Kconfig 14 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 EVENT_POWER_TRACING_DEPRECATED
  57. depends on EVENT_TRACING
  58. bool "Deprecated power event trace API, to be removed"
  59. default y
  60. help
  61. Provides old power event types:
  62. C-state/idle accounting events:
  63. power:power_start
  64. power:power_end
  65. and old cpufreq accounting event:
  66. power:power_frequency
  67. This is for userspace compatibility
  68. and will vanish after 5 kernel iterations,
  69. namely 2.6.41.
  70. config CONTEXT_SWITCH_TRACER
  71. bool
  72. config RING_BUFFER_ALLOW_SWAP
  73. bool
  74. help
  75. Allow the use of ring_buffer_swap_cpu.
  76. Adds a very slight overhead to tracing when enabled.
  77. # All tracer options should select GENERIC_TRACER. For those options that are
  78. # enabled by all tracers (context switch and event tracer) they select TRACING.
  79. # This allows those options to appear when no other tracer is selected. But the
  80. # options do not appear when something else selects it. We need the two options
  81. # GENERIC_TRACER and TRACING to avoid circular dependencies to accomplish the
  82. # hiding of the automatic options.
  83. config TRACING
  84. bool
  85. select DEBUG_FS
  86. select RING_BUFFER
  87. select STACKTRACE if STACKTRACE_SUPPORT
  88. select TRACEPOINTS
  89. select NOP_TRACER
  90. select BINARY_PRINTF
  91. select EVENT_TRACING
  92. config GENERIC_TRACER
  93. bool
  94. select TRACING
  95. #
  96. # Minimum requirements an architecture has to meet for us to
  97. # be able to offer generic tracing facilities:
  98. #
  99. config TRACING_SUPPORT
  100. bool
  101. # PPC32 has no irqflags tracing support, but it can use most of the
  102. # tracers anyway, they were tested to build and work. Note that new
  103. # exceptions to this list aren't welcomed, better implement the
  104. # irqflags tracing for your architecture.
  105. depends on TRACE_IRQFLAGS_SUPPORT || PPC32
  106. depends on STACKTRACE_SUPPORT
  107. default y
  108. if TRACING_SUPPORT
  109. menuconfig FTRACE
  110. bool "Tracers"
  111. default y if DEBUG_KERNEL
  112. help
  113. Enable the kernel tracing infrastructure.
  114. if FTRACE
  115. config FUNCTION_TRACER
  116. bool "Kernel Function Tracer"
  117. depends on HAVE_FUNCTION_TRACER
  118. select FRAME_POINTER if !ARM_UNWIND && !S390 && !MICROBLAZE
  119. select KALLSYMS
  120. select GENERIC_TRACER
  121. select CONTEXT_SWITCH_TRACER
  122. help
  123. Enable the kernel to trace every kernel function. This is done
  124. by using a compiler feature to insert a small, 5-byte No-Operation
  125. instruction at the beginning of every kernel function, which NOP
  126. sequence is then dynamically patched into a tracer call when
  127. tracing is enabled by the administrator. If it's runtime disabled
  128. (the bootup default), then the overhead of the instructions is very
  129. small and not measurable even in micro-benchmarks.
  130. config FUNCTION_GRAPH_TRACER
  131. bool "Kernel Function Graph Tracer"
  132. depends on HAVE_FUNCTION_GRAPH_TRACER
  133. depends on FUNCTION_TRACER
  134. depends on !X86_32 || !CC_OPTIMIZE_FOR_SIZE
  135. default y
  136. help
  137. Enable the kernel to trace a function at both its return
  138. and its entry.
  139. Its first purpose is to trace the duration of functions and
  140. draw a call graph for each thread with some information like
  141. the return value. This is done by setting the current return
  142. address on the current task structure into a stack of calls.
