Re: [PATCH] trace-event-python: give field dict to unhandledcallback
From: Tom Zanussi
Date: Mon May 31 2010 - 15:06:43 EST
On Mon, 2010-05-31 at 18:23 +0200, Pierre Tardy wrote:
> Ingo, Tom,
> Now rc1 is over...
>
> Any comment on this patch? It is relatively minor.
> Do you intent to accept it?
>
Yeah, sorry, long weekend here...
Yes, I like this - as you say, it is more pythonic, which is welcome
since I'm not really much of a python programmer myself.
I did try it out, and it worked fine, but I ran into one compile error
on my Ubuntu 8.10 system - the Py_DECREF() macro expands into an if
statement, see warning/error below. So putting curly braces around the
if body fixed it for me (see below)
Other than that,
Acked-by: Tom Zanussi <tzanussi@xxxxxxxxx>
> Pierre
>
> On Sat, May 29, 2010 at 5:42 PM, Pierre Tardy <tardyp@xxxxxxxxx> wrote:
> > trace_unhandled() callback does not allow to access event fields, this
> > patch resolves the problem.
> >
> > It can also been used as a more pythonic and flexible way for script
> > writters to demux event types
> >
> > This will for example greatly simplify pytimechart event demux.
> >
> > Signed-off-by: Pierre Tardy <tardyp@xxxxxxxxx>
> > ---
> > tools/perf/scripts/python/check-perf-trace.py | 3 +-
> > .../util/scripting-engines/trace-event-python.c | 51 +++++++++++++------
> > 2 files changed, 36 insertions(+), 18 deletions(-)
> >
> > diff --git a/tools/perf/scripts/python/check-perf-trace.py b/tools/perf/scripts/python/check-perf-trace.py
> > index 964d934..d9f7893 100644
> > --- a/tools/perf/scripts/python/check-perf-trace.py
> > +++ b/tools/perf/scripts/python/check-perf-trace.py
> > @@ -51,8 +51,7 @@ def kmem__kmalloc(event_name, context, common_cpu,
> >
> > flag_str("kmem__kmalloc", "gfp_flags", gfp_flags)),
> >
> > -def trace_unhandled(event_name, context, common_cpu, common_secs, common_nsecs,
> > - common_pid, common_comm):
> > +def trace_unhandled(event_name, context, event_fields_dict):
> > try:
> > unhandled[event_name] += 1
> > except TypeError:
> > diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c
> > index 81f39ca..db7c18a 100644
> > --- a/tools/perf/util/scripting-engines/trace-event-python.c
> > +++ b/tools/perf/util/scripting-engines/trace-event-python.c
> > @@ -208,7 +208,7 @@ static void python_process_event(int cpu, void *data,
> > int size __unused,
> > unsigned long long nsecs, char *comm)
> > {
> > - PyObject *handler, *retval, *context, *t, *obj;
> > + PyObject *handler, *retval, *context, *t, *obj, *dict = NULL;
> > static char handler_name[256];
> > struct format_field *field;
> > unsigned long long val;
> > @@ -232,6 +232,14 @@ static void python_process_event(int cpu, void *data,
> >
> > sprintf(handler_name, "%s__%s", event->system, event->name);
> >
> > + handler = PyDict_GetItemString(main_dict, handler_name);
> > + if (handler && !PyCallable_Check(handler))
> > + handler = NULL;
> > + if (!handler) {
> > + dict = PyDict_New();
> > + if (!dict)
> > + Py_FatalError("couldn't create Python dict");
> > + }
> > s = nsecs / NSECS_PER_SEC;
> > ns = nsecs - s * NSECS_PER_SEC;
> >
> > @@ -242,12 +250,20 @@ static void python_process_event(int cpu, void *data,
> > PyTuple_SetItem(t, n++, PyString_FromString(handler_name));
> > PyTuple_SetItem(t, n++,
> > PyCObject_FromVoidPtr(scripting_context, NULL));
> > - PyTuple_SetItem(t, n++, PyInt_FromLong(cpu));
> > - PyTuple_SetItem(t, n++, PyInt_FromLong(s));
> > - PyTuple_SetItem(t, n++, PyInt_FromLong(ns));
