1. Patchew
  2. linux
  3. [PATCH v3 0/6] Add support for Firefox's gecko profile format
  4. View patch

[PATCH v3 2/6] scripts: python: Extact necessary information from process event

Anup Sharma posted 6 patches 2 years, 5 months ago
There is a newer version of this series
[PATCH v3 2/6] scripts: python: Extact necessary information from process event
Posted by Anup Sharma 2 years, 5 months ago 
The script takes in a sample event dictionary(param_dict) and retrieves
relevant data such as time stamp, PID, TID, thread name. Also start time
is defined.

Signed-off-by: Anup Sharma <anupnewsmail@gmail.com>
---
 .../perf/scripts/python/firefox-gecko-converter.py  | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/tools/perf/scripts/python/firefox-gecko-converter.py b/tools/perf/scripts/python/firefox-gecko-converter.py
index 5b342641925c..765f1775cee5 100644
--- a/tools/perf/scripts/python/firefox-gecko-converter.py
+++ b/tools/perf/scripts/python/firefox-gecko-converter.py
@@ -21,8 +21,19 @@ sys.path.append(os.environ['PERF_EXEC_PATH'] + \
 from perf_trace_context import *
 from Core import *
 
+start_time = None
+
 def trace_end():
 	pass
 
 def process_event(param_dict):
-	pass
+	global start_time
+	# Extract relevant information from the event parameters. The event parameters
+	# are in a dictionary:
+	time_stamp = (param_dict['sample']['time'] // 1000) / 1000
+	pid = param_dict['sample']['pid']
+	tid = param_dict['sample']['tid']
+	thread_name = param_dict['comm']
+
+	# Assume that start time is the time of the first event.
+	start_time = time_stamp if not start_time else start_time
-- 
2.34.1
Re: [PATCH v3 2/6] scripts: python: Extact necessary information from process event
Posted by Ian Rogers 2 years, 5 months ago 
On Mon, Jul 10, 2023 at 4:10 PM Anup Sharma <anupnewsmail@gmail.com> wrote:
>
> The script takes in a sample event dictionary(param_dict) and retrieves
> relevant data such as time stamp, PID, TID, thread name. Also start time
> is defined.
>
> Signed-off-by: Anup Sharma <anupnewsmail@gmail.com>
> ---
>  .../perf/scripts/python/firefox-gecko-converter.py  | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/scripts/python/firefox-gecko-converter.py b/tools/perf/scripts/python/firefox-gecko-converter.py
> index 5b342641925c..765f1775cee5 100644
> --- a/tools/perf/scripts/python/firefox-gecko-converter.py
> +++ b/tools/perf/scripts/python/firefox-gecko-converter.py
> @@ -21,8 +21,19 @@ sys.path.append(os.environ['PERF_EXEC_PATH'] + \
>  from perf_trace_context import *
>  from Core import *
>

It'd be nice to have a comment here, perhaps:
# The time stamp from the first of the time ordered events.

> +start_time = None
> +
>  def trace_end():
>         pass
>
>  def process_event(param_dict):
> -       pass
> +       global start_time
> +       # Extract relevant information from the event parameters. The event parameters
> +       # are in a dictionary:
> +       time_stamp = (param_dict['sample']['time'] // 1000) / 1000
> +       pid = param_dict['sample']['pid']
> +       tid = param_dict['sample']['tid']
> +       thread_name = param_dict['comm']
> +
> +       # Assume that start time is the time of the first event.
> +       start_time = time_stamp if not start_time else start_time

I appreciate that this is one line, but it takes some getting your
head around that start_time is being assigned to itself in the common
case. I think this would be more readable as:

