Kconfig 20 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_DYNAMIC_FTRACE
  26. bool
  27. help
  28. See Documentation/trace/ftrace-design.txt
  29. config HAVE_DYNAMIC_FTRACE_WITH_REGS
  30. bool
  31. config HAVE_FTRACE_MCOUNT_RECORD
  32. bool
  33. help
  34. See Documentation/trace/ftrace-design.txt
  35. config HAVE_SYSCALL_TRACEPOINTS
  36. bool
  37. help
  38. See Documentation/trace/ftrace-design.txt
  39. config HAVE_FENTRY
  40. bool
  41. help
  42. Arch supports the gcc options -pg with -mfentry
  43. config HAVE_C_RECORDMCOUNT
  44. bool
  45. help
  46. C version of recordmcount available?
  47. config TRACER_MAX_TRACE
  48. bool
  49. config TRACE_CLOCK
  50. bool
  51. config RING_BUFFER
  52. bool
  53. select TRACE_CLOCK
  54. select IRQ_WORK
  55. config FTRACE_NMI_ENTER
  56. bool
  57. depends on HAVE_FTRACE_NMI_ENTER
  58. default y
  59. config EVENT_TRACING
  60. select CONTEXT_SWITCH_TRACER
  61. bool
  62. config GPU_TRACEPOINTS
  63. bool
  64. config CONTEXT_SWITCH_TRACER
  65. bool
  66. config RING_BUFFER_ALLOW_SWAP
  67. bool
  68. help
  69. Allow the use of ring_buffer_swap_cpu.
  70. Adds a very slight overhead to tracing when enabled.
  71. # All tracer options should select GENERIC_TRACER. For those options that are
  72. # enabled by all tracers (context switch and event tracer) they select TRACING.
  73. # This allows those options to appear when no other tracer is selected. But the
  74. # options do not appear when something else selects it. We need the two options
  75. # GENERIC_TRACER and TRACING to avoid circular dependencies to accomplish the
  76. # hiding of the automatic options.
  77. config TRACING
  78. bool
  79. select DEBUG_FS
  80. select RING_BUFFER
  81. select STACKTRACE if STACKTRACE_SUPPORT
  82. select TRACEPOINTS
  83. select NOP_TRACER
  84. select BINARY_PRINTF
  85. select EVENT_TRACING
  86. select TRACE_CLOCK
  87. config GENERIC_TRACER
  88. bool
  89. select TRACING
  90. #
  91. # Minimum requirements an architecture has to meet for us to
  92. # be able to offer generic tracing facilities:
  93. #
  94. config TRACING_SUPPORT
  95. bool
  96. # PPC32 has no irqflags tracing support, but it can use most of the
  97. # tracers anyway, they were tested to build and work. Note that new
  98. # exceptions to this list aren't welcomed, better implement the
  99. # irqflags tracing for your architecture.
  100. depends on TRACE_IRQFLAGS_SUPPORT || PPC32
  101. depends on STACKTRACE_SUPPORT
  102. default y
  103. if TRACING_SUPPORT
  104. menuconfig FTRACE
  105. bool "Tracers"
  106. default y if DEBUG_KERNEL
  107. help
  108. Enable the kernel tracing infrastructure.
  109. if FTRACE
  110. config FUNCTION_TRACER
  111. bool "Kernel Function Tracer"
  112. depends on HAVE_FUNCTION_TRACER
  113. select KALLSYMS
  114. select GENERIC_TRACER
  115. select CONTEXT_SWITCH_TRACER
  116. help
  117. Enable the kernel to trace every kernel function. This is done
  118. by using a compiler feature to insert a small, 5-byte No-Operation
  119. instruction at the beginning of every kernel function, which NOP
  120. sequence is then dynamically patched into a tracer call when
  121. tracing is enabled by the administrator. If it's runtime disabled
  122. (the bootup default), then the overhead of the instructions is very
  123. small and not measurable even in micro-benchmarks.
  124. config FUNCTION_GRAPH_TRACER
  125. bool "Kernel Function Graph Tracer"
  126. depends on HAVE_FUNCTION_GRAPH_TRACER
  127. depends on FUNCTION_TRACER
  128. depends on !X86_32 || !CC_OPTIMIZE_FOR_SIZE
  129. default y
  130. help
  131. Enable the kernel to trace a function at both its return
  132. and its entry.
  133. Its first purpose is to trace the duration of functions and
  134. draw a call graph for each thread with some information like
  135. the return value. This is done by setting the current return
  136. address on the current task structure into a stack of calls.
