From ae603c6d842f7e7f1529f040ca463be2f2edd4c8 Mon Sep 17 00:00:00 2001
From: Stefan Hajnoczi <stefanha@redhat.com>
Date: Tue, 7 Oct 2014 14:06:53 +0200
Subject: [PATCH 35/43] simpletrace: add simpletrace.py --no-header option
Message-id: <1412690820-31016-5-git-send-email-stefanha@redhat.com>
Patchwork-id: 61609
O-Subject: [RHEL7.1 qemu-kvm PATCH 04/11] simpletrace: add simpletrace.py --no-header option
Bugzilla: 1088112
RH-Acked-by: Laszlo Ersek <lersek@redhat.com>
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
It can be useful to read simpletrace files that have no header. For
example, a ring buffer may not have a header record but can still be
processed if the user is sure the file format version is compatible.
$ scripts/simpletrace.py --no-header trace-events trace-file
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
(cherry picked from commit 15327c3df049c9621ff9b542ccbfc3d17203d1f7)
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
Conflicts:
scripts/simpletrace.py
Context conflict because upstream doesn't have enabled_events[].
---
scripts/simpletrace.py | 25 ++++++++++++++++++-------
1 file changed, 18 insertions(+), 7 deletions(-)
diff --git a/scripts/simpletrace.py b/scripts/simpletrace.py
index 682ec66..b931dd2 100755
--- a/scripts/simpletrace.py
+++ b/scripts/simpletrace.py
@@ -59,8 +59,8 @@ def read_record(edict, fobj):
rechdr = read_header(fobj, rec_header_fmt)
return get_record(edict, rechdr, fobj) # return tuple of record elements
-def read_trace_file(edict, fobj):
- """Deserialize trace records from a file, yielding record tuples (event_num, timestamp, pid, arg1, ..., arg6)."""
+def read_trace_header(fobj):
+ """Read and verify trace file header"""
header = read_header(fobj, log_header_fmt)
if header is None or \
header[0] != header_event_id or \
@@ -74,6 +74,8 @@ def read_trace_file(edict, fobj):
raise ValueError('Log format %d not supported with this QEMU release!'
% log_version)
+def read_trace_records(edict, fobj):
+ """Deserialize trace records from a file, yielding record tuples (event_num, timestamp, pid, arg1, ..., arg6)."""
while True:
rec = read_record(edict, fobj)
if rec is None:
@@ -103,7 +105,7 @@ class Analyzer(object):
"""Called at the end of the trace."""
pass
-def process(events, log, analyzer):
+def process(events, log, analyzer, read_header=True):
"""Invoke an analyzer on each event in a log."""
if isinstance(events, str):
events = _read_events(open(events, 'r'))
@@ -111,6 +113,10 @@ def process(events, log, analyzer):
log = open(log, 'rb')
enabled_events = []
+
+ if read_header:
+ read_trace_header(log)
+
dropped_event = Event.build("Dropped_Event(uint64_t num_events_dropped)")
edict = {dropped_event_id: dropped_event}
@@ -142,7 +148,7 @@ def process(events, log, analyzer):
analyzer.begin()
fn_cache = {}
- for rec in read_trace_file(edict, log):
+ for rec in read_trace_records(edict, log):
event_num = rec[0]
event = edict[event_num]
if event_num not in fn_cache:
@@ -157,12 +163,17 @@ def run(analyzer):
advanced scripts will want to call process() instead."""
import sys
- if len(sys.argv) != 3:
- sys.stderr.write('usage: %s <trace-events> <trace-file>\n' % sys.argv[0])
+ 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])
sys.exit(1)
events = _read_events(open(sys.argv[1], 'r'))
- process(events, sys.argv[2], analyzer)
+ process(events, sys.argv[2], analyzer, read_header=read_header)
if __name__ == '__main__':
class Formatter(Analyzer):
--
1.8.3.1