The trace-cmd(1) stat displays the various status of the tracing (ftrace) system. The status that it shows is:
Instances: List all configured ftrace instances.
Tracer: if one of the tracers (like function_graph) is active. Otherwise nothing is displayed.
Events: Lists the events that are enable.
Event filters: Shows any filters that are set for any events
Function filters: Shows any filters for the function tracers
Graph functions: Shows any functions that the function graph tracer should graph
Buffers: Shows the trace buffer size if they have been expanded. By default, tracing buffers are in a compressed format until they are used. If they are compressed, the buffer display will not be shown.
Trace clock: If the tracing clock is anything other than the default "local" it will be displayed.
Trace CPU mask: If not all available CPUs are in the tracing CPU mask, then the tracing CPU mask will be displayed.
Trace max latency: Shows the value of the trace max latency if it is other than zero.
Kprobes: Shows any kprobes that are defined for tracing.
Uprobes: Shows any uprobes that are defined for tracing.
Error log: Dump the content of ftrace error_log file.
trace-cmd(1), trace-cmd-record(1), trace-cmd-report(1), trace-cmd-start(1), trace-cmd-stop(1), trace-cmd-extract(1), trace-cmd-reset(1), trace-cmd-split(1), trace-cmd-listen(1)
Written by Steven Rostedt, <email@example.com>
Copyright (C) 2014 Red Hat, Inc. Free use of this software is granted under the terms of the GNU Public License (GPL).