Re: [PATCH RFC 1/2] tests/throtl: add a new test 007

[Ming Lei <ming.lei@redhat.com>]

On Fri, Mar 07, 2025 at 04:03:17PM +0800, Yu Kuai wrote:
> From: Yu Kuai <yukuai3@huawei.com>
> 
> Add test for IO merge over iops limit.
> 
> Noted this test will fail for now, kernel solution is in development.
> 
> Signed-off-by: Yu Kuai <yukuai3@huawei.com>
> ---
>  tests/throtl/007     | 65 ++++++++++++++++++++++++++++++++++++++++++++
>  tests/throtl/007.out |  4 +++
>  2 files changed, 69 insertions(+)
>  create mode 100755 tests/throtl/007
>  create mode 100644 tests/throtl/007.out
> 
> diff --git a/tests/throtl/007 b/tests/throtl/007
> new file mode 100755
> index 0000000..597f879
> --- /dev/null
> +++ b/tests/throtl/007
> @@ -0,0 +1,65 @@
> +#!/bin/bash
> +# SPDX-License-Identifier: GPL-3.0+
> +# Copyright (C) 2025 Yu Kuai
> +#
> +# Test iops limit over io merge
> +
> +. tests/throtl/rc
> +
> +DESCRIPTION="basic functionality"
> +QUICK=1
> +
> +requires() {
> +	_have_program taskset
> +	_have_program fio
> +}
> +
> +# every 16 0.5k IO will merge into one 8k IO, ideally runtime is 1s,
> +# however it's about 1.3s in practice
> +__fio() {
> +	taskset -c 0 \
> +	fio -filename=/dev/$THROTL_DEV \
> +	-name=test \
> +	-size=1600k \
> +	-rw=write \
> +	-bs=512 \
> +	-iodepth=32 \
> +	-iodepth_low=16 \
> +	-iodepth_batch=16 \
> +	-numjobs=1 \
> +	-direct=1 \
> +	-ioengine=io_uring &> /dev/null
> +}
> +
> +test_io() {
> +	start_time=$(date +%s.%N)
> +
> +	{
> +		echo "$BASHPID" > "$CGROUP2_DIR/$THROTL_DIR/cgroup.procs"
> +		__fio
> +	} &
> +
> +	wait $!
> +	end_time=$(date +%s.%N)
> +	elapsed=$(echo "$end_time - $start_time" | bc)
> +	printf "%.0f\n" "$elapsed"
> +}
> +
> +test() {
> +	echo "Running ${TEST_NAME}"
> +
> +	# iolatency is 10ms, iops is at most 200/s
> +	if ! _set_up_throtl irqmode=2 completion_nsec=10000000 hw_queue_depth=2; then
> +		return 1;
> +	fi
> +
> +	test_io
> +
> +	# 300 means 50% error range, no IO should be throttled
> +	_throtl_set_limits wiops=300
> +	test_io
> +	_throtl_remove_limits
> +
> +	_clean_up_throtl
> +	echo "Test complete"
> +}
> diff --git a/tests/throtl/007.out b/tests/throtl/007.out
> new file mode 100644
> index 0000000..0d568ef
> --- /dev/null
> +++ b/tests/throtl/007.out
> @@ -0,0 +1,4 @@
> +Running throtl/007
> +1
> +1
> +Test complete

I'd suggest to check if actual iops matches with the iops limit directly,
and it isn't intuitive to compare time taken in test wrt. iops throttle.

Thanks,
Ming