Re: [PATCH v2 11/11] perf python tracepoint: Switch to using parse_events

[Arnaldo Carvalho de Melo]

On Mon, Mar 10, 2025 at 02:17:59PM -0700, Ian Rogers wrote:
> On Mon, Mar 10, 2025 at 2:16 PM Arnaldo Carvalho de Melo
> <acme@xxxxxxxxxx> wrote:
> >
> > On Mon, Mar 10, 2025 at 06:15:42PM -0300, Arnaldo Carvalho de Melo wrote:
> > > On Fri, Feb 28, 2025 at 02:23:08PM -0800, Ian Rogers wrote:
> > > > Rather than manually configuring an evsel, switch to using
> > > > parse_events for greater commonality with the rest of the perf code.
> > > >
> > > > Reviewed-by: Howard Chu <howardchu95@xxxxxxxxx>
> > > > Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> > >
> > > Now will all in place I'm trying to test it and I am getting some
> > > strange results:
> > >
> > > root@number:/home/acme/git/perf-tools-next# tools/perf/python/tracepoint.py
> > > <SNIP lots of seemingly ok lines>
> > > time 78318710956557 prev_comm=sudo prev_pid=3133818 prev_prio=120 prev_state=0x1 ==> next_comm=swapper/14 next_pid=0 next_prio=120
> > > time 78318720082300 prev_comm=swapper/16 prev_pid=0 prev_prio=120 prev_state=0x0 ==> next_comm=kworker/u112:8 next_pid=1752774 next_prio=120
> > > time 78318706232435 prev_comm=kworker/u112:17 prev_pid=1551246 prev_prio=120 prev_state=0x80 ==> next_comm=swapper/21 next_pid=0 next_prio=120
> > > time 78318708202121 prev_comm=sudo prev_pid=3133818 prev_prio=120 prev_state=0x2 ==> next_comm=swapper/25 next_pid=0 next_prio=120
> > > time 78318748346989 prev_comm=swapper/26 prev_pid=0 prev_prio=120 prev_state=0x0 ==> next_comm=gnome-terminal- next_pid=3551 next_prio=120
> > > Traceback (most recent call last):
> > >   File "/home/acme/git/perf-tools-next/tools/perf/python/tracepoint.py", line 47, in <module>
> > >     main()
> > >   File "/home/acme/git/perf-tools-next/tools/perf/python/tracepoint.py", line 42, in main
> > >     event.next_comm,
> > >     ^^^^^^^^^^^^^^^
> > > AttributeError: 'perf.sample_event' object has no attribute 'next_comm'
> > > root@number:/home/acme/git/perf-tools-next#
> > >
> > > But it shouldn't get there as there is this check:
> > >
> > >             if not isinstance(event, perf.sample_event):
> > >                 continue
> > >
> > >
> > > :-\
> > >
> > > Trying to debug that...
> >
> > And it doesn't seem related to your series, I checked and v6.13 has the
> > same problem, I nuked the build dir, etc.
> 
> Right. I'd seen the same issue.

time 79411977132102 prev_comm=sudo prev_pid=3133818 prev_prio=120 prev_state=0x2 ==> next_comm=swapper/12 next_pid=0 next_prio=120
{ type: sample }
time 79411977200343 prev_comm=kworker/u112:17 prev_pid=1551246 prev_prio=120 prev_state=0x80 ==> next_comm=swapper/16 next_pid=0 next_prio=120
{ type: sample }
time 79411964535268 prev_comm=kworker/u112:14 prev_pid=810939 prev_prio=120 prev_state=0x80 ==> next_comm=swapper/17 next_pid=0 next_prio=120
{ type: sample }
time 79411964746511 prev_comm=swapper/18 prev_pid=0 prev_prio=120 prev_state=0x0 ==> next_comm=kworker/u112:12 next_pid=2109251 next_prio=120
{ type: sample }
Traceback (most recent call last):
  File "/home/acme/git/perf-tools-next/tools/perf/python/tracepoint.py", line 48, in <module>
    main()
  File "/home/acme/git/perf-tools-next/tools/perf/python/tracepoint.py", line 43, in main
    event.next_comm,
    ^^^^^^^^^^^^^^^
AttributeError: 'perf.sample_event' object has no attribute 'next_comm'
root@number:/home/acme/git/perf-tools-next#

And it says it is a sample... 


Well, ran out of time, will try later or early tomorrow, will also try
to review the syscalltbl series and Howard's off cpu profiling.

- Arnaldo