Re: [PATCH V8 10/25] perf tools: Add example call-graph script

[Adrian Hunter]

On 21/08/15 18:28, Arnaldo Carvalho de Melo wrote:
> Em Fri, Aug 21, 2015 at 12:21:25PM -0300, Arnaldo Carvalho de Melo escreveu:
>> Em Fri, Aug 21, 2015 at 12:11:33PM -0300, Arnaldo Carvalho de Melo escreveu:
>>> [acme@zoo ~]$ perf script -s ~/libexec/perf-core/scripts/python/export-to-postgresql.py bts_example branches calls
>>> 2015-08-21 12:10:00.504126 Creating database...
>>> QSqlDatabase: QPSQL driver not loaded
>>> QSqlDatabase: available drivers: QSQLITE
>>> QSqlDatabase: an instance of QCoreApplication is required for loading driver plugins
>>> QSqlQuery::exec: database not open
>>> Traceback (most recent call last):
>>>   File "/home/acme/libexec/perf-core/scripts/python/export-to-postgresql.py", line 87, in <module>
>>>     do_query(query, 'CREATE DATABASE ' + dbname)
>>>   File "/home/acme/libexec/perf-core/scripts/python/export-to-postgresql.py", line 78, in do_query
>>>     raise Exception("Query failed: " + q.lastError().text())
>>> Exception: Query failed: Driver not loaded Driver not loaded
>>> Error running python script /home/acme/libexec/perf-core/scripts/python/export-to-postgresql.py
>>> [acme@zoo ~]$ 
>>
>> A-ha, this was missing:
>>
>> [root@zoo ~]# rpm -ql qt-postgresql 
>> /usr/lib64/qt4/plugins/sqldrivers/libqsqlpsql.so
>> [root@zoo ~]#
>>
>> [acme@zoo ~]$ perf script -s ~/libexec/perf-core/scripts/python/export-to-postgresql.py bts_example branches calls
>> 2015-08-21 12:20:01.841677 Creating database...
>> 2015-08-21 12:20:02.556853 Writing to intermediate files...
>> 2015-08-21 12:20:03.262814 Copying to database...
>> 2015-08-21 12:20:03.783109 Removing intermediate files...
>> 2015-08-21 12:20:03.790282 Adding primary keys
>> 2015-08-21 12:20:04.294342 Adding foreign keys
>> 2015-08-21 12:20:04.718238 Done
>> [acme@zoo ~]$ 
>>
>> Now to the next steps... Lets see how this looks like with BTS...
> 
> So, after running:
> 
>   [acme@zoo linux]$ python
>   tools/perf/scripts/python/call-graph-from-postgresql.py bts_example
> 
> I got a GUI and after expanding some callchains I took this screenshot:
> 
>   http://vger.kernel.org/~acme/perf/call_graph_example_intel_bts.png
> 
> Cool stuff! But it seems the COMM got messed up? I.e. that "1380:1380"
> first level after "ls".

That is, in fact, correct.  The top-level is the process (comm).  The next
level is the threads (pid/tid) for that process.  Currently, each thread is
reported separately.

For the future, there ought to be an option to combine the data for all
threads of a process, or all processes with the same comm.  Also presently
it is not tracking if a thread sets it's own comm (e.g. some multi-threaded
applications name each thread).

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