tools lib traceevent: Fix time stamp rounding issue

When rounding to microseconds, if the timestamp subsecond is between
.999999500 and .999999999, it is rounded to .1000000, when it should
instead increment the second counter due to the overflow.

For example, if the timestamp is 1234.999999501 instead of seeing:

  1235.000000

we see:

  1234.1000000

Signed-off-by: Chaos.Chen <rainboy1215@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20160209204236.824426460@goodmis.org
[ fixed incrementing "secs" instead of decrementing it ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index 9a1e48afcf89ad7a760e3ab2eae63f4cdb80c5e7..ce59f4891fa2b5e2d68e1e14572c14fecac94c94 100644 (file)
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -5429,6 +5429,11 @@ void pevent_print_event_time(struct pevent *pevent, struct trace_seq *s,
                        p = 9;
                } else {
                        usecs = (nsecs + 500) / NSECS_PER_USEC;
+                       /* To avoid usecs larger than 1 sec */
+                       if (usecs >= 1000000) {
+                               usecs -= 1000000;
+                               secs++;
+                       }
                        p = 6;
                }