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Commit | Line | Data |
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ec8f24b7 | 1 | # SPDX-License-Identifier: GPL-2.0-only |
16444a8a | 2 | # |
606576ce SR |
3 | # Architectures that offer an FUNCTION_TRACER implementation should |
4 | # select HAVE_FUNCTION_TRACER: | |
16444a8a | 5 | # |
2a3a4f66 | 6 | |
8d26487f TE |
7 | config USER_STACKTRACE_SUPPORT |
8 | bool | |
9 | ||
2a3a4f66 FW |
10 | config NOP_TRACER |
11 | bool | |
12 | ||
78d904b4 SR |
13 | config HAVE_FTRACE_NMI_ENTER |
14 | bool | |
555f386c | 15 | help |
5fb94e9c | 16 | See Documentation/trace/ftrace-design.rst |
78d904b4 | 17 | |
606576ce | 18 | config HAVE_FUNCTION_TRACER |
16444a8a | 19 | bool |
555f386c | 20 | help |
5fb94e9c | 21 | See Documentation/trace/ftrace-design.rst |
bc0c38d1 | 22 | |
fb52607a | 23 | config HAVE_FUNCTION_GRAPH_TRACER |
15e6cb36 | 24 | bool |
555f386c | 25 | help |
5fb94e9c | 26 | See Documentation/trace/ftrace-design.rst |
15e6cb36 | 27 | |
677aa9f7 SR |
28 | config HAVE_DYNAMIC_FTRACE |
29 | bool | |
555f386c | 30 | help |
5fb94e9c | 31 | See Documentation/trace/ftrace-design.rst |
677aa9f7 | 32 | |
06aeaaea MH |
33 | config HAVE_DYNAMIC_FTRACE_WITH_REGS |
34 | bool | |
35 | ||
763e34e7 SRV |
36 | config HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS |
37 | bool | |
38 | ||
8da3821b SR |
39 | config HAVE_FTRACE_MCOUNT_RECORD |
40 | bool | |
555f386c | 41 | help |
5fb94e9c | 42 | See Documentation/trace/ftrace-design.rst |
8da3821b | 43 | |
66700001 | 44 | config HAVE_SYSCALL_TRACEPOINTS |
ee08c6ec | 45 | bool |
555f386c | 46 | help |
5fb94e9c | 47 | See Documentation/trace/ftrace-design.rst |
ee08c6ec | 48 | |
a2546fae SR |
49 | config HAVE_FENTRY |
50 | bool | |
51 | help | |
52 | Arch supports the gcc options -pg with -mfentry | |
53 | ||
2f4df001 VG |
54 | config HAVE_NOP_MCOUNT |
55 | bool | |
56 | help | |
57 | Arch supports the gcc options -pg with -mrecord-mcount and -nop-mcount | |
58 | ||
cf4db259 | 59 | config HAVE_C_RECORDMCOUNT |
72441cb1 SR |
60 | bool |
61 | help | |
62 | C version of recordmcount available? | |
63 | ||
352ad25a SR |
64 | config TRACER_MAX_TRACE |
65 | bool | |
66 | ||
ea632e9f JT |
67 | config TRACE_CLOCK |
68 | bool | |
69 | ||
7a8e76a3 SR |
70 | config RING_BUFFER |
71 | bool | |
ea632e9f | 72 | select TRACE_CLOCK |
22287688 | 73 | select IRQ_WORK |
7a8e76a3 | 74 | |
78d904b4 SR |
75 | config FTRACE_NMI_ENTER |
76 | bool | |
77 | depends on HAVE_FTRACE_NMI_ENTER | |
78 | default y | |
79 | ||
5f77a88b | 80 | config EVENT_TRACING |
b11c53e1 | 81 | select CONTEXT_SWITCH_TRACER |
fc809bc5 | 82 | select GLOB |
b11c53e1 Z |
83 | bool |
84 | ||
85 | config CONTEXT_SWITCH_TRACER | |
5f77a88b TZ |
86 | bool |
87 | ||
85bac32c SR |
88 | config RING_BUFFER_ALLOW_SWAP |
89 | bool | |
90 | help | |
91 | Allow the use of ring_buffer_swap_cpu. | |
92 | Adds a very slight overhead to tracing when enabled. | |
93 | ||
c3bc8fd6 JFG |
94 | config PREEMPTIRQ_TRACEPOINTS |
95 | bool | |
96 | depends on TRACE_PREEMPT_TOGGLE || TRACE_IRQFLAGS | |
97 | select TRACING | |
98 | default y | |
99 | help | |
100 | Create preempt/irq toggle tracepoints if needed, so that other parts | |
101 | of the kernel can use them to generate or add hooks to them. | |
102 | ||
5e0a0939 SR |
103 | # All tracer options should select GENERIC_TRACER. For those options that are |
104 | # enabled by all tracers (context switch and event tracer) they select TRACING. | |
105 | # This allows those options to appear when no other tracer is selected. But the | |
106 | # options do not appear when something else selects it. We need the two options | |
107 | # GENERIC_TRACER and TRACING to avoid circular dependencies to accomplish the | |
40892367 | 108 | # hiding of the automatic options. |
5e0a0939 | 109 | |
bc0c38d1 SR |
110 | config TRACING |
111 | bool | |
7a8e76a3 | 112 | select RING_BUFFER |
c2c80529 | 113 | select STACKTRACE if STACKTRACE_SUPPORT |
5f87f112 | 114 | select TRACEPOINTS |
f3384b28 | 115 | select NOP_TRACER |
769b0441 | 116 | select BINARY_PRINTF |
5f77a88b | 117 | select EVENT_TRACING |
ea632e9f | 118 | select TRACE_CLOCK |
bc0c38d1 | 119 | |
5e0a0939 SR |
120 | config GENERIC_TRACER |
121 | bool | |
122 | select TRACING | |
123 | ||
40ada30f IM |
124 | # |
125 | # Minimum requirements an architecture has to meet for us to | |
126 | # be able to offer generic tracing facilities: | |
127 | # | |
128 | config TRACING_SUPPORT | |
129 | bool | |
0ea5ee03 | 130 | depends on TRACE_IRQFLAGS_SUPPORT |
40ada30f | 131 | depends on STACKTRACE_SUPPORT |
422d3c7a | 132 | default y |
