Replace metaperf gedents code with a more useful readdir operation; add some auto-bench scripts for metaperf runs; fix a divide-by-zero in dirperf

common.metaperf

@@ -0,0 +1,18 @@
+##/bin/sh
+
+_format_metaperf()
+{
+    perl -ne 'm/(\S+): (\d+) times, (\d+) file\(s\) namelen (\d+), time = (\S+) sec, ops\/sec=(\S+), usec\/op = (\S+)/ && { $op{$1} = $7 };
+	END { printf "%8.2f,%8.2f,%8.2f,%8.2f,%8.2f,%8.2f,%8.2f,%8.2f\n",
+		$op{"chown"}, $op{"create"}, $op{"crunlink"}, $op{"linkun"},
+		$op{"open"}, $op{"rename"}, $op{"stat"}, $op{"readdir"} }'
+}
+
+_format_header()
+{
+    # note: we're reporting only the usec/op field
+    printf "%8s,%8s,%8s,%8s,%8s,%8s,%8s,%8s\n" \
+	chown create crulink linkun open rename stat readdir
+}
+
+allops="chown create crunlink linkun open rename stat readdir"