linux-kernel - Re: [PATCH v2] block: flush all throttled bios when deleting the cgroup

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <c900fece-14a4-0b64-babb-053b38ed0dbe@huaweicloud.com>
Date: Sat, 6 Jul 2024 15:21:41 +0800
From: Li Lingfeng <lilingfeng@...weicloud.com>
To: Michal Koutný <mkoutny@...e.com>
Cc: Tejun Heo <tj@...nel.org>, josef@...icpanda.com, hch@....de,
 axboe@...nel.dk, cgroups@...r.kernel.org, linux-block@...r.kernel.org,
 linux-kernel@...r.kernel.org, yangerkun@...wei.com, yukuai1@...weicloud.com,
 houtao1@...wei.com, yi.zhang@...wei.com, lilingfeng3@...wei.com
Subject: Re: [PATCH v2] block: flush all throttled bios when deleting the
 cgroup


在 2024/7/2 22:25, Michal Koutný 写道:
> On Fri, Jun 28, 2024 at 10:04:20AM GMT, Li Lingfeng <lilingfeng@...weicloud.com> wrote:
>> I think it may be more appropriate to remove the limit of bios after the
>> cgroup is deleted, rather than let the bios continue to be throttled by a
>> non-existent cgroup.
> I'm not that familiar with this part -- can this also happen for IOs
> submitted by an exited task? (In contrast to a running task migrated
> elsewhere.)
Yes, IOs will be throttled no matter whether the task that delivers them
exits.
>> If the limit is set too low, and the original cgourp has been deleted, we
>> now have no way to make the bios complete immediately, but to wait for the
>> bios to slowly complete under the limit.
> It makes some sense, it's not unlike reparenting of memcg objects, IIRC
> flushed bios would actually be passed to a parent throtl_grp, right?
Yes, flushed bios would be throttled by the parent throtl_grp.
> Thanks,
> Michal