Merge branch 'egil/erts/tracing-support-lttng/OTP-13532'

* egil/erts/tracing-support-lttng/OTP-13532: (28 commits)
  runtime_tools: User's guide to LTTng and dyntrace
  runtime_tools: Fix Dtrace build
  erts: Fix gc messages in tracer_SUITE
  erts: Fix gc messages in sensitive_SUITE
  erts: Fix gc messages in trace_port_SUITE
  tools: Update fprof tests
  tools: Update fprof with new gc traces
  runtime_tools: Update dyntrace_lttng_SUITE tests
  runtime_tools: Add 'return_to' for call tracing
  erts: Fix return_to trace callback
  erts: Update erl_tracer documentation
  erts: Fix erl_tracer documentation typos
  Update preloaded erl_tracer.beam
  erts: Update erl_tracer type specs
  runtime_tools: Add lttng dyntrace tests
  runtime_tools: Extend 'trace' and 'enabled' tracer callbacks
  erts: Extend 'enabled' and 'trace' tracer callbacks
  runtime_tools: Extend 'enabled' tracer callbacks
  erts: Extend 'enabled' tracer callbacks
  runtime_tools: Update lttng garbage collection trace
  ...

1 files changed, 22 insertions, 19 deletions

diff --git a/erts/emulator/beam/erl_gc.c b/erts/emulator/beam/erl_gc.c
index 4698458521..df5d0f4918 100644
--- a/erts/emulator/beam/erl_gc.c
+++ b/erts/emulator/beam/erl_gc.c
@@ -593,10 +593,6 @@ garbage_collect(Process* p, ErlHeapFragment *live_hf_end,
 
     esdp = erts_get_scheduler_data();
 
-    if (IS_TRACED_FL(p, F_TRACE_GC)) {
-        trace_gc(p, am_gc_start);
-    }
-
     erts_smp_atomic32_read_bor_nob(&p->state, ERTS_PSFLG_GC);
     if (erts_system_monitor_long_gc != 0)
 	start_time = erts_get_monotonic_time(esdp);
@@ -619,18 +615,29 @@ garbage_collect(Process* p, ErlHeapFragment *live_hf_end,
      */
 
     if (GEN_GCS(p) < MAX_GEN_GCS(p) && !(FLAGS(p) & F_NEED_FULLSWEEP)) {
-	DTRACE2(gc_minor_start, pidbuf, need);
-	reds = minor_collection(p, live_hf_end, need, objv, nobj, &reclaimed_now);
-	DTRACE2(gc_minor_end, pidbuf, reclaimed_now);
-	if (reds < 0)
-	    goto do_major_collection;
-    }
-    else {
-    do_major_collection:
+        if (IS_TRACED_FL(p, F_TRACE_GC)) {
+            trace_gc(p, am_gc_minor_start, need);
+        }
+        DTRACE2(gc_minor_start, pidbuf, need);
+        reds = minor_collection(p, live_hf_end, need, objv, nobj, &reclaimed_now);
+        DTRACE2(gc_minor_end, pidbuf, reclaimed_now);
+        if (IS_TRACED_FL(p, F_TRACE_GC)) {
+            trace_gc(p, am_gc_minor_end, reclaimed_now);
+        }
+        if (reds < 0)
+            goto do_major_collection;
+    } else {
+do_major_collection:
         ERTS_MSACC_SET_STATE_CACHED_M_X(ERTS_MSACC_STATE_GC_FULL);
-	DTRACE2(gc_major_start, pidbuf, need);
-	reds = major_collection(p, live_hf_end, need, objv, nobj, &reclaimed_now);
-	DTRACE2(gc_major_end, pidbuf, reclaimed_now);
+        if (IS_TRACED_FL(p, F_TRACE_GC)) {
+            trace_gc(p, am_gc_major_start, need);
+        }
+        DTRACE2(gc_major_start, pidbuf, need);
+        reds = major_collection(p, live_hf_end, need, objv, nobj, &reclaimed_now);
+        DTRACE2(gc_major_end, pidbuf, reclaimed_now);
+        if (IS_TRACED_FL(p, F_TRACE_GC)) {
+            trace_gc(p, am_gc_major_end, reclaimed_now);
+        }
         ERTS_MSACC_SET_STATE_CACHED_M_X(ERTS_MSACC_STATE_GC);
     }
 
@@ -646,10 +653,6 @@ garbage_collect(Process* p, ErlHeapFragment *live_hf_end,
 
     erts_smp_atomic32_read_band_nob(&p->state, ~ERTS_PSFLG_GC);
 
-    if (IS_TRACED_FL(p, F_TRACE_GC)) {
-        trace_gc(p, am_gc_end);
-    }
-
     if (erts_system_monitor_long_gc != 0) {
 	ErtsMonotonicTime end_time;
 	Uint gc_time;