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 | |
8da3821b SR |
42 | config HAVE_FTRACE_MCOUNT_RECORD |
43 | bool | |
555f386c | 44 | help |
40892367 | 45 | See Documentation/trace/ftrace-design.txt |
8da3821b | 46 | |
66700001 | 47 | config HAVE_SYSCALL_TRACEPOINTS |
ee08c6ec | 48 | bool |
555f386c | 49 | help |
40892367 | 50 | See Documentation/trace/ftrace-design.txt |
ee08c6ec | 51 | |
a2546fae SR |
52 | config HAVE_FENTRY |
53 | bool | |
54 | help | |
55 | Arch supports the gcc options -pg with -mfentry | |
56 | ||
cf4db259 | 57 | config HAVE_C_RECORDMCOUNT |
72441cb1 SR |
58 | bool |
59 | help | |
60 | C version of recordmcount available? | |
61 | ||
352ad25a SR |
62 | config TRACER_MAX_TRACE |
63 | bool | |
64 | ||
ea632e9f JT |
65 | config TRACE_CLOCK |
66 | bool | |
67 | ||
7a8e76a3 SR |
68 | config RING_BUFFER |
69 | bool | |
ea632e9f | 70 | select TRACE_CLOCK |
7a8e76a3 | 71 | |
78d904b4 SR |
72 | config FTRACE_NMI_ENTER |
73 | bool | |
74 | depends on HAVE_FTRACE_NMI_ENTER | |
75 | default y | |
76 | ||
5f77a88b | 77 | config EVENT_TRACING |
b11c53e1 Z |
78 | select CONTEXT_SWITCH_TRACER |
79 | bool | |
80 | ||
25e41933 TR |
81 | config EVENT_POWER_TRACING_DEPRECATED |
82 | depends on EVENT_TRACING | |
83 | bool "Deprecated power event trace API, to be removed" | |
84 | default y | |
85 | help | |
86 | Provides old power event types: | |
87 | C-state/idle accounting events: | |
88 | power:power_start | |
89 | power:power_end | |
90 | and old cpufreq accounting event: | |
91 | power:power_frequency | |
92 | This is for userspace compatibility | |
93 | and will vanish after 5 kernel iterations, | |
f629299b | 94 | namely 3.1. |
25e41933 | 95 | |
b11c53e1 | 96 | config CONTEXT_SWITCH_TRACER |
5f77a88b TZ |
97 | bool |
98 | ||
85bac32c SR |
99 | config RING_BUFFER_ALLOW_SWAP |
100 | bool | |
101 | help | |
102 | Allow the use of ring_buffer_swap_cpu. | |
103 | Adds a very slight overhead to tracing when enabled. | |
104 | ||
5e0a0939 SR |
105 | # All tracer options should select GENERIC_TRACER. For those options that are |
106 | # enabled by all tracers (context switch and event tracer) they select TRACING. | |
107 | # This allows those options to appear when no other tracer is selected. But the | |
108 | # options do not appear when something else selects it. We need the two options | |
109 | # GENERIC_TRACER and TRACING to avoid circular dependencies to accomplish the | |
40892367 | 110 | # hiding of the automatic options. |
5e0a0939 | 111 | |
bc0c38d1 SR |
112 | config TRACING |
113 | bool | |
114 | select DEBUG_FS | |
7a8e76a3 | 115 | select RING_BUFFER |
c2c80529 | 116 | select STACKTRACE if STACKTRACE_SUPPORT |
5f87f112 | 117 | select TRACEPOINTS |
f3384b28 | 118 | select NOP_TRACER |
769b0441 | 119 | select BINARY_PRINTF |
5f77a88b | 120 | select EVENT_TRACING |
ea632e9f | 121 | select TRACE_CLOCK |
0d5c6e1c | 122 | select IRQ_WORK |
bc0c38d1 | 123 | |
5e0a0939 SR |
124 | config GENERIC_TRACER |
125 | bool | |
126 | select TRACING | |
127 | ||
40ada30f IM |
128 | # |
129 | # Minimum requirements an architecture has to meet for us to | |
130 | # be able to offer generic tracing facilities: | |
131 | # | |
132 | config TRACING_SUPPORT | |
133 | bool | |
45b95608 AV |
134 | # PPC32 has no irqflags tracing support, but it can use most of the |
135 | # tracers anyway, they were tested to build and work. Note that new | |
136 | # exceptions to this list aren't welcomed, better implement the | |
