1 # SPDX-License-Identifier: GPL-2.0-only << 2 # 1 # 3 # Architectures that offer an FUNCTION_TRACER 2 # Architectures that offer an FUNCTION_TRACER implementation should 4 # select HAVE_FUNCTION_TRACER: 3 # select HAVE_FUNCTION_TRACER: 5 # 4 # 6 5 7 config USER_STACKTRACE_SUPPORT 6 config USER_STACKTRACE_SUPPORT 8 bool 7 bool 9 8 10 config NOP_TRACER 9 config NOP_TRACER 11 bool 10 bool 12 11 13 config HAVE_RETHOOK !! 12 config HAVE_FTRACE_NMI_ENTER 14 bool 13 bool 15 << 16 config RETHOOK << 17 bool << 18 depends on HAVE_RETHOOK << 19 help 14 help 20 Enable generic return hooking featur !! 15 See Documentation/trace/ftrace-design.txt 21 API, which will be used by other fun << 22 features like fprobe and kprobes. << 23 16 24 config HAVE_FUNCTION_TRACER 17 config HAVE_FUNCTION_TRACER 25 bool 18 bool 26 help 19 help 27 See Documentation/trace/ftrace-desig !! 20 See Documentation/trace/ftrace-design.txt 28 21 29 config HAVE_FUNCTION_GRAPH_TRACER 22 config HAVE_FUNCTION_GRAPH_TRACER 30 bool 23 bool 31 help 24 help 32 See Documentation/trace/ftrace-desig !! 25 See Documentation/trace/ftrace-design.txt 33 26 34 config HAVE_FUNCTION_GRAPH_RETVAL !! 27 config HAVE_FUNCTION_GRAPH_FP_TEST 35 bool 28 bool >> 29 help >> 30 See Documentation/trace/ftrace-design.txt 36 31 37 config HAVE_DYNAMIC_FTRACE 32 config HAVE_DYNAMIC_FTRACE 38 bool 33 bool 39 help 34 help 40 See Documentation/trace/ftrace-desig !! 35 See Documentation/trace/ftrace-design.txt 41 36 42 config HAVE_DYNAMIC_FTRACE_WITH_REGS 37 config HAVE_DYNAMIC_FTRACE_WITH_REGS 43 bool 38 bool 44 39 45 config HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS << 46 bool << 47 << 48 config HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS << 49 bool << 50 << 51 config HAVE_DYNAMIC_FTRACE_WITH_ARGS << 52 bool << 53 help << 54 If this is set, then arguments and st << 55 the ftrace_regs passed into the funct << 56 by default, even without setting the << 57 This allows for use of ftrace_regs_ge << 58 ftrace_regs_get_stack_pointer(). << 59 << 60 config HAVE_DYNAMIC_FTRACE_NO_PATCHABLE << 61 bool << 62 help << 63 If the architecture generates __patc << 64 but does not want them included in t << 65 << 66 config HAVE_FTRACE_MCOUNT_RECORD 40 config HAVE_FTRACE_MCOUNT_RECORD 67 bool 41 bool 68 help 42 help 69 See Documentation/trace/ftrace-desig !! 43 See Documentation/trace/ftrace-design.txt 70 44 71 config HAVE_SYSCALL_TRACEPOINTS 45 config HAVE_SYSCALL_TRACEPOINTS 72 bool 46 bool 73 help 47 help 74 See Documentation/trace/ftrace-desig !! 48 See Documentation/trace/ftrace-design.txt 75 49 76 config HAVE_FENTRY 50 config HAVE_FENTRY 77 bool 51 bool 78 help 52 help 79 Arch supports the gcc options -pg wi 53 Arch supports the gcc options -pg with -mfentry 80 54 81 config HAVE_NOP_MCOUNT << 82 bool << 83 help << 84 Arch supports the gcc options -pg wi << 85 << 86 config HAVE_OBJTOOL_MCOUNT << 87 bool << 88 help << 89 Arch supports objtool --mcount << 90 << 91 config HAVE_OBJTOOL_NOP_MCOUNT << 92 bool << 93 help << 94 Arch supports the objtool options -- << 95 An architecture can select this if i << 96 of ftrace locations. << 97 << 98 config HAVE_C_RECORDMCOUNT 55 config HAVE_C_RECORDMCOUNT 99 bool 56 bool 100 help 57 help 101 C version of recordmcount available? 58 C version of recordmcount available? 102 59 103 config HAVE_BUILDTIME_MCOUNT_SORT << 104 bool << 105 help << 106 An architecture selects this if it so << 107 at build time. << 108 << 109 config BUILDTIME_MCOUNT_SORT << 110 bool << 111 default y << 112 depends on HAVE_BUILDTIME_MCOUNT_SORT & << 113 help << 114 Sort the mcount_loc section at build << 115 << 116 config TRACER_MAX_TRACE 60 config TRACER_MAX_TRACE 117 bool 61 bool 118 62 119 config TRACE_CLOCK 63 config TRACE_CLOCK 120 bool 64 bool 121 65 122 config RING_BUFFER 66 config RING_BUFFER 123 bool 67 bool 124 select TRACE_CLOCK 68 select TRACE_CLOCK 125 select IRQ_WORK 69 select IRQ_WORK 126 70 >> 71 config FTRACE_NMI_ENTER >> 72 bool >> 73 depends on HAVE_FTRACE_NMI_ENTER >> 74 default y >> 75 127 config EVENT_TRACING 76 config EVENT_TRACING 128 select CONTEXT_SWITCH_TRACER 77 select CONTEXT_SWITCH_TRACER 129 select GLOB << 130 bool 78 bool 131 79 132 config CONTEXT_SWITCH_TRACER 80 config CONTEXT_SWITCH_TRACER 133 bool 81 bool 134 82 135 config RING_BUFFER_ALLOW_SWAP 83 config RING_BUFFER_ALLOW_SWAP 136 bool 84 bool 137 help 85 help 138 Allow the use of ring_buffer_swap_cpu 86 Allow the use of ring_buffer_swap_cpu. 139 Adds a very slight overhead to tracin 87 Adds a very slight overhead to tracing when enabled. 140 88 141 config PREEMPTIRQ_TRACEPOINTS << 142 bool << 143 depends on TRACE_PREEMPT_TOGGLE || TRA << 144 select TRACING << 145 default y << 146 help << 147 Create preempt/irq toggle tracepoint << 148 of the kernel can use them to genera << 149 << 150 # All tracer options should select GENERIC_TRA 89 # All tracer options should select GENERIC_TRACER. For those options that are 151 # enabled by all tracers (context switch and e 90 # enabled by all tracers (context switch and event tracer) they select TRACING. 152 # This allows those options to appear when no 91 # This allows those options to appear when no other tracer is selected. But the 153 # options do not appear when something else se 92 # options do not appear when something else selects it. We need the two options 154 # GENERIC_TRACER and TRACING to avoid circular 93 # GENERIC_TRACER and TRACING to avoid circular dependencies to accomplish the 155 # hiding of the automatic options. 94 # hiding of the automatic options. 156 95 157 config TRACING 96 config TRACING 158 bool 97 bool >> 98 select DEBUG_FS 159 select RING_BUFFER 99 select RING_BUFFER 160 select STACKTRACE if STACKTRACE_SUPPOR 100 select STACKTRACE if STACKTRACE_SUPPORT 161 select TRACEPOINTS 101 select TRACEPOINTS 162 select NOP_TRACER 102 select NOP_TRACER 163 select BINARY_PRINTF 103 select BINARY_PRINTF 164 select EVENT_TRACING 104 select EVENT_TRACING 165 select TRACE_CLOCK 105 select TRACE_CLOCK 166 select NEED_TASKS_RCU << 167 106 168 config GENERIC_TRACER 107 config GENERIC_TRACER 169 bool 108 bool 170 select TRACING 109 select TRACING 171 110 172 # 111 # 173 # Minimum requirements an architecture has to 112 # Minimum requirements an architecture has to meet for us to 174 # be able to offer generic tracing facilities: 113 # be able to offer generic tracing facilities: 175 # 114 # 176 config TRACING_SUPPORT 115 config TRACING_SUPPORT 177 bool 116 bool 178 depends on TRACE_IRQFLAGS_SUPPORT !! 117 # PPC32 has no irqflags tracing support, but it can use most of the >> 118 # tracers anyway, they were tested to build and work. Note that new >> 119 # exceptions to this list aren't welcomed, better implement the >> 120 # irqflags tracing for your architecture. >> 121 depends on TRACE_IRQFLAGS_SUPPORT || PPC32 179 depends on STACKTRACE_SUPPORT 122 depends on STACKTRACE_SUPPORT 180 default y 123 default y 181 124 >> 125 if TRACING_SUPPORT >> 126 182 menuconfig FTRACE 127 menuconfig FTRACE 183 bool "Tracers" 128 bool "Tracers" 184 depends on TRACING_SUPPORT << 185 default y if DEBUG_KERNEL 129 default y if DEBUG_KERNEL 186 help 130 help 187 Enable the kernel tracing infrastruc 131 Enable the kernel tracing infrastructure. 