latency script fixup

This patch adds functionality to
*) Calculate and display the average latency
*) Make sure count is not 0

Fixes
*) in case of write, grep latency in case of dd command would
always fail. Fixed it.

Signed-off-by: Narasimhan V <sim@linux.vnet.ibm.com>

diff --git a/scripts/latency b/scripts/latency
index 85887598e66b9615b6d3def5b93bcfe2b5507d4b..908ae4ab9418c4524552666a993ff5e0d4a11dc3 100755 (executable)
--- a/scripts/latency
+++ b/scripts/latency
@@ -64,6 +64,11 @@ while getopts ":d:n:w" opt; do
   esac
 done
 
+if [ "$COUNT" == "0" ]; then
+    echo "Count can not be 0"
+    exit 1
+fi
+
 if [ -z "$DEVICE" ]; then
      echo "regress: You must specify a NVMe device using -d"
      exit 1
@@ -86,7 +91,7 @@ make install > /dev/null || exit -1
 for i in `seq 1 ${COUNT}`;
 do
     if $WRITE ; then
-        run_test dd if=/dev/urandom of=${RAND_WFILE} bs=${DATA_SIZE} count=1
+        dd if=/dev/urandom of=${RAND_WFILE} bs=${DATA_SIZE} count=1
         run_test nvme write ${DEVICE} --start-block=0 --block-count=0 \
             --metadata-size=${METADATA_SIZE} --data-size=${DATA_SIZE} \
             --data ${RAND_WFILE} --latency
@@ -98,3 +103,12 @@ do
         rm ${RAND_RFILE} > /dev/null
     fi
 done
+
+# Calculate average latency
+SUM=0
+for i in `cat ${OUTPUT} | awk '{print $3}' | xargs`
+do
+    SUM=$(($SUM + $i))
+done
+AVERAGE=$(echo "scale=2; $SUM/$COUNT" | bc -l)
+echo "Average Latency: $AVERAGE us"