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author | Stefan Hajnoczi <stefanha@redhat.com> | 2017-07-31 15:07:18 +0100 |
---|---|---|
committer | Stefan Hajnoczi <stefanha@redhat.com> | 2017-08-01 12:13:07 +0100 |
commit | d87aa138039a4be6d705793fd3e397c69c52405a (patch) | |
tree | f0880c8b8daf9469aa4df2c93b256d3f044898ce /trace | |
parent | 3932ef3ffb54baf22ab05767e827bda1834d20df (diff) | |
download | qemu-d87aa138039a4be6d705793fd3e397c69c52405a.zip qemu-d87aa138039a4be6d705793fd3e397c69c52405a.tar.gz qemu-d87aa138039a4be6d705793fd3e397c69c52405a.tar.bz2 |
trace: add trace_event_get_state_backends()
Code that checks dstate is unaware of SystemTap and LTTng UST dstate, so
the following trace event will not fire when solely enabled by SystemTap
or LTTng UST:
if (trace_event_get_state(TRACE_MY_EVENT)) {
str = g_strdup_printf("Expensive string to generate ...",
...);
trace_my_event(str);
g_free(str);
}
Add trace_event_get_state_backends() to fetch backend dstate. Those
backends that use QEMU dstate fetch it as part of
generate_h_backend_dstate().
Update existing trace_event_get_state() callers to use
trace_event_get_state_backends() instead.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20170731140718.22010-3-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'trace')
-rw-r--r-- | trace/control.h | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/trace/control.h b/trace/control.h index b931824..1903e22 100644 --- a/trace/control.h +++ b/trace/control.h @@ -96,7 +96,7 @@ static const char * trace_event_get_name(TraceEvent *ev); * trace_event_get_state: * @id: Event identifier name. * - * Get the tracing state of an event (both static and dynamic). + * Get the tracing state of an event, both static and the QEMU dynamic state. * * If the event has the disabled property, the check will have no performance * impact. @@ -105,6 +105,22 @@ static const char * trace_event_get_name(TraceEvent *ev); ((id ##_ENABLED) && trace_event_get_state_dynamic_by_id(id)) /** + * trace_event_get_state_backends: + * @id: Event identifier name. + * + * Get the tracing state of an event, both static and dynamic state from all + * compiled-in backends. + * + * If the event has the disabled property, the check will have no performance + * impact. + * + * Returns: true if at least one backend has the event enabled and the event + * does not have the disabled property. + */ +#define trace_event_get_state_backends(id) \ + ((id ##_ENABLED) && id ##_BACKEND_DSTATE()) + +/** * trace_event_get_vcpu_state: * @vcpu: Target vCPU. * @id: Event identifier name. |