From 16b8dbedfa8b0d701b7f7b9900190fa6375c2bd3 Mon Sep 17 00:00:00 2001
From: Derek Foreman <derek.foreman@collabora.com>
Date: Fri, 5 Apr 2024 07:24:57 -0500
Subject: [PATCH] perfetto: Add flows

Perfetto can assign flow ids to events, which can be used to connect
related events in tracks when they share the same id.

Signed-off-by: Derek Foreman <derek.foreman@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/28634>
---
 src/util/perf/cpu_trace.h   | 26 ++++++++++++++++++++++++++
 src/util/perf/u_perfetto.cc | 16 ++++++++++++++++
 src/util/perf/u_perfetto.h  | 13 +++++++++++++
 3 files changed, 55 insertions(+)

diff --git a/src/util/perf/cpu_trace.h b/src/util/perf/cpu_trace.h
index 75db0f7badd..72106e8fb6d 100644
--- a/src/util/perf/cpu_trace.h
+++ b/src/util/perf/cpu_trace.h
@@ -23,6 +23,12 @@
          util_perfetto_trace_begin(name);                                    \
    } while (0)
 
+#define _MESA_TRACE_FLOW_BEGIN(name, id)                                     \
+   do {                                                                      \
+      if (unlikely(util_perfetto_is_tracing_enabled()))                      \
+         util_perfetto_trace_begin_flow(name, id);                           \
+   } while (0)
+
 #define _MESA_TRACE_END()                                                    \
    do {                                                                      \
       if (unlikely(util_perfetto_is_tracing_enabled()))                      \
@@ -41,11 +47,14 @@
 #define _MESA_TRACE_BEGIN(name)                                              \
    atrace_begin(ATRACE_TAG_GRAPHICS, name)
 #define _MESA_TRACE_END() atrace_end(ATRACE_TAG_GRAPHICS)
+#define _MESA_TRACE_FLOW_BEGIN(name, id)                                     \
+   atrace_begin(ATRACE_TAG_GRAPHICS, name)
 
 #else
 
 #define _MESA_TRACE_BEGIN(name)
 #define _MESA_TRACE_END()
+#define _MESA_TRACE_FLOW_BEGIN(name, id)
 
 #endif /* HAVE_PERFETTO */
 
@@ -79,6 +88,11 @@
       __attribute__((cleanup(_mesa_trace_scope_end), unused)) =              \
          _mesa_trace_scope_begin(name)
 
+#define _MESA_TRACE_SCOPE_FLOW(name, id)                                     \
+   int _MESA_TRACE_SCOPE_VAR(__LINE__)                                       \
+      __attribute__((cleanup(_mesa_trace_scope_end), unused)) =              \
+         _mesa_trace_scope_flow_begin(name, id)
+
 static inline int
 _mesa_trace_scope_begin(const char *name)
 {
@@ -87,6 +101,16 @@ _mesa_trace_scope_begin(const char *name)
    return 0;
 }
 
+static inline int
+_mesa_trace_scope_flow_begin(const char *name, uint64_t *id)
+{
+   if (*id == 0)
+      *id = util_perfetto_next_id();
+   _MESA_TRACE_FLOW_BEGIN(name, *id);
+   _MESA_GPUVIS_TRACE_BEGIN(name);
+   return 0;
+}
+
 static inline void
 _mesa_trace_scope_end(UNUSED int *scope)
 {
@@ -101,7 +125,9 @@ _mesa_trace_scope_end(UNUSED int *scope)
 #endif /* __has_attribute(cleanup) && __has_attribute(unused) */
 
 #define MESA_TRACE_SCOPE(name) _MESA_TRACE_SCOPE(name)
+#define MESA_TRACE_SCOPE_FLOW(name, id) _MESA_TRACE_SCOPE_FLOW(name, id)
 #define MESA_TRACE_FUNC() _MESA_TRACE_SCOPE(__func__)
+#define MESA_TRACE_FUNC_FLOW(id) _MESA_TRACE_SCOPE_FLOW(__func__, id)
 
 static inline void
 util_cpu_trace_init()
diff --git a/src/util/perf/u_perfetto.cc b/src/util/perf/u_perfetto.cc
index 897e29cc4f8..077e291eca6 100644
--- a/src/util/perf/u_perfetto.cc
+++ b/src/util/perf/u_perfetto.cc
@@ -39,6 +39,8 @@ PERFETTO_TRACK_EVENT_STATIC_STORAGE();
 
 int util_perfetto_tracing_state;
 
+static uint64_t util_perfetto_unique_id = 1;
+
 static void
 util_perfetto_update_tracing_state(void)
 {
@@ -62,6 +64,20 @@ util_perfetto_trace_end(void)
    util_perfetto_update_tracing_state();
 }
 
+void
+util_perfetto_trace_begin_flow(const char *fname, uint64_t id)
+{
+   TRACE_EVENT_BEGIN(
+      UTIL_PERFETTO_CATEGORY_DEFAULT_STR, nullptr, perfetto::Flow::ProcessScoped(id),
+      [&](perfetto::EventContext ctx) { ctx.event()->set_name(fname); });
+}
+
+uint64_t
+util_perfetto_next_id(void)
+{
+   return p_atomic_inc_return(&util_perfetto_unique_id);
+}
+
 class UtilPerfettoObserver : public perfetto::TrackEventSessionObserver {
  public:
    UtilPerfettoObserver() { perfetto::TrackEvent::AddSessionObserver(this); }
diff --git a/src/util/perf/u_perfetto.h b/src/util/perf/u_perfetto.h
index 75ae00186a0..9c5f6612e0d 100644
--- a/src/util/perf/u_perfetto.h
+++ b/src/util/perf/u_perfetto.h
@@ -46,6 +46,10 @@ void util_perfetto_trace_begin(const char *name);
 
 void util_perfetto_trace_end(void);
 
+void util_perfetto_trace_begin_flow(const char *fname, uint64_t id);
+
+uint64_t util_perfetto_next_id(void);
+
 #else /* HAVE_PERFETTO */
 
 static inline void
@@ -69,6 +73,15 @@ util_perfetto_trace_end(void)
 {
 }
 
+static inline void util_perfetto_trace_begin_flow(const char *fname, uint64_t id)
+{
+}
+
+static inline uint64_t util_perfetto_next_id(void)
+{
+   return 0;
+}
+
 #endif /* HAVE_PERFETTO */
 
 #ifdef __cplusplus