From b473bbbbddd782edbe212b16fb839ec4a2e03bbd Mon Sep 17 00:00:00 2001
From: Stefan Hajnoczi <stefanha@redhat.com>
Date: Wed, 16 Aug 2017 11:47:58 +0200
Subject: [PATCH 1/4] trace: use static event ID mapping in simpletrace.stp
RH-Author: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: <20170816114759.8421-2-stefanha@redhat.com>
Patchwork-id: 75954
O-Subject: [RHV-7.4.z qemu-kvm-rhev PATCH 1/2] trace: use static event ID mapping in simpletrace.stp
Bugzilla: 1482515
RH-Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
RH-Acked-by: Markus Armbruster <armbru@redhat.com>
RH-Acked-by: John Snow <jsnow@redhat.com>
This is a partial revert of commit
7f1b588f20d027730676e627713ae3bbf6baab04 ("trace: emit name <-> ID
mapping in simpletrace header"), which broke the SystemTap flight
recorder because event mapping records may not be present in the ring
buffer when the trace is analyzed. This means simpletrace.py
--no-header does not know the event ID mapping needed to pretty-print
the trace.
Instead of numbering events dynamically, use a static event ID mapping
as dictated by the event order in the trace-events-all file.
The simpletrace.py script also uses trace-events-all so the next patch
will fix the simpletrace.py --no-header option to take advantage of this
knowledge.
Cc: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170815084430.7128-2-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
(cherry picked from commit d6b76d68054b81943648ab0af2f9634ae946854b)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
Conflicts:
scripts/tracetool/format/simpletrace_stap.py
Context conflicts because downstream lacks commit ea1ff54f7d ("trace:
ensure unique function / variable names per .stp file"). Do not
backport that commit because it is obsoleted by this patch.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
scripts/tracetool/format/simpletrace_stap.py | 22 +---------------------
1 file changed, 1 insertion(+), 21 deletions(-)
diff --git a/scripts/tracetool/format/simpletrace_stap.py b/scripts/tracetool/format/simpletrace_stap.py
index c35e662..6172ad0 100644
--- a/scripts/tracetool/format/simpletrace_stap.py
+++ b/scripts/tracetool/format/simpletrace_stap.py
@@ -21,25 +21,6 @@ from tracetool.format.stap import stap_escape
def generate(events, backend, group):
out('/* This file is autogenerated by tracetool, do not edit. */',
- '',
- 'global event_name_to_id_map',
- 'global event_next_id',
- 'function simple_trace_map_event(name)',
- '',
- '{',
- ' if (!([name] in event_name_to_id_map)) {',
- ' event_name_to_id_map[name] = event_next_id',
- ' name_len = strlen(name)',
- ' printf("%%8b%%8b%%4b%%.*s", 0, ',
- ' event_next_id, name_len, name_len, name)',
- ' event_next_id = event_next_id + 1',
- ' }',
- ' return event_name_to_id_map[name]',
- '}',
- 'probe begin',
- '{',
- ' printf("%%8b%%8b%%8b", 0xffffffffffffffff, 0xf2b177cb0aa429b4, 4)',
- '}',
'')
for event_id, e in enumerate(events):
@@ -48,7 +29,6 @@ def generate(events, backend, group):
out('probe %(probeprefix)s.simpletrace.%(name)s = %(probeprefix)s.%(name)s ?',
'{',
- ' id = simple_trace_map_event("%(name)s")',
probeprefix=probeprefix(),
name=e.name)
@@ -68,7 +48,7 @@ def generate(events, backend, group):
sizestr = ' + '.join(sizes)
# Generate format string and value pairs for record header and arguments
- fields = [('8b', 'id'),
+ fields = [('8b', str(event_id)),
('8b', 'gettimeofday_ns()'),
('4b', sizestr),
('4b', 'pid()')]
--
1.8.3.1