diff --git a/benchmark/drop_caches.sh b/benchmark/drop_caches.sh
index 9cb9e1dc9..10da129e6 100755
--- a/benchmark/drop_caches.sh
+++ b/benchmark/drop_caches.sh
@@ -1,3 +1,19 @@
 #!/bin/bash
 
-echo 3 > /proc/sys/vm/drop_caches 
+oscs=( $( find /proc/fs/lustre/osc -mindepth 1 -maxdepth 1 -type d  ) )
+
+while [ ! 0 -eq ${#oscs[@]} ]; do
+    sync
+    echo 3 > /proc/sys/vm/drop_caches 
+
+    for i in ${!oscs[@]}; do
+        fillstat=$( grep -h used_mb ${oscs[$i]}/osc_cached_mb | cut -d" " -f 2 )
+        if [ 0 == $fillstat ]; then
+            unset oscs[$i]
+        else
+            echo "skip ${oscs[$i]} $fillstat"
+        fi
+    done
+    sleep 1
+done
+