[PULL 00/14] Tracing patches

[PULL 00/14] Tracing patches

[Stefan Hajnoczi]

The following changes since commit 494a6a2cf7f775d2c20fd6df9601e30606cc2014:

  Merge tag 'pull-request-2023-09-25' of https://gitlab.com/thuth/qemu into staging (2023-09-25 10:10:30 -0400)

are available in the Git repository at:

  https://gitlab.com/stefanha/qemu.git tags/tracing-pull-request

for you to fetch changes up to ff014701ab0f09fdbf37b4c39334790f9b298253:

  scripts/analyse-locks-simpletrace.py: changed iteritems() to items() (2023-09-26 12:28:51 -0400)

----------------------------------------------------------------
Pull request

- Mads Ynddal's improvements to simpletrace.py

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

Mads Ynddal (14):
  simpletrace: add __all__ to define public interface
  simpletrace: annotate magic constants from QEMU code
  simpletrace: improve parsing of sys.argv; fix files never closed.
  simpletrace: changed naming of edict and idtoname to improve
    readability
  simpletrace: update code for Python 3.11
  simpletrace: improved error handling on struct unpack
  simpletrace: define exception and add handling
  simpletrace: made Analyzer into context-manager
  simpletrace: refactor to separate responsibilities
  simpletrace: move logic of process into internal function
  simpletrace: move event processing to Analyzer class
  simpletrace: added simplified Analyzer2 class
  MAINTAINERS: add maintainer of simpletrace.py
  scripts/analyse-locks-simpletrace.py: changed iteritems() to items()

 MAINTAINERS                          |   6 +
 scripts/analyse-locks-simpletrace.py |   2 +-
 scripts/simpletrace.py               | 372 +++++++++++++++++----------
 3 files changed, 241 insertions(+), 139 deletions(-)

-- 
2.41.0

[PULL 01/14] simpletrace: add __all__ to define public interface

[Stefan Hajnoczi]

From: Mads Ynddal <m.ynddal@samsung.com>

It was unclear what was the supported public interface. I.e. when
refactoring the code, what functions/classes are important to retain.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Message-id: 20230926103436.25700-2-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 scripts/simpletrace.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/scripts/simpletrace.py b/scripts/simpletrace.py
index 1f6d1ae1f3..b221d9a241 100755
--- a/scripts/simpletrace.py
+++ b/scripts/simpletrace.py
@@ -14,6 +14,8 @@
 from tracetool import read_events, Event
 from tracetool.backend.simple import is_string
 
+__all__ = ['Analyzer', 'process', 'run']
+
 header_event_id = 0xffffffffffffffff
 header_magic    = 0xf2b177cb0aa429b4
 dropped_event_id = 0xfffffffffffffffe
-- 
2.41.0

[PULL 02/14] simpletrace: annotate magic constants from QEMU code

[Stefan Hajnoczi]

From: Mads Ynddal <m.ynddal@samsung.com>

It wasn't clear where the constants and structs came from, so I added
comments to help.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Message-id: 20230926103436.25700-3-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 scripts/simpletrace.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/scripts/simpletrace.py b/scripts/simpletrace.py
index b221d9a241..5c230a1b74 100755
--- a/scripts/simpletrace.py
+++ b/scripts/simpletrace.py
@@ -16,6 +16,11 @@
 
 __all__ = ['Analyzer', 'process', 'run']
 
+# This is the binary format that the QEMU "simple" trace backend
+# emits. There is no specification documentation because the format is
+# not guaranteed to be stable. Trace files must be parsed with the
+# same trace-events-all file and the same simpletrace.py file that
+# QEMU was built with.
 header_event_id = 0xffffffffffffffff
 header_magic    = 0xf2b177cb0aa429b4
 dropped_event_id = 0xfffffffffffffffe
-- 
2.41.0

[PULL 03/14] simpletrace: improve parsing of sys.argv; fix files never closed.

[Stefan Hajnoczi]

From: Mads Ynddal <m.ynddal@samsung.com>

The arguments extracted from `sys.argv` named and unpacked to make it
clear what the arguments are and what they're used for.

The two input files were opened, but never explicitly closed. File usage
changed to use `with` statement to take care of this. At the same time,
ownership of the file-object is moved up to `run` function. Added option
to process to support file-like objects.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Message-id: 20230926103436.25700-4-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 scripts/simpletrace.py | 48 +++++++++++++++++++++++++++++-------------
 1 file changed, 33 insertions(+), 15 deletions(-)

diff --git a/scripts/simpletrace.py b/scripts/simpletrace.py
index 5c230a1b74..283b5918a1 100755
--- a/scripts/simpletrace.py
+++ b/scripts/simpletrace.py
@@ -9,6 +9,7 @@
 #
 # For help see docs/devel/tracing.rst
 
+import sys
 import struct
 import inspect
 from tracetool import read_events, Event
@@ -51,7 +52,6 @@ def get_record(edict, idtoname, rechdr, fobj):
         try:
             event = edict[name]
         except KeyError as e:
-            import sys
             sys.stderr.write('%s event is logged but is not declared ' \
                              'in the trace events file, try using ' \
                              'trace-events-all instead.\n' % str(e))
@@ -172,11 +172,28 @@ def end(self):
         pass
 
 def process(events, log, analyzer, read_header=True):
-    """Invoke an analyzer on each event in a log."""
+    """Invoke an analyzer on each event in a log.
+    Args:
+        events (file-object or list or str): events list or file-like object or file path as str to read event data from
+        log (file-object or str): file-like object or file path as str to read log data from
+        analyzer (Analyzer): Instance of Analyzer to interpret the event data
+        read_header (bool, optional): Whether to read header data from the log data. Defaults to True.
+    """
+
     if isinstance(events, str):
-        events = read_events(open(events, 'r'), events)
+        with open(events, 'r') as f:
+            events_list = read_events(f, events)
+    elif isinstance(events, list):
+        # Treat as a list of events already produced by tracetool.read_events
+        events_list = events
+    else:
+        # Treat as an already opened file-object
+        events_list = read_events(events, events.name)
+
+    close_log = False
     if isinstance(log, str):
         log = open(log, 'rb')
+        close_log = True
 
     if read_header:
         read_trace_header(log)
@@ -187,12 +204,12 @@ def process(events, log, analyzer, read_header=True):
     edict = {"dropped": dropped_event}
     idtoname = {dropped_event_id: "dropped"}
 
