Commit | Line | Data |
---|---|---|
16444a8a | 1 | # |
606576ce SR |
2 | # Architectures that offer an FUNCTION_TRACER implementation should |
3 | # select HAVE_FUNCTION_TRACER: | |
16444a8a | 4 | # |
2a3a4f66 | 5 | |
8d26487f TE |
6 | config USER_STACKTRACE_SUPPORT |
7 | bool | |
8 | ||
2a3a4f66 FW |
9 | config NOP_TRACER |
10 | bool | |
11 | ||
78d904b4 SR |
12 | config HAVE_FTRACE_NMI_ENTER |
13 | bool | |
555f386c | 14 | help |
40892367 | 15 | See Documentation/trace/ftrace-design.txt |
78d904b4 | 16 | |
606576ce | 17 | config HAVE_FUNCTION_TRACER |
16444a8a | 18 | bool |
555f386c | 19 | help |
40892367 | 20 | See Documentation/trace/ftrace-design.txt |
bc0c38d1 | 21 | |
fb52607a | 22 | config HAVE_FUNCTION_GRAPH_TRACER |
15e6cb36 | 23 | bool |
555f386c | 24 | help |
40892367 | 25 | See Documentation/trace/ftrace-design.txt |
15e6cb36 | 26 | |
677aa9f7 SR |
27 | config HAVE_DYNAMIC_FTRACE |
28 | bool | |
555f386c | 29 | help |
40892367 | 30 | See Documentation/trace/ftrace-design.txt |
677aa9f7 | 31 | |
06aeaaea MH |
32 | config HAVE_DYNAMIC_FTRACE_WITH_REGS |
33 | bool | |
34 | ||
8da3821b SR |
35 | config HAVE_FTRACE_MCOUNT_RECORD |
36 | bool | |
555f386c | 37 | help |
40892367 | 38 | See Documentation/trace/ftrace-design.txt |
8da3821b | 39 | |
66700001 | 40 | config HAVE_SYSCALL_TRACEPOINTS |
ee08c6ec | 41 | bool |
555f386c | 42 | help |
40892367 | 43 | See Documentation/trace/ftrace-design.txt |
ee08c6ec | 44 | |
a2546fae SR |
45 | config HAVE_FENTRY |
46 | bool | |
47 | help | |
48 | Arch supports the gcc options -pg with -mfentry | |
49 | ||
cf4db259 | 50 | config HAVE_C_RECORDMCOUNT |
72441cb1 SR |
51 | bool |
52 | help | |
53 | C version of recordmcount available? | |
54 | ||
352ad25a SR |
55 | config TRACER_MAX_TRACE |
56 | bool | |
57 | ||
ea632e9f JT |
58 | config TRACE_CLOCK |
59 | bool | |
60 | ||
7a8e76a3 SR |
61 | config RING_BUFFER |
62 | bool | |
ea632e9f | 63 | select TRACE_CLOCK |
22287688 | 64 | select IRQ_WORK |
7a8e76a3 | 65 | |
78d904b4 SR |
66 | config FTRACE_NMI_ENTER |
67 | bool | |
68 | depends on HAVE_FTRACE_NMI_ENTER | |
69 | default y | |
70 | ||
5f77a88b | 71 | config EVENT_TRACING |
b11c53e1 | 72 | select CONTEXT_SWITCH_TRACER |
60f1d5e3 | 73 | select GLOB |
b11c53e1 Z |
74 | bool |
75 | ||
76 | config CONTEXT_SWITCH_TRACER | |
5f77a88b TZ |
77 | bool |
78 | ||
85bac32c SR |
79 | config 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 | ||
5e0a0939 SR |
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 | |
40892367 | 90 | # hiding of the automatic options. |
5e0a0939 | 91 | |
bc0c38d1 SR |
92 | config TRACING |
93 | bool | |
94 | select DEBUG_FS | |
7a8e76a3 | 95 | select RING_BUFFER |
c2c80529 | 96 | select STACKTRACE if STACKTRACE_SUPPORT |
5f87f112 | 97 | select TRACEPOINTS |
f3384b28 | 98 | select NOP_TRACER |
769b0441 | 99 | select BINARY_PRINTF |
5f77a88b | 100 | select EVENT_TRACING |
ea632e9f | 101 | select TRACE_CLOCK |
bc0c38d1 | 102 | |
5e0a0939 SR |
103 | config GENERIC_TRACER |
104 | bool | |
105 | select TRACING | |
106 | ||
40ada30f IM |
107 | # |
108 | # Minimum requirements an architecture has to meet for us to | |
109 | # be able to offer generic tracing facilities: | |
110 | # | |
111 | config TRACING_SUPPORT | |
112 | bool | |
0ea5ee03 | 113 | depends on TRACE_IRQFLAGS_SUPPORT |
40ada30f | 114 | depends on STACKTRACE_SUPPORT |
422d3c7a | 115 | default y |
40ada30f IM |
116 | |
117 | if TRACING_SUPPORT | |
118 | ||
4ed9f071 SR |
119 | menuconfig FTRACE |
120 | bool "Tracers" | |
65b77242 | 121 | default y if DEBUG_KERNEL |
4ed9f071 | 122 | help |
40892367 | 123 | Enable the kernel tracing infrastructure. |
4ed9f071 SR |
124 | |
125 | if FTRACE | |
17d80fd0 | 126 | |
606576ce | 127 | config FUNCTION_TRACER |
1b29b018 | 128 | bool "Kernel Function Tracer" |
606576ce | 129 | depends on HAVE_FUNCTION_TRACER |
4d7a077c | 130 | select KALLSYMS |
5e0a0939 | 131 | select GENERIC_TRACER |
35e8e302 | 132 | select CONTEXT_SWITCH_TRACER |