137 | # irqflags tracing for your architecture. | |
138 | depends on TRACE_IRQFLAGS_SUPPORT || PPC32 | |
40ada30f | 139 | depends on STACKTRACE_SUPPORT |
422d3c7a | 140 | default y |
40ada30f IM |
141 | |
142 | if TRACING_SUPPORT | |
143 | ||
4ed9f071 SR |
144 | menuconfig FTRACE |
145 | bool "Tracers" | |
65b77242 | 146 | default y if DEBUG_KERNEL |
4ed9f071 | 147 | help |
40892367 | 148 | Enable the kernel tracing infrastructure. |
4ed9f071 SR |
149 | |
150 | if FTRACE | |
17d80fd0 | 151 | |
606576ce | 152 | config FUNCTION_TRACER |
1b29b018 | 153 | bool "Kernel Function Tracer" |
606576ce | 154 | depends on HAVE_FUNCTION_TRACER |
4d7a077c | 155 | select KALLSYMS |
5e0a0939 | 156 | select GENERIC_TRACER |
35e8e302 | 157 | select CONTEXT_SWITCH_TRACER |
1b29b018 SR |
158 | help |
159 | Enable the kernel to trace every kernel function. This is done | |
160 | by using a compiler feature to insert a small, 5-byte No-Operation | |
40892367 | 161 | instruction at the beginning of every kernel function, which NOP |
1b29b018 SR |
162 | sequence is then dynamically patched into a tracer call when |
163 | tracing is enabled by the administrator. If it's runtime disabled | |
164 | (the bootup default), then the overhead of the instructions is very | |
165 | small and not measurable even in micro-benchmarks. | |
35e8e302 | 166 | |
fb52607a FW |
167 | config FUNCTION_GRAPH_TRACER |
168 | bool "Kernel Function Graph Tracer" | |
169 | depends on HAVE_FUNCTION_GRAPH_TRACER | |
15e6cb36 | 170 | depends on FUNCTION_TRACER |
eb4a0378 | 171 | depends on !X86_32 || !CC_OPTIMIZE_FOR_SIZE |
764f3b95 | 172 | default y |
15e6cb36 | 173 | help |
fb52607a FW |
174 | Enable the kernel to trace a function at both its return |
175 | and its entry. | |
692105b8 ML |
176 | Its first purpose is to trace the duration of functions and |
177 | draw a call graph for each thread with some information like | |
40892367 | 178 | the return value. This is done by setting the current return |
692105b8 | 179 | address on the current task structure into a stack of calls. |
15e6cb36 | 180 | |
bac429f0 | 181 | |
81d68a96 SR |
182 | config IRQSOFF_TRACER |
183 | bool "Interrupts-off Latency Tracer" | |
184 | default n | |
185 | depends on TRACE_IRQFLAGS_SUPPORT | |
592913ec | 186 | depends on !ARCH_USES_GETTIMEOFFSET |
81d68a96 | 187 | select TRACE_IRQFLAGS |
5e0a0939 | 188 | select GENERIC_TRACER |
81d68a96 | 189 | select TRACER_MAX_TRACE |
85bac32c | 190 | select RING_BUFFER_ALLOW_SWAP |
81d68a96 SR |
191 | help |
192 | This option measures the time spent in irqs-off critical | |
193 | sections, with microsecond accuracy. | |
194 | ||
195 | The default measurement method is a maximum search, which is | |
196 | disabled by default and can be runtime (re-)started | |
197 | via: | |
198 | ||
156f5a78 | 199 | echo 0 > /sys/kernel/debug/tracing/tracing_max_latency |
81d68a96 | 200 | |
40892367 | 201 | (Note that kernel size and overhead increase with this option |
6cd8a4bb SR |
202 | enabled. This option and the preempt-off timing option can be |
203 | used together or separately.) | |
204 | ||
205 | config PREEMPT_TRACER | |
206 | bool "Preemption-off Latency Tracer" | |
207 | default n | |
592913ec | 208 | depends on !ARCH_USES_GETTIMEOFFSET |
6cd8a4bb | 209 | depends on PREEMPT |
5e0a0939 | 210 | select GENERIC_TRACER |
6cd8a4bb | 211 | select TRACER_MAX_TRACE |
85bac32c | 212 | select RING_BUFFER_ALLOW_SWAP |
6cd8a4bb | 213 | help |
40892367 | 214 | This option measures the time spent in preemption-off critical |