188 132 189 if FTRACE 133 if FTRACE 190 134 191 config BOOTTIME_TRACING << 192 bool "Boot-time Tracing support" << 193 depends on TRACING << 194 select BOOT_CONFIG << 195 help << 196 Enable developer to setup ftrace sub << 197 kernel cmdline at boot time for debu << 198 initialization and boot process. << 199 << 200 config FUNCTION_TRACER 135 config FUNCTION_TRACER 201 bool "Kernel Function Tracer" 136 bool "Kernel Function Tracer" 202 depends on HAVE_FUNCTION_TRACER 137 depends on HAVE_FUNCTION_TRACER 203 select KALLSYMS 138 select KALLSYMS 204 select GENERIC_TRACER 139 select GENERIC_TRACER 205 select CONTEXT_SWITCH_TRACER 140 select CONTEXT_SWITCH_TRACER 206 select GLOB << 207 select NEED_TASKS_RCU << 208 select TASKS_RUDE_RCU << 209 help 141 help 210 Enable the kernel to trace every ker 142 Enable the kernel to trace every kernel function. This is done 211 by using a compiler feature to inser 143 by using a compiler feature to insert a small, 5-byte No-Operation 212 instruction at the beginning of ever 144 instruction at the beginning of every kernel function, which NOP 213 sequence is then dynamically patched 145 sequence is then dynamically patched into a tracer call when 214 tracing is enabled by the administra 146 tracing is enabled by the administrator. If it's runtime disabled 215 (the bootup default), then the overh 147 (the bootup default), then the overhead of the instructions is very 216 small and not measurable even in mic !! 148 small and not measurable even in micro-benchmarks. 217 x86, but may have impact on other ar << 218 149 219 config FUNCTION_GRAPH_TRACER 150 config FUNCTION_GRAPH_TRACER 220 bool "Kernel Function Graph Tracer" 151 bool "Kernel Function Graph Tracer" 221 depends on HAVE_FUNCTION_GRAPH_TRACER 152 depends on HAVE_FUNCTION_GRAPH_TRACER 222 depends on FUNCTION_TRACER 153 depends on FUNCTION_TRACER 223 depends on !X86_32 || !CC_OPTIMIZE_FOR 154 depends on !X86_32 || !CC_OPTIMIZE_FOR_SIZE 224 default y 155 default y 225 help 156 help 226 Enable the kernel to trace a functio 157 Enable the kernel to trace a function at both its return 227 and its entry. 158 and its entry. 228 Its first purpose is to trace the du 159 Its first purpose is to trace the duration of functions and 229 draw a call graph for each thread wi 160 draw a call graph for each thread with some information like 230 the return value. This is done by se 161 the return value. This is done by setting the current return 231 address on the current task structur 162 address on the current task structure into a stack of calls. 232 163 233 config FUNCTION_GRAPH_RETVAL << 234 bool "Kernel Function Graph Return Val << 235 depends on HAVE_FUNCTION_GRAPH_RETVAL << 236 depends on FUNCTION_GRAPH_TRACER << 237 default n << 238 help << 239 Support recording and printing the f << 240 using function graph tracer. It can << 241 that return errors. This feature is << 242 enable it via the trace option funcg << 243 See Documentation/trace/ftrace.rst << 244 << 245 config DYNAMIC_FTRACE << 246 bool "enable/disable function tracing << 247 depends on FUNCTION_TRACER << 248 depends on HAVE_DYNAMIC_FTRACE << 249 default y << 250 help << 251 This option will modify all the call << 252 dynamically (will patch them out of << 253 replace them with a No-Op instructio << 254 compile time, a table is made of all << 255 can function trace, and this table i << 256 image. When this is enabled, functio << 257 enabled, and the functions not enabl << 258 performance of the system. << 259 << 260 See the files in /sys/kernel/tracing << 261 available_filter_functions << 262 set_ftrace_filter << 263 set_ftrace_notrace << 264 << 265 This way a CONFIG_FUNCTION_TRACER ke << 266 otherwise has native performance as << 267 << 268 config DYNAMIC_FTRACE_WITH_REGS << 269 def_bool y << 270 depends on DYNAMIC_FTRACE << 271 depends on HAVE_DYNAMIC_FTRACE_WITH_RE << 272 << 273 config DYNAMIC_FTRACE_WITH_DIRECT_CALLS << 274 def_bool y << 275 depends on DYNAMIC_FTRACE_WITH_REGS || << 276 depends on HAVE_DYNAMIC_FTRACE_WITH_DI << 277 << 278 config DYNAMIC_FTRACE_WITH_CALL_OPS << 279 def_bool y << 280 depends on HAVE_DYNAMIC_FTRACE_WITH_CA << 281 << 282 config DYNAMIC_FTRACE_WITH_ARGS << 283 def_bool y << 284 depends on DYNAMIC_FTRACE << 285 depends on HAVE_DYNAMIC_FTRACE_WITH_AR << 286 << 287 config FPROBE << 288 bool "Kernel Function Probe (fprobe)" << 289 depends on FUNCTION_TRACER << 290 depends on DYNAMIC_FTRACE_WITH_REGS << 291 depends on HAVE_RETHOOK << 292 select RETHOOK << 293 default n << 294 help << 295 This option enables kernel function << 296 The fprobe is similar to kprobes, bu << 297 entries and exits. This also can pro << 298 fprobe. << 299 << 300 If unsure, say N. << 301 << 302 config FUNCTION_PROFILER << 303 bool "Kernel function profiler" << 304 depends on FUNCTION_TRACER << 305 default n << 306 help << 307 This option enables the kernel funct << 308 in debugfs called function_profile_e << 309 When a 1 is echoed into this file pr << 310 zero is entered, profiling stops. A << 311 the trace_stat directory; this file << 312 have been hit and their counters. << 313 << 314 If in doubt, say N. << 315 << 316 config STACK_TRACER << 317 bool "Trace max stack" << 318 depends on HAVE_FUNCTION_TRACER << 319 select FUNCTION_TRACER << 320 select STACKTRACE << 321 select KALLSYMS << 322 help << 323 This special tracer records the maxi << 324 kernel and displays it in /sys/kerne << 325 << 326 This tracer works by hooking into ev << 327 kernel executes, and keeping a maxim << 328 stack-trace saved. If this is confi << 329 then it will not have any overhead w << 330 is disabled. << 331 << 332 To enable the stack tracer on bootup << 333 on the kernel command line. << 334 << 335 The stack tracer can also be enabled << 336 sysctl kernel.stack_tracer_enabled << 337 << 338 Say N if unsure. << 339 << 340 config TRACE_PREEMPT_TOGGLE << 341 bool << 342 help << 343 Enables hooks which will be called w << 344 and last enabled. << 345 164 346 config IRQSOFF_TRACER 165 config IRQSOFF_TRACER 347 bool "Interrupts-off Latency Tracer" 166 bool "Interrupts-off Latency Tracer" 348 default n 167 default n 349 depends on TRACE_IRQFLAGS_SUPPORT 168 depends on TRACE_IRQFLAGS_SUPPORT >> 169 depends on !ARCH_USES_GETTIMEOFFSET 350 select TRACE_IRQFLAGS 170 select TRACE_IRQFLAGS 351 select GENERIC_TRACER 171 select GENERIC_TRACER 352 select TRACER_MAX_TRACE 172 select TRACER_MAX_TRACE 353 select RING_BUFFER_ALLOW_SWAP 173 select RING_BUFFER_ALLOW_SWAP 354 select TRACER_SNAPSHOT 174 select TRACER_SNAPSHOT 355 select TRACER_SNAPSHOT_PER_CPU_SWAP 175 select TRACER_SNAPSHOT_PER_CPU_SWAP 356 help 176 help 357 This option measures the time spent 177 This option measures the time spent in irqs-off critical 358 sections, with microsecond accuracy. 178 sections, with microsecond accuracy. 