0598e4f0 SRV |
133 | select GLOB |
134 | select TASKS_RCU if PREEMPT | |
1b29b018 SR |
135 | help |
136 | Enable the kernel to trace every kernel function. This is done | |
137 | by using a compiler feature to insert a small, 5-byte No-Operation | |
40892367 | 138 | instruction at the beginning of every kernel function, which NOP |
1b29b018 SR |
139 | sequence is then dynamically patched into a tracer call when |
140 | tracing is enabled by the administrator. If it's runtime disabled | |
141 | (the bootup default), then the overhead of the instructions is very | |
142 | small and not measurable even in micro-benchmarks. | |
35e8e302 | 143 | |
fb52607a FW |
144 | config FUNCTION_GRAPH_TRACER |
145 | bool "Kernel Function Graph Tracer" | |
146 | depends on HAVE_FUNCTION_GRAPH_TRACER | |
15e6cb36 | 147 | depends on FUNCTION_TRACER |
eb4a0378 | 148 | depends on !X86_32 || !CC_OPTIMIZE_FOR_SIZE |
764f3b95 | 149 | default y |
15e6cb36 | 150 | help |
fb52607a FW |
151 | Enable the kernel to trace a function at both its return |
152 | and its entry. | |
692105b8 ML |
153 | Its first purpose is to trace the duration of functions and |
154 | draw a call graph for each thread with some information like | |
40892367 | 155 | the return value. This is done by setting the current return |
692105b8 | 156 | address on the current task structure into a stack of calls. |
15e6cb36 | 157 | |
bac429f0 | 158 | |
d5915816 JF |
159 | config PREEMPTIRQ_EVENTS |
160 | bool "Enable trace events for preempt and irq disable/enable" | |
161 | select TRACE_IRQFLAGS | |
162 | depends on DEBUG_PREEMPT || !PROVE_LOCKING | |
2dde6b00 | 163 | depends on TRACING |
d5915816 JF |
164 | default n |
165 | help | |
166 | Enable tracing of disable and enable events for preemption and irqs. | |
167 | For tracing preempt disable/enable events, DEBUG_PREEMPT must be | |
168 | enabled. For tracing irq disable/enable events, PROVE_LOCKING must | |
169 | be disabled. | |
170 | ||
81d68a96 SR |
171 | config IRQSOFF_TRACER |
172 | bool "Interrupts-off Latency Tracer" | |
173 | default n | |
174 | depends on TRACE_IRQFLAGS_SUPPORT | |
592913ec | 175 | depends on !ARCH_USES_GETTIMEOFFSET |
81d68a96 | 176 | select TRACE_IRQFLAGS |
5e0a0939 | 177 | select GENERIC_TRACER |
81d68a96 | 178 | select TRACER_MAX_TRACE |
85bac32c | 179 | select RING_BUFFER_ALLOW_SWAP |
22cffc2b | 180 | select TRACER_SNAPSHOT |
0b85ffc2 | 181 | select TRACER_SNAPSHOT_PER_CPU_SWAP |
81d68a96 SR |
182 | help |
183 | This option measures the time spent in irqs-off critical | |
184 | sections, with microsecond accuracy. | |
185 | ||
186 | The default measurement method is a maximum search, which is | |
187 | disabled by default and can be runtime (re-)started | |
188 | via: | |
189 | ||
156f5a78 | 190 | echo 0 > /sys/kernel/debug/tracing/tracing_max_latency |
81d68a96 | 191 | |
40892367 | 192 | (Note that kernel size and overhead increase with this option |
6cd8a4bb SR |
193 | enabled. This option and the preempt-off timing option can be |
194 | used together or separately.) | |
195 | ||
196 | config PREEMPT_TRACER | |
197 | bool "Preemption-off Latency Tracer" | |
198 | default n | |
592913ec | 199 | depends on !ARCH_USES_GETTIMEOFFSET |
6cd8a4bb | 200 | depends on PREEMPT |
5e0a0939 | 201 | select GENERIC_TRACER |
6cd8a4bb | 202 | select TRACER_MAX_TRACE |
85bac32c | 203 | select RING_BUFFER_ALLOW_SWAP |
22cffc2b | 204 | select TRACER_SNAPSHOT |
0b85ffc2 | 205 | select TRACER_SNAPSHOT_PER_CPU_SWAP |
6cd8a4bb | 206 | help |
40892367 | 207 | This option measures the time spent in preemption-off critical |
6cd8a4bb SR |
208 | sections, with microsecond accuracy. |
209 | ||
210 | The default measurement method is a maximum search, which is | |
211 | disabled by default and can be runtime (re-)started | |
212 | via: | |
213 | ||
156f5a78 | 214 | echo 0 > /sys/kernel/debug/tracing/tracing_max_latency |
6cd8a4bb | 215 | |
40892367 | 216 | (Note that kernel size and overhead increase with this option |