6cd8a4bb SR |
215 | sections, with microsecond accuracy. |
216 | ||
217 | The default measurement method is a maximum search, which is | |
218 | disabled by default and can be runtime (re-)started | |
219 | via: | |
220 | ||
156f5a78 | 221 | echo 0 > /sys/kernel/debug/tracing/tracing_max_latency |
6cd8a4bb | 222 | |
40892367 | 223 | (Note that kernel size and overhead increase with this option |
6cd8a4bb SR |
224 | enabled. This option and the irqs-off timing option can be |
225 | used together or separately.) | |
226 | ||
352ad25a SR |
227 | config SCHED_TRACER |
228 | bool "Scheduling Latency Tracer" | |
5e0a0939 | 229 | select GENERIC_TRACER |
352ad25a SR |
230 | select CONTEXT_SWITCH_TRACER |
231 | select TRACER_MAX_TRACE | |
232 | help | |
233 | This tracer tracks the latency of the highest priority task | |
234 | to be scheduled in, starting from the point it has woken up. | |
235 | ||
897f17a6 SR |
236 | config ENABLE_DEFAULT_TRACERS |
237 | bool "Trace process context switches and events" | |
5e0a0939 | 238 | depends on !GENERIC_TRACER |
b77e38aa SR |
239 | select TRACING |
240 | help | |
40892367 | 241 | This tracer hooks to various trace points in the kernel, |
b77e38aa | 242 | allowing the user to pick and choose which trace point they |
897f17a6 | 243 | want to trace. It also includes the sched_switch tracer plugin. |
a7abe97f | 244 | |
ee08c6ec FW |
245 | config FTRACE_SYSCALLS |
246 | bool "Trace syscalls" | |
66700001 | 247 | depends on HAVE_SYSCALL_TRACEPOINTS |
5e0a0939 | 248 | select GENERIC_TRACER |
0ea1c415 | 249 | select KALLSYMS |
ee08c6ec FW |
250 | help |
251 | Basic tracer to catch the syscall entry and exit events. | |
252 | ||
2ed84eeb | 253 | config TRACE_BRANCH_PROFILING |
9ae5b879 | 254 | bool |
5e0a0939 | 255 | select GENERIC_TRACER |
9ae5b879 SR |
256 | |
257 | choice | |
258 | prompt "Branch Profiling" | |
259 | default BRANCH_PROFILE_NONE | |
260 | help | |
261 | The branch profiling is a software profiler. It will add hooks | |
262 | into the C conditionals to test which path a branch takes. | |
263 | ||
264 | The likely/unlikely profiler only looks at the conditions that | |
265 | are annotated with a likely or unlikely macro. | |
266 | ||
40892367 | 267 | The "all branch" profiler will profile every if-statement in the |
9ae5b879 | 268 | kernel. This profiler will also enable the likely/unlikely |
40892367 | 269 | profiler. |
9ae5b879 | 270 | |
40892367 RD |
271 | Either of the above profilers adds a bit of overhead to the system. |
272 | If unsure, choose "No branch profiling". | |
9ae5b879 SR |
273 | |
274 | config BRANCH_PROFILE_NONE | |
275 | bool "No branch profiling" | |
276 | help | |
40892367 RD |
277 | No branch profiling. Branch profiling adds a bit of overhead. |
278 | Only enable it if you want to analyse the branching behavior. | |
279 | Otherwise keep it disabled. | |
9ae5b879 SR |
280 | |
281 | config PROFILE_ANNOTATED_BRANCHES | |
282 | bool "Trace likely/unlikely profiler" | |
283 | select TRACE_BRANCH_PROFILING | |
1f0d69a9 | 284 | help |
59bf8964 | 285 | This tracer profiles all likely and unlikely macros |
1f0d69a9 SR |
286 | in the kernel. It will display the results in: |
287 | ||
13e5befa | 288 | /sys/kernel/debug/tracing/trace_stat/branch_annotated |
1f0d69a9 | 289 | |
40892367 | 290 | Note: this will add a significant overhead; only turn this |
1f0d69a9 SR |
291 | on if you need to profile the system's use of these macros. |
292 | ||
2bcd521a SR |