359 179 360 The default measurement method is a 180 The default measurement method is a maximum search, which is 361 disabled by default and can be runti 181 disabled by default and can be runtime (re-)started 362 via: 182 via: 363 183 364 echo 0 > /sys/kernel/tracing/tra !! 184 echo 0 > /sys/kernel/debug/tracing/tracing_max_latency 365 185 366 (Note that kernel size and overhead 186 (Note that kernel size and overhead increase with this option 367 enabled. This option and the preempt 187 enabled. This option and the preempt-off timing option can be 368 used together or separately.) 188 used together or separately.) 369 189 370 config PREEMPT_TRACER 190 config PREEMPT_TRACER 371 bool "Preemption-off Latency Tracer" 191 bool "Preemption-off Latency Tracer" 372 default n 192 default n 373 depends on PREEMPTION !! 193 depends on !ARCH_USES_GETTIMEOFFSET >> 194 depends on PREEMPT 374 select GENERIC_TRACER 195 select GENERIC_TRACER 375 select TRACER_MAX_TRACE 196 select TRACER_MAX_TRACE 376 select RING_BUFFER_ALLOW_SWAP 197 select RING_BUFFER_ALLOW_SWAP 377 select TRACER_SNAPSHOT 198 select TRACER_SNAPSHOT 378 select TRACER_SNAPSHOT_PER_CPU_SWAP 199 select TRACER_SNAPSHOT_PER_CPU_SWAP 379 select TRACE_PREEMPT_TOGGLE << 380 help 200 help 381 This option measures the time spent 201 This option measures the time spent in preemption-off critical 382 sections, with microsecond accuracy. 202 sections, with microsecond accuracy. 383 203 384 The default measurement method is a 204 The default measurement method is a maximum search, which is 385 disabled by default and can be runti 205 disabled by default and can be runtime (re-)started 386 via: 206 via: 387 207 388 echo 0 > /sys/kernel/tracing/tra !! 208 echo 0 > /sys/kernel/debug/tracing/tracing_max_latency 389 209 390 (Note that kernel size and overhead 210 (Note that kernel size and overhead increase with this option 391 enabled. This option and the irqs-of 211 enabled. This option and the irqs-off timing option can be 392 used together or separately.) 212 used together or separately.) 393 213 394 config SCHED_TRACER 214 config SCHED_TRACER 395 bool "Scheduling Latency Tracer" 215 bool "Scheduling Latency Tracer" 396 select GENERIC_TRACER 216 select GENERIC_TRACER 397 select CONTEXT_SWITCH_TRACER 217 select CONTEXT_SWITCH_TRACER 398 select TRACER_MAX_TRACE 218 select TRACER_MAX_TRACE 399 select TRACER_SNAPSHOT 219 select TRACER_SNAPSHOT 400 help 220 help 401 This tracer tracks the latency of th 221 This tracer tracks the latency of the highest priority task 402 to be scheduled in, starting from th 222 to be scheduled in, starting from the point it has woken up. 403 223 404 config HWLAT_TRACER << 405 bool "Tracer to detect hardware latenc << 406 select GENERIC_TRACER << 407 select TRACER_MAX_TRACE << 408 help << 409 This tracer, when enabled will create << 410 depending on what the cpumask file is << 411 spinning in a loop looking for interr << 412 something other than the kernel. For << 413 System Management Interrupt (SMI) tak << 414 time, this tracer will detect it. Thi << 415 if a system is reliable for Real Time << 416 << 417 Some files are created in the tracing << 418 is enabled: << 419 << 420 hwlat_detector/width - time in us << 421 hwlat_detector/window - time in us << 422 iteration << 423 << 424 A kernel thread is created that will << 425 for "width" microseconds in every "wi << 426 for "window - width" microseconds, wh << 427 continue to operate. << 428 << 429 The output will appear in the trace a << 430 << 431 When the tracer is not running, it ha << 432 but when it is running, it can cause << 433 periodically non responsive. Do not r << 434 production system. << 435 << 436 To enable this tracer, echo in "hwlat << 437 file. Every time a latency is greater << 438 be recorded into the ring buffer. << 439 << 440 config OSNOISE_TRACER << 441 bool "OS Noise tracer" << 442 select GENERIC_TRACER << 443 select TRACER_MAX_TRACE << 444 help << 445 In the context of high-performance c << 446 System Noise (osnoise) refers to the << 447 application due to activities inside << 448 context of Linux, NMIs, IRQs, SoftIR << 449 can cause noise to the system. Moreo << 450 also cause noise, for example, via S << 451 << 452 The osnoise tracer leverages the hwl << 453 loop with preemption, SoftIRQs and I << 454 the sources of osnoise during its ex << 455 note of the entry and exit point of << 456 increasing a per-cpu interference co << 457 counter for each source of interfere << 458 NMI, IRQs, SoftIRQs, and threads is << 459 observes these interferences' entry << 460 without any interference from the op << 461 hardware noise counter increases, po << 462 noise. In this way, osnoise can acco << 463 interference. At the end of the peri << 464 the sum of all noise, the max single << 465 available for the thread, and the co << 466 << 467 In addition to the tracer, a set of << 468 facilitate the identification of the << 469 << 470 The output will appear in the trace << 471 << 472 To enable this tracer, echo in "osno << 473 file. << 474 << 475 config TIMERLAT_TRACER << 476 bool "Timerlat tracer" << 477 select OSNOISE_TRACER << 478 select GENERIC_TRACER << 479 help << 480 The timerlat tracer aims to help the << 481 to find sources of wakeup latencies << 482 << 483 The tracer creates a per-cpu kernel << 484 The tracer thread sets a periodic ti << 485 to sleep waiting for the timer to fi << 486 then computes a wakeup latency value << 487 the current time and the absolute ti << 488 to expire. << 489 << 490 The tracer prints two lines at every << 491 timer latency observed at the hardir << 492 activation of the thread. The second << 493 by the thread, which is the same lev << 494 ACTIVATION ID field serves to relate << 495 respective thread execution. << 496 << 497 The tracer is build on top of osnois << 498 events can be used to trace the sour << 499 IRQs and other threads. It also enab << 500 stacktrace at the IRQ context, which << 501 path that can cause thread delay. << 502 << 503 config MMIOTRACE << 504 bool "Memory mapped IO tracing" << 505 depends on HAVE_MMIOTRACE_SUPPORT && P << 506 select GENERIC_TRACER << 507 help << 508 Mmiotrace traces Memory Mapped I/O a << 509 debugging and reverse engineering. I << 510 implementation and works via page fa << 511 default and can be enabled at run-ti << 512 << 513 See Documentation/trace/mmiotrace.rs << 514 If you are not helping to develop dr << 515 << 516 config ENABLE_DEFAULT_TRACERS 224 config ENABLE_DEFAULT_TRACERS 517 bool "Trace process context switches a 225 bool "Trace process context switches and events" 518 depends on !GENERIC_TRACER 226 depends on !GENERIC_TRACER 519 select TRACING 227 select TRACING 520 help 228 help 521 This tracer hooks to various trace p 229 This tracer hooks to various trace points in the kernel, 522 allowing the user to pick and choose 230 allowing the user to pick and choose which trace point they 523 want to trace. It also includes the 231 want to trace. It also includes the sched_switch tracer plugin. 