6cd8a4bb SR |
217 | enabled. This option and the irqs-off timing option can be |
218 | used together or separately.) | |
219 | ||
352ad25a SR |
220 | config SCHED_TRACER |
221 | bool "Scheduling Latency Tracer" | |
5e0a0939 | 222 | select GENERIC_TRACER |
352ad25a SR |
223 | select CONTEXT_SWITCH_TRACER |
224 | select TRACER_MAX_TRACE | |
22cffc2b | 225 | select TRACER_SNAPSHOT |
352ad25a SR |
226 | help |
227 | This tracer tracks the latency of the highest priority task | |
228 | to be scheduled in, starting from the point it has woken up. | |
229 | ||
e7c15cd8 SRRH |
230 | config HWLAT_TRACER |
231 | bool "Tracer to detect hardware latencies (like SMIs)" | |
232 | select GENERIC_TRACER | |
233 | help | |
234 | This tracer, when enabled will create one or more kernel threads, | |
c5c1ea75 | 235 | depending on what the cpumask file is set to, which each thread |
e7c15cd8 SRRH |
236 | spinning in a loop looking for interruptions caused by |
237 | something other than the kernel. For example, if a | |
238 | System Management Interrupt (SMI) takes a noticeable amount of | |
239 | time, this tracer will detect it. This is useful for testing | |
240 | if a system is reliable for Real Time tasks. | |
241 | ||
242 | Some files are created in the tracing directory when this | |
243 | is enabled: | |
244 | ||
245 | hwlat_detector/width - time in usecs for how long to spin for | |
246 | hwlat_detector/window - time in usecs between the start of each | |
247 | iteration | |
248 | ||
249 | A kernel thread is created that will spin with interrupts disabled | |
c5c1ea75 | 250 | for "width" microseconds in every "window" cycle. It will not spin |
e7c15cd8 SRRH |
251 | for "window - width" microseconds, where the system can |
252 | continue to operate. | |
253 | ||
254 | The output will appear in the trace and trace_pipe files. | |
255 | ||
256 | When the tracer is not running, it has no affect on the system, | |
257 | but when it is running, it can cause the system to be | |
258 | periodically non responsive. Do not run this tracer on a | |
259 | production system. | |
260 | ||
261 | To enable this tracer, echo in "hwlat" into the current_tracer | |
262 | file. Every time a latency is greater than tracing_thresh, it will | |
263 | be recorded into the ring buffer. | |
264 | ||
897f17a6 SR |
265 | config ENABLE_DEFAULT_TRACERS |
266 | bool "Trace process context switches and events" | |
5e0a0939 | 267 | depends on !GENERIC_TRACER |
b77e38aa SR |
268 | select TRACING |
269 | help | |
40892367 | 270 | This tracer hooks to various trace points in the kernel, |
b77e38aa | 271 | allowing the user to pick and choose which trace point they |
897f17a6 | 272 | want to trace. It also includes the sched_switch tracer plugin. |
a7abe97f | 273 | |
ee08c6ec FW |
274 | config FTRACE_SYSCALLS |
275 | bool "Trace syscalls" | |
66700001 | 276 | depends on HAVE_SYSCALL_TRACEPOINTS |
5e0a0939 | 277 | select GENERIC_TRACER |
0ea1c415 | 278 | select KALLSYMS |
ee08c6ec FW |
279 | help |
280 | Basic tracer to catch the syscall entry and exit events. | |
281 | ||
debdd57f HT |
282 | config TRACER_SNAPSHOT |
283 | bool "Create a snapshot trace buffer" | |
284 | select TRACER_MAX_TRACE | |
285 | help | |
286 | Allow tracing users to take snapshot of the current buffer using the | |
287 | ftrace interface, e.g.: | |
288 | ||
289 | echo 1 > /sys/kernel/debug/tracing/snapshot | |
290 | cat snapshot | |
291 | ||
0b85ffc2 SRRH |
292 | config TRACER_SNAPSHOT_PER_CPU_SWAP |
293 | bool "Allow snapshot to swap per CPU" | |
294 | depends on TRACER_SNAPSHOT | |
295 | select RING_BUFFER_ALLOW_SWAP | |
296 | help | |
297 | Allow doing a snapshot of a single CPU buffer instead of a | |
298 | full swap (all buffers). If this is set, then the following is | |
299 | allowed: | |
300 | ||
301 | echo 1 > /sys/kernel/debug/tracing/per_cpu/cpu2/snapshot | |
302 | ||
303 | After which, only the tracing buffer for CPU 2 was swapped with | |
