Kconfig 15 KB

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  1. #
  2. # Architectures that offer an FUNCTION_TRACER implementation should
  3. # select HAVE_FUNCTION_TRACER:
  4. #
  5. config USER_STACKTRACE_SUPPORT
  6. bool
  7. config NOP_TRACER
  8. bool
  9. config HAVE_FTRACE_NMI_ENTER
  10. bool
  11. help
  12. See Documentation/trace/ftrace-design.txt
  13. config HAVE_FUNCTION_TRACER
  14. bool
  15. help
  16. See Documentation/trace/ftrace-design.txt
  17. config HAVE_FUNCTION_GRAPH_TRACER
  18. bool
  19. help
  20. See Documentation/trace/ftrace-design.txt
  21. config HAVE_FUNCTION_GRAPH_FP_TEST
  22. bool
  23. help
  24. See Documentation/trace/ftrace-design.txt
  25. config HAVE_FUNCTION_TRACE_MCOUNT_TEST
  26. bool
  27. help
  28. See Documentation/trace/ftrace-design.txt
  29. config HAVE_DYNAMIC_FTRACE
  30. bool
  31. help
  32. See Documentation/trace/ftrace-design.txt
  33. config HAVE_FTRACE_MCOUNT_RECORD
  34. bool
  35. help
  36. See Documentation/trace/ftrace-design.txt
  37. config HAVE_SYSCALL_TRACEPOINTS
  38. bool
  39. help
  40. See Documentation/trace/ftrace-design.txt
  41. config HAVE_C_RECORDMCOUNT
  42. bool
  43. help
  44. C version of recordmcount available?
  45. config TRACER_MAX_TRACE
  46. bool
  47. config RING_BUFFER
  48. bool
  49. config FTRACE_NMI_ENTER
  50. bool
  51. depends on HAVE_FTRACE_NMI_ENTER
  52. default y
  53. config EVENT_TRACING
  54. select CONTEXT_SWITCH_TRACER
  55. bool
  56. config GPU_TRACEPOINTS
  57. bool
  58. config CONTEXT_SWITCH_TRACER
  59. bool
  60. config RING_BUFFER_ALLOW_SWAP
  61. bool
  62. help
  63. Allow the use of ring_buffer_swap_cpu.
  64. Adds a very slight overhead to tracing when enabled.
  65. # All tracer options should select GENERIC_TRACER. For those options that are
  66. # enabled by all tracers (context switch and event tracer) they select TRACING.
  67. # This allows those options to appear when no other tracer is selected. But the
  68. # options do not appear when something else selects it. We need the two options
  69. # GENERIC_TRACER and TRACING to avoid circular dependencies to accomplish the
  70. # hiding of the automatic options.
  71. config TRACING
  72. bool
  73. select DEBUG_FS
  74. select RING_BUFFER
  75. select STACKTRACE if STACKTRACE_SUPPORT
  76. select TRACEPOINTS
  77. select NOP_TRACER
  78. select BINARY_PRINTF
  79. select EVENT_TRACING
  80. config GENERIC_TRACER
  81. bool
  82. select TRACING
  83. #
  84. # Minimum requirements an architecture has to meet for us to
  85. # be able to offer generic tracing facilities:
  86. #
  87. config TRACING_SUPPORT
  88. bool
  89. # PPC32 has no irqflags tracing support, but it can use most of the
  90. # tracers anyway, they were tested to build and work. Note that new
  91. # exceptions to this list aren't welcomed, better implement the
  92. # irqflags tracing for your architecture.
  93. depends on TRACE_IRQFLAGS_SUPPORT || PPC32
  94. depends on STACKTRACE_SUPPORT
  95. default y
  96. if TRACING_SUPPORT
  97. menuconfig FTRACE
  98. bool "Tracers"
  99. default y if DEBUG_KERNEL
  100. help
  101. Enable the kernel tracing infrastructure.
  102. if FTRACE
  103. config FUNCTION_TRACER
  104. bool "Kernel Function Tracer"
  105. depends on HAVE_FUNCTION_TRACER
  106. select FRAME_POINTER if !ARM_UNWIND && !PPC && !S390 && !MICROBLAZE
  107. select KALLSYMS
  108. select GENERIC_TRACER
  109. select CONTEXT_SWITCH_TRACER
  110. help
  111. Enable the kernel to trace every kernel function. This is done
  112. by using a compiler feature to insert a small, 5-byte No-Operation
  113. instruction at the beginning of every kernel function, which NOP
  114. sequence is then dynamically patched into a tracer call when
  115. tracing is enabled by the administrator. If it's runtime disabled
  116. (the bootup default), then the overhead of the instructions is very
  117. small and not measurable even in micro-benchmarks.
