From: Lu Jialin <lujialin4@huawei.com>
To: Tejun Heo <tj@kernel.org>, Zefan Li <lizefan.x@bytedance.com>,
Johannes Weiner <hannes@cmpxchg.org>
Cc: <cgroups@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [QUESTION]cgroup mount return -EBUSY
Date: Mon, 6 May 2024 09:50:03 +0800 [thread overview]
Message-ID: <7fd75461-2083-3da5-f25b-d77a0e21b7bc@huawei.com> (raw)
In-Reply-To: <5b5da2d3-37b3-60ee-5a94-149094cbe9dc@huawei.com>
ping
On 2024/4/26 12:55, Lu Jialin wrote:
> Hello
>
> I encountered a problem when I try to unmount the subsystem right after
> all it's subcgroups are removed, the cgroup_root would remain. Mounting
> this subsystem to another cgroup_root would return -EBUSY.
>
> The problem could be reproduced with the following script.
>
> test.sh:
>
> mkdir /tmp/test1
> mount -t cgroup -o pids pids /tmp/test1
> mkdir /tmp/test1/test
> rmdir /tmp/test1/test
> umount /tmp/test1
> mkdir /tmp/test
> mount -t cgroup -o pids,cpu none /tmp/test
>
> test.sh should return this.
> mount: mounting none on /tmp/test failed: Device or resource busy.
>
> It seems that when unmounting /tmp/test1, the original cgroup_root for
> this PID is not released.
> /test # cat /proc/cgroups
>
> #subsys_name hierarchy num_cgroups enabled
>
> cpuset 0 1 1
>
> cpu 0 1 1
>
> cpuacct 0 1 1
>
> blkio 0 1 1
>
> devices 0 1 1
>
> freezer 0 1 1
>
> net_cls 0 1 1
>
> perf_event 0 1 1
>
> net_prio 0 1 1
>
> hugetlb 0 1 1
>
> pids 1 1 1
>
> rdma 0 1 1
>
> misc 0 1 1
>
> debug 0 1 1
>
prev parent reply other threads:[~2024-05-06 1:50 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-26 4:55 [QUESTION]cgroup mount return -EBUSY Lu Jialin
2024-05-06 1:50 ` Lu Jialin [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=7fd75461-2083-3da5-f25b-d77a0e21b7bc@huawei.com \
--to=lujialin4@huawei.com \
--cc=cgroups@vger.kernel.org \
--cc=hannes@cmpxchg.org \
--cc=linux-kernel@vger.kernel.org \
--cc=lizefan.x@bytedance.com \
--cc=tj@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).