40ada30f IM |
133 | |
134 | if TRACING_SUPPORT | |
135 | ||
4ed9f071 SR |
136 | menuconfig FTRACE |
137 | bool "Tracers" | |
65b77242 | 138 | default y if DEBUG_KERNEL |
4ed9f071 | 139 | help |
40892367 | 140 | Enable the kernel tracing infrastructure. |
4ed9f071 SR |
141 | |
142 | if FTRACE | |
17d80fd0 | 143 | |
1e837945 SRV |
144 | config BOOTTIME_TRACING |
145 | bool "Boot-time Tracing support" | |
d8a953dd MH |
146 | depends on TRACING |
147 | select BOOT_CONFIG | |
1e837945 SRV |
148 | help |
149 | Enable developer to setup ftrace subsystem via supplemental | |
150 | kernel cmdline at boot time for debugging (tracing) driver | |
151 | initialization and boot process. | |
152 | ||
606576ce | 153 | config FUNCTION_TRACER |
1b29b018 | 154 | bool "Kernel Function Tracer" |
606576ce | 155 | depends on HAVE_FUNCTION_TRACER |
4d7a077c | 156 | select KALLSYMS |
5e0a0939 | 157 | select GENERIC_TRACER |
35e8e302 | 158 | select CONTEXT_SWITCH_TRACER |
0598e4f0 | 159 | select GLOB |
01b1d88b | 160 | select TASKS_RCU if PREEMPTION |
1b29b018 SR |
161 | help |
162 | Enable the kernel to trace every kernel function. This is done | |
163 | by using a compiler feature to insert a small, 5-byte No-Operation | |
40892367 | 164 | instruction at the beginning of every kernel function, which NOP |
1b29b018 SR |
165 | sequence is then dynamically patched into a tracer call when |
166 | tracing is enabled by the administrator. If it's runtime disabled | |
167 | (the bootup default), then the overhead of the instructions is very | |
168 | small and not measurable even in micro-benchmarks. | |
35e8e302 | 169 | |
fb52607a FW |
170 | config FUNCTION_GRAPH_TRACER |
171 | bool "Kernel Function Graph Tracer" | |
172 | depends on HAVE_FUNCTION_GRAPH_TRACER | |
15e6cb36 | 173 | depends on FUNCTION_TRACER |
eb4a0378 | 174 | depends on !X86_32 || !CC_OPTIMIZE_FOR_SIZE |
764f3b95 | 175 | default y |
15e6cb36 | 176 | help |
fb52607a FW |
177 | Enable the kernel to trace a function at both its return |
178 | and its entry. | |
692105b8 ML |
179 | Its first purpose is to trace the duration of functions and |
180 | draw a call graph for each thread with some information like | |
40892367 | 181 | the return value. This is done by setting the current return |
692105b8 | 182 | address on the current task structure into a stack of calls. |
15e6cb36 | 183 | |
61778cd7 SRV |
184 | config DYNAMIC_FTRACE |
185 | bool "enable/disable function tracing dynamically" | |
186 | depends on FUNCTION_TRACER | |
187 | depends on HAVE_DYNAMIC_FTRACE | |
188 | default y | |
189 | help | |
190 | This option will modify all the calls to function tracing | |
191 | dynamically (will patch them out of the binary image and | |
192 | replace them with a No-Op instruction) on boot up. During | |
193 | compile time, a table is made of all the locations that ftrace | |
194 | can function trace, and this table is linked into the kernel | |
195 | image. When this is enabled, functions can be individually | |
196 | enabled, and the functions not enabled will not affect | |
197 | performance of the system. | |
198 | ||
199 | See the files in /sys/kernel/debug/tracing: | |
200 | available_filter_functions | |
201 | set_ftrace_filter | |
202 | set_ftrace_notrace | |
203 | ||
204 | This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but | |
205 | otherwise has native performance as long as no tracing is active. | |
206 | ||
207 | config DYNAMIC_FTRACE_WITH_REGS | |
208 | def_bool y | |
209 | depends on DYNAMIC_FTRACE | |
210 | depends on HAVE_DYNAMIC_FTRACE_WITH_REGS | |
211 | ||
212 | config DYNAMIC_FTRACE_WITH_DIRECT_CALLS | |
213 | def_bool y | |
214 | depends on DYNAMIC_FTRACE | |
215 | depends on HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS | |
216 | ||
217 | config FUNCTION_PROFILER | |
218 | bool "Kernel function profiler" | |
219 | depends on FUNCTION_TRACER | |
220 | default n | |
221 | help | |
222 | This option enables the kernel function profiler. A file is created | |
223 | in debugfs called function_profile_enabled which defaults to zero. | |
224 | When a 1 is echoed into this file profiling begins, and when a | |
225 | zero is entered, profiling stops. A "functions" file is created in | |
226 | the trace_stat directory; this file shows the list of functions that | |
227 | have been hit and their counters. | |
228 | ||
229 | If in doubt, say N. | |
230 | ||
231 | config STACK_TRACER | |
232 | bool "Trace max stack" | |
233 | depends on HAVE_FUNCTION_TRACER | |
234 | select FUNCTION_TRACER | |
235 | select STACKTRACE | |
236 | select KALLSYMS | |
237 | help | |
