sys: add AdjustOOMScore() utility

thaJeztah · thaJeztah · commit 91e7d21ee825 · 2021-04-07T19:16:56.000+02:00
Handle the limits in this function so that consumers don't have to
perform the boundary checks.

Signed-off-by: Sebastiaan van Stijn &lt;github@gone.nl&gt;
diff --git a/runtime/v1/shim/client/client.go b/runtime/v1/shim/client/client.go
@@ -182,10 +182,7 @@ func setupOOMScore(shimPid int) error {
 		return errors.Wrap(err, "get daemon OOM score")
 	}
 	shimScore := score + 1
-	if shimScore > sys.OOMScoreAdjMax {
-		shimScore = sys.OOMScoreAdjMax
-	}
-	if err := sys.SetOOMScore(shimPid, shimScore); err != nil {
+	if err := sys.AdjustOOMScore(shimPid, shimScore); err != nil {
 		return errors.Wrap(err, "set shim OOM score")
 	}
 	return nil
diff --git a/runtime/v2/shim/util_unix.go b/runtime/v2/shim/util_unix.go
@@ -61,10 +61,7 @@ func AdjustOOMScore(pid int) error {
 		return errors.Wrap(err, "get parent OOM score")
 	}
 	shimScore := score + 1
-	if shimScore > sys.OOMScoreAdjMax {
-		shimScore = sys.OOMScoreAdjMax
-	}
-	if err := sys.SetOOMScore(pid, shimScore); err != nil {
+	if err := sys.AdjustOOMScore(pid, shimScore); err != nil {
 		return errors.Wrap(err, "set shim OOM score")
 	}
 	return nil
diff --git a/sys/oom_linux.go b/sys/oom_linux.go
@@ -36,6 +36,17 @@ const (
 	OOMScoreAdjMax = 1000
 )
 
+// AdjustOOMScore sets the oom score for the provided pid. If the provided score
+// is out of range (-1000 - 1000), it is clipped to the min/max value.
+func AdjustOOMScore(pid, score int) error {
+	if score > OOMScoreAdjMax {
+		score = OOMScoreAdjMax
+	} else if score < OOMScoreAdjMin {
+		score = OOMScoreAdjMin
+	}
+	return SetOOMScore(pid, score)
+}
+
 // SetOOMScore sets the oom score for the provided pid
 func SetOOMScore(pid, score int) error {
 	if score > OOMScoreAdjMax || score < OOMScoreAdjMin {
diff --git a/sys/oom_unsupported.go b/sys/oom_unsupported.go
@@ -25,6 +25,14 @@ const (
 	OOMScoreAdjMax = 0
 )
 
+// AdjustOOMScore sets the oom score for the provided pid. If the provided score
+// is out of range (-1000 - 1000), it is clipped to the min/max value.
+//
+// Not implemented on Windows
+func AdjustOOMScore(pid, score int) error {
+	return nil
+}
+
 // SetOOMScore sets the oom score for the process
 //
 // Not implemented on Windows

Original file line number	Diff line number	Diff line change
`@@ -182,10 +182,7 @@ func setupOOMScore(shimPid int) error {`
`182`	`182`	`return errors.Wrap(err, "get daemon OOM score")`
`183`	`183`	`}`
`184`	`184`	`shimScore := score + 1`
`185`		`- if shimScore > sys.OOMScoreAdjMax {`
`186`		`- shimScore = sys.OOMScoreAdjMax`
`187`		`- }`
`188`		`- if err := sys.SetOOMScore(shimPid, shimScore); err != nil {`
	`185`	`+ if err := sys.AdjustOOMScore(shimPid, shimScore); err != nil {`
`189`	`186`	`return errors.Wrap(err, "set shim OOM score")`
`190`	`187`	`}`
`191`	`188`	`return nil`
Original file line number	Diff line number	Diff line change
`@@ -61,10 +61,7 @@ func AdjustOOMScore(pid int) error {`
`61`	`61`	`return errors.Wrap(err, "get parent OOM score")`
`62`	`62`	`}`
`63`	`63`	`shimScore := score + 1`
`64`		`- if shimScore > sys.OOMScoreAdjMax {`
`65`		`- shimScore = sys.OOMScoreAdjMax`
`66`		`- }`
`67`		`- if err := sys.SetOOMScore(pid, shimScore); err != nil {`
	`64`	`+ if err := sys.AdjustOOMScore(pid, shimScore); err != nil {`
`68`	`65`	`return errors.Wrap(err, "set shim OOM score")`
`69`	`66`	`}`
`70`	`67`	`return nil`