  137. config IRQSOFF_TRACER
  138. bool "Interrupts-off Latency Tracer"
  139. default n
  140. depends on TRACE_IRQFLAGS_SUPPORT
  141. depends on !ARCH_USES_GETTIMEOFFSET
  142. select TRACE_IRQFLAGS
  143. select GENERIC_TRACER
  144. select TRACER_MAX_TRACE
  145. select RING_BUFFER_ALLOW_SWAP
  146. select TRACER_SNAPSHOT
  147. select TRACER_SNAPSHOT_PER_CPU_SWAP
  148. help
  149. This option measures the time spent in irqs-off critical
  150. sections, with microsecond accuracy.
  151. The default measurement method is a maximum search, which is
  152. disabled by default and can be runtime (re-)started
  153. via:
  154. echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
  155. (Note that kernel size and overhead increase with this option
  156. enabled. This option and the preempt-off timing option can be
  157. used together or separately.)
  158. config PREEMPT_TRACER
  159. bool "Preemption-off Latency Tracer"
  160. default n
  161. depends on !ARCH_USES_GETTIMEOFFSET
  162. depends on PREEMPT
  163. select GENERIC_TRACER
  164. select TRACER_MAX_TRACE
  165. select RING_BUFFER_ALLOW_SWAP
  166. select TRACER_SNAPSHOT
  167. select TRACER_SNAPSHOT_PER_CPU_SWAP
  168. help
  169. This option measures the time spent in preemption-off critical
  170. sections, with microsecond accuracy.
  171. The default measurement method is a maximum search, which is
  172. disabled by default and can be runtime (re-)started
  173. via:
  174. echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
  175. (Note that kernel size and overhead increase with this option
  176. enabled. This option and the irqs-off timing option can be
  177. used together or separately.)
  178. config SCHED_TRACER
  179. bool "Scheduling Latency Tracer"
  180. select GENERIC_TRACER
  181. select CONTEXT_SWITCH_TRACER
  182. select TRACER_MAX_TRACE
  183. select TRACER_SNAPSHOT
  184. help
  185. This tracer tracks the latency of the highest priority task
  186. to be scheduled in, starting from the point it has woken up.
  187. config ENABLE_DEFAULT_TRACERS
  188. bool "Trace process context switches and events"
  189. depends on !GENERIC_TRACER
  190. select TRACING
  191. help
  192. This tracer hooks to various trace points in the kernel,
  193. allowing the user to pick and choose which trace point they
  194. want to trace. It also includes the sched_switch tracer plugin.
  195. config FTRACE_SYSCALLS
  196. bool "Trace syscalls"
  197. depends on HAVE_SYSCALL_TRACEPOINTS
  198. select GENERIC_TRACER
  199. select KALLSYMS
  200. help
  201. Basic tracer to catch the syscall entry and exit events.
  202. config TRACER_SNAPSHOT
  203. bool "Create a snapshot trace buffer"
  204. select TRACER_MAX_TRACE
  205. help
  206. Allow tracing users to take snapshot of the current buffer using the
  207. ftrace interface, e.g.:
  208. echo 1 > /sys/kernel/debug/tracing/snapshot
  209. cat snapshot
  210. config TRACER_SNAPSHOT_PER_CPU_SWAP
  211. bool "Allow snapshot to swap per CPU"
  212. depends on TRACER_SNAPSHOT
  213. select RING_BUFFER_ALLOW_SWAP
  214. help
  215. Allow doing a snapshot of a single CPU buffer instead of a
  216. full swap (all buffers). If this is set, then the following is
  217. allowed:
  218. echo 1 > /sys/kernel/debug/tracing/per_cpu/cpu2/snapshot
  219. After which, only the tracing buffer for CPU 2 was swapped with
  220. the main tracing buffer, and the other CPU buffers remain the same.
  221. When this is enabled, this adds a little more overhead to the
  222. trace recording, as it needs to add some checks to synchronize
  223. recording with swaps. But this does not affect the performance
  224. of the overall system. This is enabled by default when the preempt
  225. or irq latency tracers are enabled, as those need to swap as well
  226. and already adds the overhead (plus a lot more).
  227. config TRACE_BRANCH_PROFILING
  228. bool
  229. select GENERIC_TRACER
  230. choice
  231. prompt "Branch Profiling"
  232. default BRANCH_PROFILE_NONE
  233. help
  234. The branch profiling is a software profiler. It will add hooks
  235. into the C conditionals to test which path a branch takes.
  236. The likely/unlikely profiler only looks at the conditions that
  237. are annotated with a likely or unlikely macro.
