pkg/profiler/cpu: Fix noop due to value struct (#1874)

kakkoyun · web-flow · commit 9a25aab65ef3 · 2023-07-20T10:21:04.000+02:00
This caused any process to only report on a single thread per profile cycle, which resulted in incorrect profiling data. ### Test Main (only single thread stack traces per profile) : ![CleanShot_2023-07-20_at_09 55 21](https://github.com/parca-dev/parca-agent/assets/536449/8ea317d2-981f-4d7e-b137-b1c4ed3acf83) ![CleanShot_2023-07-20_at_09 55 44](https://github.com/parca-dev/parca-agent/assets/536449/a8e9aa03-ffe7-4ecd-b975-d1dd8d3804b3) Patch (multiple thread stack traces per profile): ![CleanShot_2023-07-20_at_09 57 42](https://github.com/parca-dev/parca-agent/assets/536449/d9be5b5c-efaf-401a-b001-a3e5abed4c5b) ![CleanShot_2023-07-20_at_09 57 29](https://github.com/parca-dev/parca-agent/assets/536449/2b1617f3-dbb0-4846-8d47-2e94164bb3a7)
diff --git a/pkg/profiler/cpu/cpu.go b/pkg/profiler/cpu/cpu.go
@@ -629,7 +629,11 @@ func (p *CPU) Run(ctx context.Context) error {
 				}
 				continue
 			}
-			data.RawSamples = append(data.RawSamples, perThreadRawData.RawSamples...)
+
+			groupedRawData[pid] = profile.ProcessRawData{
+				PID:        perThreadRawData.PID,
+				RawSamples: append(data.RawSamples, perThreadRawData.RawSamples...),
+			}
 		}
 
 		processLastErrors := map[int]error{}

Original file line number	Diff line number	Diff line change
`@@ -629,7 +629,11 @@ func (p *CPU) Run(ctx context.Context) error {`
`629`	`629`	`}`
`630`	`630`	`continue`
`631`	`631`	`}`
`632`		`- data.RawSamples = append(data.RawSamples, perThreadRawData.RawSamples...)`
	`632`	`+`
	`633`	`+ groupedRawData[pid] = profile.ProcessRawData{`
	`634`	`+ PID: perThreadRawData.PID,`
	`635`	`+ RawSamples: append(data.RawSamples, perThreadRawData.RawSamples...),`
	`636`	`+ }`
`633`	`637`	`}`
`634`	`638`
`635`	`639`	`processLastErrors := map[int]error{}`