trace: track enabled events in a separate array

This is more cache friendly on the fast path, where we already have
the event id available.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Paolo Bonzini 2015-10-28 07:06:27 +01:00 committed by Stefan Hajnoczi
parent 43b48cfc3e
commit 585ec7273e
5 changed files with 14 additions and 8 deletions

View file

@ -27,7 +27,7 @@ def generate(events, backend):
out('TraceEvent trace_events[TRACE_EVENT_COUNT] = {')
for e in events:
out(' { .id = %(id)s, .name = \"%(name)s\", .sstate = %(sstate)s, .dstate = 0 },',
out(' { .id = %(id)s, .name = \"%(name)s\", .sstate = %(sstate)s },',
id = "TRACE_" + e.name.upper(),
name = e.name,
sstate = "TRACE_%s_ENABLED" % e.name.upper())

View file

@ -14,6 +14,7 @@
extern TraceEvent trace_events[];
extern bool trace_events_dstate[];
extern int trace_events_enabled_count;
@ -52,18 +53,24 @@ static inline bool trace_event_get_state_static(TraceEvent *ev)
return ev->sstate;
}
static inline bool trace_event_get_state_dynamic_by_id(int id)
{
return unlikely(trace_events_enabled_count) && trace_events_dstate[id];
}
static inline bool trace_event_get_state_dynamic(TraceEvent *ev)
{
assert(ev != NULL);
return unlikely(trace_events_enabled_count) && ev->dstate;
int id = trace_event_get_id(ev);
return trace_event_get_state_dynamic_by_id(id);
}
static inline void trace_event_set_state_dynamic(TraceEvent *ev, bool state)
{
int id = trace_event_get_id(ev);
assert(ev != NULL);
assert(trace_event_get_state_static(ev));
trace_events_enabled_count += state - ev->dstate;
ev->dstate = state;
trace_events_enabled_count += state - trace_events_dstate[id];
trace_events_dstate[id] = state;
}
#endif /* TRACE__CONTROL_INTERNAL_H */

View file

@ -17,6 +17,7 @@
#include "qemu/error-report.h"
int trace_events_enabled_count;
bool trace_events_dstate[TRACE_EVENT_COUNT];
TraceEvent *trace_event_name(const char *name)
{

View file

@ -104,7 +104,7 @@ static const char * trace_event_get_name(TraceEvent *ev);
* As a down side, you must always use an immediate #TraceEventID value.
*/
#define trace_event_get_state(id) \
((id ##_ENABLED) && trace_event_get_state_dynamic(trace_event_id(id)))
((id ##_ENABLED) && trace_event_get_state_dynamic_by_id(id))
/**
* trace_event_get_state_static:

View file

@ -18,7 +18,6 @@
* @id: Unique event identifier.
* @name: Event name.
* @sstate: Static tracing state.
* @dstate: Dynamic tracing state.
*
* Opaque generic description of a tracing event.
*/
@ -26,7 +25,6 @@ typedef struct TraceEvent {
TraceEventID id;
const char * name;
const bool sstate;
bool dstate;
} TraceEvent;