-    for event in events:
+    for event in events_list:
         edict[event.name] = event
 
     # If there is no header assume event ID mapping matches events list
     if not read_header:
-        for event_id, event in enumerate(events):
+        for event_id, event in enumerate(events_list):
             idtoname[event_id] = event.name
 
     def build_fn(analyzer, event):
@@ -225,24 +242,25 @@ def build_fn(analyzer, event):
         fn_cache[event_num](event, rec)
     analyzer.end()
 
+    if close_log:
+        log.close()
+
 def run(analyzer):
     """Execute an analyzer on a trace file given on the command-line.
 
     This function is useful as a driver for simple analysis scripts.  More
     advanced scripts will want to call process() instead."""
-    import sys
 
-    read_header = True
-    if len(sys.argv) == 4 and sys.argv[1] == '--no-header':
-        read_header = False
-        del sys.argv[1]
-    elif len(sys.argv) != 3:
-        sys.stderr.write('usage: %s [--no-header] <trace-events> ' \
-                         '<trace-file>\n' % sys.argv[0])
+    try:
+        # NOTE: See built-in `argparse` module for a more robust cli interface
+        *no_header, trace_event_path, trace_file_path = sys.argv[1:]
+        assert no_header == [] or no_header == ['--no-header'], 'Invalid no-header argument'
+    except (AssertionError, ValueError):
+        sys.stderr.write(f'usage: {sys.argv[0]} [--no-header] <trace-events> <trace-file>\n')
         sys.exit(1)
 
-    events = read_events(open(sys.argv[1], 'r'), sys.argv[1])
-    process(events, sys.argv[2], analyzer, read_header=read_header)
+    with open(trace_event_path, 'r') as events_fobj, open(trace_file_path, 'rb') as log_fobj:
+        process(events_fobj, log_fobj, analyzer, read_header=not no_header)
 
 if __name__ == '__main__':
     class Formatter(Analyzer):
-- 
2.41.0

[PULL 04/14] simpletrace: changed naming of edict and idtoname to improve readability

[Stefan Hajnoczi]

From: Mads Ynddal <m.ynddal@samsung.com>

Readability is subjective, but I've expanded the naming of the variables
and arguments, to help with understanding for new eyes on the code.

Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20230926103436.25700-5-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 scripts/simpletrace.py | 34 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/scripts/simpletrace.py b/scripts/simpletrace.py
index 283b5918a1..09511f624d 100755
--- a/scripts/simpletrace.py
+++ b/scripts/simpletrace.py
@@ -40,17 +40,17 @@ def read_header(fobj, hfmt):
         return None
     return struct.unpack(hfmt, hdr)
 
-def get_record(edict, idtoname, rechdr, fobj):
+def get_record(event_mapping, event_id_to_name, rechdr, fobj):
     """Deserialize a trace record from a file into a tuple
        (name, timestamp, pid, arg1, ..., arg6)."""
     if rechdr is None:
         return None
     if rechdr[0] != dropped_event_id:
         event_id = rechdr[0]
-        name = idtoname[event_id]
+        name = event_id_to_name[event_id]
         rec = (name, rechdr[1], rechdr[3])
         try:
-            event = edict[name]
+            event = event_mapping[name]
         except KeyError as e:
             sys.stderr.write('%s event is logged but is not declared ' \
                              'in the trace events file, try using ' \
@@ -79,10 +79,10 @@ def get_mapping(fobj):
 
     return (event_id, name)
 
-def read_record(edict, idtoname, fobj):
+def read_record(event_mapping, event_id_to_name, fobj):
     """Deserialize a trace record from a file into a tuple (event_num, timestamp, pid, arg1, ..., arg6)."""
     rechdr = read_header(fobj, rec_header_fmt)
-    return get_record(edict, idtoname, rechdr, fobj)
+    return get_record(event_mapping, event_id_to_name, rechdr, fobj)
 
 def read_trace_header(fobj):
     """Read and verify trace file header"""
@@ -103,14 +103,14 @@ def read_trace_header(fobj):
         raise ValueError('Log format %d not supported with this QEMU release!'
                          % log_version)
 
-def read_trace_records(edict, idtoname, fobj):
+def read_trace_records(event_mapping, event_id_to_name, fobj):
     """Deserialize trace records from a file, yielding record tuples (event_num, timestamp, pid, arg1, ..., arg6).
 
-    Note that `idtoname` is modified if the file contains mapping records.
+    Note that `event_id_to_name` is modified if the file contains mapping records.
 
     Args:
-        edict (str -> Event): events dict, indexed by name
-        idtoname (int -> str): event names dict, indexed by event ID
+        event_mapping (str -> Event): events dict, indexed by name
+        event_id_to_name (int -> str): event names dict, indexed by event ID
         fobj (file): input file
 
     """
@@ -122,9 +122,9 @@ def read_trace_records(edict, idtoname, fobj):
         (rectype, ) = struct.unpack('=Q', t)
         if rectype == record_type_mapping:
             event_id, name = get_mapping(fobj)
-            idtoname[event_id] = name
+            event_id_to_name[event_id] = name
         else:
-            rec = read_record(edict, idtoname, fobj)
+            rec = read_record(event_mapping, event_id_to_name, fobj)
 
             yield rec
 
@@ -201,16 +201,16 @@ def process(events, log, analyzer, read_header=True):
     frameinfo = inspect.getframeinfo(inspect.currentframe())
     dropped_event = Event.build("Dropped_Event(uint64_t num_events_dropped)",
                                 frameinfo.lineno + 1, frameinfo.filename)
-    edict = {"dropped": dropped_event}
-    idtoname = {dropped_event_id: "dropped"}
+    event_mapping = {"dropped": dropped_event}
+    event_id_to_name = {dropped_event_id: "dropped"}
 
     for event in events_list:
-        edict[event.name] = event
+        event_mapping[event.name] = event
 
