diff options
Diffstat (limited to 'kernel/trace/Kconfig')
-rw-r--r-- | kernel/trace/Kconfig | 116 |
1 files changed, 57 insertions, 59 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index d006554888dc..60e2ce0181ee 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig | |||
@@ -12,39 +12,37 @@ config NOP_TRACER | |||
12 | config HAVE_FTRACE_NMI_ENTER | 12 | config HAVE_FTRACE_NMI_ENTER |
13 | bool | 13 | bool |
14 | help | 14 | help |
15 | See Documentation/trace/ftrace-implementation.txt | 15 | See Documentation/trace/ftrace-design.txt |
16 | 16 | ||
17 | config HAVE_FUNCTION_TRACER | 17 | config HAVE_FUNCTION_TRACER |
18 | bool | 18 | bool |
19 | help | 19 | help |
20 | See Documentation/trace/ftrace-implementation.txt | 20 | See Documentation/trace/ftrace-design.txt |
21 | 21 | ||
22 | config HAVE_FUNCTION_GRAPH_TRACER | 22 | config HAVE_FUNCTION_GRAPH_TRACER |
23 | bool | 23 | bool |
24 | help | 24 | help |
25 | See Documentation/trace/ftrace-implementation.txt | 25 | See Documentation/trace/ftrace-design.txt |
26 | 26 | ||
27 | config HAVE_FUNCTION_GRAPH_FP_TEST | 27 | config HAVE_FUNCTION_GRAPH_FP_TEST |
28 | bool | 28 | bool |
29 | help | 29 | help |
30 | An arch may pass in a unique value (frame pointer) to both the | 30 | See Documentation/trace/ftrace-design.txt |
31 | entering and exiting of a function. On exit, the value is compared | ||
32 | and if it does not match, then it will panic the kernel. | ||
33 | 31 | ||
34 | config HAVE_FUNCTION_TRACE_MCOUNT_TEST | 32 | config HAVE_FUNCTION_TRACE_MCOUNT_TEST |
35 | bool | 33 | bool |
36 | help | 34 | help |
37 | See Documentation/trace/ftrace-implementation.txt | 35 | See Documentation/trace/ftrace-design.txt |
38 | 36 | ||
39 | config HAVE_DYNAMIC_FTRACE | 37 | config HAVE_DYNAMIC_FTRACE |
40 | bool | 38 | bool |
41 | help | 39 | help |
42 | See Documentation/trace/ftrace-implementation.txt | 40 | See Documentation/trace/ftrace-design.txt |
43 | 41 | ||
44 | config HAVE_FTRACE_MCOUNT_RECORD | 42 | config HAVE_FTRACE_MCOUNT_RECORD |
45 | bool | 43 | bool |
46 | help | 44 | help |
47 | See Documentation/trace/ftrace-implementation.txt | 45 | See Documentation/trace/ftrace-design.txt |
48 | 46 | ||
49 | config HAVE_HW_BRANCH_TRACER | 47 | config HAVE_HW_BRANCH_TRACER |
50 | bool | 48 | bool |
@@ -52,7 +50,7 @@ config HAVE_HW_BRANCH_TRACER | |||
52 | config HAVE_SYSCALL_TRACEPOINTS | 50 | config HAVE_SYSCALL_TRACEPOINTS |
53 | bool | 51 | bool |
54 | help | 52 | help |
55 | See Documentation/trace/ftrace-implementation.txt | 53 | See Documentation/trace/ftrace-design.txt |
56 | 54 | ||
57 | config TRACER_MAX_TRACE | 55 | config TRACER_MAX_TRACE |
58 | bool | 56 | bool |
@@ -83,7 +81,7 @@ config RING_BUFFER_ALLOW_SWAP | |||
83 | # This allows those options to appear when no other tracer is selected. But the | 81 | # This allows those options to appear when no other tracer is selected. But the |
84 | # options do not appear when something else selects it. We need the two options | 82 | # options do not appear when something else selects it. We need the two options |
85 | # GENERIC_TRACER and TRACING to avoid circular dependencies to accomplish the | 83 | # GENERIC_TRACER and TRACING to avoid circular dependencies to accomplish the |
86 | # hidding of the automatic options. | 84 | # hiding of the automatic options. |
87 | 85 | ||
88 | config TRACING | 86 | config TRACING |
89 | bool | 87 | bool |
@@ -119,7 +117,7 @@ menuconfig FTRACE | |||
119 | bool "Tracers" | 117 | bool "Tracers" |
120 | default y if DEBUG_KERNEL | 118 | default y if DEBUG_KERNEL |
121 | help | 119 | help |
122 | Enable the kernel tracing infrastructure. | 120 | Enable the kernel tracing infrastructure. |
123 | 121 | ||
124 | if FTRACE | 122 | if FTRACE |
125 | 123 | ||
@@ -133,7 +131,7 @@ config FUNCTION_TRACER | |||
133 | help | 131 | help |
