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 | |
71e308a2 SR |
27 | config HAVE_FUNCTION_GRAPH_FP_TEST |
28 | bool | |
29 | help | |
03688970 | 30 | See Documentation/trace/ftrace-design.txt |
71e308a2 | 31 | |
60a7ecf4 SR |
32 | config HAVE_FUNCTION_TRACE_MCOUNT_TEST |
33 | bool | |
34 | help | |
40892367 | 35 | See Documentation/trace/ftrace-design.txt |
60a7ecf4 | 36 | |
677aa9f7 SR |
37 | config HAVE_DYNAMIC_FTRACE |
38 | bool | |
555f386c | 39 | help |
40892367 | 40 | See Documentation/trace/ftrace-design.txt |
677aa9f7 | 41 | |
06aeaaea MH |
42 | config HAVE_DYNAMIC_FTRACE_WITH_REGS |
43 | bool | |
44 | ||
8da3821b SR |
45 | config HAVE_FTRACE_MCOUNT_RECORD |
46 | bool | |
555f386c | 47 | help |
40892367 | 48 | See Documentation/trace/ftrace-design.txt |
8da3821b | 49 | |
66700001 | 50 | config HAVE_SYSCALL_TRACEPOINTS |
ee08c6ec | 51 | bool |
555f386c | 52 | help |
40892367 | 53 | See Documentation/trace/ftrace-design.txt |
ee08c6ec | 54 | |
a2546fae SR |
55 | config HAVE_FENTRY |
56 | bool | |
57 | help | |
58 | Arch supports the gcc options -pg with -mfentry | |
59 | ||
cf4db259 | 60 | config HAVE_C_RECORDMCOUNT |
72441cb1 SR |
61 | bool |
62 | help | |
63 | C version of recordmcount available? | |
64 | ||
352ad25a SR |
65 | config TRACER_MAX_TRACE |
66 | bool | |
67 | ||
ea632e9f JT |
68 | config TRACE_CLOCK |
69 | bool | |
70 | ||
7a8e76a3 SR |
71 | config RING_BUFFER |
72 | bool | |
ea632e9f | 73 | select TRACE_CLOCK |
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 Z |
81 | select CONTEXT_SWITCH_TRACER |
82 | bool | |
83 | ||
84 | config CONTEXT_SWITCH_TRACER | |
5f77a88b TZ |
85 | bool |
86 | ||
85bac32c SR |
87 | config RING_BUFFER_ALLOW_SWAP |
88 | bool | |
89 | help | |
90 | Allow the use of ring_buffer_swap_cpu. | |
91 | Adds a very slight overhead to tracing when enabled. | |
92 | ||
5e0a0939 SR |
93 | # All tracer options should select GENERIC_TRACER. For those options that are |
94 | # enabled by all tracers (context switch and event tracer) they select TRACING. | |
95 | # This allows those options to appear when no other tracer is selected. But the | |
96 | # options do not appear when something else selects it. We need the two options | |
97 | # GENERIC_TRACER and TRACING to avoid circular dependencies to accomplish the | |
40892367 | 98 | # hiding of the automatic options. |
5e0a0939 | 99 | |
bc0c38d1 SR |
100 | config TRACING |
101 | bool | |
102 | select DEBUG_FS | |
7a8e76a3 | 103 | select RING_BUFFER |
c2c80529 | 104 | select STACKTRACE if STACKTRACE_SUPPORT |
5f87f112 | 105 | select TRACEPOINTS |
f3384b28 | 106 | select NOP_TRACER |
769b0441 | 107 | select BINARY_PRINTF |
5f77a88b | 108 | select EVENT_TRACING |
ea632e9f | 109 | select TRACE_CLOCK |
0d5c6e1c | 110 | select IRQ_WORK |
bc0c38d1 | 111 | |
5e0a0939 SR |
112 | config GENERIC_TRACER |
113 | bool | |
114 | select TRACING | |
115 | ||
40ada30f IM |
116 | # |
117 | # Minimum requirements an architecture has to meet for us to | |
118 | # be able to offer generic tracing facilities: | |
119 | # | |
120 | config TRACING_SUPPORT | |
121 | bool | |
45b95608 AV |
122 | # PPC32 has no irqflags tracing support, but it can use most of the |
123 | # tracers anyway, they were tested to build and work. Note that new | |
124 | # exceptions to this list aren't welcomed, better implement the | |
125 | # irqflags tracing for your architecture. | |
126 | depends on TRACE_IRQFLAGS_SUPPORT || PPC32 | |
40ada30f | 127 | depends on STACKTRACE_SUPPORT |