     # If there is no header assume event ID mapping matches events list
     if not read_header:
         for event_id, event in enumerate(events_list):
-            idtoname[event_id] = event.name
+            event_id_to_name[event_id] = event.name
 
     def build_fn(analyzer, event):
         if isinstance(event, str):
@@ -234,9 +234,9 @@ def build_fn(analyzer, event):
 
     analyzer.begin()
     fn_cache = {}
-    for rec in read_trace_records(edict, idtoname, log):
+    for rec in read_trace_records(event_mapping, event_id_to_name, log):
         event_num = rec[0]
-        event = edict[event_num]
+        event = event_mapping[event_num]
         if event_num not in fn_cache:
             fn_cache[event_num] = build_fn(analyzer, event)
         fn_cache[event_num](event, rec)
-- 
2.41.0

[PULL 05/14] simpletrace: update code for Python 3.11

[Stefan Hajnoczi]

From: Mads Ynddal <m.ynddal@samsung.com>

The call to `getargspec` was deprecated and in Python 3.11 it has been
removed in favor of `getfullargspec`. `getfullargspec` is compatible
with QEMU's requirement of at least Python version 3.6.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Message-id: 20230926103436.25700-6-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 scripts/simpletrace.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/simpletrace.py b/scripts/simpletrace.py
index 09511f624d..971b2a0f6a 100755
--- a/scripts/simpletrace.py
+++ b/scripts/simpletrace.py
@@ -221,7 +221,7 @@ def build_fn(analyzer, event):
             return analyzer.catchall
 
         event_argcount = len(event.args)
-        fn_argcount = len(inspect.getargspec(fn)[0]) - 1
+        fn_argcount = len(inspect.getfullargspec(fn)[0]) - 1
         if fn_argcount == event_argcount + 1:
             # Include timestamp as first argument
             return lambda _, rec: fn(*(rec[1:2] + rec[3:3 + event_argcount]))
-- 
2.41.0

[PULL 06/14] simpletrace: improved error handling on struct unpack

[Stefan Hajnoczi]

From: Mads Ynddal <m.ynddal@samsung.com>

A failed call to `read_header` wouldn't be handled the same for the two
different code paths (one path would try to use `None` as a list).
Changed to raise exception to be handled centrally. This also allows for
easier unpacking, as errors has been filtered out.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Message-id: 20230926103436.25700-7-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 scripts/simpletrace.py | 39 +++++++++++++++------------------------
 1 file changed, 15 insertions(+), 24 deletions(-)

diff --git a/scripts/simpletrace.py b/scripts/simpletrace.py
index 971b2a0f6a..8aea0d169b 100755
--- a/scripts/simpletrace.py
+++ b/scripts/simpletrace.py
@@ -37,26 +37,24 @@ def read_header(fobj, hfmt):
     hlen = struct.calcsize(hfmt)
     hdr = fobj.read(hlen)
     if len(hdr) != hlen:
-        return None
+        raise ValueError('Error reading header. Wrong filetype provided?')
     return struct.unpack(hfmt, hdr)
 
 def get_record(event_mapping, event_id_to_name, rechdr, fobj):
     """Deserialize a trace record from a file into a tuple
        (name, timestamp, pid, arg1, ..., arg6)."""
-    if rechdr is None:
-        return None
-    if rechdr[0] != dropped_event_id:
-        event_id = rechdr[0]
+    event_id, timestamp_ns, length, pid = rechdr
+    if event_id != dropped_event_id:
         name = event_id_to_name[event_id]
-        rec = (name, rechdr[1], rechdr[3])
         try:
             event = event_mapping[name]
         except KeyError as e:
-            sys.stderr.write('%s event is logged but is not declared ' \
+            sys.stderr.write(f'{e} event is logged but is not declared ' \
                              'in the trace events file, try using ' \
-                             'trace-events-all instead.\n' % str(e))
+                             'trace-events-all instead.\n')
             sys.exit(1)
 
+        rec = (name, timestamp_ns, pid)
         for type, name in event.args:
             if is_string(type):
                 l = fobj.read(4)
@@ -67,9 +65,8 @@ def get_record(event_mapping, event_id_to_name, rechdr, fobj):
                 (value,) = struct.unpack('=Q', fobj.read(8))
                 rec = rec + (value,)
     else:
-        rec = ("dropped", rechdr[1], rechdr[3])
-        (value,) = struct.unpack('=Q', fobj.read(8))
-        rec = rec + (value,)
+        (dropped_count,) = struct.unpack('=Q', fobj.read(8))
+        rec = ("dropped", timestamp_ns, pid, dropped_count)
     return rec
 
 def get_mapping(fobj):
@@ -86,22 +83,16 @@ def read_record(event_mapping, event_id_to_name, fobj):
 
 def read_trace_header(fobj):
     """Read and verify trace file header"""
-    header = read_header(fobj, log_header_fmt)
-    if header is None:
-        raise ValueError('Not a valid trace file!')
-    if header[0] != header_event_id:
-        raise ValueError('Not a valid trace file, header id %d != %d' %
-                         (header[0], header_event_id))
-    if header[1] != header_magic:
-        raise ValueError('Not a valid trace file, header magic %d != %d' %
-                         (header[1], header_magic))
+    _header_event_id, _header_magic, log_version = read_header(fobj, log_header_fmt)
+    if _header_event_id != header_event_id:
+        raise ValueError(f'Not a valid trace file, header id {_header_event_id} != {header_event_id}')
+    if _header_magic != header_magic:
+        raise ValueError(f'Not a valid trace file, header magic {_header_magic} != {header_magic}')
 
