* [Qemu-devel] [PATCH 1/2] trace: count number of enabled events
2015-10-28 6:06 [Qemu-devel] [PATCH for-2.5 0/2] trace: decrease overhead of simpletrace and stderr backends Paolo Bonzini
@ 2015-10-28 6:06 ` Paolo Bonzini
2015-10-28 6:06 ` [Qemu-devel] [PATCH 2/2] trace: track enabled events in a separate array Paolo Bonzini
2015-10-28 14:44 ` [Qemu-devel] [PATCH for-2.5 0/2] trace: decrease overhead of simpletrace and stderr backends Stefan Hajnoczi
2 siblings, 0 replies; 4+ messages in thread
From: Paolo Bonzini @ 2015-10-28 6:06 UTC (permalink / raw)
To: qemu-devel; +Cc: stefanha
This lets trace_event_get_state_dynamic quickly return false. Right
now there is hardly any benefit because there are also many assertions
and indirections, but the next patch will streamline all of this.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
trace/control-internal.h | 4 +++-
trace/control.c | 2 ++
2 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/trace/control-internal.h b/trace/control-internal.h
index 5a8df28..271bddb 100644
--- a/trace/control-internal.h
+++ b/trace/control-internal.h
@@ -14,6 +14,7 @@
extern TraceEvent trace_events[];
+extern int trace_events_enabled_count;
static inline TraceEventID trace_event_count(void)
@@ -54,13 +55,14 @@ static inline bool trace_event_get_state_static(TraceEvent *ev)
static inline bool trace_event_get_state_dynamic(TraceEvent *ev)
{
assert(ev != NULL);
- return ev->dstate;
+ return unlikely(trace_events_enabled_count) && ev->dstate;
}
static inline void trace_event_set_state_dynamic(TraceEvent *ev, bool state)
{
assert(ev != NULL);
assert(trace_event_get_state_static(ev));
+ trace_events_enabled_count += state - ev->dstate;
ev->dstate = state;
}
diff --git a/trace/control.c b/trace/control.c
index 995beb3..95fbc07 100644
--- a/trace/control.c
+++ b/trace/control.c
@@ -16,6 +16,8 @@
#endif
#include "qemu/error-report.h"
+int trace_events_enabled_count;
+
TraceEvent *trace_event_name(const char *name)
{
assert(name != NULL);
--
2.5.0
^ permalink raw reply related [flat|nested] 4+ messages in thread* [Qemu-devel] [PATCH 2/2] trace: track enabled events in a separate array
2015-10-28 6:06 [Qemu-devel] [PATCH for-2.5 0/2] trace: decrease overhead of simpletrace and stderr backends Paolo Bonzini
2015-10-28 6:06 ` [Qemu-devel] [PATCH 1/2] trace: count number of enabled events Paolo Bonzini
@ 2015-10-28 6:06 ` Paolo Bonzini
2015-10-28 14:44 ` [Qemu-devel] [PATCH for-2.5 0/2] trace: decrease overhead of simpletrace and stderr backends Stefan Hajnoczi
2 siblings, 0 replies; 4+ messages in thread
From: Paolo Bonzini @ 2015-10-28 6:06 UTC (permalink / raw)
To: qemu-devel; +Cc: stefanha
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>
---
scripts/tracetool/format/events_c.py | 2 +-
trace/control-internal.h | 15 +++++++++++----
trace/control.c | 1 +
trace/control.h | 2 +-
trace/event-internal.h | 2 --
5 files changed, 14 insertions(+), 8 deletions(-)
diff --git a/scripts/tracetool/format/events_c.py b/scripts/tracetool/format/events_c.py
index 2d97fa3..2717ea3 100644
--- a/scripts/tracetool/format/events_c.py
+++ b/scripts/tracetool/format/events_c.py
@@ -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())
diff --git a/trace/control-internal.h b/trace/control-internal.h
index 271bddb..07cb1c1 100644
--- a/trace/control-internal.h
+++ b/trace/control-internal.h
@@ -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 */
diff --git a/trace/control.c b/trace/control.c
index 95fbc07..700440c 100644
--- a/trace/control.c
+++ b/trace/control.c
@@ -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)
{
diff --git a/trace/control.h b/trace/control.h
index da9bb6b..6af7ddc 100644
--- a/trace/control.h
+++ b/trace/control.h
@@ -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:
diff --git a/trace/event-internal.h b/trace/event-internal.h
index b2310d9..86f6a51 100644
--- a/trace/event-internal.h
+++ b/trace/event-internal.h
@@ -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;
--
2.5.0
^ permalink raw reply related [flat|nested] 4+ messages in thread