linux-kernel - Re: [PATCH v2 5/7] scripts: python: implement get or create frame function

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Message-ID: <ZKyJcbX89y5ziqNi@yoga>
Date:   Tue, 11 Jul 2023 04:12:57 +0530
From:   Anup Sharma <anupnewsmail@...il.com>
To:     Namhyung Kim <namhyung@...nel.org>
Cc:     Anup Sharma <anupnewsmail@...il.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Jiri Olsa <jolsa@...nel.org>, Ian Rogers <irogers@...gle.com>,
        Adrian Hunter <adrian.hunter@...el.com>,
        linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 5/7] scripts: python: implement get or create frame
 function

On Wed, Jul 05, 2023 at 11:06:58PM -0700, Namhyung Kim wrote:
> On Wed, Jul 5, 2023 at 12:48 PM Anup Sharma <anupnewsmail@...il.com> wrote:
> >
> > The get_or_create_frame function is responsible for retrieving or
> > creating a frame based on the provided frameString. If the frame
> > corresponding to the frameString is found in the frameMap, it is
> > returned. Otherwise, a new frame is created by appending relevant
> > information to the frameTable's 'data' array and adding the
> > frameString to the stringTable.
> >
> > The index of the newly created frame is added to the frameMap.
> >
> > Signed-off-by: Anup Sharma <anupnewsmail@...il.com>
> > ---
> >  .../scripts/python/firefox-gecko-converter.py | 33 +++++++++++++++++++
> >  1 file changed, 33 insertions(+)
> >
> > diff --git a/tools/perf/scripts/python/firefox-gecko-converter.py b/tools/perf/scripts/python/firefox-gecko-converter.py
> > index 6f69c083d3ff..d5b9fb16e520 100644
> > --- a/tools/perf/scripts/python/firefox-gecko-converter.py
> > +++ b/tools/perf/scripts/python/firefox-gecko-converter.py
> > @@ -77,6 +77,39 @@ def process_event(param_dict):
> >                                 stackMap[key] = stack
> >                         return stack
> >
> > +               frameMap = dict()
> > +               def get_or_create_frame(frameString):
> > +                       frame = frameMap.get(frameString)
> > +                       if frame is None:
> > +                               frame = len(frameTable['data'])
> > +                               location = len(stringTable)
> > +                               stringTable.append(frameString)
> 
> Looks like it just always appending a new string.
> Any deduplication work later?

Although this initially came to my mind and almost all stack frames
seem to be similar for a repeated call, but I am not sure if we can dedup
because some frames do differ as the call stack progresses. For example,
a process exits a function and then calls another function, resulting in
most of the stack frames being the same but the last one being different.

> > +                               category = KERNEL_CATEGORY_INDEX if frameString.find('kallsyms') != -1 \
> > +                                               or frameString.find('/vmlinux') != -1 \
> > +                                               or frameString.endswith('.ko)') \
> > +                                               else USER_CATEGORY_INDEX
> 
> I think you can use param_dict['sample']['cpumode'].
> Please see include/uapi/linux/perf_event.h for cpumode
> values.

I am actively working on incorporating the use of param_dict
['sample']['cpumode'] to determine the category in the
upcoming v4 update. I saw in param_dict['sample']['cpumode']
values exist as 1 and 2. Can you point me to exact line in
include/uapi/linux/perf_event.h . I am not able to find it.

> > +                               implementation = None
> > +                               optimizations = None
> > +                               line = None
> > +                               relevantForJS = False
> > +                               subcategory = None
> > +                               innerWindowID = 0
> > +                               column = None
> > +
> > +                               frameTable['data'].append([
> > +                                       location,
> > +                                       relevantForJS,
> > +                                       innerWindowID,
> > +                                       implementation,
> > +                                       optimizations,
> > +                                       line,
> > +                                       column,
> > +                                       category,
> > +                                       subcategory,
> > +                               ])
> > +                               frameMap[frameString] = frame
> 
> I think it'd be better if you define the frameTable in this
> commit.

Certainly, my apologies for the disorder.

> Thanks,
> Namhyung
> 
> 
> > +                       return frame
> > +
> >         def _addThreadSample(pid, tid, threadName, time_stamp, stack):
> >                 thread = thread_map.get(tid)
> >                 if not thread:
> > --
> > 2.34.1
> >