134 | Enable the kernel to trace every kernel function. This is done | 132 | Enable the kernel to trace every kernel function. This is done |
135 | by using a compiler feature to insert a small, 5-byte No-Operation | 133 | by using a compiler feature to insert a small, 5-byte No-Operation |
136 | instruction to the beginning of every kernel function, which NOP | 134 | instruction at the beginning of every kernel function, which NOP |
137 | sequence is then dynamically patched into a tracer call when | 135 | sequence is then dynamically patched into a tracer call when |
138 | tracing is enabled by the administrator. If it's runtime disabled | 136 | tracing is enabled by the administrator. If it's runtime disabled |
139 | (the bootup default), then the overhead of the instructions is very | 137 | (the bootup default), then the overhead of the instructions is very |
@@ -150,7 +148,7 @@ config FUNCTION_GRAPH_TRACER | |||
150 | and its entry. | 148 | and its entry. |
151 | Its first purpose is to trace the duration of functions and | 149 | Its first purpose is to trace the duration of functions and |
152 | draw a call graph for each thread with some information like | 150 | draw a call graph for each thread with some information like |
153 | the return value. This is done by setting the current return | 151 | the return value. This is done by setting the current return |
154 | address on the current task structure into a stack of calls. | 152 | address on the current task structure into a stack of calls. |
155 | 153 | ||
156 | 154 | ||
@@ -173,7 +171,7 @@ config IRQSOFF_TRACER | |||
173 | 171 | ||
174 | echo 0 > /sys/kernel/debug/tracing/tracing_max_latency | 172 | echo 0 > /sys/kernel/debug/tracing/tracing_max_latency |
175 | 173 | ||
176 | (Note that kernel size and overhead increases with this option | 174 | (Note that kernel size and overhead increase with this option |
177 | enabled. This option and the preempt-off timing option can be | 175 | enabled. This option and the preempt-off timing option can be |
178 | used together or separately.) | 176 | used together or separately.) |
179 | 177 | ||
@@ -186,7 +184,7 @@ config PREEMPT_TRACER | |||
186 | select TRACER_MAX_TRACE | 184 | select TRACER_MAX_TRACE |
187 | select RING_BUFFER_ALLOW_SWAP | 185 | select RING_BUFFER_ALLOW_SWAP |
188 | help | 186 | help |
189 | This option measures the time spent in preemption off critical | 187 | This option measures the time spent in preemption-off critical |
190 | sections, with microsecond accuracy. | 188 | sections, with microsecond accuracy. |
191 | 189 | ||
192 | The default measurement method is a maximum search, which is | 190 | The default measurement method is a maximum search, which is |
@@ -195,7 +193,7 @@ config PREEMPT_TRACER | |||
195 | 193 | ||
196 | echo 0 > /sys/kernel/debug/tracing/tracing_max_latency | 194 | echo 0 > /sys/kernel/debug/tracing/tracing_max_latency |
197 | 195 | ||
198 | (Note that kernel size and overhead increases with this option | 196 | (Note that kernel size and overhead increase with this option |
199 | enabled. This option and the irqs-off timing option can be | 197 | enabled. This option and the irqs-off timing option can be |
200 | used together or separately.) | 198 | used together or separately.) |
201 | 199 | ||
@@ -222,7 +220,7 @@ config ENABLE_DEFAULT_TRACERS | |||
222 | depends on !GENERIC_TRACER | 220 | depends on !GENERIC_TRACER |
223 | select TRACING | 221 | select TRACING |
224 | help | 222 | help |
225 | This tracer hooks to various trace points in the kernel | 223 | This tracer hooks to various trace points in the kernel, |
226 | allowing the user to pick and choose which trace point they | 224 | allowing the user to pick and choose which trace point they |
227 | want to trace. It also includes the sched_switch tracer plugin. | 225 | want to trace. It also includes the sched_switch tracer plugin. |
