Re: [PATCH blktests] tests/throtl: add a new test 009

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

On Aug 13, 2026 / 22:40, Tao Cui wrote:
> From: Tao Cui <cuitao@kylinos.cn>
> 
> Test the boundary condition of removing a cgroup while it still has IO
> queued in the blk-throttle queue.  The queued bios must be flushed through
> without any blk-cgroup or blk-throttle warning.
> 
> The dmesg check matches any blk-cgroup / blk-throttle warning rather than a
> single call site, so it is not tied to one symbol.

Tao, thanks for the patch. Does this test case have corresponding kernel side
fix? I'm guessing that your recent kernel patch is the fix. If so, I suggest
to mention the kernel commit in here and the test case header comment below.

> 
> Signed-off-by: Tao Cui <cuitao@kylinos.cn>
> ---
> See also the related blkcg "store blkcg in bio" RFC:
> https://lore.kernel.org/r/20260804065313.2092022-1-yukuai@kernel.org
> 
>  tests/throtl/009     | 67 ++++++++++++++++++++++++++++++++++++++++++++
>  tests/throtl/009.out |  2 ++
>  2 files changed, 69 insertions(+)
>  create mode 100755 tests/throtl/009
>  create mode 100644 tests/throtl/009.out
> 
> diff --git a/tests/throtl/009 b/tests/throtl/009
> new file mode 100755
> index 0000000..1f4ed67
> --- /dev/null
> +++ b/tests/throtl/009
> @@ -0,0 +1,67 @@
> +#!/bin/bash
> +# SPDX-License-Identifier: GPL-3.0+
> +# Copyright (C) 2026 Tao Cui <cuitao@kylinos.cn>
> +#
> +# Regression test for removing a cgroup while IO is still queued in the
> +# blk-throttle queue.  The queued bios must be flushed without any
> +# blk-cgroup or blk-throttle warning, and without leaking the blkg
> +# reference they pin.
> +
> +. tests/throtl/rc
> +
> +THROTL_BLKDEV_TYPES="nullb"

Is there any reason to run this test case only for nullb? If not, I suggest to
remove the line above to run it for both nullb and scsi_debug.