524 232 525 config FTRACE_SYSCALLS 233 config FTRACE_SYSCALLS 526 bool "Trace syscalls" 234 bool "Trace syscalls" 527 depends on HAVE_SYSCALL_TRACEPOINTS 235 depends on HAVE_SYSCALL_TRACEPOINTS 528 select GENERIC_TRACER 236 select GENERIC_TRACER 529 select KALLSYMS 237 select KALLSYMS 530 help 238 help 531 Basic tracer to catch the syscall en 239 Basic tracer to catch the syscall entry and exit events. 532 240 533 config TRACER_SNAPSHOT 241 config TRACER_SNAPSHOT 534 bool "Create a snapshot trace buffer" 242 bool "Create a snapshot trace buffer" 535 select TRACER_MAX_TRACE 243 select TRACER_MAX_TRACE 536 help 244 help 537 Allow tracing users to take snapshot 245 Allow tracing users to take snapshot of the current buffer using the 538 ftrace interface, e.g.: 246 ftrace interface, e.g.: 539 247 540 echo 1 > /sys/kernel/tracing/sna !! 248 echo 1 > /sys/kernel/debug/tracing/snapshot 541 cat snapshot 249 cat snapshot 542 250 543 config TRACER_SNAPSHOT_PER_CPU_SWAP 251 config TRACER_SNAPSHOT_PER_CPU_SWAP 544 bool "Allow snapshot to swap per CPU" !! 252 bool "Allow snapshot to swap per CPU" 545 depends on TRACER_SNAPSHOT 253 depends on TRACER_SNAPSHOT 546 select RING_BUFFER_ALLOW_SWAP 254 select RING_BUFFER_ALLOW_SWAP 547 help 255 help 548 Allow doing a snapshot of a single C 256 Allow doing a snapshot of a single CPU buffer instead of a 549 full swap (all buffers). If this is 257 full swap (all buffers). If this is set, then the following is 550 allowed: 258 allowed: 551 259 552 echo 1 > /sys/kernel/tracing/per !! 260 echo 1 > /sys/kernel/debug/tracing/per_cpu/cpu2/snapshot 553 261 554 After which, only the tracing buffer 262 After which, only the tracing buffer for CPU 2 was swapped with 555 the main tracing buffer, and the oth 263 the main tracing buffer, and the other CPU buffers remain the same. 556 264 557 When this is enabled, this adds a li 265 When this is enabled, this adds a little more overhead to the 558 trace recording, as it needs to add 266 trace recording, as it needs to add some checks to synchronize 559 recording with swaps. But this does 267 recording with swaps. But this does not affect the performance 560 of the overall system. This is enabl 268 of the overall system. This is enabled by default when the preempt 561 or irq latency tracers are enabled, 269 or irq latency tracers are enabled, as those need to swap as well 562 and already adds the overhead (plus 270 and already adds the overhead (plus a lot more). 563 271 564 config TRACE_BRANCH_PROFILING 272 config TRACE_BRANCH_PROFILING 565 bool 273 bool 566 select GENERIC_TRACER 274 select GENERIC_TRACER 567 275 568 choice 276 choice 569 prompt "Branch Profiling" 277 prompt "Branch Profiling" 570 default BRANCH_PROFILE_NONE 278 default BRANCH_PROFILE_NONE 571 help 279 help 572 The branch profiling is a software pr 280 The branch profiling is a software profiler. It will add hooks 573 into the C conditionals to test which 281 into the C conditionals to test which path a branch takes. 574 282 575 The likely/unlikely profiler only loo 283 The likely/unlikely profiler only looks at the conditions that 576 are annotated with a likely or unlike 284 are annotated with a likely or unlikely macro. 577 285 578 The "all branch" profiler will profil 286 The "all branch" profiler will profile every if-statement in the 579 kernel. This profiler will also enabl 287 kernel. This profiler will also enable the likely/unlikely 580 profiler. 288 profiler. 581 289 582 Either of the above profilers adds a 290 Either of the above profilers adds a bit of overhead to the system. 583 If unsure, choose "No branch profilin 291 If unsure, choose "No branch profiling". 584 292 585 config BRANCH_PROFILE_NONE 293 config BRANCH_PROFILE_NONE 586 bool "No branch profiling" 294 bool "No branch profiling" 587 help 295 help 588 No branch profiling. Branch profilin 296 No branch profiling. Branch profiling adds a bit of overhead. 589 Only enable it if you want to analys 297 Only enable it if you want to analyse the branching behavior. 590 Otherwise keep it disabled. 298 Otherwise keep it disabled. 591 299 592 config PROFILE_ANNOTATED_BRANCHES 300 config PROFILE_ANNOTATED_BRANCHES 593 bool "Trace likely/unlikely profiler" 301 bool "Trace likely/unlikely profiler" 594 select TRACE_BRANCH_PROFILING 302 select TRACE_BRANCH_PROFILING 595 help 303 help 596 This tracer profiles all likely and 304 This tracer profiles all likely and unlikely macros 597 in the kernel. It will display the r 305 in the kernel. It will display the results in: 598 306 599 /sys/kernel/tracing/trace_stat/branc !! 307 /sys/kernel/debug/tracing/trace_stat/branch_annotated 600 308 601 Note: this will add a significant ov 309 Note: this will add a significant overhead; only turn this 602 on if you need to profile the system 310 on if you need to profile the system's use of these macros. 603 311 604 config PROFILE_ALL_BRANCHES 312 config PROFILE_ALL_BRANCHES 605 bool "Profile all if conditionals" if !! 313 bool "Profile all if conditionals" 606 select TRACE_BRANCH_PROFILING 314 select TRACE_BRANCH_PROFILING 607 help 315 help 608 This tracer profiles all branch cond 316 This tracer profiles all branch conditions. Every if () 609 taken in the kernel is recorded whet 317 taken in the kernel is recorded whether it hit or miss. 610 The results will be displayed in: 318 The results will be displayed in: 611 319 612 /sys/kernel/tracing/trace_stat/branc !! 320 /sys/kernel/debug/tracing/trace_stat/branch_all 613 321 614 This option also enables the likely/ 322 This option also enables the likely/unlikely profiler. 615 323 616 This configuration, when enabled, wi 324 This configuration, when enabled, will impose a great overhead 617 on the system. This should only be e 325 on the system. This should only be enabled when the system 618 is to be analyzed in much detail. 326 is to be analyzed in much detail. 619 endchoice 327 endchoice 620 328 621 config TRACING_BRANCHES 329 config TRACING_BRANCHES 622 bool 330 bool 623 help 331 help 624 Selected by tracers that will trace 332 Selected by tracers that will trace the likely and unlikely 625 conditions. This prevents the tracer 333 conditions. This prevents the tracers themselves from being 626 profiled. Profiling the tracing infr 334 profiled. Profiling the tracing infrastructure can only happen 627 when the likelys and unlikelys are n 335 when the likelys and unlikelys are not being traced. 628 336 629 config BRANCH_TRACER 337 config BRANCH_TRACER 630 bool "Trace likely/unlikely instances" 338 bool "Trace likely/unlikely instances" 631 depends on TRACE_BRANCH_PROFILING 339 depends on TRACE_BRANCH_PROFILING 632 select TRACING_BRANCHES 340 select TRACING_BRANCHES 633 help 341 help 634 This traces the events of likely and 342 This traces the events of likely and unlikely condition 635 calls in the kernel. The difference 343 calls in the kernel. The difference between this and the 636 "Trace likely/unlikely profiler" is 344 "Trace likely/unlikely profiler" is that this is not a 637 histogram of the callers, but actual 345 histogram of the callers, but actually places the calling 638 events into a running trace buffer t 346 events into a running trace buffer to see when and where the 639 events happened, as well as their re 347 events happened, as well as their results. 