228 | 226 | ||
@@ -265,19 +263,19 @@ choice | |||
265 | The likely/unlikely profiler only looks at the conditions that | 263 | The likely/unlikely profiler only looks at the conditions that |
266 | are annotated with a likely or unlikely macro. | 264 | are annotated with a likely or unlikely macro. |
267 | 265 | ||
268 | The "all branch" profiler will profile every if statement in the | 266 | The "all branch" profiler will profile every if-statement in the |
269 | kernel. This profiler will also enable the likely/unlikely | 267 | kernel. This profiler will also enable the likely/unlikely |
270 | profiler as well. | 268 | profiler. |
271 | 269 | ||
272 | Either of the above profilers add a bit of overhead to the system. | 270 | Either of the above profilers adds a bit of overhead to the system. |
273 | If unsure choose "No branch profiling". | 271 | If unsure, choose "No branch profiling". |
274 | 272 | ||
275 | config BRANCH_PROFILE_NONE | 273 | config BRANCH_PROFILE_NONE |
276 | bool "No branch profiling" | 274 | bool "No branch profiling" |
277 | help | 275 | help |
278 | No branch profiling. Branch profiling adds a bit of overhead. | 276 | No branch profiling. Branch profiling adds a bit of overhead. |
279 | Only enable it if you want to analyse the branching behavior. | 277 | Only enable it if you want to analyse the branching behavior. |
280 | Otherwise keep it disabled. | 278 | Otherwise keep it disabled. |
281 | 279 | ||
282 | config PROFILE_ANNOTATED_BRANCHES | 280 | config PROFILE_ANNOTATED_BRANCHES |
283 | bool "Trace likely/unlikely profiler" | 281 | bool "Trace likely/unlikely profiler" |
@@ -288,7 +286,7 @@ config PROFILE_ANNOTATED_BRANCHES | |||
288 | 286 | ||
289 | /sys/kernel/debug/tracing/profile_annotated_branch | 287 | /sys/kernel/debug/tracing/profile_annotated_branch |
290 | 288 | ||
291 | Note: this will add a significant overhead, only turn this | 289 | Note: this will add a significant overhead; only turn this |
292 | on if you need to profile the system's use of these macros. | 290 | on if you need to profile the system's use of these macros. |
293 | 291 | ||
294 | config PROFILE_ALL_BRANCHES | 292 | config PROFILE_ALL_BRANCHES |
@@ -305,7 +303,7 @@ config PROFILE_ALL_BRANCHES | |||
305 | 303 | ||
306 | This configuration, when enabled, will impose a great overhead | 304 | This configuration, when enabled, will impose a great overhead |
307 | on the system. This should only be enabled when the system | 305 | on the system. This should only be enabled when the system |
308 | is to be analyzed | 306 | is to be analyzed in much detail. |
309 | endchoice | 307 | endchoice |
310 | 308 | ||
311 | config TRACING_BRANCHES | 309 | config TRACING_BRANCHES |
@@ -335,7 +333,7 @@ config POWER_TRACER | |||
335 | depends on X86 | 333 | depends on X86 |
336 | select GENERIC_TRACER | 334 | select GENERIC_TRACER |
337 | help | 335 | help |
338 | This tracer helps developers to analyze and optimize the kernels | 336 | This tracer helps developers to analyze and optimize the kernel's |
339 | power management decisions, specifically the C-state and P-state | 337 | power management decisions, specifically the C-state and P-state |
340 | behavior. | 338 | behavior. |
341 | 339 | ||
@@ -391,14 +389,14 @@ config HW_BRANCH_TRACER | |||
391 | select GENERIC_TRACER | 389 | select GENERIC_TRACER |
392 | help | 390 | help |
393 | This tracer records all branches on the system in a circular | 391 | This tracer records all branches on the system in a circular |
394 | buffer giving access to the last N branches for each cpu. | 392 | buffer, giving access to the last N branches for each cpu. |
395 | 393 | ||
396 | config KMEMTRACE | 394 | config KMEMTRACE |
397 | bool "Trace SLAB allocations" | 395 | bool "Trace SLAB allocations" |
398 | select GENERIC_TRACER | 396 | select GENERIC_TRACER |