  118. config FUNCTION_GRAPH_TRACER
  119. bool "Kernel Function Graph Tracer"
  120. depends on HAVE_FUNCTION_GRAPH_TRACER
  121. depends on FUNCTION_TRACER
  122. depends on !X86_32 || !CC_OPTIMIZE_FOR_SIZE
  123. default y
  124. help
  125. Enable the kernel to trace a function at both its return
  126. and its entry.
  127. Its first purpose is to trace the duration of functions and
  128. draw a call graph for each thread with some information like
  129. the return value. This is done by setting the current return
  130. address on the current task structure into a stack of calls.
  131. config IRQSOFF_TRACER
  132. bool "Interrupts-off Latency Tracer"
  133. default n
  134. depends on TRACE_IRQFLAGS_SUPPORT
  135. depends on !ARCH_USES_GETTIMEOFFSET
  136. select TRACE_IRQFLAGS
  137. select GENERIC_TRACER
  138. select TRACER_MAX_TRACE
  139. select RING_BUFFER_ALLOW_SWAP
  140. help
  141. This option measures the time spent in irqs-off critical
  142. sections, with microsecond accuracy.
  143. The default measurement method is a maximum search, which is
  144. disabled by default and can be runtime (re-)started
  145. via:
  146. echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
  147. (Note that kernel size and overhead increase with this option
  148. enabled. This option and the preempt-off timing option can be
  149. used together or separately.)
  150. config PREEMPT_TRACER
  151. bool "Preemption-off Latency Tracer"
  152. default n
  153. depends on !ARCH_USES_GETTIMEOFFSET
  154. depends on PREEMPT
  155. select GENERIC_TRACER
  156. select TRACER_MAX_TRACE
  157. select RING_BUFFER_ALLOW_SWAP
  158. help
  159. This option measures the time spent in preemption-off critical
  160. sections, with microsecond accuracy.
  161. The default measurement method is a maximum search, which is
  162. disabled by default and can be runtime (re-)started
  163. via:
  164. echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
  165. (Note that kernel size and overhead increase with this option
  166. enabled. This option and the irqs-off timing option can be
  167. used together or separately.)
  168. config SCHED_TRACER
  169. bool "Scheduling Latency Tracer"
  170. select GENERIC_TRACER
  171. select CONTEXT_SWITCH_TRACER
  172. select TRACER_MAX_TRACE
  173. help
  174. This tracer tracks the latency of the highest priority task
  175. to be scheduled in, starting from the point it has woken up.
  176. config ENABLE_DEFAULT_TRACERS
  177. bool "Trace process context switches and events"
  178. depends on !GENERIC_TRACER
  179. select TRACING
  180. help
  181. This tracer hooks to various trace points in the kernel,
  182. allowing the user to pick and choose which trace point they
  183. want to trace. It also includes the sched_switch tracer plugin.
  184. config FTRACE_SYSCALLS
  185. bool "Trace syscalls"
  186. depends on HAVE_SYSCALL_TRACEPOINTS
  187. select GENERIC_TRACER
  188. select KALLSYMS
  189. help
  190. Basic tracer to catch the syscall entry and exit events.
  191. config TRACE_BRANCH_PROFILING
  192. bool
  193. select GENERIC_TRACER
  194. choice
  195. prompt "Branch Profiling"
  196. default BRANCH_PROFILE_NONE
  197. help
  198. The branch profiling is a software profiler. It will add hooks
  199. into the C conditionals to test which path a branch takes.
  200. The likely/unlikely profiler only looks at the conditions that
  201. are annotated with a likely or unlikely macro.
  202. The "all branch" profiler will profile every if-statement in the
  203. kernel. This profiler will also enable the likely/unlikely
  204. profiler.
  205. Either of the above profilers adds a bit of overhead to the system.
  206. If unsure, choose "No branch profiling".
  207. config BRANCH_PROFILE_NONE
  208. bool "No branch profiling"
  209. help
  210. No branch profiling. Branch profiling adds a bit of overhead.
  211. Only enable it if you want to analyse the branching behavior.
  212. Otherwise keep it disabled.
  213. config PROFILE_ANNOTATED_BRANCHES
  214. bool "Trace likely/unlikely profiler"
  215. select TRACE_BRANCH_PROFILING
  216. help
  217. This tracer profiles all the the likely and unlikely macros
  218. in the kernel. It will display the results in:
  219. /sys/kernel/debug/tracing/trace_stat/branch_annotated
  220. Note: this will add a significant overhead; only turn this
  221. on if you need to profile the system's use of these macros.
