Common options for all tracers:


        TRACEFS_OPTION_INVALID Not a valid ftrace option, used by the API to indicate an error.


        TRACEFS_OPTION_ANNOTATE Display when a new CPU buffer started.


        TRACEFS_OPTION_BIN Display the formats in raw binary.


        TRACEFS_OPTION_CONTEXT_INFO Show only the event data. Hides the comm, PID, timestamp, CPU, and other useful data.


        TRACEFS_OPTION_BLOCK When set, reading trace_pipe will not block when polled.


        TRACEFS_OPTION_DISABLE_ON_FREE When the free_buffer is closed, tracing will stop.


        TRACEFS_OPTION_DISPLAY_GRAPH When set, the latency tracers will use function graph tracing instead of function tracing.


        TRACEFS_OPTION_EVENT_FORK When set, tasks with PIDs listed in set_event_pid will have the PIDs of their children added to set_event_pid when those tasks fork.


        TRACEFS_OPTION_FUNCTION_FORK When set, tasks with PIDs listed in set_ftrace_pid will have the PIDs of their children added to set_ftrace_pid when those tasks fork.


        TRACEFS_OPTION_FUNCTION_TRACE When enabled, the latency tracers will trace functions.


        TRACEFS_OPTION_HEX Display numbers in a hexadecimal format.


        TRACEFS_OPTION_IRQ_INFO Display the interrupt, preempt count, need resched data.


        TRACEFS_OPTION_LATENCY_FORMAT Display additional information about the latency.


        TRACEFS_OPTION_MARKERS When set, the trace_marker is enabled - writable (only by root).


        TRACEFS_OPTION_OVERWRITE Controls what happens when the trace buffer is full. If set, the oldest events are discarded and overwritten. If disabled, then the newest events are discarded.


        TRACEFS_OPTION_PAUSE_ON_TRACE When set, opening the trace file for read, will pause writing to the ring buffer. When the file is closed, tracing will be enabled again.


        TRACEFS_OPTION_PRINTK_MSG_ONLY When set, trace_printk()s will only show the format and not their parameters.


        TRACEFS_OPTION_PRINT_PARENT On function traces, display the calling (parent) function as well as the function being traced.


        TRACEFS_OPTION_RAW Display raw numbers.


        TRACEFS_OPTION_RECORD_CMD Save a mapping with a pid and corresponding command.


        TRACEFS_OPTION_RECORD_TGID Save a mapping with a pid and corresponding Thread Group IDs.


        TRACEFS_OPTION_STACKTRACE Record a stack trace after any trace event.


        TRACEFS_OPTION_SYM_ADDR Display the function address as well as the function name.


        TRACEFS_OPTION_SYM_OFFSET Display not only the function name, but also the offset in the function.


        TRACEFS_OPTION_SYM_USEROBJ When TRACEFS_OPTION_USERSTACKTRACE is set, look up which object the address belongs to, and print the object and a relative address.


        TRACEFS_OPTION_TRACE_PRINTK Disable trace_printk() from writing into the buffer.


        TRACEFS_OPTION_USERSTACKTRACE Records a stack trace of the current user space thread after each trace event.


        TRACEFS_OPTION_VERBOSE When TRACEFS_OPTION_LATENCY_FORMAT is enabled, print more detailed information.
Options, specific to function tracer:


        TRACEFS_OPTION_FUNC_STACKTRACE Record a stack trace after every function.
Options, specific to function_graph tracer:


        TRACEFS_OPTION_FGRAPH_ABSTIME Display the timestamp at each line.


        TRACEFS_OPTION_FGRAPH_CPU Display the CPU number of the CPU where the trace occurred.


        TRACEFS_OPTION_FGRAPH_DURATION Display the duration of the amount of time at the end of each function, in microseconds.


        TRACEFS_OPTION_FGRAPH_IRQS Trace functions that happen inside an interrupt.


        TRACEFS_OPTION_FGRAPH_OVERHEAD Display a marker if a function takes longer than a certain amount of time.


        TRACEFS_OPTION_FGRAPH_OVERRUN Display "overrun" of the call graph, in the case of functions missed due to big callstack.


        TRACEFS_OPTION_FGRAPH_PROC Display the command of each process at every line.


        TRACEFS_OPTION_FGRAPH_TAIL Display the function name on its return.


        TRACEFS_OPTION_SLEEP_TIME Account time the task has been scheduled out as part of the function call.


        TRACEFS_OPTION_GRAPH_TIME Display the time to call nested functions, if function profiler is enabled.
Options, specific to blk tracer:


        TRACEFS_OPTION_BLK_CGNAME


        TRACEFS_OPTION_BLK_CGROUP


        TRACEFS_OPTION_BLK_CLASSIC Display a more minimalistic output.

tracefs.h


        Header file to include in order to have access to the library APIs.
-ltracefs


        Linker switch to add when building a program that uses the library.

Steven Rostedt <rostedt@goodmis.org[1]>
Tzvetomir Stoyanov <tz.stoyanov@gmail.com[2]>