The trace-cmd(1) stat displays the various status of the tracing (ftrace) system. The status that it shows is:
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.
Written by Steven Rostedt, <m[blue]firstname.lastname@example.org>