422d3c7a | 128 | default y |
40ada30f IM |
129 | |
130 | if TRACING_SUPPORT | |
131 | ||
4ed9f071 SR |
132 | menuconfig FTRACE |
133 | bool "Tracers" | |
65b77242 | 134 | default y if DEBUG_KERNEL |
4ed9f071 | 135 | help |
40892367 | 136 | Enable the kernel tracing infrastructure. |
4ed9f071 SR |
137 | |
138 | if FTRACE | |
17d80fd0 | 139 | |
606576ce | 140 | config FUNCTION_TRACER |
1b29b018 | 141 | bool "Kernel Function Tracer" |
606576ce | 142 | depends on HAVE_FUNCTION_TRACER |
4d7a077c | 143 | select KALLSYMS |
5e0a0939 | 144 | select GENERIC_TRACER |
35e8e302 | 145 | select CONTEXT_SWITCH_TRACER |
1b29b018 SR |
146 | help |
147 | Enable the kernel to trace every kernel function. This is done | |
148 | by using a compiler feature to insert a small, 5-byte No-Operation | |
40892367 | 149 | instruction at the beginning of every kernel function, which NOP |
1b29b018 SR |
150 | sequence is then dynamically patched into a tracer call when |
151 | tracing is enabled by the administrator. If it's runtime disabled | |
152 | (the bootup default), then the overhead of the instructions is very | |
153 | small and not measurable even in micro-benchmarks. | |
35e8e302 | 154 | |
fb52607a FW |
155 | config FUNCTION_GRAPH_TRACER |
156 | bool "Kernel Function Graph Tracer" | |
157 | depends on HAVE_FUNCTION_GRAPH_TRACER | |
15e6cb36 | 158 | depends on FUNCTION_TRACER |
eb4a0378 | 159 | depends on !X86_32 || !CC_OPTIMIZE_FOR_SIZE |
764f3b95 | 160 | default y |
15e6cb36 | 161 | help |
fb52607a FW |
162 | Enable the kernel to trace a function at both its return |
163 | and its entry. | |
692105b8 ML |
164 | Its first purpose is to trace the duration of functions and |
165 | draw a call graph for each thread with some information like | |
40892367 | 166 | the return value. This is done by setting the current return |
692105b8 | 167 | address on the current task structure into a stack of calls. |
15e6cb36 | 168 | |
bac429f0 | 169 | |
81d68a96 SR |
170 | config IRQSOFF_TRACER |
171 | bool "Interrupts-off Latency Tracer" | |
172 | default n | |
173 | depends on TRACE_IRQFLAGS_SUPPORT | |
592913ec | 174 | depends on !ARCH_USES_GETTIMEOFFSET |
81d68a96 | 175 | select TRACE_IRQFLAGS |
5e0a0939 | 176 | select GENERIC_TRACER |
81d68a96 | 177 | select TRACER_MAX_TRACE |
85bac32c | 178 | select RING_BUFFER_ALLOW_SWAP |
81d68a96 SR |
179 | help |
180 | This option measures the time spent in irqs-off critical | |
181 | sections, with microsecond accuracy. | |
182 | ||
183 | The default measurement method is a maximum search, which is | |
184 | disabled by default and can be runtime (re-)started | |
185 | via: | |
186 | ||
156f5a78 | 187 | echo 0 > /sys/kernel/debug/tracing/tracing_max_latency |
81d68a96 | 188 | |
40892367 | 189 | (Note that kernel size and overhead increase with this option |
6cd8a4bb SR |
190 | enabled. This option and the preempt-off timing option can be |
191 | used together or separately.) | |
192 | ||
193 | config PREEMPT_TRACER | |
194 | bool "Preemption-off Latency Tracer" | |
195 | default n | |
592913ec | 196 | depends on !ARCH_USES_GETTIMEOFFSET |
6cd8a4bb | 197 | depends on PREEMPT |
5e0a0939 | 198 | select GENERIC_TRACER |
6cd8a4bb | 199 | select TRACER_MAX_TRACE |
85bac32c | 200 | select RING_BUFFER_ALLOW_SWAP |
6cd8a4bb | 201 | help |
40892367 | 202 | This option measures the time spent in preemption-off critical |
6cd8a4bb SR |
203 | sections, with microsecond accuracy. |
204 | ||
205 | The default measurement method is a maximum search, which is | |
