'-m <file>' spits out the given stream into <file> (eg, /dev/stdout).
However, it only resolves the first symbol; it doesn't parse the entire
callgraph. If it fails to lookup then it doesn't print anything.
'-a' instead does a symbol and file:line lookup for each address in each
callgraph and will happily print the address itself with no lookup
information if it couldn't look things up.
This makes it much easier to pull out individual records from a
pmc data file and look at the callgraph information without having to
hand-decode the addresses.
Sponsored by: Netflix, Inc.