-    log_version = header[2]
     if log_version not in [0, 2, 3, 4]:
-        raise ValueError('Unknown version of tracelog format!')
+        raise ValueError(f'Unknown version {log_version} of tracelog format!')
     if log_version != 4:
-        raise ValueError('Log format %d not supported with this QEMU release!'
-                         % log_version)
+        raise ValueError(f'Log format {log_version} not supported with this QEMU release!')
 
 def read_trace_records(event_mapping, event_id_to_name, fobj):
     """Deserialize trace records from a file, yielding record tuples (event_num, timestamp, pid, arg1, ..., arg6).
-- 
2.41.0

[PULL 07/14] simpletrace: define exception and add handling

[Stefan Hajnoczi]

From: Mads Ynddal <m.ynddal@samsung.com>

Define `SimpleException` to differentiate our exceptions from generic
exceptions (IOError, etc.). Adapted simpletrace to support this and
output to stderr.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Message-id: 20230926103436.25700-8-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 scripts/simpletrace.py | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/scripts/simpletrace.py b/scripts/simpletrace.py
index 8aea0d169b..229b10aa99 100755
--- a/scripts/simpletrace.py
+++ b/scripts/simpletrace.py
@@ -32,12 +32,15 @@
 log_header_fmt = '=QQQ'
 rec_header_fmt = '=QQII'
 
+class SimpleException(Exception):
+    pass
+
 def read_header(fobj, hfmt):
     '''Read a trace record header'''
     hlen = struct.calcsize(hfmt)
     hdr = fobj.read(hlen)
     if len(hdr) != hlen:
-        raise ValueError('Error reading header. Wrong filetype provided?')
+        raise SimpleException('Error reading header. Wrong filetype provided?')
     return struct.unpack(hfmt, hdr)
 
 def get_record(event_mapping, event_id_to_name, rechdr, fobj):
@@ -49,10 +52,10 @@ def get_record(event_mapping, event_id_to_name, rechdr, fobj):
         try:
             event = event_mapping[name]
         except KeyError as e:
-            sys.stderr.write(f'{e} event is logged but is not declared ' \
-                             'in the trace events file, try using ' \
-                             'trace-events-all instead.\n')
-            sys.exit(1)
+            raise SimpleException(
+                f'{e} event is logged but is not declared in the trace events'
+                'file, try using trace-events-all instead.'
+            )
 
         rec = (name, timestamp_ns, pid)
         for type, name in event.args:
@@ -247,8 +250,7 @@ def run(analyzer):
         *no_header, trace_event_path, trace_file_path = sys.argv[1:]
         assert no_header == [] or no_header == ['--no-header'], 'Invalid no-header argument'
     except (AssertionError, ValueError):
-        sys.stderr.write(f'usage: {sys.argv[0]} [--no-header] <trace-events> <trace-file>\n')
-        sys.exit(1)
+        raise SimpleException(f'usage: {sys.argv[0]} [--no-header] <trace-events> <trace-file>\n')
 
     with open(trace_event_path, 'r') as events_fobj, open(trace_file_path, 'rb') as log_fobj:
         process(events_fobj, log_fobj, analyzer, read_header=not no_header)
@@ -276,4 +278,8 @@ def catchall(self, event, rec):
                 i += 1
             print(' '.join(fields))
 
-    run(Formatter())
+    try:
+        run(Formatter())
+    except SimpleException as e:
+        sys.stderr.write(str(e) + "\n")
+        sys.exit(1)
-- 
2.41.0

[PULL 08/14] simpletrace: made Analyzer into context-manager

[Stefan Hajnoczi]

From: Mads Ynddal <m.ynddal@samsung.com>

Instead of explicitly calling `begin` and `end`, we can change the class
to use the context-manager paradigm. This is mostly a styling choice,
used in modern Python code. But it also allows for more advanced analyzers
to handle exceptions gracefully in the `__exit__` method (not
demonstrated here).

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Message-id: 20230926103436.25700-9-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 scripts/simpletrace.py | 31 ++++++++++++++++++++-----------
 1 file changed, 20 insertions(+), 11 deletions(-)

diff --git a/scripts/simpletrace.py b/scripts/simpletrace.py
index 229b10aa99..7f514d1577 100755
--- a/scripts/simpletrace.py
+++ b/scripts/simpletrace.py
@@ -122,12 +122,13 @@ def read_trace_records(event_mapping, event_id_to_name, fobj):
 
             yield rec
 
-class Analyzer(object):
+class Analyzer:
     """A trace file analyzer which processes trace records.
 
     An analyzer can be passed to run() or process().  The begin() method is
     invoked, then each trace record is processed, and finally the end() method
-    is invoked.
+    is invoked. When Analyzer is used as a context-manager (using the `with`
+    statement), begin() and end() are called automatically.
 
     If a method matching a trace event name exists, it is invoked to process
     that trace record.  Otherwise the catchall() method is invoked.
@@ -165,6 +166,15 @@ def end(self):
         """Called at the end of the trace."""
         pass
 
+    def __enter__(self):
+        self.begin()
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        if exc_type is None:
+            self.end()
+        return False
+
 def process(events, log, analyzer, read_header=True):
     """Invoke an analyzer on each event in a log.
     Args:
@@ -226,15 +236,14 @@ def build_fn(analyzer, event):
             # Just arguments, no timestamp or pid
             return lambda _, rec: fn(*rec[3:3 + event_argcount])
 
-    analyzer.begin()
-    fn_cache = {}
-    for rec in read_trace_records(event_mapping, event_id_to_name, log):
-        event_num = rec[0]
-        event = event_mapping[event_num]
-        if event_num not in fn_cache:
-            fn_cache[event_num] = build_fn(analyzer, event)
-        fn_cache[event_num](event, rec)
-    analyzer.end()
+    with analyzer:
+        fn_cache = {}
+        for rec in read_trace_records(event_mapping, event_id_to_name, log):
+            event_num = rec[0]
+            event = event_mapping[event_num]
+            if event_num not in fn_cache:
+                fn_cache[event_num] = build_fn(analyzer, event)
+            fn_cache[event_num](event, rec)
 
     if close_log:
         log.close()
-- 
2.41.0

[PULL 09/14] simpletrace: refactor to separate responsibilities

[Stefan Hajnoczi]

From: Mads Ynddal <m.ynddal@samsung.com>

Moved event_mapping and event_id_to_name down one level in the function
call-stack to keep variable instantiation and usage closer (`process`
and `run` has no use of the variables; `read_trace_records` does).

