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

[Paolo Bonzini <pbonzini@redhat.com>]

On 12/01/2017 12:42, Andrew Jones wrote:
> On Thu, Jan 12, 2017 at 11:36:22AM +0800, Peter Xu wrote:
>> 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       |
>>    |-----------------+-----------|

wait -n is very new, so I've added "2> /dev/null" (the result will be a
busy wait).  To avoid a busy wait in the common -j1 case, I also added:

+	if [ $unittest_run_queues = 1 ]; then
+		run "$@"
+	else
+		run "$@" &
+	fi

(I tried using a named pipe too, but it's messy to open both ends
without blocking).

Paolo

>> 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
>>
>>
> 
> Reviewed-by: Andrew Jones <drjones@redhat.com> 
>