QEMU keeps track of trace event enabled/disabled state and provides
monitor commands to inspect and modify the "dstate". SystemTap and
LTTng UST maintain independent enabled/disabled states for each trace
event.
Introduce a new per-event macro that combines backend-specific dstate
like this:
#define TRACE_MY_EVENT_BACKEND_DSTATE() ( \
QEMU_MY_EVENT_ENABLED() || /* SystemTap */ \
tracepoint_enabled(qemu, my_event) /* LTTng UST */ || \
false)
This will be used to extend trace_event_get_state() in the next patch.
Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
---
scripts/tracetool/__init__.py | 1 +
scripts/tracetool/backend/__init__.py | 3 +++
scripts/tracetool/backend/dtrace.py | 12 ++++++++++++
scripts/tracetool/backend/ust.py | 5 +++++
scripts/tracetool/format/h.py | 10 ++++++++++
5 files changed, 31 insertions(+)
diff --git a/scripts/tracetool/__init__.py b/scripts/tracetool/__init__.py
index d4c204a472..0670ec17d5 100644
--- a/scripts/tracetool/__init__.py
+++ b/scripts/tracetool/__init__.py
@@ -271,6 +271,7 @@ class Event(object):
QEMU_TRACE_NOCHECK = "_nocheck__" + QEMU_TRACE
QEMU_TRACE_TCG = QEMU_TRACE + "_tcg"
QEMU_DSTATE = "_TRACE_%(NAME)s_DSTATE"
+ QEMU_BACKEND_DSTATE = "TRACE_%(NAME)s_BACKEND_DSTATE"
QEMU_EVENT = "_TRACE_%(NAME)s_EVENT"
def api(self, fmt=None):
diff --git a/scripts/tracetool/backend/__init__.py
b/scripts/tracetool/backend/__init__.py
index f735a259c0..259c6a6531 100644
--- a/scripts/tracetool/backend/__init__.py
+++ b/scripts/tracetool/backend/__init__.py
@@ -119,5 +119,8 @@ class Wrapper:
def generate(self, event, group):
self._run_function("generate_%s", event, group)
+ def generate_backend_dstate(self, event, group):
+ self._run_function("generate_%s_backend_dstate", event, group)
+
def generate_end(self, events, group):
self._run_function("generate_%s_end", events, group)
diff --git a/scripts/tracetool/backend/dtrace.py
b/scripts/tracetool/backend/dtrace.py
index c6812b70a2..17f902cc62 100644
--- a/scripts/tracetool/backend/dtrace.py
+++ b/scripts/tracetool/backend/dtrace.py
@@ -44,8 +44,20 @@ def generate_h_begin(events, group):
out('#include "%s"' % header,
'')
+ # SystemTap defines <provider>_<name>_ENABLED() but other DTrace
+ # implementations might not.
+ for e in events:
+ out('#ifndef QEMU_%(uppername)s_ENABLED',
+ '#define QEMU_%(uppername)s_ENABLED() false',
+ '#endif',
+ uppername=e.name.upper())
def generate_h(event, group):
out(' QEMU_%(uppername)s(%(argnames)s);',
uppername=event.name.upper(),
argnames=", ".join(event.args.names()))
+
+
+def generate_h_backend_dstate(event, group):
+ out(' QEMU_%(uppername)s_ENABLED() || \\',
+ uppername=event.name.upper())
diff --git a/scripts/tracetool/backend/ust.py b/scripts/tracetool/backend/ust.py
index 2adaf548d5..412592b8e0 100644
--- a/scripts/tracetool/backend/ust.py
+++ b/scripts/tracetool/backend/ust.py
@@ -38,3 +38,8 @@ def generate_h(event, group):
out(' tracepoint(qemu, %(name)s%(tp_args)s);',
name=event.name,
tp_args=argnames)
+
+
+def generate_h_backend_dstate(event, group):
+ out(' tracepoint_enabled(qemu, %(name)s) || \\',
+ name=event.name)
diff --git a/scripts/tracetool/format/h.py b/scripts/tracetool/format/h.py
index aecf249d66..e06f0f27c5 100644
--- a/scripts/tracetool/format/h.py
+++ b/scripts/tracetool/format/h.py
@@ -49,6 +49,16 @@ def generate(events, backend, group):
backend.generate_begin(events, group)
for e in events:
+ # tracer-specific dstate
+ out('',
+ '#define %(api)s() ( \\',
+ api=e.api(e.QEMU_BACKEND_DSTATE))
+
+ if "disable" not in e.properties:
+ backend.generate_backend_dstate(e, group)
+
+ out(' false)')
+
# tracer without checks
out('',
'static inline void %(api)s(%(args)s)',
--
2.13.3
