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From:   Anup Sharma <anupnewsmail@gmail.com>
Date:   Mon, 17 Jul 2023 21:13:33 +0530
To:     Ian Rogers <irogers@google.com>
Cc:     Anup Sharma <anupnewsmail@gmail.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        Adrian Hunter <adrian.hunter@intel.com>,
        linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 3/6] scripts: python: thread sample processing to
 create thread with schemas
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References: <cover.1689024635.git.anupnewsmail@gmail.com>
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On Wed, Jul 12, 2023 at 10:25:50AM -0700, Ian Rogers wrote:
> On Mon, Jul 10, 2023 at 4:13 PM Anup Sharma <anupnewsmail@gmail.com> wrote:
> >
> > The _addThreadSample function is responsible for adding a sample
> > to a specific thread. It first checks if the thread exists in
> > the thread_map dictionary.
> >
> > The markers structure defines the schema and data for
> > thread markers, including fields such as 'name',
> > 'startTime', 'endTime', 'phase', 'category', and 'data'.
> >
> > The samples structure defines the schema and data for thread
> > samples, including fields such as 'stack', 'time', and
> > 'responsiveness'.
> >
> > The frameTable structure defines the schema and data for frame
> > information, including fields such as 'location', 'relevantForJS',
> > 'innerWindowID', 'implementation', 'optimizations', 'line',
> > 'column', 'category', and 'subcategory'.
> >
> > The purpose of this function is to create a new thread structure
> > These structures provide a framework for storing and organizing
> > information related to thread markers, samples, frame details,
> > and stack information.
> >
> > The call stack is parsed to include function names and the associated
> > DSO, which are requires for creating json schema. Also few libaries
> > has been included which will be used in later commit.
> 
> nit: s/requires/required.
> nit: I think the "Also few..." statement is out-of-date.

I apologize. I will ensure to address these in the next version.

> > Signed-off-by: Anup Sharma <anupnewsmail@gmail.com>
> > ---
> >  .../scripts/python/firefox-gecko-converter.py | 70 +++++++++++++++++++
> >  1 file changed, 70 insertions(+)
> >
> > diff --git a/tools/perf/scripts/python/firefox-gecko-converter.py b/tools/perf/scripts/python/firefox-gecko-converter.py
> > index 765f1775cee5..0b8a86bdcab1 100644
> > --- a/tools/perf/scripts/python/firefox-gecko-converter.py
> > +++ b/tools/perf/scripts/python/firefox-gecko-converter.py
> > @@ -21,6 +21,7 @@ sys.path.append(os.environ['PERF_EXEC_PATH'] + \
> >  from perf_trace_context import *
> >  from Core import *
> >
> 
> A comment and type information would be useful here. map is another
> word for a dictionary, which is somewhat implied. So the information
> here is that this data structure will hold something to do with
> threads.  Perhaps say, "a map from TID to a Thread." A better variable
> name may then be tid_to_thread_map, but as map is implied you could
> do: tid_to_thread: Dict[int, Thread].

sure, I will rename this variable to tid_to_thread. However in my case
this needs to be kept a global variable, and I am not sure if I can
specify the data type for this variable since it creates a dependency
loop with the Thread class. I can leave it with just a comment
mentioning the type of key and value or I can write the type as
"Dict[int, Any]" which is not very useful.

> > +thread_map = {}
> >  start_time = None
> >
> >  def trace_end():
> > @@ -28,6 +29,57 @@ def trace_end():
> >
> >  def process_event(param_dict):
> >         global start_time
> > +       global thread_map
> > +
> > +       def _createThread(name, pid, tid):
> > +               markers = {
> > +                       'schema': {
> > +                               'name': 0,
> > +                               'startTime': 1,
> > +                               'endTime': 2,
> > +                               'phase': 3,
> > +                               'category': 4,
> > +                               'data': 5,
> > +                       },
> > +                       'data': [],
> > +               }
> > +               samples = {
> > +                       'schema': {
> > +                               'stack': 0,
> > +                               'time': 1,
> > +                               'responsiveness': 2,
> > +                               },
> > +                       'data': [],
> > +               }
> > +               frameTable = {
> > +                       'schema': {
> > +                               'location': 0,
> > +                               'relevantForJS': 1,
> > +                               'innerWindowID': 2,
> > +                               'implementation': 3,
> > +                               'optimizations': 4,
> > +                               'line': 5,
> > +                               'column': 6,
> > +                               'category': 7,
> > +                               'subcategory': 8,
> > +                       },
> > +                       'data': [],
> > +               }
> > +               stackTable = {
> > +                       'schema': {
> > +                               'prefix': 0,
> > +                               'frame': 1,
> > +                       },
> > +                       'data': [],
> > +               }
> > +               stringTable = []
> 
> Is there a missing return here?

No, I am not returning anything here.

> > +
> > +       def _addThreadSample(pid, tid, threadName, time_stamp, stack):
> > +               thread = thread_map.get(tid)
> > +               if not thread:
> > +                       thread = _createThread(threadName, pid, tid)
> > +                       thread_map[tid] = thread
> > +
> >         # Extract relevant information from the event parameters. The event parameters
> >         # are in a dictionary:
> >         time_stamp = (param_dict['sample']['time'] // 1000) / 1000
> > @@ -37,3 +89,21 @@ def process_event(param_dict):
> >
> >         # Assume that start time is the time of the first event.
> >         start_time = time_stamp if not start_time else start_time
> > +
> > +       # Parse the callchain of the current sample into a stack array.
> > +       if param_dict['callchain']:
> > +               stack = []
> > +               for call in param_dict['callchain']:
> > +                       if 'sym' not in call:
> > +                               continue
> > +                       stack.append(call['sym']['name'] + f' (in {call["dso"]})')
> 
> Rather than mix an append and an f-string, just have the f-string ie:
> stack.append(f'{call["sym"]["name"]} (in {"call["dso"]})')

Thanks for this suggestion. I will make this change.

> > +               if len(stack) != 0:
> > +                       stack = stack[::-1]
> > +                       _addThreadSample(pid, tid, thread_name, time_stamp, stack)
> > +
> > +       # 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]'
> > +               _addThreadSample(pid, tid, thread_name, time_stamp, [func + f' (in {dso})'])
> 
> Similarly:
> f'{func} (in {dso})'

Noted.

> Thanks,
> Ian
> 
> > --
> > 2.34.1
> >