640 348 641 Say N if unsure. 349 Say N if unsure. 642 350 >> 351 config STACK_TRACER >> 352 bool "Trace max stack" >> 353 depends on HAVE_FUNCTION_TRACER >> 354 select FUNCTION_TRACER >> 355 select STACKTRACE >> 356 select KALLSYMS >> 357 help >> 358 This special tracer records the maximum stack footprint of the >> 359 kernel and displays it in /sys/kernel/debug/tracing/stack_trace. >> 360 >> 361 This tracer works by hooking into every function call that the >> 362 kernel executes, and keeping a maximum stack depth value and >> 363 stack-trace saved. If this is configured with DYNAMIC_FTRACE >> 364 then it will not have any overhead while the stack tracer >> 365 is disabled. >> 366 >> 367 To enable the stack tracer on bootup, pass in 'stacktrace' >> 368 on the kernel command line. >> 369 >> 370 The stack tracer can also be enabled or disabled via the >> 371 sysctl kernel.stack_tracer_enabled >> 372 >> 373 Say N if unsure. >> 374 643 config BLK_DEV_IO_TRACE 375 config BLK_DEV_IO_TRACE 644 bool "Support for tracing block IO act 376 bool "Support for tracing block IO actions" 645 depends on SYSFS 377 depends on SYSFS 646 depends on BLOCK 378 depends on BLOCK 647 select RELAY 379 select RELAY 648 select DEBUG_FS 380 select DEBUG_FS 649 select TRACEPOINTS 381 select TRACEPOINTS 650 select GENERIC_TRACER 382 select GENERIC_TRACER 651 select STACKTRACE 383 select STACKTRACE 652 help 384 help 653 Say Y here if you want to be able to 385 Say Y here if you want to be able to trace the block layer actions 654 on a given queue. Tracing allows you 386 on a given queue. Tracing allows you to see any traffic happening 655 on a block device queue. For more in 387 on a block device queue. For more information (and the userspace 656 support tools needed), fetch the blk 388 support tools needed), fetch the blktrace tools from: 657 389 658 git://git.kernel.dk/blktrace.git 390 git://git.kernel.dk/blktrace.git 659 391 660 Tracing also is possible using the f 392 Tracing also is possible using the ftrace interface, e.g.: 661 393 662 echo 1 > /sys/block/sda/sda1/trace 394 echo 1 > /sys/block/sda/sda1/trace/enable 663 echo blk > /sys/kernel/tracing/cur !! 395 echo blk > /sys/kernel/debug/tracing/current_tracer 664 cat /sys/kernel/tracing/trace_pipe !! 396 cat /sys/kernel/debug/tracing/trace_pipe 665 397 666 If unsure, say N. 398 If unsure, say N. 667 399 668 config FPROBE_EVENTS !! 400 config KPROBE_EVENT 669 depends on FPROBE << 670 depends on HAVE_REGS_AND_STACK_ACCESS_ << 671 bool "Enable fprobe-based dynamic even << 672 select TRACING << 673 select PROBE_EVENTS << 674 select DYNAMIC_EVENTS << 675 default y << 676 help << 677 This allows user to add tracing even << 678 exit via ftrace interface. The synta << 679 and the kprobe events on function en << 680 transparently converted to this fpro << 681 << 682 config PROBE_EVENTS_BTF_ARGS << 683 depends on HAVE_FUNCTION_ARG_ACCESS_AP << 684 depends on FPROBE_EVENTS || KPROBE_EVE << 685 depends on DEBUG_INFO_BTF && BPF_SYSCA << 686 bool "Support BTF function arguments f << 687 default y << 688 help << 689 The user can specify the arguments o << 690 of the arguments of the probed funct << 691 kernel function entry or a tracepoin << 692 This is available only if BTF (BPF T << 693 << 694 config KPROBE_EVENTS << 695 depends on KPROBES 401 depends on KPROBES 696 depends on HAVE_REGS_AND_STACK_ACCESS_ 402 depends on HAVE_REGS_AND_STACK_ACCESS_API 697 bool "Enable kprobes-based dynamic eve 403 bool "Enable kprobes-based dynamic events" 698 select TRACING 404 select TRACING 699 select PROBE_EVENTS 405 select PROBE_EVENTS 700 select DYNAMIC_EVENTS << 701 default y 406 default y 702 help 407 help 703 This allows the user to add tracing 408 This allows the user to add tracing events (similar to tracepoints) 704 on the fly via the ftrace interface. 409 on the fly via the ftrace interface. See 705 Documentation/trace/kprobetrace.rst !! 410 Documentation/trace/kprobetrace.txt for more details. 706 411 707 Those events can be inserted whereve 412 Those events can be inserted wherever kprobes can probe, and record 708 various register and memory values. 413 various register and memory values. 709 414 710 This option is also required by perf 415 This option is also required by perf-probe subcommand of perf tools. 711 If you want to use perf tools, this 416 If you want to use perf tools, this option is strongly recommended. 712 417 713 config KPROBE_EVENTS_ON_NOTRACE !! 418 config UPROBE_EVENT 714 bool "Do NOT protect notrace function << 715 depends on KPROBE_EVENTS << 716 depends on DYNAMIC_FTRACE << 717 default n << 718 help << 719 This is only for the developers who << 720 using kprobe events. << 721 << 722 If kprobes can use ftrace instead of << 723 functions are protected from kprobe- << 724 recursion or any unexpected executio << 725 crash. << 726 << 727 This option disables such protection << 728 events on ftrace functions for debug << 729 Note that this might let you shoot y << 730 << 731 If unsure, say N. << 732 << 733 config UPROBE_EVENTS << 734 bool "Enable uprobes-based dynamic eve 419 bool "Enable uprobes-based dynamic events" 735 depends on ARCH_SUPPORTS_UPROBES 420 depends on ARCH_SUPPORTS_UPROBES 736 depends on MMU 421 depends on MMU 737 depends on PERF_EVENTS 422 depends on PERF_EVENTS 738 select UPROBES 423 select UPROBES 739 select PROBE_EVENTS 424 select PROBE_EVENTS 740 select DYNAMIC_EVENTS << 741 select TRACING 425 select TRACING 742 default y !! 426 default n 743 help 427 help 744 This allows the user to add tracing 428 This allows the user to add tracing events on top of userspace 745 dynamic events (similar to tracepoin 429 dynamic events (similar to tracepoints) on the fly via the trace 746 events interface. Those events can b 430 events interface. Those events can be inserted wherever uprobes 747 can probe, and record various regist 431 can probe, and record various registers. 748 This option is required if you plan 432 This option is required if you plan to use perf-probe subcommand 749 of perf tools on user space applicat 433 of perf tools on user space applications. 750 434 751 config BPF_EVENTS 435 config BPF_EVENTS 752 depends on BPF_SYSCALL 436 depends on BPF_SYSCALL 753 depends on (KPROBE_EVENTS || UPROBE_EV !! 437 depends on (KPROBE_EVENT || UPROBE_EVENT) && PERF_EVENTS 754 bool 438 bool 755 default y 439 default y 756 help 440 help 757 This allows the user to attach BPF p !! 441 This allows the user to attach BPF programs to kprobe events. 758 tracepoint events. << 759 << 760 config DYNAMIC_EVENTS << 761 def_bool n << 762 442 763 config PROBE_EVENTS 443 config PROBE_EVENTS 764 def_bool n 444 def_bool n 765 445 766 config BPF_KPROBE_OVERRIDE !! 446 config DYNAMIC_FTRACE 767 bool "Enable BPF programs to override !! 447 bool "enable/disable function tracing dynamically" 768 depends on BPF_EVENTS !! 