fix: add benign error suppression for process priority management (coder#15020)

sreya · web-flow · commit 3716afac4643 · 2024-10-08T12:02:05.000-05:00
This PR backports some benign error suppression into 2.15
diff --git a/agent/agent.go b/agent/agent.go
@@ -1669,13 +1669,12 @@ func (a *agent) manageProcessPriority(ctx context.Context, debouncer *logDebounc
 		}
 
 		score, niceErr := proc.Niceness(a.syscaller)
-		if niceErr != nil && !xerrors.Is(niceErr, os.ErrPermission) {
+		if !isBenignProcessErr(niceErr) {
 			debouncer.Warn(ctx, "unable to get proc niceness",
 				slog.F("cmd", proc.Cmd()),
 				slog.F("pid", proc.PID),
 				slog.Error(niceErr),
 			)
-			continue
 		}
 
 		// We only want processes that don't have a nice value set
@@ -1689,7 +1688,7 @@ func (a *agent) manageProcessPriority(ctx context.Context, debouncer *logDebounc
 
 		if niceErr == nil {
 			err := proc.SetNiceness(a.syscaller, niceness)
-			if err != nil && !xerrors.Is(err, os.ErrPermission) {
+			if !isBenignProcessErr(err) {
 				debouncer.Warn(ctx, "unable to set proc niceness",
 					slog.F("cmd", proc.Cmd()),
 					slog.F("pid", proc.PID),
@@ -1703,7 +1702,7 @@ func (a *agent) manageProcessPriority(ctx context.Context, debouncer *logDebounc
 		if oomScore != unsetOOMScore && oomScore != proc.OOMScoreAdj && !isCustomOOMScore(agentScore, proc) {
 			oomScoreStr := strconv.Itoa(oomScore)
 			err := afero.WriteFile(a.filesystem, fmt.Sprintf("/proc/%d/oom_score_adj", proc.PID), []byte(oomScoreStr), 0o644)
-			if err != nil && !xerrors.Is(err, os.ErrPermission) {
+			if !isBenignProcessErr(err) {
 				debouncer.Warn(ctx, "unable to set oom_score_adj",
 					slog.F("cmd", proc.Cmd()),
 					slog.F("pid", proc.PID),
@@ -2139,3 +2138,14 @@ func (l *logDebouncer) log(ctx context.Context, level slog.Level, msg string, fi
 	}
 	l.messages[msg] = time.Now()
 }
+
+func isBenignProcessErr(err error) bool {
+	return err != nil &&
+		(xerrors.Is(err, os.ErrNotExist) ||
+			xerrors.Is(err, os.ErrPermission) ||
+			isNoSuchProcessErr(err))
+}
+
+func isNoSuchProcessErr(err error) bool {
+	return err != nil && strings.Contains(err.Error(), "no such process")
+}
diff --git a/agent/agentproc/proc_unix.go b/agent/agentproc/proc_unix.go
@@ -45,16 +45,15 @@ func List(fs afero.Fs, syscaller Syscaller) ([]*Process, error) {
 
 		cmdline, err := afero.ReadFile(fs, filepath.Join(defaultProcDir, entry, "cmdline"))
 		if err != nil {
-			var errNo syscall.Errno
-			if xerrors.As(err, &errNo) && errNo == syscall.EPERM {
+			if isBenignError(err) {
 				continue
 			}
 			return nil, xerrors.Errorf("read cmdline: %w", err)
 		}
 
 		oomScore, err := afero.ReadFile(fs, filepath.Join(defaultProcDir, entry, "oom_score_adj"))
 		if err != nil {
-			if xerrors.Is(err, os.ErrPermission) {
+			if isBenignError(err) {
 				continue
 			}
 
@@ -124,3 +123,12 @@ func (p *Process) Cmd() string {
 func (p *Process) cmdLine() []string {
 	return strings.Split(p.CmdLine, "\x00")
 }
+
+func isBenignError(err error) bool {
+	var errno syscall.Errno
+	if !xerrors.As(err, &errno) {
+		return false
+	}
+
+	return errno == syscall.ESRCH || errno == syscall.EPERM || xerrors.Is(err, os.ErrNotExist)
+}
