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 EVENT_POWER_TRACING_DEPRECATED
  59. depends on EVENT_TRACING
  60. bool "Deprecated power event trace API, to be removed"
  61. default y
  62. help
  63. Provides old power event types:
  64. C-state/idle accounting events:
  65. power:power_start
  66. power:power_end
  67. and old cpufreq accounting event:
  68. power:power_frequency
  69. This is for userspace compatibility
  70. and will vanish after 5 kernel iterations,
  71. namely 3.1.
  72. config CONTEXT_SWITCH_TRACER
  73. bool
  74. config RING_BUFFER_ALLOW_SWAP
  75. bool
  76. help
  77. Allow the use of ring_buffer_swap_cpu.
  78. Adds a very slight overhead to tracing when enabled.
  79. # All tracer options should select GENERIC_TRACER. For those options that are
  80. # enabled by all tracers (context switch and event tracer) they select TRACING.
  81. # This allows those options to appear when no other tracer is selected. But the
  82. # options do not appear when something else selects it. We need the two options
  83. # GENERIC_TRACER and TRACING to avoid circular dependencies to accomplish the
  84. # hiding of the automatic options.
  85. config TRACING
  86. bool
  87. select DEBUG_FS
  88. select RING_BUFFER
  89. select STACKTRACE if STACKTRACE_SUPPORT
  90. select TRACEPOINTS
  91. select NOP_TRACER
  92. select BINARY_PRINTF
  93. select EVENT_TRACING
  94. config GENERIC_TRACER
  95. bool
  96. select TRACING
  97. #
  98. # Minimum requirements an architecture has to meet for us to
  99. # be able to offer generic tracing facilities:
  100. #
  101. config TRACING_SUPPORT
  102. bool
  103. # PPC32 has no irqflags tracing support, but it can use most of the
  104. # tracers anyway, they were tested to build and work. Note that new
  105. # exceptions to this list aren't welcomed, better implement the
  106. # irqflags tracing for your architecture.
  107. depends on TRACE_IRQFLAGS_SUPPORT || PPC32
  108. depends on STACKTRACE_SUPPORT
  109. default y
  110. if TRACING_SUPPORT
  111. menuconfig FTRACE
  112. bool "Tracers"
  113. default y if DEBUG_KERNEL
  114. help
  115. Enable the kernel tracing infrastructure.
  116. if FTRACE
  117. config FUNCTION_TRACER
  118. bool "Kernel Function Tracer"
  119. depends on HAVE_FUNCTION_TRACER
  120. select FRAME_POINTER if !ARM_UNWIND && !PPC && !S390 && !MICROBLAZE
  121. select KALLSYMS
  122. select GENERIC_TRACER
  123. select CONTEXT_SWITCH_TRACER
  124. help
  125. Enable the kernel to trace every kernel function. This is done
  126. by using a compiler feature to insert a small, 5-byte No-Operation
  127. instruction at the beginning of every kernel function, which NOP
  128. sequence is then dynamically patched into a tracer call when
  129. tracing is enabled by the administrator. If it's runtime disabled
  130. (the bootup default), then the overhead of the instructions is very
  131. small and not measurable even in micro-benchmarks.
  132. config FUNCTION_GRAPH_TRACER
  133. bool "Kernel Function Graph Tracer"
  134. depends on HAVE_FUNCTION_GRAPH_TRACER
  135. depends on FUNCTION_TRACER
  136. depends on !X86_32 || !CC_OPTIMIZE_FOR_SIZE
  137. default y
  138. help
  139. Enable the kernel to trace a function at both its return
  140. and its entry.
  141. Its first purpose is to trace the duration of functions and
  142. draw a call graph for each thread with some information like
  143. the return value. This is done by setting the current return
  144. address on the current task structure into a stack of calls.
  145. config IRQSOFF_TRACER
  146. bool "Interrupts-off Latency Tracer"
  147. default n
  148. depends on TRACE_IRQFLAGS_SUPPORT
  149. depends on !ARCH_USES_GETTIMEOFFSET
  150. select TRACE_IRQFLAGS
  151. select GENERIC_TRACER
  152. select TRACER_MAX_TRACE
  153. select RING_BUFFER_ALLOW_SWAP
  154. help
  155. This option measures the time spent in irqs-off critical
  156. sections, with microsecond accuracy.
