microbench-ci: remove description from github summary

The description on the summary is no longer needed, because we now add a label
if a significant change was detected.

Additionally, the legend is not needed, because there is no longer a scenario
where we need to indicate only a possibly regression.

Author: herkolategan

pkg/cmd/microbench-ci/report.go

@@ -180,7 +180,6 @@ func (c CompareResults) writeJSONSummary(path string) error {
 // githubSummary creates a markdown summary of the comparison results.
 func (c CompareResults) githubSummary() (string, error) {
 	buf := bytes.NewBuffer(nil)
-	regressionDetected := false
 	summaries := make([]GitHubData, 0, len(c))
 	for _, cr := range c {
 		finalStatus := NoChange
@@ -193,9 +192,6 @@ func (c CompareResults) githubSummary() (string, error) {
 			if status > finalStatus {
 				finalStatus = status
 			}
-			if status == Regressed {
-				regressionDetected = true
-			}
 			return statusToDot(status)
 		})
 		data.BenchmarkStatus = statusToDot(finalStatus)
@@ -207,19 +203,13 @@ func (c CompareResults) githubSummary() (string, error) {
 	if err != nil {
 		return "", err
 	}
-	description := "No regressions detected!"
-	if regressionDetected {
-		description = "A regression has been detected, please investigate further!"
-	}
-
 	err = tmpl.Execute(buf, struct {
 		GitHubSummaryData []GitHubData
 		Artifacts         map[Revision]string
 		Description       string
 		Commit            string
 	}{
 		GitHubSummaryData: summaries,
-		Description:       description,
 		Artifacts: map[Revision]string{
 			Old: suite.artifactsURL(Old),
 			New: suite.artifactsURL(New),

pkg/cmd/microbench-ci/template/github_summary.md

@@ -40,14 +40,4 @@ gcloud storage cp {{$url}}\* {{$rev}}/
 
 </details>
 
-<details><summary>Legend</summary>
-
-- ⚪ **Neutral:** No significant performance change.
-- 🔴 **Regression:** Likely performance regression, requiring investigation.
-- 🟢 **Improvement:** Likely performance gain.
-
-</details>
-
-{{.Description}}
-
 _built with commit: [{{.Commit}}](https://github.com/cockroachdb/cockroach/commit/{{.Commit}})_

pkg/cmd/microbench-ci/testdata/regression.txt

@@ -129,16 +129,6 @@ gcloud storage cp gs://cockroach-microbench-ci/artifacts/abcdef123//\* old/
 
 </details>
 
-<details><summary>Legend</summary>
-
-- ⚪ **Neutral:** No significant performance change.
-- 🔴 **Regression:** Likely performance regression, requiring investigation.
-- 🟢 **Improvement:** Likely performance gain.
-
-</details>
-
-A regression has been detected, please investigate further!
-
 _built with commit: [qwerty456](https://github.com/cockroachdb/cockroach/commit/qwerty456)_
 ----
 ----

pkg/cmd/microbench-ci/testdata/summary.txt

@@ -109,16 +109,6 @@ gcloud storage cp gs://cockroach-microbench-ci/artifacts/abcdef123//\* old/
 
 </details>
 
-<details><summary>Legend</summary>
-
-- ⚪ **Neutral:** No significant performance change.
-- 🔴 **Regression:** Likely performance regression, requiring investigation.
-- 🟢 **Improvement:** Likely performance gain.
-
-</details>
-
-No regressions detected!
-
 _built with commit: [qwerty456](https://github.com/cockroachdb/cockroach/commit/qwerty456)_
 ----
 ----

pkg/cmd/microbench-ci/testdata/untracked_metric.txt

@@ -159,16 +159,6 @@ gcloud storage cp gs://cockroach-microbench-ci/artifacts/abcdef123//\* old/
 
 </details>
 
-<details><summary>Legend</summary>
-
-- ⚪ **Neutral:** No significant performance change.
-- 🔴 **Regression:** Likely performance regression, requiring investigation.
-- 🟢 **Improvement:** Likely performance gain.
-
-</details>
-
-No regressions detected!
-
 _built with commit: [qwerty456](https://github.com/cockroachdb/cockroach/commit/qwerty456)_
 ----
 ----