293 | config PROFILE_ALL_BRANCHES |
294 | bool "Profile all if conditionals" | |
9ae5b879 | 295 | select TRACE_BRANCH_PROFILING |
2bcd521a SR |
296 | help |
297 | This tracer profiles all branch conditions. Every if () | |
298 | taken in the kernel is recorded whether it hit or miss. | |
299 | The results will be displayed in: | |
300 | ||
13e5befa | 301 | /sys/kernel/debug/tracing/trace_stat/branch_all |
2bcd521a | 302 | |
9ae5b879 SR |
303 | This option also enables the likely/unlikely profiler. |
304 | ||
2bcd521a SR |
305 | This configuration, when enabled, will impose a great overhead |
306 | on the system. This should only be enabled when the system | |
40892367 | 307 | is to be analyzed in much detail. |
9ae5b879 | 308 | endchoice |
2bcd521a | 309 | |
2ed84eeb | 310 | config TRACING_BRANCHES |
52f232cb SR |
311 | bool |
312 | help | |
313 | Selected by tracers that will trace the likely and unlikely | |
314 | conditions. This prevents the tracers themselves from being | |
315 | profiled. Profiling the tracing infrastructure can only happen | |
316 | when the likelys and unlikelys are not being traced. | |
317 | ||
2ed84eeb | 318 | config BRANCH_TRACER |
52f232cb | 319 | bool "Trace likely/unlikely instances" |
2ed84eeb SR |
320 | depends on TRACE_BRANCH_PROFILING |
321 | select TRACING_BRANCHES | |
52f232cb SR |
322 | help |
323 | This traces the events of likely and unlikely condition | |
324 | calls in the kernel. The difference between this and the | |
325 | "Trace likely/unlikely profiler" is that this is not a | |
326 | histogram of the callers, but actually places the calling | |
327 | events into a running trace buffer to see when and where the | |
328 | events happened, as well as their results. | |
329 | ||
330 | Say N if unsure. | |
331 | ||
e5a81b62 SR |
332 | config STACK_TRACER |
333 | bool "Trace max stack" | |
606576ce | 334 | depends on HAVE_FUNCTION_TRACER |
606576ce | 335 | select FUNCTION_TRACER |
e5a81b62 | 336 | select STACKTRACE |
4d7a077c | 337 | select KALLSYMS |
e5a81b62 | 338 | help |
4519d9e5 | 339 | This special tracer records the maximum stack footprint of the |
156f5a78 | 340 | kernel and displays it in /sys/kernel/debug/tracing/stack_trace. |
4519d9e5 IM |
341 | |
342 | This tracer works by hooking into every function call that the | |
343 | kernel executes, and keeping a maximum stack depth value and | |
f38f1d2a SR |
344 | stack-trace saved. If this is configured with DYNAMIC_FTRACE |
345 | then it will not have any overhead while the stack tracer | |
346 | is disabled. | |
347 | ||
348 | To enable the stack tracer on bootup, pass in 'stacktrace' | |
349 | on the kernel command line. | |
350 | ||
351 | The stack tracer can also be enabled or disabled via the | |
352 | sysctl kernel.stack_tracer_enabled | |
4519d9e5 IM |
353 | |
354 | Say N if unsure. | |
e5a81b62 | 355 | |
2db270a8 | 356 | config BLK_DEV_IO_TRACE |
40892367 | 357 | bool "Support for tracing block IO actions" |
2db270a8 | 358 | depends on SYSFS |
1dfba05d | 359 | depends on BLOCK |
2db270a8 FW |
360 | select RELAY |
361 | select DEBUG_FS | |
362 | select TRACEPOINTS | |
5e0a0939 | 363 | select GENERIC_TRACER |
2db270a8 FW |
364 | select STACKTRACE |
365 | help | |
366 | Say Y here if you want to be able to trace the block layer actions | |
367 | on a given queue. Tracing allows you to see any traffic happening | |
368 | on a block device queue. For more information (and the userspace | |
369 | support tools needed), fetch the blktrace tools from: | |