304 | the main tracing buffer, and the other CPU buffers remain the same. | |
305 | ||
306 | When this is enabled, this adds a little more overhead to the | |
307 | trace recording, as it needs to add some checks to synchronize | |
308 | recording with swaps. But this does not affect the performance | |
309 | of the overall system. This is enabled by default when the preempt | |
310 | or irq latency tracers are enabled, as those need to swap as well | |
311 | and already adds the overhead (plus a lot more). | |
312 | ||
2ed84eeb | 313 | config TRACE_BRANCH_PROFILING |
9ae5b879 | 314 | bool |
5e0a0939 | 315 | select GENERIC_TRACER |
9ae5b879 SR |
316 | |
317 | choice | |
318 | prompt "Branch Profiling" | |
319 | default BRANCH_PROFILE_NONE | |
320 | help | |
321 | The branch profiling is a software profiler. It will add hooks | |
322 | into the C conditionals to test which path a branch takes. | |
323 | ||
324 | The likely/unlikely profiler only looks at the conditions that | |
325 | are annotated with a likely or unlikely macro. | |
326 | ||
40892367 | 327 | The "all branch" profiler will profile every if-statement in the |
9ae5b879 | 328 | kernel. This profiler will also enable the likely/unlikely |
40892367 | 329 | profiler. |
9ae5b879 | 330 | |
40892367 RD |
331 | Either of the above profilers adds a bit of overhead to the system. |
332 | If unsure, choose "No branch profiling". | |
9ae5b879 SR |
333 | |
334 | config BRANCH_PROFILE_NONE | |
335 | bool "No branch profiling" | |
336 | help | |
40892367 RD |
337 | No branch profiling. Branch profiling adds a bit of overhead. |
338 | Only enable it if you want to analyse the branching behavior. | |
339 | Otherwise keep it disabled. | |
9ae5b879 SR |
340 | |
341 | config PROFILE_ANNOTATED_BRANCHES | |
342 | bool "Trace likely/unlikely profiler" | |
343 | select TRACE_BRANCH_PROFILING | |
1f0d69a9 | 344 | help |
59bf8964 | 345 | This tracer profiles all likely and unlikely macros |
1f0d69a9 SR |
346 | in the kernel. It will display the results in: |
347 | ||
13e5befa | 348 | /sys/kernel/debug/tracing/trace_stat/branch_annotated |
1f0d69a9 | 349 | |
40892367 | 350 | Note: this will add a significant overhead; only turn this |
1f0d69a9 SR |
351 | on if you need to profile the system's use of these macros. |
352 | ||
2bcd521a | 353 | config PROFILE_ALL_BRANCHES |
68e76e03 | 354 | bool "Profile all if conditionals" if !FORTIFY_SOURCE |
9ae5b879 | 355 | select TRACE_BRANCH_PROFILING |
2bcd521a SR |
356 | help |
357 | This tracer profiles all branch conditions. Every if () | |
358 | taken in the kernel is recorded whether it hit or miss. | |
359 | The results will be displayed in: | |
360 | ||
13e5befa | 361 | /sys/kernel/debug/tracing/trace_stat/branch_all |
2bcd521a | 362 | |
9ae5b879 SR |
363 | This option also enables the likely/unlikely profiler. |
364 | ||
2bcd521a SR |
365 | This configuration, when enabled, will impose a great overhead |
366 | on the system. This should only be enabled when the system | |
40892367 | 367 | is to be analyzed in much detail. |
9ae5b879 | 368 | endchoice |
2bcd521a | 369 | |
2ed84eeb | 370 | config TRACING_BRANCHES |
52f232cb SR |
371 | bool |
372 | help | |
373 | Selected by tracers that will trace the likely and unlikely | |
374 | conditions. This prevents the tracers themselves from being | |
375 | profiled. Profiling the tracing infrastructure can only happen | |
376 | when the likelys and unlikelys are not being traced. | |
377 | ||
2ed84eeb | 378 | config BRANCH_TRACER |
52f232cb | 379 | bool "Trace likely/unlikely instances" |
2ed84eeb SR |
380 | depends on TRACE_BRANCH_PROFILING |
381 | select TRACING_BRANCHES | |
52f232cb SR |
382 | help |
383 | This traces the events of likely and unlikely condition | |
384 | calls in the kernel. The difference between this and the | |
385 | "Trace likely/unlikely profiler" is that this is not a | |
386 | histogram of the callers, but actually places the calling | |