238 | This special tracer records the maximum stack footprint of the | |
239 | kernel and displays it in /sys/kernel/debug/tracing/stack_trace. | |
240 | ||
241 | This tracer works by hooking into every function call that the | |
242 | kernel executes, and keeping a maximum stack depth value and | |
243 | stack-trace saved. If this is configured with DYNAMIC_FTRACE | |
244 | then it will not have any overhead while the stack tracer | |
245 | is disabled. | |
246 | ||
247 | To enable the stack tracer on bootup, pass in 'stacktrace' | |
248 | on the kernel command line. | |
249 | ||
250 | The stack tracer can also be enabled or disabled via the | |
251 | sysctl kernel.stack_tracer_enabled | |
252 | ||
253 | Say N if unsure. | |
254 | ||
c3bc8fd6 JFG |
255 | config TRACE_PREEMPT_TOGGLE |
256 | bool | |
257 | help | |
258 | Enables hooks which will be called when preemption is first disabled, | |
259 | and last enabled. | |
bac429f0 | 260 | |
d5915816 JF |
261 | config PREEMPTIRQ_EVENTS |
262 | bool "Enable trace events for preempt and irq disable/enable" | |
263 | select TRACE_IRQFLAGS | |
30c93704 | 264 | select TRACE_PREEMPT_TOGGLE if PREEMPTION |
c3bc8fd6 | 265 | select GENERIC_TRACER |
d5915816 JF |
266 | default n |
267 | help | |
268 | Enable tracing of disable and enable events for preemption and irqs. | |
d5915816 | 269 | |
81d68a96 SR |
270 | config IRQSOFF_TRACER |
271 | bool "Interrupts-off Latency Tracer" | |
272 | default n | |
273 | depends on TRACE_IRQFLAGS_SUPPORT | |
592913ec | 274 | depends on !ARCH_USES_GETTIMEOFFSET |
81d68a96 | 275 | select TRACE_IRQFLAGS |
5e0a0939 | 276 | select GENERIC_TRACER |
81d68a96 | 277 | select TRACER_MAX_TRACE |
85bac32c | 278 | select RING_BUFFER_ALLOW_SWAP |
22cffc2b | 279 | select TRACER_SNAPSHOT |
0b85ffc2 | 280 | select TRACER_SNAPSHOT_PER_CPU_SWAP |
81d68a96 SR |
281 | help |
282 | This option measures the time spent in irqs-off critical | |
283 | sections, with microsecond accuracy. | |
284 | ||
285 | The default measurement method is a maximum search, which is | |
286 | disabled by default and can be runtime (re-)started | |
287 | via: | |
288 | ||
156f5a78 | 289 | echo 0 > /sys/kernel/debug/tracing/tracing_max_latency |
81d68a96 | 290 | |
40892367 | 291 | (Note that kernel size and overhead increase with this option |
6cd8a4bb SR |
292 | enabled. This option and the preempt-off timing option can be |
293 | used together or separately.) | |
294 | ||
295 | config PREEMPT_TRACER | |
296 | bool "Preemption-off Latency Tracer" | |
297 | default n | |
592913ec | 298 | depends on !ARCH_USES_GETTIMEOFFSET |
30c93704 | 299 | depends on PREEMPTION |
5e0a0939 | 300 | select GENERIC_TRACER |
6cd8a4bb | 301 | select TRACER_MAX_TRACE |
85bac32c | 302 | select RING_BUFFER_ALLOW_SWAP |
22cffc2b | 303 | select TRACER_SNAPSHOT |
0b85ffc2 | 304 | select TRACER_SNAPSHOT_PER_CPU_SWAP |
c3bc8fd6 | 305 | select TRACE_PREEMPT_TOGGLE |
6cd8a4bb | 306 | help |
40892367 | 307 | This option measures the time spent in preemption-off critical |
6cd8a4bb SR |
308 | sections, with microsecond accuracy. |
309 | ||
310 | The default measurement method is a maximum search, which is | |
311 | disabled by default and can be runtime (re-)started | |
312 | via: | |
313 | ||
156f5a78 | 314 | echo 0 > /sys/kernel/debug/tracing/tracing_max_latency |
6cd8a4bb | 315 | |
40892367 | 316 | (Note that kernel size and overhead increase with this option |
6cd8a4bb SR |
317 | enabled. This option and the irqs-off timing option can be |
318 | used together or separately.) | |
319 | ||
352ad25a SR |
320 | config SCHED_TRACER |
321 | bool "Scheduling Latency Tracer" | |
5e0a0939 | 322 | select GENERIC_TRACER |
352ad25a SR |
323 | select CONTEXT_SWITCH_TRACER |
324 | select TRACER_MAX_TRACE | |
22cffc2b | 325 | select TRACER_SNAPSHOT |
352ad25a SR |
326 | help |
327 | This tracer tracks the latency of the highest priority task | |
328 | to be scheduled in, starting from the point it has woken up. | |
329 | ||
e7c15cd8 SRRH |
330 | config HWLAT_TRACER |
331 | bool "Tracer to detect hardware latencies (like SMIs)" | |
332 | select GENERIC_TRACER | |
333 | help | |
334 | This tracer, when enabled will create one or more kernel threads, | |
c5c1ea75 | 335 | depending on what the cpumask file is set to, which each thread |
e7c15cd8 SRRH |
336 | spinning in a loop looking for interruptions caused by |
337 | something other than the kernel. For example, if a | |
338 | System Management Interrupt (SMI) takes a noticeable amount of | |
339 | time, this tracer will detect it. This is useful for testing | |
340 | if a system is reliable for Real Time tasks. | |
