perf tools: Optimize sample parsing for ordered events

Currently when using ordered events we parse the sample twice (the
perf_evlist__parse_sample function). Once before we queue the sample for
sorting:

  perf_session__process_event
    perf_evlist__parse_sample(sample)
    perf_session__queue_event(sample.time)

And then when we deliver the sorted sample:

  ordered_events__deliver_event
    perf_evlist__parse_sample
    perf_session__deliver_event

We can skip the initial full sample parsing by using
perf_evlist__parse_sample_timestamp function, which got introduced
earlier. The new path looks like:

  perf_session__process_event
    perf_evlist__parse_sample_timestamp
    perf_session__queue_event

  ordered_events__deliver_event
    perf_session__deliver_event
      perf_evlist__parse_sample

It saves some instructions and is slightly faster:

Before:
 Performance counter stats for './perf.old report --stdio' (5 runs):

    64,396,007,225      cycles:u                                                      ( +-  0.97% )
   105,882,112,735      instructions:u            #    1.64  insn per cycle           ( +-  0.00% )

      21.618103465 seconds time elapsed                                          ( +-  1.12% )

After:
 Performance counter stats for './perf report --stdio' (5 runs):

    60,567,807,182      cycles:u                                                      ( +-  0.40% )
   104,853,333,514      instructions:u            #    1.73  insn per cycle           ( +-  0.00% )

      20.168895243 seconds time elapsed                                          ( +-  0.32% )

Signed-off-by: Jiri Olsa <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

0 files changed, 0 insertions, 0 deletions