perf scripts python: Implement add sample function and thread processing

The stack has been created for storing func and dso from the callchain.
The sample has been added to a specific thread. It first checks if the
thread exists in the Thread class. Then it call _add_sample function
which is responsible for appending a new entry to the samples list.

Also callchain parsing and storing part is implemented. Moreover removed
the comment from thread.

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/5a112be85ccdcdcd611e343f6a7a7482d01f6299.1689961706.git.anupnewsmail@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/scripts/python/gecko.py b/tools/perf/scripts/python/gecko.py
index 9794924..278c3ae 100644 (file)
--- a/tools/perf/scripts/python/gecko.py
+++ b/tools/perf/scripts/python/gecko.py
@@ -40,6 +40,9 @@ CATEGORIES = None
 # The product name is used by the profiler UI to show the Operating system and Processor.
 PRODUCT = os.popen('uname -op').read().strip()
 
+# Here key = tid, value = Thread
+tid_to_thread = dict()
+
 # The category index is used by the profiler UI to show the color of the flame graph.
 USER_CATEGORY_INDEX = 0
 KERNEL_CATEGORY_INDEX = 1
@@ -153,6 +156,25 @@ class Thread:
                ))
                return frame_id
 
+       def _add_sample(self, comm: str, stack: List[str], time_ms: Milliseconds) -> None:
+               """Add a timestamped stack trace sample to the thread builder.
+               Args:
+                       comm: command-line (name) of the thread at this sample
+                       stack: sampled stack frames. Root first, leaf last.
+                       time_ms: timestamp of sample in milliseconds.
+               """
+               # Ihreads may not set their names right after they are created.
+               # Instead, they might do it later. In such situations, to use the latest name they have set.
+               if self.comm != comm:
+                       self.comm = comm
+
+               prefix_stack_id = reduce(lambda prefix_id, frame: self._intern_stack
+                                               (self._intern_frame(frame), prefix_id), stack, None)
+               if prefix_stack_id is not None:
+                       self.samples.append(Sample(stack_id=prefix_stack_id,
+                                                                       time_ms=time_ms,
+                                                                       responsiveness=0))
+
        def _to_json_dict(self) -> Dict:
                """Converts current Thread to GeckoThread JSON format."""
                # Gecko profile format is row-oriented data as List[List],
@@ -231,9 +253,36 @@ def process_event(param_dict: Dict) -> None:
        if not start_time:
                start_time = time_stamp
 
+       # Parse and append the callchain of the current sample into a stack.
+       stack = []
+       if param_dict['callchain']:
+               for call in param_dict['callchain']:
+                       if 'sym' not in call:
+                               continue
+                       stack.append(f'{call["sym"]["name"]} (in {call["dso"]})')
+               if len(stack) != 0:
+                       # Reverse the stack, as root come first and the leaf at the end.
+                       stack = stack[::-1]
+
+       # During perf record if -g is not used, the callchain is not available.
+       # In that case, the symbol and dso are available in the event parameters.
+       else:
+               func = param_dict['symbol'] if 'symbol' in param_dict else '[unknown]'
+               dso = param_dict['dso'] if 'dso' in param_dict else '[unknown]'
+               stack.append(f'{func} (in {dso})')
+
+       # Add sample to the specific thread.
+       thread = tid_to_thread.get(tid)
+       if thread is None:
+               thread = Thread(comm=comm, pid=pid, tid=tid)
+               tid_to_thread[tid] = thread
+       thread._add_sample(comm=comm, stack=stack, time_ms=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.
 def trace_end() -> None:
+       threads = [thread._to_json_dict() for thread in tid_to_thread.values()]
+
        # Schema: https://github.com/firefox-devtools/profiler/blob/53970305b51b9b472e26d7457fee1d66cd4e2737/src/types/gecko-profile.js#L305
        gecko_profile_with_meta = {
                "meta": {
@@ -252,8 +301,7 @@ def trace_end() -> None:
                        "markerSchema": [],
                        },
                "libs": [],
-               # threads will be implemented in later commits.
-               # "threads": threads,
+               "threads": threads,
                "processes": [],
                "pausedRanges": [],
        }