387 | events into a running trace buffer to see when and where the | |
388 | events happened, as well as their results. | |
389 | ||
390 | Say N if unsure. | |
391 | ||
e5a81b62 SR |
392 | config STACK_TRACER |
393 | bool "Trace max stack" | |
606576ce | 394 | depends on HAVE_FUNCTION_TRACER |
606576ce | 395 | select FUNCTION_TRACER |
e5a81b62 | 396 | select STACKTRACE |
4d7a077c | 397 | select KALLSYMS |
e5a81b62 | 398 | help |
4519d9e5 | 399 | This special tracer records the maximum stack footprint of the |
156f5a78 | 400 | kernel and displays it in /sys/kernel/debug/tracing/stack_trace. |
4519d9e5 IM |
401 | |
402 | This tracer works by hooking into every function call that the | |
403 | kernel executes, and keeping a maximum stack depth value and | |
f38f1d2a SR |
404 | stack-trace saved. If this is configured with DYNAMIC_FTRACE |
405 | then it will not have any overhead while the stack tracer | |
406 | is disabled. | |
407 | ||
408 | To enable the stack tracer on bootup, pass in 'stacktrace' | |
409 | on the kernel command line. | |
410 | ||
411 | The stack tracer can also be enabled or disabled via the | |
412 | sysctl kernel.stack_tracer_enabled | |
4519d9e5 IM |
413 | |
414 | Say N if unsure. | |
e5a81b62 | 415 | |
2db270a8 | 416 | config BLK_DEV_IO_TRACE |
40892367 | 417 | bool "Support for tracing block IO actions" |
2db270a8 | 418 | depends on SYSFS |
1dfba05d | 419 | depends on BLOCK |
2db270a8 FW |
420 | select RELAY |
421 | select DEBUG_FS | |
422 | select TRACEPOINTS | |
5e0a0939 | 423 | select GENERIC_TRACER |
2db270a8 FW |
424 | select STACKTRACE |
425 | help | |
426 | Say Y here if you want to be able to trace the block layer actions | |
427 | on a given queue. Tracing allows you to see any traffic happening | |
428 | on a block device queue. For more information (and the userspace | |
429 | support tools needed), fetch the blktrace tools from: | |
430 | ||
431 | git://git.kernel.dk/blktrace.git | |
432 | ||
433 | Tracing also is possible using the ftrace interface, e.g.: | |
434 | ||
435 | echo 1 > /sys/block/sda/sda1/trace/enable | |
436 | echo blk > /sys/kernel/debug/tracing/current_tracer | |
437 | cat /sys/kernel/debug/tracing/trace_pipe | |
438 | ||
439 | If unsure, say N. | |
36994e58 | 440 | |
6b0b7551 | 441 | config KPROBE_EVENTS |
413d37d1 | 442 | depends on KPROBES |
f850c30c | 443 | depends on HAVE_REGS_AND_STACK_ACCESS_API |
77b44d1b | 444 | bool "Enable kprobes-based dynamic events" |
413d37d1 | 445 | select TRACING |
8ab83f56 | 446 | select PROBE_EVENTS |
77b44d1b | 447 | default y |
413d37d1 | 448 | help |
40892367 RD |
449 | This allows the user to add tracing events (similar to tracepoints) |
450 | on the fly via the ftrace interface. See | |
451 | Documentation/trace/kprobetrace.txt for more details. | |
77b44d1b MH |
452 | |
453 | Those events can be inserted wherever kprobes can probe, and record | |
454 | various register and memory values. | |
455 | ||
40892367 RD |
456 | This option is also required by perf-probe subcommand of perf tools. |
457 | If you want to use perf tools, this option is strongly recommended. | |
413d37d1 | 458 | |
6b0b7551 | 459 | config UPROBE_EVENTS |
f3f096cf SD |
460 | bool "Enable uprobes-based dynamic events" |
461 | depends on ARCH_SUPPORTS_UPROBES | |
462 | depends on MMU | |
09294e31 | 463 | depends on PERF_EVENTS |
f3f096cf SD |
464 | select UPROBES |
465 | select PROBE_EVENTS | |
466 | select TRACING | |
61f35d75 | 467 | default y |
f3f096cf SD |
468 | help |
469 | This allows the user to add tracing events on top of userspace | |
470 | dynamic events (similar to tracepoints) on the fly via the trace | |
471 | events interface. Those events can be inserted wherever uprobes | |
472 | can probe, and record various registers. | |
473 | This option is required if you plan to use perf-probe subcommand | |
474 | of perf tools on user space applications. | |
475 | ||
e1abf2cc IM |
476 | config BPF_EVENTS |
