fix(profiling): compute number of allocation events correctly (#3393) (#3397)

(cherry picked from commit ec60e55)

Co-authored-by: Julien Danjou <[email protected]>

Author: mergify[bot]

ddtrace/profiling/exporter/pprof.pyx

@@ -252,7 +252,9 @@ class _PprofConverter(object):
             ),
         )
 
-        self._location_values[location_key]["alloc-samples"] = sum(event.nevents for event in events)
+        self._location_values[location_key]["alloc-samples"] = round(
+            sum(event.nevents * (event.capture_pct / 100.0) for event in events)
+        )
         self._location_values[location_key]["alloc-space"] = round(
             sum(event.size / event.capture_pct * 100.0 for event in events)
         )

releasenotes/notes/profiling-fix-memory-alloc-numbers-a280c751c8f250ba.yaml

@@ -0,0 +1,4 @@
+---
+fixes:
+  - |
+    Fixes wrong numbers of memory allocation being reported in the memory profiler.

tests/profiling/exporter/test-pprof-exporter.txt

@@ -152,7 +152,7 @@ sample {
   value: 0
   value: 0
   value: 0
-  value: 3072
+  value: 2294
   value: 104
   value: 58
   label {
@@ -414,7 +414,7 @@ sample {
   value: 0
   value: 0
   value: 0
-  value: 1024
+  value: 512
   value: 680
   value: 340
   label {
@@ -582,7 +582,7 @@ sample {
   value: 0
   value: 0
   value: 0
-  value: 2048
+  value: 1024
   value: 136
   value: 68
   label {
@@ -750,7 +750,7 @@ sample {
   value: 0
   value: 0
   value: 0
-  value: 1024
+  value: 338
   value: 133
   value: 44
   label {