Changes from version 2.3:
In trace-cmd list
o Regex expresions can be passed to the -e option to limit the events
that are displayed to what matches the regex.
o New -F option to list the event's format file. (following -e)
o New -l option to show the event's filters (following -e)
o New -R option to show the event's triggers (following -e)
o New -B option to show what buffer instances exist on the machine
In trace-cmd record (and start)
o New -R option to specify a trigger to the previous event
In trace-cmd report
o New --event <regex> option to list the event formats in the trace.dat
file that match the regex.
In trace-cmd reset
o New -B option to reset a specified buffer. Does not reset buffers
not listed (multiple -B options may be specified).
o New -t option to reset the top level buffer when a -B option is used.
If no -B option is used, the top level is reset regardless if the -t
option is specified or not.
o New -d option to delete the previously specified buffer that came after
the -B option.
In trace-cmd show
o New --tracing-on option to show the value of tracing_on (in the
debugfs/tracing directory)
o New --curent-tracer option to show the value of current_tracer
(in the debugfs/tracing directory)
o New --buffer_size option to show the value of buffer_size_kb (from
the debugfs/tracing directory).
o New --buffer_total_size opton to show the value of the
buffer_total_size_kb (from the debugfs/tracing directory).
o New --ftrace_filter option, to show the value of the
set_ftrace_filter file (from the debugfs/tracing directory).
o New --ftrace_notrace option, to show the value of the
set_ftrace_notrace file (from the debugfs/tracing directory).
o New --ftrace_pid option to show the value of the set_ftrace_pid
(from the debugfs/tracing directory).
o New --graph_function option to show the value of the set_graph_function
(from the debugfs/tracing directory)
o New --graph_notrace option to show the value of set_graph_notrace
(from the debugfs/tracing directory)
o New --cpumask option to show the value of tracing_cpumask (from the
debugfs/tracing directory).
In trace-cmd split
o New -C <cpu> option to split out the cpu buffers from a trace.dat file.
In trace-cmd stop
o New -B option to stop a specific buffer. No other buffers are affected.
Multiple buffers may be specified with multiple -B options.
o New -t option to stop the top level buffer when the -B option is used,
otherwise the top level is not affected. This is the default when -B
is not used.
New trace-cmd restart option
As trace-cmd stop just disables the ring buffer (writes '0' into tracing_on)
but trace-cmd start will reset the ring buffer and several options removing
whatever was there previously. The 'restart' command was added that is basically
the inverse of the 'stop' command (writes '1' into tracing_on). This way if
you execute trace-cmd stop and want to restart the trace without reseting anything
you can use trace-cmd restart. It includes the -B and -t options that are similar
to the new trace-cmd stop options.