477 | depends on BPF_SYSCALL | |
6b0b7551 | 478 | depends on (KPROBE_EVENTS || UPROBE_EVENTS) && PERF_EVENTS |
e1abf2cc IM |
479 | bool |
480 | default y | |
481 | help | |
482 | This allows the user to attach BPF programs to kprobe events. | |
483 | ||
8ab83f56 SD |
484 | config PROBE_EVENTS |
485 | def_bool n | |
486 | ||
3d083395 | 487 | config DYNAMIC_FTRACE |
db05021d | 488 | bool "enable/disable function tracing dynamically" |
606576ce | 489 | depends on FUNCTION_TRACER |
677aa9f7 | 490 | depends on HAVE_DYNAMIC_FTRACE |
3d083395 SR |
491 | default y |
492 | help | |
db05021d SR |
493 | This option will modify all the calls to function tracing |
494 | dynamically (will patch them out of the binary image and | |
495 | replace them with a No-Op instruction) on boot up. During | |
496 | compile time, a table is made of all the locations that ftrace | |
497 | can function trace, and this table is linked into the kernel | |
498 | image. When this is enabled, functions can be individually | |
499 | enabled, and the functions not enabled will not affect | |
500 | performance of the system. | |
501 | ||
502 | See the files in /sys/kernel/debug/tracing: | |
503 | available_filter_functions | |
504 | set_ftrace_filter | |
505 | set_ftrace_notrace | |
3d083395 | 506 | |
40892367 RD |
507 | This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but |
508 | otherwise has native performance as long as no tracing is active. | |
3d083395 | 509 | |
06aeaaea MH |
510 | config DYNAMIC_FTRACE_WITH_REGS |
511 | def_bool y | |
512 | depends on DYNAMIC_FTRACE | |
513 | depends on HAVE_DYNAMIC_FTRACE_WITH_REGS | |
514 | ||
bac429f0 SR |
515 | config FUNCTION_PROFILER |
516 | bool "Kernel function profiler" | |
493762fc | 517 | depends on FUNCTION_TRACER |
bac429f0 SR |
518 | default n |
519 | help | |
40892367 RD |
520 | This option enables the kernel function profiler. A file is created |
521 | in debugfs called function_profile_enabled which defaults to zero. | |
522 | When a 1 is echoed into this file profiling begins, and when a | |
523 | zero is entered, profiling stops. A "functions" file is created in | |
524 | the trace_stats directory; this file shows the list of functions that | |
525 | have been hit and their counters. | |
bac429f0 | 526 | |
40892367 | 527 | If in doubt, say N. |
bac429f0 | 528 | |
9802d865 JB |
529 | config BPF_KPROBE_OVERRIDE |
530 | bool "Enable BPF programs to override a kprobed function" | |
531 | depends on BPF_EVENTS | |
540adea3 | 532 | depends on FUNCTION_ERROR_INJECTION |
9802d865 JB |
533 | default n |
534 | help | |
535 | Allows BPF to override the execution of a probed function and | |
536 | set a different return value. This is used for error injection. | |
537 | ||
8da3821b SR |
538 | config FTRACE_MCOUNT_RECORD |
539 | def_bool y | |
540 | depends on DYNAMIC_FTRACE | |
541 | depends on HAVE_FTRACE_MCOUNT_RECORD | |
542 | ||
60a11774 SR |
543 | config FTRACE_SELFTEST |
544 | bool | |
545 | ||
546 | config FTRACE_STARTUP_TEST | |
547 | bool "Perform a startup test on ftrace" | |
5e0a0939 | 548 | depends on GENERIC_TRACER |
60a11774 SR |
549 | select FTRACE_SELFTEST |
550 | help | |
551 | This option performs a series of startup tests on ftrace. On bootup | |
552 | a series of tests are made to verify that the tracer is | |
553 | functioning properly. It will do tests on all the configured | |
554 | tracers of ftrace. | |
17d80fd0 | 555 | |
1f5a6b45 SR |
556 | config EVENT_TRACE_TEST_SYSCALLS |
557 | bool "Run selftest on syscall events" | |
558 | depends on FTRACE_STARTUP_TEST | |
559 | help | |
560 | This option will also enable testing every syscall event. | |
561 | It only enables the event and disables it and runs various loads | |
562 | with the event enabled. This adds a bit more time for kernel boot | |
563 | up since it runs this on every system call defined. | |
564 | ||
565 | TBD - enable a way to actually call the syscalls as we test their | |
566 | events | |
