Display help information about perf
perf help [-a|--all] [COMMAND]
With no options and no COMMAND given, the synopsis of the perf command and a list of the most commonly used perf commands are printed on the standard output.
If the option --all or -a is given, then all available commands are printed on the standard output.
If a perf command is named, a manual page for that command is brought up. The man program is used by default for this purpose, but this can be overridden by other options or configuration variables.
Note that perf --help ... is identical to perf help ... because the former is internally converted into the latter.
-a, --all
Prints all the available commands on the standard output. This option supersedes any other option.
Part of the perf(1) suite