  157. The default measurement method is a maximum search, which is
  158. disabled by default and can be runtime (re-)started
  159. via:
  160. echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
  161. (Note that kernel size and overhead increase with this option
  162. enabled. This option and the preempt-off timing option can be
  163. used together or separately.)
  164. config PREEMPT_TRACER
  165. bool "Preemption-off Latency Tracer"
  166. default n
  167. depends on !ARCH_USES_GETTIMEOFFSET
  168. depends on PREEMPT
  169. select GENERIC_TRACER
  170. select TRACER_MAX_TRACE
  171. select RING_BUFFER_ALLOW_SWAP
  172. help
  173. This option measures the time spent in preemption-off critical
  174. sections, with microsecond accuracy.
  175. The default measurement method is a maximum search, which is
  176. disabled by default and can be runtime (re-)started
  177. via:
  178. echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
  179. (Note that kernel size and overhead increase with this option
  180. enabled. This option and the irqs-off timing option can be
  181. used together or separately.)
  182. config SCHED_TRACER
  183. bool "Scheduling Latency Tracer"
  184. select GENERIC_TRACER
  185. select CONTEXT_SWITCH_TRACER
  186. select TRACER_MAX_TRACE
  187. help
  188. This tracer tracks the latency of the highest priority task
  189. to be scheduled in, starting from the point it has woken up.
  190. config ENABLE_DEFAULT_TRACERS
  191. bool "Trace process context switches and events"
  192. depends on !GENERIC_TRACER
  193. select TRACING
  194. help
  195. This tracer hooks to various trace points in the kernel,
  196. allowing the user to pick and choose which trace point they
  197. want to trace. It also includes the sched_switch tracer plugin.
  198. config FTRACE_SYSCALLS
  199. bool "Trace syscalls"
  200. depends on HAVE_SYSCALL_TRACEPOINTS
  201. select GENERIC_TRACER
  202. select KALLSYMS
  203. help
  204. Basic tracer to catch the syscall entry and exit events.
  205. config TRACE_BRANCH_PROFILING
  206. bool
  207. select GENERIC_TRACER
  208. choice
  209. prompt "Branch Profiling"
  210. default BRANCH_PROFILE_NONE
  211. help
  212. The branch profiling is a software profiler. It will add hooks
  213. into the C conditionals to test which path a branch takes.
  214. The likely/unlikely profiler only looks at the conditions that
  215. are annotated with a likely or unlikely macro.
  216. The "all branch" profiler will profile every if-statement in the
  217. kernel. This profiler will also enable the likely/unlikely
  218. profiler.
  219. Either of the above profilers adds a bit of overhead to the system.
  220. If unsure, choose "No branch profiling".
  221. config BRANCH_PROFILE_NONE
  222. bool "No branch profiling"
  223. help
  224. No branch profiling. Branch profiling adds a bit of overhead.
  225. Only enable it if you want to analyse the branching behavior.
  226. Otherwise keep it disabled.
  227. config PROFILE_ANNOTATED_BRANCHES
  228. bool "Trace likely/unlikely profiler"
  229. select TRACE_BRANCH_PROFILING
  230. help
  231. This tracer profiles all the the likely and unlikely macros
  232. in the kernel. It will display the results in:
  233. /sys/kernel/debug/tracing/trace_stat/branch_annotated
  234. Note: this will add a significant overhead; only turn this
  235. on if you need to profile the system's use of these macros.
  236. config PROFILE_ALL_BRANCHES
  237. bool "Profile all if conditionals"
  238. select TRACE_BRANCH_PROFILING
  239. help
  240. This tracer profiles all branch conditions. Every if ()
  241. taken in the kernel is recorded whether it hit or miss.
  242. The results will be displayed in:
  243. /sys/kernel/debug/tracing/trace_stat/branch_all
  244. This option also enables the likely/unlikely profiler.
  245. This configuration, when enabled, will impose a great overhead
  246. on the system. This should only be enabled when the system
  247. is to be analyzed in much detail.