Instead of passing event_mapping and event_id_to_name to the bottom of
the call-stack, we move their use to `read_trace_records`. This
separates responsibility and ownership of the information.

`read_record` now just reads the arguments from the file-object by
knowning the total number of bytes. Parsing it to specific arguments is
moved up to `read_trace_records`.

Special handling of dropped events removed, as they can be handled
by the general code.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Message-id: 20230926103436.25700-10-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 scripts/simpletrace.py | 115 +++++++++++++++++++----------------------
 1 file changed, 53 insertions(+), 62 deletions(-)

diff --git a/scripts/simpletrace.py b/scripts/simpletrace.py
index 7f514d1577..0826aef283 100755
--- a/scripts/simpletrace.py
+++ b/scripts/simpletrace.py
@@ -31,6 +31,7 @@
 
 log_header_fmt = '=QQQ'
 rec_header_fmt = '=QQII'
+rec_header_fmt_len = struct.calcsize(rec_header_fmt)
 
 class SimpleException(Exception):
     pass
@@ -43,35 +44,6 @@ def read_header(fobj, hfmt):
         raise SimpleException('Error reading header. Wrong filetype provided?')
     return struct.unpack(hfmt, hdr)
 
-def get_record(event_mapping, event_id_to_name, rechdr, fobj):
-    """Deserialize a trace record from a file into a tuple
-       (name, timestamp, pid, arg1, ..., arg6)."""
-    event_id, timestamp_ns, length, pid = rechdr
-    if event_id != dropped_event_id:
-        name = event_id_to_name[event_id]
-        try:
-            event = event_mapping[name]
-        except KeyError as e:
-            raise SimpleException(
-                f'{e} event is logged but is not declared in the trace events'
-                'file, try using trace-events-all instead.'
-            )
-
-        rec = (name, timestamp_ns, pid)
-        for type, name in event.args:
-            if is_string(type):
-                l = fobj.read(4)
-                (len,) = struct.unpack('=L', l)
-                s = fobj.read(len)
-                rec = rec + (s,)
-            else:
-                (value,) = struct.unpack('=Q', fobj.read(8))
-                rec = rec + (value,)
-    else:
-        (dropped_count,) = struct.unpack('=Q', fobj.read(8))
-        rec = ("dropped", timestamp_ns, pid, dropped_count)
-    return rec
-
 def get_mapping(fobj):
     (event_id, ) = struct.unpack('=Q', fobj.read(8))
     (len, ) = struct.unpack('=L', fobj.read(4))
@@ -79,10 +51,11 @@ def get_mapping(fobj):
 
     return (event_id, name)
 
-def read_record(event_mapping, event_id_to_name, fobj):
-    """Deserialize a trace record from a file into a tuple (event_num, timestamp, pid, arg1, ..., arg6)."""
-    rechdr = read_header(fobj, rec_header_fmt)
-    return get_record(event_mapping, event_id_to_name, rechdr, fobj)
+def read_record(fobj):
+    """Deserialize a trace record from a file into a tuple (event_num, timestamp, pid, args)."""
+    event_id, timestamp_ns, record_length, record_pid = read_header(fobj, rec_header_fmt)
+    args_payload = fobj.read(record_length - rec_header_fmt_len)
+    return (event_id, timestamp_ns, record_pid, args_payload)
 
 def read_trace_header(fobj):
     """Read and verify trace file header"""
@@ -97,17 +70,28 @@ def read_trace_header(fobj):
     if log_version != 4:
         raise ValueError(f'Log format {log_version} not supported with this QEMU release!')
 
-def read_trace_records(event_mapping, event_id_to_name, fobj):
-    """Deserialize trace records from a file, yielding record tuples (event_num, timestamp, pid, arg1, ..., arg6).
-
-    Note that `event_id_to_name` is modified if the file contains mapping records.
+def read_trace_records(events, fobj, read_header):
+    """Deserialize trace records from a file, yielding record tuples (event, event_num, timestamp, pid, arg1, ..., arg6).
 
     Args:
         event_mapping (str -> Event): events dict, indexed by name
-        event_id_to_name (int -> str): event names dict, indexed by event ID
         fobj (file): input file
+        read_header (bool): whether headers were read from fobj
 
     """
+    frameinfo = inspect.getframeinfo(inspect.currentframe())
+    dropped_event = Event.build("Dropped_Event(uint64_t num_events_dropped)",
+                                frameinfo.lineno + 1, frameinfo.filename)
+
+    event_mapping = {e.name: e for e in events}
+    event_mapping["dropped"] = dropped_event
+    event_id_to_name = {dropped_event_id: "dropped"}
+
+    # If there is no header assume event ID mapping matches events list
+    if not read_header:
+        for event_id, event in enumerate(events):
+            event_id_to_name[event_id] = event.name
+
     while True:
         t = fobj.read(8)
         if len(t) == 0:
@@ -115,12 +99,35 @@ def read_trace_records(event_mapping, event_id_to_name, fobj):
 
         (rectype, ) = struct.unpack('=Q', t)
         if rectype == record_type_mapping:
-            event_id, name = get_mapping(fobj)
-            event_id_to_name[event_id] = name
+            event_id, event_name = get_mapping(fobj)
+            event_id_to_name[event_id] = event_name
         else:
-            rec = read_record(event_mapping, event_id_to_name, fobj)
+            event_id, timestamp_ns, pid, args_payload = read_record(fobj)
+            event_name = event_id_to_name[event_id]
 
