Consider the commands:
    perf record -e sched:sched_switch -fo /tmp/perf.data  -a -- sleep 1
    perf script -i /tmp/perf.data

In v3.4 the output has the form (lines wrapped here)
    perf 29214 [005] 821043.582596: sched_switch:
prev_comm=perf prev_pid=29214 prev_prio=120
prev_state=S ==> next_comm=swapper/5 next_pid=0 next_prio=120

In 3.5 that same line has become:
    perf 29214 [005] 821043.582596: sched_switch:
<...>-29214 [005]     0.000000000: sched_switch:
prev_comm=perf prev_pid=29214 prev_prio=120
prev_state=S ==> next_comm=swapper/5 next_pid=0 next_prio=120

Note the duplicates in the output -- pid, cpu, event name. With
this patch the v3.4 output is restored:
    perf 29214 [005] 821043.582596: sched_switch:
prev_comm=perf prev_pid=29214 prev_prio=120
prev_state=S ==> next_comm=swapper/5 next_pid=0 next_prio=120

v3:
Remove that pesky newline too. Output now matches v3.4 (pre-libtracevent).

v2:
Change print_trace_event function local to perf per Steve's comments.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Acked-by: NSteven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1339698977-68962-1-git-send-email-dsahern@gmail.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>