  143. config IRQSOFF_TRACER
  144. bool "Interrupts-off Latency Tracer"
  145. default n
  146. depends on TRACE_IRQFLAGS_SUPPORT
  147. depends on !ARCH_USES_GETTIMEOFFSET
  148. select TRACE_IRQFLAGS
  149. select GENERIC_TRACER
  150. select TRACER_MAX_TRACE
  151. select RING_BUFFER_ALLOW_SWAP
  152. help
  153. This option measures the time spent in irqs-off critical
  154. sections, with microsecond accuracy.
  155. The default measurement method is a maximum search, which is
  156. disabled by default and can be runtime (re-)started
  157. via:
  158. echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
  159. (Note that kernel size and overhead increase with this option
  160. enabled. This option and the preempt-off timing option can be
  161. used together or separately.)
  162. config PREEMPT_TRACER
  163. bool "Preemption-off Latency Tracer"
  164. default n
  165. depends on !ARCH_USES_GETTIMEOFFSET
  166. depends on PREEMPT
  167. select GENERIC_TRACER
  168. select TRACER_MAX_TRACE
  169. select RING_BUFFER_ALLOW_SWAP
  170. help
  171. This option measures the time spent in preemption-off critical
  172. sections, with microsecond accuracy.
  173. The default measurement method is a maximum search, which is
  174. disabled by default and can be runtime (re-)started
  175. via:
  176. echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
  177. (Note that kernel size and overhead increase with this option
  178. enabled. This option and the irqs-off timing option can be
  179. used together or separately.)
  180. config SCHED_TRACER
  181. bool "Scheduling Latency Tracer"
  182. select GENERIC_TRACER
  183. select CONTEXT_SWITCH_TRACER
  184. select TRACER_MAX_TRACE
  185. help
  186. This tracer tracks the latency of the highest priority task
  187. to be scheduled in, starting from the point it has woken up.
  188. config ENABLE_DEFAULT_TRACERS
  189. bool "Trace process context switches and events"
  190. depends on !GENERIC_TRACER
  191. select TRACING
  192. help
  193. This tracer hooks to various trace points in the kernel,
  194. allowing the user to pick and choose which trace point they
  195. want to trace. It also includes the sched_switch tracer plugin.
  196. config FTRACE_SYSCALLS
  197. bool "Trace syscalls"
  198. depends on HAVE_SYSCALL_TRACEPOINTS
  199. select GENERIC_TRACER
  200. select KALLSYMS
  201. help
  202. Basic tracer to catch the syscall entry and exit events.
  203. config TRACE_BRANCH_PROFILING
  204. bool
  205. select GENERIC_TRACER
  206. choice
  207. prompt "Branch Profiling"
  208. default BRANCH_PROFILE_NONE
  209. help
  210. The branch profiling is a software profiler. It will add hooks
  211. into the C conditionals to test which path a branch takes.
  212. The likely/unlikely profiler only looks at the conditions that
  213. are annotated with a likely or unlikely macro.
  214. The "all branch" profiler will profile every if-statement in the
  215. kernel. This profiler will also enable the likely/unlikely
  216. profiler.
  217. Either of the above profilers adds a bit of overhead to the system.
  218. If unsure, choose "No branch profiling".
  219. config BRANCH_PROFILE_NONE
  220. bool "No branch profiling"
  221. help
  222. No branch profiling. Branch profiling adds a bit of overhead.
  223. Only enable it if you want to analyse the branching behavior.
  224. Otherwise keep it disabled.
  225. config PROFILE_ANNOTATED_BRANCHES
  226. bool "Trace likely/unlikely profiler"
  227. select TRACE_BRANCH_PROFILING
  228. help
  229. This tracer profiles all the the likely and unlikely macros
  230. in the kernel. It will display the results in:
  231. /sys/kernel/debug/tracing/trace_stat/branch_annotated
  232. Note: this will add a significant overhead; only turn this
  233. on if you need to profile the system's use of these macros.