  248. endchoice
  249. config TRACING_BRANCHES
  250. bool
  251. help
  252. Selected by tracers that will trace the likely and unlikely
  253. conditions. This prevents the tracers themselves from being
  254. profiled. Profiling the tracing infrastructure can only happen
  255. when the likelys and unlikelys are not being traced.
  256. config BRANCH_TRACER
  257. bool "Trace likely/unlikely instances"
  258. depends on TRACE_BRANCH_PROFILING
  259. select TRACING_BRANCHES
  260. help
  261. This traces the events of likely and unlikely condition
  262. calls in the kernel. The difference between this and the
  263. "Trace likely/unlikely profiler" is that this is not a
  264. histogram of the callers, but actually places the calling
  265. events into a running trace buffer to see when and where the
  266. events happened, as well as their results.
  267. Say N if unsure.
  268. config STACK_TRACER
  269. bool "Trace max stack"
  270. depends on HAVE_FUNCTION_TRACER
  271. select FUNCTION_TRACER
  272. select STACKTRACE
  273. select KALLSYMS
  274. help
  275. This special tracer records the maximum stack footprint of the
  276. kernel and displays it in /sys/kernel/debug/tracing/stack_trace.
  277. This tracer works by hooking into every function call that the
  278. kernel executes, and keeping a maximum stack depth value and
  279. stack-trace saved. If this is configured with DYNAMIC_FTRACE
  280. then it will not have any overhead while the stack tracer
  281. is disabled.
  282. To enable the stack tracer on bootup, pass in 'stacktrace'
  283. on the kernel command line.
  284. The stack tracer can also be enabled or disabled via the
  285. sysctl kernel.stack_tracer_enabled
  286. Say N if unsure.
  287. config BLK_DEV_IO_TRACE
  288. bool "Support for tracing block IO actions"
  289. depends on SYSFS
  290. depends on BLOCK
  291. select RELAY
  292. select DEBUG_FS
  293. select TRACEPOINTS
  294. select GENERIC_TRACER
  295. select STACKTRACE
  296. help
  297. Say Y here if you want to be able to trace the block layer actions
  298. on a given queue. Tracing allows you to see any traffic happening
  299. on a block device queue. For more information (and the userspace
  300. support tools needed), fetch the blktrace tools from:
  301. git://git.kernel.dk/blktrace.git
  302. Tracing also is possible using the ftrace interface, e.g.:
  303. echo 1 > /sys/block/sda/sda1/trace/enable
  304. echo blk > /sys/kernel/debug/tracing/current_tracer
  305. cat /sys/kernel/debug/tracing/trace_pipe
  306. If unsure, say N.
  307. config KPROBE_EVENT
  308. depends on KPROBES
  309. depends on HAVE_REGS_AND_STACK_ACCESS_API
  310. bool "Enable kprobes-based dynamic events"
  311. select TRACING
  312. default y
  313. help
  314. This allows the user to add tracing events (similar to tracepoints)
  315. on the fly via the ftrace interface. See
  316. Documentation/trace/kprobetrace.txt for more details.
  317. Those events can be inserted wherever kprobes can probe, and record
  318. various register and memory values.
  319. This option is also required by perf-probe subcommand of perf tools.
  320. If you want to use perf tools, this option is strongly recommended.
  321. config DYNAMIC_FTRACE
  322. bool "enable/disable function tracing dynamically"
  323. depends on FUNCTION_TRACER
  324. depends on HAVE_DYNAMIC_FTRACE
  325. default y
  326. help
  327. This option will modify all the calls to function tracing
  328. dynamically (will patch them out of the binary image and
  329. replace them with a No-Op instruction) on boot up. During
  330. compile time, a table is made of all the locations that ftrace
  331. can function trace, and this table is linked into the kernel
  332. image. When this is enabled, functions can be individually
  333. enabled, and the functions not enabled will not affect
  334. performance of the system.
