Re: [PATCH 3/3] perf events: add timehist option to record and report

Ingo Molnar
2011-02-18T07:07:23Z

* David Ahern <daahern@cisco.com> wrote:

> +--timehist::
> + Generate time history output. This shows each sample with a wall-clock
> + timestamp and address to symbol conversions. The samples are output in
> + the same order they exist in the perf.data file. The --timehist option
> + must be used with the record to get wall-clock timestamps.

Displaying samples this way is very useful, but how is this different from trace
output - i.e. 'perf script' output?

There's a 'live logging mode' feature:

perf record ./myworkload | perf inject -v -b | perf script -i -

( There's also some work going on to have a separate 'perf trace' utility that will
output a linear trace of whatever events in perf.data are. )

So unless i'm missing something it would be more useful to extend 'perf script' (or
the upcoming 'perf trace') to list regular samples in a perf.data (i.e. not rely on
-R raw trace data alone), and of course allow a straightforward utilization of real
timestamps, when available.

Thanks,

Ingo