448 depends on FUNCTION_TRACER 769 depends on FUNCTION_ERROR_INJECTION !! 449 depends on HAVE_DYNAMIC_FTRACE 770 default n !! 450 default y 771 help 451 help 772 Allows BPF to override the execution !! 452 This option will modify all the calls to function tracing 773 set a different return value. This i !! 453 dynamically (will patch them out of the binary image and >> 454 replace them with a No-Op instruction) on boot up. During >> 455 compile time, a table is made of all the locations that ftrace >> 456 can function trace, and this table is linked into the kernel >> 457 image. When this is enabled, functions can be individually >> 458 enabled, and the functions not enabled will not affect >> 459 performance of the system. 774 460 775 config FTRACE_MCOUNT_RECORD !! 461 See the files in /sys/kernel/debug/tracing: >> 462 available_filter_functions >> 463 set_ftrace_filter >> 464 set_ftrace_notrace >> 465 >> 466 This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but >> 467 otherwise has native performance as long as no tracing is active. >> 468 >> 469 config DYNAMIC_FTRACE_WITH_REGS 776 def_bool y 470 def_bool y 777 depends on DYNAMIC_FTRACE 471 depends on DYNAMIC_FTRACE 778 depends on HAVE_FTRACE_MCOUNT_RECORD !! 472 depends on HAVE_DYNAMIC_FTRACE_WITH_REGS 779 473 780 config FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_EN !! 474 config FUNCTION_PROFILER 781 bool !! 475 bool "Kernel function profiler" 782 depends on FTRACE_MCOUNT_RECORD !! 476 depends on FUNCTION_TRACER >> 477 default n >> 478 help >> 479 This option enables the kernel function profiler. A file is created >> 480 in debugfs called function_profile_enabled which defaults to zero. >> 481 When a 1 is echoed into this file profiling begins, and when a >> 482 zero is entered, profiling stops. A "functions" file is created in >> 483 the trace_stats directory; this file shows the list of functions that >> 484 have been hit and their counters. 783 485 784 config FTRACE_MCOUNT_USE_CC !! 486 If in doubt, say N. 785 def_bool y << 786 depends on $(cc-option,-mrecord-mcount << 787 depends on !FTRACE_MCOUNT_USE_PATCHABL << 788 depends on FTRACE_MCOUNT_RECORD << 789 487 790 config FTRACE_MCOUNT_USE_OBJTOOL !! 488 config FTRACE_MCOUNT_RECORD 791 def_bool y 489 def_bool y 792 depends on HAVE_OBJTOOL_MCOUNT !! 490 depends on DYNAMIC_FTRACE 793 depends on !FTRACE_MCOUNT_USE_PATCHABL !! 491 depends on HAVE_FTRACE_MCOUNT_RECORD 794 depends on !FTRACE_MCOUNT_USE_CC << 795 depends on FTRACE_MCOUNT_RECORD << 796 select OBJTOOL << 797 492 798 config FTRACE_MCOUNT_USE_RECORDMCOUNT !! 493 config FTRACE_SELFTEST 799 def_bool y !! 494 bool 800 depends on !FTRACE_MCOUNT_USE_PATCHABL << 801 depends on !FTRACE_MCOUNT_USE_CC << 802 depends on !FTRACE_MCOUNT_USE_OBJTOOL << 803 depends on FTRACE_MCOUNT_RECORD << 804 << 805 config TRACING_MAP << 806 bool << 807 depends on ARCH_HAVE_NMI_SAFE_CMPXCHG << 808 help << 809 tracing_map is a special-purpose loc << 810 separated out as a stand-alone facil << 811 to be shared between multiple tracer << 812 generally used outside of that conte << 813 selected by tracers that use it. << 814 495 815 config SYNTH_EVENTS !! 496 config FTRACE_STARTUP_TEST 816 bool "Synthetic trace events" !! 497 bool "Perform a startup test on ftrace" 817 select TRACING !! 498 depends on GENERIC_TRACER 818 select DYNAMIC_EVENTS !! 499 select FTRACE_SELFTEST 819 default n << 820 help 500 help 821 Synthetic events are user-defined tr !! 501 This option performs a series of startup tests on ftrace. On bootup 822 used to combine data from other trac !! 502 a series of tests are made to verify that the tracer is 823 data source. Synthetic events can b !! 503 functioning properly. It will do tests on all the configured 824 via the trace() action of histogram !! 504 tracers of ftrace. 825 by way of an in-kernel API. << 826 << 827 See Documentation/trace/events.rst o << 828 Documentation/trace/histogram.rst fo << 829 << 830 If in doubt, say N. << 831 505 832 config USER_EVENTS !! 506 config EVENT_TRACE_TEST_SYSCALLS 833 bool "User trace events" !! 507 bool "Run selftest on syscall events" 834 select TRACING !! 508 depends on FTRACE_STARTUP_TEST 835 select DYNAMIC_EVENTS << 836 help 509 help 837 User trace events are user-defined t !! 510 This option will also enable testing every syscall event. 838 can be used like an existing kernel !! 511 It only enables the event and disables it and runs various loads 839 events are generated by writing to a !! 512 with the event enabled. This adds a bit more time for kernel boot 840 processes can determine if their tra !! 513 up since it runs this on every system call defined. 841 generated by registering a value and << 842 that reflects when it is enabled or << 843 514 844 See Documentation/trace/user_events. !! 515 TBD - enable a way to actually call the syscalls as we test their 845 If in doubt, say N. !! 516 events 846 517 847 config HIST_TRIGGERS !! 518 config MMIOTRACE 848 bool "Histogram triggers" !! 519 bool "Memory mapped IO tracing" 849 depends on ARCH_HAVE_NMI_SAFE_CMPXCHG !! 520 depends on HAVE_MMIOTRACE_SUPPORT && PCI 850 select TRACING_MAP !! 521 select GENERIC_TRACER 851 select TRACING << 852 select DYNAMIC_EVENTS << 853 select SYNTH_EVENTS << 854 default n << 855 help 522 help 856 Hist triggers allow one or more arbi !! 523 Mmiotrace traces Memory Mapped I/O access and is meant for 857 to be aggregated into hash tables an !! 524 debugging and reverse engineering. It is called from the ioremap 858 reading a debugfs/tracefs file. The !! 525 implementation and works via page faults. Tracing is disabled by 859 gathering quick and dirty (though pr !! 526 default and can be enabled at run-time. 860 event activity as an initial guide f << 861 using more advanced tools. << 862 << 863 Inter-event tracing of quantities su << 864 supported using hist triggers under << 865 527 866 See Documentation/trace/histogram.rs !! 528 See Documentation/trace/mmiotrace.txt. 867 If in doubt, say N. !! 529 If you are not helping to develop drivers, say N. 868 530 869 config TRACE_EVENT_INJECT !! 531 config MMIOTRACE_TEST 870 bool "Trace event injection" !! 532 tristate "Test module for mmiotrace" 871 depends on TRACING !! 533 depends on MMIOTRACE && m 872 help 534 help 873 Allow user-space to inject a specifi !! 535 This is a dumb module for testing mmiotrace. It is very dangerous 874 buffer. This is mainly used for test !! 536 as it will write garbage to IO memory starting at a given address. >> 537 However, it should be safe to use on e.g. unused portion of VRAM. 875 538 876 If unsure, say N. !! 539 Say N, unless you absolutely know what you are doing. 877 540 878 config TRACEPOINT_BENCHMARK 541 config TRACEPOINT_BENCHMARK 879 bool "Add tracepoint that benchmarks t !! 542 bool "Add tracepoint that benchmarks tracepoints" 880 help 543 help 881 This option creates the tracepoint "b 544 This option creates the tracepoint "benchmark:benchmark_event". 