-            yield rec
+            try:
+                event = event_mapping[event_name]
+            except KeyError as e:
+                raise SimpleException(
+                    f'{e} event is logged but is not declared in the trace events'
+                    'file, try using trace-events-all instead.'
+                )
+
+            offset = 0
+            args = []
+            for type, _ in event.args:
+                if is_string(type):
+                    (length,) = struct.unpack_from('=L', args_payload, offset=offset)
+                    offset += 4
+                    s = args_payload[offset:offset+length]
+                    offset += length
+                    args.append(s)
+                else:
+                    (value,) = struct.unpack_from('=Q', args_payload, offset=offset)
+                    offset += 8
+                    args.append(value)
+
+            yield (event_mapping[event_name], event_name, timestamp_ns, pid) + tuple(args)
 
 class Analyzer:
     """A trace file analyzer which processes trace records.
@@ -202,20 +209,6 @@ def process(events, log, analyzer, read_header=True):
     if read_header:
         read_trace_header(log)
 
-    frameinfo = inspect.getframeinfo(inspect.currentframe())
-    dropped_event = Event.build("Dropped_Event(uint64_t num_events_dropped)",
-                                frameinfo.lineno + 1, frameinfo.filename)
-    event_mapping = {"dropped": dropped_event}
-    event_id_to_name = {dropped_event_id: "dropped"}
-
-    for event in events_list:
-        event_mapping[event.name] = event
-
-    # If there is no header assume event ID mapping matches events list
-    if not read_header:
-        for event_id, event in enumerate(events_list):
-            event_id_to_name[event_id] = event.name
-
     def build_fn(analyzer, event):
         if isinstance(event, str):
             return analyzer.catchall
@@ -238,12 +231,10 @@ def build_fn(analyzer, event):
 
     with analyzer:
         fn_cache = {}
-        for rec in read_trace_records(event_mapping, event_id_to_name, log):
-            event_num = rec[0]
-            event = event_mapping[event_num]
-            if event_num not in fn_cache:
-                fn_cache[event_num] = build_fn(analyzer, event)
-            fn_cache[event_num](event, rec)
+        for event, event_id, timestamp_ns, record_pid, *rec_args in read_trace_records(events, log, read_header):
+            if event_id not in fn_cache:
+                fn_cache[event_id] = build_fn(analyzer, event)
+            fn_cache[event_id](event, (event_id, timestamp_ns, record_pid, *rec_args))
 
     if close_log:
         log.close()
-- 
2.41.0

[PULL 10/14] simpletrace: move logic of process into internal function

[Stefan Hajnoczi]

From: Mads Ynddal <m.ynddal@samsung.com>

To avoid duplicate code depending on input types and to better handle
open/close of log with a context-manager, we move the logic of process into
_process.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Message-id: 20230926103436.25700-11-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 scripts/simpletrace.py | 26 ++++++++++++++++++--------
 1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/scripts/simpletrace.py b/scripts/simpletrace.py
index 0826aef283..6969fdd59a 100755
--- a/scripts/simpletrace.py
+++ b/scripts/simpletrace.py
@@ -201,13 +201,26 @@ def process(events, log, analyzer, read_header=True):
         # Treat as an already opened file-object
         events_list = read_events(events, events.name)
 
-    close_log = False
     if isinstance(log, str):
-        log = open(log, 'rb')
-        close_log = True
+        with open(log, 'rb') as log_fobj:
+            _process(events_list, log_fobj, analyzer, read_header)
+    else:
+        # Treat `log` as an already opened file-object. We will not close it,
+        # as we do not own it.
+        _process(events_list, log, analyzer, read_header)
+
+def _process(events, log_fobj, analyzer, read_header=True):
+    """Internal function for processing
+
+    Args:
+        events (list): list of events already produced by tracetool.read_events
+        log_fobj (file): file-object to read log data from
+        analyzer (Analyzer): the Analyzer to interpret the event data
+        read_header (bool, optional): Whether to read header data from the log data. Defaults to True.
+    """
 
     if read_header:
-        read_trace_header(log)
+        read_trace_header(log_fobj)
 
     def build_fn(analyzer, event):
         if isinstance(event, str):
@@ -231,14 +244,11 @@ def build_fn(analyzer, event):
 
     with analyzer:
         fn_cache = {}
-        for event, event_id, timestamp_ns, record_pid, *rec_args in read_trace_records(events, log, read_header):
+        for event, event_id, timestamp_ns, record_pid, *rec_args in read_trace_records(events, log_fobj, read_header):
             if event_id not in fn_cache:
                 fn_cache[event_id] = build_fn(analyzer, event)
             fn_cache[event_id](event, (event_id, timestamp_ns, record_pid, *rec_args))
 
-    if close_log:
-        log.close()
-
 def run(analyzer):
     """Execute an analyzer on a trace file given on the command-line.
 
-- 
2.41.0

[PULL 11/14] simpletrace: move event processing to Analyzer class

[Stefan Hajnoczi]

From: Mads Ynddal <m.ynddal@samsung.com>

Moved event processing to the Analyzer class to separate specific analyzer
logic (like caching and function signatures) from the _process function.
This allows for new types of Analyzer-based subclasses without changing
the core code.

