branch takes.
282
283 The likely/unlikely profiler only looks at the conditions that
284 are annotated with a likely or unlikely macro.
285
286 The "all branch" profiler will profile every if-statement in the
287 kernel. This profiler will also enable the likely/unlikely
288 profiler.
289
290 Either of the above profilers adds a bit of overhead to the system.
291 If unsure, choose "No branch profiling".
292
293config BRANCH_PROFILE_NONE
294 bool "No branch profiling"
295 help
296 No branch profiling. Branch profiling adds a bit of overhead.
297 Only enable it if you want to analyse the branching behavior.
298 Otherwise keep it disabled.
299
300config PROFILE_ANNOTATED_BRANCHES
301 bool "Trace likely/unlikely profiler"
302 select TRACE_BRANCH_PROFILING
303 help
304 This tracer profiles all likely and unlikely macros
305 in the kernel. It will display the results in:
306
307 /sys/kernel/debug/tracing/trace_stat/branch_annotated
308
309 Note: this will add a significant overhead; only turn this
310 on if you need to profile the system's use of these macros.
311
312config PROFILE_ALL_BRANCHES
313 bool "Profile all if conditionals"
314 select TRACE_BRANCH_PROFILING
315 help
316 This tracer profiles all branch conditions. Every if ()
317 taken in the kernel is recorded whether it hit or miss.
318 The results will be displayed in:
319
320 /sys/kernel/debug/tracing/trace_stat/branch_all
321
322 This option also enables the likely/unlikely profiler.
323
324 This configuration, when enabled, will impose a great overhead
325 on the system. This should only be enabled when the system
326 is to be analyzed in much detail.
327endchoice
328
329config TRACING_BRANCHES
330 bool
331 help
332 Selected by tracers that will trace the likely and unlikely
333 conditions. This prevents the tracers themselves from being
334 profiled. Profiling the tracing infrastructure can only happen
335 when the likelys and unlikelys are not being traced.
336
337config BRANCH_TRACER
338 bool "Trace likely/unlikely instances"
339 depends on TRACE_BRANCH_PROFILING
340 select TRACING_BRANCHES
341 help
342 This traces the events of likely and unlikely condition
343 calls in the kernel. The difference between this and the
344 "Trace likely/unlikely profiler" is that this is not a
345 histogram of the callers, but actually places the calling
346 events into a running trace buffer to see when and where the
347 events happened, as well as their results.
348
349 Say N if unsure.
350
351config STACK_TRACER
352 bool "Trace max stack"
353 depends on HAVE_FUNCTION_TRACER
354 select FUNCTION_TRACER
355 select STACKTRACE
356 select KALLSYMS
357 help
358 This special tracer records the maximum stack footprint of the
359 kernel and displays it in /sys/kernel/debug/tracing/stack_trace.
360
361 This tracer works by hooking into every function call that the
362 kernel executes, and keeping a maximum stack depth value and
363 stack-trace saved. If this is configured with DYNAMIC_FTRACE
364 then it will not have any overhead while the stack tracer
365 is disabled.
366
367 To enable the stack tracer on bootup, pass in 'stacktrace'
368 on the kernel command line.
369
370 The stack tracer can also be enabled or disabled via the
371 sysctl kernel.stack_tracer_enabled
372
373 Say N if unsure.
374
375config BLK_DEV_IO_TRACE
376 bool "Support for tracing block IO actions"
377 depends on SYSFS
378 depends on BLOCK
379 select RELAY
380 select DEBUG_FS
381 select TRACEPOINTS
382 select GENERIC_TRACER
383 select STACKTRACE
384 help
385 Say Y here if you want to be able to trace the block layer actions
386 on a given queue. Tracing allows you to see any traffic happening
387 on a block device queue. For more information (and the userspace
388 support tools needed), fetch the blktrace tools from:
389
390 git://git.kernel.dk/blktrace.git
391
392 Tracing also is possible using the ftrace interface, e.g.:
393
394 echo 1 > /sys/block/sda/sda1/trace/enable
395 echo blk > /sys/kernel/debug/tracing/current_tracer
396 cat /sys/kernel/debug/tracing/trace_pipe
397
398 If unsure, say N.
399
400config KPROBE_EVENT
401 depends on KPROBES
402 depends on HAVE_REGS_AND_STACK_ACCESS_API
403 bool "Enable kprobes-based dynamic events"
404 select TRACING
405 select PROBE_EVENTS
406 default y
407 help
408 This allows the user to add tracing events (similar to tracepoints)
409 on the fly via the ftrace interface. See
410 Documentation/trace/kprobetrace.txt for more details.
411
412 Those events can be inserted wherever kprobes can probe, and record
413 various register and memory values.