882 When the tracepoint is enabled, it ki 545 When the tracepoint is enabled, it kicks off a kernel thread that 883 goes into an infinite loop (calling c !! 546 goes into an infinite loop (calling cond_sched() to let other tasks 884 run), and calls the tracepoint. Each 547 run), and calls the tracepoint. Each iteration will record the time 885 it took to write to the tracepoint an 548 it took to write to the tracepoint and the next iteration that 886 data will be passed to the tracepoint 549 data will be passed to the tracepoint itself. That is, the tracepoint 887 will report the time it took to do th 550 will report the time it took to do the previous tracepoint. 888 The string written to the tracepoint 551 The string written to the tracepoint is a static string of 128 bytes 889 to keep the time the same. The initia 552 to keep the time the same. The initial string is simply a write of 890 "START". The second string records th 553 "START". The second string records the cold cache time of the first 891 write which is not added to the rest 554 write which is not added to the rest of the calculations. 892 555 893 As it is a tight loop, it benchmarks 556 As it is a tight loop, it benchmarks as hot cache. That's fine because 894 we care most about hot paths that are 557 we care most about hot paths that are probably in cache already. 895 558 896 An example of the output: 559 An example of the output: 897 560 898 START 561 START 899 first=3672 [COLD CACHED] 562 first=3672 [COLD CACHED] 900 last=632 first=3672 max=632 min= 563 last=632 first=3672 max=632 min=632 avg=316 std=446 std^2=199712 901 last=278 first=3672 max=632 min= 564 last=278 first=3672 max=632 min=278 avg=303 std=316 std^2=100337 902 last=277 first=3672 max=632 min= 565 last=277 first=3672 max=632 min=277 avg=296 std=258 std^2=67064 903 last=273 first=3672 max=632 min= 566 last=273 first=3672 max=632 min=273 avg=292 std=224 std^2=50411 904 last=273 first=3672 max=632 min= 567 last=273 first=3672 max=632 min=273 avg=288 std=200 std^2=40389 905 last=281 first=3672 max=632 min= 568 last=281 first=3672 max=632 min=273 avg=287 std=183 std^2=33666 906 569 907 570 908 config RING_BUFFER_BENCHMARK 571 config RING_BUFFER_BENCHMARK 909 tristate "Ring buffer benchmark stress 572 tristate "Ring buffer benchmark stress tester" 910 depends on RING_BUFFER 573 depends on RING_BUFFER 911 help 574 help 912 This option creates a test to stress 575 This option creates a test to stress the ring buffer and benchmark it. 913 It creates its own ring buffer such 576 It creates its own ring buffer such that it will not interfere with 914 any other users of the ring buffer ( 577 any other users of the ring buffer (such as ftrace). It then creates 915 a producer and consumer that will ru 578 a producer and consumer that will run for 10 seconds and sleep for 916 10 seconds. Each interval it will pr 579 10 seconds. Each interval it will print out the number of events 917 it recorded and give a rough estimat 580 it recorded and give a rough estimate of how long each iteration took. 918 581 919 It does not disable interrupts or ra 582 It does not disable interrupts or raise its priority, so it may be 920 affected by processes that are runni 583 affected by processes that are running. 921 584 922 If unsure, say N. 585 If unsure, say N. 923 586 924 config TRACE_EVAL_MAP_FILE << 925 bool "Show eval mappings for trace even << 926 depends on TRACING << 927 help << 928 The "print fmt" of the trace events wi << 929 instead of their values. This can caus << 930 that use this string to parse the raw << 931 how to convert the string to its value << 932 << 933 To fix this, there's a special macro i << 934 to convert an enum/sizeof into its val << 935 the print fmt strings will be converte << 936 << 937 If something does not get converted pr << 938 used to show what enums/sizeof the ker << 939 << 940 This option is for debugging the conve << 941 in the tracing directory called "eval_ << 942 names matched with their values and wh << 943 belong too. << 944 << 945 Normally, the mapping of the strings t << 946 boot up or module load. With this opti << 947 they are needed for the "eval_map" fil << 948 increase the memory footprint of the r << 949 << 950 If unsure, say N. << 951 << 952 config FTRACE_RECORD_RECURSION << 953 bool "Record functions that recurse in << 954 depends on FUNCTION_TRACER << 955 help << 956 All callbacks that attach to the fun << 957 of protection against recursion. Eve << 958 it adds overhead. This option will c << 959 file system called "recursed_functio << 960 that triggered a recursion. << 961 << 962 This will add more overhead to cases << 963 << 964 If unsure, say N << 965 << 966 config FTRACE_RECORD_RECURSION_SIZE << 967 int "Max number of recursed functions << 968 default 128 << 969 depends on FTRACE_RECORD_RECURSION << 970 help << 971 This defines the limit of number of << 972 listed in the "recursed_functions" f << 973 the functions that caused a recursio << 974 This file can be reset, but the limi << 975 size at runtime. << 976 << 977 config FTRACE_VALIDATE_RCU_IS_WATCHING << 978 bool "Validate RCU is on during ftrace << 979 depends on FUNCTION_TRACER << 980 depends on ARCH_WANTS_NO_INSTR << 981 help << 982 All callbacks that attach to the fun << 983 protection against recursion. This o << 984 ftrace (and other users of ftrace_te << 985 called outside of RCU, as if they ar << 986 also has a noticeable overhead when << 987 << 988 If unsure, say N << 989 << 990 config RING_BUFFER_RECORD_RECURSION << 991 bool "Record functions that recurse in << 992 depends on FTRACE_RECORD_RECURSION << 993 # default y, because it is coupled wit << 994 default y << 995 help << 996 The ring buffer has its own internal << 997 recursion happens it won't cause har << 998 but it does cause unwanted overhead. << 999 place where recursion was detected i << 1000 file. << 1001 << 1002 This will add more overhead to case << 1003 << 1004 config GCOV_PROFILE_FTRACE << 1005 bool "Enable GCOV profiling on ftrace << 1006 depends on GCOV_KERNEL << 1007 help << 1008 Enable GCOV profiling on ftrace sub << 1009 which functions/lines are tested. << 1010 << 1011 If unsure, say N. << 1012 << 1013 Note that on a kernel compiled with << 1014 run significantly slower. << 1015 << 1016 config FTRACE_SELFTEST << 1017 bool << 1018 << 1019 config FTRACE_STARTUP_TEST << 1020 bool "Perform a startup test on ftrac << 1021 depends on GENERIC_TRACER << 1022 select FTRACE_SELFTEST << 1023 help << 1024 This option performs a series of st << 1025 a series of tests are made to verif << 1026 functioning properly. It will do te << 1027 tracers of ftrace. << 1028 << 1029 config EVENT_TRACE_STARTUP_TEST << 1030 bool "Run selftest on trace events" << 1031 depends on FTRACE_STARTUP_TEST << 1032 default y << 1033 help << 1034 This option performs a test on all << 1035 It basically just enables each even << 1036 will trigger events (not necessaril << 1037 This may take some time run as ther << 1038 << 1039 config EVENT_TRACE_TEST_SYSCALLS << 1040 bool "Run selftest on syscall events" << 1041 depends on EVENT_TRACE_STARTUP_TEST << 1042 help << 1043 This option will also enable testing << 1044 It only enables the event and disabl << 1045 with the event enabled. This adds a << 1046 up since it runs this on every syste << 1047 << 1048 TBD - enable a way to actually call << 1049 events << 1050 << 1051 config FTRACE_SORT_STARTUP_TEST << 1052 bool "Verify compile time sorting of f << 1053 depends on DYNAMIC_FTRACE << 1054 depends on BUILDTIME_MCOUNT_SORT << 1055 help << 1056 Sorting of the mcount_loc sections t << 1057 where the ftrace knows where to patc << 1058 and other callbacks is done at compi << 1059 is not done correctly, it will cause << 1060 When this is set, the sorted section << 1061 are in deed sorted and will warn if << 1062 << 1063 If unsure, say N << 1064 << 1065 config RING_BUFFER_STARTUP_TEST 587 config RING_BUFFER_STARTUP_TEST 1066 bool "Ring buffer startup self test" 588 bool "Ring buffer startup self test" 1067 depends on RING_BUFFER 589 depends on RING_BUFFER 1068 help 590 help 1069 Run a simple self test on the ring b !! 