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| author | Stefan Hajnoczi <stefanha@redhat.com> | 2017-07-31 15:07:17 +0100 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2017-08-01 12:07:48 +0100 |
| commit | 3932ef3ffb54baf22ab05767e827bda1834d20df (patch) | |
| tree | 69fc2ecf7b7c05e98a5677c132b34d40ef1e5503 /scripts/tracetool/__init__.py | |
| parent | ea1ff54f7d2d7ac32be3c54bd171481bc2354721 (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/__init__.py')
| -rw-r--r-- | scripts/tracetool/__init__.py | 1 |
1 files changed, 1 insertions, 0 deletions
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): |