dashboard: promote OpenBSD 6.8 builders to be default

The known issue with OpenBSD 6.8 builders appears to be resolved
via CL 278732 and CL 279134. Promote them to the primary OpenBSD
post-submit builders and TryBots.

Having test coverage from OpenBSD 6.8 and 6.4 builders gives us
us more confidence that Go works on supported OpenBSD versions
(which are 6.8 and 6.7 at this time, per past policy decision
in https://golang.org/issue/15227#issuecomment-293319876).

Reduce numTryTestHelpers from 5 to 4 based on some data from
golang.org/issue/37439 showing that going from 3 to 5 helpers
doesn't make a significant difference. We can adjust further
if we learn that OpenBSD TryBots become the bottleneck.

Fixes golang/go#35712.
For golang/go#42542.
For golang/go#42064.
Updates golang/go#42426.

Change-Id: Id2fa4be7c3161f89752c1428146846fe06ca63db
Reviewed-on: https://go-review.googlesource.com/c/build/+/279512
Run-TryBot: Dmitri Shuralyov <[email protected]>
TryBot-Result: Go Bot <[email protected]>
Reviewed-by: Carlos Amedee <[email protected]>
Reviewed-by: Alexander Rakoczy <[email protected]>
Trust: Dmitri Shuralyov <[email protected]>

Author: dmitshur

dashboard/builders.go

@@ -75,9 +75,9 @@ var slowBotAliases = map[string]string{
 	"netbsd-arm":     "netbsd-arm-bsiegert",
 	"netbsd-arm64":   "netbsd-arm64-bsiegert",
 	"nocgo":          "linux-amd64-nocgo",
-	"openbsd":        "openbsd-amd64-64",
-	"openbsd-386":    "openbsd-386-64",
-	"openbsd-amd64":  "openbsd-amd64-64",
+	"openbsd":        "openbsd-amd64-68",
+	"openbsd-386":    "openbsd-386-68",
+	"openbsd-amd64":  "openbsd-amd64-68",
 	"openbsd-arm":    "openbsd-arm-jsing",
 	"openbsd-arm64":  "openbsd-arm64-jsing",
 	"openbsd-mips64": "openbsd-mips64-jsing",
@@ -2035,31 +2035,28 @@ func init() {
 		numTryTestHelpers: 5,
 	})
 	addBuilder(BuildConfig{
-		Name:              "openbsd-amd64-64",
-		HostType:          "host-openbsd-amd64-64",
-		MinimumGoVersion:  types.MajorMinor{1, 11},
-		distTestAdjust:    noTestDirAndNoReboot,
-		tryBot:            defaultTrySet(),
-		numTestHelpers:    0,
-		numTryTestHelpers: 5,
+		Name:             "openbsd-amd64-64",
+		HostType:         "host-openbsd-amd64-64",
+		MinimumGoVersion: types.MajorMinor{1, 11},
+		distTestAdjust:   noTestDirAndNoReboot,
 	})
 	addBuilder(BuildConfig{
 		Name:           "openbsd-386-64",
 		HostType:       "host-openbsd-386-64",
-		tryBot:         explicitTrySet("sys"),
 		distTestAdjust: noTestDirAndNoReboot,
 	})
 	addBuilder(BuildConfig{
 		Name:           "openbsd-amd64-68",
 		HostType:       "host-openbsd-amd64-68",
+		tryBot:         defaultTrySet(),
 		distTestAdjust: noTestDirAndNoReboot,
-		KnownIssue:     35712,
 	})
 	addBuilder(BuildConfig{
-		Name:           "openbsd-386-68",
-		HostType:       "host-openbsd-386-68",
-		distTestAdjust: noTestDirAndNoReboot,
-		KnownIssue:     35712,
+		Name:              "openbsd-386-68",
+		HostType:          "host-openbsd-386-68",
+		tryBot:            explicitTrySet("sys"),
+		distTestAdjust:    noTestDirAndNoReboot,
+		numTryTestHelpers: 4,
 	})
 	addBuilder(BuildConfig{
 		Name:         "openbsd-arm-jsing",