399 | help | 397 | help |
400 | kmemtrace provides tracing for slab allocator functions, such as | 398 | kmemtrace provides tracing for slab allocator functions, such as |
401 | kmalloc, kfree, kmem_cache_alloc, kmem_cache_free etc.. Collected | 399 | kmalloc, kfree, kmem_cache_alloc, kmem_cache_free, etc. Collected |
402 | data is then fed to the userspace application in order to analyse | 400 | data is then fed to the userspace application in order to analyse |
403 | allocation hotspots, internal fragmentation and so on, making it | 401 | allocation hotspots, internal fragmentation and so on, making it |
404 | possible to see how well an allocator performs, as well as debug | 402 | possible to see how well an allocator performs, as well as debug |
@@ -417,15 +415,15 @@ config WORKQUEUE_TRACER | |||
417 | bool "Trace workqueues" | 415 | bool "Trace workqueues" |
418 | select GENERIC_TRACER | 416 | select GENERIC_TRACER |
419 | help | 417 | help |
420 | The workqueue tracer provides some statistical informations | 418 | The workqueue tracer provides some statistical information |
421 | about each cpu workqueue thread such as the number of the | 419 | about each cpu workqueue thread such as the number of the |
422 | works inserted and executed since their creation. It can help | 420 | works inserted and executed since their creation. It can help |
423 | to evaluate the amount of work each of them have to perform. | 421 | to evaluate the amount of work each of them has to perform. |
424 | For example it can help a developer to decide whether he should | 422 | For example it can help a developer to decide whether he should |
425 | choose a per cpu workqueue instead of a singlethreaded one. | 423 | choose a per-cpu workqueue instead of a singlethreaded one. |
426 | 424 | ||
427 | config BLK_DEV_IO_TRACE | 425 | config BLK_DEV_IO_TRACE |
428 | bool "Support for tracing block io actions" | 426 | bool "Support for tracing block IO actions" |
429 | depends on SYSFS | 427 | depends on SYSFS |
430 | depends on BLOCK | 428 | depends on BLOCK |
431 | select RELAY | 429 | select RELAY |
@@ -456,15 +454,15 @@ config KPROBE_EVENT | |||
456 | select TRACING | 454 | select TRACING |
457 | default y | 455 | default y |
458 | help | 456 | help |
459 | This allows the user to add tracing events (similar to tracepoints) on the fly | 457 | This allows the user to add tracing events (similar to tracepoints) |
460 | via the ftrace interface. See Documentation/trace/kprobetrace.txt | 458 | on the fly via the ftrace interface. See |
461 | for more details. | 459 | Documentation/trace/kprobetrace.txt for more details. |
462 | 460 | ||
463 | Those events can be inserted wherever kprobes can probe, and record | 461 | Those events can be inserted wherever kprobes can probe, and record |
464 | various register and memory values. | 462 | various register and memory values. |
465 | 463 | ||
466 | This option is also required by perf-probe subcommand of perf tools. If | 464 | This option is also required by perf-probe subcommand of perf tools. |
467 | you want to use perf tools, this option is strongly recommended. | 465 | If you want to use perf tools, this option is strongly recommended. |
468 | 466 | ||
469 | config DYNAMIC_FTRACE | 467 | config DYNAMIC_FTRACE |
470 | bool "enable/disable ftrace tracepoints dynamically" | 468 | bool "enable/disable ftrace tracepoints dynamically" |
@@ -472,32 +470,32 @@ config DYNAMIC_FTRACE | |||
472 | depends on HAVE_DYNAMIC_FTRACE | 470 | depends on HAVE_DYNAMIC_FTRACE |
473 | default y | 471 | default y |
474 | help | 472 | help |
475 | This option will modify all the calls to ftrace dynamically | 473 | This option will modify all the calls to ftrace dynamically |
476 | (will patch them out of the binary image and replaces them | 474 | (will patch them out of the binary image and replace them |