341 | ||
342 | Some files are created in the tracing directory when this | |
343 | is enabled: | |
344 | ||
345 | hwlat_detector/width - time in usecs for how long to spin for | |
346 | hwlat_detector/window - time in usecs between the start of each | |
347 | iteration | |
348 | ||
349 | A kernel thread is created that will spin with interrupts disabled | |
c5c1ea75 | 350 | for "width" microseconds in every "window" cycle. It will not spin |
e7c15cd8 SRRH |
351 | for "window - width" microseconds, where the system can |
352 | continue to operate. | |
353 | ||
354 | The output will appear in the trace and trace_pipe files. | |
355 | ||
356 | When the tracer is not running, it has no affect on the system, | |
357 | but when it is running, it can cause the system to be | |
358 | periodically non responsive. Do not run this tracer on a | |
359 | production system. | |
360 | ||
361 | To enable this tracer, echo in "hwlat" into the current_tracer | |
362 | file. Every time a latency is greater than tracing_thresh, it will | |
363 | be recorded into the ring buffer. | |
364 | ||
21b3ce30 SRV |
365 | config MMIOTRACE |
366 | bool "Memory mapped IO tracing" | |
367 | depends on HAVE_MMIOTRACE_SUPPORT && PCI | |
368 | select GENERIC_TRACER | |
369 | help | |
370 | Mmiotrace traces Memory Mapped I/O access and is meant for | |
371 | debugging and reverse engineering. It is called from the ioremap | |
372 | implementation and works via page faults. Tracing is disabled by | |
373 | default and can be enabled at run-time. | |
374 | ||
375 | See Documentation/trace/mmiotrace.rst. | |
376 | If you are not helping to develop drivers, say N. | |
377 | ||
897f17a6 SR |
378 | config ENABLE_DEFAULT_TRACERS |
379 | bool "Trace process context switches and events" | |
5e0a0939 | 380 | depends on !GENERIC_TRACER |
b77e38aa SR |
381 | select TRACING |
382 | help | |
40892367 | 383 | This tracer hooks to various trace points in the kernel, |
b77e38aa | 384 | allowing the user to pick and choose which trace point they |
897f17a6 | 385 | want to trace. It also includes the sched_switch tracer plugin. |
a7abe97f | 386 | |
ee08c6ec FW |
387 | config FTRACE_SYSCALLS |
388 | bool "Trace syscalls" | |
66700001 | 389 | depends on HAVE_SYSCALL_TRACEPOINTS |
5e0a0939 | 390 | select GENERIC_TRACER |
0ea1c415 | 391 | select KALLSYMS |
ee08c6ec FW |
392 | help |
393 | Basic tracer to catch the syscall entry and exit events. | |
394 | ||
debdd57f HT |
395 | config TRACER_SNAPSHOT |
396 | bool "Create a snapshot trace buffer" | |
397 | select TRACER_MAX_TRACE | |
398 | help | |
399 | Allow tracing users to take snapshot of the current buffer using the | |
400 | ftrace interface, e.g.: | |
401 | ||
402 | echo 1 > /sys/kernel/debug/tracing/snapshot | |
403 | cat snapshot | |
404 | ||
0b85ffc2 | 405 | config TRACER_SNAPSHOT_PER_CPU_SWAP |
fc809bc5 | 406 | bool "Allow snapshot to swap per CPU" |
0b85ffc2 SRRH |
407 | depends on TRACER_SNAPSHOT |
408 | select RING_BUFFER_ALLOW_SWAP | |
409 | help | |
410 | Allow doing a snapshot of a single CPU buffer instead of a | |
411 | full swap (all buffers). If this is set, then the following is | |
412 | allowed: | |
413 | ||
414 | echo 1 > /sys/kernel/debug/tracing/per_cpu/cpu2/snapshot | |
415 | ||
416 | After which, only the tracing buffer for CPU 2 was swapped with | |
417 | the main tracing buffer, and the other CPU buffers remain the same. | |
418 | ||
419 | When this is enabled, this adds a little more overhead to the | |
420 | trace recording, as it needs to add some checks to synchronize | |
421 | recording with swaps. But this does not affect the performance | |
422 | of the overall system. This is enabled by default when the preempt | |
423 | or irq latency tracers are enabled, as those need to swap as well | |
424 | and already adds the overhead (plus a lot more). | |
425 | ||
2ed84eeb | 426 | config TRACE_BRANCH_PROFILING |
9ae5b879 | 427 | bool |
5e0a0939 | 428 | select GENERIC_TRACER |
9ae5b879 SR |
429 | |
430 | choice | |
431 | prompt "Branch Profiling" | |
432 | default BRANCH_PROFILE_NONE | |
433 | help | |
434 | The branch profiling is a software profiler. It will add hooks | |
435 | into the C conditionals to test which path a branch takes. | |
436 | ||
437 | The likely/unlikely profiler only looks at the conditions that | |
438 | are annotated with a likely or unlikely macro. | |
439 | ||
40892367 | 440 | The "all branch" profiler will profile every if-statement in the |
9ae5b879 | 441 | kernel. This profiler will also enable the likely/unlikely |
40892367 | 442 | profiler. |
9ae5b879 | 443 | |
40892367 RD |