if not start_time:
  start_time = time_stamp

Thanks,
Ian

> --
> 2.34.1
>
Re: [PATCH v3 2/6] scripts: python: Extact necessary information from process event
Posted by Ian Rogers 2 years, 5 months ago 
On Wed, Jul 12, 2023 at 10:01 AM Ian Rogers <irogers@google.com> wrote:
>
> On Mon, Jul 10, 2023 at 4:10 PM Anup Sharma <anupnewsmail@gmail.com> wrote:
> >
> > The script takes in a sample event dictionary(param_dict) and retrieves
> > relevant data such as time stamp, PID, TID, thread name. Also start time
> > is defined.
> >
> > Signed-off-by: Anup Sharma <anupnewsmail@gmail.com>
> > ---
> >  .../perf/scripts/python/firefox-gecko-converter.py  | 13 ++++++++++++-
> >  1 file changed, 12 insertions(+), 1 deletion(-)
> >
> > diff --git a/tools/perf/scripts/python/firefox-gecko-converter.py b/tools/perf/scripts/python/firefox-gecko-converter.py
> > index 5b342641925c..765f1775cee5 100644
> > --- a/tools/perf/scripts/python/firefox-gecko-converter.py
> > +++ b/tools/perf/scripts/python/firefox-gecko-converter.py
> > @@ -21,8 +21,19 @@ sys.path.append(os.environ['PERF_EXEC_PATH'] + \
> >  from perf_trace_context import *
> >  from Core import *
> >
>
> It'd be nice to have a comment here, perhaps:
> # The time stamp from the first of the time ordered events.
>
> > +start_time = None
> > +
> >  def trace_end():
> >         pass
> >
> >  def process_event(param_dict):
> > -       pass
> > +       global start_time
> > +       # Extract relevant information from the event parameters. The event parameters
> > +       # are in a dictionary:
> > +       time_stamp = (param_dict['sample']['time'] // 1000) / 1000
> > +       pid = param_dict['sample']['pid']
> > +       tid = param_dict['sample']['tid']
> > +       thread_name = param_dict['comm']
> > +
> > +       # Assume that start time is the time of the first event.
> > +       start_time = time_stamp if not start_time else start_time
>
> I appreciate that this is one line, but it takes some getting your
> head around that start_time is being assigned to itself in the common
> case. I think this would be more readable as:
>
> if not start_time:
>   start_time = time_stamp

I believe the events are guaranteed time ordered in perf script. The
ordered_event logic handles this, but I likely haven't got a full
grasp on all the corners of it. You can always assert the behavior
(comments with guarantees :-) ):

assert start_time <= time_stamp, "Events aren't time ordered"

Thanks,
Ian

> Thanks,
> Ian
>
> > --
> > 2.34.1
> >
Re: [PATCH v3 2/6] scripts: python: Extact necessary information from process event
Posted by Anup Sharma 2 years, 4 months ago 
On Wed, Jul 12, 2023 at 10:03:57AM -0700, Ian Rogers wrote:
> On Wed, Jul 12, 2023 at 10:01 AM Ian Rogers <irogers@google.com> wrote:
> >
> > On Mon, Jul 10, 2023 at 4:10 PM Anup Sharma <anupnewsmail@gmail.com> wrote:
> > >
> > > The script takes in a sample event dictionary(param_dict) and retrieves
> > > relevant data such as time stamp, PID, TID, thread name. Also start time
> > > is defined.
> > >
> > > Signed-off-by: Anup Sharma <anupnewsmail@gmail.com>
> > > ---
> > >  .../perf/scripts/python/firefox-gecko-converter.py  | 13 ++++++++++++-
> > >  1 file changed, 12 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/tools/perf/scripts/python/firefox-gecko-converter.py b/tools/perf/scripts/python/firefox-gecko-converter.py
> > > index 5b342641925c..765f1775cee5 100644
> > > --- a/tools/perf/scripts/python/firefox-gecko-converter.py
> > > +++ b/tools/perf/scripts/python/firefox-gecko-converter.py
> > > @@ -21,8 +21,19 @@ sys.path.append(os.environ['PERF_EXEC_PATH'] + \
> > >  from perf_trace_context import *
> > >  from Core import *
> > >
> >
> > It'd be nice to have a comment here, perhaps:
> > # The time stamp from the first of the time ordered events.
> >

Sure. I will add it.

> > > +start_time = None
> > > +
> > >  def trace_end():
> > >         pass
> > >
> > >  def process_event(param_dict):
> > > -       pass
> > > +       global start_time
> > > +       # Extract relevant information from the event parameters. The event parameters
> > > +       # are in a dictionary:
> > > +       time_stamp = (param_dict['sample']['time'] // 1000) / 1000
> > > +       pid = param_dict['sample']['pid']
> > > +       tid = param_dict['sample']['tid']
> > > +       thread_name = param_dict['comm']
> > > +
> > > +       # Assume that start time is the time of the first event.
> > > +       start_time = time_stamp if not start_time else start_time
> >
> > I appreciate that this is one line, but it takes some getting your
> > head around that start_time is being assigned to itself in the common
> > case. I think this would be more readable as:
> >
> > if not start_time:
> >   start_time = time_stamp

Sure. I will change it.

> I believe the events are guaranteed time ordered in perf script. The
> ordered_event logic handles this, but I likely haven't got a full
> grasp on all the corners of it. You can always assert the behavior
> (comments with guarantees :-) ):
> 
> assert start_time <= time_stamp, "Events aren't time ordered"

I dont think assert is usefull here as start_time will be initialized
and assigned only once for all the process event triggers. So, the
significance of assert is not clear to me.

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

Patchew 2.1-devel-b67e4c2

© 2016 - 2025 Red Hat, Inc.