--- /dev/null
+# sched_switch.py
+#
+# Babeltrace example script with sched_switch events
+#
+# Copyright 2012 EfficiOS Inc.
+#
+# Author: Danny Serres <danny.serres@efficios.com>
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+
+# The script takes one optional argument (pid)
+# The script will read events based on pid and
+# print the scheduler switches happening with the process.
+# If no arguments are passed, it displays all the scheduler switches.
+# This can be used to understand which tasks schedule out the current
+# process being traced, and when it gets scheduled in again.
+# The trace needs PID context (lttng add-context -k -t pid)
+
+import sys
+from babeltrace import *
+
+if len(sys.argv) < 2 or len(sys.argv) > 3:
+ raise TypeError("Usage: python sched_switch.py [pid] path/to/trace")
+elif len(sys.argv) == 3:
+ usePID = True
+else:
+ usePID = False
+
+
+ctx = Context()
+ret = ctx.add_trace(sys.argv[len(sys.argv)-1], "ctf")
+if ret is None:
+ raise IOError("Error adding trace")
+
+# Setting iterator
+bp = IterPos(SEEK_BEGIN)
+ctf_it = ctf.Iterator(ctx, bp)
+
+# Reading events
+event = ctf_it.read_event()
+while event is not None:
+ while True:
+ if event.get_name() == "sched_switch":
+ # Getting scope definition
+ sco = event.get_top_level_scope(ctf.scope.STREAM_EVENT_CONTEXT)
+ if sco is None:
+ print("ERROR: Cannot get definition scope for sched_switch")
+ break # Next event
+
+ # Getting PID
+ pid_field = event.get_field(sco, "_pid")
+ pid = pid_field.get_int64()
+
+ if ctf.field_error():
+ print("ERROR: Missing PID info for sched_switch")
+ break # Next event
+
+ if usePID and (pid != long(sys.argv[1])):
+ break # Next event
+
+ sco = event.get_top_level_scope(ctf.scope.EVENT_FIELDS)
+
+ # prev_comm
+ field = event.get_field(sco, "_prev_comm")
+ prev_comm = field.get_char_array()
+ if ctf.field_error():
+ print("ERROR: Missing prev_comm context info")
+
+ # prev_tid
+ field = event.get_field(sco, "_prev_tid")
+ prev_tid = field.get_int64()
+ if ctf.field_error():
+ print("ERROR: Missing prev_tid context info")
+
+ # prev_prio
+ field = event.get_field(sco, "_prev_prio")
+ prev_prio = field.get_int64()
+ if ctf.field_error():
+ print("ERROR: Missing prev_prio context info")
+
+ # prev_state
+ field = event.get_field(sco, "_prev_state")
+ prev_state = field.get_int64()
+ if ctf.field_error():
+ print("ERROR: Missing prev_state context info")
+
+ # next_comm
+ field = event.get_field(sco, "_next_comm")
+ next_comm = field.get_char_array()
+ if ctf.field_error():
+ print("ERROR: Missing next_comm context info")
+
+ # next_tid
+ field = event.get_field(sco, "_next_tid")
+ next_tid = field.get_int64()
+ if ctf.field_error():
+ print("ERROR: Missing next_tid context info")
+
+ # next_prio
+ field = event.get_field(sco, "_next_prio")
+ next_prio = field.get_int64()
+ if ctf.field_error():
+ print("ERROR: Missing next_prio context info")
+
+ # Output
+ print("sched_switch, pid = {}, TS = {}, prev_comm = {},\n\t"
+ "prev_tid = {}, prev_prio = {}, prev_state = {},\n\t"
+ "next_comm = {}, next_tid = {}, next_prio = {}".format(
+ pid, event.get_timestamp(), prev_comm, prev_tid,
+ prev_prio, prev_state, next_comm, next_tid, next_prio))
+
+ break # Next event
+
+ # Next event
+ ret = ctf_it.next()
+ if ret < 0:
+ break
+ event = ctf_it.read_event()
+
+del ctf_it
projects / babeltrace.git / blobdiff