Re: [PATCH blktests v2] throtl/008: Add a test for the iocost cgroup controller

[Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>]

On Jun 04, 2026 / 10:54, Bart Van Assche wrote:
> Add a test for read and write IOPS throttling.
> 
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>

Thanks for this v2 patch. I applied it with two minor changes below.

> diff --git a/tests/throtl/008 b/tests/throtl/008
> new file mode 100755
> index 000000000000..f4d3b080797a
> --- /dev/null
> +++ b/tests/throtl/008
> @@ -0,0 +1,104 @@
> +#!/bin/bash
> +# SPDX-License-Identifier: GPL-3.0+
> +# Copyright (C) 2026 Google LLC
> +#
> +# Test cgroup iocost IOPS limiting.
> +
> +. tests/throtl/rc
> +. common/fio
> +
> +DESCRIPTION="test cgroup iocost controller limits"
> +
> +requires() {
> +	_have_fio
> +	_have_program bc

This check above is in group_requires(), so I dropped it.

> +	_have_kernel_option BLK_CGROUP_IOCOST
> +}

I added set_conditions() here, so that this test can be run for both
null_blk and scsi_debug. It also makes this test case consistent with
other test cases in this group.

> +
> +run_test() {
> +	# dev_t is global to make it available in the caller.
> +	dev_t=$(<"/sys/block/${THROTL_DEV}/dev")

...