206 | disabled by default and can be runtime (re-)started | |
207 | via: | |
208 | ||
156f5a78 | 209 | echo 0 > /sys/kernel/debug/tracing/tracing_max_latency |
6cd8a4bb | 210 | |
40892367 | 211 | (Note that kernel size and overhead increase with this option |
6cd8a4bb SR |
212 | enabled. This option and the irqs-off timing option can be |
213 | used together or separately.) | |
214 | ||
352ad25a SR |
215 | config SCHED_TRACER |
216 | bool "Scheduling Latency Tracer" | |
5e0a0939 | 217 | select GENERIC_TRACER |
352ad25a SR |
218 | select CONTEXT_SWITCH_TRACER |
219 | select TRACER_MAX_TRACE | |
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 | ||
897f17a6 SR |
224 | config ENABLE_DEFAULT_TRACERS |
225 | bool "Trace process context switches and events" | |
5e0a0939 | 226 | depends on !GENERIC_TRACER |
b77e38aa SR |
227 | select TRACING |
228 | help | |
40892367 | 229 | This tracer hooks to various trace points in the kernel, |
b77e38aa | 230 | allowing the user to pick and choose which trace point they |
897f17a6 | 231 | want to trace. It also includes the sched_switch tracer plugin. |
a7abe97f | 232 | |
ee08c6ec FW |
233 | config FTRACE_SYSCALLS |
234 | bool "Trace syscalls" | |
66700001 | 235 | depends on HAVE_SYSCALL_TRACEPOINTS |
5e0a0939 | 236 | select GENERIC_TRACER |
0ea1c415 | 237 | select KALLSYMS |
ee08c6ec FW |
238 | help |
239 | Basic tracer to catch the syscall entry and exit events. | |
240 | ||
debdd57f HT |
241 | config 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 | ||
2ed84eeb | 251 | config TRACE_BRANCH_PROFILING |
9ae5b879 | 252 | bool |
5e0a0939 | 253 | select GENERIC_TRACER |
9ae5b879 SR |
254 | |
255 | choice | |
256 | prompt "Branch Profiling" | |
257 | default BRANCH_PROFILE_NONE | |
258 | help | |
259 | The branch profiling is a software profiler. It will add hooks | |
260 | into the C conditionals to test which path a branch takes. | |
261 | ||
262 | The likely/unlikely profiler only looks at the conditions that | |
263 | are annotated with a likely or unlikely macro. | |
264 | ||
40892367 | 265 | The "all branch" profiler will profile every if-statement in the |
9ae5b879 | 266 | kernel. This profiler will also enable the likely/unlikely |
40892367 | 267 | profiler. |
9ae5b879 | 268 | |
40892367 RD |
269 | Either of the above profilers adds a bit of overhead to the system. |
270 | If unsure, choose "No branch profiling". | |
9ae5b879 SR |
271 | |
272 | config BRANCH_PROFILE_NONE | |
273 | bool "No branch profiling" | |
274 | help | |
40892367 RD |
275 | No branch profiling. Branch profiling adds a bit of overhead. |
276 | Only enable it if you want to analyse the branching behavior. | |
277 | Otherwise keep it disabled. | |
9ae5b879 SR |
278 | |
279 | config PROFILE_ANNOTATED_BRANCHES | |
280 | bool "Trace likely/unlikely profiler" | |
281 | select TRACE_BRANCH_PROFILING | |
1f0d69a9 | 282 | help |
59bf8964 | 283 | This tracer profiles all likely and unlikely macros |
1f0d69a9 SR |
284 | in the kernel. It will display the results in: |
285 | ||
13e5befa | 286 | /sys/kernel/debug/tracing/trace_stat/branch_annotated |
1f0d69a9 | 287 | |
40892367 | 288 | Note: this will add a significant overhead; only turn this |
1f0d69a9 SR |
289 | on if you need to profile the system's use of these macros. |
290 | ||
2bcd521a SR |
291 | config PROFILE_ALL_BRANCHES |
292 | bool "Profile all if conditionals" | |
9ae5b879 | 293 | select TRACE_BRANCH_PROFILING |
2bcd521a SR |
294 | help |
