[kvm-unit-tests PATCH v6 3/3] run_tests: allow run tests in parallel

[Peter Xu <peterx@redhat.com>]

run_task.sh is getting slow. This patch is trying to make it faster by
running the tests concurrently.

We provide a new parameter "-j" for the run_tests.sh, which can be used
to specify how many run queues we want for the tests. Default queue
length is 1, which is the old behavior.

Quick test on my laptop (4 cores, 2 threads each) shows 3x speed boost:

   |-----------------+-----------|
   | command         | time used |
   |-----------------+-----------|
   | run_test.sh     | 75s       |
   | run_test.sh -j8 | 27s       |
   |-----------------+-----------|

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 run_tests.sh        | 12 ++++++++++--
 scripts/common.bash | 16 +++++++++++++++-
 2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/run_tests.sh b/run_tests.sh
index afd3d95..4d57ff9 100755
--- a/run_tests.sh
+++ b/run_tests.sh
@@ -13,10 +13,11 @@ function usage()
 {
 cat <<EOF
 
-Usage: $0 [-g group] [-h] [-v]
+Usage: $0 [-g group] [-h] [-v] [-j num_run_queues]
 
     -g: Only execute tests in the given group
     -h: Output this help text
+    -j: Execute tests in parallel
     -v: Enables verbose mode
 
 Set the environment variable QEMU=/path/to/qemu-system-ARCH to
@@ -28,7 +29,7 @@ EOF
 RUNTIME_arch_run="./$TEST_DIR/run"
 source scripts/runtime.bash
 
-while getopts "g:hv" opt; do
+while getopts "g:hj:v" opt; do
     case $opt in
         g)
             only_group=$OPTARG
@@ -37,6 +38,13 @@ while getopts "g:hv" opt; do
             usage
             exit
             ;;
+        j)
+            unittest_run_queues=$OPTARG
+            if (( $unittest_run_queues <= 0 )); then
+                echo "Invalid -j option: $unittest_run_queues"
+                exit 2
+            fi
+            ;;
         v)
             verbose="yes"
             ;;
diff --git a/scripts/common.bash b/scripts/common.bash
index 2dd7360..9bd560f 100644
--- a/scripts/common.bash
+++ b/scripts/common.bash
@@ -1,11 +1,19 @@
 : ${unittest_log_dir:=logs}
+: ${unittest_run_queues:=1}
 
 function run_task()
 {
 	local testname="$2"
 
+	while (( $(jobs | wc -l) == $unittest_run_queues )); do
+		# wait for any background test to finish
+		wait -n
+	done
+
 	RUNTIME_log_file="${unittest_log_dir}/${testname}.log"
-	"$@"
+
+	# start the testcase in the background
+	"$@" &
 }
 
 function for_each_unittest()
@@ -22,6 +30,8 @@ function for_each_unittest()
 	local accel
 	local timeout
 
+	trap "wait; exit 130" SIGINT
+
 	exec {fd}<"$unittests"
 
 	while read -u $fd line; do
@@ -55,5 +65,9 @@ function for_each_unittest()
 		fi
 	done
 	run_task "$cmd" "$testname" "$groups" "$smp" "$kernel" "$opts" "$arch" "$check" "$accel" "$timeout"
+
+	# wait until all tasks finish
+	wait
+
 	exec {fd}<&-
 }
-- 
2.7.4