Cleanup

probe/endpoint/procspy/background_reader_linux.go

@@ -16,9 +16,6 @@ const (
 	maxRateLimit     = 250 * time.Millisecond // Read at least 4 * fdBlockSize file descriptors per namespace per second
 	fdBlockSize      = 100
 	targetWalkTime   = 10 * time.Second // Aim at walking all files in 10 seconds
-
-	maxRateLimitF   = float64(maxRateLimit)
-	targetWalkTimeF = float64(targetWalkTime)
 )
 
 type backgroundReader struct {
@@ -57,10 +54,13 @@ func StartBackgroundReader(walker process.Walker) {
 }
 
 func (br *backgroundReader) loop() {
+	const (
+		maxRateLimitF   = float64(maxRateLimit)
+		targetWalkTimeF = float64(targetWalkTime)
+	)
+
 	rateLimit := initialRateLimit
-
 	ticker := time.Tick(rateLimit)
-
 	for {
 		start := time.Now()
 		sockets, err := walkProcPid(br.walkingBuf, br.walker, ticker, fdBlockSize)

probe/endpoint/procspy/proc_linux.go

@@ -108,14 +108,9 @@ func readProcessConnections(buf *bytes.Buffer, namespaceProcs []*process.Process
 // walkNamespacePid does the work of walkProcPid for a single namespace
 func walkNamespacePid(buf *bytes.Buffer, sockets map[uint64]*Proc, namespaceProcs []*process.Process, ticker <-chan time.Time, fdBlockSize int) error {
 
-	found, err := readProcessConnections(buf, namespaceProcs)
-	if err != nil {
+	if found, err := readProcessConnections(buf, namespaceProcs); err != nil || !found {
 		return err
 	}
-	if !found {
-		// There's no point in reading /fd/*
-		return nil
-	}
 
 	var statT syscall.Stat_t
 	var fdBlockCount int
@@ -126,20 +121,15 @@ func walkNamespacePid(buf *bytes.Buffer, sockets map[uint64]*Proc, namespaceProc
 		fdBase := filepath.Join(procRoot, dirName, "fd")
 
 		if fdBlockCount > fdBlockSize {
-			// we surpased the filedescriptor rate limit
+			// we surpassed the filedescriptor rate limit
 			<-ticker
 			fdBlockCount = 0
+
 			// read the connections again to
 			// avoid the race between between /net/tcp{,6} and /proc/PID/fd/*
-			// FIXME:refactor this
-			found, err := readProcessConnections(buf, namespaceProcs[i:])
-			if err != nil {
+			if found, err := readProcessConnections(buf, namespaceProcs[i:]); err != nil || !found {
 				return err
 			}
-			if !found {
-				// There's no point in reading /fd/*
-				return nil
-			}
 		}
 
 		fds, err := fs.ReadDirNames(fdBase)
@@ -150,6 +140,8 @@ func walkNamespacePid(buf *bytes.Buffer, sockets map[uint64]*Proc, namespaceProc
 
 		var proc *Proc
 		for _, fd := range fds {
+			fdBlockCount++
+
 			// Direct use of syscall.Stat() to save garbage.
 			err = fs.Stat(filepath.Join(fdBase, fd), &statT)
 			if err != nil {
@@ -171,8 +163,6 @@ func walkNamespacePid(buf *bytes.Buffer, sockets map[uint64]*Proc, namespaceProc
 			}
 
 			sockets[statT.Ino] = proc
-
-			fdBlockCount += 1
 		}
 
 	}