370 | ||
371 | git://git.kernel.dk/blktrace.git | |
372 | ||
373 | Tracing also is possible using the ftrace interface, e.g.: | |
374 | ||
375 | echo 1 > /sys/block/sda/sda1/trace/enable | |
376 | echo blk > /sys/kernel/debug/tracing/current_tracer | |
377 | cat /sys/kernel/debug/tracing/trace_pipe | |
378 | ||
379 | If unsure, say N. | |
36994e58 | 380 | |
77b44d1b | 381 | config KPROBE_EVENT |
413d37d1 | 382 | depends on KPROBES |
f850c30c | 383 | depends on HAVE_REGS_AND_STACK_ACCESS_API |
77b44d1b | 384 | bool "Enable kprobes-based dynamic events" |
413d37d1 | 385 | select TRACING |
8ab83f56 | 386 | select PROBE_EVENTS |
77b44d1b | 387 | default y |
413d37d1 | 388 | help |
40892367 RD |
389 | This allows the user to add tracing events (similar to tracepoints) |
390 | on the fly via the ftrace interface. See | |
391 | Documentation/trace/kprobetrace.txt for more details. | |
77b44d1b MH |
392 | |
393 | Those events can be inserted wherever kprobes can probe, and record | |
394 | various register and memory values. | |
395 | ||
40892367 RD |
396 | This option is also required by perf-probe subcommand of perf tools. |
397 | If you want to use perf tools, this option is strongly recommended. | |
413d37d1 | 398 | |
f3f096cf SD |
399 | config UPROBE_EVENT |
400 | bool "Enable uprobes-based dynamic events" | |
401 | depends on ARCH_SUPPORTS_UPROBES | |
402 | depends on MMU | |
403 | select UPROBES | |
404 | select PROBE_EVENTS | |
405 | select TRACING | |
406 | default n | |
407 | help | |
408 | This allows the user to add tracing events on top of userspace | |
409 | dynamic events (similar to tracepoints) on the fly via the trace | |
410 | events interface. Those events can be inserted wherever uprobes | |
411 | can probe, and record various registers. | |
412 | This option is required if you plan to use perf-probe subcommand | |
413 | of perf tools on user space applications. | |
414 | ||
8ab83f56 SD |
415 | config PROBE_EVENTS |
416 | def_bool n | |
417 | ||
3d083395 SR |
418 | config DYNAMIC_FTRACE |
419 | bool "enable/disable ftrace tracepoints dynamically" | |
606576ce | 420 | depends on FUNCTION_TRACER |
677aa9f7 | 421 | depends on HAVE_DYNAMIC_FTRACE |
3d083395 SR |
422 | default y |
423 | help | |
40892367 RD |
424 | This option will modify all the calls to ftrace dynamically |
425 | (will patch them out of the binary image and replace them | |
426 | with a No-Op instruction) as they are called. A table is | |
427 | created to dynamically enable them again. | |
3d083395 | 428 | |
40892367 RD |
429 | This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but |
430 | otherwise has native performance as long as no tracing is active. | |
3d083395 | 431 | |
40892367 RD |
432 | The changes to the code are done by a kernel thread that |
433 | wakes up once a second and checks to see if any ftrace calls | |
434 | were made. If so, it runs stop_machine (stops all CPUS) | |
435 | and modifies the code to jump over the call to ftrace. | |
60a11774 | 436 | |
bac429f0 SR |
437 | config FUNCTION_PROFILER |
438 | bool "Kernel function profiler" | |
493762fc | 439 | depends on FUNCTION_TRACER |
bac429f0 SR |
440 | default n |
441 | help | |
40892367 RD |
442 | This option enables the kernel function profiler. A file is created |
443 | in debugfs called function_profile_enabled which defaults to zero. | |
444 | When a 1 is echoed into this file profiling begins, and when a | |