444 | Either of the above profilers adds a bit of overhead to the system. |
445 | If unsure, choose "No branch profiling". | |
9ae5b879 SR |
446 | |
447 | config BRANCH_PROFILE_NONE | |
448 | bool "No branch profiling" | |
449 | help | |
40892367 RD |
450 | No branch profiling. Branch profiling adds a bit of overhead. |
451 | Only enable it if you want to analyse the branching behavior. | |
452 | Otherwise keep it disabled. | |
9ae5b879 SR |
453 | |
454 | config PROFILE_ANNOTATED_BRANCHES | |
455 | bool "Trace likely/unlikely profiler" | |
456 | select TRACE_BRANCH_PROFILING | |
1f0d69a9 | 457 | help |
59bf8964 | 458 | This tracer profiles all likely and unlikely macros |
1f0d69a9 SR |
459 | in the kernel. It will display the results in: |
460 | ||
13e5befa | 461 | /sys/kernel/debug/tracing/trace_stat/branch_annotated |
1f0d69a9 | 462 | |
40892367 | 463 | Note: this will add a significant overhead; only turn this |
1f0d69a9 SR |
464 | on if you need to profile the system's use of these macros. |
465 | ||
2bcd521a | 466 | config PROFILE_ALL_BRANCHES |
68e76e03 | 467 | bool "Profile all if conditionals" if !FORTIFY_SOURCE |
9ae5b879 | 468 | select TRACE_BRANCH_PROFILING |
2bcd521a SR |
469 | help |
470 | This tracer profiles all branch conditions. Every if () | |
471 | taken in the kernel is recorded whether it hit or miss. | |
472 | The results will be displayed in: | |
473 | ||
13e5befa | 474 | /sys/kernel/debug/tracing/trace_stat/branch_all |
2bcd521a | 475 | |
9ae5b879 SR |
476 | This option also enables the likely/unlikely profiler. |
477 | ||
2bcd521a SR |
478 | This configuration, when enabled, will impose a great overhead |
479 | on the system. This should only be enabled when the system | |
40892367 | 480 | is to be analyzed in much detail. |
9ae5b879 | 481 | endchoice |
2bcd521a | 482 | |
2ed84eeb | 483 | config TRACING_BRANCHES |
52f232cb SR |
484 | bool |
485 | help | |
486 | Selected by tracers that will trace the likely and unlikely | |
487 | conditions. This prevents the tracers themselves from being | |
488 | profiled. Profiling the tracing infrastructure can only happen | |
489 | when the likelys and unlikelys are not being traced. | |
490 | ||
2ed84eeb | 491 | config BRANCH_TRACER |
52f232cb | 492 | bool "Trace likely/unlikely instances" |
2ed84eeb SR |
493 | depends on TRACE_BRANCH_PROFILING |
494 | select TRACING_BRANCHES | |
52f232cb SR |
495 | help |
496 | This traces the events of likely and unlikely condition | |
497 | calls in the kernel. The difference between this and the | |
498 | "Trace likely/unlikely profiler" is that this is not a | |
499 | histogram of the callers, but actually places the calling | |
500 | events into a running trace buffer to see when and where the | |
501 | events happened, as well as their results. | |
502 | ||
503 | Say N if unsure. | |
504 | ||
2db270a8 | 505 | config BLK_DEV_IO_TRACE |
40892367 | 506 | bool "Support for tracing block IO actions" |
2db270a8 | 507 | depends on SYSFS |
1dfba05d | 508 | depends on BLOCK |
2db270a8 FW |
509 | select RELAY |
510 | select DEBUG_FS | |
511 | select TRACEPOINTS | |
5e0a0939 | 512 | select GENERIC_TRACER |
2db270a8 FW |
513 | select STACKTRACE |
514 | help | |
515 | Say Y here if you want to be able to trace the block layer actions | |
516 | on a given queue. Tracing allows you to see any traffic happening | |
517 | on a block device queue. For more information (and the userspace | |
518 | support tools needed), fetch the blktrace tools from: | |
519 | ||
520 | git://git.kernel.dk/blktrace.git | |
521 | ||
522 | Tracing also is possible using the ftrace interface, e.g.: | |
523 | ||
524 | echo 1 > /sys/block/sda/sda1/trace/enable | |
525 | echo blk > /sys/kernel/debug/tracing/current_tracer | |
526 | cat /sys/kernel/debug/tracing/trace_pipe | |
527 | ||
528 | If unsure, say N. | |
36994e58 | 529 | |
6b0b7551 | 530 | config KPROBE_EVENTS |
413d37d1 | 531 | depends on KPROBES |
f850c30c | 532 | depends on HAVE_REGS_AND_STACK_ACCESS_API |
77b44d1b | 533 | bool "Enable kprobes-based dynamic events" |
413d37d1 | 534 | select TRACING |
8ab83f56 | 535 | select PROBE_EVENTS |
6212dd29 | 536 | select DYNAMIC_EVENTS |
77b44d1b | 537 | default y |
413d37d1 | 538 | help |
40892367 RD |
539 | This allows the user to add tracing events (similar to tracepoints) |
540 | on the fly via the ftrace interface. See | |
5fb94e9c | 541 | Documentation/trace/kprobetrace.rst for more details. |
77b44d1b MH |
542 | |
543 | Those events can be inserted wherever kprobes can probe, and record | |
544 | various register and memory values. | |
545 | ||
40892367 RD |
