Re: [PATCH block-5.14] Revert "block/mq-deadline: Add cgroup support"

On 8/12/21 8:14 AM, Oleksandr Natalenko wrote:

Hi.

On středa 11. srpna 2021 21:48:19 CEST Jens Axboe wrote:

quoted

On 8/11/21 11:41 AM, Tejun Heo wrote:

quoted

From e150c6478e453fe27b5cf83ed5d03b7582b6d35e Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Wed, 11 Aug 2021 07:29:20 -1000

This reverts commit 08a9ad8bf607 ("block/mq-deadline: Add cgroup support")
and a follow-up commit c06bc5a3fb42 ("block/mq-deadline: Remove a
WARN_ON_ONCE() call"). The added cgroup support has the following issues:

* It breaks cgroup interface file format rule by adding custom elements to
a> 
  nested key-value file.

* It registers mq-deadline as a cgroup-aware policy even though all it's

  doing is collecting per-cgroup stats. Even if we need these stats, this
  isn't the right way to add them.

* It hasn't been reviewed from cgroup side.

I missed that the cgroup side hadn't seen or signed off on this one. I
have applied this revert for 5.14.

Should my commit [1] be reverted too?

Thanks.

[1] https://git.kernel.dk/cgit/linux-block/commit/?h=block-5.14&id=ec645dc96699ea6c37b6de86c84d7288ea9a4ddf

It could be, but may as well leave it for now as we're super close to
the limit anyway.

-- 
Jens Axboe