Note, that the fn_cache is important for performance in cases where the
analyzer is branching away from the catch-all a lot. The cache has no
measurable performance penalty.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Message-id: 20230926103436.25700-12-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 scripts/simpletrace.py | 60 +++++++++++++++++++++++++-----------------
 1 file changed, 36 insertions(+), 24 deletions(-)

diff --git a/scripts/simpletrace.py b/scripts/simpletrace.py
index 6969fdd59a..4136d00600 100755
--- a/scripts/simpletrace.py
+++ b/scripts/simpletrace.py
@@ -169,6 +169,35 @@ def catchall(self, event, rec):
         """Called if no specific method for processing a trace event has been found."""
         pass
 
+    def _build_fn(self, event):
+        fn = getattr(self, event.name, None)
+        if fn is None:
+            # Return early to avoid costly call to inspect.getfullargspec
+            return self.catchall
+
+        event_argcount = len(event.args)
+        fn_argcount = len(inspect.getfullargspec(fn)[0]) - 1
+        if fn_argcount == event_argcount + 1:
+            # Include timestamp as first argument
+            return lambda _, rec: fn(*(rec[1:2] + rec[3:3 + event_argcount]))
+        elif fn_argcount == event_argcount + 2:
+            # Include timestamp and pid
+            return lambda _, rec: fn(*rec[1:3 + event_argcount])
+        else:
+            # Just arguments, no timestamp or pid
+            return lambda _, rec: fn(*rec[3:3 + event_argcount])
+
+    def _process_event(self, rec_args, *, event, event_id, timestamp_ns, pid, **kwargs):
+        if not hasattr(self, '_fn_cache'):
+            # NOTE: Cannot depend on downstream subclasses to have
+            # super().__init__() because of legacy.
+            self._fn_cache = {}
+
+        rec = (event_id, timestamp_ns, pid, *rec_args)
+        if event_id not in self._fn_cache:
+            self._fn_cache[event_id] = self._build_fn(event)
+        self._fn_cache[event_id](event, rec)
+
     def end(self):
         """Called at the end of the trace."""
         pass
@@ -222,32 +251,15 @@ def _process(events, log_fobj, analyzer, read_header=True):
     if read_header:
         read_trace_header(log_fobj)
 
-    def build_fn(analyzer, event):
-        if isinstance(event, str):
-            return analyzer.catchall
-
-        fn = getattr(analyzer, event.name, None)
-        if fn is None:
-            return analyzer.catchall
-
-        event_argcount = len(event.args)
-        fn_argcount = len(inspect.getfullargspec(fn)[0]) - 1
-        if fn_argcount == event_argcount + 1:
-            # Include timestamp as first argument
-            return lambda _, rec: fn(*(rec[1:2] + rec[3:3 + event_argcount]))
-        elif fn_argcount == event_argcount + 2:
-            # Include timestamp and pid
-            return lambda _, rec: fn(*rec[1:3 + event_argcount])
-        else:
-            # Just arguments, no timestamp or pid
-            return lambda _, rec: fn(*rec[3:3 + event_argcount])
-
     with analyzer:
-        fn_cache = {}
         for event, event_id, timestamp_ns, record_pid, *rec_args in read_trace_records(events, log_fobj, read_header):
-            if event_id not in fn_cache:
-                fn_cache[event_id] = build_fn(analyzer, event)
-            fn_cache[event_id](event, (event_id, timestamp_ns, record_pid, *rec_args))
+            analyzer._process_event(
+                rec_args,
+                event=event,
+                event_id=event_id,
+                timestamp_ns=timestamp_ns,
+                pid=record_pid,
+            )
 
 def run(analyzer):
     """Execute an analyzer on a trace file given on the command-line.
-- 
2.41.0

[PULL 12/14] simpletrace: added simplified Analyzer2 class

[Stefan Hajnoczi]

From: Mads Ynddal <m.ynddal@samsung.com>

By moving the dynamic argument construction to keyword-arguments,
we can remove all of the specialized handling, and streamline it.
If a tracing method wants to access these, they can define the
kwargs, or ignore it be placing `**kwargs` at the end of the
function's arguments list.

Added deprecation warning to Analyzer class to make users aware
of the Analyzer2 class. No removal date is planned.

Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Message-id: 20230926103436.25700-13-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 scripts/simpletrace.py | 94 ++++++++++++++++++++++++++++++++----------
 1 file changed, 73 insertions(+), 21 deletions(-)

diff --git a/scripts/simpletrace.py b/scripts/simpletrace.py
index 4136d00600..cef81b0707 100755
--- a/scripts/simpletrace.py
+++ b/scripts/simpletrace.py
@@ -12,10 +12,11 @@
 import sys
 import struct
 import inspect
+import warnings
 from tracetool import read_events, Event
 from tracetool.backend.simple import is_string
 
-__all__ = ['Analyzer', 'process', 'run']
+__all__ = ['Analyzer', 'Analyzer2', 'process', 'run']
 
 # This is the binary format that the QEMU "simple" trace backend
 # emits. There is no specification documentation because the format is
@@ -130,7 +131,9 @@ def read_trace_records(events, fobj, read_header):
             yield (event_mapping[event_name], event_name, timestamp_ns, pid) + tuple(args)
 
 class Analyzer:
-    """A trace file analyzer which processes trace records.
+    """[Deprecated. Refer to Analyzer2 instead.]
+
+    A trace file analyzer which processes trace records.
 
     An analyzer can be passed to run() or process().  The begin() method is
     invoked, then each trace record is processed, and finally the end() method
@@ -188,6 +191,11 @@ def _build_fn(self, event):
             return lambda _, rec: fn(*rec[3:3 + event_argcount])
 
     def _process_event(self, rec_args, *, event, event_id, timestamp_ns, pid, **kwargs):
+        warnings.warn(
+            "Use of deprecated Analyzer class. Refer to Analyzer2 instead.",
+            DeprecationWarning,
+        )
+
         if not hasattr(self, '_fn_cache'):
             # NOTE: Cannot depend on downstream subclasses to have
             # super().__init__() because of legacy.
@@ -211,6 +219,56 @@ def __exit__(self, exc_type, exc_val, exc_tb):
             self.end()
         return False
 