546 | This option is also required by perf-probe subcommand of perf tools. |
547 | If you want to use perf tools, this option is strongly recommended. | |
413d37d1 | 548 | |
45408c4f MH |
549 | config KPROBE_EVENTS_ON_NOTRACE |
550 | bool "Do NOT protect notrace function from kprobe events" | |
551 | depends on KPROBE_EVENTS | |
552 | depends on KPROBES_ON_FTRACE | |
553 | default n | |
554 | help | |
555 | This is only for the developers who want to debug ftrace itself | |
556 | using kprobe events. | |
557 | ||
558 | If kprobes can use ftrace instead of breakpoint, ftrace related | |
559 | functions are protected from kprobe-events to prevent an infinit | |
560 | recursion or any unexpected execution path which leads to a kernel | |
561 | crash. | |
562 | ||
563 | This option disables such protection and allows you to put kprobe | |
564 | events on ftrace functions for debugging ftrace by itself. | |
565 | Note that this might let you shoot yourself in the foot. | |
566 | ||
567 | If unsure, say N. | |
568 | ||
6b0b7551 | 569 | config UPROBE_EVENTS |
f3f096cf SD |
570 | bool "Enable uprobes-based dynamic events" |
571 | depends on ARCH_SUPPORTS_UPROBES | |
572 | depends on MMU | |
09294e31 | 573 | depends on PERF_EVENTS |
f3f096cf SD |
574 | select UPROBES |
575 | select PROBE_EVENTS | |
0597c49c | 576 | select DYNAMIC_EVENTS |
f3f096cf | 577 | select TRACING |
61f35d75 | 578 | default y |
f3f096cf SD |
579 | help |
580 | This allows the user to add tracing events on top of userspace | |
581 | dynamic events (similar to tracepoints) on the fly via the trace | |
582 | events interface. Those events can be inserted wherever uprobes | |
583 | can probe, and record various registers. | |
584 | This option is required if you plan to use perf-probe subcommand | |
585 | of perf tools on user space applications. | |
586 | ||
e1abf2cc IM |
587 | config BPF_EVENTS |
588 | depends on BPF_SYSCALL | |
6b0b7551 | 589 | depends on (KPROBE_EVENTS || UPROBE_EVENTS) && PERF_EVENTS |
e1abf2cc IM |
590 | bool |
591 | default y | |
592 | help | |
5cbd22c1 PW |
593 | This allows the user to attach BPF programs to kprobe, uprobe, and |
594 | tracepoint events. | |
e1abf2cc | 595 | |
5448d44c MH |
596 | config DYNAMIC_EVENTS |
597 | def_bool n | |
598 | ||
8ab83f56 SD |
599 | config PROBE_EVENTS |
600 | def_bool n | |
601 | ||
9802d865 JB |
602 | config BPF_KPROBE_OVERRIDE |
603 | bool "Enable BPF programs to override a kprobed function" | |
604 | depends on BPF_EVENTS | |
540adea3 | 605 | depends on FUNCTION_ERROR_INJECTION |
9802d865 JB |
606 | default n |
607 | help | |
608 | Allows BPF to override the execution of a probed function and | |
609 | set a different return value. This is used for error injection. | |
610 | ||
8da3821b SR |
611 | config FTRACE_MCOUNT_RECORD |
612 | def_bool y | |
613 | depends on DYNAMIC_FTRACE | |
614 | depends on HAVE_FTRACE_MCOUNT_RECORD | |
615 | ||
08d43a5f TZ |
616 | config TRACING_MAP |
617 | bool | |
618 | depends on ARCH_HAVE_NMI_SAFE_CMPXCHG | |
08d43a5f TZ |
619 | help |
620 | tracing_map is a special-purpose lock-free map for tracing, | |
621 | separated out as a stand-alone facility in order to allow it | |
622 | to be shared between multiple tracers. It isn't meant to be | |
623 | generally used outside of that context, and is normally | |
624 | selected by tracers that use it. | |
625 | ||
7ef224d1 TZ |
626 | config HIST_TRIGGERS |
627 | bool "Histogram triggers" | |
628 | depends on ARCH_HAVE_NMI_SAFE_CMPXCHG | |
629 | select TRACING_MAP | |
7ad8fb61 | 630 | select TRACING |
7bbab38d | 631 | select DYNAMIC_EVENTS |
7ef224d1 TZ |
632 | default n |
633 | help | |
634 | Hist triggers allow one or more arbitrary trace event fields | |
635 | to be aggregated into hash tables and dumped to stdout by | |
636 | reading a debugfs/tracefs file. They're useful for | |
637 | gathering quick and dirty (though precise) summaries of | |
638 | event activity as an initial guide for further investigation | |
639 | using more advanced tools. | |
640 | ||
89e270c1 TZ |
641 | Inter-event tracing of quantities such as latencies is also |
642 | supported using hist triggers under this option. | |
643 | ||
ea272257 | 644 | See Documentation/trace/histogram.rst. |
7ef224d1 TZ |
645 | If in doubt, say N. |
646 | ||
6c3edaf9 CW |
647 | config TRACE_EVENT_INJECT |
648 | bool "Trace event injection" | |
649 | depends on TRACING | |
650 | help | |
651 | Allow user-space to inject a specific trace event into the ring | |
652 | buffer. This is mainly used for testing purpose. | |
653 | ||
654 | If unsure, say N. | |
655 | ||
81dc9f0e | 656 | config TRACEPOINT_BENCHMARK |