477 | with a No-Op instruction) as they are called. A table is | 475 | with a No-Op instruction) as they are called. A table is |
478 | created to dynamically enable them again. | 476 | created to dynamically enable them again. |
479 | 477 | ||
480 | This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but otherwise | 478 | This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but |
481 | has native performance as long as no tracing is active. | 479 | otherwise has native performance as long as no tracing is active. |
482 | 480 | ||
483 | The changes to the code are done by a kernel thread that | 481 | The changes to the code are done by a kernel thread that |
484 | wakes up once a second and checks to see if any ftrace calls | 482 | wakes up once a second and checks to see if any ftrace calls |
485 | were made. If so, it runs stop_machine (stops all CPUS) | 483 | were made. If so, it runs stop_machine (stops all CPUS) |
486 | and modifies the code to jump over the call to ftrace. | 484 | and modifies the code to jump over the call to ftrace. |
487 | 485 | ||
488 | config FUNCTION_PROFILER | 486 | config FUNCTION_PROFILER |
489 | bool "Kernel function profiler" | 487 | bool "Kernel function profiler" |
490 | depends on FUNCTION_TRACER | 488 | depends on FUNCTION_TRACER |
491 | default n | 489 | default n |
492 | help | 490 | help |
493 | This option enables the kernel function profiler. A file is created | 491 | This option enables the kernel function profiler. A file is created |
494 | in debugfs called function_profile_enabled which defaults to zero. | 492 | in debugfs called function_profile_enabled which defaults to zero. |
495 | When a 1 is echoed into this file profiling begins, and when a | 493 | When a 1 is echoed into this file profiling begins, and when a |
496 | zero is entered, profiling stops. A file in the trace_stats | 494 | zero is entered, profiling stops. A "functions" file is created in |
497 | directory called functions, that show the list of functions that | 495 | the trace_stats directory; this file shows the list of functions that |
498 | have been hit and their counters. | 496 | have been hit and their counters. |
499 | 497 | ||
500 | If in doubt, say N | 498 | If in doubt, say N. |
501 | 499 | ||
502 | config FTRACE_MCOUNT_RECORD | 500 | config FTRACE_MCOUNT_RECORD |
503 | def_bool y | 501 | def_bool y |
@@ -556,8 +554,8 @@ config RING_BUFFER_BENCHMARK | |||
556 | tristate "Ring buffer benchmark stress tester" | 554 | tristate "Ring buffer benchmark stress tester" |
557 | depends on RING_BUFFER | 555 | depends on RING_BUFFER |
558 | help | 556 | help |
559 | This option creates a test to stress the ring buffer and bench mark it. | 557 | This option creates a test to stress the ring buffer and benchmark it. |
560 | It creates its own ring buffer such that it will not interfer with | 558 | It creates its own ring buffer such that it will not interfere with |
561 | any other users of the ring buffer (such as ftrace). It then creates | 559 | any other users of the ring buffer (such as ftrace). It then creates |
562 | a producer and consumer that will run for 10 seconds and sleep for | 560 | a producer and consumer that will run for 10 seconds and sleep for |
563 | 10 seconds. Each interval it will print out the number of events | 561 | 10 seconds. Each interval it will print out the number of events |
@@ -566,7 +564,7 @@ config RING_BUFFER_BENCHMARK | |||
566 | It does not disable interrupts or raise its priority, so it may be | 564 | It does not disable interrupts or raise its priority, so it may be |
567 | affected by processes that are running. | 565 | affected by processes that are running. |
568 | 566 | ||
569 | If unsure, say N | 567 | If unsure, say N. |
570 | 568 | ||
571 | endif # FTRACE | 569 | endif # FTRACE |
572 | 570 | ||