567 | ||
fe6f90e5 PP |
568 | config MMIOTRACE |
569 | bool "Memory mapped IO tracing" | |
40ada30f | 570 | depends on HAVE_MMIOTRACE_SUPPORT && PCI |
5e0a0939 | 571 | select GENERIC_TRACER |
fe6f90e5 PP |
572 | help |
573 | Mmiotrace traces Memory Mapped I/O access and is meant for | |
574 | debugging and reverse engineering. It is called from the ioremap | |
575 | implementation and works via page faults. Tracing is disabled by | |
576 | default and can be enabled at run-time. | |
577 | ||
4d1f4372 | 578 | See Documentation/trace/mmiotrace.txt. |
fe6f90e5 PP |
579 | If you are not helping to develop drivers, say N. |
580 | ||
08d43a5f TZ |
581 | config TRACING_MAP |
582 | bool | |
583 | depends on ARCH_HAVE_NMI_SAFE_CMPXCHG | |
08d43a5f TZ |
584 | help |
585 | tracing_map is a special-purpose lock-free map for tracing, | |
586 | separated out as a stand-alone facility in order to allow it | |
587 | to be shared between multiple tracers. It isn't meant to be | |
588 | generally used outside of that context, and is normally | |
589 | selected by tracers that use it. | |
590 | ||
7ef224d1 TZ |
591 | config HIST_TRIGGERS |
592 | bool "Histogram triggers" | |
593 | depends on ARCH_HAVE_NMI_SAFE_CMPXCHG | |
594 | select TRACING_MAP | |
7ad8fb61 | 595 | select TRACING |
7ef224d1 TZ |
596 | default n |
597 | help | |
598 | Hist triggers allow one or more arbitrary trace event fields | |
599 | to be aggregated into hash tables and dumped to stdout by | |
600 | reading a debugfs/tracefs file. They're useful for | |
601 | gathering quick and dirty (though precise) summaries of | |
602 | event activity as an initial guide for further investigation | |
603 | using more advanced tools. | |
604 | ||
89e270c1 TZ |
605 | Inter-event tracing of quantities such as latencies is also |
606 | supported using hist triggers under this option. | |
607 | ||
608 | See Documentation/trace/histogram.txt. | |
7ef224d1 TZ |
609 | If in doubt, say N. |
610 | ||
fe6f90e5 PP |
611 | config MMIOTRACE_TEST |
612 | tristate "Test module for mmiotrace" | |
613 | depends on MMIOTRACE && m | |
614 | help | |
615 | This is a dumb module for testing mmiotrace. It is very dangerous | |
616 | as it will write garbage to IO memory starting at a given address. | |
617 | However, it should be safe to use on e.g. unused portion of VRAM. | |
618 | ||
619 | Say N, unless you absolutely know what you are doing. | |
620 | ||
81dc9f0e SRRH |
621 | config TRACEPOINT_BENCHMARK |
622 | bool "Add tracepoint that benchmarks tracepoints" | |
623 | help | |
624 | This option creates the tracepoint "benchmark:benchmark_event". | |
625 | When the tracepoint is enabled, it kicks off a kernel thread that | |
626 | goes into an infinite loop (calling cond_sched() to let other tasks | |
627 | run), and calls the tracepoint. Each iteration will record the time | |
628 | it took to write to the tracepoint and the next iteration that | |
629 | data will be passed to the tracepoint itself. That is, the tracepoint | |
630 | will report the time it took to do the previous tracepoint. | |
631 | The string written to the tracepoint is a static string of 128 bytes | |
632 | to keep the time the same. The initial string is simply a write of | |
633 | "START". The second string records the cold cache time of the first | |
634 | write which is not added to the rest of the calculations. | |
635 | ||
636 | As it is a tight loop, it benchmarks as hot cache. That's fine because | |
637 | we care most about hot paths that are probably in cache already. | |
638 | ||
639 | An example of the output: | |
640 | ||
641 | START | |
642 | first=3672 [COLD CACHED] | |
643 | last=632 first=3672 max=632 min=632 avg=316 std=446 std^2=199712 | |
644 | last=278 first=3672 max=632 min=278 avg=303 std=316 std^2=100337 | |
645 | last=277 first=3672 max=632 min=277 avg=296 std=258 std^2=67064 | |
646 | last=273 first=3672 max=632 min=273 avg=292 std=224 std^2=50411 | |