fc809bc5 | 657 | bool "Add tracepoint that benchmarks tracepoints" |
81dc9f0e SRRH |
658 | help |
659 | This option creates the tracepoint "benchmark:benchmark_event". | |
660 | When the tracepoint is enabled, it kicks off a kernel thread that | |
661 | goes into an infinite loop (calling cond_sched() to let other tasks | |
662 | run), and calls the tracepoint. Each iteration will record the time | |
663 | it took to write to the tracepoint and the next iteration that | |
664 | data will be passed to the tracepoint itself. That is, the tracepoint | |
665 | will report the time it took to do the previous tracepoint. | |
666 | The string written to the tracepoint is a static string of 128 bytes | |
667 | to keep the time the same. The initial string is simply a write of | |
668 | "START". The second string records the cold cache time of the first | |
669 | write which is not added to the rest of the calculations. | |
670 | ||
671 | As it is a tight loop, it benchmarks as hot cache. That's fine because | |
672 | we care most about hot paths that are probably in cache already. | |
673 | ||
674 | An example of the output: | |
675 | ||
676 | START | |
677 | first=3672 [COLD CACHED] | |
678 | last=632 first=3672 max=632 min=632 avg=316 std=446 std^2=199712 | |
679 | last=278 first=3672 max=632 min=278 avg=303 std=316 std^2=100337 | |
680 | last=277 first=3672 max=632 min=277 avg=296 std=258 std^2=67064 | |
681 | last=273 first=3672 max=632 min=273 avg=292 std=224 std^2=50411 | |
682 | last=273 first=3672 max=632 min=273 avg=288 std=200 std^2=40389 | |
683 | last=281 first=3672 max=632 min=273 avg=287 std=183 std^2=33666 | |
684 | ||
685 | ||
5092dbc9 SR |
686 | config RING_BUFFER_BENCHMARK |
687 | tristate "Ring buffer benchmark stress tester" | |
688 | depends on RING_BUFFER | |
689 | help | |
40892367 RD |
690 | This option creates a test to stress the ring buffer and benchmark it. |
691 | It creates its own ring buffer such that it will not interfere with | |
5092dbc9 SR |
692 | any other users of the ring buffer (such as ftrace). It then creates |
693 | a producer and consumer that will run for 10 seconds and sleep for | |
694 | 10 seconds. Each interval it will print out the number of events | |
695 | it recorded and give a rough estimate of how long each iteration took. | |
696 | ||
697 | It does not disable interrupts or raise its priority, so it may be | |
698 | affected by processes that are running. | |
699 | ||
40892367 | 700 | If unsure, say N. |
5092dbc9 | 701 | |
1e837945 SRV |
702 | config TRACE_EVAL_MAP_FILE |
703 | bool "Show eval mappings for trace events" | |
704 | depends on TRACING | |
705 | help | |
706 | The "print fmt" of the trace events will show the enum/sizeof names | |
707 | instead of their values. This can cause problems for user space tools | |
708 | that use this string to parse the raw data as user space does not know | |
709 | how to convert the string to its value. | |
710 | ||
711 | To fix this, there's a special macro in the kernel that can be used | |
712 | to convert an enum/sizeof into its value. If this macro is used, then | |
713 | the print fmt strings will be converted to their values. | |
714 | ||
715 | If something does not get converted properly, this option can be | |
716 | used to show what enums/sizeof the kernel tried to convert. | |
717 | ||
718 | This option is for debugging the conversions. A file is created | |
719 | in the tracing directory called "eval_map" that will show the | |
720 | names matched with their values and what trace event system they | |
721 | belong too. | |
722 | ||
723 | Normally, the mapping of the strings to values will be freed after | |
724 | boot up or module load. With this option, they will not be freed, as | |
725 | they are needed for the "eval_map" file. Enabling this option will | |
726 | increase the memory footprint of the running kernel. | |
727 | ||
728 | If unsure, say N. | |
729 | ||
730 | config GCOV_PROFILE_FTRACE | |
731 | bool "Enable GCOV profiling on ftrace subsystem" | |
732 | depends on GCOV_KERNEL | |
733 | help | |
734 | Enable GCOV profiling on ftrace subsystem for checking | |
735 | which functions/lines are tested. | |
736 | ||
737 | If unsure, say N. | |
738 | ||
739 | Note that on a kernel compiled with this config, ftrace will | |
740 | run significantly slower. | |
741 | ||
742 | config FTRACE_SELFTEST | |
743 | bool | |
744 | ||
745 | config FTRACE_STARTUP_TEST | |
746 | bool "Perform a startup test on ftrace" | |
747 | depends on GENERIC_TRACER | |
748 | select FTRACE_SELFTEST | |
749 | help | |