295 | This tracer profiles all branch conditions. Every if () | |
296 | taken in the kernel is recorded whether it hit or miss. | |
297 | The results will be displayed in: | |
298 | ||
13e5befa | 299 | /sys/kernel/debug/tracing/trace_stat/branch_all |
2bcd521a | 300 | |
9ae5b879 SR |
301 | This option also enables the likely/unlikely profiler. |
302 | ||
2bcd521a SR |
303 | This configuration, when enabled, will impose a great overhead |
304 | on the system. This should only be enabled when the system | |
40892367 | 305 | is to be analyzed in much detail. |
9ae5b879 | 306 | endchoice |
2bcd521a | 307 | |
2ed84eeb | 308 | config TRACING_BRANCHES |
52f232cb SR |
309 | bool |
310 | help | |
311 | Selected by tracers that will trace the likely and unlikely | |
312 | conditions. This prevents the tracers themselves from being | |
313 | profiled. Profiling the tracing infrastructure can only happen | |
314 | when the likelys and unlikelys are not being traced. | |
315 | ||
2ed84eeb | 316 | config BRANCH_TRACER |
52f232cb | 317 | bool "Trace likely/unlikely instances" |
2ed84eeb SR |
318 | depends on TRACE_BRANCH_PROFILING |
319 | select TRACING_BRANCHES | |
52f232cb SR |
320 | help |
321 | This traces the events of likely and unlikely condition | |
322 | calls in the kernel. The difference between this and the | |
323 | "Trace likely/unlikely profiler" is that this is not a | |
324 | histogram of the callers, but actually places the calling | |
325 | events into a running trace buffer to see when and where the | |
326 | events happened, as well as their results. | |
327 | ||
328 | Say N if unsure. | |
329 | ||
e5a81b62 SR |
330 | config STACK_TRACER |
331 | bool "Trace max stack" | |
606576ce | 332 | depends on HAVE_FUNCTION_TRACER |
606576ce | 333 | select FUNCTION_TRACER |
e5a81b62 | 334 | select STACKTRACE |
4d7a077c | 335 | select KALLSYMS |
e5a81b62 | 336 | help |
4519d9e5 | 337 | This special tracer records the maximum stack footprint of the |
156f5a78 | 338 | kernel and displays it in /sys/kernel/debug/tracing/stack_trace. |
4519d9e5 IM |
339 | |
340 | This tracer works by hooking into every function call that the | |
341 | kernel executes, and keeping a maximum stack depth value and | |
f38f1d2a SR |
342 | stack-trace saved. If this is configured with DYNAMIC_FTRACE |
343 | then it will not have any overhead while the stack tracer | |
344 | is disabled. | |
345 | ||
346 | To enable the stack tracer on bootup, pass in 'stacktrace' | |
347 | on the kernel command line. | |
348 | ||
349 | The stack tracer can also be enabled or disabled via the | |
350 | sysctl kernel.stack_tracer_enabled | |
4519d9e5 IM |
351 | |
352 | Say N if unsure. | |
e5a81b62 | 353 | |
2db270a8 | 354 | config BLK_DEV_IO_TRACE |
40892367 | 355 | bool "Support for tracing block IO actions" |
2db270a8 | 356 | depends on SYSFS |
1dfba05d | 357 | depends on BLOCK |
2db270a8 FW |
358 | select RELAY |
359 | select DEBUG_FS | |
360 | select TRACEPOINTS | |
5e0a0939 | 361 | select GENERIC_TRACER |
2db270a8 FW |
362 | select STACKTRACE |
363 | help | |
364 | Say Y here if you want to be able to trace the block layer actions | |
365 | on a given queue. Tracing allows you to see any traffic happening | |
366 | on a block device queue. For more information (and the userspace | |
367 | support tools needed), fetch the blktrace tools from: | |
368 | ||
369 | git://git.kernel.dk/blktrace.git | |
370 | ||
371 | Tracing also is possible using the ftrace interface, e.g.: | |
372 | ||
