tests: Make parallel VM start a bit more resource friendly

Wait one second between each kvm start to avoid hitting large number of
processes trying to start in parallel. This allows the VMs to be started
more efficiently for parallel-vm.py runs with large number of VMs.

Signed-off-by: Jouni Malinen <j@w1.fi>

tests/hwsim/vm/parallel-vm.py

@@ -192,7 +192,7 @@ def main():
     vm = {}
     for i in range(0, num_servers):
         print("\rStarting virtual machine {}/{}".format(i + 1, num_servers)),
-        cmd = ['./vm-run.sh', '--timestamp', str(timestamp),
+        cmd = ['./vm-run.sh', '--delay', str(i), '--timestamp', str(timestamp),
                '--ext', 'srv.%d' % (i + 1),
                '-i'] + codecov_args + extra_args
         vm[i] = {}

tests/hwsim/vm/vm-run.sh

@@ -47,6 +47,7 @@ TIMESTAMP=$(date +%s)
 DATE=$TIMESTAMP
 CODECOV=no
 TIMEWARP=0
+DELAY=0
 CODECOV_DIR=
 while [ "$1" != "" ]; do
 	case $1 in
@@ -68,6 +69,10 @@ while [ "$1" != "" ]; do
 		--timewrap ) shift
 			TIMEWARP=1
 			;;
+	        --delay ) shift
+			DELAY=$1
+			shift
+			;;
 		* )
 			RUN_TEST_ARGS="$RUN_TEST_ARGS$1 "
 			shift
@@ -89,6 +94,11 @@ else
     CODECOV=no
 fi
 
+if [ $DELAY -gt 0 ]; then
+    echo "Wait $DELAY seconds before starting VM"
+    sleep $DELAY
+fi
+
 echo "Starting test run in a virtual machine"
 
 kvm \