414
415 This option is also required by perf-probe subcommand of perf tools.
416 If you want to use perf tools, this option is strongly recommended.
417
418config UPROBE_EVENT
419 bool "Enable uprobes-based dynamic events"
420 depends on ARCH_SUPPORTS_UPROBES
421 depends on MMU
422 depends on PERF_EVENTS
423 select UPROBES
424 select PROBE_EVENTS
425 select TRACING
426 default n
427 help
428 This allows the user to add tracing events on top of userspace
429 dynamic events (similar to tracepoints) on the fly via the trace
430 events interface. Those events can be inserted wherever uprobes
431 can probe, and record various registers.
432 This option is required if you plan to use perf-probe subcommand
433 of perf tools on user space applications.
434
435config BPF_EVENTS
436 depends on BPF_SYSCALL
437 depends on (KPROBE_EVENT || UPROBE_EVENT) && PERF_EVENTS
438 bool
439 default y
440 help
441 This allows the user to attach BPF programs to kprobe events.
442
443config PROBE_EVENTS
444 def_bool n
445
446config DYNAMIC_FTRACE
447 bool "enable/disable function tracing dynamically"
448 depends on FUNCTION_TRACER
449 depends on HAVE_DYNAMIC_FTRACE
450 default y
451 help
452 This option will modify all the calls to function tracing
453 dynamically (will patch them out of the binary image and
454 replace them with a No-Op instruction) on boot up. During
455 compile time, a table is made of all the locations that ftrace
456 can function trace, and this table is linked into the kernel
457 image. When this is enabled, functions can be individually
458 enabled, and the functions not enabled will not affect
459 performance of the system.
460
461 See the files in /sys/kernel/debug/tracing:
462 available_filter_functions
463 set_ftrace_filter
464 set_ftrace_notrace
465
466 This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but
467 otherwise has native performance as long as no tracing is active.
468
469config DYNAMIC_FTRACE_WITH_REGS
470 def_bool y
471 depends on DYNAMIC_FTRACE
472 depends on HAVE_DYNAMIC_FTRACE_WITH_REGS
473
474config FUNCTION_PROFILER
475 bool "Kernel function profiler"
476 depends on FUNCTION_TRACER
477 default n
478 help
479 This option enables the kernel function profiler. A file is created
480 in debugfs called function_profile_enabled which defaults to zero.
481 When a 1 is echoed into this file profiling begins, and when a
482 zero is entered, profiling stops. A "functions" file is created in
483 the trace_stats directory; this file shows the list of functions that
484 have been hit and their counters.
485
486 If in doubt, say N.
487
488config FTRACE_MCOUNT_RECORD
489 def_bool y
490 depends on DYNAMIC_FTRACE
491 depends on HAVE_FTRACE_MCOUNT_RECORD
492
493config FTRACE_SELFTEST
494 bool
495
496config FTRACE_STARTUP_TEST
497 bool "Perform a startup test on ftrace"
498 depends on GENERIC_TRACER
499 select FTRACE_SELFTEST
500 help
501 This option performs a series of startup tests on ftrace. On bootup
502 a series of tests are made to verify that the tracer is
503 functioning properly. It will do tests on all the configured
504 tracers of ftrace.
505
506config EVENT_TRACE_TEST_SYSCALLS
507 bool "Run selftest on syscall events"
508 depends on FTRACE_STARTUP_TEST
509 help
510 This option will also enable testing every syscall event.
511 It only enables the event and disables it and runs various loads
512 with the event enabled. This adds a bit more time for kernel boot
513 up since it runs this on every system call defined.
514
515 TBD - enable a way to actually call the syscalls as we test their
516 events
517
518config MMIOTRACE
519 bool "Memory mapped IO tracing"
520 depends on HAVE_MMIOTRACE_SUPPORT && PCI
521 select GENERIC_TRACER
522 help
523 Mmiotrace traces Memory Mapped I/O access and is meant for
524 debugging and reverse engineering. It is called from the ioremap
525 implementation and works via page faults. Tracing is disabled by
526 default and can be enabled at run-time.
527
528 See Documentation/trace/mmiotrace.txt.
529 If you are not helping to develop drivers, say N.
530
531config MMIOTRACE_TEST
532 tristate "Test module for mmiotrace"
533 depends on MMIOTRACE && m
534 help
535 This is a dumb module for testing mmiotrace. It is very dangerous
536 as it will write garbage to IO memory starting at a given address.