373 | echo 1 > /sys/block/sda/sda1/trace/enable | |
374 | echo blk > /sys/kernel/debug/tracing/current_tracer | |
375 | cat /sys/kernel/debug/tracing/trace_pipe | |
376 | ||
377 | If unsure, say N. | |
36994e58 | 378 | |
77b44d1b | 379 | config KPROBE_EVENT |
413d37d1 | 380 | depends on KPROBES |
f850c30c | 381 | depends on HAVE_REGS_AND_STACK_ACCESS_API |
77b44d1b | 382 | bool "Enable kprobes-based dynamic events" |
413d37d1 | 383 | select TRACING |
8ab83f56 | 384 | select PROBE_EVENTS |
77b44d1b | 385 | default y |
413d37d1 | 386 | help |
40892367 RD |
387 | This allows the user to add tracing events (similar to tracepoints) |
388 | on the fly via the ftrace interface. See | |
389 | Documentation/trace/kprobetrace.txt for more details. | |
77b44d1b MH |
390 | |
391 | Those events can be inserted wherever kprobes can probe, and record | |
392 | various register and memory values. | |
393 | ||
40892367 RD |
394 | This option is also required by perf-probe subcommand of perf tools. |
395 | If you want to use perf tools, this option is strongly recommended. | |
413d37d1 | 396 | |
f3f096cf SD |
397 | config UPROBE_EVENT |
398 | bool "Enable uprobes-based dynamic events" | |
399 | depends on ARCH_SUPPORTS_UPROBES | |
400 | depends on MMU | |
401 | select UPROBES | |
402 | select PROBE_EVENTS | |
403 | select TRACING | |
404 | default n | |
405 | help | |
406 | This allows the user to add tracing events on top of userspace | |
407 | dynamic events (similar to tracepoints) on the fly via the trace | |
408 | events interface. Those events can be inserted wherever uprobes | |
409 | can probe, and record various registers. | |
410 | This option is required if you plan to use perf-probe subcommand | |
411 | of perf tools on user space applications. | |
412 | ||
8ab83f56 SD |
413 | config PROBE_EVENTS |
414 | def_bool n | |
415 | ||
3d083395 SR |
416 | config DYNAMIC_FTRACE |
417 | bool "enable/disable ftrace tracepoints dynamically" | |
606576ce | 418 | depends on FUNCTION_TRACER |
677aa9f7 | 419 | depends on HAVE_DYNAMIC_FTRACE |
3d083395 SR |
420 | default y |
421 | help | |
40892367 RD |
422 | This option will modify all the calls to ftrace dynamically |
423 | (will patch them out of the binary image and replace them | |
424 | with a No-Op instruction) as they are called. A table is | |
425 | created to dynamically enable them again. | |
3d083395 | 426 | |
40892367 RD |
427 | This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but |
428 | otherwise has native performance as long as no tracing is active. | |
3d083395 | 429 | |
40892367 RD |
430 | The changes to the code are done by a kernel thread that |
431 | wakes up once a second and checks to see if any ftrace calls | |
432 | were made. If so, it runs stop_machine (stops all CPUS) | |
433 | and modifies the code to jump over the call to ftrace. | |
60a11774 | 434 | |
06aeaaea MH |
435 | config DYNAMIC_FTRACE_WITH_REGS |
436 | def_bool y | |
437 | depends on DYNAMIC_FTRACE | |
438 | depends on HAVE_DYNAMIC_FTRACE_WITH_REGS | |
439 | ||
bac429f0 SR |
440 | config FUNCTION_PROFILER |
441 | bool "Kernel function profiler" | |
493762fc | 442 | depends on FUNCTION_TRACER |
bac429f0 SR |
443 | default n |
444 | help | |
40892367 RD |
445 | This option enables the kernel function profiler. A file is created |
446 | in debugfs called function_profile_enabled which defaults to zero. | |
447 | When a 1 is echoed into this file profiling begins, and when a | |