  222. config PROFILE_ALL_BRANCHES
  223. bool "Profile all if conditionals"
  224. select TRACE_BRANCH_PROFILING
  225. help
  226. This tracer profiles all branch conditions. Every if ()
  227. taken in the kernel is recorded whether it hit or miss.
  228. The results will be displayed in:
  229. /sys/kernel/debug/tracing/trace_stat/branch_all
  230. This option also enables the likely/unlikely profiler.
  231. This configuration, when enabled, will impose a great overhead
  232. on the system. This should only be enabled when the system
  233. is to be analyzed in much detail.
  234. endchoice
  235. config TRACING_BRANCHES
  236. bool
  237. help
  238. Selected by tracers that will trace the likely and unlikely
  239. conditions. This prevents the tracers themselves from being
  240. profiled. Profiling the tracing infrastructure can only happen
  241. when the likelys and unlikelys are not being traced.
  242. config BRANCH_TRACER
  243. bool "Trace likely/unlikely instances"
  244. depends on TRACE_BRANCH_PROFILING
  245. select TRACING_BRANCHES
  246. help
  247. This traces the events of likely and unlikely condition
  248. calls in the kernel. The difference between this and the
  249. "Trace likely/unlikely profiler" is that this is not a
  250. histogram of the callers, but actually places the calling
  251. events into a running trace buffer to see when and where the
  252. events happened, as well as their results.
  253. Say N if unsure.
  254. config STACK_TRACER
  255. bool "Trace max stack"
  256. depends on HAVE_FUNCTION_TRACER
  257. select FUNCTION_TRACER
  258. select STACKTRACE
  259. select KALLSYMS
  260. help
  261. This special tracer records the maximum stack footprint of the
  262. kernel and displays it in /sys/kernel/debug/tracing/stack_trace.
  263. This tracer works by hooking into every function call that the
  264. kernel executes, and keeping a maximum stack depth value and
  265. stack-trace saved. If this is configured with DYNAMIC_FTRACE
  266. then it will not have any overhead while the stack tracer
  267. is disabled.
  268. To enable the stack tracer on bootup, pass in 'stacktrace'
  269. on the kernel command line.
  270. The stack tracer can also be enabled or disabled via the
  271. sysctl kernel.stack_tracer_enabled
  272. Say N if unsure.
  273. config BLK_DEV_IO_TRACE
  274. bool "Support for tracing block IO actions"
  275. depends on SYSFS
  276. depends on BLOCK
  277. select RELAY
  278. select DEBUG_FS
  279. select TRACEPOINTS
  280. select GENERIC_TRACER
  281. select STACKTRACE
  282. help
  283. Say Y here if you want to be able to trace the block layer actions
  284. on a given queue. Tracing allows you to see any traffic happening
  285. on a block device queue. For more information (and the userspace
  286. support tools needed), fetch the blktrace tools from:
  287. git://git.kernel.dk/blktrace.git
  288. Tracing also is possible using the ftrace interface, e.g.:
  289. echo 1 > /sys/block/sda/sda1/trace/enable
  290. echo blk > /sys/kernel/debug/tracing/current_tracer
  291. cat /sys/kernel/debug/tracing/trace_pipe
  292. If unsure, say N.
  293. config KPROBE_EVENT
  294. depends on KPROBES
  295. depends on HAVE_REGS_AND_STACK_ACCESS_API
  296. bool "Enable kprobes-based dynamic events"
  297. select TRACING
  298. default y
  299. help
  300. This allows the user to add tracing events (similar to tracepoints)
  301. on the fly via the ftrace interface. See
  302. Documentation/trace/kprobetrace.txt for more details.
  303. Those events can be inserted wherever kprobes can probe, and record
  304. various register and memory values.
  305. This option is also required by perf-probe subcommand of perf tools.
  306. If you want to use perf tools, this option is strongly recommended.
  307. config DYNAMIC_FTRACE
  308. bool "enable/disable function tracing dynamically"
  309. depends on FUNCTION_TRACER
  310. depends on HAVE_DYNAMIC_FTRACE
  311. default y
  312. help
  313. This option will modify all the calls to function tracing
  314. dynamically (will patch them out of the binary image and
  315. replace them with a No-Op instruction) on boot up. During
  316. compile time, a table is made of all the locations that ftrace
  317. can function trace, and this table is linked into the kernel
  318. image. When this is enabled, functions can be individually
  319. enabled, and the functions not enabled will not affect
  320. performance of the system.
