diff --git a/cmd/camput/camput.go b/cmd/camput/camput.go
index e6ce47a72..1d4fdbe66 100644
--- a/cmd/camput/camput.go
+++ b/cmd/camput/camput.go
@@ -59,9 +59,7 @@ func init() {
 	if debug, _ := strconv.ParseBool(os.Getenv("CAMLI_DEBUG")); debug {
 		debugFlagOnce.Do(registerDebugFlags)
 	}
-	cmdmain.ExtraFlagRegistration = func() {
-		client.AddFlags()
-	}
+	cmdmain.ExtraFlagRegistration = client.AddFlags
 	cmdmain.PreExit = func() {
 		if up := uploader; up != nil {
 			up.Close()
diff --git a/cmd/camput/camput_test.go b/cmd/camput/camput_test.go
index d7f8f567d..833e4a374 100644
--- a/cmd/camput/camput_test.go
+++ b/cmd/camput/camput_test.go
@@ -169,6 +169,8 @@ func TestUploadDirectories(t *testing.T) {
 	}
 
 	defer setAndRestore(&uploadWorkers, 1)()
+	defer setAndRestore(&dirUploadWorkers, 1)()
+	defer setAndRestore(&statCacheWorkers, 1)()
 
 	e := &env{
 		Timeout: 5 * time.Second,
diff --git a/cmd/camput/files.go b/cmd/camput/files.go
index 82b3c3d83..ecb04444d 100644
--- a/cmd/camput/files.go
+++ b/cmd/camput/files.go
@@ -65,10 +65,12 @@ type fileCmd struct {
 	histo    string // optional histogram output filename
 }
 
-var flagUseSQLiteChildCache bool // Use sqlite for the statcache and havecache.
-
 var (
-	uploadWorkers = -1 // concurrent upload workers (negative means unbounded: memory hog)
+	flagUseSQLiteChildCache bool // Use sqlite for the statcache and havecache.
+
+	uploadWorkers    = 10 // concurrent upload workers (negative means unbounded: memory hog)
+	dirUploadWorkers = 5  // concurrent directory uploading workers
+	statCacheWorkers = 10 // concurrent statcache workers
 )
 
 func init() {
@@ -98,6 +100,10 @@ func init() {
 		}
 		if android.IsChild() {
 			flags.BoolVar(&cmd.argsFromInput, "stdinargs", false, "If true, filenames to upload are sent one-per-line on stdin. EOF means to quit the process with exit status 0.")
+			// limit number of goroutines to limit memory
+			uploadWorkers = 3
+			dirUploadWorkers = 2
+			statCacheWorkers = 3
 		}
 		flagCacheLog = flags.Bool("logcache", false, "log caching details")
 
@@ -936,7 +942,7 @@ func (t *TreeUpload) statPath(fullPath string, fi os.FileInfo) (nod *node, err e
 	if err != nil {
 		return nil, err
 	}
-	sort.Sort(byFileName(fis))
+	sort.Sort(byTypeAndName(fis))
 	for _, fi := range fis {
 		depn, err := t.statPath(filepath.Join(fullPath, filepath.Base(fi.Name())), fi)
 		if err != nil {
@@ -1007,9 +1013,9 @@ func (t *TreeUpload) run() {
 			}
 		})
 	} else {
-		upload = NewNodeWorker(uploadWorkers, func(n *node, ok bool) {
+		dirUpload := NewNodeWorker(dirUploadWorkers, func(n *node, ok bool) {
 			if !ok {
-				log.Printf("done with all uploads.")
+				log.Printf("done uploading directories - done with all uploads.")
 				uploadsdonec <- true
 				return
 			}
@@ -1018,7 +1024,25 @@ func (t *TreeUpload) run() {
 				log.Fatalf("Error uploading %s: %v", n.fullPath, err)
 			}
 			n.SetPutResult(put, nil)
-			if c := t.up.statCache; c != nil && !n.fi.IsDir() {
+			uploadedc <- n
+		})
+
+		upload = NewNodeWorker(uploadWorkers, func(n *node, ok bool) {
+			if !ok {
+				log.Printf("done with all uploads.")
+				close(dirUpload)
+				return
+			}
+			if n.fi.IsDir() {
+				dirUpload <- n
+				return
+			}
+			put, err := t.up.uploadNode(n)
+			if err != nil {
+				log.Fatalf("Error uploading %s: %v", n.fullPath, err)
+			}
+			n.SetPutResult(put, nil)
+			if c := t.up.statCache; c != nil {
 				c.AddCachedPutResult(
 					t.up.pwd, n.fullPath, n.fi, put, withPermanode)
 			}
@@ -1026,7 +1050,7 @@ func (t *TreeUpload) run() {
 		})
 	}
 
-	checkStatCache := NewNodeWorker(10, func(n *node, ok bool) {
+	checkStatCache := NewNodeWorker(statCacheWorkers, func(n *node, ok bool) {
 		if hook := testHookStatCache; hook != nil {
 			hook(n, ok)
 		}
@@ -1073,7 +1097,7 @@ Loop:
 			t.skipped.incr(n)
 		case n, ok := <-stattedc:
 			if !ok {
-				log.Printf("done stattting:")
+				log.Printf("done statting:")
 				dumpStats()
 				close(checkStatCache)
 				stattedc = nil
@@ -1117,11 +1141,21 @@ func (t *TreeUpload) Wait() (*client.PutResult, error) {
 	return t.finalPutRes, t.err
 }
 
-type byFileName []os.FileInfo
+type byTypeAndName []os.FileInfo
 
-func (s byFileName) Len() int           { return len(s) }
-func (s byFileName) Less(i, j int) bool { return s[i].Name() < s[j].Name() }
-func (s byFileName) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+func (s byTypeAndName) Len() int { return len(s) }
+func (s byTypeAndName) Less(i, j int) bool {
+	// files go before directories
+	if s[i].IsDir() {
+		if !s[j].IsDir() {
+			return false
+		}
+	} else if s[j].IsDir() {
+		return true
+	}
+	return s[i].Name() < s[j].Name()
+}
+func (s byTypeAndName) Swap(i, j int) { s[i], s[j] = s[j], s[i] }
 
 // trackDigestReader is an io.Reader wrapper which records the digest of what it reads.
 type trackDigestReader struct {