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authorStefan Hajnoczi <stefanha@redhat.com>2017-07-31 15:07:17 +0100
committerStefan Hajnoczi <stefanha@redhat.com>2017-08-01 12:07:48 +0100
commit3932ef3ffb54baf22ab05767e827bda1834d20df (patch)
tree69fc2ecf7b7c05e98a5677c132b34d40ef1e5503 /scripts/tracetool/backend
parentea1ff54f7d2d7ac32be3c54bd171481bc2354721 (diff)
trace: add TRACE_<event>_BACKEND_DSTATE()
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, the other backends rely on QEMU dstate. 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. [Daniel Berrange pointed out that QEMU_MY_EVENT_ENABLED() must be true by default, not false. This way events will fire even if the DTrace implementation does not implement the SystemTap semaphores feature. Ubuntu Precise uses lttng-ust-dev 2.0.2 which does not have tracepoint_enabled(), so we need a compatibility wrapper to keep Travis builds passing. --Stefan] Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 20170731140718.22010-2-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> fixup! trace: add TRACE_<event>_BACKEND_DSTATE()
Diffstat (limited to 'scripts/tracetool/backend')
-rw-r--r--scripts/tracetool/backend/__init__.py3
-rw-r--r--scripts/tracetool/backend/dtrace.py12
-rw-r--r--scripts/tracetool/backend/ftrace.py5
-rw-r--r--scripts/tracetool/backend/log.py5
-rw-r--r--scripts/tracetool/backend/simple.py5
-rw-r--r--scripts/tracetool/backend/syslog.py5
-rw-r--r--scripts/tracetool/backend/ust.py10
7 files changed, 45 insertions, 0 deletions
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..c2f3a4e5a8 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() true',
+ '#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/ftrace.py b/scripts/tracetool/backend/ftrace.py
index dd0eda4441..92f71b28f9 100644
--- a/scripts/tracetool/backend/ftrace.py
+++ b/scripts/tracetool/backend/ftrace.py
@@ -45,3 +45,8 @@ def generate_h(event, group):
event_id="TRACE_" + event.name.upper(),
fmt=event.fmt.rstrip("\n"),
argnames=argnames)
+
+
+def generate_h_backend_dstate(event, group):
+ out(' trace_event_get_state_dynamic_by_id(%(event_id)s) || \\',
+ event_id="TRACE_" + event.name.upper())
diff --git a/scripts/tracetool/backend/log.py b/scripts/tracetool/backend/log.py
index 54f0a69886..da86f6b882 100644
--- a/scripts/tracetool/backend/log.py
+++ b/scripts/tracetool/backend/log.py
@@ -48,3 +48,8 @@ def generate_h(event, group):
name=event.name,
fmt=event.fmt.rstrip("\n"),
argnames=argnames)
+
+
+def generate_h_backend_dstate(event, group):
+ out(' trace_event_get_state_dynamic_by_id(%(event_id)s) || \\',
+ event_id="TRACE_" + event.name.upper())
diff --git a/scripts/tracetool/backend/simple.py b/scripts/tracetool/backend/simple.py
index f983670ee1..c2fd1c24c4 100644
--- a/scripts/tracetool/backend/simple.py
+++ b/scripts/tracetool/backend/simple.py
@@ -42,6 +42,11 @@ def generate_h(event, group):
args=", ".join(event.args.names()))
+def generate_h_backend_dstate(event, group):
+ out(' trace_event_get_state_dynamic_by_id(%(event_id)s) || \\',
+ event_id="TRACE_" + event.name.upper())
+
+
def generate_c_begin(events, group):
out('#include "qemu/osdep.h"',
'#include "trace/control.h"',
diff --git a/scripts/tracetool/backend/syslog.py b/scripts/tracetool/backend/syslog.py
index 1ce627f0fc..668fb73fee 100644
--- a/scripts/tracetool/backend/syslog.py
+++ b/scripts/tracetool/backend/syslog.py
@@ -42,3 +42,8 @@ def generate_h(event, group):
name=event.name,
fmt=event.fmt.rstrip("\n"),
argnames=argnames)
+
+
+def generate_h_backend_dstate(event, group):
+ out(' trace_event_get_state_dynamic_by_id(%(event_id)s) || \\',
+ event_id="TRACE_" + event.name.upper())
diff --git a/scripts/tracetool/backend/ust.py b/scripts/tracetool/backend/ust.py
index 2adaf548d5..280cb7c106 100644
--- a/scripts/tracetool/backend/ust.py
+++ b/scripts/tracetool/backend/ust.py
@@ -27,6 +27,11 @@ def generate_h_begin(events, group):
out('#include <lttng/tracepoint.h>',
'#include "%s"' % header,
+ '',
+ '/* tracepoint_enabled() was introduced in LTTng UST 2.7 */',
+ '#ifndef tracepoint_enabled',
+ '#define tracepoint_enabled(a, b) true',
+ '#endif',
'')
@@ -38,3 +43,8 @@ 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)