Re: [PATCH v2] perf scripts python: Add Python 3 support to check-perf-trace.py

[Tony Jones <tonyj@suse.de>]

On 1/17/19 4:32 AM, Jiri Olsa wrote:
> On Thu, Jan 17, 2019 at 03:15:28PM +0530, Seeteena Thoufeek wrote:
>> Support both Python 2 and Python 3 in check-perf-trace.py.
>> ``print`` is now a function rather than a statement. This should have
>> no functional change.
>>
>> Fix indentation issue, replace spaces with tab
>>
>> Signed-off-by: Seeteena Thoufeek <s1seetee@linux.vnet.ibm.com>
>> Reviewed-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
> 
> hum, could you please add some info about testing those changes?
> (or even some global into 0/.. patch)
> 
> this is working for me on python2:
> 
> 	[root@krava perf]# perf script rec check-perf-trace
> 	^C
> 	[root@krava perf]# perf script   -s scripts/python/check-perf-trace.py
> 	trace_begin
> 
> 	unhandled events:
> 
> 
> 	event                                          count
> 
> 	----------------------------------------  -----------
> 
> 	raw_syscalls__sys_enter                      3509879
> 
> 
> but fails for python3:
> 
> 	[root@ibm-x3650m4-01-vm-04 perf]# perf script rec check-perf-trace
> 	^C[ perf record: Woken up 0 times to write data ]
> 	Warning:
> 	1 out of order events recorded.
> 	[ perf record: Captured and wrote 43.132 MB perf.data (490171 samples) ]
> 
> 	[root@ibm-x3650m4-01-vm-04 perf]# perf script   -s scripts/python/check-perf-trace.py
> 	Traceback (most recent call last):
> 	  File "scripts/python/check-perf-trace.py", line 18, in <module>
> 	    from perf_trace_context import *
> 	ModuleNotFoundError: No module named 'perf_trace_context'
> 	Error running python script scripts/python/check-perf-trace.py
> 
> I did not test with rpm, just did 'make install' for perf
> 
> thanks,
> jirka
> 

I'd been simultaneously working on a patch set to fix up Python3.  

It's actually already in our Factory and SLE15-SP1 releases as we had a deadline to kill Python2 usage for internal rpms. 

I was going to post once I'd fixed the last remaining issue ('import perf' is still failing [test #18]).   

I guess "you snooze you lose" :-)

https://build.opensuse.org/package/view_file/devel:tools/perf/perf.changes?expand=1

Anyhow,  the fix for the above is: 'add-trace_context-extension-module-to-sys-modules.patch' from above.

Attached below.  Verified with PYTHON=python2 and PYTHON=python3

Tony

---------------------------------

In Python3,  the result of PyModule_Create (called from
scripts/python/Perf-Trace-Util/Context.c) is not automatically added to 
sys.modules.  See: https://bugs.python.org/issue4592

Below is the observed behavior without the fix.

# ldd /usr/bin/perf | grep -i python
	libpython3.6m.so.1.0 => /usr/lib64/libpython3.6m.so.1.0 (0x00007f8e1dfb2000)

# perf record -a -e raw_syscalls:sys_enter sleep 5
[ perf record: Woken up 0 times to write data ]
[ perf record: Captured and wrote 187.177 MB perf.data (1581501 samples) ]

# perf script -g python | cat
generated Python script: perf-script.py

# perf script -s ./perf-script.py
Traceback (most recent call last):
  File "./perf-script.py", line 18, in <module>
    from perf_trace_context import *
ModuleNotFoundError: No module named 'perf_trace_context'
Error running python script ./perf-script.py

Signed-off-by: Tony Jones <tonyj@suse.de>
---
 tools/perf/util/scripting-engines/trace-event-python.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/tools/perf/util/scripting-engines/trace-event-python.c
+++ b/tools/perf/util/scripting-engines/trace-event-python.c
@@ -1494,6 +1494,7 @@ static void _free_command_line(wchar_t *
 static int python_start_script(const char *script, int argc, const char **argv)
 {
 	struct tables *tables = &tables_global;
+	PyMODINIT_FUNC (*initfunc)(void);
 #if PY_MAJOR_VERSION < 3
 	const char **command_line;
 #else
@@ -1504,24 +1505,25 @@ static int python_start_script(const cha
 	FILE *fp;
 
 #if PY_MAJOR_VERSION < 3
+	initfunc = initperf_trace_context;
 	command_line = malloc((argc + 1) * sizeof(const char *));
 	command_line[0] = script;
 	for (i = 1; i < argc + 1; i++)
 		command_line[i] = argv[i - 1];
 #else
+	initfunc = PyInit_perf_trace_context;
 	command_line = malloc((argc + 1) * sizeof(wchar_t *));
 	command_line[0] = Py_DecodeLocale(script, NULL);
 	for (i = 1; i < argc + 1; i++)
 		command_line[i] = Py_DecodeLocale(argv[i - 1], NULL);
 #endif
 
+	PyImport_AppendInittab("perf_trace_context", initfunc);
 	Py_Initialize();
 
 #if PY_MAJOR_VERSION < 3
-	initperf_trace_context();
 	PySys_SetArgv(argc + 1, (char **)command_line);
 #else
-	PyInit_perf_trace_context();
 	PySys_SetArgv(argc + 1, command_line);
 #endif