445 | zero is entered, profiling stops. A "functions" file is created in | |
446 | the trace_stats directory; this file shows the list of functions that | |
447 | have been hit and their counters. | |
bac429f0 | 448 | |
40892367 | 449 | If in doubt, say N. |
bac429f0 | 450 | |
8da3821b SR |
451 | config FTRACE_MCOUNT_RECORD |
452 | def_bool y | |
453 | depends on DYNAMIC_FTRACE | |
454 | depends on HAVE_FTRACE_MCOUNT_RECORD | |
455 | ||
60a11774 SR |
456 | config FTRACE_SELFTEST |
457 | bool | |
458 | ||
459 | config FTRACE_STARTUP_TEST | |
460 | bool "Perform a startup test on ftrace" | |
5e0a0939 | 461 | depends on GENERIC_TRACER |
60a11774 SR |
462 | select FTRACE_SELFTEST |
463 | help | |
464 | This option performs a series of startup tests on ftrace. On bootup | |
465 | a series of tests are made to verify that the tracer is | |
466 | functioning properly. It will do tests on all the configured | |
467 | tracers of ftrace. | |
17d80fd0 | 468 | |
1f5a6b45 SR |
469 | config EVENT_TRACE_TEST_SYSCALLS |
470 | bool "Run selftest on syscall events" | |
471 | depends on FTRACE_STARTUP_TEST | |
472 | help | |
473 | This option will also enable testing every syscall event. | |
474 | It only enables the event and disables it and runs various loads | |
475 | with the event enabled. This adds a bit more time for kernel boot | |
476 | up since it runs this on every system call defined. | |
477 | ||
478 | TBD - enable a way to actually call the syscalls as we test their | |
479 | events | |
480 | ||
fe6f90e5 PP |
481 | config MMIOTRACE |
482 | bool "Memory mapped IO tracing" | |
40ada30f | 483 | depends on HAVE_MMIOTRACE_SUPPORT && PCI |
5e0a0939 | 484 | select GENERIC_TRACER |
fe6f90e5 PP |
485 | help |
486 | Mmiotrace traces Memory Mapped I/O access and is meant for | |
487 | debugging and reverse engineering. It is called from the ioremap | |
488 | implementation and works via page faults. Tracing is disabled by | |
489 | default and can be enabled at run-time. | |
490 | ||
4d1f4372 | 491 | See Documentation/trace/mmiotrace.txt. |
fe6f90e5 PP |
492 | If you are not helping to develop drivers, say N. |
493 | ||
494 | config MMIOTRACE_TEST | |
495 | tristate "Test module for mmiotrace" | |
496 | depends on MMIOTRACE && m | |
497 | help | |
498 | This is a dumb module for testing mmiotrace. It is very dangerous | |
499 | as it will write garbage to IO memory starting at a given address. | |
500 | However, it should be safe to use on e.g. unused portion of VRAM. | |
501 | ||
502 | Say N, unless you absolutely know what you are doing. | |
503 | ||
5092dbc9 SR |
504 | config RING_BUFFER_BENCHMARK |
505 | tristate "Ring buffer benchmark stress tester" | |
506 | depends on RING_BUFFER | |
507 | help | |
40892367 RD |
508 | This option creates a test to stress the ring buffer and benchmark it. |
509 | It creates its own ring buffer such that it will not interfere with | |
5092dbc9 SR |
510 | any other users of the ring buffer (such as ftrace). It then creates |
511 | a producer and consumer that will run for 10 seconds and sleep for | |
512 | 10 seconds. Each interval it will print out the number of events | |
513 | it recorded and give a rough estimate of how long each iteration took. | |
514 | ||
515 | It does not disable interrupts or raise its priority, so it may be | |
516 | affected by processes that are running. | |
517 | ||
40892367 | 518 | If unsure, say N. |
5092dbc9 | 519 | |
4ed9f071 | 520 | endif # FTRACE |
40ada30f IM |
521 | |
522 | endif # TRACING_SUPPORT | |
523 |