Re: perf script: Question: Python trace processing script contains the tid of the process in the common_pid attribute

[Arun Kalyanasundaram <arunkaly@google.com>]

Hi Arnaldo,

Thank you for your reply.
I actually meant tracepoint event handlers: def
trace_unhandled(event_name, context, event_fields_dict)
The dict parameter contains an attribute "common_pid" which is
actually the "tid" of the thread. There are no other attributes that
contain the actual pid of the process. So, I was wondering if this is
something intentional? If not I can share a patch to fix this.

Best,
- Arun


On Sat, Jul 1, 2017 at 7:47 AM, Arnaldo Carvalho de Melo
<acme@redhat.com> wrote:
> Em Fri, Jun 30, 2017 at 03:40:57PM -0700, Arun Kalyanasundaram escreveu:
>> The handlers in the python script generated from "perf script" have an
>> attribute: common_pid. This attribute contains the tid of the process
>> instead of its pid. I would like to know if this is the expected behavior.
>> There are no other attributes in the Python handler that provide the pid
>> and knowing the process id is useful to be able to group all samples that
>> belong to the same process that generated different threads.
>
> Humm, you have:
>
> def process_event(param_dict):
>         event_attr = param_dict["attr"]
>         sample     = param_dict["sample"]
>         raw_buf    = param_dict["raw_buf"]
>         comm       = param_dict["comm"]
>         name       = param_dict["ev_name"]
>
> And then, on sample you have (from a recent python script for processing
> Intel PT samples):
>
> def print_common_start(comm, sample, name):
>        ts = sample["time"]
>        cpu = sample["cpu"]
>        pid = sample["pid"]
>        tid = sample["tid"]
>        print "%16s %5u/%-5u [%03u] %9u.%09u %7s:" % (comm, pid, tid, cpu, ts / 1000000000, ts %1000000000, name),
>
> - Arnaldo