Section 1: user commands and tools
NAME trace-cmd-stream – stream a trace to stdout as it is happening SYNOPSIS trace-cmd stream [OPTIONS] [command] DESCRIPTION The trace-cmd(1) stream will start tracing just like trace-cmd-record(1), except it will not record to a file and instead it will read the binary buffer as it is happening, convert it to a human readable format and…
NAME trace-cmd-stop – stop the Ftrace Linux kernel tracer from writing to the ring buffer. SYNOPSIS trace-cmd stop [OPTIONS] DESCRIPTION The trace-cmd(1) stop is a complement to trace-cmd-start(1). This will disable Ftrace from writing to the ring buffer. This does not stop the overhead that the tracing may incur. Only the updating of the ring…
NAME trace-cmd-stat – show the status of the tracing (ftrace) system SYNOPSIS trace-cmd stat DESCRIPTION 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…
NAME trace-cmd-start – start the Ftrace Linux kernel tracer without recording SYNOPSIS trace-cmd start [OPTIONS] DESCRIPTION The trace-cmd(1) start enables all the Ftrace tracing the same way trace-cmd-record(1) does. The difference is that it does not run threads to create a trace.dat file. This is useful just to enable Ftrace and you are only interested…
NAME trace-cmd-stack – read, enable or disable Ftrace Linux kernel stack tracing. SYNOPSIS trace-cmd stack DESCRIPTION The trace-cmd(1) stack enables the Ftrace stack tracer within the kernel. The stack tracer enables the function tracer and at each function call within the kernel, the stack is checked. When a new maximum usage stack is discovered, it…
NAME trace-cmd-split – split a trace.dat file into smaller files SYNOPSIS trace-cmd split [OPTIONS] [start-time [end-time]] DESCRIPTION The trace-cmd(1) split is used to break up a trace.dat into small files. The start-time specifies where the new file will start at. Using trace-cmd-report(1) and copying the time stamp given at a particular event, can be used…
NAME trace-cmd-snapshot – take, reset, free, or show a Ftrace kernel snapshot SYNOPSIS trace-cmd snapshot [OPTIONS] DESCRIPTION The trace-cmd(1) snapshot controls or displays the Ftrace Linux kernel snapshot feature (if the kernel supports it). This is useful to "freeze" an instance of a live trace but without stopping the trace. trace – cmd start -…
NAME trace-cmd-show – show the contents of the Ftrace Linux kernel tracing buffer. SYNOPSIS trace-cmd show [OPTIONS] DESCRIPTION The trace-cmd(1) show displays the contents of one of the Ftrace Linux kernel tracing files: trace, snapshot, or trace_pipe. It is basically the equivalent of doing: cat /sys/kernel/debug/tracing/trace OPTIONS -p Instead of displaying the contents of the…
NAME trace-cmd-restore – restore a failed trace record SYNOPSIS trace-cmd restore [OPTIONS] [command] cpu-file [cpu-file …] DESCRIPTION The trace-cmd(1) restore command will restore a crashed trace-cmd-record(1) file. If for some reason a trace-cmd record fails, it will leave a the per-cpu data files and not create the final trace.dat file. The trace-cmd restore will append…
NAME trace-cmd-reset – turn off all Ftrace tracing to bring back full performance SYNOPSIS trace-cmd reset [OPTIONS] DESCRIPTION The trace-cmd(1) reset command turns off all tracing of Ftrace. This will bring back the performance of the system before tracing was enabled. This is necessary since trace-cmd-record(1), trace-cmd-stop(1) and trace-cmd-extract(1) do not disable the tracer, event…
NAME trace-cmd-report – show in ASCII a trace created by trace-cmd record SYNOPSIS trace-cmd report [OPTIONS] [input-file] DESCRIPTION The trace-cmd(1) report command will output a human readable report of a trace created by trace-cmd record. OPTIONS -i input-file By default, trace-cmd report will read the file trace.dat. But the -i option open up the given…
NAME trace-cmd-record – record a trace from the Ftrace Linux internal tracer SYNOPSIS trace-cmd record [OPTIONS] [command] DESCRIPTION The trace-cmd(1) record command will set up the Ftrace Linux kernel tracer to record the specified plugins or events that happen while the command executes. If no command is given, then it will record until the user…
NAME trace-cmd-profile – profile tasks running live SYNOPSIS trace-cmd profile [OPTIONS] [command] DESCRIPTION The trace-cmd(1) profile will start tracing just like trace-cmd-record(1), with the –profile option, except that it does not write to a file, but instead, it will read the events as they happen and will update the accounting of the events. When the…
NAME trace-cmd-options – list available options from trace-cmd plugins SYNOPSIS trace-cmd options DESCRIPTION The trace-cmd(1) options command will examine all the trace-cmd plugins that are used by trace-cmd report(1) and list them. SEE ALSO trace-cmd(1), trace-cmd-record(1), trace-cmd-start(1), trace-cmd-stop(1), trace-cmd-extract(1), trace-cmd-reset(1), trace-cmd-split(1), trace-cmd-list(1), trace-cmd-listen(1) AUTHOR Written by Steven Rostedt, <m[blue]rostedt [at] goodmis.orgm[][1]> RESOURCES git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/trace-cmd.git COPYING Copyright…
NAME trace-cmd-mem – show memory usage of certain kmem events SYNOPSIS trace-cmd mem [OPTIONS][input-file] DESCRIPTION The trace-cmd(1) mem requires a trace-cmd record that enabled the following events: kmalloc kmalloc_node kfree kmem_cache_alloc kmem_cache_alloc_node kmem_cache_alloc_free It then reads the amount requested and the ammount freed as well as the functions that called the allocation. It then reports…
NAME trace-cmd-listen – listen for incoming connection to record tracing. SYNOPSIS trace-cmd listen -p port [OPTIONS] DESCRIPTION The trace-cmd(1) listen sets up a port to listen to waiting for connections from other hosts that run trace-cmd-record(1) with the -N option. When a connection is made, and the remote host sends data, it will create a…
NAME trace-cmd-list – list available plugins, events or options for Ftrace. SYNOPSIS trace-cmd list [OPTIONS] DESCRIPTION The trace-cmd(1) list displays the available plugins, events or Ftrace options that are configured on the current machine. If no option is given, then it lists all plugins, events and Ftrace options to standard output. OPTIONS -e [regex] This…
NAME trace-cmd-hist – show histogram of events in trace.dat file SYNOPSIS trace-cmd hist [OPTIONS][input-file] DESCRIPTION The trace-cmd(1) hist displays a histogram form from the trace.dat file. Instead of showing the events as they were ordered, it creates a histogram that can be displayed per task or for all tasks where the most common events appear…
NAME trace-cmd-extract – extract out the data from the Ftrace Linux tracer. SYNOPSIS trace-cmd extract [OPTIONS] DESCRIPTION The trace-cmd(1) extract is usually used after trace-cmd-start(1) and trace-cmd-stop(1). It can be used after the Ftrace tracer has been started manually through the Ftrace pseudo file system. The extract command creates a trace.dat file that can be…
NAME trace-cmd-check-events – parse the event formats on local system SYNOPSIS trace-cmd check-events [OPTIONS] DESCRIPTION The trace-cmd(1) check-events parses format strings for all the events on the local system. It returns whether all the format strings can be parsed correctly. It will load plugins unless specified otherwise. This is useful to check for any trace…