Lines Matching +full:wakeup +full:- +full:latency
1 # SPDX-License-Identifier: GPL-2.0-only
21 API, which will be used by other function-entry hooking
27 See Documentation/trace/ftrace-design.rst
32 See Documentation/trace/ftrace-design.rst
45 See Documentation/trace/ftrace-design.rst
86 See Documentation/trace/ftrace-design.rst
91 Arch supports the gcc options -pg with -mfentry
96 Arch supports the gcc options -pg with -mrecord-mcount and -nop-mcount
101 Arch supports objtool --mcount
106 Arch supports the objtool options --mcount with --mnop.
217 bool "Boot-time Tracing support"
236 by using a compiler feature to insert a small, 5-byte No-Operation
241 small and not measurable even in micro-benchmarks (at least on
267 enable it via the trace option funcgraph-retval.
278 enable it via the trace option funcgraph-retaddr.
288 enabled via the trace option func-args (for the function tracer) and
289 funcgraph-args (for the function graph tracer)
299 replace them with a No-Op instruction) on boot up. During
373 stack-trace saved. If this is configured with DYNAMIC_FTRACE
392 bool "Interrupts-off Latency Tracer"
402 This option measures the time spent in irqs-off critical
406 disabled by default and can be runtime (re-)started
412 enabled. This option and the preempt-off timing option can be
416 bool "Preemption-off Latency Tracer"
426 This option measures the time spent in preemption-off critical
430 disabled by default and can be runtime (re-)started
436 enabled. This option and the irqs-off timing option can be
440 bool "Scheduling Latency Tracer"
446 This tracer tracks the latency of the highest priority task
465 hwlat_detector/width - time in usecs for how long to spin for
466 hwlat_detector/window - time in usecs between the start of each
471 for "window - width" microseconds, where the system can
482 file. Every time a latency is greater than tracing_thresh, it will
490 In the context of high-performance computing (HPC), the Operating
494 can cause noise to the system. Moreover, hardware-related jobs can
501 increasing a per-cpu interference counter. It saves an interference
506 hardware noise counter increases, pointing to a hardware-related
526 to find sources of wakeup latencies of real-time threads.
528 The tracer creates a per-cpu kernel thread with real-time priority.
529 The tracer thread sets a periodic timer to wakeup itself, and goes
530 to sleep waiting for the timer to fire. At the wakeup, the thread
531 then computes a wakeup latency value as the difference between
536 timer latency observed at the hardirq context before the
537 activation of the thread. The second is the timer latency observed
556 default and can be enabled at run-time.
606 or irq latency tracers are enabled, as those need to swap as well
623 The "all branch" profiler will profile every if-statement in the
716 bool "Enable fprobe-based dynamic events"
742 bool "Enable kprobes-based dynamic events"
755 This option is also required by perf-probe subcommand of perf tools.
768 functions are protected from kprobe-events to prevent an infinite
779 bool "Enable uprobes-based dynamic events"
793 This option is required if you plan to use perf-probe subcommand
797 bool "Enable event-based dynamic events"
840 depends on $(cc-option,-mrecord-mcount)
863 tracing_map is a special-purpose lock-free map for tracing,
864 separated out as a stand-alone facility in order to allow it
875 Synthetic events are user-defined trace events that can be
879 by way of an in-kernel API.
891 User trace events are user-defined trace events that
917 Inter-event tracing of quantities such as latencies is also
927 Allow user-space to inject a specific trace event into the ring
1102 TBD - enable a way to actually call the syscalls as we test their
1113 is not done correctly, it will cause non-deterministic failures.
1173 tristate "Test module to create a preempt / IRQ disable delay thread to test latency tracers"
1176 Select this option to build a test module that can help test latency
1182 irq-disabled critical sections for 500us:
1185 What's more, if you want to attach the test on the cpu which the latency
1192 tristate "Test module for in-kernel synthetic event generation"
1196 functionality of in-kernel synthetic event definition and
1205 tristate "Test module for in-kernel kprobe event generation"
1209 functionality of in-kernel kprobe event definition.
1226 - Helps developers verify that nothing is broken.
1228 - Provides educational information to support the details
1230 Documentation/trace/histogram-design.rst.