  234. config PROFILE_ALL_BRANCHES
  235. bool "Profile all if conditionals"
  236. select TRACE_BRANCH_PROFILING
  237. help
  238. This tracer profiles all branch conditions. Every if ()
  239. taken in the kernel is recorded whether it hit or miss.
  240. The results will be displayed in:
  241. /sys/kernel/debug/tracing/trace_stat/branch_all
  242. This option also enables the likely/unlikely profiler.
  243. This configuration, when enabled, will impose a great overhead
  244. on the system. This should only be enabled when the system
  245. is to be analyzed in much detail.
  246. endchoice
  247. config TRACING_BRANCHES
  248. bool
  249. help
  250. Selected by tracers that will trace the likely and unlikely
  251. conditions. This prevents the tracers themselves from being
  252. profiled. Profiling the tracing infrastructure can only happen
  253. when the likelys and unlikelys are not being traced.
  254. config BRANCH_TRACER
  255. bool "Trace likely/unlikely instances"
  256. depends on TRACE_BRANCH_PROFILING
  257. select TRACING_BRANCHES
  258. help
  259. This traces the events of likely and unlikely condition
  260. calls in the kernel. The difference between this and the
  261. "Trace likely/unlikely profiler" is that this is not a
  262. histogram of the callers, but actually places the calling
  263. events into a running trace buffer to see when and where the
  264. events happened, as well as their results.
  265. Say N if unsure.
  266. config STACK_TRACER
  267. bool "Trace max stack"
  268. depends on HAVE_FUNCTION_TRACER
  269. select FUNCTION_TRACER
  270. select STACKTRACE
  271. select KALLSYMS
  272. help
  273. This special tracer records the maximum stack footprint of the
  274. kernel and displays it in /sys/kernel/debug/tracing/stack_trace.
  275. This tracer works by hooking into every function call that the
  276. kernel executes, and keeping a maximum stack depth value and
  277. stack-trace saved. If this is configured with DYNAMIC_FTRACE
  278. then it will not have any overhead while the stack tracer
  279. is disabled.
  280. To enable the stack tracer on bootup, pass in 'stacktrace'
  281. on the kernel command line.
  282. The stack tracer can also be enabled or disabled via the
  283. sysctl kernel.stack_tracer_enabled
  284. Say N if unsure.
  285. config BLK_DEV_IO_TRACE
  286. bool "Support for tracing block IO actions"
  287. depends on SYSFS
  288. depends on BLOCK
  289. select RELAY
  290. select DEBUG_FS
  291. select TRACEPOINTS
  292. select GENERIC_TRACER
  293. select STACKTRACE
  294. help
  295. Say Y here if you want to be able to trace the block layer actions
  296. on a given queue. Tracing allows you to see any traffic happening
  297. on a block device queue. For more information (and the userspace
  298. support tools needed), fetch the blktrace tools from:
  299. git://git.kernel.dk/blktrace.git
  300. Tracing also is possible using the ftrace interface, e.g.:
  301. echo 1 > /sys/block/sda/sda1/trace/enable
  302. echo blk > /sys/kernel/debug/tracing/current_tracer
  303. cat /sys/kernel/debug/tracing/trace_pipe
  304. If unsure, say N.
  305. config KPROBE_EVENT
  306. depends on KPROBES
  307. depends on HAVE_REGS_AND_STACK_ACCESS_API
  308. bool "Enable kprobes-based dynamic events"
  309. select TRACING
  310. default y
  311. help
  312. This allows the user to add tracing events (similar to tracepoints)
  313. on the fly via the ftrace interface. See
  314. Documentation/trace/kprobetrace.txt for more details.
  315. Those events can be inserted wherever kprobes can probe, and record
  316. various register and memory values.