448 | zero is entered, profiling stops. A "functions" file is created in | |
449 | the trace_stats directory; this file shows the list of functions that | |
450 | have been hit and their counters. | |
bac429f0 | 451 | |
40892367 | 452 | If in doubt, say N. |
bac429f0 | 453 | |
8da3821b SR |
454 | config FTRACE_MCOUNT_RECORD |
455 | def_bool y | |
456 | depends on DYNAMIC_FTRACE | |
457 | depends on HAVE_FTRACE_MCOUNT_RECORD | |
458 | ||
60a11774 SR |
459 | config FTRACE_SELFTEST |
460 | bool | |
461 | ||
462 | config FTRACE_STARTUP_TEST | |
463 | bool "Perform a startup test on ftrace" | |
5e0a0939 | 464 | depends on GENERIC_TRACER |
60a11774 SR |
465 | select FTRACE_SELFTEST |
466 | help | |
467 | This option performs a series of startup tests on ftrace. On bootup | |
468 | a series of tests are made to verify that the tracer is | |
469 | functioning properly. It will do tests on all the configured | |
470 | tracers of ftrace. | |
17d80fd0 | 471 | |
1f5a6b45 SR |
472 | config EVENT_TRACE_TEST_SYSCALLS |
473 | bool "Run selftest on syscall events" | |
474 | depends on FTRACE_STARTUP_TEST | |
475 | help | |
476 | This option will also enable testing every syscall event. | |
477 | It only enables the event and disables it and runs various loads | |
478 | with the event enabled. This adds a bit more time for kernel boot | |
479 | up since it runs this on every system call defined. | |
480 | ||
481 | TBD - enable a way to actually call the syscalls as we test their | |
482 | events | |
483 | ||
fe6f90e5 PP |
484 | config MMIOTRACE |
485 | bool "Memory mapped IO tracing" | |
40ada30f | 486 | depends on HAVE_MMIOTRACE_SUPPORT && PCI |
5e0a0939 | 487 | select GENERIC_TRACER |
fe6f90e5 PP |
488 | help |
489 | Mmiotrace traces Memory Mapped I/O access and is meant for | |
490 | debugging and reverse engineering. It is called from the ioremap | |
491 | implementation and works via page faults. Tracing is disabled by | |
492 | default and can be enabled at run-time. | |
493 | ||
4d1f4372 | 494 | See Documentation/trace/mmiotrace.txt. |
fe6f90e5 PP |
495 | If you are not helping to develop drivers, say N. |
496 | ||
497 | config MMIOTRACE_TEST | |
498 | tristate "Test module for mmiotrace" | |
499 | depends on MMIOTRACE && m | |
500 | help | |
501 | This is a dumb module for testing mmiotrace. It is very dangerous | |
502 | as it will write garbage to IO memory starting at a given address. | |
503 | However, it should be safe to use on e.g. unused portion of VRAM. | |
504 | ||
505 | Say N, unless you absolutely know what you are doing. | |
506 | ||
5092dbc9 SR |
507 | config RING_BUFFER_BENCHMARK |
508 | tristate "Ring buffer benchmark stress tester" | |
509 | depends on RING_BUFFER | |
510 | help | |
40892367 RD |
511 | This option creates a test to stress the ring buffer and benchmark it. |
512 | It creates its own ring buffer such that it will not interfere with | |
5092dbc9 SR |
513 | any other users of the ring buffer (such as ftrace). It then creates |
514 | a producer and consumer that will run for 10 seconds and sleep for | |
515 | 10 seconds. Each interval it will print out the number of events | |
516 | it recorded and give a rough estimate of how long each iteration took. | |
517 | ||
518 | It does not disable interrupts or raise its priority, so it may be | |
519 | affected by processes that are running. | |
520 | ||
40892367 | 521 | If unsure, say N. |
5092dbc9 | 522 | |
4ed9f071 | 523 | endif # FTRACE |
40ada30f IM |
524 | |
525 | endif # TRACING_SUPPORT | |
526 |