591 Run a simple self test on the ring buffer on boot up. Late in the 1070 kernel boot sequence, the test will 592 kernel boot sequence, the test will start that kicks off 1071 a thread per cpu. Each thread will w 593 a thread per cpu. Each thread will write various size events 1072 into the ring buffer. Another thread 594 into the ring buffer. Another thread is created to send IPIs 1073 to each of the threads, where the IP 595 to each of the threads, where the IPI handler will also write 1074 to the ring buffer, to test/stress t 596 to the ring buffer, to test/stress the nesting ability. 1075 If any anomalies are discovered, a w 597 If any anomalies are discovered, a warning will be displayed 1076 and all ring buffers will be disable 598 and all ring buffers will be disabled. 1077 599 1078 The test runs for 10 seconds. This w 600 The test runs for 10 seconds. This will slow your boot time 1079 by at least 10 more seconds. 601 by at least 10 more seconds. 1080 602 1081 At the end of the test, statistics a !! 603 At the end of the test, statics and more checks are done. 1082 It will output the stats of each per !! 604 It will output the stats of each per cpu buffer. What 1083 was written, the sizes, what was rea 605 was written, the sizes, what was read, what was lost, and 1084 other similar details. 606 other similar details. 1085 607 1086 If unsure, say N 608 If unsure, say N 1087 609 1088 config RING_BUFFER_VALIDATE_TIME_DELTAS !! 610 config TRACE_ENUM_MAP_FILE 1089 bool "Verify ring buffer time stamp d !! 611 bool "Show enum mappings for trace events" 1090 depends on RING_BUFFER !! 612 depends on TRACING 1091 help !! 613 help 1092 This will audit the time stamps on !! 614 The "print fmt" of the trace events will show the enum names instead 1093 buffer to make sure that all the ti !! 615 of their values. This can cause problems for user space tools that 1094 events on a sub buffer matches the !! 616 use this string to parse the raw data as user space does not know 1095 This audit is performed for every e !! 617 how to convert the string to its value. 1096 interrupted, or interrupting anothe << 1097 is also made when traversing sub bu << 1098 that all the deltas on the previous << 1099 add up to be greater than the curre << 1100 << 1101 NOTE: This adds significant overhea << 1102 and should only be used to test the << 1103 Do not use it on production systems << 1104 << 1105 Only say Y if you understand what t << 1106 still want it enabled. Otherwise sa << 1107 << 1108 config MMIOTRACE_TEST << 1109 tristate "Test module for mmiotrace" << 1110 depends on MMIOTRACE && m << 1111 help << 1112 This is a dumb module for testing m << 1113 as it will write garbage to IO memo << 1114 However, it should be safe to use o << 1115 << 1116 Say N, unless you absolutely know w << 1117 << 1118 config PREEMPTIRQ_DELAY_TEST << 1119 tristate "Test module to create a pre << 1120 depends on m << 1121 help << 1122 Select this option to build a test << 1123 tracers by executing a preempt or i << 1124 configurable delay. The module busy << 1125 critical section. << 1126 << 1127 For example, the following invocati << 1128 irq-disabled critical sections for << 1129 modprobe preemptirq_delay_test test << 1130 << 1131 What's more, if you want to attach << 1132 tracer is running on, specify cpu_a << 1133 command. << 1134 << 1135 If unsure, say N << 1136 << 1137 config SYNTH_EVENT_GEN_TEST << 1138 tristate "Test module for in-kernel s << 1139 depends on SYNTH_EVENTS && m << 1140 help << 1141 This option creates a test module t << 1142 functionality of in-kernel syntheti << 1143 generation. << 1144 618 1145 To test, insert the module, and the !! 619 To fix this, there's a special macro in the kernel that can be used 1146 for the generated sample events. !! 620 to convert the enum into its value. If this macro is used, then the >> 621 print fmt strings will have the enums converted to their values. 1147 622 1148 If unsure, say N. !! 623 If something does not get converted properly, this option can be >> 624 used to show what enums the kernel tried to convert. 1149 625 1150 config KPROBE_EVENT_GEN_TEST !! 626 This option is for debugging the enum conversions. A file is created 1151 tristate "Test module for in-kernel k !! 627 in the tracing directory called "enum_map" that will show the enum 1152 depends on KPROBE_EVENTS && m !! 628 names matched with their values and what trace event system they 1153 help !! 629 belong too. 1154 This option creates a test module t << 1155 functionality of in-kernel kprobe e << 1156 630 1157 To test, insert the module, and the !! 631 Normally, the mapping of the strings to values will be freed after 1158 for the generated kprobe events. !! 632 boot up or module load. With this option, they will not be freed, as >> 633 they are needed for the "enum_map" file. Enabling this option will >> 634 increase the memory footprint of the running kernel. 1159 635 1160 If unsure, say N. !! 636 If unsure, say N 1161 637 1162 config HIST_TRIGGERS_DEBUG !! 638 config TRACING_EVENTS_GPIO 1163 bool "Hist trigger debug support" !! 639 bool "Trace gpio events" 1164 depends on HIST_TRIGGERS !! 640 depends on GPIOLIB >> 641 default y 1165 help 642 help 1166 Add "hist_debug" file for each even !! 643 Enable tracing events for gpio subsystem 1167 dump out a bunch of internal detail << 1168 defined on that event. << 1169 << 1170 The hist_debug file serves a couple << 1171 644 1172 - Helps developers verify that no !! 645 endif # FTRACE 1173 << 1174 - Provides educational informatio << 1175 of the hist trigger internals a << 1176 Documentation/trace/histogram-d << 1177 << 1178 The hist_debug output only covers t << 1179 related to the histogram definition << 1180 display the internals of map bucket << 1181 running histograms. << 1182 << 1183 If unsure, say N. << 1184 646 1185 source "kernel/trace/rv/Kconfig" !! 647 endif # TRACING_SUPPORT 1186 648 1187 endif # FTRACE <<
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