dashboard/builders_test.go

@@ -108,7 +108,7 @@ func TestTrybots(t *testing.T) {
 				"misc-compile-openbsd",
 				"misc-compile-plan9",
 				"misc-compile-ppc",
-				"openbsd-amd64-64",
+				"openbsd-amd64-68",
 				"windows-386-2008",
 				"windows-amd64-2016",
 			},
@@ -134,7 +134,7 @@ func TestTrybots(t *testing.T) {
 				"misc-compile-openbsd",
 				"misc-compile-plan9",
 				"misc-compile-ppc",
-				"openbsd-amd64-64",
+				"openbsd-amd64-68",
 				"windows-386-2008",
 				"windows-amd64-2016",
 			},
@@ -160,7 +160,7 @@ func TestTrybots(t *testing.T) {
 				"misc-compile-plan9",
 				"misc-compile-ppc",
 				"misc-compile-solaris",
-				"openbsd-amd64-64",
+				"openbsd-amd64-68",
 				"windows-386-2008",
 				"windows-amd64-2016",
 
@@ -190,7 +190,7 @@ func TestTrybots(t *testing.T) {
 				"misc-compile-plan9",
 				"misc-compile-ppc",
 				"misc-compile-solaris",
-				"openbsd-amd64-64",
+				"openbsd-amd64-68",
 				"windows-386-2008",
 				"windows-amd64-2016",
 
@@ -220,8 +220,8 @@ func TestTrybots(t *testing.T) {
 				"linux-amd64",
 				"linux-amd64-race",
 				"netbsd-amd64-9_0",
-				"openbsd-386-64",
-				"openbsd-amd64-64",
+				"openbsd-386-68",
+				"openbsd-amd64-68",
 				"windows-386-2008",
 				"windows-amd64-2016",
 			},
@@ -397,9 +397,12 @@ func TestBuilderConfig(t *testing.T) {
 		{b("linux-mips64le-mengzhuo", "net"), onlyPost},
 
 		// OpenBSD.
-		{b("[email protected]", "go"), both},
-		{b("[email protected]", "go"), both},
-		{b("[email protected]", "go"), both},
+		{b("[email protected]", "go"), both},
+		{b("[email protected]", "go"), both},
+		{b("[email protected]", "go"), both},
+		{b("[email protected]", "go"), onlyPost},
+		{b("[email protected]", "go"), onlyPost},
+		{b("[email protected]", "go"), onlyPost},
 		{b("[email protected]", "go"), none}, // golang.org/issue/42426.
 		{b("[email protected]", "go"), onlyPost},
 		{b("[email protected]", "go"), onlyPost},
@@ -523,8 +526,8 @@ func TestBuilderConfig(t *testing.T) {
 		{b("[email protected]", "exp"), none},
 		{b("freebsd-amd64-11_2", "exp"), none},
 		{b("freebsd-amd64-12_0", "exp"), none},
-		{b("openbsd-amd64-62", "exp"), none},
 		{b("openbsd-amd64-64", "exp"), none},
+		{b("openbsd-amd64-68", "exp"), none},
 		{b("js-wasm", "exp"), none},
 
 		// exp is experimental; it doesn't test against release branches.
@@ -539,7 +542,7 @@ func TestBuilderConfig(t *testing.T) {
 		{b("darwin-amd64-10_12", "build"), none},
 		{b("darwin-amd64-10_14", "build"), none},
 		{b("darwin-amd64-10_15", "build"), onlyPost},
-		{b("openbsd-amd64-64", "build"), none},
+		{b("openbsd-amd64-68", "build"), none},
 		{b("linux-amd64-fedora", "build"), none},
 		{b("linux-amd64-clang", "build"), none},
 		{b("linux-amd64-sid", "build"), none},