537 However, it should be safe to use on e.g. unused portion of VRAM.
538
539 Say N, unless you absolutely know what you are doing.
540
541config TRACEPOINT_BENCHMARK
542 bool "Add tracepoint that benchmarks tracepoints"
543 help
544 This option creates the tracepoint "benchmark:benchmark_event".
545 When the tracepoint is enabled, it kicks off a kernel thread that
546 goes into an infinite loop (calling cond_sched() to let other tasks
547 run), and calls the tracepoint. Each iteration will record the time
548 it took to write to the tracepoint and the next iteration that
549 data will be passed to the tracepoint itself. That is, the tracepoint
550 will report the time it took to do the previous tracepoint.
551 The string written to the tracepoint is a static string of 128 bytes
552 to keep the time the same. The initial string is simply a write of
553 "START". The second string records the cold cache time of the first
554 write which is not added to the rest of the calculations.
555
556 As it is a tight loop, it benchmarks as hot cache. That's fine because
557 we care most about hot paths that are probably in cache already.
558
559 An example of the output:
560
561 START
562 first=3672 [COLD CACHED]
563 last=632 first=3672 max=632 min=632 avg=316 std=446 std^2=199712
564 last=278 first=3672 max=632 min=278 avg=303 std=316 std^2=100337
565 last=277 first=3672 max=632 min=277 avg=296 std=258 std^2=67064
566 last=273 first=3672 max=632 min=273 avg=292 std=224 std^2=50411
567 last=273 first=3672 max=632 min=273 avg=288 std=200 std^2=40389
568 last=281 first=3672 max=632 min=273 avg=287 std=183 std^2=33666
569
570
571config RING_BUFFER_BENCHMARK
572 tristate "Ring buffer benchmark stress tester"
573 depends on RING_BUFFER
574 help
575 This option creates a test to stress the ring buffer and benchmark it.
576 It creates its own ring buffer such that it will not interfere with
577 any other users of the ring buffer (such as ftrace). It then creates
578 a producer and consumer that will run for 10 seconds and sleep for
579 10 seconds. Each interval it will print out the number of events
580 it recorded and give a rough estimate of how long each iteration took.
581
582 It does not disable interrupts or raise its priority, so it may be
583 affected by processes that are running.
584
585 If unsure, say N.
586
587config RING_BUFFER_STARTUP_TEST
588 bool "Ring buffer startup self test"
589 depends on RING_BUFFER
590 help
591 Run a simple self test on the ring buffer on boot up. Late in the
592 kernel boot sequence, the test will start that kicks off
593 a thread per cpu. Each thread will write various size events
594 into the ring buffer. Another thread is created to send IPIs
595 to each of the threads, where the IPI handler will also write
596 to the ring buffer, to test/stress the nesting ability.
597 If any anomalies are discovered, a warning will be displayed
598 and all ring buffers will be disabled.
599
600 The test runs for 10 seconds. This will slow your boot time
601 by at least 10 more seconds.
602
603 At the end of the test, statics and more checks are done.
604 It will output the stats of each per cpu buffer. What
605 was written, the sizes, what was read, what was lost, and
606 other similar details.
607
608 If unsure, say N
609
610config TRACE_ENUM_MAP_FILE
611 bool "Show enum mappings for trace events"
612 depends on TRACING
613 help
614 The "print fmt" of the trace events will show the enum names instead
615 of their values. This can cause problems for user space tools that
616 use this string to parse the raw data as user space does not know
617 how to convert the string to its value.
618
619 To fix this, there's a special macro in the kernel that can be used
620 to convert the enum into its value. If this macro is used, then the
621 print fmt strings will have the enums converted to their values.
622
623 If something does not get converted properly, this option can be
624 used to show what enums the kernel tried to convert.
625
626 This option is for debugging the enum conversions. A file is created
627 in the tracing directory called "enum_map" that will show the enum
628 names matched with their values and what trace event system they
629 belong too.
630
631 Normally, the mapping of the strings to values will be freed after
632 boot up or module load. With this option, they will not be freed, as
633 they are needed for the "enum_map" file. Enabling this option will
634 increase the memory footprint of the running kernel.
635
636 If unsure, say N
637
638config TRACING_EVENTS_GPIO
639 bool "Trace gpio events"
640 depends on GPIOLIB
641 default y
642 help
643 Enable tracing events for gpio subsystem
644
645endif # FTRACE
646
647endif # TRACING_SUPPORT
648