  335. See the files in /sys/kernel/debug/tracing:
  336. available_filter_functions
  337. set_ftrace_filter
  338. set_ftrace_notrace
  339. This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but
  340. otherwise has native performance as long as no tracing is active.
  341. config FUNCTION_PROFILER
  342. bool "Kernel function profiler"
  343. depends on FUNCTION_TRACER
  344. default n
  345. help
  346. This option enables the kernel function profiler. A file is created
  347. in debugfs called function_profile_enabled which defaults to zero.
  348. When a 1 is echoed into this file profiling begins, and when a
  349. zero is entered, profiling stops. A "functions" file is created in
  350. the trace_stats directory; this file shows the list of functions that
  351. have been hit and their counters.
  352. If in doubt, say N.
  353. config CPU_FREQ_SWITCH_PROFILER
  354. bool "CPU frequency switch time profiler"
  355. select GENERIC_TRACER
  356. help
  357. This option enables the CPU frequency switch profiler. A file is
  358. created in debugfs called "cpu_freq_switch_profile_enabled", which
  359. defaults to zero. When a 1 is echoed into this file, profiling begins.
  360. When a zero is echoed, profiling stops. A "cpu_freq_switch" file is
  361. also created in the trace_stats directory; this file shows the
  362. switches that have occurred and duration statistics.
  363. If in doubt, say N.
  364. config FTRACE_MCOUNT_RECORD
  365. def_bool y
  366. depends on DYNAMIC_FTRACE
  367. depends on HAVE_FTRACE_MCOUNT_RECORD
  368. config FTRACE_SELFTEST
  369. bool
  370. config FTRACE_STARTUP_TEST
  371. bool "Perform a startup test on ftrace"
  372. depends on GENERIC_TRACER
  373. select FTRACE_SELFTEST
  374. help
  375. This option performs a series of startup tests on ftrace. On bootup
  376. a series of tests are made to verify that the tracer is
  377. functioning properly. It will do tests on all the configured
  378. tracers of ftrace.
  379. config EVENT_TRACE_TEST_SYSCALLS
  380. bool "Run selftest on syscall events"
  381. depends on FTRACE_STARTUP_TEST
  382. help
  383. This option will also enable testing every syscall event.
  384. It only enables the event and disables it and runs various loads
  385. with the event enabled. This adds a bit more time for kernel boot
  386. up since it runs this on every system call defined.
  387. TBD - enable a way to actually call the syscalls as we test their
  388. events
  389. config MMIOTRACE
  390. bool "Memory mapped IO tracing"
  391. depends on HAVE_MMIOTRACE_SUPPORT && PCI
  392. select GENERIC_TRACER
  393. help
  394. Mmiotrace traces Memory Mapped I/O access and is meant for
  395. debugging and reverse engineering. It is called from the ioremap
  396. implementation and works via page faults. Tracing is disabled by
  397. default and can be enabled at run-time.
  398. See Documentation/trace/mmiotrace.txt.
  399. If you are not helping to develop drivers, say N.
  400. config MMIOTRACE_TEST
  401. tristate "Test module for mmiotrace"
  402. depends on MMIOTRACE && m
  403. help
  404. This is a dumb module for testing mmiotrace. It is very dangerous
  405. as it will write garbage to IO memory starting at a given address.
  406. However, it should be safe to use on e.g. unused portion of VRAM.
  407. Say N, unless you absolutely know what you are doing.
  408. config RING_BUFFER_BENCHMARK
  409. tristate "Ring buffer benchmark stress tester"
  410. depends on RING_BUFFER
  411. help
  412. This option creates a test to stress the ring buffer and benchmark it.
  413. It creates its own ring buffer such that it will not interfere with
  414. any other users of the ring buffer (such as ftrace). It then creates
  415. a producer and consumer that will run for 10 seconds and sleep for
  416. 10 seconds. Each interval it will print out the number of events
  417. it recorded and give a rough estimate of how long each iteration took.
  418. It does not disable interrupts or raise its priority, so it may be
  419. affected by processes that are running.
  420. If unsure, say N.
  421. endif # FTRACE
  422. endif # TRACING_SUPPORT