750 | This option performs a series of startup tests on ftrace. On bootup | |
751 | a series of tests are made to verify that the tracer is | |
752 | functioning properly. It will do tests on all the configured | |
753 | tracers of ftrace. | |
754 | ||
755 | config EVENT_TRACE_STARTUP_TEST | |
756 | bool "Run selftest on trace events" | |
757 | depends on FTRACE_STARTUP_TEST | |
758 | default y | |
759 | help | |
760 | This option performs a test on all trace events in the system. | |
761 | It basically just enables each event and runs some code that | |
762 | will trigger events (not necessarily the event it enables) | |
763 | This may take some time run as there are a lot of events. | |
764 | ||
765 | config EVENT_TRACE_TEST_SYSCALLS | |
766 | bool "Run selftest on syscall events" | |
767 | depends on EVENT_TRACE_STARTUP_TEST | |
768 | help | |
769 | This option will also enable testing every syscall event. | |
770 | It only enables the event and disables it and runs various loads | |
771 | with the event enabled. This adds a bit more time for kernel boot | |
772 | up since it runs this on every system call defined. | |
773 | ||
774 | TBD - enable a way to actually call the syscalls as we test their | |
775 | events | |
776 | ||
6c43e554 SRRH |
777 | config RING_BUFFER_STARTUP_TEST |
778 | bool "Ring buffer startup self test" | |
779 | depends on RING_BUFFER | |
780 | help | |
fc809bc5 | 781 | Run a simple self test on the ring buffer on boot up. Late in the |
6c43e554 SRRH |
782 | kernel boot sequence, the test will start that kicks off |
783 | a thread per cpu. Each thread will write various size events | |
784 | into the ring buffer. Another thread is created to send IPIs | |
785 | to each of the threads, where the IPI handler will also write | |
786 | to the ring buffer, to test/stress the nesting ability. | |
787 | If any anomalies are discovered, a warning will be displayed | |
788 | and all ring buffers will be disabled. | |
789 | ||
790 | The test runs for 10 seconds. This will slow your boot time | |
791 | by at least 10 more seconds. | |
792 | ||
793 | At the end of the test, statics and more checks are done. | |
794 | It will output the stats of each per cpu buffer. What | |
795 | was written, the sizes, what was read, what was lost, and | |
796 | other similar details. | |
797 | ||
798 | If unsure, say N | |
799 | ||
a48fc4f5 SRV |
800 | config MMIOTRACE_TEST |
801 | tristate "Test module for mmiotrace" | |
802 | depends on MMIOTRACE && m | |
803 | help | |
804 | This is a dumb module for testing mmiotrace. It is very dangerous | |
805 | as it will write garbage to IO memory starting at a given address. | |
806 | However, it should be safe to use on e.g. unused portion of VRAM. | |
807 | ||
808 | Say N, unless you absolutely know what you are doing. | |
809 | ||
f96e8577 | 810 | config PREEMPTIRQ_DELAY_TEST |
a48fc4f5 | 811 | tristate "Test module to create a preempt / IRQ disable delay thread to test latency tracers" |
f96e8577 JFG |
812 | depends on m |
813 | help | |
814 | Select this option to build a test module that can help test latency | |
815 | tracers by executing a preempt or irq disable section with a user | |
816 | configurable delay. The module busy waits for the duration of the | |
817 | critical section. | |
818 | ||
79393723 VRB |
819 | For example, the following invocation generates a burst of three |
820 | irq-disabled critical sections for 500us: | |
821 | modprobe preemptirq_delay_test test_mode=irq delay=500 burst_size=3 | |
f96e8577 JFG |
822 | |
823 | If unsure, say N | |
824 | ||
9fe41efa TZ |
825 | config SYNTH_EVENT_GEN_TEST |
826 | tristate "Test module for in-kernel synthetic event generation" | |
827 | depends on HIST_TRIGGERS | |
828 | help | |
829 | This option creates a test module to check the base | |
830 | functionality of in-kernel synthetic event definition and | |
831 | generation. | |
832 | ||
833 | To test, insert the module, and then check the trace buffer | |
834 | for the generated sample events. | |
835 | ||
836 | If unsure, say N. | |
837 | ||
64836248 TZ |
838 | config KPROBE_EVENT_GEN_TEST |
839 | tristate "Test module for in-kernel kprobe event generation" | |
840 | depends on KPROBE_EVENTS | |
841 | help | |
842 | This option creates a test module to check the base | |
843 | functionality of in-kernel kprobe event definition. | |
844 | ||
845 | To test, insert the module, and then check the trace buffer | |
846 | for the generated kprobe events. | |
847 | ||
848 | If unsure, say N. | |
849 | ||
4ed9f071 | 850 | endif # FTRACE |
40ada30f IM |
851 | |
852 | endif # TRACING_SUPPORT | |
853 |