  238. The "all branch" profiler will profile every if-statement in the
  239. kernel. This profiler will also enable the likely/unlikely
  240. profiler.
  241. Either of the above profilers adds a bit of overhead to the system.
  242. If unsure, choose "No branch profiling".
  243. config BRANCH_PROFILE_NONE
  244. bool "No branch profiling"
  245. help
  246. No branch profiling. Branch profiling adds a bit of overhead.
  247. Only enable it if you want to analyse the branching behavior.
  248. Otherwise keep it disabled.
  249. config PROFILE_ANNOTATED_BRANCHES
  250. bool "Trace likely/unlikely profiler"
  251. select TRACE_BRANCH_PROFILING
  252. help
  253. This tracer profiles all likely and unlikely macros
  254. in the kernel. It will display the results in:
  255. /sys/kernel/debug/tracing/trace_stat/branch_annotated
  256. Note: this will add a significant overhead; only turn this
  257. on if you need to profile the system's use of these macros.
  258. config PROFILE_ALL_BRANCHES
  259. bool "Profile all if conditionals"
  260. select TRACE_BRANCH_PROFILING
  261. help
  262. This tracer profiles all branch conditions. Every if ()
  263. taken in the kernel is recorded whether it hit or miss.
  264. The results will be displayed in:
  265. /sys/kernel/debug/tracing/trace_stat/branch_all
  266. This option also enables the likely/unlikely profiler.
  267. This configuration, when enabled, will impose a great overhead
  268. on the system. This should only be enabled when the system
  269. is to be analyzed in much detail.
  270. endchoice
  271. config TRACING_BRANCHES
  272. bool
  273. help
  274. Selected by tracers that will trace the likely and unlikely
  275. conditions. This prevents the tracers themselves from being
  276. profiled. Profiling the tracing infrastructure can only happen
  277. when the likelys and unlikelys are not being traced.
  278. config BRANCH_TRACER
  279. bool "Trace likely/unlikely instances"
  280. depends on TRACE_BRANCH_PROFILING
  281. select TRACING_BRANCHES
  282. help
  283. This traces the events of likely and unlikely condition
  284. calls in the kernel. The difference between this and the
  285. "Trace likely/unlikely profiler" is that this is not a
  286. histogram of the callers, but actually places the calling
  287. events into a running trace buffer to see when and where the
  288. events happened, as well as their results.
  289. Say N if unsure.
  290. config STACK_TRACER
  291. bool "Trace max stack"
  292. depends on HAVE_FUNCTION_TRACER
  293. select FUNCTION_TRACER
  294. select STACKTRACE
  295. select KALLSYMS
  296. help
  297. This special tracer records the maximum stack footprint of the
  298. kernel and displays it in /sys/kernel/debug/tracing/stack_trace.
  299. This tracer works by hooking into every function call that the
  300. kernel executes, and keeping a maximum stack depth value and
  301. stack-trace saved. If this is configured with DYNAMIC_FTRACE
  302. then it will not have any overhead while the stack tracer
  303. is disabled.
  304. To enable the stack tracer on bootup, pass in 'stacktrace'
  305. on the kernel command line.
  306. The stack tracer can also be enabled or disabled via the
  307. sysctl kernel.stack_tracer_enabled
  308. Say N if unsure.
  309. config BLK_DEV_IO_TRACE
  310. bool "Support for tracing block IO actions"
  311. depends on SYSFS
  312. depends on BLOCK
  313. select RELAY
  314. select DEBUG_FS
  315. select TRACEPOINTS
  316. select GENERIC_TRACER
  317. select STACKTRACE
  318. help
  319. Say Y here if you want to be able to trace the block layer actions
  320. on a given queue. Tracing allows you to see any traffic happening
  321. on a block device queue. For more information (and the userspace
  322. support tools needed), fetch the blktrace tools from:
  323. git://git.kernel.dk/blktrace.git
  324. Tracing also is possible using the ftrace interface, e.g.:
  325. echo 1 > /sys/block/sda/sda1/trace/enable
  326. echo blk > /sys/kernel/debug/tracing/current_tracer
  327. cat /sys/kernel/debug/tracing/trace_pipe
  328. If unsure, say N.
  329. config KPROBE_EVENT
  330. depends on KPROBES
  331. depends on HAVE_REGS_AND_STACK_ACCESS_API
  332. bool "Enable kprobes-based dynamic events"
  333. select TRACING
  334. select PROBE_EVENTS
  335. default y
  336. help
  337. This allows the user to add tracing events (similar to tracepoints)
  338. on the fly via the ftrace interface. See
  339. Documentation/trace/kprobetrace.txt for more details.
  340. Those events can be inserted wherever kprobes can probe, and record
  341. various register and memory values.