  321. See the files in /sys/kernel/debug/tracing:
  322. available_filter_functions
  323. set_ftrace_filter
  324. set_ftrace_notrace
  325. This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but
  326. otherwise has native performance as long as no tracing is active.
  327. config FUNCTION_PROFILER
  328. bool "Kernel function profiler"
  329. depends on FUNCTION_TRACER
  330. default n
  331. help
  332. This option enables the kernel function profiler. A file is created
  333. in debugfs called function_profile_enabled which defaults to zero.
  334. When a 1 is echoed into this file profiling begins, and when a
  335. zero is entered, profiling stops. A "functions" file is created in
  336. the trace_stats directory; this file shows the list of functions that
  337. have been hit and their counters.
  338. If in doubt, say N.
  339. config CPU_FREQ_SWITCH_PROFILER
  340. bool "CPU frequency switch time profiler"
  341. select GENERIC_TRACER
  342. help
  343. This option enables the CPU frequency switch profiler. A file is
  344. created in debugfs called "cpu_freq_switch_profile_enabled", which
  345. defaults to zero. When a 1 is echoed into this file, profiling begins.
  346. When a zero is echoed, profiling stops. A "cpu_freq_switch" file is
  347. also created in the trace_stats directory; this file shows the
  348. switches that have occurred and duration statistics.
  349. If in doubt, say N.
  350. config FTRACE_MCOUNT_RECORD
  351. def_bool y
  352. depends on DYNAMIC_FTRACE
  353. depends on HAVE_FTRACE_MCOUNT_RECORD
  354. config FTRACE_SELFTEST
  355. bool
  356. config FTRACE_STARTUP_TEST
  357. bool "Perform a startup test on ftrace"
  358. depends on GENERIC_TRACER
  359. select FTRACE_SELFTEST
  360. help
  361. This option performs a series of startup tests on ftrace. On bootup
  362. a series of tests are made to verify that the tracer is
  363. functioning properly. It will do tests on all the configured
  364. tracers of ftrace.
  365. config EVENT_TRACE_TEST_SYSCALLS
  366. bool "Run selftest on syscall events"
  367. depends on FTRACE_STARTUP_TEST
  368. help
  369. This option will also enable testing every syscall event.
  370. It only enables the event and disables it and runs various loads
  371. with the event enabled. This adds a bit more time for kernel boot
  372. up since it runs this on every system call defined.
  373. TBD - enable a way to actually call the syscalls as we test their
  374. events
  375. config MMIOTRACE
  376. bool "Memory mapped IO tracing"
  377. depends on HAVE_MMIOTRACE_SUPPORT && PCI
  378. select GENERIC_TRACER
  379. help
  380. Mmiotrace traces Memory Mapped I/O access and is meant for
  381. debugging and reverse engineering. It is called from the ioremap
  382. implementation and works via page faults. Tracing is disabled by
  383. default and can be enabled at run-time.
  384. See Documentation/trace/mmiotrace.txt.
  385. If you are not helping to develop drivers, say N.
  386. config MMIOTRACE_TEST
  387. tristate "Test module for mmiotrace"
  388. depends on MMIOTRACE && m
  389. help
  390. This is a dumb module for testing mmiotrace. It is very dangerous
  391. as it will write garbage to IO memory starting at a given address.
  392. However, it should be safe to use on e.g. unused portion of VRAM.
  393. Say N, unless you absolutely know what you are doing.
  394. config RING_BUFFER_BENCHMARK
  395. tristate "Ring buffer benchmark stress tester"
  396. depends on RING_BUFFER
  397. help
  398. This option creates a test to stress the ring buffer and benchmark it.
  399. It creates its own ring buffer such that it will not interfere with
  400. any other users of the ring buffer (such as ftrace). It then creates
  401. a producer and consumer that will run for 10 seconds and sleep for
  402. 10 seconds. Each interval it will print out the number of events
  403. it recorded and give a rough estimate of how long each iteration took.
  404. It does not disable interrupts or raise its priority, so it may be
  405. affected by processes that are running.
  406. If unsure, say N.
  407. endif # FTRACE
  408. endif # TRACING_SUPPORT