647 | last=273 first=3672 max=632 min=273 avg=288 std=200 std^2=40389 | |
648 | last=281 first=3672 max=632 min=273 avg=287 std=183 std^2=33666 | |
649 | ||
650 | ||
5092dbc9 SR |
651 | config RING_BUFFER_BENCHMARK |
652 | tristate "Ring buffer benchmark stress tester" | |
653 | depends on RING_BUFFER | |
654 | help | |
40892367 RD |
655 | This option creates a test to stress the ring buffer and benchmark it. |
656 | It creates its own ring buffer such that it will not interfere with | |
5092dbc9 SR |
657 | any other users of the ring buffer (such as ftrace). It then creates |
658 | a producer and consumer that will run for 10 seconds and sleep for | |
659 | 10 seconds. Each interval it will print out the number of events | |
660 | it recorded and give a rough estimate of how long each iteration took. | |
661 | ||
662 | It does not disable interrupts or raise its priority, so it may be | |
663 | affected by processes that are running. | |
664 | ||
40892367 | 665 | If unsure, say N. |
5092dbc9 | 666 | |
6c43e554 SRRH |
667 | config RING_BUFFER_STARTUP_TEST |
668 | bool "Ring buffer startup self test" | |
669 | depends on RING_BUFFER | |
670 | help | |
671 | Run a simple self test on the ring buffer on boot up. Late in the | |
672 | kernel boot sequence, the test will start that kicks off | |
673 | a thread per cpu. Each thread will write various size events | |
674 | into the ring buffer. Another thread is created to send IPIs | |
675 | to each of the threads, where the IPI handler will also write | |
676 | to the ring buffer, to test/stress the nesting ability. | |
677 | If any anomalies are discovered, a warning will be displayed | |
678 | and all ring buffers will be disabled. | |
679 | ||
680 | The test runs for 10 seconds. This will slow your boot time | |
681 | by at least 10 more seconds. | |
682 | ||
683 | At the end of the test, statics and more checks are done. | |
684 | It will output the stats of each per cpu buffer. What | |
685 | was written, the sizes, what was read, what was lost, and | |
686 | other similar details. | |
687 | ||
688 | If unsure, say N | |
689 | ||
681bec03 JL |
690 | config TRACE_EVAL_MAP_FILE |
691 | bool "Show eval mappings for trace events" | |
9828413d SRRH |
692 | depends on TRACING |
693 | help | |
681bec03 JL |
694 | The "print fmt" of the trace events will show the enum/sizeof names |
695 | instead of their values. This can cause problems for user space tools | |
696 | that use this string to parse the raw data as user space does not know | |
9828413d SRRH |
697 | how to convert the string to its value. |
698 | ||
699 | To fix this, there's a special macro in the kernel that can be used | |
681bec03 JL |
700 | to convert an enum/sizeof into its value. If this macro is used, then |
701 | the print fmt strings will be converted to their values. | |
9828413d SRRH |
702 | |
703 | If something does not get converted properly, this option can be | |
681bec03 | 704 | used to show what enums/sizeof the kernel tried to convert. |
9828413d | 705 | |
681bec03 JL |
706 | This option is for debugging the conversions. A file is created |
707 | in the tracing directory called "eval_map" that will show the | |
9828413d SRRH |
708 | names matched with their values and what trace event system they |
709 | belong too. | |
710 | ||
711 | Normally, the mapping of the strings to values will be freed after | |
712 | boot up or module load. With this option, they will not be freed, as | |
681bec03 | 713 | they are needed for the "eval_map" file. Enabling this option will |
9828413d SRRH |
714 | increase the memory footprint of the running kernel. |
715 | ||
716 | If unsure, say N | |
717 | ||
ddd70280 TS |
718 | config TRACING_EVENTS_GPIO |
719 | bool "Trace gpio events" | |
720 | depends on GPIOLIB | |
721 | default y | |
722 | help | |
723 | Enable tracing events for gpio subsystem | |
724 | ||
4ed9f071 | 725 | endif # FTRACE |
40ada30f IM |
726 | |
727 | endif # TRACING_SUPPORT | |
728 |