  317. This option is also required by perf-probe subcommand of perf tools.
  318. If you want to use perf tools, this option is strongly recommended.
  319. config DYNAMIC_FTRACE
  320. bool "enable/disable ftrace tracepoints dynamically"
  321. depends on FUNCTION_TRACER
  322. depends on HAVE_DYNAMIC_FTRACE
  323. default y
  324. help
  325. This option will modify all the calls to ftrace dynamically
  326. (will patch them out of the binary image and replace them
  327. with a No-Op instruction) as they are called. A table is
  328. created to dynamically enable them again.
  329. This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but
  330. otherwise has native performance as long as no tracing is active.
  331. The changes to the code are done by a kernel thread that
  332. wakes up once a second and checks to see if any ftrace calls
  333. were made. If so, it runs stop_machine (stops all CPUS)
  334. and modifies the code to jump over the call to ftrace.
  335. config FUNCTION_PROFILER
  336. bool "Kernel function profiler"
  337. depends on FUNCTION_TRACER
  338. default n
  339. help
  340. This option enables the kernel function profiler. A file is created
  341. in debugfs called function_profile_enabled which defaults to zero.
  342. When a 1 is echoed into this file profiling begins, and when a
  343. zero is entered, profiling stops. A "functions" file is created in
  344. the trace_stats directory; this file shows the list of functions that
  345. have been hit and their counters.
  346. If in doubt, say N.
  347. config FTRACE_MCOUNT_RECORD
  348. def_bool y
  349. depends on DYNAMIC_FTRACE
  350. depends on HAVE_FTRACE_MCOUNT_RECORD
  351. config FTRACE_SELFTEST
  352. bool
  353. config FTRACE_STARTUP_TEST
  354. bool "Perform a startup test on ftrace"
  355. depends on GENERIC_TRACER
  356. select FTRACE_SELFTEST
  357. help
  358. This option performs a series of startup tests on ftrace. On bootup
  359. a series of tests are made to verify that the tracer is
  360. functioning properly. It will do tests on all the configured
  361. tracers of ftrace.
  362. config EVENT_TRACE_TEST_SYSCALLS
  363. bool "Run selftest on syscall events"
  364. depends on FTRACE_STARTUP_TEST
  365. help
  366. This option will also enable testing every syscall event.
  367. It only enables the event and disables it and runs various loads
  368. with the event enabled. This adds a bit more time for kernel boot
  369. up since it runs this on every system call defined.
  370. TBD - enable a way to actually call the syscalls as we test their
  371. events
  372. config MMIOTRACE
  373. bool "Memory mapped IO tracing"
  374. depends on HAVE_MMIOTRACE_SUPPORT && PCI
  375. select GENERIC_TRACER
  376. help
  377. Mmiotrace traces Memory Mapped I/O access and is meant for
  378. debugging and reverse engineering. It is called from the ioremap
  379. implementation and works via page faults. Tracing is disabled by
  380. default and can be enabled at run-time.
  381. See Documentation/trace/mmiotrace.txt.
  382. If you are not helping to develop drivers, say N.
  383. config MMIOTRACE_TEST
  384. tristate "Test module for mmiotrace"
  385. depends on MMIOTRACE && m
  386. help
  387. This is a dumb module for testing mmiotrace. It is very dangerous
  388. as it will write garbage to IO memory starting at a given address.
  389. However, it should be safe to use on e.g. unused portion of VRAM.
  390. Say N, unless you absolutely know what you are doing.
  391. config RING_BUFFER_BENCHMARK
  392. tristate "Ring buffer benchmark stress tester"
  393. depends on RING_BUFFER
  394. help
  395. This option creates a test to stress the ring buffer and benchmark it.
  396. It creates its own ring buffer such that it will not interfere with
  397. any other users of the ring buffer (such as ftrace). It then creates
  398. a producer and consumer that will run for 10 seconds and sleep for
  399. 10 seconds. Each interval it will print out the number of events
  400. it recorded and give a rough estimate of how long each iteration took.
  401. It does not disable interrupts or raise its priority, so it may be
  402. affected by processes that are running.
  403. If unsure, say N.
  404. endif # FTRACE
  405. endif # TRACING_SUPPORT