> > - PyTuple_SetItem(t, n++, PyInt_FromLong(pid));
> > - PyTuple_SetItem(t, n++, PyString_FromString(comm));
> >
> > + if (handler) {
> > + PyTuple_SetItem(t, n++, PyInt_FromLong(cpu));
> > + PyTuple_SetItem(t, n++, PyInt_FromLong(s));
> > + PyTuple_SetItem(t, n++, PyInt_FromLong(ns));
> > + PyTuple_SetItem(t, n++, PyInt_FromLong(pid));
> > + PyTuple_SetItem(t, n++, PyString_FromString(comm));
> > + } else {
> > + PyDict_SetItemString(dict, "common_cpu", PyInt_FromLong(cpu));
> > + PyDict_SetItemString(dict, "common_s", PyInt_FromLong(s));
> > + PyDict_SetItemString(dict, "common_ns", PyInt_FromLong(ns));
> > + PyDict_SetItemString(dict, "common_pid", PyInt_FromLong(pid));
> > + PyDict_SetItemString(dict, "common_comm", PyString_FromString(comm));
> > + }
> > for (field = event->format.fields; field; field = field->next) {
> > if (field->flags & FIELD_IS_STRING) {
> > int offset;
> > @@ -272,22 +288,25 @@ static void python_process_event(int cpu, void *data,
> > obj = PyLong_FromUnsignedLongLong(val);
> > }
> > }
> > - PyTuple_SetItem(t, n++, obj);
> > + if (handler)
> > + PyTuple_SetItem(t, n++, obj);
> > + else
> > + PyDict_SetItemString(dict, field->name, obj);
> > +
> > }
> > + if (!handler)
> > + PyTuple_SetItem(t, n++, dict);
> >
> > if (_PyTuple_Resize(&t, n) == -1)
> > Py_FatalError("error resizing Python tuple");
> >
> > - handler = PyDict_GetItemString(main_dict, handler_name);
> > - if (handler && PyCallable_Check(handler)) {
> > + if (handler) {
> > retval = PyObject_CallObject(handler, t);
> > if (retval == NULL)
> > handler_call_die(handler_name);
> > } else {
> > handler = PyDict_GetItemString(main_dict, "trace_unhandled");
> > if (handler && PyCallable_Check(handler)) {
> > - if (_PyTuple_Resize(&t, N_COMMON_FIELDS) == -1)
> > - Py_FatalError("error resizing Python tuple");
> >
> > retval = PyObject_CallObject(handler, t);
> > if (retval == NULL)
> > @@ -296,6 +315,8 @@ static void python_process_event(int cpu, void *data,
> > }
> >
> > Py_DECREF(t);
> > + if (!handler)
> > + Py_DECREF(dict);
This produces a warning, treated as an error:
CC util/scripting-engines/trace-event-python.o
cc1: warnings being treated as errors
util/scripting-engines/trace-event-python.c: In function
âpython_process_eventâ:
util/scripting-engines/trace-event-python.c:318: error: suggest explicit
braces to avoid ambiguous âelseâ
make: *** [util/scripting-engines/trace-event-python.o] Error 1
The if statement expands to:
if (!handler)
if ( --(dict)->ob_refcnt != 0) ; else
( (*((PyObject*)(dict))->ob_type->tp_dealloc)((PyObject *)((PyObject
*)(dict))));
Changing the line to:
if (!handler) {
Py_DECREF(dict);
}
fixes the compile error for me...
My system is:
Ubuntu 8.10
Python 2.5.2 (r252:60911, Oct 5 2008, 19:29:17)
Thanks,
Tom
> > }
> >
> > static int run_start_sub(void)
> > @@ -548,12 +569,10 @@ static int python_generate_script(const char *outfile)
> > }
> >
> > fprintf(ofp, "def trace_unhandled(event_name, context, "
> > - "common_cpu, common_secs, common_nsecs,\n\t\t"
> > - "common_pid, common_comm):\n");
> > + "event_fields_dict):\n");
> >
> > - fprintf(ofp, "\t\tprint_header(event_name, common_cpu, "
> > - "common_secs, common_nsecs,\n\t\tcommon_pid, "
> > - "common_comm)\n\n");
> > + fprintf(ofp, "\t\tprint ' '.join(['%%s=%%s'%%(k,str(v))"
> > + "for k,v in sorted(event_fields_dict.items())])\n\n");
> >
> > fprintf(ofp, "def print_header("
> > "event_name, cpu, secs, nsecs, pid, comm):\n"
> > --
> > 1.7.0.4
> >
> >
>
>
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/