perf scripts python: Extact necessary information from process event

The script takes in a sample event dictionary(param_dict) and retrieves
relevant data such as time stamp, PID, TID, and comm for each event.
Also start time is defined as a global variable as it need to be passed
to trace_end for gecko meta information field creation.
Signed-off-by: Anup Sharma <anupnewsmail@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/19910fefcfe4be03cd5c2aa3fec11d3f86c0381b.1689961706.git.anupnewsmail@gmail.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/scripts/python/gecko.py

@@ -20,10 +20,22 @@ sys.path.append(os.environ['PERF_EXEC_PATH'] + \
 from perf_trace_context import *
 from Core import *
 
+# start_time is intialiazed only once for the all event traces.
+start_time = None
+
 # Uses perf script python interface to parse each
 # event and store the data in the thread builder.
 def process_event(param_dict: Dict) -> None:
-	pass
+	global start_time
+	global tid_to_thread
+	time_stamp = (param_dict['sample']['time'] // 1000) / 1000
+	pid = param_dict['sample']['pid']
+	tid = param_dict['sample']['tid']
+	comm = param_dict['comm']
+
+	# Start time is the time of the first sample
+	if not start_time:
+		start_time = time_stamp
 
 # Trace_end runs at the end and will be used to aggregate
 # the data into the final json object and print it out to stdout.