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300b4c33 | 1 | #!/usr/bin/env python3 |
24a3136a | 2 | # sched_switch.py |
300b4c33 | 3 | # |
24a3136a | 4 | # Babeltrace example script with sched_switch events |
300b4c33 | 5 | # |
24a3136a | 6 | # Copyright 2012 EfficiOS Inc. |
300b4c33 | 7 | # |
24a3136a | 8 | # Author: Danny Serres <danny.serres@efficios.com> |
300b4c33 | 9 | # |
24a3136a DS |
10 | # Permission is hereby granted, free of charge, to any person obtaining a copy |
11 | # of this software and associated documentation files (the "Software"), to deal | |
12 | # in the Software without restriction, including without limitation the rights | |
13 | # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
14 | # copies of the Software, and to permit persons to whom the Software is | |
15 | # furnished to do so, subject to the following conditions: | |
300b4c33 | 16 | # |
24a3136a DS |
17 | # The above copyright notice and this permission notice shall be included in |
18 | # all copies or substantial portions of the Software. | |
19 | ||
20 | # The script takes one optional argument (pid) | |
21 | # The script will read events based on pid and | |
22 | # print the scheduler switches happening with the process. | |
23 | # If no arguments are passed, it displays all the scheduler switches. | |
24 | # This can be used to understand which tasks schedule out the current | |
25 | # process being traced, and when it gets scheduled in again. | |
26 | # The trace needs PID context (lttng add-context -k -t pid) | |
27 | ||
28 | import sys | |
29 | from babeltrace import * | |
30 | ||
31 | if len(sys.argv) < 2 or len(sys.argv) > 3: | |
32 | raise TypeError("Usage: python sched_switch.py [pid] path/to/trace") | |
33 | elif len(sys.argv) == 3: | |
34 | usePID = True | |
35 | else: | |
36 | usePID = False | |
37 | ||
74ea15ad JG |
38 | traces = TraceCollection() |
39 | ret = traces.add_trace(sys.argv[len(sys.argv)-1], "ctf") | |
24a3136a DS |
40 | if ret is None: |
41 | raise IOError("Error adding trace") | |
42 | ||
74ea15ad | 43 | for event in traces.events: |
24a3136a DS |
44 | while True: |
45 | if event.get_name() == "sched_switch": | |
46 | # Getting scope definition | |
24d5c942 | 47 | sco = event.get_top_level_scope(CTFReader.scope.STREAM_EVENT_CONTEXT) |
24a3136a DS |
48 | if sco is None: |
49 | print("ERROR: Cannot get definition scope for sched_switch") | |
50 | break # Next event | |
51 | ||
52 | # Getting PID | |
db551f28 | 53 | pid_field = event.get_field_with_scope(sco, "pid") |
3c2ce778 | 54 | if pid_field is None: |
24a3136a DS |
55 | print("ERROR: Missing PID info for sched_switch") |
56 | break # Next event | |
3c2ce778 | 57 | pid = pid_field.get_value() |
24a3136a DS |
58 | if usePID and (pid != long(sys.argv[1])): |
59 | break # Next event | |
60 | ||
24d5c942 | 61 | sco = event.get_top_level_scope(CTFReader.scope.EVENT_FIELDS) |
24a3136a DS |
62 | |
63 | # prev_comm | |
db551f28 | 64 | field = event.get_field_with_scope(sco, "prev_comm") |
3c2ce778 | 65 | if field is None: |
24a3136a | 66 | print("ERROR: Missing prev_comm context info") |
3c2ce778 | 67 | prev_comm = field.get_value() |
24a3136a DS |
68 | |
69 | # prev_tid | |
db551f28 | 70 | field = event.get_field_with_scope(sco, "prev_tid") |
3c2ce778 | 71 | if field is None: |
24a3136a | 72 | print("ERROR: Missing prev_tid context info") |
3c2ce778 | 73 | prev_tid = field.get_value() |
24a3136a DS |
74 | |
75 | # prev_prio | |
db551f28 | 76 | field = event.get_field_with_scope(sco, "prev_prio") |
3c2ce778 | 77 | if field is None: |
24a3136a | 78 | print("ERROR: Missing prev_prio context info") |
3c2ce778 | 79 | prev_prio = field.get_value() |
24a3136a DS |
80 | |
81 | # prev_state | |
db551f28 | 82 | field = event.get_field_with_scope(sco, "prev_state") |
3c2ce778 | 83 | if field is None: |
24a3136a | 84 | print("ERROR: Missing prev_state context info") |
3c2ce778 | 85 | prev_state = field.get_value() |
24a3136a DS |
86 | |
87 | # next_comm | |
db551f28 | 88 | field = event.get_field_with_scope(sco, "next_comm") |
3c2ce778 | 89 | if field is None: |
24a3136a | 90 | print("ERROR: Missing next_comm context info") |
3c2ce778 | 91 | next_comm = field.get_value() |
24a3136a DS |
92 | |
93 | # next_tid | |
db551f28 | 94 | field = event.get_field_with_scope(sco, "next_tid") |
3c2ce778 | 95 | if field is None: |
24a3136a | 96 | print("ERROR: Missing next_tid context info") |
3c2ce778 | 97 | next_tid = field.get_value() |
24a3136a DS |
98 | |
99 | # next_prio | |
db551f28 | 100 | field = event.get_field_with_scope(sco, "next_prio") |
3c2ce778 | 101 | if field is None: |
24a3136a | 102 | print("ERROR: Missing next_prio context info") |
3c2ce778 | 103 | next_prio = field.get_value() |
24a3136a DS |
104 | |
105 | # Output | |
106 | print("sched_switch, pid = {}, TS = {}, prev_comm = {},\n\t" | |
107 | "prev_tid = {}, prev_prio = {}, prev_state = {},\n\t" | |
108 | "next_comm = {}, next_tid = {}, next_prio = {}".format( | |
109 | pid, event.get_timestamp(), prev_comm, prev_tid, | |
110 | prev_prio, prev_state, next_comm, next_tid, next_prio)) | |
111 | ||
112 | break # Next event |