+class Analyzer2(Analyzer):
+    """A trace file analyzer which processes trace records.
+
+    An analyzer can be passed to run() or process().  The begin() method is
+    invoked, then each trace record is processed, and finally the end() method
+    is invoked. When Analyzer is used as a context-manager (using the `with`
+    statement), begin() and end() are called automatically.
+
+    If a method matching a trace event name exists, it is invoked to process
+    that trace record.  Otherwise the catchall() method is invoked.
+
+    The methods are called with a set of keyword-arguments. These can be ignored
+    using `**kwargs` or defined like any keyword-argument.
+
+    The following keyword-arguments are available, but make sure to have an
+    **kwargs to allow for unmatched arguments in the future:
+        event: Event object of current trace
+        event_id: The id of the event in the current trace file
+        timestamp_ns: The timestamp in nanoseconds of the trace
+        pid: The process id recorded for the given trace
+
+    Example:
+    The following method handles the runstate_set(int new_state) trace event::
+
+      def runstate_set(self, new_state, **kwargs):
+          ...
+
+    The method can also explicitly take a timestamp keyword-argument with the
+    trace event arguments::
+
+      def runstate_set(self, new_state, *, timestamp_ns, **kwargs):
+          ...
+
+    Timestamps have the uint64_t type and are in nanoseconds.
+
+    The pid can be included in addition to the timestamp and is useful when
+    dealing with traces from multiple processes:
+
+      def runstate_set(self, new_state, *, timestamp_ns, pid, **kwargs):
+          ...
+    """
+
+    def catchall(self, *rec_args, event, timestamp_ns, pid, event_id, **kwargs):
+        """Called if no specific method for processing a trace event has been found."""
+        pass
+
+    def _process_event(self, rec_args, *, event, **kwargs):
+        fn = getattr(self, event.name, self.catchall)
+        fn(*rec_args, event=event, **kwargs)
+
 def process(events, log, analyzer, read_header=True):
     """Invoke an analyzer on each event in a log.
     Args:
@@ -278,30 +336,24 @@ def run(analyzer):
         process(events_fobj, log_fobj, analyzer, read_header=not no_header)
 
 if __name__ == '__main__':
-    class Formatter(Analyzer):
+    class Formatter2(Analyzer2):
         def __init__(self):
-            self.last_timestamp = None
+            self.last_timestamp_ns = None
 
-        def catchall(self, event, rec):
-            timestamp = rec[1]
-            if self.last_timestamp is None:
-                self.last_timestamp = timestamp
-            delta_ns = timestamp - self.last_timestamp
-            self.last_timestamp = timestamp
+        def catchall(self, *rec_args, event, timestamp_ns, pid, event_id):
+            if self.last_timestamp_ns is None:
+                self.last_timestamp_ns = timestamp_ns
+            delta_ns = timestamp_ns - self.last_timestamp_ns
+            self.last_timestamp_ns = timestamp_ns
 
-            fields = [event.name, '%0.3f' % (delta_ns / 1000.0),
-                      'pid=%d' % rec[2]]
-            i = 3
-            for type, name in event.args:
-                if is_string(type):
-                    fields.append('%s=%s' % (name, rec[i]))
-                else:
-                    fields.append('%s=0x%x' % (name, rec[i]))
-                i += 1
-            print(' '.join(fields))
+            fields = [
+                f'{name}={r}' if is_string(type) else f'{name}=0x{r:x}'
+                for r, (type, name) in zip(rec_args, event.args)
+            ]
+            print(f'{event.name} {delta_ns / 1000:0.3f} {pid=} ' + ' '.join(fields))
 
     try:
-        run(Formatter())
+        run(Formatter2())
     except SimpleException as e:
         sys.stderr.write(str(e) + "\n")
         sys.exit(1)
-- 
2.41.0

[PULL 13/14] MAINTAINERS: add maintainer of simpletrace.py

[Stefan Hajnoczi]

From: Mads Ynddal <m.ynddal@samsung.com>

In my work to refactor simpletrace.py, I noticed that there's no
maintainer of it, and has the status of "odd fixes". I'm using it from
time to time, so I'd like to maintain the script.

I've added myself as reviewer under "Tracing" to be informed of changes
that might affect simpletrace.py.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Message-id: 20230926103436.25700-14-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 MAINTAINERS | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 355b1960ce..81625f036b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3170,6 +3170,7 @@ F: stubs/
 
 Tracing
 M: Stefan Hajnoczi <stefanha@redhat.com>
+R: Mads Ynddal <mads@ynddal.dk>
 S: Maintained
 F: trace/
 F: trace-events
@@ -3182,6 +3183,11 @@ F: docs/tools/qemu-trace-stap.rst
 F: docs/devel/tracing.rst
 T: git https://github.com/stefanha/qemu.git tracing
 
+Simpletrace
+M: Mads Ynddal <mads@ynddal.dk>
+S: Maintained
+F: scripts/simpletrace.py
+
 TPM
 M: Stefan Berger <stefanb@linux.ibm.com>
 S: Maintained
-- 
2.41.0

[PULL 14/14] scripts/analyse-locks-simpletrace.py: changed iteritems() to items()

[Stefan Hajnoczi]

From: Mads Ynddal <m.ynddal@samsung.com>

Python 3 removed `dict.iteritems()` in favor of `dict.items()`. This
means the script currently doesn't work on Python 3.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Message-id: 20230926103436.25700-15-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 scripts/analyse-locks-simpletrace.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/analyse-locks-simpletrace.py b/scripts/analyse-locks-simpletrace.py
index 63c11f4fce..d650dd7140 100755
--- a/scripts/analyse-locks-simpletrace.py
+++ b/scripts/analyse-locks-simpletrace.py
@@ -75,7 +75,7 @@ def get_args():
            (analyser.locks, analyser.locked, analyser.unlocks))
 
     # Now dump the individual lock stats
-    for key, val in sorted(analyser.mutex_records.iteritems(),
+    for key, val in sorted(analyser.mutex_records.items(),
                            key=lambda k_v: k_v[1]["locks"]):
         print ("Lock: %#x locks: %d, locked: %d, unlocked: %d" %
                (key, val["locks"], val["locked"], val["unlocked"]))
-- 
2.41.0

Re: [PULL 00/14] Tracing patches

[Stefan Hajnoczi]

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Applied, thanks.

Please update the changelog at https://wiki.qemu.org/ChangeLog/8.2 for any user-visible changes.

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