  342. This option is also required by perf-probe subcommand of perf tools.
  343. If you want to use perf tools, this option is strongly recommended.
  344. config UPROBE_EVENT
  345. bool "Enable uprobes-based dynamic events"
  346. depends on ARCH_SUPPORTS_UPROBES
  347. depends on MMU
  348. depends on PERF_EVENTS
  349. select UPROBES
  350. select PROBE_EVENTS
  351. select TRACING
  352. default n
  353. help
  354. This allows the user to add tracing events on top of userspace
  355. dynamic events (similar to tracepoints) on the fly via the trace
  356. events interface. Those events can be inserted wherever uprobes
  357. can probe, and record various registers.
  358. This option is required if you plan to use perf-probe subcommand
  359. of perf tools on user space applications.
  360. config PROBE_EVENTS
  361. def_bool n
  362. config DYNAMIC_FTRACE
  363. bool "enable/disable function tracing dynamically"
  364. depends on FUNCTION_TRACER
  365. depends on HAVE_DYNAMIC_FTRACE
  366. default y
  367. help
  368. This option will modify all the calls to function tracing
  369. dynamically (will patch them out of the binary image and
  370. replace them with a No-Op instruction) on boot up. During
  371. compile time, a table is made of all the locations that ftrace
  372. can function trace, and this table is linked into the kernel
  373. image. When this is enabled, functions can be individually
  374. enabled, and the functions not enabled will not affect
  375. performance of the system.
  376. See the files in /sys/kernel/debug/tracing:
  377. available_filter_functions
  378. set_ftrace_filter
  379. set_ftrace_notrace
  380. This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but
  381. otherwise has native performance as long as no tracing is active.
  382. config DYNAMIC_FTRACE_WITH_REGS
  383. def_bool y
  384. depends on DYNAMIC_FTRACE
  385. depends on HAVE_DYNAMIC_FTRACE_WITH_REGS
  386. config FUNCTION_PROFILER
  387. bool "Kernel function profiler"
  388. depends on FUNCTION_TRACER
  389. default n
  390. help
  391. This option enables the kernel function profiler. A file is created
  392. in debugfs called function_profile_enabled which defaults to zero.
  393. When a 1 is echoed into this file profiling begins, and when a
  394. zero is entered, profiling stops. A "functions" file is created in
  395. the trace_stats directory; this file shows the list of functions that
  396. have been hit and their counters.
  397. If in doubt, say N.
  398. config FTRACE_MCOUNT_RECORD
  399. def_bool y
  400. depends on DYNAMIC_FTRACE
  401. depends on HAVE_FTRACE_MCOUNT_RECORD
  402. config FTRACE_SELFTEST
  403. bool
  404. config FTRACE_STARTUP_TEST
  405. bool "Perform a startup test on ftrace"
  406. depends on GENERIC_TRACER
  407. select FTRACE_SELFTEST
  408. help
  409. This option performs a series of startup tests on ftrace. On bootup
  410. a series of tests are made to verify that the tracer is
  411. functioning properly. It will do tests on all the configured
  412. tracers of ftrace.
  413. config EVENT_TRACE_TEST_SYSCALLS
  414. bool "Run selftest on syscall events"
  415. depends on FTRACE_STARTUP_TEST
  416. help
  417. This option will also enable testing every syscall event.
  418. It only enables the event and disables it and runs various loads
  419. with the event enabled. This adds a bit more time for kernel boot
  420. up since it runs this on every system call defined.
  421. TBD - enable a way to actually call the syscalls as we test their
  422. events
  423. config MMIOTRACE
  424. bool "Memory mapped IO tracing"
  425. depends on HAVE_MMIOTRACE_SUPPORT && PCI
  426. select GENERIC_TRACER
  427. help
  428. Mmiotrace traces Memory Mapped I/O access and is meant for
  429. debugging and reverse engineering. It is called from the ioremap
  430. implementation and works via page faults. Tracing is disabled by
  431. default and can be enabled at run-time.
  432. See Documentation/trace/mmiotrace.txt.
  433. If you are not helping to develop drivers, say N.
  434. config MMIOTRACE_TEST
  435. tristate "Test module for mmiotrace"
  436. depends on MMIOTRACE && m
  437. help
  438. This is a dumb module for testing mmiotrace. It is very dangerous
  439. as it will write garbage to IO memory starting at a given address.
  440. However, it should be safe to use on e.g. unused portion of VRAM.
  441. Say N, unless you absolutely know what you are doing.
  442. config TRACEPOINT_BENCHMARK
  443. bool "Add tracepoint that benchmarks tracepoints"
  444. help
  445. This option creates the tracepoint "benchmark:benchmark_event".
  446. When the tracepoint is enabled, it kicks off a kernel thread that
  447. goes into an infinite loop (calling cond_sched() to let other tasks
  448. run), and calls the tracepoint. Each iteration will record the time
  449. it took to write to the tracepoint and the next iteration that
  450. data will be passed to the tracepoint itself. That is, the tracepoint
  451. will report the time it took to do the previous tracepoint.
  452. The string written to the tracepoint is a static string of 128 bytes
  453. to keep the time the same. The initial string is simply a write of
  454. "START". The second string records the cold cache time of the first
  455. write which is not added to the rest of the calculations.
  456. As it is a tight loop, it benchmarks as hot cache. That's fine because
  457. we care most about hot paths that are probably in cache already.
  458. An example of the output:
  459. START
  460. first=3672 [COLD CACHED]
  461. last=632 first=3672 max=632 min=632 avg=316 std=446 std^2=199712
  462. last=278 first=3672 max=632 min=278 avg=303 std=316 std^2=100337
  463. last=277 first=3672 max=632 min=277 avg=296 std=258 std^2=67064
  464. last=273 first=3672 max=632 min=273 avg=292 std=224 std^2=50411
  465. last=273 first=3672 max=632 min=273 avg=288 std=200 std^2=40389
  466. last=281 first=3672 max=632 min=273 avg=287 std=183 std^2=33666
  467. config RING_BUFFER_BENCHMARK
  468. tristate "Ring buffer benchmark stress tester"
  469. depends on RING_BUFFER
  470. help
  471. This option creates a test to stress the ring buffer and benchmark it.
  472. It creates its own ring buffer such that it will not interfere with
  473. any other users of the ring buffer (such as ftrace). It then creates
  474. a producer and consumer that will run for 10 seconds and sleep for
  475. 10 seconds. Each interval it will print out the number of events
  476. it recorded and give a rough estimate of how long each iteration took.
  477. It does not disable interrupts or raise its priority, so it may be
  478. affected by processes that are running.
  479. If unsure, say N.
  480. config RING_BUFFER_STARTUP_TEST
  481. bool "Ring buffer startup self test"
  482. depends on RING_BUFFER
  483. help
  484. Run a simple self test on the ring buffer on boot up. Late in the
  485. kernel boot sequence, the test will start that kicks off
  486. a thread per cpu. Each thread will write various size events
  487. into the ring buffer. Another thread is created to send IPIs
  488. to each of the threads, where the IPI handler will also write
  489. to the ring buffer, to test/stress the nesting ability.
  490. If any anomalies are discovered, a warning will be displayed
  491. and all ring buffers will be disabled.
  492. The test runs for 10 seconds. This will slow your boot time
  493. by at least 10 more seconds.
  494. At the end of the test, statics and more checks are done.
  495. It will output the stats of each per cpu buffer. What
  496. was written, the sizes, what was read, what was lost, and
  497. other similar details.
  498. If unsure, say N
  499. endif # FTRACE
  500. endif # TRACING_SUPPORT
  501. if TRACING
  502. # MTK enhancements
  503. config MTK_SCHED_TRACERS
  504. bool "MTK Sched Tracers"
  505. select CONTEXT_SWITCH_TRACER
  506. help
  507. Mediatek enhancements to vanilla linux kernel. Include export task
  508. status and other information in sched_switch events, and track irq
  509. duration when irq is disabled / enabled.
  510. If unsure, say N
  511. config MTK_FTRACE_DEFAULT_ENABLE
  512. bool "enable MTK events by default"
  513. depends on MTK_SCHED_TRACERS
  514. help
  515. Enable ftrace at bootup e.g., enlarge ring_buffer size and enable
  516. configured events at bootup. With ftrace enabled and trace collected
  517. at exceptions, developers can better analyze the problem
  518. If unsure, say N
  519. config MTK_KERNEL_MARKER
  520. bool "MTK Kernel Marker API"
  521. depends on KALLSYMS
  522. help
  523. Export trace_marker in kernel space. Mark the user-defined points,
  524. such as systrace events in user space, to visualize via systrace html
  525. files
  526. If unsure, say N
  527. endif # TRACING